All posts by Jonas Heath

Droplets suspended in mid-air with acoustic levitation instead of test tubes: a revolution for chemists?

Chemical laboratories may in the future abandon the classical test tubes to use drops of liquid suspended in mid-air by the method of acoustic levitation.

This is the project that Jack Beauchamp, a researcher at the California Institute of Technology, is working on, according to which inside the drop suspended in mid-air it is possible to trigger the chemical reactions that are currently confined in the tubes. Acoustic levitation is possible by exploiting the energy emitted by small, very powerful speakers that operate at a frequency imperceptible to the human ear.

In a new study, published in Angewandte Chemie International Edition, Beauchamp and colleagues describe the technique they are developing, research that represents, according to the scientist himself, “the first successful use of acoustic levitation as a reactor “without walls” in a detailed study of chemical reactions.”

They have already experimented with the use of these droplets with an anti-cancer drug. They made the latter react with lipids, biomolecules at the base of the cell membrane structure. Using the mass spectrometer, they “smelled” the chemical signature emitted by the droplet when the drug reacted with the lipid.

During the experiment, they used a drop of water one millimeter in diameter suspended in mid-air and illuminated by red laser light.

“As far as I know, we are the only people who do serious chemistry in this way, examining the kinetics and the mechanism of the reactions involved,” Beauchamp himself says.


Links/Sources:

https://onlinelibrary.wiley.com/doi/abs/10.1002/anie.201902815

Electric circuit mimics barn owl brain to locate sounds

A group of researchers is trying to imitate, through electrical circuits, the brain circuits of the barn owl, one of the most known species of owl, as well as one of the most widespread, also called common barn owl to distinguish it from other members of its family.

According to a team of engineers at Pennsylvania State University, these birds are characterized by a particular ability to use sound to locate prey, a technique that could be used for electronic devices built for navigation in general and for the identification of the origin of a sound in particular. In particular, researchers are analyzing a particular model of localization called Jeffress model.

The latter, developed by Lloyd Jeffress in 1948, explains just how acoustic systems in nature are able to record and analyze even the smallest differences in the time of arrival of sound to the ears of animals in order to identify the precise location that generates the same sound. As Sarbashis Das, assistant professor of mechanical engineering and one of the authors of the study, explains, “Owls understand which direction the sound is coming from one to two degrees. Humans are not that precise. Owls use this skill mainly because they hunt at night and their eyesight isn’t that good.”

The electrical circuit created by Das and his team of engineers can slow down the input signal and can determine the point of origin of the sound, just as barnacles do: “In fact, nature has done much of the work for us. All we have to do now is adapt these neurobiological architectures for our semiconductor devices,” explains Das himself.

Staring at seagulls makes them less likely to steal food

According to a new, special study conducted by researchers at the University of Exeter, staring at seagulls makes them less likely to steal food. The researchers carried out several tests on 74 seagulls and found that on average it took the seagulls 21 seconds longer to get close to food if there was a human being staring at them.

If there was a human around to look at them, most of the seagulls would fly away or not approach the food. Only 27 of the 74 seagulls approached. As Madeleine Goumas, a researcher at the Center for Ecology and Conservation at Exeter, explains, it was interesting to discover that most gulls were intimidated by the mere glance.

These animals, in fact, are increasingly seen as aggressive and willing to do almost anything to get food, as suggested by many funny videos on the net. However, according to Neeltje Boogert, another expert who participated in the study, “Seagulls learn very quickly, so if they can get food from humans once, they might look for more. This means that if they learn that the human eye doesn’t produce negative consequences for them, it won’t be long before being stared at becomes a normal thing and they start to approach food fearlessly and in increasing numbers.”

The same researchers recommend in any case to all those who are used to eating outdoors, situations that occur more and more often during the summer, to look around often because the seagulls are used to take food when we are distracted, taking us by surprise: “It seems that just looking at the seagulls will reduce the possibility that they will tear your food,” Boogert himself reveals.


Links/Sources:

https://royalsocietypublishing.org/doi/10.1098/rsbl.2019.0405

Scientists discover regulatory gene of schizophrenia

A group of researchers at the Philadelphia Children’s Hospital announced that they had identified a gene that “acts as a major regulator of schizophrenia” when the brain develops during its early stage.

The researchers used special computational tools by analyzing or large collections of brain tissue. These results may be useful in treating schizophrenia, considered one of the most complex and difficult to treat neuropsychiatric disorders.

Researchers used two independent datasets of biological samples from schizophrenic parties or control subjects. They then used an algorithm developed by Columbia University to reconstruct gene transcription networks and identified the TCF4 gene, considered by the researchers themselves as a regulator of schizophrenia.

