It’s possible that I shall make an ass of myself. But in that case one can always get out of it with a little dialectic. I have, of course, so worded my proposition as to be right either way (K.Marx, Letter to F.Engels on the Indian Mutiny)
Wednesday, September 04, 2024
Learning like a teenager
Zebra finches defy age-related learning limits
Max-Planck-Gesellschaft
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Reactivate lost learning abilities: even old zebra finches can learn new songs again.
Credit: MPI for Biological Intelligence/ Julia Kuhl
We all know the adage, "You can't teach an old dog new tricks." As we age, our ability to learn new skills, like mastering a foreign language or picking up a musical instrument, seems to fade. The culprit? A decline in brain plasticity—the brain's capacity to rewire itself and adapt to new challenges. But what if we could rewind the clock on this age-related decline? A new study led by Daniela Vallentin at the Max Planck Institute for Biological Intelligence offers a tantalizing glimpse into this possibility.
Vallentin's team focused on zebra finches, songbirds known for their elaborate vocalizations. Like many animals, zebra finches have a critical period for song learning, within their first 90 days of life. After this window closes, their brains become less flexible, and inhibitory neurons put the brakes on further learning. The researchers wondered: Could they lift this neural blockade and restore the birds' youthful learning ability?
Using cutting-edge techniques like optogenetics, they precisely switched off these inhibitory neurons in adult zebra finches. The results were remarkable. The birds, once thought to be stuck with their existing repertoire, began to add new elements to their songs. "We observed an expansion of the adult animals' vocal repertoire that was previously thought impossible," says Fabian Heim, the study's lead author.
Implications for Human Aging
This discovery extends far beyond the realm of birdsong. It suggests that the brain's capacity for learning may be far more resilient than previously thought. Similar learning windows exist in humans, affecting everything from language acquisition to social development. If scientists can identify and manipulate the mechanisms that control these critical periods, it could open doors to new therapies for neurodegenerative diseases and injuries that impair learning. Imagine a future where the adage about old dogs and new tricks is finally retired.
Natural selection may create inter-species exploitation
PNAS Nexus
A modeling study suggests that one-sided interspecies cooperation can spontaneously emerge and persist over time, despite only one species benefitting. Evolutionary game theory, and the prisoner’s dilemma in particular, are often used to model the evolution of cooperation within a single species. In the prisoner’s dilemma, both parties benefit by cooperating, but the greatest benefit is earned by a defector who plays with a cooperator. The temptation to cheat tends to push players towards defection, even though mutual defection returns a lower payoff to both parties. Christoph Hauert and György Szabó used the prisoner’s dilemma game to model inter-species cooperation, taking as their inspiration mutualisms, such as the relationships between flowering plants and their pollinators or nitrogen-fixing bacteria and the plants in which they live. The authors set up a model of cooperation between two identical species of equal population size with identical generation times situated on two separate lattices, such that interactions occur between species while competition is fiercest within species. This setup could represent the arrangement of microbes in a biofilm. In the model, the individuals are sessile, and each compete with four neighbors of the same species and potentially assist five neighbors of the other species. “Fitter” individuals, in terms of points won, reproduce more often. By adjusting the cost-to-benefit ratio of cooperation, various dynamic patterns of cooperation and defection are produced. For some values of the cost-to-benefit ratio, the authors find an unexpected pattern in which one species consistently cooperates, donating to the other species at a cost to itself, and yet its partner consistently defects, failing to reciprocate. According to the authors, under some conditions, natural selection may favor asymmetric states where one species exploits the other.
Biodiesel, a green alternative to conventional diesel, has been shown to reduce carbon dioxide emissions by up to 74%. Biodiesel is produced through transesterification, converting triglycerides into biodiesel and producing glycerol as a low-value byproduct. Since glycerol makes up about 10% of the output, efforts have focused on boosting its value. One method involves electrochemical oxidation, turning glycerol into high-value three-carbon compounds like dihydroxyacetone (DHA) and glyceraldehyde (GLYD), though past approaches often yielded unstable or low-value products under strong alkaline conditions.
In a study published in theJournal of Catalysis on 15 August 2024 researchers led by Associate Professor Tomohiro Hayashi from Tokyo Institute of Technology (Tokyo Tech) and Professor Chia-Ying Chiang from National Taiwan University of Science and Technology, Taiwan, have developed a highly selective and efficient glycerol electrooxidation (GEOR) process that can lead to the production of valuable 3-carbon (3C) products.
“Establishing an electrochemical route for a highly selective and efficient glycerol electrooxidation process to desirable 3C products is essential for biodiesel production,” says Hayashi and Chiang.
