Researchers discover one of the world's darkest rivers

by Peter Rüegg, ETH Zurich

The water of the Ruki River in the Congo Basin is as dark as tea due to a high concentration

 of dissolved organic substances. Credit: Matti Barthel / ETH Zurich

When the researchers came upon the Ruki River, they were quite taken aback. The water in this river, a tributary of the mighty Congo River, is so dark that you literally can't see your hand in front of your face. "We were struck by the color of the river," says ETH Zurich researcher Travis Drake, who has just published a study in the journal Limnology and Oceanography on the Ruki together with colleagues from the Sustainable Agroecosystems Group, led by Johan Six, as well as from other universities.

Comparisons with other major tropical rivers show that the Ruki may even be the blackest large blackwater river on Earth—it's certainly a lot darker than the famous Rio Negro in the Amazon.

The reason the water is black is that it contains large amounts of dissolved organic material and hardly any sediment because of the river's low gradient. These carbon-rich substances are mostly washed into the river by the rain, which falls on dead jungle vegetation and leaches out organic compounds from the decomposing plant material. What's more, the river floods the forest in the rainy season. It can take weeks for the often waist-deep water to slowly retreat, during which time it leaches organic substances. "The Ruki is essentially jungle tea," Drake says.

Peaty bogs and virgin rainforest

It's not just the dark water that's special. The Ruki, which is one kilometer wide and empties into the Congo, is unique in its entirety. Its drainage basin, which is four times the size of Switzerland, is still covered by untouched primary lowland rainforest. Along the river, there are big peat bogs containing gigantic amounts of undecomposed dead plant material, which makes them significant carbon sinks.

Despite its uniqueness and size, the Ruki has never before been scientifically studied. While the river's different seasonal water levels have been documented since the 1930s, no data on its chemical composition has been available up to now. Nobody had yet determined how much dissolved organic carbon (DOC) is in the water and, above all, where it comes from.

So in 2019, Drake and his colleagues set up a measuring station near the city of Mbandaka, a short distance upstream from where the Ruki and the Congo converge, and measured the water discharge every two weeks and daily water level for a year to determine the annual streamflow.

"Our measurement methods on site were quite basic," Drake says. He relates that Mbandaka has no permanent power supply, only a few diesel generators and hardly any infrastructure—not even a power drill to install the flood level marker. "So we often had to improvise," he says with a smile.

Credit: ETH Zurich

What water samples reveal about the Ruki

Water samples were collected with each discharge measurement and sent to the lab at ETH Zurich for analysis. There, the researchers determined the samples' DOC content as well as the age of the organic material based on the radioactive carbon in the DOC. Among other things, they wanted to find out whether the peat along the river releases carbon (and at some point decomposes into CO2).

The researchers decided to examine the water because it contains carbon signatures from the entire drainage area, which in turn convey information about origin and land use. The advantage of water analysis: "We need to collect samples from only one location to gain information about a huge area—like a doctor who takes a blood sample to determine the condition of a patient's health," says the study's co-author, Matti Barthel.

Unexplored hydrology

The analyses confirmed the visual impression: "The Ruki is one of the most DOC-rich river systems in the world," Barthel says. Its water contains four times as much organic carbon compounds as the Congo's and 1.5 times as much as the Rio Negro's in the Amazon.

And although the Ruki's drainage basin makes up only a twentieth of the entire Congo Basin, a fifth of the dissolved organic carbon in the Congo comes from this one tributary.

DOC usually comes in the form of organic acids that increase the acidity of the river water. This stimulates the release of carbon dioxide (CO2) as the acids dissolve carbonates present in the water. "CO2 emissions are relatively high across the Ruki's entire drainage basin but not dissimilar to other tropical rivers," Drake explains. This is because the Ruki is a sluggish and placid river, which makes it more difficult for the CO2 in the water to escape into the air. "In a turbulent river, we'd see higher emissions," he says.

