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"Silk from caddisfly larvae – known to western fly fishermen as 'rock rollers' – may be useful some day as a medical bioadhesive for sticking to wet tissues," says Russell Stewart, an associate professor of bioengineering and principal author of a new study of the fly silk's chemical and structural properties.
"I picture it as sort of a wet Band-Aid, maybe used internally in surgery – like using a piece of tape to close an incision as opposed to sutures," he adds. "Gluing things together underwater is not easy. Have you ever tried to put a Band-Aid on in the shower? This insect has been doing this for 150 million to 200 million years."
The new study, funded by the National Science Foundation, is set for publication this week in Biomacromolecules, a journal of the American Chemical Society.
There are thousands of caddisfly species worldwide in an order of insects named Trichoptera that are related to Lepidoptera, the order that includes moths and butterflies that spin dry silk. Because caddisflies are eaten by trout, fly fishermen use caddisfly lures. Some species spend their larval stages developing underwater, and build an inch-long, tube-shaped case or shelter around themselves using sticky silk and grains of rock or sand. Other species use silk, small sticks and pieces of leaves.
Each larva has a head and four legs that stick out from the tube. The larval case often is conical because it gets wider as the larva grows. A caddisfly larva eventually pupates, sealing off the tube as it develops into an adult fly and then hatches.
Aquatic caddisflies and terrestrial butterflies and moths diverged from a common silk-spinning ancestor some 150 million to 200 million years ago. Caddisflies now live around the world in waters ranging from fast streams to quiet marshes.
"The caddisflies' successful penetration into diverse aquatic habitats is largely due to the inventive use by their larva of underwater silk to build elaborate structures for protection and food gathering," the new study says.
Caddisflies fall into subgroups. Brachycentrus echo, the species Stewart studied, is one of the casemakers, which build their case and then drag it along with them underwater as they forage for food. Some caddisfly larva are retreatmakers, which build a stationary dome-shaped shelter glued to a rock, with a silk net to catch passing food.
From Sea Glue to Sticky Fly Silk
Stewart studies natural adhesives, including glue produced in intertidal ocean waters by the sandcastle worm. It has potential as glue for repairing small broken bones.
He got interested in caddisfly larva adhesive silk tape after he was contacted by a Smithsonian Institution scientist who showed him several of the tube-shaped larval cases.
"We looked inside a case through a microscope and saw these silk struts between the rocks and realized this is really interesting," he says. "So I came home and put on my fly fishing boots and started wandering mountain streams looking for caddisfly larvae."
Stewart and study co-author Ching Shuen Wang – who works in Stewart's lab – studied the caddisfly species B. echo from the lower Provo River about an hour south of Salt Lake City. Bioengineering undergraduate student Nick Ashton gathered the fly larvae and figured out how to keep them alive in the lab.
"There's just a fascinating diversity of these insects. Their adhesive is able to bond to a wide range of surfaces underwater: soft and hard, organic and inorganic. If we could copy this adhesive it would be useful on a wide range of tissue types."
Caddisfly larvae extrude adhesive silk ribbon out of an organ known as the spinneret. The products of two silk glands converge there, so the extruded adhesive looks like a double ribbon with a seam the long way. The larvae weave this sticky mesh back and forth around sand grains, sticks or leaf pieces to create the tubes they occupy.
Stewart and colleagues grew caddisfly larvae in aquariums, but with glass beads instead of the sand and rock grains found in streams. The larvae expanded their rock cases using the beads, which were glued together from the inside by wet silk ribbons.
The researchers broke off some beads to obtain clean samples of silk. They analyzed the silk using several methods, including scanning electron microscopy, which showed how silk fibers stitched together the glass beads from inside of the shelter case.
"It's like using Scotch tape on the inside of a box to hold it together," Stewart says. "It's really like a tape more than anything else – a tape that works underwater."
Stewart hasn't studied the strength of the caddisfly silk, but plans to do so.
"Individual threads aren't very strong, but it lays down dozens of them. If we can copy this material and make tape out of it, the bond strength would go up dramatically."
The Chemistry and Structure of Wet Silk from Caddisflies
Stewart's study included detailed analysis of the chemistry and structure of the caddisfly silk, showing how it is similar to what silkworm moths produce for use in textiles and even to spider web silk, but with adaptations that make it work underwater.
Stewart says his goal was to characterize the adhesive silk fiber "for the purpose of trying to copy it" so a synthetic version can be used as a surgical adhesive.
he found the caddisfly silk is a fiber made of large proteins named fibroin (fye-bro-in) with an amino acid named serine making up a fifth of the amino acids in fibroin.
The key difference between dry silks from moths and butterflies and wet silks from caddisflies is that the serines in the silk from caddisflies are "phosphorylated," meaning phosphates are added to the serines as the fibroin silk protein is synthesized.
"Phosphates are well-known adhesion promoters used in dental fixtures such as crowns or fillings," says Stewart. "They are also in latex paints that are water-based, and the phosphates increase the adhesion of those paints. The paint industry discovered this fairly recently. Caddisflies have been doing this for at least 150 million years."
The phosphates attached to the serines are negatively charged. Other amino acids in the protein are positively charged. Stewart found that is a key factor in making silk underwater. Chains of proteins – each with alternating regions of positive and negative charges – line up in parallel with positive and negative charges attracting each other.
"Imagine those chains aligned side-by-side, but staggered so the pluses and minuses are lined up, which then forms silk fibers with lots and lots of these protein chains in one fiber," Stewart says. "You wouldn't be able to make shirts out of it, but you might be able to make wet Band-Aids."
Stewart made a counterintuitive finding about how wet silks are made. "These fibroin proteins that make up the silks are water-soluble because of the electrical charges. Ironically – and this is our hypothesis for now – the association of those plus or minus charges makes them water-insoluble. This is how you make a silk fiber under water."
Comparison with amino acids from three other caddisfly species found great similarities, suggesting other caddisflies also use phosphorylation to spin silk underwater.
Stewart says caddisfly silk and sandcastle worm glue are similar: their proteins are heavily phosphorylated and have a large number of positively charged amino acids.
He says the ability to make adhesives underwater now has been identified in four phyla – major categories of living organisms – that include caddisflies, sandcastle worms, mussels and sea cucumbers.
"They came to this underwater adhesion solution completely independently," showing that it repeatedly evolved because of its value in helping the creatures live and thrive, Stewart says.
For information of the University of Utah College of Engineering, see: http://www.coe.utah.eduUniversity of Utah Public Relations
Scientists uncover the role of a protein in production & survival of myelin-forming cells
19.07.2018 | Advanced Science Research Center, GC/CUNY
NYSCF researchers develop novel bioengineering technique for personalized bone grafts
18.07.2018 | New York Stem Cell Foundation
For the first time ever, scientists have determined the cosmic origin of highest-energy neutrinos. A research group led by IceCube scientist Elisa Resconi, spokesperson of the Collaborative Research Center SFB1258 at the Technical University of Munich (TUM), provides an important piece of evidence that the particles detected by the IceCube neutrino telescope at the South Pole originate from a galaxy four billion light-years away from Earth.
To rule out other origins with certainty, the team led by neutrino physicist Elisa Resconi from the Technical University of Munich and multi-wavelength...
For the first time a team of researchers have discovered two different phases of magnetic skyrmions in a single material. Physicists of the Technical Universities of Munich and Dresden and the University of Cologne can now better study and understand the properties of these magnetic structures, which are important for both basic research and applications.
Whirlpools are an everyday experience in a bath tub: When the water is drained a circular vortex is formed. Typically, such whirls are rather stable. Similar...
Physicists working with Roland Wester at the University of Innsbruck have investigated if and how chemical reactions can be influenced by targeted vibrational excitation of the reactants. They were able to demonstrate that excitation with a laser beam does not affect the efficiency of a chemical exchange reaction and that the excited molecular group acts only as a spectator in the reaction.
A frequently used reaction in organic chemistry is nucleophilic substitution. It plays, for example, an important role in in the synthesis of new chemical...
Optical spectroscopy allows investigating the energy structure and dynamic properties of complex quantum systems. Researchers from the University of Würzburg present two new approaches of coherent two-dimensional spectroscopy.
"Put an excitation into the system and observe how it evolves." According to physicist Professor Tobias Brixner, this is the credo of optical spectroscopy....
Ultra-short, high-intensity X-ray flashes open the door to the foundations of chemical reactions. Free-electron lasers generate these kinds of pulses, but there is a catch: the pulses vary in duration and energy. An international research team has now presented a solution: Using a ring of 16 detectors and a circularly polarized laser beam, they can determine both factors with attosecond accuracy.
Free-electron lasers (FELs) generate extremely short and intense X-ray flashes. Researchers can use these flashes to resolve structures with diameters on the...
13.07.2018 | Event News
12.07.2018 | Event News
03.07.2018 | Event News
19.07.2018 | Earth Sciences
19.07.2018 | Power and Electrical Engineering
19.07.2018 | Materials Sciences | <urn:uuid:1eccb08d-5017-4436-a0cf-635bdb269306> | 3.828125 | 2,369 | Content Listing | Science & Tech. | 43.045293 | 95,605,070 |
Nine anemonefish species were reared in the laboratory, and individuals were released in the field (Lizard Island, Australia and Madang, Papua New Guinea) at different distances and orientations away from natural (anemone species the fishes are found with in nature) and unnatural species of host anemones. Experiments were conducted to examine factors that could affect the settlement behaviors of the fishes: current velocity, distance and orientation of the fishes to the anemones, chemical vs visual cues, and presence of conspecific or heterospecific fishes. The fishes were usually attracted toward natural host species of anemones but not towards unnatural host anemone species nor to pieces of dead coral. Host selection during settlement provided the best explanation for the host specificity patterns displayed by anemonefishes in nature. The fishes used chemical cues released from the anemones to identify and locate the appropriate host species and could effectively locate the anemones from a maximum distance of 8 m downstream. Fishes released upstream or to the side of anemones (where anemone chemicals were assumed to be reduced or absent) were much less successful in locating anemones. The ability of the fishes to locate natural host anemones was strongly reduced when there was no water current. The presence of resident anemonefishes on host species of anemones did not influence the attraction behavior of anemonefishes released downstream from the anemones. Once the released fishes got close to or entered the anemones, the resident fishes would generally bite and chase them until the recruits left the anemones. Most fishes were not stung upon initial contact with the anemones.
Mendeley saves you time finding and organizing research
Choose a citation style from the tabs below | <urn:uuid:ed1c1d39-f9d4-44b3-b619-a47b45ab7647> | 3.6875 | 364 | Academic Writing | Science & Tech. | 5.854518 | 95,605,111 |
Welcome to The Sound of Science on WNIJ.
(K) We’re answering listener questions this month and today we have another summer question. Andy asks, “Why do things look wavy when looking at them across the roadway in the summer?”
(P) Great question, Andy. There’s a lot of science in the answer. First, you likely know from experience that the air you are looking through when things look wavy is hotter than the air around it. That’s usually from heat radiating off a dark surface like the road or the hood of your car. Let’s talk about what that does to light speed.
You may have heard that light travels at a constant speed, which is true in empty space. As it passes through matter, including air and other transparent materials, it interacts with the electrons and nuclei of the atoms, slowing it down. Each solid material has a unique effect on the speed of light; we measure that as the index of refraction. Refraction is another word for bending light.
(K) What’s that got to do with things looking wavy when looking through hot air?
(P) We’re getting there. Let’s look at air. It’s a gas, so its density depends on temperature as well as pressure. The hotter the air, the less dense it is. Therefore, as it gets hotter there are fewer molecules per cubic centimeter. Fewer particles for the light to interact with as it passes through the hot air means light travels faster through hot air than through denser, cold air. So, the index of refraction of air depends on temperature.
Light bends when it goes from a medium to another medium with a different index of refraction. That’s how prisms work or…
(K) Or why my straw looks bent at the surface of the water in my glass.
(P) Yes, so as light goes through air of different temperatures, it’s going through media of different indices of refraction and is bent.
(K) So, Andy, the next time you see that wavy effect when looking over the hood of your car, think of the bumpy ride that light took to reach your eyes.
(P) Keep your questions coming by emailing them to firstname.lastname@example.org.
(K) This is the Sound of Science on WNIJ, (P) where you learn something new every day. | <urn:uuid:8ca27382-2a66-4943-9c9f-b705a626a159> | 3.6875 | 522 | Audio Transcript | Science & Tech. | 74.125455 | 95,605,137 |
Probability is a statistical measure of the chance that an event will occur. An event, in probability, describes a set of outcomes. So for example, when two die are rolled, the events (the sums of the numbers) that may happen are: 2, 3, 4, 5, 6, 7, 8, 9, 10, 11 and 12. It can be seen that 1 is not an event as a minimum of 1 must be rolled on each die. However, each event is not associated with the same probability as some of the numbers are more likely to be rolled.
For example, the sum of the numbers equaling 2 has the probability of 1/36 to be rolled – this is because there is only one combination of die rolls out of 36 which can add up to 2. On the other hand, the sum of the numbers equaling 7 has the probability of 6/36 to be rolled – this is because there are 6 combinations of die rolls out of 36 which can add up to 7. These are (1+6), (6+1), (2+5), (5+2), (3+4), (4+3).
The probability of an event is commonly written as the number of outcomes that constitute the event divided by the total number of possible outcomes, which for the number 7 is 6/36 = 1/6. Thus, it can be seen that understanding probability is a practical skill for everyday life.© BrainMass Inc. brainmass.com July 16, 2018, 11:53 pm ad1c9bdddf | <urn:uuid:1644803f-c5e0-4836-bf8a-a5b2dc187e66> | 4.21875 | 322 | Knowledge Article | Science & Tech. | 73.599597 | 95,605,141 |
Templeton, a software architect and futurist, tells of a hypothetical machine that could bring down the internet (and much of society with it). Such a machine would harness the principles of quantum mechanics and boast problem-solving capabilities both amazing and scary:
"It seems possible in theory to do very, very huge amounts of computing in quantum mechanics, sort of as some people would imagine it as though you were tapping into millions and trillions and billions of parallel universes and having computations take place in all those parallel universes until an answer is found in one and is revealed to you in your universe."
While a computer with those capabilities would in most cases be a triumph, it could also spell disaster if placed in the wrong hands. For example, much of the cryptography employed to keep our computer network secure relies on math problems that are tremendously difficult to solve. Utilizing quantum mechanics, a theoretical quantum computer would almost certainly be able to crack the code:
"And if that lock can be broken, because the quantum computer makes easy what everyone else believe to be incredibly hard, the person with the quantum computer could break most of the cryptography, all the traffic you see going across the web, a lot of the financial transaction traffic, a lot of the authentication, all of that stuff becomes vulnerable to a computer that's done that."
Thanks to Edward Snowden, it's been revealed that the NSA is currently researching how to create its own quantum computer. Templeton takes solace in that information because it means that they don't already have one. And, he points out, they may never have one. After all, the machine is only the stuff of theory at this point. If someone were able to build one, Templeton says we'd know of its existence thanks to the legions of panicking Wall Street executives.
Templeton concludes with a discussion of D-Wave, a Canadian company that has created a machine sometimes referred to as a quantum computer. The D-Wave device solves many of the difficult problems a theoretical quantum computer would, but without the ability to crack highly-complicated cryptography. Instead, it focuses on optimization:
"...having a really complex system and trying to find the most efficient, the lowest energy, the lowest cost way to deal with it. And so that type of quantum computer could help us a lot at solving big business problems, big data problems"
While neither the D-Wave or the hypothetical NSA quantum computer will ever make an appearance at your work desk, their capabilities could have a lasting effect on how the world does business. We'll just have to wait and see.
For more on the quantum computing, watch this clip from Templeton's Big Think Interview: | <urn:uuid:68887bce-b500-47a2-a170-42fb03c7cae4> | 2.859375 | 548 | Audio Transcript | Science & Tech. | 37.163878 | 95,605,152 |
Ants are one of the most regular and crucial group of insects. In 1985 Taylor and Brown categorized the Australian fauna and classified them in 9 subfamilies, with 95 genera and an approximate total of 4000 species. The chief characteristic of ants are their waist. It is usually made up of one or two knobs (which are the first one or two segments of their abdomen) instead of the single petiole of the hymnopterans. The antennae have a unique elbow, with the scape almost as long as the segments past the elbow, with protruding mandibles. Ants reside in colonies made up of several castes and sub castes: winged females, winged males and numerous sub castes of workers. Colonies generally have hundreds to several thousand individuals, though the amount is less than 100 to more than a million. Winged females and males only appear during times that are suitable for mass mating flights. The male ends up dying after mating and the females shed their wings and generally start a new colony, or sometimes end up being the part of an existing one. To start a colony the female lays a small number of eggs and then feeds the larvae till they are mature.
These first workers then own up to the function of nest building and look after this first queen who’s only remaining purpose is to lay eggs.
The worker sub castes consist of the worker minors who perform nest building, food foraging and nursery care; workers with big heads called soldiers defend the nest. Certain species have a sophisticated sub caste named repletes, which play the role of being storage vessel for the colony nectar supply.
Ant nests are generally in the ground, but you can also find them in trees and even among silk-joined leaves in the green tea ant, Oecophylla smaragdina, which dominates in the tropic region. The infamous Australian ants are aggressive stinging bull ants, which belong to the large endemic genus Myrmecia. Amid the ground nesting ants, the meat ants, Iridomyrmex are the famous red and black scavengers which dominate the more arid regions. One of the biggest genera is Polyrhachis, which consist of metallic species and the ‘golden-bum’ ants.
Ants have a diverse diet that consists of predators and scavengers, plant eaters, fungus eaters and other specialties or combination of all of these. Certain species of plants, especially in the tropics share a special bond with a particular ant species. The so-called ‘ant-plants’ have special chambers that is colonized by ants, and it also feeds the ants in return for protection from herbivores. Another ant relationship comprises of specialized species in eight other insect orders called myrmecophiles. These reside within the nests of ants either as predators or scavengers, or are actively stimulated by the ants as they excrete sweet secretions favored as ant food. Certain ants actually ‘farm’ aphids, scale insects and some butterfly larvae to meet this purpose.
The following hymenopteran groups, the sphecid wasps (formerly superfamily Sphecoidea) and the bees (superfamily Apoidea), are now considered as a part of one group under the umbrella of the family Apoidea. | <urn:uuid:849ddf52-9550-487a-aa99-79d3fb5d887a> | 3.5625 | 686 | Knowledge Article | Science & Tech. | 40.912634 | 95,605,160 |
A well above average Atlantic hurricane season is on tap for 2008, according to the latest seasonal forecast
issued today by Dr. Bill Gray and Phil Klotzbach of Colorado State University (CSU). The Gray/Klotzbach team is calling for 15 named storms, 8 hurricanes, and 4 intense hurricanes. An average season has 10-11 named storms, 6 hurricanes, and 2 intense hurricanes. The new forecast is a bump up from their December forecast, which called for 13 named storms, 7 hurricanes, and 3 intense hurricanes. The new forecast calls for an above average chance of a major hurricane hitting the U.S., both along the East Coast (45% chance, 31% chance is average) and the Gulf Coast (44% chance, 30% chance is average). The Caribbean is also forecast to have an above average risk of a major hurricane.
The forecasters cited several reasons for their forecast of an active season:
1) Above-average sea surface temperatures (SSTs) in the eastern subtropical Atlantic and cooler-than-normal SSTs in the South Atlantic have weakened the Bermuda-Azores High. This has resulted in lower surface wind speeds over the tropical Atlantic, and these weak trade winds are expected to persist into hurricane season. Weak trade winds reduce the amount of evaporative cooling of the ocean, resulting in warmer SSTs and lower surface pressures during hurricane season. Hurricanes like to form in an environment with low surface pressures and high SSTs.
2) Hurricane activity in the Atlantic is lowest during El Niño years and highest during La Niña or neutral years. The current strong La Niña event has begun weakening noticeably in the past few weeks. However, there is probably not time for a full-fledged El Niño event to replace it by hurricane season, and it is expected that we will have weak La Niña or neutral conditions this hurricane season. None of the computer models are forecasting a switch over to El Niño conditions this year (Figure 1). Keep in mind, though, that the accuracy of these long range models is poor, particularly for forecasts made in March and April.
3) We are in the midst of an active hurricane period that began in 1995.How accurate are the April forecasts?
Today's forecast includes the statement, "These real-time operational early April forecasts have not shown forecast skill over climatology" during the 13-year period 1995-2007. In other words, today's forecast has no skill, and should merely be viewed as an interesting experimental research product. I like the fact that they are trying to make useful seasonal hurricane forecasts, but we should wait until their June 3 forecast before putting faith in their 2008 hurricane season forecasts. The CSU team has posted an Excel spreadsheet
of their forecast errors (expressed as a mathematical correlation coefficient, where positive means a skilled forecast, and negative means they did worse than climatology). You can see from their numbers that the December and April forecasts have near zero skill, but the early June forecasts have substantial skill. To rectify their poor April forecast skill, the CSU team is trying a new scheme for this year's April forecast. Hopefully the new scheme will show positive skill forecasting upcoming hurricanes seasons, and not just "hindcasting" the past ones. For now, you're best off just paying attention to their early June forecast, which has been quite skillful over the past ten years.Figure 1.
Computer model forecasts of El Niño/La Niña made in March. The forecasts that go above the red line at +0.5°C denote El Niño conditions; -0.5°C to +0.5°C denote neutral conditions, and below -0.5°C denote La Niña conditions. Image credit: Columbia University's IRI
.2008 Atlantic hurricane season forecast from Tropical Storm Risk, Inc.
The British private forecasting firm Tropical Storm Risk, Inc.
(TSR), issued a 2008 Atlantic hurricane season forecast this week as well. TSR has almost the same forecast as the CSU team--14.8 named storms, 7.8 hurricanes, and 3.5 intense hurricanes. Unlike the CSU team, these numbers represent a decrease
from their December forecast numbers, which were 15.4 named storms, 8.3 hurricanes, and 3.7 intense hurricanes. I like how they put their skill level right next to their forecast numbers: 7% skill at forecasting the number of named storms, 11% skill for hurricanes, and 10% skill for intense hurricanes. That's not much better than flipping a coin, but it is better than the near-zero forecast skill of the Gray/Klotzbach April forecasts. However, TSR doesn't mention the fact that part of their skill may be due to the fact that they issue forecasts of fractional storms (we're not going to get 7.8 hurricanes this year!) If we round these numbers to whole storms, the TSR skill numbers may decrease.
TSR projects that four named storms will hit the U.S., with 1.7 of these being hurricanes. In the Lesser Antilles Islands of the Caribbean, TSR projects 1.5 named storms, 0.7 of these being hurricanes. TSR cites one main factor for their forecast of an active season: slower than normal trade winds July-September over the Caribbean. Trade winds are forecast to be 0.4 meters per second (about 1 mph) slower than average, which would create greater spin for developing storms, and allow the oceans to heat up due to reduced evaporational cooling. TSR forecasts that SSTs will be near average in the tropical Atlantic during hurricane season.Figure 2.
Accuracy of long-range forecasts of Atlantic hurricane season activity performed by Bill Gray and Phil Klotzbach of Colorado State University (colored squares) and TSR (colored lines). The CSU team's April forecast skill is not plotted, but is near zero. The skill is measured by the Mean Square Skill Score (MSSS), which looks at the error and squares it, then compares the percent improvement the forecast has over a climatological forecast of 10 named storms, 6 hurricanes, and 2 intense hurricanes. TS=Tropical Storms, H=Hurricanes, IH=Intense Hurricanes, ACE=Accumulated Cyclone Energy
, NTC=Net Tropical Cyclone Activity. Image credit: TSR | <urn:uuid:f46605a6-b1f9-427c-8f42-74a285c80652> | 2.828125 | 1,310 | Personal Blog | Science & Tech. | 51.587864 | 95,605,167 |
What do you do when the volcano whose beauty you've admired for so long suddenly wakes with a shiver and blows a plume of steam and ash into the sky?
The Scientific American Blog Network turns 1 today! Scicurious wrote a poem for the occasion.Hard to believe we're so young, innit? We've got a long-established magazine behind us, and so many veteran science bloggers, that it feels longer, at least to me.
(Apologies to Mount St. Helens fans. I didn't have this week's installment written up in advance, and now my uterus has attacked. We'll get on with the saga next week.
The earthquake activity at Mount St. Helens had built to a crescendo. When a volcano shakes this hard, it almost always spells trouble: magma rising, an eruption imminent.
This is the trouble with beginnings: the beginning is often subtle, and unrecognizable at the time. It's only in retrospect that we can go back, look at sequences of events until we find a place to stab a finger down and say, "Here.
Prelude to a Catastrophe: "One of the Most Active and Most Explosive Volcanoes in the Cascade Range"
Imagine being an extraterrestrial geologist in geostationary orbit above the Pacific Northwest in the 1970s. You're the first explorers to reach Earth (underpants-thieving aliens aside), and you haven't got a lot of data on this little blue marble.
"The town and its fluctuating fortunes are a humble reminder that much of human history has been influenced by the vagaries of the geologic processes that shape the land we inhabit, form the minerals from which we construct our civilizations, and produce the riches we covet." -Lon Abbott and Terri Cook, Geology Underfoot in Northern Arizona .
Dr. David Johnston's always there, on the volcano where he died. He was among the first geologists on the ground when Mount St. Helens woke up in March of 1980.
We knew she was dangerous. People remarked on her beauty: "Surprisingly symmetrical (pdf)," "Fuji-san of America." She was perfect, a flawless volcanic cone cloaked in deep green forests and mantled in brilliant white snow.
Dear Mount St. Helens,Thirty-two years ago, I made you a get-well card. You'd just blown your top that morning, which looked like it must have hurt to my my five year-old eyes.
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Leslie Looney is a University of Illinois astronomy professor and director of the Laboratory for Astronomical Imaging. He spoke with News Bureau physical sciences editor Lois Yoksoulian about what to expect for the Aug. 21 total solar eclipse.
What is a total solar eclipse? Are they rare?
A total solar eclipse is when the moon completely blocks out the sun - it will be dark during the day. A total solar eclipse occurs when the moon is perfectly aligned between the sun and Earth. Since the moon’s orbit is inclined by 5 degrees and a total solar eclipse can only occur when the orbits are completely aligned, total solar eclipses only happen somewhere on Earth every 18 months or so. Every 18 months is not really rare, but since only those lucky few in totality can see them, a total solar eclipse can seem rare. For example, there has not been a total solar eclipse in Illinois since 1869, two years after the founding of the University of Illinois.
Why is the Aug. 21 eclipse taking the path that it is and why is southern Illinois such a popular viewing destination?
The eclipse path is determined by the relative positions of the moon, Earth and sun, which depends on their orbits. For every eclipse path, one location will have the longest eclipse duration, which is the best place in the world to see that eclipse, discounting weather. On Aug. 21, the shadow in southern Illinois will be 71 miles in diameter and moving at nearly twice the speed of sound. So, the location of the longest duration is in southern Illinois with two minutes and 41.6 seconds. The University of Illinois viewing event will be in the closest village to the longest duration with easy I-57 access - Goreville, Ill., with two minutes and 39.8 seconds. However, anywhere in totality is a good place to see the total solar eclipse.
What will the eclipse look like along the path of totality?
The moon completely covers the sun and you are standing in the shadow of the moon. This creates an eerie and weird darkness, revealing stars and planets in the daytime and the ghostly solar corona. These, along with a small temperature drop and the confused quiet of birds and animals combine to provide the most exciting few minutes in astronomy.
What time will the eclipse happen?
In Illinois, the eclipse will take about three hours in total as the moon moves across the face of the sun. The moon makes first contact with the sun around 11:53 a.m. Over the next hour, the moon slowly blocks more and more of the sun. In southern Illinois, the moon blocks the sun completely and totality starts at 1:20 p.m., lasting up to two minutes and 41 seconds. Afterward, the moon slowly moves off the sun with the eclipse ending at 2:48 p.m. In Urbana-Champaign, totality will not occur, but the sun will be mostly blocked, which will happen around 1:21 p.m., too.
Urbana-Champaign is not along the path of totality, so what will it look like here?
The sun will be 93 percent blocked, which, surprisingly, you won’t really notice. However, if you look at the sun with eclipse glasses, it will look very cool. I encourage you to look in the shade of trees or bushes. You don’t normally notice, but the shade has tens to hundreds of little images of the sun projected by small holes in the leaves or canopy. During a partial eclipse, these will look more and more crescent-shaped as the eclipse proceeds, which is really surprising. This is one of my favorite effects during a partial eclipse.
Last but not least, what is the best and safest way to observer the eclipse?
Staring at the sun is bad for your eyes, and you can permanently damage them. Do not stare at the sun - no matter if it is eclipsing or not. Do not use sunglasses to look at the sun - that is even worse than using your naked eyes. You must use eclipse glasses , which block 100 percent of harmful UV light and 99.999 percent of intense visible light. You can also make a simple pinhole camera out of a cereal box to project the image of the sun during the eclipse. During totality you will not need any eye protection - take in the beauty of the event. But once any sunlight pokes through, the eclipse glasses have to go back on. | <urn:uuid:6ed1bc6f-7cc6-42fb-9166-c8061b540488> | 3.3125 | 909 | Audio Transcript | Science & Tech. | 61.474496 | 95,605,210 |
- Capillarity and capillary action
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Draw a neat, labelled diagram for a liquid surface in contact with a solid, when the angle of contact is acute.
If two capillary tubes of different diameters are partially dipped in the same liquid vertically, then the rise of liquid ..........
a) is same in both the tubes
b) is more in the tube of larger ~iameter
c) will not be in smaller diameter tube
d) is more in the tube of smaller diameter
Calculate the density of paraffin oil, if glass capillary of diameter 0.25 mm dipped in paraffin oil of surface tension 0.0245 N/m rises to a height of 4 cm. (Angle of contact of paraffin with glass = 28° and acceleration due to gravity = 9.8 m/s2.)
A soap bubble of radius 12 cm is blown. Surface tension of soap solution is 30 dyne/cm. Calculate the work done in blowing the soap bubble. | <urn:uuid:46bd4366-b929-4324-a05d-95c3ea65e638> | 3.265625 | 218 | Tutorial | Science & Tech. | 70.642939 | 95,605,213 |
Exoplanets are also known as extrasolar planets as these planets exist outside our solar system and orbit some other stars. Special telescopes and methods are needed to find them. The first ever exoplanet was discovered in 1992 named 51 Pegasi b which was similar to Jupiter in radius. Since then hundreds of other have been found. Some of them could sustain organic life.
The closest exoplanet to the Earth is Alpha Centauri Bb. It was first discovered in 2012. They are identified using methods like transit photometry and radial velocity.
Quick Facts: –
- Till now, only two exoplanets have been directly observed using earth based telescopes.
- The oldest exoplanet that has been discovered is ‘PSR B1620-26b’. It is estimated to be around 13 billion years old.
- The lightest exoplanet discovered till now is a planet in the Gliese 581 system. Gliese 581 is a small red dwarf.
- All the exoplanets are completely different from each other.
- The habitable zone of a star can be defined as the area where liquid water could exist on a planet’s surface.
- In 2014, Kepler Mission found an earth-sized planet named Kepler 186f. It is located in the habitable zone of a star.
- PSR 1267+12 B and C are the first Pulsar planets that were found in 1992. One of them is a super earth.
- There can be various types of an exoplanet like water world, super earth, hot Jupiter, gas giant, ice giants, Exo earth, hot Neptune, chthonian planets etc.
- Kepler 11-f is a planet that orbits a sun like star. This planet itself is 2.3 times more massive as compared to the earth.
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Rotating wheel space station
A rotating wheel space station, or von Braun wheel, is a hypothetical wheel-shaped space station that rotates about its axis, thus creating an environment of artificial gravity. Occupants of the station would experience centripetal acceleration according to the following equation,
where is the angular velocity of the station, is its radius, and is linear acceleration at any point along its perimeter.
In principle, the station could be configured to simulate the gravitational acceleration of Earth (9.81 m/s2).
Both scientists and science fiction writers have thought about the concept of a rotating wheel space station since the beginning of the 20th century. Konstantin Tsiolkovsky wrote about using rotation to create an artificial gravity in space in 1903. Herman Potočnik introduced a spinning wheel station with a 30-meter diameter in his Problem der Befahrung des Weltraums (The Problem of Space Travel). He even suggested it be placed in a geostationary orbit.
In the 1950s, Wernher von Braun and Willy Ley, writing in Colliers Magazine, updated the idea, in part as a way to stage spacecraft headed for Mars. They envisioned a rotating wheel with a diameter of 76 meters (250 feet). The 3-deck wheel would revolve at 3 RPM to provide artificial one-third gravity. It was envisaged as having a crew of 80.
In 1959, a NASA committee opined that such a space station was the next logical step after the Mercury program. The Stanford torus, proposed by NASA in 1975, is an enormous version of the same concept, that could harbor an entire city.
NASA has never attempted to build a rotating wheel space station, for several reasons. First, such a station would be very difficult to construct, given the limited lifting capability available to the United States and other spacefaring nations. Assembling such a station and pressurizing it would present formidable obstacles, which, although not beyond NASA's technical capability, would be beyond available budgets. Second, NASA considers the present space station, the ISS, to be valuable as a zero gravity laboratory, and its current microgravity environment was a conscious choice.
More recently, NASA has explored plans for a Nautilus X centrifuge demonstration project. If flown, this would add a centrifuge sleep quarters module to the ISS. This makes it possible to experiment with artificial gravity without destroying the usefulness of the ISS for zero g experiments. It could lead to deep space missions under full g in centrifuge sleeping quarters following the same approach.
Stanford torus, 1975 NASA concept.
Description of a rotating wheel space station in Herman Potočnik's The Problem of Space Travel (1929)
A NASA engineer takes a walk in simulated zero gravity around a mock-up of a full-scale, 7.3 m (24 ft) diameter space station in 1964.
Many space stations and ships use a rotating design.
1968: Arthur C. Clarke's novel 2001: A Space Odyssey was developed concurrently with Stanley Kubrick's film version of 2001. In it, the rotating space station Space Station V provides artificial gravity and features prominently on the book's first-edition cover.
1984: The Peter Hyams directed film 2010 features a battleship-size, Russian built spacecraft (designed by futurist artist Syd Mead), the Leonov, which has a continuously rotating central section, providing an artificial gravity for the occupants.
1985: The novel Ender's Game features a multi-ringed station, called "Battle School," with varying levels of simulated gravity. As the characters ascend through the station towards the center, there is a noticeable decline in the feeling of gravity.
1994: The humans in the science fiction series Babylon 5 use rotating sections to provide artificial gravity. Earth Alliance space stations such as the Babylon series (hence the name of the series), transfer stations such as the one at Io near the main Sol system jump gate, and EarthForce Omega-Class Destroyers made extensive use of rotating sections to lengthen deployment times and increase mission flexibility as the effects of zero gravity are no longer a concern.
1999: The Japanese manga and anime Planetes has its main story set in "The Seven," the 7th wheel orbital station, and a 9th is under construction by 2075. In the Zenon trilogy (Zenon: Girl of the 21st Century, Zenon: The Zequel and Zenon: Z3), 13-year-old Zenon lives on a rotating space station owned by the fictional WyndComm from 2049 though 2054, but it is not designed in a way that would allow for artificial gravity through centripetal force.
