Every kilogram of predator needs a fixed amount of prey.
Every kilogram of meat-eating mammal needs 111 kilograms of prey to sustain it, say two ecologists. The rule holds from weasels to bears.
With many species of carnivore endangered, the discovery could help conservationists work out how to maintain a species’ resource base.
Chris Carbone, of the Institute of Zoology, London, and John Gittleman, of the University of Virginia, found the rule when they compare
Scientists in America have made the first steps in identifying a group of genes which may be involved in the progression of breast cancer from non-invasive to invasive, the 3rd European Breast Cancer Conference in Barcelona heard today (Thursday 21 March).
Professor Craig Allred, Director of Breast Pathology at the Breast Center, Baylor College of Medicine, Houston, USA, used a technique called microarray to discover which genes might be involved in causing ductal carcinoma in situ (DCIS) to
Mushrooms (of course, those grown in an ecologically safe area) accumulate many microelements good for human and animal health, in particular, selenium. The natural cycle of selenium was studied by a team from the Vernadsky Institute of Geochemistry and Analytical Chemistry in Moscow.
The scientific expedition worked in the eastern part of the Meshchera (at the meeting point of the Moscow, Ryazan, and Vladimir areas). Scientists found selenium in many natural objects (soil, grass, le
Because living organisms contain millions of different molecules, identifying or separating any single one of these from their natural environment in order to carry out research work or perform diagnoses is quite like looking for a needle in a haystack. A number of molecular separation technologies are of course available, and are used by laboratories on a daily basis, but they are often unwieldy and costly. Scientists the world over are therefore attempting to develop a new generation of analytic de
Formidable catalogue puts army of ants online.
After four years of cooperation and tenacity worthy of their quarry, ant experts have completed Antbase, a centralized, online information resource cataloguing all 11,000 known species of ant.
Its creators hope that Antbase will one day become the ant equivalent of GenBank, the public database of genetic sequence data, and a boon not just for ant specialists, but for entomologists and ecologists of every kind.
Ant ta
Fusion may explain adult stem-cell morphing.
The hyped ability of adult stem cells to sprout replacement tissue types is being called into question. They may instead be fusing with existing cells, say two new reports, creating genetically mixed-up tissues with unknown health effects.
Recent studies have shown that adult stem cells transplanted from one tissue, such as blood, can spawn the cell types of another, such as nerves. The findings have stirred intense interest in st
Chemists copy from cells to make a tunnel for salt
Chemists have finally achieved what every human cell can do. They have designed and built from scratch a gate for electrically charged chlorine atoms to pass through 1 .
George Gokel and colleagues at Washington University in St Louis, Missouri, based their gate on biological proteins that transport chloride ions from one side of our cell membranes to the other. Like these, the synthetic channel can be opene
Many chemicals commonly used in medications such as over-the-counter painkillers or birth control pills end up far from their intended destination – in American streams. According to a new report, published online today by the journal Environmental Science and Technology, a number of the waterways contain complex cocktails of compounds.
The 30-state study, conducted by the U.S. Geological Survey, tested 139 streams for 95 organic contaminants – ranging from medications and hormones to inse
A robot submarine expedition under the Antarctic sea ice has discovered a major food reserve in the Southern Ocean. The findings, reported this week in SCIENCE, show a dense band of the shrimp-like krill under the ice, five times more concentrated than in open water. The importance of sea ice as a nursery for krill – key food for penguins, whales and fish – has long been suspected, but these are the first large scale measurements.
Scientists from the British Antarctic Survey, the Open Univer
A molecular pump that helps to keep cells flush with energy has been visualised by scientists at Imperial College, London.
The structure of the pump, a key enzyme in bacterial respiration, reveals for the first time one of the molecular mechanisms that underpins cellular respiration, and confirms a Nobel Prize-winning theory proposed over 40 years ago by Briton Peter Mitchell.
Professor So Iwata and colleagues from the Laboratory of Membrane Protein Crystallography, Imperial Colleg
A team of chemists and physicists at the Universities of Liverpool and Oxford have shown that hydrogen transmits magnetism. This discovery could be the first step to a new class of magnetic materials, and opens up a new field of chemistry.
The team, headed by Professor Matthew Rosseinsky of the Department of Chemistry, University of Liverpool, and including Dr Stephen Blundell of the University of Oxford, has prepared a new magnetic oxide material in which for the first time the dominant ma
Early humans came out of Africa again and again.
There were at least three major waves of early human migration out of Africa, our DNA suggests. Apparently the wanderers made love, not war: gene patterns hint that later emigrants bred with residents.
Human origins are contentious. Most researchers agree that there have been several major migrations out of Africa. Some hold that human populations in many regions evolved in parallel after Homo erectus left Africa around two mi
Gloves are coming off in ancient bacteria bust-up.
A claim to have found evidence of the oldest living things on Earth is being fiercely contested. The argument looks set to run and run, and no one may win, but it may lead to a better understanding of the origins of life on our planet.
The debate is academic, but its implications are not. The ’fossil bacteria’ in question are around 3.5 billion years old. That’s roughly one billion years older than the only confirmed fossil
Under the agreement, the two companies will work to develop affinity-based products for use in the production processes for protein-based pharmaceuticals. The development of these products will be based on Affibodies™, a novel class of small, robust affinity proteins designed to bind desired protein targets. Financial details of the agreement were not disclosed.
“The use of Affibodies™ opens up new possibilities for large-scale protein purification for production of protein based pharmaceuti
Ancestors of the flightless figurehead of extinction island-hopped.
The flightless dodo’s ungainly shape hid an island-hopping past, say researchers. DNA from the extinct bird has revealed its place in the pigeon family tree, and suggests how it came to end up on its home, and graveyard, the island of Mauritius 1 .
The dodo’s strange appearance led to centuries of wrangling over its ancestry. “It’s the figurehead of extinction, yet little is known about its e
The reindeer`s antlers make the beauty and the pride of a male, being a reliable weapon during spring tournaments. In autumn the antlers are no longer needed, so reindeers shed the antlers and grow them up anew in the next season. With the majority of the reindeer types, the male sex hormones control the growth of the antlers. But the reindeer`s doe has also got antlers. A pregnant doe carries antlers throughout winter, as the antlers help a doe to get food from under the snow, to keep off predators
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