computer models how buds grow into leaves posted on march 02, 2012 at 08 : 24 : 51 am " a bud does not grow in all directions at the same rate, " said samantha fox from the john innes centre on norwich research park. " otherwise leaves would be domed like a bud, not flat with a pointed tip. " by creating a computer model to grow a virtual leaf, the bbsrc - funded scientists managed to discover simple rules of leaf growth. - advertisement - similar to the way a compass works, plant cells have an inbuilt orientation system. instead of a magnetic field, the cells have molecular signals to guide the axis on which they grow. as plant tissues deform during growth, the orientation and axis changes. the molecular signals become patterned from an early stage within the bud, helping the leaf shape to emerge. the researchers filmed a growing arabidopsis leaf, a relative of oil seed rape, to help create a model which could simulate the growing process. they were able to film individual cells and track them as the plant grew. it was also important to unpick the workings behind the visual changes and to test them in normal and mutant plants. " the model is not just based on drawings of leaf shape at different stages, " said professor enrico coen. " to accurately recreate dynamic growth from bud to leaf, we had to establish the mathematical rules governing how leaf shapes are formed. " with this knowledge programmed into the model, developed in collaboration with professor andrew bangham ' s team at the university of east anglia, it can run independently to build a virtual but realistic leaf. professor douglas kell, chief executive of bbsrc said : " this exciting research highlights the potential of using computer and mathematical models for biological research to help us tackle complex questions and make predictions for the future. computational modelling can give us a deeper and more rapid understanding of the biological systems that are vital to life on earth. " the model could now be used to help identify the genes that control leaf shape and whether different genes are behind different shapes. " this simple model could account for the basic development and growth of all leaf shapes, " said fox. " the more we understand about how plants grow, the better we can prepare for our future - - providing food, fuel and preserving diversity. "


irish druids and old irish early religions of the one of the most philosophical statements from max muller is to this effect : " whatever we know of early religion, we always see that it presupposes vast periods of an earlier development. " this is exhibited in the history of all peoples that have progressed in civilization, though we may have to travel far back on the track of history to notice transformations of thought or belief. when the late dr. birch told us that a pyramid, several hundreds of years older than the great pyramid, contained the name of osiris, we knew that at least the osirian part of egyptian mythology was honoured some six or seven thousand years ago what the earlier development of religion there was, or how the conception of a dying and risen osiris arose, at so remote a period, may well excite our wonder. professor jebb writes - - " there was a time when they ( early man ) began to speak of the natural powers as persons, and yet had not forgotten that they were really natural, powers, and that the persons ' names were merely signs? yet this goes on the assumption that religion - - or rather dogmas thereof - - sprang from reflections upon natural phenomena. in this way, the french author of sirius satisfied himself, particularly on philological grounds, that the idea, of god sprang from an association with thunder and the barking of a dog. we are assured by max muller, that religion is a word that has changed from century to century, and that " the word rose to the surface thousands of years ago. " taking religion to imply an inward feeling of reverence toward the unseen, and a desire to act in obedience to the inward law of right, religion has existed as long as humanity itself. what is commonly assumed by the word religion, by writers in general, is dogma or belief. the importance of this subject was well put forth by the great sanscrit scholar in the phrase, " the real history of man is the history of religion. " this conviction lends interest and weight to any investigations into the ancient religion of ireland ; though plowden held that " few histories are so charged with fables as the annals of ireland. " it was herder who finely said, " our earth owes the seeds of all higher culture to a religious tradition, whether literary or oral. " in proportion as the so - called supernatural gained an ascendancy, so was man really advancing from the materialism and brutishness of savagedom. lecky


seeds of all higher culture to a religious tradition, whether literary or oral. " in proportion as the so - called supernatural gained an ascendancy, so was man really advancing from the materialism and brutishness of savagedom. lecky notes " the disposition of man in certain stages of society towards the miraculous. " but was buckle quite correct in maintaining that " all nature conspired to increase the authority of the imaginative faculties, and weaken the authority of the reasoning ones "? it is not to be forgotten in our inquiry that, as faiths rose in the east, science has exerted its force in the west. fetishism can hardly be regarded as the origin of religion. as to those writers who see in the former the deification of natural objects, max muller remarks, " they might as well speak of primitive men mummifying their dead bodies before they had wax to embalm them with. " myth has been styled the basis of religion not less than of history ; but how was it begotten? butler, in english, irish, and scottish churches, writes - - " to separate the fabulous from the probable, and the probable from the true, will require no ordinary share of penetration and persevering industry. " we have certainly to remember, as one has said, that " mythic history, mythic theology, mythic science, are alike records, not of facts, but beliefs. " andrew lang properly calls our attention to language, as embodying thought,, being so liable to misconception and misinterpretation. names, connected with myths, have been so variously read and explained by scholars, that outsiders may well be puzzled. how rapidly a myth grows, and is greedily accepted, because of the wish it may be true, is exemplified in the pretty story, immortalized by music, of jessie of lucknow, who, in the siege, heard her deliverers, in the remote distance, playing " the campbells are coming. " there never was, however, a jessie brown there at that time ; and, as one adds, jessie has herself " been sent to join william tell and the other dethroned gods and in the hibbert lectures, professor rhys observes, " the greek myth, which distressed the thoughtful and pious minds, like that of socrates, was a survival, like the other scandalous tales about the gods, from the time when the ancestors of the greeks were savages. " may it not rather have been derived by homer


you have to like the attitude of thomas henning ( max - planck - institut fur astronomie ). the scientist is a member of a team of astronomers whose recent work on planet formation around tw hydrae was announced this afternoon. their work used data from esa ’ s herschel space observatory, which has the sensitivity at the needed wavelengths for scanning tw hydrae ’ s protoplanetary disk, along with the capability of taking spectra for the telltale molecules they were looking for. but getting observing time on a mission like herschel is not easy and funding committees expect results, a fact that didn ’ t daunt the researcher. says henning, “ if there ’ s no chance your project can fail, you ’ re probably not doing very interesting science. tw hydrae is a good example of how a calculated scientific gamble can pay off. ” i would guess the relevant powers that be are happy with this team ’ s gamble. the situation is this : tw hydrae is a young star of about 0. 6 solar masses some 176 light years away. the proximity is significant : this is the closest protoplanetary disk to earth with strong gas emission lines, some two and a half times closer than the next possible subjects, and thus intensely studied for the insights it offers into planet formation. out of the dense gas and dust here we can assume that tiny grains of ice and dust are aggregating into larger objects and one day planets. image : artist ’ s impression of the gas and dust disk around the young star tw hydrae. new measurements using the herschel space telescope have shown that the mass of the disk is greater than previously thought. credit : axel m. quetz ( mpia ). the challenge of tw hydrae, though, has been that the total mass of the molecular hydrogen gas in its disk has remained unclear, leaving us without a good idea of the particulars of how this infant system might produce planets. molecular hydrogen does not emit detectable radiation, while basing a mass estimate on carbon monoxide is hampered by the opacity of the disk. for that matter, basing a mass estimate on the thermal emissions of dust grains forces astronomers to make guesses about the opacity of the dust, so that we ’ re left with uncertainty — mass values have been estimated anywhere between 0. 5 and 63 jupiter masses, and that ’ s a lot of play. error bars like these have left us guessing about the properties of this disk. the new work takes a different


re left with uncertainty — mass values have been estimated anywhere between 0. 5 and 63 jupiter masses, and that ’ s a lot of play. error bars like these have left us guessing about the properties of this disk. the new work takes a different tack. while hydrogen molecules don ’ t emit measurable radiation, those hydrogen molecules that contain a deuterium atom, in which the atomic nucleus contains not just a proton but an additional neutron, emit significant amounts of radiation, with an intensity that depends upon the temperature of the gas. because the ratio of deuterium to hydrogen is relatively constant near the sun, a detection of hydrogen deuteride can be multiplied out to produce a solid estimate of the amount of molecular hydrogen in the disk. the herschel data allow the astronomers to set a lower limit for the disk mass at 52 jupiter masses, the most useful part of this being that this estimate has an uncertainty ten times lower than the previous results. a disk this massive should be able to produce a planetary system larger than the solar system, which scientists believe was produced by a much lighter disk. when henning spoke about taking risks, he doubtless referred to the fact that this was only the second time hydrogen deuteride has been detected outside the solar system. the pitch to the herschel committee had to be persuasive to get them to sign off on so tricky a detection. but 36 herschel observations ( with a total exposure time of almost seven hours ) allowed the team to find the hydrogen deuteride they were looking for in the far - infrared. water vapor in the atmosphere absorbs this kind of radiation, which is why a space - based detection is the only reasonable choice, although the team evidently considered the flying observatory sofia, a platform on which they were unlikely to get approval given the problematic nature of the observation. now we have much better insight into a budding planetary system that is taking the same route our own system did over four billion years ago. what further gains this will help us achieve in testing current models of planet formation will be played out in coming years. the paper is bergin et al., “ an old disk that can still form a planetary system, ” nature 493 ( ( 31 january 2013 ), pp. 644 – 646 ( preprint ). be aware as well of hogerheijde et al., “ detection of the water reservoir in a forming planetary system, ” science 6054 ( 2011 ), p. 338. the latter, many of whose