According to Drake, the carbon isotope analysis also shows that most of the carbon comes from the forest vegetation, not the peat. Only for a short period of time at the end of the rainy season between March and April, after peak flow, do the researchers find evidence of the peat bogs releasing carbon into the water. It's not clear how and why this happens at that particular time. "Overall, however, we see very little peat in the river," Drake says. "And that's good news, because it also means that the peat bogs are stable."

At present, he says, there is no danger that the organic material contained in the peat bogs will be released, since they are under water almost all year round and thus not exposed to oxygen. However, companies have taken an interest in the Ruki Basin's natural resources. Changes in land use such as deforestation could alter the river regime. This might lead to peat bogs falling dry and being decomposed by bacteria, which would release a huge amount of CO2. "The peat bogs in the Congo Basin store some 29 billion tons of carbon," Barthel says. "It would be better for the climate if they stayed wet."

A long-standing research project

Johan Six and his group have been studying the Congo Basin's carbon cycle since 2008. The Congo is one of the most important tropical river systems on Earth. It carries huge amounts of carbon out into the sea. The vegetation in its drainage basin affects its carbon cycle, as does land use. It was during a scouting trip to study the carbon cycle—the biogeochemistry—of the Congo Basin that the researchers came across the Ruki River.

After their side trip to the Ruki, the scientists are now studying other tributaries of the Congo, such as the Kasaï and the Fimi River—and completing the carbon puzzle piece by piece.

More information: Travis W. Drake et al, Hydrology drives export and composition of carbon in a pristine tropical river, Limnology and Oceanography (2023). DOI: 10.1002/lno.12436

Journal information: Limnology and Oceanography

Provided by ETH Zurich 

Biogeochemical insights from a major Amazonian river

 

International ocean satellite monitors how El Niño is shaping up

by JPL/NASA

Credit: Unsplash/CC0 Public Domain

Sentinel-6 Michael Freilich is the latest satellite contributing to a 30-year sea level record that researchers are using to compare this year's El Niño with those of the past.

Not all El Niño events are created equal. Their impacts vary widely, and satellites like the U.S.-European Sentinel-6 Michael Freilich help anticipate those impacts on a global scale by tracking changes in sea surface height in the Pacific Ocean.

Water expands as it warms, so sea levels tend to be higher in places with warmer water. El Niños are characterized by higher-than-normal sea levels and warmer-than-average ocean temperatures along the equatorial Pacific. These conditions can then propagate poleward along the western coasts of the Americas. El Niños can bring wetter conditions to the U.S. Southwest and drought to regions in the western Pacific, including Indonesia. This year's El Niño is still developing, but researchers are looking to the recent past for clues as to how it is shaping up.

There have been two extreme El Niño events in the past 30 years: the first from 1997 to 1998 and the second from 2015 to 2016. Both caused shifts in global air and ocean temperatures, atmospheric wind and rainfall patterns, and sea level. The maps above show sea levels in the Pacific Ocean during early October of 1997, 2015, and 2023, with higher-than-average ocean heights in red and white, and lower-than-average heights in blue and purple. Sentinel-6 Michael Freilich captured the 2023 data, the TOPEX/Poseidon satellite collected data for the 1997 image, and Jason-2 gathered data for the 2015 map.

The maps above show sea levels in the Pacific Ocean during early October of 1997, 2015, and 2023, in the run up to El Niño events. Higher-than-average ocean heights appear red and white, and lower-than-average heights are in blue and purple. Credit: NASA/JPL-Caltech

By October 1997 and 2015, large areas of the central and eastern Pacific had sea levels more than 7 inches (18 centimeters) higher than normal. This year, sea levels are about 2 or 3 inches (5 to 8 centimeters) higher than average and over a smaller area compared to the 1997 and 2015 events. Both of the past El Niños reached peak strength in late November or early December, so this year's event may still intensify.

"Every El Niño is a little bit different," said Josh Willis, Sentinel-6 Michael Freilich project scientist at NASA's Jet Propulsion Laboratory in Southern California. "This one seems modest compared to the big events, but it could still give us a wet winter here in the Southwest U.S. if conditions are right."