2007: The "Presidium" sector of the Citadel space station in the Mass Effect series of video games comprises a rotating toroidal section connected to a docking ring, with five large "wards" radiating out from the central ring like a flower's petals. In addition, Arcturus Station, the human seat of government on the galactic stage (not shown in the games, but described in detail) is also mentioned as being a rotating Stanford torus.
2011: Most space stations in the Expanse series make use of artificial gravity by rotation, most notably Tycho Station. Even larger celestial objects like Ceres and Eros have been hollowed out and spun up to generate gravitational pull for their inhabitants.
2013: The Neil Blomkamp film Elysium has an enormous space station called Elysium (an open-roofed station 20 to 45 kilometres (12 to 28 mi) in diameter, somewhere between a much-larger open-roofed Bishop Ring and a smaller, fully enclosed Stanford Torus.) The station in the movie supports a city and habitat for the privileged upper classes of Earth.
2015: Thunderbird 5 in the ITV TV show Thunderbirds Are Go features a rotating gravity ring section on the space station which features a glass floor to observe the Earth below. The series is set in the year 2060. The NASA-designed Hermes in the film The Martian was capable of space travel to Mars.
|Wikimedia Commons has media related to Rotating wheel space station.|
- Space habitat
- Space colonization
- Stanford torus, a design for a 1.8 kilometres (1.1 mi) diameter space habitat capable of housing 10,000 to 140,000 permanent residents, proposed in 1975 by NASA.
- Bishop Ring (habitat)
- O'Neill cylinder, a 5 miles (8.0 km) diameter space settlement design proposed in 1976 by Gerard K. O'Neill.
- Man Will Conquer Space Soon!, a famous series of 1950s magazine articles detailing Wernher von Braun's plans for manned spaceflight.
- Mars Direct, proposal for a manned Mars mission. It contains a design to generate artificial gravity by tethering a "Habitat Unit" to a rocket stage and rotating them about a common axis.
- Space stations and habitats in popular culture
- Ryan, Cornelius (editor; also associate editor of Collier's magazine—it is stated on the dust jacket flap that half of the contents of the book initially appeared in the Collier’s magazine series of articles "Man Will Conquer Space Soon!") Across the Space Frontier New York: September 1952, Viking Press. See Chapter 4 by Willy Ley--"A Station in Space" Pages 98-117; frontispiece of book has Chesley Bonestell illustration of entire wheel space station in orbit above Central America; pages 106 and 107 has cutaway illustration of interior of wheel space station; page 100 mentions that it is designed for a crew of 80. In the introduction on page xii it is mentioned that the rotating wheel space station will orbit 1,075 miles above Earth and will cost $4,000,000,000 in 1952 dollars.
- Space station. Retrieved from http://www.daviddarling.info/encyclopedia/S/space_station.html.
- "Home, Sweet Home". NASA. 25 May 2001. Archived from the original on 2006-09-29.
- List of popular fiction space stations; not all centrifugal: http://tvtropes.org/pmwiki/pmwiki.php/Main/SpaceStation
- Allain, Rhett (5 June 2013). "Gravity in the Elysium Space Station". Wired.com. Archived from the original on 22 December 2016. Retrieved 22 May 2018. | <urn:uuid:46d07597-19ff-46f3-8583-d560898cd50c> | 4.40625 | 1,747 | Knowledge Article | Science & Tech. | 47.612721 | 95,605,222 |
The technology needed to cut the world’s greenhouse gas emissions by 85% by 2050 already exists, according to a joint statement by eleven of the world’s largest engineering organisations, including the UK's Institution of Mechanical Engineers (IMechE).
The problem lies with politicians and the consequent lack of legislation and finance needed to ramp up efforts to tackle climate change.
The professional bodies, together representing 1.2 million engineers, submitted their opinion to the South African Deputy High Commissioner as part of preparations for the UN Framework Convention on Climate Change which is to be held in Durban from November 28 to December 9, (COP 17).
Has Reading Council missed your bin collection? - [image: Black bin landscape s] A number of people have contacted us recently with the council missing their bin collection. This is what we would advise y...
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Space Research & Astronomy
By Bryan Dyne, 25 June 2018
The Curiosity rover and the constellation of satellites orbiting Mars are using the storm to study Martian weather and climate.
By Don Barrett and Patrick Martin, 9 February 2018
The new rocket has two purposes, neither of them connected with the advance of science: to boost the wealth of billionaire Elon Musk, and to expand the military arsenal of the Pentagon.
By Don Barrett, 18 October 2017
The initial detections by the LIGO, Virgo and Fermi collaborations were followed up by observations involving more than 3,500 astronomers.
By Bryan Dyne, 6 October 2017
The announcement comes seven weeks after the detection of the fourth gravitational wave by the two Advanced LIGO detectors and the Advanced Virgo detector.
By Don Barrett, 16 September 2017
After 20 years of insights into Saturn, its rings, its moons and the Solar System as a whole, Cassini’s mission has ended.
By Bryan Dyne, 9 August 2017
This year also marks the 20th anniversary of NASA’s Pathfinder mission, which paved the way for all subsequent Mars landers and rovers.
By Bryan Dyne, 6 June 2017
The Cassini spacecraft has uncovered molecular hydrogen in material erupting from the subsurface ocean of Saturn’s moon.
By Bryan Dyne, 24 February 2017
The discovery of the new planetary system was based on collaboration towards a common goal whose driving force was the pursuit of knowledge, not the amassing of personal wealth.
By Bryan Dyne, 21 October 2016
The Trace Gas Orbiter successfully entered orbit but data indicates that the Schiaparelli probe crash-landed.
By Bryan Dyne, 14 October 2016
The past two years of data from Rosetta have provided an unprecedented understanding of comets and the formation of our Solar System.
By Don Barrett, 27 August 2016
The main differences between Earth and the newly discovered Proxima b are the very different physical characteristics of their respective parents’ stars.
By Joe Mount, 15 August 2016
The Sloan Digital Sky Survey has enabled scientists to make the most precise measurements yet of dark energy and the acceleration of the expansion of the Universe.
By Bryan Dyne, 15 July 2016
During the past year, the NASA spacecraft has sent back images showing canyons, plains, mountains and evidence for liquid water on Pluto.
By Bryan Dyne, 5 July 2016
Juno’s mission will reveal the interior structure of Jupiter, the largest planet in the solar system, and answer significant questions about its formation.
By Bryan Dyne, 29 June 2016
The prospects of finding another planet similar to our own are steadily increasing.
By Bryan Dyne, 13 February 2016
The discovery of gravitational waves is a vindication of science and the ability of human reason to tackle and overcome the most complex problems.
By Will Morrow, 12 February 2016
The LIGO Collaboration has published the first direct detection of gravitational waves, ripples in the fabric of space and time.
By Bryan Dyne, 29 September 2015
The dark streaks observed on Mars are most likely salt deposits left behind from liquid water flows across the Martian surface.
By Don Barrett, 25 July 2015
At a time of the momentous discovery of planets around other stars, no money can be found to examine them.
By Patrick Martin, 17 July 2015
The flyby of Pluto by the spacecraft New Horizons—a scientific achievement of the first order—stands in contrast to the seemingly intractable social crises on our own planet.
By Bryan Dyne, 15 July 2015
The Pluto encounter is the first time that a spacecraft has ever visited the distant world.
By Thomas Gaist, 8 July 2015
The Pentagon is developing new space war capabilities and modernizing its nuclear arsenal to prepare for “great power struggles” against China and Russia.
By Bryan Dyne, 8 July 2015
Pluto, a world too small and distant to be seen in detail even with Earth’s best telescopes, is the farthest object explored by a space probe.
By Bryan Dyne, 22 June 2015
Over the course of its lifetime, Messenger has sent back more than 275,000 images of the planet Mercury.
By Bryan Dyne, 24 April 2015
While it is a public relations boon for NASA, Hubble's true importance lies in its continued and vast contributions to astronomy.
By Bryan Dyne, 28 March 2015
Recent evidence of nitrogen in the soil and of an ancient Martian ocean increases the likelihood that Mars once housed life.
By Bryan Dyne, 7 March 2015
Dawn is the first spacecraft to successfully orbit two extraterrestrial bodies.
By Patrick Martin, 8 December 2014
The unmanned test flight is only the first step in plans to resume US manned space flight by the year 2021.
By Bryan Dyne and Don Barrett, 1 December 2014
An international telescope array entering operation has produced the first detailed image showing a planetary system in formation around a young star
By Bryan Dyne, 15 November 2014
The landing of Philae is an important reminder that humanity is capable of great things—capabilities that are constrained not by the productive capacity of mankind, but by the organization of society.
By Don Barrett and Bryan Dyne, 13 November 2014
With its touchdown on Wednesday, the Philae module became the first spacecraft to land on the surface of a comet.
By Don Barrett, 12 November 2014
Technical limitations cannot explain the failure of mankind to maintain a constant tempo of more and more ambitious explorations throughout the solar system and into interstellar space.
By Bryan Dyne, 1 November 2014
The two space disasters in the span of one week highlight the growing prominence of private companies in space missions.
By Patrick Martin, 25 September 2014
Mangalyaan is designed to showcase the growing technical abilities of the Indian Space Research Organization, especially following the failure of a Chinese mission to Mars in 2012.
A historic first in solar system exploration
By Don Barrett, 8 August 2014
The European Space Agency probe reached its target comet after a journey of more than ten years.
By Don Barrett, 4 July 2014
Over the past decade, Cassini has continuously returned data on Saturn's rings, numerous moons and the planet itself.
By Bryan Dyne, 21 April 2014
This is the first exoplanet detected that potentially has liquid water on its surface.
By Bryan Dyne, 14 April 2014
The remake of Carl Sagan’s Cosmos, hosted by Neil deGrasse Tyson, has its moments, but does not go far enough either in its exposition of science or its criticism of anti-science.
By C. Frederick Graves, 24 March 2014
The finding by astronomers working at the South Pole provides confirmation of a key aspect of the Big Bang theory, called the inflationary hypothesis.
By Douglas Lyons, 18 March 2014
The US military is planning to launch two satellites later this year and two more in 2016 to lay the basis for space hegemony over countries such as China and Russia.
By Bryan Dyne, 9 November 2013
Data from the Kepler spacecraft has established that Earth-sized planets in the habitable zone of Sun-like stars are common in the Universe.
By Bryan Dyne, 21 October 2013
The theoretical prediction and subsequent discovery of the Higgs boson has provided a greater insight into the origin of mass of subatomic particles.
NASA scientists announce historic leap in human exploration
By Kevin Reed, 4 October 2013
Voyager 1 has done science continuously for 36 years and spanning a journey of 19 billion kilometers.
By Bryan Dyne, 6 August 2013
During its mission so far, NASA’s Curiosity rover has found strong evidence that life similar to terrestrial microbes could have existed on ancient Mars.
A decade of infrared space astronomy comes to a close
By Don Barrett, 7 May 2013
On April 29, the Herschel Space Observatory exhausted its supply of ultra-cold liquid helium coolant, required to do its most sensitive observations.
By Bryan Dyne, 22 April 2013
Earth-like extra-solar planets have been found orbiting in the “habitable zone,” where radiation levels would permit the existence of the building blocks of life.
By Bryan Dyne, 28 March 2013
NASA is halting all public outreach programs as a result of $900 million in budget cuts forced by the sequester.
By Bryan Dyne, 24 October 2012
A planet with similar mass to the Earth has been found orbiting α Centauri B, our closest interstellar neighbor.
By Bryan Dyne, 28 September 2012
Voyager 1 and 2 have flown through the Solar System for 35 years and now Voyager 1 is on the verge of becoming humanity’s first interstellar spacecraft.
By Patrick Martin, 10 August 2012
Despite efforts to portray it as a triumph for “American values,” the successful landing of the Curiosity rover was the product of collective social effort and scientific planning that is the antithesis of profit-mad individualism.
By Bryan Dyne, 7 August 2012
Curiosity, NASA’s latest Mars rover, has successfully landed on target at Gale crater.
By Don Barrett, 5 June 2012
The Sun, the planet Venus and the Earth will line up so that Venus appears to pass across the disk of the Sun.
By Aidan Claire, 17 May 2012
The European Space Agency (ESA) has announced a €1.1 billion unmanned mission to the ice moons of the planet Jupiter.
By Patrick Martin, 19 August 2011
The American manned space program is shutting down indefinitely, an event that has considerable historical significance.
By William Whitlow, 5 August 2011
The Herschel Space Observatory has identified a twisted ring of dust and gas at the centre of the Milky Way galaxy. Parts of the ring have been seen before but this is the first time it has been observed as a whole.
By Patrick Martin, 20 July 2011
The NASA mission will study the two largest asteroids, first Vesta, then Ceres.
By Bryan Dyne, 6 June 2011
The planet Gliese 581 d is believed to be twice the mass of Earth, and could sustain liquid water on the side that faces its star.
By Patrick Martin, 25 March 2011
MESSENGER is the first space mission to Mercury in more than three decades.
By Bryan Dyne and Don Barrett, 18 March 2011
The physics research conducted in 2010 has allowed for the Large Hadron Collider to extend its operations through 2011 and 2012.
By Chris Talbot, 11 March 2011
Astronomical observation directly confirms the nebular hypothesis of Kant and Laplace.
By a reporter, 18 February 2011
The fly-by took place on February 14, some 210 million miles from Earth
By Chris Talbot, 28 January 2011
NASA has confirmed this month that its Kepler space observatory has now identified the smallest yet planet outside our solar system, exoplanet Kepler-10b.
By Patrick Martin, 22 January 2011
The two robot exploration vehicles have revolutionized scientific understanding of the planet.
By Chris Talbot, 10 December 2010
The new bacteria was discovered by a research team at Mono Lake, California.
By Chris Talbot, 18 November 2010
A giant structure around our Milky Way galaxy has been discovered by the NASA Fermi Gamma-ray Space Telescope.
By Bryan Dyne, 19 July 2010
For the first time in the history of the search for planets outside the solar system, astronomers have observed a planet going from one side of its parent star to the other.
By Bryan Dyne, 13 March 2010
One month after its successful launch, NASA’s Solar Dynamics Observatory has begun capturing high-resolution images of solar phenomena at 10-second intervals.
By Bryan Dyne, 2 February 2010
NASA reported last month that Kepler, the first spacecraft dedicated to searching for planets beyond our solar system, has discovered its first five extrasolar planets. Though they are uninhabitable for Earth-like life—four of the five are even larger than Jupiter—their rapid discovery indicates that Kepler is fully capable of achieving its primary mission, finding a planet resembling Earth, in future years.
By Patrick Martin, 17 November 2009
The deliberate crashing of a US rocket into the surface of the Moon has produced evidence of “a significant amount” of water ice, a discovery that could revolutionize the exploration of the Earth’s satellite and even open the way to long-term settlement.
By Bryan Dyne, 23 September 2009
The first images from the repaired and upgraded telescope include a dazzling combination of planetary nebula, star clusters and galaxies.
By Hector Cordon, 15 August 2009
The International Year of Astronomy 2009 has been designated by the International Astronomy Union and UNESCO in honor of the 400th anniversary of the discoveries of Galileo Galilei and Johannes Kepler, two of the most important pioneers of modern astronomy.
By Patrick Martin, 20 July 2009
Forty years ago, two American astronauts became the first human beings to land on the Moon. This historic feat is all the more remarkable because manned exploration of Earth’s satellite inaugurated by Apollo 11 ended little more than three years later.
By Bryan Dyne, 23 June 2009
New instruments on the Hubble Space Telescope are currently undergoing calibration following the latest upgrade to the venerable scientific instrument.
By Bryan Dyne, 24 March 2009
On March 6, the US National Aeronautics and Space Administration successfully launched the Kepler mission, which will observe 100,000 stars in search of smaller, Earth-sized planets.
By Hector Cordon, 1 December 2008
In a breakthrough expected to foster further discoveries, two teams of astronomers have for the first time directly imaged planets orbiting stars outside the solar system.
By John Chan, 13 October 2008
China's third manned space flight, launched on September 25 and returning to earth on September 28, was its most ambitious. Some 40 years after the Soviet Union and the US, China has become only the third country to conduct a space walk.
By Robert Stevens, 14 February 2005
“If I have seen further, it is by standing on the shoulders of giants”—Sir Isaac Newton
New findings present theoretical challenge
By Peter Symonds, 17 March 1999
"There are more things in heaven and earth Horatio, than are dreamt of in your philosophy." Hamlet, Act 1, Scene V
By Joseph Bradshaw, 13 January 1997
Detailed discussion of his work and materialist outlook, and includes a focus on his attitude to Trotsky. | <urn:uuid:ce6fa104-1344-4a15-9ca7-92032ffe4a9e> | 2.875 | 3,009 | Content Listing | Science & Tech. | 38.642752 | 95,605,253 |
Unpolarized light is passing through three successive polarizers placed one after the other. Polarizing axis of Polarizer 1 is vertically arranged i.e. polarizing axis is making 0 degree angle with vertical axis. Next polarizers, Polarizer 2 and Polarizer 3 are placed in such a way that their polarizing axis are making 30 and 90 degree angle with vertical axis respectively. (a) Find the intensity of light coming out of 3rd polarizer. And (b) show what will happen if second polarizer is removed. (intensity of incident unpolarized light as 1 unit)© BrainMass Inc. brainmass.com July 20, 2018, 3:12 am ad1c9bdddf
A. When polarised light is passing through the polariser the intensity of light passes through the polariser is given by
I = Io * Cos^2(theta) ; Where, Io - intensity of incident light and theta - angle between polarization direction of incident light and axis of polarizer.
Now in our case incident light is unpolarized light beam which can be taken as a mixture of linear polarizations uniformly for all possible angles (0 degree to 360 degree ...
This solution provides a step-wise calculation guide with a detailed explanation. | <urn:uuid:3dd27b79-b997-4dc2-83b5-971100c80d55> | 3.609375 | 260 | Tutorial | Science & Tech. | 42.913667 | 95,605,277 |
Android applications can store application data in SQLite databases. In this tutorial, you learn how SQLite databases are designed and manipulated.
Here we begin by designing and using a simple SQLite database to manage chess tournament scores. This tutorial is meant as a brief overview of how SQLite databases work. This knowledge will then be used in future development tutorials to implement database-driven Android applications.
Android applications can create and manipulate their own private SQLite relational databases. Developers can also inspect and modify databases on a given Android emulator or device using the sqlite3 command-line tool provided as part of the Android SDK tool called Android Debug Bridge (adb).
In this tutorial, we assume that you have some understanding of relational databases, in theory, but require a bit of a refresher course before you use them within your Android applications. This particular tutorial does not require any tools; it’s more a theoretical exercise.
However, if you are planning to develop Android applications which rely upon SQLite databases, you will need to install the tools necessary for Android development, such as the Android SDK and the Eclipse IDE. Check out the many other helpful Android tutorials available here on Mobiletuts+ to help you work through these tasks.
What is SQLite?
SQLite is a lightweight relational database engine. SQLite is fast and has a small footprint, making it perfect for Android devices. Instead of the heavyweight server-based databases like Oracle and Microsoft SQL Server, each SQLite database is stored within a single file on disk. Android applications can choose to store private application data in a SQLite database.
Note: If you’re familiar with SQL, then SQLite will be very easy to pick up. SQLite is basically a stripped-down SQL database engine for embedded devices. For specific information about SQLite and its features, functionality, and limitations, see the SQLite online documentation.
A Quick Review of Database Fundamentals
A database is simply a structured way of storing data in a persistent fashion. Data is stored in tables. A table has columns with different datatypes. Each row in a table represents a data record. You may find it helpful to think of a table like an Excel spreadsheet. For an object oriented programming perspective, each table in a database often represents an object (represented by a class). Each table column represents a class attribute. Each record in a table represents a specific instance of that object.
Let’s look at a quick example. Let’s say you have a company database with a table called Employee. The Employee table might have five typed columns: EmployeeID (number), FirstName (string), LastName (string), Title (string) and Salary (number). You could then add a record to the data base for an employee named John Doe and a separate record for an employee named Anne Droid.
Data within a database is meant to be inspected and manipulated. Data within a table can be:
- Added (using the
- Modified (using the
- Removed (using the
You can search for specific data within a database using what is called a query. A query (using the SELECT command) may involve one table, or multiple tables. To create a query, you must specify the tables, data columns, and data values of interest using SQL command language. Each SQL command is terminated with a semicolon (;).
The Chess Tournament Database
The best way to truly understand how SQLite databases function is to work through a simple example, so let’s do so. Let’s pretend that we have an application that keeps track of player scores from a casual chess tournament. Player scores are recorded and then, at the end of a series of matches, the winner is determined. Each player’s overall tournament score is calculated from their performance on:
- Four warm-up heats (weight: 10% of overall score each)
- One semi-final (weight: 25% of overall score)
- One final (weight: 35% of overall score)
Note: For the tournament, player scores could be based upon a formula that factors in the time it took to win the game and the type and number of pieces left on the board at the end of the game. This way, a strong player will receive a high score for losing few powerful pieces and winning the game quickly. Perhaps style and attitude are included by the judges to encourage fun, light play. How scores are calculated is really not important to how we define our database; we just store them in the database. For simplicity, we will assume that scores are based on a scale of 0–100.
Designing the Database Schema
A database schema is simply the definition of the structure of the database in terms of tables, data columns and such. The schema for our tournament database is quite simple:
The TournamentScores database schema has three tables:
- The Players table contains player information.
- The Games table contains information about each game and how much it counts toward the player’s overall tournament score.
- The GameResults table contains all players’ game scores.
SQLite3 has support for the following common datatypes for columns:
REAL(floating point values)
TEXT(UTF-8 or UTF-16 string; encoded using database encoding)
Once you’ve determined which columns are necessary for each table, you’re ready to create some tables within your database schema.
Working with Tables
Let’s begin by creating the Players table. This table requires a unique player id to reference each player. We can make this the primary key (to uniquely identify a record in this table) and set its autoincrement attribute. Autoincrement means that each time a new player record is added, the record will get a new, unique player id. We also want to store the first and last name of each player-no nulls allowed.
Here we can use the CREATE TABLE SQL statement to generate the Players table:
CREATE TABLE Players ( id INTEGER PRIMARY KEY AUTOINCREMENT, fname TEXT NOT NULL, lname TEXT NOT NULL );
The Games table is very similar. We need a unique game id to reference each game. We also want a friendly name for each game and a weight value for how much the game counts towards the player’s final tournament score (as a percentage). Here’s the SQL statement to create the Games table:
CREATE TABLE Games ( id INTEGER PRIMARY KEY AUTOINCREMENT, gamename TEXT, weight REAL DEFAULT .10 CHECK (weight<=1));
You can also delete tables using the DROP TABLE statement. For example, to delete the Games table, use the following SQL command:
DROP TABLE Games;
Populating Tables with Data Records
Before we move on, let’s add some data to these tables. To add a record to the Players table, you need to specify the column names and the values in order. For example, the following SQL statement uses the INSERT command to add a record for chess player Bobby Fisher:
INSERT into Players (fname, lname) VALUES ('Bobby', 'Fisher');
While we’re at it, we’ll add two more players: Bart Simpson (a very pitiful chess player) and Garry Kasparov (perhaps the best chess player ever). At the same time, we need to add a bunch of records to the Games table. First we add the semi-final, which counts for 25 percent of the player’s tournament score:
INSERT into Games (gamename, weight) VALUES ('Semi-Final', .25);
Then we add a couple warm-up heats, which use the default weight of 10 percent:
INSERT into Games (gamename) VALUES ('Warm-up Heat 1');
Finally, we add a final worth 35 percent of the total tournament score:
INSERT into Games (gamename, weight) VALUES ('Final', .35);
Querying Tables for Results with SELECT
How do we know the data we’ve added is in the table? Well, that’s easy. We simply query for all rows in a table using a SELECT statement:
SELECT * FROM Games;
This returns all records in the Games table:
id gamename weight ----- --------------- ------ 1 Semi-Final 0.25 2 Warm-up Heat 1 0.1 3 Warm-up Heat 2 0.1 4 Warm-up Heat 3 0.1 5 Warm-up Heat 4 0.1 6 Final 0.35
Using Column Aliases and Calculated Columns
We can also create our own columns and alias them. For example, we can create a column alias called PlayerName that is a calculated column: It’s the player’s first and last names concatenated using the || operator, separated by a space:
SELECT fname||' '|| lname AS PlayerName, id FROM Players;
This query produces the following results:
PlayerName id ------------ -- Bobby Fisher 1 Bart Simpsen 2 Garry Kasparov 3
Altering Data in Tables
Bart’s (player id 2) last name is spelled incorrectly. To update the Players table to reflect the correct spelling, you can use the UPDATE command:
UPDATE Players SET lname='Simpson' WHERE playerid=2;
You can delete rows from a table using the DELETE function. For example, to delete the record we just updated:
DELETE FROM Players WHERE playerid=2;
You can delete all rows in a table by not specifying the WHERE clause:
DELETE FROM Players;
Using Foreign Keys and Composite Keys
Now that we have our Players and Games all set up, let’s create the GameResults table. This is a more complicated table. The GameResults table pairs up player ids from the Players table with game ids from the Games table and then lists the score that the player earned for the specific game. Columns, which link to other tables in this way, are often called foreign keys. We want unique player-game pairings, so we create a composite primary key from the player and game foreign keys, to uniquely identify a GameResults record. Lastly, we enforce that the scores are whole numbers between 0 and 100.
CREATE TABLE GameResults ( playerid INTEGER REFERENCES Players(id), gameid INTEGER REFERENCES Games(id), score INTEGER CHECK (score<=100 AND score>=0), PRIMARY KEY (playerid, gameid));
(Note: SQLite does not enforce foreign key constraints, but you can set them up anyway and enforce the constraints by creating triggers.)
Now it’s time to insert some data to the GameResults table. Let’s say Bobby Fisher (player id 1) received a score of 82 points on the semi-final (game id 1). You could use the following SQL command to insert the appropriate record into the GameResults table:
INSERT into GameResults (playerid, gameid, score) VALUES (1,1,82);
Now let’s assume the tournament is played and the scores are added to the GameResults table. Bobby is a good player, Bart is a terrible player, and Garry always plays a perfect game. Once the records have been added to the GameResults table, we can perform a SELECT * command to list all records in the table, or we can specify columns explicitly like this:
SELECT playerid, gameid, score FROM GameResults;
Here are the results from this query:
playerid gameid score ---------- ---------- ----- 1 1 82 1 2 88 1 3 78 1 4 90 1 5 85 1 6 94 2 1 10 2 2 60 2 3 50 2 4 55 2 5 45 2 6 65 3 6 100 3 5 100 3 4 100 3 3 100 3 2 100 3 1 100
As you can see, this listing is not particularly “human-readable”.
Querying Across Multiple Tables Using JOIN
Wouldn’t it be more helpful if the names of the players and Games were shown instead of their numeric ids? Querying and combining data in SELECT statements is often handled by performing a JOIN with multiple table sources; there are different kinds of JOINS. When you work with multiple tables, you need to specify which table that a column belongs to (especially when columns are named the same, such as with all these different id columns). You can refer to columns by their column name or by their table name, then a dot (.), and then the column name.
Let’s relist the player scores again, only this time, include the name of the game and the name of the player. Also, we limit our results only to the score for the Final (game id 6):
SELECT Players.fname||' '|| Players.lname AS PlayerName, Games.gamename, GameResults.score FROM GameResults JOIN Players ON (GameResults.playerid=Players.id) JOIN Games ON (GameResults.gameid=Games.id) WHERE gameid=6;
which gives us the following results (you could leave off the WHERE to get all Games):
PlayerName gamename score ------------------ -------------- ----- Bobby Fisher Final 94 Bart Simpson Final 65 Garry Kasparov Final 100
Executing More Complex Queries
The sky’s the limit when it comes to the queries you could perform here. For our example, the most important query is the one that tells us who won the tournament.
Here is the final query for calculating the tournament rankings:
SELECT Players.fname||' '|| Players.lname AS PlayerName, SUM((Games.weight*GameResults.score)) AS TotalWeightedScore FROM GameResults JOIN Players ON (GameResults.playerid=Players.id) JOIN Games ON (GameResults.gameid=Games.id) GROUP BY GameResults.playerid ORDER BY TotalWeightedScore DESC;
This query gathers information from several different tables using JOINs and calculates the tournament results in a readable way. So let’s look at what this query does:
- Each player’s full name is displayed as the first result column (calculated from their first and last name)
- Each player’s tournament score is displayed as the second result column (calculated from the weighted scores of all games played by a given player)
- The result records are listed in descending order based upon the tournament scores (first place, second place, etc.)
The results from this query are shown below:
PlayerName TotalWeightedScore ------------------------- ----------------- Garry Kasparov 100.0 Bobby Fisher 87.5 Bart Simpson 46.25
This concludes our exploration of a simple SQLite database example: a chess tournament database. Hopefully you’ve reacquainted yourself with relational database concepts like tables, records, and queries and familiarized yourself with many of the commonly used SQLite commands. Finally, you’ve walked through the design and usage of an example database. Now that you’ve got a handle on how SQLite databases work, you’re ready to use them within your Android applications (the topic of our next tutorial in this series).
About the Authors
Mobile developers Lauren Darcey and Shane Conder have coauthored several books on Android development: an in-depth programming book entitled Android Wireless Application Development and Sams TeachYourself Android Application Development in 24 Hours. When not writing, they spend their time developing mobile software at their company and providing consulting services. They can be reached at via email to firstname.lastname@example.org, via their blog at androidbook.blogspot.com, and on Twitter @androidwireless. | <urn:uuid:508ac447-8a6f-4c1c-a461-34c3f60d9a91> | 3.453125 | 3,314 | Tutorial | Software Dev. | 49.939388 | 95,605,278 |
posted by zetty
On a cold day, you take a breath, inhaling 0.50 L of air whose initial temperature
is −10°C. In your lungs, its temperature is raised to 37°C. Assume that the
pressure is 101 kPa and that the air may be treated as an ideal gas. What is the
total change in translational kinetic energy of the air you inhaled? | <urn:uuid:cc208919-604f-4485-8f8e-ff3f4be573f2> | 2.703125 | 87 | Q&A Forum | Science & Tech. | 75.2 | 95,605,289 |
Microsoft Excel is TheRaven's weapon of choice in the war on data. You know data. Not the StarTrek character, who didn't espouse data at all. "Data" in StarTrek was actually the exact opposite - he provided information. Excel is the single best tool for converting mass amounts of useless data into valuable information. Wholesale improvements made to technology underpinning Excel2007 led to a huge increase in capacity. Microsoft also achieved a dramatic improvement in Excel's visual tools, which include charts and graphics. All Excel2007 improvements carry through to Excel2010.
TheRaven constructed a simple image using only Excel graphics. It isn't going to win any awards but it does illustrate some of the flexibility and color options now provided with plain-vanilla Excel. It's theme expresses TheRaven's view regarding a key climate change topic. (Hint: basic chemistry).
If "basic chemistry" didn't make the lights go on, TheRaven doesn't want to be annoying. After all, no one will ever accuse TheRaven of being an artist. The image theme ("ice will melt") refers to inevitability of permanent, consequential climate change in context of a particular compound. Each object in the image represents a methane molecule, composed of one carbon atom and four hydrogen atoms.
Methane is discussed as either as a climate remediation solution or a ticking time bomb. It's posited to replace coal and possibly gasoline. Rising ocean temperatures have sparked fear over possibly catastrophic implications of methane hydrate. Such fears haven't spurred meaningful action. As of 2007, the US got 49% of it's electricity from coal, which is only three percentage points less than in 1990.
Methane in the atmosphere imposes a potent greenhouse effect. It traps multiple orders of magnitude more heat than carbon dioxide. Substitution of methane for coal or uncontrolled release due to suddenly melting of methane hydrates ends up in the same place. Substituting methane for coal would cut CO2 output in half per equivalent unit of energy. This may seem like a step in the right direction but the remaining half is still huge and this solution doesn't address the biggest carbon emitter (China) and the future reigning champ (India).
As China builds coal-fired generating plants like mad and India is desperate to supply 500,000,000 people with electricity, replacing U.S. coal with methane would lower the global price for coal. This would provide a perverse economic incentive to China and India to burn more of it. Given the relentless pace of Chinese and Indian economic growth, the net beneficial impact on global CO2 would likely be negligible. Viewing methane as part of the solution only guarantees that the only ice left on Earth will be indoors and that Mardi Gras will be looking for a new home.
UPDATE: The New York Times reviews a new HBO documentary on domestic gas drilling here.
8 months ago | <urn:uuid:7b776455-db99-4c67-8ce1-7bb425bfaee3> | 2.625 | 589 | Personal Blog | Science & Tech. | 42.325193 | 95,605,297 |
Vim is a highly configurable text editor built to enable efficient text editing. It is an improved version of the vi editor distributed with most UNIX systems.
Vim is often called a "programmer's editor," and so useful for programming that many consider it an entire IDE. It's not just for programmers, though. Vim is perfect for all kinds of text editing, from composing email to editing configuration files.
minor feature: patch 8.1.0200: spellbadword() not tested
Problem: spellbadword() not tested.
Solution: Add a test.
Micro GNU Emacs-like text editor for UNIX
major feature: Latest features and fixes from OpenBSD, as well as lots of stability fixes from static code analysis.
CMOC is a 6809-generating cross-compiler for a subset of the C language. It produces executables for the Motorola 6809 processor for the Color Computer .BIN format, the OS-9 format and for the Vectrex game console. It runs under GNU/Linux and other Unix-like environments.
minor feature: Binary literals (e.g., 0b101010 for 42).
Bit fields are now accepted by the compiler, but each field is allocated as a full char, int or long.
The manual now documents how to include an arbitrary binary file in the executable. (See the section "Merging a binary file with the executable".)
Several minor bug fixes. (See the NEWS file for details.)
Calibre is an e-book library management application, viewer and editor. It's also commonly used for e-book file format conversion and syncing to reader devices. Calibre also simplifies downloading news from the web and converting them into e-book form, and can act as content server for online access to your book collection.
minor feature: Release: 3.28 20 Jul, 2018
New features Allow creating rules to transform author names when adding books to calibre. Accessible via Preferences- gt;Adding books- gt;Adding actions
Add a similar author mapper tool to manipulate author names in the existing library. Accessible via Preferences- gt;Toolbars.
Add a similar author mapper tool for metadata downloading, accessible via Preferences- gt;Metadata download.
Comments Editor: Add options to change the case of the selected text to the right click menu
Edit book: When sorting non text files in the File list recognize numbers in the file names
calibredb catalog: Recognize file extensions even when they are not lowercase.
New news sources.
Il Post by frafra. Bloomberg Columnists by Dale Furrow
Improved news sources.
Sunday Times Magazine UK. The Economist. The Houston Chronicle. El cohete a la luna. CBC Canada.
MONARC - Method for an optimised analysis of risks
minor feature: MONARC users who open the home page in the web interface will see an image
in the bottom left corner with the text "up-to-date" in green, "update
Available" in orange or "security update available" in red.
This will make outdated version more visible for users of MONARC. This
Version checking is performed thanks to adedicated service.
The import and export functions have been improved;.
Creation of recommendation and missing field;.
Make an easy link to implement the recommendation directly from the risk view.
a in the table Risk treatment plan management.
Problem on date parsing with the date-picker with non-US browsers (when using
it is not possible to reset the duedate attribute of a recommendation
Since the introduction of the date-picker.
Review and correct the functionality of import by fusion or merge.