Selective oxidation of glycerol is challenging due to its structure. Glycerol has three –OH groups: two on primary carbon atoms and one on a secondary carbon atom. This arrangement creates steric hindrance, making it hard for reactants to target specific –OH groups for oxidation. In alkaline conditions, the –OH groups also cause unwanted side reactions that break carbon-carbon bonds, resulting in two-carbon or one-carbon compounds instead of the desired three-carbon products.
To address this, the researchers conducted GEOR using sodium borate and bicarbonate buffer as a mild alkaline electrolyte and a nickel-oxide (NiOx) catalyst. The sodium borate helps protect certain –OH group, improving the selectivity of the reaction, while the NiOx catalyst enhances the efficiency of the electrooxidation process. Sodium borate forms coordination complexes with glycerol’s primary and secondary alcohol groups to form GLYD and DHA respectively. However, the final product depends on the ratio of borate to glycerol. To understand how different concentrations of glycerol and borate affect the electrooxidation process, a fixed concentration of 0.1 M borate buffer was reacted with varying concentrations of glycerol (0.01, 1, 2.0 M) and a fixed concentration of 0.1 M glycerol with varying concentrations of borate buffer (0.01, 0.05, 0.10, and 0.15 M). while maintaining a pH of 9.2.
Higher borate concentrations were found to increase the selectivity for 3C products, particularly DHA, with the highest selectivity of up to 80% observed at a borate concentration of 0.15 M. This improvement is attributed to the increased buffer capacity provided by the borate solution, which helps maintain a stable pH during the reaction and stabilizes the borate-glycerol complex for further oxidation into 3C compounds. Conversely, increasing the glycerol concentration reduced both the yield and selectivity of 3C products. At a glycerol concentration of 1 M, GLYD was the main product, with a selectivity of 51%.
The difference in the type of 3C product was found to be related to the formation of different glycerol-borate complexes. Using Raman spectroscopy, the researchers found higher borate concentrations favor six-membered ring complexes, promoting secondary –OH oxidation and DHA production. Conversely, higher glycerol concentrations favor five-membered ring complexes, leading to primary –OH oxidation and GLYD formation.
"Five-membered ring complexes were more likely to form in the electrolyte with a borate-to-glycerol ratio of 0.1, whereas six-membered ring complexes became more prominent in the electrolyte with a borate-to-glycerol ratio of 1.5," says Hayashi and Chiang.
These findings present a promising strategy for transforming glycerol into valuable products, boosting the sustainability and profitability of biodiesel production.
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About Tokyo Institute of Technology
Tokyo Tech stands at the forefront of research and higher education as the leading university for science and technology in Japan. Tokyo Tech researchers excel in fields ranging from materials science to biology, computer science, and physics. Founded in 1881, Tokyo Tech hosts over 10,000 undergraduate and graduate students per year, who develop into scientific leaders and some of the most sought-after engineers in industry. Embodying the Japanese philosophy of “monotsukuri,” meaning “technical ingenuity and innovation,” the Tokyo Tech community strives to contribute to society through high-impact research.
Institute of Science Tokyo (Science Tokyo) will be established on October 1, 2024, following the merger between Tokyo Medical and Dental University (TMDU) and Tokyo Institute of Technology (Tokyo Tech), with the mission of “Advancing science and human wellbeing to create value for and with society.”
Tuning selectivity toward three-carbon product of glycerol electrooxidation in borate buffer through manipulating borate/glycerol molar ratio
Novel green chemistry: A safe, low-cost, and eco-friendly conversion process for the synthesis of sulfonyl fluorides, a world first!
A research group including researchers from Osaka University has developed a method to safely and cost-effectively convert thiols and disulfides, which are easily accessible raw materials, into sulfonyl fluorides
Osaka University
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A new, safe and low-cost synthetic reaction process for sulfonyl fluorides
Osaka, Japan – For the first time in the world, thiols and disulfides were converted into sulfonyl fluorides using SHC5® and KF, expanding "click chemistry" with high efficiency and low environmental impact. This green process, yielding only NaCl and KCl as byproducts, is expected to become the preferred method in chemical and industrial synthesis.
The concept of "click chemistry” is known for its high chemical selectivity, high yield, and rapid connection of molecules. Since its inception, click chemistry has demonstrated broad utility across various fields, including synthesis, materials science, chemical biology, and pharmaceutical development, garnering immense popularity.
