Sunday, June 02, 2024

 AFRIKA

Cultural and linguistic networks of Central African hunter-gatherers have ancient origin


Evolutionary anthropology



UNIVERSITY OF ZURICH

BaYaka hunter-gatherers 

IMAGE: 

BAYAKA HUNTER-GATHERERS IN CONGO PLAYING MUSICAL INSTRUMENTS AND DANCING, WHICH HELPS THEM TO SPREAD CULTURAL TRAITS AND SPECIALIZED VOCABULARY BETWEEN DIFFERENT GROUPS.

view more 

CREDIT: RODOLPH SCHLAEPFER, UNIVERSITY OF ZURICH




Central Africa has been occupied by hunter-gatherer populations for hundreds of thousands of years, according to recent research based on genetic, archaeological and paleoenvironmental data. However, contemporary hunter-gatherers living in the Congo Basin speak languages that they have acquired from their agricultural neighbors, the Bantu, in recent times. This raises the question which elements of ancient cultural diversity in Central Africa stem from long-term evolution and regional cultural exchange predating agriculture, and which aspects are influenced by interactions with farming communities.

Culture, language and genes co-evolve

An international team of researchers led by Andrea Migliano from the Department of Evolutionary Anthropology at the University of Zurich (UZH) has discovered previously unknown links between culture, language and genes among different hunter-gatherer populations in Central Africa. “We found that the distribution of musical instruments among hunter-gatherers correlates very strongly with those genetic segments that are of ancient origin. So, these populations were exchanging musical instruments long before there were any agricultural populations in the region,” says Migliano.

The project was developed by Cecilia Padilla-Iglesias, PhD student and first author. The timing of genetic exchanges between populations can be inferred by tracing the origins of specific genome segments. To this end, the researchers assembled genetic data from eleven Central African hunter-gatherer groups and divided their DNA into segments based on the timing of the exchanges: those introduced through introgression or exchange with Bantu populations, those from recent exchanges between hunter-gatherer populations, and those of ancient origin.

Additionally, the team compiled an extensive dataset of musical instruments and foraging tools, along with their names from historical documents and ethnographies. They then compared how the structure of cultural diversity – the similarity between groups in musical instrument and subsistence tool repertoires, based on the presence or absence of similar musical instruments – correlated with genetic diversity at different points in time.

Extensive social networks spanning thousands of kilometers

“It was surprising that, although the different Central African hunter-gatherer groups speak languages from very different families, they share a disproportionate number of words related to music. Therefore, these words can be traced back to a time before the hunter-gatherer populations adopted the languages of their Bantu neighbors,” says anthropologist Andrea Migliano.

The results suggest that extensive interactions among hunter-gatherer groups in the Congo Basin, even those separated by thousands of kilometers, influenced not only their genetic makeup but also their linguistic and cultural traits. These extensive social networks helped maintain a cultural diversity that evolved thousands of years before the arrival of the agriculture in the region. Migliano adds: “The large-scale cultural networking of modern humans has deep roots in the past, at least in Central Africa.”

Biobased building materials less sustainable than concrete in South Africa, experts find


UNIVERSITY OF BRISTOL





Scientists at the University of Bristol have discovered that mycelium composites, biobased materials made from fungi and agricultural residues, can have a greater environmental impact than conventional fossil-fuel-based materials due to the high amount of electricity involved in their production.

In the findings, published today in Scientific Reports, the team show that this is further exacerbated in countries like South Africa where fossil fuel is the main source of electricity. This isn’t helped by mycelium composites’ shorter lifespan and the need for multiple replacements over the duration of long-term applications, thereby increasing their overall environmental impact.

Despite this discovery, they also concluded that the overall potential damage on the environment caused by this technology can be mitigated by incorporating alternative energy sources like firewood.

Lead author Stefania Akromah explained: “Mycelium composites are considered a sustainable alternative to traditional fossil fuel derived materials.

“However, the sustainability of these materials depends on various location-specific factors like resource availability, economic structures, cultural practices, and regulations.