MONARC application: email@example.com:admin.
SSH login: monarc:password.
Mysql root login: root:bdd13ca944f684b69333d240b95db1ccf404a42f50e0bc9a371ee8033d676f47.
Mysql MONARC login: sqlmonarcuser:1b1f9eab332cd9ec3e06c9bbf7b927e29087bd10277bb38321bf6a7448b07e16.
rpmrebuild is a tool to build an RPM file from a package that has already been installed
in a basic use, rpmrebuild use do not require any rpm building knowledge
(On debian, the equivalent product is dpkg-repack)
minor feature: - apply patch from Bruce Jerrick : Handle Requires(pre,post,preun,postun)
- add new requires syntax with if ( redhat-rpm-config )
Database Subsetting and Relational Data Browsing Tool. Navigate bidirectionally through the database by following foreign-key-based or user-defined relationships. Exports consistent, referentially intact row-sets from relational databases. Removes data w/o violating integrity. Generates topologically sorted SQL-DML, hierarchically structured XML. and DbUnit datasets.
minor feature: for "Can't connect to SOCKS proxy:http" #8.
Comprehensive usability improvements of the data browser.
Animated row-to-row links.
Increased rendering quality of row-to-row link.
Automatic layouting of data browser desktop.
Using working-table-scope "LOCAL_DATABASE" led to concurrency problems and connection leaks.
Update of SQL keyword catalog to SQL 2003 standard.
Added context menu to columns view of results table.
The community platform duck.co is DuckDuckGos developer hub. Its reference implementation is written in Perl and required PostgreSQL. It includes the forum, blogs, comments, an idea collection, translation tools, development testbeds for the instant-answer extensions (Perl, via JSON API), mailing list integration, and documentation features.
minor feature: Restoring a broken image
Just import JSON symbols once.
Do not show ivalidate button for Translation in use.
Explanatory message for how Translation in use works.
Hack in a working msgstr delete instead of requiring another translation.
Make function selection more robust - check the instance is translation.
Basic filtering for bogus msgstrs to reduce admin overhead.
Bunch of dummy accessors to stop templates carping.
Return 403 for msgstr delete denied, don't just croak.
Imports and helpers.
New test user with access to all languages.
Add "good" and "bad" translations to a locale to be published.
Make sure no translation in the bad set made it to locale package.
msgstr delete: Make sure it works, access restrictions in place.
Release IA pages version: 0.214.0.
Exclude node_modules from build.
Highlight converts sourcecode to HTML, RTF, LaTeX, TeX, SVG, Pango, BBCode and terminal escape sequences with coloured syntax highlighting. Language definitions and colour themes are customizable Lua scripts. It provides a plug-in interface to tweak syntax parsing and coloring.
major feature: -fixed gcc 8 compilation warnings
-fixed Ruby string interpolation
-added support for ALAN IF
-added 107 Base16 themes https://github.com/chriskempson/base16
-updated Rust and Java reserved words lists
-moved extras/css-themes into extras/themes-resources
-GUI: added Base16 theme selection checkbox
-CLI: added --base16 option to enable the new themes
-CLI: accept - as argument to read from stdin
QMMP is an Qt-based audio-player. The user interface is similar to Winamp or XMMS, which compatible skins can be used of. It supports a plethora of audio formats, like MP3, Ogg Vorbis/Opus, FLAC, Musepack, WavePack, MOD files, AAC, Audio CDs, WMA and other ffmpeg-supported encodings, PCM, MIDI, SID, and Chiptune files. It provides DSP plugins, lyrics downloading, equalizers and visualizers, supports common audio APIs and sinks, and is cross-platform.
minor bugfix: disabling global shortcuts during configuration; improved global hotkey plugin; fixed 4 bugs; test build for MS Windows.
Mustangproject is a APL licensed java ZUGFeRD library.
ZUGFeRD is a open european invoice PDF metadata standard. Additionally to being a human-readable and printable PDF file, ZUGFeRD invoices e.g. contain amounts, payment modalities and tax rates in a machine-readable way, allowing automated invoice processing.
minor bugfix: Fixed a nullpointerexception the importer raised on some input (issue #60) files and the library available via maven again (#61).
It's now also possible to skip parse() and go from zi.extract to e.g. zi.getAmount() in the importer.
Zanata is a web-based Java editor for software translation. It exposes a REST API for external integration, can work on DocBook through PO files, property files, XLIFF and other formats. It requires JBoss EAP or WildFly and uses CDI, React, GWT and Hibernate.
minor feature: Some TypeScript errors
Re-enable TypeScript type checking.
(ZNTA-2638) remove borders from antd buttons using btn-link styling.
Feat(ZNTA-2075) styling changes to editor search and replace styling.
TypeScript compiler errors.
Feat(ZNTA-2544) remove duplicate button from dashboard settings.
Remove unused import.
Tweak tslint settings.
Merge branch 'master' into ZNTA-2638.
Merge branch 'master' into frontend-ui-.
(ZMTA-2279) revert antd select refactor, update icons to antd.
Merge branch 'master' into frontend-ui-.
(ZNTA-2279) position of glossary languageSelect icon and count.
(ZNTA-2279) alignment of languageSelect icon and count with select.
Refactor(ZNTA-2529) WIP: remove react-bootstrap css from frontend com .
Refactor(ZNTA-2529) remove unused css (WIP).
Refactor(ZNTA-2529) WIP: frontend pages, remove react-bootstrap.
: nav link.
Merge commit '5313f278e353c03649eaa4a8caa0fc8d1cda1df6' into HEAD.
Refactor(ZNTA-2529) remove react-bootstrap styling from frontend cont .
Feat(ZNTA-2075) remove unused props from SearchReplace component.
Feat(ZNTA-2075) update editor snapshot.
Enable TypeScript's strict option, ts-ignore old violations.
Refactor(ZNTA-2529) remove unused css from style.less, refactor Edita .
Merge branch 'master' of https://github.com/zanata/zanata-platform in .
Chore: Jest configuration for TypeScript.
Merge branch 'master' of github.com:zanata/zanata-platform into edito .
: typescript strict checks.
(test): upgrade account tests to Kotlin and.
(test): convert dashboard tests to Kotlin.
Merge branch 'master' of https://github.com/zanata/zanata-platform in .
: java find- exposing internal representation of Date.
Refactor(ZNTA-2529) WIP: remove react-bootstrap from frontend.
Refactor(ZNTA-2529) remove bstrapReact wrapper from frontend.
Refactor(ZNTA-2529) react-bootstrap nav to antd less file.
Refactor(ZNTA-2529) update f
Poppler is librarified PDF rendering toolkit derived from the Xpdf 3.0 code base. It can utilize X11-independent rendering backends like Cairo, Splash, or Qt4 Arthur. It's not designed for platform-agnosticy, but proper BSD/Linux integration; is used by various PDF applications (Evince, Okular, TeXStudio, pdftotext, Zathura, Xournal, Inkscape), and comes with a set of command-line tools of its own.
major bugfix: Core:
Lots of security/leak found by oss-fuzz.
Splash: Optimize some files, making them 20 faster (now for AABGR8).
Pdfsig: Compile with libc != glibc..
pass import is a password store extension allowing you to import your password database to a password store repository conveniently. It natively supports import from 20 different password managers. More manager support can easily be added.
Wireshark is a network protocol analyzer. It allows to inspect network traffic or capture it for offline analysis. It allows to deeply analyze protocols, provides a three pane package browser or a console tool. It can filter and colorize according to complex and custom rule sets. It also allows VoIP analysis, and understands a plethora of capture and compression formats.
Live data can be read from Ethernet, IEEE 802.11, PPP/HDLC, ATM, Bluetooth, USB, Token Ring, Frame Relay, FDDI, and others network types. It also includes decryption support for common protocols, and can export results.
minor feature: The following vulnerabilities have been :
BGP dissector large loop. 2 . 3 CVE-2018-14342.
ISMP dissector crash. 5 . 6 CVE-2018-14344.
Multiple dissectors could crash. 8 . 9 CVE-2018-14340.
ASN.1 BER dissector crash. 11 . 12 CVE-2018-14343.
MMSE dissector infinite loop. 14 . 15 CVE-2018-14339.
DICOM dissector crash. 17 . 18 CVE-2018-14341.
Bazaar dissector infinite loop. 20 . 21 CVE-2018-14368.
HTTP2 dissector crash. 23 . 24 CVE-2018-14369.
CoAP dissector crash. 26 . 27 CVE-2018-14367.
IEEE 802.11 dissector crash. 29 .
The following have been :
ISMP.EDP "Tuples" dissected incorrectly. ( 30 ).
Wireshark crashes when changing profiles. ( 31 ).
Crash when switching to TRANSUM enabled profile. ( 32 ).
Wireshark crashes with single quote string display filter. ( 33 14084).
randpkt can write packets that libwiretap can't read. ( 34 14107).
Crafted UDP packet causes large memory usage. ( 35 ).
Error received from dissect_wccp2_hash_assignment_info(). ( 36 14573).
Extraction of SMB file results in wrong size. ( 37 ).
Crafted UDP packet causes large memory usage. ( 38 ).
IP address to name resolution doesn't work in TShark. ( 39 14711).
proto_tree_add_protocol_format might leak memory. ( 40 ).
tostring for NSTime objects in lua gives wrong results. ( 41 14720).
DICOM dissector needs to check for packet offset overflow. ( 42 14742).
Formatting of OSI area addresses/address pregoes past the end
of the area address/address pre. ( 43 ).
ICMPv6 Router Renumbering - Packet Dissector - malformed. ( 44 14755).
WiMAX HARQ MAP decoder segfaults when length is too short. ( 45 14780).
HTTP PUT request following a HEAD request is not correctly decoded.
SYNC PDU type 3 miss the last PDU length. ( 47 ).
Reversed 128 bits service UUIDs when Bluetooth Low Energy | <urn:uuid:812f8cb0-2b16-4bab-bae4-a4c082ca0e52> | 2.640625 | 3,476 | Structured Data | Software Dev. | 52.022974 | 95,605,301 |
Osmosis is the movement of solvent molecules through a semipermiable membrane.When two solutions of the same solvent are seperated by a semipermiable membrane,solvent molecules migrate through the membrane from the solution of low concentration to the solution of high concentration.
Certain membranes allow solvent molecules to pass through them but not solute molecuels,such a membranes is called semipermiable.
Figure above depicts the operation of a semipermiable membrane.This is an experiment to demonstrate the osmosis.
A concentrated glucose solution is placed in an inverted funnel whose mouth is sealed with a semipermeable membrane.The funnel containing the glucose solution is then placed in a beaker of pure water.As the water flows from the beaker through the membrane into the funnel,the liquid level rises in stem of the funnel.
The glucose solution will continues to rise up the funnel stem until the downward pressure exerted by the solution above the membrane eventually stops the upward flow of solvent in this case water.
In general, osmotic pressure is a colligative property of a solution equal to the pressure that when applied to the solution just stops osmosis.
So, the pressure increase needed to equalize the transfer rates is called osmotic pressure Π.
Π = MRT
osmotic pressure Π of a solution is related to the molar concentration of solute M.R is the gas constant & T is the absolute temperature.
Osmotic pressure plays an important role in the bilogical chemistry because the cells of human body are encased in semipermeable membrane and bathed in body fluid.The solution surrounding the cell must have an osmotic pressure equal to that within th cell.Otherwise, water would either leave the cell,dehydrating it or enter the cell and possibly burst the membrane.
Determination of molar mass
The measurment of Π provides a convenient way to determine the molar mass of a compound.The osmotic pressure equation can be solved for the molar mass after molarity is expressed in terms of mass and molar mass;
Π = MRT so Π = mRT/V (MM)
rearrangment gives an equation for molar mass:
MM = m RT/ Π V | <urn:uuid:4e907648-dd0f-477e-9cc2-d1cc06538b6b> | 3.765625 | 479 | Tutorial | Science & Tech. | 33.574688 | 95,605,336 |
Brazil: Origins - the road to space
In 1957, the International Geophysical Year, two students from the Technical Institute of Aeronautics (ITA) in São José dos Campos, in the Brazilian province of São Paulo, wrote a letter to the US Naval Research Laboratory. Fernando de Mendonça and Julio Alberto de Morais Coutinho wanted to install a device to monitor the signals from the Vanguard Project satellites that were developed at that time. The Naval Research Laboratory accepted their proposal and a Minitrack station was set up in São José dos Campos with the aid of the Institute of Research and Development (IPD), which, like ITA, formed a part of the Brazilian Aeronautics Technical Center (???). The students had the Minitrack station ready when the Soviet Union astonished the world by launching the first artificial satellite, Sputnik, on 4th October 1957. Within a week, Mendonça and Coutinho had adapted the Minitrack station to monitor Sputnik’s transmissions. In January 1958, they were also able to receive the signals from the first American artificial satellite, Explorer-1.1 Mendonça and Coutinho can so be associated with all the people who developed Brazil’s national space research, from the very beginning.
KeywordsSpace Activity Synthetic Aperture Radar International Space Station Naval Research Laboratory Artificial Satellite
Unable to display preview. Download preview PDF.
- 1.Oliveira, F. de: Caminhos Para ? Espaç?/Pathways to Space. Institute Nacional de Pesquisas Espaciais (INPE)-São Jose dos Campos, 1991.Google Scholar
- 2.Jane’s Space Directories, 1986-2008.Google Scholar
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When during evolution did plants learn to conserve water? The first attempts in this regard have been discovered by an international research team with a moss. The findings also revealed how evolution affects molecules.
The first plants to venture out of the sea and onto land 500 million years ago were green algae. They had to cope with the fact that they were no longer constantly surrounded by water. This meant that they ran the serious risk of withering slowly in the event of a drought.
The moss Physcomitrella patens was a pioneer in water conservation matters during evolution.
(Photo: Pirex / Wikimedia Commons)
A later generation of terrestrial plants, mosses, resolved this problem quite cleverly: If water is in short supply, they do dry out slowly but as soon as they come into contact with water once more their photosynthesis starts up again and they continue to grow. Mosses manage to do this because they acquired a tolerance to dessication during their evolution as a land dweller.
Enzyme OST1 has a key function
Mosses, like all other plants, produce the stress hormone abscisic acid (ABA) when a water shortage occurs. This in turn boosts the production of special proteins that protect it from drying out, known as dehydrins. These ensure that the mosses survive a period of drought without any major loss of function. The production of these dehydrins is particularly reliant on, among other things, the enzyme OST1.
Even with more highly evolved plants, this enzyme ensures that excessive water loss is avoided. However, it does not just do that here via anti-dessication proteins, but using a second path as well: It activates the anion channel SLAC1 of the guard cells in the plant’s epidermis. Thereupon, the guard cells close the pores through which vital carbon dioxide flows into the plant, but through which water is also lost to the environment.
When did guard cells first appear during evolution? The first land-dwelling algae and also the relatively simple liverwort do not yet possess any. It is only with the more highly evolved mosses that guard cells appear, albeit only sparsely still: They are only located on a pinhead-like structure that the moss uses to disseminate its spores.
Results published in “Current Biology”
When during evolution did plants learn to control the production of dehydrins using the enzyme OST1? And when did they begin to use this enzyme to activate the anion channel of the guard cells? These questions have been answered by Würzburg plant biologists Dietmar Geiger and Rainer Hedrich with counterparts from Freiburg, Madrid, Riyadh, Uppsala, Kyoto, and West Lafayette. Their findings have been published in the journal “Current Biology”.
The researchers compared OST1 enzymes and SLAC1 channels from four different highly evolved plants: They examined the terrestrial alga Klebsormidium nitens, the common liverwort Marchantia polymorpha, the moss Physcomitrella patens, and the thale cress Arabidopsis thaliana as a representative of more highly evolved plants.
Structure of the anion channel proved decisive
It emerged that all OST1 variants do not differ markedly in their gene sequence and that they can all boost the production of dehydrins. Likewise, all OST1 variants can activate the anion channel of the thale cress. Yet, they failed with the channels of the alga and liverwort. The key to water conservation must therefore lie in the structure of the channel.
With the moss examined, which is younger in developmental history terms than the liverwort, the scientists discovered something unusual: It possesses two forms of anion channel, and one of them reacts already to OST1 – albeit very weakly. If the second, fully inactive channel is modified based on the model of the OST1-sensitive channels, it becomes increasingly active.
As a result, the research team has shown that even very early on during evolution OST1 had matured to such an extent that it is able to control dehydrin production. On the other hand, the channel SLAC1 did not acquire the ability to react to OST1 until moss emerged. “Evolution played with the structure of the channel and with its function until such time as it could be controlled by the existing ABA dehydrin signalling pathway and could assume the task of being a water conservation button,” says Hedrich.
Search for a further evolutionary playground
Does this mean that the question of the evolution of water conservation has been answered? Not yet, believes the Würzburg professor: “The guard cells of the mosses and of the later ferns react only weakly, if at all, to the water stress hormone ABA. We therefore need to examine yet when, on the path to becoming a highly evolved flowering plant, all the functional components of the ABA-dependent signalling pathway gathered in the guard cells. We presume that the playground for the optimization of this path lies in the transition from ferns to early flowering plants.”
Stomatal Guard Cells Co-opted an Ancient ABA-Dependent Desiccation Survival System to Regulate Stomatal Closure, Christof Lind, Ingo Dreyer, Enrique J. López-Sanjurjo, Katharina von Meyer, Kimitsune Ishizaki, Takayuki Kohchi, Daniel Lang, Yang Zhao, Ines Kreuzer, Khaled A.S. Al-Rasheid, Hans Ronne, Ralf Reski, Jian-Kang Zhu, Dietmar Geiger, and Rainer Hedrich, Current Biology, published online on March 19, 2015, http://www.cell.com/current-biology/abstract/S0960-9822%2815%2900131-1
Prof. Dr. Rainer Hedrich, Department of Botany I (Plant Physiology and Biophysics), University of Würzburg, T +49 (0)931 31-86100, email@example.com
Robert Emmerich | Julius-Maximilians-Universität Würzburg
World’s Largest Study on Allergic Rhinitis Reveals new Risk Genes
17.07.2018 | Helmholtz Zentrum München - Deutsches Forschungszentrum für Gesundheit und Umwelt
Plant mothers talk to their embryos via the hormone auxin
17.07.2018 | Institute of Science and Technology Austria
For the first time ever, scientists have determined the cosmic origin of highest-energy neutrinos. A research group led by IceCube scientist Elisa Resconi, spokesperson of the Collaborative Research Center SFB1258 at the Technical University of Munich (TUM), provides an important piece of evidence that the particles detected by the IceCube neutrino telescope at the South Pole originate from a galaxy four billion light-years away from Earth.
To rule out other origins with certainty, the team led by neutrino physicist Elisa Resconi from the Technical University of Munich and multi-wavelength...
For the first time a team of researchers have discovered two different phases of magnetic skyrmions in a single material. Physicists of the Technical Universities of Munich and Dresden and the University of Cologne can now better study and understand the properties of these magnetic structures, which are important for both basic research and applications.
Whirlpools are an everyday experience in a bath tub: When the water is drained a circular vortex is formed. Typically, such whirls are rather stable. Similar...
Physicists working with Roland Wester at the University of Innsbruck have investigated if and how chemical reactions can be influenced by targeted vibrational excitation of the reactants. They were able to demonstrate that excitation with a laser beam does not affect the efficiency of a chemical exchange reaction and that the excited molecular group acts only as a spectator in the reaction.
A frequently used reaction in organic chemistry is nucleophilic substitution. It plays, for example, an important role in in the synthesis of new chemical...
Optical spectroscopy allows investigating the energy structure and dynamic properties of complex quantum systems. Researchers from the University of Würzburg present two new approaches of coherent two-dimensional spectroscopy.
"Put an excitation into the system and observe how it evolves." According to physicist Professor Tobias Brixner, this is the credo of optical spectroscopy....
Ultra-short, high-intensity X-ray flashes open the door to the foundations of chemical reactions. Free-electron lasers generate these kinds of pulses, but there is a catch: the pulses vary in duration and energy. An international research team has now presented a solution: Using a ring of 16 detectors and a circularly polarized laser beam, they can determine both factors with attosecond accuracy.
Free-electron lasers (FELs) generate extremely short and intense X-ray flashes. Researchers can use these flashes to resolve structures with diameters on the...
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The EMRP project ‘Metrology for ocean salinity and acidity’ developed measurement methods, standards and tools to improve the accuracy of ocean data used for climate monitoring and modelling.
The project’s outputs enable the traceable calibration of sensor networks and satellite systems.
This will allow scientists to reliably identify small changes in long-term oceanographic data series.
1. Understanding ocean acidity
Oceans are the largest active carbon sinks on Earth. As the amount of carbon dioxide in the Earth’s atmosphere has increased, so too has the acidity of our oceans. Small changes in acidity have a significant effect on the marine eco-system. Monitoring pH is vital if we are to protect marine life and maintain the effectiveness of the ocean as a carbon reservoir.
This case study shows how the project has helped to establish the traceability chain for seawater pH with the development of primary and reference methods for pH measurements. These accurate methods have been adopted by the oceanographic community.
In addition, the project team contributed validation methods to new ISO standard for using spectrophotometric methods to determine pH in seawater. They are also working with an oceanographic institute which is the sole provider of a seawater buffer solution, which resists a change in pH when a small amount of acid is added, used to calibrate field-based oceanographic instrumentation.
Read the full ‘Understanding ocean acidity’ case study
2. Understanding our oceans
Oceans play a key role in regulating the global climate system. The interaction of oceans with the Earth’s atmosphere is strongly linked to seawater properties such as salinity. Oceans must be accurately monitored to identify long-term climate trends and measurements of their properties must be comparable regardless of where and when they are made.
This case study shows how the project provided a reference method for ocean salinity, which makes practical salinity measurements traceable. Possible long-term drifts in the chemical composition of the standard seawater solution can now be accounted for and eliminated.
Thanks to this successful project the measurement community has been invited to sit on the prestigious Joint Committee for the Properties of Seawater, the organisation responsible formaintaining and improving seawater standards. The project outputs will make a substantial contribution towards improving the accuracy of ocean salinity and density measurements which provide key input into global climate models.
Read the full ‘Understanding our oceans’ case study
3. Monitoring ocean oxygen levels
Decreasing oxygen levels in the world’s oceans, driven by increasing ocean temperatures, are expected to have a major impact on the carbon cycle and our climate, as well as ocean life.
This case study shows how a comparison exercise organised by the project has helped promote best measurement practice within the oceanography community, including a provider of environmental monitoring services and equipment developing a new oxygen sensor.
Monitoring oxygen levels in the world’s oceans is important in the development of robust models for climate change and evaluating the oceans ability to absorb carbon dioxide.
This validation paves the way to increased use of automated oxygen sensors and will lead to a significant increase in the oceanography community’s capacity to produce high-accuracy dissolved oxygen data for robust climate trend analysis.
Read the full ‘Monitoring ocean oxygen levels’ case study
Road surface photometric characteristics: measurement systems and results workshop more
Project consortium is part of the once in a lifetime endeavour to fundamentally change the principles and practice of thermometry more
International GAS Analysis Conference recognises the high quality of EURAMET project research more | <urn:uuid:8a3bbd27-7796-4511-9a08-873b227325d9> | 3.09375 | 732 | News (Org.) | Science & Tech. | 11.604037 | 95,605,353 |
How sensitive are neuronal networks to external interference? To what extent are neuronal network processes incudung the thinking patterns of the brain predefined? These questions have been investigated by Sven Jahnke, Raoul-Martin Memmesheimer and Marc Timme at the Bernstein Center for Computional Neuroscience and the Max Planck Institute for Dynamics and Self-Organisation. They have found out that, under certain conditions, neuronal networks are more predictable than was previously assumed (Physical Review Letters, Feb. 1st, 2008)
The brain is one of the most complex objects evolution has created - more than 100 billion neurons communicate with one another through a widely branched network. Neurons process information represented as electrical impulses. Each cell computes the signals of the presynaptic cells. When it generates an impulse itself, depends on the result of this calculation. Marc Timme and collaborators have now mathematically analyzed such a system of neuronal signal transmission and have verified their theory by means of computer simulations. As in the brain, the dynamics of neuronal signal transmission in the mathematical model does not follow a recognizable order; the way in which neuronal impulses are transmitted appears to be unforeseeable. But how unpredictable is such a system really?
Researchers call a system "chaotic" if slight differences in the initial states lead to very different outcomes after long times. The behavior of chaotic systems thus cannot be predicted in the long-term. "The beat of a butterfly's wing in the Amazon Jungle can cause a hurricane in Europe", as the mathematician and meteorologist Edward N. Lorenz visualized this effect in the 1960s. In 1996 researchers of the Hebrew University in Israel demonstrated in a theoretical study that the observed irregular neuronal activity of the brain may be explained by chaotic behavior. Thus, the network would develop a very different dynamics, even if only a single neuron transmitted a signal a fraction of a second earlier or later. In the last ten years many neuroscientists assumed that such chaotic behavior generally accounts for the observed irregularities.
"If patterns of neuronal activity are similar enough, they do not develop an entirely different dynamics, as would be expected from a chaotic system. Quite in contrast, they conform to one another in the long-term", Memmesheimer explains. In the brain this could contribute to the highly precise emergence of temporal activity patterns, so that information in such networks can be processed and calculated to a high accuracy.
Although the network appears to be highly irregular according to statistical measures, this is not necessarily an indication of a chaotic system. Rather, it can be predictable over a longer period of time. "We still have to examine more closely the circumstances under which the brain's reaction is predicatble rather that chaotic", Timme adds. In any case, the dynamics of neuronal networks is, even though highly irregular, not always as complicated as previously thought.
Pollen taxi for bacteria
18.07.2018 | Technische Universität München
Biological signalling processes in intelligent materials
18.07.2018 | Albert-Ludwigs-Universität Freiburg im Breisgau
For the first time ever, scientists have determined the cosmic origin of highest-energy neutrinos. A research group led by IceCube scientist Elisa Resconi, spokesperson of the Collaborative Research Center SFB1258 at the Technical University of Munich (TUM), provides an important piece of evidence that the particles detected by the IceCube neutrino telescope at the South Pole originate from a galaxy four billion light-years away from Earth.
To rule out other origins with certainty, the team led by neutrino physicist Elisa Resconi from the Technical University of Munich and multi-wavelength...
For the first time a team of researchers have discovered two different phases of magnetic skyrmions in a single material. Physicists of the Technical Universities of Munich and Dresden and the University of Cologne can now better study and understand the properties of these magnetic structures, which are important for both basic research and applications.
Whirlpools are an everyday experience in a bath tub: When the water is drained a circular vortex is formed. Typically, such whirls are rather stable. Similar...
Physicists working with Roland Wester at the University of Innsbruck have investigated if and how chemical reactions can be influenced by targeted vibrational excitation of the reactants. They were able to demonstrate that excitation with a laser beam does not affect the efficiency of a chemical exchange reaction and that the excited molecular group acts only as a spectator in the reaction.
A frequently used reaction in organic chemistry is nucleophilic substitution. It plays, for example, an important role in in the synthesis of new chemical...
Optical spectroscopy allows investigating the energy structure and dynamic properties of complex quantum systems. Researchers from the University of Würzburg present two new approaches of coherent two-dimensional spectroscopy.
"Put an excitation into the system and observe how it evolves." According to physicist Professor Tobias Brixner, this is the credo of optical spectroscopy....
Ultra-short, high-intensity X-ray flashes open the door to the foundations of chemical reactions. Free-electron lasers generate these kinds of pulses, but there is a catch: the pulses vary in duration and energy. An international research team has now presented a solution: Using a ring of 16 detectors and a circularly polarized laser beam, they can determine both factors with attosecond accuracy.
Free-electron lasers (FELs) generate extremely short and intense X-ray flashes. Researchers can use these flashes to resolve structures with diameters on the...
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12.07.2018 | Event News
03.07.2018 | Event News
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As NASA begins its third decade of global ocean and land measurements, these discoveries point to important questions about how ecosystems will respond to a changing climate and broad-scale changes in human interaction with the land.
Most of the data is gleaned from NASA's SeaWiFS (Sea-Viewing Wide Field-of-View Sensor) satellite, which continuously monitored algae blooms on surface of the planet's oceans, as well as information supplied by the space agency's Terra, Aqua and Suomi NPP weather satellites. The polar ice caps can be seen expanding and shrinking with the alternating seasons.
"As the satellite archive expands, you see more and more dynamics emerging", said Jeffrey Masek, chief of the Biospheric Sciences Laboratory at NASA.
Damiani: "Il Napoli favorito contro il Milan. Ancelotti ottimo per la Nazionale"
Grandissima sorpresa per quel che concerne la successione di Ventura sulla panchina della Nazionale italiana . Si complica la caccia a Carlo Ancelotti per la panchina della Nazionale .
NASA oceanographer Jeremy Werdell, who took part in the project, says it's like watching Earth breathe.
NASA launched this satellite in 1997, allowing them to track life on earth through 20 years of satellite imaging.
In considerably smaller Lake Erie, one of the five Great Lakes in North America, more and more contaminating algae blooms are apparent - appearing red and yellow.
Here's why Katy Perry is 'banned indefinitely' from China
The ensemble caused intense backlash, as the sunflower has become the adopted symbol of anti-China protesters one year prior. Representatives for Hadid and Victoria's Secret did not respond to INSIDER's requests for comment about the situation.
All this data can provide resources for policymakers as well as commercial fishermen and many others, according to Werdell.
And as concentrations of carbon dioxide in the atmosphere continue to rise and warm the climate, NASA's observations could also play a critical role in monitoring carbon as it moves through the Earth system.
Scientists can use the satellite imagery to help predict where crops will both thrive and suffer and inform farmers how to respond.
Mauricio Pochettino dealt Toby Alderweireld injury blow
Alderweireld has not played for Spurs since pulling up against Real Madrid in the Champions League on November 1. Basically you need to focus on what is important and not focus on the trophy too much. | <urn:uuid:14a4ab8b-b36c-4975-87ae-a6fa83401d39> | 3.1875 | 519 | Content Listing | Science & Tech. | 28.883552 | 95,605,375 |
Origin of Life. What is Life? Life resists a simple, one-sentence definition because it is associated with numerous emergent properties - properties that emerge as a result of interactions between components But, we can recognize life without defining it, by recognizing its properties:
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A universal minimal cell must contain the following::
The lipid’s charged polar head (hydrophyllic) can form a weak bond with a water molecule, but the uncharged, nonpolar tail (hydrophobic) cannot.
Deamer took mixtures of fatty acids, glycerol, and phosphates and found that in the right concentrations they formed into lipids, and in turn, the lipids spontaneously assembled into liposomes.
How did the early organic molecules and other biological molecules become self-replicating and self-regulating? | <urn:uuid:09eb2582-a618-40ed-a5b0-a91d10825949> | 3.078125 | 237 | Truncated | Science & Tech. | 20.095424 | 95,605,397 |
With help from a common aquarium pet and a recently released online database of human genetic variation, a collaborative team of Penn State researchers has found what could be the most important skin color gene identified to date.
The team, led by cancer geneticist Keith Cheng, M.D., Ph.D., a Jake Gittlen Cancer Research Foundation researcher in the Penn State Cancer Institute, at Penn State College of Medicine, Penn State Milton S. Hershey Medical Center, in collaboration with University Park anthropologist Mark Shriver, Ph.D., found that a change in just one amino acid in one gene plays a major role in determining why people of European descent have lighter skin than people of African descent.
The find could lead to further research using the protein coded by the pigmentation gene as a target for treatment of malignant melanoma, the most deadly form of skin cancer, as well as to research on ways to modify skin color without damaging it by tanning or using harsh chemical lighteners.
Megan Wald Manlove | EurekAlert!
O2 stable hydrogenases for applications
23.07.2018 | Max-Planck-Institut für Chemische Energiekonversion
Scientists uncover the role of a protein in production & survival of myelin-forming cells
19.07.2018 | Advanced Science Research Center, GC/CUNY
A new manufacturing technique uses a process similar to newspaper printing to form smoother and more flexible metals for making ultrafast electronic devices.
The low-cost process, developed by Purdue University researchers, combines tools already used in industry for manufacturing metals on a large scale, but uses...
For the first time ever, scientists have determined the cosmic origin of highest-energy neutrinos. A research group led by IceCube scientist Elisa Resconi, spokesperson of the Collaborative Research Center SFB1258 at the Technical University of Munich (TUM), provides an important piece of evidence that the particles detected by the IceCube neutrino telescope at the South Pole originate from a galaxy four billion light-years away from Earth.
To rule out other origins with certainty, the team led by neutrino physicist Elisa Resconi from the Technical University of Munich and multi-wavelength...
For the first time a team of researchers have discovered two different phases of magnetic skyrmions in a single material. Physicists of the Technical Universities of Munich and Dresden and the University of Cologne can now better study and understand the properties of these magnetic structures, which are important for both basic research and applications.
Whirlpools are an everyday experience in a bath tub: When the water is drained a circular vortex is formed. Typically, such whirls are rather stable. Similar...
Physicists working with Roland Wester at the University of Innsbruck have investigated if and how chemical reactions can be influenced by targeted vibrational excitation of the reactants. They were able to demonstrate that excitation with a laser beam does not affect the efficiency of a chemical exchange reaction and that the excited molecular group acts only as a spectator in the reaction.
A frequently used reaction in organic chemistry is nucleophilic substitution. It plays, for example, an important role in in the synthesis of new chemical...
Optical spectroscopy allows investigating the energy structure and dynamic properties of complex quantum systems. Researchers from the University of Würzburg present two new approaches of coherent two-dimensional spectroscopy.
"Put an excitation into the system and observe how it evolves." According to physicist Professor Tobias Brixner, this is the credo of optical spectroscopy....
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1. Many organisms respond to threats such as stress and predation by expressing a defended phenotype (phenotypic plasticity) or inducing the expression of a defended phenotype in offspring (transgenerational phenotypic plasticity). While defended phenotypes can increase resistance to a predator or stress, in the absence of the inducing agent defended phenotypes often have poorer performance. Producing a defended phenotype unnecessarily has been termed a phenotype-environment mismatch. 2. Most studies have focused on the benefits of a defended phenotype along a single environ-mental gradient (i.e. the presence ⁄ absence of the inducing agent) but in nature, organisms must face conditions that vary across a number of environmental gradients simultaneously. By focus-ing on the costs and benefits of a defended phenotype in a single dimension alone we risk under-estimating the strength and likelihood of phenotype-environment mismatches. 3. For the marine bryozoan Bugula neritina, we examined the performance of individuals with an induced, defended phenotype (pollution resistance) relative to individuals with an undefended phenotype across a number of different environments. We found that individuals with the defended phenotype were more sensitive to osmotic stress, but surprisingly, were less susceptible to predation than individuals with the undefended phenotype. 4. Our findings suggest that the costs and benefits associated with expressing a defended phenotype are more complex than previously realized because the full consequences of induced phenotypes are only unmasked when performance in multiple environments is examined.