( preprint ). be aware as well of hogerheijde et al., “ detection of the water reservoir in a forming planetary system, ” science 6054 ( 2011 ), p. 338. the latter, many of whose co - authors also worked on the bergin paper, used herschel data to detect cold water vapor in the tw hydrae disk, with this result : our herschel detection of cold water vapor in the outer disk of tw hya demonstrates the presence of a considerable reservoir of water ice in this protoplanetary disk, sufﬁcient to form several thousand earth oceans worth of icy bodies. our observations only directly trace the tip of the iceberg of 0. 005 earth oceans in the form of water vapor. clearly, tw hydrae has much to teach us. addendum : this jpl news release notes that although a young star, tw hydrae had been thought to be past the stage of making giant planets : “ we didn ’ t expect to see so much gas around this star, ” said edwin bergin of the university of michigan in ann arbor. bergin led the new study appearing in the journal nature. “ typically stars of this age have cleared out their surrounding material, but this star still has enough mass to make the equivalent of 50 jupiters, ” bergin said.


interviewing children about past events : evaluating the nichd interview protocol this study, conducted by the nichd in collaboration with lancaster university in lancaster, england, will evaluate the accuracy of information obtained from children using an adapted version of nichd ' s interview protocol. the nichd protocol was developed to help forensic interviewers obtain information from children who may be victims of or witnesses to a crime about their experiences. this study does not involve forensic interviews, but is designed to obtain information from children about an event that takes place at their school. the study will examine how children report a brief interaction with an unfamiliar adult, how the memory of the event changes over time, and how the use of different interview techniques can help children give a fuller and more accurate accounts of past experiences. children 5 and 6 years of age who attend local schools in the lancaster, england, area may be eligible for this study. participants will be told that they are going to have their pictures taken and will be escorted by a researcher to a room at the school with another researcher who is posing as a photographer. the " photographer " and the child will put on a costume, such as a pirate ' s outfit, over their street clothes, helping each other put on pieces of the costume. the photographer will take pictures of the child in the costume. they will each take off the costumes and the child will be told that he or she will receive the photographs at a later time. another researcher posing as a photographer will come into the room, interrupting the event, and begin to argue with the first photographer about who had booked the equipment. they will resolve the argument and apologize to the child for the interruption. about 6 weeks after the event, the children will be interviewed using the adapted version of nichd interview protocol. half will be interviewed first about the staged event ( the photo session ), followed by an interview about a fictitious event ( e. g., a class visit to the fire station ) that could plausibly have happened but did not. the other half of the children will be interviewed first about the fictitious event and then about the staged event. the children will be interviewed according to one of the following three procedures : - the nichd protocol preceded by a rapport - building phase that includes the rules of the interview and open - ended questions about the child and a recently experienced event - the nichd protocol preceded by a rapport - building phase that includes the rules of the interview and direct questions about the child and a recently experienced event, or - the nichd protocol preceded by the


questions about the child and a recently experienced event - the nichd protocol preceded by a rapport - building phase that includes the rules of the interview and direct questions about the child and a recently experienced event, or - the nichd protocol preceded by the rules of the interview and open - ended questions about the child, but no opportunity to practice talking about a recently experienced event. after the interviewer has elicited as much information as is likely to be gained from verbal questions, he or she will present the child with a line drawing of a gender neutral person and ask the child to indicate where the child was touched by the photographer and where the child touched the photographer. any child who provides a report of the fictitious event will be interviewed in the same way about the fictitious event. after 1 year, the children will be interviewed again in the same manner as the 6 - week interview. the interviews will be audio - and videotaped to record the kind of information the children talk about and compare it to what actually happened in the event. | official title : | | evaluating the nichd interview protocol in an analog study | | study start date : | | january 2004 | | estimated study completion date : | | october 2006 | the nichd interview protocol was designed to aid forensic interviewers in adhering to best standards of practice when interviewing children. field studies evaluating its use have demonstrated improvements in both interviewer behavior, and the amount and quality of information obtained from children, compared to interviews conducted prior to its implementation in test sites. because field studies were conducted in forensic settings, however, it has not been possible to evaluate the protocol ' s effect on the accuracy of information reported by children. this present study therefore aims to evaluate the accuracy of information obtained using the nichd interview protocol in an analog study. in addition the study is designed to explore children ' s willingness to provide details of a suggested, non - experienced event, and the effectiveness of including a human figure drawing as an auxiliary technique for eliciting further information. furthermore, we will explore the importance of the pre - substantive / rapport - building phase of interviews, and the impact this has on children ' s reports of experienced and suggested events. finally, we will explore the effectiveness of the interview protocol with children when a long delay has occurred between the event and the interview. children will take part, individually, in a staged event at their school, and approximately six weeks later, be interviewed at the university about what they experienced. in addition, children will be asked to talk about a suggested


between the event and the interview. children will take part, individually, in a staged event at their school, and approximately six weeks later, be interviewed at the university about what they experienced. in addition, children will be asked to talk about a suggested fictitious event ( one that has not happened ). the order of the interviews will be counter - balanced across children and rapport - building conditions. some children will be interviewed with an open - ended script that includes practice in episodic memory, some with a script made up of direct questions, including a practice in episodic memory, and some with one that uses open - ended questions but does not provide practice in talking about an event from episodic memory. approximately one year later children will be interviewed again, so that we can examine children ' s reports in protocol interviews over a long delay. children ' s reports will be analyzed for both overall amount and accuracy of information reported, as well as in response to the different cues and props given in the course of the interview. it is not anticipated that the study will pose any risks to the children involved, and we expect that both the staged event and the interviews will be enjoyable and stimulating. we expect that the results of the study will provide further support for the use of nichd interview as a safe and effective means of interviewing children about past experiences. in addition to general information on children ' s eyewitness capabilities, the study is expected to supplement field studies by contributing knowledge about the accuracy of children ' s memory using the nichd interview protocol. | united states, maryland | | national institute of child health and human development ( nichd ) | | bethesda, maryland, united states, 20892 |


the national science foundation available languages : english, spanish this classroom - tested learning module gives a condensed, easily - understood view of the development of atomic theory from the late 19th through early 20th century. the key idea was the discovery that the atom is not an " indivisible " particle, but consists of smaller constituents : the proton, neutron, and electron. it discusses the contributions of john dalton, j. j. thomson, ernest rutherford, and james chadwick, whose experiments revolutionized the world view of atomic structure. see related materials for a link to part 2 of this series. atomic structure, cathode ray experiment, electron, helium atom, history of atom, history of the atom, hydrogen atom, neutron, proton metadata instance created july 12, 2011 by caroline hall october 10, 2012 by caroline hall last update when cataloged : january 1, 2006 aaas benchmark alignments ( 2008 version ) 4. the physical setting 4d. the structure of matter 6 - 8 : 4d / m1a. all matter is made up of atoms, which are far too small to see directly through a microscope. 9 - 12 : 4d / h1. atoms are made of a positively charged nucleus surrounded by negatively charged electrons. the nucleus is a tiny fraction of the volume of an atom but makes up almost all of its mass. the nucleus is composed of protons and neutrons which have roughly the same mass but differ in that protons are positively charged while neutrons have no electric charge. 9 - 12 : 4d / h2. the number of protons in the nucleus determines what an atom ' s electron configuration can be and so defines the element. an atom ' s electron configuration, particularly the outermost electrons, determines how the atom can interact with other atoms. atoms form bonds to other atoms by transferring or sharing electrons. 10. historical perspectives 10f. understanding fire 9 - 12 : 10f / h1. in the late 1700s and early 1800s, the idea of atoms reemerged in response to questions about the structure of matter, the nature of fire, and the basis of chemical phenomena. 9 - 12 : 10f / h3. in the early 1800s, british chemist and physicist john dalton united the concepts of atoms and elements. he proposed two ideas that laid the groundwork for modern chemistry : first, that elements are formed from small, indivisible particles called atoms, which are identical for a given element but different from any other element ; and second, that chemical compounds are


proposed two ideas that laid the groundwork for modern chemistry : first, that elements are formed from small, indivisible particles called atoms, which are identical for a given element but different from any other element ; and second, that chemical compounds are formed from atoms by combining a definite number of each type of atom to form one molecule of the compound. 9 - 12 : 10f / h4. dalton figured out how the relative weights of the atoms could be determined experimentally. his idea that every substance had a unique atomic composition provided an explanation for why substances were made up of elements in specific proportions. this resource is part of a physics front topical unit. topic : particles and interactions and the standard model unit title : history and discovery this classroom - tested learning module gives a condensed, easily - understood view of the development of atomic theory from the late 19th through early 20th century. the key idea was the discovery that the atom is not an " indivisible " particle, but consists of smaller constituents : the proton, neutron, and electron. it discusses the contributions of john dalton, j. j. thomson, ernest rutherford, and james chadwick, whose experiments revolutionized the world view of atomic structure. % 0 electronic source % a carpi, anthony % d january 1, 2006 % t visionlearning : atomic theory i % i visionlearning % v 2013 % n 21 may 2013 % 8 january 1, 2006 % 9 text / html % u http : / / www. visionlearning. com / library / module _ viewer. php? mid = 50 & l = disclaimer : compadre offers citation styles as a guide only. we cannot offer interpretations about citations as this is an automated procedure. please refer to the style manuals in the citation source information area for clarifications.


an electron is a subatomic particles of spin 1 / 2. it couples with photons and, thus, is electrically charged. it is a lepton with a rest mass of 9. 109 * 10 − 31kg and an electric charge of − 1. 602 * 10 − 19 c, which is the smallest known charge possible for an isolated particle ( confined quarks have fractional charge ). the electric charge of the electron e is used as a unit of charge in much of physics. electron pairs within an orbital system have opposite spins due to the pauli exclusion principle ; this characteristic spin pairing allows electrons to exist in the same quantum orbital, as the opposing magnetic dipole moments induced by each of the electrons ensures that they are attracted together. current theories consider the electron as a point particle, as no evidence for internal structure has been observed. as a theoretical construct, electrons have been able to explain other observed phenomena, such as the shell - like structure of an atom, energy distribution around an atom, and energy beams ( electron and positron beams ). - ↑ massimi, m. ( 2005 ). pauli ' s exclusion principle, the origin and validation of a scientific principle. cambridge university press. pp. 7 – 8 - ↑ mauritsson, j.. " electron filmed for the first time ever ". lunds universitet. retrieved 2008 - 09 - 17. http : / / www. atomic. physics. lu. se / research / attosecond _ physics - ↑ chao, a. w. ; tigner, m. ( 1999 ). handbook of accelerator physics and engineering. world scientific. pp. 155, 188. isbn 981 - 02 - 3500 - 3.


