Glyphosate affects brood care in bumblebees
The decline of insects, and pollinators in particular like bumblebees, is a growing threat to ecosystems and economies worldwide. The increasing use of pesticides in agriculture is considered to be a driver of the phenomenon, but the most widely used herbicide, glyphosate, may contribute more than previously thought according to a new study on bumblebees in the journal Science.
The research found that glyphosate affects the ability of bumblebee colonies to regulate the temperature of their brood.
“When resources become scarce, you see very clearly that the collective thermal behaviour of bumblebee colonies that have been chronically exposed to glyphosate is affected,” says lead author Dr Anja Weidenmüller, from the Centre for the Advanced Study of Collective Behaviour at the University of Konstanz, Germany. “They cannot keep their brood warm for as long.”
This is concerning since, according to Weidenmüller, “bumblebee colonies are under really high pressure to grow as quickly as possible within a short period of time.” If the bumblebees cannot maintain the necessary brood temperature, the brood will develop more slowly or not at all.
“Sublethal effects, i.e. effects on organisms that are not lethal but can be seen, for example, in the animals’ physiology or behaviour, can have a significant negative impact and should be taken into account when pesticides are approved in future,” she says.
Iron catalyst could make important chemical reactions cheaper
Catalysts speed up chemical reactions by offering an alternate way for chemicals to react with one another. This can allow reactions to occur at lower temperatures, or direct reactions to favour certain products, all without the catalyst itself being consumed.
But many catalysts are made of precious metals that can be expensive and harmful to the environment.
Now, chemists have designed a new catalyst made of iron – a much cheaper and more environmentally friendly metal – to facilitate the olefin metathesis reaction, according to a new study in Nature Catalysis.
“The olefin metathesis reaction is among the most widely applicable catalytic reactions for carbon-carbon double bond formation,” explains lead author Satoshi Takebayashi, a researcher at the Okinawa Institute of Science and Technology Graduate University (OIST), Japan. “Carbon-carbon double bonds are an important bond found in many chemical products.”
The current popular catalyst for this reaction is made from the precious metal ruthenium. However, the iron catalyst is unstable and less reactive when exposed to air and moisture, so these limitations need to be fixed before it will be able to replace ruthenium.
How the brain responds to surprising events
When your brain needs you to pay attention to something important, such as an unexpected outcome, it triggers the release of noradrenaline to help learn from the event, according to new research published in Nature.
Noradrenaline, also known as norepinephrine, is a neuromodulator produced by a structure deep in the brain called the locus coeruleus. It has widespread effects throughout the brain, and cognitive scientists have now found, through studying mice, that it plays a key role in signalling surprise.
“What this work shows is that the locus coeruleus encodes unexpected events, and paying attention to those surprising events is crucial for the brain to take stock of its environment,” says senior author Mriganka Sur, the Newton Professor of Neuroscience in the Department of Brain and Cognitive Sciences at Massachusetts Institute of Technology (MIT), US.
The researchers also discovered that, in addition to its role in signalling surprise, noradrenaline helps to stimulate behaviour that leads to a reward, particularly in situations where there is uncertainty over whether a reward will be offered.
The consequences of climate change in the Alps are visible from space
Global warming has had a particularly pronounced impact on the European Alpine region and now new research has found that the mountain range is becoming greener.
Using high-resolution satellite imagery, ecologists have shown that vegetation above the treeline has increased in more than 77% of the Alps, and snow cover is also decreasing – albeit so far only slightly.
The Alps are becoming greener because plants are colonising new areas and the vegetation is generally becoming denser and taller. This phenomenon of “greening” due to climate change is already well documented in the Arctic.
“Alpine plants are adapted to harsh conditions, but they’re not very competitive,” says lead author Dr Sabine Rumpf, assistant professor in the Department of Environmental Sciences at the University of Basel, Switzerland.
As environmental conditions change, these specialised species lose their advantage and are outcompeted.
“The unique biodiversity of the Alps is therefore under considerable pressure,” Rumpf says.
A bias towards citing scientific research from certain countries
There is a citation bias in science, according to a new study, and that could mean that globally diverse voices are less likely to be heard and recognised.
The study found that scientific papers from researchers in a small number of highly active countries (such as the USA, UK and China) are at the core of scientific research and are more likely to be cited than those from other countries (for example Brazil, Mexico and Turkey) – even if they covered similar subject matters.
Sociologists examined the text and citations of nearly 20 million scientific papers across 150 fields, published between 1980 and 2012, and developed a way to measure the difference between the number of citations that would be expected for a paper (based on the text contained within it), and the actual number of citations the paper received, using computer modelling.
The findings have been published in Nature Human Behaviour.