Mendeley saves you time finding and organizing research
Choose a citation style from the tabs below | <urn:uuid:97b64005-d42c-428d-af0c-ad8f69f9db8e> | 3.1875 | 325 | Academic Writing | Science & Tech. | 4.579457 | 95,605,437 |
In this issue, you’ll meet a couple who are using goats to control invasive plant species on their property. Then, we’ll look at how some species have adapted to roadside habitat—to their detriment. Once we’re off the road, we’ll take you up on the roof to install solar panels. You’ll find out about how citizen scientists are using rainy day data to contribute to climate research and then, after the rain has passed, you’ll dig around in the dirt, breath in some bacteria and be healthier for it. We’ll learn that literacy goes beyond the alphabet, find out how lichen could function as a climate change indicator and come face to face with challenge, change, and rock climbing. | <urn:uuid:4dd0a8e3-3cad-49fc-a11f-46b90fef75dc> | 2.515625 | 156 | Truncated | Science & Tech. | 55.028429 | 95,605,463 |
Analysis of Cytoplasmically Inherited Mutants
Although cytoplasmic mutants have been documented in higher plants, they have not been studied as well as in lower eukaryotes, such as yeast and Chlamydomonas. Very few potential chloroplast mutations have been described in maize, in contrast to several in Chlamydomonas and some in other higher plants. (See Börner and Sears 1986.) The only examples of cytoplasmically inherited, defective plastids in maize appear to result from the action of nuclear genes, such as iojap. (See Walbot and Coe 1979.) In plants homozygous for iojap, some plastids show a loss of chloroplast pigments and ribosomes. The ribosome-less plastids are then inherited maternally. Other nuclear gene mutations that affect photosynthetic function have been identified on the basis of a high chlorophyll fluorescence phenotype (hcf; Miles 1982). Over one hundred nuclear hcf mutations have now been identified in maize, and they are all inherited as typical, recessive Mendelian factors (Miles and Metz 1985).
KeywordsCytoplasmic Male Sterility Chloroplast Pigment Mitochondrial Genotype Chloroplast Mutation Nuclear Gene Mutation
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(mē'zŏn) [Gr.,=middle (i.e., middleweight)], class of elementary particles whose masses are generally between those of the lepton class of lighter particles and those of the baryon class of heavier particles. From a technical point of view mesons are strongly interacting bosons; i.e., they participate in the strong nuclear force and are described by the Bose-Einstein statistics, which apply to all particles not covered by the Pauli exclusion principle. The lightest meson is the pion, whose mass is about 270 times that of the electron. Heavier mesons include the kaon (K meson), eta meson, and a number of higher-mass recurrences of the lighter mesons. The heaviest mesons are heavier than some baryons, such as the proton and neutron, but their classification as mesons is based on their behavior rather than on their mass. The existence of mesons was first predicted in 1935 by Hideki Yukawa, who theorized that they could be responsible for the force holding the nucleus of an atom together. In 1936 a particle was discovered by Carl D. Anderson and Seth Neddermeyer that had a mass close to that predicted for the Yukawa particle. However, the behavior of this particle, the muon, did not correspond to that of the theory at all. The muon was subsequently reclassified as a lepton rather than a meson. The particle predicted by Yukawa was the pion, which was not discovered until 1947 by C. F. Powell and coworkers. Both the muon and the pion were first observed in secondary cosmic rays, being produced in the upper atmosphere by collisions between primary cosmic rays and the atoms of the atmosphere. Since then mesons have been produced and observed in large numbers in laboratories where high-energy particle collisions can be achieved with the aid of a particle accelerator. It is now known that each type of meson consists of a quark bound to an antiquark.
Subatomic particle , member of a subgroup of hadrons , all of which have either zero or integral spin . They include the pions, kaons, and...
(pì'ŏn) or pi meson, lightest of the meson family of elementary particles. The existence of the pion was predicted in 1935 by Hideki Yukawa, who theo
Any member of a family of subatomic particles composed of a quark and an antiquark (see antimatter). Mesons are sensitive to the strong force, have | <urn:uuid:cdbb03d9-f1e5-4451-bb40-b0490707b5b8> | 3.734375 | 528 | Knowledge Article | Science & Tech. | 50.630577 | 95,605,497 |
Determination of Gold Nanoparticle Sizes
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- Daron Chua
In this experiment, the objectives of this experiment was to understand the diverse applications of gold nanoparticles and to synthersize Colloidal gold nanoparticles by "liquid chemical method".
Z-average of nanoparticles for the reddish solution and the greyish solution was 60.86 and 50.40 respectively. However it was noted that there were impurities in the solution hence affecting the Z-average. As such, the colour of the solution and the Z-average did not tally.
It was discovered that by adding salt into the solutions there will be colour change. This is due to NaCl aggregating the nanoparticles together. This causes the nanoparticles to absorb the red light hence reflecting the solution in a more blue colour.
Other methods of forming gold nanoparticles and a diverse application for gold nanoparticles were noted.
The objectives of this experiment was to understand the diverse applications of gold nanoparticles. Colloidal gold nanoparticles were synthesized by means of "liquid chemical method".
Liquid Chemical Method
Most of the gold nanoparticles are produced in a liquid ("liquid chemical methods") byreduction of hydrogen tetrachloroautate (H[AuCl4]). By dissolving H[AuCl4], the solution is rapidly stirred while a reducing agent is being added. This causes Au3+ ions to be reduced to neutral goldatoms. As more and more of these gold atoms form, the solution becomes supersaturated, and gold gradually starts toprecipitatein the form of sub-nanometer particles. The rest of the gold atoms that form stick to the existing particles, and, if the solution is stirred vigorously enough, the particles will be fairly uniform in size showing the solution as red.To prevent the particles from aggregating, some sort of stabilizing agent that sticks to the nanoparticle surface is usually added. Also, gold colloids can be synthesized without stabilizers bylaser ablationsin liquids. They can be functionalized with various organic ligands to create organic-inorganic hybrids with advanced functionality.
Several methods that revolve around this idea are Turkevich method, brust method and perrault method, etc.
Colloidal goldis a suspension particles ofgoldin a fluid, usually water. The liquid is usually either an intense red colour (for particles less than 100nm) or blue/purple (for larger particles).
As particle size increases, the wavelength of surface plasmon resonance related absorption shifts to longer, redder wavelengths. Red light is then absorbed, and blue light is reflected, yielding solutions with a pale blue or purple color. A change in temperature will also affect which the gold to be at a different energy band. The diameter of gold nanoparticles determines the Wavelength of light absorbed as shown on the diagram illustrated above.
- 0.1g of H[AuCl4] was dissolved in 500ml distilled water to obtain 1.0mM hydrogen tetrachloroautate.
- 0.5g of Na3C6H5O7.2H2O (trisodium citrate dehydrate) was dissolved in 50ml of distilled water to obtain 1% concentration.
- 0.5g of NaCl was dissolved in 10ml of distilled water.
- 20ml of 1.0mM H[AuCl4] was added to a conical flask.
- The conical flask was placed in a stirring hot plate and a magnetic stir bar was added.
- 2 samples were prepared. One was stirred continuously even it was at boiling point. The other sample stopped stirring once it was boiled.
- 2ml of 1% solution of trisodium citrate dehydrate was then added to the boiling solution. Gold Sol was gradually formed as citrate reduces the gold (III).
- Presence of a colloidal suspension was observed by the reflection of a laser beam from the particles.
- The solution of both samples were being transferred to two test tubes.
- 5 - 10 drops of 1M NaCl solution was added into one of the test tubes and the color change of the solution was being observed.
- The two solutions in the test tubes were being filtered with a 0.45 um syringe filter. The solutions were subsequently transferred into a sample holder.
- The "Malvern" Zetasizer Nano S Light scattering equipment was used to measure the size of the nanoparticles in the two sample holder. (0.47 refractive index was used.)
Results as follows :
Solution with spin even at boiling point :
Colour observed : Reddish Brown
Size of Gold nanoparticle : 63.77 with 3 peaks
Peak 1 : 41.1, Peak 2 : 433.2, Peak 3 : 3913
Solution without spin at boiling point :
Colour observed : Greyish / Bluish / Clear
Size of Gold nanoparticle : 53.31 with 3 peaks
Peak 1 : 143.9, Peak 2 : 1.651, Peak 3 : 3213
67.54nm - 63.63nm = 2.91nm
Size of Gold nanoparticle (Reddish/Brown) Z-Average
63.77nm - 2.91nm = 60.86 nm
Size of Gold nanoparticle (Greyish/Blue) Z-Average
53.31nm - 2.91 nm = 50.40 nm
From the results, Z average for the reddish brown solution was calculated at 60.86nm, while the greyish/blue was calculated at 50.40nm.
With reference to theory, the results concluded by Z-average is inaccurate. By right, anything at the blue shift is of a larger particle size. By reading off the highest intensity peaks of both graphs of red and blue solutions, size of particles were 41.1nm and 143.9nm respectively. Ideally 1 peak in the chart would be best.
Other peaks that affected the Z-average were probably impurities. This error may be due to carelessness of assuming all equipments provided for the experiment were clean. Hence there could be dirt or dust trapped whatsoever.
In order to obtain even smaller particle sizes, adding of all solutions should have been done slowly, for example adding trisodium citrate drop by drop, allowing the droplet to fully react with the solution before adding in another. With that, the mixing part is no doubt the most crucial process parameter of the experiment.
Other factors that affect particle sizes are mixing time and temperature and concentration. Different temperatures within the reaction will cause heat and mass transfer gradients. A low concentration of solution will yield too low of a result and lastly for our case, mixing time. Insufficient mixing time/stoppage of mixing will disallow the nanoparticles to disperse. Hence having a larger particle size.
1. Explain the functions of trisodium citrate used in this experiment.
In this experiment, Trisodium citrate acts as an reducing agent to reduce hydrogen tetrachloroautate in order to produce spheroidal gold paticles. In general, the greater the concentration and power of the reducing agent. The smaller the resultant gold particles in the suspension.
2. Account for the colour change observed in step 4.6
In step 4.6 of the practical booklet, NaCl solution is added into the solution causing a colour change. By adding NaCl into the solution, it causes the gold nanoparticle surface charge to turn neutral, causing the nanoparticle to aggregate. As a result the solution colour changes from red to black - blue. As for the greyish - bluish solution, it turns to a even clearer solution.
A larger particle size will cause absorption of the red light hence reflecting the solution as blue.
3. State two other synthesis methods for gold nanoparticles beside the "liquid chemical" method.
One method for the experimental generation of gold particles is by sonolysis. The process is based on ultrasound. It uses the reaction of an aqueous solution of HAuCl4withglucose. The reducing agentsare hydroxyl radicals and sugar pyrolysis radicals. The morphology obtained is that of nanoribbons with width 30–50nm and length of several micrometers. These ribbons are very flexible and can bend with angles larger than 90°. When glucose is being replaced by cyclodetrin (a glucose oligomer), only spherical gold particles are obtained.
Block Copolymer-mediated Method
Other method for gold nanoparticles is by using a block copolymer.In this synthesis methodology, block copolymer plays the dual role of a reducing agent as well as a stabilizing agent.
The formation of gold nanoparticles comprises three main steps:
- reduction of gold salt ion by block copolymers in the solution and formation of gold clusters,
- adsorption of block copolymers on gold clusters,
- and further reduction of gold salt ions on the surfaces of these gold clusters for the growth of gold particles in steps.
This method usually has a limited-yield (nanoparticle concentration), which does not increase with the increase in the gold salt concentration. Recently a test has been done that by adding trisodium citrate in 1:1 molar ratio increases the gold formation by many gold.
4. Cite some other application in addition to those mentioned under "introduction".
- Electronics - Gold nanoparticles are designed for use as conductors from printable inks to electronic chips. As the world of electronics become smaller, nanoparticles are important components in the chip design. Nanoscale gold nanoparticles are being used to connect resistors, conductors, and other elements of an electronic chip.
- Probe - Gold nanoparticles are relatively dense, making them useful as probes for transmission electron microscopy.
- Catalyst - Gold nanoparticles are used as catalysts in a number of chemical reactions. The surface of a gold nanoparticle can be used for selective oxidation or in certain cases the surface can reduce a reaction (nitrogen oxides). Gold nanoparticles are being developed for fuel cell applications. These technologies would be useful in the automotive and display industry.
In conclusion, the experiment was not very successful as there were impurities in the solution. Hence the Z average was being affected. However objectives were met as colloidal gold was being synthesized and applications of gold particles were also understood.
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Global warming and solar anomaly
During 2002-2008, there was no increase in global temperature, though green house gas concentrations had increased. Sun is the ultimate source of energy. It has been, therefore, examined if there was any anomaly in the solar characteristics during this period. The sunspot number data has been used for this purpose. This parameter has an 11-year solar activity cycle and the same is found in the global temperature. But the trend in sun’s output, after removing solar activity effect, does not match with the long term trend of global temperature. Peculiarities in the duration and in the peak value of solar cycle 23 were identified which might have portended the increase of global temperature during 2002-2008. The possibility of the pause of increase in temperature could also be that the heat generated due to the increase in the greenhouse gas concentration was absorbed in deep ocean layer.
Global temperature, Sunspot number, Solar flux (10.7 cm), Total solar irradiance, Total ozone
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Cut a line segment of 15 cm into two line segments so that their lengths are in ratio 2:1. What length will each have?
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The conversion of forests, grasslands, shrublands and wetlands to cropland over the course of three centuries profoundly changed the surface of the Earth and the carbon cycle of the terrestrial ecosystem in Northeast China.
In a new study published in the Beijing-based journal SCIENCE CHINA Earth Sciences, a team of researchers from Beijing Normal University, Nanjing University of Information Science & Technology, and the Institute of Geographic Sciences and Natural Resources Research of the Chinese Academy of Sciences, present new calculations on carbon emissions triggered by the expansion of cropland in this region between 1680 and 1980.
"Using regional land cover reconstructions from historical records, with a bookkeeping model, we estimated the carbon sink changes caused by historical cropland expansion in Northeast China during the past 300 years," state researchers Li Beibei, Fang Xiuqi, Ye Yu and Zhang Xuezhen.
In a new study titled, "Carbon emissions induced by cropland expansion in Northeast China during the past 300 years," these researchers state that during the three centuries until 1980, approximately 38% of the grassland and 20% of the forest and shrubland were converted to cropland.
"The carbon emission induced by cropland expansion between 1683 and 1980 was 1.06–2.55 Gt C（gigaton of carbon）," they state..
"The primary source of carbon emissions was forest reclamation (taking 60% of the total emissions in the moderate scenario), the secondary source was grassland cultivation (taking 27%), and the tertiary sources were shrubland and wetland reclamation (taking 13%)," they add.
"The carbon emission estimation in this study was lower than those in previous studies," they explain, "because of the improved land use data quality and various types of land use change considered."
These researchers reconstructed land cover during the period 1680-1980 by consulting historical documents including government files, Russian investigations in Northeast China, documents of the Manchurian Railway, and official statistics.
Both deforestation and grasslands reclamation for agricultural development has triggered large carbon emissions into the atmosphere. Land cover across Northeast China experienced dramatic changes during that period because of large-scale migration and agricultural development.
After Manchu warriors seized control of Beijing in 1644, they established the Qing Dynasty but closed off their homeland in northern Manchuria to migration by common Han Chinese citizens.
"The Qing Dynasty government then changed its policy from prohibiting to encouraging Han's migration for agriculture in the second half of the 19th century," state the researchers.
“The Hans’ migration and subsequent land reclamations resulted in a rapid increase of carbon emissions to 0.197 Gt C in 1850–1899, 0.758 Gt C in 1900–1949, and 0.371 Gt C in 1950–1980,” they explain.
From 1683 to 1980, between 35.5×103 and 97.4×103 square kilometers of forest were converted into cropland, along with 93.4×103 to 94.7×103 square kilometers of grassland, 23.1×103 to 61.8×103 square kilometers of shrubland, and 10×103 to 11.1×103 square kilometers of wetland.
Migration and the conversion of forests and grasslands into cultivated land proceeded northward, through what are now called Liaoning Province, Jilin Province, and Heilongjiang Province, from the end of the 1800s onward.
"Since 1900," the co-authors of the new study explain, "carbon emissions from Heilongjiang Province have greatly increased and even exceeded the total emissions of the other two provinces."
"During the 20th century," they add, "the largest increase in cropland occurred in Heilongjiang Province."
The co-authors of the new paper also explain that while previous studies focused mainly on carbon emissions from land use changes in terms of forest ecosystems, their research found that the conversion of non-forest ecosystems likewise played an important role in developing cropland and triggering carbon emissions.
"The carbon loss per unit area of the forest reclamation was larger than that in other, non-forest ecosystems, which caused the estimation in this study to be lower than Houghton et al.'s (2003) and Ge et al.'s (2008a) estimates," they state.
"The estimates of emissions from this study were lower than those from Houghton et al. (2003) and Ge et al. (2008a)," they add, "because this study used higher spatial resolution land use data based on historical documents and included disturbances of non-forest ecosystems such as steppe, shrub, and swamp."
This work was supported by the China Global Change Research Program (Grant No. 2010CB950103), the National Natural Science Foundation of China (Grant Nos. 40901099, 40571165), the Fundamental Research Funds for the Central Universities (Grant No. 2009SAP-2), and the Scientific Research Funds of Nanjing University of Information Science & Technology (Grant No. S8112090001).
See the article:
Li B B, Fang X Q, Ye Y, et al. 2014. Carbon emissions induced by cropland expansion in Northeast China during the past 300 years. SCIENCE CHINA: Earth Sciences, 57: 2259–2268, doi: 10.1007/s11430-014-4894-4
SCIENCE CHINA Earth Sciences is produced by Science China Press, a leading publisher of scientific journals in China that operates under the auspices of the Chinese Academy of Sciences. Science China Press presents to the world leading-edge advances made by Chinese scientists across a spectrum of fields. http://www.scichina.com/english/
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“The orca’s main source of food is Chinook salmon. And the whales are suffering from malnutrition,” said NOAA Fisheries Scientist Mary Ruckelshaus.
“But by increasing salmon production in hatcheries, the whales’ appetites may be fed at the expense of recovering wild Chinook. Releasing large numbers of salmon raised in hatcheries can lead to the decline of wild salmon.”
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Simple construction, analysis and modification of binary data.
bitstring is a pure Python module designed to help make the creation and analysis of binary data as simple and natural as possible. BitStrings can be constructed from integers (big and little endian), hex, octal, binary, strings or files. They can be sliced, joined, reversed, inserted into, overwritten, etc. with simple functions or slice notation. They can also be read from, searched and replaced, and navigated in, similar to a file or stream.
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Individuals show great diversity in their ability to identify scents and odors. More importantly, males and females greatly differ in their perceptual evaluation of odors, with women outperforming men on many kinds of smell tests.
Sex differences in olfactory detection may play a role in differentiated social behaviors and may be connected to one's perception of smell, which is naturally linked to associated experiences and emotions. Thus, women's olfactory superiority has been suggested to be cognitive or emotional, rather than perceptual.
Previous studies investigating the biological roots of greater olfactory sensitivity in women have used imaging methods that allow gross measures of brain structures. The results of such studies have been controversial, leaving unanswered the question of whether differences in olfactory sensitivity have biological roots or whether they represent a mere by-product of social and cognitive differences between genders.
The isotropic fractionator, a fast and reliable technique previously developed by a group of researchers at Federal University of Rio de Janeiro, measures the absolute number of cells in a given brain structure such as the olfactory bulb, which is the first brain region to receive olfactory information captured by the nostrils.
Using this technique, a group of researchers led by Prof. Roberto Lent from the Institute of Biomedical Sciences at the Federal University of Rio de Janeiro and the National Institute of Translational Neuroscience, Ministry of Science and Technology in Brazil, has finally found biological evidence in the brains of men and women that may explain the olfactory difference between genders.
The group examined post-mortem brains from seven men and 11 women who were all over the age of 55 at the time of death. All individuals were neurologically healthy and none worked in professions requiring exceptional olfactory abilities, such as coffee-tasting or professional cooking. By calculating the number of cells in the olfactory bulbs of these individuals, the group (that also included researchers from the University of São Paulo, the University of California, San Francisco, and the Albert Einstein Hospital in São Paulo) discovered that women have on average 43% more cells than men in this brain structure. Counting neurons specifically, the difference reached almost 50% more in women than men.
The question remains whether this higher cell number accounts for the differences in olfactory sensitivity between sexes. "Generally speaking, says Prof. Lent, larger brains with larger numbers of neurons correlate with the functional complexity provided by these brains. Thus, it makes sense to think that more neurons in the female olfactory bulbs would provide women with higher olfactory sensitivity".
The fact that few cells are added to our brains throughout life suggests that women are already born with these extra cells. But why do women's brains have this pre-wired ability? What mechanisms are responsible for this higher number of cells in their olfactory bulbs? Some believe this olfactory ability is essential for reproductive behaviors such as pair bonding and kin recognition.
If this holds true, then superior olfactory ability is an essential trait that has been inherited and then maintained throughout evolution, an idea expressed by Romanian playwright Eugene Ionesco when he said "a nose that can see is worth two that sniff".
The research paper entitled Sexual dimorphism in the human olfactory bulb: females have more neurons and glial cells than males has been published on PLOS ONE and is available at http://dx.plos.org/10.1371/journal.pone.0111733
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red dwarf Any of a large group of main-sequence stars, mainly M and K stars, that are much cooler, smaller, and less massive than the Sun (about 0.1–0.7 MO ). The convective motion within these stars, in combination with their rotation, generates a magnetic field, and the stars display a range of magnetically initiated phenomena similar to and sometimes more energetic than those occurring on the Sun. These include starspots, flares, and hot chromospheres and coronae. See also flare stars; dwarf star. | <urn:uuid:1fe0b4a7-b349-4190-b38f-7137ed89c46f> | 3.484375 | 139 | Structured Data | Science & Tech. | 45.655357 | 95,605,557 |
Chapter 5 Photosynthesis and Cellular Respiration. Section 5-1. Directly/indirectly, almost all energy in LTs needed for metabolism comes from the sun . Section 5-1. Building Molecules that Store Energy: Photosynthesis : process by which light energy is converted to chemical energy.
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Stage 2: Production of ATP via Krebs Cycle
Krebs cycle: series of rxns in the mitochondria where 6 NADH, 2 FADH2, and 2 ATP are made | <urn:uuid:f60dc0be-f175-4f37-90b9-0a412276f9af> | 2.5625 | 169 | Truncated | Science & Tech. | 44.879286 | 95,605,589 |
Species Detail - Stygnocoris sabulosus - Species information displayed is based on all datasets.
Terrestrial Map - 10kmDistribution of the number of records recorded within each 10km grid square (ITM).
Marine Map - 50kmDistribution of the number of records recorded within each 50km grid square (WGS84).
insect - true bug (Hemiptera)
18 February (recorded in 1895)
20 October (recorded in 1994)
National Biodiversity Data Centre, Ireland, Stygnocoris sabulosus, accessed 22 July 2018, <https://maps.biodiversityireland.ie/Species/85741> | <urn:uuid:16f9a558-3ac4-430e-a9be-eb518c7bc4f8> | 2.59375 | 145 | Structured Data | Science & Tech. | 32.087233 | 95,605,627 |
+44 1803 865913
Edited By: Peter T Bobrowsky and Hans Rickman
In 1908 an atmospheric explosion in northern Siberia released energy equivalent to 15 Mton of TNT. Can a comparable or larger NEO affect us again? When the next NEO strikes Earth will it be large enough to destroy a city? Will the climate change significantly? Can archaeology and anthropology provide insights into the expected cultural responses with NEO interactions? Does society have a true grasp of the actual risks involved? Is the Great Depression a good model for the economic collapse that could follow a NEO catastrophe? This volume provides a necessary link between various disciplines and comet/asteroid impacts.
The Geologic Record of Destructive Impact Events on Earth.- The Archaeology and Anthropology of Quaternary Period Cosmic Impact.- Celestial Objects and Events in Archaeology and Popular Culture.- The Asteroid Impact Hazard and Interdisciplinary Issues.- Understanding the Near-Earth Object Population.- Physical Properties of NEOs and Risks of an Impact.- Evaluating the Risk of Impacts and the Efficiency of Risk Reduction.- Physical Effects of Comet and Asteroid Impacts.-Frequent Ozone Depletion Resulting from Impacts of Asteroids and Comets.- Tsunami as a Destructive Aftermath of Oceanic Impacts.- The Climatic Effects of Asteroid and Comet Impacts.- The Tunguska Event.- Atmospheric Megacryometeor Events Versus Small Meteorite Impacts.- Social Science and Near-Earth Objects.- Perception of Risk from Asteroid Impact.- Hazard Risk Assessment of a Near Earth Object.- Social Perspectives on Comet/Asteroid Impact Hazard.- The Societal Implications of a Comet/Asteroid Impact on Earth.- Disaster Planning for Cosmic Impacts.- Insurance Coverage of Meteorite, Asteroid and Comet Impacts.- The Economic Consequences of Disasters due to Asteroid and Comet Impacts.- Communicating Impact Risk to the Public.- Impact Risk Communication Management.- Towards Rational International Policies on the NEO Hazard.- A Road Map for Creating a NEO Research Program in Developing Countries.
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A Real Time Research Documentary on Mass Extinction
and an urgent Call for Action on Climate and Biodiversity
For significant updates, follow @dhushara on Twitter
This page maintains a real-time update of human impact on the biosphere, focused on global warming
and catastrophic climate change,
species extinction, deforestation, habitat loss, population and other issues, so that the reader can keep pace with the emerging situation.
This is a situation we are all very well aware of and it is critical to the future of Earth and the viablility of humanity as a species
that every single one of us makes it our prime and central aim in life to personally ensure that the world remains naturally resilient,
to provide future generations with a reasonable prospect of continued survival. Action is absolutely essential and urgent!!
A WORLD WARNING: Populism, Tribalism and the Future of Planet Earth
Any source research articles included are password protected to protect copyright.
Use these only for genuine research purposes. The password is .
Comparison of the evolution of the universe from the big bang and the evolution of life shows that life on Earth has existed for a full third of the universes lifetime and can thus be considered a long-term stable feature of cosmic evolution. Astronomical events, including impacts and possibly also nearby supernovae, have always played a major role in causing mass extinctions, accompanied by ensuing volcanism possibly as a secondary consequence of the impacts themselves. However the advent of global human impact on the biosphere is threatening in the next century to cause a mass extinction more serious than the extinction event that wiped out the dinosaurs. This process is caused both by direct impacts such as deforestation and habitat destruction, by the effects of potentially irreversible climate crisis, the sheer effects of population explosion and by genetically modifying the very species upon which we depend, without conserving their naturally viable forms, so that our future becomes brittle and fragile, dependent on maintaining artificial growing environments and high-tech food distribution processes which would be disabled globally by the slightest of astronomical disturbances, leading directly towards human extinction. For a single species to cause a mass extinction of life's diversity, possibly lasting 10 million years in one or two centuries is thus terminal folly. This folly is compounded by the ever increasing ecomnomc and medical value biological resources have in the genetic epoch. There is thus a paramount need for us to rediscover our relationship with the natural universe and to take the responsibility to regenerate genetic and biological diversity to sustain our own future generations.
Species Diversity and Species Extinction
Above: Time lapse of loss of glacial ice cover Himalayas 1921 - 2011 BBC (GlacierWorks, Royal Geographical Society and Fondazione Sella O.n.l.u.s.).
Below: World regions having 0, 5, 50,100 and 200 days over 95oF left under the Paris accord and right without Paris (Climate Impact Lab).
Click maps to enlarge. Note that the right hand scenario could result in particularly severe changes to the climate of the Amazon basin.
Climate Change, Global Warming, and Ocean Rise
Latest high accuracy predictions show no sign of population growth peak by 2100. Left: World population trends in the latest 2014 study show high confidence estimates of world population growing from the current 7 billion to 11 billion by 2100 with no sign of reduction (10% and 5% variations in darkening colours). Right: Growth by continent with Africa failing to curb population growth (Gerland P et al. 2014 World population stabilization unlikely this century Science 346 234 doi:10.1126/science.1257469). This shows that the unrestrained population growth is largely confined to Africa, with other continents stabilizing and some countries expereincing a population decline due to rapidly falling fertility rates.
Population: For a complete discussion, see The Population Bomb
Left: Ozone hole trends 1979-2013. Right: Jan-Dec 2016. Due to newer contaminants from making PVC, closing the ozone hole may be delayed for 30 more years.
The Ozone Hole
Biofuels and Peak Oil | <urn:uuid:a90a0f22-4995-451b-8ac9-6c0e9e1bbb8b> | 2.71875 | 834 | Content Listing | Science & Tech. | 30.660303 | 95,605,640 |
The worldwide consumption of energy has increased every year by several percentages in the last decades. Nowadays, a large amount of energy is produced by fossil fuels and to a certain extent by nuclear energy. However, these resources are limited and their use has a serious environmental impact. Solar light is the most important source of regenerative energy and represents an inexhaustible energy source. Owing to this fact the attention has been drawn during the last few years towards Solar cells. Moreover, to overcome barriers such as effective cost efficiency and commercial feasibility, methods of energy generations have turned to Organic Photovoltaics devices. The advantages being: generation of cost effective devices, use of renewable sources of energy and easy flexibility. In recent years rapid development in design has led to progressive PCE of organic solar cell from 3% to almost 9-10%. To improve the efficiency of organic solar cells it is, therefore, crucial to understand what limits the cell’s performance and efficiency. The scattering from the metal nanoparticles is a way of increasing the light absorption and the efficiency in organic solar cells. This review discusses the recent significant technological developments that were presented in the literature with the basic mechanisms at work, which will help improve the organic photovoltaic performance and provide an outlook to future prospects in this area.
Sakshum K, Kushagra K, Gauravi X and Prakhar K
All Published work is licensed under a Creative Commons Attribution 4.0 International License
Copyright © 2018 All rights reserved. iMedPub LTD Last revised : July 15, 2018 | <urn:uuid:12049d8c-4539-4632-8bf3-4656a779ffc8> | 3.140625 | 316 | Academic Writing | Science & Tech. | 24.049293 | 95,605,643 |
The sun has not risen above the North Pole since mid-September. The sea ice—flat, landlike, windswept, and stretching as far as the eye can see—has been bathed in darkness for months.
But later this week, something extraordinary will happen: Air temperatures at the Earth’s most northernly region, in the middle of winter, will rise above freezing for only the second time on record.
On Wednesday, the same storm system that last week spun up deadly tornadoes in the American southeast will burst into the far north, centering over Iceland. It will bring strong winds and pressure as low as is typically seen during hurricanes.
That low pressure will suck air out of the planet’s middle latitudes and send it rushing to the Arctic. And so on Wednesday, the North Pole will likely see temperatures of about 35 degrees Fahrenheit, or 2 degrees Celsius. That’s 50 degrees hotter than average: It’s usually 20 degrees Fahrenheit below zero there at this time of year.
Winter temperatures have only snuck above freezing at the North Pole once before. Eric Holthaus, Slate’s meterologist, could not find an Arctic expert who had witnessed above-freezing temperatures at the pole between December and early April.
2015 is the warmest year ever recorded. Thirteen of the top 14 warmest years on the books have happened this century. And here in the United States, it has been a hot, strange month. Many cities across the northeast smashed their Christmas and Christmas Eve temperature records not at midday, but at the stroke of midnight. For the hundred-plus years that New York temperatures have been recorded, the city has never been warmer than 63 degrees Fahrenheit on a December 24. Yet at 1 a.m. on Christmas Eve of this year, the thermometer measured 67 degrees.
Some of this North American heat is a regular feature of every El Niño. (Indeed, I wrote about this El Niño-associated heat a few weeks ago.) But in the Arctic, this level of warmth is unprecedented. In order for this huge, hot storm to reach Iceland on Wednesday, it’s punching right through the Jet Stream, the atmospheric “river” that brings temperate weather to Europe. Yet El Niño should typically reinforce this current, explains the climate writer Robert Scribbler—for the Jet Stream to weaken is a sign that something else is going on.
While institutional science will take years, if not decades, to confirm a correlation between human-forced climate change and strong North Atlantic storms, Scribbler believes that Wednesday’s insane warmth at the pole resembles the southern incursions of the “polar vortex” that have been seen in recent winters. These changes are related to human-forced climate change, he writes: a sign that something in the atmosphere has gone “dreadfully wrong.”
We want to hear what you think. Submit a letter to the editor or write to email@example.com. | <urn:uuid:2e8d1c03-8ceb-4952-bb3d-57f143b3cf23> | 3.25 | 617 | Truncated | Science & Tech. | 51.914885 | 95,605,650 |
A senior member of the consortium and IMB researcher Professor David Hume said transcriptome describes all of the information read from the genome by a cell at any given time.
"Essentially, we need to understand the language that cells use to read DNA in order to know how processes in the body are controlled," Professor Hume said.
"This knowledge will be a major resource to the biomedical research community."
Part of understanding the language of cells lies in identifying promoters - the DNA regions at the start of genes that regulate their activity.
"We have identified the core promoters of the large majority of genes in the mouse and human genomes, expanding the number of known promoters by five- to ten-fold," Professor Hume said.
The findings of the consortium have also upended the traditional view that each gene has a single promoter and a single starting position.
The team found that, while genes that are only turned on in a specific tissue or at a specific point in time use the traditional model of a single start site, genes used in many tissues have a broad distribution of start sites.
This new model may help explain why some organisms, such as humans, are much more complex than simple organisms such as worms, despite having a similar number of genes.
If some genes have a broad range of start sites, individual species can differ subtly in the way they control these genes, meaning the genes can evolve faster, and organisms with these genes can become more complex.
The consortium also found that many pseudogenes – traditionally thought to be "fossils" of ancient genes – are actually active, and are therefore likely to have some as yet unknown function.
The results obtained by the FANTOM consortium, led by the Japanese scientific institute RIKEN and Genome Network Project, have been published in the current edition of the prestigious journal Nature Genetics in a paper of which Professor Hume is corresponding author and first co-author.
Professor David Hume | EurekAlert!
Barium ruthenate: A high-yield, easy-to-handle perovskite catalyst for the oxidation of sulfides
16.07.2018 | Tokyo Institute of Technology
The secret sulfate code that lets the bad Tau in
16.07.2018 | American Society for Biochemistry and Molecular Biology
For the first time ever, scientists have determined the cosmic origin of highest-energy neutrinos. A research group led by IceCube scientist Elisa Resconi, spokesperson of the Collaborative Research Center SFB1258 at the Technical University of Munich (TUM), provides an important piece of evidence that the particles detected by the IceCube neutrino telescope at the South Pole originate from a galaxy four billion light-years away from Earth.
To rule out other origins with certainty, the team led by neutrino physicist Elisa Resconi from the Technical University of Munich and multi-wavelength...
For the first time a team of researchers have discovered two different phases of magnetic skyrmions in a single material. Physicists of the Technical Universities of Munich and Dresden and the University of Cologne can now better study and understand the properties of these magnetic structures, which are important for both basic research and applications.
Whirlpools are an everyday experience in a bath tub: When the water is drained a circular vortex is formed. Typically, such whirls are rather stable. Similar...
Physicists working with Roland Wester at the University of Innsbruck have investigated if and how chemical reactions can be influenced by targeted vibrational excitation of the reactants. They were able to demonstrate that excitation with a laser beam does not affect the efficiency of a chemical exchange reaction and that the excited molecular group acts only as a spectator in the reaction.
A frequently used reaction in organic chemistry is nucleophilic substitution. It plays, for example, an important role in in the synthesis of new chemical...
Optical spectroscopy allows investigating the energy structure and dynamic properties of complex quantum systems. Researchers from the University of Würzburg present two new approaches of coherent two-dimensional spectroscopy.
