European colonization accelerated erosion tenfold

UNIVERSITÉ CATHOLIQUE DE LOUVAIN

Research News

 

IMAGE: CLEARANCE OF NATIVE FORESTS FOR CULTIVATION ACCELERATES SOIL EROSION AND CAUSES RAPID SEDIMENTATION IN ALLUVIAL PLAINS. PHOTO TAKEN AT THE BIO BIO REGION (CHILE) view more 

CREDIT: VEERLE VANACKER

Rates of soil erosion and alluvium accumulation in North America accelerated 10-fold after Europeans colonized the continent, according to new research carried out by scientists from China, Belgium and USA.

In a paper published today in Nature Communications, the researchers show how humans have altered the North American landscape at a rate far in excess of what nature alone can achieve. The results, they suggest, may have implications for instructing land management and restoration efforts.

Prof. David Kemp from China University of Geosciences in Wuhan said "On nearly every continent, humans are altering the natural landscape, and modifying the land to meet our needs for agriculture, energy and water security. One key consequence of our actions is an increase in sediment movement, particularly soil erosion.

"We knew already that when European colonizers started farming in North America there was an increase in erosion. This led to the deposition of large amounts of river and floodplain sediment, known as alluvium. Our study quantifies this increase across the continent as a whole, and reveals an order of magnitude jump in rates of alluvium deposition soon after Europeans arrived".

Prof. Veerle Vanacker, of Université catholique de Louvain, explained "When we use these data to quantify landscape change, we find that in the past century humans have moved as much sediment on North America as it would take natural processes to move in up to 3000 years."

She added "What these findings mean is that anthropogenic activities have unprecedented impact on sediment dynamics. Unsustainable land use practices entail large societal costs in terms of soil fertility decline, flooding and stream degradation and direct costs for soil and watershed restoration. The study improves our ability to set benchmarks for erosion monitoring and control. "

Prof. Peter Sadler of University of California, Riverside, added "To arrive at our conclusions, we compiled and analysed a large database of alluvium accumulation rates that extend back to a time well before the first Europeans lived on the continent.

"What really stood out in these data was the observation that for the past 40,000 years, rates of alluvium accumulation hardly changed at all and the landscape was quite stable. It was only in the last 200 years that the rates suddenly increased - right around the time that Europeans started intensive farming."

###

More details: Kemp, D.B., Sadler, P.M. & Vanacker, V. The human impact on North American erosion, sediment transfer, and storage in a geologic context. Nature Communications, 11, 6012 (2020). https://doi.org/10.1038/s41467-020-19744-3

CAPTION

Water and soil conservation measures, such as wooden dams, are very effective in reducing runoff and transferring sediment to the alluvial plain. Photo taken in the Andes (Ecuador)

CREDIT

Veerle Vanacker

 

Geoscientists use zircon to trace origin of Earth's continents

PENN STATE

Research News

 

IMAGE: JESSE REIMINK, ASSISTANT PROFESSOR OF GEOSCIENCES AT PENN STATE, IS AMONG A TEAM OF RESEARCHERS TO USE THE MINERAL ZIRCON TO HELP UNDERSTAND HOW THE EARTH'S CONTINENTS FORMED BILLIONS OF... view more 

CREDIT: PENN STATE

Geoscientists have long known that some parts of the continents formed in the Earth's deep past, but the speed in which land rose above global seas -- and the exact shapes that land masses formed -- have so far eluded experts.

But now, through analyzing roughly 600,000 mineral analyses from a database of about 7,700 different rock samples, a team led by Jesse Reimink, assistant professor of geosciences at Penn State, thinks they're getting closer to the answers.

The researchers say that Earth's land masses began to slowly rise above sea level about 3 billion years ago. When their interpretation is combined with previous work, including work from other Penn State researchers, it suggests that continents took roughly 500 million years to rise to their modern heights, according to findings recently published in Earth and Planetary Science Letters.

To reach this conclusion, scientists applied a unique statistical analysis to crystallization ages from the mineral zircon, which is reliably dateable and is frequently found in sedimentary rocks. While these researchers did not date these samples, the samples were all dated using the the uranium-lead decay system. This method measures the amount of lead in a sample and calculates from the well established rate of uranium decay, the age of the crystal. When zirconium forms, no lead is incorporated into its structure, so any lead is from uranium decay.

The minerals found in the sedimentary rock samples originally formed in older magmas but, through erosion and transport, traveled in rivers and were eventually deposited in the ocean where they were turned into sedimentary rock beneath the surface of the sea floor. The ages of zircons retrieved from individual rock samples can be used to tell the type of continent they were eroded from.

The ages of zircons from Eastern North American rocks are, for instance, different from those of land masses such as Japan, which was formed by much more recent volcanic activity.

"If you look at the Mississippi River, it's eroding rocks and zircons from all over North America. It's gathering mineral grains that have a massive age range from as young as a million years to as old as a few billions of years," Reimink said. "Our analysis suggests that as soon as sediment started to be formed on Earth they were formed from sedimentary basins with a similarly large age range."

Sediments are formed from weathering of older rocks, and carry the signature of past landmass in time capsules such as zircons. The research doesn't uncover the overall size of primordial continents, but it does speculate that modern-scale watersheds were formed as early as 2.7 billion years ago.

"Our research matches nicely with the preserved rock record," Reimink said.

This finding is critical for a few reasons. First, knowing when and how the continents formed advances research on the carbon cycle in the land, water and atmosphere. Secondly, it gives us clues as to the early origins of Earth. That could prove useful as we discover more about life and the formation of other planets. Earth is a life-sustaining planet, in part, because of how continental crust influences our atmospheric and oceanic composition. Knowing how and when these processes occurred could hold clues to the creation of life.