Kai Wang, a researcher at the Philadelphia Hospital and first in charge of the study, says “since hundreds, or even thousands, of genes can contribute to the risk of schizophrenia, it is essential to understand which are the most important, by controlling the central networks of the disease. Identifying the key regulators can help us achieve priority goals for new treatments in the future.”


Links/Sources:

https://www.chop.edu/news/scientists-identify-gene-master-regulator-schizophrenia

https://advances.sciencemag.org/content/5/9/eaau4139

New laser device to detect anti-personnel mines can also be used on vehicles

A new antipersonnel mine detector will be presented at the Laser Congress of the Optical Society held in Vienna. This detector could solve the problem of efficiency with regard to the detection of anti-personnel mines in the ground in moving vehicles.

Usually, vehicles are used to speed up the detection of mines, but this also lowers the level of accuracy. In a vehicle, even the best detectors are disturbed by sound or vibration from external sources. The Laser Doppler vibrometers (LDV), a very sensitive and promising new technology for the detection of anti-personnel mines and other buried objects, also suffer from this disturbance.

A group of researchers from the University of Mississippi has therefore built a new detector that, according to the press release, effectively detects buried objects even when the same detector is the movement and therefore also when it is on a vehicle.

The new device, called Laser Interferometric Differential Laser Sensor (LAMBDIS), provides the same accuracy as the LDV system while being much less sensitive to motion.

“Our new device overcomes this challenge by using a series of laser beams and then combining their signals to create a pattern of rapid detection that is also robust enough to compensate for movement and other ‘noises’ that could overwhelm other techniques. LAMBDIS provides a measurement of vibration fields with a high sensitivity, while having a low sensitivity to the entire movement of the body of the object or the sensor itself, allowing operation from a moving vehicle,” says Vyacheslav Aranchuk, project leader researcher.

The new device used detects doppler displacement using the interference of light reflected from different points on the object, as Aranchuk himself explains.


Links/Sources:

https://www.osa.org/en-us/about_osa/newsroom/news_releases/2019/sensor_detects_buried_osa_laser_congress/

Non-alcoholic fatty liver disease caused by intestinal bacteria?

A group of researchers found that non-alcoholic fatty liver disease (NAFLD), a condition that sees the progressive accumulation of fat in liver cells, could be linked to the intestinal microbiome according to a new study conducted by the Chinese research team.

In fact, there has never been a clear explanation of the mechanism leading to the accumulation of fat in the liver, a condition that is so extensive that it affects one billion people worldwide, although in many cases it does not cause symptoms. It only causes symptoms when this accumulation exceeds certain limits and, in the most serious cases, can also lead to cirrhosis or liver cancer.

The researchers analyzed the case of a Chinese man who had had unexplained attacks of poisoning for 10 years and who showed high levels of alcohol in his blood despite not being a great drinker. Also, when he drank sugary drinks, he tended to get drunk. The doctors found that his condition was caused by strains of intestinal bacteria relegated to synthesizing alcohol from ingested foods, particularly sugars.

By doing more research on NAFLD patients, researchers at the Beijing Capital Institute of Paediatrics, who then published the study on Cell Metabolism, found that Klebsiella pneumonia is more present in a number of people suffering from this disease. In addition, by performing experiments on mice, this bacterium caused liver damage.

Klebsiella pneumonia could, therefore, explain the non-alcoholic fatty liver disease as the evidence seems quite convincing, as gastroenterologist Anna Mae Diehl, a NAFLD expert who commented on the results of the study on Science, also states. This discovery could be decisive for the development of better methods to counter this disease.

Researchers have already treated mice exposed to this bacterium in the laboratory with special beans that affect precisely this species of bacterium: rodents seemed no longer to suffer the same liver abnormalities. These results give rise to the hope that a bean-based therapy could be useful to treat the disease in humans as well.


Links/Sources:

https://www.sciencemag.org/news/2019/09/microbe-got-man-drunk-could-help-explain-common-liver-disease

https://www.cell.com/cell-metabolism/fulltext/S1550-4131(19)30447-4

Dark matter detectable with gravitational wave observers according to Japanese researchers

A group of researchers from the University of Tokyo proposes a new method for intercepting dark matter, a matter that does not interact with ordinary matter and whose existence has been presumed because of its large-scale gravitational effect.

One of the theories about dark matter is that it is made by particular particles called assions, a very light particle that could be detected by laser-based experiments.

Yuta Michimura of the Physics Department of the University of Tokyo states in the press release: “We assume that the assion is very light and barely interacts with our familiar types of matter. Therefore, he is considered a good candidate for dark matter. We don’t know the mass of assions, but we think it has a lower mass than electrons. Our universe is full of dark matter and it is estimated that there are 500 grams of dark matter within the Earth, about the mass of a squirrel.”