"Put an excitation into the system and observe how it evolves." According to physicist Professor Tobias Brixner, this is the credo of optical spectroscopy....
Ultra-short, high-intensity X-ray flashes open the door to the foundations of chemical reactions. Free-electron lasers generate these kinds of pulses, but there is a catch: the pulses vary in duration and energy. An international research team has now presented a solution: Using a ring of 16 detectors and a circularly polarized laser beam, they can determine both factors with attosecond accuracy.
Free-electron lasers (FELs) generate extremely short and intense X-ray flashes. Researchers can use these flashes to resolve structures with diameters on the...
13.07.2018 | Event News
12.07.2018 | Event News
03.07.2018 | Event News
16.07.2018 | Physics and Astronomy
16.07.2018 | Life Sciences
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Film crew dives into the incredible secret world of the giant manta ray
Gliding through the oceans like ghosts, these mysterious manta rays have been captured in unique footage filmed off the coast of Mozambique.
Biologist Andrea Marshall is shown performing a ballet-like dance with the inquisitive giant fish, which she described as 'the most beautiful underwater birds.'
Manta rays feed on plankton and sometimes skim the reefs with their mouths. It is not known what they feed on when migrating
Filming a manta at a 'cleaning station'. Injured rays are frequent visitors so their wounds can be cleaned by tiny, butterfly fish
The experienced diver has been based in the coastal African country since 2003. She spent last year swimming with the black-winged creatures alongside a film crew for a BBC documentary.
Until recently it was thought there was only one species of manta ray, but Dr Marshall realised many of the rays - that can grow up to 23ft long - displayed different markings and behaviour.
These ocean-faring rays did not stick to the shallow reefs like the others, but migrated 700miles to the Maldives, which is the longest migration known for a fish in the Indian ocean.
The mantas were tracked by the team using a GPS system, which revealed they made their epic voyage in just 60 days.
More than a a hundred manta rays, mostly pregnant females, gather in the Maldives each year. They were filmed for a BBC documentary
A juvenile manta feeds in the Maldives. There are two species of manta rayes - one has a useless sting and the other doesn't have a sting
They also retained a vestigial sting adapted from their sting ray cousins - which has become useless over the centuries and is harmless to humans.
The 30-year-old researcher concluded she was observing two separate species of mantas - one of them totally new to science. The larger mantas kept the name Manta birostris, while Dr Marshall named the reef-going mantas Manta alfredi, after an early biologist.
During her close encounters with the rays, Dr Marshall spotted huge scars on their bodies that had been inflicted by large sharks. She also observed them queuing up to have their wounds tended by cleaner fish, which bit off the dead tissue.
Her research also uncovered a unique gathering place for pregnant female reef mantas in the Maldives, which could be crucial to the species survival. Females only give birth to a single pup after 12 months and Dr Marshall found they rarely gave birth two years in a row.
Dr Marshall works to protect the large and charismatic species at the Manta Ray & Whale Shark Research Centre at Tofo Beach in southern Mozambique.
The documentary's director Mark Woodward said: 'Out at sea, giant mantas risk being captured and gutted for their fins by unregulated fishing, to meet the online demand for so-called traditional Chinese remedies.'
'Andrea: Queen of the Mantas' will be shown on BBC Two at 8pm on Wednesday, 11 November
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International Space Station
The International Space Station is the most expensive single object ever built by the human race to date. It orbits the earth every 90 minutes, amazingly that 16 times daily. It travels at a whopping speed of 5 miles per second. It is made up of hundreds of major and minor components. Currently it is the third brightest object in the night sky after the Moon and Venus. A total of 16 countries were involved in the construction of ISS which are Norway, Spain, Sweden, the USA, Germany, Italy, the Netherlands, Brazil, Denmark, Japan, Belgium, Canada, Switzerland Russia, France and the United Kingdom.
Quick Facts: –
- The ISS flies at an average altitude of 248 miles – 399 km
- It was taken into space piece by piece and then built in orbit.
- The systems on the International Space Station are being controlled by 52 different computers.
- There are two bathrooms, a gymnasium, a 360° view bay window in the space station.
- Approximately seven tons of food supplies are required to support a crew of three people for 6 months.
- The solar array wingspan is 240 feet which is longer than that of a Boeing 777 200/300 model.
- The electrical systems on the ISS include 8 miles of wire.
- Astronauts on the space station do not sit down for a meal. They just stabilize themselves and float.
- The internal pressurized volume of the ISS is 32,333 cubic feet.
- It has more liveable space than a six bedroom apartment.
- Oxygen comes in the space station through a process called electrolysis.
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Although a population of bacteria may be genetically identical, individual bacteria within that population can act in radically different ways.
As these bacterial cells divide, chemotaxis machinery (bright blue and red) localize in one daughter cell.
Credit: Samuel Miller lab/University of Washington
This phenomenon is crucial in the bacteria's struggle for survival. The more diversity a population of bacteria has, the more likely it will contain individuals able to take advantage of a new opportunity or overcome a new threat, including the threat posed by an antibiotic.
In a recent study, researchers at the University of Washington showed that when a bacterial cell divides into two daughter cells there can be an uneven distribution of cellular organelles. The resulting cells can behave differently from each other, depending on which parts they received in the split.
"This is another way that cells within a population can diversify. Here we've shown it in a bacterium, but it probably is true for all cells, including human cells," said Dr. Samuel Miller, UW professor of microbiology, genome sciences, and medicine and the paper's senior author.
Bridget Kulasekara, who obtained a Ph.D in the UW Molecular and Cellular Biology Program, was the paper's lead author. Other contributors included: Hemantha Kulasekara, Matthias Christen, and Cassie Kamischke, who work in Miller's lab, and Paul Wiggins, UW assistant professor of physics and bioengineering. The paper appears in the online journal eLife.
In an earlier paper, Miller and his colleagues showed that when bacteria divided, the concentration of an important regulatory molecule, called cyclic diguanosine monophosphate (c-di-GMP). was unevenly distributed between the two progeny. c-di-GMP is a second messenger molecule. That finding was published in the journal Science in 2010.
Second messenger molecules transmit signals from sensors or receptors on the cell's external membrane to targets within the cell, where they can rapidly alter a wide variety of cellular functions, such as metabolism and mobility.
The ability to respond to external stimuli quickly is important for the bacteria's survival. For instance, to stay alive, a bacterium must not hesitate to swim towards nutrients or away from toxins. This directional movement of microorganisms, spurred by the presence of a helpful or harmful substance, is known as chemotaxis.
"The effect of second messengers is almost immediate," said Miller. "They allow bacteria to change their behavior within seconds."
To detect the difference in c-di-GMP levels between cells, the researchers used a technique called Förster resonance energy transfer microscopy, or FRET microscopy. This allowed them to measure nanomolar changes of the concentration of c-di-GMP within individual bacteria as the changes happened second by second.
Different concentrations of c-di-GMP can have a profound influence on a cell's behavior. For example, in the bacteria Pseudomonas aeruginosa, cells with high levels of c-di-GMP tend to remain still, adhere to surfaces and form colonies. Those with low levels, on the other hand, tend to actively swim about by using a corkscrew-shaped propeller located at one end of the bacterium.
In the latest study, the Miller and his colleagues worked out the molecular mechanism behind the difference in c-di-GMP concentrations seen between daughter cells.
When Pseudomonas cells divide, they pinch in half to create two daughter cells. Although the cells are genetically identical, only one daughter cell can inherit the bacterium's single propeller. The other cell can synthesize its own propeller, but immediately after division the two cells are quite different.
What Miller and his coworkers report in the eLife paper is that the daughter cell that inherits the propeller also inherits an enzyme that is closely associated with the propeller that degrades c-di-GMP, as well as the organelle involved in directing movement toward or away from stimuli that activates this enzyme.
Together these two organelles work in concert to lower the concentration of c-di-GMP and control swimming.
"What we have shown is that the uneven inheritance of organelles is another way cells have to create diversity and increase the chances of the survival of its species," Miller said.
He added that his team's findings may help explain how bacteria resist antibiotic treatments by always having some cells in their populations be in a slow-growing, resting state. Since antibiotics target fast-growing cells, these resting cells are more likely to survive the treatment. The findings might also help explain how some bacteria are able to adhere to and colonize surfaces such as urinary catheters, intravenous lines and heart valves.
In ongoing research, Miller's team is trying to get a better understanding of the signals that can change second messenger concentrations very quickly and is screening compounds that could interfere with or alter those signals. Such compounds could be used to combat drug resistance, for instance, or inhibit a bacterium's ability to adhere to surfaces and form slime-like colonies, called biofilms, that are highly resistant to antibiotics.
The new paper, as well as the earlier study, which appeared in the journal Science in 2010, are both available free online.
Kulasekara et al. c-di-GMP heterogeneity is generated by the chemotaxis machinery to regulate flagellar motility. ELife. 2013;2:e01402. Chisten M et al. Asymmetrical Distribution of the Second Messenger c-di-GMP upon Bacterial Cell Division. Science. 2010; 328(5983):1295-1297 DOI: 10.1126/science.1188658
The research was funded by the National Institute of Allergy and Infectious Diseases (Grant number: 5U54AI057141-09) the National Science Foundation Graduate Research Fellowship (Grant number 2007047910) and the National Institutes of Health (Grant number 1R21NS067579-0).
Leila Gray | EurekAlert!
World’s Largest Study on Allergic Rhinitis Reveals new Risk Genes
17.07.2018 | Helmholtz Zentrum München - Deutsches Forschungszentrum für Gesundheit und Umwelt
Plant mothers talk to their embryos via the hormone auxin
17.07.2018 | Institute of Science and Technology Austria
For the first time ever, scientists have determined the cosmic origin of highest-energy neutrinos. A research group led by IceCube scientist Elisa Resconi, spokesperson of the Collaborative Research Center SFB1258 at the Technical University of Munich (TUM), provides an important piece of evidence that the particles detected by the IceCube neutrino telescope at the South Pole originate from a galaxy four billion light-years away from Earth.
To rule out other origins with certainty, the team led by neutrino physicist Elisa Resconi from the Technical University of Munich and multi-wavelength...
For the first time a team of researchers have discovered two different phases of magnetic skyrmions in a single material. Physicists of the Technical Universities of Munich and Dresden and the University of Cologne can now better study and understand the properties of these magnetic structures, which are important for both basic research and applications.
Whirlpools are an everyday experience in a bath tub: When the water is drained a circular vortex is formed. Typically, such whirls are rather stable. Similar...
Physicists working with Roland Wester at the University of Innsbruck have investigated if and how chemical reactions can be influenced by targeted vibrational excitation of the reactants. They were able to demonstrate that excitation with a laser beam does not affect the efficiency of a chemical exchange reaction and that the excited molecular group acts only as a spectator in the reaction.
A frequently used reaction in organic chemistry is nucleophilic substitution. It plays, for example, an important role in in the synthesis of new chemical...
Optical spectroscopy allows investigating the energy structure and dynamic properties of complex quantum systems. Researchers from the University of Würzburg present two new approaches of coherent two-dimensional spectroscopy.
"Put an excitation into the system and observe how it evolves." According to physicist Professor Tobias Brixner, this is the credo of optical spectroscopy....
Ultra-short, high-intensity X-ray flashes open the door to the foundations of chemical reactions. Free-electron lasers generate these kinds of pulses, but there is a catch: the pulses vary in duration and energy. An international research team has now presented a solution: Using a ring of 16 detectors and a circularly polarized laser beam, they can determine both factors with attosecond accuracy.
Free-electron lasers (FELs) generate extremely short and intense X-ray flashes. Researchers can use these flashes to resolve structures with diameters on the...
13.07.2018 | Event News
12.07.2018 | Event News
03.07.2018 | Event News
17.07.2018 | Information Technology
17.07.2018 | Materials Sciences
17.07.2018 | Power and Electrical Engineering | <urn:uuid:20010f4c-2fb3-44ec-944d-17010e028893> | 3.546875 | 1,923 | Content Listing | Science & Tech. | 38.256251 | 95,605,680 |
Just as Gotham City uses the Bat Signal to call for Batman's aid, a new tool developed by scientists from the Sanford-Burnham Medical Research Institute in La Jolla, California, should serve as the cellular equivalent for children with glycosylation disorders, sometimes called "CDG syndromes."
In a new report appearing online in The FASEB Journal (http://www.fasebj.org), scientists describe how they used a green fluorescent protein to identify the presence of genes—known and unknown—associated with a wide variety of glycosylation-related diseases. By being able to identify exactly which genes are defective, researchers can develop treatments and therapies to correct the root causes of these diseases rather than merely treating the symptoms.
Glycosylation is an enzymatic process that coats proteins, lipids or other organic molecules with sugar molecules. It helps cells "stick" together, and proteins fold and work properly, among other things. When this process does not function correctly, it causes diseases involving intellectual disability, digestive problems, seizures and low blood sugar.
"We hope this glowing protein will help light the path for the discovery of new genes that cause genetic disorders in children," said Hudson Freeze, Ph.D., a senior researcher involved in the work from the Genetic Disease Program at Sanford-Burnham Medical Research Institute in La Jolla, California. "It's not Harry Potter's magic wand, but we hope it will offer a way to test for new therapies in these kids. They're counting on us."
To make this advance, Freeze and colleagues engineered cells from children with glycosylation disorders so the cells would glow to indicate when there was a glycosylation problem related to a defective or missing gene. Once the problematic, glowing cells were "rescued" by inserting a healthy gene into the cell or correcting a defective gene's function, the cells stopped glowing. This new tool may be used in high-throughput screening to identify therapeutic molecules that improve glycosylation in defective cells, including stem cells. In addition, this advance may serve as the foundation for a new diagnostic tool for patients.
"These glowing proteins serve as a hotline between distressed cells and researchers hoping to restore their normal function," said Gerald Weissmann, M.D., Editor-in-Chief of The FASEB Journal. "Knowing when and where there are cells with flawed glycosylation pathways should allow researchers to rapidly screen for compounds that may have therapeutic potential."
Receive monthly highlights from The FASEB Journal by e-mail. Sign up at http://www.faseb.org/fjupdate.aspx. The FASEB Journal (http://www.fasebj.org) is published by the Federation of the American Societies for Experimental Biology (FASEB) and is the most cited biology journal worldwide according to the Institute for Scientific Information. In 2010, the journal was recognized by the Special Libraries Association as one of the top 100 most influential biomedical journals of the past century. FASEB is composed of 26 societies with more than 100,000 members, making it the largest coalition of biomedical research associations in the United States. Celebrating 100 Years of Advancing the Life Sciences in 2012, FASEB is rededicating its efforts to advance health and well-being by promoting progress and education in biological and biomedical sciences through service to our member societies and collaborative advocacy.
Details: Marie-Estelle Losfeld, Francesca Soncin, Bobby G. Ng, Ilyas Singec, and Hudson H. Freeze. A sensitive green fluorescent protein biomarker of N-glycosylation site occupancy. FASEB J. doi:10.1096/fj.12-211656 ; http://www.fasebj.org/content/early/2012/06/11/fj.12-211656.abstract
Cody Mooneyhan | EurekAlert!
World’s Largest Study on Allergic Rhinitis Reveals new Risk Genes
17.07.2018 | Helmholtz Zentrum München - Deutsches Forschungszentrum für Gesundheit und Umwelt
Plant mothers talk to their embryos via the hormone auxin
17.07.2018 | Institute of Science and Technology Austria
For the first time ever, scientists have determined the cosmic origin of highest-energy neutrinos. A research group led by IceCube scientist Elisa Resconi, spokesperson of the Collaborative Research Center SFB1258 at the Technical University of Munich (TUM), provides an important piece of evidence that the particles detected by the IceCube neutrino telescope at the South Pole originate from a galaxy four billion light-years away from Earth.
To rule out other origins with certainty, the team led by neutrino physicist Elisa Resconi from the Technical University of Munich and multi-wavelength...
For the first time a team of researchers have discovered two different phases of magnetic skyrmions in a single material. Physicists of the Technical Universities of Munich and Dresden and the University of Cologne can now better study and understand the properties of these magnetic structures, which are important for both basic research and applications.
Whirlpools are an everyday experience in a bath tub: When the water is drained a circular vortex is formed. Typically, such whirls are rather stable. Similar...
Physicists working with Roland Wester at the University of Innsbruck have investigated if and how chemical reactions can be influenced by targeted vibrational excitation of the reactants. They were able to demonstrate that excitation with a laser beam does not affect the efficiency of a chemical exchange reaction and that the excited molecular group acts only as a spectator in the reaction.
A frequently used reaction in organic chemistry is nucleophilic substitution. It plays, for example, an important role in in the synthesis of new chemical...
Optical spectroscopy allows investigating the energy structure and dynamic properties of complex quantum systems. Researchers from the University of Würzburg present two new approaches of coherent two-dimensional spectroscopy.
"Put an excitation into the system and observe how it evolves." According to physicist Professor Tobias Brixner, this is the credo of optical spectroscopy....
Ultra-short, high-intensity X-ray flashes open the door to the foundations of chemical reactions. Free-electron lasers generate these kinds of pulses, but there is a catch: the pulses vary in duration and energy. An international research team has now presented a solution: Using a ring of 16 detectors and a circularly polarized laser beam, they can determine both factors with attosecond accuracy.
Free-electron lasers (FELs) generate extremely short and intense X-ray flashes. Researchers can use these flashes to resolve structures with diameters on the...
13.07.2018 | Event News
12.07.2018 | Event News
03.07.2018 | Event News
17.07.2018 | Information Technology
17.07.2018 | Materials Sciences
17.07.2018 | Power and Electrical Engineering | <urn:uuid:12e33ae0-6b96-4939-bd70-45ece242564e> | 3.578125 | 1,471 | Content Listing | Science & Tech. | 42.275765 | 95,605,681 |
A new feature has been added to COBS analysis page enabling the observer to plot the date of perihelion on the lightcurve graph.
It does not look like much now — just a 19th-magnitude smudge tucked away in southwestern Virgo — but a newly discovered comet could become something special 10 months from now.
The extraterrestrial rock is tumbling through space alongside thousands of similar objects in our solar systems main asteroid belt, roughly between the orbits of Mars and Jupiter.
S. Larson reports that images of the main-belt minor planet (596) show the object to be in apparent outburst with a comet-like appearance.
A new feature has been added to COBS analysis page enabling the observer to filter the observation data by observation type.
A. Boattini reports his discovery of a faint comet with a moderately diffuse coma that is 6"-7" wide and a central condensation that is about 3"-4" in size on four 30-s co-added CCD exposures taken with the Mt. Lemmon 1.5-m reflector in Arizona.
This morning EPOXI, the spacecraft formerly known as Deep Impact, flew within 435 miles (700 km) of the nucleus of Comet 103P/Hartley 2. Images taken during the encounter are being downloaded from the spacecraft throughout the day. A few of the images have been released by the EPOXI team and can be found here.
S. Nakano, Sumoto, Japan, reports the visual discovery of a comet independently by Kaoru Ikeya ...
Under the scope of CARA project, comet 103P/Hartley is continuously monitored by a group of dedicated observers, using small and medium size remote telescopes, now available worldwide.
Comet 103P/Hartley is currently in the middle of Auriga moving to the southeast at a little over 3° per day. With closest approach to Earth on Oct. 20 (0.121 AU) and closest approach to the Sun on Oct. 28 (1.059 AU), the comet is as big and bright as it will probably get for this return. Unfortunately, the bright Full Moon will make observing the comet difficult for the next week and a half. | <urn:uuid:35d1daf9-5013-413f-8504-9b953f1ad841> | 3.09375 | 454 | Content Listing | Science & Tech. | 58.231857 | 95,605,695 |
The biophysical principles and mechanisms by which membrane proteins insert and fold into a biomembrane have mostly been studied with bacteriorhodopsin and outer membrane protein A (OmpA). This review de-scribes the assembly process of the monomeric outer membrane proteins of Gram-negative bacteria, for which OmpA has served as an example. OmpA is a two-domain outer membrane protein composed of a 171-residue eight-stranded beta-barrel transmembrane domain and a 154-residue periplasmic domain. OmpA is translocated in an unstructured form across the cytoplasmic membrane into the periplasm. In the periplasm, unfolded OmpA is kept in solution in complex with the molecular chaperone Skp. After binding of periplasmic lipopolysaccharide, OmpA insertion and folding occur spontaneously upon interaction of the complex with the phospholipid bilayer. Insertion and folding of the beta-barrel transmembrane domain into the lipid bilayer are highly synchronized, i.e. the formation of large amounts of beta-sheet secondary structure and beta-barrel tertiary structure take place in parallel with the same rate constants, while OmpA inserts into the hydrophobic core of the membrane. In vitro, OmpA can successfully fold into a range of model membranes of very different phospholipid compositions, i. e. into bilayers of lipids of different headgroup structures and hydrophobic chain lengths. Three membrane-bound folding intermediates of OmpA were discovered in folding studies with dioleoylphosphatidylcholine bilayers. Their formation was monitored by time-resolved distance determinations by fluorescence quenching, and they were structurally distinguished by the relative positions of the five tryptophan residues of OmpA in projection to the membrane normal. Recent studies indicate a chaperone-assisted, highly synchronized mechanism of secondary and tertiary structure formation upon membrane insertion of beta-barrel membrane proteins such as OmpA that involves at least three structurally distinct folding intermediates.
Mendeley saves you time finding and organizing research
Choose a citation style from the tabs below | <urn:uuid:06aa7a0e-3997-49ca-8089-1ffcb84c5850> | 2.578125 | 469 | Academic Writing | Science & Tech. | 10.381559 | 95,605,735 |
The environmental challenges facing our planet have never been more acute. SEFARI research helps to show how we can protect and restore our natural capital – our soils, biodiversity and ecosystems – and develop effective ways to manage the land and water to improve environmental condition. SEFARI works to better understand how biological, chemical and physical processes can allow us to tackle climate change, adapt to changes coming our way, and build a more resilient and well-functioning environment.
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Climate and the Environment
22 Feb 2018
Recently there has been a rapid increase in the spread and number of non-native tree pests and pathogens around the world. Traditionally the impact of tree diseases and pests has been assessed in terms of their impact on forestry and the loss of wood products.
13 Jun 2018 - 15:25
We are pleased that Professor Ian Toth, Head of the Plant Health Centre, is able to tell us more about this new virtual centre and why working together is crucial for enhancing Scotland's resilience in the face of threats to arable crops, trees, horticulture, and wild plants.
29 May 2018 - 15:33
We are pleased that Annemarie Gibson of Circamedia, an Edinburgh-based film and multimedia production company, has provided us with some insights into what excited her whilst learning about SEFARI research and ultimately telling our story on film. | <urn:uuid:16527c6b-4044-4c61-9a45-ff25d4b8164c> | 2.953125 | 280 | Content Listing | Science & Tech. | 29.551397 | 95,605,747 |
Climate change: PV foresight
Innovations are the on the rise as it has been mentioned in the website of the White House that innovations of any sort or form will be supported by the US government to address the believed phenomenon of change is permanent. So, the idea of production of electricity will also change. It has seen a shift from human to water by making turbines and making them run via falling waters from height. Then coal shoves it to product electricity which was abandoned by some as it was causing pollution. Later, nuclear was allowed to make oneself developed economy as per the declaration of UN org meeting. Now, we are planning for solar.
Whatever has been done before was somehow marginalized for its drawbacks on society, environment or something which was said to be important. Climate change was the main slogan of the scientists to bring in new technologies for the production of electricity. To stop it or reduce it significantly, Turkey is showing remarkable project to use solar tech for electricity production using solar panels in one of its city, the Anatolia.
Will it really work in the way the planners are planning or will it again reveal some sort of issue which will be realized later on. The issue may then stop the PV (photo voltaic) panels from selling in bulk. What can be the issue. Being a Devils Advocate, an expert may conclude after observing the tech patterns of the past that we may suffer the climate change still but it will be a bit different.
The technologies employed in the past were of fission reaction type. The reaction will produce heat which was conserved by nature in something like oil, coal or human etc. Now, it is going to have the reverse reaction which is sort of fusion in type. The energy which is out there from the Sun, will be conserved into PV panels which later can be used by the appliances at homes. Sun energy will be used which may result in some photons absorbed which were previously used by surroundings containing plants, water, animals, humans etc.
The energy used for charging the batteries will not be used by the large number of species existing on the world. They are trillions known to us but may be much greater number is not known to us. When pure energy from sun is not there which produces vitamins in human body for skin and other parts of the body then it is expected that the future of PV panels may be in danger.
When it way the oil, none knew of the O-Zone layer which later on was discovered and later found to be getting damaged from the green house gas affect. Now, the climate change is observed to cause the havoc in the norther hemisphere melting the ice capt which is making the extreme cool winds to flow to the south. Extreme cold weather in Europe is because of this impact of rising oil consumption in the world. When everyone will turn to PV panels, same would be expected though it will somewhat different but with issues.
Man is for mistaking the for-granted blessings by nature to spoil nature and reconcile later when it is too late.
Sun is better than “sunlight” at night; so workout the days, rest-in dark night.
https://www.technologytimes.pk/climate-change-pv-foresight/Articleschange,Climate,Foresight,PV Innovations are the on the rise as it has been mentioned in the website of the White House that innovations of any sort or form will be supported by the US government to address the believed phenomenon of change is permanent. So, the idea of production of electricity will...Technology TimesTechnology Times firstname.lastname@example.orgAdministratorTechnology Times is Pakistan's First Newspaper on Science and TechnologyTechnology Times | <urn:uuid:02db3dbb-e26b-41bf-af4e-f1c27bf0d51a> | 2.71875 | 751 | Truncated | Science & Tech. | 48.477825 | 95,605,753 |
To navigate, birds require a ‘map’ (to tell them home is south, for example) and a ‘compass’ (to tell them where south is), with the sun and the Earth’s magnetic field being the preferred compass systems.
A new paper provides evidence that the information pigeons use as a map is in fact available in the atmosphere: odours and winds allow them to find their way home. The results are now published in Biogeosciences, an open access journal of the European Geosciences Union (EGU).
Experiments over the past 40 years have shown that homing pigeons get disoriented when their sense of smell is impaired or when they don’t have access to natural winds at their home site. But many researchers were not convinced that wind-borne odours could provide the map pigeons need to navigate. Now, Hans Wallraff of the Max Planck Institute for Ornithology in Seewiesen, Germany, has shown that the atmosphere does contain the necessary information to help pigeons find their way home.
In previous research, Wallraff collected air samples at over 90 sites within a 200 km radius around a former pigeon loft near Würzburg in southern Germany. The samples revealed that the ratios among certain ‘volatile organic compounds’ (chemicals that can be a source of scents and odours) in the atmosphere increase or decrease along specific directions. “For instance, the percentage of compound A in the sum A+B or A+B+C+D increases the farther one moves from north to south,” Wallraff explains.
These changes in compound ratios translate into changes in perceived smell. But a pigeon that has never left its loft does not know in what directions what changes occur – unless it has been exposed to winds at its home site.
At home, a bird is thought to associate certain smells with particular wind directions. “If the percentage of compound A increases with southerly winds, a pigeon living in a loft in Würzburg learns this wind-correlated increase. If released at a site some 100 km south of home, the bird smells that the ratio of compound A is above what it is on average at its loft and flies north,” Wallraff explains. To use an analogy, a person in Munich could smell an Alpine breeze when there is wind blowing from the south. When displaced closer to the mountains, they would detect a strong Alpine scent and remember that, at home, that smell is associated with southerly winds: the person would know that, roughly, they needed to travel north to find home.
But this explanation of how pigeons might use wind-borne odours to find their loft was just a hypothesis: Wallraff still needed to prove that the atmosphere does indeed contain the basis of the map system pigeons need to navigate. In the new Biogeosciences paper, he develops a model showing that ‘virtual pigeons’ with only knowledge of winds and odours at home, can find their way back to their lofts by using real atmospheric data.
“My virtual pigeons served as tools to select those volatile compounds whose spatial distributions, combined with variations dependent on wind direction, were most suitable for homeward navigation,” explains Wallraff.
The model uses an iterative approach to imitate animal evolution by introducing random mutations in the virtual pigeons, making them most sensitive to those volatile compounds that are most effective for navigation. By selecting the best mutations in the course of thousands of generations, the model creates virtual pigeons capable of finding their bearings as well as real pigeons, showing that even inexperienced birds could use atmospheric information for navigation. The findings present a missing piece in the puzzle of homing pigeon navigation, confirming that winds and odours can indeed work as a map system.
“Work with real pigeons was the beginning of the story. In this research, I wanted to find out whether and in what way the chemical atmosphere fulfils the demands for avian navigation. Eventually, to identify the chemical compounds birds actually use for home-finding, we will need real birds again. But this is far in the future.”*More information*
Full citation: Wallraff, H. G.: Ratios among atmospheric trace gases together with winds imply exploitable information for bird navigation: a model elucidating experimental results, Biogeosciences, 10, 6929-6943, doi:10.5194/bg-10-6929-2013, 2013.
The *European Geosciences Union (http://www.egu.eu)* is Europe’s premier geosciences union, dedicated to the pursuit of excellence in the Earth, planetary, and space sciences for the benefit of humanity, worldwide. It is a non-profit interdisciplinary learned association of scientists founded in 2002. The EGU has a current portfolio of 15 diverse scientific journals, which use an innovative open access format, and organises a number of topical meetings, and education and outreach activities. Its annual General Assembly is the largest and most prominent European geosciences event, attracting over 11,000 scientists from all over the world. The meeting’s sessions cover a wide range of topics, including volcanology, planetary exploration, the Earth’s internal structure and atmosphere, climate, energy, and resources. The 2014 EGU General Assembly is taking place is Vienna, Austria from 27 April to 2 May 2014. For information regarding the press centre at the meeting and media registration, please check http://media.egu.eu closer to the time of the conference.
If you wish to receive our press releases via email, please use the press release subscription form at http://www.egu.eu/news/subscribe/. Subscribed journalists and other members of the media receive EGU press releases under embargo (if applicable) 24 hours in advance of public dissemination.*Contacts*
Colorectal cancer risk factors decrypted
13.07.2018 | Max-Planck-Institut für Stoffwechselforschung
Algae Have Land Genes
13.07.2018 | Julius-Maximilians-Universität Würzburg
For the first time ever, scientists have determined the cosmic origin of highest-energy neutrinos. A research group led by IceCube scientist Elisa Resconi, spokesperson of the Collaborative Research Center SFB1258 at the Technical University of Munich (TUM), provides an important piece of evidence that the particles detected by the IceCube neutrino telescope at the South Pole originate from a galaxy four billion light-years away from Earth.
To rule out other origins with certainty, the team led by neutrino physicist Elisa Resconi from the Technical University of Munich and multi-wavelength...
For the first time a team of researchers have discovered two different phases of magnetic skyrmions in a single material. Physicists of the Technical Universities of Munich and Dresden and the University of Cologne can now better study and understand the properties of these magnetic structures, which are important for both basic research and applications.
Whirlpools are an everyday experience in a bath tub: When the water is drained a circular vortex is formed. Typically, such whirls are rather stable. Similar...
Physicists working with Roland Wester at the University of Innsbruck have investigated if and how chemical reactions can be influenced by targeted vibrational excitation of the reactants. They were able to demonstrate that excitation with a laser beam does not affect the efficiency of a chemical exchange reaction and that the excited molecular group acts only as a spectator in the reaction.
A frequently used reaction in organic chemistry is nucleophilic substitution. It plays, for example, an important role in in the synthesis of new chemical...
Optical spectroscopy allows investigating the energy structure and dynamic properties of complex quantum systems. Researchers from the University of Würzburg present two new approaches of coherent two-dimensional spectroscopy.
"Put an excitation into the system and observe how it evolves." According to physicist Professor Tobias Brixner, this is the credo of optical spectroscopy....
Ultra-short, high-intensity X-ray flashes open the door to the foundations of chemical reactions. Free-electron lasers generate these kinds of pulses, but there is a catch: the pulses vary in duration and energy. An international research team has now presented a solution: Using a ring of 16 detectors and a circularly polarized laser beam, they can determine both factors with attosecond accuracy.
Free-electron lasers (FELs) generate extremely short and intense X-ray flashes. Researchers can use these flashes to resolve structures with diameters on the...
13.07.2018 | Event News
12.07.2018 | Event News
03.07.2018 | Event News
13.07.2018 | Event News
13.07.2018 | Materials Sciences
13.07.2018 | Life Sciences | <urn:uuid:129c32cb-87aa-4938-8b2e-b1e3b4fab397> | 3.734375 | 1,871 | Content Listing | Science & Tech. | 43.932901 | 95,605,767 |
Solar radiation management (SRM) geoengineering has been proposed as one means of helping avoid the occurrence of dangerous climate change and undesirable state transitions ('tipping points') in the Earth system. The irreversible melting of the Greenland Ice Sheet is a case in point-a state transition that could occur as a result of CO2-driven elevated global temperatures, and one leading to potentially catastrophic sea-level rise. SRM schemes such as the creation of a 'sunshade' or injection of sulfate aerosols into the stratosphere could reduce incoming solar radiation, and in theory balance, in a global mean, the greenhouse warming resulting from elevated concentrations of CO2 in the atmosphere. Previous work has highlighted that a geoengineered world would have: warming towards the poles, cooling in the tropics, and a reduction in the global hydrological cycle, which may have important implications for the Greenland Ice Sheet. Using a fully coupled global climate model in conjunction with an ice sheet model, we assess the consequences for the mass balance of the Greenland Ice Sheet of the reorganization of climate patterns by the combination of high CO2 and geoengineering. We find that Greenland surface temperature and precipitation anomalies, compared to the pre-industrial situation, decrease almost linearly with increasing levels of SRM geoengineering, but that these combine to create a highly non-linear response of the ice sheet. The substantial melting of the Greenland Ice Sheet predicted for four times pre-industrial CO2 levels is prevented in our model with only a partial application of SRM, and hence without having to fully restore the global average temperature back to pre-industrial levels. This suggests that the degree of SRM geoengineering required to mitigate the worst impacts of greenhouse warming, such as sea-level rise, need not be as extensive as generally assumed
To submit an update or takedown request for this paper, please submit an Update/Correction/Removal Request. | <urn:uuid:f2089011-b078-4ed7-813a-b42caad0efaa> | 3.140625 | 384 | Academic Writing | Science & Tech. | 9.054525 | 95,605,778 |
|HEAR home > species info > invertebrates > Lactrodectrus sp. (Theridiidae)|
|Taxonomy & nomenclature||Dispersal and pathways||Distribution||In the news|
Black-widow spiders are already "in the wild" in Kahului, Maui
Black widow spider sighting on Maui is described in a posting to the Hawaii Invasive Species Committee internet discussion list
In the news
Creepy critter caught in grapes
A black widow spider was found in a bunch of grapes purchased at the Kona Costco (Honolulu Star Bulletin, 11/6/2008).
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The Hawaiian Ecosystems at Risk (HEAR) project was historically funded by the Pacific Basin Information Node (PBIN) of the National Biological Information Infrastructure (NBII) through PIERC (USGS) with support from HCSU (UH Hilo). More details are available online.
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As you may know, this is Bat Week where people aim to raise awareness of all things bat. I’m going to contribute by writing an article that was suggested by Louise (click her name to see her work) in an earlier post which I wrote.
