text stringlengths 144 682k |
|---|
YellowBridge Chinese Language & Culture
Chinese Language Center
Chinese Mysticism Feng Shui
Feng Shui is the ancient Chinese art of living in harmony with your environment. It literally translates into wind and water. Feng Shui is often defined as the art of placement because much of it revolves around determining the positive or negative directions for the people, their dwellings, and the relationship between them.
Understanding the Basics
Central to Feng Shui is the belief in the existence of a unifying vital force called Qi (Chi). Qi is invisible, undetectable by our five senses, or for that matter any physical instrument. Qi pervades all things and beings in existence. It animates us, binds us, and moves us through our life cycles. However, Qi, like air, is not of uniform quality. Some is fresh or nourishing while some are stale or detrimental.
In fact, the qualities of Qi can be anywhere between two extremes, commonly known as yin yang. Yin is the female end and is represented by the color black. Yang is the male end and is represented by the color white. The well-known yin yang symbol represents the eternal, dynamic interaction between these two opposites.
Like subatomic particles of modern physics, the interaction of yin and yang give rise to everything that exists, i.e. all things are made up of varying proportions of yin and yang.
Understanding Trigrams
If we represent Yin as a broken line and Yang as a solid line and created all possible ying/yang combinations of three lines, we would end up with the eight symbols shown below.
☵ ☷ ☳ ☴ ☰ ☱ ☶ ☲
Each 3-line symbol is called a trigram. Each trigram has a unique name and is associated with certain attributes such as a compass direction, numeric value, element, color, etc. A partial list of the associated attributes is shown below.
Kǎn Kūn Zhèn Xùn Qián Duì Gèn
Numeric Value 1 2 3 4 6 7 8 9
Compass Direction N SW E SE NW W NE S
Element Water Earth Wood Wood Metal Metal Earth Fire
There are several standard ways of arraging the sequence of the eight trigrams. One of the best known arrangements places the trigrams around the yin yang symbol. This arrangement is known as the bagua (literally "eight trigrams").
Another typical arrangement is show above. By placing each trigram in each corresponding compass direction and putting the value of 5 at the center, we get the magic square shown below. If you add the numeric value of each trigram across each row, column, or diagonal, you'll see that they always add up to 15. Variations of the magic square are at the core of much of the analysis performed in traditional Feng Shui techniques.
Schools of Feng Shui
See also |
How to Raise Smart Kids
Guest post by Judith McLean
Few people would doubt that intellect and academic performance are linked and so ensuring your child’s intellect is nurtured throughout their development is of critical importance to all parents who have their child’s best interests at heart.
As highlighted by experts in the fields of neuroscience and child psychology, childhood is a time for substantial brain development and there are in fact a number of evidence based methods to cultivate intelligence effectively.
So what can we do as parents to make our kids smarter? Here are some of the best evidence based ways to raise smart kids:
1. Drop the Stereotypes
When thinking about intelligence, there are quite a few stereotypes surrounding the topic, which are somewhat problematic, since they are not only discriminatory in nature, but also can have negative consequences on a child’s intellectual development.
One of the most common stereotypes regarding intelligence is the belief that it is a fixed phenomenon and since it’s largely genetic cannot be changed or influenced in any way. But evidence shows that individuals who hold this belief are less likely to learn from their errors and less likely to succeed in academia.
Another common belief involves social stereotypes and academic performance. For example, most people have heard statements such as “Asian kids excel in Math” and “Girls are better at language and verbal ability”. However, evidence highlights that views like these can demoralize academic performance.
2. Exercise & Intelligence
A considerable amount of research has been conducted, which explores the link between exercise and its effects on intelligence. For example, studies on mice have shown that aerobic exercise stimulates brain growth, specifically in an area of the brain called the hippocampus that is linked to learning and memory.
The effects of aerobic exercise in children has also been investigated and found that children with higher levels of aerobic fitness were able to better perform in terms of accuracy and reaction time. Some studies have even demonstrated that fitter children have more volume in the hippocampus region of the brain – an area linked to memory that in turn is linked to academic performance.
Therefore, it’s easy to conclude that in order for kids to excel in academia exercise should be a key component of every child’s routine.
3. Sleep & Intelligence
We all know how awful it feels when we haven’t had enough sleep, so you might have already guessed how important sleep is to academic and cognitive performance. Unsurprisingly there is a considerable amount of evidence that demonstrates the importanceof sleep in relation to learning.
Some studies have demonstrated that short naps after learning something new can help us retain that knowledge and information. Of course, it’s not common for educational institutions to allow kids to sleep on site, but it’s certainly an option for parents that homeschool their children.
Studies have also shown that a chronic lack of sleep has a long-term negative impact on cognitive performance. For instance, in one study that tracked toddlers with sleep problems, it was demonstrated that they performed poorly in tests once they reached 6 years of age.
4. Play Enhances Learning
Kids love to play, so it’s certainly welcome news to discover that play is extremely beneficial to the learning child. There are many reasons for this, but let us explore some of the most famous discoveries.
Several studies in recent decades have demonstrated that kids learn and retain information better when they are given the opportunity for frequent, intermittent bursts of play. For instance, one study carried out it 2006 found that kids pay more attention to their teacher when they have recently returned from a break.
There is some circumstantial evidence too. For instance, countries that have the highest academic achievement, such as Japan and China, commonly allow students to have breaks every 50 minutes.
Other studies have demonstrated that what is referred to as “sociodramatic play.” What kids do when they pretend play leads to improved academic and linguistic performance.
Therefore, it’s worth taking note that your child will probably perform better if they are given the opportunity for frequent bursts of play. It’s often tempting to persevere until you think your child has understood a new concept, but evidence suggest that this may not be the most effective route to success.
5. Negative & Limiting Beliefs
How personal beliefs can impact learning and development have already been mentioned, but there have been a number of studies carried out that demonstrate this and highlight why it’s important not to hold negative and self-limiting beliefs.
For example, studies have demonstrated that people who are likely to believe that intelligence is a fixed trait that can’t be altered are more prone to avoid challenges. They are also more prone to not learn from their previous mistakes, and this has been demonstrated using brain scans.
Does your child say things like: “I can’t do that” or “I’m not that type of person”. If so, then these types of beliefs ought to be challenged and not left to fester and lay down roots, since research suggests that negative personal beliefs can also present a barrier to academic performance.
Perhaps most surprising is the fact that evidence shows that too much praise can also have a negative impact on a child’s academic performance. This is somewhat counter-intuitive, as it’s often assumed that positivity leads to positive behavior. However, some studies have demonstrated that constant praise can lead to a lack of motivation and reinforce a feeling of “nowhere to go for help” when they do fail.
Judith McLean is a parent to two boys, business owner and likes to help others develop their kids in a positive and proactive way! You can check out more of Judith’s writing at MomBible.
Judith’s writing concentrates on the childhood development, practical parenting techniques and behavioral science. She is currently studying child psychology and hopes to contribute greatly to this field.
Speak Your Mind
CommentLuv badge
Before you go! Subscribe for all the latest updates!
This site is protected by |
Graql Rules
Graql uses machine reasoning to perform inference over data and relationship types as well as to provide context disambiguation and dynamically-created relationships. This allows you to discover hidden and implicit associations between data instances through short and concise statements.
The rule-based reasoning allows automated capture and evolution of patterns within the knowledge graph. Graql reasoning is performed at query time and is guaranteed to be complete. Thanks to the reasoning facility, common patterns in the knowledge graph can be defined and associated with existing schema elements. The association happens by means of rules. This not only allows you to compress and simplify typical queries, but offers the ability to derive new non-trivial information by combining defined patterns.
Once a given query is executed, Graql will not only query the knowledge graph for exact matches but will also inspect the defined rules to check whether additional information can be found (inferred) by combining the patterns defined in the rules. The completeness property of Graql reasoning guarantees that, for a given content of the knowledge graph and the defined rule set, the query result shall contain all possible answers derived by combining database lookups and rule applications.
In this section we shall briefly describe the logics behind the rules as well as how can we define pattern associations by suitably defined rules. You may also want to review our example of how to work with Graql rules.
Graql Rules
Graql rules assume the following general form:
when {rule-body} then {rule-head}
People familiar with Prolog/Datalog, may recognise it as similar:
{rule-head} :- {rule-body}.
In logical terms, we restrict the rules to be definite Horn clauses. These can be defined either in terms of a disjunction with at most one unnegated atom or an implication with the consequent consisting of a single atom. Atoms are considered atomic first-order predicates - ones that cannot be decomposed to simpler constructs.
In our system we define both the head and the body of rules as Graql patterns. Consequently, the rules are statements of the form:
q1 ∧ q2 ∧ ... ∧ qn → p
where qs and the p are atoms that each correspond to a single Graql statement. The “when” of the statement (antecedent) then corresponds to the rule body with the “then” (consequent) corresponding to the rule head.
The implication form of Horn clauses aligns more naturally with Graql semantics as we define the rules in terms of the “when” and “then” blocks which directly correspond to the antecedent and consequent of the implication respectively.
Graql Rule Syntax
In Graql we refer to the body of the rule as the “when” of the rule (antecedent of the implication) and the head as the “then” of the rule (consequent of the implication). Therefore, in Graql terms, we define rule objects in the following way:
when {
then {
Each dotted line corresponds to a single Graql variable pattern. The rule label is optional and can be omitted, but it is useful if we want to be able to refer to and identify particular rules in the knowledge graph.
In Graql, the “when” of the rule is required to be a conjunctive pattern, whereas the “then” should be atomic - contain a single pattern. If your use case requires a rule with a disjunction in the “when” part, please notice that, when using the disjunctive normal form, it can be decomposed into series of conjunctive rules.
Defining rules
Rules are treated as inherent members of the schema. As a result they require the define keyword for their creation. A rule is then defined by specifying its label followed by when and then blocks. The label is necessary if we want to refer to the rule later.
A classic reasoning example is the ancestor example. The two Graql rules R1 and R2 stated below define the ancestor relationship, which can be understood as either happening between two generations directly between a parent and a child or between three generations when the first generation hop is expressed via a parentship relationship and the second generation hop is captured by an ancestor relationship.
when {
(parent: $p, child: $c) isa Parent;
then {
(ancestor: $p, descendant: $c) isa Ancestor;
when {
(ancestor: $c, descendant: $d) isa Ancestor;
then {
(ancestor: $p, descendant: $d) isa Ancestor;
Defining the above rules in terms of predicates and assuming left-to-right directionality of the roles, we can summarise them in the implication form as:
R1: parent(X, Y) → ancestor(X, Y)
R2: parent(X, Z) ∧ ancestor(Z, Y) → ancestor(X, Y)
Retrieving defined rules
To retrieve rules, we refer to them by their label in a match statement:
match $x label R1; get;
match $x label R2; get;
or as a joint statement:
match {$x label R1;} or {$x label R2;}; get;
Deleting rules
To delete rules we refer to them by their label and use the undefine keyword. For the case of the rules defined above, to delete them we write:
undefine R1 sub rule;
undefine R2 sub rule;
To persist the result, executing a commit; statement is also required.
Allowed Graql Constructs in Rules
The tables below summarise Graql constructs that are allowed to appear in a when-then (body-head) blocks of a rule.
We define atomic queries as queries that contain at most one potentially rule-resolvable statement. That means atomic queries contain at most one statement that can potentially appear in the “then” of any rule.
Description when then
atomic queries
conjunctive queries x
disjunctive queries x x
Variable Patterns
Below are listed the variable patterns that are allowed to be defined in rule heads together with specific remarks.
Description Pattern Example remarks
entity $x isa person; type strictly needs to be specified, variable needs to be bound
attribute $x has age 20; value predicate needs to be specific (=)
relationship (parent: $x, child: $y) isa parentship; type strictly needs to be specified, all roles need to be explicitly specified and non-meta
Type Properties
Type properties deal with schema elements and are not allowed to form rule heads.
Description Pattern Example when then
sub $x sub type; x
plays $x plays parent; x
has $x has firstname; x
relates marriage relates $x; x
is-abstract $x is-abstract; x
datatype $x isa attribute, datatype string; x
regex $x isa attribute, regex /hello/; x
Where Next?
There is a complete example of how to work with Graql rules available, and reasoning is also discussed in our quick start tutorial. |
Transportation and logistics
Automobile Technology
Automobile Technicians also work in garages and workshops that are not associated with particular manufacturers. Where this is the case they may experience a wider range of light vehicles and use alternative equipment, parts and materials. The trained and competent Light Vehicle Automobile Technician will service and repair a range of light vehicles
Heavy Truck Maintenance
The Heavy Truck Maintenance Technician maintains and repairs large machines and industrial equipment, both towed and self-propelled, used in mining, forestry, agriculture, landscaping, material handling, and transportation. The technician must be able to maintain and repair internal combustion engines and components, both stationary and mobile, as well as on-highway and off-highway vehicles, both motorized and towed; tracked and rubber-tired equipment; ground-engaging equipment; and earth-moving equipment.
Maintenance and repair can involve individual components or entire systems, requiring the technician to have skill with engines, hydraulics, electronics, braking systems, and much more. The technician must use specific tools to diagnose function, make adjustments, repair or replace defective components or systems, test repairs for proper performance, interpret instructions in technical manuals, write service reports, and ensure that the work meets manufacturers specifications and the requirements of legislation. The technician is frequently the interlocutor between the employer, the customer, and the manufacturer. This experience can allow the technician to advance to senior roles such as trainer, supervisor, or manager.
Heavy Vehicle Technology
The Heavy Vehicle Technician maintains and repairs agricultural machinery. The machinery may be large or small, basic or advanced, and include tractors, forage harvesters, balers, bale wrappers, mowers, combine harvesters, crop sprayers, fertiliser distributors, tillage and slurry handling equipment. According to type and purpose, the machinery may be used primarily or entirely off the road.
For servicing and repair the Heavy Vehicle Technician may normally work on the owners premises and land, which is usually but not always a farm. Some Technicians will be based in a workshop that serves a particular area or type of machine. The Technician will be required to provide both routine and exceptional support to those owning or leasing the machinery. Some machines and units have a largely seasonal use, while others are required for many purposes year-round. Whatever the requirement, for this time-sensitive sector reliability, efficiency and effectiveness are essential. |
Author: Biscuola Stefania
Date: 31/01/2014
"An autosomal recessive disease in which gene expression of glucose-6-phosphatase (which normally catalyze reactions that ultimately convert glycogen compounds to glucose) is absent, resulting in hypoglycemia due to lack of glucose production. Accumulation of glycogen in liver and kidney leads to organomegaly, particularly massive hepatomegaly. Increased concentrations of lactic acid and hyperlipidemia appear in the plasma. Clinical gout often appears in early childhood."
The overall incidence of GSDI is 1 in 100,000 individuals. The most common forms of GSD I are designated GSD Ia and GSD Ib, the former accounting for over 80% of diagnosed cases and the latter for less than 20%. A few rarer forms have been described. In the United States, GSD Ia has an incidence of approximately 1 in 50,000 to 100,000 births. None of the glycogenoses are currently detected by standard or extended newborn screening.
Signs and symptoms of this condition typically appear around the age of 3 or 4 months, when babies start to sleep through the night and do not eat as frequently as newborns. Affected infants may have low blood sugar (hypoglycemia), which can lead to seizures. They can also have a buildup of lactic acid in the body (lactic acidosis acidosis.com/), high blood levels of a waste product called uric acid (hyperuricemia), and excess amounts of fats in the blood (hyperlipidemia). As they get older, children with GSDI have thin arms and legs and short stature. An enlarged liver may give the appearance of a protruding abdomen. The kidneys may also be enlarged. Affected individuals may also have diarrhea and deposits of cholesterol in the skin (xanthomas).
In the end the diagnosis is conirmed by laboratory and genetic techniques such as liver biopsy with electron microscopy, assay of glucose-6-phosphatase activity in the tissue or specific gene testing.
Prenatal diagnosis has been made by fetal liver biopsy at 18–22 weeks of gestation, but no fetal treatment has been proposed. Prenatal diagnosis is possible with fetal DNA by chorionic villus sampling when a fetus is known to be at risk.
Hypertriglyceridemia resulting from amplified triglyceride production is another indirect effect of impaired gluconeogenesis, amplified by chronically low insulin levels. During fasting, the normal conversion of triglycerides to free fatty acids, ketones, and ultimately glucose is impaired. Triglyceride levels in GSD I can reach several times normal and serve as a 2 clinical index of "metabolic control".
Kidney effects:Kidneys are usually 10 to 20% enlarged with stored glycogen. This does not usually cause clinical problems in childhood, with the occasional exception of a Fanconi syndrome syndrome.com/ with multiple derangement of renal tubular reabsorption, including proximal renal tubular acidosis with bicarbonate and phosphate wasting. However, prolonged hyperuricemia can cause uric acid nephropathy. In adults with GSD I, chronic glomerular damage similar to diabetic nephropathy may lead to renal failure.
GSD Ia results from mutations of G6PC, the gene for glucose-6-phosphatase. G6PC is located on chromosome 17q21.
GSD Ib results from mutations of the gene for SLC37A4 or G6PT1, the G6P transporter.
GSD Ic Ic.com/ results from mutations of SLC17A3 or SLC37A4.
Without adequate metabolic treatment, patients with GSD I have died in infancy or childhood of overwhelming hypoglycemia and acidosis. Those who survived were stunted in physical growth and delayed in puberty, because of chronically low insulin levels, mental retardation. Recurrent, severe hypoglycemia is considered preventable with appropriate treatment.
Additional problems reported in adolescents and adults with GSD I have included hyperuricemic gout, pancreatitis, and chronic renal failure. Despite hyperlipidemia, atherosclerotic complications have been infrequently reported.
Avoidance of other sugars: Intake of carbohydrates which must be converted to G6P to be utilized (e.g., galactose and fructose) should be minimized. Although elemental formulas are available for infants, many foods contain fructose or galactose in the forms of sucrose or lactose. Adherence becomes a contentious treatment issue after infancy. The treatment of GSD type Ia involves a careful monitoring of the affected person’s diet, both in frequency of meals and type of foods eaten. People with GSD type Ia should avoid foods with sucrose (table sugar), fructose (sugar from fruits), and lactose and galactose (sugars found in milk). They need to eat around the clock, typically every 1 to 3 hours during the day and every 3 to 4 hours at night, to maintain healthy blood sugar levels. Physicians often recommend people with GSD type 1a drink cornstarch mixed with water, soy formula, or soy milk. Cornstarch is digested slowly and therefore releases its glucose gradually, helping to safely extend the time between meals.
The Diseases DatabaseGSD1
OMIM single geneGSD1
Kegg PathwayGSD1
2014-06-26T07:45:34 - Laura Carrera
2014-04-06T19:33:15 - Laura Carrera
AddThis Social Bookmark Button |
Solar Energy Lab Report
Solar Energy Lab Report
By: Jenzel, Carrie, and Emily
Abstract (Carrie)
For this project, the group created a 31-solar cell line by soldering each cell together through wires. The highest DC voltage obtained in direct sunlight was 12.34 volts, and the lowest DC voltage obtained was indoors without a flashlight, giving off 4.37 volts at most.
Introduction (Jenzel)
When there is a sunny day, the sun shines almost 1000 watts of power per square meter on
the entire planet. So, if we can get all that energy, we can power up the entire planet for no cost at all! Although it is a great alternative to fuel, the question that is being looked into is…how does solar energy work?
Inside a solar panel are photovoltaic cells (photo = light, voltaic = electricity), made from a semiconductor type of material called silicon (Si). A semiconductor has an N-type and a P-type of its element in it. The silicon atom’s valence (or outer) shell is filled with 4 of 8 electrons, so it needs 4 more to be neutral. When sunlight strikes on the solar panel, some electrons are knocked off its bonds, making them move around freely (free carriers). Photovoltaic cells also have either one or more magnetic fields that force the free carriers to move in one direction (called a current). Once wired up to a load (the object that needs to be powered up), the electrons pass through the wire and power up the object.
In order to make the solar panel more efficient, solar panels are doped (adding impurities to an atom) with boron or phosphorous. Silicon mixed with phosphorous take less energy for their electrons to break loose from them because some of the extra phosphorous atoms are not in a bond, and the other atoms beside it aren’t holding it together. So, more than normal electrons break free in that silicon, the silicon becomes N-type. If pure silicon was used, it wouldn’t work as well because N-type silicon is a better conductor.
The P-type silicon is doped with boron, an element that only has 3 electrons in its valence shell. This means that it has more holes, a place where there are no electrons, and they move the same way electrons do. When N-type silicon and P-type silicon are placed next to each other, the electrons in the N-type rush over to the P-type silicon so that it can balance out the charges.
Since the electrons, the N-type silicon becomes positive. So, the electrons try to go back to the N-type where there are holes, but the electric field (made when they crossed to the P-type silicon) prevents them from returning, and now they are stuck. The only way that they can get back is through an external path (wires). The wires are connected to the load, and as the electrons pass through it, it powers up the load with electricity. Once it gets back to the N-type silicon, the P-type is unbalanced again, so they cross to the other silicon and then go back through the wire. This continuous cycle creates consistent electricity, powering up the load with the necessary electricity that it needs to work.
For our project, our final design consists of a line of solar cells, soldered and held together by wires. Our hypothesis for this project is that with a 31-solar cell line, it will be able to create at least 10 volts, hopefully more. Since every solar cell will be hit by sunlight, we will be able to get much more voltage than before, which is why we think that it is a good design. We also believe that it might actually get the mixer to work because with a high voltage, it will be able to power up the mixer.
Parts of a Solar Panel
A. Cover Glass
B. Anti-Reflective Coating
C. Contact Grid
D. N-Type Silicon
E. P-Type Silicon
F. Back Contact
Materials and Methods (Carrie)
- Broken solar paneling
- Sunlight
- Styrofoam
- Multimeter
- Soldering Iron
- Wires
- Metal Meltable Wire
1. Solder broken pieces of solar paneling together (the amount used is up to you)
2. Scratch the ribbon wire (the white line on solar paneling) to ease soldering
3. Lay the pieces on Styrofoam for easy and stable soldering, solder in an over-under effect to receive both negative and positive charges from solar cells
4. Make sure to have enough wire on the ends of the panel pieces, to make it easier when connecting to a load
5. Take cells into a source of light (preferably sunlight), and check voltage every now and then until it stabilizes (check every 5-10 mins)
6. Record data in a table, telling how many solar cells were used, and how much DC voltage was produced
Results (Emily)
Using a Flashlight Indoors
Solar Cells Voltage Produced (DC)
2 .762
6 1.308
10 2.022
13 2.669
18 4.10
26 5.10
30 6.36
Without a Flashlight Indoors
Solar Cells Voltage Produced (DC)
1 .10
5 .73
10 1.37
15 2.23
20 2.93
25 3.63
30 4.37
Outside, 2:51 PM
Solar Cells Voltage Produced (DC)
1 .36
5 1.95
10 3.79
15 5.45
20 7.08
25 9.43
30 12.34
Best Results (30 Cells): 12.34 Volts, outside in the sunlight
Worst Results (30 Cells): 4.37 Volts, nighttime and no extra light but the two overhead lights
Conditions were the same for the other test indoors, but a flashlight was used. Using lots of lighting simulated what it would be like during the day. Leaving the solar panels in any source of light made the results more accurate because the voltage stabilized. The 31-solar cell line also lit up an LED indoors with a flashlight. All the solar cells used are different sizes and that affects their voltage. Bigger solar cells cover more area and so more sunlight hits
Conclusions (Jenzel)
Well, when it was tested, it actually ended up getting around 12.5 volts with sunlight, which was a pretty good voltage for us. We only tried to go for 6 volts, and it actually doubled with our new final design that Emily was able to produce. It ended up powering up the LED, but for some reason, it couldn’t power up the incandescent bulb, the motor, and the hot plate. From the hypothesis that we made, it is partly true. We did end up getting more than 10 volts during testing, but it wasn’t able to power up the mixer. So, we were half right on our hypothesis.
Maybe, if we end up getting to redo this project and having more time, we’d probably try to get more solar cells in order to increase the voltage even more. That would probably be able to power up the mixer/hot plate once we get to a certain voltage. Also, our final design didn’t look really neat, so maybe if we found some way to make it look better, that would make it seem more professional.
|
Silver Nitrate Can React With Alkali
- Sep 27, 2017 -
Silver nitrate is a strong oxidant, corrosive, Silver Nitrate environmental pollutants. With some organic matter or sulfur, phosphorus mixed grinding, impact can be burned or exploded; silver nitrate is corrosive. Once the skin stained with silver nitrate solution, there will be black spots, which is due to the formation of a black protein silver.
Silver nitrate has a certain toxicity, into the body to produce serious corrosion of the gastrointestinal tract, adult lethal dose of about 10 grams. Baptist silver nitrate can cause severe abdominal pain, vomiting, bloody stool, and even gastrointestinal perforation occurred. Can cause skin and eye burns. Long-term exposure to the goods of the workers will appear systemic silver syndrome. Performance includes: the body's skin a wide range of pigmentation, gray-blue or shallow stone color; eye silver caused by eye damage; respiratory silver calm caused by chronic bronchitis and so on.
Closed operation, to enhance ventilation. Silver Nitrate Against the solution when the operator should wear rubber gloves and goggles, should not be dropped on the skin.
Skin contact: Remove contaminated clothing and rinse thoroughly with soap and water.
Store in a cool, ventilated place; should be stored in a brown or black bottle. Away from fire, heat. Avoid light. The reservoir temperature does not exceed 30 ℃, relative humidity does not exceed 80%. The packaging must be sealed and not damp. Should be easy to (with) fuel, Silver Nitrate reducing agent, alkali, alcohol, edible chemicals stored separately, avoid mixed storage.
Silver nitrate in the case of organic matter gray black, decomposition of silver. Pure silver nitrate is stable to light, but because of the general product purity is not enough, Silver Nitrate its aqueous solution and solid are often stored in the brown reagent bottle. Silver nitrate is heated to 440 ° C to decompose into silver, nitrogen, oxygen and nitrogen dioxide. The aqueous solution and the ethanol solution were neutral to the litmus and the pH was about 6. The boiling point of 444 ° C (decomposition). There is oxidation. In the presence of organic matter, see the light becomes gray or grayish black. Silver nitrate reacts with a series of reagents for precipitation or coordination (see coordination compounds). For example, with hydrogen sulfide reaction, the formation of black silver sulfide Ag2S precipitation; with potassium chromate reaction, the formation of reddish brown silver chromate Ag2CrO4 precipitation; with sodium hydrogen phosphate reaction, the formation of yellow silver phosphate Ag3PO4 precipitation; Silver Nitrate reaction with halogen ions, To form silver halide AgX precipitate. But also with the role of alkali, the formation of brown black silver oxide Ag2O precipitation; with the role of oxalate ions to form white silver oxalate Ag2C2O4 precipitation. Silver nitrate can react with NH3, CN-, SCN- and so on to form various coordination molecules
Previous:Inorganic Compound Role Next:Silver Nanoparticle Dynamic Process |
Researchers report initial success in promising approach to prevent tooth decay
Yüklə 257.11 Kb.
ölçüsü257.11 Kb.
1 2 3 4 5 6 7 8
'Finally freed'
In doing so, Prof Nicolelis believes they present us with a glimpse of how technology may enhance or even transform us as "the brain is finally freed from the body and it can act upon the world directly".
This mind reading technology is now appearing in some humans.
Following a devastating car accident, 23-year-old Erik Ramsey was left paralysed form the neck down. He's unable to move, talk or eat without assistance, yet his brain remains intact.
Now Erik is at the centre of an experimental therapy to try and restore his ability to speak by connecting his brain to a computer.
When Erik thinks a sound the computer reads Erik's brain activity and turns it in to an actual sound.
To date, Erik and the computer are able to make just a few basic sounds, but the hope remains that within a matter of years he will be able to make useful, vocal communication once more.
Earlier this year US scientists implanted a sensor in a paralysed man's brain that has enabled him to control objects by using his thoughts alone.
But rather than offer us hope, another leading computer scientist believes these inroads in to the mind threaten oblivion.
Professor Hugo de Garis is the architect of some of the world's most complex neural networks - computers that evolve their own intelligence.
Now he is deeply conflicted over the future he is helping to create.
Prof De Garis believes that in a matter of years machine intelligence will supersede our own by a factor of millions.
These so called artilects - short for artificial intellects - will be so powerful that they will appear "almost God-like".
But Prof De Garis fears that they may not be quite so benign.
"How will they feel about us - an inferior species?" he asks before drawing a doom-filled analogy.
"...They may treat us like mosquitoes; as pests," and simply wipe us out, he says.
Horizon is broadcast on BBC Two on 24 October at 2100 BST. Or watch online after that at the Horizon website.
Global ecosystems 'face collapse'
The group's biannual Living Planet Report said the natural world was being degraded "at a rate unprecedented in human history".
Terrestrial species had declined by 31% between 1970-2003, the findings showed.
It warned that if demand continued at the current rate, two planets would be needed to meet global demand by 2050.
The biodiversity loss was a result of resources being consumed faster than the planet could replace them, the authors said.
They added that if the world's population shared the UK's lifestyle, three planets would be needed to support their needs.
The planet's resources are overused by 25%
Per capita the US uses four times the resources of South Africa
Polar bear populations have declined by 30%
The nations that were shown to have the largest "ecological footprints" were the United Arab Emirates, the United States and Finland.
Paul King, WWF director of campaigns, said the world was running up a "serious ecological debt".
"It is time to make some vital choices to enable people to enjoy a one planet lifestyle," he said.
Debtor countries are defined as consuming their own natural resources, or resources from elsewhere, more quickly than they can recover, or they may be releasing more CO2 than they can absorb themselves.
The report, compiled by the Zoological Society of London (ZSL) and the Global Footprint Network, is based on data from two indicators:
* Living Planet Index - assesses the health of the planet's ecosystems
* Ecological Footprint - measures human demand on the natural world
The Living Planet Index tracked the population of 1,313 vertebrate species of fish, amphibians, reptiles, birds and mammals from around the world.
It found that these species had declined by about 30% since 1970, suggesting that natural ecosystems were being degraded at an unprecedented rate.
The Ecological Footprint measured the amount of biologically productive land and water to meet the demand for food, timber, shelter, and absorb the pollution from human activity.
The report concluded that the global footprint exceeded the earth's biocapacity by 25% in 2003, which meant that the Earth could no longer keep up with the demands being placed upon it.
The findings echo a study published earlier this month that said the world went into "ecological debt" on 9 October this year.
Countries are shown in proportion to the amount of natural resources they consume.
The study by UK-based think-tank New Economics Foundation (Nef) was based on the Ecological Footprint data compiled by the Global Footprint Network, which also provided the figures for this latest report from the WWF.
'Large-scale collapse'
One of the report's editors, Jonathan Loh from the Zoological Society of London, said: "[It] is a stark indication of the rapid and ongoing loss of biodiversity worldwide.
"Populations of species in terrestrial, marine and freshwater ecosystems have declined by more than 30% since 1970," he added.
"In the tropics the declines are even more dramatic, as natural resources are being intensively exploited for human use."
The report outlined five scenarios based on the data from the two indicators, ranging from "business as usual" to "transition to a sustainable society".
Under the "business as usual" scenario, the authors projected that to meet the demand for resources in 2050 would be twice as much as what the Earth could provide.
They warned: "At this level of ecological deficit, exhaustion of ecological assets and large-scale ecosystem collapse become increasingly likely."
To deliver a shift towards a "sustainable society" scenario would require "significant action now" on issues such as energy generation, transport and housing.
The latest Living Planet Report is the sixth in a series of publications which began in 1998.
MIT's pint-sized car engine promises high efficiency, low cost
Ethanol empowers the little engine that could
Nancy Stauffer, Laboratory for Energy and the Environment
MIT researchers are developing a half-sized gasoline engine that performs like its full-sized cousin but offers fuel efficiency approaching that of today's hybrid engine system--at a far lower cost. The key? Carefully controlled injection of ethanol, an increasingly common biofuel, directly into the engine's cylinders when there's a hill to be climbed or a car to be passed.
These small engines could be on the market within five years, and consumers should find them appealing: By spending about an extra $1,000 and adding a couple of gallons of ethanol every few months, they will have an engine that can go as much as 30 percent farther on a gallon of fuel than an ordinary engine. Moreover, the little engine provides high performance without the use of high-octane gasoline.
Given the short fuel-savings payback time--three to four years at present U.S. gasoline prices--the researchers believe that their "ethanol-boosted" turbo engine has real potential for widespread adoption. The impact on U.S. oil consumption could be substantial. For example, if all of today's cars had the new engine, current U.S. gasoline consumption of 140 billion gallons per year would drop by more than 30 billion gallons.
"There's a tremendous need to find low-cost, practical ways to make engines more efficient and clean and to find cost-effective ways to use more biofuels in place of oil," said Daniel R. Cohn, senior research scientist in the Laboratory for Energy and the Environment and the Plasma Science and Fusion Center (PSFC).
Cohn, John B. Heywood, the Sun Jae Professor of Mechanical Engineering and director of the Sloan Automotive Laboratory, and Leslie Bromberg, a principal researcher at the PSFC, have an engine concept that promises to achieve those goals.
For decades, efforts to improve the efficiency of the conventional spark-ignition (SI) gasoline engine have been stymied by a barrier known as the "knock limit": Changes that would have made the engine far more efficient would have caused knock--spontaneous combustion that makes a metallic clanging noise and can damage the engine. Now, using sophisticated computer simulations, the MIT team has found a way to use ethanol to suppress spontaneous combustion and essentially remove the knock limit.
With knock essentially eliminated, the researchers could incorporate into their engine two operating techniques that help make today's diesel engines so efficient, but without causing the high emissions levels of diesels. First, the engine is highly turbocharged. In other words, the incoming air is compressed so that more air and fuel can fit inside the cylinder. The result: An engine of a given size can produce more power.
The combined changes could increase the power of a given-sized engine by more than a factor of two. But rather than seeking higher vehicle performance--the trend in recent decades--the researchers shrank their engine to half the size. Using well-established computer models, they determined that their small, turbocharged, high-compression-ratio engine will provide the same peak power as the full-scale SI version but will be 20 to 30 percent more fuel efficient.
But designing an efficient engine isn't enough. "To actually affect oil consumption, we need to have people want to buy our engine," said Cohn, "so our work also emphasizes keeping down the added cost and minimizing any inconvenience to the driver."
The ethanol-boosted engine could provide efficiency gains comparable to those of today's hybrid engine system for less extra investment--about $1,000 as opposed to $3,000 to $5,000. The engine should use less than five gallons of ethanol for every 100 gallons of gasoline, so drivers would need to fill their ethanol tank only every one to three months. And the ethanol could be E85, the ethanol/gasoline mixture now being pushed by federal legislation.
Through their startup company, Ethanol Boosting Systems LLC, the researchers are working with their Ford collaborators on testing and developing this new concept. If all goes as expected, within five years vehicles with the new engine could be on the road, using an alternative fuel to replace a bit of gasoline and make more efficient use of the rest.
Extensively Drug-Resistant Tuberculosis Is an Emerging Threat, Reports International Team of Researchers
October 26, 2006 — (BRONX, NY) — Strains of tuberculosis (TB) that are resistant to both first-line and second-line drugs could threaten the success of not only tuberculosis programs, but also HIV treatment programs worldwide, according to an article published online this week in The Lancet. The report details a study by a team of investigators from the United States and South Africa, who found that highly resistant strains of TB were more common than previously thought in a rural area of KwaZulu Natal, South Africa, and were associated with high death rates in patients with HIV infection. TB accounts for approximately 1.7 million deaths worldwide, each year, and is the leading cause of death in HIV-infected patients in low-income countries.
In the study, presented by Dr. Neel Gandhi, assistant professor of medicine at the Albert Einstein College of Medicine of Yeshiva University, the researchers tested patients with suspected tuberculosis for MDR and XDR strains. They found that of 1,539 patients, 221 had MDR tuberculosis, and 53 of these had XDR tuberculosis. The prevalence rates in a group of 475 patients with confirmed tuberculosis were 39% for MDR and 6% for XDR tuberculosis—higher rates than previously reported in the area. All patients with XDR disease who were tested for HIV were co-infected with the virus, and all but one died.
(Dr. Gandhi conducted this research while he completing fellowships at Yale University School of Medicine and Emory University. He joined the Einstein faculty in August 2006.)
Further complicating the problem posed by multidrug-resistance is the fact that the epidemics of tuberculosis and HIV in South Africa are closely linked. Risk of tuberculosis disease is greatly increased in people with HIV infection, and multidrug-resistant (MDR) tuberculosis is emerging as a major cause of death in these patients. The term extensively drug-resistant (XDR) tuberculosis has recently been used to describe strains that are resistant to second-line drugs—i.e., drugs that are used if the recommended first drug treatment regimen fails.
Investigation of the patients’ histories and the genetic makeup of the infecting bacteria suggested that transmission of XDR strains had occurred recently, that transmission between individuals had occurred, and that some patients had been infected while in hospital. The researchers say that these findings are worrying, since hospitals in low-income countries have limited infection-control facilities and a high proportion of susceptible HIV-infected patients. They recommend action to tackle the problem of resistant strains that could jeopardise attempts to control tuberculosis and prevent mortality in HIV patients.
In addition to Dr. Gandhi, other researchers involved in the collaborative project were Dr. Gerald Friedland, director of the AIDS Program at Yale University; Dr. Tony Moll, of the Church of Scotland Hospital in Tugela Ferry, South Africa; and Drs. Willem Sturm, Robert Pawinksi and Umesh Lalloo, of the Nelson R. Mandela School of Medicine, in Durban, South Africa.
UWM brain research supports drug development from jellyfish protein
Testing of aequorin yields promising results
Testing of aequorin has yielded promising results, said Mark Y. Underwood of Quincy Bioscience located in Madison. Researcher James Moyer, Jr., an assistant professor at UW-Milwaukee, subjected brain cells to the "lab" equivalent of a stroke, and more than half treated with aequorin survived without residual toxicity.
Why does it work? Diseases like Alzheimer's are associated with a loss of "calcium-binding" proteins that protect nerve cells, said Moyer. Calcium is necessary for communication between neurons in the brain, and learning and memory are not possible without it. But too much of it leads to neuron death, interfering with memory and contributing to neurodegenerative diseases.
"There are ways in which cells control the influx of calcium, such as sequestering it by binding it with certain proteins," said Moyer. "If it weren't for these proteins, the high level of calcium would overwhelm the neuron and trigger a cascade of events ultimately leading to cell death."
Calcium-binding proteins decline with age, however, limiting the brain's ability to control or handle the amount of calcium "allowed in."
Moyer, like Underwood, is interested in the "calcium hypothesis of aging and dementia," which is just one of many theories that attempts to explain what is going on in neuron degeneration.
Moyer's research centers on brain changes that occur as a result of aging. Specifically, he is interested in the part of the brain called the hippocampus, which is responsible for forming new memories. These capabilities not only deteriorate in neurodegenerative disorders such as Alzheimer's disease, but they also become impaired simply by aging.
Aging increases the number of "doors" that allow calcium ions to enter the cells, he said.
Moyer's work also has implications outside of disease. He is able to show that at middle age, when the animal's learning ability or memory is not yet impaired, it already shows a drop in the number of neurons that contain an important calcium-binding protein.
"That cellular changes precede memory deficits indicates there is a window of opportunity for intervention before it's too late," he says. "Once the cells are lost, there is little chance of regaining normal brain function."
Profiles of serial killers have limitations
Serial killer profiles
(SACRAMENTO, Calif.) – Dennis Rader, the notorious BTK murderer who eluded capture for more than 30 years until his arrest in 2005, did not fit precisely into the FBI's method for profiling serial killers on the basis of crime scenes.
And Aileen Wuornos, the Florida prostitute executed in 2002 for slaying seven men over a two-year period in the early 1990s, didn't fit at all because the database of convicted serial killers used by the FBI in developing their profiling method did not include women.
The cases of Rader and Wuornos are among the topics to be explored during a panel discussion led by Dr. Charles L. Scott, a forensic psychiatrist at UC Davis Health System, at the annual meeting of the American Academy of Psychiatry and the Law Friday at the Marriott Hotel in downtown Chicago. Scott will examine the way the bureau develops the personality profiles used by investigators in serial murder cases. He also will look at alternative profiling methods, such as one developed by a crime writer that uses motive to sketch a female offender's likely character traits.
"The FBI profiling method has many positive attributes. But it also has some inherent limitations," Scott said. Scott, associate professor of clinical psychiatry with the Department of Psychiatry and Behavioral Science, will be one of four panelists in the talk, dubbed "Serial Killers: From Cradle to Grave." It is one of many events slated at the meeting, which began Thursday and runs through Sunday. The annual conference seeks to cover the major issues facing forensic psychiatrists.
Scott has extensive experience in legal psychiatric issues. He directs the psychiatry department's forensic case seminar, which trains psychiatrists in criminal and civil psychiatric evaluations, including assessments on insanity, competency to stand trial, personal injury evaluations, medical malpractice and danger assessments. He also serves as psychiatric consultant to the Sacramento County Jail and directs his department's forensic psychiatry residency program, overseeing training and education in landmark mental health law cases.
The purpose of Friday's panel discussion is not to critique the FBI, Scott said. Instead, it is to acquaint forensic psychiatrists with how the bureau profiles serial killers, defined as someone who has killed at least three times.
"Often, forensic psychiatrists are not trained in how the FBI does its analysis," Scott said.
Such training is important, Scott said, because forensic psychiatrists can play "an important collaborative role" with law enforcement when it comes to profiling. To support his view, Scott will cite a study that found psychiatrists were more accurate than police in profiling murder suspects. To an FBI agent, the crime scene is the key.
"The FBI would say the crime scene is like a fingerprint," Scott said. Interpreted properly, "it is likely to identify the kind of offender who would do this."
According to Scott, the bureau categorizes murder crime scenes as either organized or disorganized. An organized crime scene is one in which the killer exerted careful control of the environment and left little evidence behind. This suggests a well-educated and socially competent suspect. In a disorganized crime scene, things are left in disarray and evidence is plentiful. This suggests a murderer with a low level of education and social competence who may habitually use alcohol or drugs.
The problem with that approach, Scott said, is that crime scenes often have both organized and disorganized components. Take Rader's first crime scene, when he killed Joseph and Julie Otero and their two children on Jan. 15, 1974. There was clear evidence of advance planning and the murderer's domination of the environment – Rader both strangled and suffocated his victims, forcing them to pass out and then allowing them to revive somewhat "as a way to extend their death," Scott said.
But, Scott said, there were disorganized elements as well. Rader -- or BTK for Bind, Torture, and Kill -- left behind the Venetian blind cords he used as a strangling device. He also did not get rid of the bodies. While Scott stated that he has not seen any FBI profile of the BTK killer, who was sentenced to 10 consecutive life sentences last summer, Scott said that "Rader had many of the characteristics of an organized killer." For example, Rader, a resident of a Wichita, Kan., suburb, was employed and lived near his crime scenes. As a result, Scott said the signs of disorganization that were present in his first crime scene and in subsequent ones were potential red herrings, at least in terms of developing a profile. Rader was not, for example, under the influence of alcohol during his killings, nor did he frequently travel and change jobs -- traits of an organized killer under the FBI scheme.
When the FBI develops profiles of serial killers, Scott said the bureau is relying on interviews its investigators have conducted with 36 convicted sexual or serial murderers. Scott said a shortcoming with the database is that it does not include a single female serial killer. Consequently, its applicability to someone like Wuornos, portrayed in the 2003 movie "Monster" by Charlize Theron, "just isn't there," Scott said.
The database's relevance to non-Caucasian serial killers is also lacking, Scott said, as 90 percent of the men interviewed were white. It also doesn't explain a "very rare subset -- children who serially kill," Scott said. Probably the most well-known in this category, Scott said, is Jesse Pomeroy, a Massachusetts boy who, in the 1870s, brutalized other boys when he was only 12 and who killed a 10-year-old girl when he was 14.
Dostları ilə paylaş:
1 2 3 4 5 6 7 8
Verilənlər bazası müəlliflik hüququ ilə müdafiə olunur © 2017
rəhbərliyinə müraciət
Ana səhifə |
Logo TwoI teach a course in Roman law for final-year students, and I always set aside a few seminars to discuss the legal aspects of selling slaves: documents recording slave sales, the sale of free persons as if they were slaves, and of course slaves with “defects” or special qualities. Roman slave law is emotionally tough. We bring disciplined minds to the texts, but we can’t close our intellect to the human beings we’re discussing. We struggle most when we talk about the buyer’s protections against “faulty” slaves. The quotation marks defend our humanity; the Romans weren’t so queasy, probably because status-types were embedded in their thinking, and the legal incidents of status had to be meticulously explored. One inevitable incident was the fact that humans, as items of commerce, could have shortcomings. This led the Roman jurists enthusiastically to discuss limbs, senses, and dispositions. The discussion shocks us, but what shocks us further, as Prof. Carrasco reveals, is how deeply the specific rules on slave sales had penetrated the popular mind. |
On humanism: the ethical and scientific inadequacies of a secular religion
Secular humanism is on the rise, and boasts some high-profile and outspoken celebrities amongst its ranks, like Stephen Fry, Ricky Gervais, Sue Cook, and even our own national treasure, Tim McGarry.
In Northern Ireland, humanists, although relatively small in numbers, are a vocal lot, who can often be found working behind the scenes of various movements, from abortion-choice and LGBTQI+ advocacy to campaigns for euthanasia, and the removal of prayer in public institutions. Bizarrely, for all their talk of social justice and empathy, they don’t do much actual charity work, preferring instead to leave that to others.
While it’s true, from a Christian viewpoint, that not everything about humanism is bad – indeed, some of their causes are admirable – it does present a sizeable threat to Christianity. For that reason, Christians ought to know what it’s about and how to effectively counter its claims and recognise its inadequacies. Here goes.
What exactly is humanism?
The term humanism can mean many things. Just as there are many different types of religion, there are many types of humanism, covering a wide range of beliefs with some overlapping elements. From these elements, a core set of humanistic beliefs has emerged, sometimes referred to as ‘secular humanism’.
Over the years, humanists have gathered together to officially declare these beliefs in the form of manifestos. There have been three (and a bit) humanist manifestos so far: Humanist Manifesto I (1933), Humanist Manifesto II (1973), and Humanist Manifesto III (2003). (There was also a spinoff manifesto called Secular Humanist Declaration (1980), but this was mainly considered to be a prologue to the third manifesto).
It is apparent, then, given its multiple revisions, that humanism sees itself as something that evolves with culture; what is wrong today may not necessarily be wrong in thirty years and vice versa, so we shouldn’t rule out more manifestos (or maybe a manifesto manifesto to help us keep track of the manifestos). For now, though, the core tenants of secular humanism can be summarised as such:
• Non-theism: most secular humanists deny the existence of God, but virtually all deny the need for a God.
• Naturalism: this an essential belief for secular humanism that follows from the denial of theism. If there is no supernatural – no God – then everything is explainable by natural laws alone.
• Evolutionism: for the secular humanist, evolution is a sufficient way of explaining origins. That is, in the absence of a Creator God, all living things and the entire universe are the product of chance plus time plus matter.
• Ethical relativism: most secular humanists don’t do moral absolutes. There are no God-given, unchangeable moral laws, therefore ethical standards must be determined by man. Such standards are subject to change over time as societies evolve, and are relative to different cultures.
• Human self-sufficiency: this is a central tenant. All humanists believe that man is capable of solving his own problems without divine help. To quote Sue Cook: “I have long felt in sympathy with the Humanist movement. I put an extra ‘ o’ in God and put my faith in the overall Good in humanity.”
Humanism: religion in disguise
Humanists are quick to tell everyone that their beliefs are informed solely by science, reason, and rationality – and are often at pains to dismiss religion entirely. But, whether today’s humanists know it or not, the history of humanism is steeped in religion.
Humanist Manifesto I clearly emphasises the importance of religion and, before that, two founding fathers of humanism, Henri Saint-Simon and Auguste Comte, dreamed of a religion for all humanity, a universal civilisation based on science. In fact, Comte even set up a humanist sect and declared himself a high priest.
Julian Huxley, another eminent humanist, was, despite being an ardent atheist, a big fan of religion. One day while reading an essay by Lord Morely, he read the words: “The next great task of science will be to create a religion for humanity.” Challenged by these words to create a scientific religion, he coined the name ‘evolutionary humanism’. The rest is history.
So while it’s true that humanism entails no God, it certainly entails religion. Religion is simply a belief system, often with a figurehead, that attempts to answer the following big questions: 1) origins, 2) meaning, 3) morality, and 4) destiny. Humanism ticks all these boxes. Their figurehead is Charles Darwin; they believe our origins lie in the evolutionary process; they believe morality is subjective and culturally determined; they believe that nothing happens after death. This is religion 101.
But worse than that – it’s faith! Why? Because what Darwin taught us, if true, allows no room for secular hope.
Sure, scientific progress has helped us to live longer and healthier, but it has done precisely nothing for our ethics. Humans today are as destructive and as greedy as ever, only now, thanks to scientific and technological progress, we can kill, destroy, rape, and pillage on much larger scales. The post-enlightenment world, littered with the ruins of many a secular utopia, is proof of this.
Of course, on atheistic naturalism, such destructive behaviour is merely the evolutionary path of one particular beast – the human being – so to believe that things can or should be any different, as humanists do, takes a considerable amount of faith.
So the first thing we need to know about humanism is that it’s not science – it’s a secular religion. It is a post-Christian faith that preaches humans can be saved if only they accept science and progress as their lord and saviour.
The scientific inadequacy of secular humanism
Despite what you might read on some Internet forums, Christians and humanists aren’t that far apart when it comes to science. Both groups agree that the universe is governed by laws, such as thermodynamics and gravity, and that knowledge of these laws is helpful in understanding how the universe operates.
The conflict, then, is not about operation but origination. And this is where secular humanism starts to unravel. As previously discussed, secular humanists have a naturalistic view of origins – the idea that the universe is uncaused – but this is deeply unscientific.
The two most fundamental principles of science are observation and repetition, but since the origins of the universe were not observed and have not been repeated, we must then look at the present as a key to the past. And we know from studying the present that every event has an adequate cause. Now, if every event has a cause, it follows that the whole universe has a cause. This has led scientists to the conclusion that it all started with a Big Bang – something that is entirely consistent with the Christian narrative.
This is not a happy conclusion for secular humanists, as astrophysicist Robert Jastrow writes:
Belief in a Creator God is fully consistent with what science says about how the universe works. Conversely, the secular humanist position, despite claiming the scientific high ground, is worse than magic. Something can’t come from nothing. Life can’t come from non-life.
By avoiding this conclusion, humanists are saying that reason only applies to certain events in the universe, but not all events. This is flat-out irrational. Yet they still believe.
Ethical absurdity: absolutely no absolutes, absolutely
Many humanists believe that morality is relative and that values are subject to change. Ethics are situational, they say. Humanist Manifesto II states, “We affirm that moral values derive their source from human experience, needing no theological or ideological sanctions.” Since there is no ultimate Law Giver, there can be no ultimate Law – “Humanism asserts that the nature of the universe depicted by modern science makes unacceptable any supernatural or cosmic guarantees of human values”.
In other words, secular humanism denies all absolutes – absolutely. For the discerning reader, of course, this is a house built with Wotsits and Flumps. Firstly, is the claim “everything is relative” relative or non-relative? If it’s non-relative, then it’s absolute. If it’s absolute, then the claim is self-defeating. Conversely, if the claim is relative, then it could be wrong – so it can be dismissed.
So this begs the question: do secular humanists believe that humanism is true? They certainly act and write like they do. You’ll notice that humanism always gets revised, never rejected. Their faith is unshakable. So they obviously believe humanism to be the One True Path. The irony here, of course, is that this absolutistic approach is at complete odds with their denial of absolutes. You don’t often hear humanists say, “there are no absolute moral values, except the values of secular humanism.” That would be dogma – a trait they abhor in others.
And yet, that is exactly how they behave. Not only are humanists inconsistent in principle by denying moral absolutes, they are inconsistent in practice. Humanists continually violate their own rules when they say things like: “love is love,” and “no women should be denied an abortion”, or “we demand separation of church and state!” Really? Says who? Sue Cook?
No. It is obvious, then, that from both the writings and actions of humanists that they do believe in some moral absolutes. Just not the ones that they disagree with.
Even humanists need God
One of the biggest pieces of evidence for God can be found in the very people who rail against Him. The confessions of many secular humanists and other non-theists demonstrate this. The atheist and existential humanist Jean-Paul Satre confessed, “I needed God. I reached out for religion, I long for it, it was the remedy.” And the French atheist Albert Camus admitted, “nothing can discourage the appetite for divinity in the heart of man.”
Most tellingly, the historian and atheist Will Durant said this in a newspaper interview:
You and I are living in a shadow … because we are operating on the Christian ethical code which was given us, unfused with the Christian faith … but what will happen to our children …? We are not giving them an ethics warmed up with a religious faith. They are living on a shadow of a shadow.
So why do self-professed rationalists place their faith in a system that exists in the shadow of a shadow with no solid philosophical grounding? The answer is, quite simply, “anything but God, thank you very much.” To quote the famous atheist, Friedrich Nietzsche, “If one were to prove this God of the Christians to us, we should be even less able to believe in him.” I think that says it all.
There are many other areas where secular humanism falls short, such as its many internal consistencies (Existential vs. Scientific Humanism, Egocentric vs. Social Humanism, etc.) and its often-bitter infighting (some humanists are in favour of abortion, others are pro-life. Some are capitalists, others communists. Some are charitable, others are egoists). But when we examine their core beliefs – the beliefs canonised in the three manifestos and a declaration – they reveal many contradictions and absurdities. They claim to be scientific, but they violate basic laws of science. They claim to be rational, but they cannot account for the existence of rationality. They claim that nothing exists outside of nature, but they stand outside of nature to tell us what’s right and wrong. Secular humanists do not hold to a consistent position, so there’s simply no rational justification for being one.
4 thoughts on “On humanism: the ethical and scientific inadequacies of a secular religion
1. Lisa
What makes me chuckle the most about this piece is that you proclaim here (and indeed on your About me page) that you don’t believe that something can come from nothing so, therefore, god must exist.
It always baffles me that religious folk don’t question who made their god in the first place. If you think about it sensibly, you’re still going to end up at a situation where something comes from nothing. You’re just placing that moment a bit further back in time…
1. The Bigot Post author
Hi Lisa, thanks for reading and commenting – I’m glad it made you chuckle.
I’ll try my best to think about this sensibly. Here goes. When we appeal to science and philosophy, the first thing to note is that an infinite regress of causes is logically impossible. That is, the universe could not be infinite because that would require an infinite number of events happening before we could even have this conversation – which means we wouldn’t be having this conversation. You can only go so far back in time. Therefore, there was a beginning.
Now, if time and space came began to exist (as science, philosophy, and theology all indicate), this means, by necessity, that there was a First Cause. Since nothing caused that First Cause (because it is, by definition, a first cause), we can know two things about it: 1) It must have been an act of will (because no natural event took place before it), and 2) It must be self-existent (or else it would not be a first cause). Something with these two attributes is, by definition, a God. Which God is a seperate question.
So, when you ask “who made their god?” what you’re really asking is, “Who is the real God?” because the real God — the First Cause — does not, and could not, have a cause.
2. David Ferguson
Hi Lisa, the main reason why religious people don’t question who made God is because their understanding of Him is that He is self-existent. Self-existent entities are, by definition, not made by anyone or anything. Nothing precedes them and nothing is required to precede them.
If you can’t get your head around that, try this: if God made the universe, time must be one of the things He made. But your question (“Who made God?”) implies a “before”, a this-then-that sequence which does not make any sense unless you assume the passage of time.
2. Lisa Wilton
No, I’m not asking “who is the real god?” at all. I’m pointing out the fact that the same problem exists when you think about the creation of the universe or the creation of a god. You’re talking about things being illogical in one sentence and then going on to say that a god coming into existence is somehow logical. I didn’t suggest that there was an infinite regress of causes, in any case. I’m just pointing out that the thing you are using to disprove one theory, is still a problem in your own theory.
Leave a Reply
|
Multimodal Hci In User Interface Design
in User
Multimodal HCI is at the intersection of several disciplines that include psychology, computer vision, user interface design ,and artificial intelligence just to name a few. Computers have become integrated into everyday objects and tasks (often termed ubiquitous and pervasive computing) and so it has become important to facilitate a natural interaction between users and computers that simulate the way humans interact with each other face-to-face. Multimodal HCI aims to discern the ways in which humans interact with each other in order to translate these processes to the human and computer interaction.
Multimodal HCI encompasses a wide range of modalities. A modality is a mode of communication according to human sense or type of computer input device. Typically modalities are divided into two categories:
1.Human senses: sight, touch, hearing, smell, taste, and cognitive/emotional abilities
2.Computer input devices: cameras, haptic sensors, microphones, olfactory (all meant to emulate the human senses)
Together these modalities can be used to construct various types of user interface designs in order to increase usability. In this article I will briefly overview the functions of each modality and then discuss the benefits of multimodal user interface design.
Multimodalities and their application in user interface design
The above mentioned categories exist to understand how, particularly related to user interface design, humans and computers utilize the same functions and can thus complement each other for a more positive user experience.
The human senses category helps designers understand how humans take in and process information. Sight has to do with what a user sees on an interface words, images etc. Hearing has to do with the audio aspect of a user interface, whether it be music, commands, or conversation between two people. While smell and, especially, taste are less important in relation to traditional user interface design, they are still important for designers to consider since they can affect the other senses, and the synergy of all the senses ultimately affects the users cognitive and emotional state. From a design perspective, it is critical to understand the cognitive and emotional state that results from a user employing a user interface. This can help to detect and track the users task execution, motivations, and level of satisfaction with a design.
Computer input devices mimic the human senses in order to help people relate to computer interfaces (and conversely to help computers relate to people). Cameras function like an eye and mimic the visual sense, and haptic sensors are a tactile feedback technology (think of the mouse) mimicing the sense of touch. Microphones and speakers enable a user to hear and make sounds. Olfactory devices can stir up a users sense of smell; a process called machine olfaction employed by SMBO instruments (commonly referred to as electronic noses) uses a complex array of chemical sensors and pattern recognition algorithms to allow computers to mimic the sense of smell.
Why is multimodal HCI important to user interface design?
Multimodality is an incredibly wide-ranging and complex aspect of HCI, and we have only given a very brief overview of it in this article. However, it is important to have at least a rudimentary understanding of it in relation to interface design because at its core it attempts to understand how humans function as an integrated system of senses and cognitive abilities, thus allowing UI designers to let computers mimic and/or complement these processes. Understanding the full range of human senses and emotions can allow designers to construct user interfaces that capitalize on what senses and emotions their target group is most reliant upon or most influenced by. The user interface can then facilitate the users ability to perform tasks and achieve goals at a much more efficient rate, and ultimately lead towards a more optimally usable system. Stating that optimal usability is one of the ultimate goals of multimodal HCI and interface design may seem like a cop out, and probably a bit redundant, but in terms of user interface design optimal usability is always the ultimate goal, but its hard to reach if designers dont grasp the critical methods and paths of getting there.
Author Box
Martin Metz has 1 articles online Interface Design, Wireframing Software, Wireframes, Wireframe Tool , Interface Design Software, Interface Prototyping , Usability Testing, Wireframes and Clickable Wireframes.
Add New Comment
Multimodal Hci In User Interface Design
Log in or Create Account to post a comment.
Security Code: Captcha Image Change Image
This article was published on 2011/04/13 |
3 Simple Strategies To Stop Sleep Apnea
If you have ever visited a sleep medicine physician, he or she may have recommended that you make an appointment with a sleep clinic to undergo a sleep study. The study will help determine if you have sleep apnea, which refers to episodic periods of breathing cessation during your sleep cycle.
If left untreated, sleep apnea may raise your risk for cardiovascular disease, high blood pressure, and excessive daytime sleepiness. There are, however, some simple things you can do at home to reduce your risk. Here are three easy strategies to help reduce your risk for sleep apnea and how they work to lower your risk:
Side Sleeping
If you sleep on your back, your airway can become obstructed. This is especially common in people who are overweight or who carry excess weight around their necks, By simply sleeping on your side, the airway will be kept open, which will help prevent apneic episodes.
Also, if you take certain medications, it can cause the relaxation of the muscles in your tongue, and if you sleep on your back, your tongue can relax into your throat. Sleeping on your side will help prevent this type of airway obstruction and may even help reduce episodes of snoring.
Lose A Few Pounds
Being overweight can dramatically raise your risk for sleep apnea. Visceral fat can place pressure upon your diaphragm, impairing your breathing. Also, as stated above, too much fat around the circumference of your neck can also impair your breathing.
Losing just a few pounds can help reduce the frequency and severity of sleep apnea episodes, reducing your risk for heart disease and hypertension. If you are unable to lose weight on your own, make an appointment with your physician, who will recommend strategies to help you shed excess weight. In the meantime, decrease your intake of sugary, high carbohydrate foods, and limit you intake of alcohol. Talking a walk after dinner will also help burn calories and may also help relieve joint pain, improve your breathing, and enhance your energy levels.
Treat GERD
If you have GERD, or gastroesophageal reflux disease, you may be at a higher risk for snoring and sleep apnea. Acid reflux can irritate your vocal cords and cause pharyngeal swelling, both risk factors in the development of apnea. If you have GERD, see your doctor.
In the meantime, try taking an over-the-counter antacid or acid-blocking medication that will which help neutralize irritating stomach acid. In addition, avoid GERD trigger foods such as chocolate, coffee, tomatoes, citrus fruit, and peppermint. Sleeping with the head of your bed elevated will also help keep stomach acid from traveling up into your throat and irritating your airway.
If you snore, wake up gasping for air, or experience excessive daytime sleepiness, make an appointment with a sleep medicine doctor at a clinic like Elkview General Hospital. When sleep apnea is recognized and treated properly, you may be less likely to develop complications such as high blood pressure, low energy levels, and cardiovascular disease. |
Anonymous / AP
On Nov. 9, 2011, the Zenit-2SB rocket with the Phobos-Ground probe blasted off from its launch pad at the Cosmodrome Baikonur, Kazakhstan.
updated 1/31/2012 8:11:55 AM ET 2012-01-31T13:11:55
The unmanned probe was to have gone to the Mars moon of Phobos, taken soil samples and brought them back. But it became stuck in Earth orbit soon after its launch on Nov. 9. It fell out of orbit on Jan. 15, reportedly off the coast of Chile, but no fragments have been found.
But Russian news agencies on Tuesday quoted him as saying an investigation showed the probable cause was "localized influence of heavily radiated space particles."
Popovkin, speaking in the city of Voronezh where the report was presented to Deputy Prime Minister Dmitry Rogozin, said two units of the Phobos-Ground probe's onboard computer system went into an energy-saving "restart" mode, apparently due to the radiation, while the craft was in its second orbital circuit.
1. Space news from
1. KARE
Teen's space mission fueled by social media
2. Buzz Aldrin's vision for journey to Mars
3. Giant black hole may be cooking up meals
4. Watch a 'ring of fire' solar eclipse online
It was not immediately clear why the units could not be brought out of that mode.
Popovkin was quoted as saying that some microchips used on the craft were imported and possibly of inadequate quality to resist radiation. He did not specify where the chips were manufactured.
Popovkin also said the craft's builder, Moscow-based NPO Lavochkin, should have taken into account the possibility of radiation interfering with the operation and said Lavochkin officials would face punishment for the oversight.
Russia's space program has suffered a series of notable failures in recent months, including the August crash of an unmanned ship that was to send supplies to the International Space Station. That crash forced the postponement of a manned launch to the space station because the booster rocket that failed in the crash was similar to the ones used in manned missions.
On Tuesday, Russian news agencies said a manned launch to the space station that had been scheduled for March 30 will be postponed for about 45 days because tests of the capsule showed flaws in its hermetic seals.
Photos: Month in Space: January 2014
loading photos...
1. Southern stargazing
2. A balloon's view
3. Spacemen at work
4. Special delivery
5. Accidental art
6. Supersonic test flight
7. Red lagoon
8. Fire on the mountain
9. Where stars are born
10. Cygnus takes flight
11. A long, long time ago...
12. Frosty halo
1. Editor's note:
This image contains graphic content that some viewers may find disturbing.
2. Editor's note:
This image contains graphic content that some viewers may find disturbing.
3. Editor's note:
This image contains graphic content that some viewers may find disturbing.
4. Editor's note:
This image contains graphic content that some viewers may find disturbing.
Discussion comments
Most active discussions
1. votes comments
2. votes comments
3. votes comments
4. votes comments |
Close Menu
Emilie's Education Series: Malt
Aug 09, 2013 Comments (0) | Tags: Beer Geekery Emilies Education Series: Malt
There's a lot that goes into malt. What is it made of? What is the action of malting? Read on for the answers, my friend!
Primarily, malt is barley. Barley goes through the malting process and then, can officially be called "malt." Barley is the most common used grain for malting because it enables one to extract sugars and enzymes for the <a href="">wort</a> (also known as malty sugar water) during the brewing process.
There are two types of barely: 2-Row and 6-Row. At Ninkasi, we primarily use 2-Row malt because of its mild flavor, plump kernels rich with sugars, and for the fact that it is low in protein content.
So what does it mean to malt barley? It all begins with the stage that the barley is in before it goes through the malting process. First, the barley goes through controlled germination. Basically, germination means the barley seed has sprouted. After the seed sprouts, it is dried to preserve the enzymes, which contains sugars used for fermentation.
After the malt is dried, there are many things that can be done. The malt can be heated, toasted, and/or roasted in a kiln. This will give the malt its different degrees of strength, color and flavor.
Malt is a huge part of the brewing process. Not only does it contribute to the strength, color and flavor of beer but it is responsible for providing the sugars that are used for fermentation. At Ninkasi, we have two large grain silos that hold our foundation malts. One silo holds 60,000 pounds and the second silo holds 20,000. We get malt delivered to the brewery every other day and receive about 45,000 pounds at a time. Now you can imagine that is a TON of malt!
Comments (0)
Add a Comment
|
Unmanned Aerial Vehicle (UAV) Air Patrol and Safety Solution in the Mining Area
In mining areas especially Oil and Gas either on shore or off shore, monitoring and maintenance programs are important every day to reduce errors and increase worker safety. Extensive areas and difficult terrain make inspection and maintenance time-consuming. Moreover, the area exposed to radiation, is very dangerous if done by human labor.
Technological advancements offer a sophistication to replace the human role of doing these things. Technology that can replace the human role is a flying robot or commonly called the unmanned aerial vehicle or more popularly called the drone.
Drone tool that presents the advantages of digital image can be utilized to monitor mining area. The tasks that the drone can do include the following aspects:
Emergency state
1. Monitor mining conditions from the air to accelerate rescue response in case of work accident, it means that drone can be safety solution to the worker. Maybe we can call it uav safety solution.
2. Monitor leakage and equipment damage.
Quick response to security systems and emergencies
1. Conducting air patrols to oversee all mining areas, by capturing visual movements directly so as to oversee the movement of workers and suspicious persons.
2. By displaying a real time visual of the drone can help speed up the officer’s response to crack down on any emergency situation.
Port area supervision solutions
1. Forming crew for navigation while leaning his ship to the port.
2. Port Monitoring and Vessel Traffic Control
3. Supervise the loading and unloading of goods from and to the port
4. Such as in mining areas, drones also oversee emergencies and safety
Mapping the mining area is very important and should be done. In this case the use of drones is considered to be very effective compared to using surveyors of mining services. In a day the surveyor can only mapping an area of 10 hectares while the drone can mapping an area of 1000 hectares in a single flying with a height of 300 meters and photographing the work area of 200 meters.
While exploring, companies often determine the calculation of available mineral reserves and open access roads. This activity requires a top visual appearance of the mine site area, both relying on drones in capturing processed data and producing topographic maps and image maps. Furthermore, in the calculation activities of coal reserves, volumes, and depth of the borehole, the calculation is done by comparing the upper limit with the lower limit. Topographic maps are also used here as the upper boundary of the mine site which will be compared to the lower limit obtained from the geological survey results.
Every mining company has the responsibility to reclaim / rehabilitate damaged environments. This reclamation is done by replanting or reforesting an area damaged by the mining activity. These changes should be managed to avoid adverse environmental impacts such as erosion, sedimentation, poor drainage, entry of weeds / pest / plant diseases, surface / ground water pollution by toxic materials and others. Before starting the reclamation activities there is of course basic planning. The company must see how much damage the mine site experienced. Drones back can be utilized, with not consuming enough time and able to produce a map with a high enough resolution, drones can be the company’s handle to perform a fast and precise reclamation.
Increasing the utilization of drones, the productivity of natural resource exploitation will increase. The strong foundation and proper implementation are able to maintain and improve the productivity of Indonesia’s natural resources and one of them in the mining industry. |
"Numerical Pattern"
Given the following number representing a pattern:
2053 = 2^0 + 5^3 = 1 + 125 = 126
Note: ^ means exponent
Look above at the number "20"; in this sequence it represents 2 to the 0 power which is 1. The other number "53" represents 5 to the 3rd power which is 125. Then final answer is calculated by the sum of each term.
Given this number below:
What is the answer using the above pattern?
This is a fairly simple challenge once you understand the pattern... loop over the number with jumps of 2, find the power for the current 2 and add that to the result. PHP is useful for this challenge as there is no need for string to no conversion! |
Skip to content
• Research article
• Open Access
• 1Email author,
• 1,
• 2,
• 1,
• 1,
• 1 and
• 3, 4
BMC Biology201412:23
• Received: 11 December 2013
• Accepted: 21 March 2014
• Published:
• Collective cell migration
• Neural crest
• Directional migration
• Enteric nervous system
Neural crest cells are a transient migratory embryonic cell population. Previous imaging studies of cranial neural crest cells in Xenopus and chick embryos have revealed the organization of the cells as they migrate, the rules guiding their behavior and some of the molecular bases of the interactions [1, 2]. In both species, the cells move as a collective from one location to another; in chick embryos, there is a “follow the leader” chain migration in which the spatial order of cells is retained [37]. In Xenopus, several concomitant behaviors have been identified including “run and tumble” in which phases of directional migration are interspersed with phases of small random movements, “mutual co-attraction” in which cells retain the same neighbors for long periods of time, and “contact inhibition of locomotion” in which cells polarize and disperse upon contact with each other [812].
A sub-population of vagal level (caudal hindbrain) neural crest cells migrates into and along the developing gut, and gives rise to most of the enteric nervous system [1317]. The neural crest cells that colonize the gut migrate further than other embryonic cells because the gut is growing as the cells migrate [18, 19]. The migration of ENCCs exhibits two important differences from neural crest cell populations that have been examined in detail previously. First, not only must some ENCCs migrate caudally to reach the distal regions of the gut, each gut region through which ENCCs migrate must be populated by ENCCs to ensure there is an even distribution of enteric neurons along the entire gut; this behavior has been termed “directional dispersion” [20]. In contrast, analyses of migrating cranial and trunk neural crest cells have been performed as the entire cell population migrates collectively from one location to another. Studies of ENCC migration to date have focused on the caudal advance of the ENCC wavefront [2127]. ENCCs migrate in chains with high cell-cell contact [21, 23, 24, 28], and so little is known about how individual ENCCs behave to ensure that all regions of the gut are also evenly populated with ENCCs. We had previously assumed that each gut region is colonized by sub-populations of ENCCs stopping as the wavefront of ENCCs moves caudally [23]. The migration of ENCCs is an excellent model to examine how individual cells behave in a population that both migrates directionally and populates regions along the migratory route.
A second important characteristic of the migration of ENCCs is that a subpopulation of ENCCs starts to differentiate into neurons that project neurites caudally along the same pathways that ENCCs are migrating [29, 30]. The relationship between growing neurites and migrating ENCCs is still unclear, and it is unknown which leads the way at the migratory wavefront.