. an alternative definition of " carrying capacity " is the number of human beings combined with the average per capita usage of resources which if exceeded even for a short period of time will result in the inability of the earth provide the resources necessary for civilization to continue causing a rapid and horrendous decline in the human population. while no one knows what the carrying capacity of the earth may be, it cannot be infinite - - it must be finite. no matter how much the average per capita usage of resources is reduced the earth could not support 1 trillion human beings. similarly, if the per capita usage of resources were increased such that each human being used 30 times the amount of resources used by the average american is highly unlikely that the earth could support 1 billion human beings. at present human population is growing. it is highly likely that the average per capita usage of resources will continue to increase due to the rapidly growing economies of india and china and the growing economies of many of the other nations of the world. therefore, a very strong case can be made that humanity will shortly exceed the carrying capacity of the earth, if humanity already has not exceeded that capacity. if humanity exceeds the carrying capacity and takes no immediate action to reduce the population and / or the usage of resources to reduce it ' s impact on the planet below carrying capacity, then humans will enter into a violent competitions for the resources necessary to survive and the horrors set forth in 1 ( a ) will occur. in simple terms, it will be each and every man / group / religion / nation / culture against every other man / group / religion / nation / culture in order to obtain resources which the earth can provide so that the individual survives - - pure violent darwinism. billions will die and die horribly and more importantly the catastrophe will use up and / or destroy any remaining resources such that civilization will be unable to restart forever or at least for thousands of years 2. does society, no matter how defined, have a right to limit the number of children a person produces by coercion or is the right to determine how many children a person produces absolute and society has no right to interfere with that decision? in considering this question limit yourself to the right i have set forth above and do not consider how that right could or would be enforced and whether enforcing that right would be harmful or beneficial to society. those questions and any and all others would have to be considered, evaluated and discussed only if the right to limit the number of children a person produces by coercion exists in society. as far as i


. com ( it is spelled with a ' k " and not a " c " ) - - pay particular attention to his book " scarcity ". the reasons for your answers to these questions would be most appreciated. since no rational person would want to control population growth by the horrors set forth in paragraph 1 ( a ) above, there are in reality only two ways to control population growth / reduce population growth to zero / make it negative. no one can present a logically and factually supported case that the voluntary action ( as defined in paragraph 1 above ) of humanity will reduce population growth to zero prior to the commencement of the horrors described in paragraph 1 ( a ) with absolute certainty. in other words, there is some level of probability that if humanity were to limit itself to voluntary action to control population growth that action will fail and humanity will exceed the carrying capacity of the earth such that the horrors described in paragraph 1 ( a ) would occur. no one knows what is the chance of success or what is the chance of failure of voluntary action - - no one knows if the chance of success is 70 % and the chance of failure is 30 % or 80 / 20 or 60 / 40 or 50 / 50 or any other combination of numbers. however, there is a chance of failure and failure will lead to the collapse of society / the collapse of the social order / the destruction of civilization and to the horrors described in paragraph 1 ( a ). more importantly, there is a vastly greater chance of failure of voluntary action if population growth not only has to be reduced to zero but made negative to substantially reduce the human population from the current 7 billion or from the future 10 billion ( year 2100 ) to a much lower number in order for our species to survive for a reasonable period of time. a number of experts ( whatever the word " expert " means ) ( david pimental of cornell university and james lovelock of gaia fame, for example ) have presented factually and logically supported cases that the earth ' s carrying capacity is 2 billion or less of our species. humanity ignores at its peril the work of these experts. if the chance of success / failure is one set of numbers for voluntary action relating to reducing population growth zero, then there is a second set of numbers for success / failure in which the success side of the equation is substantially reduced and failure side of the equation is substantially increased in considering voluntary action in relation to population reduction. since chance of failure of voluntary action could result in the horrific deaths of billions, perhaps as many


failure in which the success side of the equation is substantially reduced and failure side of the equation is substantially increased in considering voluntary action in relation to population reduction. since chance of failure of voluntary action could result in the horrific deaths of billions, perhaps as many as 9. 6 billion - - ( 10. 1 billion alive in 2100 less the possible carrying capacity of 0. 5 billion = reduction of 9. 6 billion ), the question becomes - - - - what level of possible failure of voluntary action is acceptable to humankind? of course, the number of horrific deaths could be substantially less than 9. 6 billion. however, since no one can guarantee with 100 % certainty that the voluntary action will not prevent a substantial number of horrific deaths, the leaders of humanity have a duty to convene one or more conferences of the best minds presently on our planet to evaluate and consider coercive population control. it cannot be denied that many arguments can be made against coercive population control - - - the experiment in india a number of years ago was a failure, humanity could equate coercive population control with the actions of adolph hitler or racists, it will take as long to impose coercive control as to make voluntary action successful and many others. coercive population control need not be discriminatory. if each couple in the entire world were limited to one child, no religion, group, nationality, race, culture, etc., would benefit at the expense of any other religion, group, nationality, race or culture. this essay is not intended discuss or debate the advantages / disadvantages, or the problems / benefits of coercive population control. rather, the purpose of this essay is to show that humanity must consider and evaluate coercive population control because there is a substantial, but undefined, risk that voluntary action will lead to the horrific deaths of a substantial number of human beings in the very near future - - - - probably before the year 2050 and almost certainly before the year 2100. jason g. brent email @ example. com comments are not moderated. please be responsible and civil in your postings and stay within the topic discussed in the article too. if you find inappropriate comments, just flag ( report ) them and they will move into moderation que.


use it or lose it? researchers investigate the dispensability of our dna | october 2, 2008 our genome contains many genes encoding proteins that are similar to those of other organisms, suggesting evolutionary relationships ; however, protein - coding genes account for only a small fraction the genome, and there are many other dna sequences that are conserved across species. what are these sequences doing, and do we really need them at all? in a study published online today in genome research ( www. genome. org ), researchers have delved into this mystery and found that evolution has actively kept them in our genome. before the human genome was sequenced, researchers estimated the genome might contain upwards of 140, 000 protein - coding genes, but surprisingly, sequencing revealed only about 20, 000, accounting for less than 2 % of the entire genome. previously, dr. gill bejerano of stanford university found that lurking within the other 98 % of the genome are stretches of sequences, known as ultraconserved elements, which are identical between humans and animals such as rodents and chickens, even though hundreds of millions of years of independent evolution separates them. other evidence has suggested that ultraconserved sequences can harbor critical functions, such as regulation of the activity of certain genes. yet research in this field has produced laboratory results that are seemingly in disagreement : some ultraconserved elements can be deleted from the mouse genome and produce no observable effect on mice. bejerano cautions that laboratory experiments such as these may not be able to detect slow evolutionary forces at work. " with this in mind, we set out to examine the genomic data, much as someone would examine archaeological data, in search of similar deletion events that have happened naturally, and more importantly, were retained in the wild. " " an analogy i like to entertain is that of plate tectonics : a fraction of the phenomena may be strong enough to be directly measured by our instruments, but to appreciate its full magnitude we must dig into the geological record, " said bejerano. " this digging into the genomic record is what our current work was all about. bejerano and graduate student cory mclean studied the genomes of six mammals, investigating ultraconserved elements that are shared between primates and closely related mammals, were present in the ancestor of modern rodents, but have been lost in the rodent lineage more recently. the researchers found that the genomic evidence supports an important biological role for ultraconserved elements, as well as thousands of other non -