Bats are what are known as an “indicator species”, which simply means that the presence (or absence) of bats can indicate how healthy an ecosystem is. The reasons for this are numerous and there is a full paper below should you be curious. To summarise though, bats are very fussy little creatures. Things like pollution, deforestation, climate change and agriculture can all cause bat populations to suffer. Therefore if bats are present we can usually imply that an area is “healthy” as otherwise there would be no bats.
Bats as indicator species is not a particularly new theory but it is one that was never really recognised. I went through a 4-year university degree without anybody mentioning it. Come to think of it I am not sure anyone actually mentioned bats (maybe I was asleep?). A more common example of indicator species are lichens, which do not grow in areas of high pollution.
In many ways bats are ideal for use as indicator species. Bats can be surveyed easily and in a variety of ways (feeding rates, numbers seen, population etc), they are geographically well spread, and they show clear responses to change in their habitat. They also reproduce slowly which means they do not evolve rapidly to changes and so their populations tend to drop when facing adverse stimuli. Of course bats are also vital for crop success and pest control. Keeping the bats happy means the need for less agricultural chemicals and prevents a vicious cycle whereby the more chemicals are used, the fewer bats there are and the more chemicals need to be used.
Essentially, bats are critically overlooked in just about all aspects. Encouraging people to protect bats will likely result in a benefit to whole ecosystems. In a sense we need to make bats a sort of flagship species, like a panda. People try to save the flagship species and this results in the saving of habitats and the protection of many other species. It certainly doesn’t do any harm to protect bats and there are many ways you can help which are given in a link below.
Happy Bat Week!
How to help?
1,243 total views, 1 views today | <urn:uuid:fdd7e01d-e8af-49be-92e7-922527ac992f> | 3.28125 | 489 | Personal Blog | Science & Tech. | 50.574076 | 95,605,800 |
Current issue: 52(2)
Under compilation: 52(3)
The frequency of years when Scots pine (Pinus sylvestris L.) produces cones and seeds affects its reproduction in the north. The study area covered most of the pine lands in Northern Finland. Scots pine seems to be able to produce cones relatively often in the north. The amount of seeds produced in one year was, however, not sufficient to produce a dense seedling stand. Thus, the natural pine stands contain usually trees in different ages-classes, which have germinated in different years. The cone production is highest in 150-170 years old trees. Pine also needs warm summers to produce viable seeds. Brush fires avail the growth of seedlings, because they clear of ground vegetation that hinders germination of seeds. The seedlings need also moisture to survive; good regeneration years have often had rainy summers.
The PDF includes a summary in German. | <urn:uuid:0aa47b1b-2ec4-44d8-9f88-7293d09fe705> | 3.46875 | 190 | Truncated | Science & Tech. | 53.686091 | 95,605,807 |
The principal solutions to biodiversity loss are the reduction of land and soil degradation, especially related to agriculture, and the integration of biodiversity strategies with other major environmental concerns such as climate change, and also with human development concerns such as poverty reduction.
In addition, conservation through regulated protected areas and national parks will remain an important solution to biodiversity loss. However, its limitations in tackling the full extent of the biodiversity crisis have increased resolve to find solutions which coexist with human agency rather than exclude it. Described as the sustainable use of biodiversity, this is one of the three core objectives of the UN Convention on Biological Diversity (CBD).
This objective must place its greatest emphasis on agriculture, by far the most significant cause of biodiversity loss. However, governments in the poorest countries face dilemmas in pursuing their goal of reducing poverty amongst the world’s 475 million smallholdings of less than two hectares, without neglecting biodiversity.
Modern high-technology farming yields plentiful and cheap food but is associated with mono-culture land environments where soil is eroding and biodiversity has been cast aside. Furthermore, the UN Food and Agriculture Organization estimates that about three-quarters of the genetic diversity once found in agricultural crops has been lost over the last century. Just three staple crops – wheat, maize and rice – now provide more than half of plant-based calories in the human diet. Thousands of traditional crops have not only been discarded for food production but have themselves become threatened species.
Importing this model, involving consolidation and modernisation of small farms, brokered by agribusiness corporations, may not therefore be the obvious strategic choice it seems. An alternative approach seeks higher yields that can be achieved through intense husbandry on small farms. Described as “agro-ecology” or “eco-farming”, this low input model requires skills in soil regeneration, nitrogen fixation, natural pest control and agro-forestry, each of which depends on greater variety of crops and peripheral plants.
Reconciliation of these polarised approaches to agriculture is critical to both food security and biodiversity. The debate illustrates how the goal of sustainable use of biodiversity falls firmly within the global challenge of sustainable development. Strategic solutions to food security, poverty reduction and health can benefit from, and contribute to, flourishing natural ecosystems supported by stable biodiversity. Relatively straightforward policies such as wetlands management and greening cities can also advance multiple goals.
International policymakers and negotiators on environmental issues face their own challenges in integrating biodiversity across their agendas. Detailed implementation of multilateral agreements increasingly overlaps. This difficulty is most apparent in the three separate 1992 UN Conventions addressing the interconnected problems of biodiversity, climate change and desertification.
Choices made by individual consumers in richer countries also have a vital role to play. For example, certification of seafood products, such as that offered by the Marine Stewardship Council, provides the purchaser with reassurance of sustainable fishing methods.
Some of the world’s major corporations are beginning to acknowledge not just the reputational risk of environmentally damaging products but also the more fundamental business risk of ecosystem failure. Commodities such as coffee and cocoa are integral to the global economy, yet dependent on delicate ecosystems.
A vision of a world economy in which ecosystems and biodiversity are recognised as the highest and non-negotiable tier of economic capital, framing policymaking and business strategies, therefore remains elusive. However, an innovative path to achieve supremacy of ecosystems has been pioneered in New Zealand and India in 2017. Successful petitions have been brought to grant legal rights to rivers of especial cultural significance, as though the ecosystem has human agency. The implications are uncertain but any development affecting these rivers is likely to encounter legal hurdles.
more Biodiversity briefings (updated May 2018)
Importance of Biodiversity
Biodiversity Loss and Planetary Boundaries
Causes of Biodiversity Loss
Climate Change and Biodiversity
Conservation of Biodiversity
Sustainable Development Goals for Biodiversity
Biodiversity Finance and Economics
Biodiversity Access and Benefit-Sharing
Source Material and Useful Links | <urn:uuid:f389e8c5-622e-4634-99ca-3fb89a3ee7c6> | 4.03125 | 839 | Knowledge Article | Science & Tech. | 1.697472 | 95,605,832 |
What do you mean by deep cloning and shallow cloning
Java supports two different types of cloning
- Shallow cloning - java's object.clone() gives a shallow copy of the object being cloned. Here the object cloned is copied without its contained object. Shallow cloning is a bitwise copy of an object. New object is created which is an exact copy of the original one. In case of contained objects just the references are copied.
- Deep cloning - as object.clone() method yields shallow copy, to achieve deep copy classes needs to be adjusted (check note below). Here the original object is copied along with its contained objects (note: here the entire graph of objects are traversed and copied.) Each object in the graph is responsible of cloning itself through the clone method.So, In deep cloning, complete duplicate copy of the original copy is created.
- If the object wants to be able to clone itself it first needs to implement Cloneable interface else object is going to throw CloneNotSupportedException when the clone method is called.
- Second the object needs to make the clone() method public.
- Next in the clone method call the super.clone()
- You need not do anything special for primitive data types, its wrapper objects and immutable objects like String, the super.clone() method automatically creates a copy of them.
- When you perform a deep copy involving collections the objects in the collection also needs to implement Cloneable.
Problems with cloning
- The entire object graph needs to be cloned, which is tiresome and error prone and difficult to maintain. Care should be taken when there is a modification to the classes.
- Care should also be taken in circular reference of object, the reference object should be created only once. Ex Say Department contains Employee class and Employee inturn refers Department, care should be taken that the reference department is created only once.
- If the class is not available for modification (third party classes), and there is a need for cloning, you need to create a new class by sub-classing and then overriding the clone method.
- Also its problematic to clone a polymorphic variable, as the decision has to wait till the runtime.
Alternatives to cloning
Java Serialization offers an alternative for cloning (key here is the object and all the referenced objects needs to be serializable), here the entire object tree is traversed and serialized, and de-serializing it later will yield the exact state but a different copy of the original serialized object. However the cost of serialization is its performance, as this involves writing and reading from the stream. | <urn:uuid:76c39d89-a98e-467c-a3ce-5c9debaaa24c> | 3.5625 | 537 | Tutorial | Software Dev. | 40.570212 | 95,605,840 |
Publisher: Wikibooks 2012
Number of pages: 193
This book is about the topic of mathematical analysis, particularly in the field of engineering. It attempts to be a companion piece to high-level engineering texts that will rely on a certain fundamental mathematical background among readers. This will build on topics covered in Probability, Algebra, Linear Algebra, Calculus, and Ordinary Differential Equations.
Home page url
Download or read it online for free here:
by J.M. Warren, W.H. Rutherford - Copp, Clark
In this book an attempt has been made to present the subject of Elementary Mathematics in a way suitable to industrial students in our technical schools. The fundamentals as herein presented will form a basis for a wide range of industries.
by Patrick Juola, Stephen Ramsay - Zea Books
Scholars of all stripes are turning their attention to materials that represent enormous opportunities for the future of humanistic inquiry. The purpose of the book is to impart the concepts that underlie the mathematics they are likely to encounter.
by Stephen Siklos - Open Book Publishers
The book is intended to help candidates prepare for entrance examinations in mathematics and scientific subjects. It is a must read for any student wishing to apply to scientific subjects at university level and for anybody interested in mathematics.
by MacGregor Campbell - Annenberg Foundation
Mathematics Illuminated is a text for adult learners and high school teachers. It explores major themes of mathematics, from humankind's earliest study of prime numbers, to the cutting-edge mathematics used to reveal the shape of the universe. | <urn:uuid:d0908533-6371-42c0-9bf2-e66b70297640> | 3.171875 | 325 | Content Listing | Science & Tech. | 31.766067 | 95,605,852 |
The increasing atmospheric CO2 concentration probably will have significant direct effects on vegetation whether predicted changes in climate occur or not. Averaging over many prior greenhouse and growth chamber studies, plant growth and yield have typically increased more than 30%, with a doubling of CO2 concentration. Such a doubling also causes stomatal conductance to decrease about 37 which typically increases leaf temperatures more than 1-degrees-C, and which may decrease evapotranspiration, although increases in leaf area counteract the latter effect. Interactions between CO2 and climate variables also appear important. In one study the growth increase from near-doubled CO2 ranged from minus 60% at 12-degrees-C to 0% at 19-degrees-C to plus 130% at 34-degrees-C, suggesting that if the climate warms, the average growth response to doubled CO2 could be consistently higher than the 30% mentioned above. Even when growing in nutrient-poor soil, the growth response to elevated CO2 has been large, in contrast to nutrient solution studies which showed little response. Several studies have suggested that under water-stress, the CO2 growth stimulation is as large or larger than under wellwatered conditions. Therefore, the direct CO2 effect will compensate somewhat, if not completely, for a hotter drier climate. And if any climate change is small, then plant growth and crop yields will probably be significantly higher in the future high-CO2 world.
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Heat-loving or thermophilic bacteria (pictured here in orange and yellow) thrive in the extreme environment of hot springs such as this one in Yellowstone National Park. The microbes, which include photosynthetic cyanobacteria, form extensive multispecies communities called microbial mats that can be seen with the naked eye. Over time, the microbial mats interact with minerals in the water, forming hardened structures called microbialites—part rock, part microbe (pictured here as white pearl-shaped structures). This is an ancient process—the oldest fossil microbial mats, called stromatolites, are estimated to be around 3.5 billion years old.
For more on the amazing worlds of microbes watch “I Contain Multitudes”
This photograph was captured along the edge of a thermal stream flowing out from Octopus Spring, a hot spring in Yellowstone National Park, Wyoming, U.S.A.
Scott Chimileski, PhD and Roberto Kolter, PhD, Harvard Medical School, Boston, MA.
As seen in Life at the Edge of Sight: A Photographic Exploration of the Microbial World, Harvard University Press, 2017. | <urn:uuid:e4da9bef-7f25-4a87-8fde-3725c4c7293f> | 3.953125 | 234 | Knowledge Article | Science & Tech. | 35.690143 | 95,605,961 |
Oxy-fuel circulating fluidized bed combustion (CFBC) has an advantage of being operated with high oxygen concentration, making it a better choice for CO2 capture. In order to study the emission of nitrogen oxides and SO2 under O2/RFG (recycle flue gas) firing mode with an overall O2 concentration of 50%, oxy-fuel combustion experiments with Datong coal were carried out in a 0.1MWth oxy-fuel CFBC apparatus. The effects of different operating conditions on gaseous pollution emission, including gas staging combustion, oxygen staging combustion, and excess oxygen ratio were investigated. The experimental results show that a lower secondary flow ratio improves the sulfur capture efficiency, although the fuel N conversion increases slightly. Oxygen staging combustion, which means decreasing the oxygen concentration in the primary flow and increasing it in the secondary flow, is a new and safe method for oxy-fuel combustion with high oxygen concentration. A reasonably low excess oxygen ratio for the oxy-fuel CFBC operation is beneficial to simultaneously enable a decrease in the fuel N conversion and an improvement in the sulfur capture efficiency.
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Measures of Dispersion > Coefficient of Dispersion
What is a Coefficient of Dispersion (COD)?
The term “coefficient of dispersion” can mean a few different things in statistics. There isn’t one formula or definition that is universal. Everything depends on the context of where you’re using the coefficient and what you want to do with it:
- Informally, some people use “coefficient of dispersion” interchangeably with “Coefficient of Variation”.
- The Karl Pearson Coefficient of dispersion is simply the ratio of the standard deviation to the mean.
- Green’s COD (Cx) is suitable when dealing with densities. The formula is: sample variance/sample mean – 1/Σ(x-1).
- As a measure of dispersion around a median, you can use the formula:
This is almost exclusively used to deal with property and market values. For solution steps, see this New York State government sheet.
- The Quartile Coefficient of Dispersion (see below), which is one of the more popular versions of COD found in research.
What is a Quartile Coefficient of Dispersion?
- Q1 is the first quartile,
- Q3 is the third quartile.
The CoD tells you how spread out data sets are relative to each other. For example, if one data set has a CoD of 0.5 and another has a CoD of 0.10, then data set 1 is 5 times as great (0.5/0.10) as data set 2.
What is the quartile coefficient of dispersion for the following set of numbers?
2, 4, 6, 8, 10, 12, 14
Step 1 :Find the 25th percentile (Q1) and the 75th percentile (Q3). There are a few ways you can do this. One of the easiest ways is to use our interquartile range calculator. By hand, see: Finding Quartiles.
Plugging the data set into the calculator, we get:
- Q1 = 25th percentile = 4
- Q2 = 75th percentile = 12.
Bonett, D. G. (2006). Confidence interval for a coefficient of quartile variation. Computational Statistics & Data Analysis. 50 (11): 2953–2957
Green, R. (1966). Measurements of non-randomness in spatial distribution. Res. Popul. Ecol. 8:1-7.
M. Kendall and A. Stuart, The advanced theory of Statistics, Vol. 1, 4th Edition, Charles Grifin and Co.
If you prefer an online interactive environment to learn R and statistics, this free R Tutorial by Datacamp is a great way to get started. If you're are somewhat comfortable with R and are interested in going deeper into Statistics, try this Statistics with R track.Comments? Need to post a correction? Please post on our Facebook page. | <urn:uuid:143c9d29-0115-422a-bcbc-ba88a5fbdcb7> | 3.28125 | 635 | Tutorial | Science & Tech. | 70.427894 | 95,605,970 |
Photo courtesy of Kansas State UniversityMANHATTAN — Forget chemicals, catalysts, and expensive machinery—a Kansas State University team of physicists has discovered a way to mass-produce graphene with three ingredients: hydrocarbon gas, oxygen, and a spark plug.
Their method is simple: Fill a chamber with acetylene or ethylene gas and oxygen. Use a vehicle spark plug to create a contained detonation. Collect the graphene that forms afterward.
Chris Sorensen, Cortelyou-Rust university distinguished professor of physics, is the lead inventor of the recently issued patent, "Process for high-yield production of graphene via detonation of carbon-containing material." Other Kansas State University researchers involved include Arjun Nepal, postdoctoral researcher and instructor of physics, and Gajendra Prasad Singh, former visiting scientist.
"We have discovered a viable process to make graphene," Sorensen said. "Our process has many positive properties, from the economic feasibility, the possibility for large-scale production and the lack of nasty chemicals. What might be the best property of all is that the energy required to make a gram of graphene through our process is much less than other processes because all it takes is a single spark."
Graphene is a single atom-thick sheet of hexagonally coordinated carbon atoms, which makes it the world's thinnest material. Since graphene was isolated in 2004, scientists have found it has valuable physical and electronic properties with many possible applications, such as more efficient rechargeable batteries or better electronics.
Video credit: Kansas State University
For Sorensen's research team, the serendipitous path to creating graphene started when they were developing and patenting carbon soot aerosol gels. They created the gels by filling a 17-liter aluminum chamber with acetylene gas and oxygen. Using a spark plug, they created a detonation in the chamber. The soot from the detonation formed aerosol gels that looked like "black angel food cake," Sorensen said.
But after further analysis, the researchers found that the aerosol gel was more than lookalike dark angel food cake—it was graphene.
"We made graphene by serendipity," Sorensen said. "We didn't plan on making graphene. We planned on making the aerosol gel and we got lucky."
But unlike other methods of creating graphene, Sorensen's method is simple, efficient, low-cost, and scalable for industry.
Photo courtesy of Kansas State UniversityOther methods of creating graphene involve "cooking" the mineral graphite with chemicals—such as sulfuric acid, sodium nitrate, potassium permanganate, or hydrazine—for a long time at precisely prescribed temperatures. Additional methods involve heating hydrocarbons to 1,000 degrees Celsius in the presence of catalysts.
Such methods are energy intensive—and even dangerous—and have low yield, while Sorensen and his team's method makes larger quantities with minimal energy and no dangerous chemicals.
"The real charm of our experiment is that we can produce graphene in the quantity of grams rather than milligrams," Nepal said.
Now the research team—including Justin Wright, doctoral student in physics, Camp Hill, Pennsylvania—is working to improve the quality of the graphene and scale the laboratory process to an industrial level. They are upgrading some of the equipment to make it easier to get graphene from the chamber seconds—rather than minutes—after the detonation. Accessing the graphene more quickly could improve the quality of the material, Sorensen said.
The patent was issued to the Kansas State University Research Foundation, a nonprofit corporation responsible for managing technology transfer activities at the university.
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Washington: A new monkey species with unique calico colouring has been spotted in the Amazon rainforest.
Due to deforestation in the region, the new monkey species, believed to be belonging to the Pithecia genus, is already endangered, the researchers suggested.
The new saki Saki monkey (any primate member of the Pithecia genus) was spotted on three separate occasions in a part of the Amazon rain forest, according to a new study from the University of Mato Grosso in Brazil.
"We sent the first pictures to an expert, but everything suggests that it is a new species. The characteristics are very different," biologist Manoel dos Santos Filho was quoted as telling Brazilian news agency G1 Globo.
These animals live in rainforests ranging across South America from South Colombia to Central Brazil, Nature World News reported.
They can reach up to 50 centimeters long and weigh about 4.4 pounds.
This species is very elusive in nature and they rarely leave the trees that they live in. | <urn:uuid:e519e9b5-9e1c-4958-a379-fc8cd6140dc6> | 2.71875 | 211 | News Article | Science & Tech. | 39.535758 | 95,606,038 |
Simultaneous estimation of survival, reproduction, and movement is essential to understanding how species maximize lifetime reproduction in environments that vary across space and time. We conducted a four-year, capture-recapture study of three populations of eastern tiger salamanders (Ambystoma tigrinum tigrinum) and used multistate mark-recapture statistical methods to estimate the manner in which movement, survival, and breeding probabilities vary under different environmental conditions across years and among populations and habitats. We inferred how individuals may mitigate risks of mortality and reproductive failure by deferring breeding or by moving among populations. Movement probabilities among populations were extremely low despite high spatiotemporal variation in reproductive success and survival, suggesting possible costs to movements among breeding ponds. Breeding probabilities varied between wet and dry years and according to whether or not breeding was attempted in the previous year. Estimates of survival in the nonbreeding, forest habitat varied among populations but were consistent across time. Survival in breeding ponds was generally high in years with average or high precipitation, except for males in an especially ephemeral pond. A drought year incurred severe survival costs in all ponds to animals that attempted breeding. Female salamanders appear to defer these episodic survival costs of breeding by choosing not to breed in years when the risk of adult mortality is high. Using stochastic simulations of survival and breeding under historical climate conditions, we found that an interaction between breeding probabilities and mortality limits the probability of multiple breeding attempts differently between the sexes and among populations.
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ESA's XMM-Newton observatory has discovered the best-ever candidate for a very rare and elusive type of cosmic phenomenon: a medium-weight black hole in the process of tearing apart and feasting on a nearby star،spacedaily reported.
There are various types of black hole lurking throughout the Universe: massive stars create stellar-mass black holes when they die، while galaxies host supermassive black holes at their centres، with masses equivalent to millions or billions of Suns.
Lying between these extremes is a more retiring member of the black hole family: intermediate-mass black holes. Thought to be seeds that will eventually grow to become supermassive، these black holes are especially elusive، and thus very few robust candidates have ever been found.
Now، a team of researchers using data from ESA's XMM-Newton X-ray space observatory، as well as NASA's Chandra X-Ray Observatory and Swift X-Ray Telescope، has found a rare telltale sign of activity. They detected an enormous flare of radiation in the outskirts of a distant galaxy، thrown off as a star passed too close to a black hole and was subsequently devoured.
"This is incredibly exciting: this type of black hole hasn't been spotted so clearly before،" says lead scientist Dacheng Lin of the University of New Hampshire، USA.
"A few candidates have been found، but on the whole they're extremely rare and very sought after. This is the best intermediate-mass black hole candidate observed so far."
This breed of black hole is thought to form in various ways. One formation scenario is the runaway merger of massive stars lying within dense star clusters، making the centres of these clusters one of the best places to hunt for them. However، by the time such black holes have formed، these sites tend to be devoid of gas، leaving the black holes with no material to consume and thus little radiation to emit - which in turn makes them extremely difficult to spot.
"One of the few methods we can use to try to find an intermediate-mass black hole is to wait for a star to pass close to it and become disrupted - this essentially 'activates' the black hole's appetite again and prompts it to emit a flare that we can observe،" adds Lin.
"This kind of event has only been clearly seen at the centre of a galaxy before، not at the outer edges."
Lin and colleagues sifted through data from XMM-Newton to find the candidate. They identified it in observations of a large galaxy some 740 million light-years away، taken in 2006 and 2009 as part of a galaxy survey، and in additional data from Chandra (2006 and 2016) and Swift (2014).
"We also looked at images of the galaxy taken by a whole host of other telescopes، to see what the emission looked like optically،" says co-author Jay Strader of Michigan State University، USA.
"We spotted the source flaring in brightness in two images from 2005 - it appeared far bluer and brighter than it had just a few years previously. By comparing all the data we determined that the unfortunate star was likely disrupted in October 2003 in our time، and produced a burst of energy that decayed over the following 10 years or so."
The scientists believe that the star was disrupted and torn apart by a black hole with a mass of around fifty thousand times that of the Sun.
Such star-triggered outbursts are expected to only happen rarely from this type of black hole، so this discovery suggests that there could be many more lurking in a dormant state in galaxy peripheries across the local Universe.
"This candidate was discovered via an intensive search of XMM-Newton's X-ray Source Catalogue، which is filled with high-quality data covering large areas of sky، essential for determining how large the black hole was and what happened to cause the observed burst of radiation،" says Norbert Schartel، ESA Project Scientist for XMM-Newton.
"The XMM-Newton X-ray Source Catalogue is presently the largest catalogue of this type، containing more than half a million sources: exotic objects like the one discovered in our study are still hidden there and waiting to be discovered through intensive data mining،" adds co-author Natalie Webb، director of the XMM-Newton Survey Science Center at theResearch Institute in Astrophysics and Planetology (IRAP) in Toulouse، France.
"Learning more about these objects and associated phenomena is key to our understanding of black holes. Our models are currently akin to a scenario in which an alien civilisation observes Earth and spots grandparents dropping their grandchildren at pre-school: they might assume that there's something intermediate to fit their model of a human lifespan، but without observing that link، there's no way to know for sure. This finding is incredibly important، and shows that the discovery method employed here is a good one to use،" concludes Norbert.
“ON Live” satellite channel featured a reported about the news. | <urn:uuid:5b5e2796-0884-4da8-b89d-c0bc3260a22b> | 3.234375 | 1,071 | News Article | Science & Tech. | 33.512203 | 95,606,058 |
Redox Equilibria: Variable Oxidation States, Electrode Potentials, Electrochemical Series
Edited by Jamie (ScienceAid Editor), Taylor (ScienceAid Editor), vcdanht
Variable Oxidation States
On of the properties of transition metals is their variable oxidation states. This is crucial for looking at their reactions; the rules for working out the oxidation number is exactly the same in transition metals. The oxidation state of a metal can change in redox reactions. We represent this change of individual elements in half equations. Have a look at the example below.
When combining half equations; once you have them both (one for reduction and one for oxidation), you must make the number of electrons in each the same, then it is a simple matter of combining the two.
When a zinc wire is placed in a solution of zinc ions, an equilibrium of electrons leaving and joining zinc is set up. Zn (s) ==>> Zn2+ + 2e- By convention however, half equations are written as reductions, therefore the above equilibrium will be reversed. This also means that any enthalpy change will also be reversed.
If the equilibrium is more to the right and the zinc dissolves, a negative charge will build up. This arrangement is called a half cell, and if we could measure the charge, it would indicate how readily electrons are released and hence how good a reducing agent the metal is. This is the electrode potential.
It is possible however to form a circuit and measure the potential difference using a voltmeter. In order to do this, two half cells are made and connected via a salt bridge. A simple salt bridge would be filter paper soaked in salt solution. A wire cannot be used to complete the circuit because that would create another half cell.
Below the diagram is written the standard representation of cells. The single lines represent a change in phase and the double lines (sometimes dashed) represent the salt bridge. It can also be written if the oxidation state of a species changes, in this case a comma separates them. Or, if a platinum electrode is used because the particular element does not exist has a solid (as is the case with the standard hydrogen electrode) it will be written as below.
Pt | H2 (aq) | 2H+ (aq) || ...
In order to compare the electrode potential of different metals, it is important to use a standard cell to connect to other half cells to. For this, we use the hydrogen electrode.
Hydrogen is bubbled in to the solution and the black platinum wire is used to conduct electricity to the voltmeter. The potential of the hydrogen electrode is defined as zero, so when it is connected to another half cell the voltage, known as the electromotive force (e.m.f or E) can be measured - this is the electrode potential. However, the hydrogen electrode is difficult to use so it is much easier to use a secondary standard such as the calomel electrode or silver/silver chloride. These are calibrate against the hydrogen electrode. To calculate the standard E (Eθ) the second cell must be in standard conditions too: ions at 1 moldm-3, 298K.
A more positive Eθ means the metal is a strong oxidizing agent (a substance oxidizing another and itself reduced), and negative are strong reducing agents.
A list of electrode potentials is called an electrochemical series and these can be used to predict the direction of a redox reaction. It is possible to calculate the feasibility of a redox reaction using their E values the calculations involved are outlined below.
Referencing this Article
If you need to reference this article in your work, you can copy-paste the following depending on your required format:
APA (American Psychological Association)
Redox Equilibria: Variable Oxidation States, Electrode Potentials, Electrochemical Series. (2017). In ScienceAid. Retrieved Jul 22, 2018, from https://scienceaid.net/chemistry/physical/redeq.html
MLA (Modern Language Association) "Redox Equilibria: Variable Oxidation States, Electrode Potentials, Electrochemical Series." ScienceAid, scienceaid.net/chemistry/physical/redeq.html Accessed 22 Jul 2018.
Chicago / Turabian ScienceAid.net. "Redox Equilibria: Variable Oxidation States, Electrode Potentials, Electrochemical Series." Accessed Jul 22, 2018. https://scienceaid.net/chemistry/physical/redeq.html.
Categories : Physical
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Since C is not an object oriented language, creating a derived hash table requires sticking together some boilerplate routines with a few differences specific to the type of hash table you want to create.
An example of a derived hash table is the linker hash table.
The structures for this are defined in
functions are in
You may also derive a hash table from an already derived hash table. For example, the a.out linker backend code uses a hash table derived from the linker hash table.
220.127.116.11 Define the derived structures 18.104.22.168 Write the derived creation routine 22.214.171.124 Write other derived routines
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According to Natural News, radiation from Fukushima has reached the shores of California. This has been confirmed by county officials in Half Moon Bay, California, who conducted radiation tests and found a 500% increase in radiation on the beaches there.
It has been confirmed that TEPCO lied about radiation readings at the Fukushima Dai-Ichi nuclear power plants. Actual radiation releases were as much as 18 times higher than "official" reports.
It is now widely believed by nuclear experts that radioactive elements such as cesium-137 have entered the food chain in the Pacific Ocean and have begun to arrive on the shores of California. This means seafood caught in the Pacific Ocean must now be tested for radiation.
For more information, log onto:
"It is no exaggeration to say that the fate of Japan and the whole world depends on No. 4 reactor." - Mitsuhei Murata, Former Japanese Ambassador to Switzerland and Senegal, Executive Director, the Japan Society for Global System and Ethics.
If reactor No. 4 suffers even a minor earthquake, it could set off a chain reaction of events that quickly lead to North America becoming uninhabitable by humans for centuries to come. Imagine California, Oregon and Washington states being inundated with radiation -- up to 85 times the radiation release from Chernobyl. We're talking about the end of human life on the scale of continents.
According to Mr. Robert Alvarez, former Senior Policy Adviser to the Secretary and Deputy Assistant Secretary for National Security and the Environment at the U.S. Department of Energy:
"The No. 4 pool is about 100 feet above ground, is structurally damaged and is exposed to the open elements. If an earthquake or other event were to cause this pool to drain this could result in a catastrophic radiological fire involving nearly 10 times the amount of Cs-137 released by the Chernobyl accident. The infrastructure to safely remove this material was destroyed as it was at the other three reactors. Spent reactor fuel cannot be simply lifted into the air by a crane as if it were routine cargo. In order to prevent severe radiation exposures, fires and possible explosions, it must be transferred at all times in water and heavily shielded structures into dry casks. As this has never been done before, the removal of the spent fuel from the pools at the damaged Fukushima-Dai-Ichi reactors will require a major and time-consuming re-construction effort and will be charting in unknown waters."
To see some fascinating and interesting clips regarding the horrifying truth about the Fukushima issue and more, one can easily log onto: | <urn:uuid:950f21f7-dee9-451b-88f9-e88956c81b29> | 3.078125 | 522 | Personal Blog | Science & Tech. | 38.096453 | 95,606,110 |
The role of the US Great Plains low-level jet in nocturnal migrant behavior
- 333 Downloads
The movements of aerial animals are under the constant influence of atmospheric flows spanning a range of spatiotemporal scales. The Great Plains nocturnal low-level jet is a large-scale atmospheric phenomenon that provides frequent strong southerly winds through a shallow layer of the airspace. The jet can provide substantial tailwind assistance to spring migrants moving northward, while hindering southward migration during autumn. This atmospheric feature has been suspected to play a prominent role in defining migratory routes, but the flight strategies used with respect to these winds are yet to be examined. Using collocated vertically pointing radar and lidar, we investigate the altitudinal selection behavior of migrants over Oklahoma during two spring and two autumn migration seasons. In general, migrants choose to fly within the jet in spring, often concentrating in the favorable wind speed maximum. Autumn migrants typically fly below the jet, although some will rapidly climb to reach altitudes above the inhibiting winds. The intensity of migration was relatively constant throughout the spring due to the predominantly favorable southerly jet winds. Conversely, autumn migrants were more apt to delay departure to wait for the relatively infrequent northerly winds.
KeywordsAeroecology Lidar Low-level jet Migration Radar Wind assistance
The lidar and Ka-band radar data were obtained from the Atmospheric Radiation Measurement (ARM) Climate Research Facility, a U.S. Department of Energy Office of Science user facility sponsored by the Office of Biological and Environmental Research. This work was partially supported by NSF Grant EF-1340921. The authors wish to thank Dr. Tim Bonin for providing the lidar processing algorithm. Discussions with Dr. Alan Shapiro improved the work contained herein.
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- Widener K, Bharadwaj N, Johnson K (2012) Ka-band arm zenith radar handbook. ARM Technical report DOE/SC-ARM/TR-106, 19 pGoogle Scholar | <urn:uuid:7f0c9f37-c3bb-4206-a3f8-2496a93e06ec> | 2.875 | 775 | Academic Writing | Science & Tech. | 42.955669 | 95,606,132 |
Rutgers' Nicole Fahrenfeld leads research documenting impacts in stream water and sediments from a wastewater disposal facility
Wastewater from oil and gas operations -- including fracking for shale gas -- at a West Virginia site altered microbes downstream, according to a Rutgers-led study.
The study, published recently in Science of the Total Environment, showed that wastewater releases, including briny water that contained petroleum and other pollutants, altered the diversity, numbers and functions of microbes. The shifts in the microbial community indicated changes in their respiration and nutrient cycling, along with signs of stress.
The study also documented changes in antibiotic resistance in downstream sediments, but did not uncover hot spots, or areas with high levels of resistance. The findings point to the need to understand the impacts on microbial ecosystems from accidental releases or improper treatment of fracking-related wastewater. Moreover, microbial changes in sediments may have implications for the treatment and beneficial reuse of wastewater, the researchers say.
"My hope is that the study could be used to start making hypotheses about the impacts of wastewater," said Nicole Fahrenfeld, lead author of the study and assistant professor in Rutgers' Department of Civil and Environmental Engineering. Much remains unknown about the impacts of wastewater from fracking, she added.
"I do think we're at the beginning of seeing what the impacts could be," said Fahrenfeld, who works in the School of Engineering. "I want to learn about the real risks and focus our efforts on what matters in the environment."
Underground reservoirs of oil and natural gas contain water that is naturally occurring or injected to boost production, according to the U.S. Geological Survey (USGS), whose scientists contributed to the study. During fracking, a fracturing fluid and a solid material are injected into an underground reservoir under very high pressure, creating fractures to increase the porosity and permeability of rocks.
Liquid pumped to the surface is usually a mixture of the injected fluids with briny water from the reservoir. It can contain dissolved salt, petroleum and other organic compounds, suspended solids, trace elements, bacteria, naturally occurring radioactive materials and anything injected into wells, the USGS says. Such water is recycled, treated and discharged; spread on roads, evaporated or infiltrated; or injected into deep wells.
Fracking for natural gas and oil and its wastewater has increased dramatically in recent years. And that could overwhelm local infrastructure and strain many parts of the post-fracking water cycle, including the storage, treatment, reuse, transportation or disposal of the wastewater, according to the USGS.
For the Rutgers-USGS study, water and sediment samples were collected from tributaries of Wolf Creek in West Virginia in June 2014, including an unnamed tributary that runs through an underground injection control facility.
The facility includes a disposal well, which injects wastewater to 2,600 feet below the surface, brine storage tanks, an access road and two lined ponds (now-closed) that were used to temporarily store wastewater to allow particles to settle before injection.