We used mice in which all ENCCs express the photoconvertible protein, KikGR [26] and so the behavior of individual ENCCs, their interactions with all other ENCCs, and their location with respect to the migratory wavefront, could be examined. We also examined the role of signaling via endothelin receptor type B (EDNRB) in migratory behavior. Detailed information about the migratory behavior of individual ENCCs at the cellular level is likely to provide clues as to the molecular mechanisms involved, and the data are also essential for the development of models of the colonization of the gut by ENCCs.
Ednrb-hKikGR mice, in which all ENCCs show KikGR fluorescence, were used [26]. KikGR is a photoconvertible protein that changes its emission from green to red following exposure to ultraviolet or violet light [4]. Individual or groups of KikGR cells in explants of embryonic gut were photoconverted from green to red, and then time-lapse imaging was performed in which three-dimensional image z-stacks were collected at two- to five-minute intervals on a confocal microscope. The majority of experiments were performed using explants of gut from E12.5 Ednrb-hKikGR mice because at this age, the ENCC migratory wavefront is in the mid-colon, and the colon is relatively straight [31]; as a result, the migratory wavefront of ENCCs could be imaged for over 24 hours. In contrast, at E11.5, the ENCC wavefront is difficult to define because of transmesenteric ENCCs, which migrate from the midgut across the mesentery into the proximal colon [26].
Variability in speed and direction of migration of individual ENCCs at different distances from the migratory wavefront
ENCCs at defined locations with respect to the most caudal ENCC at the beginning of imaging were photoconverted; 210 photo-converted ENCCs within 1.2 mm of the most caudal ENCC in explants of E12.5 colon were tracked. Every cell that remained within the field of view for a minimum of two hours (mean imaging time per cell = 5.0 ± 0.02 hours (±s.e.m.); n = 50 explants) was included in this analysis, including cells with neuronal morphologies and solitary cells. To examine how ENCC behavior varies with location, speed (total distance traversed/time), overall direction of migration, tortuosity and rate of caudal advance of individual ENCCs were determined in 150 μm bins from the migratory wavefront for up to 1,200 μm rostrally (Figure 1).
Figure 1
Figure 1
Behavior of ENCCs at different locations. A. An example of a preparation of E12.5 colon. The location of the most caudal cell is indicated with a yellow dotted line. B. The speed of ENCCs. ENCCs between 750 and 1,500 μm from the wavefront migrated significantly slower than those within 450 μm of the most caudal cell. C. The angle of migration between the beginning of end of imaging for each cell, relative to the long axis of the gut, which was defined as 0°. Only angles between 0 and 180° were used. D. Tortuosity; there were no significant differences between the tortuosity of ENCCs at different locations. E. Rate of caudal advance was defined as the longitudinal distance an ENCC advanced caudally during the imaging period regardless of the route (see Figure 2F). ENCC < 150 μm and > 750 μm from the most caudal cell showed the lowest rates of caudal advance. All data are shown as mean ± s.e.m. and were analyzed using ANOVAs followed by Tukey’s post-hoc tests. Asterisks indicate P < 0.05. ENCCs, enteric neural crest-derived cells.
The mean speed of ENCCs within 450 μm of the wavefront was significantly higher than those >750 μm from the wavefront (ANOVA followed by Tukey’s post-hoc test; Figure 1). However, the speeds of individual ENCCs were variable, and some ENCCs migrating within thick strands migrated at approximately 130 μm/h for over four hours (Figure 2A, B). “Migration” was defined as displacement of the center of the cell body a minimum of 20 μm every two hours. All photoconverted ENCCs analyzed migrated except one, which jiggled, but did not change location.
Figure 2
Figure 2
Variability in caudal advance of individual ENCCs. A. Cells that were 600 to 700 μm from the wavefront (white arrow) were photoconverted. B. Some photoconverted cells migrated caudally along existing strands with high speed and directionality (cells “a” and “b”, white and aqua tracks), and nine hours later, one of the cells (cell a) was very close to the wavefront; cell “a” migrated 980 μm in nine hours before going out of the field of view. Cell “a” (white track) also reversed direction and migrated rostrally for one hour, before migrating caudally again (white open arrow). C’. Another cell (arrow in C’) was imaged for 16 hours. C. This is an enlarged image of C’ with a color time track showing that it exhibited a complex, circular pathway; despite migrating at 70 μm/h, it advanced caudally only 140 μm after 16 hours. D. A red channel only showing a photoconverted cell (asterisk) that continues to advance caudally after it is first rounded up (arrow). E, F. Local leapfrogging at the migratory wavefront. E. The most caudal cell (yellow arrow) at the commencement of imaging was photoconverted. F. Ten hours later, the cell (yellow arrow) was > 200 μm behind the most caudal cell. Caudal advance was defined as the longitudinal caudal displacement of an ENCC during the imaging period regardless of its pathway; this cell advanced caudally only 70 μm in 10 h. The other red cells in this image are photoconverted cells that were out of the field of view (rostral) at the beginning. G-I. Correlations for the entire ENCC population shown in Figure 1 between speed and angle (G), caudal advance and angle (H) and caudal advance and speed (I). R2 is the correlation coefficient. A negative value for the rate of caudal advance means that the ENCC moved rostrally during the imaging period. ENCCs, enteric neural crest-derived cells.
Overall migration direction was defined as the angle between the locations at the beginning and end of imaging relative to the long axis of the gut. Thus, a cell that was directly caudal to its starting position at the end of imaging had an overall migration direction of 0° regardless of its positions at intermediate times. For these analyses, we only used angles between 0° and 180° and did not distinguish between circumferential clockwise (90°) and counterclockwise (270°) migration around the gut. ENCCs that were <150 μm or >750 μm from the wavefront had higher overall migration angles than ENCCs 150 to 600 μm from the wavefront (ANOVA followed by Tukey’s post-hoc test; Figure 1C). Within thick strands oriented parallel to the long axis of the gut, most ENCCs migrated caudally (Additional file 1: Movie 1), and cells about to undergo cell division often continued to advance caudally even after rounding up for division (Figure 2D). However, ENCCs were also regularly observed that migrated in the opposite direction from most ENCCs in a strand, and a cell migrating in one direction could suddenly reverse direction (Figure 2B, cell a, 2F; Additional file 1: Movie 1). Furthermore, some cells followed very circuitous pathways (Figure 2C, cell c; Additional file 2: Movie 2). There was no correlation between speed and angle of migration (R 2 = 0.02; linear regression for entire ENCC population; Figure 2G).
Tortuosity is a measure of the deviation from a straight line and is calculated by dividing the accumulated travel distance by the distance between the first and last points. There was no significant difference in the tortuosities of ENCCs at different locations (ANOVA; Figure 1D). Although tortuosity is a commonly measured parameter in migration studies, it does not take direction into consideration, so it is not very informative for understanding ENCC migration.
The rate of caudal advance was defined as the longitudinal caudal displacement/time of an ENCC, regardless of the route (Figure 2F). Individual ENCCs < 150 μm and > 750 μm from the most caudal cell had significantly lower rates of caudal advance than those 300 to 450 μm from the wavefront (ANOVA followed by Tukey’s post-hoc test; Figure 1E). Consequently, there is considerable local leapfrogging at the wavefront, and we did not observe any “pioneer” ENCCs that remained at the front of the ENCC population for more than two hours (Figure 2E, F).
Gut regions behind the wavefront are primarily populated by ENCCs with low directionality
ENCCs with low rates of caudal advance will populate a region, rather than migrate into new regions. We examined whether the ENCCs that populate a region migrate at the same speed as other ENCCs but non-directionally, or whether they show similar directionality to other ENCCs but migrate slower. Linear regression analyses revealed that for caudal advance versus speed R 2 = 0.24, while for caudal advance versus angle there was an inverse correlation with R 2 = 0.51 (Figure 2H, I). Hence, low directionality appears to play a larger role than decreased speed in reducing caudal advance, and populating gut regions behind the wavefront.
This conclusion was strengthened by the observation that ENCCs remain migratory in regions that have been long colonized by ENCCs. Cells in the E12.5 proximal colon, adjacent to the cecum (around 1 to 1.2 mm from the wavefront), commonly advanced caudally (Figure 3A, B). More orally, there was no mass caudally-directed movement of ENCCs within the mid and caudal small intestine of E12.5 mice (Figure 3C, D), which were initially colonized by ENCCs 24 to 36 hours previously. However, the ENCC network in the small intestine was very dynamic and most ENCCs migrated, but in variable directions (Figure 3E, F) and at variable speeds (mean ± s.e.m. = 25 ± 2 μm/h; n = 13). There was also extensive process extension and retraction. Migration of ENCCs in regions that had been colonized for up to 24 hours was also confirmed in the pre-cecal gut of E11.5 mice (Figure 3G, H).
Figure 3
Figure 3
Behavior of ENCCs rostral to the wavefront. A, B. E12.5 proximal colon, approximately 1.1 mm behind the wavefront, red channel only. B. A total of 3.5 hours after photoconversion, many cells had migrated caudally (white arrows), and there was also some dispersal of cells rostrally for a short distance (yellow arrows). C, D. E12.5 mid-small intestine, red channel only. D. Although the cells were very dynamic, after seven hours, only a small number of cells (arrows) had migrated substantial distances longitudinally. E, F. E12.5 distal small intestine; three small groups of cells (seven cells in total) were photoconverted. F. Tracks of the seven cells showing that they migrated variable distances in variable directions. G, H. E11.5 gut. Individual cells (arrows) in a variety of locations were photoconverted (G). H. Tracks of photoconverted cells overlaid on red channel only. Most cells in the pre-cecal gut were migratory, but often in a circumferential direction (H). Pre-cecal ENCCs migrated slower (tracks are shorter) than post-cecal ENCCs. ENCCs, enteric neural crest-derived cells.
Solitary ENCCs follow an undirected random walk
As described previously [22], transiently solitary ENCCs were commonly observed close to the migratory wavefront. Most solitary ENCCs were solitary for only 2 to 3 hours, but one ENCC was solitary for 14 hours. The behavior of ENCCs that were solitary for a minimum of two hours was examined to reveal the effect of cell-cell contact on migratory behavior. We first examined whether the trajectories of solitary ENCCs were mathematically consistent with a random walk, which is a pathway consisting of a succession of independent random steps [32]. A power-law was fitted to the time evolution of the square of the displacement for solitary ENCCs (n = 21, see Methods). Cells undergoing a random walk exhibit a linear mean square displacement in which the constant α = 1, whereas cells undergoing directed migration have a parabolic mean square displacement. For solitary ENCCs, α = 1.35 ± 0.58. As α is approximately 1, our data are consistent with the idea that solitary ENCC trajectories follow a random walk. In contrast, chains of ENCCs show an overall caudal advance. This was confirmed when the directions of migration (0° to 360° relative to the long axis of the gut) for solitary and non-solitary ENCCs, all within 150 μm of the most caudal cell, were determined at 10-minute intervals (note that the analyses in Figure 1B only determined the angle between the start and finish positions). The migration angles of solitary ENCCs were significantly different from those ENCCs in contact with other ENCCs (Watson’s U2 test for angles; [33]), with non-solitary ENCCs migrating caudally more frequently than solitary cells (Figure 4D, E). Moreover, although both solitary and non-solitary ENCCs exhibited variable behaviors, solitary ENCCs migrated significantly slower (P = 0.003, Figure 4A) and exhibited higher tortuosity (P = 0.025, Figure 4B; unpaired two-tailed t tests) than non-solitary ENCCs (all cells analyzed were < 150 μm from the most caudal cell). The difference in the rate of caudal advance only just reached statistical significance (12.4 μm/h for non-solitary ENCCs versus 1.7 μm/h for solitary ENCCs, P = 0.049, Figure 4C) due to large variability; in contrast to solitary cells, some non-solitary ENCCs migrated rostrally or caudally for considerable distances (Figure 4C). Of note, 38% of non-solitary ENCCs advanced caudally at > 20 μm/h whereas none of the solitary ENCCs (Figure 4C) advanced caudally at > 20 μm/h showing that a sub-population of non-solitary ENCCs is mainly responsible for migrating into new gut regions. In summary, although both solitary and non-solitary ENCCs close to the migratory wavefront exhibit very variable migratory behaviors, ENCCs in contact with other ENCCs migrate significantly faster and with a caudal bias, whereas the trajectories of solitary ENCCs are consistent with an undirected random walk.
Figure 4
Figure 4
Comparison of solitary and non-solitary cells within 150 μm of the wavefront. Scatter plots for the speed (A), tortuosity (B) and rate of caudal advance (C) of solitary (green) and non-solitary (magenta) ENCCs (mean ± 1 standard deviation). Compared to non-solitary cells, solitary cells migrated significantly slower (P = 0.003), exhibited higher tortuosity (P = 0.025) and had a lower rate of caudal advance (P = 0.049; n = 65 non-solitary ENCCs and 33 solitary ENCCs; unpaired t tests). D. Polar histograms showing the direction of migration measured at 10-minute intervals. The migration angles of solitary ENCCs were significantly different from those ENCCs in contact with other ENCCs (Watson’s U2 test for angles; n = 35 non-solitary and 22 solitary ENCCs, randomly chosen for analysis). E. Examples of tracks of non-solitary (magenta) and solitary (green) cells.
ENCCs do not retain their spatial order
Cranial neural crest cells in chick and zebrafish maintain the same neighbors for extensive periods of time and so the spatial order of cells is largely retained [4, 10, 34]. We examined the spatial order of ENCCs within 1 mm of the most caudal cell in the E12.5 colon. When small groups of ENCCs (two to eight cells) were photoconverted, they migrated in variable directions and it was very rare for any of the cells to have retained contact with their original neighbors after two hours (Figure 5A, B). There was considerable mixing of cells in different locations (Figure 5C-E; Additional file 3: Movie 3). Thus, although there is no large scale longitudinal mixing of ENCCs in the small intestine (see Figure 3C, D), within 1 mm of the wavefront, the spatial order of cells is not retained.
Figure 5
Figure 5
Spatial order of cells within 1 mm of the migratory wavefront in the E12.5 colon. A. The small group of cells (arrow) that were in contact with each other when photoconverted. B. Tracks of six of the cells in the subsequent five hours showing that they migrated in a variety of directions. C-E. A different E12.5 colon explant to show intermixing of ENCCs. C’. Red and green channels showing photoconversion of four groups of cells, which were 80, 200, 600 and 1,000 μm from the most caudal cell at the commencement of imaging. C. Red channel only showing the extents of initial locations of each group, which are marked by the pale green, yellow, blue and pink bars. D, E The spatial extents of cells two hours (D) and four hours (E) later are shown by the darker green, yellow, blue and red bars. The darker lines indicate the furthest extent of dispersal of cells from each group, not the number of cells; more cells dispersed caudally than rostrally from each group of photoconverted cells. ENCCs, enteric neural crest-derived cells.
Interactions between ENCCs are mainly adhesive
Detailed observations of the interactions between ENCCs are described in Additional file 4: Figures S1 and S2. In brief, ENCCs at the fronts of chains extended filopodia and lamellipodia in a variety of directions into unoccupied regions (Additional file 5: Movie 4) and ENCCs within chains extended processes within and outside of chains (Additional file 4: Figure S1). There was no significant difference between the protrusive activities of ENCCs that were 200 to 400 μm (where new ENCC network is still forming) and 500 to 800 μm (where the network is largely established) from the wavefront (Additional file 4: Figure S1). The predominant type of interaction between chains of ENCCs was adhesive interactions (Additional file 4: Figure S2; Additional file 5: Movie 4).
ENCCs migrate in close association with neurites but neurites show higher directionality
Neurite behavior
A sub-population of ENCCs starts to express pan-neuronal markers soon after they enter the gut [29]. Neuron-like cells can occur within 100 μm of the wavefront, and possess a single, persistent caudally-directed neurite [30]. In agreement with our earlier study [26], neurons migrated slower than non-neuronal ENCCs (neurons: 43 ± 4 μm/h, n = 18; non-neuronal cells: 64 ± 3 μm/h, n = 76; unpaired two-tailed t test; P <0.05; neurons and non-neuronal ENCCs included in this analysis were 200 to 800 μm from the wavefront. The cells are also included in the data shown in Figure 1).
When groups of ENCCs spanning the entire width of the caudal small intestine or colon were photoconverted, labeled neurites were only observed on the caudal side (Figure 6A; Additional file 6: Movie 5). However, in the longer established ENCC network of the E12.5 small intestine and proximal colon, neurites that projected circumferentially were also commonly observed following photoconversion of small groups of ENCCs (Figure 6B).
Figure 6
Figure 6
Behavior of neurites. A. A total of 5.5 hours following photoconversion of the entire diameter of the E12.5 colon (hashed box), 600 μm from the wavefront. Numerous neurites (white arrows) were present on the caudal side. More cells migrated caudally than rostrally. B. A neuron with a circumferentially projecting neurite in the E12.5 proximal colon. C. Neurites do not normally explore outside of the ENCC network. Growth cone of a neurite in the E12.5 colon, which was often bifurcated (arrows), and only explored within the ENCC network. The main shaft of the neurite is marked by an asterisk. D. Polar frequency histogram showing the direction of neurite advance (n = 9) and migrating ENCCs (n = 6) measured at 10-minute intervals. The directions of neurite advance were significantly different from ENCC migration direction (Watson’s U2 test for angles). E. Close association between a growing neurite and an individual ENCC. The growing tip (white arrow) of the neurite (orange) initially extends circumferentially and then the neurite extends caudally. It grew in close association with a photoconverted (red) ENCC (yellow arrow) for over 2.5 hours. The neuron cell body (asterisk) also migrates. F. Segments of Ednrb-hKikGR small intestine were placed at both ends of an explant of RetTGM/TGM small intestine, which lacks ENCCs. When ENCCs from the two populations were approximately 100 μm apart, the rostrally migrating population was photoconverted (time = 0). When the two populations collided, chains of intermingled cells formed (arrow, 2.5 h). Both populations then ceased to advance, although red neurites (open arrows) continue to grow rostrally for over 15 hours, well beyond the most rostral ENCC (arrow). G. Tracings of two ENCCs in the initial stages of neurite projection that were imaged for 12 hours (top cell) and 7 hours (bottom). ENCCs, enteric neural crest-derived cells.
The growth cones at the tips of growing neurites only explored within the ENCC network (Figure 6C). This was in contrast to the lamellipodia and filopodia of ENCCs, which commonly extended outside of the ENCC networks (see Additional file 4: Figure S1). We observed several examples where a growth cone advanced caudally in concert with a particular ENCC for over two hours (Figure 6E). The rate of caudal advance of neurites (measured as the longitudinal distance advanced caudally regardless of the pathway) was 39 ± 5 μm/h (n = 8), which is similar to the rate at which the ENCC population advances caudally (35 to 40 μm/h) [21, 23, 35]. We compared the directionality of neurite extension with that of migrating ENCCs; the neurites were 200 to 800 μm from the wavefront, and the six ENCCs analyzed were all from one preparation and were in a group that was 500 μm from the wavefront. Neurites showed more directional (longitudinal) advance than the ENCCs (Figure 6D; Watson’s U2 test for angles; [33]).
When ENCCs are introduced into explants of small intestines lacking ENCCs (from RetTGM/TGM mice), they migrate equally well rostrally as they do caudally [36]. In the current study we used a similar co-culture system to examine the behavior of neurites in a rostrally-migrating population of ENCCs. Segments of small intestine from Ednrb-hKikGR mice were placed at the rostral and caudal ends of explants of aneural small intestines from RetTGM/TGM mice (Figure 6F). The ENCC population migrating rostrally was photoconverted from green to red just prior to encountering the caudally-migrating population (Figure 6F). The caudally-migrating (green) and rostrally-migrating (red) ENCCs adhered to each other to form chains of intermingled cells. It was not possible to analyze the effects of collisions between ENCCs migrating in opposite directions on individual cell behavior because high levels of cell-cell contact prevented us from obtaining pre-collision data for individual ENCCs. After forming a network, the red and green ENCCs continued to migrate for at least 22 hours, but non-directionally (Figure 6F). In contrast, red neurites continued to grow rostrally (Figure 6F). We were unable to visualize whether any of the red ENCCs also projected neurites caudally.
Initial extension of neurites
Most neuron-like ENCCs in the E11.5 and E12.5 gut project caudally [37, 38]. Four of the movies of the E12.5 colon contained photoconverted ENCCs undergoing neuritogenesis. In all cases, the neurite formed from a thin process that continued to elongate. In two out of four cells, the neurites did not initially emerge from the caudal side of the cell bodies, and in three out of four cells, the neurites did not initially project caudally, but first projected rostrally or circumferentially prior to projecting caudally (Figure 6G). These data suggest that most individual neuron precursors are not polarized prior to extending a neurite.
Neurite-ENCC interactions at the migratory wavefront
Neurites are closely associated with ENCCs, but it is currently unclear whether neurites or ENCCs are the lead elements in the caudal migration. We photoconverted every ENCC in the E12.5 mid-colon, except for those within approximately 100 μm of the most caudal cell; photoconverted (red) KikGR protein from nerve cell bodies > 100 μm from the wavefront rapidly spread into the caudally directed neurites among green ENCCs (Figure 7A). Neurites were commonly observed in association with ENCCs at the migratory wavefront, but they were usually located just behind, or a few cells behind, the most caudal ENCC in a chain (Figure 7B,C). If a neurite were present close to the wavefront, migrating ENCCs usually used the neurite as a substrate to advance caudally (Figure 7D, E; Additional file 7: Movie 6). However, some ENCCs extended filopodia and lamellipodia away from neurites, and ENCCs were observed to detach from neurites. We also observed chains of migrating ENCCs that broke to reveal that there was no accompanying neurite (Figure 7F). In addition, we observed neurites extend in association with ENCCs, but the ENCCs then migrated away, or migrated rostrally back along the neurite, leaving a neurite without accompanying ENCCs (Figure 7C). In summary, ENCCs lead the way with neurites often located just rostral to the leading ENCCs; these neurites generally act as substrates for the following ENCCs. However, chains of ENCCs can extend without an accompanying neurite. We did not observe any neurites extending caudally in advance of migrating ENCCs.
Figure 7
Figure 7
Interactions between neurites and migrating ENCCs at the migratory wavefront. A. A diagram showing photoconversion of all ENCCs, except the most caudal ENCCs, which results in photoconversion of the caudally-projecting neurites. B. The tip (open arrow) of a red, caudally-projecting neurite (arrows) is located at the back of the most caudal cell (yellow asterisk). C. The tip (open arrow) of a red neurite (arrows) advances slightly behind a migrating ENCC. Even though the neurite advanced in association with migrating ENCCs, 2.5 hours later, there were few ENCCs associated with some sections of the neurite (arrows). D. The tip (open arrow) of a caudally projecting neurite (arrows) is just rostral to the most caudal group of ENCCs, but it acts as a substrate for ENCCs (blue, pink and white asterisks) just behind the most caudal ENCCs. E. Adhesive interactions between a neurite (red) and a migrating ENCC. F. Not all chains of ENCCs have neurites associated with them. Two ENCCs (white and blue asterisks) extend caudally as a chain. After they lose contact with the ENCCs behind and join another chain, no neurites are visible (boxed area). ENCCs, enteric neural crest-derived cells.
Relationship between ENCC migration direction and neurite orientation well behind the wavefront
There are prominent, longitudinally-oriented bundles of neurites in regions long colonized by ENCCs [38, 39]. Here, we reported the paradoxical observations that migrating ENCCs often use neurites as substrates, and that ENCCs well behind the wavefront migrate, but mostly circumferentially (see above). Examination of fixed preparations of small intestinea from E12.5 Ednrb-hKikGR mice that had been immunostained using the neurite marker, Tuj1, revealed a fine neurite network without any detectable orientation at the same focal plane as most of the ENCCs (Figure 8A, B). Thick bundles of longitudinally-oriented neurites were present deeper (closer to the circular muscle layer) than the majority of ENCCs (Figure 8C, D).
Figure 8
Figure 8
Thick bundles of longitudinally-oriented neurites are deeper (closer to the lumen) than the majority of ENCCs. Single optical sections of whole-mount preparations of E12.5 small intestine of an Ednrb-hKikGR mouse that was also immunostained using an antibody to Tuj1 (magenta). A, B. Single optical section at a focal plane in which there is the highest density of ENCCs. There is a plexus of Tuj1+ cell bodies and neurites with no obvious orientation. C, D. At the focal plane of the longitudinally-oriented neurite bundles, the density of ENCCs is lower. ENCCs, enteric neural crest-derived cells.
Inhibition of EDNRB signaling primarily affects individual ENCC speed
The caudal advance of ENCCs along colonic explants is retarded by the EDNRB inhibitor, BQ-788 [4042]. We examined whether the delay is due to individual ENCCs migrating slower and/or less directionally. ENCCs in colonic explants from E12.5 Ednrb-hKikGR mice exposed to BQ-788 (20 μM) migrated significantly slower than control ENCCs, except those that were 150 to 300 μm behind the wavefront (Figure 9A; two-tailed t tests, P < 0.05, except for 150 to 300 μm ENCCs where P = 0.13; 162 cells were tracked in 12 colon explants exposed to BQ-788; the control data are the same as those shown in Figure 1B, C). Four ENCCs were stationary in the presence of BQ-788. Although EDNRB signaling is known to influence the rate of neuronal differentiation of ENCCs [43, 44], the decrease in migration speed of individual ENCCs exposed to BQ-788 for 10 hours was not associated with any detectable change in the proportion of Hu + neurons (Additional file 4: Figure S3). There was no significant difference in the direction of migration between control and BQ-788-exposed ENCCs except for ENCCs that were 600 to 750 μm from the wavefront (two-tailed t tests; Figure 9B). As in control mice, BQ-788-treated ENCCs that were 0 to 150 μm from the most caudal cell showed lower directionality than ENCCs further rostral, and there was no correlation between angle and speed (R 2 = 0.01; linear regression for entire cell population). These data show that inhibition of EDNRB signaling primarily affects the speed at which individual ENCCs migrate. Unlike control explants, in some BQ-788-treated explants, we observed neurites transiently in advance of ENCCs (Figure 9C).
Figure 9
Figure 9
Inhibition of EDNRB signaling primarily affects the speed of ENCC migration. A, B. The speed and angle of migration (mean ± s.e.m.) of tracked control ENCCs (these are the same data as shown in Figure 1) and ENCCs in explants exposed to the EDNRB antagonist, BQ-788 (20 μM). A. ENCC speed in explants exposed to BQ-788 is significantly lower than in control explants, except for ENCCs that were 150 to 300 μm from the migratory wavefront (t tests). B. The angle of migration between the locations at the beginning and end of imaging for each ENCC, relative to the long axis of the gut. Only angles between 0° and 180° were used. The angles of ENCCs exposed to BQ-788 were not significantly different from controls except for ENCCs that were 600 to 750 μm from the wavefront, where BQ-788-treated ENCCs migrated at a higher angle than control ENCCs. C. E12.5 colon explant exposed to BQ-788. The growth cone (arrows) of a neurite is in advance of the most caudal ENCC cell body. An ENCC cell body (asterisk) uses the neurite as a substrate. EDNRB, endothelin receptor type B; ENCCs, enteric neural crest-derived cells.
Most migratory cell populations that have been studied in detail to date migrate as a collective from one location to another. In contrast, the formation of an enteric nervous system along the entire gut requires that some ENCCs advance caudally while others populate each region, which has been termed “directional dispersion” [20]. In this study we showed that a characteristic of ENCCs is their variability in migratory behavior, particularly directionality. Most ENCCs appeared to migrate according to their own individual program while maintaining contact with other ENCCs - for example, ENCCs did not retain their neighbors and cells migrating in opposite directions within the same chain were commonly observed. We suggest that variability in ENCC behavior, but with an overall caudal bias, results in the colonization of each gut region as well as the caudal advance of some ENCCs. Despite the variability, our study shows that ENCCs behave differently when solitary compared to groups, and therefore meet the definition of collective migration [45]. For the majority of time, the behavior of ENCCs did not in general conform to the types of migratory behaviors described previously for neural crest populations that migrate as a collective from one location to another [4, 810]. However, some behaviors described for other neural crest populations, including contact inhibition of locomotion, were exhibited occasionally, and we cannot rule out the possibility that non-predominant behaviors play an important role in ENCC migration.
Colonization of all regions of the gut with ENCCs
The ENCCs that populate a gut region are those that show the lowest rate of caudal advance. Our data show low ENCC caudal advance is more highly correlated with low directionality than with low speed. Thus, the gut is colonized primarily by ENCCs migrating non-directionally, although ENCCs migrating slower than the rest of the population also contribute to gut colonization. Furthermore, it was not possible to separate the ENCC population in the E12.5 colon into two distinct groups - those that advanced caudally and those that did not.
A recent imaging study using biosensors revealed that ENCC migration speed was positively correlated with Rac1 and Cdc42 activities and inversely correlated with protein kinase A (PKA) activity [46]. Hence the activities of Rac1, Cdc42 and PKA are likely to play a role in determining the rate at which an ENCC advances caudally by regulating ENCC speed. We showed that directionality is also an important determinant in whether an ENCC will advance caudally, and that there was no correlation between direction and speed. Future live imaging of signaling molecule activities in ENCCs are required to reveal whether migration direction is correlated with the activity of signaling molecules at particular subcellular locations within an ENCC, as has been performed in living Xenopus cranial neural crest cells [9] and fixed ENCCs [47].
Unexpectedly, most ENCCs were still migratory in regions of the gut that had been colonized for over 24 hours, although they migrated slower than ENCCs closer to the wavefront. Many ENCCs in long-colonized regions migrated circumferentially. This was also surprising as there are prominent longitudinally-oriented neurite bundles in colonized regions of the gut [38, 48], and we showed that ENCCs advancing caudally often use neurites as a migratory substrate. However, we also demonstrated that the thick longitudinally-oriented neurites are located deeper than the un-oriented neurite network associated with most ENCCs. In Ednrb mutant mice where ENCC migration is delayed, the E14.5 mid-colon is colonized by ENCCs migrating circumferentially from a dorsal mesenteric strand [40]. Combined the data suggest that as the gut matures, it favors the circumferential migration of ENCCs. The mechanisms promoting circumferential migration remain to be identified, but are unlikely to be related to the vasculature as the blood vessel network in the mouse intestine is mostly associated with the mucosal crypts and the submucosa [23, 49], whereas the circumferential migration reported in the current study is mainly in the outer mesenchyme where the myenteric plexus will later form. Furthermore, circumferentially migrating ENCCs migrated within the existing ENCC network.
Consistent with our earlier study [23], we found that the shapes of the ENCC networks first laid down are retained over time. As we now show that most ENCCs continue to migrate after they colonize each gut region, we propose that the ENCC network is maintained by a scaffold of un-oriented neurites that is present at the same level as the majority of ENCCs. In the mature gut, myenteric ganglia are long structures that are oriented parallel to the circular muscle layer. In contrast, the clusters of ENCC present early in ENS development are not oriented in any particular direction and are dynamic in their composition. Hence, major reorganization of the ENCCs occurs prior to mature ganglion formation.
During development of the lateral line in zebrafish, cells migrate collectively along the body of the embryo and deposit cell clusters called rosettes at discrete locations; these are the progenitors of mechanosensory organs [50]. A recent study showed that the deposition of a sub-population of cells to form rosettes during the migration of the collective involves the formation of microtubule-dependent adherens junctions [51]. The formation of mechanosensory organs at distinct intervals in the zebrafish lateral line is, however, different from the directional dispersion of ENCCs, as ENCCs are dispersed evenly along the entire length of the gut. Like ENCCs, other neural crest-derived cell populations, such as Schwann cells and melanocytes, evenly populate structures as they migrate distally. The migratory behavior of these cell types has not yet been examined in detail, but a study of intact skin explants from E14.5 mice showed that melanoblasts remained migratory in regions already colonized [52]. Unlike ENCCs, however, melanocytes are found as solitary cells that exhibit repulsive interactions upon contact with other melanocytes and consequently maintain individual territories [52].
Frontal advance
Earlier studies have shown that ENCCs at the migratory wave front are mainly responsible for populating uncolonized regions of the gut; this process has been termed “frontal advance” [22, 26, 27]. Our data are in agreement with this model but provide some refinements. First, we show that there is considerable local leapfrogging of ENCCs at the wavefront because the most caudal cells on average show low directionality and hence low caudal advance. Thus, within the frontal advance zone, ENCCs do not retain their spatial order. Previous studies in which small regions of mesenchyme in explants of chick gut were replaced with quail gut mesenchyme suggested that the ENCC frontal advance zone is only around 200 to 300 μm long [27]. Our data show that ENCCs advancing caudally are not found in a distinct zone with definable boundaries - ENCCs located 300 to 450 μm from the most caudal cell showed the highest average rate of caudal advance, and the probability that an ENCC would advance caudally decreased caudo-rostrally thereafter so that in the small intestine (> 1.2 mm from the wavefront), there was no significant caudal advance even though most of the cells were still migratory. It is likely that the length of the ENCC frontal advance zone varies with age and species.
ENCCs at the migratory wavefront show low directionality
Cranial and trunk neural crest cells in the chick migrate in chains with clear leading cells [3, 53, 54]. Even excluding solitary cells, our data show that the extreme wavefront ENCCs migrate with lower directionality than ENCCs that are 150 to 600 μm from the wavefront. Druckenbrod and Epstein (2007) [22] tracked individual ENCCs in the chick gut that had been labeled with GFP by electroporation and, consistent with the current study, ENCC behavior was shown to be variable, and to vary at different distances from the wavefront. However, ENCCs within 200 μm of the wavefront were observed to show the most directional migration [22]. Hence, there may be some species differences in the behaviors of ENCCs.
We were unable to shed light on the unresolved question of why chains of ENCCs advance into uncolonized regions. Unlike follow-the-leader chain migration of neural crest cells in chicks [54], our study showed that the protrusive activity of ENCCs does not vary with location. Combined, the data are consistent with the idea that ENCCs cannot detect the polarity of the gut, but preferentially migrate into areas of low ENCC density while retaining contact with other ENCCs.
Role of ENCC-ENCC contact
Our study shows that although ENCCs generally do not maintain the same neighbors for long, there are strong transient adhesive interactions between neighboring ENCCs. The molecular bases of the adhesive interactions between ENCCs are not completely understood but L1CAM and β1 integrins play roles [5559]. Despite the strong adhesive interactions, ENCCs that are transiently solitary are frequently observed at the migratory wavefront [22]. For follow-the-leader chain migration of cranial and trunk neural crest cells, it has been suggested that cells in a chain follow a path of lesser resistance through the ECM and, therefore, migrate faster than solitary cells [7]. Consistent with this idea, the speed of solitary ENCCs was significantly slower than ENCCs in chains. Furthermore, ENCCs in chains migrated more directionally than solitary ENCCs suggesting that cell-cell contact is essential for ENCCs to respond to environmental cues as has been shown for cranial neural crest cells in Xenopus[9] (see below).
Role of EDNRB signaling
Endothelin-3 (EDN3) acting at EDNRB receptors expressed on ENCCs is essential for the normal colonization of the gut by ENCCs [6063]. Interpretation of the migratory behavior of ENCCs in Ednrb null mutant mice is difficult because the entry of neural crest-derived cells into the gut is delayed and thus the gut environment through which ENCCs migrate is older than in wildtype mice [40]. Our data, using a pharmacological inhibitor of EDNRB, reveal that EDNRB signaling primarily promotes migration speed, rather than directionality. EDNRB signaling is likely to affect ENCC migration via PKA activity [46, 64]. Although it is well established that EDNRB signaling inhibits ENCC differentiation [65], we showed that exposure of explants to the EDNRB inhibitor in the timespan of our experiments was not sufficient to result in any detectable changes in neuronal differentiation. Thus the effect of inhibition of EDNRB signaling on ENCC migration cannot be entirely due to an enhancement of neuronal differentiation and our data therefore support the conclusions of a previous study [40] showing that EDNRB signaling has a direct effect on ENCC migration, as well as an indirect effect via its influence on differentiation. It will be interesting to determine whether the delay in the caudal advance of the ENCC population in other models of Hirschsprung disease is due to perturbed speed or directionality of individual ENCCs.
Longitudinal growth of axons
We showed that neurites within the E12.5 colon advance caudally with overall high directionality, implying that neurites can detect the longitudinal axis and the polarity of the gut. However, when ENCCs were introduced into the caudal end of explants of aneural small intestine, some neurites grew orally. Our data are consistent with the idea that neurites use a property of the gut tube to detect the longitudinal axis of the gut, but the mechanism regulating the direction of neurite growth remains to be determined. We have previously suggested that the direction of neurite growth might be determined by the direction of ENCC migration [30]. However, in the current study, when the orally projecting neurites in the co-cultures encountered a population of ENCCs migrating anally, they continued to grow orally. Furthermore, following pharmacological inhibition of EDNRB signaling, neurites were observed in advance of ENCCs, showing that ENCCs are not required for longitudinal neurite extension. In control explants, the growth cones of the growing neurites did not explore outside of the ENCC network, and thus it appears highly unlikely that neurites normally navigate along longitudinally-oriented structural components of the gut wall, outside of the ENCC network. Mature enteric neurons also include subtypes that project circumferentially or orally [66]. Some circumferentially projecting neurons were observed at E12.5, but only in the small intestine and proximal colon.
Role of neurites in ENCC migration
Sacral neural crest cells migrate into the hindgut along the axons of extrinsic neurons [15]. Neurites (from intrinsic neurons) are present in close apposition to chains of vagal ENCC, but it was previously unclear whether neurites or ENCCs lead the way; in fixed tissue the most caudal structure is most commonly an ENCC, but it is also not unusual to observe neurites in advance of ENCCs [67]. Our data show that ENCCs lead the way down the gut, with neurites following a short distance behind. Furthermore, the growth cones of neurites only explored within the ENCC network, and as a result, neurites always advanced in concert with chains of ENCCs. Sometimes ENCCs were observed to reverse direction and migrate back along a neurite or to migrate away from a neurite, which explains why neurites are sometimes observed caudal to the most caudal ENCC in fixed tissue. Our data also show that neurites act as substrates for migrating ENCCs. Although neurites are not required for the extension of chains of ENCCs into unpopulated regions, it is possible that longitudinally oriented neurites facilitate the directional migration of ENCCs towards the wavefront. Previous studies have provided evidence both for and against an essential role for neurites in ENCC migration. Humans with mutations in the gene encoding kinesin binding protein (KBP) have Hirschsprung disease [68], and studies in neuronal cell lines, primary cortical neurons and zebrafish have shown that the main role of KBP appears to be in neurite formation [6971]. On the other hand, mutant mice with defects in the longitudinal projections of neurites do not exhibit any delay in ENCC migration [38] showing that longitudinal neurite projections are not essential, or that only a small number of longitudinally oriented neurites is necessary, for normal ENCC migration. To reveal the role of neurites in ENCC migration conclusively, future studies are required in which neurite formation is blocked in differentiating neurons.
Individual ENCC are unable to detect gradients of morphogens along the gut
A number of molecules that influence the migration of ENCC in vitro are found in gradients along the gut [7274]. For example, GDNF is chemoattractive to ENCCs in cultured explants, and Gdnf is expressed in a spatial and temporal gradient from the stomach to the cecum coincident with the migration of ENCCs towards the cecum [75, 76]. The side of the cell body from which axons emerge and the initial direction of axon growth of some CNS neurons can be influenced by gradients of guidance factors [77, 78]. We provide two lines of evidence to suggest that individual ENCCs cannot sense the polarity of the gut. First, our data suggest that the polarization of an ENCC cell body required for the initial formation of an axon is random, and that neurites must project for a minimum distance, or exist for a minimum amount of time, before they are able to detect the longitudinal axis of the gut. Second, the migration of solitary ENCCs was consistent with an unbiased random walk. This implies that individual ENCCs are unable to detect chemotactic gradients along the gut. In Xenopus, groups of cranial neural crest cells show a strong chemotactic response towards the chemokine, Sdf1, but single cells respond poorly and thus cell-cell interactions are essential for chemotaxis of cranial neural crest cells towards Sdf1 [9]. It would therefore be very interesting to determine whether solitary ENCCs show a chemotactic response to GDNF.
ENCCs exhibit variable speeds and directionalities, but with a caudal bias, and this results in the population of each gut region as well as the caudal advance of some ENCCs. Hence, the gut is not populated by cells stopping, but by cells migrating non-directionally. ENCCs remain migratory after colonizing each gut region, which might be a mechanism to ensure an even density of cells as the gut grows. Despite the variability in behavior, ENCCs overall behave differently in groups compared to solitary cells and therefore meet the definition of collective migration [45]. Moreover, previous studies have shown that ENCCs can act cooperatively in the regulation of proliferation and migration [60, 79]. Chains of ENCCs appear to advance caudally because they prefer regions with low ENCC density, whereas neurites can detect the longitudinal axis of the gut and exhibit directional growth, although they do not lead the way down the gut. Future studies are needed of other cell populations that exhibit directional dispersion to reveal if the behavior of ENCCs can be generalized.
Ednrb-hKikGR mice, in which all ENCCs express the photoconvertible protein, KikGR, [26] were used for all experiments. C57BL/6 mice were time-, plug-mated to Ednrb-hKikGR mice. Segments of small intestines from E11.5 RetTGM/TGM mice [80] were also used for some experiments. Mice carrying E11.5 or E12.5 embryos were killed by cervical dislocation. All experiments were approved by the Anatomy & Neuroscience, Pathology, Pharmacology and Physiology Animal Ethics Committee of the University of Melbourne.
Time-lapse imaging and analysis
The guts from E11.5 or E12.5 Ednrb-hKikGR mice weres dissected in DMEM/F12 containing 20 mM glutamine, 10% FBS and penicillin/streptomycin, and attached across a “V” cut into a piece of filter paper as described previously [81]. The filter paper was inverted and placed in a 35-mm coverslip-bottomed dish. A stainless steel ring was placed on the edge of the filter paper support to prevent movement. In some experiments, the culture medium also contained the EDNRB antagonist, BQ-788 (Sigma-Aldrich, Castle Hill, NSW, Australia; 20 μM), which was added three to four hours prior to the commencement of imaging. Co-cultures were also set up in which segments of small intestine from E11.5 Ednrb-hKikGR mice were placed at both the rostral and caudal ends of segments of small intestine from RetTGM/TGM mice, which lack ENCCs [36]. The co-cultures were grown in an incubator at 37°C with 5% CO2 for 24 to 48 hours prior to imaging. Preparations to be imaged were placed in an environmental chamber, held at 37°C, mounted on an inverted Leica SP5 laser confocal microscope (North Ryde, NSW, Australia). Photoconversion of individual or groups of KikGR + cells was performed using a 405 nm laser and the regions of interest (ROI) function on the confocal microscope. Z-series images were obtained through the ENCC network at 2.5-, 3-, 4- or 5-minute intervals using X10, X20 or X40 oil immersion objectives. Cell tracking (manual and automatic), and measurements of angles and distances, were performed on videos of projected z-series using Axiovision (Zeiss, North Ryde, NSW, Australia) or ImageJ (National Institutes of Health, USA) software. Filopodial extensions were quantified by counting the number of new filopodial extensions outside of the ENCC network in a 100 × 200 μm area at five-minute intervals for three hours. Immunohistochemistry was performed using Tuj1 antibodies (Covance, North Ryde, NSW, Australia) as reported previously [39].
Random walk analysis
To determine whether solitary ENCCs moved in a random walk, data describing the (x(t), y(t)) coordinates of 21 solitary ENCC trajectories (ENCCs that were not in contact with any other ENCCs for a minimum of two hours) were analyzed. First, to detect whether there was any bias in the motion, the time evolution of the displacement in the x-direction and y-direction was estimated by calculating
X t = x t - x 0 , Y t = y t - y 0 .
We then fitted the observed X(t), Y(t) data to the following model
X t = ν x t , Y t = ν y t .
This fitting procedure allowed us to estimate the drift velocities v x and v y . An unbiased random walk has v x = v y = 0. Our data suggest that the mean drift in the x-direction is v x = 0.020 ± 0.062 μm/minute, and the mean drift in the y-direction is v y = 0.020 ± 0.078 μm/minute. Here we have quantified the uncertainty in our estimates using the sample standard deviation. Since we only have a relatively small number of trajectories, the sample standard deviation is large. In summary, given the large variability in our data, our estimates of v x and v y are sufficiently close to zero to conclude that the motion is, on average, unbiased.
To determine whether the motion followed a standard unbiased random walk, we fitted a power-law to the time evolution of the square of the displacement
r 2 t = β t α ,
Where r2(t) = X2(t) + Y2(t), and α and β are positive constants; for a standard unbiased random walk, α = 1. To determine whether our data are consistent with an unbiased random walk, we fitted the data for each solitary ENCC trajectory to Equation (3) to give 21 estimates of α from which we could estimate an average value of this exponent. To fit our data, we rearranged Equation (3) to obtain
log 10 r 2 t t = log 10 β + α - 1 log 10 t .
By fitting a straight line to a plot of log 10 r 2 t t as a function of log10(t), the least-squares estimate of the slope of that line provided us with an estimate of (α - 1).
endothelin receptor type B
enteric neural crest-derived cells
kinesin binding protein
protein kinase A.
This study was supported by grant and fellowship support from NHMRC Australia to HMY (1047953 and 1002506).
Authors’ Affiliations
Department of Anatomy & Neuroscience, University of Melbourne, Melbourne, 3010, VIC, Australia
School of Mathematical Sciences, Queensland University of Technology, GPO Box 2434, Brisbane, 4001, QLD, Australia
RIKEN Center for Developmental Biology, Laboratory for Neuronal Differentiation and Regeneration, Kobe, Japan
Division of Neural Differentiation and Regeneration, Department of Physiology and Cell Biology, Graduate School of Medicine, Kobe University, Kobe 650-0017, Japan
1. Kulesa PM, Bailey CM, Kasemeier-Kulesa JC, McLennan R: Cranial neural crest migration: new rules for an old road. Dev Biol. 2010, 344: 543-554. 10.1016/j.ydbio.2010.04.010.PubMed CentralPubMedView ArticleGoogle Scholar
2. Theveneau E, Mayor R: Neural crest delamination and migration: from epithelium-to-mesenchyme transition to collective cell migration. Dev Biol. 2012, 366: 34-54. 10.1016/j.ydbio.2011.12.041.PubMedView ArticleGoogle Scholar
3. Rupp PA, Kulesa PM: A role for RhoA in the two-phase migratory pattern of post-otic neural crest cells. Dev Biol. 2007, 311: 159-171. 10.1016/j.ydbio.2007.08.027.PubMedView ArticleGoogle Scholar
4. Kulesa PM, Teddy JM, Stark DA, Smith SE, McLennan R: Neural crest invasion is a spatially-ordered progression into the head with higher cell proliferation at the migratory front as revealed by the photoactivatable protein, KikGR. Dev Biol. 2008, 316: 275-287. 10.1016/j.ydbio.2008.01.029.PubMed CentralPubMedView ArticleGoogle Scholar
5. McLennan R, Dyson L, Prather KW, Morrison JA, Baker RE, Maini PK, Kulesa PM: Multiscale mechanisms of cell migration during development: theory and experiment. Development. 2012, 139: 2935-2944. 10.1242/dev.081471.PubMed CentralPubMedView ArticleGoogle Scholar
6. Wynn ML, Kulesa PM, Schnell S: Computational modelling of cell chain migration reveals mechanisms that sustain follow-the-leader behaviour. J R Soc Interface. 2012, 9: 1576-1588. 10.1098/rsif.2011.0726.PubMed CentralPubMedView ArticleGoogle Scholar
7. Wynn ML, Rupp P, Trainor PA, Schnell S, Kulesa PM: Follow-the-leader cell migration requires biased cell-cell contact and local microenvironmental signals. Phys Biol. 2013, 10: 035003-10.1088/1478-3975/10/3/035003.PubMed CentralPubMedView ArticleGoogle Scholar
8. Carmona-Fontaine C, Matthews HK, Kuriyama S, Moreno M, Dunn GA, Parsons M, Stern CD, Mayor R: Contact inhibition of locomotion in vivo controls neural crest directional migration. Nature. 2008, 456: 957-961. 10.1038/nature07441.PubMed CentralPubMedView ArticleGoogle Scholar
9. Theveneau E, Marchant L, Kuriyama S, Gull M, Moepps B, Parsons M, Mayor R: Collective chemotaxis requires contact-dependent cell polarity. Dev Cell. 2010, 19: 39-53. 10.1016/j.devcel.2010.06.012.PubMed CentralPubMedView ArticleGoogle Scholar
10. Carmona-Fontaine C, Theveneau E, Tzekou A, Tada M, Woods M, Page KM, Parsons M, Lambris JD, Mayor R: Complement fragment C3a controls mutual cell attraction during collective cell migration. Dev Cell. 2011, 21: 1026-1037. 10.1016/j.devcel.2011.10.012.PubMed CentralPubMedView ArticleGoogle Scholar
11. Scarpa E, Roycroft A, Theveneau E, Terriac E, Piel M, Mayor R: A novel method to study contact inhibition of locomotion using micropatterned substrates. Biol Open. 2013, 2: 901-906. 10.1242/bio.20135504.PubMed CentralPubMedView ArticleGoogle Scholar
12. Moore R, Theveneau E, Pozzi S, Alexandre P, Richardson J, Merks A, Parsons M, Kashef J, Linker C, Mayor R: Par3 controls neural crest migration by promoting microtubule catastrophe during contact inhibition of locomotion. Development. 2013, 140: 4765-4775.Google Scholar
13. Le Douarin NM, Teillet MA: The migration of neural crest cells to the wall of the digestive tract in avian embryo. J Embryol Exp Morphol. 1973, 30: 31-48.PubMedGoogle Scholar
14. Yntema CL, Hammond WS: The origin of intrinsic ganglia of trunk viscera from vagal neural crest in the chick embryo. J Comp Neurol. 1954, 101: 515-541. 10.1002/cne.901010212.PubMedView ArticleGoogle Scholar
15. Burns AJ, Le Douarin NM: The sacral neural crest contributes neurons and glia to the post- umbilical gut: spatiotemporal analysis of the development of the enteric nervous system. Development. 1998, 125: 4335-4347.PubMedGoogle Scholar
16. Barlow AJ, Wallace AS, Thapar N, Burns AJ: Critical numbers of neural crest cells are required in the pathways from the neural tube to the foregut to ensure complete enteric nervous system formation. Development. 2008, 135: 1681-1691. 10.1242/dev.017418.PubMedView ArticleGoogle Scholar
17. Durbec PL, Larsson-Blomberg LB, Schuchardt A, Costantini F, Pachnis V: Common origin and developmental dependence on c-ret of subsets of enteric and sympathetic neuroblasts. Development. 1996, 122: 349-358.PubMedGoogle Scholar
18. Newgreen DF, Southwell B, Hartley L, Allan IJ: Migration of enteric neural crest cells in relation to growth of the gut in avian embryos. Acta Anat. 1996, 157: 105-115. 10.1159/000147871.PubMedView ArticleGoogle Scholar
19. Obermayr F, Hotta R, Enomoto H, Young HM: Development and developmental disorders of the enteric nervous system. Nat Rev Gastroenterol Hepatol. 2013, 10: 43-57.PubMedView ArticleGoogle Scholar
20. Theveneau E, Mayor R: Can mesenchymal cells undergo collective cell migration? The case of the neural crest. Cell Adh Migr. 2011, 5: 490-498. 10.4161/cam.5.6.18623.PubMed CentralPubMedView ArticleGoogle Scholar
21. Druckenbrod NR, Epstein ML: The pattern of neural crest advance in the cecum and colon. Dev Biol. 2005, 287: 125-133. 10.1016/j.ydbio.2005.08.040.PubMedView ArticleGoogle Scholar
22. Druckenbrod NR, Epstein ML: Behavior of enteric neural crest-derived cells varies with respect to the migratory wavefront. Dev Dyn. 2007, 236: 84-92. 10.1002/dvdy.20974.PubMedView ArticleGoogle Scholar
23. Young HM, Bergner AJ, Anderson RB, Enomoto H, Milbrandt J, Newgreen DF, Whitington PM: Dynamics of neural crest-derived cell migration in the embryonic mouse gut. Dev Biol. 2004, 270: 455-473. 10.1016/j.ydbio.2004.03.015.PubMedView ArticleGoogle Scholar
24. Zhang Y, Kim TH, Niswander L: Phactr4 regulates directional migration of enteric neural crest through PP1, integrin signaling, and cofilin activity. Genes Dev. 2012, 26: 69-81. 10.1101/gad.179283.111.PubMed CentralPubMedView ArticleGoogle Scholar
25. Breau MA, Dahmani A, Broders-Bondon F, Thiery JP, Dufour S: Beta1 integrins are required for the invasion of the caecum and proximal hindgut by enteric neural crest cells. Development. 2009, 136: 2791-2801. 10.1242/dev.031419.PubMedView ArticleGoogle Scholar
26. Nishiyama C, Uesaka T, Manabe T, Yonekura Y, Nagasawa T, Newgreen DF, Young HM, Enomoto H: Trans-mesenteric neural crest cells are the principal source of the colonic enteric nervous system. Nat Neurosci. 2012, 15: 1211-1218. 10.1038/nn.3184.PubMedView ArticleGoogle Scholar
27. Simpson MJ, Zhang DC, Mariani M, Landman KA, Newgreen DF: Cell proliferation drives neural crest cell invasion of the intestine. Dev Biol. 2007, 302: 553-568. 10.1016/j.ydbio.2006.10.017.PubMedView ArticleGoogle Scholar
28. Corpening JC, Deal KK, Cantrell VA, Skelton SB, Buehler DP, Southard-Smith EM: Isolation and live imaging of enteric progenitors based on Sox10-Histone2BVenus transgene expression. Genesis. 2011, 49: 599-618. 10.1002/dvg.20748.PubMed CentralPubMedView ArticleGoogle Scholar
29. Baetge G, Gershon MD: Transient catecholaminergic (TC) cells in the vagus nerves and bowel of fetal mice: relationship to the development of enteric neurons. Dev Biol. 1989, 132: 189-211. 10.1016/0012-1606(89)90217-0.PubMedView ArticleGoogle Scholar
30. Young HM, Jones BR, McKeown SJ: The projections of early enteric neurons are influenced by the direction of neural crest cell migration. J Neurosci. 2002, 22: 6005-6018.PubMedGoogle Scholar
31. Kapur RP, Yost C, Palmiter RD: A transgenic model for studying development of the enteric nervous system in normal and aganglionic mice. Development. 1992, 116: 167-175.PubMedGoogle Scholar
32. Codling EA, Plank MJ, Benhamou S: Random walk models in biology. J R Soc Interface. 2008, 5: 813-834. 10.1098/rsif.2008.0014.PubMed CentralPubMedView ArticleGoogle Scholar
33. Zar JH: Biostatistical analysis. Biostatistical analysis. 1999, Upper Saddle River, NJ, USA: Prentice-Hall, Inc., 4Google Scholar
34. Ridenour DA, McLennan R, Teddy JM, Semerad C, Haug JS, Kulesa PM: The neural crest cell cycle is related to phases of migration in the head. Development. 2014, 141: 1095-1103. 10.1242/dev.098855.PubMed CentralPubMedView ArticleGoogle Scholar
35. Allan IJ, Newgreen DF: The origin and differentiation of enteric neurons of the intestine of the fowl embryo. Am J Anat. 1980, 157: 137-154. 10.1002/aja.1001570203.PubMedView ArticleGoogle Scholar
36. Anderson RB, Bergner AJ, Taniguchi M, Fujisawa H, Forrai A, Robb L, Young HM: Effects of different regions of the developing gut on the migration of enteric neural crest-derived cells: a role for Sema3A, but not Sema3F. Dev Biol. 2007, 305: 287-299. 10.1016/j.ydbio.2007.02.020.PubMedView ArticleGoogle Scholar
37. Hao MM, Anderson RB, Kobayashi K, Whitington PM, Young HM: The migratory behavior of immature enteric neurons. Dev Neurobiol. 2009, 69: 22-35. 10.1002/dneu.20683.PubMedView ArticleGoogle Scholar
38. Sasselli V, Boesmans W, Vanden Berghe P, Tissir F, Goffinet AM, Pachnis V: Planar cell polarity genes control the connectivity of enteric neurons. J Clin Invest. 2013, 123: 1763-1772. 10.1172/JCI66759.PubMed CentralPubMedView ArticleGoogle Scholar
39. Hao MM, Moore RE, Roberts RR, Nguyen T, Furness JB, Anderson RB, Young HM: The role of neural activity in the migration and differentiation of enteric neuron precursors. Neurogastroenterol Motil. 2010, 22: e127-e137.PubMedGoogle Scholar
40. Druckenbrod NR, Epstein ML: Age-dependent changes in the gut environment restrict the invasion of the hindgut by enteric neural progenitors. Development. 2009, 136: 3195-3203. 10.1242/dev.031302.PubMedView ArticleGoogle Scholar
41. Nagy N, Goldstein AM: Endothelin-3 regulates neural crest cell proliferation and differentiation in the hindgut enteric nervous system. Dev Biol. 2006, 293: 203-217. 10.1016/j.ydbio.2006.01.032.PubMedView ArticleGoogle Scholar
42. Sidebotham EL, Woodward MN, Kenny SE, Lloyd DA, Vaillant CR, Edgar DH: Localization and endothelin-3 dependence of stem cells of the enteric nervous system in the embryonic colon. J Pediatr Surg. 2002, 37: 145-150. 10.1053/jpsu.2002.30239.PubMedView ArticleGoogle Scholar
43. Hearn CJ, Murphy M, Newgreen D: GDNF and ET-3 differentially modulate the numbers of avian enteric neural crest cells and enteric neurons in vitro. Dev Biol. 1998, 197: 93-105. 10.1006/dbio.1998.8876.PubMedView ArticleGoogle Scholar
44. Wu JJ, Chen JX, Rothman TP, Gershon MD: Inhibition of in vitro enteric neuronal development by endothelin-3: mediation by endothelin B receptors. Development. 1999, 126: 1161-1173.PubMedGoogle Scholar
45. Theveneau E, Mayor R: Neural crest migration: interplay between chemorepellents, chemoattractants, contact inhibition, epithelial-mesenchymal transition, and collective cell migration. Wiley Interdiscip Rev Dev Biol. 2012, 1: 435-445. 10.1002/wdev.28.PubMedView ArticleGoogle Scholar
46. Goto A, Sumiyama K, Kamioka Y, Nakasyo E, Ito K, Iwasaki M, Enomoto H, Matsuda M: GDNF and endothelin 3 regulate migration of enteric neural crest-derived cells via protein kinase A and Rac1. J Neurosci. 2013, 33: 4901-4912. 10.1523/JNEUROSCI.4828-12.2013.PubMedView ArticleGoogle Scholar
47. Fu M, Sato Y, Lyons-Warren A, Zhang B, Kane MA, Napoli JL, Heuckeroth RO: Vitamin A facilitates enteric nervous system precursor migration by reducing Pten accumulation. Development. 2010, 137: 631-640. 10.1242/dev.040550.PubMed CentralPubMedView ArticleGoogle Scholar
48. Hao MM, Young HM: Development of enteric neuron diversity. J Cell Mol Med. 2009, 13: 1193-1210. 10.1111/j.1582-4934.2009.00813.x.PubMed CentralPubMedView ArticleGoogle Scholar
49. Delalande JM, Natarajan D, Vernay B, Finlay M, Ruhrberg C, Thapar N, Burns AJ: Vascularisation is not necessary for gut colonisation by enteric neural crest cells. Dev Biol. 2014, 385: 220-229. 10.1016/j.ydbio.2013.11.007.PubMed CentralPubMedView ArticleGoogle Scholar
50. Aman A, Piotrowski T: Cell migration during morphogenesis. Dev Biol. 2010, 341: 20-33. 10.1016/j.ydbio.2009.11.014.PubMedView ArticleGoogle Scholar
51. Revenu C, Streichan S, Dona E, Lecaudey V, Hufnagel L, Gilmour D: Quantitative cell polarity imaging defines leader-to-follower transitions during collective migration and the key role of microtubule-dependent adherens junction formation. Development. 2014, 141: 1282-1291. 10.1242/dev.101675.PubMedView ArticleGoogle Scholar
52. Mort RL, Hay L, Jackson IJ: Ex vivo live imaging of melanoblast migration in embryonic mouse skin. Pigment Cell Melanoma Res. 2010, 23: 299-301. 10.1111/j.1755-148X.2010.00669.x.PubMed CentralPubMedView ArticleGoogle Scholar
53. Kulesa PM, Fraser SE: Neural crest cell dynamics revealed by time-lapse video microscopy of whole embryo chick explant cultures. Dev Biol. 1998, 204: 327-344. 10.1006/dbio.1998.9082.PubMedView ArticleGoogle Scholar
54. Teddy JM, Kulesa PM: In vivo evidence for short- and long-range cell communication in cranial neural crest cells. Development. 2004, 131: 6141-6151. 10.1242/dev.01534.PubMedView ArticleGoogle Scholar
55. Anderson RB, Turner KN, Nikonenko AG, Hemperly J, Schachner M, Young HM: The cell adhesion molecule L1 is required for chain migration of neural crest cells in the developing mouse gut. Gastroenterology. 2006, 130: 1221-1232. 10.1053/j.gastro.2006.01.002.PubMedView ArticleGoogle Scholar
56. McKeown SJ, Wallace AS, Anderson RB: Expression and function of cell adhesion molecules during neural crest migration. Dev Biol. 2013, 373: 244-257. 10.1016/j.ydbio.2012.10.028.PubMedView ArticleGoogle Scholar
57. Breau MA, Pietri T, Eder O, Blanche M, Brakebusch C, Fassler R, Thiery JP, Dufour S: Lack of beta1 integrins in enteric neural crest cells leads to a Hirschsprung-like phenotype. Development. 2006, 133: 1725-1734. 10.1242/dev.02346.PubMedView ArticleGoogle Scholar
58. Broders-Bondon F, Paul-Gilloteaux P, Carlier C, Radice GL, Dufour S: N-cadherin and beta1-integrins cooperate during the development of the enteric nervous system. Dev Biol. 2012, 364: 178-191. 10.1016/j.ydbio.2012.02.001.PubMedView ArticleGoogle Scholar
59. Watanabe Y, Broders-Bondon F, Baral V, Paul-Gilloteaux P, Pingault V, Dufour S, Bondurand N: Sox10 and Itgb1 interaction in enteric neural crest cell migration. Dev Biol. 2013, 379: 92-106. 10.1016/j.ydbio.2013.04.013.PubMedView ArticleGoogle Scholar
60. Kapur RP, Sweetser DA, Doggett B, Siebert JR, Palmiter RD: Intercellular signals downstream of endothelin receptor-B mediate colonization of the large intestine by enteric neuroblasts. Development. 1995, 121: 3787-3795.PubMedGoogle Scholar
61. Baynash AG, Hosoda K, Giaid A, Richardson JA, Emoto N, Hammer RE, Yanagisawa M: Interaction of endothelin-3 with endothelin-B receptor is essential for development of epidermal melanocytes and enteric neurons. Cell. 1994, 79: 1277-1285. 10.1016/0092-8674(94)90018-3.PubMedView ArticleGoogle Scholar
62. Bondurand N, Natarajan D, Barlow A, Thapar N, Pachnis V: Maintenance of mammalian enteric nervous system progenitors by SOX10 and endothelin 3 signalling. Development. 2006, 133: 2075-2086. 10.1242/dev.02375.PubMedView ArticleGoogle Scholar
63. Druckenbrod NR, Powers PA, Bartley CR, Walker JW, Epstein ML: Targeting of endothelin receptor-B to the neural crest. Genesis. 2008, 46: 396-400. 10.1002/dvg.20415.PubMed CentralPubMedView ArticleGoogle Scholar
64. Barlow A, de Graaff E, Pachnis V: Enteric nervous system progenitors are coordinately controlled by the G protein-coupled receptor EDNRB and the receptor tyrosine kinase RET. Neuron. 2003, 40: 905-916. 10.1016/S0896-6273(03)00730-X.PubMedView ArticleGoogle Scholar
65. Heanue TA, Pachnis V: Enteric nervous system development and Hirschsprung's disease: advances in genetic and stem cell studies. Nat Rev. 2007, 8: 466-479. 10.1038/nrn2137.View ArticleGoogle Scholar
66. Furness JB: The enteric nervous system and neurogastroenterology. Nat Rev Gastroenterol Hepatol. 2012, 9: 286-294. 10.1038/nrgastro.2012.32.PubMedView ArticleGoogle Scholar
67. Stewart AL, Young HM, Popoff M, Anderson RB: Effects of pharmacological inhibition of small GTPases on axon extension and migration of enteric neural crest-derived cells. Dev Biol. 2007, 307: 92-104. 10.1016/j.ydbio.2007.04.024.PubMedView ArticleGoogle Scholar
68. Brooks AS, Bertoli-Avella AM, Burzynski GM, Breedveld GJ, Osinga J, Boven LG, Hurst JA, Mancini GM, Lequin MH, de Coo RF, Matera I, de Graaff E, Meijers C, Willems PJ, Tibboel D, Oostra BA, Hofstra RM: Homozygous nonsense mutations in KIAA1279 are associated with malformations of the central and enteric nervous systems. Am J Hum Genet. 2005, 77: 120-126. 10.1086/431244.PubMed CentralPubMedView ArticleGoogle Scholar
69. Alves MM, Burzynski G, Delalande JM, Osinga J, van der Goot A, Dolga AM, de Graaff E, Brooks AS, Metzger M, Eisel UL, Shepherd I, Eggen BJ, Hofstra RM: KBP interacts with SCG10, linking Goldberg-Shprintzen syndrome to microtubule dynamics and neuronal differentiation. Hum Mol Genet. 2010, 19: 3642-3651. 10.1093/hmg/ddq280.PubMedView ArticleGoogle Scholar
70. Lyons DA, Naylor SG, Mercurio S, Dominguez C, Talbot WS: KBP is essential for axonal structure, outgrowth and maintenance in zebrafish, providing insight into the cellular basis of Goldberg-Shprintzen syndrome. Development. 2008, 135: 599-608. 10.1242/dev.012377.PubMedView ArticleGoogle Scholar
71. Drevillon L, Megarbane A, Demeer B, Matar C, Benit P, Briand-Suleau A, Bodereau V, Ghoumid J, Nasser M, Decrouy X, Doco-Fenzy M, Rustin P, Gaillard D, Goossens M, Giurgea I: KBP-cytoskeleton interactions underlie developmental anomalies in Goldberg-Shprintzen syndrome. Hum Mol Genet. 2013, 22: 2387-2399. 10.1093/hmg/ddt083.PubMedView ArticleGoogle Scholar
72. Lake JI, Heuckeroth RO: Enteric nervous system development: migration, differentiation, and disease. Am J Physiol Gastrointest Liver Physiol. 2013, 305: G1-24. 10.1152/ajpgi.00452.2012.PubMed CentralPubMedView ArticleGoogle Scholar
73. Laranjeira C, Pachnis V: Enteric nervous system development: recent progress and future challenges. Auton Neurosci. 2009, 151: 61-69. 10.1016/j.autneu.2009.09.001.PubMedView ArticleGoogle Scholar
74. Sasselli V, Pachnis V, Burns AJ: The enteric nervous system. Dev Biol. 2012, 366: 64-73. 10.1016/j.ydbio.2012.01.012.PubMedView ArticleGoogle Scholar
75. Natarajan D, Marcos-Gutierrez C, Pachnis V, de Graaff E: Requirement of signalling by receptor tyrosine kinase RET for the directed migration of enteric nervous system progenitor cells during mammalian embryogenesis. Development. 2002, 129: 5151-5160.PubMedGoogle Scholar
76. Young HM, Hearn CJ, Farlie PG, Canty AJ, Thomas PQ, Newgreen DF: GDNF is a chemoattractant for enteric neural cells. Dev Biol. 2001, 229: 503-516. 10.1006/dbio.2000.0100.PubMedView ArticleGoogle Scholar
77. Mai J, Fok L, Gao H, Zhang X, Poo MM: Axon initiation and growth cone turning on bound protein gradients. J Neurosci. 2009, 29: 7450-7458. 10.1523/JNEUROSCI.1121-09.2009.PubMedView ArticleGoogle Scholar
78. Cheng PL, Poo MM: Early events in axon/dendrite polarization. Annu Rev Neurosci. 2012, 35: 181-201. 10.1146/annurev-neuro-061010-113618.PubMedView ArticleGoogle Scholar
79. Barlow AJ, Dixon J, Dixon MJ, Trainor PA: Balancing neural crest cell intrinsic processes with those of the microenvironment in Tcof1 haploinsufficient mice enables complete enteric nervous system formation. Hum Mol Genet. 2012, 21: 1782-1793. 10.1093/hmg/ddr611.PubMed CentralPubMedView ArticleGoogle Scholar
80. Enomoto H, Crawford PA, Gorodinsky A, Heuckeroth RO, Johnson EM, Milbrandt J: RET signaling is essential for migration, axonal growth and axon guidance of developing sympathetic neurons. Development. 2001, 128: 3963-3974.PubMedGoogle Scholar
81. Hearn CJ, Young HM, Ciampoli D, Lomax AE, Newgreen D: Catenary cultures of embryonic gastrointestinal tract support organ morphogenesis, motility, neural crest cell migration, and cell differentiation. Dev Dyn. 1999, 214: 239-247. 10.1002/(SICI)1097-0177(199903)214:3<239::AID-AJA7>3.0.CO;2-O.PubMedView ArticleGoogle Scholar |
Processor and Kernel Memory Bug
There are two new vulnerabilities called Meltdown and Spectre with the latter affecting nearly every device in the world. That’s billions of devices.
Meltdown and Spectre have been known vulnerabilities for quite some time, but research teams had been under embargo. Details began to trickle out yesterday, and as a result of that trickle, there was a lot of speculation that led to many inaccurate assumptions about the full extent of the vulnerabilities and who and what was affected.
Yesterday was not the planned public disclosure day which highlights the difficulty in coordinating multiparty research disclosure.
The Meltdown vulnerability only affects Intel CPU’s. Intel opted for performance over security by allowing a program to read kernel data that’s in memory to include passwords and other sensitive information.
Meltdown allows an attacker to bypass the isolation between user applications and the operating system in virtual memory (stored on your hard drive) and RAM (physical memory). Personal computers and cloud infrastructure are affected by Meltdown. As far as cloud infrastructure goes, if you use Amazon Web Services, Google Cloud, Microsoft Azure and any other cloud company the uses Intel CPU’s and Xen PV, you can expect maintenance messages alerting you of planned downtime.
Meltdown was discovered by Jann Horn of Google’s Project Zero, Werner Haas and Thomas Prescher of Cyberus Technology, and Daniel Grus, Moritz Lipp, Stefan Mangard, and Michael Schwarz of Graz University of Technology.
Tom Lendacky, an AMD software engineer, had this to say about the Meltdown “AMD processors are not subject to the types of attacks that the kernel page table isolation feature protects against. The AMD microarchitecture does not allow memory references, including speculative references, that access higher privileged data when running in a lesser privileged mode when that access would result in a page fault.
There are patches available for Linux called KAISER Windows, and OS X. There are is also software hardening in the works for browsers to mitigate the chance of malicious Javascript in a web page from exploiting Meltdown.
Spectre affects nearly every device on planet earth and allows programs to access and read the memory locations of other programs that can contain any information that particular program uses. If the program is a browser, it can include which websites you’re visiting, how tabs you have open, and credentials.
Specifically, Spectre allows an attacker to trick an application into leaking data even if the developers used best practices when creating their software. Following best practices can also lead to an increased attacker surface making more data available to attackers. Spectre is the hardest of the two vulnerabilities to exploit, but also the most difficult to fix.
Spectre is a design flaw that can only be fixed in the upcoming generation of CPU’s and on.