, were present in the ancestor of modern rodents, but have been lost in the rodent lineage more recently. the researchers found that the genomic evidence supports an important biological role for ultraconserved elements, as well as thousands of other non - coding elements that are resistant to deletion. " the functional importance of ultraconserved elements is reinforced by the observation that the elements are rarely lost in any species, " said mclean. " in fact, they are over 300 - fold less likely to be lost than genomic loci which evolve neutrally in our genome. " bejerano explained that while loss of some elements may have a significant impact on the fitness of a species and the loss of other elements might be harder to detect in the laboratory, nearly all changes to these regions are picked up by evolution and swept out of the population. " perhaps our most striking observation is one of sheer magnitude, " bejerano said. " our work highlights how essential these dozens of thousands of regions are to the natural evolution of a species even as their actual functions remain, at large, a mystery. " scientists from stanford university ( stanford, ca ) contributed to this study. this work was supported by a stanford bio - x graduate fellowship and the edward mallinckrodt, jr. foundation. gill bejerano, ph. d. ( email @ example. com ; + 1 - 650 - 723 - 7666 ) has agreed to be contacted for more information. interested reporters may obtain copies of the manuscript from peggy calicchia, editorial secretary, genome research ( firstname. lastname @ example. org ; + 1 - 516 - 422 - 4012 ). about the article : the manuscript will be published online ahead of print on october 2, 2008. its full citation is as follows : mclean, c., and bejerano, g. dispensability of mammalian dna. genome res. doi : 10. 1101 / gr. 080184. 108. about genome research : genome research ( www. genome. org ) is an international, continuously published, peer - reviewed journal published by cold spring harbor laboratory press. launched in 1995, it is one of the five most highly cited primary research journals in genetics and genomics. about cold spring harbor laboratory press : cold spring harbor laboratory press is an internationally renowned publisher of books, journals, and electronic media, located on long island, new york. it is a division of cold spring harbor laboratory, an innovator in life science research


heat is a sad fact of life for current generation electronics. any android, iphone, or blackberry user can tell you that smartphones tend to get pretty hot at times. and by today ' s standards a balmy 85 degrees celsius, while hot enough to cook an egg, is a pretty " good " operating temperature for a high - powered pc graphics processing unit. but that could all soon change, according to the results of a new study by researchers at the university of illinois. examining graphene transistors, a team led by mechanical science and engineering professor william king [ profile ] and electrical and computer engineering professor eric pop [ profile ] made a remarkable discovery - - graphene appears to self - cool. i. what is graphene? graphene is somewhat like a miniature " fence " of carbon. the material consists of a single - atom thick layer composed of hexagonal units. at each point of the hexagon sits a carbon atom that is bonded to its three close neighbors. the material behaves like a semiconductor, despite being made of organic atoms. it offers remarkable performance at an incredibly small scale, thus the electronics industry views it as a potential material to power electronic devices of the future. a variety of methods exist for producing graphene. the earliest method was an exfoliation technique that involved stripping individual graphene layers off a layer of graphite ( the material found in pencil lead ) - - this technique ( as of 2008 ) cost as much as $ 100m usd to produce a single cubic centimeter of material. however, rapid advances in production have allowed manufacturers to begin scaling up production to the point where tons of exfoliated graphene can now be produced. techniques promise to drop the price even further. one method, epitaxial growth on silicon cost $ 100 per cubic centimeter in 2009. its limitation is that, obviously, it requires silicon ( eliminating some desirable properties like flexibility ). south korean researchers have tested another promising method, nickel metal transfer. graphene is fascinating from a physics perspective. in 2005 physicists at the university of manchester and the philip kim group from columbia university demonstrated that quasiparticles inside graphene were massless dirac fermions. these unusual particles help give rise to the material ' s unique characteristics. ii. graphene as a self - cooling device despite the extreme interest in the material, deal of mystery still surrounds graphene. because it is so extremely thin, it is difficult to test and measure accurately certain properties of the material. overcoming technical challenges,


. graphene as a self - cooling device despite the extreme interest in the material, deal of mystery still surrounds graphene. because it is so extremely thin, it is difficult to test and measure accurately certain properties of the material. overcoming technical challenges, the university of illinois team used an atomic force microscope tip as a temperature probe to make the first nanometer - scale temperature measurements of a working graphene what they found was that the resistive heating ( " waste heat " ) effect in graphene was weaker than its thermo - electric cooling effect at times. this is certainly not the case in silicon or other semiconductors where resistive heating far surpasses cooling effects. what this means is that graphene circuits may not get hot like traditional silicon - based ones. this could open the door to dense 3d chips and more. further, as the heat is converted back into electricity by the device, graphene transistors may have a two - fold power efficiency gain, both in ditching energetically expensive fans and by recycling heat losses into usable electricity. professor king describes, " in silicon and most materials, the electronic heating is much larger than the self - cooling. however, we found that in these graphene transistors, there are regions where the thermoelectric cooling can be larger than the resistive heating, which allows these devices to cool themselves. this self - cooling has not previously been seen for graphene devices. " professor pop adds, " graphene electronics are still in their infancy ; however, our measurements and simulations project that thermoelectric effects will become enhanced as graphene transistor technology and contacts improve. " a paper has been published [ full text ] in nanotechnology ' s most prestigious peer - reviewed journal, nature nanoscience. university of illinois graduate student kyle undergraduate feifei lian and postdoctoral researcher myung - ho bae [ profile ] are listed as co - authors on the paper. iii. what ' s next? the study should provide even more motivation for semiconductor manufacturing companies like intel, globalfoundries, and tmsc to lay down the process work necessary to mass - produce circuits based on graphene transistors, capacitors, etc. as for the university of illinois team, they plan to next use their new measurement technique to analyze carbon nanotubes and other novel structures that are of interest to future electronics applications. their work is funded via a grant from the air force office of scientific research and the office of naval research.


a new approach to improving system performance by terry costlow embedded. com ( 01 / 05 / 10, 08 : 20 : 00 pm est ) speed is a key element in most every electronic design. whether engineers are creating complex image processing applications or designing systems that extend battery life by working swiftly before returning to sleep mode, speed is a critical factor in a product ' s success. though hardware usually gets first consideration when design teams look for ways to improve speed, that ' s not usually the most effective path. it ' s fairly straightforward to run the features and functions of a product faster without making any hardware changes. streamlining software so it runs at optimal rates can bring significant improvements in a way that ' s so easy to implement units in the field can be enhanced. that ' s far more cost effective than redesigning hardware. three of the four basic components in system speed are in software : operating systems, compilers and application software. hardware is the critical fourth phase, but altering processors, memories, bus architectures and data channels is difficult. altering the operating system is also difficult once the os has been selected. that leaves optimizing the software that runs above the operating system as the most straightforward way to increase speed. applications packages, middleware and drivers take center stage when development teams focus on the features and functions that attract customers. but this software is typically overlooked when the focus shifts to performance. that ' s a mistake. significant performance increases can be achieved when acceleration techniques are applied to software that resides above the operating system. it ' s rare that speed can ' t be boosted by 20 percent ( or even doubled or quadrupled ) especially when utilizing an outside firm that specializes in software acceleration who can assist with streamlining programs. click here to read more...


micro vs macro micro and macro are prefixes that are used before words to make them small or big respectively. this is true with micro and macroeconomics, micro and macro evolution, microorganism, micro lens and macro lens, micro finance and macro finance, and so on. the list of words that makes use of these prefixes is long and exhaustive. many people confuse between micro and macro despite knowing that these prefixes signify small and large respectively. this article takes a closer look at the two prefixes to find out their differences. to understand the difference between micro and macro, let us take up the example of micro and macro evolution. to signify evolution that takes place within a single species, the word microevolution is used whereas evolution that transcends the boundaries of species and takes place on a very large scale is termed as macroevolution. though the principles of evolution such as genetics, mutation, natural selection, and migration remain the same across microevolution as well as macro evolution, this distinction between microevolution and macroevolution is a great way to explain this natural phenomenon. another field of study that makes use of micro and macro is economics. while the study of the overall economy and how it works is called macroeconomics, microeconomics focuses on the individual person, company, or industry. thus, the study of gdp, employment, inflation etc. in an economy is classified under macroeconomics. microeconomics is the study of forces of demand and supply inside a particular industry effecting the goods and services. so it is macroeconomics when economists choose to concentrate upon the state of the economy in a nation whereas the study of a single market or industry remains within the realms of microeconomics. there is also the study of finance where these two prefixes are commonly used. thus, we have microfinance where the focus is upon the monetary needs and requirements of a single individual where there is also macro finance where financing by the banks or other financial institutions is of very large nature. micro and macro are derived from greek language where micro means small and macro refers to large. these prefixes are used in many fields of study such as finance, economics, evolution etc. where we have words like micro finance and macro finance, micro evolution and macro evolution etc. studying something at a small level is micro while studying it on a large scale is macro analysis. financing the needs of an individual may be micro financing whereas the financial needs of a builder requiring money for a


presenting - ' amasia ', the next supercontinent! ever since earth has been in existence there have been the formation and breaking apart of many supercontinents - while pangaea, that existed between 150 - 300 million years ago is the most well - known, prior to that was nuna ( 1. 8 billion years ago ), rodina ( 1 billion years ago ) and many more that cannot be verified because 2 billion year - old rocks containing evidence of magnetic fields, are hard to find. and while most scientists are in agreement that rodina, nuna and pangaea did exist, there is very little consensus on the continents they comprised of - some experts believe that they were the same ones, while others think that the wandering landmasses reassembled on the opposite sides each time - about 180° away from where the previous supercontinent had come together. now, a group of geologists led by yale university graduate student ross mitchell have a new theory - they think that each supercontinent came together about 90° from its predecessor. that is, the geographic center of rodina was about 88° away from the center of nuna, whilst the center of panagea, believed to have been located near modern - day africa, was about 88° away from the center from its super giant predecessor, rodina. these calculations that were reported earlier this year were based not only on the paleolatitude ( the latitude of a place at some time in the past, measured relative to the earth ' s magnetic poles in the same period ) of the ancient supercontinents, but also, for the first time the paleolongitude, that ross measured by estimating how the locations of the earth ' s magnetic poles have changed through time. while the theory is interesting, what is even more so is that the team has also come up with a model of the next supercontinent. if their estimates are accurate, over the next few hundred million years, the tectonic plates under the americas and asia will both drift northward and merge. this means that modern day north and south america will come together and become one giant landmass, displacing the caribbean sea completely. a similar movement in eurasia ( australia and south eastern asia ) will cause the arctic ocean to disappear causing the continents to fuse with canada. the result? a ginormous continent that they call ' amasia '. the one thing that is not too clear is if antarctica will be part of this