However, sulfonyl fluoride is a key compound in the sulfur-fluorine exchange (SuFEx) click reaction, which links molecules together, and its synthesis initially required the use of SO2F2 gas or KHF2, both of which are highly toxic and difficult to handle. To achieve the safe and environmentally-friendly synthesis of sulfonyl fluoride, synthetic chemists have explored various chemical reaction processes.
In this study, it was developed for the first time in the world that sulfonyl fluoride can be efficiently synthesized by reacting the easily-handled and highly-reactive SHC5® and KF (potassium fluoride) with thiols or disulfides. This is a green synthetic process that produces only non-toxic sodium and potassium salts as by-products, resulting in minimal environmental impact.
This chemical reaction enabled the environmentally-friendly and tailor-made synthesis of a broad scope of sulfonyl fluorides containing aromatic, aliphatic, and heterocyclic groups.
The synthetic protocol is very simple, enabling the low-cost, scalable, and safe production of sulfonyl fluorides. This new method is expected to become the first choice for sulfonyl fluoride synthesis in both the chemical and industrial sectors.
"Developing new organic synthetic protocols to create useful compounds, such as pharmaceuticals, is a highly important research theme, particularly from the perspective of the Sustainable Development Goals (SDGs)," says corresponding authors of the study Masayuki Kirihara, Shinobu Takizawa, and Mohamed S. H. Salem. "Furthermore, developing reaction processes that consider the environmental impact of by-products is becoming increasingly important. We will continue to disseminate research from Japan that focuses on the green synthesis of useful compounds with ripple effects across various fields."
### The article, “Green and Efficient Protocols for the Synthesis of Sulfonyl Fluorides Using Potassium Fluoride as the Sole Fluorine Source,” was published in ACS Sustainable Chemistry & Engineering at DOI: https://doi.org/10.1021/acssuschemeng.4c03951
About Osaka University Osaka University was founded in 1931 as one of the seven imperial universities of Japan and is now one of Japan's leading comprehensive universities with a broad disciplinary spectrum. This strength is coupled with a singular drive for innovation that extends throughout the scientific process, from fundamental research to the creation of applied technology with positive economic impacts. Its commitment to innovation has been recognized in Japan and around the world. Now, Osaka University is leveraging its role as a Designated National University Corporation selected by the Ministry of Education, Culture, Sports, Science and Technology to contribute to innovation for human welfare, sustainable development of society, and social transformation. Website: https://resou.osaka-u.ac.jp/en
About Shizuoka Institute of Science & Technology Shizuoka Institute of Science and Technology (SIST) was established on April 4, 1991 in Fukuroi city, Shizuoka prefecture in Japan. The university has an enrolment of approximately 1500 students in two faculties: the Faculty of Science and Technology and the Faculty of Informatics. Website: https://www.sist.ac.jp/en.html
Green and Efficient Protocols for the Synthesis of Sulfonyl Fluorides Using Potassium Fluoride as the Sole Fluorine Source
An image expressing the value of the study: Liquid representing water resources with an organic synthesis reaction in a flask, emphasizing environmental sustainability.
Credit
Reprinted with permission from ACS Sustainable Chem. Eng. 2024, 12, 32, 12135–12142. Copyright 2024 American Chemical Society.
Wild and human-cared spotted dolphins harbor different gastrointestinal microbiomes
KeAi Communications Co., Ltd.
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Hindgut microbial community members of wild (left) and human-cared (right) spotted dolphins at phylum (a), family (b), and genus (c) level.
A recent study published in Water Biology and Security highlighted the significant role of food source variations in shaping the gut microbiome of spotted dolphins, even when they inhabit similar environments.
“The gut microbiome serves crucial functions in food digestion and acts as a secondary immune system for the host. Despite increasing recognition of their importance, our understanding of marine mammal gut microbiomes remains limited due to challenges in sampling,” shares corresponding author Peijun Zhang, a professor at the Institute of Deep-sea Science and Engineering, Chinese Academy of Sciences.
Several factors such as phylogeny, environment and diet can influence the composition and structure of gut microbes. However, identifying the dominant driving force remains unclear. In a prior study by the team, significant differences in gut microbiomes among marine mammal species above the family level, even when exposed to similar diets and aquatic environments, were shown. Building on this, the present study investigates the impact of food variations—wild dolphins feeding on natural prey versus human-cared dolphins with a restricted fish diet—while controlling for environmental factors within the same geographical population of spotted dolphins.
“We used the V4 region of the 16S rRNA gene for gut microbe classification, and found notable differences in the gastrointestinal microbial community structure between wild and human-cared dolphins, both overall and at specific sites,” explains Zhang. “Interestingly, microbial diversity in their gastrointestinal tracts did not differ significantly, suggesting that disparities primarily stem from variations in microbiota composition.”
