Study questions whether mammography saves lives.
Breast-cancer screening programmes may not save lives, according to a new examination of clinical trials. The controversial findings have led to calls for a re-evaluation of the routine monitoring procedure undergone by numerous women.
Mammography, X-ray breast imaging, is used in Europe and the United States to catch cancers early. “We’ve based a national screening programme on a set of results which do not stand up to scrut
ATTO-TEC® has developed the second generation of fluorescent dyes which are stable at room temperature for more than six months.
With Atto 520, Atto 565 and Atto 590 we are pleased to offer three stable fluorescent dyes as amine-reactive succinimidyl esters which will be available from November 2001 on. This allows researchers an easy handling for selectively target- labeling by linking a fluorophore to primary amine groups on proteins or modified nucleic acids.
Further stable activate
Meterologists look up for long-range forecasts.
Looking high into the atmosphere now might tell us whether we’re in for a white Christmas. Unusual stratospheric conditions herald changes in winter weather in the Northern Hemisphere up to two months later, say US researchers 1 .
The finding won’t let your weather forecaster warn you to wrap up warm two months hence, but it may be a valuable addition to meteorologists’ toolkits. “The effect works on average, bu
Deforestation is drying out cloud forests.
“It drips,” says ecologist Robert Lawton, describing the Costa Rican cloud forest, “and it’s plastered with plants of all sizes climbing over each other. Stand still for long and they’re growing on you.”
Now the lush life he describes may be threatened. Satellite pictures show that deforestation at the foot of western Costa Rican mountains is drying out swirling summit mists.
When warm, wet tradewinds blowing off the Caribb
Two techniques may help deduce proteins’ functions.
Imagine trying to guess what machines do just be looking at them. Even a can-opener would pose problems, if you didn’t know about cans. This is the challenge that faces molecular biologists as they try to make sense of protein molecules in the cell.
Two new techniques may help. One deduces a protein’s function from its shape; the other deduces its shape from a list of component parts 1 , 2 .
A large, long-term study confirms that diet can help some epileptic children.
A strict high-fat, low-carbohydrate, calorie-restricted diet reduces seizures in children with intractable epilepsy. So concludes the largest and longest trial of an eating plan that was first suggested almost a century ago.
For about two years, epileptic youngsters on a ’ketogenic diet’ eat 25% less than normal and consume 90% of their daily calories as fats. They take vitamins and minerals to avo
European subsidies to enhance farmland wildlife may not be working.
The effectiveness of schemes that seek to promote biodiversity by paying farmers to cut back on intensive agriculture could be called into question by some research findings from Holland.
The incentive programmes, which already cost the European Union 1.7 billion euros (US$1.5 billion) each year and are rapidly expanding in scope, are partly motivated by the desire of European governments to subsidize farmin
About half of all patients with hereditary breast or ovarian cancer have mutations in a gene called BRCA1. Now the first images of the protein the gene encodes, BRCA1, are helping researchers work out how the mutations cause human disease.
The pictures reveal fine detail of how BRCA1 interacts with other proteins. Such information should help researchers work out how BRCA1 prevents cells becoming cancerous. They suspect that it is involved in DNA repair, controlling cell division and regula
Chemists build molecules by paring them down
Complex molecules, such as many drugs, can be fiddly to assemble. By binding their starting compounds in chains 1 , chemists in Denmark may have found a way speed the automated chemical synthesis of such complicated products.
Les Miranda and Morten Meldal of Carlsberg University in Copenhagen have solved the following problem. Complex molecules are usually built up from a core with several near-identical hooks on w
Mathematician Ian Stewart talks to Nature Science Update about snowflakes, sticklebacks and a new kind of science.
Ian Stewart was turned on to mathematics at the age of seven. A broken collarbone freed him from an uninspiring teacher allowing his mother to ignite his interest in numbers while he was laid up at home.
His writing career began with a series of how-to manuals for now-defunct early 1980s microcomputers. It has since broadened into popular science and science fi
Chameleons can reel in prey anywhere within two-and-a-half body lengths of their jaws. Their tongues can overcome even a bird’s weight and reluctance to be eaten. How? Muscles that are unique among backboned animals, researchers now reveal.
Anthony Herrel of the University of Antwerp, Belgium, and colleagues put crickets at different distances from the noses of two chameleon species, Chameleo calyptratus and Chameleo oustaletti. The tongues of these 12-cm-long reptiles pull at maximum stren
Sperm go slow without a crucial protein.
The discovery of a protein that is crucial to sperm swimming in mice could lead to new male or female contraceptives or fertility treatments.
The protein forms a channel through the membrane of the sperm tail. It controls the inflow of calcium ions that trigger swimming.
All humans have the gene that encodes the channel, but it is switched on only in sperm cells. This would lessen the risk of side-effects from any channel-blo
A new way to find genes and map disease.
A new technique should aid the hunt for genes in the human genome sequence. The method, which tracks only switched-on genes in cells, will help researchers to distinguish between diseased and normal tissues, and could point the way to new treatments.
Andrew Simpson, of the Ludwig Institute for Cancer Research in Sao Paulo, Brazil, and colleagues have produced a whopping 700,000 DNA tags, representing the genes that are active in 24 no
Stripes help chemists shop for molecules.
Scientists may soon be sticking bar-coded metal rods into molecules to see what they do in a crowd 1 . The rods could help to track the functions and interactions of genes, and may aid drug discovery.
At only a few thousandths of a millimetre long, the rods are small enough to fit inside a single red blood cell. Christine Keating, of Pennsylvania State University, and colleagues cast them inside cylindrical pores in a
Sequencers expose secret chromosome centre.
February’s celebrations hid a dark secret: the human genome sequencers hadn’t touched the hearts of our chromosomes. Now, at last, one chromosome’s inscrutable midpoint, its centromere, has given up its genetic secrets.
Centromeres look like the ’waist’ in an X. They share out chromosomes fairly when a cell divides. Defective centromeres may underlie many cancers, in which problems with chromosome movement
Cosmic lens magnifies faint galactic building-block.
Astronomers have peered deep into space and time and spotted a baby galaxy. Their results suggest that the tiny star-forming region may have helped to build today’s Universe 1 .
“We believe this is one of the galactic building-blocks that join together to make larger galaxies,” says Konrad Kuijken, of the Kapteyn Institute in Groningen, the Netherlands, a member of the team that found the object. The mergin
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