researchers at new jersey institute of technology ( njit ) have developed an inexpensive solar cell that can be painted or printed on flexible plastic sheets. “ someday, homeowners will even be able to print sheets of these solar cells with inexpensive home - based inkjet printers. consumers can then slap the finished product on a wall, roof or billboard to create their own power stations, ” said somenath mitra, ph. d., lead researcher, professor and acting chair of njit ’ s department of chemistry and environmental sciences. harvesting energy directly from abundant solar radiation using solar cells is increasingly emerging as a major component of future global energy strategy, mitra said. yet, when it comes to harnessing renewable energy, challenges remain. expensive, large - scale infrastructures, such as windmills or dams, are necessary to drive renewable energy sources, such as wind or hydroelectric power plants. purified silicon, also used for making computer chips, which continue to rise in demand, is a core material for fabricating conventional solar cells. however, the processing of a material such as purified silicon is beyond the reach of most consumers. “ developing organic solar cells from polymers, however, is a cheap and potentially simpler alternative, ” mitra said. “ we foresee a great deal of interest in our work because solar cells can be inexpensively printed or simply painted on exterior building walls and / or rooftops. imagine some day driving in your hybrid car with a solar panel painted on the roof, which is producing electricity to drive the engine. the opportunities are endless. ” the solar cell developed at njit uses a carbon nanotubes complex, which is a molecular configuration of carbon in a cylindrical shape. although estimated to be 50, 000 times smaller than a human hair, just one nanotube can conduct current better than any conventional electrical wire. mitra and his research team took the carbon nanotubes and combined them with tiny carbon fullerenes ( sometimes known as buckyballs ) to form snake - like structures. buckyballs trap electrons, although they can ’ t make electrons flow. add sunlight to excite the polymers, and the buckyballs will grab the electrons. nanotubes, behaving like copper wires, then will be able to make the electrons or current flow. “ someday, i hope to see this process become an inexpensive energy alternative for households around the world, ” mitra said. ec


food systems are often described as comprising four sets of activities : those involved in food production, processing and packaging, distribution and retail, and consumption. all encompass social, economic, political, and environmental processes and dimensions. to analyze the interactions between global environmental change and food systems, as well as the tradeoffs among food security and environmental goals, a food system can be more broadly conceived as including the determinants ( or drivers ) and outcomes of these activities. the determinants comprise the interactions between and within biogeophysical and human environments that determine how food system activities are performed. these activities lead to a number of outcomes, some of which contribute to food security and others that relate to the environment and other societal concerns. these outcomes are also affected directly by the determinants. food security is the principal policy objective of a food system. food security outcomes are described in terms of three components and their subcomponents : food availability, i. e., production, distribution, and exchange ; food access, i. e., affordability, allocation, and preference ; and food use, i. e., nutritional and social values and safety. although the food system activities have a large influence on food security outcomes, these outcomes are also determined directly by socio - political and environmental drivers. these outcomes vary by historical, political, and social context. to capture these concepts holistically and to allow the analysis of impacts of global environmental change, adaptations, and feedbacks, a food system must include :


a typical bpm uses a differential pressure sensor to measure cuff or arm pressure. as the output of this sensor lies within a few micro volts ( 30 - 50µv ), the output pressure signal has to be amplified using a high - gain instrumentation amplifier with a good common mode rejection ratio ( cmrr ). usually the gain and cmrr need to be around 150 and 100 db respectively. the frequency of oscillatory pulses in the pressure signal lies between 0. 3 - 11hz with an amplitude of a few hundred microvolts. these oscillations are extracted using band - pass filters with gain around 200 and cutoff frequency at 0. 3 - 11hz. a 10 - bit adc with a speed of 50 hz is used to digitize the pressure sensor and oscillatory signal. two timers are used to calculate the heart rate and implement safety timer functionality. a safety timer regulates the pressure kept on a subject ’ s arm for a certain period of time. this safety timer is a part safety regulation in aami standards. a microcontroller core calculates the systolic and diastolic pressures values using an oscillometric algorithm. the cuff is inflated and deflated using motors driven by pwms. a typical non - contact digital thermometer uses a transducer, also called a thermopile, consisting of a micro machine embedded membrane with thermocouples to measure thermocouple temperature and a thermistor to measure ambient temperature. the thermocouple generates a dc voltage corresponding to the temperature difference in its junctions. the output of the thermocouple is on the order of a few µv. the signal from the thermocouple is amplified using a low - noise precision amplifier. a voltage divider is constructed with the thermistor and external precision voltage reference. this voltage divider converts the change in thermistor resistance with respect to temperature to change in voltage. voltages from the thermocouple and thermistor are used to calculate the thermocouple and ambient temperatures. the temperature is obtained from voltages using a polynomial function given by the sensor manufacturer or through a look - up table with pre - stored readings. the ambient temperature is added to the thermocouple temperature to get the final temperature measurement. a segment lcd driver, rtc, push buttons, eeprom and usb are the other peripherals needed in both of the above applications.


arterial blood gases made easyby - iain hennessey, mbchb ( hons ), bsc ( hons ), mrcs, mmis, specialty registrar, paediatric surgery, manchester royal infirmary, manchester, uk - alan japp, mbchb ( hons ), bsc ( hons ), mrcp, clinical research fellow, department of cardiovascular research, university of edinburgh, uk arterial blood gas analysis plays an indispensable role in the assessment and management of patients with a huge range of acute medical and surgical problems. its importance as a key tool in the work - up of acutely unwell patients rivals that of the ecg and the chest x - ray. this book covers all aspects of the arterial blood gas in a simple, user - friendly manner. the first part explains the technique, the values obtained and common patterns of abnormalities, while the second part comprises a series of worked examples and case scenarios to allow the reader to put this system into practice. medical undergraduates at all stages of training, junior doctors in a & e, anaesthetics, surgery, acute medicine and respiratory medicine paperback, 152 pages published : september 2007 imprint : churchill livingstone - part 1 : the abg explained pulmonary gas exchange : the basics disorders of gas exchange acid base balance : the basics disorders of acid base balance abg sampling technique when and why is an abg required? making abg interpretation easy part 2 : the abg in practice the 2nd part of the book contains a series of 25 clinical scenarios each requiring interpretation of an arterial blood gas as the end point. each scenario comprises a 2 page spread. the first page includes information on history and examination findings, with or without other important test results. the opposing page shows the abg result in the style of a computer print - out and list a series of questions for the reader to answer. each scenario has a corresponding " explanation " page at the back of the book.


forest fire protection, " explained nicolas raffalli of ceren. " within the entente region we have an existing fire database called promethee, which is filled out either by firemen, forestry workers or policemen across the 13 departments making up the region. " current methods of recording fire damage vary greatly by country or region. the purpose of this new service – part of a portfolio of earth observation services known as risk - eos – is to develop a standardised burn scar mapping methodology for use throughout europe, along with enabling more accurate post - fire damage assessment and analysis of vegetation re - growth and manmade changes within affected areas. " we want to link up promethee with this burn scar mapping product from risk - eos to have a good historical basis of information, " raffalli added. " the benefit is that it makes possible a much more effective protection of the forest. " characterising the sites of past fires to a more thorough level of detail should mean that service users can better forecast where fires are most likely to break out in future, a process known as risk mapping. having been validated and geo - referenced, burn scar maps can then be easily merged with other relevant geographical detail. the vast majority of fires are started by the actions of human beings, from discarding cigarette butts up to deliberate arson. checking burn scar occurrences against roads, settlements and off - road tracks is likely to throw up correlations. these can be extrapolated elsewhere to help identify additional areas at risk where preventative measures should be prioritised. and overlaying burn scar maps with a chart of forest biomass has the potential to highlight zones where new blazes would burn the fiercest. once such relatively fixed environmental elements, known as static risks, are factored in, other aspects that change across time – including temperature, rainfall and vegetation moisture – can be addressed. these variables are known as dynamic risks. at the end of the risk mapping process, the probability of fire breaking out in a particular place and time can be reliably calculated. the risk - eos burn scar mapping service began last year. the intention is to develop further fire - related services by the end of 2007, including daily risk maps combining eo with meteorological and vegetation data. another planned service will identify ' hot spots ' during fires, and map fire events twice a day, permitting an overall assessment of its development and the damage being done. a ' fires memory atlas ' set up at national or regional level will allow the routine sharing of all