Spectre was reported by Jann Horn of Google’s Project Zero, Paul Kocker in collaboration with Daniel Genkin of the University of Pennsylvania and the University of Maryland, Mike Hamburg of Rambus, Moritz Lipp of the Graz University of Technology, and Yuval Yarom of the University of Adelaide and Data61.
A proof-of-concept has been developed by a Ph.D. student at Vrije Universiteit Amsterdam that exploits Meltdown.
Intel released a statement addressing the inaccuracies of reports.
AMD and ARM also released statements concerning their products but didn’t directly address the plethora of inaccurate information.
Statement from ARM
Official statement from AMD
Source: The Register, Intel, LKML, Meltdown Attack |
Test-retest reliability assessment using graphical methods
UPDATE (2018-05-17): as explained in the now updated previous post, the shift function for pairwise differences, originally described as a great tool to assess test-retest reliability, is completely flawed. The approach using scatterplots remains valid. If you know of other graphical methods, please leave a comment.
Test-retest reliability is often summarised using a correlation coefficient, often without illustrating the raw data. This is a very bad idea given that the same correlation coefficient can result from many different configurations of observations. Graphical representations are thus essential to assess test-retest reliability, as demonstrated for instance in the work of Bland & Altman.
The R code for this post is on github.
Example 1: made up data
Let’s look at a first example using made up data. Imagine that reaction times were measured from 100 participants in two sessions. The medians of the two distributions do not differ much, but the shapes do differ a lot, similarly to the example covered in the previous post.
The kernel density estimates above do not reveal the pairwise associations between observations. This is better done using a scatterplot. In this plot, strong test-retest reliability would show up as a tight cloud of points along the unity line (the black diagonal line).
Here the observations do not fall on the unity line: instead the relationship leads to a much shallower slope than expected if the test-retest reliability was high. For fast responses in session 1, responses tended to be slower in session 2. Conversely, for slow responses in condition 1, responses tended to be faster in condition 2. This pattern would be expected if there was regression to the mean [wikipedia][ Barnett et al. 2005], that is, particularly fast or particularly slow responses in session 1 were due in part to chance, such that responses from the same individuals in session 2 were closer to the group mean. Here we know this is the case because the data are made up to have that pattern.
We can also use a shift function for dependent group to investigate the relationship between sessions, as we did in the previous post.
The shift function reveals a characteristic difference in spread between the two distributions, a pattern that is also expected if there is regression to the mean. Essentially, the shift function shows how the distribution in session 2 needs to be modified to match the distribution in session 1: the lowest deciles need to be decreased and the highest deciles need to be increased, and these changes should be stronger as we move towards the tails of the distribution. For this example, these changes would be similar to an anti-clockwise rotation of the regression slope in the next figure, to align the cloud of observations with the black diagonal line.
To confirm these observations, we also perform a shift function for pairwise differences.
This second type of shift function reveals a pattern very similar to the previous one. In the [previous post], I wrote that this “is re-assuring. But there might be situations where the two versions differ.” Well, here are two such situations…
Example 2: ERP onsets
Here we look at ERP onsets from an object detection task (Bieniek et al. 2016). In that study, 74 of our 120 participants were tested twice, to assess the test-retest reliability of different measurements, including onsets. The distributions of onsets across participants is positively skewed, with a few participants with particularly early or late onsets. The distributions for the two sessions appear quite similar.
With these data, we were particularly interested in the reliability of the left and right tails: if early onsets in session 1 were due to chance, we would expect session 2 estimates to be overall larger (shifted to the right); similarly, if late onsets in session 1 were due to chance, we would expect session 2 estimates to be overall smaller (shifted to the left). Plotting session 2 onsets as a function of session 1 onsets does not reveal a strong pattern of regression to the mean as we observed in example 1.
Adding a loess regression line suggests there might actually be an overall clockwise rotation of the cloud of points relative to the black diagonal.
The pattern is even more apparent if we plot the difference between sessions on the y axis. This is sometimes called a Bland & Altman plot (but here without the SD lines).
However, a shift function on the marginals is relatively flat.
Although there seems to be a linear trend, the uncertainty around the differences between deciles is large. In the original paper, we wrote this conclusion (sorry for the awful frequentist statement, I won’t do it again):
“across the 74 participants tested twice, no significant differences were found between any of the onset deciles (Fig. 6C). This last result is important because it demonstrates that test–retest reliability does not depend on onset times. One could have imagined for instance that the earliest onsets might have been obtained by chance, so that a second test would be systematically biased towards longer onsets: our analysis suggests that this was not the case.”
That conclusion was probably wrong, because the shift function for dependent marginals is inappropriate to look at test-retest reliability. Inferences should be made on pairwise differences instead. So, if we use the shift function for pairwise differences, the results are very different! A much better diagnostic tool is to plot difference results as a function of session 1 results. This approach suggests, in our relatively small sample size:
• the earlier the onsets in session 1, the more they increased in session 2, such that the difference between sessions became more negative;
• the later the onsets in session 1, the more they decreased in session 2, such that the difference between sessions became more positive.
This result and the discrepancy between the two types of shift functions is very interesting and can be explained by a simple principle: for dependent variables, the difference between 2 means is equal to the mean of the individual pairwise differences; however, this does not have to be the case for other estimators, such as quantiles (Wilcox & Rousselet, 2018).
Also, tThe discrepancy shows that I reached the wrong conclusion in a previous study because I used the wrong analysis. Of course, there is always the possibility that I’ve made a terrible coding mistake somewhere (that won’t be the first time – please let me know if you spot a fatal mistake). So l Let’s look at another example using published clinical data in which regression to the mean was suspected.
Example 3: Nambour skin cancer prevention trial
The data are from a cancer clinical trial described by Barnett et al. (2005). Here is Figure 3 from that paper:
“Scatter-plot of n = 96 paired and log-transformed betacarotene measurements showing change (log(follow-up) minus log(baseline)) against log(baseline) from the Nambour Skin Cancer Prevention Trial. The solid line represents perfect agreement (no change) and the dotted lines are fitted regression lines for the treatment and placebo groups”
Let’s try to make a similarly looking figure.
Unfortunately, the original figure cannot be reproduced because the group membership has been mixed up in the shared dataset… So let’s merge the two groups and plot the data following our shift function convention, in which the difference is session 1 – session 2.
Regression to the mean is suggested by the large number of negative differences and the negative slope of the loess regression: participants with low results in session 1 tended to have higher results in session 2. This pattern can also be revealed by plotting session 2 as a function of session 1.
The shift function for marginals suggests increasing differences between session quantiles for increasing quantiles in session 1.
This result seems at odd with the previous plot, but it is easier to understand if we look at the kernel density estimates of the marginals. Thus, plotting difference scores as a function of session 1 scores probably remains the best strategy to have a fine-grained look at test-retest results.
A shift function for pairwise differences shows a very different pattern, consistent with the regression to the mean suggested by Barnett et al. (2005).
To assess test-retest reliability, it is very informative to use graphical representations, which can reveal interesting patterns that would be hidden in a correlation coefficient. Unfortunately, there doesn’t seem to be a magic tool to simultaneously illustrate and make inferences about test-retest reliability.
It seems that the shift function for pairwise differences is an excellent tool to look at test-retest reliability, and to spot patterns of regression to the mean. The next steps for the shift function for pairwise differences will be to perform some statistical validations for the frequentist version, and develop a Bayesian version.
That’s it for this post. If you use the shift function for pairwise differences to look at test-retest reliability, let me know and I’ll add a link here.
Barnett, A.G., van der Pols, J.C. & Dobson, A.J. (2005) Regression to the mean: what it is and how to deal with it. Int J Epidemiol, 34, 215-220.
Bland JM, Altman DG. (1986). Statistical methods for assessing agreement between two methods of clinical measurement. Lancet, i, 307-310.
Bieniek, M.M., Bennett, P.J., Sekuler, A.B. & Rousselet, G.A. (2016) A robust and representative lower bound on object processing speed in humans. The European journal of neuroscience, 44, 1804-1814.
A new shift function for dependent groups?
The scatterplot reveals more clearly the relationship between conditions:
Reaction times and other skewed distributions: problems with the mean and the median (part 4/4)
This is part 4 of a 4 part series. Part 1 is here.
In this post, I look at median bias in a large dataset of reaction times from participants engaged in a lexical decision task. The dataset was described in a previous post.
After removing a few participants who didn’t pay attention to the task (low accuracy or too many very late responses), we’re left with 959 participants to play with. Each participant had between 996 and 1001 trials for each of two conditions, Word and Non-Word.
Here is an illustration of reaction time distributions from 100 randomly sampled participants in the Word condition:
Same in the Non-Word condition:
Skewness tended to be larger in the Word than the Non-Word condition. Based on the standard parametric definition of skewness, that was the case in 80% of participants. If we use a non-parametric estimate instead (mean – median), it was the case in 70% of participants.
If we save the median of every individual distribution, we get the two following group distributions, which display positive skewness:
The same applies to distributions of means:
So we have to worry about skewness at 2 levels:
• individual distributions
• group distributions
Here I’m only going to explore estimation bias as a result of skewness and sample size in individual distributions. From what we learnt in previous posts, we can already make predictions: because skewness tended to be stronger in the Word than in the Non-Word condition, the bias of the median will be stronger in the former than the later for small sample sizes. That is, the median in the Word condition will tend to be more over-estimated than the median in the Non-Word condition. As a consequence, the difference between the median of the Non-Word condition (larger RT) and the median of the Word condition (smaller RT) will tend to be under-estimated. To check this prediction, I estimated bias in every participant using a simulation with 2,000 iterations. I assumed that the full sample was the population, from which we can compute population means and population medians. Because the Non-Word condition is the least skewed, I used it as the reference condition, which always had 200 trials. The Word condition had 10 to 200 trials, with 10 trial increments. In the simulation, single RT were sampled with replacements among the roughly 1,000 trials available per condition and participant, so that each iteration is equivalent to a fake experiment.
Let’s look at the results for the median. The figure below shows the bias in the long run estimation of the difference between medians (Non-Word – Word), as a function of sample size in the Word condition. The Non-Word condition always had 200 trials. All participants are superimposed and shown as coloured traces. The average across participants is shown as a thicker black line.
As expected, bias tended to be negative with small sample sizes. For the smallest sample size, the average bias was -11 ms. That’s probably substantial enough to seriously distort estimation in some experiments. Also, variability is high, with a 80% highest density interval of [-17.1, -2.6] ms. Bias decreases rapidly with increasing sample size. For n=60, it is only 1 ms.
But inter-participant variability remains high, so we should be cautious interpreting results with large numbers of trials but few participants. To quantify the group uncertainty, we could measure the probability of being wrong, given a level of desired precision, as demonstrated here for instance.
After bootstrap bias correction (with 200 bootstrap resamples), the average bias drops to roughly zero for all sample sizes:
Bias correction also reduced inter-participant variability.
As we saw in the previous post, the sampling distribution of the median is skewed, so the standard measure of bias (taking the mean across simulation iterations) does not provide a good indication of the bias we can expect in a typical experiment. If instead of the mean, we compute the median bias, we get the following results:
Now, at the smallest sample size, the average bias is only -2 ms, and it drops to near zero for n=20. This result is consistent with the simulations reported in the previous post and confirms that in the typical experiment, the average bias associated with the median is negligible.
What happens with the mean?
The average bias of the mean is near zero for all sample sizes. Individual bias values are also much less variable than median values. This difference in bias variability does not reflect a difference in variability among participants for the two estimators of central tendency. In fact, the distributions of differences between Non-Word and Word conditions are very similar for the mean and the median.
Estimates of spread are also similar between distributions:
IQR: mean RT = 78; median RT = 79
MAD: mean RT = 57; median RT = 54
VAR: mean RT = 4507; median RT = 4785
This suggests that the inter-participant bias differences are due to the shape differences observed in the first two figures of this post.
Finally, let’s consider the median bias of the mean.
For the smallest sample size, the average bias across participants is 7 ms. This positive bias can be explained easily from the simulation results of post 3: because of the larger skewness in the Word condition, the sampling distribution of the mean was more positively skewed for small samples in that condition compared to the Non-Word condition, with the bulk of the bias estimates being negative. As a result, the mean tended to be more under-estimated in the Word condition, leading to larger Non-Word – Word differences in the typical experiment.
I have done a lot more simulations and was planning even more, using other datasets, but it’s time to move on! Of particular note, it appears that in difficult visual search tasks, skewness can differ dramatically among set size conditions – see for instance data posted here.
Concluding remarks
The data-driven simulations presented here confirm results from our previous simulations:
• if we use the standard definition of bias, for small sample sizes, mean estimates are not biased, median estimates are biased;
• however, in the typical experiment (median bias), mean estimates can be more biased than median estimates;
• bootstrap bias correction can be an effective tool to reduce bias.
Given the large differences in inter-participant variability between the mean and the median, an important question is how to spend your money: more trials or more participants (Rouder & Haaf 2018)? An answer can be obtained by running simulations, either data-driven or assuming generative distributions (for instance exGaussian distributions for RT data). Simulations that take skewness into account are important to estimate bias and power. Assuming normality can have disastrous consequences.
Despite the potential larger bias and bias variability of the median compared to the mean, for skewed distributions I would still use the median as a measure of central tendency, because it provides a more informative description of the typical observations. Large sample sizes will reduce both bias and estimation variability, such that high-precision single-participant estimation should be easy to obtain in many situations involving non-clinical samples. For group estimations, much larger samples than commonly used are probably required to improve the precision of our inferences.
Although the bootstrap bias correction seems to work very well in the long run, for a single experiment there is no guarantee it will get you closer to the truth. One possibility is to report results with and without bias correction.
For group inferences on the median, traditional techniques use incorrect estimations of the standard error, so consider modern parametric or non-parametric techniques instead (Wilcox & Rousselet, 2018).
Miller, J. (1988) A warning about median reaction time. J Exp Psychol Hum Percept Perform, 14, 539-543.
Rouder, J.N. & Haaf, J.M. (2018) Power, Dominance, and Constraint: A Note on the Appeal of Different Design Traditions. Advances in Methods and Practices in Psychological Science, 1, 19-26.
Bayesian shift function
Two distributions can differ in many ways, yet the standard approach in neuroscience & psychology is to assume differences in means. That’s why the first step in exploratory data analysis should always be detailed graphical representations (Rousselet et al. 2016, 2017). To help quantify how two distributions differ, a fantastic tool is the shift function – an example is provided below. It consists in plotting the difference between group quantiles, as a function of the quantiles in one group. The technique was first described in the 1970s by Doksum (1974; Doksum & Sievers, 1976), and later refined by Wilcox using the Harrell-Davis quantile estimator (Harrell & Davis, 1982) in conjunction with two percentile bootstrap methods (Wilcox 1995; Wilcox et al. 2014). The technique is related to delta plots and relative distribution methods (see details in Rousselet et al. 2017).
The goal of this post is to get feedback on my first attempt to make a Bayesian version of the shift function. Below I describe three potential strategies. My main motivation for making a Bayesian version is that the shift function comes with frequentist confidence intervals and p values. Although I still use confidence intervals to describe sampling variability, they are inherently linked to p values and tend to be associated with major flaws in interpretation (Morey et al. 2016). And my experience is that if p values are available, most researchers will embark on lazy and irrational decision making (Wagenmakers 2007). P values would not be a problem if they were just used as one of many pieces of evidence, without any special status (McShane et al. 2017).
Let’s consider a toy example: two independent exGaussian distributions, with n = 100 in each group.
The two groups clearly differ, as expected from the generative process (see online code). A t-test on means suggests a large uncertainty about the group difference:
difference = – 65 ms [-166, 37]
t = -1.26
p = 0.21
A shift function provides much more information about how the two groups differ.
The x-axis shows the quantiles of group 1 (here only the 9 deciles, which is a good default). The y-axis shows the difference between deciles of group 1 and group 2. Intuitively, the difference shows by how much group 2 would need to be shifted to match group 1, for each decile. The coloured labels show the quantile differences. I let you go back and forth between the density estimates and the shift function to understand what’s going on. Another detailed description is provided here if needed.
Strategy 1: Bayesian bootstrap
A simple strategy to make a Bayesian shift function is to use the Bayesian bootstrap instead of a percentile bootstrap. The percentile bootstrap can already be considered a very cheap way to create Bayesian posterior distributions, if we make the strong (and wrong) assumption that our observations are the only possible ones. Rasmus Bååth provides a detailed introduction to the Bayesian bootstrap, and it’s R implementation on his blog. There is also a video.
Using the Bayesian bootstrap, and 95% highest density intervals (HDI) of the posterior distributions, the shift function looks very similar to the original version, as expected.
Except now we’re dealing with credible intervals, and there are no p values, so users have to focus on quantification!
Strategy 2: Bayesian quantile regression
Another strategy is to use quantile regression, which comes in a Bayesian flavour using the asymmetric Laplacian likelihood family. To do that, I’m using the amazing brms R package by Paul Bürkner.
To get started with Bayesian statistics and the brms package, I recommend this excellent blog post by Matti Vuorre. Many other great posts are available here.
Using the default priors from brms, we can fit a quantile regression line for each group and for each decile. The medians (or means, or modes) and 95% HDIs of the posterior distributions can then be used to create a shift function.
Again, the results are quite similar to the original ones, although this time the quantiles do differ a bit from those in the previous versions because we use the medians of the posterior distributions to estimate them. Also, I haven’t looked in much detail at how well the model fits the data. The posterior predictive samples suggest the fits could be improved, but I have too little experience to make a call.
Strategy 3: Bayesian model with exGaussians
The third strategy is to fit a descriptive model to the distributions, generate samples from the posterior distributions, and compute quantiles from these predicted values. Here, since our toy model simulates reaction time data using exGaussian distributions, it makes sense to fit an exGaussian family to the data. More generally, exGaussian distributions are very good at capturing the shape of RT data (Matzke & Wagenmakers, 2009).
Again, the results look similar to the original ones. This strategy has the advantage to require fitting only one model, instead of a new model for each quantile in strategy 2. In addition, we get an exGaussian fit of the data, which is very useful in itself. So that would probably be my favourite strategy.
Questions to you, reader
Does this make even remotely sense?
Which strategy seems more promising?
The clear benefit of strategies 2 and 3 is that they can easily be extended to create hierarchical shift functions, by fitting simultaneously observations from multiple participants. Whereas for the original shift function using the percentile bootstrap, I don’t see any obvious way to make a hierarchical version.
You might want to ask, why not simply focus on modelling the distributions instead of looking at the quantiles? Modelling the shape of the distributions is great of course, but I don’t think it can achieve the same fine-grained quantification achieved by the shift function. Another approach of course would be to fit a more psychologically motivated model, such as a diffusion model. I think these three approaches are complementary.
Doksum, K. (1974) Empirical Probability Plots and Statistical Inference for Nonlinear Models in the two-Sample Case. Annals of Statistics, 2, 267-277.
Blakeley B. McShane, David Gal, Andrew Gelman, Christian Robert, Jennifer L. Tackett (2017) Abandon Statistical Significance. arXiv:1709.07588
Matzke, D. & Wagenmakers, E.J. (2009) Psychological interpretation of the ex-Gaussian and shifted Wald parameters: a diffusion model analysis. Psychon Bull Rev, 16, 798-817.
Morey, R.D., Hoekstra, R., Rouder, J.N., Lee, M.D. & Wagenmakers, E.J. (2016) The fallacy of placing confidence in confidence intervals. Psychon Bull Rev, 23, 103-123.
Rousselet, G.A., Foxe, J.J. & Bolam, J.P. (2016) A few simple steps to improve the description of group results in neuroscience. The European journal of neuroscience, 44, 2647-2651.
Rousselet, G., Pernet, C. & Wilcox, R. (2017) Beyond differences in means: robust graphical methods to compare two groups in neuroscience, figshare.
Wagenmakers, E.J. (2007) A practical solution to the pervasive problems of p values. Psychonomic bulletin & review, 14, 779-804.
Wilcox, R.R. (1995) Comparing Two Independent Groups Via Multiple Quantiles. Journal of the Royal Statistical Society. Series D (The Statistician), 44, 91-99.
Wilcox, R.R., Erceg-Hurn, D.M., Clark, F. & Carlson, M. (2014) Comparing two independent groups via the lower and upper quantiles. J Stat Comput Sim, 84, 1543-1551.
Cohen’s d is biased
The R notebook associated with this post is available on github.
Cohen’s d is a popular measure of effect size. In the one-sample case, d is simply computed as the mean divided by the standard deviation (SD). For repeated measures, the same formula is applied to difference scores (see detailed presentation and explanation of variants in Lakens, 2013).
Because d relies on a non-robust measure of central tendency (the mean), and a non-robust measure of dispersion (SD), it is a non-robust measure of effect size, meaning that a single observation can have a dramatic effect on its value, as explained here. Cohen’s d also makes very strict assumptions about the data, so it is only appropriate in certain contexts. As a consequence, it should not be used as the default measure of effect size, and more powerful and informative alternatives should be considered – see a few examples here. For comparisons across studies and meta-analyses, nothing will beat data-sharing though.
Here we look at another limitation of Cohen’s d: it is biased when we draw small samples. Bias is covered in detail in another post. In short, in the one-sample case, when Cohen’s d is estimated from a small sample, in the long run it tends to be larger than the population value. This over-estimation is due to a bias of SD, which tends to be lower than the population’s SD. Because the mean is not biased, when divided by an under-estimated SD, it leads to an over-estimated measure of effect size. The bias of SD is explained in intro stat books, in the section describing Student’s t. Not surprisingly it is never mentioned in the discussions of small n studies, as a limitation of effect size estimation…
In this demonstration, we sample with replacement 10,000 times from the ex-Gaussian distributions below, for various sample sizes, as explained here:
The table below shows the population values for each distribution. For comparison, we also consider a robust equivalent to Cohen’s d, in which the mean is replaced by the median, and SD is replaced by the percentage bend mid-variance (pbvar, Wilcox, 2017). As we will see, this robust alternative is also biased – there is no magic solution I’m afraid.
m: 600 600 600 600 600 600 600 600 600 600 600 600
md: 509 512 524 528 540 544 555 562 572 579 588 594
m-md: 92 88 76 72 60 55 45 38 29 21 12 6
m.den: 301 304 251 255 201 206 151 158 102 112 54 71
md.den: 216 224 180 190 145 157 110 126 76 95 44 68
m.es: 2.0 2.0 2.4 2.4 3.0 2.9 4.0 3.8 5.9 5.4 11.1 8.5
md.es: 2.4 2.3 2.9 2.8 3.7 3.5 5.0 4.5 7.5 6.1 13.3 8.8
m = mean
md = median
den = denominator
es = effect size
m.es = Cohen’s d
md.es = md / pbvar
Let’s look at the behaviour of d as a function of skewness and sample size.
Effect size d tends to decrease with increasing skewness, because SD tends to increase with skewness. Effect size also increases with decreasing sample size. This bias is stronger for samples from the least skewed distributions. This is counterintuitive, because one would think estimation tends to get worse with increased skewness. Let’s find out what’s going on.
Computing the bias normalises the effect sizes across skewness levels, revealing large bias differences as a function of skewness. Even with 100 observations, the bias (mean of 10,000 simulation iterations) is still slightly larger than zero for the least skewed distributions. This bias is not due to the mean, because we the sample mean is an unbiased estimator of the population mean.
Let’s check to be sure:
So the problem must be with the denominator:
Unlike the mean, the denominator of Cohen’s d, SD, is biased. Let’s look at bias directly.
SD is most strongly biased for small sample sizes and bias increases with skewness. Negative values indicate that sample SD tends to under-estimate the population values. This is because the sampling distribution of SD is increasingly skewed with increasing skewness and decreasing sample sizes. This can be seen in this plot of the 80% highest density intervals (HDI) for instance:
The sampling distribution of SD is increasingly skewed and variable with increasing skewness and decreasing sample sizes. As a result, the sampling distribution of Cohen’s d is also skewed. The bias is strongest in absolute term for the least skewed distributions because the sample SD is overall smaller for these distributions, resulting in overall larger effect sizes. Although SD is most biased for the most skewed distributions, SD is also overall much larger for them, resulting in much smaller effect sizes than those obtained for less skewed distributions. This strong attenuation of effect sizes with increasing skewness swamps the absolute differences in SD bias. This explains the counter-intuitive lower d bias for more skewed distributions.
As we saw previously, bias can be corrected using a bootstrap approach. Applied, to Cohen’s d, this technique does reduce bias, but it still remains a concern:
Finally, let’s look at the behaviour of a robust equivalent to Cohen’s d, the median normalised by the percentage bend mid-variance.
The median effect size shows a similar profile to the mean effect size. It is overall larger than the mean effect size because it uses a robust measure of spread, which is less sensitive to the long right tails of the skewed distributions we sample from.
The bias disappears quickly with increasing sample sizes, and quicker than for the mean effect size.
However, unlike what we observed for d, in this case the bias correction does not work for small samples, because the repetition of the same observations in some bootstrap samples leads to very large values of the denominator. It’s ok for n>=15, for which bias is relatively small anyway, so at least based on these simulations, I wouldn’t use bias correction for this robust effect size.
Beware of small sample sizes: they are associated with increased variability (see discussion in a clinical context here) and can accentuate the bias of some effect size estimates. If effect sizes tend to be reported more often if they pass some arbitrary threshold, for instance p < 0.05, then the literature will tend to over-estimate them (see demonstration here), a phenomenon exacerbated by small sample sizes (Button et al. 2013).
Can’t say it enough: small n is bad for science if the goal is to provide accurate estimates of effect sizes.
To determine how the precision and accuracy of your results depend on sample size, the best approach is to perform simulations, providing some assumptions about the shape of the population distributions.
Lakens, D. (2013) Calculating and reporting effect sizes to facilitate cumulative science: a practical primer for t-tests and ANOVAs. Front Psychol, 4, 863.
Wilcox, R.R. (2017) Introduction to Robust Estimation and Hypothesis Testing. Academic Press, 4th edition., San Diego, CA.
Reaction times and other skewed distributions: problems with the mean and the median (part 3/4)
Bias is defined as the distance between the mean of the sampling distribution (here estimated using Monte-Carlo simulations) and the population value. In part 1 and part 2, we saw that for small sample sizes, the sample median provides a biased estimation of the population median, which can significantly affect group comparisons. However, this bias disappears with large sample sizes, and it can be corrected using a bootstrap bias correction. In part 3, we look in more detail at the shape of the sampling distributions, which was ignored by Miller (1988).
Sampling distributions
Let’s consider the sampling distributions of the mean and the median for different sample sizes and ex-Gaussian distributions with skewness ranging from 6 to 92 (Figure 1). When skewness is limited (6, top row), the sampling distributions are symmetric and centred on the population values: there is no bias. As we saw previously, with increasing sample size, variability decreases, which is why studies with larger samples provide more accurate estimations. The flip side is that studies with small samples are much noisier, which is why their results tend not to replicate…
Figure 1
When skewness is large (92, middle row), sampling distributions get more positively skewed with decreasing sample sizes. To better understand how the sampling distributions change with sample size, we turn to the last row of Figure 1, which shows 50% highest-density intervals (HDI). Each horizontal line is a HDI for a particular sample size. The labels contain the values of the interval boundaries. The coloured vertical tick inside the interval marks the median of the distribution. The red vertical line spanning the entire plot is the population value.
Means For small sample sizes, the 50% HDI is offset to the left of the population mean, and so is the median of the sampling distribution. This demonstrates that the typical sample mean tends to under-estimate the population mean – that is to say, the mean sampling distribution is median biased. This offset reduces with increasing sample size, but is still present even for n=100.
Medians With small sample sizes, there is a discrepancy between the 50% HDI, which is shifted to the left of the population median, and the median of the sampling distribution, which is shifted to the right of the population median. This contrasts with the results for the mean, and can be explained by differences in the shapes of the sampling distributions, in particular the larger skewness and kurtosis of the median sampling distribution compared to that of the mean (see code on github for extra figures). The offset between 50% HDI and the population reduces quickly with increasing sample size. For n=10, the median bias is already very small. From n=15, the median sample distribution is not median bias, which means that the typical sample median is not biased.
Another representation of the sampling distributions is provided in Figure 2: 50% HDI are shown as a function of sample size. For both the mean and the median, bias increase with increasing skewness and decreasing sample size. Skewness also increases the asymmetry of the sampling distributions, but more for the mean than median.
Figure 2
So what’s going on here? Is the mean also biased? According to the standard definition of bias, which is based on the distance between the population mean and the average of the sampling distribution of the mean, the mean is not biased. But this definition applies to the long run, after we replicate the same experiment many times. In practice, we never do that. So what happens in practice, when we perform only one experiment? In that case, the median of the sampling distribution provides a better description of the typical experiment than the mean of the distribution. And the median of the sample distribution of the mean is inferior to the population mean when sample size is small. So if you conduct one small n experiment and compute the mean of a skewed distribution, you’re likely to under-estimate the true value.
Is the median biased after all? The median is indeed biased according to the standard definition. However, with small n, the typical median (represented by the median of the sampling distribution of the median) is close to the population median, and the difference disappears for even relatively small sample sizes.
Is it ok to use the median then?
If the goal is to accurately estimate the central tendency of a RT distribution, while protecting against the influence of outliers, the median is far more efficient than the mean (Wilcox & Rousselet, 2018). Providing sample sizes are large enough, bias is actually not a problem, and the typical bias is actually very small, as we’ve just seen. So, if you have to choose between the mean and the median, I would go for the median without hesitation.
It’s more complicated though. In an extensive series of simulations, Ratcliff (1993) demonstrated that when performing standard group ANOVAs, the median can lack power compared to other estimators. Ratcliff’s simulations involved ANOVAs on group means, in which for each participant, very few trials (7 to 12) are available for each condition. Based on the simulations, Ratcliff recommended data transformations or computing the mean after applying specific cut-offs to maximise power. However, these recommendations should be considered with caution because the results could be very different with more realistic sample sizes. Also, standard ANOVA on group means are not robust, and alternative techniques should be considered (Wilcox 2017). Data transformations are not ideal either, because they change the shape of the distributions, which contains important information about the nature of the effects. Also, once data are transformed, inferences are made on the transformed data, not on the original ones, an important caveat that tends to be swept under the carpet in articles’ discussions… Finally, truncating distributions introduce bias too, especially with the mean – see next section (Miller 1991; Ulrich & Miller 1994)!
At this stage, I don’t see much convincing evidence against using the median of RT distributions, if the goal is to use only one measure of location to summarise the entire distribution. Clearly, a better alternative is to not throw away all that information, by studying how entire distributions differ (Rousselet et al. 2017). For instance, explicit modelling of RT distributions can be performed with the excellent brms R package.
Other problems with the mean
In addition to being median biased, and a poor measure of central tendency for asymmetric distributions, the mean is also associated with several other important problems. Standard procedures using the mean lack of power, offer poor control over false positives, and lead to inaccurate confidence intervals. Detailed explanations of these problems are provided in Field & Wilcox (2017) and Wilcox & Rousselet (2018) for instance. For detailed illustrations of the problems associated with means in the one-sample case, when dealing with skewed distributions, see the companion reproducibility package on figshare.
If that was not enough, common outlier exclusion techniques lead to bias estimation of the mean (Miller, 1991). When applied to skewed distributions, removing any values more than 2 or 3 SD from the mean affects slow responses more than fast ones. As a consequence, the sample mean tends to underestimate the population mean. And this bias increases with sample size because the outlier detection technique does not work for small sample sizes, which results from the lack of robustness of the mean and the SD. The bias also increases with skewness. Therefore, when comparing distributions that differ in sample size, or skewness, or both, differences can be masked or created, resulting in inaccurate quantification of effect sizes.
Truncation using absolute thresholds (for instance RT < 300 ms or RT > 1,200 ms) also leads to potentially severe bias of the mean, median, standard deviation and skewness of RT distributions (Ulrich & Miller 1994). The median is much less affected by truncation bias than the mean though.
In the next and final post of this series, we will explore sampling bias in a real dataset, to see how much of a problem we’re really dealing with. Until then, thanks for reading.
[GO TO POST 4/4]
Field, A.P. & Wilcox, R.R. (2017) Robust statistical methods: A primer for clinical psychology and experimental psychopathology researchers. Behav Res Ther, 98, 19-38.
Miller, J. (1991) Reaction-Time Analysis with Outlier Exclusion – Bias Varies with Sample-Size. Q J Exp Psychol-A, 43, 907-912.
Ratcliff, R. (1993) Methods for dealing with reaction time outliers. Psychol Bull, 114, 510-532.
Ulrich, R. & Miller, J. (1994) Effects of Truncation on Reaction-Time Analysis. Journal of Experimental Psychology-General, 123, 34-80.
A quick review of Reader et al. EJN 2018
Here is a quick review of a paper that just came out in the European Journal of Neuroscience. I flagged one concern on Twitter, and the authors asked me to elaborate, so here I provide a short assessment of the sort I write when scanning through a paper I get to edit for the journal. This short assessment would then be added to the reviewers’ comments in my decision letter, or would be used as feedback as part of an editorial rejection.
Repetitive transcranial magnetic stimulation reveals a role for the left inferior parietal lobule in matching observed kinematics during imitation
Reader et al. EJN 2018
Participants: please report min, max, median age
Instead of splitting the analysis between hand and finger gestures, it would have been more powerful to perform a hierarchical analysis including a gesture factor. This sort of item analysis could dramatically alter the outcome of your analyses:
If the separate analysis of different gestures was not planned, then the sub-analyses must be corrected for multiple comparisons. In your case, it seems that most effects would not be significant, following the usual arbitrary p<0.05 cut-off.
The permutation + t-test procedure to investigate sequences is quite good. It would probably give you more power to include the size of the t values, by computing cluster sums, instead of cluster lengths. Also, you could consider TFCE, which provides a cluster free approach, with Matlab code available:
The multiple sequence tests should be corrected for multiple comparisons, for instance by using a maximum cluster sum statistics, where the max is taken across all comparisons.
The use of t-tests on means should be justified.
The results are presented mostly using t and p values, and whether an arbitrary p<0.05 threshold was reached. Results would be better presented by focusing on effect sizes, in their original units, individual differences, and mentioning t and p values only in passing, as pieces of evidence without a special status.
It’s great to use figures with scatterplots; however, for paired designs it is essential to also show distributions of pairwise differences. See guidelines for instance here:
The little stars and crosses should be removed from all figures. The emphasis should be on effect sizes and individual differences, which are best portrayed by showing scatterplots of pairwise differences. Also, using different tests, whether parametric or not, would give different p values, so the exact p values are only indicative, especially if the goal is to determine if <0.05.
The discussion should better qualify the results. For instance, this conclusion uses p values to incorrectly imply that the null hypothesis can be accepted, and that effect sizes were zero:
“Whilst stimulation did not influence imitation accuracy, there was some evidence for differences between accuracy in meaningful and meaningless action performance.”
The sample size is rather small, so the discussion should mention the risk of effect sizes being completely off.
To have to contact the corresponding author to get data and code is not a good short term or long term solution. Instead, please upload the material to a third-party repository.
“the fact that” is an awful construction that can be avoided by rephrasing. For instance:
“may reflect the fact that the differences”
“may reflect that the differences” |
Psychology Night Research Posters and Presentations
Faculty Sponsor, if applicable
Dr. Sandra Virtue
Project Abstract
In this study, we investigated how the cerebral hemispheres process puns during reading. Participants read puns and completed a lexical decision (i.e., word identification task) to word or nonword targets presented quickly in each visual field-hemisphere that either matched the literal or the figurative interpretation of a pun. For example, after reading the sentence “The inventor of the hay baling machine made a bundle,” participants were presented with either the target word “straw” (i.e., representing the literal interpretation of the pun) or the target word “dollars” (i.e., representing the figurative interpretation of the pun) in the right visual field—left hemisphere or left visual field—right hemisphere. We predict greater facilitation for target words related to both the figurative and literal interpretation of the pun in the right hemisphere compared to the left hemisphere. This pattern of results would suggest that the right hemisphere plays a unique role when individuals process puns during reading.
Type of Research
Doctoral-Undergraduate Opportunity for Scholarship (DUOS)
image preview |
Conceptual Questions in Computer Networks basedgate study material for computer science - Part1
gate 2018, computer network questions for gate cse 2018, computer science study material for gate 2018, study material for gate computer science,
Some Typical Questions in Computer Networks for GATE CSE Exam
Hello, friends today in this Computer Science Study Material for Gate I am going to discuss some conceptual questions in computer networks. Here are these questions and their answer.
Q1.How does address resolution is performed in Arp?
Answer: The table lookup approach to address resolution requires a data structure that contains information about address bindings. The table consists of an array. Each entry in the array contains a pair [P, H] where P is a protocol address and H is the equivalent hardware address. A separate address binding table is used for each physical network. Consequently, all IP addresses in a given table have the same prefix. For example, the following address binding table corresponds to a network with the class C number therefore, each IP address in the table will begin with 197.15.3 prefix. The chief advantage of this table lookup approach is that a table can store the address bindings for an arbitrary set of computers on a given network.
Q2: What are MIB variables?
Answer: MIB (Management Information Base ) variables: MIB is a set of named items that an SNMP agent understands. To monitor or control a remote computer, a manager must fetch or store values to MIB variables. Because SNMP does not specify a set of MIB variables, the design is flexible. The separation of communication protocol from the definition of the objects permits to define MIB variable as needed. there are MIB variables that correspond to protocols like UDP, TCP, IP, and ARP, as well as MIB variables for network hardware such as Ethernet. In addition to simple variables such as integers that correspond to counters, a MIB can include a variable that corresponds to a table or an array.
tricky questions in computer networks
Q3: How physical addressing is performed in WAN?
Answer: WAN networks operate similarly to a LAN. Each WAN technology defines the exact frame format a computer uses when sending and receiving data. Each computer connected to a WAN is assigned a physical address. When sending a frame to another computer, the sender must supply the destination’s address.
Many WANs use a hierarchical addressing scheme that makes forwarding more efficient.Hierarchical addressing scheme divides an address into multiple parts. The simplest scheme divides address into two parts; the first part identifies packet switch, and second part identifies computer
attached to that packet switch.
Q4: What is CIDR?
Answer: CIDR is a new addressing scheme for the internet which allows for more efficient allocation of IP addresses that old class A, B, and C addressing scheme. Instead of being limited to network identifier (or prefixes) of 8, 16, or 24 bits, CIDR currently uses prefixes anywhere from 13 to 27 bits. Thus, the block of addresses can be assigned to a network as small as 32 hosts or to those with 500,000 hosts. This allows for address assignments that much more closely fit an organization’s specific need.
A CIDR address includes the standard 32- bit address and also information on how many bits are used for the network prefix. For example in CIDR address, the /25 indicates that the first 25 bits are used to identify unique network leaving the remaining bits to identify the specific host.
Q5: Does it make sense for two domain servers to contain exactly the same set of names? Why or why not?
Answer: Yes. It is very advantageous for two domain servers containing the same set of names. If there is only one server than traffic on one server would be intolerable because it would be the only server to receive all the request and handle them appropriately. If there is more than one server containing the same set of data then geographically closet server will respond thus reducing the load on one server. Also if one server is down due to some problem then another server containing the same set of data can be used to fulfill the incoming requests.
I hope that this Study Material for gate Computer Science will be beneficial for computer science students. Later we will also discuss some other important questions in computer networks for gate cse exam.
addressing modes types,1,advance-java,2,advancejava,1,aktu entrance exam,1,aktu exam schedule,1,ASP,1,bare machine,1,base register and limit register,1,Basic Computer network questions,1,C Programming,15,C Plus Plus,1,C Programming,2,C Programming MCQ,2,C Programming Questions,2,C programming study material for gate exam,13,Cache Memory,1,CBNST Program,1,Childcare,1,CJ,2,Cloud Computing,1,COA GATE Questions,1,components of use case diagram,1,Computer Architecture,2,Computer architecture based questions for gate exam,11,Computer Network,3,Computer Network Study Material,4,Computer network study material for gate,2,Computer Networks,7,Computer Science Study Material for Gate,20,computer science study material for gate exam,36,content based image retrieval content based image retrieval system,1,contiguous memory allocation,2,Core Java,8,COre Java Interview Questions,1,core java interviews questions,1,cyber crime report,1,Cyber crime status,1,cybercrime and security,1,cybercrime examples,1,Data link Layer Questions,1,Data Mining,1,Data Structure Questions,1,Data Transmission Architecture,1,Data Transmission in wsn,1,DBMS,4,dbms question paper,1,DE,1,Digital Electronics,1,DS,1,dynamic linking,1,dynamic linking in memory management,1,Electroencephalogram,1,File Handling,1,file management in operating system notes,1,FOC,1,Fundamenatl of Computer,1,Gate 2017,5,Gate 2017 Admit card,1,Gate 2017 Exam Schedule,1,Gate 2017 Syllabus,1,gate 2018,1,gate cse study material,1,gate practice set,10,gate study material for computer science,18,Gate study material for computer science 2017,1,GatePreviousYear,1,General,3,HCL Aptitude Test,1,HR Interview Questions,1,HTML,1,Image Processing,1,Important Date of Gate 2017 Exam,1,Information Security Policy,1,internal and external fragmentation,1,JS,1,lagrange's interpolation formula,1,lagrange's interpolation formula examples,1,Looping in C,1,MComputing,1,memory fragmentation,1,memory management,1,memory management questions and answer in os,1,Motivational,4,NCER,2,Numerical Techniques Lab,1,OOT,1,Operating System,12,Operating System Gate Questions,1,Operating System Objective Questions,4,Operating System Questions Bank,1,Operating system questions for gate,1,Operating System Study material,2,operating system study material for gate exam,16,Operating system tutorial,2,page swapping,1,paged memory allocation,1,paged memory allocation in operating system,1,paging technique of memory management .paging technique,1,paging technique of memory management program in c,1,Pointer in C,5,Process based question for gate,1,Quiz on non conventional energy resources,1,Regression testing,1,relocation in memory management,1,relocation registe,1,relocation register,1,resident monitor,1,resident monitor in operating system,1,routing table,1,segmentation in memory management,1,segmentation in memory management in operating system,1,Servlet,1,session tracking,1,session tracking in java,1,session tracking in servlet,1,Software Engineering,10,Software Engineering baes study material for gate,1,software engineering interview questions,1,Software Quality Assurance,3,software verification methods,1,SPM,1,Structure in C,1,Study Material for gate Computer Science,11,swapping in memory management,1,swapping in operating system,1,TCS Code Vita,1,TCS Interview Questions,1,Technical Interview,1,Technical Questions from DBMS,1,Thrashing in Operating System,1,Threads concept in operating system,1,Tips to Learn Coding,1,Top 30 Core Java Interview Questions with Answer,2,top down approach,1,top down approach in programming,1,Types of operating system,1,UML,1,use case diagram explanation,1,website uses cookies,1,what is cookies website,1,What is process control block ?,1,what is software testing?,1,Wireless Sensor Network,3,worst fit algorithm for memory allocation,1,XML,1,
Computer Science Junction: Conceptual Questions in Computer Networks basedgate study material for computer science - Part1
Computer Science Junction |
What is placenta previa marginalis grade 2?
Placenta previa. Normally, the position of the placenta is near the top of the womb. In some cases however, the placenta stays in the lower portion (part) of the womb, and either partially or completely covers the cervix (neck of the womb). The described grading is when the placenta reaches the cervix, but doesn't cover it. |
A few weeks ago I was contacted by a journalist who is writing a story about relationships between first cousins. She was curious to get a genetic counsellor’s view on the issue. When two people have children together who are related, this is called consanguinity. This word comes from the Latin meaning from the same blood. In the Australian culture which heralds from the British Isles, marriage between first cousins is not common, is not encouraged and has a certain stigma surrounding it. However in other cultures, first cousin relationships are not only okay, they are actively encouraged. Having children with a relative like a cousin can even have advantages. “Keeping it in the family” so to speak. Families are already aware of what “they are getting into”. They understand the each other’s background and financial backgrounds.
However most people are cognizant of the fact that there can be a higher chance of having a child with an illness when one has children with a relative. This is due to what is known as recessive inheritance. Some conditions, such as Down syndrome, are linked to the mother’s age. The older the mother is at conception, the higher her chance of having a child with a chromosome problem. Dominant conditions can spontaneously occur, due to a fault or mutation in a gene in the egg or the sperm. The chance of this happening actually increases with the age of the father. However when two people are related, they have a higher chance of both being carriers of the same recessive condition. All of our genes come in pairs; one from each parent. With recessive genetic conditions, an affected person has two copies of the same gene that is not working properly. Their parents who have one working, and one non-working copy of the gene are known as carriers. Our relatives are more likely to be carriers of the same genetic conditions and this is why the rate of genetic conditions is higher in people who are born to first cousins.
What most people don’t realize though is that this risk still isn’t really high. The chance of any two unrelated people having a child with a medical problem is about 3%. When two people who are cousins have a child, their chance of having a child with a medical condition is doubled to 6%. So more than 90% of the time there are no problems. This is explained in more details in the fact sheet written by The Centre for Genetics Education, which I have shared the link below. Genetic counsellors are equipped with the knowledge and skills to help people who are seeking information regarding first cousin marriages. We provide this medical information in a non-judgmental way free from stigma. However consanguinity is not to be confused with incest, which is sexual relations between close relatives such as siblings or parents and children. This is illegal. Consanguinity isn’t something that a lot of people this a lot about. But people in consanguineous relationships often think about it a lot. There can be guilt and shame associated with the stigma. I hope knowing a bit more about this topic can help diminish this.
Fact sheet
Lift for Li Fraumeni syndrome #Lift4LFS
Last week I was lucky enough to attend a conference called the “Familial Aspects of Cancer Research + Practice”. This annual conference is arranged by the Kathleen Cunningham Foundation Consortium for Research into Familial Breast Cancer or kconfab for short. It is attended by scientists working in familial cancer from all over Australasia and the world and is also attended by genetic counsellors and doctors as well. There are presentations about many different aspects of cancer that runs through the family, but my favourite talk this year was by the Li Fraumeni association of Australasia.
Li Fraumeni syndrome (LFS) is a genetic condition where people with a gene change (mutation) in a gene called tp53 live with a high predisposition to developing cancer. People have a 50% chance of developing their first cancer by the age of 50 and up to a 100% chance of having cancer by the age of 80. LFS follows what is known as an autosomal dominant meaning that when a person with LFS has a child, there is a 50% or 1 in 2 chance of passing this changed gene on. The tp53 is often referred to as the “guardian” of the genome meaning that when there is a mistake or fault in this gene, it can have a devastating effect on the body.
The Li – Fraumeni Syndrome Association (LFSA) was created in the USA in 2010 as a way of providing and facilitating advocacy, support and information for those affected by LFS. The Australia and New Zealand chapter of the Li – Fraumeni Syndrome Association has recently launched. The mission of the LSFA is to bring together medical practitioners, researchers and scientists, patients and caregivers to further good research and care of individuals and families with LFS. Check out their video on youtube!
LFS video
Three Identical Strangers
Yesterday I went to see a movie called “Three Identical Strangers”. It’s the story of three identical male triplets separated at birth and reunited at the age of 19. As a genetic counsellor I often ponder the question of nature versus nurture and this movie investigates this theme superbly. Identical twins and triplets are born with the same genetic make-up. However when these type of siblings are reared apart, there is an argument that this informs or gives an indication to which traits or attributes have a strong genetic or hereditary component and which ones are more due to one’s environment.
Research tells us that the most rigorous experiments or studies are ones called “randomized control trials” where a group of participants are randomly assigned to being an active participant or being a control. In medicine we see this type of trial where a group of people with the same condition are randomly divided into receiving either a medication or treatment under investigation or they are given a placebo and are what are known as controls. However with adoption studies, because we have modern day ethic committees who oversee all research conducted, a researcher cannot randomly assign newborns to being either adopted or to stay with their birth parents so observational studies are performed. This is where people “assign” themselves and researchers observe differences.
In psychology, these types of studies were conducted to measure personality or behavioural traits such as extroversion and psychological disorders such as depression. I am often asked if conditions such as autism or depression are “genetic”. When people say “genetic” in this context, they mean is there a strong inherited link. Science is not at the stage where there is a simple genetic test for traits or conditions like depression or autism. In reality, like most things, there is a combination between genes and environment; we may be born with a predisposition however how we are brought up or what we are exposed to can greatly influence the development of these attributes.
People are amazed with how identical twins (either separated at birth or not) are similar. I feel that these similarities are encouraged and reinforced. Twins separated and reunited like seeing what they have in common. It reminds me of when people start a new romantic relationship, couples dwell in what they have in common. It is not usually until later do couples consider how they are different.
Isn’t it lovely that we as humans have influence on what we experience or how we are as people? Our personalities and our traits and what makes us, us are not set in stone. It can change. We can change. If we have three copies of chromosome 21 we will have Down syndrome or if we have two serious mutations in our CFTR gene we will have cystic fibrosis. However if both of our parents have schizophrenia, it does not mean that we will also have this illness. If many of our relatives are outgoing, it does not mean that our children will be too. Three Identical Strangers is a fantastic documentary combining the things that I love; genetics, psychology, the theme of nature versus nurture and ethics. If this sounds like your cup of tea, check it out!
Demystifying Genetics with John Conaghan
This podcast can be accessed via Apple iTunes Podcasts at5
or on Buzzsprout at
Welcome to a podcast all about Huntington disease (HD). Joining me in this podcast is Senior Social Worker John Conaghan. I love all my guests and love all of my conversations about demystifying genetics, however this podcast feels special. John is such a caring and empathic worker and his kindness shines through in this conversation.
Insight GenomicaWe discuss what Huntington disease is and how it affects people with the condition and also the affect it has on their families. John has a long history of working with people and families affected with HD. John was working before the gene for HD was discovered. We talk about what it was like when genetic testing for the HD gene became available. Before direct genetic testing was available, a less sophisticated test called “linkage” was available and John discusses the issues with this type of testing and the hope that came with direct genetic testing. The new hope is that of genetic therapies that may come.
Huntington disease is a dominant genetic condition characterized by a triad of:
• Cognitive impairment
• Involuntary movements / the lose of the ability to mobilise
• Personality change
Process of presymptomatic testing of unaffected people
HD is a progressive neurological condition with onset usually in midlife. We discuss the process of unaffected people go through when they would like to have testing to see if they have the gene change which will lead to them developing the condition. One of the worries that comes with predictive testing is the fear that people who find out they are gene positive is that they may choose to suicide. If someone tests positive they may choose a different course of actiions such as a different profession or course of study than if they tested negative. The way that presymptomatic testing is provided has relaxed or evolved over the years.
Issues that John and I discuss include:
• Self selection for those who present for HD testing and ego strength
• Grief within the family in relation to HD
• The concept of the loss of the health parent and a caring role
• Family dynamics
• Survivor guilt
• The role of genetic counselling in HD
• Patient focused genetic counselling & the genetic counselling alliance
• Self determination
HD factsheets
HD support groups
Reciprocal Translocations
A translocation is the term used to describe a rearrangement of chromosome material between two or more chromosomes. There are two main types of translocations; reciprocal and Robertsonian translocations. In this blog piece, I will discuss reciprocal translocations.
In each of our body cells (excluding our egg or sperm cells) inside the nucleus we have 23 pairs of chromosomes. They are numbered 1 to 22 in descending order of size and the remaining pair of chromosomes are our sex chromosomes; XX for females and XY for males. A reciprocal translocation is where part of one chromosome breaks and exchanges with part of another chromosome, which has also broken off. Said another way, two chromosomes break and these broken pieces swap and join back together. When no genetic material is lost, this is said to be a balanced reciprocal translocation. Reciprocal translocations can involve any of the chromosomes.
Carriers of a balanced reciprocal translocation may not even be aware that they are carrying a chromosomal anomaly. Depending on the location of the break, if no interruption of the genetic information in the DNA code occurs, a carrier of a balanced translocation will have no symptoms and will not affect their development or health. However occasionally where the chromosomes break, if this is in the middle of an important gene, for example, the person may have some associated health issues. Most translocations are spontaneous, meaning, they occurred in the egg or the sperm that went on to create a person. However sometimes translocations can be inherited.
Balanced reciprocal translocation carriers are at risk of having chromosomes in their eggs or sperm with genetic material gained or lost and this could result in a pregnancy that has an unbalanced reciprocal translocation. Having extra or missing bits of chromosome can cause a wide variety of health problems including mild to severe health problems and developmental delay.
If someone is at risk of being a carrier of a balanced reciprocal translocation, they can have a genetic test examining their chromosomes. This test is called a karyotype and the scientists in the laboratory will be able to see if and where a translocation has occurred. A more detailed chromosome test called a microarray may also be ordered to see exactly where the breakpoints are and to see if any genetic material has been added or lost.
When a partner in a couple has a balanced translocation they may experience infertility or recurrent miscarriages. In some cases it may be possible to have Non Invasive Prenatal Testing (NIPT), which is a blood test on the pregnant mother from 10 weeks gestation, to see if the pregnancy has a translocation. In some cases NIPT is not possible. If this is the case, an invasive test during the pregnancy such as a chorionic villus sampling (CVS) or amniocentesis may be performed to examine the baby’s chromosomes.
Couples presenting for genetic counselling due to a reciprocal translocation can be challenging from a psychosocial point of view as well. Having long periods of infertility or miscarriage after miscarriage can be very taxing on couples. IVF is one technique that couples can utilize to increase their chances of having a baby. Other options would include donor egg, sperm or embryos or adoption.
Genetic Counselling Melbourne - Blog Directory
What is Genetic Counselling?
What is Genetic Counselling?
As a genetic counsellor, “what is genetic counselling?” is the most common question I am asked. Most people are not aware of ever having met a genetic counsellor and do not know what genetic counselling is or what genetic counsellors do. Genetic counselling is a relatively new profession and there is quite a bit of controversy surrounding our professional name and whether it is the best description of what our role entails.
Genetic counselling is aimed at providing information and support to people who have or are at risk of genetic disorders. A genetic counsellor is a postgraduately trained health care professional who can identify your risk factors and provides clear information about the chances of being affected by a specific genetic condition. Usually when you have a health related question or concern you go and see a General Practitioner. If this issue is genetics related, you may be referred to see a genetic counsellor.
Genetic counsellors are health care professionals who integrate their knowledge on medical genetics, basic science and counselling theory with their skills in genetic risk assessment and communication to educate their clients on a diverse set of genomic or genetic indications. They help people to understand their genetic contributions to disease. These professionals are employed in diverse settings such as public hospitals, community health centres, IVF clinics, university research facilities and private medical centres. Genetic counsellor usually have an undergraduate degree in science, nursing, social work, teaching or psychology followed by a two years masters course in genetic counselling. Once qualified and practicing in the field, genetic counsellors usually undergo an accreditation process to become certified.
Genetic counsellors investigate the genetic history of your family, arrange for appropriate genetic testing, interpret the details about your disorder, evaluate the inheritance patterns and review the options available to treat your medical condition. They will also liaise with your general practitioner and other medical specialists in regards to your results.
Some common examples of when you may meet with a genetic counsellor include:
• You have undergone routine pregnancy screening tests and have received a high risk result
• You have a strong family history of a particular condition and would like information about your risks and about genetic testing
• You have just had a diagnosis of breast or ovarian cancer and your medical oncologist would like to know whether you have an inherited reason for your history of cancer
• You have a child with a recessive condition like cystic fibrosis and would like to discuss carrier testing and options for following pregnancies
It is a rewarding and fulfilling professional and I love doing my job. There is an international shortage of genetic counsellors so it might just be a great new vocation for you too.
Happy Friday
Matt Burgess
Consultant Genetic Counsellor
Genetic Condition – HFE – Hereditary Haemochromatosis
Genetic Condition – HFE – Hereditary Haemochromatosis
HFE – Hereditary Haemochromatosis is a common genetic condition in which sufferers have an abnormally high level of iron uptake into various organs in their body. It is an iron overload disorder. HFE – Hereditary Haemochromatosis was also known as Bronze diabetes in the past due to the colour that an affected person may turn without treatment. Early symptoms include weakness, fatigue, abdominal pain and weight loss. If left untreated, HFE – Hereditary Haemochromatosis can lead to skin discolouration, diabetes and heart problems.
Inheritance / genetic counselling
HFE – Hereditary Haemochromatosis follows an autosomal recessive pattern of inheritance. A personal affected with this condition has two faulty copies of their HFE gene; one inherited from their mother and the other from their father. If an affected person’s parents had one working copy of HFE and one copy with a mutation, they are referred to as being a carrier of HFE – Hereditary Haemochromatosis. A person with HFE – Hereditary Haemochromatosis can only pass on a faulty copy of the HFE gene meaning that all of their children will either be carriers if they inherit a working copy of the HFE gene from their other parent or at risk of developing the condition if they inherit a faulty copy of the HFE gene from each parent. Siblings of a person with HFE – Hereditary Haemochromatosis usually have a 25% risk of also having the condition, however if their parent also has the condition then 50% of their children are at risk.
Molecular genetics
This condition is due to a mutation in the HFE gene, which is located on the short arm of chromosome 6 at location 6p22.2. A gene is made of DNA and DNA is made of four chemicals referred to as bases (A, G, C & T). These bases combine together in a pattern to code for one of 20 amino acids. Amino acids strung together form a protein. There are three common mutations in the HFE gene; C282Y, H63D and S65C.
About 60 – 90% of people with two copies of the C282Y mutation will develop iron overload in their lifetime, whereas only about 5% of people with a C282Y and H63D combination will develop the condition. About 1% of people with two copies of H63D will go onto having iron overload.
HFE – Hereditary Haemochromatosis is the most common genetic condition in Australia and one of the most common genetic conditions in Caucasians. HFE – Hereditary Haemochromatosis is uncommon in people with African and Asian decent. HFE – Hereditary Haemochromatosis is more common in men than women.
The most common treatment for HFE – Hereditary Haemochromatosis is blood letting to reduce iron levels in the blood.
Differential diagnoses
Not everyone with iron overload will have HFE – Hereditary Haemochromatosis. Other types of Hereditary Haemochromotosis include Juvenile hereditary haemochromotosis (also known as hereditary haemochromotosis type 2) and TFR2 – Hereditary Haemochromatosis.
Happy Australia Day
Happy Australia Day! Today is the 26th January and is a national public holiday in Australia. Australia day commemorates the arrival of the British colonizers, along with many convicts, into Australia in 1788. Unfortunately the day is having an increasing negative connotation associated with it. Some refer to today as Invasion Day and there are discussions about whether our national day should be changed to another day. It was heartwarming to hear in a recent survey that the majority of Australians want to celebrate a national day and they don’t mind which day the holiday falls on. I feel the same way. I do like the idea around having our national day on May 8 (Mate Day); that really would be quintessentially Australian. However I do like celebrating our national holiday in summer.
I feel very lucky to have been born here and to have grown up in this great country. It made me laugh this morning when my partner put on an Aussie playlist on Spotify and listened to classics such as “We Come From A Land Downunder” and “You’re the Voice” while eating our crumpets for breakfast. This led me to think about what it means to be Australian. Australia is a multicultural country. We have people either born from, or have links to, many nations from around the world in our nation, many of which are represented here in Melbourne. My parents live in Newcastle, which is a much smaller city in Australia. When they came to visit a year or two ago I took on a personal challenge, without telling them, of eating a different cuisine every meal. We had Aussie classics like a good old-fashioned Aussie BBQ, I took them for yum cha for brunch and we had Vietnamese Bahn Mi’s for lunch. We had North African for dinner one night and on another I took them to my favourite Italian Australian Asian fusion restaurant, Franco Choos, for dinner.
As a genetic counsellor and someone who is passionate about genetics, I have been accused of relating everything back to genetics. Australia is a nation with a diverse cultural mix with people living here with vast ethnic backgrounds. But this also means that we have a mixture of genetic makeups from around the world. One way of taking a look at this makeup is through ancestry testing. I am half Zambian and half Caucasian Australian. Like many people who undergo ancestry testing, I was a little surprised with my results. As expected, about half of my makeup is African. However a large component is Scandinavian. This surprised me as I expected the remaining genetic mix to be from the British Isles. It just makes me want to go to Scandinavia even more. The ancestry test offered by my company Insight Genomica is a little different from many on the market. Most of the ancestry products break ancestry down into several broad groups whereas ours is much more defined. It was developed by a university academic population geneticist with over 800 reference populations and 36 different gene pools. So if finding out more about your ethnic background or ancestry appeals to you, feel free to get in touch.
Happy Friday!
Matt Burgess, Consultant Genetic Counsellor
New Year Resolutions
Hello and Happy New Year! I am lucky enough to be writing this first blog post of the year from sunny Byron Bay in Northern New South Wales, Australia. I’m away on vacation with my partner for some summer fun in the sun and some much-needed relaxation time after a busy and happy 2017. As I sit here contemplating 2017 and envisioning 2018, like most of you, I think about the New Years resolutions that I have made.
Continue reading “New Year Resolutions” |
skip to main content
How Caribbean music has influenced other cultures
How Caribbean music has influenced other cultures
One of the Caribbean’s greatest exports to the rest of the world has been its music, which is a wonderful blend of styles from the descendants of Indigenous Caribbeans, African slaves and European and Indian settlers.
Whether it’s reggae, salsa, dancehall or calypso, the music of the Caribbean has gained worldwide popularity and had a noticeable impact on many other cultures.
Here’s a quick look at how the music of the Caribbean has influenced the rest of the world.
United Kingdom
The 50s and 60s saw waves of Caribbean immigrants arriving on British shores, with large communities forming, primarily in port cities such as London and Liverpool.
It was in these places, predominantly working-class areas such as Tottenham and Brixton, with large Jamaican populations, where the likes of reggae and ska started to make their way into the British consciousness.
More specifically, a ‘sound system culture’ started to surface, where huge stacks of speakers would be set up to provide the Caribbean soundtracks to local street parties.
While much of Britain initially distanced itself from its new Caribbean neighbours and their culture, one subculture welcomed them: the skinheads.
Skinheads were generally working-class youths, who found that they actually had more in common with Caribbean immigrants than they did with the British upper and middle classes and the two groups bonded over a mutual love of ska music (amongst other things).
While the skinhead culture was unfortunately hijacked by racist groups in later years, it was one of the first examples of British culture embracing Caribbean music.
By the 1970s, reggae started to influence a more unlikely group of artists; the new punk bands such as The Clash and The Sex Pistols.
Whether it was the basslines, anti-establishment stance (or perhaps that they both enjoyed a bit of recreational drug taking!), the two clashing styles became unlikely bedfellows, with the most notable example being The Clash’s Guns of Brixton, which spoke of the lives of young Caribbean youths in the area at the time.
The Mainstream
In time, more mainstream pop and rock songs came to embrace Caribbean music too, such as Roxanne by The Police, Eric Clapton’s cover of I Shot the Sherriff by Bob Marley and Do You Really Want to Hurt Me by Culture Club, to name a few!
Jumping forward to the modern day, Caribbean music styles such as reggae, dub and dancehall can all be seen in modern electronic music, with the likes of jungle, drum and bass, dubstep and trip-hop all owing a lot to the Caribbean.
Hip Hop
Over in the US, Caribbean music’s influence has most notably been felt in the creation of one of the world’s most popular genres of today: hip hop.
Like in the UK, many Caribbean immigrants arrived around the 50s and 60s, and again they settled in the port cities, predominantly the South Bronx in New York City.
These new arrivals took the Caribbean style of ‘toasting’ (talking/chanting over a rhythm or beat) and began to rap over beats which eventually became hip hop as we know it today, and many of the world’s most famous rappers came from Caribbean backgrounds, such as The Notorious B.I.G. (Jamaica) and Grandmaster Flash, who was born right here in Barbados.
This documentary from Complex explores the impact of the Caribbean in a bit more depth if you want to find out more.
As you can see, the music of the Caribbean has spread much further than this chain of islands, influencing the modern music landscape in a massive way!
Whether you’re a music lover or not, music is an important part of island life here in Barbados, and with a trip to Royal Westmoreland, you’re sure to find yourself swaying to the beat of the Caribbean sounds!
|
Expository Essay: Just How To Write Like an expert?
Textbooks, news, magazine articles, or any kinds of magazines are examples of expository writing. These are articles that focus on presenting information that is factual being objective. Expository essays are often written from a point that is third-person of.
Nonetheless, the utilization of the first-person perspective could also be used with respect to the guidelines or circumstances given.
The primary objective with this essay would be to provide information. Like most other essays, each paragraph is organized into three parts. They are the subject sentence, supporting sentences, and concluding the phrase. There are numerous kinds of expository essays and techniques obtainable in writing these kind of piece.
In this guide, you will see simple tips to find the appropriate framework and use the various approaches to composing an essay that is expository.
Choose the subject
In picking the theme of one’s essay, you must think about your audience. Identify their interests and choose the topic that is appropriate them.
This task shall help you figure out the content and also the certain topic that will differ with respect to the audience that is intended. This may additionally allow you to filter and select the information that is different’ll compose in your essay.
Choose the appropriate structure of the essay
You will find three main forms of expository essays you might pick from on the basis of the topic you’ve got chosen.
First could be the type that is informative of. That is utilized in explaining an ongoing process, describing a category, or providing a definition that is long of that is complicated.
Another kind you could utilize could be the compare-contrast approach where two things may be compared. The differences claimed can be huge or little, according to your aims.
Finally, you are able to work with a cause and impact format in your essay. This is utilized to explain why the action of just one thing contributes to a result that is specific.
Create a plan
An overview would allow you to prepare the flow that is whole of essay. Choose the topic sentence you will speak about in most paragraph and specify the different supporting subjects that will support your theme. This outline could also be helpful you concentrate on the topic of one’s essay all through the entire process and prevent you from incorporating unneeded information.
Research your facts
Once you’ve your outline, researching in regards to the subjects you selected can be achieved. Search through several printed materials and sources that are internet find content for your essay.
Provide factual and information that is objective reliable sources. Count on trustworthy sources and make certain to cite them. Most of the sources needs to be seen to avoid plagiarism. Doing this research will provide step-by-step and reliable information that you can make use of to develop your essay.
Develop a draft
Your draft must are the introduction, body http://www.custom-writings.net, and summary. Follow your outline and verify that the given information you provide is factual and objective. Citing sources can help establish credibility also that may improve the content of one’s essay.
Notice the use of transitional words to simply help your readers stick to the a few ideas presented in your essay. Making use of the 3rd individual point of view (he, she, and something) is most regularly utilized for expository writing or virtually any sort of writing that includes a business-minded or persuasive aim or purpose.
Read the draft
Finally, go through the essay to enhance your projects. Verify the grammar, spelling, and phrase structures through the entire paper that is whole. Mark all mistakes and fix them. Evaluate your piece considering most of the information you supplied.
Compare it along with your outline to make it concise and ensure your essay has a flow. Requesting comments and feedback from a buddy or an expert will help in the also improvement of one’s essay.
Once you’ve checked every thing and also you feel quite happy with the last output, now you can submit it to your professor. |
Stone sculpture and portrayal of women
By Nyasha Chabururuka
ONE of the most recurrent themes since the inception of Shona stone sculpture half a century ago has been the portrayal of women in the revered art form. No doubt, Shona stone sculpture has been used as a communication tool addressing gender concerns through its portrayal of human images. Feminists argue that women are defined as minors throughout their lives, answerable first to their fathers and brothers when they are young and to their husbands and brothers-in-law when they are married. In his unpublished thesis, Joseph Mandizvidza acknowledged that this was a result of years of misinformation that the woman is the inferior ‘other’ who has to be given direction upon every turn by a man. The mainstream media, particularly television, radio and print media, have often portrayed women as mothers and care-givers on one extreme end while the other depicts them as a witches and homewreckers. However, sculpture connoisseur Celia Winter-Irving says Shona stone sculpture stepped in to check the balance by presenting women as equal to their male counterparts, catapulting the local art work to the apex of international art rankings among the very best in the world of art. First Generation sculptors have often been accused of perpetuating the stereotype of women as sex objects, a trend that has been watered down by younger sculptors who now present women as equals to their male counterparts. A number of prominent sculptors have hogged the limelight with claims that their sculptures are gender sensitive as they endeavour to shoot down the negative portrayal of women in the mainstream media. Winter-Irving once noted: “Stone sculpture is a powerful medium that communicates and speaks louder than the words of poet, writer and singer … A way to study women and who they have actually become is through stone sculpture … Gender distinctions are no longer valid in terms of who is expected to do what and go where.” Although most artistes live and work in Zimbabwe, come from patriarchal families, are Shona, and indigenous to Zimbabwe, they had a developed knowledge of the traditional beliefs from their parent cultures. First Generation sculptors have often come under fire from critics who argue that they carved sculptures that promoted patriarchy as men were depicted as the ‘head of the family’ and were given other superior roles and positions. Such themes were given much prominence with most of the renowned sculptors like Joram Mariga carving pieces titled ‘Family Protector’ and ‘Head of the Family’, among others. They carved a face or strong image of a man standing behind small figures which resembled the children and their mother. Critics argue that this was (and still is) done by including symbols of authority and masculinity in most depictions of men. Of the younger artistes, Dominic Benhura has a piece titled ‘Pleading’, which shows a kneeling woman with hands raised towards the face of a man who is raising a stick, as if she is praying. McFadden (1992) argues that in today’s media, images of women are mainly used to sell market products. Benhura concurs with this argument, contending that sculptors use nude women bodies to sell their artistic talents. Most sculpted images of churned out by male sculptors are of women’s bodies, either nude or as objects of beauty. Women, on the other hand have argued that women’s bodies depicted in sculpture should not expose women’s bodies as that makes them feel ‘undressed’. Former National Gallery of Zimbabwe director Doris Kamupira (2006) pointed out that women complained during exhibitions about images associated with them. Said Kamupira: “Women often complain about the nude images, they bitterly state that sculptors provoke their minds as they even go on to expose the most sensitive reproductive parts of a woman, while some are accused of creating humour out of the woman body.” Many of the new generation sculptors portray women as nurturers, mothers, care-givers, men’s source of entertainment, weak, beggars and rightful bearers of all burdens that affect the family. Anderson Mukomberanwa’s piece ‘Pondering Woman’, which shows a naked woman with pronounced sexual parts has often been castigated for exposing women’s reproductive parts such as breasts and genitals. A piece like ‘Mama Africa’ by Walter Ndundu has been championed for depicting breasts as a sign of life, food and support to all people as mother’s milk is the primary food source for every new-born baby. Some argue that the breasts suggest fertility, meaning the fruitfulness of the continent and also the bounteousness of food in Africa. There are various themes that sprout from stone sculpture, and most sculptors concentrate on more or less the same themes, but deal differently with them. One recurrent theme in Shona stone sculpture is ‘mother and child’. Some portray the mother as the pillar of strength for the child, while others depict the mother suffering in her bid to raise her child. Sculptures from Benhura elucidate pride in the woman figure by showing mothers playing with their children such as the piece ‘Swing Me Mama’. There are other artists whose pieces trace the powerful traditional African roles of women as spirit mediums. These include pieces such as ‘Mbuya Nehanda’ by Agnes Nhanhongo sculpted in 1987, ‘Spiritual Woman’ by Lazarus Takawira, and ‘Mystical Mermaid’ carved by Letwin Mugavazi. Hence Shona stone sculpture is one medium that is actively empowering women, with a few exceptions where women are labelled as a ‘witch’ or ‘widow’ which give negative connotations about the woman’s image. The different interpretations in the symbol of the woman figure reveals that people do not view the images through one eye. Some women applaud sculptures depicting naked women figures saying they celebrate the beauty of an African woman, who has accentuated curves and a voluptuous bust and backside.
Please enter your comment!
Please enter your name here |
The science of liquorice: whether you love the dark root – or hate it
By Simon Cotton - University of Birmingham
Decisions, decisions, decisions - Image Credit: J. Schulpen/T. Branches
There are foods that can split families, or even just couples. Love it or hate it foods. Marmite (and the Antipodean alternative, Vegemite) is one. Then there’s Brussels sprouts, blue cheese, chilli peppers, coriander (cilantro), tomatoes (especially the cooked variety) … and liquorice.
