Covid Brazil variant ‘may spread more easily’

The first detailed studies of the P.1 variant suggest it may be up to twice as transmissible.

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Rarest seal breeding site discovered

Scientists have discovered a previously unknown breeding site used by the world’s rarest seal species.

The Mediterranean monk seal is classified as “endangered,” with a total population of about 700.

The new study — by the University of Exeter and the Society for the Protection of Turtles (SPOT) — used camera-traps to confirm breeding in caves in northern Cyprus, with at least three pups born from 2016-19 at one cave.

Only certain caves are suitable for monk seal breeding and resting, so — although the numbers are small — the researchers say urgent action is needed to protect these caves.

“This area of coastline in being developed rapidly, especially for construction of hotels,” said Dr Robin Snape, of the Centre for Ecology and Conservation on Exeter’s Penryn Campus in Cornwall.

“A survey of the coast in 2007 found 39 possible breeding caves, and some of these have already been destroyed.

“The main breeding site we identify in this study currently has no protected status, and we are working with local authorities to try to change this.”

Lead author Dr Damla Beton, of SPOT, added: “Another major threat to monk seals in this area is bycatch (accidental catching by fisheries).

“We are working with fishers and government ministries to ensure protection areas at sea, because at present no measures are implemented to mitigate bycatch in the core areas used by these seals.”

The team has now established long-term monitoring of the breeding caves, aiming to determine the size of this seal population.

The study, carried out in collaboration with the Middle Eastern Technical University with the support of the local authorities, received funding from the MAVA Foundation.

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Materials provided by University of Exeter. Note: Content may be edited for style and length.

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The time is ripe! An innovative contactless method for the timely harvest of soft fruits

Most people are probably familiar with the unpleasant feeling of eating overripe or underripe fruit. Those who work in agriculture are tasked with ensuring a timely harvest so that ripeness is at an optimal point when the fruit is sold, both to minimize the amount of fruit that goes to waste and maximize the quality of the final product. To this end, a number of techniques to assess fruit ripeness have been developed, each with their respective advantages and disadvantages depending on the type of produce.

Although biochemical and optical methods exist, mechanical techniques are the most widely used. They indirectly assess ripeness based on the fruit’s firmness. In turn, firmness is quantified by observing the vibrations that occur on the fruit when mechanical energy is accurately delivered through devices such as hammers, pendulums, or speakers. Unfortunately, these approaches fall short for softer fruits, which are more readily damaged by the contact devices used.

In a recent study published in Foods, a team of scientists from Shibaura Institute of Technology (SIT), Japan, addressed this issue through an innovative method for measuring the firmness of soft fruits using laser-induced plasma (LIP). This work is a sort of follow-up of a previous study in which LIP was used to quantify the firmness of harder fruits.

But what is LIP and how is it used? Plasma is a state of matter similar to the gaseous state but in which most particles have an electric charge. This energetic state can be produced in normal air by focusing a high-intensity laser beam onto a small volume. Because the generated plasma “bubble” is unstable, it immediately expands, sending out shockwaves at ultrasonic speeds. Professor Naoki Hosoya and colleagues at SIT had successfully used LIP shockwaves generated close to the surface of apples to excite a type of vibration called 0S2 mode, colloquially referred to as “football mode vibration” because of how the resulting deformation looks on spherical bodies. They then verified that the frequency of the 0S2 mode vibrations was correlated with the firmness of the fruit.

However, soft fruits do not exhibit 0S2 mode vibrations, so the team had to analyze an alternative type of oscillation: Rayleigh waves. These are waves that occur exclusively on the surface of bodies without penetrating far into the interior. Using Kent mangoes, a setup for generating LIP, and commercially available laser-based vibrometers, the scientists verified that the velocity at which Rayleigh waves propagate is directly related to the firmness of the mangoes. Because the propagation velocity markedly decreases with storage time, it provides a reliable way to indirectly assess ripeness.

The team went further and looked for the best position on the mangoes’ surface to determine the velocity of Rayleigh waves. Mangoes, as well as other soft fruits, have large seeds inside, which can alter the propagation of surface waves in ways that are detrimental to measurements. “The results of our experiments indicate that Rayleigh waves along the ‘equator’ of the mango are better for firmness assessment compared to those along the ‘prime meridian’,” explains Hosoya. The experiments also revealed that cavities within the fruit’s flesh or decay can greatly affect the results of the measurements. Thus, as Hosoya adds, they will keep investigating which is the best area to measure firmness in mangoes using their novel approach.