Indicator microbes were determined both in wild dolphin (five ASVs) and human-cared dolphin (three ASVs) groups. Furthermore, numerous potentially pathogenic bacteria were identified, underscoring the need for comprehensive future research on marine mammal gut microbiology.
“Our findings not only enhance the understanding of spotted dolphin gut microbiology, but also shed light on the similarities and differences in gastrointestinal microbial communities within the same marine mammal species, particularly when food source variations play a significant role in their ecology,” adds Zhang.
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Contact the author: Peijun Zhang, Institute of Deep-sea Science and Engineering, Chinese Academy of Sciences, pjzhang@idsse.ac.cn
The publisher KeAi was established by Elsevier and China Science Publishing & Media Ltd to unfold quality research globally. In 2013, our focus shifted to open access publishing. We now proudly publish more than 100 world-class, open access, English language journals, spanning all scientific disciplines. Many of these are titles we publish in partnership with prestigious societies and academic institutions, such as the National Natural Science Foundation of China (NSFC).
Conventionally, decision-making is portrayed as a rational process: individuals calculate potential risks and aim to maximise benefits. Yet, our brains do not always endorse rational action, particularly when an immediate response is required. Sometimes, individuals mistakenly choose objectively worse options because of how these options are perceived in a given context.
For instance, if an investor is presented with the opportunity to purchase a portfolio of shares with a 60% probability of yielding profit, they are likely to accept. However, if informed that there's a 40% chance of the portfolio incurring losses, they will probably decline the offer. Similarly, two circles of identical diameter may appear different in size depending on the shapes surrounding them. The context is what determines our evaluation of the available options.
The researchers aimed to investigate whether context consistently influences our decisions or whether the degree of human rationality varies depending on socioeconomic and cultural factors such as country of origin, status, religion, political system, and others.
An international team of authors, including researchers at the HSE Institute for Cognitive Neuroscience, conducted a study involving volunteers across eleven countries of remarkably different socio-economic and cultural makeup. More than 500 nationals of Russia, France, Argentina, India, China and some other countries performed a decision-making task consisting of two phases. During the first phase, participants were asked to choose between two options, each linked to either obtaining a reward or facing the risk of losing it. In each round, the options were reiterated, forming various combinations to establish contexts in which these options were perceived as either more or less rewarding. Thus, participants had the opportunity to maximise their rewards based on learning from previous rounds; however, all participants without exception, irrespective of nationality, made suboptimal decisions and incorrectly evaluated the options in certain contexts.
To assess the reproducibility of context-dependent results from the first phase of the experiment, the study authors instructed participants to perform a second task involving a choice between two options presented in the same contexts but with known variables. For instance, the participating volunteers were informed that they could either receive a substantial reward with a 50% probability or opt for a guaranteed but small reward. By consistently administering such lotteries, it becomes possible to identify the threshold at which individuals cease taking risks and choose the safe option. This threshold is individual and depends on a person's risk preference, which, as revealed, is a culture-specific characteristic. Thus, Russian nationals exhibited average risk preferences, Chinese and Japanese participants demonstrated the highest risk propensity, while residents of India and Chile emerged as the most risk-averse.
'Previously, it was believed that the primary factor influencing our decisions was our willingness to take risks. However, through our research, we discovered that this is not always the case. Our decision-making primarily depends on how we receive information: whether we experience the situation first-hand or are informed about it,’ explains co-author of the study Oksana Zinchenko, Senior Research Fellow at the Institute for Cognitive Neuroscience, HSE University. 'We have demonstrated that human consciousness exhibits a certain cognitive limitation, which is a shared characteristic not contingent on our beliefs, attitudes, or nationality.'
According to the authors, the findings from this study may find practical application in economics, psychology, marketing, and other fields.
Ultrasound technology could be key to enabling the biological breakdown of so-called 'forever chemicals', say researchers from the University of Surrey. 'Forever chemicals' are a class of extremely persistent synthetic chemicals that, even at low levels, may increase cancer risk and cause hormonal disruption and developmental abnormalities.
The research team has been awarded £947,000 from UK Research and Innovation (UKRI) to conduct a first-of-its-kind pilot that will use ultrasound technology in combination with biodegradation to break down per- and poly-fluoroalkyl substances (PFAS), which are still commonly found in products like pizza boxes, dental floss, and cookware.
SonoBio is a hybrid technology that combines high-frequency ultrasound with the activity of microorganisms to treat PFAS and turn them into relatively harmless carbon dioxide and fluoride.