Water samples were shipped to Rutgers, where they were analyzed. Sediment samples were analyzed at the Waksman Genomics Core Facility at Rutgers. The study generated a rich dataset from metagenomic sequencing, which pinpoints the genes in entire microbial communities, Fahrenfeld noted.
"The results showed shifts in the microbial community and antibiotic resistance, but this site doesn't appear to be a new hot spot for antibiotic resistance," she said. The use of biocides in some fracturing fluids raised the question of whether this type of wastewater could serve as an environment that is favorable for increasing antimicrobial resistance. Antimicrobial resistance detected in these sediments did not rise to the levels found in municipal wastewater - an important environmental source of antimicrobial resistance along with agricultural sites.
Antibiotics and similar drugs have been used so widely and for so long that the microbes the antibiotics are designed to kill have adapted to them, making the drugs less effective, according to the U.S. Centers for Disease Control and Prevention. At least 2 million people become infected with antibiotic-resistant bacteria each year in the U.S., with at least 23,000 of them dying from the infections.
"We have this really nice dataset with all the genes and all the microbes that were at the site," Fahrenfeld said. "We hope to apply some of these techniques to other environmental systems."
Study authors include Rutgers undergraduate Hannah Delos Reyes and Rutgers doctoral candidate Alessia Eramo. Other authors include Denise M. Akob, Adam C. Mumford and Isabelle M. Cozzarelli of the U.S. Geological Survey's National Research Program. Mumford earned a doctorate in microbiology at Rutgers.
Todd B. Bates | EurekAlert!
Barium ruthenate: A high-yield, easy-to-handle perovskite catalyst for the oxidation of sulfides
16.07.2018 | Tokyo Institute of Technology
The secret sulfate code that lets the bad Tau in
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For the first time ever, scientists have determined the cosmic origin of highest-energy neutrinos. A research group led by IceCube scientist Elisa Resconi, spokesperson of the Collaborative Research Center SFB1258 at the Technical University of Munich (TUM), provides an important piece of evidence that the particles detected by the IceCube neutrino telescope at the South Pole originate from a galaxy four billion light-years away from Earth.
To rule out other origins with certainty, the team led by neutrino physicist Elisa Resconi from the Technical University of Munich and multi-wavelength...
For the first time a team of researchers have discovered two different phases of magnetic skyrmions in a single material. Physicists of the Technical Universities of Munich and Dresden and the University of Cologne can now better study and understand the properties of these magnetic structures, which are important for both basic research and applications.
Whirlpools are an everyday experience in a bath tub: When the water is drained a circular vortex is formed. Typically, such whirls are rather stable. Similar...
Physicists working with Roland Wester at the University of Innsbruck have investigated if and how chemical reactions can be influenced by targeted vibrational excitation of the reactants. They were able to demonstrate that excitation with a laser beam does not affect the efficiency of a chemical exchange reaction and that the excited molecular group acts only as a spectator in the reaction.
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Ultra-short, high-intensity X-ray flashes open the door to the foundations of chemical reactions. Free-electron lasers generate these kinds of pulses, but there is a catch: the pulses vary in duration and energy. An international research team has now presented a solution: Using a ring of 16 detectors and a circularly polarized laser beam, they can determine both factors with attosecond accuracy.
Free-electron lasers (FELs) generate extremely short and intense X-ray flashes. Researchers can use these flashes to resolve structures with diameters on the...
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HTML stands for Hyper Text Markup Language. The purpose of HTML is to make web pages or web documents. A markup language process and present the information within markup tags.
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Determination Of The Thermal Offset Of The Eppley Precision Spectral Pyranometer
Smith, A. M.
Rutledge, C. K.
Charlock, T. P.
Mahan, J. Robert
MetadataShow full item record
Eppley's precision spectral pyranometer (PSP) is used in networks around the world to measure down-welling diffuse and global solar irradiance at the surface of the Earth. In recent years several studies have shown significant discrepancy between irradiances measured by pyranometers and those computed by atmospheric radiative transfer models. Pyranometer measurements have been questioned because observed diffuse irradiances sometimes are below theoretical minimum values for a pure molecular atmosphere, and at night the instruments of ten produce nonzero signals ranging between +5 and -10 W m(-2). We install thermistor sondes in the body of a PSP as well as on its inner dome to monitor the temperature gradients within the instrument, and we operate a pyrgeometer (PIR) instrument side by side with the PSP. We derive a relationship between the PSP output and thermal radiative exchange by the dome and the detector and a relationship between the PSP output and the PIR thermopile output (net-IR). We determine the true PSP offset by quickly capping the instrument at set time intervals. For a ventilated and shaded PSP, the thermal offset can reach -15 W m(-2) under clear skies, whereas it remains close to zero for low overcast clouds. We estimate the PSP thermal offset by two methods: (1) using the PSP temperatures and (2) using the PIR net-IR signal. The offset computed from the PSP temperatures yields a reliable estimate of the true offset (+/-1 W m(-2)). The offset computed from net-IR is consistent with the true offset at night and under overcast skies but predicts only part of the true range under clear skies. (C) 2001 Optical Society of America. | <urn:uuid:b3357d0b-9c40-47fc-af17-4b5f466f4e14> | 2.765625 | 433 | Academic Writing | Science & Tech. | 47.619628 | 95,606,167 |
Scientists uncover dinosaur footprint that may be world’s largest
Scientists have found what could be the world’s largest dinosaur footprint — measuring nearly 1.7 metres (5.6 ft) — on a remote part of Australia’s northwestern coastline
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Sydney: Scientists have found what could be the world’s largest dinosaur footprint — measuring nearly 1.7 metres (5.6 ft) — on a remote part of Australia’s northwestern coastline.
The footprint from a giant sauropod dinosaur was among 21 types of tracks found on the Dampier Peninsula in Western Australia, 130 km (80 miles) from the beach resort town of Broome.
“They are bigger than anything that has been recorded anywhere in the world,” said Steve Salisbury, the lead author of a joint study by the University of Queensland and James Cook University.
Sauropods were four-legged plant-eaters with long necks and tails, pillar-like legs and immense bodies. Sauropod footprints measuring 1.2 metres (4 feet) were found in Germany in 2015.
The rocks containing the tracks at Dampier date back 127 million to 144 million years, older than previous dinosaur fossil discoveries in Australia, Salisbury said.
“Most of our dinosaur fossils come from the east coast, or east Australia, and they are between 115 million and 90 million years old,” Salisbury said.
The scientists also found tracks from six types of meat-eating dinosaurs and the first evidence of armoured stegosaurs.
The study was initiated by the indigenous Goolarabooloo community, which has known about the tracks for generations and feared the footprints on James Price Point would be lost after it was chosen as a potential site for an LNG project, Salisbury said.
Scientists used drones and light aircraft to photograph the tracks on the peninsula, which is known for its difficult terrain, weather and tides.
“What makes it really tricky is that the rocks where the tracks occur are only in the intertidal zone,” Salisbury said.
“They are under water half the time and there are daily tides of up to 10 meters,” he said. Reuters
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On August 6, 2012, the NASA Curiosity rover landed on Mars at the base of Mount Sharp, a mountain the size of Kilimanjaro (roughly 19,000 feet) in the middle of Gale Crater. Nina Lanza, space scientist at the Los Alamos National Laboratory, remembers the day well. As part of the team that built ChemCam, one of the ten instruments on the rover, she spent three months at the Jet Propulsion Laboratory in California, living on “Mars time” to follow Curiosity’s first “steps.”
ChemCam stands for “chemistry camera” and comprises a laser-induced breakdown spectroscopy (LIBS) instrument and a Remote Micro Imager (RMI). It was built at the Los Alamos National Laboratory in collaboration with the French space agency CNES. Nina Lanza and postdoctoral fellow Patrick Gasda are two of the Los Alamos scientists who work on the instrument.
“We get to shoot a laser on Mars for a living,” Lanza says, grinning.
And the laser on ChemCam is extremely powerful. When focused on a target, it vaporizes a small amount of material by heating Martian rocks to a temperature that’s roughly equivalent to that of the surface of the sun. “When we fire at a nearby target,” Gasda explains, “the elements get excited and, as they come down from that excited state, they emit light.”
By looking at the light emitted by the target, scientists can analyze the composition of rocks and soils on Mars. Previous Mars missions have found ice in the near-surface at high latitudes, begging the question: was there ever water on other parts of Mars at some point? And if there was—does that mean there could have been life, too?
With the very first laser shots from ChemCam, the answer was a definitive yes. “ChemCam discovered that all Martian dust is hydrated,” Lanza explains. “Given how dusty Mars is, this means that water is everywhere on the planet. We also found evidence that water was flowing in Mars’s past.”
“Gale Crater was filled with water,” Gasda adds. “From the sequence of sedimentary rocks we know of flowing streams in the crater that converged to a large body of still water that likely lasted for millions of years.”
“Curiosity gave us a picture of Gale Crater as an extremely habitable system,” Lanza continues. “We know that on Earth systems like this, with long-lasting neutral pH waters, would definitely support life.”
But how do you go about finding evidence for life? You search for clues, in other words, unique markers that identify biological activity.
“A potential marker could be manganese minerals,” Lanza says. In 2016 Curiosity found rocks rich in manganese-oxides at a location called Kimberley. “Manganese deposits in the terrestrial geological record mark the shift to higher concentrations of atmospheric oxygen due to the emergence of photosynthesis. This means that there could have been more oxygen in the Martian atmosphere in the past.”
Water. Oxygen. What about other building blocks of life? How do we look for those?
“Some nucleic and amino acids have been found in space,” Gasda tells me. “However, sugars like ribose—the R in RNA, one of the first building blocks of life—are too unstable to be found in space. In order to have life, you need molecules that stabilize these sugars in water. Borates are particularly promising molecules for stabilizing sugars.”
Boron is highly soluble in water. In 2013 researchers from the University of Hawaii found boron in a meteorite from Mars. That’s when Gasda became interested in this quest. “Once we knew that Gale Crater had once hosted a large body of water, it was natural to search for borates in those sediments.”
ChemCam did indeed find boron on Mars in 2016. Together with the manganese oxides, this is still not sufficient evidence for life on Mars, but it shows that some of the raw ingredients were present. The scientists are primed to keep looking. Curiosity has been on Mars almost five years (or 1660 sols), and its data is helping researchers fine-tune the instruments for the next Mars rover, provisionally named Mars 2020, to be launched in July 2020.
“We need to look for biosignatures,” Lanza says. “And we may not find them. But if we don’t, to me, the most striking question would be: what if there were indeed all the ingredients for life on Mars, yet life never happened? What made Earth so unique that life could happen here but nowhere else?”
Gasda nods. “And if we are indeed unique, shouldn’t this make us feel more special, and make us more cautious about the way we treat our planet and our biodiversity?”
I mention the current political climate, with the planned budget cuts to scientific research, and the appalling denial of any intervention to curb global warming.
“These cuts to basic research are disheartening,” Lanza says. “People often think of NASA research as esoteric and out of touch. And yet almost everyone has GPS technology on their smart phones today, something we owe to space research. Take the electron as another example. I’m sure people in the nineteenth century found J. J. Thomson’s research on the electron to be highly academic, with few practical applications. Yet without his discovery we wouldn’t have electricity, and our lives today would be fundamentally different.”
“The best measure for progress,” Lanza concludes, “is when you can’t imagine the knowledge you are going to gain. Let the science surprise you.”
Nina Lanza is a staff scientist, and Patrick Gasda is a postdoctoral research fellow, both in the Space and Remote Sensing group at the Los Alamos National Laboratory and on the science team for the Curiosity Mars rover mission. The opinions expressed here are their own and not their employer’s. Both will be speaking at the March for Science in Santa Fe, New Mexico, on April 22nd. | <urn:uuid:227a8e41-a06a-44e3-8629-b4f0ec117232> | 4.375 | 1,345 | News Article | Science & Tech. | 51.018981 | 95,606,178 |
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Fill in the blanks below.
Neptune cannot be seen using the _____________________________ alone. Neptune was the first planet whose existence was predicted mathematically in ___________________________ independently by J.C. Adams and Le Verrier (the planet Uranus's orbit was perturbed by an unknown object which turned our to be another gas giant, Neptune). Neptune was then observed by J.G. Galle and d'Arrest later that year. Neptune was named for the mythical Roman god of the seas.
Neptune is about 30,775 miles (49,528 km) in diameter. This is 3.88 times the diameter of the Earth. If Neptune were _____________________________, it could hold almost 60 _____________________________.
Neptune's mass is about 1.02 x 1026 kg. This is over 17 times the _____________________________ of the Earth, but the gravity on Neptune is only 1.19 times of the gravity on Earth. This is because it is such a large planet (and the _____________________________ force a planet exerts upon an object at the planet's surface is proportional to its mass and to the inverse of its radius squared). A 100-pound person would weigh _________________________ pounds on Neptune.
Each day on Neptune takes 19.1 Earth hours. A year on Neptune takes 164.8 Earth years; it takes almost 165 Earth years for Neptune to orbit the Sun once. Since _____________________________ was discovered in 1846, it has not yet completed a single revolution around the __________________________.
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Recent accomplishments of CDFW's scientific community
Porcupine1: NRVP participants Greg Moore, Mike Maulhardt, Charles Brown and Ben Smith volunteered to service and maintain porcupine stations at Red Lake Wildlife Area.
Not to put too fine a point on it, but studying California’s porcupines hasn’t traditionally been a high priority for CDFW.
Wildlife research funding is limited, especially for non-game species, and species listed as threatened or endangered are typically given top priority. That means that scientists sometimes need to be creative – and frugal – in their efforts to survey and manage non-listed, non-game species.
Stacy Anderson, a CDFW senior environmental scientist specialist based in Rancho Cordova, recently conducted a pilot project that does just that.
Anderson developed an interest in the North American porcupine (Erethizon dorsatum) in 2017, after acknowledging that anecdotal evidence seems to indicate their numbers are on the decline.
Porcupines have historically inhabited diverse habitats including Humboldt County, along the Sacramento River, in the Coast Ranges, the Klamath Mountains, the southern Cascades, the Modoc Plateau and the Sierra Nevada. But in her conversations with unit biologists and wildlife officers in some of these areas, Anderson took note that many were reporting a substantial decrease in the number of calls from residents whose property – typically wood structures such as decks and outhouses – had been damaged by porcupines in recent decades. Informal surveys of veterinarians across the state also indicated a decline in the number of pet owners seeking quill removal from their pets.
Perhaps most telling, CDFW’s Sierra Nevada monitoring project, which has studied portions of the Sierra for the past nine years, has documented only seven porcupine sightings out of 750 stations surveyed via trail camera.
“We are worried about them because we don’t have a lot of sightings,” Anderson said. They live in low densities and they have only have one baby per year, so they don’t repopulate quickly.”
Recognizing the need to gather more information, Anderson and Evan King, another CDFW environmental scientist, launched a pilot effort last year to improve surveillance of porcupine, with a long-term goal of determining distribution and population numbers.
Anderson and King were inspired by the work of Uldis Roze, a researcher who has long studied porcupines in the Catskills of New York by using wood soaked in salt brine as a porcupine attractant. His research indicates that porcupines show a strong seasonality of salt use, which peaks in April through May and August through September. Because porcupines’ diet of plant matter is generally low in sodium (salt), they seek out other dietary sources of sodium to maintain normal levels in their bodies.
Anderson and King theorized that brined wood could be effective in attracting California porcupines, too. A plan was made to soak stakes made from 2x2s in a sodium brine to monitor activity. In theory, tooth scrapings on the wood could also be identified to species.
“It’s not a full-blown study – it’s just a way to test a plan of action that can maybe be used in a study later,” Anderson explained. “We don’t want to waste valuable resources on untested methodology, so this is a way to find out first if the methodology is going to work. It’s a low-cost, high yield approach.”
Twenty-three stations were set up for the 2017 pilot project, which was conducted from April to October. Members of CDFW’s Natural Resources Volunteer Program, who support departmental operations, supplied much of the labor, and the study costs were kept low. Expenses added up to less than $100, including salt for brining and wood. Trail cameras borrowed from other researchers were utilized to help monitor the stations.
Researchers were pleased to learn that the porcupines took to their efforts with a grain of salt (so to speak). They determined that brined-wood monitoring is more effective than traditional bait or game-trail monitoring, at least in the study area in northern Sierra and along the Sacramento River. Preliminary results indicate that the brined wood appeared to lure porcupines into the area of a camera station -- although most did not approach the wood and fewer still left a distinctive chew mark on the brined wood. But the trail cameras provided clear, useful photographs.
“We still have unanswered questions about this technique that will need to be addressed before we can consider it a success,” Anderson said. “However, our pilot efforts are promising.”
CDFW is seeking additional funding through state wildlife grants and collaborative efforts with other researchers and agencies to gain a better understanding of the North American porcupine’s status. Anderson plans to continue refining the methodology of her study, along with other survey techniques including habitat surveys, feeding signs, tree girdling, scat searches and the use of detection dogs.
Anderson also encourages members of the public to help CDFW’s efforts by reporting detections of live or “roadkill” porcupines.
CDFW Photos. Top Photo: Porcupine photo by CDFW Warden Chad Alexander.
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Around the world, freshwater ecosystems support tens of thousands of unique species and hundreds of millions of people. Zeb Hogan leads a multi-year effort to document the 30+ species of giant freshwater fish, the real life Loch Ness monsters of the aquatic world. Through the project, Hogan travels to the most endangered of these environments, striving to understand and save threatened fish and identify ways to sustain the livelihoods of people who share their habitats. Zeb’s search for the world’s largest freshwater fish is about far more than finding the big one. It is the story of the health of the world’s rivers and lakes. It is the story of the people who depend on fish and freshwater to survive. And it’s the story of how we view our world, and how the existence of these amazing fish make our lives richer, and Earth a better home, not just for us but for all life, big and small.
Presenter information: Dr. Zeb Hogan has spent the last 20 years studying the world’s freshwater ecosystems, working to merge conservation science with education and action. He is currently a research assistant professor at the University of Nevada-Reno, a National Geographic Society Fellow, United Nations Convention on Migratory Species Scientific Councilor for Fish, and presenter for the National Geographic television series “Monster Fish.” Zeb’s research with the Mekong Fish Conservation Project and other National Geographic-sponsored projects have aided in understanding migratory patterns and population structures of imperiled giant freshwater fish. Zeb received his Ph.D. in ecology from the University of California, Davis in 2004. His research has been featured in scientific journals including Science, American Scientist, and Conservation Biology and popular publications such as Wired, Time, and National Geographic Magazine.
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Details07/26/2018 18:30:0007/26/2018 19:30:00America/Los_AngelesFrances Humphrey Lecture Series: Monster Fish by Zeb HoganReno, NV
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Rotation is key to the performance of salad spinners, toy tops, and centrifuges, but recent research suggests a way to harness rotation for the future of mankind's energy supply. In papers published in Physics of Plasmas in May and Physical Review Letters this month, Timothy Stoltzfus-Dueck, a physicist at the U.S. Department of Energy's (DOE) Princeton Plasma Physics Laboratory (PPPL), demonstrated a novel method that scientists can use to manipulate the intrinsic – or self-generated – rotation of hot, charged plasma gas within fusion facilities called tokamaks. This work was supported by the DOE Office of Science.
Such a method could prove important for future facilities like ITER, the huge international tokamak under construction in France that will demonstrate the feasibility of fusion as a source of energy for generating electricity. ITER's massive size will make it difficult for the facility to provide sufficient rotation through external means.
Rotation is essential to the performance of all tokamaks. Rotation can stabilize instabilities in plasma, and sheared rotation – the difference in velocities between two bands of rotating plasma – can suppress plasma turbulence, making it possible to maintain the gas's high temperature with less power and reduced operating costs.
Today's tokamaks produce rotation mainly by heating the plasma with neutral beams, which cause it to spin. In intrinsic rotation, however, rotating particles that leak from the edge of the plasma accelerate the plasma in the opposite direction, just as the expulsion of propellant drives a rocket forward.
Stoltzfus-Dueck and his team influenced intrinsic rotation by moving the so-called X-point – the dividing point between magnetically confined plasma and plasma that has leaked from confinement – on the Tokamak à Configuration Variable (TCV) in Lausanne, Switzerland. The experiments marked the first time that researchers had moved the X-point horizontally to study plasma rotation. The results confirmed calculations that Stoltzfus-Dueck had published in a 2012 paper showing that moving the X-point would cause the confined plasma to either halt its intrinsic rotation or begin rotating in the opposite direction. "The edge rotation behaved just as the theory predicted," said Stoltzfus-Dueck.
A surprise also lay in store: Moving the X-point not only altered the edge rotation, but modified rotation within the superhot core of the plasma where fusion reactions occur. The results indicate that scientists can use the X-point as a "control knob" to adjust the inner workings of fusion plasmas, much like changing the settings on iTunes or a stereo lets one explore the behavior of music. This discovery gives fusion researchers a tool to access different intrinsic rotation profiles and learn more about intrinsic rotation itself and its effect on confinement.
The overall findings provided a "perfect example of a success story for theory-experiment collaboration," said Olivier Sauter, senior scientist at École Polytechnique Fédérale de Lausanne and co-author of the paper.
Along with the practical applications of his research, Stoltzfus-Dueck enjoys the purely intellectual aspect of his work. "It’s just interesting," he said. "Why do plasmas rotate in the way they do? It's a puzzle."
PPPL, on Princeton University's Forrestal Campus in Plainsboro, N.J., is devoted to creating new knowledge about the physics of plasmas — ultra-hot, charged gases — and to developing practical solutions for the creation of fusion energy. Results of PPPL research have ranged from a portable nuclear materials detector for anti-terrorist use to universally employed computer codes for analyzing and predicting the outcome of fusion experiments. The Laboratory is managed by the University for the U.S. Department of Energy’s Office of Science, which is the largest single supporter of basic research in the physical sciences in the United States, and is working to address some of the most pressing challenges of our time. For more information, please visit science.energy.gov.
Raphael Rosen | newswise
Nano-kirigami: 'Paper-cut' provides model for 3D intelligent nanofabrication
16.07.2018 | Chinese Academy of Sciences Headquarters
Theorists publish highest-precision prediction of muon magnetic anomaly
16.07.2018 | DOE/Brookhaven National Laboratory
For the first time ever, scientists have determined the cosmic origin of highest-energy neutrinos. A research group led by IceCube scientist Elisa Resconi, spokesperson of the Collaborative Research Center SFB1258 at the Technical University of Munich (TUM), provides an important piece of evidence that the particles detected by the IceCube neutrino telescope at the South Pole originate from a galaxy four billion light-years away from Earth.
To rule out other origins with certainty, the team led by neutrino physicist Elisa Resconi from the Technical University of Munich and multi-wavelength...
For the first time a team of researchers have discovered two different phases of magnetic skyrmions in a single material. Physicists of the Technical Universities of Munich and Dresden and the University of Cologne can now better study and understand the properties of these magnetic structures, which are important for both basic research and applications.
Whirlpools are an everyday experience in a bath tub: When the water is drained a circular vortex is formed. Typically, such whirls are rather stable. Similar...
Physicists working with Roland Wester at the University of Innsbruck have investigated if and how chemical reactions can be influenced by targeted vibrational excitation of the reactants. They were able to demonstrate that excitation with a laser beam does not affect the efficiency of a chemical exchange reaction and that the excited molecular group acts only as a spectator in the reaction.
A frequently used reaction in organic chemistry is nucleophilic substitution. It plays, for example, an important role in in the synthesis of new chemical...
Optical spectroscopy allows investigating the energy structure and dynamic properties of complex quantum systems. Researchers from the University of Würzburg present two new approaches of coherent two-dimensional spectroscopy.
"Put an excitation into the system and observe how it evolves." According to physicist Professor Tobias Brixner, this is the credo of optical spectroscopy....
Ultra-short, high-intensity X-ray flashes open the door to the foundations of chemical reactions. Free-electron lasers generate these kinds of pulses, but there is a catch: the pulses vary in duration and energy. An international research team has now presented a solution: Using a ring of 16 detectors and a circularly polarized laser beam, they can determine both factors with attosecond accuracy.
Free-electron lasers (FELs) generate extremely short and intense X-ray flashes. Researchers can use these flashes to resolve structures with diameters on the...
13.07.2018 | Event News
12.07.2018 | Event News
03.07.2018 | Event News
16.07.2018 | Life Sciences
16.07.2018 | Physics and Astronomy
13.07.2018 | Event News | <urn:uuid:00d3580c-caa8-46da-bdd0-a8763b438cd8> | 3.59375 | 1,486 | Content Listing | Science & Tech. | 35.797262 | 95,606,238 |
Jakobshavn Isbrae is Greenland's fastest moving outlet glacier and a major contributor to sea level rise. We analyze new gravity and magnetic profiles across the glacier, extending from the mouth of the outlet fjord to 64 km inland of the 2008 grounding line. Our results provide new insights into Jakobshavn Isbrae's geologic underpinnings and 5 controls on the basal velocities. Earlier studies of basal processes minimized basal slip as a fast flow mechanism. Currently, velocities are up to double those considered in these studies, necessitating a reanalysis of the basal conditions. The gravity field along the glacier's main trunk cannot be attributed to the gravitational effect of bed topography and the overlying ice sheet. We interpret the remaining gravity signal as 10 evidence of up to 2400 m of low density sediment beneath the main trunk. Examining recent velocities, we find basal slip is a major contributor to ice flow along most of the sediment filled trough. Within 54 km of the grounding line, only isolated 1–3 km wide regions have velocities that possibly result solely from internal deformation of the ice. We conclude soft bed sliding over the thick sediment wedge beneath Jakobshavn 15 Isbrae is the dominant mechanism of fast flow.
Mendeley saves you time finding and organizing research
Choose a citation style from the tabs below | <urn:uuid:5961ef8e-0ab1-4cb9-89db-78e99ea2c1ae> | 3 | 282 | Academic Writing | Science & Tech. | 34.727854 | 95,606,252 |
Sentry milk-vetch (Astragalus cremnophylax Barneby var. cremnophylax Barneby) was listed as an endangered species on December 5, 1990 (55 FR 50184-50187) pursuant to the Endangered Species Act of 1973, as amended (16 U.S.C. 1531 et seq.). In 2006, when the sentry milk-vetch recovery plan was published (U.S. Fish and Wildlife Service 2006), the plant was known to be found at only three locations on the South Rim. Since that time, additional populations of sentry milk-vetch have been discovered on the South and North Rims. Currently there are five wild populations on the North Rim, four wild populations on the South Rim, and three introduced populations on the South Rim.
A summary of the 2016 field season accomplishments is presented here.
Maricopa Point Annual Monitoring. Maricopa Point was monitored by the Grand Canyon National Park vegetation program staff in May. A total of 1150 SMV were recorded, up from 935 in 2015. Combined with reintroduced plants, this brings the total population of sentry milk-vetch plants at Maricopa Point to 1,524, with all but 146 of the wild plants and 5 of the reintroduced plants outside the transect boundaries tagged to facilitate long-term monitoring.
Seed and Cutting Collection and Propagation. A total of 1,087 seeds were collected from three wild sites on the South Rim. Of these, 691 seeds were propagated with a 75% success rate. All seed from the Shoshone wild population was put into storage. No seed were collected from reintroduced or North Rim populations in 2016. A total of 284 cuttings were collected from South Rim sites; all were propagated with only a 13% success rate. Staff continue experimenting with cutting propagation, with the most successful mix being two parts perlite and one park coconut husk.
Site Mapping and Census. For the past two years, vegetation and GIS staff have completed detailed GIS mapping of all known sentry milk-vetch sites. The mapping is to 24 cm accuracy and is completed in conjunction with a complete census. The final mapping will be complete by November 2016. We have documented 16,705 plants in the park, with 9,103 on the South Rim and 7,602 on the North Rim. Of these, four populations have over 1,000 plants.
Supplemental Plantings at Grandview, Maricopa, and Busco Points. In 2016, staff continued to plant, water, and maintain each of the South Rim reintroduction sites. There are currently 121 living plants at Grandview (45% survival), 603 plants at Busco Point (79% survival), and 215 plants alive at the Maricopa reintroduction sites (70% survival). Crews watered the new plantings at all sites 4-5 times a week, and the older plantings 2-3 times a week, and completed exotic plant removal and other site maintenance throughout the season.
New Propagation Protocols. Staff continued to refine the propagation protocols, including the use of mist lines for more frequent and standardized water delivery, and grow lamps to encourage more compact growth forms. A new soil mix was used, containing more native soil relative to other soil components to increase likelihood of inoculation and decrease outplanting stress. The current mix is composted native mulch, native soil, sand, perlite, vermiculite and coconut husk. Fewer plants need to be propagated in the next few years, with a goal of getting each of the re-introduction sites to over 1000 plants but not doing any additional planting beyond that because of the overall success of the wild populations.
U.S. Fish and Wildlife Service. 2006. Sentry Milk-vetch (Astragalus cremnophylax Barneby var. cremnophylax Barneby) Recovery Plan. U.S. Fish and Wildlife Service, Albuquerque, New Mexico.
Prepared by Jean Palumbo (SCPN) and Lori Makarick (GRCA), 2016.
Series: Recovering the Endangered Sentry Milk-Vetch in Grand Canyon National Park | <urn:uuid:e235aa64-4187-4b3e-b902-6a07785ce483> | 3.171875 | 879 | Knowledge Article | Science & Tech. | 57.286576 | 95,606,253 |
Dinosaur discoveries - NSF news releases since 1998
March 5, 2004
(Releases are listed from most recent to oldest.)
Evidence of a "Lost World": Antarctica Yields Two Unknown Dinosaur Species — February 26, 2004
"Against incredible odds, researchers working in separate sites, thousands of miles apart in Antarctica have found what they believe are the fossilized remains of two species of dinosaurs previously unknown to science. One of the two finds, which were made less than a week apart, is an early carnivore that would have lived many millions of years after the other, a plant-eating beast, roamed the Earth. One was found at the sea bottom, the other on a mountaintop."
"Digging Dinosaurs: How scientists put the pieces together"; backgrounder on Antarctic discoveries - February 2004
"Books and movies have created in the public mind vivid images of what dinosaur hunters do. In some cases, fiction approaches the reality, but seldom does it do justice to the physical labor in the harshest conditions and painstaking intellectual rigor that goes into finding and interpreting dinosaur remains. When Judd Case...and James E. Martin...stumbled across what they believe are the fossilized remains of a new dinosaur species on the Antarctic Peninsula, they quickly put the pieces together in their heads. Years of education, training and experience enabled them to recognize and make sense out of what others might have ignored..."
"Not All Aerial Reptiles Were Level-headed, CT Scans Show";
Inside view of pterosaurs' brain yields insights to posture, behavior - October 29, 2003
"With its 13-foot wing span, a flying dinosaur soars above a lake, scanning for dinner as its shadow glides across the water’s surface below.... While such a scene would have occurred more than 100 million years ago, a study released this week gives a clearer picture of what went on inside the pterosaur's head. When scientists using skull fossils examined the neuroanatomy responsible for flight control and prey spotting, they found key structures to be specialized and enlarged, a discovery that could revise views of how vision, flight, and the brain itself evolved."
"Dinosaur Cannibal Unearthed in Madagascar" - April 2, 2003
"The exotic island of Madagascar, situated off the southeast coast of Africa, was a dangerous place to live 65 million to 70 million years ago. Crocodiles swarmed in the rivers, and a 30-foot-long, meat-eating dinosaur named Majungatholus atopus stalked the plains. Like most carnivorous dinosaurs, Majungatholus had teeth perfectly suited for ripping into flesh. But what was on the menu? Until now, this question has remained a mystery...."
"New Study Suggests Missing Link that Explains How Dinosaurs Learned to Fly" - January 16, 2003
"Two-legged dinosaurs may have used their forelimbs as wing-like structures to propel themselves rapidly up steep inclines long before they took to the skies, reports a University of Montana researcher.... The new theory adds a middle step that may link two current and opposing explanations for how reptiles evolved into flying birds. According to Kenneth Dial, author of the report, the transition from ground travel to flight may have required a 'ramp-up' phase...."
"Augmented Reality Brings Dinosaurs into the 21st Century" news tip – October 22, 2002:
"Paleontologists and computer scientists have joined forces to paint fossils with digital flesh and create dynamic models that reveal how dinosaurs may have looked, walked and attacked prey. Called "augmented reality" (AR), researchers have used the new techniques to fit muscles onto a predator's jawbone and to interpret a mysterious feature in dinosaur footprints...."
"Dinosaurs' Large Noses May Have Been Key to Physiological Processes";
NSF-funded research redefines the extinct creatures' appearance - August 2, 2001
"With only bones for clues, scientists continue to puzzle over many details of dinosaur appearances and physiology. Detective work by a paleontologist at Ohio University now indicates that the creatures' fleshy nasal passages were larger than had been thought, which could lead to more-realistic depictions and greater understanding of their respiratory functions...."
"New Long-Necked Dinosaur Discovered in Madagascar" - August 1, 2001
"The fossilized remains of a new, nearly complete long-necked sauropod dinosaur were recently unearthed on the island of Madagascar. The discovery was announced today in the journal Nature.... 'The discovery of this dinosaur is particularly exciting because it confirms a close relationship between the titanosaurs and brachiosaurs, something that could only be surmised previously.'...."
"New Predatory Dog-Sized Dinosaur Unearthed on Madagascar" - January 24, 2001
"Fossilized remains of a bizarre, dog-sized predatory dinosaur were recently recovered on the island of Madagascar.... These fossils, which date to the Late Cretaceous period (about 65-70 million years ago), represent a dinosaur new to science, dubbed Masiakasaurus knopfleri. Masiakasaurus was relatively small, as dinosaurs go...much of which consisted of its long neck and tail. The total mass of this small carnivore would have been approximately 35 kilograms (80 lbs.), roughly that of a German Shepherd dog.
"Oregon State University scientists....have completed a study of what they say is the world's most perfectly preserved fossil of a theropod, or meat-eating dinosaur. They believe it provides an unprecedented view of the biology of these ancient reptiles. The bottom line? You wouldn't want to meet a theropod in a dark alley. The research....offers insights into dinosaur metabolism, the warm-blooded versus cold-blooded debate, the question of whether or not dinosaurs might have been the ancestors of birds, and the biology that helped them dominate the world—and eventually may have led to their extinction...."
"Several specimens of a large predatory dinosaur – including a nearly complete, exquisitely preserved skull – were recently recovered on the island of Madagascar.... The 65- to 70-million-year-old fossils, attributed to an animal called Majungatholus atopus (a theropod dinosaur), and dating to the Late Cretaceous period, were unearthed on an international expedition...."
"New Dinosaur Finds in Antarctica Paint Fuller Picture of Past Ecosystem" - February 6, 1998
"A team of Argentinean and U.S. scientists has found fossils of a duck-billed dinosaur, along with remains of Antarctica's most ancient bird and an array of giant marine reptiles, on Vega Island off the eastern side of the Antarctic Peninsula. The tooth of a duck-billed dinosaur, or hadrosaur, was found in sands about 66-67 million years old, from the Cretaceous period (about 1-2 million years before the asteroid impact that contributed to the extinction of the dinosaurs).
Sean Kearns, NSF, (703) 292-8070, email: email@example.com
The National Science Foundation (NSF) is an independent federal agency that supports fundamental research and education across all fields of science and engineering. In fiscal year (FY) 2018, its budget is $7.8 billion. NSF funds reach all 50 states through grants to nearly 2,000 colleges, universities and other institutions. Each year, NSF receives more than 50,000 competitive proposals for funding and makes about 12,000 new funding awards.