| " money doesn ' t grow on trees " = don ' t waste money because it isn ' t always easy to come by | " watch how much you spend because money doesn ' t grow on trees. " " have a green thumb " = special ability at making plants grow well " she has a real green thumb for growing beautiful decorative trees. " more of randall ' s favorite learning resources [ quiz script | text completion quiz ] recycling and protecting the environment is very important in our world today. now, you will listen to an award - winning essay on trees in which a girl explains why she loves trees? what ideas would you expect to hear in such an essay? | i. pre - listening exercises [ top ] | helpful tip : deforestation is a serious problem around the world, and planting new trees never seems to keep up with the demand. you can help by recycling paper and even just simply reusing paper for different purposes. | listen to the conversation by pressing the " play audio " button and answer the questions. press the " final score " button to check your quiz. | ii. listening exercises [ top ] | [ other audio options : play realmedia | play window media ] listen to the conversation again as you read the quiz script and do the text completion quiz. | iii. post - listening exercises [ top ] | what environmental problems can you think that pose great danger to nature and our world ( e. g., acid rain, deforestation, water pollution )? are these threats caused by human activity or by natural occurrences? what are some solutions to these problems? share your ideas on these important issues. now, write your opinions on a similar topic at randall ' s esl blog here. randall ' s sites : daily esl | esl blog | ezslang | train your accent | tips for students | hiking in utah


this little led - lit cube is much more than just a paper lantern : it ’ s a translucent and flexible thin - film electronic circuit that hooks up a battery to an led, limber enough to be folded into an origami box. and the coolest thing about circuits like these? you can make them at home. in what follows, we combine basic electronics ( an led throwie ) and papercraft ( a traditional origami balloon ) to make what might be called an “ led foldie. ” the circuitry consists of aluminum foil traces, ironed onto adhesive paper such as freezer paper, photo mounting paper, or even a laser printed pattern. something constructed this way can then be folded so fit an led and battery to complete the circuit. the first step in designing a three - dimensional circuit like this is to see where the parts go. after that we will unfold the model, draw circuit paths between the points that we want to connect, and go from there. to get started, we first folded an origami balloon, and then inserted the components where we wanted them. the balloon has a convenient pocket on the side for a lithium coin cell, and a single hole that allows you to point an led into the interior of the balloon. ( and you can follow along with balloon folding in this flickr photo set. ) we marked up the locations of the battery and led terminals on the origami balloon – while still folded – and then unfolded our “ circuit board. ” at this point, we have the component locations marked, but no lines drawn between them. the next step is to add those circuitry lines ( circuit board wires, or traces ) between the battery and led. one thing to keep in mind for interfacing papercraft to electronics : it ’ s helpful if the circuit traces fold over the leads for the led in order to maintain good contact. after connecting the dots ( so to speak ) we have the resulting layout of our circuit. ( see pdf below as well. ) pretty simple here – only two wires! the two round pads contact the two sides of the battery, and the two angled pads contact the two leads of the led. the next step is to actually fabricate our circuit board. we ’ ve actually found two slightly different techniques that work well, so we ’ ll show you both. first is the “ freezer paper ” method ( which also works with sheets of dry mount adhesive ), where you laminate foil traces to the plastic - coated paper. second


basal in morphology and harder to classify? if the latter, then why insist that the problem is now solved? 173 alan feduccia sets out an important fact concerning the dino - birds said to have been found in china : the " feathers " on the fossils said to be those of feathered dinosaurs are definitely not bird feathers. a considerable body of evidence shows that these fossil traces have nothing at all to do with bird feathers. he says this in an article published in the auk magazine : having studied most of the specimens said to sport protofeathers, i, and many others, do not find any credible evidence that those structures represent protofeathers. many chinese fossils have that strange halo of what has become known as dino - fuzz, but although that material has been " homologized " with avian feathers, the arguments are far less than convincing. 174 citing richard o. prum, one of the supporters of the dino - bird claims, as an example, feduccia goes on to mention the prejudiced approach so prevalent on the subject : prum ' s view is shared by many paleontologists : birds are dinosaurs ; therefore, any filamentous material preserved in dromaeosaurs must represent protofeathers. 175 latest research has dealt a severe blow to feathered dinosaur claims the fossilized structures referred to as dinosaur feathers were shown by theagarten ( solly ) lingham - soliar, a paleontologist from durban - westville university in south africa to be nothing more than decayed connective tissue. professor lingham - soliar performed an experiment by burying a dolphin in river mud, semi - permeable to air for a year. the reason a dolphin was selected was that its flesh is easy to analyze. at the end of this period, the professor examined the dolphin ' s bunches of collagen — which constitutes connective tissue in the bodies of most living things — under a microscope. according to him, the decayed collagen in the dolphin ' s body bore " a striking resemblance to feathers. " 1 the german magazine naturwissenschaften commented that : " the findings throw serious doubt on the virtually complete reliance on visual image by supporters of the feathered dinosaur thesis and emphasize the need for more rigorous methods of identification using modern feathers as a frame of reference. " 2 with this finding, it emerged that even a dolphin could leave behind traces of apparent feathers. this once again showed that there are no grounds for regarding extinct


emphasize the need for more rigorous methods of identification using modern feathers as a frame of reference. " 2 with this finding, it emerged that even a dolphin could leave behind traces of apparent feathers. this once again showed that there are no grounds for regarding extinct dinosaurs with " feathers " as proto - birds. 1. stephen strauss, " buried dolphin corpse serves science, " 11 november 2003 ; http : / / www. theglobeandmail. com / servlet / articlenews / tpstory / lac / 20031111 / udino11 / tpscience / according to feduccia, one factor that invalidates this preconception is the presence of these same traces in fossils that have no relationship with birds : most important, " dino - fuzz " is now being discovered in a number of taxa, some unpublished, but particularly in a chinese pterosaur and a therizinosaur, which has teeth like those of prosauropods. most surprisingly, skin fibers very closely resembling dino - fuzz have been discovered in a jurassic ichthyosaur and described in detail. some of those branched fibers are exceptionally close in morphology to the so - called branched protofeathers ( " prum protofeathers " " ) described by xu. that these so - called protofeathers have a widespread distribution in archosaurs is evidence alone that they have nothing to do with feathers. 176 feduccia recalls that various structures found around these fossils and thought to belong to them, were later determined to consist of inorganic matter : one is reminded of the famous fernlike markings on the solnhofen fossils known as dendrites. despite their plantlike outlines, these features are now known to be inorganic structures caused by a solution of manganese from within the beds that reprecipitated as oxides along cracks or along bones of fossils. 177 the fossil beds preserve not only an indefinite structure such as dino - fuzz but also bird feathers. but all the fossils presented as feathered dinosaurs have been found in china. why should these fossils have not emerged from anywhere else in the world — feduccia draws attention to this intriguing state of affairs : one must explain also why all theropods and other dinosaurs discovered in other deposits where integument is preserved exhibit no dino - fuzz, but true reptilian skin, devoid of any featherlike material ( feduccia 1999 ), and why typically chinese dromaeosaurs preserving dino - fuzz do not normally preserve


dinosaur, was introduced as an alleged dino - bird, the report admitted, " feathers, however, have not yet been found. " 182 despite this reservation, the media drew the animal as a feathered creature, and the missing details were added using plenty of creative imagination. the most evident objection to this so - called missing link is again, an error in dating. this alleged intermediate form fossil is 75 million years younger than archaeopteryx, itself a species of flying bird. this fossil is therefore a specimen that demolished the ancestral relationship claimed by evolutionists. in the same way that this fossil provides no evidence for evolution, it also demolished the ancestral relationship claimed by evolutionists. according to ohio university professor of zoology john ruben : a point that too many people always ignored, however, is that the most birdlike of the dinosaurs, such as bambiraptor and velociraptor, lived 70 million years after the earliest bird, archaeopteryx. so you have birds flying before the evolution of the first birdlike dinosaurs. we now question very strongly whether there were any feathered dinosaurs at all. what have been called feathered dinosaurs were probably flightless birds. 183 evolutionists use a few bird - like characteristics as grounds for their preconceived interpretations. yet the effort of building a line of descent based on similarities is full of contradictions that evolutionists cannot explain. whenever evolutionists construct an alleged evolutionary relationship between clearly different living things based on similar structures, they immediately close the subject by describing it as " parallel evolution. " they claim that living things with similar complex organs but with no ancestors in common, evolved independently. however, since they cannot account for the origin of these complex organs in even one living thing, their statements that these organs supposedly evolved several times presents a serious predicament. alan feduccia states that certain similarities between birds and dinosaurs do not show any evolutionary relationship between the two groups : bambiraptor is a small dinosaur, but it does have a number of birdlike features, as do many other forms. however there is nothing special about hollow bones, as some mammals and frogs have them. the problem, of course, is that bambiraptor is some 80 million years beyond archaeopteryx, and yet is claimed to be the dinosaur most close to bird ancestry. that alone should be a red flag, and a warning that the situation is far more complicated than suspected. 184 3 ) confuciusornis sanctus : identical to modern birds two


the fossils protarchæopteryx robusta and caudipteryx zoui do not belong to dinosaurs, but to extinct flightless birds. the efforts to portray these creatures as dinosaurs is an example of evolutionists ' eagerness to produce evidence. in the summer of 1996, farmers working in the yixian formation found three separate turkey - sized fossils, so well preserved as to give genuine evidence of bird feathers. at first, ji qiang and his colleague ji shu - an concluded that these fossils must belong to a single species. noting their surprising similarity to archaeopteryx, they gave the creature the name protarchaeopteryx robusta. during his research in the autumn of 1997, philip currie concluded that these fossils belonged to two different species, neither of which resembled archaeopteryx. the second species was given the name caudipteryx zoui. 186 the discoveries of the protarchæopteryx robusta and caudipteryx zoui fossils were depicted as evidence that birds evolved from theropod dinosaurs. 187 the popular press stated that these fossils were definitely the so - called ancestors of birds. one commentator even wrote that the dinosaur - bird link was " now pretty close to rock solid. " 188 however, this certainty was again, only a biased interpretation. according to evolutionist claims, caudipteryx and protarchaeopteryx were small dinosaurs whose bodies were largely covered in feathers. but on their wings and tails were longer and more complex feathers, arranged like those in present - day birds. however, it is no surprise that these creatures should have feather arrangements similar to modern birds ', because their feathers are symmetrically shaped, as observed in present - day flightless birds. 189 therefore, the creatures in question are flightless birds, not dinosaurs. in severely criticizing the dino - bird dogma, larry martin and alan feduccia stated that these fossils were flightless bird species like the modern ostrich. 190 but adherents of the dino - bird theory are reluctant to accept this because they want to classify the creatures as dinosaurs, even though this fossil provides no support for evolutionist claims. indeed, this fossil represents a new contradiction to evolutionists ' alleged ancestral relationships. according to the evolutionist scenario, these dinosaurs and modern birds both have a special bone that lets them bend their wrists. again according to evolutionist claims, this feature enabled them to move their forefeet in a wide manner, to catch fleeing