Personally, I’ve always liked liquorice, but there are others who feel very differently about it. There are known to be genetic reasons behind a dislike of some foods such as Brussels sprouts or coriander but no one has established this for liquorice.
Liquorice has a long history; the root of the plant Glycyrrhiza glabral has been used medicinally for over 4,000 years.
Liquorice has anti-inflammatory, antibacterial and antiviral properties and has been used, notably in traditional Chinese medicine, for the treatment of gastric ulcers and liver disorders, such as hepatitis B.
Among its less beneficial effects on the body is raised blood pressure, caused by the glycyrrhizic acid it contains, if you eat too much. Through its interaction with the hormone aldosterone, it causes reabsorption of sodium and excretion of potassium, resulting in an increase in sodium levels and a decrease in potassium levels – one symptom of which is muscular weakness. And pregnant women have been advised to avoid it because it pushes up levels of cortisol, the stress hormone. A study just published upon which this advice is based, drew on several hundred children born in Finland in 1998. They found that mothers who ate more liquorice (salmiak, liquorice with added ammonium chloride) gave birth to children who were more likely to have lower IQs and to suffer from ADHD.
Liquorice root - Image Credit: gokalpiscan/Pixabay CC0 1.0
Sweet smell of success
We more usually think of liquorice in confectionery, where an extract of raw liquorice is heated up with other ingredients such as flour, treacle, flavourings and colourings to produce a sweet, thickened product. In Britain, it is closely associated with the Yorkshire town of Pontefract, where it was first grown nearly 1,000 years ago after it was brought to Britain from the Middle East. In 1760, an apothecary named Charles Dunhill first produced “Pontefract cakes”, flat, circular sweets. Dark salty liquorice is hugely popular in northern European countries such as Holland and Sweden.
Liquorice is used as a flavouring in substances as diverse as tea and tobacco, and in drinks like the Egyptian erk sous and the French pastis. The sweetness of liquorice is principally due to the glycyrrhizin (or glycyrrhizic acid), which is around 40 times sweeter than sucrose (table sugar).
The aromas of raw liquorice and heat-processed liquorice are due to a blend of chemicals, recently identified by a research group in Munich, led by Peter Schieberle, a distinguished flavour scientist.
The team achieved this by first separating the complex mixtures of chemicals present in the liquorice, and then identifying each one by spectroscopic techniques. Aroma experts then examined each compound to find which of the molecules present actually contributed towards it (around 50). Finally, they reconstituted a mixture of these molecules, each present at its “natural” concentration, to see if the mixture had the characteristic liquorice smell (it did).
So there is no single molecule which has a liquorice smell by itself; what we smell is a blend of odours from all these molecules, which our brain “integrates”. The molecules anethole (also found in aniseed, fennel and star anise) and estragole (also found in tarragon) supply an “aniseed” note, but there are many other important compounds that contribute, including 1,8-cineole eucalyptus, 2-acetyl-1-pyrroline, responsible for the “popcorn” note of many cereal products like bread and rice, and a number of aldehydes such as (E,Z)-2,6-nonadienal (found in cucumbers).
The heat-processed liquorice extract has many molecules in common with raw liquorice, but some are unique to it like maltol, which contributes a caramel note, and 3-hydroxy-4,5-dimethylfuran-2(5H)-one (sotolone), also with a caramel note at low concentrations and which is responsible for the flavour of raw cane sugar.
Many of the extra molecules are generated in the heating process from reactions, such as those between sugars and amino acids present in the raw liquorice root.
So enjoy your liquorice – if you do. Just don’t overdo it.
Source: The Conversation |
Why light at night should become a conservation issue
Feb 8
Written by:
2/8/2015 9:03 PM RssIcon
Very often those who are avid bird watchers know something about light at night (LAN) because lights from buildings at night confuse migratory birds, and can lead to many bird deaths from crashes and exhaustion. Those who help the turtles along certain beaches also understand light pollution, as baby turtles look to the light reflecting off the sea to know which way to go. Light pollution causes them to go the wrong way.
Educating a wider audience
But many conservationists, even those who think of themselves as friends of nature but not necessarily activists, are almost entirely unaware of LAN issues. I discovered this when I noticed that Big Agnes introduced a line of tents with electric lighting built into it, and detailed some reasons why that can be detrimental to human health in an online forum.
Let's just say that much of the reception to me not thinking these tents were a good idea was met with a less than welcome reception from many. Yes, I realize there are many ways to light a tent - flashlights, lanterns, phones, etc. But often when provided with more light, people tend to use it. Plus, integrated lighting is harder to filter out than that of a flashlight or even battery-powered lantern.
That's not to say there weren't those who agreed with me; there were. Mostly they also knew about astronomy though. So let's begin there, this being an astronomy website blog.
Red light, white light
Amateur astronomers know that red light preserves dark adaptation. When we are looking for some 'faint fuzzy' at the eyepiece of our telescope, the more dark adapted we are, the more we see. But to find those objects in the first place, a star chart is required. Before tablets, smartphones and laptops, a paper chart or book was the way to find those objects. A way to see those was needed. A red-tape or cellophane covered flashlight (the dimmer, the better), helped to preserve dark adaptation.
The quickest way to ruin it? White light.
But here's the thing: Not all white light is created equal. Oh sure, for ruining dark adaptation, any old white light will do. Let's go back in time a few centuries though.
Fire and light
Before the invention of the electric light, how did we humans get by and manage after dark? Even under a completely moonless sky, the human eye can still see; it is amazingly sensitive to light even 1 millionth that of the full Sun. But that doesn't mean we feel particularly safe or see well at those levels; however, with a waxing/waning gibbous Moon up to a full Moon, humans see remarkably well - even with a bit of color. But to see even better than moonlight, we had one other option available:
Campfire, candles, whale oil lamps, torches, you name it, and they all pretty much had one thing in common: They were yellow/orange/red in color. While the Moon produced white light, at maximum, it's only 1 lux of light - not enough to harm sleep.
But that all changed when we added artificial light at night to our after-sunset environment. Not only was there more light, as we advanced, the type of light changed. A few incandescents didn't alter much; they were relatively dim, and are heavily skewed towards warmer colors like fire. But then they got brighter, and we added streetlights, like mercury vapor and high pressure sodium. Today, LED's are being introduced, and with little study on their effects on not only humans, but the wider environment. And those have a bigger problem: LED's have a lot of blue in their light.
Color of light matters to sleep
See, during the day, even on cloudy days, we get a lot of blue wavelengths of light. The photosensitive cells in our retina called melanopsin are sensitive to blue light - specifically, the 440nm to 460nm range - and turn off all our "sleep" physiology, and tell our brain to turn on the "wake up" physiological processes.
And it doesn't take much blue light to do this - 1 lux of blue light can suppress melatonin, the key hormone required for sleeping well. Some people can sleep without it, but most won't get as good of sleep without it. Increasingly, researchers are also finding links to obesity, diabetes, breast and prostate cancers from this reduced melatonin. And why is melatonin reduced?
Blue light. It turns off your "go to sleep" switches. It's the "wake up" color of light for humans. It doesn't matter that you're not seeing a blue sky - ANY blue wavelengths will do the trick. And what is rich in blue light?
LED lights, specifically, the high intensity ones. That is, all the ones in the following:
• Computer screens
• Smartphone screens
• Tablet screens
• HD televisions
Plus, every LED light that has that "icy-cold" look to it? Hi intensity LED. Flashlight? Hi intensity LED. Those headlights you hate to see coming because they hurt and look purplish? Hi intensity LED's. All the same thing. Lots of blue, and your eyes tell your brain, "Stay awake!"
There's no curtains or blindfolds in nature
How does this affect anything with respect to camping? I know - this is a long story to get here, but it's worth understanding. Light matters too. Many who complain about light streaming into their bedrooms at night and can't sleep are told, "Buy light block curtains!" or "Put on a blindfold sleeping mask."
Easy to say if you're a human. But how are animals supposed to do that?
We know there are detrimental effects of LAN that affects more than the sky. Bats find more insects near lights, which have both altered their feeding due to the light being present. We've learned of spiders who have done the same. But what about about the nocturnal creatures who are avoiding the light, trying to stay away from it? They've been affected too.
Be a good house guest
If we really want to "Leave no trace" shouldn't we be using less light - or at least, a lot less of the light that affects animals when we are out in THEIR home, the Great Outdoors? If we really call ourselves conservationists, why are we putting a creature-comfort of lighting into a tent, where we should be trying to sleep at night, of which that light is known to suppress melatonin and harm our ability to sleep well?
We need to be thinking about more than just ourselves. I'm not saying that we can't enjoy the great outdoors at night, and that so doing requires us to turn off every piece of illumination. We can use some artificial illumination. But we need to be respectful of our environment. We know not to feed the raccoons because it alters their behavior in negative ways. We know to use bear canisters in bear country, because it keeps from altering their behavior that can wind up being detrimental to humans from interactions with bears.
So shouldn't we be more respectful of our non-human hosts when camping? Shouldn't we offer up less light, more 'naturally-colored' light such as that from fire, or at the very least, illumination levels that are at the level of the full Moon, or less?
What to do?
Use a red light, preferably a dim one, but at least use red as much as possible. Or if you're in a spot where you can, use a campfire. If you must use white light, keep it on for only as long as you need it, then turn it off in favor of a red one. We're the house guests in nature; don't be a bad one by blinding the hosts with blue-rich LED's. That's artificially altering their environment, just like leaving food out and changing their behavior.
I can't think of a better way to respect nature than to allow it to remain as close to natural as possible. And the side benefit of all this? We see more stars, too. And that's preserving a huge natural resource that's right over our heads, which everyone can then enjoy.
Your name:
Gravatar Preview
Your email:
(Optional) Email used only to show Gravatar.
Your website:
Security Code
Enter the code shown above in the box below
Add Comment Cancel
The Nightlight
|
Sunday, June 17, 2018
In this Sutra there is mention of unit of Time . We call it KSHANA. OR MOMENT . .This moment was preceded by another Moment and then next one will follow . So there is series of moments and the Flow of Time continues. There is no beginning or end to it. So the time is made up of many moments. Like anything in this world is made of atomic and subatomic particles - time is made of smallest possible units , called KSHANA. In quantum theory , the smallest unit of time is Planck time .
The time that a photon will take to travel Plank distance . In Hindu religion , we have gradually increasing units of time as followes-KSHANA, followed by PAL , followed by GHATIKA,then AHORATRA then PAKSHA, MAS ,RHUTU, FOLLOWED by AYAN, SAUWATSAR,YUGA AND MANWANTAR AND THEN KALPA.How is KSHANA determined or measured? In VYASBHASHY it is mentioned that the time that it takes for subatomic particle to go from 'previous 'position to 'next position ' is called KSHANA. So even at that time the idea of atom and subatomic particles was there and it was 'known' that the subatomic particles are in motion and not still . That is why the THINGS always CHANGE . So the change is all the time happening .
The second part of the change is to know in detail as to what happens to 'things' when we can not 'observe' any change superficially. The food that we eat has 3 parts , one with Tamasic Guna , becomes -gets excreted , then part of the food that has Rajasic Guna becomes Flesh , and the Satwic part of the food becomes the Mind . So when we eat predominantly Satwic food , our mind is calk , when we eat predominantly Rajasic food we are full of energy and action and the Tamasic predominant food leads to laziness . The water that we drink also is similar in effect . Tamasic part becomes urine and the Rajasic part becomes blood and the Satwic part becomes PRAN , This is the Knowledge that can not be achieved by GROSS observation . Simple example may be how a child understands steps in a stair case and how an adult knows them . The child does not know exactly how many steps are there or that they are they are narrow or not . The adult knows as to the number of steps and the nature . When we have done the concentration on the 'CHANGE IN THING FROM ONE MOMENT OR KSHANA TO OTHER MOMENT OR KSHANA 'we can Know it .Since this Knowledge is at the level of CHITTA , which is different that the SPIRIT or Purusha-this is different than the PURUSHKHYATI that was described in Sutra 49.
No comments:
Post a Comment |
Skip to navigation | Skip to content
Big data is watching you
Electronic spy
Friend or foe? Technologies like sensor networks enable us to gather enormous volumes of data at prodigious speeds and often in complex forms (Source: nevarpp/iStockphoto)
Data!data!data!" he cried impatiently. "I can't make bricks without clay." So said Sherlock Holmes in The Adventure of the Copper Beeches.
He may have found a latter-day ally in Attorney-General George Brandis, who is seeking to force telcos to keep data on your telephone calls and internet usage for up to two years, for the potential use of law enforcement agencies.
Technically we now have the ability to do what the Attorney-General wants. It's been made possible by the tsunami we call 'big data'. But is this revolution a friend or foe?
Data is the lifeblood of research and more recently it has gained similar importance for business and industry.
Technologies like sensor networks enable us to gather enormous volumes of data at prodigious speeds and often in complex forms. Where research data was once a set of meticulously measured points, for example in an agricultural experiment, it now might be a sequence of images or a video being captured in real time.
Big data represents a complete break with the way data was collected and interpreted. That methodology was developed early in the 20th century by Sir Ronald Fisher and his colleagues at the Rothamsted Agricultural Station. They developed sophisticated ways of collecting data to ensure systematic biases were removed in properly designed experiments. These statistical ideas and tools dominated the experimental programs of many disciplines for the best part of a century.
All measurements are subject to uncertainty, or experimental error. Data collection was an expensive business and the tools that were developed allowed experimenters to design their experiments in ways that ensured the data were collected efficiently and could be interpreted to take account of the uncertainty.
The change to the world of big data leads to new possibilities in research and industrial applications. For example, a quality inspector monitoring the performance of a manufacturing line of non-woven fabric would, until fairly recently, have had to stop the line and snip bits out to measure things like tensile strength and porosity. Now a camera positioned over the line can capture a continuous video image where these key parameters can be extracted by real-time algorithms from the video data. Instead of a small number of data values to assess the quality of a manufactured roll of fibre there is a 'big data' set of enormous richness and value with far greater interpretative power.
Similarly, a chain of supermarkets captures data in real time at every checkout at every store in its network. The data being generated in this fashion is potentially of immense value to the parent company. What is being sold in Marrickville versus St Ives versus Parramatta? What is the company going to source from its suppliers to meet the demand? How does it manage to get the right goods to the right customers at the right time?
This process of extracting information from these very large data sets is often referred to as 'data mining'. It's all about extracting valuable ore (information) from dross.
Furthermore, these procedures are being seen as giving companies a major advantage in targeting the needs of its customers. A recent headline in the Sydney Morning Herald ran: 'Banks Narev eyes massive opportunity CBA mines big data to stay competitive'.
The driver here is the desire to get inside the heads of its customers. So is it paying off?
Over 10 years, banking customers' satisfaction with their banks has reportedly risen, with the satisfaction of CBA customers rising from less than 65 per cent to 85 per cent over that period. Much of the rise is attributed to the availability of apps to assist with many once cumbersome banking processes. At the same time, these apps allow banks to monitor customer data and tailor products to their needs.
Information service providers like Amazon and Google rely on sophisticated algorithms to extract patterns from big data and come up with, for example, annoyingly accurate predictions of books, DVDs etc that we might like based on our past purchases.
The payoffs for companies making the most effective use of big data to inform key business decisions mean that companies not embracing the big data revolution may well be setting themselves up for failure.
But it's not just big corporations that are benefiting from this revolution. Our ability to capture and interpret massive data sets has major potential benefits in health, the environment, traffic management and broadly across many areas of scientific research.
In medicine for example, a new discipline called bioinformatics lets researchers trawl through increasingly tractable maps of the human genome to identify patterns associated with particular gene configurations and disease patterns. Identifying adverse patterns in so-called biomarkers will enable medical practitioners to predict the onset of diseases much earlier and establish counter-measures to prevent their occurrence.
So in fact, big data may just save your life!
^ to top
Downside of big data
But interpreting and using big data has its problems. There is so much of it for a start and the rigorous statistical methods that could be used to interpret data from designed experiments have not really kept up with the data tsunami.
The result is that it is perfectly possible to generate specious results from the analysis of big data, like when Amazon suggests (as a result of some mystical association) that you might be interested in a book in which you don't have the vaguest interest.
That's not really a problem until such spurious associations lead to inappropriate medical diagnoses or credit restrictions, for example. Or when an algorithm wrongly associates your telephone or internet usage with terrorism.
The use of big data puts the onus on its promoters to carefully explain the purpose and process of such data capture and the uses to which it will be put.
There is much still to be learned about the capture, storage, retrieval and interpretation of big data.
We don't really understand how to deal with uncertainty in these huge data sets despite the advances in 'machine learning' algorithms used in data mining. This means we need a new statistical revolution to support their interpretation.
Without it we will never be quite sure we can trust and control the outcomes.
About the author:Dr Ron Sandland AM is a statistician. He became deputy chief executive of CSIRO in 1999 and was awarded the CSIRO Medal for Lifetime Achievement in 2006. He was president of the Statistical Society of Australia from 1993 to 1995 and awarded honorary life membership in 1998. He is currently chair of the Australian Mathematical Sciences Institute Board, the Steering Committee of the Australian National Data Service, and the Advisory Board of the Australian Centre of Excellence in Risk Analysis. He was awarded the Order of Australia in 2007.
Tags: science-and-technology, mathematics
^ to top
Published 17 September 2014 |
When we’re finishing up a delicious home cooked meal, we often take our plates over to the bin and scrape away the leftovers without giving it a moment’s thought. If it’s not enough to warrant another serving, why keep it? This casual disposal of leftover is common throughout the UK and countless other countries, but what impact might this small act be having on the problem of global food waste?
The figures above aren’t just alarming, they’re astronomical. Throwing away food is something that we all do subconsciously every day, and while we can take steps to shop more responsibly and cook smaller portions, a little bit of waste at the end of the day is almost inescapable at times – particularly if you’re cooking for a big family. What you can control, however, is how that waste is managed. Imagine the good you could do with just a small change to how you disposed of your leftovers…
Now, picture how easy it would be to make a difference directly from your home. It would mean less waste to take to landfill, and you’ll have an odour-free, hygienically clean kitchen without worrying about yesterday evening’s leftovers sitting in your bin. We simply need to think differently about the amount of waste we produce, and how to better manage it from day-to-day.
This is already starting to become an easier process with the emergence of apps who are tackling food waste from the suppliers side of things, as they can now buy and sell excess produce.
Around the world, dozens of apps are directing perfectly good food away from bins and into rumbling stomachs. From redistributing leftovers to poorer communities in LEDC’s to luring Dutch shoppers into supermarkets to buy lingering produce, app designers are finding ways to stem the flow of food to landfill. Here’s why you should consider jumping on the band wagon:
Global Food Waste: The Numbers Behind the Problem
Infographic Source: Insinkerator
No related content found. |
Previous 出谷纪:Chapter 16 Next
出谷纪 Exodus
1以色列子民全会众从厄林起程，来到厄林和西乃之间的欣旷野，时在离埃及后第二月第十五日。1The Israelites left Elim and the entire community reached the desert of Sin, between Elim and Sinai, on the fifteenth day of the second month after leaving Egypt.
2以色列子民全会众在旷野里都抱怨梅瑟和亚郎。2In the desert the whole community of Israel grumbled against Moses and Aaron
3以色列子民向他们说：「巴不得我们在埃及国坐在肉锅旁，有食物吃饱的时候，死在上主的手中！你们领我们到这旷野里来，是想叫这全会众饿死啊！」3and said to them, "If only we had died by the hand of Yahweh in Egypt when we sat down to caldrons of meat and ate all the bread we wanted, whereas you have brought us to this desert to let the whole assembly die of starvation!"
4上主向梅瑟说：「看，我要从天上给你们降下食物，百姓要每天出去收歛当日所需要的，为试探他们是否遵行我的法律。4Yahweh then said to Moses, "Now I am going to rain down bread from heaven for you. Each day the people are to gather what is needed for that day. In this way I will test them to see if they will follow my Teaching or not.
5但到第六天，他们准备带回来的食物要比每天多一倍。」5On the sixth day when they prepare what they have brought in, they will find that there is twice as much as they gather each day."
6梅瑟和亚郎对全以色列子民说：「今晚你们要知道，是上主领你们出了埃及国；6Then Moses and Aaron said to the people of Israel, "In the evening you will know that it was Yahweh who brought you out of Egypt,
7明早你们要看见上主的荣耀，因为你们抱怨上主的话，他已听见了。我们算什么？你们竟抱怨我们！」7and in the morning you will see the Glory of Yahweh. For he has heard your grumbling against him, because: who are we that you should grumble against us?
8梅瑟又说：「晚上上主要给你们肉吃，早晨你们可以吃饱，因为上主听见了你们抱怨他所说的怨言。我们算什么？你们不是抱怨我们，而是抱怨上主。」8In the evening Yahweh will give you meat to eat and in the morning bread to satisfy your hunger, because Yahweh heard your grumbling. You are not grumbling against us but against Yahweh, for who are we?"
9梅瑟向亚郎说：「你向以色列子民全会众说：你们应走到上主前，因为他听见了你们的怨言。」9Then Moses directed Aaron to say to the whole community of Israel, "Draw near to Yahweh for he has heard your complaints."
10亚郎正向以色列子民全会众说话的时候，他们转面朝向旷野，看见上主的荣耀显现在云彩中。10It happened that as Aaron was speaking to the full assembly of Israel, they turned towards the desert and saw the Glory of Yahweh in the midst of the cloud.
11那时上主向梅瑟说：11Then Yahweh spoke to Moses,
12「我听见了以色列子民的怨言。你给他们说：黄昏的时候你们要有肉吃，早晨要有食物吃饱，这样你们就知道，我是上主，你们的天主。」12"I have heard the complaints of Israel. Speak to them and say: Between the two evenings you will eat meat, and in the morning you will have bread to your heart's content; then you shall know that I am Yahweh, your God!"
13到了晚上，有鹌鹑飞来，遮盖了营幕；到了早晨，营幕四周落了一层露水。13In the evening quails came up and covered the camp. And in the morning, dew had fallen around the camp.
14露水升化之后，在旷野的地面上，留下稀薄的碎屑，稀薄得好像地上的霜。14When the dew lifted, there was on the surface of the desert a thin crust like hoarfrost.
15以色列子民一见，就彼此问说：「这是什么？」原来他们不知道这是什么。梅瑟告诉他们说：「这是上主赐给你们吃的食物。15The people of Israel upon seeing it said to one another, "What is it?" for they didn't know what it was. Moses told them, "It is the bread that Yahweh has given you to eat."
16上主曾这样吩咐说：你们应按每人的食量去收歛，按照你们帐幕的人数去拾取，每人一『曷默尔』。16"This is what Yahweh commanded: Gather it according to the amount each one eats, about four liters a piece, and according to the number of persons each of you has in his tent."
17以色列子民就照样作了；收歛的时候，有的多，有的少，17This is what the people of Israel did. They gathered it, some more, others less.
18但他们用『曷默尔』衡量时，那多收的，也没有剩余；那少收的，也没有缺少；各人正按他们的食量收歛了。18But when they measured it with an omer, he that had gathered more didn't have too much while the man who had gathered less didn't have too little. Each one had as much as he needed.
19梅瑟向他们说：「谁也不准将一些留到早晨。」19And Moses said to them, "Let no one leave any of it till the morning."
20但他们没有听梅瑟的话；有些人把一些留到早晨，但都被虫子咬烂，发生臭味；梅瑟遂向他们发怒。20But they did not listen to Moses and some of them left it till morning. It bred worms and became foul, and Moses was angry with them.
21于是他们每天早晨按各人的食量去收歛；太阳一发热，就融化了。21Every morning each one gathered as much as he could eat, and when the sun grew hot it melted.
22到了第六天他们收歛了两倍的食物，每人二『曷默尔』；会众的首领来向梅瑟报告此事。22On the sixth day they gathered the double amount of bread, two omers each, and the leader of the people came to tell Moses.
23梅瑟向他们说：「上主曾这样吩咐说：明天是安息日，是祝圣于上主的安息圣日；你们要烤的，就烤罢！要煮的，就煮罢！凡吃了剩下的，应保留到次日。」23He said to them, "This is what Yahweh commanded: Tomorrow you shall rest, for that day is a Rest - or sabbath - sacred to Yahweh.
24他们就照梅瑟所吩咐的，把吃了剩下的，留到次日也没有发臭，也没有虫咬。24Bake today what you have to bake and boil what you have to boil, and you shall put aside what is left over to be kept till the next day." So they put it aside until morning as Moses had ordered and its smell was not foul and it was free of maggots.
25梅瑟说道：「今天吃这些罢！因为今天是敬上主的安息日，今天在野外什么也找不到。25And Moses said, "Eat it today, for this is a day of Rest - or sabbath - in honor of Yahweh. Today you will not find it in the fields.
26六天你们可去收歛，但第七天是安息日，什么也没有。」26For six days you will gather it, but on the seventh day, the Sabbath, there will be none."
27到了第七天，百姓中有人去收歛，但什么也没有找到。27Some of the people went out on the seventh day but found none.
28上主向梅瑟说：「你们不守我的命令和我的法律要到何时呢？28Then Yahweh said to Moses, "How long will you refuse to obey my commands and my laws?
29看上主给你们立了安息日，为此到第六天他给你们两天的食物；到第七天各人都应留在家内，不准任何人离开自己的地方。」29Yahweh has given you this Resting Day! That is why on the sixth day he gave you bread for two days. Let everyone stay where he is, and no one go out of his place on the seventh day."
30这样百姓在第七天守了安息日。30And so the people rested on the seventh day.
31以色列家给这食物取名叫「玛纳」。它像胡荽的种子那样白，滋味好似蜜饼。31The people of Israel called this food manna. It was white like coriander seed and it tasted like wafers made with honey.
32梅瑟说：「上主这样吩咐说：装满一『曷默尔』玛纳，留给你们的后代子孙，为使他们能看到我领你们出离埃及国时，在旷野里养活你们的食物。」32And Moses said, "This is what Yahweh commanded: 'Take a measure of manna and keep it for future generations to let them see the bread I gave you to eat in the desert when I brought you out of Egypt."
33梅瑟向亚郎说：「拿一个罐子，装满一『曷默尔』玛纳，放在上主面前，留给你们的后代子孙。」33Then Moses said to Aaron, "Take a jar and fill it with a measure of manna and place it before Yahweh for your descendants."
34亚郎就照上主吩咐梅瑟的话，将玛纳放在约版前面，保留起来。34Accordingly Aaron put a full measure of manna in the jar as Yahweh had commanded Moses and placed it before the slabs of divine statement to be kept there.
35以色列子民吃玛纳四十年之久，直到进入有人居住的地方为止；他们吃玛纳，直到进入客纳罕地的边界。35The people of Israel ate the manna until they came to an inhabited land. They ate it for forty years
36一『曷默尔』是一『厄法』的十分之一。36up to the time they reached the border of Canaan.
Previous 出谷纪:Chapter 16 Next
Produced by |
CJ Tool and Mouldings Logo
The History of Plastic Products
What are plastics and where do they come from?
Plastic is a word that originally meant ‘easily shaped and pliable.’ Recently, it became a name for a group of materials called polymers.
Over the last century and a half, we have learned how to make synthetic polymers, sometimes using natural substances like cellulose, but more often using the plentiful carbon atoms provided by petroleum and fossil fuels.
Polymers have become an essential part of the manufacturing industry to make plastic products.
The first synthetic plastic
In 1869, the first synthetic polymer was invented by John Wesley Hyatt, by treating cellulose, derived from cotton fibre, with camphor, Hyatt discovered a plastic that could be crafted into a variety of shapes and made to imitate natural substances such as ivory and linen.
This discovery was marked in history, as this was the first-time human manufacturing was not constrained by nature. Humans could now create new materials for their plastic products.
The development of new plastics
Leo Baekeland invented Bakelite in 1907. Bakelite is the first fully synthetic plastic, as it contained no molecules found in nature. Bakelite could be shaped or moulded into almost anything providing endless possibilities for plastic products.
The Future of Plastics
Plastic is now critical for modern life, to create plastic products such as computers, phones, and lifesaving medical devices. It is clear we cannot live without certain plastic products. Innovators are working to develop bioplastics which are much more environmentally friendly than conventional plastics. Some scientists are working on creating plastic products that are completely biodegradable and some are working on ways to make recycling much more efficient.
Here at CJ Tool and Mouldings, we are a plastic injection moulding company in the West Midlands, we offer a full range of services including design, tooling, moulding and assembly.
Added: 26 Sep 2017 11:10
Back to News |
"I often ask them questions that I don't have the answers to because I want them to think for themselves and not just tell me what they think I want to hear or what they think the 'right' answer is," Suttle said in an email. "I consider it vital that they learn how to question everything, to resist the urge to believe the single story, the stereotype or the first thing they hear. In essence, I want them to read more and not be easily duped."
The kids have heard about fake news. Who hasn't? President Donald Trump and his advisers have used those words repeatedly to refer to national news outlets — without evidence — and those national news outlets reported how fake news articles from partisan and fringe groups shared on Facebook and Twitter swayed voters in November.
So what is "fake news," exactly? And how does one pick it out on a slick website with a legitimate-sounding name?
Down the hall during the next class period, journalism teacher Eric Comeras used a checklist to show students how to evaluate an online news source: Does it use excessive punctuation?!?!? ALL CAPS? Is there a byline? Are the media outlet's editorial standards posted anywhere? Is there a current date on the story?
Here was No. 1: "Gauge your emotional reaction: Is it strong? Are you angry? Are you intensely hoping that the information turns out to be true? False?"
At Licking Valley, the class discussed an article on a recent Stanford University study showing that a majority of youngsters aren't savvy about discerning lies online. For example, nearly 40 percent of high-schoolers thought the mutated daisies were the real deal.
"You're narrowing them in their thinking by only allowing them to look at certain sites," said senior Grant McHugh.
Senior Jenna Smith agreed: "Students should be more self-aware. They need to know when they're being lied to." |
It's Cool and Crazy, Man!
Your Shopping cart is empty.
Availability: In Stock
Bookmark and Share
The Lost Highway is a four-volume history of country music that utilizes rare film footage and interviews to trace the history and growth of country music, from its roots in mountain music, through bluegrass to the emergence of Hank Williams and honky-tonk, the rise of the pop-friendly Nashville Sound, the emergence of chart-topping female artists and the success of Alt. Country.
Note: This title comes on two discs.
The Big Bang of country music took place in Bristol, Tennessee in August 1927. It was in an abandoned hat factory that East Coast talent scout Ralph Peer set up portable recording equipment and recorded sessions with Jimmie Rodgers and The Carter Family. Rodgers went on to become the first national star of country music, creating a blueprint for almost every solo performer to follow. The influence of the Carter Family, with their soulful gospel harmonies and intricate guitar playing, can be heard in every harmony group since.
Country music has roots in the rural southeast Mountain Traditions of Tennessee, Kentucky and West Virginia. Songs would be passed down through generations and, because of the isolation of the Appalachians, many songs survived unknown to the outside world until the beginning of the 20th century.
The Role of Radio was important in the development of country music. By 1938, ten million rural families owned radio sets, often run off car batteries. To cater to this audience radio stations began running barn dance shows, the most popular of which was the Grand Ole Opry broadcast from Nashville.
Bluegrass, named after the bluegrass state of Kentucky, was a 1940s development that took traditional string-based mountain songs and built precise vocal arrangements around them. Bill Monroe, a mandolin-playing singer with the highest-pitched voice in all of popular music, was the godfather of bluegrass.
Honky Tonk music came out of the beer-joints and roadside bars; known locally as honky tonks. They were rowdy places; hot beds of beer, lust and fistfights, where performers needed to play loud to compete with the noise. The result was a harsher, amplified and more driven sound, which took as its subject the very essence of bar life; loving, cheating and drinking.
Pioneered by Ernest Tubb, who sang over an electrified guitar for the first time, it also attracted the young Hank Williams who would go on to write such classic Honky Tonk songs as "Your Cheatin' Heart" and "I'm So Lonesome I Could Cry." Hank Williams was a prolific writer and an alcoholic, whose haunting gospel influenced songs are wracked with guilt and remorse and reflect his own troubled life, echoing the ups and downs of a turbulent marriage. Yet such is their power that never had pain and sadness sounded so good.
Honky Tonk barely survived the advent of Elvis Presley and rock 'n' roll. Nashville reacted by closing ranks and creating a smoother more pop friendly brand of country that came to be known as the Nashville Sound.
Producers Owen Bradley and Chet Atkins would use session artists to lay down an instrumental background with the singer performing vocals, which would then be sweetened with strings and lush vocal choirs giving the sound a smoothness and sophistication far removed from the twanginess of traditional country. Jim Reeves and Eddy Arnold, both of whom had once flirted with honky tonk, built huge careers on the back of the Nashville Sound.
Beyond Nashville is the story of the outsiders from all over America who again and again have rejuvenated country by going beyond Nashville; from the Bakersfield Sound of the 1950s through to the outlaw movement of the 1970s to alt. country today.
Migrants from the Texas and Oklahoma dustbowls in the 1930s kept their music alive in the honky-tonks and juke joints of California's San Joachim Valley. By the 1950s their music had developed a hard-edged amplified sound and a distinct freewheeling identity of its own that challenged the country music establishment. The Bakersfield Sound is exemplified in the music of Buck Owens and Merle Haggard.
Throughout the 50s and 60s, there had been various attempts to recapture the grit and honesty of country but it was the Outlaw Movement, in the mid 1970s, spearheaded by the Texas duo of Willie Nelson and Waylon Jennings, which really managed to restore something of the original maverick and rebel spirit to the music.
In the 1980s new blood came in the form of the so-called New Traditionalist Movement. A series of offbeat country artists issued new albums that had a freshness of approach and honesty unknown since the heyday of honky tonk. Record companies scrabbled to sign dozens of handsome, young, new country artists; a phenomenon sometimes tagged "white hat country".
The most exciting movement of recent years, Alt. Country (alternative country) is committed to a back-to-basics, anti-corporate approach. In particular, alt. country artists see their spiritual forefathers as hardcore country artists; like Hank Williams and Johnny Cash; who have rebelled against sanitized but popular music in the past.
The first million selling record by a country female artist was Patsy Montana's, "I Wanna Be A Cowboy's Sweetheart" in 1935. She became a country institution, giving Female Country Artists their first new solo style; one that would be adopted by many women singers in the 1940s and 1950s. But it would be artists like honky tonker Jean Shepard and Patsy Cline, one of the greatest country pop stylists of the Nashville Sound era, who really opened things up for women.
The biggest impact of women performers though came in the 1960s with the arrival of Dolly Parton, Tammy Wynette and Loretta Lynn. Loretta Lynn was the Hillbilly Feminist, a honky tonk-rooted artist not afraid to write songs like, "Don't Come Home-a-Drinkin' With Lovin' On Your Mind" and "Your Squaw Is On The Warpath." Tammy Wynette is country music for many people. She sang about women wronged but also about staying with those men doing the wronging.
Note: This title comes on two discs.
Our discs are guaranteed for life.
If a disc ever stops playing correctly
tell us and we'll replace for free.
You might also dig the following titles...
Product Tags
Other people marked this title with these tags:
What are tags? |
According to documentation records, honey was the first natural sweetener put into use. From a million years ago to the present, it continues to sweeten and benefit the body.
What Is White Honey?
Despite its name, white honey actually is not purely white. The honey is, however, much lighter than traditional honeys and oftentimes a very light amber color, but also dependent on the source of the honey. Common producers of white honey are flowers from the kiawe tree, native to Hawaii, and depicts the distinctive white honey – smooth and creamy. The desirable characteristics of white honey occur by its natural crystallization process. Since the traditional honey is produced mainly in Hawaii, obtaining the product may be hard to come across in most common grocers. To supply white honey seekers, honey pollenated by various flowers (including sage, alfalfa, and fireweed) are artificially crystallized, with the variable sources responsible for disparities of white honey products. For instance, lighter honeys offer a lighter taste and sweetness compared to darker honeys. But despite the source, all white honeys provide a spreadable, off-white sweetener while offering health benefits when consumed, especially with its raw form.
White Honey Health Benefits
Unlike most sugar, particularly common table sugar, white honey provides more than calories. And though it is comparable to sugar calorically, it offers valuable vitamins and minerals including B vitamins, vitamin A, calcium, copper, phosphorous, potassium, and zinc. Additionally, powerful antioxidants are rich in honey. The nutritional totality of honey can ultimately provide the following benefits:
Disease Prevention
The high antioxidant content of honey is shown to protect the body against multiple diseases including heart disease. The offered antioxidants may also protect against cancer by reducing damage to the body’s cells.
Digestive Health
Raw honey can be quite beneficial to gut health and often used to treat digestive issues. Though the research is lacking, individuals use raw honey to treat diarrhea. But research supports honey as an effective treatment for Helicobacter pylori, a cause of peptic ulcers occurring in gastrointestinal tract.
Cold Relief
Especially when dealing with a sore throat, honey can act as a natural remedy to relieve the pain. Raw honey can also act as a cough suppressant, even comparing to over-the-counter cough medicine.
Athletic Optimization
During physical performance, especially endurance exercise, carbohydrate is the body’s primary energy source. Not only does honey contain 17 grams of carbohydrate per tablespoon, but offers slow-burning fructose. The slower release of fructose (compared to glucose) may sustain athletes throughout longer periods of physical activity.
Baking Use
Though not directly a health benefit, white honey is suggested to be ideal for baking. Compared to other honeys, white honey best retains moisture for longer periods of time. The lighter taste also makes white honey an excellent sugar alternative, especially to reduce sweetness in products.
Careful Considerations
Mostly related to its microbial content, raw honey does hold some risk and should be warned with caution. The risks are primarily pointed to botulism, harmful bacteria, that may cause illness and symptoms that resemble food poisoning. Children under the age of one should not be introduced to all raw forms of honey while individuals who are immunocompromised should also use raw honey with caution.
Reference: Ajibola A, Chamunorwa JP, Erlwanger KH. Nutraceutical values of natural honey and its contribution to human health and wealth. Nutrition and Metabolism. 2012. |
List of oldest continuously inhabited cities
From Wikipedia, the free encyclopedia
Jump to navigation Jump to search
This is a list of present-day cities by the time period over which they have been continuously inhabited. The age claims listed are generally disputed. Differences in opinion can result from different definitions of "city" as well as "continuous habitation" and historical evidence is often disputed. Caveats (and sources) to the validity of each claim are discussed in the "Notes" column.
Northern and the Horn[edit]
Name Historical region Location Continuously inhabited since Notes
Luxor (as Waset, better known by its Greek name Thebes) Ancient Egypt Egypt c. 3200 BC First established as capital of Upper Egypt, Thebes later became the religious capital of the nation until its decline in the Roman period.
Annaba (as Hippo Regius) Numidia Algeria 12th century BC Founded by the Phoenicians in the 12th century BC, it is the birthplace of St. Augustine of Hippo[1][better source needed]
Tripoli (as Oea) Libya c. 700 BC Founded in the 7th century BC, by the Phoenicians.[2]
Constantine (as Cirta) Algeria c. 600 BC Founded in the 6th century BC, by the Phoenicians.[3][better source needed]
Benghazi (as Euesperides) Cyrenaica Libya c. 525 BC Founded in the 5th century BC, by the Greeks.[4]
Tangier Carthage Morocco c. 500 BC Founded by the Carthageans, later chief city of the Roman Province of Mauretania Tingitana.
Axum Kingdom of Axum Ethiopia c. 400 BC Ancient capital of the Kingdom of Axum.
Alexandria Ancient Egypt Egypt 332 BC Founded by Alexander the Great.[5]
Mogadishu Bilad al-Barbar Somalia c. 200 BC Successor of the ancient trading power of Sarapion.
Old Cairo Egypt Egypt c. 100 AD Babylon Fortress moved to its current location in the reign of Emperor Trajan, forming the core of Old or Coptic Cairo[unreliable source?].[6]
Zeila/Avalite Bilad al-Barbar Somalia 1st century AD Major trading city in the Horn of Africa.
Kismayo Bilad al-Barbar, after the 13th century part of the Ajuran Empre Somalia 4th century The Kismayo area was originally a small fishing settlement and expanded to a major trading city on the Somali coast.[7]
Fes (as Fes-al-Bali) Morocco 789 Founded as the new capital of the Idrisid Dynasty.[8]
Marrakesh (Murakuc) Morocco 1070 Founded by the Almoravid Dynasty.[unreliable source?][9]
Name Historical region Location Continuously inhabited since Notes
Igodomigodo Kingdom of Benin Nigeria c. 400 BC[citation needed] City of Benin, the oldest cities in Nigeria.
Ife Osun State Nigeria c. 350 BC Earliest traces of habitation date to the 4th century BC.[10]
Jenne-Jeno Mali c. 250 BC One of the oldest known cities in sub-Saharan Africa.[11]
Zanzibar Swahili Coast Tanzania 1st–3rd centuries AD[citation needed] A Greco-Roman text between the 1st and 3rd centuries AD, the Periplus of the Erythraean Sea, mentioned the island of Menuthias (Ancient Greek: Μενουθιάς), which is probably Unguja, an island suburb of the city.
Walata Ghana Empire Mauritania 7th-10th centuries A Mande Soninke town founded during the apogee of the Ghana Empire. It would remain a relevant, even dominant, trade town until being supplanted Timbuktu in the 15th Century.[12]
Sofala Swahili Coast Mozambique c. 700[citation needed] One of the oldest harbours documented in Southern Africa.
Pate Swahili Coast Kenya 8th century[citation needed] According to the Pate Chronicle, the town of Pate was founded by refugees from Oman in the 8th century.
Mombasa Swahili Coast Kenya 900[citation needed] The strategic location of this historical Swahili trading centre has seen it fall under the control of many countries.
Moroni Swahili Coast Comoros 10th century[citation needed] Founded, possibly during the 10th century, as the capital of a sultanate connected commercially to Zanzibar in Tanzania.
Kano Kano State Nigeria 11th century The foundation for the construction of Kano City Walls was laid by Sakri Gijimasu from 1095 – 1134, and was completed in the middle of the 14th century during the reign of Zamnagawa.[13]
Timbuktu Mali Empire Mali 11th century Settled by Tuareg traders as an outpost, its incorporation into the Mali Empire and Mande, Soninke, and Songhai settlement from the 13th century rapidly developed the town.[14]
Malindi Swahili Coast Kenya 13th–14th centuries[citation needed] Once rivaled only by Mombasa for dominance in this part of East Africa, it was first referenced in writing by Abu al-Fida (1273–1331), a Kurdish geographer and historian.
Quelimane Swahili Coast Mozambique 1400[citation needed] One of the oldest towns in the region, one tradition says that Vasco da Gama, in 1498, enquired about the name of the place from workers in the fields outside the settlement.
Tanga Swahili Coast Tanzania 1500[citation needed] The earliest documentation about Tanga roots from the Portuguese who established a trading post as part of their East African coastal territory and controlled the region for over 200 years between 1500 and 1700.
Lagos Kingdom of Benin Nigeria 16th century Initially established as a war camp for soldiers from the Kingdom of Benin.[15]
Ouidah Kingdom of Whydah Benin 16th century The primary port of the Kingdom of Whydah, originally called Glehue by the Fon inhabitants. The town was conquered by the Kingdom of Dahomey in the 18th century and eventually exported more than 1 million slaves.[16]
Cape Town Dutch East India Company South Africa 1652 Founded by Dutch settlers from Dutch East India Company and is the oldest city in South Africa.
Kumasi Ashanti Empire Ghana c. 1680[citation needed] Founded as Akan village and capital of the Kumaseman State, later becoming capital of Ashanti Empire.
North America[edit]
Name Historical region Location Continuously inhabited since Notes
Flores Maya civilisation, then New Spain Guatemala 1st millennium BC[17] Formerly Nojpetén, the capital of the Itza kingdom, it has been occupied continuously since prehispanic times.[18] Earliest archaeological traces date back to 900–600 BC, with major expansion of the settlement occurring around 250–400 AD.[19] Ethnohistoric documents claim the founding of Nojpetén in the mid-15th century AD.[20]
Acoma Pueblo Puebloan peoples US c. 1144 AD Acoma Pueblo is said to of besn[clarification needed] founded during the 1200s, but extant buildings from the 1100s and the consensus of Tribal peoples support the 1144 date.
Oraibi, Arizona Puebloan peoples US c. 1150
Tucson Hohokam US c. 1300[21] Hohokam village founded at the base of Sentinel Peak, later Tohono O'odam. Afterwards, became a Spanish presidio.[22]
Santo Domingo New Spain Dominican Republic 1496 Oldest European settlement in the New World.
San Juan New Spain Puerto Rico 1508 Oldest continuously inhabited city in a US territory.
Nombre de Dios, Colón New Spain Panama 1510 Oldest continuously inhabited European settlement in continental America.
Baracoa New Spain Cuba 1511 Oldest European settlement in Cuba.
Havana New Spain Cuba 1519 Oldest major city in Cuba, established 1515, granted city status in 1592 by Philip II of Spain as "Key to the New World and Rampart of the West Indies".
Veracruz New Spain Mexico 1519 Oldest continuously inhabited European established settlement in the North American continent.
Panama City Cueva Civilisation. After European colonisation: New Spain Panama 1519[23] Oldest European settlement on the Pacific.
Quebec City New France Canada 1608 Oldest city in Canada and oldest French-speaking city in the Americas.
Hopewell, Virginia Virginia Company US 1613 Founded as Bermuda City in 1613 and later known as City Point, Virginia, this location has undergone several name changes but has remained continuously inhabited.
Plymouth, Massachusetts Plymouth Colony US 1620 Fourth oldest continuously inhabited European-founded city in the United States[24]
St. John's, Newfoundland and Labrador Newfoundland Colony Canada c. 1630 Some claims[citation needed] to being the oldest city in Canada. Incorporated in 1883; inhabited continuously since sometime after 1630.
Saint John New France Canada 1631 Oldest incorporated city in Canada.
Trois-Rivières New France Canada 1634 Fourth oldest city in Canada.
Montreal New France Canada 1642 Fifth oldest city in Canada.
Sault Ste. Marie, Michigan New France US 1668 Oldest European-founded city in the Midwestern United States and third oldest US city west of the Appalachian Mountains.
Philadelphia County Pennsylvania Colony US 1681
Victoria Colony of Vancouver Island Canada 1843 Oldest city on the West Coast of Canada.
South America[edit]
Name Historical region Location Continuously inhabited since Notes
Piura Peru Peru 1532 Oldest European-founded city in Peru.[26]
Lima Peru Peru 1535 Second oldest continuously inhabited European-settled capital city in South America. The oldest being Quito.
Santiago del Estero Río de la Plata Argentina 1553 Oldest continuously inhabited city in Argentina.
Central and Southern[edit]
Name Historical region Location Continuously inhabited since Notes
Varanasi Kashi Uttar Pradesh, India 1800 BC Recent excavations at Aktha and Ramnagar, two sites very near to Varanasi, show them to be from 1800 BC.
Allahabad (Prayag) Vatsa Uttar Pradesh, India 1750 BC[27][28] Archaeological sites in India, such as Kosambi and Jhusi near Allahabad in present-day Uttar Pradesh show iron implements in the period 1800–1200 BC.Kosambi or Kaushambi was an important city in ancient India, located on the Yamuna River about 56 kilometres (35 mi) southwest of its confluence with the Ganges at Prayag (modern Allahabad).[29]
Balkh (as Bactra) Bactria Balkh Province, Afghanistan 1500 BC[citation needed]
Kabul Gandhara Kabul, Afghanistan c. 1170 BC
Samarqand Sogdiana Uzbekistan 700 BC[citation needed]
Ujjain Malwa Madhya Pradesh, India c. 600 BC.[30] Rose to prominence in c. 600 BC as capital of Avanti.
Rajagriha (Rajgir) Magadha Bihar, India 600 BC[citation needed]
Vaisali Magadha Bihar, India 500 BC[unreliable source?][31]
Patna Magadha Bihar, India 5th century BC[32] As Pataliputra was founded by Ajatashatru.
Kanchipuram Pallavas TamilNadu, India 2nd Century BC Place of all 4 (budha/jain/saiva/vainava) learning and the birth place of Chanakya
Anuradhapura Kingdom of Rajarata North Central Province, Sri Lanka 4th century BC[33]
Madurai Pandyan Kingdom Tamil Nadu, India 3rd century BC Megasthenes may have visited Madurai during the 3rd century BCE, with the city referred as "Methora" in his accounts.[34] The view is contested by some scholars who believe "Methora" refers to the north Indian city of Mathura, as it was a large and established city in the Mauryan Empire.[35]
Peshawar Gandhara Khyber Pakhtunkhwa, Pakistan 2nd century BC[36] Ongoing excavations in the Gorkhatri area have uncovered evidence of the earliest building in the city.
Bamyan Bactria Bamyan Province, Afghanistan 1st century AD
Kathmandu-Patan, Lalitpur Nepal Kathmandu valley, Nepal 2nd century AD The epigraphically attested history of Kathmandu valley begins in the 2nd century.
Dacca Dhaka Bangladesh 7th century
Tiruvannamalai Pallava dynasty or Hoysala Empire Tamil Nadu, India 9th century The recorded history of the town dates back to the ninth century, as seen from a Chola inscriptions in the temple.[37][38]
Name Historical region Location Continuously inhabited since Notes
Yanshi, Henan (Erlitou Site) Xia dynasty (Erlitou culture) Henan, China c. 1900 BC
Luoyang (as Xibo, Luoyi, Zhongguo, Henan, Dongdu, Shendu) Shang Dynasty Henan, China c. 1600 BC
Xi'an (as Haojing, Fenghao, Chang'an, Jingzhao, Daxing) Zhou Dynasty Shaanxi, China c. 1100 BC
Handan Jin Hebei, China c. 1080 BC
Beijing (as Ji, Youzhou, Fanyang, Yanjing, Zhongdu, Dadu) Ji, Yan Beijing, China c. 1045 BC Paleolithic homo sapiens lived in the caves from about 27,000 to 10,000 years ago.[39]
Zibo (as Yingqiu, Linzi, Qiling, Zichuan, Boping) Qi Shandong, China c. 1045 BC The Lord of Qi, Jiang Ziya, set the capital of his manor at Yingqiu(营丘), which is today's Linzi District.
Jingzhou (as Jinan, Yingdu, Jiangling, Jingsha, Nanjun) Chu Hubei, China c. 689 BC
Hefei (as Luyi, Ruyin, Luzhou, Hezhou, Lujiang) Zhou Dynasty Anhui, China c. 650 BC The Viscount of Lu was asked to set the capital of his manor at Luyi(庐邑), which is in the north of today's downtown Hefei.
Suzhou (as Gusu, Wu, Pingjiang) Wu Jiangsu, China 514 BC
Taiyuan (as Jinyang) Jin Shanxi, China c. 497 BC
Nanjing (as Yecheng, Moling, Jianye, Jiankang, Jinling, Yingtian, Jiangning) Wu Jiangsu, China c. 495 BC Fu Chai, Lord of the State of Wu, founded a fort named Yecheng (冶城) in today's Nanjing area.
Changsha (as Linxiang, Xiangzhou, Tanzhou, Tianlin) Chu Hunan, China c. 365 BC
Liaoyang (as Xiangping, Changping, Liaodong, Pingzhou, Liaozhou, Dongdu, Dongjing) Yan Liaoning, China c. 279 BC
Guangzhou (as Panyu) Qin Dynasty Guangdong, China 214 BC[citation needed]
Hangzhou (as Lin'an, Yuhang, Qiantang) Qin Dynasty Zhejiang, China c. 200 BC The city of Hangzhou was founded about 2,200 years ago during the Qin Dynasty.
Nara (as Heijō-kyō) Japan Japan 710 Built as a new capital city in 710.
Kyoto (as Heian-kyō, and sometimes known in the west as Miyako) Japan Japan 794 Shimogamo Shrine was built in the 6th century, but the city was officially founded as Heian-kyō when it became the capital in 794.
Name Historical region Location Continuously inhabited since Notes
Jakarta Tarumanagara Indonesia 397 AD[40] Despite the popular belief that Jakarta (Jayakarta) was founded by Demak Sultanate in 1527 AD,[41] Jakarta is the oldest and the biggest city in the South East Asia region. The area of North Jakarta around Tugu area was inhabited far earlier since early 5th century. Tugu inscription (probably written around 417 AD) discovered in Batutumbuh hamlet, Tugu village, Koja, North Jakarta, mentioned King Purnawarman of Tarumanagara undertook hydraulic projects; the irrigation and water drainage project of the Chandrabhaga river and the Gomati river near his capital.[40]
Palembang Srivijaya Indonesia 683[42] Believed to be the oldest city in the Malay realm, capital of the Srivijaya empire. According to Kedukan Bukit inscription[42] Jayanasa established Srivijaya kingdom in Palembang area.
Luang Prabang Muang Sua Laos 698
Yogyakarta Mataram Kingdom Indonesia 732[43] The historic realm of Mataram of Southern Central Java region, which corresponds to today Yogyakarta city and its surrounding has its root in 8th century Mataram Kingdom. According to Canggal inscription dated 732, the area traditionally known as "Mataram" became the capital of the Medang Kingdom, identified as Mdang i Bhumi Mataram established by King Sanjaya.[43] The city reestablished again as the capital of Mataram Sultanate in 1587, and Yogyakarta Sultanate in 1755.
Siem Reap Khmer Empire Cambodia 801[44] Capital of the Khmer Empire.
Bagan Pagan Empire Myanmar 849[45]
Magelang Mataram Indonesia 907 Magelang was established on 11 April 907. Magelang was then known as a village called Mantyasih, which is now known as Meteseh.[46]
Bandar Seri Begawan Po-ni and Bruneian Empire Brunei 977[47] Oldest city in Borneo.
Butuan Rajahnate of Butuan Philippines 1001[48][49] Oldest continuously inhabited city in Mindanao.
Yangon Konbaung Dynasty Myanmar 1043[51] Yangon was founded as Dagon in the early 11th century (circa 1028–1043) by the Mon but was renamed to "Yangon" after King Alaungpaya conquered Dagon.
Surabaya Janggala Kingdom Indonesia 1045[52]:147
The port city of Janggala or Hujung Galuh was one of the two Javanese capital city that was formed when Airlangga abdicated his throne iin 1045 n favour of his two sons.[52]:147 The Kingdom of Janggala comprised the northeastern part of the Kingdom of Kahuripan. The other Kingdom was Kediri. Derived its name from the words "suro" (shark) and "boyo" (crocodile), two creatures which are in a local myth.[53]
Singapore Singapura Singapore 1170[54]
Singhapala Rajahnate of Cebu Philippines 13th century[55][56] Ancient city founded by Sri Rajahmura Lumaya or Sri Lumay, a half Tamil Chola prince.[57] Now part of Barangay Mabolo in Northern district of Cebu City.[55][56]
Banda Aceh Aceh Sultanate Indonesia 1205
Sukhothai Sukhothai Kingdom Thailand 1238
Manila Tondo and Rajahnate of Maynila Philippines 1258[58] A settlement in the Manila area already existed by the year 1258. This settlement was ruled by Rajah Avirjirkaya whom described as a "Majapahit Suzerain". This settlement was attacked by a Bruneian commander named Rajah Ahmad, who defeated Avirjirkaya and established Manila as a "Muslim principality".[58] By 1570, when the Spanish, led by Miguel López de Legazpi, arrived, it was still inhabited and led by at least one Lakan and several Rajahs.
Ayutthaya Ayutthaya Kingdom Thailand 1351
Derived its name from the holy Hindu city of Ayodhya, the birthplace of Lord Rama and the setting of the epic Ramayana. Ayutthaya was the capital city of Siam from 1351 until 1767.
Muar Majapahit Malaysia 1361[59]
Phnom Penh Khmer Empire Cambodia 1372[60]
Malacca Malacca Sultanate Malaysia 1396[61]
Hội An Nguyễn dynasty Vietnam 14th century[62]
Bogor Sunda Kingdom Indonesia 1482
Ruins of ancient city of Damascus
Ruins of ancient city of Damascus
Ruins in Byblos
Ruins in Byblos
Ancient city of Aleppo
Ancient city of Aleppo
Damascus Levant Syria Chalcolithic; 3rd millennium BC[63] Damascus is often claimed to be the oldest continuously inhabited city in the world. Excavations at Tell Ramad on the outskirts of the city have demonstrated that the general area was inhabited as early as 9000 BC. However, it is not documented as an important city until the arrival of the Aramaeans.[63][64]
Byblos (Jubayl) Levant Lebanon Chalcolithic; 3000 BC[65][66] Settled from the Neolithic (carbon-dating tests have set the age of earliest settlement around 7000[67]), a city since the 3rd millennium BC.[68][65] Byblos had a reputation as the "oldest city in the world" in Antiquity (according to Philo of Byblos).
Gaziantep Anatolia Southeastern Anatolia, Turkey c. 3650 BC[69] Although most modern scholars place the Classical Antiochia ad Taurum at Gaziantep, some maintain that it was located at Aleppo. Furthermore, that the two cities occupy the same site is far from established fact.[70] Assuming this to be the case, the founding date of the present site would be about 1000 BC.[71]
Jericho Levant Palestine 1st millennium BC Traces of habitation from 9000 BC.[72][73] Fortifications date to 6800 BC (or earlier), making Jericho the earliest known walled city.[74]
Archaeological evidence indicates that the city was destroyed and abandoned several times (sometimes remaining uninhabited for hundreds of years at a time), with later rebuilding and expansion.[75][76]
Beirut Levant Lebanon 3000 BC[78]
Jerusalem (Old City) Levant Israel/Palestine 2800 BC[79]
Tyre Levant Lebanon 2750 BC[80]
Jenin Levant Palestine c. 2450 BC[81] Jenin's history goes back to 2450 BC, when it was built by the Canaanites. After 1244, Jenin flourished economically because of its location on the trade route, until a major earthquake completely destroyed the city.[82]
Aleppo Levant Syria 2nd millennium BC
Homs Levant Syria possibly early 3rd century BC May have been founded by Seleucus I Nicator
Erbil Mesopotamia Iraqi Kurdistan, Iraq 2300 BC[83][84] The Citadel of Arbil is a fortified settlement in Erbil, Iraqi Kurdistan. The city corresponds to ancient Arbela. Settlement at Erbil (Kurdish: Hewlêr) can be dated back to possibly 5000 BC, but not urban life until c. 2300.
Kirkuk (as Arrapha) Mesopotamia Kirkuk Governorate, Iraq 3000–2200 BC[85]
Jaffa Levant Israel c. 2000 BC Archaeological evidence shows habitation from 7500 BC.[86]
Sidon Levant Lebanon 2nd millennium BC Sidon becomes a city-state during the 2nd millennium BC.[87]
Hebron Levant Palestine c. 1500 BC "Hebron is considered one of the oldest cities and has been continuously inhabited for nearly 3500 years."[88]
Gaza Levant Palestine c. 1000 BC While evidence of habitation dates back at least 5,000 years, it is said to be continuously inhabited for a little more than 3,000 years.[89][90]
Hamadan (as Ecbatana) Media Iran c. 800 BC[91]
Yerevan Urartu Armenia 782 BC Founded as Erebuni. The Shengavit Settlement in the southwestern district of Yerevan was founded in the late 4th millennium BC, during the Calcolithic period.
Lod Levant Israel 200 AD[92]
Tabriz Caucasus Iran 3rd-7th century AD The earliest elements of the present Tabriz are claimed to be built either at the time of the early Sassanids in the 3rd or 4th century AD, or later in the 7th century.[93]
Yazd Media Iran 5th century AD[94] It has long been a haven for Zoroastrians.[94]
Name Historical region Location Continuously inhabited since Notes
Sydney New South Wales Australia 1788 Oldest city in Australia and oldest city in Oceania. Radiocarbon dating suggests human activity occurred in and around Sydney for at least 30,000 years, in the Upper Paleolithic period.[95][96] However, numerous Aboriginal stone tools found in Sydney's far western suburbs' gravel sediments were dated to be from 45,000 to 50,000 years BP, which would mean that humans could have been in the region earlier than thought.[97][98] The first people to occupy the Sydney region were an Indigenous Australian group called the Eora.[99][100]
Hobart Tasmania Australia 1803 Second oldest city in Australia. Prior to British settlement, the area had been occupied for at least 8,000 years, but possibly for as long as 35,000 years,[101] by the semi-nomadic Mouheneener tribe, a sub-group of the Nuennone, or South-East tribe.[102]
George Town Tasmania Australia 1804 Third oldest city in Australia.
Newcastle New South Wales Australia 1804 Fourth oldest city in Australia.
Launceston Tasmania Australia 1806 Fifth oldest city in Australia.
Kerikeri Northland New Zealand c. 1818 Oldest European-founded settlement in New Zealand.
Bluff Southland New Zealand 1824 Previously known as Campbelltown, the oldest European-founded settlement in the South Island.
Brisbane Queensland Australia 1825 Oldest city in Northern Australia, State Capital.
Albany Western Australia Australia 1827 Oldest city in the West Coast of Australia.
Melbourne Victoria Australia 1835 Before the arrival of European settlers, the area was occupied for an estimated 31,000 to 40,000 years.[104] At the time of European settlement, it was inhabited by under 20,000 hunter-gatherers from three indigenous regional tribes: the Wurundjeri, Boonwurrung and Wathaurong.[105][106]
Adelaide South Australia Australia 1836 State Capital.
Wellington Wellington Region New Zealand 1839 New Zealand's capital city from 1865 until the present day.
Auckland Auckland Region New Zealand 1840 New Zealand's capital city from 1841 - 1865.
Darwin Northern Territory Australia 1869 Territory Capital.
Name Historical region Location Continuously inhabited since Notes
Argos Neolithic, Mycenaean Greece Greece 6th–5th millennium BC[108] The city has been cycling between village and city status for 7,000 years. Recorded history begins in latter 1st millennium BC.
Athens Neolithic, Mycenaean Greece Attica, Greece 5th–4th millennium BC[109][110][111][page needed] Recorded history begins in 1400 BC.
Plovdiv Thrace Plovdiv Province, Bulgaria 2nd-1st millennium BC Thracian foundation, conquered by Phillip II of Macedon in 342 BC.
Chania Crete Crete, Greece c. 1700–1500 BC[112][unreliable source?] Minoan foundation as Kydonia.
Thebes Mycenaean Greece Boeotia, Greece c. 1600–1250 BC[113] Mycenaean foundation.
Larnaca Alashiya Cyprus c. 1400 BC[citation needed] Mycenaean, then Phoenician colony.
Trikala Mycenaean Greece Thessaly, Greece before 1200 BC[citation needed] Founded as Trikke.
Chalcis Mycenaean Greece Greece before 1200 BC[citation needed] Mentioned by Homer.
Cádiz Iron Age Iberia Andalusia, Spain 1100 BC[citation needed] founded as Phoenician Gadir, "Europe's oldest city".[114][115] It has archaeological remains dating to 3100 years.[116][117]
Patras Mycenaean Greece Greece c. 1100 BC[citation needed] Founded by Patreus.
Chios Chios North Aegean, Greece c. 1100 BC[citation needed]
Nicosia Mycenaean Greece Cyprus c. 1050 BC[citation needed] Mycenaean foundation as Ledra. Archaeological evidence of continuous habitation since the beginning of the Bronze Age 2500 years BC.[citation needed]
Zadar Illyricum Croatia c. 1000 BC[citation needed] Founded by Liburnians. Oldest continuously inhabited city in Croatia. Main Liburnian settlement.
Mytilene Lesbos North Aegean, Greece 10th century BC[citation needed]
Vani Colchis Imereti, Georgia before 8th century BC[118][119]
Seville Iron Age Iberia Andalusia, Spain 8th century BC[citation needed] founded as Tartessian Spal.[120]
Málaga Iron Age Iberia Andalusia, Spain 8th century BC[citation needed] founded as Phoenician Malaka.[121][page needed]
Mdina Antiquity Malta Malta 8th century BC[122] founded as Phoenician Melite.
Cagliari Sardinia Sardinia, Italy 8th century BC[citation needed] Founded by Phoenicians from Tyre as Krly, Caralis in Roman times, Callaris in Middle Ages.
Messina (as Zancle) Sicily Sicily, Italy 8th century BC[citation needed]
Reggio di Calabria (as Rhégion) Magna Graecia Calabria, Italy 743 BC[123] Continuous habitation since approximately 1500 BC, as we have notice about the Ausonian-Italic pre-Greek settlement and about the sculptor Léarchos of Reggio (late 15th century BC)[124] and King Iokastos (early 13th century BC).[125]
Palermo (as זִיז, Ziz) Phoenicia Sicily, Italy 734 BC[citation needed] Settlement presence since approximately 8000 BC, as we know through cave drawings in the area now known as Addaura, but continuous documented habitation since the Phoenician times (734 BC is traditionally considered as the founding year).
Syracuse Sicily Sicily, Italy 734 BC[citation needed] A colony of the Greek city of Corinth.
Volterra Tuscany Tuscany, Italy c. 725 BC[citation needed] An Etruscan mining settlement.[126]
Crotone (as Kroton) Calabria Magna Graecia, Italy 710 BC[citation needed] Greek colony.
Taranto (as Taras) Magna Graecia Apulia, Italy 706 BC[citation needed] Founded as the only Spartan colony by the Partheniae, children of unmarried Spartan women and perioikoi, free non-citizen residents of Sparta and her territories.
Corfu, Kerkyra Corfu Ionian Islands, Greece 700 BC[citation needed] A colony of the Greek city of Corinth.
Kerch (as Panticapaeum) pre-Roman Crimea Region of Ukraine occupied by Russia 7th century BC[citation needed] Greek colony.
Feodosiya (as Theodosia) pre-Roman Crimea Region of Ukraine occupied by Russia 7th century BC[citation needed] Greek colony.
Istanbul/Byzantion Thrace Anatolia Turkey 685 BC Anatolia; 667 BC Thrace[citation needed] Neolithic site dated to 6400 BC, over port of Lygos by Thracians c. 1150 BC. Greek colony.
Naples Magna Graecia Italy c. 680 BC[127] Actually the date at which an older settlement close by, called Parthenope, was founded by settlers from Cumae. This eventually merged with Neapolis proper, which was founded c. 470 BC.
Ibiza (as 'Ybsm) Balearic Islands Spain 654 BC[citation needed] Founded by the Phoenicians, according to Diodorus Siculus, book 5, chap. 16. Date consistent with archaeological finds.[128]
Durrës Illyria Albania 627–625 BC[129] Formerly Epidamnos.
Sozopol Thrace Burgas Province, Bulgaria 610 BC Founded by Miletian colonists around 610 BCE, was named Apollonia Pontica in honour of the patron deity of Miletus - Apollo. The Ancient authors identify the philosopher named Anaximander as the founder of the city.
Edessa, Greece Macedonia Greece before the 6th century BC[citation needed] Greek city, capital of the kingdom of Macedon up to the 6th century BC.
Marseilles (as Massilia) Gaul France 600 BC[citation needed] A colony of the Greek city of Phocaea.
Kavala Macedonia Greece 6th century BC[citation needed] Greek colony. Founded as Neapolis.
Mangalia Dacia Romania 6th century BC[citation needed] Founded as Callatis.
Constanţa Dacia Romania 6th century BC[citation needed] Founded as Tomis.
Mantua Po Valley Lombardy, Italy 6th century BC[citation needed] Village settlement since c. 2000 BC; became an Etruscan city in the 6th century BC.
Milan Po Valley, Cisalpine Gaul Lombardy, Italy 6th century BC Founded by the Insubres in the 6th century BC according to Titus Livy. Conquered by the Romans in 222 BC.
Bilhorod-Dnistrovskyi (as Tyras) Pontic Greeks Bessarabia, Ukraine 6th century BC[citation needed]
Kutaisi Colchis Imereti province, Georgia 6th to 4th century BC Archaeological evidence indicates that the city functioned as the capital of the kingdom of Colchis in the sixth to fifth centuries BC.[130]
Varna Thrace Bulgarian Black Sea Coast, Bulgaria 585-570 BC[citation needed] Founded[131] as Odessos by settlers from the Greek city of Miletus.
Sant Martí d'Empúries (as Emporion) Iberia Catalonia, Spain c. 575 BC[citation needed] A colony of the Greek city of Phocaea. Present Sant Martí is on the ancient Palaiopolis of Emporion, in an island next to the coast; in 550 BC, the inhabitants moved to the mainland, creating the Neapolis: Palaiapolis remained as a small neighbourhood.
Lamia Greece before the 5th century BC[citation needed] Greek city. First mentioned 424 BC
Serres Macedonia Greece 5th century BC[citation needed] Greek city. First mentioned in the 5th century BC as Siris.
Veria Macedonia Greece c. 432 BC[citation needed] Greek city. First mentioned by Thucydides in 432 BC.
Rhodes Rhodes, Aegean Sea Dodecanese, Greece c. 408 BC[citation needed] Greek city.
Sofia Moesia Sofia Valley, Bulgaria 4th century BC[citation needed] Celtic foundation as Serdica.[132]
Metz Gaul France 4th century BC[citation needed] Founded as the oppidum of Celtic Mediomatrici. However, Human permanent presence has been established in the site since 2500 BC.
Qabala (as Kabalaka) Caucasian Albania Azerbaijan 4th century BC[citation needed] Archeological evidence indicates that the city functioned as the capital of the Caucasian Albania as early as the 4th century BC.[133]
Stara Zagora Thrace Bulgaria 342 BC[citation needed] It was called Beroe in ancient times and was founded by Phillip II of Macedon[134][135][136][137] although a Thracian settlement neolithic inhabitation have been discovered as well. It also has the oldest copper mines in Europe (5th millennium BC)
Thessaloniki Macedonia (ancient kingdom) Greece 315 BC[citation needed] Greek city. Founded as a new city in the same place of the older city Therme.
Berat Macedonia (ancient kingdom) Albania 314 BC[citation needed] Founded[138] by Cassander as Antipatreia.
Vukovar Illyria Croatia 300 BC[citation needed] Vučedol culture.
Belgrade Illyria Serbia 279 BC[139] The present day territory of Belgrade continuously inhabited for more than 7000 years. Proto-urban Vinča culture prospered around Belgrade in the 6th millennium BC. The fortified city of Belgrade founded around 279 BC as Singidunum.
Niš Illyria Serbia 279 BC[citation needed] Founded as Navissos. Neolithic settlements date to 5000–2000 BC.
Cartagena (as Carthago Nova) Iberia Spain 228 BC[citation needed] Carthaginian colony, founded by Hasdrubal Barca.
Tarragona (as Tarraco) Iberia Catalonia, Spain 218 BC[citation needed] Roman colony, founded by Gnaeus and Publius Cornelius Scipio.
Stobi/Gradsko Macedonia Republic of Macedonia 217 BC[citation needed] Founded as Stobi by Philip V of Macedon.
Valencia Iberia Valencia, Spain 138 BC Roman colony founded as Valentia Edetanorum.
Sremska Mitrovica Illyria Serbia 1st century BC[citation needed] Founded as Sirmium. Neolithic settlements date to 5000 BC and are with other archeological findings evidence to continuous habitation.
Smederevo Illyria Serbia 1st century BC[citation needed] Founded as Semendria.
Évora Lusitania Portugal 53 BC (Roman conquest)[citation needed] Evidence of Lusitanian settlement prior to Roman occupation.
Paris Lutetia France 52 BC[citation needed] Archaeological evidence indicates human habitation as early as 4200 BC.[140] During the Gallic Wars, Caesar's armies set fire to Lutetia "a town of the Parisii, situated on an island on the river Seine."[141] While only a garrison at best on the Île de la Cité during some periods after 1st and 2nd century, was renamed Paris in 360 AD[142][143]
Zürich (Lindenhof) Gaul Switzerland c. 50 BC[citation needed] Lakeside settlement traces dating to the Neolithic.
Cologne Germania Inferior Germany 38 BC[citation needed] Founded in 38 BC by the Ubii, a Germanic tribe, as Oppidum Ubiorum. In 50 AD, the Romans adopted the location as Colonia Claudia Ara Agrippinensium and the city became in 85 AD the capital of the Roman province "Germania Inferior".