Dr Madeleine Bussemaker, project lead from the University of Surrey, said:
"These chemicals are everywhere, found in nearly every person and countless everyday products. They're incredibly tough to break down, which is why they stick around in our bodies and the environment for decades.
"That is why we are delighted to have the support of UKRI in our effort to one day render obsolete the 'forever chemicals' tag attached to these persistent chemicals."
Current methods struggle to fully degrade PFAS, especially when using biological processes alone. While high-frequency ultrasound can completely break down PFAS, it is most effective in certain forms and for high concentrations. The engineering of biological processes, with microbial electrochemistry, can recover energy and make the process more sustainable. So, by combining high-frequency ultrasound with (electro)microbial action, SonoBio could be a powerful, sustainable solution for the complete breakdown and removal of PFAS from the environment.
Professor Claudio Avignone Rossa from the University of Surrey said:
"This is a strong project directed to address the important issue of the 'forever chemicals', ubiquitous substances affecting human, animal and environmental health and wellbeing. This is a multi- and inter-disciplinary collaboration that combines our strong basic and applied background in chemistry, microbiology, biochemistry and bioanalysis, allowing us to design strategies to degrade those pollutants and reduce their severe, long-lasting effects."
The pilot begins in 2025.
Note to editors
Dr Madeleine Bussemaker is available for interview; please contact mediarelations@surrey.ac.uk to arrange.
Levels of one ‘forever chemical’ are increasing in groundwater, study finds
American Chemical Society
Rain and water in ponds and lakes slowly seeps into the soil, moving through minute cracks to refill underground aquifers. Per- and polyfluoroalkyl substances (PFAS), often described as forever chemicals, can tag along into groundwater that’s later removed for drinking. Researchers in ACS’ Environmental Science & Technology Letters analyzed water from over 100 wells in Denmark for one particularly persistent PFAS: trifluoroacetate. They report steadily increasing levels of the forever chemical in recent decades.
Trifluoroacetate forms when fluorinated gases, such as refrigerants, and fluorinated pesticides partially degrade in the environment. Water passing through air and soil picks up trifluoroacetate, transporting the persistent and mobile compound into groundwater aquifers. However, potable groundwater sources haven’t been widely tested for trifluoroacetate because there isn’t a regulatory limit for it beyond the European Environment Agency’s (EEA) limit on total PFAS in drinking water of 0.5 parts per billion (ppb). So, Christian Albers and Jürgen Sültenfuss wanted to thoroughly assess groundwater in Denmark for this contaminant, looking for potential changes in the past 60 years.
The researchers collected samples from 113 groundwater monitoring wells around Denmark. They analyzed the samples for trifluoroacetate and, using an established tritium-helium isotope method, calculated how long ago the water entered the underground aquifers. Overall, their data showed a trend of increasing trifluoroacetate concentrations since the 1960s. Specifically, groundwater from:
Before 1960 had unmeasurable levels.
1960 to 1980 contained 0.06 ppb on average.
1980 to 2000 contained 0.24 ppb on average.
2000 to the 2020s contained 0.6 ppb on average, which exceeds the EEA’s total PFAS limit in drinking water.
The researchers attribute concentration differences within time periods to changing atmospheric deposition, plant uptake and local pesticide application. For example, pesticides that might be precursors for trifluoroacetate have been applied to agricultural areas within Denmark since the late 1960s. On the basis of those observations, the researchers say that trifluoroacetate concentrations could be used to categorize when groundwater entered aquifers, such as after 1985 or before 2000, rather than using more sophisticated and tedious dating methods that require isotopes. Additionally, Albers says some particularly high trifluoroacetate concentrations in groundwater less than 10 years old could suggest local sources have recently become more important, such as fluorinated pesticide applications.
The authors acknowledge funding from the Danish Environmental Protection Agency and the Danish Groundwater Monitoring Program.
The American Chemical Society (ACS) is a nonprofit organization chartered by the U.S. Congress. ACS’ mission is to advance the broader chemistry enterprise and its practitioners for the benefit of Earth and all its people. The Society is a global leader in promoting excellence in science education and providing access to chemistry-related information and research through its multiple research solutions, peer-reviewed journals, scientific conferences, eBooks and weekly news periodical Chemical & Engineering News. ACS journals are among the most cited, most trusted and most read within the scientific literature; however, ACS itself does not conduct chemical research. As a leader in scientific information solutions, its CAS division partners with global innovators to accelerate breakthroughs by curating, connecting and analyzing the world’s scientific knowledge. ACS’ main offices are in Washington, D.C., and Columbus, Ohio.