. according to the evolutionist scenario, these dinosaurs and modern birds both have a special bone that lets them bend their wrists. again according to evolutionist claims, this feature enabled them to move their forefeet in a wide manner, to catch fleeing prey with their long arms and gripping talons. this allegedly powerful beating movement represented an important part of the wingbeats the today ' s birds use to fly. however, such interpretations are scientifically invalid, because flight consists of far more complex actions than just wing beating : any forward beating movement gives rises to a counter impulse that propels the bird backward. for the purpose of flight, the main flight feathers are arranged at such an angle as to push the air back and propel the birds forwards. as in planes, the wings have a special aerofoil shape, which causes air to flow faster over the upper surface than the lower. this, according to the bernoulli principle, reduces air pressure on the upper surface and creates lift. this is the main factor in take - off, but there is also the question of newton ' s third law — the reaction to the air being propelled downward. ). 191 while refuting the theory of evolution ' s dino - bird claims, the world of science also confirms that living things are perfectly created. the attitude of evolutionist scientists clearly reveals that they are blindly devoted to the theory in question. in addition, the structure of a wing hypothesized to catch prey is very different from that created for beating in flight. a feathered wing is no advantage to a bird using its wings to catch prey, because a feathered wing ' s broad surface will only increase air resistance and make movement more difficult. if, the bird flapped for hunting, as evolutionists maintain then its wing structure should help the bird move forward by pushing air back. therefore, it would be a greater advantage for the bird ' s wings to let air pass through them, like a sieve or flyswatter. thus evolutionist accounts are full of illogicalities that conflict with their own claims. in addition to its feathers, caudipteryx has a series of other features showing it to be a bird — such as that it was carnivorous. caudopteryx was portrayed as a theropod since it was first unearthed, it was thought to be a carnivore. 192 but there were no teeth in its lower skull and lower jaw, and the first two fossil specimens contained the remains of crops that birds use for digesting plant


of connecticut university had this to say : the stiff, bristlelike fibers that outline the fossils lack the detailed organization seen in modern feathers. 196 another important point is that sinosauropteryx had bellows - like lungs, like those in reptiles. according to many researchers, these show that the animal could not have evolved into modern - day birds with their high - performance lungs. 6 ) eoalulavis hoyasi shares with wing structure of modern - day birds the wing structure in eoalulavis hoyasi is also present in certain present - day flying birds. the feathers on this bird ' s wing contain a small bunch of feathers attached to the " finger ". when the bird wishes to slow down or descend to earth, it decreases the angle of the wing to the horizon. this allows air to flow over the wing ' s top surface and to stop without falling. another fossil to demolish evolutionist claims was eoalulavis hoyasi. this, estimated at some 120 million years old, is older than all the known theropod specimens. nonetheless, wing structure in eoalulavis hoyasi is identical to some modern - day flying birds. this proves that vertebrates identical in many respects to modern birds were flying 120 million years ago. 197 any suggestion that theropods, which appeared after this creature, were the ancestors of birds is clearly irrational. this bird ' s wing has a bunch of small feathers attached to the " finger. " recognizable as the alula, this structure is a basic feature of many birds alive today and consisting of several feathers that permits the bird to engage in various maneuvers during flight. but it had never before been encountered in a fossil bird from the mesozoic. this new bird was given the name eoalulavis hoyasi, or " ancient bird with an alula. " 198 its presence shows that this bird, the size of a chaffinch, was able to fly and maneuver as well as modern - day birds. the alula functions like the wing flap on an airplane. when the bird wants to reduce its speed or landing, it increases of its wing to the horizon. the drag produced by this wing position helps the bird to slow down. but when the angle between the direction of the air flow and the wing surface gets too steep, turbulence over the wing increases until the bird loses the lift necessary to maintain flight. like an airplane under similar circumstances, the bird is in danger of stalling in midair.


between the direction of the air flow and the wing surface gets too steep, turbulence over the wing increases until the bird loses the lift necessary to maintain flight. like an airplane under similar circumstances, the bird is in danger of stalling in midair. the alula now enters the equation. by raising this small appendage, the bird creates a slot between it and the main part of the wing, similar to what happens when a pilot deploys a craft ' s wing flaps. the slot allows air to stream over the main wing ' s upper surface, easing turbulence and allowing the bird ( or plane ) to brake without stalling. 199 birds 120 million years ago were using the same technology as that employed present. this realization added yet another insuperable difficulty facing the theory of evolution. 7 ) unenlagia comahuensis : a dino - bird based on artists ' imaginations fernando e. novas of the argentine museum of natural sciences in buenos aires and pablo f. puerta of the paleontology museum in trelew announced a new fossil, said to be 90 million years old, in the 22 may, 1997, edition of nature magazine, under the caption " missing link. " 200 they named this fossil unenlagia comahuensis, meaning " half - bird from north - west patagonia. " this fossil, discovered in argentina ' s patagonia region, consisted of more than 20 pieces of the creatures leg, rib and shoulder bones. based on these fragments, artists drew a creature complete with a neck, jaw and tail — and subsequently announced that this fossil was an intermediate stage in the transition from dinosaurs to birds. however, unenlagia comahuensis is manifestly a dinosaur, in many respects. in particular, certain features of its skull and the bone formations behind its eyes closely resemble those of theropods. there is also no evidence at all that it bore feathers. evolutionist scientists, however, claimed that by raising its forearms, it could make similar movements to those used by birds for flying. but clearly, these prejudiced guesses and assumptions cannot be regarded as definitive proof. on account of its different features, lawrence m. witmer of ohio university describes this creature as a genuine " mosaic ". 201 alan feduccia also states that unenlagia comahuensis cannot be a missing link between dinosaurs and birds, emphasizing that it lived 55 million years after archaeopteryx. 202 as feduccia stressed in a 1996 article written together with


air pollution is a broad term applied to all chemical and biological agents that modify the natural characteristics of the atmosphere. some definitions also consider physical perturbations such as noise pollution, heat, radiation or light pollution as air pollution. some definitions include the term harmful as a requisite to consider a change to the atmosphere as pollution. the sources of air pollution are divided in two groups : anthropogenic ( caused by human activity ) and natural. natural sources include : anthropogenic sources are mostly related to burning different kinds of fuel. they include : - volcanic activity - dust from natural sources, usually large areas of land with little or no vegetation - gases, such as methane, emitted by the digestion of animals, usually cattle. - smoke from wildfires. - dust and chemicals from farming, especially of erodible land, see dust bowl - industrial activity in general. - vehicles with internal - combustion engines. - stoves and incinerators, specially coal ones. - paint fumes, or other toxical vapors. contaminants of air can be divided in particles and gases. particles are classified by their sizes. a usual division is in pm10 and pm2. 5. pm10 are particles whose size is less than 10 microns ( 0. 01 mm ) ; they are dangerous to humans because they can be breathed and reach the lungs. pm2. 5 are particles whose size is less than 2. 5 microns ( 0. 0025 mm ), and they are even more dangerous because they can pass the alveoli and reach the blood. important pollutant gases include : the worst single incident of air pollution to occur in the united states occurred in donora, pennsylvania in late october, 1948 - davis, devra, when smoke ran like water : tales of environmental deception and the battle against pollution, basic books, 2002, hardcover, 316 pages, isbn 0 - 465 - 01521 - 2


donald ervin knuth knuth, donald ervin ( noth, kənothˈ ) [ key ], 1938 –, american mathematician and computer scientist, b. milwaukee, wis., grad. case institute of technology ( b. s. and m. s., 1960 ) and california institute of technology ( ph. d., 1963 ). while still a graduate student, knuth was contracted to write a book about the construction of computer compilers ( see programming language ). what he wrote instead turned into his monumental series the art of computer programming ( 3 vol., 1968 – ), an overview of programming algorithms, each described with mathematical rigor, that has been translated into six languages. disappointed with the state of computer typesetting, knuth developed a typesetting program that has become the standard for mathematics and physics. he taught at the california institute of technology from 1962 until 1968, when he joined the faculty at stanford univ., becoming professor emeritus in 1993. his writings include surreal numbers ( 1974 ), literate programming ( 1992 ), and digital typography ( 1999 ). the columbia electronic encyclopedia, 6th ed. copyright © 2012, columbia university press. all rights reserved. see more encyclopedia articles on : computers and computing, biographies