Trier Galia Belgica Germany 30 BC[citation needed] Oldest Roman city in Germany.
Nijmegen Netherlands c. 17 BC[citation needed] Oldest city in the Netherlands.
Augsburg Raetia, Roman Empire Germany 15 BC Third oldest city in Germany after Cologne and Trier. Located in the Swabian region of Bavaria. Founded by the Romans as Augusta Vindelicorum.
Chur Raetia Prima Grisons, Switzerland 15 BC[citation needed] habitation since the 4th millennium BC (Pfyn culture).
Worms Germania Superior Germany 14 BC[citation needed] The name of the city derives from the Latin designation Borbetomagus which is of Celtic origin.
Skopje Macedonia (Roman province) Republic of Macedonia 13-11 BC Founded in the time of Roman Emperor Octavian Augustus as Scupi.
Strasbourg Germania Superior France 12 BC First official mention as the Roman camp of Argentoratum. The area had been populated since the Middle Paleolithic.[144]
Tongeren Germania Inferior Belgium 10 BC[citation needed] Oldest city in Belgium.
Novi Sad Illyria Serbia 1st century AD[citation needed] Founded as Cusum.
Baku Absheron peninsula Azerbaijan 1st century AD[citation needed] The first written evidence for Baku dates to the 1st century AD.[145]
Bath (as Aquae Sulis) Britannia England 43 AD[citation needed][dubious ] The city was established as a spa town by the Romans in 43 AD.[146]
Winchester (as Venta Belgarum) Britannia England c. 70 AD[citation needed] Winchester was built as a Roman town in c. 70 AD.[147]
York (as Eboracum) Britannia England c. 72 AD[citation needed] The city was founded in or around AD 72 when the 9th Roman Legion set up camp there.[148]
Vinkovci (as Cibalae) Balkans Croatia 2nd century AD Became a municipium under Hadrian[149]
Trenčín (as Laugaricio) Slovakia before 179 AD[citation needed] First mentioned in 179 AD on a Roman inscription on Trenčín castle rock, when Roman army was stationed in settlement Laugaricio. Settlement was probably Germanic, and since the 7th century Slavic.
Vienna Pannonia Austria c. 300[citation needed] "It is uncertain when Vindobona became a municipium; this elevation seems to have taken place at the beginning of the 3d c. A.D."[150]
Verdun Lotharingia France 4th century[citation needed] Seat of the bishop of Verdun from the 4th century, but populated earlier.
Kiev State of the Antes Ukraine 482[151] Founded by Slavic tribe leader Kyi. Some sources[clarification needed] suggest Kiev was founded in 640 BC.
Prague Bohemia Czech Republic 6th century[citation needed] The first written record dates back to the 10th century.
Inverness Pictland Scotland 6th century[citation needed] A settlement was established by the 6th century when St Columba visited the Pictish King Brude at his fortress there.[152]
Glasgow Dál Riata or Alt Clut Scotland 6th century[citation needed] A settlement was founded in the 6th century[153] by St Mungo, who is the city's patron Saint.[154]
Ioannina Byzantine Empire Greece 527–565[citation needed] Founded by emperor Justinian I.
Aberdeen Pictland Scotland c. 580[citation needed] A settlement was established by c. 580 when records show the city's first church was built then. However, there is archaeological evidence of settlements in the area dating back to 6000 BC.[155]
Edinburgh as Din Eidyn Gododdin Scotland c. 580[citation needed] Edinburgh is mentioned as a settlement in the poem Y Gododdin, traditionally dated to around the late 6th and early 7th centuries.[156] The Poem uses The Brythonic name Din Eidyn (Fort of Eidyn) for Edinburgh and describes it as the capital of Gododdin. It is not until around 638 that the city starts being referred to as Edin-burh or Edinburgh, after the city was conquered by the Angles of Bernicia.[157]
Kraków (Wawel Hill) Lesser Poland Poland 8th century[158] The first written record dates back to the 10th century.
Ribe Jutland Denmark 704–710[159] Oldest town in Denmark.
Staraya Ladoga Russia 753[160]
Aarhus Denmark c. 770[161]
Heraklion Crete Greece 824[citation needed] Founded by the Saracens.
Veliky Novgorod Russia 859[citation needed]
Polatsk Belarus 862[citation needed]
Xanthi Thrace Greece before 879[citation needed] First medieval reference as Xantheia.
Uzhhorod (as Ungvár) Duchy of Laborec Ukraine before 895 First mentioned in Gesta Hungarorum.
Halych Galicia Ukraine 898 First mentioned in Gesta Hungarorum.
Gniezno Greater Poland Poland before 940 Early Slavonic settlements are dated to the 8th century.[162] An important Piast stronghold that gave birth to a medieval town is believed to be erected at least around 940 AD[163]
Vitebsk Belarus 947[citation needed]
Poznań Greater Poland Poland before 968 Settled from at least the 9th century AD,[164] Poznań is one of the suggested places of the AD 966 Baptism of Poland.[165] Poznań Cathedral was raised to the status of a cathedral around 968.
Székesfehérvár Hungary 972 Founded by Grand Prince Géza. The first catholic temple of the Kingdom of Hungary was built here after the foundation of the city.
Skara Sweden 988[citation needed]
Lund Denmark Sweden c. 990[166]
Västerås Sweden 990[167]
Trondheim Norway Norway 997[citation needed] Founded by king Olav Tryggvason. Archaeological findings of city settlement back to the 8th century.
Deventer The Netherlands The Netherlands 956[citation needed]
Gdańsk Pomerania Poland 997[168] Gdańsk became capital of Duchy of Pomerania (approximate date).[168]
See also[edit]
1. ^ List of oldest continuously inhabited cities
3. ^ fr:Constantine (Algérie)#P.C3©riode antique
6. ^ "Fort Babylon In Cairo". Retrieved 2013-01-19.
11. ^ McIntosh, Susan Keech; McIntosh, Roderick J. "Jenne-jeno, an ancient African city". Rice University Anthropology. Archived from the original on 2011-07-20
12. ^ Cleaveland, Timothy. "Becoming Walāta: A history of Saharan social formation and transformation." (Portsmouth, N.H.: Heinemann, 2002)
13. ^ Centre, UNESCO World Heritage. "Ancient Kano City Walls and Associated Sites - UNESCO World Heritage Centre".
14. ^ Saad, Elias. "Social history of Timbuktu: 1400-1900. The role of Muslim scholars and notables. (Ann Arbor, Michigan: University of Michigan Press, 1980)
15. ^ Mann, Kristin (2007). Slavery and the Birth of an African City. Indiana University Press.
16. ^ Anderson, David and Rathbone, Richard. "Africa's Urban Past." Oxford: Oxford University Press, 2000) Pg. 85-87
17. ^ Gámez, Laura (2007). J.P. Laporte; B. Arroyo; H. Mejía), eds. "Salvamento arqueológico en el área central de Petén: Nuevos resultados sobre la conformación y evolución del asentamiento prehispánico en la isla de Flores" (PDF). Simposio de Investigaciones Arqueológicas en Guatemala (in Spanish). Guatemala City, Guatemala: Museo Nacional de Arqueología y Etnología. XX, 2006: 259–260, 269. Archived from the original (PDF) on 2017-02-05. Retrieved 2016-11-29.
20. ^ Rice, Prudence M. (2009). "The Kowoj in Geopolitical-Ritual Perspective". In Prudence M. Rice and Don S. Rice (eds.). The Kowoj: identity, migration, and geopolitics in late postclassic Petén, Guatemala. Boulder, Colorado, US: University Press of Colorado. p. 43. ISBN 978-0-87081-930-8. OCLC 225875268.
21. ^ Thiel, J. Homer. Cultural History of the Tucson Basin and the Project Area. pp. 7–11.
22. ^ Downum, Charles E. (1993). Between Desert and River. Tucson, AZ: University of Arizona Press. pp. 1–30. ISBN 9780816518128.
27. ^ "The origins of Iron Working in India: New evidence from the Central Ganga plain and the Eastern Vindhyas by Rakesh Tewari (Director, U.P. State Archaeological Department)" (PDF).
28. ^ Upinder Singh, ed. (2009). A History of Ancient and Early Medieval India:From the Stone Age to the 12th Century. Pearson Education India. pp. 280–283. ISBN 9788131711200.
29. ^ Rohan L. Jayetilleke (5 December 2007). "The Ghositarama of Kaushambi". Daily News. Archived from the original on 4 June 2011. Retrieved 29 October 2008.
31. ^ "".
32. ^ "Pataliputra". Encyclopædia Britannica. Retrieved 30 January 2011.
34. ^ Harman, William. P (1992). The sacred marriage of a Hindu goddess. Motilal Banarsidass. pp. 30–36. ISBN 978-81-208-0810-2.
35. ^ Quintanilla, Sonya Rhie (2007). History of Early Stone Sculpture at Mathura, Ca. 150 BCE-100 CE. Concept Publishing Company. p. 2. ISBN 90-04-15537-6.
36. ^ "Ruins of 2,000-year-old city found near Peshawar".
37. ^ "Tiruvannamali Historical moments". Tiruvannamalai Municipality. 2011. Archived from the original on 2013-10-29. Retrieved 2012-12-29.
38. ^ Southern Circle (1903). Epigraphy. Madras: Archaeological Survey of India. p. 5.
39. ^ "Beijing". UNESCO.
42. ^ a b J. G. De Casparis (1978). Indonesian Chronology. BRILL Academic. pp. 15–24. ISBN 90-04-05752-8.
44. ^ "Angkor National Museum website". Retrieved 2011-01-31.
45. ^ "The promise—and the pitfalls".
46. ^ According to a local act number 6 (1989)[not specific enough to verify]
48. ^ "Timeline of history". Archived from the original on 2009-11-23. Retrieved 2009-10-09.
50. ^ Bullough, Nigel (1995). Mujiyono PH, ed. Historic East Java: Remains in Stone (Indonesian 50th independence day commemorative ed.). Jakarta: ADLine Communications. p. 19.
55. ^ a b "The Aginid -".
56. ^ a b "Early Cebu History".
57. ^ Ouano-Savellon, Romola (11 August 2018). ""Aginid Bayok Sa Atong Tawarik": Archaic Cebuano and Historicity in a Folk Narrative". Philippine Quarterly of Culture and Society. 42 (3/4): 189–220 – via JSTOR.
58. ^ a b Henson, Mariano A (1955). The Province of Pampanga and its towns (A.D. 1300–1955) with the genealogy of the rulers of central Luzon. Manila: Villanueva Books.
59. ^ The story is recorded in JMBRAS magazine, October 1935, Volume XIII Part 2, page 15 - 16.
60. ^ Peace of Angkor Phnom Penh Archived 2007-04-16 at the Wayback Machine.. Retrieved July 27, 2007.
63. ^ a b [1], Ancient City of Damascus – UNESCO
69. ^ The world's oldest cities,
70. ^ "Gaziantep". Retrieved 15 October 2015.
74. ^ Michal Strutin, Discovering Natural Israel (2001), p. 4.
77. ^ a b "Rayy", Encyclopædia Britannica
81. ^ "for about years – Google". Retrieved 15 October 2015.
85. ^ either The destruction of the Kirkuk Castle by the Iraqi regime. Archived 2006-05-04 at the Wayback Machine. or History Channel[dead link] for the earlier date
86. ^ Excavations at Ancient Jaffa (Joppa). Tel Aviv University.
87. ^ Mogens Herman Hansen (2000). "The concepts of city-state and city-state culture". In Hansen, Mogens Herman. A Comparative Study of Thirty City-state Cultures: An Investigation, Volume 21. Kgl. Danske Videnskabernes Selskab. p. 20. ISBN 978-8778761774. Retrieved 20 February 2017.
90. ^ "Life at the Crossroads [New Edition]: A History of Gaza". Rimal Books. Archived from the original on 2011-07-15. Retrieved 2009-01-24.
92. ^ Cecil Roth, Encyclopaedia Judaica, 1972, p. 619.
94. ^ a b "Yazd - Iran".
101. ^ "Encyclopaedia Britannica – History of Tasmania". Retrieved 17 July 2008.
112. ^ Hogan, C Michael (January 23, 2008). "Cydonia". The Modern Antiquarian. Retrieved March 31, 2012. The most powerful centre of western Crete, Cydonia produced Bronze Age pottery and Linear B writings circa 1700 to 1500 BC, and was one of the first cities of Europe to mint coinage. (Pashley, 1837)
114. ^;
116. ^ Phoenicians according to the Iberian protohistoric architecture project.
117. ^ Nash, Elizabeth (9 October 2007). "'Europe's oldest city' is found - Europe, World - The Independent". The Independent. London: INM. ISSN 0951-9467. OCLC 185201487. Retrieved 19 May 2011.
119. ^ "Vani".
121. ^ The Phoenicians and the West. Retrieved 15 October 2015.
122. ^ Cassar, Carmel (2000). A Concise History of Malta. Msida: Mireva Publications. ISBN 1870579526
124. ^ Domenico Spanò Bolani (1857). Storia di Reggio di Calabria ... sino all'anno ... 1797 (in Italian). Retrieved 2 June 2017.
130. ^ Gela Gamkrelidze. RESEARCHES IN IBERIA-COLCHOLOGY. Edited by David Braiind (Prof, of University of Exeter (UK)) // Olar LORDKIPANIDZE CENTRE OF ARCHAEOLOGY OF GEORGIAN NATIONAL MUSEUM. P. 43 "According to the data on archaeological excavations on the Gabashvili, Dateshidze and Ukimerioni hills in Kutaisi, an urban-type settlement of the 6-5 cent. BC was found to be concentrated"
133. ^ "6.2 Revisiting History: Ancient Gabala". Retrieved 15 October 2015.
139. ^ "Историја Београдске тврђаве" (in Serbian). June 2016. Archived from the original on 2011-09-05.
140. ^ "Chronologie". Retrieved 15 October 2015.
141. ^ Caesar's Commentaries on the Gallic Wars, book 7
142. ^ Archived 2008-12-12 at the Wayback Machine.
143. ^ Classical Antiquities, by Johann Joachim Eschenburg, 1860, p 6
144. ^ "Du Paléolithique au Néolithique". Musées de la ville de Strasbourg. Retrieved 3 September 2018.
145. ^ "Azerbaijan – Walled City of Baku with the Shirvanshah's Palace..." Archived from the original on 2 January 2008. Retrieved 14 October 2007.
146. ^ Visit Bath, History and Heritage |
148. ^ York Museums Trust, History of, Roman,
149. ^ Report on the Situation of Urban Archaeology in Europe. Council of Europe Publishing. 1999. p. 54. ISBN 978-9287136718. Retrieved 2 November 2017.
151. ^ Lyachynska, O. Kyiv’s 1,530th birthday marked with fun, protest. Kyiv Post. 31 May 2012
153. ^ Glasgows-timeline |("Archived copy". Archived from the original on 2005-04-15. Retrieved 2011-06-17.
154. ^ Saint Mungo |"Archived copy". Archived from the original on 2011-06-22. Retrieved 2011-06-17.
155. ^ City of Aberdeen,
157. ^ "Y Gododdin". Retrieved 2013-01-19.
158. ^ "Wawel". Retrieved 15 October 2015.
159. ^ K. Kris Hirst. "Ribe – What is Ribe". Archaeology. The About Group. Archived from the original on 2013-01-17. Retrieved 22 August 2012.
160. ^ Chernykh, N.B. (1985). Дендрохронология древнейших горизонтов Старой Ладоги (по материалам раскопки Земляного городище) (Dendrochronology of the Oldest Layers of Staraya Ladoga (from the Excavation Materials)). Новые археологические открытия (New Archeological Discoveries). I. Leningrad. p. 79.
163. ^ "Welcome to Gniezno". Retrieved 2016-08-15.
166. ^ Archived December 24, 2008, at the Wayback Machine.
167. ^ "Västerås historia - Västerå".
External links[edit] |
Diseases & Conditions A - Z
powered by Talix
Secondary Amenorrhea
What is secondary amenorrhea?
Amenorrhea is the absence of menstruation. Secondary amenorrhea occurs when you’ve had at least one menstrual period and you stop menstruating for three months or longer. Secondary amenorrhea is different from primary amenorrhea. It usually occurs if you haven’t had your first menstrual period by age 16.
A variety of factors can contribute to this condition, including:
• birth control use
• certain medications that treat cancer, psychosis, or schizophrenia
• hormone shots
• medical conditions such as hypothyroidism
• being overweight or underweight
What causes secondary amenorrhea?
During a normal menstrual cycle, estrogen levels rise. Estrogen is a hormone responsible for sexual and reproductive development in women. High estrogen levels cause the lining of the uterus to grow and thicken. As the lining of the womb thickens, your body releases an egg into one of the ovaries.
The egg will break apart if a man’s sperm doesn’t fertilize it. This causes estrogen levels to drop. During your menstrual period you shed the thickened uterine lining and extra blood through the vagina. But this process can be disrupted by certain factors.
Hormonal imbalances
A hormonal imbalance is the most common cause of secondary amenorrhea. A hormonal imbalance can occur as a result of:
Hormonal birth control can also contribute to secondary amenorrhea. Depo-Provera, a hormonal birth control shot, and hormonal birth control pills, may cause you to miss menstrual periods. Certain medical treatments and medications, such as chemotherapy and antipsychotic drugs, can also trigger amenorrhea.
Structural issues
Conditions such as polycystic ovary syndrome (PCOS) can cause hormonal imbalances that lead to the growth of ovarian cysts. Ovarian cysts are benign, or noncancerous, masses that develop in the ovaries. PCOS can also cause amenorrhea.
Scar tissue that forms due to pelvic infections or multiple dilation and curettage (D and C) procedures can also prevent menstruation.
D and C involves dilating the cervix and scraping the uterine lining with a spoon-shaped instrument called a curette. This surgical procedure is often used to remove excess tissue from the uterus. It’s also used to diagnose and treat abnormal uterine bleeding.
Lifestyle factors
Body weight can affect menstruation. Women who are overweight or who have less than 15 percent body fat may stop getting menstrual periods. This is especially true for athletes who train extensively or excessively.
Emotional stress is another possible cause of secondary amenorrhea. Your body may respond to extreme stress by disrupting your normal menstrual cycle. Your menstrual periods will most likely resume once you work through your tension and anxiety.
Symptoms of secondary amenorrhea
The primary symptom of secondary amenorrhea is missing several menstrual periods in a row. Women may also experience:
Diagnosing secondary amenorrhea
Your doctor will first want you to take a pregnancy test to rule out pregnancy. Your doctor may then run a series of blood tests. These tests can measure the levels of testosterone, estrogen, and other hormones in your blood.
Your doctor may also use imaging tests to diagnose secondary amenorrhea. MRI, CT scans, and ultrasound tests allow your doctor to view your internal organs. Your doctor will be looking for cysts or other growths on your ovaries or in the uterus.
Treatment for secondary amenorrhea
The treatment for secondary amenorrhea varies depending on the underlying cause of your condition. Hormonal imbalances can be treated with supplemental or synthetic hormones. Your doctor may also want to remove ovarian cysts, scar tissue, or uterine adhesions causing you to miss your menstrual periods.
Your doctor may also recommend making certain lifestyle changes if your weight or exercise routine is contributing to your condition. Ask your doctor for a referral to a nutritionist or dietitian, if necessary. These specialists can teach you how to manage your weight and physical activity in a healthy manner.
Content licensed from:
Written by: Erica Roth
Medically reviewed on: May 24, 2017: Michael Weber, MD
Symptom Search
Drug Interaction Checker
Pill Identifier
Drugs A-Z
Eating Raw Cookie Dough is Even Riskier, FDA Warns
|
Deciphering Occupation Codes Appended to the 1930 Census in One Step
The following codes have been summarized from the 200+ page 1930 Census Bureau publication "Classified Index of Occupations". These codes were put on the census pages well after the enumeration was done, and therefore provide no additional information. However, sometimes knowing the code can help you determine the occupation in cases where the quality of the microfilm is poor or the handwriting of the enumerator is difficult to read.
These codes were transcribed by C. Marie Taylor of the Family History Library in Salt Lake City.
Group 1: First character is a digit between 0 and 7 or is the letter V
occupation level
Group 2: First character is 8 or 9
© Stephen P. Morse, Joel D. Weintraub, David R. Kehs, 2002 |
When Is an Extension Cord Bad?
Extension cords are vulnerable to damage.
Extension cords are vulnerable to damage. (Image: extension cable image by Gudellaphoto from Fotolia.com)
Damaged extension and appliance cords are responsible for many home electrical fires. They are prone to damage from many causes and should always be inspected before use. Knowing a "good" cord from a "bad" one is important.
Video of the Day
The only non-flexible parts of a cord are the plugs. This makes them vulnerable to knocks, and crushing and flexing damage when, for example, they are dropped, run over by vehicles or trapped in door or window frames. Cracked and broken plugs may expose you to live components and permit water to enter and cause a short circuit.
Cut, crushed or damaged insulation may expose live wires and allow water to enter the cord. It creates a risk of fire, electric shock and death. The outer insulation should be present where the cord enters the plug and must continue as far as the cord grip within it.
Broken Wires
A fizzing sound from either plug, or a power supply that becomes intermittent, may indicate a loose or broken wire. Broken and loose wires cause "arcing," tiny sparks of electricity jumping across the gap in the wire. This creates heat and may eventually melt the cord or set it on fire.
Promoted By Zergnet
You May Also Like
|
Birth and Bereavement Support
Pregnancy, miscarriage or pregnancy loss, infertility, and the postpartum period can tremendously challenge an individual's mental health.
An individual who has endured the unbearable loss of a pregnancy is suddenly cast into a world of unknowns. This isn't what they expected. Everything has turned upside down. If a clinical depression descends upon the already weary soul, loss and pain become deeper and darker. If left untreated, PPD can (and often does) affect an individual's ability to participate in their daily life, which in turn affects family, friends, employers, and the community at large.
As many as 1 in 4 pregnancies end in loss. Unfortunately, individual's are often left to suffer alone, because although we expect there to be some stage of “normal grief,” most friends and family are eager for individual's who have experienced a loss to return to their “old self.” This, in turn, can leave the individual feeling misunderstood and drive them further into isolation. Understandably, this can create the opportunity for depression to emerge.
Studies have also determined that during the first year after loss, supportive counselling (peer and/or professional) was effective in reducing overall emotional disturbance, anger, and depression. The conclusion was that the caring attention from peers and counsellors had positive and significant effects on the integration of loss and improvement of self-esteem in the first year subsequent to miscarrying. This is important because many individual's feel they need to suffer in silence and may not feel it's appropriate to ask for help or may resist reaching out.
Giving a woman permission to grieve sufficiently, and more importantly supporting her through that grief, can ease the pain of her loss and promote healing. |
Percentage Calculator
Use this versatile percentage calculator to easily calculate the percentage difference between two numbers, to calculate percent change (percentage increase, percentage decrease), and to find out what % is a given number from any other given number.
Share calculator:
Put it on your site!
get code
What is a percentage?
A percentage is a dimensionless number, represented as a fraction of 100, e.g. 50 out of 100 can be written as 50%, and 1 out of 10 can be written as 10%. A percentage is by definition a ratio. The sign for percent is "%", but the abbreviation "pct" is sometimes used in its place, while in older literature and documents one can encounter "per cent", where "cent" is an abbreviation of the Latin "centum" which literally means "one hundred", so the phrase means "per one hundred" - the literal definition of percentage.
Percentages have a wide array of application in many disciplines and everyday usage which is why having a percentage calculator can be very handy. They are common in statistics, social sciences, economics, finance, accounting. In everyday usage we often encounter percent off coupons. Promotions, sales, and various discounts are often expressed as percentage from a previous reference price of an item or service. Percentages can be used when measuring productivity or load of a person or machine, e.g. "he is working at 100%" (at maximum capacity).
Percentage increase or decrease are used to describe the relative growth or decline of something, e.g. a population, capital, personal wealth, etc. Differences between any two objects can be expressed as ratios or as percentage difference. The measurement error of a tool or process can be described in terms of percent error.
How to calculate percent change?
This is what most people mean when they want to know "how to calculate percentage", but for other possible percentage calculations see below. Percent change calculations are common when comparing quantities, business metrics, or other measurements from two time periods, or when comparing a new state of things to an old state of things. Our percentage calculator is of great assistance for calculating percent increase / decrease, but you can also calculate percentage change on your own.
For example, say you are reviewing the performance of your business on a monthly basis and you see that the past month you had 80 customers while the month before you were able to acquire only 64. To find out the growth rate of your business you need to calculate percent change using the formula:
Percent change = new / old * 100 - 100
where new is the newer quantity or measure, and old is the older quantity or measure. In the above example this would be 80 / 64 * 100 - 100 = 1.25 * 100 - 100 = 125 - 100 = 25%. Your monthly percentage change (percent growth, percent increase) was thus 25 percent.
In another situation, you might be examining a proposition to increase your salary from $100,000 a year to $120,000 a year to keep you on the payroll and want to know what percent is the new salary versus your old one. You divide 120,000 by 100,000 to get 1.2, then multiply by 100 to get 120. Minus 100 leaves 20%. Therefore, you were offered a 20% increase of your salary and as the new salary is 120% of your current salary.
How to calculate X is what percent of Y?
Let's say you are a car salesman and you have a car originally priced at $50,000, but you have done some calculation and determine that you can take $5,000 off the price of the car and still be ahead after the sale. How can you determine what percentage is $5,000 from $50,000? The formula to use is:
x is x / y * 100 % of y
so in this case that would be 5,000 / 50,000 * 100 = 0.1 * 100 = 10%. If you were to offer a $5,000 discount on a $50,000 car, that would be a 10% discount.
In another example you might want to calculate what percentage of your total yearly income you have to pay in taxes. If your yearly income is $80,000 and you have calculated that your total tax amount is $36,000, then your tax rate is 36,000 / 80,000 / 100 = 0.45 * 100 = 45%, since $36,000 is 45 percent of $80,000. You can do all these calculations easily using our online percentage calculator.
How to calculate percent difference?
Percentage difference of two numbers (quantities): a and b is calculated using the formula:
Percent Difference = |a - b| / ((a + b) / 2) * 100 percent
For example, if one item costs $5 and another costs $6 the percent difference between them is: |5 - 6| / ((5 + 6) / 2) * 100 = 1 / (11 / 2) * 100 = 1 / 5.5 * 100 = 18.18%. Please, note that this doesn't mean that 5 is 18.18% smaller than 6, or that 6 is 18.18% larger than 5. The correct percentages if you are asking the question of "what percent is a from b" would be 16.66% and 20%, respectively, as explained above.
Percentage difference is useful in few situations, so it should be used with care. For example, one should not use it when comparing time periods, as the first metric is another state of the second metric, so percent change is the appropriate calculation. Similarly, calculating a price change should not be done using percentage difference.
Compounding and averaging percentages
Percentages should not be added up (compounded) or averaged like simple numbers, as this will result in an incorrect end result. Compounding is often encountered in finance, e.g. when calculating compound interest or multi-year return of a financial portfolio. Averaging percentages is often encountered in business calculations, for example to determine the average growth of a company, but also in finance and banking where average growth of an asset or asset portfolio may be calculated.
Here is an example of adding percentages: say you have a $100,000 bank deposit at a 2% interest rate, applied yearly at the end of the year. If you keep it for 5 years, you might think that the way to calculate your deposit's value at the end of the 5-year period is to simply multiply 2% x 5 = 10% (or, equivalently, 2% + 2% + 2% + 2% + 2% = 10%). By this calculation you would expect to have $110,000 at the end of the period (10% of 100,000 is $10,000). However, you will have $110,408, since at the end of each year you will get your interest and then in the following years you will also accrue interest over the interest from the first year. And so on for the second, third...
To average percentage growth a year, it would be incorrect to just sum up the growth % in each year and then divide by the number years. Let us say you have an asset that grew 5% the first year, 6% the second year, 10% the third year, and then lost 10% the fourth year. The growth is not 5% + 6% + 10% - 10% = 11%, but it is instead the geometric mean: 2.4549% times the number of years = 2.4549 x 4 = 9.82%.
The above peculiarities are also the reason why if you lose 25% of some asset, you need to grow it 33.33% to recoup the loss. A quick calculation that you can also do using our percent calculator, shows that $10,000 * 25% = $7,500, while $10,000 of $7,500 = 133.33% (or $10,000 - $7,500 = $2,500 to return to zero, and $2.500 is 33.33% of $7,500).
Cite this calculator & page
Georgiev G.Z., "Percentage Calculator", [online] Available at: URL [Accessed Date: 24 Sep, 2018]. |
Starting Strong V
Transitions from Early Childhood Education and Care to Primary Education
image of Starting Strong V
English French
Developmental continuity in transitions from early childhood education and care to primary school
To ensure continuity in young children’s development, high-quality ECEC needs to be followed by quality education throughout school, and particularly during the first years of primary education. Collaboration is the watchword for developmental continuity, and is explored here for a range of actors involved in child development, including children themselves, their parents, ECEC and primary school staff, and community services. The chapter draws on a survey of OECD countries and partner countries to outline key trends across jurisdictions, as well as similarities and differences. It describes five main challenges highlighted by participating countries that are hindering developmental continuity, along with a wealth of practical strategies for tackling them. It concludes with some pointers for policy development as food for thought for countries seeking to improve developmental continuity in transitions.
English French
This is a required field
Please enter a valid email address
Approval was a Success
Invalid data
An Error Occurred |
Lincoln’s Death, New Nation: April 1865 to 1877
Modern-Day Movies
Who was the youngest person to serve in the Civil War?
He seems to have been Johnny Clem of Licking County, Ohio. Christened John Joseph Clem, he was born in August 1851 and was just under ten years of age when the war began. His mother died at about that time, and young Johnny Clem determined on a life of adventure. He was mustered into the 22nd Michigan on May 1, 1863.
Harper’s Weekly ran an image of Johnny Clem in February 1864, with the twelve-year-old boy wearing the uniform of a sergeant. He had a sad expression, but this was typical of many photographs and images from that time: nineteenth-century Americans did not “smile” for the camera in the style of their descendants. When the war was over, Johnny Clem petitioned President Grant, who made him a second lieutenant in the 24th U.S. Infantry. Clem lived to a ripe old age.
|
Sir Tim Berners-Lee
The creator of the Internet
What I know
Sir Tim Berners-Lee Was the creator of the Internet. He wanted to create the Internet so people from around the world could communicate to each other. He is now in his 60s and is still a healthy man. In 2004 he was knighted by Queen Elizabeth ii for his outstanding work.
Big image
Sir Tim Berners Lee was the inventor of HTML and "The world wide web" he wanted to make this so you could store things like work and lots more. He thought it was a good idea so people could share and upload things. This has made a big impact on "The World Wide Web "because of him this has made people be able to make apps online and games such as YouTube , What's App and loads more. |
Busy. Please wait.
show password
Forgot Password?
Don't have an account? Sign up
Username is available taken
show password
Already a StudyStack user? Log In
Reset Password
Remove Ads
Don't know
remaining cards
Pass complete!
"Know" box contains:
Time elapsed:
restart all cards
Normal Size Small Size show me how
Causes of the AR
What group formed as a cause of the Stamp Act? Sons of Liberty
What was being taxed during the Stamp Act? All paper materials anything made with paper.
What did the Townsend Acts Tax? Everyday items like glass, lead paints, paper, and tea.
What were the writs of assistance? It helped the British in forcing rights or laws.
What was the Boston Massacre? It started out by a soldier being harassed by a whig apprentice. Then a group of colonists join in on the argument, a group of British soldiers join the colonists start throwing snowballs, then the British start firing.
How many colonists were killed? 5 colonists were killed and 2 officers were found guilty of manslaughter. Then came the Tea Act.
What was the Tea Act? The East India Company put a tax on tea so that they wouldn't go bankrupt and colonists did not like that at all so it lead to the Boston Tea Party.
What was the Boston Tea Party? Sam Adams was the leader of this, the colonists dressed up like mohawk indians and they stormed onto the first ship and dumped all of the tea out into the Boston Harbor.
What five punishments did the coercive acts give out. First Punishment was they closed the Boston Tea Harbor 2nd was they closed down their government and revoke their charter, 3rd was the quartering act which required colonists to house and feed the British soldiers. 4th was Any British official accused of
a crime would be tried in in Great Britain, and the 5th was Governor Hutchinson was removed from office.
First Continental Congress when did it occur and what were the three decisions? Occurred in 1774 the three decisions were it encouraged the colonists to boycott british goods, they told the militia to be ready to fight, They send a declaration of rights to King George the third, a list of ten rights they believed that they should
have as British citizens.
What happened in the Battle of Lexington and Concord Paul Revere and William Dawes warned the colonists that the redcoats are coming the first shot was fired at Lexington the British went to concord to capture an arms cache and to capture Sam Adams and John Hancock. British won the first battle but the
colonists made the British retreat back to Boston and they killed and wounded 250 British soldiers, so the Colonists won the second battle.
What did the Second Continental Congress decide? The second continental congress they formed the continental army and put President George Washington in charge. They authorized the printing of money to pay for the soldiers. They form a committee to deal with foreign countries. They made an Olive
Branch Petition
Created by: 19ImmelZ |
Printer Friendly
Steven Johnson (New York: Riverhead Books, 2014)
Stepping outside, you are met by 98 degree heat, 98 percent humidity, and the blinding Florida summer sun. It is 22 steps to the mailbox and 22 steps back. Even that short trip generates a visible all-body sweat and you feel the beginning of sunburn on your nose. Who would choose to live in this environment? The answer is that almost no one chose to before the widespread availability of air conditioning. Without the safe comfort of a temperature- and humidity-controlled home, it was not only uncomfortable but unsafe to live in Florida's summer heat. Our comfortable indoor climate is a relatively new invention, stemming from the entrepreneurial efforts of Fredric Tudor who, in 1835, shipped New England lake ice to the sweltering inhabitants of Savannah, Georgia. He simply wanted to put ice chips in their drinks and give them an essential tool for making ice cream and similar treats, but these blocks also offered the localized comfort of cooler air. That got some creative people thinking, eventually leading to the invention of the first air conditioners. The central air conditioning that followed from that in the mid-1940s changed the nation's population patterns and allowed the economic potential of America's southern states to be harvested.
In How We Got to Now, Steven Johnson explores the history of climate control and five other innovations that have had a significant impact on the shape of society and the fortunes of countries. Johnson's "long zoom of history" perspective integrates invention, application, society, and politics to illuminate the wide-ranging effects key technologies have had on entire societies. In just six chapters--Glass, Cold, Sound, Clean, Time, and Light--he illustrates the role these pivotal innovations played in the emergence of modern society. In the process, he explores the unique, surprising, and thought-provoking family lineage of these key technologies.
The result is an engaging, illuminating narrative with unexpected twists. For instance, how does a meteor strike in Russia contribute to the invention of the telescope? How does ice exportation change the political landscape of a country? How do primitive cave paintings inform the invention of military sonar? How do the disposal practices for human waste open the doors for underground rail transportation? How do clocks and lights come together to create an entirely new circadian pattern for human beings?
Johnson explored some of the same inventors and innovations in his previous book, Where Good Ideas Come From. There, though, he used these examples to distill seven properties of idea generation. In How We Got to Now, Johnson looks at these key developments in their historical context, producing a book that ties small technical discoveries to larger technologies and trends and maps their impact on society and politics. The inventors' personal stories are linked to wider forces and the connections that tie individual ideas together, and allow small inventions to become world-changing forces, are explored. The narratives vividly demonstrate how little is actually accomplished in an individual Eureka moment, and how truly game-changing technologies require decades-long experiments with many unproductive branches to perfect. Using Johnson's own analogy, these technologies have required hundreds of Steve Jobses--people who did not invent the MP3 player, but turned the technology someone else invented into something that met a societal need.
Avid readers of science history will already be familiar with the stories of Galileo Galilei, Willis Carrier, Thomas Edison, and Alexander Graham Bell. But How We Got to Now pays tribute to the contributions of dozens of lesser-known inventors who are just as interesting and worthy of historical recognition, and perhaps provides perspective on the way that truly revolutionary technologies emerge in tiny steps. My favorite chapters were the first, on the evolution of glass, and the last, on the importance of artificial light. The chapters between, although they are still interesting, generally focus on a much narrower range of ideas tied into a much shorter shared history. As a result, they do not provide the same revelatory insight as the opening and closing sections. If you find yourself losing interest in these middle chapters, jump to the light before putting the book aside.
Roger Smith
CTO/Florida Hospital Nicholson Center
COPYRIGHT 2015 Industrial Research Institute Inc.
Copyright 2015 Gale, Cengage Learning. All rights reserved.
Article Details
Printer friendly Cite/link Email Feedback
Author:Smith, Roger
Publication:Research-Technology Management
Article Type:Book review
Date:Mar 1, 2015
Previous Article:Collective Genius: The Art and Practice of Leading Innovation.
Next Article:Developing intuition and building teams: Martin Jung: as Senior Vice President, Research Structural Materials, for BASF, Martin Jung relies on...
|
Skip to main content
Explore URMC
Arrhythmia Surgery
For some patients, surgery may be required to regulate an irregular heartbeat.
If your heartbeat is too slow or irregular, your surgeon might insert an electronic pacemaker to regulate your heart rate. The permanent pacemaker is inserted through a small incision in the upper chest close to a major vein. Then the pacemaker wire is moved through the vein and into the heart. The wire carries signals between the heart and the pacemaker, which the surgeon attaches to the wire and places in a protected area underneath the skin or under the muscle. The pacemaker then delivers an electrical impulse whenever it detects a slowing or irregularity of heart rhythm.
Implantable Defibrillator
Similar to a pacemaker, a defibrillator is another device implanted into the chest that monitors heart rate. While pacemakers are used when a patient suffers from a slow or irregular heartbeat, defibrillators are used when a patient's heartbeat sometimes becomes too fast. The defibrillator can sense when the heart rate increases, and will then send out electrical signals to bring the heart rate back down to normal.
For more information about cardiac surgery or to refer a patient for a consultation, call us at (585) 275-5384. |
How to make homemade eco-friendly soap
{ 0 comments } Housekeeping
Respecting the environment also means changing our everyday behaviour, such as the soap we use at home: you can make homemade eco-friendly soap with simple and natural ingredients without using industrial products that can cause allergies and irritation.
One way to make homemade soap is the cold method. This the more simple method, especially when compared to the hot technique. In the cold process, the caustic soda is not heated directly, whereas in the hot process it is.
The three basic ingredients necessary for the production of soap (hot or cold), are oil (any kind: olive oil, sunflower, coconut, beeswax), caustic soda and water.
Homemade eco-friendly soap recipe: ingredients
You will need to use these ingredients in the following quantities:
• 1 kg oil (if you use olive oil)
• 128 g of caustic soda
• 300 g water
Please note that caustic soda is a dangerous product and must be handled with extreme caution. Here are a few essential precautions: keep caustic soda out of the reach of children or pets and avoid contact with eyes, skin and mucous membranes, as it is highly corrosive and burns the skin. It is, therefore, necessary to use plastic gloves and swimming goggles (or transparent eye goggles) when using caustic soda and when mixing it with water and oil.
DISCOVER: Homemade eco friendly cleaners
Similarly, a headscarf wrapped around the nose and mouth is highly recommended because of the steam produced by diluted sodium hydroxide. It is also advisable to use disposable containers which you use only for the production of soap.
Homemade eco-friendly soap recipe: step-by-step preparation
Put the weighed oil in a non-stick metal saucepan. Heat over low heat to 60°C (you can help yourself by using a kitchen thermometer). Slowly pour the soda in the water (never the other way round). Mix well and check the temperature of the water as it tends to rise rapidly to 80-90°.
Cool the soda and water mixture down too 45-50°C and pour slowly into the saucepan with the oil in order to get a homogenous mixture. Pour into a glass jar. The circular movement generated from pouring should trigger a hydrolysis reaction which could be verified after 3-4 minutes.
FOCUS: eco friendly diy
Once the mixture has changed color and consistency and it sticks a little in the pot, you can add essential oils or spices to your soap while mixing with a wooden spoon.
Pour the obtained mixture in a mould (made of wood, cardboard or plastic) and cover well as the soda will continue to react with the oil. Finally, after 24 hours, you can turn out the solid soap with gloves and then cut into desired shape.
Leave the soap for 4 to 5 weeks in a cool, dry place before using. Only after this time will the caustic soda have disappeared.
You might also like:
Leave a Comment |
ES2015 Lesson 2: Function scope, block scope, constants – Solutions
Exercise 1: Check the following riddle:
Determine the values logged to the console.
• (A) is not printed out, because we accessed guessMe2 in its temporal dead zone, resulting in an error
• (B) is printed out, the value of guessMe1 comes from the outside, while guessMe2 is assigned a value the line above this console.log statement
• (C) is printed out, the value of guessMe2 is not influenced by the definition inside the block. In this scope, the definition in line 2 holds
• (D) and (E) are obviously not printed out, as the arrow function is not called anywhere
• (F) is printed out with the same values as (C)
Exercise 2: Modify the code such that all six console logs print out their values exactly once, and the printed values are the following:
You are not allowed to touch the console logs, just the rest of the code.
In the first block, move the let declaration to the top of the block, to avoid the temporary dead zone belonging to guessMe2 in the first console log. Now that the temporal dead zone is removed, the try-catch block serves no purpose anymore.
In order to execute the fourth and the fifth console logs, we have to invoke the function. Note that self-invoking functions are not necessary anymore in ES2015, as we should only be using block scoped variables anyway, and creating blocks to separate scope is sufficient.
Without moving the declaration of guessMe1 inside the self-invoking function to the top, the console log D would log undefined. Even though it does not make a difference, I also moved the let declaration of guessMe2 to the top.
Exercise 3: Add the linter of your choice to your text editor or IDE. Configure your linter such that you never have to worry about leaving a temporal dead zone unnoticed.
Solution: There is no exact solution to this exercise. Read my article about ESLint if you are interested in learning the basics of linting. Configure the text editor of your choice to run with ESLint.
For var declarations, I used the vars-on-top rule. There was no such rule in ESLint for let and const declarations (proof).
If you go down the line of not allowing var at all, use the no-var rule.
Regarding the temporal dead zone, the no-use-before-define rule parses and spots variable use in the temporal dead zone. |
5. Coin Use in Britain in the Early 5th Century
5.1 Coin use c. 407-430
The contents of late Roman precious metal hoards suggest that coinage did circulate in Britain during and probably after the reign of Constantine III (AD 407-11). There are coins struck for him and for Arcadius and Honorius in the Hoxne hoard, dating to AD 407-8, which have been clipped suggesting that they had been in circulation for some time before deposition (Guest 2005, nos 748-53). Clipped coins of Constantine III are also found in the Coleraine hoard (see above) and the Haynes hoard (Robertson 2000, 1621; Inscker and Orna-Ornstein 2009, 385, nos 97-8). What is significant is that the Constantine III issues found in Britain are nearly all from his early issues of AD 407-8. This suggests that later coins of Constantine III did not arrive in Britain in significant numbers, possibly due to the rebellion against Roman authority recorded in AD 409 by Zosimus (1982 6, 5-6). The notable examples of later issues of Constantine III come from Richborough and the Patching hoard (West Sussex), which was deposited many decades later c.AD 470, when one can argue that Roman coin use in Britain had long since ceased (Reece 1968, 200; Orna-Ornstein 2009, 392, no. 43) (Figures 1-2).
If silver coinage continued to be in circulation after the reign of Constantine III, albeit in dwindling numbers and alongside hack-silver and ingots, bronze coinage seems to have ceased to circulate widely in great numbers earlier (see above). As we have already noted, Theodosian bronze coins , in hoards and as stray finds, tend to be found in greatest numbers at military and urban sites and at nodal points on the road network. Although most Theodosian bronze coins are struck before c.AD 395 (see above), the few 5th-century pieces found suggest that there was possibly still some supply of bronze coinage in the province until c.AD 430 (These nummi probably arrived with individuals in a similar manner to earlier quadrantes in the 1st and 2nd centuries (McIntosh and Moorhead 2012)). The early 5th century VRBS ROMA FELIX, GLORIA ROMANORVM and CONCORDIA AVGGG pieces (see above) quite probably arrived in the years AD 407-11. However, the three Honorius pieces (dating to c.AD 410-23; see above) and five Valentinian III pieces (dating to c.AD 425-35; see above) must have arrived significantly after the traditional date for the collapse of the Diocese. |
The History of cosmonautics
The methodology of extra-curricular activities
“History of cosmonautics”
Goal . formation of knowledge about the history of space exploration.
Learning objectives:
Secondary . formation of concepts:
– theoretical and practical assumptions kosmonavtiki research;
– about the history of space research in Russia and abroad.
The principle of operation
Obviously, enough people settled on the planet. Now he rushes into space to other planets, other worlds. Me some time ago, suddenly puzzled question that, maybe, the desire to space as it is genetically built into the human population. Give this thought to those who insist on the theory of extraterrestrial origin of life. Perhaps this is an argument in the dispute. Life originated in space and was for the planet entered, so man tends back. The truth is, other living creatures, tearing at the limits of Earthly comfort I do not know.
One way or another, but wanting to hit the road for a week not in Komarovo, and the ISS, among the millionaires abound. It is a pity that the station still more and to carry back only the tourists are not going. Today for money on the ISS managed to get only five people. The other fly to work. This is a troublesome thing – busy with tourists, but as it turned out very favorable.
Space, generally, requires a lot of money. Considering that not every person can afford to buy a car, it to deal with space transportation passengers can afford not every rich country. Probably, for this reason, we seek cheaper ways of delivering goods or passengers to low earth orbit. Continue reading
Long-term manned space missions is now impossible
The answer to the question of how in the coming years will be Russia’s contribution into the process of full exploration by the inhabitants of the Earth, not yet clear
Before the first manned flights into space, many physicians feared that in weightlessness the astronaut may be a different disease: ulcers and kidney stones, sudden weight loss, softening of bones, decreased muscle tone, the development of sea-sickness, disturbance of the orientation and other misfortunes. But in reality it turned out that astronauts in General are more or less able to adapt to microgravity and not to experience any serious discomfort, especially in flight conditions, the duration of which does not exceed 6-10 months. In order to reduce harmful effects to a minimum, the astronauts, while in orbit, exercise, diet, etc.
But how will affect the human body long-term space flight, lasting several years, physiologists have collected insufficient data.
In light of the active conversations and different messages about the future of manned human flight to Mars, which include the experiment “Mars-500” and recent statements by President Barack Obama . this information is very necessary. Continue reading
The biggest planet in the Universe
Continue reading →
Jupiter, the largest planet in the Solar system
The planets and moons in orbit of the Sun The largest planet in the Solar system. this is a Jupiter belonging to the class of gas giants. Ancient astronomers were…
Continue reading →
The atmosphere of the cosmos
Continue reading → |
viernes, 20 de julio de 2012
European Day for Victims of Hate Crimes
In Memoriam of Oslo´s Massacre
July the 22nd
European Day for Victims of Hate Crimes
One year ago, Norway suffered the worst massacre since World War II. 76 people were murdered, most of them just because their political ideas as young members of Labour Party. That’s why some European NGOs are asking for an European Day for Victims of Hate Crimes, in order to preserve their memory and dignity and raise awareness about destructive capacity of those ideologies that promotes hatred and violence.
The unnamable killer is a terrorist inspired by the ideology of intolerance. Ideas shared by a Right Wing Extremist willing to destroy democracy and whipped out values of equality, tolerance and diversity. They clearly intend to terminate the global Human Rights advances.
The July 22nd hatred motivated terrorist attack wasn´t an isolate tragedy. Another hate crime have shocked European Society. German neo-Nazi murders scandal linked to intelligence service, racist crimes in Italy, harassment of Roma people in central Europe, attacks to jews and muslims, desecration of religious places and homophobic aggressions are some examples of this wave of hate and violence in Europe.
Europe is not very used to remembrance however memory is more important than ever in order to preserve the victim´s dignity. We need more commitment and determination against racism and related intolerance. Democratic courage is required for a better struggle against the imminent threat of poisoned extremist ideologies.. Europe assumed values of equality, tolerance and diversity after the tragedy of Holocaust in order to shout “never again”, these principles are in danger and that means vulnerability for human beings.
An European Day for Victims of Hate Crimes is part of a comprehensive strategy to defeat ideologies that promote hatred and violence, and a way to preserve human dignity, democratic values, and Human Rights. The July 22nd attack was a turning point for the struggle against intolerance. The shared sorrow of Utoya and Oslo is a call for justice emerging from an irreparable loss of human lives. This is why ONGs are proposing to the European Parliament to set up this European Day for Victims of Hate Crimes. Besides we encourage civil society, institutions and citizens to support this initiative.
In Oslo, Madrid, Rome, Paris, Warsaw, Berlin…. … July the 22nd
0 comentarios:
Publicar un comentario |
Nunavut became Canada's newest, largest and most northern territory on April 1, 1999 separating from the Northwest Territories. There are no paved roads in Nunavut and most long distance travel between the 28 communities is done by air or boat. Alert, at the very tip of Ellesmere Island is North America's northernmost community, however much of Nunavut’s land and ocean is covered with ice for most of the year. 85% of Nunavut’s population is Inuit, many of which still hunt, trap and fish for survival. The mostly uninhabited land remains to be Canada’s true north; it also holds the shipwrecks of some of the early arctic explorers who were looking for the northwest passage.
|
Eating to Reverse Disease
Caroline Margonis
More Americans are diagnosed with a form of cardiovascular disease than any other country, making America the land of broken hearts.
Long-Distance Running: An Investigation Into its Impact on Human Health
Rachel Dermack
Long-distance running has helped our species survive and evolve. Elements of the human physique, like the Achilles tendon and the length of the human body, make our bodies primed for running. Studies show that running can ease depression and anxiety.
Competitive Youth Sports and the Rise of Overuse, Burnout, and Career-Ending Injury
Ginny Moses
Youth sports should be a healthy outlet for children, but the hypercompetitive environment of organized sports puts children’s minds and bodies at risk of overuse, burnout, and career-ending injury. Thirty percent of children involved in organized sports will sustain a serious injury.
The Unknown Link: Epigenetics, Metabolism, and Nutrition
Nafiah Enayet
An Orphaned Disease Worth Adopting: The Case For Duchenne Muscular Dystrophy
Jeremy Pasteris
Duchenne Muscular Dystrophy (DMD) is an incurable disease that kills most of its subjects by their early twenties.
Improving College Exam Performance with L-theanine and Caffeine
Henry Gong
Murky Waters: Turbidity's Effect on Aquatic Predation
Zachary Locklear
Temporary pond ecosystems are a fascinating and underexplored kind of ecosystem. This paper aims to investigate predation within these systems, particularly in respect to temporary ponds in North Carolina and the key creatures that inhabit them.
What is Love? Understanding The Process of Human Mate Selection
Stephanie Liffland
When humans experience attraction, most people are not aware of myriad biological processes driving their desire. This paper seeks to synthesize different research on the processes behind human mate selection.
Race Against Time: The Development of Antibiotic Resistance
Caleb Wooley
Antibiotic treatments have been around since the discovery of penicillin in 1928. For the last 70 years, antibiotics have treated numerous people and prevented severe outbreaks of bacterial infections.
Regenerative Medicine: The Interplay of Stem Cells and Polymer Science
Marcus Valcarce-Aspegren
Regenerative medicine is one of the most exciting frontiers of medicine. It has the potential to save millions of lives through the growth of new, healthy organs. People die every day waiting on organ transplant lists that might soon be unnecessary.
Tracing the Evolution of Our Universe through Blackbody Photon Dynamics
Arjun Raghavan
How was our universe actually created? Its history can be understood by examining the elementary particles and photons that were present at the start of its creation.
Beyond the Medicine: Reducing Breast Cancer Deaths in African-American Women
Sarah Chen
This paper will explore a solution to reduce the number of breast cancer deaths in African-American women. African-American women are equally as likely as white women to get breast cancer. However, African-American women are 41% more likely than white women to die from breast cancer. |
Monday, February 12, 2018
Lingering Questions: King Arthur Legend Of the Sword
When Arthur is first brought to meet Sir Bedivere (pictured above), Bedivere wears this little green hat and peels an egg; why? We know that the head symbolizes our thoughts, because our thoughts originate in our head, so anything on our head (hair, hats, etc) can communicate what or how a character thinks. Green symbolizes new life, new hope; food (the egg he peels) symbolizes that which we are "taking in," we are going to digest and "go over" in review and mediation; eggs in particular symbolize new life and birth (as in, "the born king") but Bedivere also peels the egg, suggesting that he intends to "peel away" the layers of Arthur and get to know who he is beneath the surface, which is the opposite of what Vortigern did with his nephew: after Arthur pulled the sword, Vortigern had Arthur's coffers robbed and the brothel burned and his friends and family arrested; in other words, Vortigern only needed--and wanted--to know Arthur on the surface, whereas Bedivere intends on examining Arthur on level of his deeper character instead of making judgment calls based on what Bedivere sees and artificially learns about Arthur. So, when Arthur meets Bedivere, Bedivere thinks that having found--and saved--Arthur is the new life the Resistance needed, and the born king can finally lead them to victory over Vortigern.
Please note the interesting jacket we see Bedivere wearing in this image: brown and gold. Brown symbolizes dirt, because we are either "dirty" like dirt (as in corrupt, or sexually promiscuous) or we are humble, lowering ourselves to the level of dirt in spite of how great we might truly be. We know Bedivere occupied a high-level in Uther's government--we see him and Goosefat Bill advising the king after Mordred's failed attack on Camelot--and this is the meaning of the gold we see in Bedivere's jacket pictured above: Bedivere was in a high position in the king's army and esteem, so in spite of Bedivere having occupied such an important position, Bedivere is also a humble man, which is why Arthur comes to trust him (for example, when The Mage arrives, Bedivere trusts her and trusts the dream Merlin sent Bedivere so Bedivere would recognize The Mage when she appeared; rather than distrust the future of the Resistance to her, Bedivere does trust her).
So, this Christmas, everyone I love received a copy of King Arthur Legend Of the Sword,.... if they didn't receive a copy of it, they know where they stand with me. After my sister saw it, which she loved, she had some very good questions which I failed to cover in any of the posts I have made on the film, which are numerous, so I decided to attempt to get some kind of a post up with my favorite film of 2017. Her first question: why did Vortigern (Jude Law) let The Mage return to Arthur in exchange for Excalibur? Didn't Voritgern know how powerful The Mage was?
Why is there not a relationship developed between The Mage and Arthur? Originally, Astrid Berges-Frisby was cast to portray Guinevere, the legendary queen to King Arthur, but during filming, Charlie Hunnam (Arthur) and director/writer Guy Ritchie confirmed that they mutually decided to drop the romantic angle between Arthur and The Mage/Guinevere. This article goes so far as to suggest that The Mage and Guinevere are two entirely separate characters. So, which is it? We will probably never know, unless a miracle allows Ritchie to go ahead and make the other five reported storylines of the King Arthur Legend Of the Sword narrative he originally intended. Prior to opening, KA was projected to make $25 million against a production budget of $175 million (plus another $100 million for advertising and promotions); unfortunately, it only made $15 million opening weekend, and even after home movie release, has grossed around $142 million (this doesn't tally in, however, all the copies of the film I purchased for gifts for Christmas,....) so, while there were at least 5 more planned films in the sequence, none of them are going to be made now, unless, however, Sherlock Holmes 3 and Aladdin are major box office successes, in which case, it's possible that Ritchie could use his sway at that point to take another stab at the KA story.
So, back to The Mage.
Of all the characters of 2017, she is definitely my favorite: Ritchie provides for us what I would deem the "quintessential woman of power and personal success," that is to say, she's the exact opposite of what feminists think a woman should be, but what I believe God created woman to become. So, if she's so awesome, why isn't there a relationship? I think it's to Arthur's credit that he doesn't get romantically involved with her,... or any woman we see. He grew up in a brothel, so he grew up seeing what happens to men and woman who engage in sexual relations outside of marriage and, in short, Arthur doesn't want to become that kind of man, or a woman he loves to become that kind of woman. At one point in the montage of Arthur growing up in the brothel, we see him numerous times watching a man beating one of the women who raised him, and either Arthur not being able to do anything about it, or Arthur himself also being beaten, until the end of that montage when a "customer" goes to strike Arthur and, instead of being beaten by the man, Arthur--the young man now, with his own strength--is able to stop the man's fist in mid-air before it hits Arthur's face. This is significant for at least two reasons. First, Arthur isn't growing up with the attitude that women are commodities, even though the women in the brothel have made themselves exactly that; secondly, it foreshadows how Arthur will stop Vortigern from beating him. In the final battle of Vortigern against Arthur, Arthur has been knocked down and can't get up; he has a vision of his father giving Arthur Excalibur and when Vortigern is about to strike the death blow to Arthur, Arthur is able to stand and block the blow: if Vortigern killed Arthur in that scene, it would have also been killing England, because Arthur was the rightful heir, so in the brothel scene, when Arthur defends the girls by stopping that "customer," it symbolizes the prostitute (a woman of child-bearing age) as England, the motherland which gave birth to Arthur, and Arthur rising up to defend it against those parasites who want to pillage England for their own gains, like Vortigern. So, in not treating The Mage as one of the prostitutes he grew up with, Arthur creates a vision of a "new England" which will not be bound to the sexual slavery the old England was bound to under Vortigern, rather, The Mage symbolizes spiritual freedom and advancement instead of prostitutes' slavery to being sex slaves.
Vortigern believed he had successfully killed all the Mages: if he didn't kill them during "the purges" he disguised while Uther was still alive, Vortigern killed them after he took the throne; when Arthur goes to the the "Darklands" so he can understand why he keeps looking away when his father dies, Arthur picks up the arm bone of a skeleton wearing a Mage bracelet, verifying the purge Vortigern staged against all Mages who didn't support himself and Mordred in their coup against Uther. Knowing Arthur grew up in a brothel, Vortigern just assumes The Mage is Arthur's whore and nothing else, certainly not the power behind the new king. This is where Guy Ritchie stands out against other film makers: we can ask "Why? Why didn't Vortigern realize a Mage was still living?" and Ritchie wants us to ask that, because if we don't, the film is nearly pointless.
When Arthur is brought to the hide-out from which the Resistance has been operating, and he first meets Sir Bedivere, and meets Goosefat Bill for the second time, Goosefat--who Arthur had turned over to Black Legs earlier in the film--wants to teach Arthur a lesson and slap him around a bit. Seeing that he is going to have to possibly fight Goosefat, Arthur tells Goosefat not to bother taking Goosefat's ring off; Goosefat takes his ring off, then hits in the face, and comments to Arthur, "Now that would have hurt much more had I left the ring on." What does that mean? A ring symbolizes a covenant, a promise, a vow; so to whom has Goosefat made a vow? King Uther Pendragon, to be loyal to him,.... and, consequently, to Uther's heir, i.e., Arthur. Goosefat isn't completely reconciled to the idea that the "Born King" has been living in a brothel, and aided the Black Legs in turning Goosefat in when Arthur could have hid him (from Goosefat's perspective). So, Goosefat taking his ring off before hitting Arthur (basically for revenge in turning him in earlier in the film) is a sign that he's "suspending" his oath (the ring) to Uther to be loyal to Uther and Uther's heir, which is why, after hitting Arthur, Goosefat comments, "That would have hurt a lot more if I had left the ring on," but it's more that it would have hurt Goosefat more, not Arthur, because that would have been a sign of Goosefat hitting and physically assaulting his king (Arthur) and not honoring Uther to him he would have made a vow of loyalty. In other words, Goosefat realizes that down the road, if Arthur is crowned king in the near future, Arthur could have Goosefat put to death for having recognized that he was Uther's heir (Arthur pulled the sword) and still roughed him up anyway.
Voritgern is arrogant, and that's why he doesn't believe there possibly could be any Mages left after he set out to destroy them all; we saw the same arrogance with Hillary Clinton and her 2016 campaign, the arrogance she had that she was above the law and no one could possibly bring her down. Arrogance is the reason Ritchie has his Arthur grow up on the streets: when the prostitutes first find Arthur and have his hair cut, we know that hair symbolizes our thoughts, and the beautiful, golden hair of the young prince is shaved right off; why? So Arthur won't think of himself as being royalty (his "golden curls" are "gold" and "gold" symbolizes royalty because gold is the only gift worthy of royalty, so he thinks of himself as being royal).
Why does the Sea Witch (the creature granting Vortigern power when he rings the bell after he has killed someone) demand the blood of someone he loves as her price for power? For at least two reasons: first, forcing Vortigern to sacrifice someone he loves means he's putting power over love; similarly, the other reason is that Vortigern puts his appetites over the person's love for him. For example, when Vortigern takes his wife to the sacrificial spot, she calls him "my love" and pleads for him to tell her what is wrong so she can help him; with his loving wife out of the way, Vortigern will continue making evil decisions, rather than allow himself to be stopped by someone who genuinely loves him and wants what is truly best for him (this is like God giving us the Ten Commandments to keep us from sin, so we don't self-sabotage ourselves in making bad decisions). In choosing power, Vortigern choose self-hatred, because he all ready hates himself, and refuses to allow anyone to love him: remember, he asks Maid Maggie, "Do the people love me?" and she has to take a really circuitous path to give him the answer he wants to hear. No one loves you, Vortigern, especially you, you know you are unlovable, that's why you want power instead of love: so you can take revenge on people for not loving you in spite of you intentionally making yourself unloveable. Because love is the power that is the greatest power there is ("God is love") by removing the person who Vortigern loves, and who loves him, the Sea Witch insures her own power over Vortigern's soul because no one will be able to reach Vortigern and convince him to be converted.
Arthur does, however, develop incredible confidence, and confidence is different from arrogance because confidence comes from knowing who you are because of what you have accomplished, whereas arrogance is thinking better of yourself than you really are in spite of what you have failed to accomplish. Remember: when Arthur sits in the jail cell after having pulled the sword and Vortigern asks him, "What would you have become, had you inherited the advantages of your father's kingdom?" we know what the answer is: Arthur would have become Vortigern. Every bit as conceited, manipulative and power-hungry as his uncle, not having been properly humbled would have made Arthur a man of the appetites rather than a man who cared about others more than himself.
After the failed assassination attempt of Vortigern, when Goosefat Bill shoots an arrow and kills Mercia and Back Lack is wounded then dies, Vortigern sits beside Back Lack attempting to find information about who tried to kill him and Back Lack's son, Blue, bursts in and acts like he doesn't know Back Lack at all, to which Vortigern comments, "I wish I had a son." Why does Vortigern say this? Does he not love his daughter? Women, if you will recall, symbolize the motherland: older women, beyond child-bearing years, are the symbol of the traditions and customs of the culture of that land; women who are capable of bearing children symbolize the motherland itself, the land which gave birth to the hero and helped shape his value and how he identifies himself; girls, not at the age of child-bearing, symbolize the future of the motherland. Now, when Voritgern kills his wife, Vortigern kills that part of the motherland which gave birth to himself, and we see this in the dramatic changes of the landscape that take place between the death of Uther and when Arthur is grown and his uncle Vortigern has altered English society and the landscape so it's drape and dark. When Vortigern killed his wife, he also killed the future of the English economy; how? Men symbolize the active principle of the means of economic production. Older men, again symbolize the Founding Fathers, whereas men still in their prime are the economy while boys are the future of that economy. What does Vortigern do with all the boys of England? He sells them into slavery. What does Vortigern do when his brother's son, his nephew, Arthur, appears from nowhere? He tries to have him put to death. Vortigern doesn't want a son: Vortigern admires the traits he sees in others (like Blue's quick thinking and survival skills that Vortigern knows he himself doesn't possess) and Vortigern certainly admires the way Arthur thrived in the gutter and made such a cozy position of leadership for himself, because Vortigern couldn't have done that either. So why does Vortigern say he wishes he had a son, when all he does is put the Sons of England (the young boys for whom he is responsible as their king) and the son of his brother to death? This is typical of someone who doesn't know what he wants. However, there is another reason why Vortigern has a daughter and not a son: socialism. Capitalism is going to be represented by the vitality of a man (think of X-Men's Wolverine prior to the film Logan coming out: his ability to regenerate made Wolverine an excellent example of capitalism's ability to re-generate and grow); socialism, on the other hand, is about passive employees who are dependent upon the state, not individuals who make their own living. So if Vortigern had truly wanted a son, he would have become a capitalist; however, that's not what he really wanted, he wanted power, and Vortigern's inability to reconcile what he wants with reality is a symptom typical of liberals.
Why does Back Lack die? We know that no one ever dies unless they are all ready dead, that is, they exhibit traits/values when alive which means those traits/values cannot be allowed to continue in the "new world" the hero forges, so the character dies as a result of their traits/values. Back Lack, however, sacrifices himself for his friends and his son, so the act of sacrificing one's self means they have fulfilled life to the fullest, they have realized the true value of love and laid down their life for it. Vortigern cutting Back Lack's ear, however, acts an important symbol: ears are our ability to hear "on a deeper level," a spiritual message or something not clearly spoken; when Vortigern cuts off Back Lack's ear and then speaks into it, this re-iterates the symbolism of ears, and telling us clearly that there is, indeed, something else to which we should be listening; what? The same message we have been seeing throughout the film: Vortigern, as a symbol of socialism, makes his wife and daughter die for his ambition, however, Uther and Back Lack both sacrifice themselves for their sons and, in his way, Arthur sacrifices himself for England, because he doesn't want to carry Excalibur anymore, it has cost him too many friends and dear ones (which is why the Lady of the Lake has to convince him to make the sacrifice of his will to defeat Vortigern). So, the message of the film we should be "hearing" is that fathers need to sacrifice themselves (staying with the mother, working hard to provide, overcoming addictions, etc.) instead of the sons sacrificing for the fathers (abortion, growing up without a father).
My sister also wanted to know about Vortigern's wife: why didn't anyone realize she was missing after Vortigern sacrificed her to gain power to kill Uther? First, those closest to Vortigern, such as Mercia, knew Vortigern sold his soul for power and what the price for that power was (remember, we see Mercia watching Vortigern summon a fireball Vortigern holds in his hand and Mercia isn't the least bit surprised by it; we saw similar imagery in Guy Ritchie's Sherlock Holmes and the Satanic rituals of Blackwood). Secondly, there is the daughter of Vortigern; why didn't she say something about her missing mom?
This is really the heart of the film, because what is Arthur continuously referred to? The born king. This is Ritchie's huge contribution to current "feminist thought," namely, that it's always been from women that men derive their power. For example, Uther is king because Uther was the first born of his mother's womb; Vortigern was born second. Had Uther sired Arthur with another woman other than the queen (pictured above) then Arthur would have been a bastard, and basically born in a brothel, as he tells Vortigern after Arthur has been arrested for pulling the sword; it's his mother's womb that gives Arthur his legitimacy and the right to rule; it's the Lady of the Lake who bound Excalibur to Uther and his line, and it is, of course, The Mage who wields the power necessary for Arthur to fight Votigern. When Vortigern (in the "Skeletor" guise we see him in when he is in a state of possession) kills Uther's queen, how does he do it? He throws a stake through her womb, attempting to curse Arthur's legitimacy and seal Vortigern's own "authority."
Remember the "graffiti" we see on the walls of Londinium? That is the sign of the feminine, so the idea of kingship has always been intimately bound to the power of the queen.
Now, feminists would say, "This isn't the same thing because 'making a king' isn't the same thing as having the power yourself, and if you don't have that power yourself, then you are nothing." There is a very interesting bit of "marginalia to the film, included in the Blu-Ray special features on making Excalibur: the invented a special set of runes for the film, just to be engraved upon the blade of the sword, even though it's never interpreted, and never comes up in the film, the translation is, "Take me up, cast me away," (something close to that), because "taking" Excalibur has to be seen as a duty, not a power-move, something which comes from desire, rather, love; Excalibur is a means to achieve peace, not an end of itself. To "cast away," means you will feel the burden of the power--rather like the One Ring in The Lord Of the Rings--and if you have a good heart, you will not want to bear that power (rather like Frodo) so this is why we see Arthur do exactly this in the film: after Back Lack has died, and Arthur feels unworthy and there is too much pressure on him, we see him cast Excalibur into the lake and then run from his duty and responsibility; it's then the Lady of the Lake, a woman, tells him he is chosen and he must take the power of Excalibur for the welfare of others. Feminists, however, would behave just like Voritgern, and employ that power for themselves, rather than the greater good of society.
There are two important facts we can deduce about Princess Catia (Vortigern's daughter). First, she doesn't obey Vortigern: when we are introduced to Maid Maggie (Annabelle Wallis) we see Voritgern tell Catia to put the bird back into its cage and Catia blatantly doesn't do it. Secondly, Catia seems to be quite fond of birds she keeps in cages. These two details help us to put together that Catia isn't afraid of her father because she knows he is a weak man: he has only the trappings of power, but because Vortigern has no power over himself, he also doesn't have any power over her (in this case, to make her obedient to his word). Like the birds in cages with which she surrounds herself, Catia, too, is caged like a bird, so she doesn't realize how dark and hard the world can be (the exact opposite of her cousin, Arthur). How does this fit in with Catia's mother's disappearance? Catia knows Vortigern killed her mother, so she doesn't show any love for Vortigern so she won't face the same fate as her mother. If she doesn't love her father, he won't love her, either, so he won't sacrifice Catia the way he sacrificed Catia's mother.
Twisted, isn't it?
In my original post, I noted that the Darklands sequence was a microcosm of the entire film: what happens to Arthur in the Darklands has all ready happened to him, or will happen to him. Because the sequence happened so quickly, I wasn't able to point by point reconstruct the events, but I was able to recognize them (like the bats picking up Arthur and carrying him from one to another was a metaphor of the guards putting Arthur on the ship that took him to Camelot, then being arrested for drawing the sword, then being "rescued" by the Resistance). I am fully confident the entire Darklands sequence can be explained in terms of other scenes of the film: for example, the first time Arthur sees the giant snake in the Darklands is equivalent to when the snake crawls out of the sleeve of The Mage; it's little on her arm, but it's a huge threat; then, when Arthur stops in the stream and a large rodent blocks his way, the snake comes and devours the rodent in one bite, which foreshadows the snake snatching up Mischief John (Vortigern's guard who tells Arthur he has to get home because it's his night to cook, and if Arthur does anything to hurt him, it will be repaid on the boy and The Mage). We know the wolves with glowing eyes symbolize the Black Legs: one, Goosefat Bill calls Mercia "Head of the wolf pack," and because when Arthur goes to Vortigern's castle, he sees the eyes of the Black Legs glowing like the eyes of the wolves in the Darklands. I don't need to explain anymore, you can figure out the rest on your own since this much has been suggested for you, however, I did want to point out that this is always the sign of excellent writing, being able to create a microcosm section of the narrative in this fashion.
What about the parts of the Darklands sequence which haven't happened yet? In a way, the parts which have all ready happened to Arthur make perfect sense because the Darklands sequence is like a dream-state, and Arthur's unconscious--which he has fought the whole film--tries communicating to him so he can remember why he looked away at the moment of his father's death. So, that part is like a dream. What about the future events?
If you shared any of these same questions, I hope this helps: please realize, however (and this is for myself, too) that KALS is an incredible film and we will continue discovering aspects of the narrative to decode and question every time we see it. I wish you a happy and prosperous New Year, filled with God's blessings and grace! Hopefully, I can start posting again.
Eat Your Art Out,
The Fine Art Diner |
Prev | Next | Contents | Roman Gods
The Manes were the spirits of the departed, and were of two kinds, viz., Lemures (or Larvæ) and Lares. {186}
The Lemures were those Manes who haunted their former abodes on earth as evil spirits, appearing at night under awful forms and hideous shapes, greatly to the alarm of their friends and relatives. They were so feared that a festival, called the Lemuralia, was celebrated in order to propitiate them.