Provided by JPL/NASA 

International sea level satellite spots early signs of El Niño

 

Drought conditions expose rivers to hotter water temperatures

by University of Birmingham

Credit: Pixabay/CC0 Public Domain

As climate change warms the planet and droughts are anticipated to become more frequent and extreme, a new study reveals how reduced water flows and rising atmospheric temperatures are set to heat our rivers—creating major challenges for aquatic life, ecosystems, and society.

Water temperature is an important control for all the physical, chemical, and biological processes in rivers. It is particularly important for organisms that cannot regulate their own body temperature, such as fish. River temperature is important for human health and industrial, domestic, and recreational uses by people.

Scientists have identified three primary mechanisms that drive river water temperature increases during droughts: atmospheric energy inputs; physical habitat influences (shading and river channel shapes controlling flow); and the contributions of different water sources—groundwater tends to cool rivers in summer.

A review published in Hydrological Processes, led by University of Birmingham in collaboration with the University of Nottingham and the Scottish Government's Marine Directorate, highlights that intense shortwave radiation during hot and dry periods is likely to be the biggest factor of high river water temperatures.

This combined with declining water levels and volumes, and slower flow velocities during droughts will warm up waters more quickly. However, the authors emphasize that cooling effects from groundwater inputs, channel shading and evaporation can offset high temperatures in certain circumstances.

Co-author David Hannah, Professor of Hydrology and UNESCO Chair in Water Sciences at the University of Birmingham, commented, "Rising river water temperatures can have significant and often detrimental implications for aquatic life, impacting both individual species and entire ecosystems.

"Drought conditions often coincide with high atmospheric temperatures and such trends will become more intense and frequent with climate change—with major implications for river water temperatures due to the combination of intense solar radiation and lower (and slower) water flows.

"However, certain management interventions such as riverside planting, and river restoration initiatives—including recreating natural channel forms and reconnecting groundwaters—could help to offset high thermal extremes during droughts if interventions are well targeted."

The researchers note that more holistic, catchment-wide approaches to river restoration are required that consider how high river water temperature extremes can be offset while delivering other environmental and ecological benefits. The study authors call for new scientific approaches examining how the processes operating across the three mechanisms they have identified interact—helping to better inform models capable of estimating where and when high river thermal extremes are likely to occur during droughts.

Lead-author Dr. James White, from the University of Birmingham, commented, "Our work highlights critical future research questions that will help us to better model river water temperature dynamics during droughts—helping river managers to work out how thermal extremes could be better managed through mitigation and adaptation strategies."

More information: J. C. White et al, Drought impacts on river water temperature: A process‐based understanding from temperate climates, Hydrological Processes (2023). DOI: 10.1002/hyp.14958

Provided by University of Birmingham Rising river temperatures hold important clues about climate and other human impacts

 

Invasive plant species threaten 66% of India's natural areas

by British Ecological Society

Several water bodies that are important habitat and resource for many endangered species

 like the Asian elephant are invaded by the water hyacinth (Pontederia crassipes), a plant

 native to tropical America. Credit: Jayanta Guha.

Invasive plant species management in India has historically been constrained by a lack of information regarding the spread of invasions. So to combat this, scientists from the Wildlife Institute of India were forced to come up with a unique solution.

They decided to integrate an invasive plant assessment with India's national assessment of tiger populations, taking place every four years and monitoring 358,000 km2 of natural areas. A mobile app was used to sample 158,000 plots of land, ultimately revealing that 66% of wilderness areas had been invaded by invasive plant species, including Lantana camara, Prosopis juliflora, and Chromolaena odorata.

The study is published in the Journal of Applied Ecology.

Professor Qamar Qureshi from the Wildlife Institute of India explains, "The tiger project was intended to monitor the changing status of the animals and their habitat. Plant invasions end up altering these habitats and revealing intricate ecological changes. In the end, it just made sense to monitor both plants and tigers simultaneously."

India's legacy of human modifications, historical propagation of invasive plants, shifting soil moisture regime, and altered cycles of natural disturbances are among the leading drivers that likely facilitate invasions.