In short, the team at SIT has engineered an innovative strategy to assess the ripeness of soft fruits from outside. “Our system,” remarks Hosoya, “is suitable for non-contact and non-destructive firmness assessment in mangoes and potentially other soft fruits that do not exhibit the usual 0S2 mode vibrations.” Further refinement of such firmness assessment methods will hopefully make them more reliable and accessible for the agricultural industry. With any luck, their widespread adoption will ensure that fruits reach your plate only when the time is ripe!

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Materials provided by Shibaura Institute of Technology. Note: Content may be edited for style and length.

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Predicting microbial interactions in the human gut

The human gut consists of a complex community of microbes that consume and secrete hundreds of small molecules — a phenomenon called cross-feeding. However, it is challenging to study these processes experimentally. A new study, published in Nature Communications, uses models to predict cross-feeding interactions between microbial species in the gut. Predictions from such computational methods could eventually help doctors get a more complete understanding of gut health.

The microbial community, or microbiome, of the gut is known to influence human health. Previous studies have focused on determining the types of microbes that are present. Unfortunately, this information is not enough to understand the microbiome.

“The gut environment is shaped by small molecules known as metabolites, which are excreted by the microbial community,” said Sergei Maslov (BCXT/CABBI), a professor of bioengineering and Bliss faculty scholar. “Although it is possible to measure these metabolites experimentally, it is cumbersome and expensive.”

The researchers had previously published a study where they used experimental data from other studies to model the fate of metabolites as they pass through the gut microbiome. In the new study, they have used the same model to predict new microbial processes that have not been determined before.

“What we eat passes into our gut, and there is a cascade of microbes which release metabolites,” said Akshit Goyal, a postdoctoral fellow at MIT and a collaborator of the Maslov lab. “Biologists have measured these molecules in human stools, we have shown that you can use computational models to predict the levels of some.”

Measuring every metabolite and trying to understand which microbe might be releasing it can be challenging. “There is a large universe of possible cross-feeding interactions. Using this model, we can aid experiments by predicting which ones are more likely to occur in the gut,” Goyal said.

The model was also supported by genomic annotations, which explain which microbial genes are responsible for processing the metabolites. “We are confident of our modelling predictions because we also checked whether the microbes contain the genes necessary for carrying out the associated reactions. About 65% of our predictions were supported by this information,” said Veronika Dubinkina, a PhD student in bioengineering.

The researchers are now working to improve the model by including more experimental data. “Different people have different strains of gut microbes. Although these different strains have many genes in common, they differ in their capabilities,” Dubinkina said. “We need to collect more data from patients to understand how different microbial communities behave in different hosts.”

“We are also interested in determining how fast the microbes consume and secrete the metabolites,” said Tong Wang, a PhD student in physics. “Currently the model assumes that all the microbes consume metabolites at the same rate. In reality, the rates are different and we need to understand them to capture the metabolite composition in the gut.”

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Materials provided by Carl R. Woese Institute for Genomic Biology, University of Illinois at Urbana-Champaign. Original written by Ananya Sen. Note: Content may be edited for style and length.

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Covid vaccines cut risk of serious illness by 80% in over-80s

The UK will soon be in a “very different world”, government scientists promise after the success of the jabs.

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Covid: Teachers’ risk ‘similar’ to other under-65s

The study measured infection rates in school staff and pupils in November and December.

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Covid-19: Critical care beds shortage prompts calls for review

The UK has 7.3 critical care beds per 100,000 people, compared to Germany’s 33.8 and the US’s 34.3.

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Covid-19: Officials hunt Brazil virus variant case in England

The whereabouts of one infected person is unknown, as they did not give their full contact details.

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Covid-19: More than 20 million in UK have had first jab

The milestone is a “huge national achievement” and “every jab makes a difference”, Boris Johnson says.

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Covid-19: Free rapid testing for pupils’ families in England

Pupils’ households and bubbles will be offered tests to take themselves at home twice a week.

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