According to Koji Nagano, another researcher involved in this study, current models indicate that assions can affect the polarization of light and this suggests that they could be intercepted if light is reflected several times back into an optical cavity in turn made by two separate parallel mirrors.

As the researcher himself points out, structures like these are those of observatories to detect gravitational waves. For this reason, researchers suggest using observatories such as LIGO in the United States, Virgo in Italy or KAGRA in Japan to hunt down assions.

In fact, only relatively simple and especially low-cost modifications would suffice, which would not compromise their main functions and would not reduce the level of sensitivity necessary to identify distant gravitational waves.

According to the researchers, this would be a much more precise method than those used in the past to detect assions.


Links/Sources:

https://journals.aps.org/prl/abstract/10.1103/PhysRevLett.123.111301

Global warming makes mating for birds more difficult

The phenomenon of global warming makes it difficult for birds to mate according to a study conducted by researchers from the University of East Anglia (UEA) and the University of Porto (CIBIO-InBIO). Researchers focused in particular on Tetrax tetrax, also known as the minor bustard or the meadow hen, a species classified as “vulnerable” in Europe.

Males of this species spend the period from April to May in search of females: they tend to stretch upwards, swell their necks and make a strange cry, a sort of puff, also to defend the territory from other males in any sexual competition. The researchers have discovered that the heat is forcing more and more this species of bird to choose, just in the summer period, between the mating and the shelter from the heat and the sun, or the rest, seen that the energy it assimilates is limited and the heat itself can take away a lot of it.

The study, published in PLOS ONE, also mentions the circadian rhythms of this bird evidently influenced by temperature, which consequently influences the mating season of these birds. In addition, the researchers noted that if the average temperature increased, the number of birds that could be seen around during the flirting season decreased in parallel.

Researchers analyzed in particular various areas of the Iberian Peninsula.

According to Mishal Gudka, principal author of the study, this research shows how this global phenomenon related to warming can directly affect the behavioral mechanisms of animals, in this case birds, even in a very important phase such as mating. This is even more true for birds that, in order to mate, put in place extravagant or quite energetic performances, which is evidently not easier in an increasingly hot climate.


Links/Sources:

https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0221999

Lack of sleep may adversely affect fat metabolism according to a new study

A new study highlights the problems that can lead to a lack of sleep or irregular sleep. The study, this time published in the Journal of Lipid Research, points out that food metabolism can be changed with only a few days of deprivation.

What is changed is above all the way in which fat is metabolized in food, something that can regulate satiety and therefore also weight intake. The link between lack of sleep and metabolism is not new and has already been established by several studies. Orfeu Buxton, Professor at the State University of Pennsylvania and senior author of this study, reports in the press release that other studies have already shown that there are links between higher risks of obesity (and in parallel of all related diseases, including diabetes) and the limitation of sleep in the long term.

However, most of these studies focused mostly on glucose metabolism, which in itself is the basis for diabetes itself. Few or almost none studies have evaluated the connection of sleep itself with the digestion of lipids.

The study began when Kelly Ness was a researcher at the University of Washington. The tests were performed on 15 healthy men in their 20s who spent a week sleeping very much at home. After this first phase, the participants were forced to sleep in the laboratory for 10 days and for five of these for no more than five hours per night.

The same researchers worked hard to keep them awake and to provoke the state of prolonged irregular sleep. After nights of sleep restriction, the researchers offered the participants fat-rich dinners, and the participants themselves showed a greater appreciation of these meals than when they ate the same restful meal.

By analyzing the blood samples, the researcher found that the same restriction of sleep affected the lipid response. In essence, the body found it more difficult to metabolize the fats that more easily accumulated and prepared people to fatten.

It was a study in itself imperfect and still limited in terms of variety of participants but still suggests the importance of sleep for human metabolism.


Links/Sources:

http://www.jlr.org/content/early/2019/09/04/jlr.P094375

Social isolation during adolescence changes brain development in mice

Social isolation can change brain development as well as changing behavior in adulthood, at least in mice, according to a press release of the Society for Neuroscience and its study published in eNeuro.

The researchers carried out experiments on female mice by housing them for long periods during adolescence alone. Since the brain was still in development, the researchers were able to follow the changes during growth. They noted that the brain of mice in isolation showed an atypical pathway and this mainly concerned the prefrontal cortex, an area where cortical development was partially interrupted.

In addition, these mice, once adults and reintroduced into the social environment, showed overly repetitive habitual behavior. According to researchers, during adolescence, there is a critical period during which excessive social isolation compromises brain structure and adult behavior.

Previous research had already found links between brain development and social experience.


Links/Sources:

https://www.eneuro.org/content/early/2019/09/16/ENEURO.0318-19.2019