India has one of the world's highest population densities. Therefore, demand for food, energy and infrastructure are poised to intensify, potentially escalating the already rampant invasions even more.

A tiger exploring thickets of Lantana camara, a high-concern invasive plant in India. 

Credit: Karthik Rugvedi

Using the data collected in the national-scale invasive plant assessment, the researchers developed a model to identify priority restoration sites, namely those where invasions are in their initial stages, with preference for those within already protected areas. Protecting these sites requires less investment and intervention, while still delivering promising biodiversity returns.

Professor Y. V. Jhala, also from the Wildlife Institute of India, says, "Personal judgments are often used to select and manage invasive species and areas. Without understanding the ecological or landscape-scale context of invasions, such investments rarely achieve the objective of ecological restoration. Using our strategic prioritization plan can ensure that limited resources are invested in a manner that maximizes long-term biodiversity gains."

The study's inclusion in the recent tiger report published by the government of India underscores the highest political recognition of the threats brought by biological invasions. While the study provides a critical stepping stone towards evidence-based restoration, several challenges persist.

"Managing invasive species demands more than mere removal—it necessitates context-sensitive restoration, stakeholder participation, and adaptive holistic policies that can enable positive changes," says Dr. Ninad Avinash Mungi from Aarhus University, who partnered with the Wildlife Institute of India for the study.

India has been long awaiting a dedicated policy framework on managing invasions and restoring ecosystems, but for now, the new study provides timely guidance.

As the United Nations' decade for Ecosystem Restoration unfolds, India's proactive stance in monitoring invasive species by integrating it with flagship programs sets an example of responsible and forward-looking conservation efforts. Amidst densely populated and invaded regions, this research paves a path towards effective restoration, rekindling ecological optimism.

More information: Ninad Avinash Mungi et al, Distribution, drivers and restoration priorities of plant invasions in India, Journal of Applied Ecology (2023). DOI: 10.1111/1365-2664.14506

Journal information: Journal of Applied Ecology 

Provided by British Ecological Society A 'natural weapon': Study shows large herbivores keep invasive plants at bay

 

Refugee legal reforms will have a disproportionate impact on sexually diverse asylum claimants, UK study warns

by University of Exeter

Credit: CC0 Public Domain

Refugee legal reforms will have a disproportionate impact on sexually diverse claimants, academics have warned.

Researchers have said the Nationality and Borders Act is a missed opportunity to resolve other issues about how to make clear assessments about people's sexual backgrounds and this means that potentially inaccurate decisions will continue to be made.

The commentary, by Alex Powell, from Oxford Brookes University, and Raawiyah Rifath, from the University of Exeter, is published in the journal Legal Studies.

It says the UK government should urgently provide details of how processes of individual assessment, such as those required to be undertaken before any prospective claimant might be transferred to Rwanda under the memorandum of understanding between the UK and Rwanda, will be undertaken.

Dr. Powell said, "Given the lack of any framework of secondary legislation, it is not clear how the question of whether or not a country is safe for a given claimant will be addressed."

The Nationality and Borders Act has created new barriers to asylum claims and this may substantially limit the ability of many claimants to rely on refugee protection in the UK.

Rifath said "The well-established impact of trauma on memory, the limitations on the ability of many claimants to procure objective evidence from their country of origin, and barriers faced while attempting to gather evidence in the UK makes it very hard for people to navigate asylum claims."

"The nature of sexual diversity claims means that claimants often have very limited access to 'objective' tangible evidence expected by the Home Office, this results in their claim heavily relying on their oral testimony and narrative during their substantive asylum interview."

Dr. Powell said, "In recent years there has been a switch from 'discretion' to disbelief, acts as the main barrier for claimants attempting to seek asylum on the basis of their sexual diversity. In the context of the changes to the standard of proof, and the increased focus on the journeys those seeking safety have taken to get to the UK, there are many areas where this disbelief may become exacerbated."

