Researchers studying amphibians at a national park in Spain show that rising temperatures are closely linked to outbreaks of the chytrid fungus.

Chytrid fungus is a major contributor to the decline of amphibian populations around the world, threatening many species with extinction.

Details are published in the journal Proceedings of the Royal Society B.

"We have found an association between increasing temperatures and amphibian disease in a mountain region in Spain," said Dr Matthew Fisher of Imperial College London.

"This is a global emerging amphibian pathogen which is one of the worst vertebrate infectious diseases found so far. It is causing a huge amount of extinction and disease within amphibian populations."

More than 100 species of amphibians are known to be affected by the chytrid fungus (Batrachochytrium dendrobatidis). Some are very susceptible and die quickly while others which are more resistant are carriers of the pathogen.

The disease is already credited with wiping out frogs and toads in large numbers in Australia and South America.

Climate link

Dr Fisher and his Spanish colleagues uncovered an association between the emergence of the disease and global warming while studying changes in the number of midwife toads in Spain's Penalara Natural Park between 1976 and 2002.

The chytrid fungus, or BD as it is sometimes called, infects the skins of amphibians such as frogs, toads, salamanders and newts and interferes with their ability to absorb water.

Dr Fisher said climate change could be worsening the impact of the disease in one of two ways.

Warming temperatures could be reducing the amphibians' ability to mount a successful immune response to the fungus. Amphibians are cold-blooded so their ability to respond to the pathogen could change along with the external temperature.

On the other hand, global warming could be increasing the fungus' ability to grow faster on the amphibian and cause more disease.

"This is a wake-up call that we are losing biodiversity fast," Dr Fisher said. "Climate change appears to be changing patterns of disease and previously resistant species are becoming highly infected - even, in a number of cases, becoming extinct."

The Global Amphibian Assessment has warned that a third of the world's amphibian species are in danger of extinction, many because of the chytrid fungus.

On Tuesday, Hwang told the court some of the research funds "were used for expenses while in touch with the mafia in Russia", without going into detail about how the money was spent, or how the mafia had helped him to obtain the tissue samples.

Meanwhile, the fallen scientist's lawyers said they planned to seek a court order to retrieve samples of what Hwang claims to be the world's first cloned embryonic stem cells.

Seoul National University deemed the samples to be from mutated eggs, not cloned stem cells, after questions were raised about Hwang's breakthroughs - reported in the journal Science in 2004 - at the university laboratory. The school has since refused to return the samples to Hwang after firing him earlier this year, his lawyer, Jung Keun-hwa, said.

"We have a plan to conduct more tests," Mr Jung told the court, adding that Hwang believed further tests could show that the samples were, indeed, genuine cloned stem cells.

Hwang has maintained that anything that was falsified in his research findings was done by staff at his laboratory who deceived him into thinking the results were real.

In court yesterday, Hwang said allegations that he ordered his researchers to fabricate DNA test results were "a story like a novel". He said: "I didn't even know the means to fabricate DNA tests", adding that "it was very clear" his researchers had lied to prosecutors.

Researchers have testified at previous hearings, however, that they couldn't question or disobey Hwang, who was senior to them.

Hwang is facing charges for allegedly accepting £1.1 million in private donations based on the outcome of the falsified research, and of embezzling about £450,000 in private and government research funds. If convicted, he faces at least three years in prison.

Hwang's claims of world-leading advances in the new field of stem-cell research were discredited after revelations last year of ethics lapses that culminated in him admitting that forged evidence had been used for some of his academic papers.

Despite the scandal over forged research, Hwang resumed work in August at a new private laboratory, where he was expected to focus on animal stem-cell research. A trained vet, he is believed to have succeeded in creating the world's first cloned dog.

At the last court hearing in September, lawyers for Hwang's associates, who are facing similar charges, began their defence.

Hwang's purported breakthroughs, which were published in leading international science journals, thrust South Korea to the fore of stem-cell research, which some scientists believe could help to create innovative new cures for untreatable diseases.

Stem cells are the basic cells that can grow into all kinds of tissue, and cloning them could create a way for patients to be treated with cells matching their own DNA, so minimising the risk of rejection.
Rocky road to recreating a lost giant

SUCCESSFUL cloning of a woolly mammoth has long been a favoured pursuit of scientists working in the field.

Preserved parts of the ancient giants have been found in permafrost at various sites around the world - most notably in Siberia.

Their discovery has led to speculation that the creatures could be recreated to walk the Earth again after around 10,000 years of extinction. However, so far none of the recovered genetic material has been of sufficient quality for scientists to extract the DNA required for a cloning attempt to be made.