It appears extremely probable that the superstitions with regard to ghosts, haunted houses, &c., which exist even at the present day, owe their origin to this very ancient pagan source.
The Lares Familiares were a much more pleasing conception. They were the spirits of the ancestors of each family, who exercised after death a protecting power over the well-being and prosperity of the family to which they had in life belonged. The place of honour beside the hearth was occupied by the statue of the Lar of the house, who was supposed to have been the founder of the family. This statue was the object of profound veneration, and was honoured on all occasions by every member of the family; a portion of each meal was laid before it, and it was believed to take an active part in all family affairs and domestic events, whether of a sad or joyful nature. Before starting on any expedition the master of the house saluted the statue of the Lar, and, on his return, a solemn thanksgiving was offered to this, the presiding deity of his hearth and home, in grateful acknowledgment of his protection; whereupon the statue was crowned with garlands of flowers, these being the favourite offerings to the Lares on all occasions of especial family rejoicing.
The first act of a bride on entering her new abode was to do homage to the Lar, in the belief that he would exercise over her a protecting influence and shield her from evil.
In addition to those above enumerated there were also public Lares, who were guardians of the state, highroads, country, and sea. Their temples were always open for any pious worshipper to enter, and on their altars public sacrifices were offered for the welfare of the state or city. {187}
Prev | Next | Contents |
SWOT Analysis – Strengths, Weaknesses, Opportunities, Threats
Word count: 97
Write out your company / organisation’s:
• Strengths
• Weakness
• Opportunities
• Threats
• How will you build on your strengths?
• How will you overcome your weaknesses
• How will you take opportunities?
• How will you protect yourself from the threats?
Attributed to Albert Humphrey at Stanford in the 1960s. Refers to how well the internal situation of a company compares to the external requirements of the industry.
Equates to a strategic examination of the advantages, disadvantages, possibilities and dangers of the present situation. When undertaking a SWOT analysis emphasis is put on achieving an objective and whether it is realistic. If not then the process is repeated with a different objective |
What is the FFC?
How does it work?
Who needs Fitch?
The Fitch Warranty
FFC Kits and Prices
Frequently asked Question's
Magazine Reviews
Performance Reports
Emission Tests
Motorcycles &
Powersports Equip.
Small Gas Equip.
Lawn & Garden
Automobiles &
Light Trucks
Heavy Equipment
Marine Equipment
Heating Systems
Video Gallery
Installation Pictures
Team Fitch
News Updates
About APSI
FFC Manufacturer
We Accept:
The Fitch Fuel Catalyst and Fuel
By: Al Berlin, Ph.D Research & Product Development for Advanced Power Systems Prior to working on the development of the Fitch Fuel Catalyst Dr. Al Berlin was Director of Analytic Services for United Oil Products, a developer of the exhaust catalytic converter.
What Is a Catalyst?
A catalyst reduces the energy threshold required and helps promote a chemical reaction. A substance is classified as a catalyst if it returns to its original state at the conclusion of the reaction sequence and is available to participate in subsequent reactions. Catalysts are useful because they minimize the energy required to perform a task and therefore save energy and money.
For example a vessel containing hydrochloric acid and tin will be stable. Upon adding a minute dose of a few hundredths of a grain of platinum, hydrogen gas will begin to boil off. At the end of the reaction, the platinum is in its original condition.
The Fitch Fuel Catalyst induces chemical reactions among fuel molecules at low temperatures such as those our vehicles and fuel tanks experience and it returns to its original state at the conclusion of the reaction ready to initiate a new sequence.
Reformulation of Hydrocarbon Fuel via Fitch Fuel Catalyst
Fuels are complex. Most of us think of fuels such as gasoline as a homogeneous commodity without realizing that it is not perfect or uniform. As purchased at the pump fuel is a mixture of about forty primary but as many as a thousand secondary different species of hydrocarbon molecules. If fuel were pure there would be few or only one type of molecule. Natural gas types of molecules are too short and light, and diesel fuel and asphalt types of molecules are too long and heavy for gasoline, yet many of these light and heavy molecules are in the gasoline available at the pump.
Refineries, where fuel is manufactured from crude cannot remove all non-conforming molecules to make a pure fuel. And once fuel leaves the refinery, it is subject to attack by oxygen, ozone, and microorganisms (bacteria yeast and mold) that grow in the fuel and alter it ingesting fuel molecules and expelling non-conforming molecules as by-products. Whether these non-conforming molecules are present in small quantities when fuel leaves the refinery or increase in number with the passage of time due to the above influences of oxygen or microorganism attack, they prevent engines from performing at their optimum level and prevent extraction of the maximum energy from the fuel.
These non-standard molecules cannot be efficiently and completely burned in engines that weren't designed for them. When fuel does not combust completely, it does not contribute its maximum potential energy. Some of it forms carbon deposits and gums, and some of it passes through the engine unburned and must be processed by the catalytic converter.
This is one reason that today's vehicles need an exhaust catalytic converter to reduce toxic auto emissions. These toxic gasses (Unburned Hydrocarbons UHC and Carbon Monoxide CO) would not exist if the fuel / energy conversion in the engine was perfect. Exhaust system catalytic converters provide an environment for a chemical reaction where unburned hydrocarbons completely combust hence the combustion process continues but as it is outside the engine combustion chamber no useful energy is extracted. Over time, engines develop problems caused by sub-optimal fuel including gumming and constriction of fuel systems and carbon deposits in the combustion chamber and exhaust system.
With a Fitch Fuel Catalyst it is possible to deal with fuel problems in an effective way. The Fitch Fuel Catalyst reformulates fuel prior to combustion on board the vehicle, preventing oxygen and most diseases from attacking the fuel and reversing any degradation that may have occurred prior to the fuel being introduced to the vehicle. The Fitch Fuel Catalyst assists the combustion process by insuring that fuel is highly uniform, potent, consistent, and stable. It performs its function at the temperatures experienced in fuel tanks without any requirement for elevated temperatures or pressures, which is what makes the Fitch Fuel Catalyst so convenient and useful.
This Fitch Fuel reforming Catalyst is not an additive. It is an alloy that provides a platform or an environment for a series of reactions among fuel molecules. These reactions result in transformed or reformulated fuel. The resultant Fitch treated fuel is of molecular length and structures that make it more conducive to complete combustion. Fitch reformulated fuel is what the engine designer had in mind. As a result, the engine converts the chemical energy in the fuel to mechanical energy in an inherently more stable and complete process. The energy or power extracted from the fuel is greater, and the toxic exhaust emissions are lower, frequently by more than half. As this fuel catalyst alloy is not an additive it will function for the life of the engine.
This wonderful product is suitable for engines designed yesterday, today, and tomorrow, as they burn the same fuel. Through the use of the Fitch Fuel Catalyst it is possible to make a material difference in power, fuel economy and air quality, simultaneously regardless of the engine in question. The higher the fuel quality the better the engine can perform.
What does the Fitch Fuel Catalyst do to fuel to improve it?
One way to describe how The Fitch Fuel Catalyst benefits the consumer or engine builder is by the differences in the composition of the fuel that results from exposure to the catalyst.
In gasoline (C7 - C11) we have measured changes due to the presence of the Fitch Fuel Catalyst. Here are some of the more significant ones and the implication of them.
Analyses of the gasoline distribution after contact with the FFC shows changes in the composition of organic compounds in gasoline.
1. Light non-gasoline hydrocarbons present in the untreated fuel like C1 - C4 are markedly diminished and
2. Branched hydrocarbons larger than C4 were enhanced
Experimental data confirm that the Fitch Fuel Catalyst successfully:
1. Suppresses bacterial growth in gasoline minimizing this problem
2. Improves the Oxidation Stability of gasoline as measured by ASTM D525
The structure of a hydrocarbon molecule (straight, ring, or branched in shape) as well the number of carbon and hydrogen atoms per molecule is important to how well a molecule performs in a combustion engine. Molecules with the same number of hydrogen and carbon atoms but with different structures behave differently in an engine. Highly branched fuel molecules have been shown to be more desirable than straight chain molecules even when the number of carbon and hydrogen atoms per molecule is identical. An increase in the branched compounds and a reduction in the small light hydrocarbons enhances octane number of gasoline leading to improvement in engine performance and reduction of soot. More complex (branched) fuel molecules such as those produced through the influence of the Fitch Fuel Catalyst reduce power robbing knock. It has been determined through experiment that branched fuel molecules such as iso-octane are much less likely to knock compared to normal pentane.
The distribution curve of the various molecular weights and structures within gasoline show a reduction in the less desirable molecule population after exposure to the Fitch Fuel Catalyst and a marked increase in the concentration of molecules of desirable weight and structure. These modifications in the fuel improvement result in the improvements in power and emissions measured in engine tests.
Higher-octane fuels allow for more advanced spark timing. Advanced spark timings produce higher in-cylinder pressures and temperatures producing greater engine output torque and power.
The high fuel quality resulting from exposure to the Fitch Fuel Catalyst insures quality of combustion. The Fitch Fuel Catalyst is an octane enhancer and fuel stabilizer in one permanent device.
See Emissions Reports for specific examples these changes in fuel make in lowering emissions, increasing power, and improving fuel economy.
In diesel fuels the Fitch Fuel Catalyst helps break undesirable highly branched long molecules and converts them into more desirable low octane long straight hydrocarbon chains. This helps the cetane rating of the diesel fuel and assists the engine extract more power from a gallon of fuel.
Call Toll Free for more Information, or to Order.
Distributed in Canada by PMC Ltd.
Copyright © 2003 PMC Ltd. |
Giant pufferfish
Giant pufferfish
Z605/1510 Rights Managed
Request low-res file
530 pixels on longest edge, unwatermarked
Request/Download high-res file
Uncompressed file size: 49.4MB
Downloadable file size: 5.4MB
Price image Pricing
Please login to use the price calculator
Caption: Juvenile giant pufferfish (Arothron stellatus). When threatened, pufferfish gulp down water. This causes them to swell to up to twice their normal body size. It is a solitary animal found in the tropical Indo-West Pacific. It feeds on corals, sponges and crustaceans, crushing and grinding them with its powerful jaws and sharp teeth. Pufferfish are a delicacy in Japan, where they are eaten as sushi. However, they contain a powerful toxin, tetrodotoxin, that is fatal to humans, and so need to be prepared with care. Photographed in Lembeh Strait, North Sulawesi, Indonesia.
Keywords: animal, aquatic, arothron stellatus, biological, biology, blowfish, carnivore, carnivorous, edible, fauna, fish, food, giant pufferfish, indonesia, juvenile, lembeh strait, marine, marine biology, nature, north sulawesi, one, poison, poisonous, single, solitary, tetrodotoxin, toxic, ttx, underwater, wildlife, zoological, zoology
|
How London Got Its Name
By M@ Last edited 26 months ago
How London Got Its Name
Ancient names
People lived in the area we now call London long before the Romans arrived. For millennia, small tribes would have ranged across the land and fished in the Thames. Several prehistoric structures have been discovered. It's possible to see 6,000-year-old timbers during very low tide at Vauxhall, for example. Yet no strong evidence of permanent settlement has ever been found.
With no settled population, perhaps the region had no name until the Romans founded the city around 43 AD. However, it's unlikely that the Romans conjured their name of Londinium from nowhere. Some linguists suggest that they adapted an existing name, possibly Plowonida, from the pre-Celtic words plew and nejd, which together suggest a wide, flowing river (i.e. the Thames). This then became Lowonidonjon in Celtic times, and eventually Londinium. Another theory suggests a Celtic place name of Londinion, either derived from the name of a local chieftain, or the Celtic word lond (meaning 'wild'). There is no consensus and, in the absence of written records, we will probably never know.
Mythical founding
Roman London
We now step back into verified historical territory. The Romans founded the first known settlement of any note in 43AD, and at some point soon after called it Londinium. The first written record comes from around 117AD, when Tacitus tells us "Londinium...though undistinguished by the name of a colonia, was much frequented by a number of merchants and trading vessels." Here, he's writing about the city some 60 years before...around 15 years after its founding. Other sources referring to the city by its Roman name are surprisingly rare, but include grammatical and syntactical variations such as Londinio, Londiniensi and Londiniensium. Around the year 368, the city was renamed Augusta, as shown on numerous coins from the era. It is thought that the name was predominantly used by officials, as a way of highlighting the city as an important imperial centre.
Anglo-Saxon London
Roman domination of London effectively ended in 410, when the legions were withdrawn to tackle some pressing domestic matters (Rome was being sacked). We know very little about London over the next two hundred years. The city inside the Roman walls was at some point abandoned. Germanic tribes, whom we now call Anglo-Saxons, took over the area and established a colony around Aldwych and Covent Garden. Sources from the 7th and 8th century name this port as Lundenwic, which means 'London settlement or trading town'. In the year 886, Alfred the Great resettled the land inside the still-standing Roman walls, and shored up the defences. The rejuvenated stronghold was known as Lundenburh, meaning the fortified town of London. The old port area near Covent Garden was largely abandoned, and referred to as Ealdwic ('old settlement'). We now know it as Aldwych.
London arises
The city slowly grew around Alfred's City and the religious centre of Westminster. Following the Norman conquest, records begin to show the area referred to by its modern name, or similar versions such as Lundin, Londoun, Lunden and Londen. Over the centuries, the spelling settled down on London. However, the geographic definition of 'London' has changed over the years. Until recent centuries, places such as Westminster or Southwark would have been considered distinct from 'London', the name for the Square Mile within the old Roman walls. Even today, we refer to this area as The City of London, a city within a city. Boundary changes, such as the creation of the County of London, and Greater London are fascinating in their own right, but beyond the scope of this article.
Nicknames for London
Another, less well known nickname for London is The Great Wen. A 'wen' is what today we'd call a sebaceous cyst. The phrase was coined in the 1820s by William Cobbett, who was comparing the rapidly growing city to a biological swelling. The phrase lives on in the name of an excellent London blog by journalist Peter Watts (who, incidentally, previously edited a much lamented section of Time Out called The Big Smoke).
Suggestions, Please!
As you can see, our city has enjoyed many names over the millennia. Yet, it's been pretty stable for the past 900 years. Time for a change, we reckon. So please unleash your best suggestions — silly, serious, mildly offensive, whatever... — in the comments below. Perhaps we can effect a change for the 2000th anniversary of Londinium in 2043.
See also: How London's boroughs got their names.
Last Updated 28 July 2016 |
Calgary NE Dental Clinic
by Dr. Michael Popp on Oct 17, 2016
Categorized under Family Dentistry
Bleeding or inflamed gums can cause discomfort and can also be a sign of other underlying health issues. This post provides an overview of some of the potential causes of bleeding or inflamed gums, short-term and long-term effects of this condition, as well as some of the options that may be used to treat or prevent bleeding gums.
Potential causes
There are several possible causes for gums that are irritated, feel tender, or bleed during brushing or flossing. These reasons include plaque and tartar that has mineralized around the tooth, bacteria, or infection. Improper brushing or flossing might contribute to this situation, or a patient might require more frequent check-ups and dental cleaning.
At other times, a patient is following what seems to be good brushing or flossing techniques, but they are accidentally creating gum irritation. An example of this would be flossing too harshly or aggressively, or brushing with a stiff-bristled toothbrush that aggravates sensitive gums. Similarly, certain at-home whitening trays or treatments can leak past the tray and create gum irritation or pain, especially if the whitening treatment is left on for a longer period of time than necessary.
Bleeding gums can also be connected to health-related issues such as vitamin deficiencies, smoking, or conditions such as diabetes, heart conditions, or a change in hormones. In certain cases it can also be a sign of health issues within the mouth, such as gum disease, malocclusion or oral cancer. Since each individual’s case is different, it is important to visit a dentist or dental hygienist if you are experiencing bleeding or sensitive gums so that these professionals can help determine the cause of the issue, and develop the best dental care treatment plan possible.
Short-term effects of bleeding gums
In the short term, bleeding gums can cause pain or irritation, as well as bad breath. It can also make it difficult for a patient to wear an appliance such as a retainer or invisible brace such as Invisalign. Brushing or flossing may become more painful.
Long-term effects of gum disease
Bleeding gums can sometimes be a sign of gum disease. This can progress to stages either slowly or rapidly depending on the patient, but it is most treatable when caught early. If a patient has gingivitis, a dentist or dental hygienist can conduct teeth cleaning and procedures such as root planing or scaling, and help the patient with a follow-up treatment plan to maintain good dental health. However, periodontitis and advanced periodontitis can create more discomfort for the patient and come with other effects such as receding gums, which can expose the roots of the teeth and create even more sensitivity in the gum area. Furthermore, if periodontitis goes untreated for too long, a patient may also have issues such as deterioration of the bones surrounding the teeth, which may cause changes in tooth placement or bite.
Suggestions for bleeding gums
Anyone experiencing gum sensitivity or bleeding should adjust their brushing and flossing routine if they feel this may be the cause, and notify their dentist at their next visit. At the visit, it can be helpful to notify your dentist or hygienist if you have been experiencing any other health changes.
The best way to address gum sensitivity is by prevention: following a good brushing and flossing routine as well as attending regularly scheduled dental appointments can help prevent problems and allows your dentist or dental hygienist to address small problems before they become more severe.
Want to Learn More?
Thoughts about the post
comments powered by Disqus
Give us a Shout!
Visit our Office
Marlborough Dental Centre
1141-3800 Memorial Drive NE
Calgary, AB, T2A 2K2
Give us a Shout
P: 403-248-2066
Office Hours
Mon-Fri: 9am - 9pm
Sat: 9am - 5pm
Sun: 10am - 3pm
Send us a message
Please fill out all required fields
Have Questions? Call Us Today At
Call Us |
A monument to Euphrosyne of Polotsk in Minsk near Belarusian state University
Sculpture, monuments, memorials
Belarus has been famous for its reverent attitude to wisdom and various ways of seeking knowledge for many centuries. Fr om the early times, when it was a sword and blood to decide everything, people had formed the opinion that the greatest power was in knowledge. Euphrosyne of Polotsk became a striking example of that. She devoted her life to serving God and to educating people. Her amazing intelligence and literacy were unique for that time, because women were denied the opportunity to obtain any education in the twelfth century.
Aspirations and high ideals
The noble princess was the granddaughter of Polotsk Prince Vseslav the Sorcerer. The opportunity to travel gave him knowledge and wisdom, he brought up his granddaughter the same way. There is evidence in the old manuscripts that Euphrosyne, or Predslava, has differed from other girls, her peers, for her intelligence and gentle beauty since early age. When parents decided to marry her, she ran away to the monastery, Saint Sophia Cathedral in Polotsk. Having tonsured and received the name of Euphrosyne, she threw herself into books.
She founded the convent; it became the place wh ere nuns fully devoted themselves to the service to the Lord. Being engaged in icon painting, weaving, they also recorded some chronicles and were taught to read and write. In addition to the Bible, Byzantine and Roman Divine tales became the sources of education. Gradually, the monastery became the center of education for all the lands in Western Russia. Works of Cyril and Methodius, outstanding enlighteners of the Slavic region, John Chrysostom, a well-known preacher of Christianity and "the Tale of bygone years" with other various chronicles were kept in the walls of the Cathedral.
Euphrosyne rewrote manually not only religious books but also collections of aphorisms and chronicles. Besides, Euphrosyne wrote some works of her own – the prayers to the Lord and sermons, she translated from Latin and Greek. The convent can be considered the first school in history which was fairly ruled by Euphrosyne. She also founded a monastery.
Philanthropic activities to people’s benefit
Among other things, Lazar Bogsha made a cross at the request of Euphrosyne in 1161. It has become a unique relic, bearing the historical foundations of the religion of those times. That artifact didn’t yield the Byzantine works of art in technique. The label, printed by the master, contained the information about the manufacturer, the time and the quantity of material taken. Due to that fact the masterpiece can be considered a kind of monument to handwriting.
The cross had changed its location many times, and, unfortunately, it disappeared entirely during the Second World War. It is listed in the international wanted list up to the present time, but the famous Brest master N. Kuzmich has made an identical copy under its image, which is now kept in the Holy Transfiguration Church in Polotsk.
Having made a pilgrimage to Palestine and Jerusalem, Euphrosyne died in 1173. Her relics are stored in the Spaso-Efrosinyevsky monastery, which was built at her initiative and under her leadership. A part of it has remained intact to the present day. Euphrosyne was recognized as a Saint both in Catholicism and Orthodoxy. Her efforts were not in vain, her love for learning, for self-improvement, her own views and ideals have passed on to us.
In 1999, a monument carved by a talented sculptor Igor Golubev was established in the memory of Euphrosyne of Polotsk. It is located in Minsk near Belarusian state University. The initiator of this project, and the sponsor as well, was a true patriot of Belarus, the businessman and the historian Yuri Ivanovski.
Map location
Back to the list
Recommended accommodation
, Minsk , Belarus
• Distance to airport: 42 km
, Minsk , Belarus
• Distance to airport: 44 km
, Minsk , Belarus
• Distance to airport: 44 km |
Public Release:
Parasites of endangered animals should be conserved
University of Otago
Conservation managers who try to keep members of endangered animal species parasite-free are well-intentioned but this approach is misguided, according to a new research paper co-authored by a zoologist at New Zealand's University of Otago.
In a paper appearing in the journal Trends in Ecology and Evolution, Otago's Professor Hamish Spencer and US evolutionary biologist Professor Marlene Zuk argue that there are good reasons why parasites should be conserved along with their endangered hosts.
The pair writes that "captive rearing programmes, as well as zoos and other facilities, take for granted that keeping their animals healthy and parasite-free is essential, since by definition parasites reduce their host's fitness. But the elimination of a natural complement of parasites might have unintended consequences.
"Because parasites have been co-evolving with their hosts for so long, they have become part of the external environment, and removing parasites, even if it has some positive effects on an individual host's health, has the potential to wreak havoc with ecological systems."
Professor Spencer says that for example, exposure to parasites might be crucial to the host animal's development of a fully functional immune system and hence to its survival.
"Exposure to parasites in early life can confer improved resistance to the same parasites later on, and recent research shows that such exposure may enhance the overall development and efficacy of the immune system in defending against a wide variety of infections."
Professors Zuk and Spencer note that zoos and other captive animal facilities generally have extensive anti-parasite procedures, and when animals are reared they are not inoculated with a standard assortment of parasitic organisms.
"Perhaps more worryingly, protocols of reintroduction programmes often require the very opposite, with animals dosed with a range of anti-parasitic treatments before release."
The researchers assert that "the conservation of parasites might well be an essential part of the conservation of their hosts. Thus, if the goal of conservation is to maintain biodiversity, as well as the ecological and evolutionary processes that generate and sustain it, then parasites must also be conserved for their host's sake."
Professor Spencer says they are not calling for conservation managers to completely ignore parasites and that major parasite infestation obviously needs to be treated, but low levels of a variety of parasite infections might even improve conservation outcomes.
|
Christianity Distinctiveness Essay
Submitted By pattia
Words: 392
Pages: 2
Religions are broadly defined as the quest for an experience of the Transcendent. There are similarities and differences between religions; each having differences to make that religion unique. Christianity has a few characteristics that make it distinctly different from other worldly religions. From the Bible passage John 8, 1-11, one can see some of these differences. For example, the passage gives us a personal relationship with God through Jesus Christ. We have his son as a pathway to knowing and loving God. No other religion can offer that. Islam believes in Allah, a sole God. They cannot create that personal connection with God because he could not send anyone to be with them. Same with Judaism, they believe in a single God, not the trinity that Christianity believes in. This is one way Christianity differs from other religions. Another point one finds from the reading of John’s gospel is how kind Jesus is to the woman who committed adultery. He states that the one person who has not sinned can cast the stone at her. Since everyone has sinned, no one casts a stone and Jesus does not condemn her. Instead, he just encourages her to not sin. This is different from Buddhism’s concept of suffering. They think that the world has a constant suffering that people must end by using the Noble Eightfold Path. Christians are not given specific steps like the eightfold path to end suffering. Instead, they find guidance from Jesus to stop sins, and when they stop sinning, they have less suffering. Jesus did not… |
Osteochondritis dissecans occurs most often in children and adolescents. It can cause symptoms either after an injury to a joint or after several months of activity, especially high-impact activity such as jumping and running, that affects the joint. The condition occurs most commonly in the knee, but also occurs in elbows, ankles and other joints.
Doctors stage osteochondritis dissecans according to the size of the injury, whether the fragment is partially or completely detached, and whether the fragment stays in place. If the loosened piece of cartilage and bone stays in place, you may have few or no symptoms. For young children whose bones are still developing, the injury might heal by itself.
Surgery might be necessary if the fragment comes loose and gets caught between the moving parts of your joint or if you have persistent pain.
When to see a doctor
The cause of osteochondritis dissecans is unknown. The reduced blood flow to the end of the affected bone might result from repetitive trauma — small, multiple episodes of minor, unrecognized injury that damage the bone. There might be a genetic component, making some people more inclined to develop the disorder.
Risk factors
Osteochondritis dissecans occurs most commonly in children and adolescents between the ages of 10 and 20 who are highly active in sports.
Osteochondritis dissecans can increase your risk of eventually developing osteoarthritis in that joint.
Adolescents participating in organized sports might benefit from education on the risks to their joints associated with overuse. Learning the proper mechanics and techniques of their sport, using the proper protective gear, and participating in strength training and stability training exercises can help reduce the chance of injury.
Sept. 07, 2018
1. Maruyama M, et al. Diagnosis and treatment of osteochondritis dissecans of the humeral capitellum. Journal of Orthopaedic Science. 2018;23:213.
2. Osteochondritis dissecans. American Academy of Orthopaedic Surgeons. https://orthoinfo.aaos.org/en/diseases--conditions/osteochondritis-dissecans. Accessed Aug. 6, 2018.
3. Hergenroeder AC, et al. Osteochondritis dissecans (OCD): Clinical manifestations and diagnosis. https://www.uptodate.com/contents/search. Accessed Aug. 2, 2018.
4. Osteochondritis dissecans. Genetic and Rare Diseases Information Center. https://rarediseases.info.nih.gov/diseases/12703/osteochondritis-dissecans. Accessed Aug. 7, 2018.
5. Hergenroeder AC, et al. Management of osteochondritis dissecans (OCD). https://www.uptodate.com/contents/search. Accessed Aug. 2, 2018.
6. A guide to safety for young athletes. American Academy of Orthopaedic Surgeons. https://orthoinfo.aaos.org/en/staying-healthy/a-guide-to-safety-for-young-athletes. Accessed Aug. 8, 2018. |
Falls & Osteoporosis
A fall is defined as “inadvertently coming to a lower ground”. While falls are serious at any age, but in the elderly, it often poses a major threat to older adults’ quality of life, often causing a decline in self-care ability and participation in physical and social activities. Fear of falling often is like a viscous cycle where it further limits one’s activity, resulting in prolonged bedrest and further aggravating the situation where the elderly will eventually suffer from loss of muscle bulk and strength following disuse from reduced mobility. This sequence of reactions often leads to premature admission to care homes as well as financial burden to the individual and society as a whole.
Falls and fall-related injuries are a common and serious problem for old people. It is essentially a medical condition that most elderly fear. People aged 65 and older have the highest risk of falling, with 30% of people older than 65 and 50% of people older than 80 falling at least once a year. Malaysia like any Asian countries around the region is facing an ageing tsunami. Population survey revealed that currently 7.1 % of Malaysian are over aged 65 and in 3 years’ time, this number will approach 10%. It is therefore a problem that can only get worse as the population ages, bringing in its wake higher healthcare costs and lower quality of life for those affected. Despite its serious impact in an ageing population like Malaysia, falls in the elderly are often viewed as an inevitable consequence of ageing and often ignored in clinical practice resulting in multiple falls at home eventually needing to be admitted to hospital due to osteoporotic bone fractures.
Given the problems associated with falls, the Malaysian Society of Geriatric Medicine recommends any individual age 65 or older be evaluated if he or she has a fall or complains of difficulty with balance. This evaluation is meant to prevent the next fall and it typically has multiple contributing factors including vision (cataracts, macular degeneration, glaucoma or diabetic eye changes), uncontrolled pain (due to arthritis, particularly in back, hips or knees), muscle weakness (often related to prolonged period of inactivity), medications (risk of falls increases with number of medications an individual takes; lightheadedness, particularly when getting up from lying down or seated, can be an indicator that blood pressure medications are too strong; psychotropic medications like antidepressants and antipsychotic medications all increase the danger of falls). By addressing these issues, the possibility of falls can be reduced.
The most serious and feared complication following a fall is to sustain an osteoporotic fracture. Osteoporosis is a bone disease that occurs when the body loses too much bone, makes too little bone or both and weakens as we get older. It is often called a silent killer because one cannot feel bones weakening. Breaking a bone is often the first sign of osteoporosis or a patient may notice that he or she is getting shorter or their upper back is curving forward. Over the age of 60, 1 in 2 females will develop osteoporosis while 1 in 5 men will suffers from this silent disease. The most frightening thing about osteoporosis is that it is silent and the consequences of osteoporotic fractures can be devastating. Typically fractures occur at the wrist, hip and backbone. The most serious fracture is the hip fracture, 20% of patients post hip fracture will die within a year and only half survived after 5 years. 1 in 3 becomes wheelchair bound and almost 80% will lose independence with self-caring ability. Therefore, it is prudent to recognize the risk factors associated with osteoporosis. These include: Positive family history; age over 60; early menopause before age 45, slender body frame; previous fracture after minimal trauma; smoking; drinking alcohol; housebound; low exposure to sunlight; medications like steroids, anticancer drugs etc; other disease e.g. thyroid problems and diabetes.
To diagnose osteoporosis will either require a bone densitometry scan which is radiation free and simple to do; as well as widely available in hospitals. The prevention of osteoporosis involves a diet rich in calcium and vitamin D as well as exercise three times a week especially the weight bearing ones like walking or jogging. Once diagnosis is obtained and evaluated by a doctor, treatment should be started. The choices of medications are multiple and it is best to discuss the options with your doctor. Knowing the risk factors and implementation of preventive measures and treatment are critical to maintaining your health and wellbeing.
This article is by Dr Lawrence Lee Hong Khoh is a Consultant Geriatrician, a physician that specializes in elderly care at Timberland Medical Centre.
*The information in this article is not intended to replace a one-on-one relationship with a qualified health care professional and is not intended as medical advice to diagnose or treat a health problem or disease. You should consult your health care provider if you have or suspect you may have a health problem. |
A Piece of Steak
A Piece of Steak
“It was the iron law of the game. One man might have a hundred hard fights in him, another man only twenty; each, according to the make of him and the quality of his fibre, had a definite number, and, when he had fought them, he was done.”
The story deals with Tom King, a boxer who is at the very end of his career. Once a great star who spent money freely and generously on himself and others, he is now so poor that the local merchants will not even loan him enough money for a piece of steak. Before his fight against a rising star, Sandel, he eats only bread and gravy and must send his wife and children to bed without food.
“This is the story of the great war that Rikki-Tikki-Tavi fought single-handed, through the bath-rooms of the big bungalow in Segowlee cantonment.”
The Scarlet Letter
|
Stamina Foods for the Summer – Grilled Eels and Mudfish Soup
Eels are a high protein food that are rich is essential amino acids. They contain 150 times as much Vitamin A compared to other fishes, and are effective for eliminating oxygen free radicals, protecting the eye, preventing cancer, and promoting growth and fertility.
In particular, eels are high in omega 3 fatty acids (EPA, DHA), which help prevent adult diseases, form brain cells and neural tissue, and lower the cholesterol level.
Eels are high in cholesterol compared to other fishes, but since eels also contain unsaturated fatty acids and tocopherols, the cholesterol is flushed out of the system. Eels are also high in minerals such as iron and calcium, and the B vitamins help with the digestion.
[Source: Grilled eels,]
Mudfish boosts stamina, gives energy, and helps replenish water, and are also rich in calcium and protein.
The sticky coating on the mudfish’s skin mostly consists of mucin, which protects the digestive tract and helps with digestion. Mucin is also contained in animals or vegetables such as snakes, snails, frogs, and yams, but the mudfish is the best and safest source of mucin because wild animals may be infected with germs. Mudfish contains lots of calcium, and the Chueotang, or spicy mudfish soup, is especially high in calcium as it is made with ground whole mudfish.Unlike most fish or meats, the mudfish contains a lot of vitamin A, which helps protect the skin, enhances resistance against germs, and builds up mucous tissue in the respiratory system. The fish contains unsaturated fat, helping to prevent adult diseases.
[Source: Chueotang,]
Culture News
Leave a Reply
|
Clogher Cassidy’s
This is the story of one branch of the Cassidys originally from Drumbar, a townland on the outskirts of Donegal Town, County Donegal, Ireland. The story begins with my great grandfather John Cassidy, who was born in Drumbar in April 1802.
At the time of writing, little is known about the family, except that, according to the Spinning Wheel Premium Entitlement Lists of 1796, when free spinning wheels were given to a number of households that were growing flax, one of them was John Cassidy (Drumbar), who was probably my great great grandfather.
Under the Tenement Act of 1842, a national system of land taxation was introduced. This was based on an estimation of the valuation of land or property of each landowner or householder. A survey of all landholders was conducted in the 1840s and 1850s.
The valuation was supervised by Richard Griffith and even today it is referred to as Griffith’s Valuation. This report lists nine Cassidy families in the Donegal Town area. They were Anne Cassidy of Ardatowel, Owen Cassidy of Main Street in Donegal Town, two Francis Cassidys of Drumbar, two widow Cassidys of Drumbar and two William Cassidys of Drumbar.
As Catholic schools were forbidden by law, John Cassidy’s only formal education was gained through attending what was known as a “hedge school.” These were usually held in the open fields behind a hedge. During his teenage years, both he and a relative worked as farm laborers for two landowners in the Donegal Town area. When his relative decided to marry the landowner’s only daughter, it caused quite a problem for all concerned. Like the laws governing the schools, Catholics were forbidden by law from becoming land owners. To overcome this problem, John Cassidy’s relative joined the church of his bride-to-be – the Church of Ireland. In doing so, the rest of the Cassidy family ended all contact with this member of the family, and so it has remained, until now.
Hopefully my research will lead to a reunion of all the Cassidys of that period.
John and Kitty Cassidy
John Cassidy married Kitty McGinty, born 1806 in the townland of Barnesmore, County Donegal. They settled in the townland of Clogher in the parish of Townawilly, County Donegal. The townland of Clogher, which means “stony place” is situated three miles north of Donegal Town, just off the main Donegal/Ballybofey Road. It is surrounded by mountains. To the east is Clogher, to the north is Barnesmore, and to the west is Townawilly and the Bluestack Mountains with their mesmerizing waterfall, known as The Greymare’s Tail that rushes from its summit into Lough Eske in the valley below. It was into such surroundings that John and Kitty Cassidy settled and raised six children – three boys and three girls.
Their small holding consisted of the following – a two-roomed thatched cottage and ten acres of land. Their annual rent was three pound for the land and ten shillings for the cottage.
Today all that remains of their home is a few large stones that are still close to the original site. Also visible is the plot of ground where they grew their potatoes, and, although it was in the middle of a hay field, thankfully, both my grandfather Hugh and my father, William, preserved it in its original form.
John shared a further two acres of land with his neighbor Bryan Moss. It was there that he grazed his sheep. Each year John would sell some of the flock in the market in Donegal Town. The money gained from those sales was used to pay the rent and meet other family needs. Anything that disrupted that way of life would have meant financial ruin and possible eviction.
The Cassidy Murder
When one of John’s sheep went missing during the first famine years (1831-33) he undertook an extensive search of the locality. He eventually found the horns of the animal that had his markings at the rear of a cottage that was rented by a woman known as the widow Kelly.
Mrs. Kelly had two sons who spent their time stealing from their neighbors. When John Cassidy confronted them, they denied having any involvement in the disappearance of the animal. Shortly afterward, the Kelly family decided to immigrate to the United States. The day they were leaving, the Kelly brothers paid a visit to John Cassidy’s home where they proceeded to give him a terrible beating that left him confined to bed for a number of weeks.
In the spring of 1838, John Cassidy’s oldest son, also named John, boarded a sailing ship called the Zephyr that was anchored at the Hassins in Donegal Bay and sailed to New Brunswick, Canada. From there, he made his way to New York where the Kelly family was living. One morning, as one of the Kelly brothers was standing on a railway station platform, he failed to notice his former neighbor standing behind him. As the train entered the station, John Cassidy pushed him in front of the train.
He died instantly.
As there were many witnesses present, John fled across the US. He settled in Seattle, where he worked on the construction of the Seattle/Montana railway. Little else is known of this member of our family, except for an unconfirmed report that he served as a town sheriff in Butte, Montana. John never returned to Donegal.
The Cassidys During the Famine Years
We – the present generation – cannot even begin to imagine how difficult it must have been for John and Kitty Cassidy to rear their family during an era of a cholera epidemic, two potato famines (1831-33 and 1843-47). These two disasters alone saw the population of Donegal fall from 296,448 in 1841 to 255, 158 in 1851. That downward trend continued through emigration, right up to 1971 when the population of the county stood at 108,549. The fact that our ancestors survived at all was a miracle. Not only did they survive, but quite a number of them helped to shape the Ireland of today.
John Cassidy died in 1882 at age 80. His wife Kitty died in 1890 at the age of 86. Their grave, which is located at the rear of Saint Agatha’s Church in Clar is marked with a large Celtic headstone that was erected by John’s son Hugh (my granddad) in memory of his parents and his first wife Ann Mulreany (1863-1884) of Screen, Donegal, who died at the age of 21 in childbirth one year after they were married.
As already mentioned, their oldest son, John, immigrated to the US, as did their daughter Hanna.
–Frank Cassidy (1835-1899) was born in Clogher and married Sally Freel (1836-1912) born in Inver, County Donegal, daughter of Francis Freel and Katie McCracken. Francis and Sally lived in the townland of Aughlim, County Donegal. They had 10 children, and most of their descendants now live in the United States.
–Jane Cassidy (1840-1926) married Patrick Meehan (1840-1930) born in Inver, County Donegal, son of James Meehan and Sally Freel. Jane and Patrick lived in Dooring Point, Inver. They had 12 children, and their descendants are to be found in various Irish counties and in the US.
–Sara Ann Cassidy married Brian Meehan, brother of Patrick Meehan, shortly after they were married. They immigrated to Georgia in the United States. They had four songs.
The youngest member of John and Kitty Cassidy’s children was my grandfather Hugh, who was born in Clogher in 1851. In 1858, at the age of seven, Hugh began attending Ardeeven National School. The following year, the landlords closed the school because the local tenants refused to pay higher rents that were being demanded of them. History was repeating itself like his father before him. The rest of Hugh’s education was gained through the hedge school. Hugh would later become a teacher at one of those hedge schools.
Sometime in the 1870s, Hugh immigrated to the US. He lived and worked with his brother John in Seattle. On his return to Clogher, he built a new house. It was the first house in the parish to have a slated roof and two upstairs bedrooms. This house was the family home until a new house was build in 1986. To the left of the house, Hugh had a garden where he grew his potatoes and vegetables. It also had apple, pear, strawberry, and gooseberry trees. But pride of place went to this favorite dish, the rhubarb patch. Hugh also planted 60 trees, most of which are still growing today.
A Tradition of Military Service
As already mentioned, Hugh’s first wife, Ann Mulreany died the year after they were married. His second wife was Mary Ann Kennedy, born 1866 in Inver, County Donegal, one of 10 children of Charlie Kennedy and Madge Gildea who was born in Clogher. Hugh and Mary Ann had seven children – five boys and two girls. All five of their sons served either in the army or police, and in some cases, both.
John (1890-1918) R.I.C.
–Charlie (1892-1976) R.I.C./British Army, France 1916-18. On his return, he served in the Liverpool Police. Charlie’s four sons served in both the armed forces and the police. John and Frank in the army, Jerry erved as soldier and policeman. Charlie served in the R.A.F. during World War II. He was shot down over Belgium in 1942 and spent three years in a prisoner of war camp.
–Tom (1904-1927), member of the Irish Republican Army 1918-22. He was one of the first to join the newly formed Irish Police Force (An Garda Siochana) in May of 1922. He was promoted to sergeant in September of that year. Sadly, Tom died in 1927 at the age of 23.
–William (1907-1979) He spent six years in the Irish Army
–Dan (1909-1987), He spent three years in the Irish Army 1928-1931.
That tradition of service has been continued into this generation by Hugh’s grandsons Danny Cassidy, who served in the Irish Guards, and John, who is a member of An Garda Sichonna in Donegal and his great granddaughter Patricia Hegarty, who is an officer in the Metropolitan Police Force in London.
Hugh and Marry Ann’s daughters were Annie (1899-1949) married Connal Thomas (1882-1947). They lived in Edergole, in the parish of Killymard, County Donegal. They had six children.
Catherine (Kitty) (1902-1977) married William Hegarty (1896-1968). They lived in Donegal Town and had six children.
The Sacrifices of the Cassidy Women
In compiling this family tree, I would like to put on record the enormous contributions and personal sacrifices that were made by the Cassidy women down the years. For example, whatever land was available was shared among the sons. The daughters had only two options: they could get married, provided they had a dowry (i.e. money or cattle). Even when married, their troubles were far from over. Firstly, they were expected to share the workload of the farm. Saving hay/turf, milking cows, etc. plus all the household chores. They would also be expected to give birth to at least six children. As healthcare as we know it was unheard of back then, each birth could mean death of the mother. Indeed, it was common practice to save the child at the expense of the mother.
The daughters’ second option was immigration, usually to the United States. For some, it meant never seeing their family again. Even in this new world, the daughter was at a disadvantage. Whereas the men worked in the construction industry with their fellow countrymen, the women were employed as housemaids or in factories and found themselves working and living among strangers. This did not stop them from playing a pivotal role in the well-being of their family back home. They used their money to help pay the rent, later to buy the smallholding, provide a dowry for a sister, pay the passage of a family member traveling to the US. Bust most importantly, once married, they ensured that their children received the best possible education.
Hugh Cassidy and the Law
By 1922, the people of Ireland had lost all faith in British justice. The dominant political force in the country was Sinn Fein, who set up their own courts. One of the people who served as a court judge in Donegal was Hugh Cassidy. In 1986, a group of barristers were asked to study the decisions reached by the judges of that period. They concluded that, although these men had no formal training, their decisions, which were based on commons sense rather than the rule of law, were in most cases correct.
One of the many regular visitors to the Cassidy household and close friend of Hugh Cassidy was a man named Mickey Brown. Mickey’s wife died at a young age. They had four children who were reared by relatives in Ballybofey, County Donegal. It has been said but not yet confirmed that his graddaughter is Rosemary Brown, born in Derry, better known as Dana, well known singer and presently member of the European Parliament.
My grandfather died on December 4, 1946 at the age of 95. He was laid to rest with his parents in Clar. This is also the final resting place of his first wife Anne Mulreany, his daughter Annie, sons John, Tom, and Dan. My grandmother died in 1952. Her grave is located at the top of the hill, at the rear of Clar church. This is also the final resting place of my parents, William and Kathleen Cassidy. The grave is marked with a white headstone bearing their names.
This is but the beginning of this family history. Today the descendants of John and Kitty Cassidy are to be found in the four corners of the world and it would be impossible for any one individual to compile a family tree that would include them all. Such a task can only be achieved with the help of each family unit.
It is my dearest wish that this goal will be achieved.
John Cassidy
Dublin, Ireland |
Educational Adventure
Where is the Educational Adventure located?
Ravna, Balta Berilovac, Knjaževac Municipality, Timok County
Who is it intended for?
Children 8-12 years old, youth, families with children.
What can be done or learnt here?
Archaeology and ecology probe (extracurricular activity) will give you the opportunity to explore the site as true archaeologists and undertake an adventure of searching objects from the past. You will find out what sorts of things can be found in the soil, what is the benefit and what are the consequences to the environment.
Pottery workshop (related to folk tradition) represents an encounter with an old handiwork technique that made Knjaževac and the vicinity famous, due to the skill of the master potters. In the specific environment of the reconstructed village community, you will learn how to use leg operated pottery wheel and to make your own clay souvenir, alone, or helped by your friends;
Conservation workshop (extracurricular activity) will enable you to mend the unmendable. You will combine the parts of ceramic dishes, found on the nearby ancient ages site, into beautiful antique bowls and learn the secrets of conservation through play;
Knjaževac from A to Z, (extracurricular activity) a brief alphabetical overview of the Knjaževac area’s attractions and values, given in a form of a game and quiz, takes you on a journey of knowledge;
From trail to treasure, (extracurricular activity) with the help of an illustrated map, solving puzzles and tasks. By moving around, you learn the skill of orienteering and get to know the landmarks of Knjaževac;
Getting around nature – orientation, camping, nutrition, erecting bivouacs (related to Nature Watch and World around Us, National Tradition) In the beautiful environment, at the foot of the Stara Mountain, aided by an experienced guide, you will learn the skills of orienteering in nature, how to nurture yourself and survive in nature, how to erect a tent and find an appropriate location for bivouac;
From sheering to the loom – training in the old techniques of weaving, knitting and embroidery (related to Nature Keepers and World around Us, National Tradition), instructed by the skilful embroiderers, knitters and weavers, you will pass the journey from the sheered fleece and stranded thread to a lovely scarf, belt or shirt ornament;
Old shepherd’s games (related to Nature Keepers and World around Us, National Tradition), How did children on the Stara Mountain entertain themselves while they guarded their herds on the mountain pastures? Learn it through games aided by the experienced shepherds from the Stara mountain, together with your friends;
Saved by the Bell and other school related stories, (related to Nature Watch and World around Us, National Tradition) shall be told in a classroom of the old village school, featuring the use of old teaching resources, as well as strict and morose village teacher;
Knots (extracurricular activity) Nikola shall explain which one is harder, to tie or to untie the knot, be that a sailor’s, ambulance, hunter’s or some other type. There is only one way to find out, to learn to do it properly.
Where are the activities performed?
In Ravna Archaeo-Ethno Park, in the nearby school, in the Local Heritage Museum in Knjaževac, in the town of Knjaževac, in the schoolyard of the village school in Balta Berilovac, by the nearby river, on Babin Zub and on the Stara Mountain;
How many days can you spend here?
Educational Adventure offers daily, weekend, 5 and 7 days programmes, including the accommodation in the Stara Mountain Mountaineering Lodge;
When can you visit the Educational Adventure?
Educational Adventure is organized from May to October.
Where can you stay?
Accommodation in the village school and Ravna Archaeo-Ethno Park for smaller groups (25-30 participants), Mountaineering Lodge Babin Zub on the Stara Mountain for 50-60 participants, hotel on the Stara Mountain for families with children.
How many guests can the Educational Adventure receive?
Group size: 5-50 participants.
How can you reach the Educational Adventure?
Address and contact data:
Zavičajni muzej Knjaževac (Local Heritage Museum of Knjaževac), Karađorđeva 15, 19350 Knjaževac, +381 19 731 407; e-mail:;
Turistička organizacija Knjaževac (Knjaževac Tourism Organization), Knjaza Miloša 37, +381 19 735 230,
Contents and possibilities the Educational Adventure offers: |
Ways Women Earn Less Than Men
Posted April 11, 2018
California women lose a combined total of more than $84.2 billion every year to the gender wage gap.
Every year, organizers with the National Committee on Pay Equity choose a date in April to mark "National Equal Pay Day", which, in theory, represents the extra time in the year a woman would have to work to make as much as a white man did the previous year. Titled #20percentcounts, it aims to boost awareness about what it's really like for women to make, on average, 20 percent less than a man does. Researchers estimate women bring home $7,000 less than their male counterparts, enough to pay for nearly a year of child care, 48 weeks of groceries, and five months of mortgage and utilities payments. Since managers on average earn two times the salary of non-managers, this contributes significantly to the overall gender wage gap, the report found. Wyoming has the largest gap between men and women at 36 percent with NY and DE taking the top spots at 11 percent.
According to Pew Research, African American women on average earn only 66 cents and Latinas on average earn only 60 cents for every dollar earned by white, non-Hispanic men. The Woman in the Room group is inviting workers to send anonymous emails from the Woman in the Room address to their bosses, demanding action on equal pay. Latinas made 54 cents for every dollar paid to white men a year ago, according to the report. They may also only have one child, a factor that also influences how quickly a woman can close the spousal wage gap.
Some of Canada's largest banks, engineering firms, retailers and other companies pay their female British employees substantially less than their male counterparts and give out lower bonuses, according to gender pay disclosures filed in the United Kingdom. When asked who they believed would fix the pay gap, respondents to a recent survey about money commissioned by Glamour said that that, well...it was on them.
WSP's hourly wage gap was 25 per cent while its women received 55 per cent lower bonuses, while SNC-Lavalin said its wage gap was 38 per cent and the bonus gap was 67 per cent.
It's not enough to fight for paycheck fairness or to demand that companies be more transparent about what they pay men and women.
The National Partnership's study indicated that wage inequality is a top concern for women across the country. To highlight the disparity between white men's earnings and those of black women, there is a separate day specifically for black women each year called Black Women's Equal Pay Day, which was held on July 31 last year.
By now, you might be feeling a little annoyed about this, but the worst part is that it sucks way more for women of color.
Celebrities such as Catt Sadler from ENews spoke out about the pay difference between her and her co-anchor Jason Kennedy, who have both been working on the channel for the same amount of years causing Sadler to eventually quit her job on the popular network. |
Home > Publications > Rethinking School Reform
Rethinking School Reform
By Hasina Deary
It's a typical cartoon scene: Popeye off sailing or toting a sledge hammer doing whatever Popeye does to make a living, while Olive Oyl who does not have a job lounges around. Olive is skinny to the point of hospitalization. Popeye obviously does not share his spinach. Olive Oyl, in her frail condition has a tendency to be vulnerable to Bluto's frequent abductions. Bluto is the big, brawny bully who Popeye grapples with from cartoon to cartoon. Poor Olive is whisked away by the hair or thrown kicking and screaming over Bluto's shoulder. Her only salvation is knowing that Popeye will be coming to save her. "Help me, help me, Popeye!" Magically, he hears Olive's call for help. Popeye, her hero. He struggles with his can of spinach, but in the end the tattooed avenger saves Olive Oyl. It is so silly. Olive Oyl's only redeeming quality as a woman is the fact she is never stuck in the kitchen. Popeye, the strong and courageous, also prepares his own meals.
Why wasn't Olive ever smart enough to lock the doors so Bluto couldn't get in or clever enough to save herself? It is a disgusting example of the "Help Me Syndrome" so often portrayed in cartoons.
In Sleeping Beauty, the silly little princess pricked her finger, causing an entire kingdom to slumber. Peace was restored after the prince rode into town, fought with a witch in dragon's form, then kissed the Sleeping Beauty. All is well, another princess saved.
Why are women constantly in need of male rescue? Does the industry feed on some women's twisted fantasy to be saved by a make-believe Prince Charming? It might be said that these are old cartoons and women today have evolved. But Disney's three latest productions have at least one scene where the female character's life was in jeopardy, only to be spared by her male counterpart.
In The Little Mermaid, Eric steers a ship's mast through the evil Ursula's torso, freeing Ariel from the curse. After Belle from Beauty and the Beast tries to leave the castle she is attacked by slanty-eyed wolves. Lucky for her, the Beast came and fought off the angry hounds. A sigh of relief is breathed, another pretty face saved. Even in Aladdin, Disney's most progressive cartoon, Aladdin, the street-smart hero, first comes to Princess Jasmine's aid when she nearly has her hand cut off after being accused of thievery. In the end of the movie, we see Jasmine trapped in a huge hourglass. Her cries for help are drowned out by the sand that fills the glass. Finally, Aladdin breaks the glass to save Jasmine. Ahh.
While the women in Disney's three recent cartoons are a step up from the nonstop pathetic whining of Olive Oyl, they still lack independence and basic survival skills. They may be called a heroine, but by no means are they the woman hero. Indeed, they are merely girls in need of rescue. The misconception that females must be male-dependent is reiterated, even if they basically have things going for them. Belle wanted more than her "provincial life." So they want more, but never can they attain it by themselves.
Rarely do we see brave women saving others. Wonder Woman is the only woman cartoon character I know who has ever been the rescuer. She saves men, women, and children (but mostly women and children). Of course, she has to have Super Heroine powers to do it. She could not just be Mindy MacGyver, the normal girl, who uses her mind to solve probems. Instead cartoons are made about beautiful girls who sing and read, and bright-eyed, headstrong princesses who are all capable of thinking, but ultimately succeed because of the love of a man. I think it is time to change the outdated formulas of love and near-death rescue scenes. I challenge the cartoon makers to find a new happy ending.
This material is from the online presentation for Rethinking School Reform: Views From The Classroom, edited by Linda Christensen and Stan Karp, published by Rethinking Schools. For more information see www.rethinkingschools.org/rsr
Summer 2003 |
Population of Cities in Fiji (2018)
Over 1 Million
100,000 to 1 Million
10,000 to 100,000
• Suva
• Lautoka
• Nadi
• Labasa
• Ba
• Levuka
• Ahau
An archipelago in the South Pacific ocean, Fiji consists of more than three hundred islands and is known for its spectacular landscapes, beaches and coral reefs. It has two main islands, Viti Levu and Vanua Levu, and these are home to the majority of the population of almost 900,000 residents. The capital city of Suva is on Viti Levu, and is a port city that still retains some British colonial architecture. Most of the population of Viti Levu live in and around Suva – in fact, its population of 600,000 accounts for the majority of both main islands.
The second-largest island, Vanua Levu, was previously known as Sandalwood Island, and lies to the north of Viti Levu. Vanua Levu has a population of around 135,000 residents. The largest settlement on the island is Labasa, which has a population of almost 30,000, and is a major centre of Fiji's sugar industry. Other parts of Vanua Levu are very popular tourist destinations for diving and yachting. Of the remaining islands, only 110 are permanently inhabited and these are home to the remaining population of Fiji.
Fiji has 0 cities with more than a million people, 0 cities with between 100,000 and 1 million people, and 5 cities with between 10,000 and 100,000 people. The largest city in Fiji is Suva, with a population of 77,366 people.
Suva is the capital and largest metropolitan city in Fiji.
Lautoka is known as the Sugar City because of its sugarcane belt areas.
Name 2018 Population Location |
Ecnomus (256 BCE)
Battle of Ecnomus (256 BCE): naval battle in the First Punic War, in which the navy of the unexperienced Romans unexpectedly defeated the well-trained navy of the Carthaginians. This was one of the largest battles in ancient history.
In 256, the Romans sent a fleet of no less than 330 ships from Sicily to Africa, where the army aboard was supposed to strike at the Carthaginian homeland. Before crossing the Mediterranean, it encountered a Carthaginian navy of 350 ships, not far from modern Licata, at Ecnomus, an early third-century city founded by refugees from Gela.
The fight at Ecnomus was to be one of the greatest battles in history, because both sides sent more than 140,000 men to the front. We can be confident about these figures because they are based on crew numbers. The Romans won the battle, and could continue to Africa, where they were eventually defeated.
The story is told by Polybius of Megalopolis in his History of the World 1.25.5-29.1, which is offered here in the translation by W. R. Paton, and was taken from LacusCurtius.
Strategic Objectives
Both sides thought that they fought now on equal terms, and both threw themselves most thoroughly into the task of organizing naval forces and disputing the command of the sea, while in the meantime the land forces accomplished nothing worthy of mention, but spent their time in minor operations of no significance.
The Romans, therefore, after making preparations as I said, for the coming summer, set to sea with a fleet of 330 decked ships of war and put in to Messana.note Starting again from there they sailed with Sicily on their right hand, and doubling Cape Pachynus they came round to Ecnomus, because their land forces too happened to be just in that neighborhood. The Carthaginians, setting sail with 350 decked vessels, touched at Lilybaeum,note and proceeding thence came to anchor off Heraclea Minoa.
Tactical Preparations
Battle of Ecnomus, first stage
About the same time the Carthaginian commanders briefly addressed their forces. They pointed out to them that in the event of victory in the battle they would be fighting afterwards for Sicily, but that if defeated they would have to fight for their own country and their homes, and bade them take this to heart and embark. When all readily did as they were ordered, as their general's words had made clear to them the issues at stake, they set to sea in a confident and menacing spirit. The commanders, when they saw the enemy's order, adapted their own to it. Three-quarters of their force they drew up in a single line, extending their right wing to the open sea for the purpose of encircling the enemy and with all their ships facing the Romans. The remaining quarter of their force formed the left wing of their whole line, and reached shoreward at angle with the rest.
Battle of Ecnomus, second stage
Model of the "raven"
At one and the same time Hanno with the right wing, which had held its distance in the first attack, sailed across the open sea and fell upon the ships of the triarii, causing them great embarrassment and distress. Meanwhile that part of the Carthaginian force which was posted near the shore, changing their former formation and deploying into line with their prows facing the enemy, attacked the vessels which were towing the horse-transports. Letting go their tow-lines this squadron met and engaged the enemy. Thus the whole conflict consisted of three parts, and three sea-battles were going on at a wide distance from each other.
As the respective forces were in each case of equal strength owing to their disposition at the outset, the battle also was fought on equal terms. However, in each case things fell out as one would expect, when the forces engaged are so equally matched. Those who had commenced the battle were the first to be separated, for Hamilcar's division was finally forced back and took to flight.
The battle of Ecnomus, third stage
Lucius [Manlius] was now occupied in taking the prizes in tow, and Marcus [Atilius Regulus], observing the struggle in which the triarii and horse-transports were involved, hastened to their assistance with such of the ships of the second squadron as were undamaged. When he reached Hanno's division and came into conflict with it, the triarii at once took heart, though they had had much the worst of it, and recovered their fighting spirit.
The Carthaginians, attacked both in front and in the rear, were in difficulties, finding themselves surrounded, to their surprise, by the relieving force, and giving way, they began to retreat out to sea. Meanwhile both Lucius [Manlius], who was by this time sailing up and observed that the third squadron was shut in close to the shore by the Carthaginian left wing, and Marcus [Atilius Regulus], who had now left the horse-transports and triarii in safety, hastened together to the relief of this force which was in grave peril; for the state of matters now was just like a siege, and they all would evidently have been lost if the Carthaginians had not been afraid of the ravens and simply hedged them in and held them close to the land instead of charging, apprehensive as they were of coming to close quarters.
The consuls, coming up rapidly and surrounding the Carthaginians, captured 50 ships with their crews, a few managing to slip out along shore and escape. The separate encounters fell out as I have described, and the final result of the whole battle was in favor of the Romans. The latter lost 24 sail sunk and the Carthaginians more than 30. Not a single Roman ship with its crew fell into the enemy's hands, but 64 Carthaginian ships were so captured.
This page was created in 2004; last modified on 10 June 2017. |
Self-Ownership: The Foundation of Freedom
So let's forget about democracy, and concentrate on freedom.
It sounds simple enough, perhaps even self-evident. But by exploring the ramifications of such an idea, one's commitment to freedom is keenly tested.
I also believe this concept is not difficult to understand or explain to others. And yet in grasping the import and ongoing consequences of such a term, one can see the revolutionary implications of it.
Self ownership means just one thing, that YOU are the owner of your life--your body, your mind, your energy, and any consequent results of your life's efforts.
If you are not sure of this--or disagree--then simply ask yourself, "If I am NOT the rightful owner of my own life, then who is?"
The ownership of your own body leads to many predictable conclusions. The most obvious are that you are able to make decisions about your own body, and consequently, your own life.
To illustrate: You are the one who decides what you must eat to sustain your body. You are the one who decides whether or not to take a particular drug to cure an illness. You are the one who decides what to read, in order to stimulate or entertain your own mind.
It would be ludicrous for you to pass this responsibility on to someone else--in order that they may impose their choices on you. (And censorship is wrong for this very reason.)
But owning your life is more than just owning your physical body. It is more than just deciding what to wear, what to eat and what to read. Your life also includes your mind. And with your mind you are able to do a lot of things that are equally defined as "your" life.
To illustrate: If you spent ten hours of your life, last week, on the creation of a new coffee table for your home, then that object is the result of your own life's effort. You expended your own energy in its creation. And, as a result, it is now your property--and rightly so, because it was created by your energy and intention. Ultimately, it is a product of your mind--brought to fruition via the actions of your body.
In making it, you may have purchased timber off someone who grew the trees on his own land, or a timber merchant who specialises in selling furniture grade materials--thereby engaging in the voluntary exchange of property.
In this way, life and property are inseparable. A man without any property is dead!
So a natural consequence of owning your own life, is owning that which your life creates, or trades with others--property.
There can be no such thing as self-ownership, if there is no property. One automatically leads to the other. Self ownership implies a proprietary interest in your own life and the material results of your life's actions.
Now, if you own your own life, then it stands to reason that every other individual on this planet also owns his or her own life. The only exceptions would be those whose lives are the legal and/or moral responsibility of someone else--as in the relationship between parents and their young children. But children grow up, and assume full property rights over their own lives.
Now the question arises, "What type of society would grow and evolve out of the recognition of each person's self-ownership?"
Obviously, it would be a society where such self-ownership was respected; where all interaction between self-owners was on the basis of voluntary agreement. In a society of self-owners, everyone would be truly equal--equal in their status as owners of themselves. No masters. No slaves.
Such a society would be "free" in the true meaning of the word--an environment where every individual was free to pursue his life as the legitimate owner of his life.
It also raises the question as to what countries can legitimately call themselves "free." Obviously, to have any meaning, a free country would have to be one where self-ownership was sacrosanct. If it was not, then it would not be free. "You're either with us or against us." You're either free or you are not.
Are there shades of freedom? Are there places where one can be freer than somewhere else? Of course there are. Freedom can be measured by the yardstick of exactly how much self-ownership is permitted. So it's quite possible to talk of one country having more freedom than another. However, to claim the moral high ground of being a FREE country--as in truly free--then it would be necessary to show that each and every person was indeed free. No existing country passes that test.
Let's test some scenarios.
Are you living in a country where you can speak your mind? Where you can speak out against the government? Can you write a book which criticises your government without getting thrown in jail?
Are you living in a country where you can ingest any substance into your own body--like tobacco and other drugs? Or are laws and regulations in place which limit your freedom to do so?
Are you living in a country where you get to keep the money you earn--i.e., the money you receive for expending your life's energy last week, last month, or last year? Or does your government take a chunk of your money off you by force--to give to others who have demanded it?
Are you living in a country where you can freely trade your property with the property of others--without any interference? Or are you required to apply for licenses, or pay levies on such transactions?
You get the picture.
In fact, by the definition I have offered--that freedom is the societal condition in which you are the effective owner of your own life--no country is fully free.
Yes, various countries will allow for some freedom, some exercise of your personal ownership rights. Some countries are more free and some less free. But none can claim to be fully free.
Hong Kong was reasonably free before being handed back to China. It was relatively free, because an individual had a great deal of control over his own life. There was no democracy--but there was a good deal of practical freedom.
The USA is free in some ways--but unfree in others. There are millions of people incarcerated because of drug-related "crimes"--which in a free society would not exist. People can now be held without trial. And if the USA brings back the military draft, then they will have taken another major step back from freedom.
Even in Iraq--before the invasion--some freedoms existed in the midst of restrictions.
For example, in Iraq everyone had guns (and most still do). And one expat Iraqi, who returned from the USA, said that provided he did not criticise Saddam, he was relatively free to get on with his life as he saw fit.
The same could be said for China. If you just mind your own business, you can make a fortune, and keep most of it. Just don't go shouting your mouth off against the Communist leadership!
The EU is pondering the banning of the image of the swastika. It appears they don't see the contradiction in their actions--to limit freedom in the name of protecting it.
Yes, every nation is a basket case of contradictions when it comes to having freedom. No nation is free. There are no free societies. So, you have to search for a place where you can live with the most freedom. It's a case of choosing the "best of a bad bunch."
But ultimately, freedom begins "at home." And the first test of your own commitment to freedom is to ask yourself, "Am I willing to grant every other individual the right to his or her own life?"
Keep in mind, we're talking here about mutual recognition of such a right. If someone breaks into your house and steals the home entertainment system you worked so hard to pay for, then such a person has broken the freedom code--and forfeits his own freedom. How it is forfeited depends on the type of society. But in a rational, free society, the emphasis would be on ensuring that such a person made restitution--by expending his own effort to pay for the property so stolen. With interest, of course!
Freedom is not that hard to understand--just hard to implement, because the majority of people are NOT prepared to grant others the ownership of their own lives, and prefer the "busybody" approach to social organisation. This characteristic is reflected in the body politic--where we get the government we deserve. Or more correctly, the government the majority deserve. And until we understand freedom as individuals, and grant that freedom to our neighbours, all efforts to bring freedom to the world will fail miserably.
Your rating: None
David MacGregor's picture
Columns on STR: 26
|
The Aword
• Increase font size
• Default font size
• Decrease font size
Effects of Opioids on the Body
E-mail Print PDF
As you can see from the table above, activation of opiate receptors can have various effects.
Pain is modulated by action on specific sites in the central nervous system, particularly the dorsal horns of the spinal cord and the periaqueductal grey matter. Recent studies suggest that peripheral action may also occur.
Opiates not only affect sites along the pain pathways, but also the respiratory centre, cough impulse (depresses cough reflex by acting on a cough centre in the medulla), the vomiting centre (stimulation of chemoreceptor trigger zone in area postrema of the medulla causing nausea and vomiting) and also inhibit gut motility(propuslive peristaltic waves in the colon are decreased) : constipation is due to this and to increased colonic tone (spasm) and increased tone of anal sphincter.
They also affect the hormonal (endocrine) system(cause release of antidiuretic hormone which may explain the fluid retention that can occur) and the hypothalamus, which regulates body temperature. To begin with, body temperature is lowered, but it rises with chronic use of high doses.
Morphine releases histamine, a chemical that takes part in the inflammatory response (such as in nettle hives/ insect bites/ allergy reaction). Dilation of cutaneous blood vessels and subsequent histamine release can lead to flushing in the chest, neck and face, as well as to itching and sweating.
Miosis (pin point pupil) is due to (m and k receptors) excitatory action of the parasympathetic nerve innervating the pupil . This may result in difficulty with close-up focussing, for example, difficulty reading the telephone directory. Tolerance does not appear to develop to miosis.
Urinary urgency but difficulty in urination may occur due to inhibition of urinary voiding reflex. The amplitude of ureteral contractions may be increased. Opiates can also lead to urinary retention by causing spasm of the bladder sphincter, particularly in men with prostatism.
Biliary colic and epigastric distress results from tone increase in the sphincter of Oddi and in the bile duct causing increase in pressure in the biliary tract (this increases pain of gall stones). Opiates reduce gastric, pancreatic and biliary secretions.
They are also known to affect the immune system in a complex manner. Studies of drug abuse have found that there may be a degree of immunosuppression due to these drugs and this can lead to increased susceptibility to infections in vulnerable patients. Whether this is a problem with prescribed doses is unclear.
Sedation and `mental clouding' are known side-effects of opioids.
The mood changes are related to the effects on the limbic system and nucleus accumbens. Opioids do not tend to cause the euphoria experienced by recreational users when used for pain relief. However, they may reduce the negative emotional response to pain.
Some of the untoward effects from opioids are in fact exploited to treat conditions such as diarrhoea, cough and shortness of breath in acute left heart failure (which causes fluid in the lungs). |
Khnumhotep and Niankhkhnum First on Record Bisexuals
Khnumhotep and Niankhkhnum
eg bi a
Khnumhotep (pronunciation: xaˈnaːmaw-ˈħatpew) and Niankhkhnum (pronunciation: nij-daˌnax-xaˈnaːmaw) were ancient Egyptian royal servants. They shared the title of Overseer of the Manicurists in the Palace of King Niuserre during the Fifth Dynasty of Egyptian pharaohs, c. 2400 BCE, and are listed as “royal confidants” in their joint tomb.
Khnumhotep and Niankhkhnum are depicted in the tomb with their respective families. It has been proposed that they were the sons of Khabaw-khufu and Rewedzawes. They appear to have had three brothers named Titi, Nefernisut, and Kahersetef. Three possible sisters are also attested. They are named Neferhotep-hewetherew, Mehewet and Ptah-heseten.
eg bi 1
Entrance to the mastaba of Khnumhotep and Niankhkhnum
Niankhkhnum’s wife was named Khentikawes. They appear in the tomb with three sons named Hem-re, Qed-unas and Khnumhezewef. Three daughters are mentioned as well and their names are Hemet-re, Khewiten-re and Nebet. At least one grand-son is mentioned. Irin-akheti was the son of Hem-re and his wife, Tjeset.
Khnumhotep had a wife by the name of Khenut. Khnumhotep and Khenut had at least five sons named Ptahshepses, Ptahneferkhu, Kaizebi, Khnumheswef and Niankhkhnum -the younger (named after his uncle) as well as a daughter named Rewedzawes.
The Tomb
Coordinates: 29.86795°N 31.219416°E
eg bi 2
eg bi 3
The mastaba of Khnumhotep and Niankhkhnum.
The tomb of Khnumhotep and Niankhkhnum was discovered by Egyptologist Ahmed Moussa in the necropolis at Saqqara, Egypt in 1964, during the excavation of the causeway for the pyramid of King Unas. It is the only tomb in the necropolis where men are displayed embracing and holding hands. In addition, the men’s chosen names (both theophorics to the creator-god Khnum) form a linguistic reference to their closeness:
Niankhkhnum means “joined to life” and Khnumhotep means “joined to the blessed state of the dead'”, and together the names can be translated as “joined in life and joined in death”
In a banquet scene, Niankhkhnum and Khnumhotep are entertained by dancers, clappers, musicians and singers; in another, they oversee their funeral preparations. In the most striking portrayal, the two embrace, noses touching, in the most intimate pose allowed by canonical Egyptian art, surrounded by what would appear to be their heirs. The superstructure of their tomb
“was almost completely destroyed because king Unas built his [tomb] causeway over it. It has been reconstructed using the decorated blocks that were found during excavation, and is now open to the public. The part of the tomb that was put into the rock is well preserved. The quality of the painted reliefs is excellent, especially in the first of the rock cut chambers. The various scenes on the western side of the tomb include fishing and fowling in the marshes, stock breeding, papyrus gathering and fights among the boatmen. opposite are agricultural scenes and scenes of sculptors and jewellers at work.”
Pillared Entrance
The façade of the mastaba is made up of a pillared portico. The front is inscribed and Niankhkhnum is depicted on the left, while Khnumhotep is depicted on the right. The inscriptions accompanying the men is virtually identical, with only the names being different.
eg bi b
First vestibule
This space is fairly small. The west side is decorated with a funerary procession for Niankhkhnum and the east side shows a matching funerary procession for Khnumhotep.
The south wall shows the two men seated before an offering table. Niankhkhnum is seated on the right, while Khnumhotep is seated on the left. The table with offerings stretches out between them. Below the offering scene the two men are depicted hunting and fishing. On the left Khnumhotep stands on papyrus boat. He is accompanied by his wife Khenut and a son and daughter. On the right Niankhkhnum is depicted in a similar manner. He is accompanied by his wife Khentkawes and a son and daughter as well.
First and Second Chamber
eg bi 4
East wall in the first chamber.
At the entrance scenes of baking bread and brewing beer are depicted. Barley is carefully measured out and turned into bread. Some of the bread is mixed with a date beverage and fermented to produce some type of beer.
Other scenes include goat herding, ship building, harvesting scenes, sailing, netting of birds, etc.
The east wall contains a legal text. Below this text several people are depicted thought to be the family of the two men. At the very bottom ships are shown. The men are shown standing before the main cabin of the ship.
Antechamber and Offering Chamber
eg bi 5
Niankhkhnum, Khnumhotep and their children depicted on a pillar.
The antechamber is a fully decorated rock-cut room. The scenes show people in agricultural scenes including the weighing of corn and grain, the ploughing of the fields and harvesting.
A pillar depicts the two men with their children. The respective wives are not depicted in this scene. Niankhkhnum’s three sons and three daughters are depicted behind him. The inscriptions give their respective names. Similarly, Khnumhotep’s five sons and one daughter appear behind him.