Rifath said, "The Home Office asylum policy instructions guide decision-makers to seek stereotypical and linear narratives from sexually diverse asylum seekers. These narratives are problematic given the diverse cultures and experiences of claimants. These concerns with Home Office decision-making are an ongoing issue and the legal changes are unlikely to result in improved decision-making."

"We are concerned the changes will contribute to the wider masculine way in which Refugee Status is understood, able to comprehend the claims of those who are engaged in public actions which are self-evidently political, but largely unable to comprehend those whose persecution or nexus grounds occur in private or outside of public view."

As predicted by the commentary, the Government has now abandoned aspects of the Nationality and Borders Act 2022, including the two-tiered approach to protection claims while expediting the Illegal Migration Bill.

More information: Alex Powell et al, Sexual diversity and the Nationality and Borders Act 2022, Legal Studies (2023). DOI: 10.1017/lst.2023.21

Provided by University of Exeter 

Legal indifference to refugees

Researchers: There is a need for more accurate accounting of nitrous oxide from agricultural crop residues

by Aarhus University

Credit: CC0 Public Domain

There is a need for changing the way of accounting greenhouse gases from agriculture. The current inventory of nitrous oxide from plant residues relies solely on the amount of nitrogen in the residues, while crucial factors such as the degradability of plant residues are not included. According to the researchers, this leads to misleading inventories, which also misrepresents possible mitigation measures.

Crop residues are an important resource in agriculture. They contribute carbon to the soil, increase soil fertility and play an important role in the agricultural ecosystem, but they also play a role in relation to energy supply and recycling of nutrients. Crop residues can be very diverse and have widely different composition and properties. They can be cover crops, grass, grass-clover, vegetables, straw, etc. They may consist of residues from roots or from aboveground crop parts.

"All in all, there is large diversity in the quality of the crop residues that are added to the soil as part of the general cultivation practice," says Professor and Department head Jørgen E. Olesen from the Department of Agroecology at Aarhus University.

He has headed a new scientific study highlighting the differences in crop residues and how they affect nitrous oxide emissions from agricultural fields in different ways.

"Crop residues are essential for maintaining soil fertility, and in addition, they play a major role in maintaining or increasing the carbon content in the soil. Unfortunately, they also contribute to the emission of nitrous oxide," says Jørgen E. Olesen.

Clash with current emission inventories

IPCC—The Intergovernmental Panel on Climate Change—prepares guidelines for how to make national inventories of greenhouse gas emissions, including nitrous oxide emissions, when crop residues are returned to the fields.

The IPCC is an international organization established in 1988 by the World Meteorology Organization (WMO) and the United Nations Environment Program (UNEP). The purpose of the IPCC is to assess scientific knowledge about climate change, its causes, impacts and possible adaptation and mitigation strategies.

The IPCC plays a key role in gathering and assessing the latest scientific literature on climate change and preparing reports that inform politicians and decision-makers worldwide. IPCC reports are used as the basis for international climate negotiations and policy development.

The organization is known for publishing comprehensive assessments of climate science, including reports on greenhouse gases, sea level rises, temperature changes and other aspects of climate change.

The work of the IPCC therefore plays a crucial role in understanding and managing climate change at global level.

The IPCC's inventory method includes nitrous oxide from crop residues such as annual cereal and seed crops, root crops, vegetables, fodder crops and grassland renewal.

"Non-harvestable crops such as cover crops are not taken into account," explains Jørgen E. Olesen, who adds that the biochemical properties of crop residues and their degradability of carbon and nitrogen are also not included in the accounting of emissions.

"The current method only considers the nitrogen content in the plant residues, but our studies show that the degradability of carbon in plant residues actually is more important. There is therefore a need for an improved accounting method so that inventories are accurate and mitigation measures can be effective," says Jørgen E. Olesen.

Difference between ripe and unripe crop residues

According to the researchers, there may be large differences in how much nitrous oxide the crop residues emit.

"Many different factors come into play when you look at the extent of nitrous oxide emissions from crop residues. A very important factor is the concentration of degradable carbon and nitrogen. When the concentration is high, the potential for producing nitrous oxide also increases," says Jørgen E. Olesen.