“Our main focus was to determine if producing mycelium composites is sustainable in Africa and to identify which manufacturing processes have the most potential to damage the environment.”

Now team plans to evaluate the environmental impact of mycelium composite technology under various scenarios aimed at reducing the overall footprint, to conduct uncertainty analysis to verify the accuracy of the current results, and to compare the footprint of mycelium composites with other emerging green materials that are or could be used in Africa. Additionally, they are also looking to investigate the economic feasibility and social implications of the technology to provide a comprehensive evaluation of its sustainability.

Stefania continued: “Africa faces heightened vulnerability to climate change impacts owing to its limited financial resources, making it crucial to mitigate these impacts as much as possible.

“This study offers valuable insights that can be used to proactively address the potential impact of this technology on the environment and human health.

“It was interesting to find that even a technology that is generally perceived as sustainable can sometimes have a greater environmental impact than conventional fossil-fuel-based materials. This highlights the importance of life cycle assessment studies and the need to carefully consider all factors, including energy sources and lifespan, when evaluating new materials.”

“Stefania’s work just demonstrates that it’s important, when conducting LCAs, that geographical considerations, and cultural practices, are taken into account, to calculate sustainability. The right decisions can then be made to ensure that manufacturing has as low an impact as possible, while also contributing to local economies and African livelihoods.”, said Professor Steve Eichhorn, Director of the Centre for Doctoral Training in Composites, Science and Manufacturing (CoSEM) – from which this study was funded.

The research was conducted using a life cycle assessment (LCA) methodology following the ISO 14040 and 14044 standards for evaluating the environmental impact of materials or processes.

 

‘Potential Environmental Impact of Mycelium Composites on African Communities’ by Stefania Akromah, Neha Chandarana, Jemma L. Rowlandson and Stephen J. Eichhorn in Scientific Reports.

Rapid urbanization in Africa transforms local food systems and threatens biodiversity



INTERNATIONAL INSTITUTE FOR APPLIED SYSTEMS ANALYSIS





Since the early 2000s, Africa’s urban population has more than doubled, reaching over 600 million in 2020. If current growth continues, the urban population is expected to double again by 2050. In Africa, the annual rate of urban area expansion has surpassed the rate of urban population growth. Globally, future urban area expansion is expected to cause significant food production losses, reduce biodiversity, and increase land-use change emissions, jeopardizing human livelihoods and the natural environment.

Typically, recent research on the environmental impact of urban expansion treats it as the conversion of various land covers to urban land, focusing only on the direct effects. In a new study, published in Nature Sustainability, IIASA researchers and their colleagues demonstrate the complexity of expected urbanization and its multiple environmental impacts.

“As Africa is urbanizing the fastest, its food system is also transforming rapidly. This puts a lot of pressure on food security in what is already the most food-insecure region in the world,” notes Koen De Vos, study author and a guest research assistant in the Integrated Biospheres Futures Research Group of the IIASA Biodiversity and Natural Resources Program. “In our study, we consider both direct land-use changes and indirect effects, such as agricultural displacement and dietary shifts associated with urbanization, particularly concerning rice consumption.”


The researchers developed a method to integrate all of this information using the GLOBIOM model, creating an elaborate, complex, and multidimensional study that is unprecedented in its scope. Results show that, contrary to common belief, urban area expansion has a limited impact on food production losses, as agricultural land simply expands elsewhere. At the same time, the impact on natural lands is more significant, as it encompasses not only the direct effects of urban area expansion but also the subsequent displacement of agricultural land.

The most important environmental spillover effects arise from dietary changes, particularly rice consumption. As people eat more rice in African cities, more rice needs to be produced, resulting in greater reliance on imports and local production. Consequently, this leads to an increase in methane emissions, additional loss of natural lands, changes in water usage, and biodiversity loss.

“This result adds to the growing evidence that our diets will be one of the major drivers of planetary health,” explains Marta Kozicka, a study coauthor and IIASA researcher in the Integrated Biospheres Futures Research Group.

In their study, the research team highlights that policymakers should adopt holistic approaches in the decision-making process. Integrating indirect land-use effects and dietary shifts into land-use planning and policymaking is essential to tackle future sustainability challenges.
 

