340 articles from THURSDAY 16.7.2020

Researchers solve a long-standing problem in organic chemistry

Chemists have for a long time been interested in efficiently constructing polyenes - not least in order to be able to use them for future biomedical applications. However, such designs are currently neither simple nor inexpensive. Scientists have now found a bio-inspired solution to the problem.

Syncing NASA laser, ESA radar for a new look at sea ice

With a small nudge to a satellite's orbit, scientists will soon have simultaneous laser and radar measurements of ice, providing new insights into Earth's frozen regions. On July 16, the European Space Agency (ESA) begins a series of precise maneuvers that will push the orbit of its radar-carrying CryoSat-2 satellite about half a mile higher—putting it in sync with NASA's laser-carrying Ice,...

Chemists develop bioinspired strategy for the controlled synthesis of polyenes

They occur in nature, are reactive and play a role in many biological processes: polyenes. It is no wonder that chemists have for a long time been interested in efficiently constructing these compounds—not least in order to be able to use them for future biomedical applications. However, such designs are currently neither simple nor inexpensive and present organic chemists with major challenges....

Pioneering method reveals dynamic structure in HIV

Viruses are scary. They invade our cells like invisible armies, and each type brings its own strategy of attack. While viruses devastate communities of humans and animals, scientists scramble to fight back. Many utilize electron microscopy, a tool that can "see" what individual molecules in the virus are doing. Yet even the most sophisticated technology requires that the sample be frozen and...

Principles to enhance research integrity and avoid 'publish or perish' in academia

Amid growing criticism of the traditional "publish or perish" system for rewarding academic research, an international team has developed five principles that institutions can follow to measure and reward research integrity. Publishing on July 16, 2020 in the open access journal PLOS Biology, the team believes that applying these principles in academic hiring and promotion will enhance scientific...

Membrane technology could cut emissions and energy use in oil refining

New membrane technology developed by a team of researchers from the Georgia Institute of Technology, Imperial College London, and ExxonMobil could help reduce carbon emissions and energy intensity associated with refining crude oil. Laboratory testing suggests that this polymer membrane technology could replace some conventional heat-based distillation processes in the future.

'Proofreading' proteins stop and reel in DNA to correct replication errors

On the DNA assembly line, two proofreading proteins work together as an emergency stop button to prevent replication errors. New research from North Carolina State University and the University of North Carolina at Chapel Hill shows how these proteins—MutL and MutS—prevent DNA replication errors by creating an immobile structure that calls more proteins to the site to repair the error. This...

New study sheds light on how nutrient-starved cells recycle internal components

The idea of the cell as a city is a common introduction to biology, conjuring depictions of the cell's organelles as power plants, factories, roads, libraries, warehouses and more. Like a city, these structures require a great deal of resources to build and operate, and when resources are scarce, internal components must be recycled to provide essential building blocks, particularly amino acids,...

A population of asteroids of interstellar origin inhabits the Solar System

A study conducted by scientists at São Paulo State University's Institute of Geosciences and Exact Sciences (IGCE-UNESP) in Rio Claro, Brazil, has identified 19 asteroids of interstellar origin classified as Centaurs, outer Solar System objects that revolve around the Sun in the region between the orbits of Jupiter and Neptune.

About 94 per cent of wild bee and native plant species networks lost

Climate change and an increase in disturbed bee habitats from expanding agriculture and development in northeastern North America over the last 30 years are likely responsible for a 94 per cent loss of plant-pollinator networks, researchers found. The researchers looked at plant-pollinator networks from 125 years ago through present day.

Two paths of aging: New insights on promoting healthspan

Scientists have unraveled key mechanisms behind the mysteries of aging. They isolated two distinct paths that cells travel during aging and engineered a new way to genetically program these processes to extend lifespan. Cells embark upon either a nucleolar or mitochondrial path early in life, and follow this ''aging route'' throughout their entire lifespan through decline and death. At the heart...

Megaphages harbor mini-Cas proteins ideal for gene editing

Cas proteins like CRISPR-Cas9 have great potential for gene therapy to treat human disease and for altering crop genes, but the gene-targeting and gene-cutting Cas proteins are often large and hard to ferry into cells with viral vectors such as adenovirus. Scientists have now discovered a hypercompact Cas protein, Cas-phi, that should work better. It is half the size of Cas9 and apparently evolved...

Evidence for decades-old theory to explain the odd behaviors of water

A new study provides strong evidence for a controversial theory that at very cold temperatures water can exist in two distinct liquid forms, one being less dense and more structured than the other. Researchers conducted computer simulations of water molecules to discover the critical point at the transition between the two forms.

Dangerous blood clots form in leg arteries of COVID-19 patients

COVID-19 is associated with life-threatening blood clots in the arteries of the legs, according to a new study. Researchers said COVID-19 patients with symptoms of inadequate blood supply to the lower extremities tend to have larger clots and a significantly higher rate of amputation and death than uninfected people with the same condition.

How a New Effort to Trace Emissions, Led by Al Gore, Could Reshape Climate Talks

As countries entered the final months of talks ahead of the Paris Agreement in 2015, China offered a big revelation: the country had burned substantially more coal than it had previously acknowledged in the preceding years. Many diplomats took the voluntary acknowledgment as a sign of good faith. Nonetheless, the update underscored the broader challenges that climate change activists face when...

Revealing Brazil's rotten agribusinesses

Following reports that Brazil's current deforestation rate—1 million hectares—is the highest in a decade, a peer-reviewed study published in Science today finds that 18-22%, and possibly more, of Brazil's annual exports to the European Union are potentially contaminated with illegal deforestation, while identifying for the first time the specific producers of soy in Brazil responsible for...

A brainwide atlas of synapses across the mouse life span

Synapses connect neurons together to form the circuits of the brain, and their molecular composition controls innate and learned behavior. We analyzed the molecular and morphological diversity of 5 billion excitatory synapses at single-synapse resolution across the mouse brain from birth to old age. A continuum of changes alters synapse composition in all brain regions across the life span....

A programmable fate decision landscape underlies single-cell aging in yeast

Chromatin instability and mitochondrial decline are conserved processes that contribute to cellular aging. Although both processes have been explored individually in the context of their distinct signaling pathways, the mechanism that determines which process dominates during aging of individual cells is unknown. We show that interactions between the chromatin silencing and mitochondrial pathways...