You often see a high concentration of both easily degradable carbon and nitrogen in immature crop residues, such as cover crops, grass, legumes and vegetables, while mature crop residues such as straw do not have such high concentrations.

"A distinction between mature and immature crop residues could help to ensure a more accurate estimation of the short-term effects of crop residues on nitrous oxide emissions. For the more long-term effects, i.e., years and decades, we should account for the residual effects on soil quality and nitrogen content. They are affected by local climatic conditions, just as the soil conditions are of importance," says Jørgen E. Olesen.

Targeted mitigation of nitrous oxide emissions

"There is a critical need for new and targeted strategies when it comes to reducing nitrous oxide from crop residues. Globally, approx. 9% of agricultural emissions of nitrous oxide stem from the input of crop residues to the fields. However, such strategies require that the accounting of emissions from crop residues becomes more accurate," says Jørgen E. Olesen.

A distinction between mature and immature crop residues may be an approach that, according to the researchers, could improve the accuracy of the inventories. It will also improve the possibilities of targeting and finding appropriate mitigation strategies.

"Reviewing how we calculate emissions from specific crop residues and determine the right time and place to use them requires more research. There are also important questions in the research into emissions from crop residues that we still need to answer," says Jørgen E. Olesen, who points out that there is a need for more research into:

• Develop and validate nitrous oxide emission factors for mature and immature crop residues
• Assess emissions from belowground residues from harvested crops
• Improve data on managing different types of crop residues, especially immature residues
• Evaluate long-term effects of crop residues inputs on nitrous oxide emissions

The research is published in the journal Global Change Biology.

More information: Jørgen E. Olesen et al, Challenges of accounting nitrous oxide emissions from agricultural crop residues, Global Change Biology (2023). DOI: 10.1111/gcb.16962

Journal information: Global Change Biology 

Provided by Aarhus University Researchers examine emission factors for nitrous oxide from synthetic and organic fertilizers

 

Glacial rock flour creates new opportunities for Greenlandic agriculture

by Camilla Brodam Galacho, Aarhus University

Here, you can see how the glacier flour is distributed across the test plots. Subsequently, 

the glacier flour has been plowed into the soil, and grass has been sown across the entire

 field. Credit: Peter L. Weber

New research indicates that the use of glacial rock flour could enhance water absorption in cultivated fields in Greenland. This could be groundbreaking for Greenlandic agriculture as the use of glacial rock flour may reduce the risk of water erosion and improve plant growth conditions.

The study is published in the Soil Science Society of America Journal.

Even though it may not be the first place that comes to mind for agriculture, modern farming has been present in Greenland for approximately 100 years. The focus has been on sheep and grass for livestock feed, but in recent years, crops like potatoes and beets have been commercially cultivated as well.

However, it's not always easy to farm in Greenland, and there can be various reasons for this. One of them is that the soil's ability to absorb water is not very good.

"A recent study analyzed soil from 23 grazed and cultivated areas in South Greenland, revealing that 99% of the soil was water-repellent. In fact, 98% of the soil exhibited an extreme degree of water repellency," says postdoc Peter L. Weber from the Department of Agroecology at Aarhus University.

When the soil can't absorb water

When soil can't absorb water, as is the case in Greenland, it is referred to as hydrophobicity. This is a phenomenon where the soil struggles to take in water due to a fatty-like layer on soil particles. This layer can originate from decomposed plant tissues, root exudates from plants, or the composition of fungi and microorganisms in the soil.

When the soil cannot absorb water properly, it can limit agricultural production by increasing surface runoff, and consequently, erosion. It also reduces the infiltration of water from rain or irrigation, as well as the availability of nutrients for the plants.

"Considering the high prevalence of soil that cannot effectively absorb water in Greenland, we are naturally looking for methods to improve the soil's water absorption capacity. Various methods have been tested in different parts of the world, such as changing the way we cultivate the land, using soil conditioners, and irrigation. Another approach is to increase the soil's clay content, which is widely used in other parts of the world," says Professor Lis Wollesen de Jonge from the Department of Agroecology at Aarhus University.