Other plans to extract sperm DNA from the remains with which to impregnate a female elephant and produce a hybrid animal have thus far failed to yield results.

The CLOUD experiment is designed to explore the microphysical interactions between cosmic rays and clouds. Cosmic rays are charged particles that bombard the Earth's atmosphere from outer space. Studies suggest that cosmic rays may influence the amount of cloud cover through the formation of new aerosols (tiny particles suspended in the air that seed cloud droplets). Clouds exert a strong influence on the Earth's energy balance, and changes of only a few per cent have an important effect on the climate. The CLOUD prototype experiment aims to investigate the effect of cosmic rays on the formation of new aerosols.

Understanding the microphysics in controlled laboratory conditions is a key to unravelling the connection between cosmic rays and clouds. CLOUD will reproduce these interactions for the first time by sending a beam of particles - the "cosmic rays" - from CERN's Proton Synchrotron into a reaction chamber. The effect of the beam on aerosol production will be recorded and analysed.

The collaboration comprises an interdisciplinary team from 18 institutes and 9 countries in Europe, the United States and Russia. It brings together atmospheric physicists, solar physicists, and cosmic ray and particle physicists to address a key question in the understanding of clouds and climate change. "The experiment has attracted the leading aerosol, cloud and solar-terrestrial physicists from Europe; Austria, Denmark, Finland, Germany, Switzerland and the United Kingdom are especially strong in this area" says the CLOUD spokesperson, Jasper Kirkby of CERN. "CERN is a unique environment for this experiment. As well as our accelerators, we bring the specialist technologies, experimental techniques and experience in the integration of large, complex detectors that are required for CLOUD." An example in the present CLOUD prototype is the gas system, designed by CERN engineers, which produces ultra-pure air from the evaporation of liquid oxygen and liquid nitrogen. "It's probably the cleanest air anywhere in the world", says Kirkby.

The first results from the CLOUD prototype are expected by the summer of 2007. The full CLOUD experiment includes an advanced cloud chamber and reactor chamber equipped with a wide range of external instrumentation to monitor and analyse their contents. The temperature and pressure conditions anywhere in the atmosphere can be re-created within the chambers, and all experimental conditions can be controlled and measured - including the "cosmic ray" intensity and the contents of the chambers. The first beam data with the full CLOUD experiment is expected in 2010.

The results of this latest study were published in the journal NeuroReport. The scientists used DTI - which tracks the movement of water through brain tissue - to measure the structural integrity of the white matter that acts as cables to wire the parts of the brain together. Normally, water molecules move, or diffuse, in a direction parallel to the orientation of the nerve fibers of the white matter. They're aided by the coherent structure of the fibers and a process called myelination, in which a sheath is formed around the fibers that speeds nerve impulses. The movement of water is more dispersed if the structural integrity of the tissue is low - i.e., if the fibers are less dense, less coherently organized, or less myelinated - as it was with the participants with autism in the Carnegie Mellon study. Researchers found this dispersed pattern particularly in areas in and around the corpus callosum, the large band of nerve fibers that connects the two hemispheres of the brain.

"These reductions in white matter integrity may underlie the behavioral pattern observed in autism of narrowly focused thought and weak coherence of different streams of thought," said Marcel Just, director of the Center for Cognitive Brain Imaging and a co-author of the latest study. "The new findings also provide supporting evidence for a new theory of autism that attributes the disorder to underconnectivity among brain regions," Just said.

In 2004, Just and his colleagues proposed the underconnectivity theory based on a groundbreaking study in which they discovered abnormalities in the white matter that suggested a lack of coordination among brain areas in people with autism. This theory helps explain a paradox of autism: Some people with autism have normal or even superior skills in some areas, while many other types of thinking are disordered.

Last summer, Just led a team of researchers that found for the first time that the abnormality in synchronization among brain areas is related to the abnormality in the white matter. They discovered that key portions of the corpus callosum seem to play a role in the limitation on synchronization. In people with autism, anatomical connectivity - based on the size of the white matter - was found to be positively correlated with functional connectivity, which is the synchronization of the active brain regions. They also found that the functional connectivity was lower in those participants in whom the autism was more severe.

These studies, along with the latest paper, are providing a comprehensive picture of the autistic brain, whose components operate with less coordination than is normally the case, and which is less reliant on frontal components and more reliant on posterior components. The latest DTI finding shows that some of the frontal-posterior communication fiber tracts are abnormal, consistent with the lower degree of frontal-posterior coordination.

"The brain components in autism function more like a jam session and less like a symphony," Just said.

The latest study was co-authored by Rajesh K. Kana and Timothy A. Keller of the Center for Cognitive Brain Imaging. This research was supported by the National Institute of Child Health and Human Development.