Useful NSF Web Sites:
NSF Home Page: https://www.nsf.gov
NSF News: https://www.nsf.gov/news/
For the News Media: https://www.nsf.gov/news/newsroom.jsp
Science and Engineering Statistics: https://www.nsf.gov/statistics/
Awards Searches: https://www.nsf.gov/awardsearch/ | <urn:uuid:132e0287-6a80-463a-b1c9-211c986d5b8b> | 3.234375 | 1,652 | Content Listing | Science & Tech. | 49.70349 | 95,606,272 |
Increased summer precipitation apparently helping to spread spores of pathogen
Biologists studying a lethal blight of lodgepole pines in northwestern British Columbia present strong evidence in the September issue of BioScience that climate change is to blame for the outbreak. The blight, caused by the fungus Dothistroma septosporum, causes trees to lose their needles and, in the case of the British Columbia outbreak, eventually die. D. septosporum has long been recognized as a pathogen of pines, but although it is considered a serious disease of exotic plantations in the Southern Hemisphere, it has until now been considered a minor threat to northern temperate forests. Lodgepole pines are an economically important species, being used in construction and for pulp.
Alex Woods and his colleagues at the British Columbia Forest Service and the University of Alberta investigated climate records in the area of the outbreak. The records provided no evidence of warming in the affected area in recent years, but they did reveal a clear increase in summer precipitation over the past decade. That constituted a smoking gun, because D. septosporums life cycle depends on summer moisture for spore distribution. The increase in precipitation had no clear link to a known climatic oscillation that might have explained it, and the authors conclude that it is most likely related to a directional climate trend. The report of Woods et al. appears to represent one of a growing number of examples of an indirect effect of climate change, because increased summer precipitation would have been expected, absent D. septosporum, to benefit lodgepole pines.
Donna Royston | EurekAlert!
Scientists uncover the role of a protein in production & survival of myelin-forming cells
19.07.2018 | Advanced Science Research Center, GC/CUNY
NYSCF researchers develop novel bioengineering technique for personalized bone grafts
18.07.2018 | New York Stem Cell Foundation
For the first time ever, scientists have determined the cosmic origin of highest-energy neutrinos. A research group led by IceCube scientist Elisa Resconi, spokesperson of the Collaborative Research Center SFB1258 at the Technical University of Munich (TUM), provides an important piece of evidence that the particles detected by the IceCube neutrino telescope at the South Pole originate from a galaxy four billion light-years away from Earth.
To rule out other origins with certainty, the team led by neutrino physicist Elisa Resconi from the Technical University of Munich and multi-wavelength...
For the first time a team of researchers have discovered two different phases of magnetic skyrmions in a single material. Physicists of the Technical Universities of Munich and Dresden and the University of Cologne can now better study and understand the properties of these magnetic structures, which are important for both basic research and applications.
Whirlpools are an everyday experience in a bath tub: When the water is drained a circular vortex is formed. Typically, such whirls are rather stable. Similar...
Physicists working with Roland Wester at the University of Innsbruck have investigated if and how chemical reactions can be influenced by targeted vibrational excitation of the reactants. They were able to demonstrate that excitation with a laser beam does not affect the efficiency of a chemical exchange reaction and that the excited molecular group acts only as a spectator in the reaction.
A frequently used reaction in organic chemistry is nucleophilic substitution. It plays, for example, an important role in in the synthesis of new chemical...
Optical spectroscopy allows investigating the energy structure and dynamic properties of complex quantum systems. Researchers from the University of Würzburg present two new approaches of coherent two-dimensional spectroscopy.
"Put an excitation into the system and observe how it evolves." According to physicist Professor Tobias Brixner, this is the credo of optical spectroscopy....
Ultra-short, high-intensity X-ray flashes open the door to the foundations of chemical reactions. Free-electron lasers generate these kinds of pulses, but there is a catch: the pulses vary in duration and energy. An international research team has now presented a solution: Using a ring of 16 detectors and a circularly polarized laser beam, they can determine both factors with attosecond accuracy.
Free-electron lasers (FELs) generate extremely short and intense X-ray flashes. Researchers can use these flashes to resolve structures with diameters on the...
13.07.2018 | Event News
12.07.2018 | Event News
03.07.2018 | Event News
19.07.2018 | Materials Sciences
19.07.2018 | Earth Sciences
19.07.2018 | Life Sciences | <urn:uuid:118e8584-90b6-417a-a5db-5ce20c1e6e93> | 3.25 | 971 | Content Listing | Science & Tech. | 36.568301 | 95,606,286 |
Widely spaced telescopes also determined asteroid pair's shapes
When the double asteroid Patroclus-Menoetius passed directly in front of a star on the night of Oct. 20, a team of volunteer astronomers across the U.S. was waiting.
Observing the event, known as an occultation, from multiple sites where each observer recorded the precise time the star was obscured, yielded the first accurate determination of the two objects' size and shape. The analysis was led by Dr. Marc W. Buie, staff scientist in Southwest Research Institute's (SwRI) Space Studies Department in Boulder, Colo.
The team effort was a pilot program of the Research and Education Collaborative Occultation Network (RECON), whose recently announced expansion was made possible through a $1 million National Science Foundation grant.
Managed jointly by SwRI and Cal Poly (California Polytechnic State University), RECON supplies telescopes to schools and citizen scientists in rural western states from north-central Washington to southwest Arizona for occultation observations. With the grant, RECON membership will grow from 13 pilot communities to 40.
The October collaborative observations involved volunteers distributed east-west across the United States. Observers were from the International Occultation Timing Association (IOTA) as well as a subset of RECON's observer team. Eleven of 36 observation sites were able to record the occultation. Seven of those were analyzed to estimate an outline, or an elliptical limb fit, of Patroclus of 125 kilometers (km) by 98 km. Six of the observations were combined for Menoetius and yielded a size of 117 km by 93 km.
"Previous estimates of the shape of the asteroid pair had indicated essentially spherical objects," Buie said. "Our new observations indicate a significantly more non-spherical shape, and that shape is identical for the two bodies."
Based on this occultation data combined with previous data, both objects possess axial ratios of 1.3:1.21:1, which indicates a mostly oblate shape, or one that appears flattened at the poles and slightly bulged at the equator.
"The very similar shapes of the pair suggest that they were both spinning much faster when they formed," Buie said. "The current system is in a doubly synchronous state, much like Pluto and Charon, where they orbit each other in the same time it takes for them to rotate."
This asteroid pair orbits the Sun in the Jupiter Trojan cloud of asteroids at 5 AU, or Astronomical Units, from the Sun. (One AU equals the distance from the Sun to Earth). "It shows striking similarities to objects from the more distant Kuiper Belt, suggesting that perhaps this object was relocated inward at some time in the early history of the solar system," Buie said.
Joe Fohn | EurekAlert!
What happens when we heat the atomic lattice of a magnet all of a sudden?
18.07.2018 | Forschungsverbund Berlin
Subaru Telescope helps pinpoint origin of ultra-high energy neutrino
16.07.2018 | National Institutes of Natural Sciences
For the first time ever, scientists have determined the cosmic origin of highest-energy neutrinos. A research group led by IceCube scientist Elisa Resconi, spokesperson of the Collaborative Research Center SFB1258 at the Technical University of Munich (TUM), provides an important piece of evidence that the particles detected by the IceCube neutrino telescope at the South Pole originate from a galaxy four billion light-years away from Earth.
To rule out other origins with certainty, the team led by neutrino physicist Elisa Resconi from the Technical University of Munich and multi-wavelength...
For the first time a team of researchers have discovered two different phases of magnetic skyrmions in a single material. Physicists of the Technical Universities of Munich and Dresden and the University of Cologne can now better study and understand the properties of these magnetic structures, which are important for both basic research and applications.
Whirlpools are an everyday experience in a bath tub: When the water is drained a circular vortex is formed. Typically, such whirls are rather stable. Similar...
Physicists working with Roland Wester at the University of Innsbruck have investigated if and how chemical reactions can be influenced by targeted vibrational excitation of the reactants. They were able to demonstrate that excitation with a laser beam does not affect the efficiency of a chemical exchange reaction and that the excited molecular group acts only as a spectator in the reaction.
A frequently used reaction in organic chemistry is nucleophilic substitution. It plays, for example, an important role in in the synthesis of new chemical...
Optical spectroscopy allows investigating the energy structure and dynamic properties of complex quantum systems. Researchers from the University of Würzburg present two new approaches of coherent two-dimensional spectroscopy.
"Put an excitation into the system and observe how it evolves." According to physicist Professor Tobias Brixner, this is the credo of optical spectroscopy....
Ultra-short, high-intensity X-ray flashes open the door to the foundations of chemical reactions. Free-electron lasers generate these kinds of pulses, but there is a catch: the pulses vary in duration and energy. An international research team has now presented a solution: Using a ring of 16 detectors and a circularly polarized laser beam, they can determine both factors with attosecond accuracy.
Free-electron lasers (FELs) generate extremely short and intense X-ray flashes. Researchers can use these flashes to resolve structures with diameters on the...
13.07.2018 | Event News
12.07.2018 | Event News
03.07.2018 | Event News
19.07.2018 | Materials Sciences
19.07.2018 | Earth Sciences
19.07.2018 | Life Sciences | <urn:uuid:63f418f2-1b0d-4d40-9e4d-a96ebae9ec50> | 3.4375 | 1,220 | Content Listing | Science & Tech. | 41.533262 | 95,606,287 |
Saturday, July 12, 2014
7 Of The Most Fascinating And Powerful Materials Science
We often hear of new technological improvements - robots, gadgets, phones, vehicles, medicine and more. But these are just part of the picture of scientific achievement. No less important is the field of chemical engineering, which has invented some amazing materials in recent years, materials that may forever change our lives.
These are 7 of the most fascinating and powerful materials science has come up with in recent years.
Aerogel is the proud holder of 15 mentions in the Guinness Book of Records, which is more than any material has ever had. Also known as the 'frozen smoke', a nickname resulting looking like solid smoke, aerogel is actually 99.8% empty space, which explains its semi-transparent look. This material is a terrific insulator. With a shield made from aerogel, you could challenge any flamethrower without danger - it will take it without you feeling a thing. It does the same with cold. With enough of it, you could build a comfortable house on the moon. Another amazing factoid - an inch of aerogel could have an internal structure so complex that an inch long piece could have a surface area as long as football field.
2. Carbon nanotubes
Imagine long chains of carbon, these super-structures are bonded together by the greatest power in all of the chemical world, the sp2 bond. These carbon nanotubes have been constructed with length-to-diameter ratio of up to 132,000,000:1, significantly larger than for any other material.
This means they are exceptionally strong, and in fact, may be the only material humanity will be able to use to construct the 'space elevator' that will cart people and cargo up and down from space stations hovering above the earth. Carbon nanotubes are 300 times stronger than steel, meaning you could potentially build towers hundreds of kilometers tall (or thousands of feet).
Metamaterials are artificial materials engineered to have properties that may not be found in nature. They are assemblies of multiple individual elements fashioned from conventional microscopic materials such as metals or plastics, but the materials are usually arranged in periodic patterns. Metamaterials gain their properties not from their composition, but from their exactingly-designed structures. Their precise shape, geometry, size, orientation and arrangement can affect the waves of light or sound in an unconventional manner, creating material properties which are unachievable with conventional materials.These metamaterials achieve desired effects by incorporating structural elements of sub-wavelength sizes, i.e. features that are actually
smaller than the wavelength of the waves they affect. The primary research in metamaterials investigates materials with negative refractive index. Negative refractive index materials appear to permit the creation of super lenses which can have a spatial resolution below that of the wavelength. In other words - it makes invisibility cloaks.
Nanodiamond was convincingly demonstrated to be produced by compression of graphite in 2003 and in the same work found to be much harder than bulk diamond, which makes it the hardest known material, while also being incredibly strong, light, and made of the most common element you can find - carbon. It is an amazing heat conductor and has the highest melting point of all materials. Machines built with this material would be lighter, stronger and more powerful than anything we have today.
5. Amorphous metal
By cooling molten metal quickly before it has time to re-align its particles in a solid shape, we can created amorphous metals - metals that have a disorganized atomic structure. Due to this structure anomaly, they are twice as strong as steel, and a few armies are considering using them for shields. In addition to their strength, amorphous metals have improved electricity conductivity
and can improve the efficiency of a power grid by up to 40%, saving a huge amount of energy and the burning of fossil fuels.
6. Transparent Alumina
This material is 3 times as strong as steel, while being transparent. There are so many applications for this that the mind boggles. Imagine buildings made of transparent, stronger steel. It will reduce visual pollution in the cities. Many structures that stand alone could be invisible (with just a little opaqueness so we know they are there of course).
In about 10 years, you and everyone you know will probably know all about E-textiles. In fact, you'll be covered with them. Why carry our cell phones around when we can just wear them? Clothes in the future will be embedded with these tiny E-Textiles (already existing today) that can monitor our health, project videos, make phone calls and bring up information
from the Internet when we need it. The possibilities are endless.
By Nancy Messieh, If you have the Facebook mobile app installed on your phone, chances are it’s storing a lot more of your location hi...
afrocaribe.iespana.es/ franco_luambo_makiadi.htm I could not resist publishing this here. Aggrey Mukasa, a Mwiri OB of mine sent it to one ...
A mushroom-shaped tree 1 A tree in Ficus, Philippines 2 Young mango trees under water 3 The baobab trees... | <urn:uuid:1adc7dd4-e8f7-4420-a2f5-84cb550709a0> | 3.21875 | 1,096 | Listicle | Science & Tech. | 42.997963 | 95,606,290 |
Stream Line Doppler lidar measurements of wind speed and direction with the duo-beam method in the surface air layer
The results of retrieval of wind speed and direction from measurements of radial velocity by a Stream Line pulsed coherent Doppler lidar using the duo-beam method and conical scanning are presented. These results are compared with data of a sonic anemometer (point sensor).
Keywordscoherent Doppler lidar sonic anemometer wind duo-beam method
Unable to display preview. Download preview PDF.
- 1.V. A. Banakh and I. N. Smalikho, Coherent Doppler Wind Lidars in Turbulent Atmosphere (Publishing House of IAO SB RAS, Tomsk, 2013) [in Russian].Google Scholar
- 8.I. N. Smalikho, V. A. Banakh, A. V. Falits, and Yu. A. Rudi, “Determination of the turbulent energy dissipation rate from data measured by a “Stream Line” lidar in the atmospheric surface layer,” Opt. Atmos. Okeana 28 (10), 901–905 (2015).Google Scholar
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- 10.V. A. Banakh, I. N. Smalikho, A. A. Sukharev, and A. V. Falits, “Lidar visualization of jet flows and internal gravity waves in the atmospheric boundary layer,” Opt. Atmos. Okeana 29 (8), 694–702 (2016).Google Scholar
- 14.I. N. Smalikho, E. L. Pichugina, V. A. Banakh, and A. Brewer, “Pulsed coherent lidar measurements of wind-turbine generated wake under different atmospheric conditions,” Izv. Vyssh. Ucheb. Zaved. Fiz. 55 (8), 91–95 (2012).Google Scholar | <urn:uuid:58fa2a03-48ff-4e7c-8a15-8abf89c2f9d9> | 2.75 | 594 | Truncated | Science & Tech. | 70.267898 | 95,606,322 |
Birds of a feather may flock together, but that doesn't mean they share a genetic background. Though birds were first classified into groups primarily based on appearance, research forthcoming in The Auk: Ornithological Advances by Brett Benz of the American Museum of Natural History, Mark Robbins of the University of Kansas Biodiversity Institute, and Kevin Zimmer of the Los Angeles County Museum of Natural History demonstrates that this method isn't necessarily accurate: in a group of very similar-looking South American woodpecker species, genetic analysis has now shown one to be only a distant cousin of the others, in an intriguing case of visual mimicry. By copying the appearance of larger, socially dominant woodpecker species, it reduces the aggression and competitive interference that it receives from them and has more access to food resources as a result.
The most familiar type of mimicry typically involves warning or "aposematic" coloration, in which a harmless species apes the color patterns of a dangerous or unappealing one to avoid predators; a famous instance is the Viceroy butterfly, which shares the striking colors of the more noxious Monarch. By contrast, the Helmeted Woodpecker (Dryocopus galeatus) represents an example of a different and less well understood form of mimicry, known as interspecific social dominance mimicry or ISDM.
The shy and little-known species shares the red crest, black back, and barred underside of two larger woodpeckers Dryocopus lineatus and Campephilus robustus, all of which occupy the same habitat and share similar food preferences.
The Helmeted Woodpecker's similarity in appearance makes the larger, more dominant woodpecker species less likely to attack it, due to the costs of aggression between members of the same species. Though they had been previously classified in Dryocopus due to the remarkable similarities in their appearance, genetic analysis by Benz and his colleagues suggests that the Helmeted Woodpecker is actually not closely related to other Dryocopus woodpeckers at all and belongs in a different genus, Celeus. An independent group of researchers using the same data recently reported similar results in a paper published in the Journal of Ornithology.
"Co-author Mark Robbins and I had just finished a phylogenetic study examining species limits and vocalizations in Celeus woodpeckers when Mark, who was attending a meeting in Brazil, had the opportunity to observe a Helmeted Woodpecker at Intervales State Park," according to Benz.
"Upon hearing the bird vocalize, Mark was stunned that its call sounded nothing like Neotropical Dryocopus, and immediately knew we needed to examine its taxonomic status in the context of our recent Celeus study given that the Helmeted Woodpecker calls were most similar to several other Celeus species.
Upon returning from Brazil, Mark consulted with co-author Kevin Zimmer, who had independently arrived at the same conclusions about the Helmeted Woodpecker belonging with Celeus, based on his behavioral observations spanning 20 years of fieldwork in Brazil." As Benz puts it, "The Helmeted Woodpecker is basically a typical Celeus in Dryocopus clothing."
"After several decades working on the discovery of the avian Tree of Life, it is still amazing what we are discovering! Reconstructing the phylogeny of these woodpeckers has corrected a century-old classification mistake, but more interestingly, it has revealed an unexpected new example of avian mimicry," adds Richard Prum of Yale University, one of the originators of the ISDM hypothesis.
"It has only recently been appreciated that small species may benefit from deceptively mimicking larger species to protect themselves from aggressive attack. This is similar to how a 12-year-old kid walking home from school will look and act tough to try to prevent himself from being harassed by older, bigger kids."
Relatively little is known about the ecology and natural history of the Helmeted Woodpecker, which is found in Brazil, Paraguay, and Argentina, but it has experienced dramatic population declines and vanished from much of its former range due to deforestation. Hopefully, this new discovery about its evolutionary relationships and visual deception may increase interest in the species, as it provides an opportunity for scientists to further test predictions associated with ISDM. Ultimately, bringing the Helmeted Woodpecker's sneaky strategy into the light may be what saves it from oblivion.
"Phylogenetic relationships of the Helmeted Woodpecker (Dryocopus galeatus): A case of interspecific mimicry?" will be published on September 30, 2015, and will be available at http://www.
About the journal: The Auk: Ornithological Advances is a peer-reviewed, international journal of ornithology that began in 1884 as the official publication of the American Ornithologists' Union. In 2009, The Auk was honored as one of the 100 most influential journals of biology and medicine over the past 100 years.
Rebecca Heisman | EurekAlert!
O2 stable hydrogenases for applications
23.07.2018 | Max-Planck-Institut für Chemische Energiekonversion
Scientists uncover the role of a protein in production & survival of myelin-forming cells
19.07.2018 | Advanced Science Research Center, GC/CUNY
A new manufacturing technique uses a process similar to newspaper printing to form smoother and more flexible metals for making ultrafast electronic devices.
The low-cost process, developed by Purdue University researchers, combines tools already used in industry for manufacturing metals on a large scale, but uses...
For the first time ever, scientists have determined the cosmic origin of highest-energy neutrinos. A research group led by IceCube scientist Elisa Resconi, spokesperson of the Collaborative Research Center SFB1258 at the Technical University of Munich (TUM), provides an important piece of evidence that the particles detected by the IceCube neutrino telescope at the South Pole originate from a galaxy four billion light-years away from Earth.
To rule out other origins with certainty, the team led by neutrino physicist Elisa Resconi from the Technical University of Munich and multi-wavelength...
For the first time a team of researchers have discovered two different phases of magnetic skyrmions in a single material. Physicists of the Technical Universities of Munich and Dresden and the University of Cologne can now better study and understand the properties of these magnetic structures, which are important for both basic research and applications.
Whirlpools are an everyday experience in a bath tub: When the water is drained a circular vortex is formed. Typically, such whirls are rather stable. Similar...
Physicists working with Roland Wester at the University of Innsbruck have investigated if and how chemical reactions can be influenced by targeted vibrational excitation of the reactants. They were able to demonstrate that excitation with a laser beam does not affect the efficiency of a chemical exchange reaction and that the excited molecular group acts only as a spectator in the reaction.
A frequently used reaction in organic chemistry is nucleophilic substitution. It plays, for example, an important role in in the synthesis of new chemical...
Optical spectroscopy allows investigating the energy structure and dynamic properties of complex quantum systems. Researchers from the University of Würzburg present two new approaches of coherent two-dimensional spectroscopy.
"Put an excitation into the system and observe how it evolves." According to physicist Professor Tobias Brixner, this is the credo of optical spectroscopy....
13.07.2018 | Event News
12.07.2018 | Event News
03.07.2018 | Event News
23.07.2018 | Science Education
23.07.2018 | Health and Medicine
23.07.2018 | Life Sciences | <urn:uuid:cc8caf28-1b2d-4867-8adf-52acf2765c88> | 3.875 | 1,618 | Content Listing | Science & Tech. | 27.815114 | 95,606,343 |
On Saturday night, June 02, 2018, an asteroid disintegrated after it lit up above the surface of the earth, in the sky. It lasted only a few hours and was lost forever. In Botswana, a fireball was seen in the sky by the natives. The fireball was identified as an asteroid hurling down towards the earth at a speed of 10 miles per second. There was instant chaos amongst the people as it indicated a big disaster if the asteroid had hit the surface of the earth.
In the West of Johannesburg, a webcam in the rural area captured an ignited object moving quickly with a bright flash. NASA immediately started investigating the purpose and determined that the asteroid may collide with earth. The locations identified for collision were the Southern Africa, The Indian Ocean, and New Guinea. Soon the name of the asteroid was declared – 2018 LA.
Speculations were made how much damage could be caused, and what | <urn:uuid:649be8f5-98bf-4985-aafb-dc3c285c6803> | 3.671875 | 186 | News Article | Science & Tech. | 49.49956 | 95,606,354 |
Weitere Kapitel dieses Buchs durch Wischen aufrufen
In this chapter, the reduction and removal of Cr(VI) from aqueous solution by microplasma are explained, which represents a new and fascinating realm of plasma science for the first time. The effect of various process parameters on the Cr(VI) reduction efficiency and the effect of initial pH and ethanol on the removal of Cr(VI) are systematically examined. The optimum condition for Cr(VI) reduction was initial pH at 2 with stir where the microdischarge gas was argon with the flow rate of 60 mL/min. The reduction efficiency of Cr(VI) increased with an increase in input power but decreased with an increasing initial concentration of Cr(VI). In particular, additive hydroxyl radical scavenger (ethanol) greatly improved the reduction efficiency and facilitated the removal of chromium dissolved in the solution. The best removal efficiency was obtained when the pH was 6. In addition, the energy efficiency of microplasma to reduce Cr(VI) is 2.0 × 10−4 mg/J and is comparable to that in electrolysis and other forms of glow discharge. The advantages, such as low cost, scalability, and easy operating techniques, of this approach have broad prospects in water treatment (Xiao in Removal of hexavalent chromium in water and preparation of cuprous oxide nanoparticles by microplasma. Yat–sen University, 2012, ; Du in Non-Thermal arc plasma technology and application. BeiJing: Chemical Industry Press, 2015, .
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Du CM. Non-Thermal arc plasma technology and application. BeiJing: Chemical Industry Press; 2015.
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Valix M, Cheung WH, Zhang K. Role of heteroatoms in activated carbon for removal of hexavalent chromium from wastewaters. J Hazard Mater. 2006;135(1–3):395–405. CrossRef
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Wang J, Sun Y, Miao H, Xu J, Feng J. Simultaneous removal of aqueous Cr(VI) and phenol by corona discharge plasma. Acta Sci Vet. 2012;32(10):2415–21.
Ke Z, Huang Q, Zhang H, Yu Z. Reduction and removal of aqueous Cr(VI) by glow discharge plasma at the gas–solution interface. Environ Sci Technol. 2011;45(18):7841–7. CrossRef
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Park SJ, Eden JG, Chen J, Liu C. Microdischarge devices with 10 or 30 μm square silicon cathode cavities: pd scaling and production of the XeO excimer. Appl Phys Lett. 2004;85(21):4869–71. CrossRef
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- Reduction and Removal of Cr(VI) from Aqueous Solution by Microplasma
- Springer Singapore
- Chapter 4
Fallstudie Überschwemmungskarten/© Thaut Images | Fotolia | <urn:uuid:059a2d8c-307f-4e78-8606-8d42a593c24a> | 2.546875 | 3,099 | Content Listing | Science & Tech. | 69.078619 | 95,606,405 |
Artist depiction of an asteroid on a collision course with Earth.
An asteroid on a collision course with Earth is inevitable. Astronomer Michael Lund explains how a new telescope under construction in Chile will become a vital tool for detecting objects that could devastate our planet.
Letitia Wright in
Black Panther. Popular discussions about the movie demonstrate a desire for representation in commercial media.
Black Panther arrives at a moment of possibility. Its popularity demonstrates that people are crying out for chances to see themselves and their communities portrayed with dignity—as heroes.
Small asteroids can be hard to spot. But what kind of threat do they pose to the Earth?
The 2017 Geminids as seen from Ecuador, against the backdrop of the splendid Milky Way (centre) and the Large Magellanic Cloud (right).
Your guide to some of the best meteor showers for 2018. Where to look and when in both the northern and southern skies to catch nature's fireworks.
Ten new remote cameras will soon be scouring the British night skies for meteorites.
The Sun is currently middle-aged, having celebrated its 4,568,000,000th birthday at some point in the last million years.
In five or seven billion years time, the Sun's life will come to an end. And it will be really spectacular - if you're watching from far enough away.
Patience can be rewarded as with this composite of the 2016 Geminids meteor shower, seen over Mt Teide volcano on the Canary Islands, off Spain.
2017 is looking to be a spectacular year for meteor showers. So here's what to look out for in both the northern and southern skies.
How to save the Earth from an asteroid strike.
Large asteroid hits on Earth have the potential to wipe out humanity so knowing how to detect and deflect them is vital. But we know very little about the interior make up of many asteroids.
The annual Perseid meteor shower gives us a glimpse of remnants from the early formation of the solar system.
On February 29, night suddenly becomes day.
Was it a UFO? Was it a high-tech plane? Here's what lucky people really saw over Scotland on February 29.
A meteor exploding over the South Pacific on February 6 was the biggest since the Chelyabinsk meteor in 2013. Here are some other fiery visitors.
The destructive meteor trace that fell on Chelyabinsk, Russia, in 2013.
A meteoriticist takes a look at the evidence surrounding a tragic death – and gives her verdict on whether it was caused by a meteorite.
The November 27 fireball as photographed by the Desert Fireball Network observatory at William Creek, South Australia.
Desert Fireball Network
It's no easy task to find a meteorite that's just been seen flashing across the sky. But it helps if you have an automatic network of "eyes" on the night sky.
A brilliant fireball lights up the sky above the Southern Ocean at the 12 Apostles National Park on the Great Ocean Road, Victoria, Australia.
Many meteor showers are a regular annual event, but what you can see varies from year to year. So which showers will be the best for 2016?
A composite image of the Geminid Meteors.
Phil Hart/Tanya Hill
A darkened moon is promising to allow us to see one of the best meteor showers of the year, so long as the skies are clear.
The big hole left behind tells only part of the story.
The Barringer meteor crater is an iconic Arizona landmark, more than 1km wide and 170 metres deep, left behind by a massive 300,000 tonne meteorite that hit Earth 50,000 years ago with a force equivalent…
The early solar system was once a turbulent place.
The early solar system was a busy place with plenty of meteorite impacts on the new planets and moons. But finding evidence of such impacts on Earth can be tricky.
Hurricane Arthur photographed by ESA astronaut Alexander Gerst.
Astronauts living on the ISS get to experience the wonders of the universe's natural phenomena like no one else.
A sacred moment for stargazers: the Perseid meteor shower in August, 2009.
From a meteor shower to 67P's closest approach to the sun: prepare to be amazed by comets.
Aboriginal stories dating back many thousands of years talk of a fire from the sky in an area now home to the Henbury meteorite craters, in the Northern Territory.
We can learn much about meteor strikes in ancient Australia by examining the oral traditions of indigenous people. | <urn:uuid:15a655ca-5309-4a82-a409-03f3b9077add> | 2.890625 | 943 | Content Listing | Science & Tech. | 55.758702 | 95,606,435 |
Lucerne Leaf Roller
(formerly known as Conchylis divulsana)
ARCHIPINI, TORTRICINAE, TORTRICIDAE, TORTRICOIDEA
(Photo: courtesy of Agriculture Western Australia)
The Caterpillars of this species are an agricultural pest in Australia, feeding on various crops and herbaceous garden plants, including :
The caterpillars grow to a length of about 1 cm.
The adult moths have light brown forewings, with a darker diagonal band across each wing, and pale grey hindwings. The moths have a wingspan of about 1.5 cms.
The species is found over the whole of Australia including
The moths have also been found in
The pheromones of this species have been determined, and synthetic versions used to trap the moths.
Further reading :
Ian F.B. Common,
Moths of Australia,
Melbourne University Press, 1990, pp. 59, 68, 278.
Tortricites & Tineites,
List of the Specimens of Lepidopterous Insects in the Collection of the British Museum,
Part 28 (1863), p. 364, No. 117.
(updated 4 September 2011, 11 July 2018) | <urn:uuid:f29ff4b4-fa75-47c8-a08d-391ca3af91b4> | 2.984375 | 267 | Knowledge Article | Science & Tech. | 55.60892 | 95,606,452 |
Effects of climate variability and change on sea temperature, currents, and water mass distribution are likely to affect the productivity and structure of high-latitude ecosystems. This paper focuses on the Barents Sea (BS), a productive Arcto–boreal shelf ecosystem sustaining several ecologically and economically important fish species. The water masses in the region are classified as Atlantic, Arctic, and mixed, each having a distinct ecological signature. The pronounced increase in temperature and a reduction in the area covered by Arctic water that has taken place during the past decade have affected the ecology of the region. An increase in biomass of lipid-rich euphausiids in recent years, possibly linked to the temperature increase, has apparently provided good feeding and growth conditions for several species, including capelin and young cod. The observed reduction in Arctic zooplankton may on the other hand have negative implications for polar cod and other zooplankton predators linked to the Arctic foodweb. Despite these changes, the BS at present seems to maintain relatively stable levels of boreal zooplankton biomass and production, with no significant changes in the abundances of Calanus finmarchicus or the episodic immigrant C. helgolandicus.
Mendeley saves you time finding and organizing research
Choose a citation style from the tabs below | <urn:uuid:d74c62c8-d4e5-443b-bc62-4325309bbe0a> | 2.890625 | 270 | Academic Writing | Science & Tech. | 8.919701 | 95,606,461 |
Atmospheric Aerosol Properties and Climate Impacts (SAP 2.3)
Atmospheric aerosols are suspensions of solid and/or liquid particles in air. Aerosols are ubiquitous in air and are often observable as dust, smoke, and haze. Both natural and human processes contribute to aerosol concentrations. On a global basis, aerosol mass derives predominantly from natural sources, mainly sea salt and dust. However, anthropogenic (manmade) aerosols, arising primarily from a variety of combustion sources, can dominate in and downwind of highly populated and industrialized regions, and in areas of intense agricultural burning. This report critically reviews current knowledge about global distributions and properties of atmospheric aerosols, as they relate to aerosol impacts on climate. It assesses possible next steps aimed at substantially reducing uncertainties in aerosol radiative forcing estimates. Current measurement techniques and modeling approaches are summarized, providing context. As a part of the Synthesis and Assessment Product in the Climate Change Science Program, this assessment builds upon recent related assessments, including the Fourth Assessment Report of the Intergovernmental Panel on Climate Change (IPCC AR4, 2007) and other Climate Change Science Program reports. The objectives of this report are (1) to promote a consensus about the knowledge base for climate change decision support, and (2) to provide a synthesis and integration of the current knowledge of the climate-relevant impacts of anthropogenic aerosols for policy makers, policy analysts, and general public, both within and outside the U.S. government and worldwide.
- Paperback | 128 pages
- 215.9 x 279.4 x 7.37mm | 394.62g
- 03 Feb 2015
- United States
- black & white illustrations | <urn:uuid:030b314f-dc1e-4156-844f-7cbaee522454> | 3.515625 | 352 | Product Page | Science & Tech. | 23.413009 | 95,606,487 |
Gujrat based lab discovers sub-Saturn size planet
Physical Research Lab (PRL) based in Gujrat have discovered a sub-Saturn or super-Neptune sized planet around a Sun like star. The team of scientists and engineers led by Prof. Abhijit Chakraborty discovered the planet which is 6 times the radii and 27 times the mass of Earth. The planet has been named EPIC 211945201b or K2-236b.
This discovery makes it 23rd planetary system known to man which has mass between 10-70 Earth mass and size of 4-8 radii of Earth. India, with this discovery, is among the select few countries which have discovered planetary systems beyond our own solar system.
PARAS (PRL Advance Radial-velocity Abu-sky Search)
This discovery was possible because of indigenously designed spectrograph PARAS which is has 1.2m telescope integrated into it, which measured the mass of the planet accurately. The spectrograph is located in PRL’s Gurushikhar Observatory in Mount Abu. PARAS is the first spectrograph in Asia which can measure the mass of an planet going around a star. | <urn:uuid:4e24672c-364b-4e09-93b7-5b0d8450d619> | 2.671875 | 253 | News Article | Science & Tech. | 51.132422 | 95,606,493 |
How stars evolve
Stars take a variety of form throughout their lives
Supergiants If the star begins life big enough, normally above ten solar masses, it will become a supergiant.
They can be thousands of times bigger than our Sun.
Main sequence stars These range from between 0.08 and 10 solar radii, with masses around 0.1 to 100-times the Sun. Our Sun is a main sequence star.
White dwarfs Stars with less than 1.4 solar masses will not end their life in a dramatic explosion, instead they leave behind a small core of electron-degenerate matter known as a white dwarf.
Neutron stars (off chart) Stars between 1.4 and three solar masses will end their life in a dramatic explosion, or supernova, leaving behind a neutron star.
Quark stars (off chart) Stars slightly too heavy to remain stable as neutron stars could potentially turn into quark stars.
When main sequence stars use up all of their fuel, the expand to become giants. Our Sun will become a
Red Giant in around 5 billion years. | <urn:uuid:14ad0067-4cd7-40e7-959c-3d3702d8e437> | 3.765625 | 227 | Knowledge Article | Science & Tech. | 70.449175 | 95,606,520 |