Sarbjit Singh 的个人资料Sarbjit Singh Gill: A Mi...照片日志列表更多 ![]() | 帮助 |
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4月20日 Chimps More Evolved Than Humans?April 16, 2007 — A comparison of human and chimpanzee genes has revealed a startling possibility: chimps may have evolved more than humans in the 6 or 7 million years since both diverged from a common ancestor. A study comparing human and chimp genes that appear to have evolved since we parted ways shows that humans have about 154 such genes and our nearest primate relative a whopping 233. Read more....http://dsc.discovery.com/news/2007/04/16/evolution_arc.html 2月15日 Large squid lights up for attackBig deep-sea squid emit blinding flashes of light as they attack their prey, research shows.
1月6日 Scan shows how brains plot futureBrain scans have given US scientists a clue about how we create a mental image of our own future.
5月20日 Study shows apes can plan aheadBonobos and orangutans - just like humans - are capable of future planning, according to a study. Full story: http://news.bbc.co.uk/go/em/-/1/hi/sci/tech/4996942.stmDeep-sea fish stocks 'plundered'Tuna and other deep-sea fish are on the verge of extinction because of failing fishing regulation, a report says. Full story: http://news.bbc.co.uk/go/em/-/1/hi/sci/tech/4996268.stm5月10日 Dolphins 'have their own names'Scientists at St Andrews University discover dolphins recognise each other by name rather than tone of voice. Full story: http://news.bbc.co.uk/go/em/-/1/hi/scotland/edinburgh_and_east/4750471.stm
What's next then ? They have email addresses too and have name cards? LOL 5月3日 More species slide to extinctionThe polar bear, hippo and many sharks are among species newly listed as threatened with extinction. Full story: http://news.bbc.co.uk/go/em/-/1/hi/sci/tech/4963526.stm4月18日 Yummy mummy feeds young its skinAn international group of scientists has described an animal that provides nutrition for its young by letting them peel off and eat its skin.
3月16日 Nanotech helps blind hamsters seeBlind hamsters have their sight restored using nanotechnology, according to new research.
Full story: http://news.bbc.co.uk/go/em/-/1/hi/sci/tech/4801728.stm2月22日 DNA 'could predict your surname'
Forensic scientists could use DNA retrieved from a crime scene to predict the surname of the suspect, a study suggests. Full story: http://news.bbc.co.uk/go/em/-/1/hi/sci/tech/4736984.stm2月17日 Music intensifies ecstasy effects
Listening to loud music exacerbates the effects on the brain of taking ecstasy, researchers have found. Full story: http://news.bbc.co.uk/go/em/-/1/hi/health/4716500.stm2月12日 How sperms can go into overdriveFROM the BBC.
Researchers have identified a key component of the mechanism sperm use to speed up their progress to the egg.
The chemical change converts the sperm's tail motion from a steady swimming undulation to a whip-cracking snap. The Harvard Medical School team believe their work could potentially aid the study of male infertility, and the design of new contraceptives. The research is published in the journal Nature.
The sudden change in the motion of a sperm's tail is known as hyperactivation. The process is thought to be triggered by the alkaline environment found inside the female reproductive tract. The Harvard team had already identified a protein called CatSper1 - which is only found in the sperm tail - as key to the process. In the latest study they were able to show just why the protein plays such a key role. The researchers used a sophisticated technique called patch clamp recording, to monitor electrical activity with the sperm cell. The technique is widely used to examine other cells, but until now it had not been applied to sperm cells, which are constantly wriggling around, and are protected by tough outer membranes. The results showed that CatSper1 plays a central role in controlling the flow of calcium ions into the sperm cell. It is thought that it is this flow of ions that triggers hyperactivation. Lead researcher Dr David Clapham said: "No one had ever seen inside sperm cells to measure all the currents that control their activity. "We are already measuring many of these currents and beginning to answer questions about what they are and what they do." New contraception Dr Clapham said CatSper1 was a good target for new forms of contraception. "We know that defects in CatSper1 block fertilization in mice. "And since the channels in human sperm are very similar, there is no reason to believe you couldn't develop a male or female birth control pill that would block the protein before it functions to hyperactivate sperm, preventing fertilisation." Dr Allan Pacey, senior lecturer at the University of Sheffield, said: "The sperm tail is an incredibly complex and elegant machine that we really struggle to understand at the molecular level. "This kind of approach is a real step forward. "We know that hyperactivation is crucial to successful fertilisation, and we suspect that in some men this might be why they have difficulty in conceiving with their partners, if we could better understand the molecules involved in that process we might be able to diagnose the problem earlier and therefore save the couple both time and heartache. "This research could also help us understand how sperm actually find and reach the egg in the first place as we suspect that hyperactivated motility is also involved in that process too. "If we could understand that mystery too, that would be fantastic." 11月27日 CO2 'highest for 650,000 years'Antarctic ice shows current levels of carbon dioxide are 30% higher than at any time in the past 650,000 years. Full story: http://news.bbc.co.uk/go/em/-/1/hi/sci/tech/4467420.stm |
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