Proposed homosexuality
eg bi c
Clip to Evernote
This entry was posted in Egyptology, Gays, He/Shes, History, Lesbians, Nude and dressed Middle Eastern beautiful people, مزز عريا وبالملابس. Bookmark the permalink. |
Digit_sum help - how to separated characters in a list
I've been searching for a way to solve this for an hour, and I'm getting really discouraged. :frowning:
Regarding this exercise: https://www.codecademy.com/courses/python-intermediate-en-rCQKw/0/4?curriculum_id=4f89dab3d788890003000096#
I'm getting this error:
"Traceback (most recent call last):
File "python", line 14, in
File "python", line 3, in digit_sum
TypeError: 'int' object is not iterable"
and this:
"Oops, try again. Does your digit_sum function take exactly one argument (a positive integer)? Your code threw a "'int' object is not iterable" error."
What I want to do is be able to separate every letter/number in n[], even if they are not already separated (ex: '143' would be '1', '4', '3', not '143'). and add them together, x. Ideas for separating each item in a list? Something like n[0:] or something?
Thank you in advance. :slight_smile:
def digit_sum(n):
n == []
for num in n:
x == 0
if num % 1 == 0:
x += num
elif num == str('num'):
x += num
print 'error'
edit: I realize there is a lot wrong with my code, I'm still learning.
n == []
why use two equal signs? this means, check if equal. This is usually something you do in a if condition. To name a variable n and give it a empty list as value, use a single equal sign
then the error you get, which is here:
for num in n:
n is an integer. Integers are not iterable. You could convert to string? Strings are iterable
Thank you! That makes sense... silly mistakes.
I changed it a bit but am still getting errors.
This is the new code:
def digit_sum(num):
num = []
for i in num: #for each item in the list..
x = 0
if i % 1 == 0: #if i is indeed an integer..
if i > -10 and i < 10: # & a single digit..
x +=i #add to the growing sum
digits = [int(d) for d in str(i)]
x += digits #form a str, break str, sum
(I don't know how to print this with the indentations, sorry.)
This is the error message:
"Oops, try again. Your function fails on digit_sum(434). It returns None when it should return 11."
Any ideas? :confused:
I scratched it and started over. I looked through the FAQ and found something that, when I wrote it out on paper, worked wonderfully. So I tried to write it in my own way and something is off, but I'm not sure what.
def digit_sum(n):
digits = []
for n in digits:
sum = 0
while n > 0:
remainder = n % 10
sum = remainder + sum
n = n // 10
return n
return sum
This is the error I'm getting:
Yet if I do the math on paper, using the steps in my function, I get 11, so maybe its formatting again?
Any ideas would be very appreciated.
your latest approach doesn't require a for loop.
The while loop alone is enough. Get rid of the for loop, and you should be good.
given n = n // 10 will eventually make n zero, the loop will become false
a single digit (1-9) divided by 10 (and then floored) will be zero
Thanks. I took the for loop out but am still getting the same error message.
def digit_sum(n):
sum = 0
while n > 0:
remainder = n % 10
sum = remainder + sum
n = n // 10
return n
return sum
pretty close now, a function ends the moment a return keyword is reached
so you should return sum, not n
Why do we return sum instead of n?
because sum contains the total/sum of n, and we need to return that, that was the point of the exercise? To write a function which returns the digits sum, which you stored in sum variable
A post was split to a new topic: Digit sum
|
Open main menu
Phenolphthalein is a chemical compound with the formula C20H14O4 and is often written as "HIn" or "phph" in shorthand notation. Phenolphthalein is often used as an indicator in acid–base titrations. For this application, it turns colorless in acidic solutions and pink in basic solutions. It belongs to class of dyes known as Pthalein dyes.
Sample of solid phenolphthalein.jpg
Preferred IUPAC name
Other names
3D model (JSmol)
ECHA InfoCard 100.000.914
Molar mass 318.33 g·mol−1
Appearance White powder
Density 1.277 g/cm3 (32 °C (90 °F))
Melting point 258–263 °C (496–505 °F; 531–536 K) [1]
400 mg/L in water
Solubility in other solvents Insoluble in benzene or hexane, very soluble in ethanol and ether, slightly soluble in DMSO
UV-vismax) 552 nm (1st)
374 nm (2nd)[1]
A06AB04 (WHO)
GHS signal word Danger
H341, H350, H361[1]
P201, P281, P308+313[1]
NFPA 704
☒N verify (what is ☑Y☒N ?)
Infobox references
Phenolphthalein is slightly soluble in water and usually is dissolved in alcohols for use in experiments. It is a weak acid, which can lose H+ ions in solution. The phenolphthalein molecule is colorless, and the phenolphthalein ion is pink.When a base is added to the phenolphthalein, the molecule ⇌ ions equilibrium shifts to the right, leading to more ionization as H+ ions are removed. This is predicted by Le Chatelier's principle.
Phenolphthalein adopts four different states in aqueous solution: Under very strongly acidic conditions, it exists in protonated form (HIn+), providing an orange coloration. Between strongly acidic and slightly basic conditions, the lactone form (HIn) is colorless. The doubly deprotonated (In2-) phenolate form (the anion form of phenol) gives the familiar pink color. In strongly basic solutions, phenolphthalein's pink color undergoes a rather slow fading reaction and becomes completely colorless above 13.0 pH. The rather slow fading reaction that produces the colorless In(OH)3− ion is sometimes used in classes for the study of reaction kinetics.
Species H3In+ H2In In2− In(OH)3−
pH <0 0−8.2 8.2−12.0 >13.0
Conditions strongly acidic acidic or near-neutral basic strongly basic
Color orange colorless pink to fuchsia colorless
An animation of the pH dependent reaction mechanism: H3In+ → H2In → In2− → In(OH)3−
Phenolphthalein's pH sensitivity is exploited in other applications: Concrete has naturally high pH due to the calcium hydroxide formed when Portland cement reacts with water. As the concrete reacts with carbon dioxide in the atmosphere, pH decreases to 8.5-9. When a 1% phenolphthalein solution is applied to normal concrete, it turns bright pink. However, if it remains colorless, it shows that the concrete has undergone carbonation. In a similar application, spackling used to repair holes in drywall contains phenolphthalein. When applied, the basic spackling material retains a pink coloration; when the spackling has cured by reaction with atmospheric carbon dioxide, the pink color fades.[3]
Phenolphthalein is used in toys, for example as a component of disappearing inks, or disappearing dye on the Hollywood Hair Barbie hair. In the ink, it is mixed with sodium hydroxide, which reacts with carbon dioxide in the air. This reaction leads to the pH falling below the color change threshold as hydrogen ions are released by the reaction:
OH(aq) + CO2(g)CO2−
(aq) + H+(aq)
To develop the hair and "magic" graphical patterns, the ink is sprayed with a solution of hydroxide, which leads to the appearance of the hidden graphics by the same mechanism described above for color change in alkaline solution. The pattern will eventually disappear again because of the reaction with carbon dioxide. Thymolphthalein is used for the same purpose and in the same way, when a blue color is desired.[4]
Medical usesEdit
Phenolphthalein has been used for over a century as a laxative, but is now being removed from over-the-counter laxatives[5] because of concerns over carcinogenicity.[6][7] Thymolphthalein is a related laxative made from thymol.
Despite concerns regarding its carcinogenicity, the use of phenolphthalein as a laxative is unlikely to cause ovarian cancer.[8] Phenolphthalein has been found to inhibit human cellular calcium influx via store-operated calcium entry (SOCE, see Calcium release activated channel § Structure). This is effected by its inhibiting thrombin and thapsigargin, two activators of SOCE that increase intracellular free calcium.[9]
Phenolphthalein has been added to the European Chemicals Agency's candidate list for Substances of Very High Concern (SVHC).[10]
A reduced form of phenolphthalein, phenolphthalin, which is colorless, is used in a test to identify substances thought to contain blood, commonly known as the Kastle-Meyer test. A dry sample is collected with a swab or filter paper. A few drops of alcohol, then a few drops of phenolphthalin, and finally a few drops of hydrogen peroxide are dripped onto the sample. If the sample contains hemoglobin, it will turn pink immediately upon addition of the peroxide, because of the generation of phenolphthalein. A positive test indicates the sample contains hemoglobin and, therefore, is likely blood. A false positive can result from the presence of substances with catalytic activity similar to heme. This test is not destructive to the sample; it can be kept and used in further tests. This test has the same reaction with blood from any animal, so further testing would be required to determine whether it originates from a human.
Phenolphthalein can be synthesized by condensation of phthalic anhydride with two equivalents of phenol under acidic conditions (hence the name). It was discovered in 1871 by Adolf von Baeyer.[11][12][13]
Synthesis of phenolphthalein:[14]
The reaction can also be catalyzed by a mixture of zinc chloride and thionyl chloride.[15]
See alsoEdit
1. ^ a b c d e "Phenolphthalein". Retrieved 7 October 2014.
2. ^ "Universal Indicator". ISCID Encyclopedia of Science and Philosophy. Archived from the original on September 25, 2006.
3. ^ US 6531528, Ronald D. Kurp, "Ready to use spackle/repair product containing dryness indicator", assigned to Dap Products Inc.
4. ^ Toystore
5. ^ Spiller, H. A.; Winter, M. L.; Weber, J. A.; Krenzelok, E. P.; Anderson, D. L.; Ryan, M. L. (May 2003). "Skin Breakdown and Blisters from Senna-Containing Laxatives in Young Children". The Annals of Pharmacotherapy. 37 (5): 636–639. doi:10.1345/aph.1C439. PMID 12708936.
6. ^ Dunnick, J. K.; Hailey, J. R. (1996). "Phenolphthalein Exposure Causes Multiple Carcinogenic Effects in Experimental Model Systems" (pdf). Cancer Research. 56 (21): 4922–4926. PMID 8895745.
7. ^ Tice, R. R.; Furedi-Machacek, M.; Satterfield, D.; Udumudi, A.; Vasquez, M.; Dunnick, J. K. (1998). "Measurement of Micronucleated Erythrocytes and DNA Damage during Chronic Ingestion of Phenolphthalein in Transgenic Female Mice Heterozygous for the p53 Gene". Environmental and Molecular Mutagenesis. 31 (2): 113–124. doi:10.1002/(SICI)1098-2280(1998)31:2<113::AID-EM3>3.0.CO;2-N. PMID 9544189.
8. ^ Cooper, G. S.; Longnecker, M. P.; Peters, R. K. (2004). "Ovarian Cancer Risk and Use of Phenolphthalein-Containing Laxatives". Pharmacoepidemiology and Drug Safety. 13 (1): 35–39. doi:10.1002/pds.824. PMID 14971121.
9. ^ Dobrydneva, Y.; Wilson, E.; Abelt, C. J.; Blackmore, P. F. (2009). "Phenolphthalein as a Prototype Drug for a Group of Structurally Related Calcium Channel Blockers in Human Platelets". Journal of Cardiovascular Pharmacology. 53 (3): 231–240. doi:10.1097/FJC.0b013e31819b5494. PMID 19247192.
10. ^ "Phenolphthalein - Substance Information - ECHA". Retrieved 2017-11-06.
11. ^ Baeyer, A. (1871). "Ueber eine neue Klasse von Farbstoffen". Berichte der Deutschen Chemischen Gesellschaft. 4 (2): 555–558. doi:10.1002/cber.18710040209.
12. ^ Baeyer, A. (1871). "Ueber die Phenolfarbstoffe". Berichte der Deutschen Chemischen Gesellschaft. 4 (2): 658–665. doi:10.1002/cber.18710040247.
13. ^ Baeyer, A. (1871). "Ueber die Phenolfarbstoffe". Polytechnisches Journal. 201 (89): 358–362.
14. ^ Max Hubacher, U.S. Patent 2,192,485 (1940 to Ex Lax Inc)
15. ^ U.S. Patent 2,522,939
External linksEdit |
ArtsAutosBooksBusinessEducationEntertainmentFamilyFashionFoodGamesGenderHealthHolidaysHomeHubPagesPersonal FinancePetsPoliticsReligionSportsTechnologyTravel
Prince Bi Gan
Updated on June 4, 2010
Prince Bi Gan was one of the three uncles of the tyranny King Zhou (Chou) of Shang Dynasty.
Bi Gan also written as prince Pi Kan, or the prince Pî-kan, his character and conducts was widely discussed by all kinds of philosophy schools.
Confucius highly praised Bi Gan, and said: “In three of the Yin there was love”. But Chuang Tzu disaproved of Bi Gan's behaviour, he thinks that it's Bi Gan's fond of good fame incurred his own death, in Chuang tzu, chapter IV :
The Death of Bi Gan
Bi Gan repeatedly remonstrated to the king regarding his behavior and incurred the king's wrath, the King shouted at him, "I heard that a sage's heart has seven apertures! Today, I would like to check it out!" The king ordered to cut open Bi Gan's chest to see how many compartments or holes in his heart. Bi Gan cut his heart out by himself.
Legend has it that when his chest was cut open, Bi Gan grabbed his heart and pulled it out of his body to be given to King Chou. He did not lose his life, nor shed a single drop of blood. Instead, he walked out of the palace, and went straight home. Yet upon the last few steps on reaching home, a female huckster yelled from behind, 'Hey, Cheap water spinach!' Bi Gan startled and looked back, then realized that he was walking without heart, and died.
Why did King Chou cut open Prince Bi Gan's heart? Because Bi Gan and Viscount Wei, and lord Chi were together known as "The Three Kindhearted Men of Shang" in the kingdom. King Chou might be jealous of the three men's good fame and wanted to revenge.
In the Book of Investiture of the Gods (or The Creation of the Gods) it was Daji , King Chou's favourite concubine, took revenge on Bi Gan. Once Daji awoke one morning and began to cough blood, she created the excuse that half a person's heart is needed within soup as a medicine to cure her ailment. As the Prime Minister, Bi Gan should sacrifice half his heart as a "showing of love to his king".
The Viscount of Wei resigned and went into exile, the lord of Ch´i became a slave, then he faked insanity and was relieved of his post. But Pi-kan was disemboweled and died for his reproofs.
King Wu raised a tumulus over Pi-kan's grave, and released the viscount of Chi from prison, after he defeated and killed King Chou of Shang.
Prince Bi Gan became the God of Wealth
According to the book The Creation of the Gods, Bi Gan actually didn't die after his heart was dug out, he went into the midst of the common people to distribute treasure, and became the God of Wealth, all merchants under the blessing of Bi Gan do honest business, never cheating anyone.
Descendants of Bi Gan
The Origin of the Lin surname was said to be related to Prince Bi Gan. When he was arrested, Bi Gan's pregnant wife escaped into the forest, and her baby was born in the forest, it is said that she grabbed hold of two trees and gave birth to a baby boy between two trees. The Chinese character of the surname Lin is depicted by two trees.
The Chinese legend also mentions that Wang family are descendants of Prince Bi Gan, and know as the 'The Bi clan of Wang family'.
0 of 8192 characters used
Post Comment
No comments yet.
This website uses cookies
Show Details
LoginThis is necessary to sign in to the HubPages Service.
AkismetThis is used to detect comment spam. (Privacy Policy)
Google AdSenseThis is an ad network. (Privacy Policy)
Index ExchangeThis is an ad network. (Privacy Policy)
SovrnThis is an ad network. (Privacy Policy)
Facebook AdsThis is an ad network. (Privacy Policy)
AppNexusThis is an ad network. (Privacy Policy)
OpenxThis is an ad network. (Privacy Policy)
Rubicon ProjectThis is an ad network. (Privacy Policy)
TripleLiftThis is an ad network. (Privacy Policy) |
Biological Invasions
, Volume 11, Issue 7, pp 1483–1487 | Cite as
Invasive rodents on islands: integrating historical and contemporary ecology
• Donald R. Drake
• Terry L. Hunt
The colonization of islands by humans dramatically transformed environments, initiating extinctions, extirpations, and a complex array of ecosystem changes (e.g. Kirch 1997; Grayson 2001; Anderson 2008; Athens et al. 2002; McConkey and Drake 2002; Steadman 2006; Kennett et al. 2006). Researchers in historical ecology have described these human-induced transformations as consequences of forest clearing, fire, and the introduction and establishment of a portmanteau biota (Crosby 2004). Rodents (especially the rats Rattus exulans, R. rattus, and R. norvegicus) may have been the most widely introduced vertebrates to accompany humans in our history of global dispersal. Indeed, one could argue that rats (Rattus spp.) are the original invasive “species”—from the colonization of the Pacific Islands to the global expansion of Europeans. Ecological, palaeoecological, and archaeological studies have documented the direct and indirect impacts of rodents on native plants and animals, and implicated them in transforming many island environments (e.g. Atkinson 1985; Diamond 1985; Athens et al. 2002; Steadman 2006; Towns et al. 2006; Hunt 2007; Jones et al. 2008). However, in some cases, effects attributed to rodents are based on circumstantial evidence, and a better understanding of the role played by rodents awaits integration of historical and contemporary ecology. Today, the integration of these fields has become increasingly important, because invasions and threats of extinction continue, and because ecological restoration of islands frequently depends on understanding rodent ecology in order to predict the consequences of their removal (Towns and Broome 2003; Caut et al. 2007).
Based on the dramatic ecological impacts observed in contemporary field studies, ecologists have typically adopted a default hypothesis that invasive rats must have had strong impacts in the past (see critical review by Towns et al. 2006). In contrast, archaeologists and palaeoecologists have, until recently, viewed human-induced impacts on island ecosystems largely as consequences of forest clearing and fire. Focusing on such direct human activities, these researchers have been reluctant to attribute major impacts to the direct or indirect effects of rats. For us this contrast came into focus when Stephen Athens (Athens et al. 2002; see Athens 2008) reported findings from his integrated palaeoecological and archaeological research on the Ewa Plain of Oahu, Hawaiian Islands. Athens, an archaeologist, showed with a detailed palaeoenvironmental and archaeological record that rats (R. exulans) introduced by Polynesians to the Hawaiian Islands some 1,000 years ago likely had a catastrophic impact on some native lowland forests. He offered this explanation for a record where fire or other direct human modifications of the forest (e.g. forest clearance for agriculture) could not account for widespread deforestation and the associated avifaunal extirpations. Athens’s research in Hawaii stimulated wide discussion among ecologists, palaeoecologists, and archaeologists. Can invasive rats really play a significant role in island deforestation and species extinction? The answer seems to lie somewhere between historical and contemporary disciplines, calling upon researchers to integrate models from ecology with the diachronic trajectories of environmental change.
To begin to meet this challenge, we convened an interdisciplinary conference in 2007 at the University of Hawaii. Our goal was to examine the role of invasive rodents (especially Rattus spp.) on islands, from prehistoric to contemporary times. Our hope was to address the many questions that seemed to have fallen between ecological field studies and palaeoenvironmental research. The conference brought together more than 140 researchers from disparate fields, all of whom share an interest in building the foundations for an integrated understanding of rodents’ roles in environmental transformations, for highlighting management issues, and fostering future research. The contents of this special issue of Biological Invasions represent the range of scientific fields and geographical regions examined by contributors to the conference.
Palaeoecological and archeological evidence of rodent invasions
The idea of islands as laboratories—comparative “experiments” in evolution—has long stimulated ecologists, biogeographers, human biogeographers, and archaeologists (e.g. MacArthur and Wilson 1967; Terrell 1997; Burney 1997; Fitzhugh and Hunt 1997; Drake et al. 2002; Vitousek 2002). Island ecosystems have been shaped by history, including effects of human colonization, biotic introductions, extinctions, and widespread direct and indirect habitat modifications. Research integrating archaeology and palaeoecology has provided records for dramatic and sometimes rapid biotic transformations of islands. At the same time, the historical ecological record has revealed that initial biotic invasions by humans (and their commensals) in pristine island ecosystems often have no clear analogs in contemporary environments. This makes the past all the more interesting from a biological perspective, but also more complicated given the uniqueness of these historical events and their profound and continuing effects.
Several papers in this special issue of Biological Invasions provide comparative and historical baselines detailing what we know of patterns of introduction of commensal vertebrates in the Pacific Islands (Anderson 2008; Matisoo-Smith and Robins 2008), as well as their prehistoric impacts (Athens 2008; Prebble and Wilmshurst 2008; Russell et al. 2008; see also Hunt 2007). The archaeological and palaeoecological records reveal how the effects of invasive species may vary significantly by island ecology, biogeography, and history. However, in many respects, detailed models for the ecology of invasive species and the relative vulnerability of islands remain to be more fully developed.
Modern, direct impacts of invasive rodents
Islands are renowned for having highly endemic and disharmonic biotas in which species often play unexpected ecological roles (Carlquist 1974; Drake et al. 2002; Whitaker and Fernandez-Palacios 2007). Because most remote islands lack native, terrestrial mammals, introduced rodents can assume highly novel ecological roles following colonization. Several contributions review the ecological effects of invasive rats (Rattus spp.) on specific groups of native taxa in specific island groups, including: rare plants in French Polynesia (Meyer and Butaud 2008), past and present invertebrates in New Zealand (Gibbs 2008), and land snails in Hawaii (Hadfield and Saufler 2008). In addition, Ruffino et al. (2008) use data from hundreds of Mediterranean islands to investigate how burrowing seabirds have managed to persist on some islands for 2,000 years after the introduction of R. rattus. They hypothesize that specific topographic features may provide refugia that minimize rats’ access to burrows, thus allowing some birds to escape predation. Harris (2008) reviews the effects of introduced rodents (Rattus spp. and Mus musculus) on small, native, island mammals. It is surprising this topic has received so little attention, given the obvious theoretical interest in understanding, e.g. how introduced rodents interact with their nearest ecological equivalents—native rodents. Finally, Traveset et al. (2008) provide a comprehensive review of the impacts of seven species of invasive rodents on the native plants, invertebrates, reptiles, birds, and mammals of the Balearic and Canary Islands. In addition to direct impacts, some of these species of rodents are affecting plant populations and communities indirectly by altering pollination and seed dispersal mutualisms (see also Traveset and Richardson 2006). While research on the impacts of invasive rodents has revealed much, continuing studies point to many critical, yet largely unresolved issues in both ecological and palaeoecological timescales.
Complex ecological interactions and their implications for management and restoration
While the direct consumption of insular species by invasive rodents has been relatively well documented, far less is known about their community and ecosystem level effects (but see Fukami et al. 2006). Understanding these broader, often indirect ecological effects is a critical precursor to successful restoration of insular ecosystems following rodent eradication (Zavaleta et al. 2001; Lorvelec and Pascal 2005; Courchamp et al. 2003; Caut et al. 2007, 2008a). For example, Caut et al. (2008b) demonstrate how undesirable side effects of eradication (e.g. ecological release of other invasive alien species) can be predicted and circumvented by characterizing trophic interactions prior to the eradication. Mulder et al. (2008) compare sets of islands in New Zealand with different histories of invasion by—and eradication of—R. exulans. They conclude that some of the rats’ main ecosystem-level effects occur because rats eliminate seabirds and hence seabird-associated nutrient inputs and physical disturbances. Thus, rat eradication alone is unlikely to return such islands to their original state; their restoration will require at least the reintroduction of seabirds. Towns (2008) uses patterns of island recovery following eradications of (mainly) R. exulans in New Zealand to estimate the original impacts of invasion. He notes that rodent eradications are not the reverse of rodent invasions, in part because natural recovery of island species is likely to be limited mainly to those not already eliminated from the islands by rats, or to those with good recolonizing ability. Ogden and Gilbert (2008) describe increases in populations of native plants and birds following suppression of three species of rodents on a large, inhabited island in New Zealand. They provide valuable insight into the social aspects of developing and carrying out alien species control when a large, resident community is directly involved.
Other rodents
Though they may be the most widely introduced rodents, it is clear from several of the above studies that rats are not the only invasive rodents that adversely affect islands. Simberloff (2008) systematically reviews the range of rodent species that have been introduced to islands (often deliberately) and points out their potential for ecosystem-level impacts. Finally, Angel et al. (2008) review the effects of the widely-distributed but underappreciated house mouse (Mus musculus) on islands in the Southern Ocean, where it is increasingly recognized as a conservation threat (Wanless et al. 2007), especially on islands lacking other introduced mammals.
Future directions
A valuable outcome of the conference, and papers resulting from it, has been to highlight areas in need of further research. A recurrent theme is the need for linkage across a range of ecological processes and timescales. For example, while there is ample evidence that invasive rats consume seeds of island plants (e.g. McConkey et al. 2003; Hunt 2007; Wilmshurst et al. 2008), direct field evidence for recruitment limitation is rare (Campbell and Atkinson 2002). Resolving this issue is complicated by ecosystem history, because some key ecological processes were undoubtedly altered before they could be studied directly (e.g. pollination, seed predation, or seed dispersal). Hence, we are often left with only contemporary patterns of plant abundance as evidence from which to infer the mechanism of population decline (e.g. Towns 2008). Controlled field and experimental research, cross-referenced with palaeoecological data, will be critical for determining which traits make plant species vulnerable or resistant to invasive rodents (e.g. seed size, chemical defenses, dependence on vulnerable mutualists, or evolution in the presence of endemic insular rodent species). Understanding these effects in more detail will enable us to disentangle direct impacts of rodents from those of other forces of environmental change, such as fire, forest clearance, or climate change. And, of course, the same arguments apply to understanding changes in island faunas. In addition, future research must address the complex, indirect effects of rodent invasions and eradications (Zavaleta et al. 2001; Fukami et al. 2006; Mulder et al. 2008). Indirect effects may best be studied by bringing ecologists and conservationists together to take advantage of planned eradications of rodents and reintroductions of native species, both of which should ideally be informed by paleoecological and historical data describing the target system’s pre-rodent state.
In a broader sense, it is time to determine in what areas contemporary ecology, palaeoecology, and archaeology can inform each other and in what areas they cannot (Flessa and Jackson 2005). Because the same few species of rodents have invaded so many different islands, they may be ideal organisms for development of fine-grained models that integrate contemporary ecological studies with multiple lines of historical evidence from palaeoecology and archaeology.
1. Anderson A (2008) The rat and the octopus: initial human colonization and the prehistoric introduction of domestic animals to Remote Oceania. Biol Invasions. doi: 10.1007/s10530-008-9403-2 Google Scholar
2. Angel A, Wanless RM, Cooper J (2008) Review of impacts of the introduced house mouse on islands in the Southern Ocean: are mice equivalent to rats? Biol Invasions. doi: 10.1007/s10530-008-9401-4 Google Scholar
3. Athens JS (2008) Rattus exulans and the catastrophic disappearance of Hawaii’s native lowland forest. Biol Invasions. doi: 10.1007/s10530-008-9402-3 Google Scholar
4. Athens JS, Tuggle HD, Ward JV, Welch DJ (2002) Avifaunal extinctions, vegetation change, and Polynesian impacts in prehistoric Hawai`i. Archaeol Ocean 37:57–78Google Scholar
5. Atkinson IAE (1985) The spread of commensal species of Rattus to oceanic islands and their effects on island avifaunas. In: Moors PJ (ed) Conservation of island birds. ICBP Technical Publication, Cambridge, pp 35–81Google Scholar
6. Burney DA (1997) Tropical islands as Paleoecological laboratories: gauging the consequences of Human arrival. Hum Ecol 25:437–457CrossRefGoogle Scholar
7. Campbell DJ, Atkinson IAE (2002) Depression of tree recruitment by the Pacific rat (Rattus exulans Peale) on New Zealand’s offshore islands. Biol Conserv 107:19–35CrossRefGoogle Scholar
8. Carlquist S (1974) Island biology. Columbia University Press, New YorkGoogle Scholar
9. Caut S, Angulo E, Courchamp F (2008a) Dietary shift of an invasive predator: rats, seabirds and sea turtles. J Appl Ecol 45:428–437PubMedCrossRefGoogle Scholar
10. Caut S, Angulo E, Courchamp F (2008b) Avoiding surprise effects on Surprise Island: alien species control in a multi-trophic level perspective. Biol Invasions. doi: 10.1007/s10530-008-9397-9 Google Scholar
11. Caut S, Casanovas JG, Virgos E, Lozano J, Witmer GW, Courchamp F (2007) Rats dying for mice: modelling the competitor release effect. Austral Ecol 32:858–868CrossRefGoogle Scholar
13. Crosby AW (2004) Ecological imperialism: the biological expansion of Europe, 900–1900. Cambride University Press, CambridgeGoogle Scholar
14. Diamond J (1985) Rats as agents of extermination. Nature 318:602–603CrossRefGoogle Scholar
15. Drake DR, Mulder CPH, Towns DR, Daugherty CH (2002) The biology of insularity: an introduction. J Biogeogr 29:563–569CrossRefGoogle Scholar
16. Fitzhugh B, Hunt TL (1997) Introduction: islands as laboratories: archaeological research in comparative perspective. Hum Ecol 25:481–490CrossRefGoogle Scholar
17. Flessa KW, Jackson ST (2005) Forging a common agenda for ecology and paleoecology. Bioscience 55:1030–1031CrossRefGoogle Scholar
19. Gibbs GW (2008) The end of an 80-million year experiment: a review of evidence describing the impact of introduced rodents on New Zealand’s ‘mammal-free’ invertebrate fauna. Biol Invasions. doi: 10.1007/s10530-008-9408-x Google Scholar
20. Grayson DK (2001) The archaeological record of human impacts on animal populations. J World Prehist 15:1–68CrossRefGoogle Scholar
21. Hadfield MG, Saufler JE (2008) The demographics of destruction: isolated populations of arboreal snails and sustained predation by rats on the island of Moloka’i 1982–2006. Biol Invasions. doi: 10.1007/s10530-008-9409-9 Google Scholar
22. Harris DB (2008) Review of negative effects of introduced rodents on small mammals on islands. Biol Invasions. doi: 10.1007/s10530-008-9393-0 Google Scholar
23. Hunt TL (2007) Rethinking Easter Island’s ecological catastrophe. J Archeol Sci 34:485–502CrossRefGoogle Scholar
25. Kennett D, Anderson A, Prebble M, Conte E, Southon J (2006) Prehistoric human impacts on Rapa, French Polynesia. Antiquity 80:340–354Google Scholar
26. Kirch PV (1997) Microcosmic histories: island perspectives on ‘global’ change. Am Anthropol 99:30–42CrossRefGoogle Scholar
27. Lorvelec O, Pascal M (2005) French attempts to eradicate non-indigenous mammals and their consequences for native biota. Biol Invasions 7:135–140CrossRefGoogle Scholar
29. Matisoo-Smith E, Robins J (2008) Mitochondrial DNA evidence for the spread of Pacific rats through Oceania. Biol Invasions. doi: 10.1007/s10530-008-9404-1 Google Scholar
30. McConkey KR, Drake DR (2002) Extinct pigeons and declining bat populations: are large seeds still being dispersed in the tropical Pacific? In: Levey DJ, Silva WR, Galetti M (eds) Seed dispersal and frugivory: ecology, evolution and conservation. CAB International, Wallingford, pp 381–395Google Scholar
32. Meyer J-Y, Butaud J-F (2008) The impacts of rats on the endangered native flora of French Polynesia (Pacific Islands): drivers of plant extinction or coup de grâce species? Biol Invasions. doi: 10.1007/s10530-008-9407-y Google Scholar
33. Mulder CPH, Grant-Hoffman MN, Towns DR, Bellingham PJ, Wardle DA, Durrett MS, Fukami T, Bonner KI (2008) Direct and indirect effects of rats: does rat eradication restore ecosystem functioning of New Zealand seabird islands? Biol Invasions. doi: 10.1007/s10530-008-9396-x Google Scholar
34. Ogden J, Gilbert J (2008) Prospects for the eradication of rats from a large inhabited island: community based ecosystem studies on Great Barrier Island, New Zealand. Biol Invasions. doi: 10.1007/s10530-008-9398-8 Google Scholar
35. Prebble M, Wilmshurst JM (2008) Detecting the initial impact of humans and introduced species on island environments in Remote Oceania using palaeoecology. Biol Invasions. doi: 10.1007/s10530-008-9405-0 Google Scholar
36. Ruffino L, Bourgeois K, Vidal E, Duhem C, Paracuellos M, Escribano F, Sposimo P, Baccetti N, Pascal M, Oro D (2008) Invasive rats and seabirds after 2,000 years of an unwanted coexistence on Mediterranean islands. Biol Invasions. doi: 10.1007/s10530-008-9394-z Google Scholar
37. Russell JC, Abdelkrim J, Fewster RM (2008) Early colonisation population structure of a Norway rat island invasion. Biol Invasions. doi: 10.1007/s10530-008-9406-z Google Scholar
38. Simberloff D (2008) Rats are not the only introduced rodents producing ecosystem impacts on islands. Biol Invasions. doi: 10.1007/s10530-008-9400-5 Google Scholar
39. Steadman DW (2006) Extinction & biogeography of tropical pacific birds. University of Chicago Press, ChicagoGoogle Scholar
40. Terrell JE (1997) The postponed agenda: archaeology and human biogeography in the twenty-first century. Hum Ecol 25:419–436CrossRefGoogle Scholar
41. Towns DR (2008) Eradications as reverse invasions: lessons from Pacific rat (Rattus exulans) removals on New Zealand islands. Biol Invasions. doi: 10.1007/s10530-008-9399-7 Google Scholar
43. Towns DR, Broome KG (2003) From small Maria to massive Campbell: forty years of rat eradications from New Zealand islands. N Z J Zool 30:377–398Google Scholar
44. Traveset A, Nogales M, Alcover JA, Delgado JD, Lopez-Darias M, Igual JM, Godoy D, Bover P (2008) A review of the effects of alien rodents in the Balearic (Western Mediterranean Sea) and Canary Islands (Eastern Atlantic Ocean). Biol Invasions. doi: 10.1007/s10530-008-9395-y Google Scholar
45. Traveset A, Richardson DM (2006) Biological invasions as disruptors of plant reproductive mutualisms. Trends Ecol Evol 21:208–216PubMedCrossRefGoogle Scholar
46. Vitousek PM (2002) Oceanic islands as model systems for ecological studies. J Biogeogr 29:573–582CrossRefGoogle Scholar
48. Whitaker RJ, Fernandez-Palacios JM (2007) Island biogeography: eology, evolution and conservation. Oxford University Press, New YorkGoogle Scholar
49. Wilmshurst JM, Anderson AJ, Higham TFG, Worthy TH (2008) Dating late prehistoric dispersal of Polynesians to New Zealand using the commensal Pacific rat. Proc Natl Acad Sci USA 105:7676–7680PubMedCrossRefGoogle Scholar
50. Wilmshurst JM, Higham TFG (2004) Using rat-gnawed seeds to independently date the arrival of Pacific rats and humans in New Zealand. The Holocene 14:801–806CrossRefGoogle Scholar
51. Zavaleta ES, Hobbs RJ, Mooney HA (2001) Viewing invasive species removal in a whole-ecosystem context. Trends Ecol Evol 16:454–459CrossRefGoogle Scholar
Copyright information
© Springer Science+Business Media B.V. 2008
Authors and Affiliations
1. 1.Botany DepartmentUniversity of HawaiiHonoluluUSA
2. 2.Anthropology DepartmentUniversity of HawaiiHonoluluUSA
Personalised recommendations |
Tang and Song Achievements
Tang and Song Achievements
Pg 170
• 7.3.2 Describe agricultural, technological,
and commercial developments during the
Tang and Song periods.
• 7.3.5 Trace the historic influence of such
discoveries as tea, the manufacture of
paper, wood-block printing, the compass,
and gunpowder.
• The Tang and Song dynasties were
periods of great wealth and progress.
Changes in farming formed the basis for
other advances in Chinese civilization.
• The Tang and Song dynasties were
periods of economic, cultural, and
technological accomplishments.
• 1.Advances in agriculture led to increased
trade and population growth.
• 2.Cities and trade grew during the Tang
and Song dynasties.
• 3.The Tang and Song dynasties produced
fine arts and inventions.
Advances in Agriculture
Cities and Trade
City Life
Trade in China and Beyond
– porcelain
• Arts and Inventions
– woodblock printing
– Gunpowder
– compass.
• Artists and Poets
• Important Inventions
• If YOU were there... It is the year 1270.
You are a rich merchant in a Chinese city
of about a million people. The city around
you fills your senses. You see people in
colorful clothes among beautiful buildings.
Glittering objects lure you into busy shops.
You hear people talking—discussing
business, gossiping, laughing at jokes.
You smell delicious food cooking at a
restaurant down the street.
• How do you feel about your city?
Song dynasties were periods of great
wealth and progress. Changes in farming
formed the basis for other advances in
Chinese civilization.
Advances in Agriculture
• Chinese civilization had always been
based on agriculture. Over thousands of
years, the Chinese had become expert
farmers. In the north farmers grew wheat,
barley, and other grains. In the warmer
and wetter south they grew rice.
During the Song dynasty, though,
Chinese farming reached new heights.
The improvement was largely due to new
irrigation techniques. For example, some
farmers dug underground wells. A new
irrigation device, the dragon backbone
pump, allowed one person to do the work
of several. With this light and portable
pump, a farmer could scoop up water and
pour it into an irrigation canal. Using these
new techniques, farmers created elaborate
irrigation systems.
• Under the Song, the amount of land under
cultivation increased. Lands along the
Chang Jiang that had been wild now
became farmland. Farms also became
more productive, thanks to the discovery
of a new type of fast-ripening rice.
Because it grew and ripened quickly, this
rice enabled farmers to grow two or even
three crops in the time it used to take to
grow just one.
Chinese farmers also learned to grow
new crops, such as cotton, efficiently.
Workers processed cotton fiber to make
clothes and other goods. The production
of tea, which had been grown in China for
centuries, also increased.
• Agricultural surpluses helped pay taxes to
the government. Merchants also traded
food crops. As a result, food was abundant
not just in the countryside but also in the
cities. Because food was plentiful, China's
population grew. During the Tang dynasty,
the population had been about 60 million.
During the Song dynasty, the farmers of
China fed a country of nearly 100 million
people. At the time, China was the largest
country in the world.
Rice has long been a vital crop in southern China, where the
warm, wet climate is perfect for rice growing.
Copyright © by Holt, Rinehart and Winston. All rights
reserved. Terms of Use. Credits. Privacy Policy.
• Cities and Trade
• Throughout the Tang and Song dynasties,
much of the food grown on China's farms
flowed into the growing cities and towns.
China's cities were crowded, busy places.
Shopkeepers, government officials,
doctors, artisans, entertainers, religious
leaders, and artists made them lively
places as well.
• City Life
• China's capital and largest city during the Tang dynasty
was Chang'an (chahng-AHN), a huge, bustling trade
center. With a population of more than a million, it was
by far the largest city in the world at the
Chang'an, like other trading cities, had a mix of
people from many cultures—China, Korea, Persia,
Arabia, and Europe. It was also known as a religious and
philosophical center, not just for Buddhists and Daoists
but for Asian Christians as well.
Cities continued to grow under the Song. Several
cities, including the northern Song capital, Kaifeng (KYfuhng), had about a million people. A dozen more had
populations of close to half a million.
• Trade in China and Beyond
• Trade grew along with Chinese cities. This trade,
combined with China's agricultural base, made China
richer than ever before.
Much trade took place within China itself. Traders
used the country's rivers to ship goods on barges and
The Grand Canal, a series of waterways that linked
major cities, carried a huge amount of trade goods,
especially farm products. Construction on the canal had
begun during the Sui dynasty. During the Tang dynasty,
it was improved and expanded. The Grand Canal
allowed the Chinese to move goods and crops from
distant agricultural areas into cities.
• The Chinese also carried on trade with other
lands and peoples. During the Tang dynasty,
most foreign trade was over land routes leading
west to India and Southwest Asia, though
Chinese traders also went to Korea and Japan
in the east. The Chinese exported many goods,
including tea, rice, spices, and jade. However,
one export was especially important—silk. So
valuable was silk that the Chinese tried to keep
the method of making it secret. In exchange for
their exports, the Chinese imported different
foods and plants, wool, glass, gold, and silver.
• During the Song dynasty, maritime trade,
or sea trade, became more important.
China opened its Pacific ports to foreign
traders. The sea-trade routes connected
China to many other countries. During this
time, the Chinese also developed another
valuable product—a thin, beautiful type
of pottery called porcelain.
• All of this trade helped create a strong
economy. As a result, merchants became
important members of Chinese society
during the Song dynasty. Also as a result
of the growth of trade and wealth, the
Song invented the world's first system of
paper money in the 900s.
• Arts and Inventions
• While China grew rich economically, its
cultural riches also increased. In literature,
art, and science, China made huge
• Artists and Poets
• The artists and writers of the Tang dynasty
were some of China's greatest. Wu
Daozi (DOW-tzee) painted murals that
celebrated Buddhism and nature. Li Bo
and Du Fu wrote poems that readers still
enjoy for their beauty. This poem by Li Bo
expresses the homesickness that one
feels late at night:
• “Before my bed
there is bright moonlight
So that it seems
like frost on the ground:
Lifting my head
I watch the bright moon,
Lowering my head
I dream that I'm home”
–Li Bo, "Quiet Night Thoughts"
• Also noted for its literature, the Song
period produced Li Qingzhao (chingZHOW), perhaps China's greatest female
poet. She once said that the purpose of
her poetry was to capture a single moment
in time.
Artists of both the Tang and Song
dynasties made exquisite objects in clay.
Tang figurines of horses clearly show the
animals' strength. Song artists made
porcelain items covered in a pale green
glaze called celadon (SEL-uh-duhn).
• Important Inventions
• The Tang and Song dynasties produced
some of the most remarkable—and most
important—inventions in human history.
Some of these inventions influenced
events around the world.
• According to legend, a man named Cai
Lun invented paper in the year 105 during
the Han dynasty. A later Tang invention
built on Cai Lun's achievement—
woodblock printing, a form of printing
in which an entire page is carved into a
block of wood. The printer applies ink to
the block and presses paper against the
block to create a printed page. The world's
first known printed book was printed in this
way in China in 868.
• Another invention of the Tang dynasty was
gunpowder Gunpowder is a mixture of
powders used in guns and explosives.
It was originally used only in fireworks, but
it was later used to make small bombs and
rockets. Eventually, gunpowder was used
to make explosives, firearms, and
cannons. Gunpowder dramatically altered
how wars were fought and, in doing so,
changed the course of human history.
• One of the most useful achievements of Tang
China was the perfection of the magnetic
compass. This instrument, which uses the
earth's magnetic field to show direction,
revolutionized travel. A compass made it
possible to find direction more accurately than
ever before. The perfection of the compass had
far-reaching effects. Explorers the world over
used the compass to travel vast distances. The
navigators of trading ships and warships also
came to rely on the compass. Thus, the
compass has been a key factor in some of the
most important sailing voyages in history.
• The Song dynasty also produced many
important inventions. Under the Song, the
Chinese invented movable type. Movable
type is a set of letters or characters that
are used to print books.
• Unlike the blocks used in block printing,
movable type can be rearranged and
reused to create new lines of text and
different pages.
The Song dynasty also introduced the
concept of paper money. People were
used to buying goods and services with
bulky coins made of metals such as
bronze, gold, and silver. Paper money was
far lighter and easier to use. As trade
increased and many people in China grew
rich, paper money became more popular.
• The Tang and Song dynasties were
periods of great advancement. Many great
artists and writers lived during these
periods. Tang and Song inventions also
had dramatic effects on world history. In
the next section you will learn about the
government of the Song dynasty.
Identify facts about the Tang and
Song dynasties.
Related flashcards
Song dynasty painters
20 cards
Han dynasty
19 cards
Create Flashcards |
Did you know that using honey is a great way to speed up wound healing? As per some findings, honey is more effective than antibiotics.
honey as wound healer
image credit
How Honey Works?
Honey has been found to kill most of bacterial cells and can even prevent infections from occurring. Make sure you use raw honey to dress your wound.
When honey gets diluted with the tissues and blood of the wound, hydrogen peroxide is produced thru a glucose oxidase enzyme reaction. This is released slowly and provides anti-bacterial activity, while keeping your tissue healthy and undamaged.
How to Use Honey?
Just apply it on your wound and bandage it up. Make sure to rinse any cut or scraped area well with water. Also, make sure to remove any dirt or any other debris. Change the bandage at least every 4-6 hours until healed.
Related Articles:
1. Honey as a Natural Wound Healer
2. Find Out How This Honey Kills More Bacteria Than All Available Antibiotics
3. What to Treat Using a Mixture of Honey and Cinnamon/a> |
Embryology Flashcards Preview
MSK Week 1 > Embryology > Flashcards
Flashcards in Embryology Deck (49):
What is Ovum Factor?
Signal from the zygote at 3-5 hours telling the mother's immune system not to attack it
What is EPF?
Early Pregnancy Factor. Released by the zygote at 24 hours, this protein further suppresses the mother's immune system.
What two signals are absolutely necessary for implantation to take place?
Ovum factor and EPF
When does implantation occur?
6 - 10 days
What is the bilaminar disc and when does it form?
Forms at 12 days. It is the source of all future tissues in the body, including MSK tissues.
What comprises the bilaminar disc (i.e., why is it called bilaminar)?
It is two layered. Has an epiblast cellular layer and a hypoblast cellular layer
What occurs at 15 days?
1. Epiblast cells detach and migrate to the primitive streak 2. When they arrive, they submerge and fan out between the two layers to become the endoderm, mesoderm, and ectoderm. This migration and sorting is called gastrulation
Primitive streak?
Deep groove and portal for the rapidly moving cells to enter, submerge beneath the epiblast layer, and stream cranially. Displacing the hypoblast cells, these migrating cells become the mesoderm.
Primitive node?
Acts on the migrating cells via specific factors, and after the modified cells reach their destinations, they attach, grow, and become specific organs of the body.
Common condition caused by EtOH uptake during gastrulation
Holoprosencephaly - Forebrain fails to develop into two hemispheres, usually leading to death before birth. Those that live will range in symptoms, but most have defects in the face and brain along with brain function.
Common condition associated with taking seritonin reuptake inhibitors for depression and axiety
Caudal Dysgenesis - Malformation/lack of formation of tailbone or lower vertebrae
During development, what do we see at 21 days?
2 distinct layers: Ectoderm, mesoderm, and endoderm
Where does the MSK system develop from SPECIFICALLY?
Paraxial and lateral plate mesoderm (which later becomes mesenchyme) + neral crest cells
What are somitomeres?
Pairs of tissue blocks formed from the loose masses of paraxial mesoderm alongside the neural tube. Some are destined for the head region and some eventually become the somites of the body wall and limbs
What is longitudinal folding, when does it occur and what does it cause?
Longitudinal folding occurs at Days 17-28 and involves bringing the structures of the heart ventrally. Differential growth will further position these structures in the right places.
What is lateral folding, when does it occur?
Lateral folding occurs simultaneously to longitudinal folding at 15-21 days. It involves layers migrating ventrally to pinch off part of the yolk sac which forms the alimentary canal, and also forms the body wall.
What is the segmentation clock?
Cyclic waves of expression and suppression from extremely specialized genes
Stages of Somite progression:
1. Start as initially solid clumps of mesodermal cells 2. Hollow out, migrate and differentiate into MSK precursors of bone, muscle, connective tissues and skin
Abaxial Myotome
Becomes the ventral muscles of the limb and body wall
Primaxial myotome
Becomes the dorsal muscles of the back
Becomes the skeleton
Intermediate Strip
Becomes the dermis of the neck, back, and trunk
Two meanings for Dermatome:
1. Part of a somite 2. Strip of skin innervated by one spinal segment
Developmental layers that make up the axial skeleton
Sclerotome, which si the paraxial and lateral plate mesoderm and the cephalad part of the neural crests which makes up the brain case
Folic Acid supplements during development can help with what?
Preventing spina bifida occulta
What is meningocele?
Interruption of the development process causing the midline to not fully close
Pectus Excavatum
Thought to be related to an overgrowth of the rib cartilages
When do limb buds appear?
4 weeks
When does limb rotation occur?
7-8 weeks
Upper limb rotations at 7 weeks?
Rotate laterally so that the thumbs are positioned on the radial side and the elbows point posteriorly (palms up)
Lower limb rotations at 7 weeks?
Rotate medially so that the great toes are medial and the knees point anteriorly (soles down)
What programs limb growth?
AER - Apical Ectodermal Ridge
What does the AER do SPECIFICALLY?
Induces outward growth along the limb axis and is present by day 29.
What is the "progress zone?"
Subjacent to the AER, this strip contains coordinating cells.
Processes of Endochondral Ossification:
1. Mesenchymal cells condense into chondrocytes which move into patterns to form the shape of the future bone. 2. Angiogenesis occurs 3. Epiphyseal plates are formed 4. Osteoblasts differentiate and bind in a pattern, leading to production of the osteoid which is then mineralized into bone.
What causes syndactyly?
When apoptosis between the AER segments fails, leading to fusion of the fingers.
What is intramembranous ossification?
Ossification process of the skull. Radiating bone spicules coalesce into flat bones
What is the neurocranium?
Brain case
What is the viscerocranium?
Facial Skeleton
What forms the viscerocranium?
1st and 2nd pharyngeal arches - A core of neural crest cells and somatic and lateral plate mesoderm
Q image thumb
A image thumb
Q image thumb
A image thumb
Q image thumb
A image thumb
Q image thumb
A image thumb
Q image thumb
A image thumb
Q image thumb
A image thumb
Q image thumb
A image thumb
Q image thumb
A image thumb
Specifics on Limb rotation Progression
At 5 weeks, upper and lower limbs have formed as finlike appendages pointing laterally and caudally
At 6 weeks, limbs bend anteriorly, so elbows and knees point laterally, palms and soles face the trunk
At 7 weeks, upper limbs have undergone 90 degree torsion about their long axes, but in opposite directions [elbows point caudally, knees cranially]
At 8 weeks, torsion of lower limbs results in twisted or "barber pole" arrangement, resulting in birth positions |
Proper Office Lighting Leads To Better Productivity & Health
Creating a comfortable and healthy work environment encourages productivity among employees. Providing adequate lighting is an important part of creating a comfortable work environment. While fluorescent lighting has been a popular light source in office buildings for the last several decades, fluorescent lighting is not always adequate for the needs of office workers. Understanding why workers respond better to a particular type of light source can help you ensure that the lighting in your building meets the needs of your employees.
How Bodies Respond to Light
The sun produces a full spectrum of light. Exposure to sunlight triggers a cycle in the human body. This cycle, known as circadian rhythm, tells people when to go to sleep and when to wake. Exposure to full spectrum light can also regulate hormones, which in turn can help people stay healthy. Without sufficient exposure to the full spectrum of light, hormones can become imbalanced and health problems can follow.
Traditional fluorescent lights cover a limited range on the spectrum. Exposure to too much fluorescent light in the office can disrupt circadian rhythms.
What You Can Do as an Employer
While fluorescent lighting is the standard for office buildings across the country, there are ways to ensure that your employees are exposed to adequate amounts of full-spectrum light.
• Install full spectrum fluorescent lights. Full-spectrum fluorescent lights have a warmer, more hospitable glow than standard fluorescent lights. Full-spectrum fluorescents also ensure that employees get the light they need to regulate their internal cycles.
• Rely on natural lighting. Natural light from windows and skylights makes office spaces more beautiful and can also help your employees get a healthy dose of natural sunshine.
• Hold events outside. Holding office-wide staff events outdoors can help ensure your employees get exposure to sunlight.
• Encourage employees to spend time outside. Devising a wellness campaign that encourages employees to spend time outside can ensure that your employees get sufficient light to be healthy. There are many ways that you can encourage your employees to spend time outside. Arranging for walking meetings, forming employee exercise groups, and coordinating wellness challenges can all increase the amount of time that your employees spend time outdoors.
• Allow employees to use incandescent lights at their work stations. Letting employees use lamps at their desk ensures that your employees will get exposure to a larger range of light while at work.
• Provide extra breaks throughout the day to spend time outside. Giving employees dedicated time to spend outside can help make up for lighting problems inside the office.
HealthyWorks Can Help
If you’re currently struggling to develop your company’s wellness program or need help creating a healthy, safe work environment, HealthyWorks can help. We offer wellness services to companies in need. To get started, call us today at (412) 877-6834. |
Magazine article Multimedia & Internet@Schools
Paper and E-Paper
Magazine article Multimedia & Internet@Schools
Paper and E-Paper
Article excerpt
IT took thousands of years to standardize the "book." The book's history is quite interesting. I've seen the Rosetta stone several times at the British Museum. Our records of early language and the various early alphabets are largely from carvings on rocks (with a few limbs, teeth, tusks, and bones thrown in for good measure). With the invention of paper, we find pages and scrolls. I had the opportunity to see some of the Dead Sea Scrolls, which are fascinating to view as such conventions as paragraphs, indenting, etc., hadn't been adopted yet. I saw one of the Gutenberg Bibles at the Library of Congress, and it's quite beautiful. Gutenberg may have popularized printing, but it was many years before the format of the book become standard and the publishing (versus printing) industry developed.
Look at the beautiful books from this era. Called illuminated books or manuscripts, these books are truly lovely. Then, over the years, the beauty of the printed page degraded until we were producing high numbers of ugly computer printouts. But the Web brought back the illumination (and reduced the pin-fed printout piles). Bright pictures, charts, intense interest in type faces and sizes, streaming or animated movement, and other innovations brought visual interest to the pages we were scrolling and reading with wonder again.
Have you seen the Harry Potter movies or read the books? Harry's own books (or at least those in the Hogwarts library) are amazing! You open the book and see a blank page-which magically starts to have text appear. You can sometimes write on the page only to have it answer. Occasionally a picture comes to life and communicates with you. Sometimes it's oneway direct communication and sometimes it can respond to spoken questions. Is it magic? Is it impossible to do in real life? Maybe.
The recent merger of Adobe and Macromedia sent my imagination flying. Adobe, of course, creates the wildly popular proprietary Acrobat PDF (portable document format) for storing and sharing documents. Macromedia creates the FLASH software plug-in that lets you create animations for the Web. It's easy to imagine a document that contains animations. Imagine electronic science textbooks that show the experiment in progress. Imagine simple alphabet readers with animated letters. Imagine books that engage the reader while still respecting the communication qualities of text.
You've probably heard of e-paper and e-ink. This is the emerging technology that creates thin, flexible, paperlike displays. The simple definition from Wikipedia, the free online encyclopedia, states:
Electronic paper, or e-paper, is a technology that allows the text on a piece of paper to be re-written. The "paper" is actually made of organic electronics that use conductive plastic which contains tiny balls that respond to an electric charge, changing the page in much the same way that pixels change on a computer monitor. Electronic paper was developed in order to overcome some of the limitations of computer monitors. For example, the backlighting of monitors is hard on the human eye, whereas electronic paper reflects light just like normal paper. It is easier to read at an angle than flat screen monitors. Because it is made of plastic, electronic paper has the potential to be flexible. It is light and potentially inexpensive.
Sony has used e-paper technology as part of its LIBRI PDA device since 2004. Fujitsu debuted flexible electronic paper in July 2005 [http://www.overclockers]. Most excitingly, this e-paper is not only bendable, but it supports color! It has an image memory ability, which means that it doesn't need power to sustain the picture on the paper. …
Search by... Author
Show... All Results Primary Sources Peer-reviewed
|
If you have brown spots on leaves along with a sticky material, you probably have scale. The sticky substance is honeydew that they excrete.
Scale insects are sedentary and feed on the plant's sap. Sap is mostly sugar and water, so they end up excreting large amounts of sugars that they don't need to get the proteins and minerals that they do need, which occur in much smaller amounts in sap.
Scale insects are most effectively controlled with horticultural oil. If the plant is small, complete submersion in a solution of 2 ounces of horticultural oil per gallon of water will do a much better job than simply spraying the plant. |
Place an Order
Instant price
Struggling with your work?
Get it right the first time & learn smarter today
Place an Order
Banner ad for Viper plagiarism checker
Overview of and Applications of Choke Coils
Published: Wed, 13 Dec 2017
A choke is an inductor designed to block (have a high reactance to) a particular frequency in an electrical circuit while passing signals of much lower frequency ordirect current.
Choke coils are inductances that isolate AC frequency currents from certain areas of a radio circuit. Chokes depend upon the property of self-inductance for their operation. They can be used to block alternating current while passing direct current (contrast with capacitor). Common-mode choke coils are useful in a wide range of prevention of electromagnetic interference (EMI) and radio frequency interference (RFI) from power supply lines and for prevention of malfunctioning of electronic equipment.
Types and construction
Chokes used in radio circuits are divided into two classes – those designed to be used with audio frequencies, and the others to be used with radio frequencies. Audio frequency coils, usually called A.F. chokes, can have ferro magnetic iron cores to increase their inductance. Chokes for higher frequencies (ferrite chokes or choke baluns) have ferrite cores. Chokes for even higher frequencies have air cores. Radio frequency coils, (R.F. chokes), usually don’t have iron cores. In high power service so much heat would be produced in making and destroying the field in the core that the coil would burn up.
Solid-state chokes
Solid-state chokes (SSC) can manage higher currents than traditional chokes. It reduces the high frequency buzzing noise when running under high electrical currents
Chokes Explained
A choke is used in place of a series resistor because the choke allows better filtering (less residual AC ripple on the supply, which means less hum in the output of the amp) and less voltage drop. An “ideal” inductor would have zero DC resistance. If you just used a larger resistor, you would quickly come to a point where the voltage drop would be too large, and, in addition, the supply “sag” would be too great, because the current difference between full power output and idle can be large, especially in a class AB amplifier.
Capacitor input or choke input filter?
There are two common power supply configurations: capacitor input and choke input. The capacitor input filter doesn’t necessarily have to have a choke, but it may have one for additional filtering. The choke input supply by definition must have a choke. Capacitor input filters are by far the most commonly used configuration in guitar amplifiers (in fact, I can’t think of a production guitar amp that used a choke input filter).
The capacitor input supply will have a filter capacitor immediately following the rectifier. It may or may not then have a second filter composed of a series resistor or choke followed by another capacitor. The “cap, inductor, cap” network is commonly called a “Pi filter” network. The advantage of the capacitor input filter is higher output voltage, but it has poorer voltage regulation than the choke input filter. The output voltage approaches sqrt(2)*Vrms of the AC voltage. The choke input supply will have a choke immediately following the rectifier. The main advantage of a choke input supply is better voltage regulation, but at the expense of much lower output voltage. The output voltage approaches (2*sqrt(2)/Pi)*Vrms of the AC voltage. The choke input filter must have a certain minimum current drawn through it to maintain regulation. The voltage difference between the two filter types can be quite large. For example, assume you have a 300-0-300 tranny and a full-wave rectifier. If you use a capacitor input filter, you’ll get a no-load max DC voltage of 424 volts, which will sag down to a voltage dependent on the load current and the resistance of the secondary windings. If you use the same transformer with a choke input filter, the peak output DC voltage will be 270V, and will be much more highly regulated than the capactor input filter (less variations in supply voltage with variations in load current).
How to select a choke:
DC current
DC resistance
For a typical choke input supply, you need a choke with no more than 100-200 ohms or so DCR. A capacitor input supply typically might use a choke with a 250 ohm – 1K DCR. The higher the resistance, the more voltage drop and the poorer the regulation, but the cost will be lower.
Voltage rating
Common Mode Choke Theory
A common mode choke may be used to reduce a type of electrical noise known as common mode noise. Electro-magnetic interference (E.M.I.) in the circuit’s environment is one source of electrical noise. E.M.I. induces or couples unwanted electrical signals into the circuit. It is desirable to filter out the unwanted noise signals without significantly affecting the desired signal. Environmental sources of E.M.I. often create an independent return path (ground path) for the electrical noise signals. The return path of the desired signal is a different path. Because there are two different return paths, a common mode choke can be used to significantly block (hence reduce) the unwanted noise signal (at the load) without significant reduction in the desired signal.
A.C. power lines provide a good example. They are known to carry significant levels of electrical noise. Their long length gives environmental E.M.I. ample opportunity to generate unwanted electrical noise into the power lines. Figure 2 illustrates an application without a common mode choke. The power line voltage, “Vs”, causes current, “Iz”, to flow through the load, “Z”. At any non-zero instance, Current “Iz” flows into “Z” through one power line wire and returns through the other power line wire. E.M.I. voltage, “Vnc1”, causes current “Inc1”, to flow through the load “Z”. Similarly, E.M.I. voltage, Vnc2 causes current “Inc2” to flow through the load “Z”. Because the E.M.I is generating both “Vnc1” and “Vnc2” the two voltages tend to be in phase. There is very little current flow between them. Current “Inc1” does not flow through both power line wires. It flows through one power line wire and through the ground path. Similarly, current “Inc2” does not flow through both power line wires. It flows through one power line wire and through the ground path. In this example only “Vnc1” produces electrical noise across load “Z” because the “Vnc2” end of “Z” is grounded. In practice, the effective ground point could occur somewhere between the two ends of load “Z”.
Figure 3 illustrates the same application with a common mode choke. The common mode choke has two windings. Each winding of the common mode choke is inserted between the end of a power line wire and the load. As in Figure 1, current “Iz” flows through both power line wires and currents “Inc1” and “Inc2” each flow through one power line wire and return through the ground path. Observe that current “Iz” flows through both windings but in opposing winding directions, while currents “Inc1” and Inc2” each flow through only one winding and in the same winding direction. The ground path does not flow through a winding.
The inductance of winding A restricts (reduces) the flow of current “Inc1” (when compared to Figure 1), thereby reducing the noise voltage across “Z”. Similarly the inductance of winding B restricts (hence reduces) the flow of current “Inc2”. Windings A and B have the same number of turns. The ampere-turns created by Current “Iz” (but excluding any “Inc1” current component) flowing through winding A is cancelled by the opposing ampere-turns created by current “Iz” flowing through winding B. Ideally, the cancellation results in zero inductance and no restriction (no reduction) of current “Iz”. “Iz” produces the same voltage across load “Z” as it does in Figure 1. In practice this will not be true. The common mode choke will have some leakage flux between windings A and B hence incomplete cancellation. Windings A and B will have some winding resistance. Both of these will have some effect on “Iz” (reduces “Iz”).
In contrast, the load current “Iz” flowing through both windings A and B of the differential choke shown in Figure 1 do not cancel, hence “Iz” will be restricted (reduced). Differential chokes are useful when the electrical noise frequencies are much higher than the operating frequencies. The higher choke impedance at the high frequencies block the electrical noise while having a tolerable effect at the operating frequencies.
Some common mode chokes are intentionally designed to have significant leakage inductance. The leakage inductance acts in series with the load hence the leakage inductance provides differential noise filtering. One common mode choke functions like the combined chokes shown in Figure 1 but may differ in levels.
Three-phase choke coil REO
three-phase choke
The conventional output-choke has a very good storage capacity. It functions like a typical series inductance and smoothes the symmetrical, effective current and the asymmetrical, parasitic current. The voltage rise is limited to less than 500 V/µs. The line to line voltage peaks at the motor terminals are lower than 1000 V. This solution attenuates the cable-conducted disturbance really well, even in the lower frequency range. The electromagnetic radiation from cables is attenuated considerably. Losses and typical motor noise, caused by harmonics, are reduced. Applications
An inductor is used as the energy storage device in some switched-mode power supplies. The inductor is energized for a specific fraction of the regulator’s switching frequency, and de-energized for the remainder of the cycle. This energy transfer ratio determines the input-voltage to output-voltage ratio. This XL is used in complement with an active semiconductor device to maintain very accurate voltage control.
Larger value inductors may be simulated by use of gyrator circuits.
1. http://www.aikenamps.com/Chokes.html
2. www.thefreedictionary.com/choke+coil
3. http://www.butlerwinding.com/store.asp?pid=28349
4. www.wikipedia.com
5. www.google.com
6. www.britannica.com/EBchecked/topic/114020/choke-coil
Reference Copied to Clipboard.
Reference Copied to Clipboard.
Reference Copied to Clipboard.
Reference Copied to Clipboard.
Reference Copied to Clipboard.
Reference Copied to Clipboard.
Reference Copied to Clipboard.
Request Removal
More from UK Essays |
The Square Kilometre Array (SKA)
Sat, Jul 18th, 2015 11:00 by capnasty NEWS
The Guardian looks at the Square Kilometre Array, the most powerful radio array located in the most isolated and radio quiet places in the world. These radio telescopes will listen to the very distant noises from the furthest corners of the universe.
The telescope will be perhaps 10,000 times more powerful than any we currently have, and we will need a supercomputer more advanced than anything yet built to analyse the data it produces. Right now we can spot planets circling around distant stars. The SKA will be able to spot the equivalent of an airport radar system on one of those very, very distant planets.
It will also allow us to dig down into the ancient history of our universe, and there’s no knowing what it will find there, or what it will mean for us.
You may also be interested in:
Seeding Lifeless Planets With Earth's Microbes
How They Poop In Space
Initiative Wants to Listen for Alien Signals from Tabby's Star |
Tag Archives: featured
Learning Guides
Python List Comprehension: An Intro and 5 Learning Tips
Python list comprehension: an introduction and 5 great tips to learn
Python list comprehension empowers you to do something productive with code. This applies even if you’re a total code newbie. At code(love), we’re all about teaching you how to code and embrace the future, but you should never use technology just for its own sake.
Python list comprehension allows you to do something useful with code by filtering out certain values you don’t need in your data and changing lists of data to other lists that fit specifications you design. Python list comprehension can be very useful and it has many real-world applications: it is technology that can add value to your work and your day-to-day.
To start off, let’s talk a bit more about Python lists. A Python list is an organized collection of data. It’s perhaps easiest to think of programming as, among other things, the manipulation of data with certain rules. Lists simply arrange your data so that you can access them in an ordered fashion.
Let’s create a simple list of numbers in Python.
numbers = [5,34,324,123,54,5,3,12,123,657,43,23]
print (numbers)
[5, 34, 324, 123, 54, 5, 3, 12, 123, 657, 43, 23]
You can see that we have all of the values we put into the variable numbers neatly arranged and accessible at any time. In fact, we can access say, the fifth variable in this list (54) at any time with Python list notation, or we can access the first 5 and last 5 values in the list.
print(numbers[:5]); print(numbers[-5:]); print(numbers[4])
[5, 34, 324, 123, 54]
[12, 123, 657, 43, 23]
If you want to learn more about how to work with Python lists, here is the official Python documentation and an interactive tutorial from Learn Python to help you play with Python lists.
Python list comprehensions are a way to condense Python for loops into lists so that you apply a formula to each value in the old list to create a new one. In other words, you loop a formula or a set of formulae to create a new list from an old one.
What can Python list comprehensions do for you?
Here’s a simple example where we filter out exactly which values in our numbers list are below 100. We start by applying the [ bracket, then add the formula we want to apply (x < 100) and the values we want to apply it to for (x in numbers -> numbers being the list we just defined). Then we close with a final ] bracket.
lessthan100 = [x < 100 for x in numbers]
print (lessthan100)
[True, True, False, False, True, True, True, True, False, False, True, True]
#added for comparision purposes
See how everything above 100 now gives you the value FALSE?
Now we can only display which values are below 100 in our list and filter out the rest with an if filter implemented in the next, which is followed by the if trigger.
lessthan100values = [x for x in numbers if x < 100]
[5, 34, 54, 5, 3, 12, 43, 23]
We can do all sorts of things with a list of numbers with Python list comprehension.
We can add 2 to every value in the numbers list with Python list comprehension.
plus2 = [x + 2 for x in numbers]
print (plus2)
[7, 36, 326, 125, 56, 7, 5, 14, 125, 659, 45, 25]
We can multiply every value by 2 in the numbers list with Python list comprehension.
multiply2 = [x * 2 for x in numbers]
[10, 68, 648, 246, 108, 10, 6, 24, 246, 1314, 86, 46]
And this isn’t just restricted to numbers: we can play with all kinds of data types such as strings of words as well. Let’s say we wanted to create a list of capitalized words in a string for the sentence “I love programming.”
codelove = "i love programming".split()
codelovecaps = [x.upper() for x in codelove]
print(codelove); print(codelovecaps)
['i', 'love', 'programming']
Hopefully by now, you can grasp the power of Python list comprehension and how useful it can be. Here are 5 tips to get you started on learning and playing with data with Python list comprehensions.
1) Have the right Python environment set up for quick iteration
When you’re playing with Python data and building a Python list comprehension, it can be hard to see what’s going on with the standard Python interpreter. I recommend checking out iPython Notebook: all of the examples in this post are written in it. This allows you to quickly print out and change list comprehensions on the fly. You can check out more tips on how to get the right Python setup with my list of 11 great resources to learn and work in Python.
2) Understand how Python data structures work
In order for you to really work with Python list comprehensions, you should understand how data structures work in Python. In other words, you should know how to play with your data before you do anything with it. The official documentation on the Python website for how you can work with data in Python is here. You can also refer again to our resources on Python.
3) Have real-world data to play with
I cannot stress enough that while a Python list comprehension is useful even with pretend examples, you’ll never really understand how to work with them and get things done until you have a real-world problem that requires list comprehensions to solve.
Many of you came to this post with something you thought list comprehensions could solve: that doesn’t apply to you. If you’re one of those people who are looking to get ahead and learn without a pressing problem, do look at public datasets filled with interesting data. There’s even a subreddit filled with them!
Python list comprehension with code(love)
Real-world data with code(love)
4) Understand how to use conditionals in list comprehensions
One of the most powerful applications of Python list comprehensions is the ability to be able to selectively apply different treatments to different values in a list of values. We saw some of that power in some of our first examples.
If you can use conditionals properly, you can filter out values from a list of data and selectively apply formulas of any kind to different values.
The logic for this real-life example comes to us from this blog post and Springboard’s Data Science Career Track.
Imagine you wanted to find every even power of 2 from 1 to 20.
In mathematical notation, this would look like the following:
A = {x² : x in {0 … 20}}
B = {x | x in A and x even}
square20 = [x ** 2 for x in range(21)]
evensquare20 = [x for x in square20 if x % 2 == 0]
print (evensquare20)
[0, 4, 16, 36, 64, 100, 144, 196, 256, 324, 400]
In this example, we first find every square power of the range of numbers from 1 to 20 with a list comprehension.
Then we can filter which ones are even by adding in a conditional that only returns TRUE for values that when divided by 2 return a remainder of 0 (even numbers, in other words).
We can then combine the two into one list comprehension.
square20combined = [x ** 2 for x in range(21) if x % 2 == 0]
Sometimes, it’s better not to do this if you want things to be more readable for your future self and any audience you’d like to share your code with, but it can be more efficient.
5) Understand how to nest list comprehensions in list comprehensions and manipulate lists with different chained expressions
The power of list comprehensions doesn’t stop at one level. You can nest list comprehensions within list comprehensions to make sure you chain multiple treatments and formulae to data easily.
At this point, it’s important to understand just what list comprehensions do again. Because they’re condensed for loops for lists, you can think about how combining outer and inner for loops together. If you’re not familiar with Python for loops, please read the following tutorial.
This real-life example is inspired from the following Python blog.
list = [(x,y) for x in range(1,10) for y in range(0,x)]
[(1, 0), (2, 0), (2, 1), (3, 0), (3, 1), (3, 2), (4, 0), (4, 1), (4, 2), (4, 3), (5, 0), (5, 1), (5, 2), (5, 3), (5, 4), (6, 0), (6, 1), (6, 2), (6, 3), (6, 4), (6, 5), (7, 0), (7, 1), (7, 2), (7, 3), (7, 4), (7, 5), (7, 6), (8, 0), (8, 1), (8, 2), (8, 3), (8, 4), (8, 5), (8, 6), (8, 7), (9, 0), (9, 1), (9, 2), (9, 3), (9, 4), (9, 5), (9, 6), (9, 7), (9, 8)]
If we were to represent this as a series of Python for loops instead, it might be easier to grasp the logic of a Python list comprehension. As we move from the outer loop to the inner loop, what happens is that for each x value from 1 to 9 (for x in range(1,10)), we print out a range of values from 0 to x.
for x in range(1,10):
for y in range(0,x):
1 0
2 0
2 1
3 0
3 1
3 2
4 0
4 1
4 2
4 3
5 0
5 1
5 2
5 3
5 4
6 0
6 1
6 2
6 3
6 4
6 5
7 0
7 1
7 2
7 3
7 4
7 5
7 6
8 0
8 1
8 2
8 3
8 4
8 5
8 6
8 7
9 0
9 1
9 2
9 3
9 4
9 5
9 6
9 7
9 8
The chain of for loops we just went over has the exact same logic as our initial list comprehension. You’ll notice though that in a for loop, you will print seperate values while in a list comprehension it will produce a new list, which allows us to use Python list notation to play with the data.