Reference
De Vos, K., Janssens, C., Jacobs, L., Campforts, B., Boere, E., Kozicka, M., Leclère, D., Havlík, P., Hemerijckx, L.M., Van Rompaey, A., Maertens, M., Govers, G. (2024) African food systems and biodiversity affected by urbanization via dietary shifts rather than area expansion. Nature Sustainability DOI: 10.1038/s41893-024-01362-2
 

About IIASA:

The International Institute for Applied Systems Analysis (IIASA) is an international scientific institute that conducts research into the critical issues of global environmental, economic, technological, and social change that we face in the twenty-first century. Our findings provide valuable options to policymakers to shape the future of our changing world. IIASA is independent and funded by prestigious research funding agencies in Africa, the Americas, Asia, and Europe.

 

Surprising properties of elastic turbulence discovered


Revealing elastic turbulence has more in common with classical Newtonian turbulence than expected


OKINAWA INSTITUTE OF SCIENCE AND TECHNOLOGY (OIST) GRADUATE UNIVERSITY

Liquid springs 

IMAGE: 

A POLYMER STRETCHING IN THE ELASTIC TURBULENT FLOW. THE POLYMERS IN THE LIQUID ACT LIKE MICRO SPRINGS, GETTING STRETCHED BY THE FLUID MOTION BEFORE GIVING ENERGY BACK TO THE FLUID WHEN CONTRACTING.

view more 

CREDIT: PROF. MARCO E. ROSTI/OIST




Blood, lymph fluid and other biological liquids can have surprising and sometimes troubling properties. Many of these biological solutions are non-Newtonian fluids, a type of liquid that is characterized by a non-linear relationship between stress and strain. Consequently, non-Newtonian fluids don’t necessarily behave as one would expect from a liquid. For example, some of these peculiar fluids deform when touched lightly but will act almost as a solid when a strong force is applied. 

And biological solutions are no exception when it comes to unique properties - one of them being elastic turbulence. A term that describes the chaotic fluid motion that results from adding polymers in small concentrations to watery liquids. This type of turbulence exists only in non-Newtonian fluids.

Its counterpart is classical turbulence, occurring in Newtonian fluids, for example in a river when the water at high speed flows past a bridge's pillar. While mathematical theories exist to describe and predict classical turbulence, elastic turbulence yet awaits such tools despite their importance for biological samples and industrial applications. “This phenomenon is important in microfluidics, for example when mixing small volumes of polymeric solutions which can be difficult. “They don’t mix well because of the very smooth flow,” explains Prof. Marco Edoardo Rosti, head of the Complex Fluids and Flows Unit.   

So far scientists have thought of elastic turbulence as completely different from classical turbulence, but the Lab’s most recent publication in the journal Nature Communications might change this view. Researchers from OIST worked collaboratively with scientists from TIFR in India and NORDITA in Sweden to reveal that elastic turbulence has more in common with classical Newtonian turbulence than expected.  

“Our results show that elastic turbulence has a universal power-law decay of energy and a so far unknown intermittent behavior. These findings allow us to look at the problem of elastic turbulence from a new angle,” explains Prof. Rosti. When describing a flow, scientists often use a velocity field, “we can look at the distribution of velocity fluctuations to make statistical predictions about flow,” says Dr. Rahul K. Singh, the publication’s first author.  

When studying classical Newtonian turbulence, researchers measure velocity over the entire flow and use the difference between two points to create a velocity difference field. “Here we measure velocity at three points and compute the second differences. First, a difference is computed by subtracting fluid velocities measured at two different points. We then subtract two such first differences yet again, which gives us the second difference,” explains Dr. Singh. 

This type of research came with an additional challenge - running these complex simulations requires the power of advanced supercomputers, “our simulations sometimes run for four months and output a huge amount of data,” says Prof. Rosti. This added level of detail led to a surprising finding - that the velocity field in elastic turbulence is intermittent. To illustrate what intermittency in flow looks like, Dr. Singh uses the electrocardiogram (ECG) as an example.

