Group items matching
in title, tags, annotations or urlDoes promiscuity prevent extinction? - 0 views
-
-
Known as 'polyandry' among scientists, the phenomenon of females having multiple mates is shared across most animal species, from insects to mammals. This study suggests that polyandry reduces the risk of populations becoming extinct because of all-female broods being born. This can sometimes occur as a result of a sex-ratio distortion (SR) chromosome, which results in all of the Y chromosome 'male' sperm being killed before fertilisation. The all-female offspring will carry the SR chromosome, which will be passed on to their sons in turn resulting in more all-female broods. Eventually there will be no males and the population will die out. For this study, the scientists worked with the fruitfly Drosophila pseudoobscura. They gave some populations the opportunity to mate naturally, meaning that the females had multiple partners. The others were restricted to having one mate each. They bred several generations of these populations, so they could see how each fared over time. Over fifteen generations, five of the twelve populations that had been monogamous became extinct as a result of males dying out. The SR chromosome was far less prevalent in the populations in which females had the opportunity to have multiple mates and none of these populations became extinct. The study shows how having multiple mates can suppress the spread of the SR chromosome, making all-female broods a rarity. This is because males that carry the SR chromosome produce only half as many sperm as normal males. When a female mates with multiple males, their sperm will compete to fertilise her eggs. The few sperm produced by males carrying the SR chromosome are out-competed by the sperm from normal males, and the SR chromosome cannot spread.
-
Promiscuous females may be the key to a species' survival, according to new research by the Universities of Exeter and Liverpool. Published today (25 February) in Current Biology, the study could solve the mystery of why females of most species have multiple mates, despite this being more risky for the individual.
Learn More About Dairy Farming - 1 views
There is so much about dairy farming that is not known by the common public. With the majority of people going back to organic farming and natural products, this kind of dairy products has a lot of...
Ben Young Landis How Twitter Amplifies Your Reach: Example from the "School of Athens" Post. « Ben Young Landis - 0 views
-
"My link was shared by Bora Zivkovic, whose network is immense. And in turn, the link was shared by Twitter users in Greece, Germany, Belgium and throughout the United States. In the end, the blogpost wound up with 109 readers on January 22nd - with about 50 via Twitter, 26 via Facebook, and others via LinkedIn and elsewhere. When each person shared the link with her or his network, the momentum is carried forward, pushing out to new networks and new degrees of separation. Social sharing is a bit like the emails you would get forwarded by your relatives (you know, those emails). The deeper you scroll down the thread, the less sender names you recognize. But with Twitter, and using analytics like WordPress or Google, you can actually trace how a little link travels through different social networks, and eventually back to your website. Also, because many people embed a small bio or website link in their Twitter profile, I can quickly see who has retweeted and read my link. I can read their tweets to get an idea of their profession and passions,"
3D-printing synthetic tissues | KurzweilAI - 0 views
-
Droplet network printer ""We aren't trying to make materials that faithfully resemble tissues, but rather structures that can carry out the functions of tissues," said Professor Hagan Bayley of Oxford University's Department of Chemistry, who led the research. "We've shown that it is possible to create networks of tens of thousands of connected droplets. The droplets can be printed with protein pores to form pathways through the network that mimic nerves and are able to transmit electrical signals from one side of a network to the other.""
Company profile | In2Care, Bill&Melinda Foundation - 0 views
-
"In2Care is a private limited company registered and based in the Netherlands. Founded and privately owned by three leading entomologists, a serial entrepreneur and a chief commercial officer, In2Care has more than 30 years of combined research experience in vector control. Our core expertise lies in the translation of scientific knowledge into novel insect control products. We offer low-cost, proven, primarily biological solutions to combat disease-carrying mosquitoes"
Bibliographic Framework Transition Initiative (Library of Congress) - 0 views
-
The Library of Congress is launching a review of the bibliographic framework to better accommodate future needs. A major focus of the initiative will be to determine a transition path for the MARC 21 exchange format in order to reap the benefits of newer technology while preserving a robust data exchange that has supported resource sharing and cataloging cost savings in recent decades. This work will be carried out in consultation with the format's formal partners -- Library and Archives Canada and the British Library -- and informal partners -- the Deutsche Nationalbibliothek and other national libraries, the agencies that provide library services and products, the many MARC user institutions, and the MARC advisory committees such as the MARBI committee of ALA, the Canadian Committee on MARC, and the BIC Bibliographic Standards Group in the UK.
Research - 0 views
-
OCLC Research is one of the world's leading centers devoted exclusively to the challenges facing libraries and archives in a rapidly changing information technology environment. Our mission is to expand knowledge that advances OCLC's public purposes of furthering access to the world's information and reducing library costs. Since 1978, we have carried out research and made technological advances that enhance the value of library services and improve the productivity of librarians and library users.
Piezo-rubber creates potential for wearable energy system - 0 views
-
As we continue to carry around items that insist on requiring electricity to work, portable-even wearable-energy-generating systems are looking very attractive. A group of researchers has recently looked into the use of piezoelectric materials, which generate an electric field or potential when placed under mechanical stress. By placing these materials on a rubbery or flexible surface, they created a material that can generate the highest rate of energy conversion reported for similar systems. While these are still far from the market, the metrics of the flexible piezoelectrics so far are very promising.