With this in mind, you can make your code more efficient and easily manipulable with a Python list comprehension.
I hope you enjoyed my introduction to Python List Comprehensions. If you want to check out more content on learning code, check out the rest of my content at code-love.com! Please comment if you want to join the discussion, and share if this created value for you 🙂
Open Stories
make the leap with code(love)
make the leap with code(love)
That was my first mistake.
Meaningful Multimedia
Entrepreneurship is a marathon, not a sprint.
IPO with code(love)
IPO with code(love)
Learning Lists
Five things you should know before you learn code.
Download / By Kamil Lehmann
I wish I knew that there should be an organized way to approach learning code, and that learning code wasn’t just about learning in isolation—it is about building knowledge upon knowledge.
I wouldn’t have tried to learn more complex languages like Python before learning about HTML/CSS, the foundation of the web.
You should know about sites like Codeacademy which organize code learning in a structured, and fun fashion. You should know about Bentobox, something that offers you a structured plan to approach learning code.
2-Free resources
I wish I knew just how many free resources were out there to learn code. It would have helped me get a sense of what learning could be done, and where I could go.
You should take a look at things like reSRC, an online directory of free resources to learn code, and this list of 31 free resources to learn how to code.
I wish I knew that a lot of coding was built around frameworks, coding templates which set the foundation for easier coding. I wish I knew that one of the cardinal rules of coding was “Don’t Repeat Yourself”—and that means that if someone has built a solution already, go ahead and use it.
Frameworks make coding easier. They build a foundation that you can wrap around your code and play with—invaluable if you’re just beginning to learn how to code.
You should take a look at frameworks such as JQuery, which simplifies interactive elements of a website, and Bootstrap, which simplifies how you style a website.
I wish I knew just how valuable it was having somebody around who knew what they were doing. When I got stuck, I finally approached some programmers I knew, and they helped me immensely.
You should look for mentors or programs like Ladies Learning Code where you are connected with some.
5-Learning by doing
I wish I knew just how much easier learning code would be if I thought about building projects, and getting my code to fit those practical applications.
Nothing beats struggling through Q and A forums like StackOverflow, looking desperately for the right answer and finding it. The learning you’ll get will flow naturally.
You should look for a great idea, and try to build something to learn code. You’ll be adding to the foundation of the Internet, while learning at the same time.
These are the things I wish I knew about learning code before I embarked on my journey. It’s far from complete, but looking back, any one of these steps would have helped me learn faster, and would’ve gotten me to be where I want to be in the future—now.
Getting the learning right allows you to build the future you envision, giving you a voice in the participatory process that is the modern digital economy. It empowers you to build what you can: getting it right can mean the difference between the ideas you see through to fruition , to those you have seen languish behind. Don’t hesitate to start now.
Longform Reflections
Three essential questions entrepreneurs have to ask themselves
Do you want to learn how to build great startups? Of course you do. Join our mailing list.
Do you want to do good, or do well?
I went to a Startup Weekend where one of the judges asked this question point-blank to a team. They were doing what they claimed to be an e-commerce platform for social good. While that was all well and good—the problem was that it is hard to do both.
As human beings, I think we are all inclined to create as much social impact as possible, and to do as much as good as we can. To me, that’s the basis of human decency.
We shouldn’t kid ourselves though. It’s hard to do either good or well, nevermind both. So many ideas that I have seen fail seem confused on what they are there for.
That creates a host of issues. A team that is trying to get money and creates social impact will always face the conflict between how much they charge, and how much they want society to benefit. The team will split between people motivated by creating good, and those motivated by creating wealth.
A startup wins on a simple idea that it can communicate well. Complicating it by trying to do things that conflict will help nobody. The idea will die and be unable to do good or well.
If you want to do good, consider building a non-for-profit idea that supported by a foundation like Khan Academy is. Be explicit that you are not looking for wealth. If you want to do well, build the idea you want, and make it clear everybody is in it for wealth.
There are ideas that can straddle both, but it takes a skilled executioner to work on those. It’s important here to be honest with oneself before muddying the waters. There are some that can prove me wrong and build ideas that do good, and well—but those will be the exception, and not the rule.
Doing good or doing well with code(love)
Is your idea a community or a commodity?
This is an important question. Is what you’re producing something that will get people coming back, and feeling at home? Or is it something people can use over and over again because they need it, with no emotions attached?
The former has loads of potential. Many of the most successful ideas of our time have come because they assemble communities of like-minded individuals to create beautiful things. Yet it is incredibly hard to make money off of a community because it takes time to build it. This is time that is not well-reflected with return on investment until your constituents fully assemble.
A commodity, meanwhile, can make money for you immediately—but it’ll never have the magic of a fully formed community.
Make sure you know what you’re building. Different paths will have different implications on your business strategy, your need for financing, and your ultimate goal. If you’re building a community, get ready for the long haul. If you’re building a commodity, make sure you sell as much as you can.
Community or commodity with code(love)
Build or buy?
This is a decision that you will face at every turn. There are so many ready-made solutions that you can buy rather than build yourself for startups. Each one will accelerate your progress exponentially.
Google Analytics can do your data analytics for you. Zendesk can help do your customer service for you. Stripe can help you deal with payments.
Building takes time. No matter what, nothing is free. You have to determine what your startup is built to do, and what you should build and what you should buy.
A startup that buys everything is not disruptive in the slightest. A startup that builds everything will die under the weight of the time it wastes.
This will be a constant question, something that will follow you all the way to the time where you have to decide whether or not to acquire your first startup.
Entrepreneurship with code(love)
Entrepreneurship is a set of questions. Every minute brings new ones that you have to ask yourself. Part of the thrill of it all is not knowing where the hell you’re going at any given time: in many ways, building a startup is about answering one question at a time in an endless stream.
I’ve been through it enough times to know that these are the important questions for me. What are the important ones for you?
Open Stories
The story behind the world’s fastest growing car classifieds.
This is the open story of Fritz Simons, a co-founder of Carmudi, a startup that bills itself as the world’s fastest growing car classifieds. If this story inspires you to build, join our mailing list.
Carmudi with code(love)
Carmudi with code(love)
1. What is the ultimate vision of Carmudi?
Carmudi will revolutionise the way vehicle are traded. We are combining technological expertise with a passion for cars in order to offer our customers the best possible experience. For us this means making buying and selling vehicles easy, safe and fast. We are only at the start of our journey but we are working extremely hard every single day to get there.
2. How did you achieve your current success?
We are simply faster than anyone else. This results from a combination of being very customer focused and extremely execution driven. We spend a lot of time understanding the market we operate in and leverage everything we learn immediately by making it influence our priorities and goals. At such an early phase of a company, one must be able to react very quickly.
3. How did you get into founding a tech enterprise? What’s your advice in regards to understanding technology and code?
The Internet changes the way people think and go about their lives. As an entrepreneur I can be part of this change and impact people’s life for the better. This is why I ended up in tech and founding Carmudi. Of course, my understanding of technology helps me every day. Get yourself excited about it and spend time to learn from everyone around you.
4. What do you find fascinating about cars personally?
For some, cars are merely a means of transportation. For others they are a hobby and status symbol. Cars fascinate me because they have their own different meanings for different people. I myself am a car enthusiast having dedicated my entire working career to the automotive industry.
5. What are your tips for building a great team and establishing an excellent company culture?
Only hire people you are fully convinced of. This is time consuming but will pay off from day one. Then get every single one in the team enthusiastic about the company vision and product. This serves as the basis for a fruitful company culture.
6. What is special about Carmudi’s company culture?
We all love cars and we all believe in our vision. Everyone wants to make the next step to making car trading better for our clients. Thus, the environment is productive and this is fun for everyone.
7. Where does your drive of being an entrepreneur come from?
It comes from the ambition to make a meaningful impact. To achieve this you have to take responsibility and ownership of what you are doing as well as be prepared to take risks. This is the true basis for entrepreneurship.
Technology and Society
Creating a Startup – The Importance of Now!
Build now with code(love)
Open Stories
MakeWorks: A Co-Working Space that Mixes Physical and Digital
We live in an exciting time where the Internet of Things and connected devices are rapidly breaking down barriers between the physical and digital world. MakeWorks is at the frontier of what is happening, as a co-working space designed for connected devices.
Here is an interview with the founder, Mike.
1) Describe what Makeworks is.
MakeWorks is Toronto’s first coworking studio of its kind, catering to both digital and physical focused startups. The 10,000 sq ft facility is located in a restored shoe factory, and broken up into four parts: a coworking space seating 120 people; a prototyping and electronics lab; a makerspace, and a large event space for meetups, prototyping and pop-up concepts.
2) What is the ultimate vision behind Makeworks?
To be Canada’s leading coworking studio and community platform for entrepreneurs all along the digital-physical spectrum.
3) What are some examples of cool projects being built in Makeworks?
Sprout Guerilla (moss grafitti wall art), Pawly (robotic dog companion), Orchard (used smartphone buying platform), Makelab (creative technology experiential agency), Sensimat (smart wheelchair technology), and many more applying every day!
4) How does one become a part of the Makeworks community?
Simply apply at makeworks.com and schedule a tour with Steph, our GM!
Defining the Future
The No-Bullshit Startup Dictionary: A
I have an admission for you. I’m addicted to startup buzzwords.
Seriously addicted. Somebody once told me that I sounded like a corporate lorem ipsum generator. I wasn’t even surprised.
I don’t mean to do it—it’s just that startup buzzwords are so comfortable. Their familiar confines help mark me as being part of a very exclusive set of knowledge holders. They elevate me and put others down. They include those I want to talk with, and exclude those I don’t. A small part of me hates what I just said. A large part of me does it anyways.
To atone for my sins, I’ve decided to create a startup dictionary. No bullshit: a simple definition of the term, and an example. Next time you have to listen to me or anybody else who talks in buzzwords, you’ll at least be able to understand what we are talking about: and you should be part of the conversation.
If there’s anything I’m missing, please comment below.
Download / By James Tarbotton
Startup Dictionary with code(love)
Let’s start from the beginning:
The No-Bullshit Startup Dictionary: A
Tweet: The No-Bullshit Startup Dictionary by @Rogerh1991 #startups #tech http://ctt.ec/4JR4w+
A/B Split Test: A random experiment where you test two variants of something against each other and see the results. Most often used to test variant A of a webpage and variant B to see which performs best, and gets more views and clicks. Example: See this case study by Optimizely.
Acquihire: When a larger company buys a smaller company just to acquire the people behind the smaller company. Example: Facebook’s acquisition of essentially failed New York startups, Hot Potato and Drop.io for their employees.
Agile: Agile refers to agile software development. This means that instead of spending many years developing a web platform, many startups now release web platforms in a short time, then use live customer feedback to develop successive improvements on the first version. Example: See this test first, develop later mentality in action.
AirBnB: A web platform that allows you to rent out somebody’s guest room for a night or two, and to loan out your spare space as well. Typically seen in explanations like “My company is the AirBnB for 3D Printing”. Example: Check out their website.
Alibaba: A web platform that is used as a trading platform for wholesalers around the world. Most often brought up because they are about to go public and raise lots of money. Example: Check out their website.
Ajax: Ajax is a set of techniques that allow a webpage to reload data from the server without you having to reload the page itself. Example: Gmail was one of the pioneers of this.
Angel: An angel investor is often one of the very first people to provide funding for a startup in return for shares in your startup. Example: Paul Buchheit is the creator of Gmail, and has active angel investments in about 40 startups.
AngelList: A web platform where angel investors connect with startup founders. Example: Check it out here.
Annual Recurring Revenue: Typically applied because a lot of startups work on a monthly subscription basis, annual recurring revenue is a prediction of how much revenue is locked in with subscribers that will pay every year. Example: How Aaron Levie, CEO of Box, views Annual Recurring Revenue for his subscription based business.
API: An application programming interface is a set of standards for how software should communicate with one another. Web APIs allow for the easy transfer of data from one platform to another. Example: Twitter’s API allows you to search through tweets.
Asynchronous I/O: A form of input/output in technology that allows for many processes to happen at the same time, rather than going through one process at a time. Can often allow webpages to load faster. Example: The modern web software platform Node.JS built on Javascript is based on this technology and concept, allowing for real-time applications to get new data without reloading.
AWS: Amazon Web Services is a popular hosting solution for many startups. They host their websites on servers owned by AWS, which charges a fee for the service. Example: Check out their website.
Watch out for the rest of the series covering the rest of the alphabet—join our mailing list!
Open News
CodeHS Teaches Code in Schools
They have a free interactive code lesson users can access at http://codehs.com/signup_start once they’ve signed up for a free account.
Class in a box
Class in a box with CodeHS and code(love)
|
An analysis of the topic of the fairy tales by hans christian andersen and the comprehensive overvie
2017-12-19 folklore in the oral tradition, hans christian andersen’s fairy tales an analysis of the meaning and importance of fairytales with a psychoanalytical. 2003-4-17 the ugly duckling is a classic tale of hans christian andersen's fame rests among andersen's other best known fairy tales are 'little ugly. Introduction: towards a definition of the literary principles for a definition of the literary fairy of this period was hans christian andersen,. Eldon andersen richard adams watkin's salad book spanish comprehensive practice & testing stephen levy moving with math by topic: level a-d myths,. 200512239758964 - download as excel fairy edition, 1st year tales advanced introduct advanced integrating the most curre a comprehensive general business.
an analysis of the topic of the fairy tales by hans christian andersen and the comprehensive overvie 2016-3-17 moving foward: problematic ideologies in twenty-first based on hans christian andersen’s not fractured fairy tales” (2007) a comprehensive overview.
2014-7-18 and fairy tales writing lessons in influencing hans christian andersen pt 2 introduce topic-clincher relationship read “aesop—mixed up. 2 天前 the little mermaid summary hans christian andersen homework help summary (masterpieces of world literature, andersen's fairy tales hans christian andersen. 2014-5-15 fantasy and fairytale in children's literature hans christian andersen’s stories began to it is a matter of grave importance that fairy tales should be. Childism and grimms tales this is a comprehensive compilation and analysis of the most recent and hans christian andersen that give us courage to.
This topic hans christian andersen's fairy tales: fairy tales: a comprehensive lesson overview of the folkloric fairy tale known as. 2017-1-12 hans christian andersen and the danish golden 30 fairy tales by hans christian andersen of the topic to be investigated a brief overview of.
Full text of see and hear : the journal on audio-visual learning see other formats. Fairy tales & fables: study guide & homework help review famous fairy tales and fables with this thumbelina by hans christian andersen: themes & analysis. 2017-11-27 a list of every word of the year selection released by dictionarycom dictionarycom's first word of the year was chosen in 2010. 2008-5-20 elements found in fairy tales a fairy tale is a fictional story that may feature folkloric characters historic analysis seeing tales a way to preserve history,.
9780735813946 0735813949 hans christian andersen's fairy tales, hans christian nursing - a comprehensive benchmarks and financial gap analysis,. 2018-5-28 talk:hans christian andersen many of the fairy tales may this link about hans christian andersen and music has a good overview of andersen. 2018-6-9 a fairy tale, wonder tale, magic his own analysis identified fairy tales by their simultaneously, writers such as hans christian andersen and george macdonald.
Teaching about story structure using fairy tales hans christian andersen: fairy tales and stories thank you for providing such a comprehensive unit. 2017-10-5 lesson overview students write descriptions and create portraits of characters from the fairy tales of hans christian andersen using a variety of media. ''the little mermaid'', a fairy tale by hans christian andersen, is filled with dramatic and interesting characters in this lesson, you will learn.
2018-6-5 free summary and analysis of the events in jacob and wilhelm grimm's grimms' fairy grimms' fairy tales by jacob and wilhelm clever hans. 2017-10-1 from the beast to the blonde: on fairy tales and their tellers and hans christian andersen started writing down the if you love fairy tales and their. The symbolic meaning of the fairy tale of the nightingale as reflection as reflection of the authors' personal from hans christian andersen‘s fairy. The nightingale lesson plans and worksheets from thousands of teacher-reviewed resources fairy tales hans christian anderson .
Fairy tales from before fairy tales jan m ziolkowski not only provides a comprehensive overview of the theoretical debates about hans christian andersen,. This remarkable study of the grimms' children and household tales and their danish translators has much to offer its most significant finding, to my mind, may be that it shows the close relationship between jacob and wilhelm grimm, the danish translators, and hans christian andersen in the creation of what now is called the grimms' fairy. Full text of random reminiscences see other formats.
Rated 3/5 based on 34 review
2018. Education database. |
Monday, 25 May 2015
Something of an abnormal post here, for a TALK episode that will follow over the next few days...
Today we're looking at the Battle of Gallipoli, this is the place to find all the photos and pics from the trip to Gallipoli that I mentioned in the TALK episode you have hopefully listened to already (ETA on the episode is 28/52015), so I hope you'll have a gander at these photos here, and perhaps get a better feel for what happened this time 100 years ago in the process.
Ottoman Empire over the years
First of all, the facts. The Ottoman Empire entered the war against the allies in early November 1914, after weeks of wrangling on both sides. Following its clear position, the question then was how to deal with this strategically placed, yet somewhat 'sick' new enemy in the Central Powers camp. For some in the British camp, the idea emerged of an ambitious plan to knock the Ottomans out of the war and then drive south from its captured territories to Germany.
View of the peninsula from satellite; note the narrowness of the waterway and thus its critical strategic location. The southern, European facing side was where most action occurred.
To counter this, Germany had to invest yet more men and materials into the flagging empire to ensure that its weak spots could withstand the kind of offensives that the allies were planning. Both sides worked at a furious pace, but it wasn't until early 1915 that the idea of attacking Turkey was seriously considered, mainly because, in the allied camp, the Western Front of Flanders was still the main event, and the French government didn't under any circumstances want British or indeed French soldiers moved away from the front and tasked with some barely conceived, harebrained scheme on the other side of Europe. Opinions began to shift with the onset of deadlock and trench warfare in the west though, as trenches from the Swiss border to the sea were established after the First Battle of Ypres in late November 1914, and from that point on the objective was to punch a hole in the enemy's defences that would end such a stagnation of military affairs.
Hindenburg at Tannenburg, the greatest Russian defeat in living memory, late August 1914.
Devastation left behind following the First Battle of Ypres, November 1914.
Stabilisation of the fronts: the red line denotes the positions of the trench system that served as the de facto limits of success for both sides in early 1915. The impetus for both sides was thus breaking the deadlock, and the allies looked to Germany's newest ally to achieve this.
So, the attention was turned to the Ottoman Empire- more specifically, its critical waterway known as the Dardanelles. The plan being to sail up the Straits and attack Constantinople. If it sounded too easy, that's because it was, but in November 1914 a small engagement by the Royal Navy had knocked out a large fort at the entrance. The event was celebrated by command, but it had the double negative effect of both lulling Britain into a false sense of security and demonstrating to the Turks that a LOT of work had to be done where their defences were concerned. So, over the following weeks the Turks set to work, and with German aid had established a formidable series of defences along the entrance to the Dardanelles, while the allies- secure in the belief that the endeavour would not be overtly taxing- grossly underestimated the gravity of what was about to face them. When the naval attack failed, and the allies lost 6 vessels to the Turkish shore guns, the decision was made to call off the attack. Already, pressure was on Sir Winston Churchill, a principle architect of the plan, and David Lloyd George, a major advocate of the idea, to show results, and the decision was made to capture the peninsula first, and then bring the force of the navy to bear once the guns were forcibly silenced.
Sir Ian Hamilton, the man tasked with commanding the allies and achieving his objectives at Gallipoli. He, like many of his superiors, has a lot to answer for.
General Liman Von Sanders, Germany's deadliest import where the allies were concerned. In terms of bolstering the Turks and providing them with much needed advice and assistance, von Sanders' role in the Gallipoli campaign is highly underrated and deserves to be re-examined.
Lieutenant-General William 'Birdy' Birdwood, commander of the ANZAC forces. Though born in India and somewhat foreign to the ANZACs he commanded, most grew fond of him in their time in Gallipoli.
For Sir Ian Hamilton, commander of the allies forces about to take their places and invade the Gallipoli Peninsula, his was a task filled with uncertainty. The best information about the peninsula came from outdated French made maps sourced from the Crimean Wars over 50 years before, while secrecy was not watertight and Ian even held an interview with an Egyptian newspaper over the necessity of a landing before the campaign began, as if to wave a giant flag in the face of Liman von Sanders and warn the Turks of their impending arrival. As if he hadn't had enough time to prepare the region already for just such a campaign as the allies were planning, von Sanders now had proof from the horse's mouth that these very defences would soon be put to the test. For Sir Ian Hamilton though, such concerns as predictability or preparation did not seem within his vocabulary. A buzzsaw awaited those he commanded as April neared its end and soldiers massed in eager expectation just off the Straits on the island of Lemnos.
The major plan involved landings at Cape Helles, the southern end of the peninsula. These were to be undertaken by British and Irish soldiers of the 29th Division. Their objective was to storm ashore and seize the high ground- a tactic that will become familiar in the campaign. The Cape Helles landing area stretched across the length of the tip, and so was divided into numerous beaches;
S, V, W, X and Y, with V and W constituting the 'main event' of the landings in the region, and the others designed to provide support. However, once they had landed at dawn on 24th April, it became clear that the plan was flawed. The limited opposition faced by those that landed on all beaches other than V and W meant that the latter two landings lagged behind what were meant to be diversions.
The planned landings at Cape Helles, note W and V at the southermost end of the peninsula.
Detailed map of the landings and the objectives. Note how apparently close everything is. Sometimes we forget that metres separated the men from the enemy and their mission, not miles, and yet it was no easier a task because of this. Formidable defences at V and W beaches prevented much progress, while at S beach the objectives were completed within a few hours.
Some critical commanders had been killed during the Cape Helles landings, which further compromised the venture. Reinforcements were diverted to V beach in an attempt to force the area, but the task was far too great. Names of objectives like Hill 138 and Hill 141 would become the bane of the soldiers, who simply hadn't been prepared for what lay ahead. The Turks were entrenched, and in some cases, to ensure the element of 'surprise', no preliminary bombardment took place to cover the British landings, the result was carnage. In many ways it's hard to imagine the reality of what faced those that landed at V beach, so the best way is to show you the photos I took of the area. These are the first batch of the photos I took, having been in Turkey from 10-14th May 2015; these ones are of the Cape Helles memorial site:
Cape Helles Memorial Site
Monument, literally ten minutes walk from V Beach, with stunning surrounding views
Close up, each side had a different dedication
Names, names and more names surround the walls both inside and outside the monument, denoting the butcher's bill for the Cape Helles landings. Not a Twamley in sight, unless I missed one. For a few strange moments I felt unusually disappointed, until I realised exactly what a Twamley on the wall would have meant- that he would have died just as pointlessly as every other name here.
Stunning views in all directions, since we're literally on the tip of the Peninsula.
Beautiful sunshine and the coast of Turkey proper in the distance. Note also the ruins of the fort; that was the fort which blew up after the allied direct hit in November 1914. It essentially guards the entrance to the Dardanelles waterway. Upon landing here the 29th division was met with fire from the coast in the distance as well as from this hill that I took the picture from.
This is the land atop the cliffs that the Turks would have ran across on V Beach. It felt strangely eerie to be in this place, where 100 years before men would have fought for their lives.
Below is V Beach itself. Even now it's hard to believe it was so beautiful, considering the absolute hell that the whole region meant for so many men. Note how people were able to just casually walk up its edge- a task impossible for men just like these folks in the picture 100 years before.
The very same trenches atop V Beach that would have inhabited the defending Turks
This is the view that would have greeted the 29th division as they landed on the beach; steep cliffs impossible to scale from the sea, and granting the defender all the advantages in the world. There was very little in the way of cover where we were standing, and I can only imagine the fear that would have gripped men just like me once they realised the gravity of their task.
Perhaps because of the task's impossibility, it's not surprising to find a cemetery so close to the actual beach where so many men would have landed. Within were buried the remnants of the 29th division of Brits and Irish, an whoever else was unfortunate enough to have to support them. At least 600 men are estimated to be buried here, but some records put it at 800.
Another view of the cliffs that would be scaled by the 29th; the entrance to the cemetery on the right
The entire graveyard was pristine. Birds were singing and the sun beamed down, it was almost possible to forget that 100 years ago, this very ground was the last place of rest for so many as the battle waged overhead.
Another view of the cemetery on V Beach
This was the moment I almost cried. Having felt strangely emotional up to this point, seeing this grave among the others, I read that Mr J. Kiernan from the Royal Dublin Fusiliers, at 21 years old, had died at this spot. It wasn't the fact that he seemed so like me, it was the fact that this happened 100 years ago to the day that I was looking at this grave- that really brought it home. I knelt down and said a small prayer, not really sure what I was praying for, but just in awe of the fact that here, on 11th May 2015 I was able to see J. Kiernan and that I also had a chance to pay my respects.
And some other miscellaneous photos of the French cemetery, the Turkish monument etc.
The French cemetery
We counted at least 3,000 graves
Stunning white monument; the beauty of it all suggests that it won't ever be forgotten, yet the French contribution is very rarely discussed these days
The major Turkish monument on the primary plateau. Note the line of flags where my friend tried to get a better look and had a whistle blown at him to clear off; the Turks take their monument very seriously
This is the sight that greets you as you walk to the primary plateau above
Here is the mural that would be directly behind you in the first photo. Once again, Mustafa Kemal Attaturk takes center stage, and not for the last time
The 57th Memorial Monument, dedicated to the memory of that division who suffered catastrophic losses during the Gallipoli Campaign. It was this division that was the first to answer the call to defend their homeland against the invading ANZACs at Anzac Cove, and the unit who Attaturk is supposed to have said 'I do not order you to fight, I order you to die'.
Old Man Monument, so-called after its depiction of the last surviving soldier from Gallipoli, Hüseyin Kaçmaz. Also depicted is his granddaughter, who regularly visited the site with him. In 1993, he met with the last surviving ANZAC soldier, a New Zealander, and the two shook hands. These two men, who would have both been in their early 100's, were an unforgettable symbol of the past, and yet they made their peace with that past, setting an example for the rest of the world in the process.
Another statue of Attaturk, this one a tad more controversial, since it sits beside the New Zealand monument (not pictured here, it's behind the back of photographer). When the NZ monument was commissioned, all seemed well and good, yet a few years later the Turkish government had inexplicably erected their own status of Attaturk right beside theirs. Thanks to the Danish students accompanying us on the trip for filling me in on those details. The fellows posing for the picture are the graduates of the Turkish navy, or so we reckoned anyway. Note how seriously the statue of Attaturk is taken; we were dared to jump in and photobomb them, but we weren't that brave...
Unfortunately, Cape Helles was not the only landing site. Where would Gallipoli be without ANZAC cove and everything awful that landing suggested? Anzac Cove was designed to support the landing at Cape Helles by cutting the Ottoman communications in the hills behind the Turks. Once in place, the Anzacs were to hold the high ground and ready themselves to link up with the successful Cape Helles landings, once the latter had cleared away the opposition with relative ease, because don't forget chaps, you'll be landing relatively unopposed. The navy will blow Jonny Turk to pieces, and even if not, just give him a good run with the bayonet and he'll scatter! The reality, of course, was a poles apart from what the Anzacs were told to expect, and as a result they walked into yet another buzzsaw.
The landings at Anzac Cove, with Pugg's Plateau serving as a major initial objective, and the higher hills in the background serving as the further objectives. Nobody stopped to imagine that the Turks would expect a landing, or that they would realise the value of the high ground.
The actual progress that was made, compared with the objective in the distance.
What follows are further photos of Anzac Cove, its beaches, cemeteries and related images, taken on 12 May 2015;
Anzac Cove, angle 1
Anzac Cove, angle 2. In the distance is Suvla Bay, another landing that consumed countless lives
Anzac Cove, angle 3. Still I am struck by the beauty of it all; if I didn't know what had happened here, I'd swear this was a holiday resort. The sun was very strong, and that was only standing still, so it doesn't take much imagination to suppose that the men that fought here would have had huge problems with dehydration and sunstroke, not to mention disease.
The infamous ridges of Anzac Cove, only now do they appear so incredibly daunting, seeing them in real life is even more incredible. How the men managed to scale this is beyond me; how they looked at it and thought to themselves that it was a task within the realm of possibility is beyond me also
Another angle of the ridges that would have given invaluable cover to the defending Turks, with the Anzacs having to rush up the space in between, facing fire on both sides as they did so.
Anzac Cove, angle 4. The birds were signing so loudly that at some stages we couldn't hear our guide. I'd like to think that the birds somehow knew what had happened here 100 years before. That they knew the pain and anguish men in this area once went through, and that to compensate, they sing extra loudly, to try and cover up what was once hell on earth for so many, and a meat grinder for so many others. I got the sense that, having endured what it had a century before, there was no pain left, and that now there was only this startling beauty
Looking down south from where we were standing atop Anzac Cove, so in other words having turned 180 degrees from the above picture. That crop of grey hair belongs to our lovely tour guide, who had lived in the region and given tours just like ours for decades. It is such obviously beautiful scenery, and even now is treated as almost holy ground. To think that 100 years before it would have been a hive of activity, as the allies attempted to supply their Anzac brethren now ashore.
Next are the photos I took of Shrapnel Valley, which during the times of the landings 100 years ago looked like this;
Nowadays, it's a pristine cemetery and grounds, with freshly cut green grass, marble white headstones and the customary dedication at the leading monument which reads 'Their Name Liveth For Evermore'
Shrapnel Valley Cemetery and Memorial Grounds
Plugge's Plateau, and the view of Anzac Cove that I depicted earlier in this blog, were accessed by following the remnants of the trenches that way and up a seriously steep hill.
It's difficult not to feel a tad emotional about this one; his parents bringing this slab of rock from so many miles away in Oz, just so their late son could be laid to rest next to his native ground. I can only imagine how difficult that journey must have been for the family, I can only hope it was therapeutic to arrive here at last and put it here in its rightful place.
This epitaph was especially striking for me. Some tried to find significance in the loss by emphasising honour, duty or respect for one's mates. This one is heart wrenchingly tragic in its truths. All his friends would have, following this loss, was his picture on the wall, because friends, despite the honour and heroism involved, could not take pride in this man's sacrifice. They didn't want a hero, they just wanted their friend back, and now they'd never see him again.
I tried to get a feel for what this place once was by taking a good few shots of the surrounding countryside. Note the hills on this side, as well as the other sides. No wonder it was named Shrapnel Valley, the entire region was a funnel for soldiers to walk through and somehow survive, while being attacked on all sides by bombs, heavy machine guns and explosive shells that inflicted such horrible wounds as only shrapnel could.
Hills surround the cemetery...
Headstones line the grounds
He died for his country's honour, an interesting concept when one considers the grief stricken tragic plea of the other headstone. It just goes to show that people will try to find significance in the loss in a number of ways; some will never accept that the loss was worth it, others will cling desperately to the idea that it was. The poor people that had to endure this.
We next visited Plugge's Plateau (pronounced 'Pluggy'), which served as a major base of operations for the Anzacs after it was captured within a few hours of the landing.
How it looked back then, note the tents strewn across the so-called command center where Colonel Arthur Plugge, commander of the New Zealand Auckland Battalion established his HQ
Plugge's is the smallest of the cemeteries in the region, dedicated to only 21 Anzac deaths
Despite this, it's no less important than the others, nor is it any less beautiful. We visited it on our way to take the numerous photos of Anzac Cove.
We then visited the cemetery at Ari Burnu, the name once given to Anzac Cove, before the Turkish Government officially renamed it after the Anzacs in 1985. Its the most impressive site in the region, and was once the area where the Anzac Day Dawn Service was held, until it was moved in 2000 to a an even larger area that we'll encounter a bit later in this blog.
ANZAC resting place
The striking white monuments that are the signature of the memorial sites here
The first of 7 graves chosen for their character
So simple; private yet public, short yet sweet. Epitaphs like these emphasise the human element that is so critical to preserve, so that these names do not become mere statistics
The only Jewish headstone I encountered in my travels
We also visited Lone Pine Cemetery, where the ANZAC ceremony a few months ago had been held. Our guide told us that only two weeks before we arrived, 10,000 people had flocked to the area to commemorate ANZAC day 100 years on. It was a truly breathtaking experience.
Lone Pine Cemetery, 1920.
21 years after the battle; the first ceremony to take place on the new grounds, Lone Pine, 1936. Recently constructed is the Monument to the Missing, a beautiful idea that ensures even those who have not found a final resting place can still have their collective memory respected here.
Lone Pine today, and no that is not the pine it is named after (apparently many people presume that it is); that tree no longer stands, but it is a nice dedication nonetheless.
Lone Pine view from the step up, with back facing the monument.
Within the open door of the Monument to the Missing were a countless artifacts dedicated at the time of the ANZAC ceremony weeks before. Some contained pleas to distant relatives, some calls to late ancestors, others thanked them for their sacrifice, and hoped that they could be at peace.
Even after all that had been lost, the allies had not given up on the idea of Gallipoli. A grand offensive was planned for August, whereby the allies hoped to attack on all fronts and mount a landing at Suvla Bay, a little bit north of Anzac Cove. The entire operation, unfortunately, was filled with breathtaking carelessness and criminal stupidity on the allied side, as generals with no grasp of the situation repeatedly send wave after wave of young men to their deaths in a hopeless quest to dislodge the advantaged Turk. This was the Battle of the Nek, so named after the bottleneck that the ridge appeared to take the shape of. One war correspondent, Charles Bean, compared it to 'attacking a frying pan from the handle'. It was madness, and it was meant only as part of another objective, yet the original accompanying objective was never completed. When word came that this attack was to go ahead anyway, many believed it was a death sentence. It even got off to an awful start, with the preliminary bombardment finishing 7 minutes earlier than it was meant to.
General Sir Alexander Godley, the man in charge of the offensives at the battle of the Nek in early August 1915. Responsible for neglecting his troops, to the extent that he commissioned wave after wave of slaughter at the Battle of the Nek, not to mention elsewhere, Godley would be privately vilified by his troops, yet publicly his career flourished. He would lead the ANZACs again on the Western Front, and in late 1917 would again come under scrutiny for ordering the continuation of the Third Battle of Ypres, also known as Passchendaele. Yet, unfortunately, Godley wasn't the only one doing so, he was part of the cancer of careless within the British Army, he did not invent it or play the sole role in its continuation. He has a lot to answer for, nonetheless, and his name should be among the other controversial ones such as Douglas Haig and Lord Kitchener for what he did at the Battle of the Nek, where the flower of Australia, not to mention many other nations, was trampled upon and slaughtered for no gain whatsoever, save another gleaming memorial
This meant that, rather than facing at least semi-stunned or lesser prepared defenders when the time to go over the top came, the allies would face prepared, well-dug in and incredulous Turkish defenders, who couldn't believe that their enemy would attack at such a disadvantage. The guns, not just of the defenders here, but of other Turks placed a few hundred meters away on nearby hills, were able to rain down murderous fire from the outset. When the first wave were all wiped out, the second wave went ahead anyway, as did the the third. There was definite protest, to the extent that only part of the 4th wave went ahead, but still, it was nowhere near what should have been done. The command were so blatantly detached from the reality on the ground that condemning their actions doesn't come close to justice. They threw men to their deaths with a psychotic, despicable sense of laxness that in any other place, at any other time, they would be murderers. Yet here, on this piece of land, they remained in control of it all.
It makes me so angry to read and hear about, and there is a real sense of tragedy in this cemetery;
Much like everything else in Gallipoli, this cemetery wasn't always so pristine...
Here was the site where Charles Bean, war correspondent for the ANZACs, found the human bones (visible in this photo) of the Battle of the Nek in 1919, and they mercifully led to the creation of a proper cemetery (below under construction)
Cemetery of the Nek under construction, 1923.
Plaque of dedication to those that fell
Artists' impression of the Nek, 1924
What follows are additional photos I encountered/took myself;
Turkish soldiers, equipped with the latest model of German Maxim gun that proved so devastating
Lancashire Fusiliers on their way to W beach, where most would meet their end. So substantial were their losses that W Beach is often referred to as Lancashire Landing in some histories
French soldiers at Cape Helles
ANZAC soldiers land at Pugge's Plateau
Smashed portion of one of the forts tasked with defending ANZAC Cove
One of the trench systems atop the Nek
Such systems stretched underground, as one side attempted to overtake the other
One of the many demonstrations of what such warfare would have been like 100 years ago, with soldiers sometimes as close as 8 meters to one another's lines. This was taken just before we got the ferry across to Cannakkele, on the Turkish side of the Dardanelles (and where that horse from the film Troy is held)
Just in case you thought I was lying, here is the horse!
So yes, that's going to do I think. I know this has been something of a long-winded, photo packed post, and I'm sure the episode will be something similar, knowing myself and Sean! I feel like it was worth it though, like this is a story that needs to be told. If you can care about Gallipoli, or at least don't think of it as some event unimportant or uninteresting to you, then I have accomplished something here. Trust me when I say, having visited these place, Gallipoli is a story that needs to be told, and it is a story just as relevant today as it was a century ago. It is about youth, naivety, grief, loss, sacrifice, terror, death and tragedy. It is the place that a dominion became a nation. It is also a place forever associated with failure, and symbolic of what happens when you underestimate your enemy. The real tragedy in my view is that the allies would do it all again the following July. With just as little preparation, with just as little care for men's lives and with just as little 'success', the Somme eclipsed Gallipoli for all the wrong reasons, and claimed the lives of men whose only crime was to volunteer (or be conscripted) into an army which they believed would use their life, not waste it.
The 4 lads in Gallipoli, when we weren't drinking beer, we were here! From left to right is Caelan, Jack, Adam and myself. Good thing the world didn't require us to do what our generation, 100 years ago did... I don't know what would have happened if it had!
The Irish Gallipoli crew, seated here at the base of the Turkish monument. From left to right Kristina, YanLi, Val, Adam, Liam, Caelan, ME, Dawn, Lia, Jack and our dear leader (and my dissertation supervisor) William Mulligan. Thanks for the fun times folks!
I shudder to think of what the youth of today would do, if faced with a situation like that today. So many of the graves I saw contained the names of men whose lives had ended before they had even reached the stage of mine. I, at 23, was older than most of the casualties I came across. Yet, having seen what I've seen, I know deep down that I would never have it within me to go over the top as they did. I am sincerely thankful that nobody in our generation will ever have to. I, personally want those I love; my friends, family and other half, to have more to remember me by than, as that ringing epitaph said my 'photo on the wall'.
Thanksssssssssss for reading history friends! Thanks also to Lia Brazil for letting me steal her photos (my phone had died) and to this website for their great advice and pics:
1. Not listened as this ep is still phantom as far as the podcast feed is concerned. The last ep there is the last on the Swedish Deluges.
2. I went to Gallipoli a few years ago when I was home exchanging in Istanbul. Glad to see your photos as my camera was swiped before I downloaded the photos. Gallipoli is a very moving place. |
[Kim Seong-kon] Korea: Seven decades ago and now
By Kim Seong-kon
• Published : Aug 28, 2018 - 17:20
• Updated : Aug 28, 2018 - 17:20
Recently, I came across some embarrassing, but intriguing, articles about Korea in the mid-20th century. One was related to Western missionaries who lived in Korea right after the Korean War to help with the reconstruction of the war-torn country.
In reports and letters they sent back to their countries, the missionaries invariably wrote, “The Korean people were so impetuous and emotional that they quarreled or fought all day long. But fortunately, nobody died because no one had guns.” Then they added, “Meanwhile, government officials were like vampires who were sucking the blood of the ordinary people.”
I also came by a newspaper article about Chinese government documents written about Korea just before the liberation. One of them wrote, “The Koreans are not good at unity and tend to be factionalized. There are so many factions in the exile government located in China. They are antagonizing one another, exhibiting jealousy and resentment. Unfortunately, there is no great leader in Korea who can lead the nation in the right direction.”
It continued, “The Korean people have personality issues; they are self-centered and always blame others. Younger people despise older people for their uselessness and incompetence, while older people accuse younger people of being ignorant and impertinent.” Another Chinese government document wrote, “Koreans would neither listen to others nor accept different opinions. They do not want to concede and are busy protecting their vested interests only.”
Today, however, South Korea has radically changed. Visit any government office, and you will find Korean government officials there are surprisingly nice and friendly. Perhaps they are some of the finest civil servants in the world. Embarrassingly, however, other observations of foreign missionaries and politicians seven decades ago still seem to remain valid.
Undeniably, we still tend to be so impetuous that our emotions frequently cloud our judgment. Oftentimes, we are self-centered and turn a deaf ear to different opinions, only trying to protect our own vested interests. We are overtly jealous and resentful, myopic and closed-minded. And we are still divided by political ideologies and antagonize each other. Moreover, we are still witnessing chronic factional skirmishes between the young and the old, between the rich and the poor, and between the conservative and the progressive.
Furthermore, we still blame others. We blame other countries even for our own mistakes and incompetence. Our politicians, too, have always blamed the previous government for their failures in policies, and condemned anyone who worked in it.
However, it would be wrong if the present government tried to incriminate everybody who served the previous government. No advanced country would do such a thing.
If our politicians would only stop blaming the previous government and call for unity instead, their popularity would rise considerably. If not, people will eventually grow weary of it and turn their backs to it.
By the same token, it would be equally unwise if the opposition party members were too busy faultfinding in all of their quarrels with the governing party. Although they are political foes, there are times when they need to unite and collaborate for national security and other concerns. Regrettably, our politicians do not seem to care.
For the past seven decades since the Korean War, South Korea has shown admirable traits and accomplished spectacular things. Very few countries have succeeded in economic development, cultural prosperity, and advanced technology, not to mention democratization, as far and as fast as South Korea has.
Furthermore, the Korean people have overcome the International Monetary Fund crisis and hosted the Olympic Games, the World Cup, and the Winter Olympic Games successfully. It is no wonder South Korea is much admired as a role model for developing countries.
It is a shame that we have not yet been able to shake off the above-mentioned undesirable old habits yet. It is true that old habits die hard. Yet, we should try. We cannot afford to repeat our past mistakes again and again. The world is watching us now. We must show that we have truly changed and we can be much better than seven decades ago.
These days, there are so many important things we should be doing together, hand in hand and side by side. It is well known that South Korea is currently in the vortex of an international crisis due to the recent conflicts between China, Japan, North Korea and the United States. If we continue to be divided by different factions and antagonize one another, we will not be able to overcome the impending crisis we will face soon. Then, it will be too late to regret or redeem our mistakes.
We can deal with external crisis with the help of other countries. When it comes to internal disintegration, however, there is nothing much we or other countries can do. In order to survive the next crisis and thrive in the future, we should be different from seven decades ago.
By Kim Seong-kon
Kim Seong-kon is a professor emeritus of English at Seoul National University and visiting professor at Kyung Hee Cyber University. He can be reached at sukim@snu.ac.kr -- Ed. |
Communication CNN
Amelia Arsenault
• LAST MODIFIED: 31 March 2016
• DOI: 10.1093/obo/9780199756841-0044
Ted Turner launched Cable News Network (CNN), the world’s first twenty-four-hour news channel, in 1980. Broadcast network journalists and media pundits initially dismissed CNN as the “Chicken Noodle Network,” pointing to its poor production values and small audience share. However, the channel gradually built an audience-base with its twenty-four-hour coverage of such events as the space shuttle Challenger disaster in 1986, the fall of the Berlin Wall in 1989, and the Gulf War in 1991, providing the first major rival to ABC, CBS, and NBC, the three free-to-air broadcast networks that had dominated American television journalism since the advent of television. In the ensuing years, CNN, now a subsidiary of the global media conglomerate Time Warner (see the Oxford Bibliographies article Time Warner) has evolved into a globally available multi-channel news organization that includes CNN Headline News (launched in 1982), CNN International (launched in 1985), CNN Airport Network (launched in 1992), and CNN Español (launched in 1997). In addition to these channels, CNN’s parent company Turner Broadcasting (a subsidiary of Time Warner) has entered into several joint ventures bearing the CNN brand and featuring selected CNN programming, including a health-care news channel designed specifically for doctors office waiting rooms called Accent Health (launched in 1995), CNN+ (a Madrid-based franchise that operated 1999–2010), CNN Turk (launched in 1999), CNNj (Japan, launched in 2003), CNN-Indian Broadcasting Network (launched in 2005), and CNN Chile (launched in 2008). CNN also maintains a stable of digital delivery platforms including (launched in 1995),, a partnership with Asahi Interactive in Japan (launched in 2000), CNN International Mexico (launched in 1999), and CNN Arabic (launched in 2002). As the first and the largest privately owned global twenty-four -hour news channel, CNN has attracted the interest of communication scholars studying a broad array of phenomenon. This article outlines resources that range from examinations of CNN as a media institution, to explorations of the political and social implications of CNN content for politics and foreign policy, to studies that treat CNN as a proxy measure for larger transformations in the global media and communications environment, to explorations of CNN’s impact on journalism practices. Many of these sources use CNN as an exemplar of broader trends in media, political communication, and journalism rather than the main subject of analysis. Beginning in the 1990s, for example, political communication scholars began to refer to and debate the presence of the “CNN effect,” a shorthand term referring to the influence of twenty-four-hour news media on the conduct of foreign and domestic politics. On the domestic front, CNN is commonly compared with its main rivals, Fox News Network and MSNBC. While scholars concerned with international communication often examine CNN in contrast to other major twenty-four-hour private and publically owned global news broadcasters such as BBC (United Kingdom), Al-Jazeera English (Qatar), Deutche Welle (Germany), and France 24.
General Overviews
The CNN stable of networks has undergone a continual process of transformation engendered by transfers in ownership (e.g., Time Warner bought Turner and its CNN networks in 1996), the rise of new competitors (e.g., MSNBC and Fox News Channel), and broader changes in media consumption, delivery, and production mechanisms. There is no one centralized source for general overviews and background information about CNN and its affiliated networks. The CNN website and annual reports are embedded within the larger Time Warner stable of properties and only contain limited information. This section provides suggested sources for those seeking CNN performance data, audience data, and footage and transcripts. Scholars interested in general overviews pertaining to CNN ownership and evolution since 1996 should also consult the Oxford Bibliographies entry on Time Warner.
back to top
How to Subscribe
|
From Seo Wiki - Search Engine Optimization and Programming Languages
Jump to: navigation, search
Paradigm multiparadigm: object-oriented, procedural, structured
Appeared in 1979
Designed by Mike Cowlishaw
Developer Mike Cowlishaw & IBM
Stable release ANSI X3.274 (1996)
Typing discipline dynamic, everything is a string (ClassicREXX) or object (ObjectRexx)
Major implementations IBM NetREXX, Open Object Rexx, Regina, others
Dialects Object Rexx, Open Object Rexx, NetRexx
Influenced by PL/I, EXEC 2, BASIC
REXX (REstructured eXtended eXecutor) is an interpreted programming language which was developed at IBM. It is a structured high-level programming language which was designed to be both easy to learn and easy to read. Both proprietary and open source interpreters for REXX are available on a wide range of computing platforms, and compilers are available for IBM mainframes.
Rexx is widely used as a glue language, macro language, and is often used for processing data and text and generating reports; these similarities with Perl mean that Rexx works well in CGI programming and it is indeed used for this purpose. Rexx is also used as an internal macro language in some software including the ZOC terminal emulator. Additionally, the Rexx language can be used for scripting and macros in any programme which uses Windows Scripting Host ActiveX scripting engines languages (e.g. VBScript and JScript) if one of the Rexx engines (see below) are installed.
Rexx is supplied with OS/2 versions 2.0 and up and Rexx script for OS/2 have the filename extension .cmd, as do shell scripts as is the case with Windows NT type operating systems—the first line of the script determines which it is.
REXX has the following characteristics and features:
• simple syntax
• small instruction set containing just two dozen instructions
• freeform syntax
• typeless variables
• character string basis
• dynamic data typing (no declarations)
• no reserved keywords (except in local context)
• arbitrary numerical precision
• decimal arithmetic (floating-point)
• a rich selection of built-in functions (especially string and word processing)
• automatic storage management
• crash protection
• content addressable data structures
• associative arrays
• straightforward access to system commands and facilities
• simple error-handling, and built-in tracing and debugger
• few artificial limitations
• simplified I/O facilities
• unconventional operators
• does not fully support Unix style command line parameters (except specific implementations)
• does not provide basic terminal control as part of the language (except specific implementations)
• does not provide a generic way to include functions and subroutines from external libraries (except specific implementations)
REXX has just twenty-three, largely self-evident, instructions (e.g., call, parse, and select) with minimal punctuation and formatting requirements. It is essentially an almost free-form language with only one data-type, the character string; this philosophy means that all data are visible (symbolic) and debugging and tracing are simplified.
REXX was designed and first implemented, in assembly language, as an ‘own-time’ project between 20 March 1979 and mid-1982 by Mike Cowlishaw of IBM, originally as a scripting programming language to replace the languages EXEC and EXEC 2[1]. It was designed to be a macro or scripting language for any system. As such, REXX is considered a precursor to Tcl and Python. Rexx was also intended by its creator to be a simplified and easier to learn version of the PL/I programming language.
It was first described in public at the SHARE 56 conference in Houston, Texas, in 1981[2], where customer reaction, championed by Ted Johnston of SLAC, led to it being shipped as an IBM product in 1982.
Over the years IBM included REXX in almost all of its operating systems (VM/CMS, VM/GCS, MVS TSO/E, AS/400, VSE/ESA, AIX, CICS/ESA, PC-DOS, and OS/2), and has made versions available for Novell NetWare, Windows, Java, and Linux.
The first non-IBM version was written for PC-DOS by Charles Daney in 1984/5. Other versions have also been developed for Atari, AmigaOS, Unix (many variants), Solaris, DEC, Windows, Windows CE, PocketPC, MS-DOS, Palm OS, QNX, OS/2, Linux, BeOS, EPOC32, AtheOS, OpenVMS, OpenEdition, Macintosh, and Mac OS X.[3]
Several freeware versions of REXX are available. In 1992, the two most widely-used open-source ports appeared: Ian Collier's REXX/imc for Unix and Anders Christensen's Regina (later adopted by Mark Hessling) for Windows and Linux. BREXX is well-known for WinCE and PocketPC platforms.
In 1996 ANSI published a standard for REXX: ANSI X3.274–1996 “Information Technology – Programming Language REXX”. More than two dozen books on REXX have been published since 1985.
Since the mid-1990s, two newer variants of REXX have appeared:
• NetRexx — which compiles to Java byte-code via Java source code; this has no reserved keywords at all, and uses the Java object model, and is therefore not generally upwards-compatible with ‘classic’ REXX.
• Object REXX — which is an object-oriented generally upwards-compatible version of REXX.
In 1990, Cathy Dager of SLAC organized the first independent REXX symposium, which led to the forming of the REXX Language Association. Symposia are held annually.
REXX marked its 25th anniversary on 20 March 2004, which was celebrated at the REXX Language Association’s 15th International REXX Symposium in Böblingen, Germany, in May 2004.
On October 12, 2004, IBM announced their plan to release their Object REXX implementation under the Common Public License. Recent releases of Object Rexx contain a ActiveX WSH scripting engine implementing this version of the Rexx language.
A command-line Rexx interpreter is also installed with ooRexx, and it is also possible to run ooRexxScript programmes from the command line by means of the CScript command (WScript may also be run from the command line) invoking the Windows Scripting Host.
A Rexx IDE, RxxxEd, has been developed for Windows. RxSock for network communication as well as other add-ons to and implementations of Regina Rexx have been developed, and a Rexx interpreter for the Windows command line is supplied in most Resource Kits for various versions of Windows and works under all of them as well as MS-DOS.
Originally it was just called "Rex", "A Reformed EXecutor"; the extra "X" was added to avoid collisions with other products' names. The expansion of Rexx to the REstructured EXtended EXecutor is believed to be a backronym. REX was originally all uppercase because the mainframe code was uppercase oriented. The style in those days was to have all-caps names (partly because almost all code was still all-caps then). For the product it became REXX, and both editions of Mike Cowlishaw's book use all-caps. By the 1990s it was largely written Rexx or, with small caps: REXX. As of 2008, Mike Cowlishaw seems to prefer Rexx, IBM documents use REXX, and the ANSI standard uses REXX.
Traditional forms:
do until [condition]
do while [condition]
With an index variable:
do i = x [to y ][by z]
The step increment (z above) may be omitted and defaults to 1. The upper limit (y above) can also be omitted, which makes the loop continue forever. You can also loop forever without an index variable with this:
do forever
A program can break out of the current loop with the leave instruction (which is the normal way to exit a "forever" loop), or can short-circuit it with the iterate instruction. The do while and do until forms are equivalent to:
do forever
if [condition] then leave
do forever
if [condition] then leave
Testing conditions with IF
if [condition] then
For single instructions, DO and END can also be omitted:
if [condition] then
Testing for multiple conditions
SELECT is REXX's CASE structure, like many other constructs derived from PL/I:
when [condition] then
when [condition] then
[instructions] or NOP
NOP indicates no instruction is to be executed.
Simple variables
say hello /* => HELLO */
hello = 25
say hello /* => 25 */
hello = "say 5 + 3"
say hello /* => say 5 + 3 */
interpret hello /* => 8 */
drop hello
say hello /* => HELLO */
Compound variables
do i = 1 to 10
stem.i = 10 - i
i = 'Monday'
stem.i = 2
In REXX it is also possible to set a default value for a stem.
stem. = 'Unknown'
stem.1 = 'USA'
stem.44 = 'UK'
stem.33 = 'France'
The whole stem can also be erased with the DROP statement.
drop stem.
add_word: procedure expose dictionary.
parse arg w
n = dictionary.0 + 1
dictionary.n = w
dictionary.0 = n
m = 'July'
d = 15
y = 2005
day.y.m.d = 'Friday'
Features similar to REXX compound variables are found in many other languages (associative arrays in AWK, hashes in Perl, Hashtables in Java, etc). Most of these languages provide an instruction to iterate over all the keys (or tails in REXX terms) of such a construct, but this is lacking in classic REXX. Instead it is necessary to keep auxiliary lists of tail values as appropriate. For example in a program to count words the following procedure might be used to record each occurrence of a word.
add_word: procedure expose count. word_list
parse arg w .
if count.w = 1 then word_list = word_list w
and then later
do i = 1 to words(word_list)
w = word(word_list,i)
say w count.w
At the cost of some opacity it is possible to combine these techniques into a single stem.
add_word: procedure expose dictionary.
parse arg w .
dictionary.w = dictionary.w + 1
then do
n = dictionary.0+1
dictionary.n = w
dictionary.0 = n
and later
do i = 1 to dictionary.0
w = dictionary.i
say i w dictionary.w
However, REXX provides no safety net here, so if one of your words happens to be a whole number less than dictionary.0 the above technique will fail mysteriously.
Recent implementations of REXX, including IBM's Object REXX and the open source implementations like ooRexx include a new language construct to simplify iteration over the value of a stem, or over another collection object such as an array, table, list, etc.
do i over stem.
say i '-->' stem.i
Keyword instructions
parse [upper] origin template
where origin specifies the source:
• linein (standard input, e.g. keyboard)
• pull (REXX data queue or standard input)
• source (info on how program was executed)
• value (an expression) with
the keyword with is required to indicate where the expression ends
• var (a variable)
• version (version/release number)
and template can be:
• list of variables
• column number delimiters
• literal delimiters
upper is optional; if you specify it, data will be converted to upper case.
Using a list of variables as template
myVar = "John Smith"
parse var myVar firstName lastName
say "First name is:" firstName
say "Last name is:" lastName
displays the following:
First name is: John
Last name is: Smith
Using a delimiter as template:
myVar = "Smith, John"
parse var myVar LastName "," FirstName
say "First name is:" firstName
say "Last name is:" lastName
also displays the following:
First name is: John
Last name is: Smith
Using column number delimiters:
myVar = "(202) 123-1234"
parse var MyVar 2 AreaCode 5 7 SubNumber
say "Area code is:" AreaCode
say "Subscriber number is:" SubNumber
displays the following:
Area code is: 202
Subscriber number is: 123-1234
The INTERPRET instruction is powerful and one of the two reasons why writing REXX compilers isn't trivial, the other reason being REXX's decimal arbitrary precision arithmetic:
/* a touch of LISP */
X = 'square'
SQUARE: return arg(1) * arg(1)
This displays 16 and exits. Because variable contents in REXX are strings, including rational numbers with exponents and even entire programs, REXX offers to interpret strings as evaluated expressions.
This feature could be used to pass functions as function parameters, such as passing SIN, COS, etc. to a procedure to calculate integrals.
/* terminated by input "exit" or similar */
do forever ; interpret linein() ; end
A slightly more sophisticated REXX calculator:
X = 'input BYE to quit'
// (PULL is a shorthand for parse upper pull like ARG for parse upper arg.)
The power of the INTERPRET instruction had other uses. The Valour software package relied upon Rexx's interpretive ability to implement an OOPS environment. Another use was found in an unreleased WestinghouseTemplate:Dn product called Time Machine that was able to fully recover following a fatal error.
numeric digits 10 /* only limited by available memory */
say 999999999 + 1 /* => 1000000000 */
numeric fuzz 3
numeric form engineering
numeric digits 50
n = 2
r = 1
do forever /* Newton's method */
rr = (n/r+r)/2
if r=rr then leave
say "Root" n "=" r /* Root 2 = 1.414213562373095048801688724209698078569671875377 */
numeric digits 50
e = 2.5
f = 0.5
do n = 3
f = f / n
ee = e + f
if e=ee then leave
Error handling and exceptions
It is possible in REXX to intercept and deal with errors and other exceptions, using the SIGNAL instruction. There are seven system conditions: ERROR, FAILURE, HALT, NOVALUE, NOTREADY, LOSTDIGITS and SYNTAX. Handling of each can be switched on and off in the source code as desired.
This example will run until stopped by the user:
signal on halt;
do a = 1
say a
do 100000 /* a delay */
say "The program was stopped by the user"
Function VALUE can be used to get the value of variables without triggering a NOVALUE condition, but its main purpose is to read and set environment variables - similar to POSIX getenv and putenv.
ERROR Positive RC from a system command
HALT Abnormal termination (see above)
NOVALUE An unset variable was referenced (see above)
SYNTAX Invalid program syntax, or some error condition not covered above
LOSTDIGITS Significant digits are lost (ANSI REXX, not in TRL second edition)
When a condition is handled by SIGNAL ON, the SIGL and RC system variables can be analyzed to understand the situation. RC contains the REXX error code and SIGL contains the line number where the error arose.
ChangeCodePage: procedure /* protect SIGNAL settings */
signal on syntax name ChangeCodePage.Trap
return SysQueryProcessCodePage()
See also
• Callaway, Merrill. The Rexx Cookbook: A Tutorial Guide to the Rexx Language in OS/2 & Warp on the IBM Personal Computer. WHITESTONE, 1995. ISBN 0-96-327734-0.
• IBM Redbooks. Implementing Rexx Support in Sdsf. Vervante, 2007. ISBN 0-738-48914-X.
• Rudd, Anthony S. Practical Usage of Rexx. Ellis Horwood Ltd., 1991. ISBN 0-13682-790-X.
External links
Classic interpreters
• Regina: open-source (LGPL) interpreter for Linux, BSD, Windows, etc.
• REXX/imc: open-source (nonstandard license) interpreter for Unix and Linux systems.
• BREXX: open-source (GPL) interpreter for DOS, Linux, Windows CE, etc.
• Reginald: free interpreter for Windows.
• roo!: freeware interpreter for Windows with object-oriented extensions from Kilowatt Software.
• r4: freeware interpreter for Windows from Kilowatt Software.
• REXX for Palm OS: shareware interpreter for Palm OS from Jaxo Inc.
• S/REXX: commercial interpreter for UNIX and Windows from Benaroya.
• uni-REXX: commercial interpreter for UNIX from The Workstation Group Ltd.
Other interpreters
da:REXX de:REXX es:REXX eu:REXX fr:Restructured Extended Executor ko:REXX is:REXX he:REXX nl:Rexx ja:REXX no:REXX pl:REXX pt:REXX ru:REXX sl:REXX fi:REXX sv:REXX tg:REXX tr:REXX zh:REXX
Personal tools
Served in 0.405 secs. |
Vanuatu, is a country located at Melanesia, it has an area of 12,190 Km2, so it is one of the smallest countries in the world.
Vanuatu, with a population of 276,244 people, it is one of the least populous country in the world ant it has a moderate population density, 23 people per km2.
The capital is Port Vila and its currency is Vanuatu vatu
Vanuatu is holding the 184 position by nominal GDP. Its national debt in 2016 was 332 millions of euros368 millions of dollars, ( 46.06% debt-to-GDP ratio) and its public debt per capita is 1,228€ euros per inhabitant1,360$ dollars per inhabitant.
In terms of the human development index (HDI) of Vanuatu, which is the index used by the United Nations to measure the progress of a country, was 0.603 points in 2017, leaving it in 138th place in the table of 189 countries published.
If the reason to visit Vanuatu are business, you must know it's in the 90th of the Doing Business ranking , which provides objective measures of business regulations for local firms.
In the tables at the bottom of the page, you can see more information about the economy and demography of Vanuatu, if you want to see information about other countries click here
Vanuatu Economy
Comptes nationaux - Government
Annual GDP [+]2017764M.€
Annual GDP [+]2017863M.$
GDP per capita [+]20172,765€
GDP per capita [+]20173,124$
Debt [+]2016332
Debt [+]2016368
Debt (%GDP) [+]201646.06%
Debt Per Capita [+]20161,228€
Debt Per Capita [+]20161,360$
Deficit (M.€) [+]2016-44
Deficit (M.$) [+]2016-49
Deficit (%GDP) [+]2016-6.12%
Expenditure (M.€) [+]2016266.2
Expenditure (M.$) [+]2016294.6
Education Expenditure (M.€) [+]201538.7
Education Expenditure (M.$) [+]201543.0
Education Expenditure (%Bud.) [+]201522.30%
Gov. Health Exp. (%Bud.) [+]201417.94%
Expenditure (%GDP) [+]201636.91%
Expenditure Per Capita [+]2016984€
Expenditure Per Capita [+]20161,090$
Education Expenditure P.C [+]2015144€
Education Expenditure P.C [+]2015160$
Gov. Health Exp. P.C. [+]2014105€
Gov. Health Exp. P.C. [+]2014140$
Corruption Index [+]201743
Doing Business [+]201890º
Standard VAT [+]01/01/201112.50%
Exports [+]201742.5 M.€
Exports [+]201748.0 M.$
Exports % GDP [+]20175.56%
Imports [+]2017345.2 M.€
Imports [+]2017390.0 M.$
Imports % GDP [+]201745.20%
Trade balance [+]2017-302.7 M.€
Trade balance [+]2017-342.0 M.$
Trade balance % GDP [+]2017-39.63%
Density [+]201723
Population [+]2017276,244
Immigrant stock [+]20173,245
Remittance received (M.$) [+]201618.9
% Immigrant [+]20171.17%
Remittance sent (M.$) [+]201650.5
Emigrant stock [+]20178,785
% Emigrant [+]20173.18%
HDI [+]20170.603
Birth Rate [+]201625.86‰
Fertility Rate [+]20163.28
Crude death rate [+]20164.78‰
Life expectancy [+]201672.13
Number of homicides [+]20156
Rate Homicides per 100.000 [+]20152.13
Energy and Environment
CO2 Tons per capita [+]20160.51 |
The purpose of this project is to investigate the relationship between the voltage loss across several resistors and the current flowing through there. I have to also determine from my data an equation describing this relationship and measure the Electrical Resistance that is measured in Ohms.
Set up
For this lab, you will need:
• 3 Resistors connecting wires
• 1 Breadboard
• 1 Voltmeter
• 1 power supply (breadboard)
• 1 Ammeter
Here is a schematic diagram of the lab:
1) Set the voltage of the knob to 0 volts in a clockwise direction.
2) Now, connect the resistor to the breadboard. Do not turn the power on yet.
3) With an alligator wire, connect the power supply with the lower post of the ammeter
4) With an alligator clip, connect the positive side of the power supply to the positive terminal of the ammeter. After that, connect the black terminal of the ammeter to the top post of the resistor bracket. This will complete the circuit but, still, do not turn the power on. Now, set the ammeter to its highest reading scale.
5) Now using alligator clips, connect the positive voltmeter terminal to the top resistor post and the negative probe to the bottom resistor post. All of this will connect the voltmeter in a parallel branch circuit across the resistor. This will tell you how many volts are lost during the whole process. Set the Voltmeter to 10 VDC.
6) Check all your connections and system otherwise, something could be wrong and ruin he whole experiment, the voltmeter, and the ammeter.
7) DO tables to record all your data since we are going to have four trials. One at its maximum current, one at 23 and the last one about 1/3.
8) DO all of these four trials and do not stay the circuit turned on because everything can come overheated and all the equipment could ruin so do it fast and accurately.
10) After you do all of these trials, do a graph and calculate the slopes for every trial.
Here is the data that I collected from the lab and here are the tables with all my results:
Maximum Voltage
Trial Current ± 0.05 Voltage ±0.05
0 0 0
1 0.4 4.2
2 0.6 6.8
3 0.9 9.6
4 1.1 11.4
5 1.4 14.6
2/3 Voltage
Trial Current ± 0.05 Voltage ±0.05
6 1.9 12
5 1.7 10.7
4 1.3 8.2
3 1 6.4
2 0.7 4.5
1 0.4 2.4
0 0 0
1/3 Voltage
Trial Current ± 0.05 Voltage ±0.05
8 3.9 8.04
7 3.6 7.5
6 3.3 6.88
5 3 6.32
4 2.5 5.3
3 2 4.31
2 1 2.23
1 0.5 1.15
0 0 0
Bulb Voltage
Trial current ± 0.05 Voltage ± 0.05
0 1.8 10.45
1 1.4 6.2
2 1 3.6
3 0.6 1.41
4 0.2 0.4
5 0 0
Here is all the data that I got from the whole lab. In this next part of the lab, I am going to have a graph showing the resistance of each of the voltages from the charts above. With this graph I'm going to try to find the slopes and try to prove and see which trial had the most resistance and why the graphs looks like that.
The first conclusion that we can make according the electrical resistance is that when it was at its maximum voltage it had a lower resistance and in the other hand, when you have less voltage you have more resistance. When the breadboard was set to maximum voltage, the resistance was very low because electrons crash less times and the electrons take more time to go around a whole phases so that is what makes the higher voltage to have a lower resistance.
You can also prove this by using the formula V=IR. The one who had an intermediate resistance was the 2/3 voltage which was in the middle between 1/3 and maximum voltage. In the part where we had the maximum resistance was in 1/3 voltage. Electrons take shorter time to go around the breadboard that what causes the electrons to crash faster and because there is too much crushing, the ammeter starts to get warmer because there is too much friction and energy loss from the electrons.
That energy goes to heat, that why the equipment started burning out because of this friction. We can also see the bulb's graph, which starts at very little and then grows up quickly. The graph looks like an exponential graph, which is indeed, what the bulb was doing. It was almost increasing double as you raised up the voltage in the breadboard. I can make those conclusions from the graph that I have.
When I looked at the data tables, they seemed to be correct until Mr. Horn said that it was wrong because the ammeter was not going at a constant range so we had to do the first part again but it was no problem. You can see there is a lot of deviation in the tables. That was because the volt and the ammeter did not stayed constant so we calculated an estimate for all numbers and we came up with this number 0.05, which really worked out great.
We could had done this lab better is we had an accurate equipment because at the beginning we had to change station because the power supply was not working. The ammeter and the voltmeter were not working well because they could not stay still, it was always jumping like from 1.53 to 1.58 and then to 2.49 so we could not read an exact measurement. I think that other than that, we did a good lab. |
3D Modeling vs. CAD vs. BIM: What's the Difference?
Lauren Fram
Lauren Fram | October 23, 2017
Computers have become a vital part of almost every industry, but where computers are truly revolutionary is within design industries.
From industrial designers to architects, filmmakers to video game developers, designing on a computer in 3D has changed the way professionals in design industries work. The 3D design software landscape today is vast and often overlaps, so it can be difficult to know whether you need 3D modeling, BIM or CAD software. Comparing these three categories may give you a better idea of what will work best for you.
What is 3D modeling software?
3D modeling software is the most general of the 3D design categories. All 3D design software will have some method of 3D modeling, but 3D modeling software is primarily used to create 3D assets for animation. The most basic 3D modeling software will only permit you to create 3D models, but most programs often include tools for animation, texture painting or rendering.
3D modeling suites such as 3ds Max Design, Cinema 4D and Modo often offer a variety of methods for sculpting. Polygonal modeling, spline modeling, digital sculpting, procedural modeling and 3D scanning are all methods available to users of 3D modeling software.
What is building design and BIM software?
BIM (building design and building information modeling) tools are specifically meant to aid in the design and construction of buildings. Architects, contractors and engineers use the software to visualize, design and coordinate the construction of a building end to end.
BIM software is similar to CAD (and technically falls under the CAD umbrella), but the difference is that all the tools are for designing a building. Both 2D and 3D modeling tools are often included in BIM, which allows for creating construction documents and visualizations.
While there is some overlap with 3D modeling programs, BIM 3D modeling tools are less robust and flexible than those in a dedicated 3D modeling software. A BIM tool may have a library of doors, windows, stairways and other objects to make the process of designing a building faster and easier.
What is CAD software?
CAD software is primarily used by various fields of engineering to design parts, tools or entire projects, such as a bridge. With the advent of 3D printing, CAD software is what’s often used to create designs for 3D printing. Typically, CAD software is used to design an object in 3D, create 2D schematics of that object for manufacturing, and then make edits to the design.
While 3D modeling is mostly used for artistic and entertainment industries and BIM is specifically for designing buildings, CAD can be used within almost any industry. With the invention of 3D printing, CAD tools are what are often used to create designs to be 3D printed. There are even several free CAD programs specifically designed for 3D printing like Tinkercad and FreeCAD.
Ultimately, your industry will likely dictate which 3D modeling solution category is best for you. If you are in an artistic industry, you will probably be using 3D modeling. If you are involved with architecture, you will likely be using BIM solutions. And if you are an engineer or wish to create things using 3D printers, you will probably use CAD products.
Regardless of your industry, these products will help you create better models more efficiently.
Lauren Fram
Lauren Fram
|
Escondido Public Library
by John Steinbeck
The Grapes of Wrath follows the Joad family as they try to escape the Dust Bowl in Oklahoma by heading out west to California to try to make a new life. Ma, Pa, and Tom carry the rest of the family, along with Jim Casy, as they face the hardships and cruelness of migrants heading west, dealing with the law, religion, and social interactions that the define the Joad's and the rest of the migrants. The unity of love and community and the idea of a whole rather than individuality during the harsh times is seen through out Steinbeck's work.
This book is one of my favorites, as it depicts the hardships of people who are trying to make a living in a fast paced society such as America. Also, how Steinbeck was able to capture what was going on in the era the book was written about through people that were going through it. The use of multiple symbols and motifs are what really made me think and what Steinbeck intended and they way he made everything fall into place.
This novel is for those who like the seriousness side of books rather than the over zealous books. This is for those who are moved by words and what is happening in their society that is affecting them. If you want to see change in questionable parts of your society, then The Grapes of Wrath will positively motivate you in doing so.
Anthony, 16
smileyFind at the Library |
Subsets and Splits
No community queries yet
The top public SQL queries from the community will appear here once available.