“In an ECG measurement the signal has small fluctuations interrupted by very sharp peaks. This sudden large burst is called intermittency,” says Dr. Singh. In classical fluids, such fluctuations between small and very large values had already been described but only for turbulence that occurs at high flow speeds. The researchers were surprised to now find the same pattern in elastic turbulence occurring at very small flow speeds, “at these low speeds we did not expect to find such strong fluctuations in the velocity signal,” emphasizes Dr. Singh.

Their findings are not only a big step towards a better understanding of the physics behind low velocity turbulence but also lay the foundations for developing a complete mathematical theory describing elastic turbulence. “With a perfect theory, we could make predictions about the flow and design devices that can alter mixing of liquids. This might be useful when working with biological solutions,” says Prof. Rosti.

 

Viper-mimicking snake from Asia is a unique branch in the reptile evolutionary tree




UNIVERSITY OF HELSINKI
mock viper 

IMAGE: 

MOCK VIPERS NOT ONLY LOOK LIKE TREE-DWELLING VIPERS BUT ALSO ACT LIKE THEM. INTRIGUINGLY, THEY HAVE A FAKE ‘FANG’ IN THE FRONT OF THEIR MOUTH, WHICH BEFOOLS A PREDATOR INTO THINKING THAT THEY POSSESS VENOM FANGS DURING AN OPEN-MOUTHED THREAT DISPLAY. HOWEVER, THERE IS ALSO AN ACTUAL FANG IN THE BACK OF THE JAW, WHICH CARRIES A WEAK VENOM EFFECTIVE ONLY ON THEIR LIZARD PREY. 

view more 

CREDIT: RUSHEN JAIHAN




The evolutionary history of the mock viper has been solved by an international research team led by scientists from the University of Helsinki. This mildly venomous viper look-alike represents a totally unique branch in the tree of life of snakes.

The evolutionary history of the mock viper, a mildly venomous, widely distributed Asian snake that mimics highly venomous vipers for self-defence, has been solved. The mock viper represents a completely unique branch in the tree of life of snakes, and hence, it has been allocated into its own new family named Psammodynastidae

This small, feisty snake has long presented a puzzle to evolutionary scientists due to its unresolved evolutionary history. To solve the puzzle, the researchers analysed DNA sequences of over 4500 genes and several dozen high-resolution micro-computed tomographic scans. 

“Mock vipers are part of the superfamily Elapoidea, a major group of snakes to which one-fifth of global serpent diversity belongs. Evolutionary diversification within this superfamily happened very rapidly approximately 50 million years ago. Rapid evolutionary diversifications are probably the most challenging evolutionary scenario for a geneticist or evolutionary biologist to resolve”, says the lead researcher Sunandan Das from the University of Helsinki.  

Mock vipers not only look like tree-dwelling vipers but also act like them. Intriguingly, they have a fake ‘fang’ in the front of their mouth, which befools a predator into thinking that they possess venom fangs during an open-mouthed threat display. However, there is also an actual fang in the back of the jaw, which carries a weak venom effective only on their lizard prey. The Elapoidea superfamily has multiple snake families with various types of venom and fangs, for example cobras and mambas.  

Another completely new family-level lineage, Micrelapidae, within Elapoidea was discovered in 2023 by Sunandan and Professor Juha Merilä. 

“The discovery of a new family of any vertebrate animals is surprisingly rare, an almost once-in-a-century phenomenon. This is a lifetime achievement for an evolutionary biologist. You rarely, if ever, see descriptions of whole new families of well-studied vertebrate animals anymore.’’ says Sunandan.  

The inference of the phylogenetic position of mock vipers, along with that of other elapoid snakes, will pave the way for a much better understanding of snake venom fang origin and evolution. Long, unique branches in the phylogeny, like that of mock vipers, contains a high degree of evolutionary distinctiveness, an index used by biologists for prioritising conservation. Hence, reinstating the mock viper or Psammodynastes into its own ‘dynasty’ also serves an important conservation goal. 