However, using clay requires local availability, which is not abundant in Greenlandic soil. On the other hand, there is an abundance of glacial rock flour.

Glacial rock flour enhances the soil's water absorption

The special flour forms when rocks are crushed and broken down as glaciers move over the terrain. Greenland has a significant amount of glacial rock flour, and according to researchers, it is rich in minerals and has shown potential benefits for agriculture.

"It has a remarkably high content of clay particles. Therefore, we have examined whether it would be beneficial to use local glacial rock flour to improve water absorption in Greenlandic agricultural soil," says Weber.

No prior studies exist, so the researchers conducted two field experiments in South Greenland to investigate how the addition of glacial rock flour in different quantities affects the soil's water absorption capability.

"The results of our experiments show that using glacial rock flour can be beneficial for improving the water absorption capacity of Greenlandic agricultural soil. This is a positive outcome for Greenlandic agriculture. We will now continue our work, including studying the long-term effects of using glacial rock flour," explains Weber.

This study is part of a larger research effort to understand and improve farming conditions in Greenland. Climate change significantly impacts the region's agricultural sector, and researchers are exploring various methods to ensure sustainable and productive farming practices, including the use of glacial rock flour for soil improvement.

More information: Peter L. Weber et al, Glacial rock flour reduces the hydrophobicity of Greenlandic cultivated soils, Soil Science Society of America Journal (2022). DOI: 10.1002/saj2.20505

Journal information: Soil Science Society of America Journal 

Provided by Aarhus University Greenlandic glacial rock flour can help fight climate change, show two new studies

 

Emotional expression is about fostering connections, not asserting individuality

by Jared Wadley, University of Michigan

Credit: Unsplash/CC0 Public Domain

When someone expresses their emotions, they show their passion and authentic individuality. As self-evident as it might seem, this may reflect a cultural bias, says a University of Michigan researcher.

A new study by University of Michigan psychology professor Shinobu Kitayama and colleagues focuses on the emotional expression of Latin Americans, U.S. residents, and Japanese. Specifically, the researchers tested the participants' independence and feelings of closeness to others, also described as interdependence.

By knowing these differences, people can have a better understanding and acceptance of other cultures, said Kitayama, the Robert B. Zajonc Collegiate Professor of Psychology and director of the Culture & Cognition Program at the Department of Psychology.

"Much of the research in psychology is based on the notion that emotional expression is a display of one's passion," he said. "But this whole notion may have been deeply ingrained into what one may call a Western perspective."

Latin Americans expressing positive emotions seem to be more about fostering connections and strengthening social bonds rather than asserting individuality, the research showed.

In two separate analyses, Kitayama and colleagues tested whether Latin Americans possess an open expression of positive emotions related to social engagement.

In Study 1, with nearly 600 participants who were asked about their emotional responses to different situations, researchers compared Latin Americans from Chile and Mexico with U.S. residents, a group known to be highly independent.

Latin Americans expressed positive socially engaging emotions, particularly in response to negative events affecting others. U.S. residents favored positive socially disengaging emotions, such as pride, especially in response to personally favorable circumstances.

In Study 2, which involved about 550 participants who completed the same questionnaire found in the first study, researchers looked at the responses by Latin Americans from Colombia, comparing them with U.S. residents and Japanese citizens.

Japanese participants expressed positive emotions less than others, but displayed a higher tendency to express negative socially engaging emotions, such as guilt and shame, compared to both groups.

Latin Americans were expressive of positive socially engaging emotions, whereas Japanese were less expressive overall. Moreover, when Japanese expressed emotions, they emphasized negative socially engaging emotions, the study showed.

More information: Paper:Emotionally expressive interdependence in Latin America: Triangulating through a comparison of three cultural zones. Preprint: scholars.duke.edu/publication/1490221

Provided by University of Michigan Are people with more peace of mind better at regulating emotions?

 

New insights into the genetics of the common octopus: Genome at the chromosome level decoded

by University of Vienna

Octopus vulgaris. Credit: Antonio, Valerio Cirillo (BEOM SZN), 2023

Octopuses are fascinating animals—and serve as important model organisms in neuroscience, cognition research and developmental biology.

