Knowledge Update - Results from #1250 (2024)

New York, Dec 2 (IANS)In a step aimed at preventing future outbreak of diseases such as dengue, Zika and chikungunya, researchers in Brazil have developed a test that analyses clinical samples from patients to diagnose infection by 416 viruses found in the world's tropical regions.

The tool can be used by reference laboratories to assist epidemiological surveillance by detecting pathogens with the potential to cause epidemics in humans.

"The number of patients with suspected dengue, Zika or chikungunya infection will increase when summer arrives," said lead author of the study Victor Hugo Aquino, Professor at University of Sao Paulo at Ribeirao Preto.

"Conventional methods are frequently unable to confirm diagnosis of these diseases, so we don't know which viruses are circulating," Aquino noted.

If a tool like this had been available when Zika began circulating in Brazil, it might have been possible to restrict its spread to the initial outbreak location, he said.

"We took a long time to realise an epidemic was under way because no one was thinking of Zika at the time," he said.

In addition to the pathogens, the platform detects others that as yet have been identified only sporadically but could become epidemics.

Examples include Mayaro, an alphavirus related to chikungunya that is transmitted by wild mosquitoes such as Haemagogus janthinomys, and Oropouche, which to date has caused epidemics confined to riverine communities in the Amazon region and is transmitted mainly by midges of the species Culicoides paraensis.

"There are several other viruses that haven't yet caused problems in humans but may do so one day," Aquino said.

"They're evolving all the time, and with the degradation of natural environments infectious agents once confined to natural niches could spread farther afield," Aquino pointed out.

Although the platform is designed above all to detect pathogens transmitted by arthropods such as mosquitoes and ticks, it can also diagnose infectious agents transmitted by small mammals, like hantavirus, said the study published in the journal PLoS Neglected Tropical Diseases.

​New York, Dec 2 (IANS)Dramatic climate cycles on early Mars, triggered by buildup of greenhouse gases, may be the key to understanding how liquid water left its mark on the planet's surface, a study says.

Using climate models, the researchers showed warming periods -- caused when greenhouse gases reached a certain tipping point -- lasted millions of years on Mars, melting the glaciers that covered the surface of the planet, thereby creating liquid water.

Scientists have long debated how deep canyons and extensive valley networks -- like the kinds carved by running water over millions of years on Earth -- could form on Mars some 3.8 billion years ago, a time many believe the planet was frozen.

Previous studies suggested asteroid impacts might have warmed the planet, creating steam atmospheres that led to rain. But those warm periods would have much shorter durations and struggle to produce enough water, the researchers said.

"We think Mars had to be warm for millions to tens of millions of years, and the impact hypothesis can keep it warm for thousands of years," said study co-author Jim Kasting, Professor at Pennsylvania State University in the US.

"In terms of water, we need millions of meters of rainfall, and they (previous studies) can get hundreds of meters," Kasting said.

The new study suggest a glacier-covered early Mars could have experienced long warm periods, lasting up to 10 million years at a time, caused by a thick atmosphere of carbon dioxide and hydrogen.

The team, which published its findings in the journal Earth and Planetary Science Letters, found the warming cycles would have lasted long enough, and produced enough water, to create the features.

"With the cycling hypothesis, you get these long periods of warmth that give you sufficient time to form all the different Martian valley networks," Natasha Batalha, graduate student at Pennsylvania State University, explained.

​Moscow, Dec 2 (IANS)Scientists at the Far Eastern Federal University have invented a new method of producing nuclear fuel using electric current, said the university on Friday.

Main advantages of the new technology are low cost, quick manufacturing process, and improvement of product quality, Xinhua news agency reported.

Fuel can be produced even from uranium dioxide powder, which is not suitable for common technology, it said.

"The key idea of our method is heating with electric current. It flows through a mould that already has some powder on it. In such conditions, uranium oxide fuel experiences the powerful pulsed discharge and mechanical pressure simultaneously," said Ivan Tananaev, head of the department of nuclear technologies at the school of natural sciences.