The missing puzzle piece: A striking new snake species from the Arabian Peninsula



PENSOFT PUBLISHERS
Rhynchocalamus hejazicus 

IMAGE: 

 RHYNCHOCALAMUS HEJAZICUS PICTURED IN LIFE.

view more 

CREDIT: FULVIO LICATA




Researchers have discovered a new distinctive and secretive snake species in the Hejaz region of Saudi Arabia.

Rhynchocalamus hejazicus is a small snake bearing a black collar and reddish colouration, distinguishing it from its closest relatives. A uniformly black ‘melanistic morphotype’ of the species has also been discovered.

The new species is widely distributed and fills much of the existing distribution gap between the Levant and the coastal regions of Yemen and Oman for the genus Rhynchocalamus.

An international team led by scientists from the Centro de Investigação em Biodiversidade e Recursos Genéticos (CIBIO), Portugal, and Charles University, Czech Republic, published their discovery in Zoosystematics and Evolution, an open-access journal published by Pensoft on behalf of Museum für Naturkunde Berlin.

Rhynchocalamus hejazicus inhabits sandy and stony soils with varying vegetation cover and can be found in habitats disturbed by humans, suggesting that the species should not be categorised as threatened according to IUCN criteria.

Little is known about the species’ natural history and behaviour, and further monitoring and conservation efforts are necessary to better understand its ecological dynamics and natural history. However, it appears that Rhynchocalamus hejazicus has mainly nocturnal activity as all individuals were encountered active at night.

"The discovery of a new species of snake widespread in the central-western regions of Saudi Arabia is surprising and gives rise to the hope that more undiscovered species might be present in the Kingdom" the authors say.

Most of the observations of the new species are the result of intense sampling efforts in a vast area around the ancient Arabic oasis city of AlUla, fostered by the Royal Commission for AlUla, Saudi Arabia, which is pushing forward scientific activities and explorations to promote conservation in the region. The intensifying of field studies in Saudi Arabia in the last years is leading to fruitful collaborations and such important findings as this study, to which many experts from multiple teams have contributed significantly.

The discovery of such a distinctive snake highlights the existing gap in the description of rare and secretive species, and the need to enhance sampling efforts and monitoring strategies to fully capture species diversity in unexplored areas.

Original source

Licata F, Pola L, Šmíd J, Ibrahim AA, Liz AV, Santos B, Patkó L, Abdulkareem A, Gonçalves DV, AlShammari AM, Busais S, Egan DM, Ramalho RMO, Smithson J, Brito JC (2024) The missing piece of the puzzle: A new and widespread species of the genus Rhynchocalamus Günther, 1864 (Squamata, Colubridae) from the Arabian Peninsula. Zoosystematics and Evolution 100(2): 691-704. https://doi.org/10.3897/zse.100.123441

Rhynchocalamus hejazicus pictured in life.

CREDIT

Fulvio Licata

Habitats of Rhynchocalamus hejazicus: Top: Shaaran NR, AlUla County, Medina Province, KSA; bottom left: Wadi Al-Azraq, Jabal Salma, Hail Province, KSA; bottom right: Harrat Khaybar, Hail Province, KSA.

CREDIT

Fulvio Licata and Adel A. Ibrahim

 

The effect of combinations of antibiotics and natural products on the antimicrobial resistance of Staphylococcus aureus and Pseudomonas aeruginosa



Natural Products on the Antimicrobial Resistance of Staphylococcus aureus and Pseudomonas aeruginosa



BENTHAM SCIENCE PUBLISHERS




The growing resistance of bacteria to existing antimicrobial drugs is a major problem, making it essential to find new ways to treat bacterial infections. Sometimes, antibiotics alone are not effective enough. To address this, combining different drugs is often used. One approach is to use a combination of antibiotics and plant extracts or phytochemicals. This combination therapy is particularly useful for patients with serious infections caused by drug-resistant pathogens.