To gain a deeper understanding of their biology and evolutionary history, validated data on the composition of their genome is needed, which has been lacking until now. Scientists from the University of Vienna together with an international research team have now been able to close this gap and, in a study, determined impressive figures: 2.8 billion base pairs—organized in 30 chromosomes.

What sounds so simple is the result of complex, computer-assisted genome analyses and comparisons with the genomes of other cephalopod species. The research has just been published in G3: Genes / Genomes / Genetics.

Octopuses, together with squid and cuttlefish, belong to a group of coleoid cephalopods consisting of several hundreds of species that are characterized by highly diversified lifestyles, body structure and adaptations to their environment. The study of these animals looks back on a long tradition, especially since the neuronal plasticity of the octopus brain—meaning the brain's ability to change and adapt as you learn and experience new things—provides evidence for the existence of functionally analogous structures to the brains of mammals.

This is making them a comparative model group for neurophysiological studies. Also, their ability to regenerate parts of their bodies as well as the rapid changes of their body patterns, which are important for camouflage and communication, make octopuses a popular research subject for studying how these innovative traits arose—and how they have changed—during evolution.

Closing a gap

In the research community there has been a rising need for detailed knowledge on cephalopod genomes to understand the evolution of their unique traits and their biology. An important contribution to this aim is encoding the common octopus' genome at chromosome level—an information that has not been available until now.

This has now been remedied by a research team from the University of Vienna, which—together with colleagues from the KU Leuven (Belgium), the Centro Nacional de Análisis Genómico (CNAG; Spain) and the Stazione Zoologica Anton Dohrn (Italy)—"supplied" the missing data and carried out extensive, molecular biological and computer-assisted studies of the octopus genome.

"With our current technologies used in genomics research, we were able to create a kind of 'genome map' for the octopus, showing how genetic information is arranged at the chromosome level," explains study first author Dalila Destanović, a scientist at the Simakov Laboratory in the Department of Neuroscience and Developmental Biology at the University of Vienna.

This reference genome, which is highly resolved at the chromosome level, will allow the scientific community to better understand the characteristics and biology of these fascinating animals on the one hand, and also to trace the evolutionary history of Octopus vulgaris on the other. Research teams can now further investigate or understand the evolutionary trajectory of coleiid cephalopods and more distantly related mollusks such as clams or snails.

2.8 billion base pairs—30 chromosomes

In fact, the researchers were able to identify 30 chromosomes in the Octopus vulgaris genome, in which 99.34% of 2.8 billion base pairs are arranged. This means that scientists now have a high-quality reference sequence that will serve as a basis for further studies on the function of genes and thus for a better understanding of biological properties of the common octopus.

The chromosomal structure of the Octopus vulgaris genome will also provide insight into the dynamic evolutionary history of these organisms by estimating chromosome rearrangement rates. Already, by comparing the Octopus vulgaris genome with the genomes of four other octopus species, the researchers have been able to show that all chromosomes exhibit numerous structural changes that have occurred during evolution by breaking off pieces of chromosomes, rearranging them and reconnecting them at the same chromosome.

"Even among closely related species, we observed numerous structural changes of the chromosomes. This finding poses questions on genome dynamics throughout their evolutionary history and opens the door to investigate how this relates to their unique traits", explains Dalila Destanović.

The dynamic evolutionary history of the octopus genome spans a period of 44 million years—and many exciting research questions are still open. The results of the current study will amount to answering some of these questions by bridging traditional Octopus vulgaris research in neurobiology, behavior and development to molecular genetic insights in these areas.

More information: Darrin Schultz, A chromosome-level reference genome for the common octopus, Octopus vulgaris (Cuvier, 1797), G3: Genes / Genomes / Genetics (2023). DOI: 10.1093/g3journal/jkad220

Journal information: G3 Genes|Genomes|Genetics 

Provided by University of Vienna Octopus brain and human brain share the same 'jumping genes'