math is the basis for music, but for those of us who aren ’ t virtuosic at either, the connection isn ’ t always easy to grasp. which is what makes the videos of vi hart, a “ mathemusician ” with a dedicated youtube following, so wonderful. hart explains complex phenomena - - from cardioids to carl gauss - - using simple ( and often very ) funny means. as maria popova pointed out yesterday, hart ’ s latest video is a real doozy. in it, she uses a music box and a mobius strip to explain space - time, showing how the two axes of musical notation ( pitch and tempo ) correspond to space and time. using the tape notation as a model for space - time, she cuts and folds it to show the finite ways you can slice and dice the axes. then, she shows us how you can loop the tape into a continuous strip of twinkling notes : if you fold space - time into a mobius strip, you get your melody, and then the inversion, the melody played upside down. and then right side up again. and so on. so rather than folding and cutting up space - time, just cut and tape a little loop of space - time, to be played over, and over. it ’ s a pretty magical observation, and it makes even me - - the prototypical math dunce - - wish i ’ d tried harder. yet there ’ s still time : hart works for the khan academy, a nonprofit that offers free educational videos about math, biology, and more. check it out. [ h / t brain pickings ]


the colors are the different echo intensities ( reflectivity ) measured in dbz ( decibels of z ) during each elevation scan. " reflectivity " is the amount of transmitted power returned to the radar receiver. reflectivity ( designated by the letter z ) covers a wide range of signals ( from very weak to very strong ). so, a more convenient number for calculations and comparison, a decibel ( or logarithmic ) scale ( dbz ), is used. the dbz values increase as the strength of the signal returned to the radar increases. each reflectivity image you see includes one of two color scales. one scale ( far left ) represents dbz values when the radar is in clear air mode ( dbz values from - 28 to + 28 ). the other scale ( near left ) represents dbz values when the radar is in precipitation mode ( dbz values from 5 to 75 ). notice the color on each scale remains the same in both operational modes, only the values change. the value of the dbz depends upon the mode the radar is in at the time the image was created. the scale of dbz values is also related to the intensity of rainfall. typically, light rain is occurring when the dbz value reaches 20. the higher the dbz, the stronger the rainrate. depending on the type of weather occurring and the area of the u. s., forecasters use a set of rainrates which are associated to the dbz these values are estimates of the rainfall per hour, updated each volume scan, with rainfall accumulated over time. hail is a good reflector of energy and will return very high dbz values. since hail can cause the rainfall estimates to be higher than what is actually occurring, steps are taken to prevent these high dbz values from being converted to rainfall.


it is from the traditional family that we absorb those universal ideals and principles which are the teaching of jesus, the bedrock of our religious faith. we are taught the difference between right and wrong, and about the law, just punishment and discipline. what do you first do when you learn to swim? you make mistakes, do you not? and what happens? you make other mistakes, and when you have made all the mistakes you possibly can without drowning - and some of them many times over - what do you find? that you can swim? well - life is just the same as learning to swim! do not be afraid of making mistakes, for there is no other way of learning how to live! the past is for learning from and letting go. you can ' t revisit it. it vanishes. every human being is born an heir to an inheritance to which he can succeed only in a process of learning. we pay a heavy price for our fear of failure. it is a powerful obstacle to growth. it assures the progressive narrowing of the personality and prevents exploration and experimentation. there is no learning without some difficulty and fumbling. if you. i used to think that prayer should have the first place and teaching the second. i now feel it would be truer to give prayer the first, second, and third places, and teaching the fourth. i am not afraid of storms, for i am learning how to sail my ship. on any longer view, man is only fitfully committed to the rational to thinking, seeing, learning, knowing. believing is what he \ ' s really proud of. racing is a process of learning where the edge lies. the soul of man is nourished by learning, as the body is by food. it is because modern education is so seldom inspired by a great hope that it so seldom achieves great results. the wish to preserve the past rather than the hope of creating the future dominates the minds of those who control the teaching of the young. curiosity is the wick in the candle of learning. teaching is the greatest act of optimism the whole art of teaching is only the art of awakening the natural curiosity of young minds for the purpose of satisfying it afterwards. if we value independence, if we are disturbed by the growing conformity of knowledge, of values, of attitudes, which our present system induces, then we may wish to set up conditions of learning which make for uniqueness, for self - direction, and for self - initiated learning. the praises of others may be of use


, of values, of attitudes, which our present system induces, then we may wish to set up conditions of learning which make for uniqueness, for self - direction, and for self - initiated learning. the praises of others may be of use in teaching us, not what we are, but what we ought to be. liberty without learning is always in peril and learning without liberty is always in vain whenever you make a mistake or get knocked down by life, don ' t look back at it too long. mistakes are life ' s way of teaching you. your capacity for occasional blunders is inseparable from your capacity to reach your goals. no one wins them all, and your failures, when they happen, are just part of your growth. shake off your blunders. how will you know your limits without an occasional failure? never quit. your turn will come. don ' t look for more honor than your learning merits. you can teach a student a lesson for a day ; but if you can teach him to learn by creating curiosity, he will continue the learning process as long as he lives. i am learning all the time. the tombstone will be my diploma. the most useful piece of learning for the uses of life is to unlearn what is untrue. learning is a treasure that will follow its owner everywhere. anyone who stops learning is old, whether at twenty or eighty. the only kind of learning which significantly influences behavior is self - discovered or self - appropriated learning - truth that has been assimilated in experience.


and wind aloft forecasts. if the forecasts are bang - on, that means the model of the atmosphere is accurate and the other forecasts should be pretty good. if the wind forecast is incorrect, then the other forecasts might be too. generally, a wind that is more southerly or easterly than forecast means the surface weather will be worse than forecast. a stronger wind than forecast means that the low pressure area causing the wind is stronger than forecast. wind shear is important, too. defined as a change in direction and / or velocity over distance or height, wind shear can result in enthusiastic turbulence and can create low - altitude hazards around airports. there is always wind shear in frontal zones and where areas of strong wind ( jet streams, streaks or cores ) aloft interact with areas of lighter winds. temperature & dewpoint : this is really basic, but these items give clues to a lot of things. we learn early and often that if they are close, the flying weather suffers. they are especially important as the day is ending and beginning, when a small spread can result in rapidly deteriorating weather after sunset, or fog at and just after sunrise. if there is a big difference in the temperature and dewpoint ahead of and behind a cold front, there is probably a lot of action in the frontal zone. also, if the temperature aloft is warmer than forecast, that means more moisture. the ability of the atmosphere to hold moisture doubles with every 11 degrees celsius rise in temperature. that is why, when the talking heads say a heavy rain would have been so much snow, they don ' t know what they are talking about.


. | | % m | | month number ( 01? 12 ). | | % m | | minute ( 00? 59 ). | | % p | | am / pm indicator. | | % s | | seconds ( 00? 59 ). | | % u | | week of year ( 00? 52 ) when sunday starts the week. | | % w | | weekday number ( sunday = 0 ). | | % w | | week of year ( 01? 52 ) when monday starts the week. | | % x | | locale specific date format ( e. g., feb 19 1997 ). | | % x | | locale specific time format ( e. g., 20 : 10 : 13 ). | | % y | | year without century ( 00? 99 ). | | % y | | year with century ( e. g. 1997 ). | | % z | | time zone name. | table 13 - 3. unix - specific clock formatting keywords. | % d | | date as % m / % d / % y ( e. g., 02 / 19 / 97 ). | | % e | | day of month ( 1? 31 ), no leading zeros. | | % h | | abbreviated month name. | | % n | | inserts a newline. | | % r | | time as % i : % m : % s % p ( e. g., 02 : 39 : 29 pm ). | | % r | | time as % h : % m ( e. g., 14 : 39 ). | | % t | | inserts a tab. | | % t | | time as % h : % m : % s ( e. g., 14 : 34 : 29 ). | the clock clicks command returns the value of the system ' s highest resolution clock. the units of the clicks are not defined. the main use of this command is to measure the relative time of different performance tuning trials. the following command counts the clicks per second over 10 seconds, which will vary from system to system : example 13 - 1 calculating clicks per second. set t1 [ clock clicks ] after 10000 ; # see page 218 set t2 [ clock clicks ] puts " [ expr ( $ t2 - $ t1 ) / 10 ] clicks / second " = > 1001313 clicks / second the clock scan command parses a date string and returns a seconds


a recursive function typically contains a conditional expression which has three parts : recursive functions can be much simpler than any other kind of function. indeed, when people first start to use them, they often look so mysteriously simple as to be incomprehensible. like riding a bicycle, reading a recursive function definition takes a certain knack which is hard at first but then seems simple. there are several different common recursive patterns. a very simple pattern looks like this : ( defun name - of - recursive - function ( argument - list ) " documentation... " ( if do - again - test body... ( name - of - recursive - function next - step - expression ) ) ) each time a recursive function is evaluated, a new instance of it is created and told what to do. the arguments tell the instance what to do. an argument is bound to the value of the next - step - expression. each instance runs with a different value of the next - step - expression. the value in the next - step - expression is used in the do - again - test. the value returned by the next - step - expression is passed to the new instance of the function, which evaluates it ( or some transmogrification of it ) to determine whether to continue or stop. the next - step - expression is designed so that the do - again - test returns false when the function should no longer be repeated. the do - again - test is sometimes called the stop condition, since it stops the repetitions when it tests false.