Seven antibiotics (gentamicin, ceftazidime, ciprofloxacin, doxycycline, amoxicillin, ceftriaxone, and azithromycin) were obtained from a local pharmacy. Minimum inhibitory concentrations (MIC) were determined using the broth micro-dilution method. Various antimicrobial combinations were tested on 20 multidrug-resistant (MDR) clinical isolates (10 S. aureus and 10 P. aeruginosa). Additionally, the antibacterial activity of several volatile oils (limonene, rosemary, salvia, thyme, and black pepper), plant extracts (moringa seed, curcumin, and capsicum), and phytochemicals (thymol and chitosan) was evaluated against S. aureus and P. aeruginosa using the broth micro-dilution method.

Our results showed that combining ceftriaxone with ciprofloxacin or gentamicin had a strong synergistic effect against S. aureus. Additionally, combining amoxicillin with ceftazidime reduced the MIC by five to six times. For MDR P. aeruginosa isolates, the combination of azithromycin with doxycycline reduced the MIC of azithromycin by about five to six times. The combination of gentamicin with ceftriaxone was also significant. Among natural compounds, thymol, rosemary oil, curcumin, capsicum, and moringa seed extract showed the highest synergistic activity with the tested antibiotics against S. aureus and P. aeruginosa.

In conclusion, the development of new antibiotics is lacking, so improving existing ones is crucial. Our study indicates that combining antibiotics and antibiotics with natural plant compounds are very promising strategies for tackling complex bacterial resistance.

Read this article here; https://bit.ly/44XRY0z

For publishing scholarly article in Bentham journals, please visit: https://bentham.manuscriptpoint.com/?utm_source=eurekanews&utm_medium=website&utm_campaign=callforpapers

 

Combating carbon footprint: novel reactor system converts carbon dioxide into usable fuel


New reactor design converts CO2 emissions from small boilers into methane fuel, offering a promising approach to combating climate change

Peer-Reviewed Publication

SHIBAURA INSTITUTE OF TECHNOLOGY

Schematic of the distributor-type membrane reactor for CO2 capture 

IMAGE: 

RESEARCHERS FROM JAPAN AND POLAND HAVE DEVELOPED A REACTOR DESIGN THAT EFFICIENTLY CAPTURES CO2 EMISSIONS AND CONVERTS THEM INTO USABLE METHANE FUEL. THIS BREAKTHROUGH COULD SIGNIFICANTLY REDUCE GREENHOUSE GAS EMISSIONS, PAVING THE WAY FOR A CARBON-NEUTRAL FUTURE.

view more 

CREDIT: PROFESSOR MIKIHIRO NOMURA FROM SIT, JAPAN





Reducing carbon emissions from small-scale combustion systems, such as boilers and other industrial equipment, is a key step towards building a more sustainable, carbon-neutral future. Boilers are widely used across various industries for essential processes like heating, steam generation, and power production, making them significant contributors to greenhouse gas emissions.

Boilers are generally quite efficient. As a result, it is difficult to reduce CO2 emissions simply by improving the combustion efficiency. Therefore, researchers are exploring alternative approaches to mitigating the environmental impact of CO2 emissions from boilers. One promising strategy to this end is to capture the CO2 emitted from these systems and convert it into a useful product, such as methane.

To implement this strategy, a specific type of membrane reactor, called the distributor-type membrane reactor (DMR), is needed that can facilitate chemical reactions as well as separate gases. While DMRs are used in certain industries, their application for converting CO2 into methane, especially in small-scale systems like boilers, has remained relatively unexplored.

This research gap was addressed by a group of researchers from Japan and Poland, who were led by Professor Mikihiro Nomura from Shibaura Institute of Technology in Japan and Prof. Grzegorz Brus from AGH University of Science and Technology in Poland. Their findings were published online on 17 April 2024 in Volume 82 of the Journal of CO2 Utilization.

The team conducted a two-pronged approach to the problem through numerical simulations and experimental studies to optimize the reactor designs for efficient conversion of CO2 from small boilers into methane. In their simulation, the team modeled how gases flow and react under different conditions. In turn, this enabled them to minimize the temperature variations, ensuring that energy consumption is optimized while methane production remains dependable.