A mini-laboratory for all cases - Research News 03-2010-Topic 5 - Fraunhofer-Gesellschaft - 0 views
-
»We’ll just have to wait for the results of the laboratory tests.« These words are familiar to many patients. It then usually takes several days for specimens to be sent to the laboratory and analyzed and for the doctor to receive the results. For many illnesses, however, a speedy diagnosis is crucial if the treatment is to be successful. In future, the patient might only have to sit in the waiting room for a few minutes until the results are ready. In a joint project, researchers from seven Fraunhofer institutes have developed a modular platform for in vitro diagnosis which enables various types of bioanalysis – of blood and saliva for example – to be conducted in the doctor’s surgery. »Thanks to its modular design our IVD platform is so flexible that it can be used for all possible bioanalytical tasks,« states Dr. Eva Ehrentreich-Förster from the Fraunhofer Institute for Biomedical Engineering (IBMT) in Potsdam-Golm.The core element of the mini-laboratory is a disposable cartridge made of plastic which can be fitted with various types of sensor. For an analysis the doctor fills the cartridge with reagents – binding agents which indicate the presence of certain substances such as antigens in the specimen material. Various tests or assays are available for different types of analysis. To perform an assay, the doctor only has to place the relevant substances in the cartridge and the test then takes place automatically. »We have optimized the assays so that up to 500 assay reactions can be conducted in parallel in a single analysis step,« explains Dr. Ehrentreich-Förster. Even in the case of complex analyses the doctor obtains a result within about 30 minutes. A new module on the reverse side of the cartridge also makes it possible to analyze the specimen material at DNA level.Once the cartridge has been prepared, the doctor places it in the measurement system. The results can be read out with either optical or electrochemical biosensors. The researchers have installed a readout window for both methods in the measurement system, which features a bypass through which the specimen is pumped.
YouTube - Sam Harris SALT - 2 views
-
December 9th, 02005 - Sam Harris"The View From The End Of The World"This is an audio only presentation. This talk took place in the Conference Center Golden Gate Room, San Francisco. Quote: With gentle demeanor and tight argument, Sam Harris carried an overflow audience into the core of one of the crucial issues of our time: What makes some religions lethal? How do they employ aggressive irrationality to justify threatening and controlling non-believers as well as believers? What should be our response? Harris began with Christianity. In the US, Christians use irrational arguments about a soul in the 150 cells of a 3-day old human embryo to block stem cell research that might alleviate the suffering of millions. In Africa, Catholic doctrine uses tortured logic to actively discourage the use of condoms in countries ravaged by AIDS. "This is genocidal stupidity," Harris said. Faith trumps rational argument. Common-sense ethical intuition is blinded by religious metaphysics. In the US, 22% of the population are CERTAIN that Jesus is coming back in the next 50 years, and another 22% think that it's likely. The good news of Christ's return, though, can only occur following desperately bad news. Mushroom clouds would be welcomed. "End time thinking," Harris said, "is fundamentally hostile to creating a sustainable future." Harris was particularly critical of religious moderates who give cover to the fundamentalists by not challenging them. The moderates say that all is justified because religion gives people meaning in their life. "But what would they say to a guy who believes there's a diamond the size of a refrigerator buried in his backyard? The guy digs out there every Sunday with his family, cherishing the meaningthe quest gives them." "I've read the books," Harris said. "God is not a moderate." The Bible gives strict instructions to kill various kinds of sinners, and their relatives, and on occasion their entire towns. Yet slavery is challenged nowhere in the New or
Astronomers discover complex organic matter in the universe | KurzweilAI - 1 views
-
Organic compounds of unexpected complexity exist throughout the universe, Prof. Sun Kwok and Dr. Yong Zhang of the University of Hong Kong have discovered, suggesting that complex organic compounds can be synthesized in space even when no life forms are present. The organic substance they found contains a mixture of aromatic (ring-like) and aliphatic (chain-like) components that are so complex, their chemical structures resemble those of coal and petroleum. Since coal and oil are remnants of ancient life, this type of organic matter was thought to arise only from living organisms. Unidentified radiation from the universe The researchers investigated an unsolved phenomenon: a set of infrared emissions detected in stars, interstellar space, and galaxies, known as "Unidentified Infrared Emission features." From observations taken by the Infrared Space Observatory and the Spitzer Space Telescope, Kwok and Zhang showed that the astronomical spectra have chemical structures that are much more complex that previously thought. By analyzing spectra of star dust formed in exploding stars called novae, they show that stars are making these complex organic compounds on extremely short time scales of weeks, and ejecting it into the general interstellar space, the region between stars. "Our work has shown that stars have no problem making complex organic compounds under near-vacuum conditions," says Kwok. "Theoretically, this is impossible, but observationally we can see it happening." Most interestingly, this organic star dust is similar in structure to complex organic compounds found in meteorites. Since meteorites are remnants of the early Solar System, the findings raise the possibility that stars enriched the early Solar System with organic compounds. The early Earth was subjected to severe bombardments by comets and asteroids, which potentially could have carried organic star dust. Whether these delivered organic compounds played any role in the development of l