The team further found that, unlike traditional methods that channel gases into a single location, a distributed feed design could spread the gases out into the reactor instead of sending them in from one place. This, in turn, results in a better distribution of CO2 throughout the membrane, preventing any location from overheating. “This DMR design helped us reduce temperature increments by about 300 degrees compared to the traditional packed bed reactor,” explains Prof. Nomura.

Beyond the distributed feed design, the researchers also explored other factors influencing the reactors efficiency and discovered that one key variable was the CO2 concentration in the mixture. Changing the amount of CO2 in the mixture affected how well the reaction worked. “When the CO2 concentration was around 15%, similar to what comes out of the boilers, the reactor was much better at producing methane. In fact, it could produce about 1.5 times more methane compared to a regular reactor that only had pure CO2 to work with,” highlights Prof. Nomura.

Additionally, the team investigated the impact of reactor size, finding that increasing the size of the reactor facilitated the availability of hydrogen for the reaction. There was, however, a tradeoff to be considered as the benefit of higher hydrogen availability required careful temperature management to avoid overheating.

The study thus presents a promising solution to the problem of tackling a major source of greenhouse gas emissions. By utilizing a DMR, low-concentration CO2 emissions can be successfully converted into usable methane fuel. The benefits gained thereof are not limited to methanation alone but can also be applied to other reactions, making this method a versatile tool for efficient CO2 utilization even for households and small factories.

 

***

 

Reference

DOI: https://doi.org/10.1016/j.jcou.2024.102763

 

About Shibaura Institute of Technology (SIT), Japan

Shibaura Institute of Technology (SIT) is a private university with campuses in Tokyo and Saitama. Since the establishment of its predecessor, Tokyo Higher School of Industry and Commerce, in 1927, it has maintained “learning through practice” as its philosophy in the education of engineers. SIT was the only private science and engineering university selected for the Top Global University Project sponsored by the Ministry of Education, Culture, Sports, Science and Technology and had received support from the ministry for 10 years starting from the 2014 academic year. Its motto, “Nurturing engineers who learn from society and contribute to society,” reflects its mission of fostering scientists and engineers who can contribute to the sustainable growth of the world by exposing their over 9,500 students to culturally diverse environments, where they learn to cope, collaborate, and relate with fellow students from around the world.

Website: https://www.shibaura-it.ac.jp/en/

 

About Professor Mikihiro Nomura from SIT, Japan

Professor Mikihiro Nomura leads the Separation Systems Engineering Laboratory at Shibaura Institute of Technology, Japan. With a focus on ceramic membrane separation technology, Prof. Nomura aims to advance efficient separation processes for hydrogen, carbon dioxide, and wastewater, contributing to the realization of a carbon-neutral society. Through innovative approaches and a commitment to sustainability, he and his team strive to address pressing environmental challenges with cutting-edge engineering solutions.

 

Funding Information

This study was supported by the Polish National Agency for Academic Exchange under the Strategic Partnerships Programme, Project No. BPI/PST/2021/1/00023 (project title: Strategic cooperation with Japan in the field of Energy and Environmental Engineering) and partially by the “Excellence Initiative-Research University” program of the AGH University of Krakow, and by JSPS KAKENHI Grant Number JP23K04479.

 

Investigating the origin of circatidal rhythms in freshwater snails


Snails synchronize rhythms with tides, revealing adaptability to environmental changes



CHIBA UNIVERSITY

Examining activity and transcriptome rhythms of snails from both tidal and nontidal populations 

IMAGE: 

A HYPOTHESIS ON THE PROCESS OF ADAPTATION TO THE TIDAL ENVIRONMENT IN A FRESHWATER SNAIL. THE CIRCATIDAL RHYTHM IS NOT EXPRESSED IN NONTIDAL INDIVIDUALS UNDER NATURAL CONDITIONS. IN THE EARLY STAGE OF ADAPTATION TO THE TIDAL ENVIRONMENT, THE FLEXIBILITY OF BIOLOGICAL RHYTHMS ALLOWED SNAILS TO COPE WITH TIDAL CYCLES. SUBSEQUENTLY, SOME GENETIC CHANGES OCCURRED, AND SNAILS SHOWED A MORE PRONOUNCED CIRCATIDAL RHYTHM IN THE TIDAL ENVIRONMENT.

view more 

CREDIT: TAKUMI YOKOMIZO FROM THE CENTER FOR ECOLOGICAL RESEARCH, KYOTO UNIVERSITY




Organisms, including humans, follow a schedule that coordinates important bodily functions such as sleep-wake cycles, metabolism, hormone production, cognitive function, and feeding habits to environmental cycles. While most organisms possess circadian rhythms synchronized with the 24-hour day-night cycle, they have also developed other internal clocks to suit their local environments. Marine animals have evolved circatidal rhythms, aligning activities with the 12.4-hour tidal cycle, complementing circadian rhythms.

Researchers from Chiba University have discovered that snails living in downstream tidal areas have biological rhythms synchronized with the tidal cycles, unlike those in nontidal regions. This observation raises the question of whether circatidal rhythms develop due to differences in habitat or are caused by genetic variations between the populations. 

Building on their previous findings, Associate Professor Yuma Takahashi, along with Dr. Takumi Yokomizo from Chiba University (at the time of the study, and currently a post-doc researcher at the Center for Ecological Research, Kyoto University), revealed that freshwater snails living in tidal environments gradually adjust their biological rhythms to synchronize with the tidal cycles. The study published in the journal Heredity on March 27, 2024, offers insights into the adaptability and potential divergence of biological rhythms in response to tidal environments.

“This study revealed genetic and non-genetic changes in biological rhythms while adapting to tidal environments in a freshwater snail. This result could lead to an understanding of the role of biological clocks in the adaptation to rhythmic environment, which is one of the most important issues in chronobiology,” says Dr. Takahashi. The researchers collected freshwater snails (Semisulcospira reiniana) from tidal and nontidal areas along the Kiso River in Japan, 20 km apart. Snails were divided into two groups: one exposed to a regular 24-hour light-dark cycle, while the other experienced a simulated 12-hour tidal cycle, alternating between submersion during high tide and exposure to air during low tide.

Following a 4-week entrainment period, the researchers analyzed the behavior and genetic expression patterns of the snails in darkness at a constant temperature of 23°C. Among the snails from non-tidal areas, there were no significant differences in the intensity of the circadian and circatidal rhythms between the two groups. However, snails from tidal areas that were exposed to the simulated tidal cycle showed stronger circatidal rhythms compared to the control group. Interestingly, both the tidal and non-tidal populations exposed to the simulated tide showed an increase in the number of circatidal oscillating genes and a decrease in the circadian oscillating genes (genes that fluctuate in activity in tune with the tidal and diurnal cycle, respectively). Snails that had already adapted to the tidal cycles in the rivers in their early life had a greater number of circatidal oscillating genes compared to the nontidal population. 

These results imply that the expression rhythms of genes controlled by the biological clock are sensitive to environmental changes, and can be influenced by genetic changes that result from environmental adaptation. “Our study focused on the flexibility of biological clocks and found their potential to change biological rhythms according to dominant environmental cycles,” says Dr. Takahashi. 

Disruptions to biological rhythms can negatively impact various physiological processes. The findings of this study may enhance our understanding of how organisms adapt to changing environmental conditions and prove valuable in the treatment of chronobiological diseases in the future.


About Associate Professor Yuma Takahashi from Chiba University
Dr. Yuma Takahashi is an Associate Professor at the Graduate School of Science, Chiba University. He has a Ph.D. from the University of Tsukuba and has held research fellowships at the University of Tsukuba and Tohoku University. His research focuses on integrating hierarchies and time scales and includes topics like gene expression variation, developmental fluctuations, phenotypic plasticity, and rapid adaptation. Dr. Takahashi has published numerous articles on damselflies, Drosophila, and freshwater snails, exploring the genetic and environmental factors shaping their evolutionary trajectories. He has won numerous awards, including the Miyaji Award from the Ecological Society of Japan and the Population Ecology Young Scientist Award.