"Whenever we're able to determine processes that led to our existence, it relates to the really profound questions such as: Are we unique? Is Earth unique in the universe? And are there other Earths out there," Reimink said. "These findings help lead us down the path to the answers we need about Earth that allow us to compare our planet to others."

###

Joshua Davies of Université du Québec à Montréal and Alessandro Ielpi of Laurentian University contributed to this research.

The Natural Sciences and Engineering Research Council of Canada partially supported this work.

After 100 years, Cornell University plant pathologists revisit fire blight hypothesis

AMERICAN PHYTOPATHOLOGICAL SOCIETY

Research News

 

IMAGE: FLY FEEDING ON THE OOZE DROPLET IN THE EXPERIMENTAL CHAMBER. view more 

CREDIT: MATTHEW BOUCHER

Historically credited as being the first bacterium ever characterized as a plant pathogen, fire blight is a bacterial disease that leads to significant losses of pear and apple. The role of insects in the spread of this disease has been long studied. In a new study, plant pathologists based at Cornell University and Cornell AgriTech take a hypothesis that has been more or less ignored for 100 years and provided support for its validity.

According to first author Matthew Boucher, the study describes a long hypothesized but never experimentally supported transmission mechanism for fire blight. Boucher and colleagues show that flies in an apple orchard can acquire the bacterial agent (Erwinia amylovora) of fire blight from sugary droplets exuding from diseased apple trees and subsequently transmit the bacterium to uninfected shoots so long as those shoots are damaged in some way.

"This transmission mechanism is mechanical, the bacterium does not appear to have a close evolutionary relationship with any given insect and may seem inefficient to an unsuspecting observer," explained Boucher. "However, we show that the massive populations of E. amylovora in the sugary droplets exuding from trees allow flies to acquire enough bacteria for the population to persist in and on flies for as long as seven days in some cases."

Flies can continually shed bacteria over the course of those seven days, resulting in multiple opportunities for a single insect to initiate an infection.

"Demonstrating that bacterial populations can survive within the insect is important because previous research largely discounted E. amylovora survivability within an insect." More research is needed, especially under field conditions, but this is an exciting step toward understanding the diversity of interactions between plants, insects, and phytopathogens.

"We also show that insects do not need to have intimated, co-evolved relationships with plant pathogens to be important agents in the disease cycle. There are only one or two similar pathogens in documented research, but there are likely more out there that need to be studied to advance our knowledge of this end of the disease-vector spectrum," Boucher said when asked what makes his work groundbreaking. "As a collective work, we show the importance of integrating historical literature into modern research and revisiting topics and hypothesis that may not have been technologically feasible to investigate when they were first proposed."

###

This work is a foundational study that will provide excellent context for future researchers interested in the topic. For more information, read "Interactions Between Delia platura and Erwinia amylovora Associated with Insect Mediated Transmission of Shoot Blight" published in PhytoFrontiers.

Watching the Arctic thaw in fast-forward

ALFRED WEGENER INSTITUTE, HELMHOLTZ CENTRE FOR POLAR AND MARINE RESEARCH

Research News

 

The Arctic is warming more quickly than almost any other region on Earth as a result of climate change. One of the better known: the continually shrinking summer sea-ice extent in the Arctic. But global warming is also leaving its mark on terrestrial permafrost. For several years, permafrost regions have been thawing more and more intensively in North America, Scandinavia and Siberia - e.g. in the extreme northwest of Alaska. Permafrost is soil that has remained permanently frozen to depths of up to several hundred metres, often since the last glacial period, roughly 20,000 years ago, or in some cases even longer.

The permafrost regions near the city of Kotzebue, Alaska, are dotted with hundreds of thaw lakes. These are formed when the permafrost soils begin to thaw and subside. Meltwater from the soil or from the winter snowfall and summer rainfall collects in the hollows. Some are several thousand years old and were formed since the end of the last glacial period. But in recent years, the lake landscape has changed due to more frequent relatively mild winters there. In summer, the permafrost soils thaw extensively and they don't completely refreeze in winter, which means that the lakes' shores become unstable and collapse, causing water to drain from the lakes. Researchers from the Alfred Wegener Institute, Helmholtz Centre for Polar and Marine Research (AWI) observed a particularly extreme example of this in the seasons 2017 and 2018: within a year, more lakes drained than ever before - roughly 190 in total. "The scale shocked us," says AWI geographer Ingmar Nitze. "The winter 2017/2018 was extremely wet and warm. Conditions were similar to those our climate models predict will be normal by the end of this century. In a way, we caught a glimpse of the future. By then, widespread lake drainage will have reached a catastrophic scale."

As Nitze and his co-authors report in the journal The Cryosphere, the mean temperature in the 2017/2018 season was circa five degrees Celsius above the long-term average. In Kotzebue, the winter temperature is usually about minus 20 degrees - but in that year the temperature was 10 to 20 degrees higher on several days. Furthermore, as a result of the moist air, there was a significant amount of snow. Since snow insulates the soil against the cold air in winter, the active layer and upper permafrost that had partially thawed in summer did not refreeze sufficiently during this relatively mild winter. A chain of factors likely led to the drainage of the lakes, one of which was the fact that the permafrost around the shores had degraded, facilitating lateral drainage. In addition, the large amount of meltwater from the thawing snow masses increased the lake water levels. Making matters worse, the water was able to drain easily, cutting veritable flood channels through the thawed soil surface layer. "With a depth of one to three metres, the lakes are relatively shallow and so drain quickly," explains Ingmar Nitze. Fortunately, since the region is sparsely populated, no major damage was done. But that's not the point, adds the researcher. "This drainage event simply shows the extreme scale of warming and impacts to tundra and permafrost landscapes that we'll see in the Arctic in the coming decades. But above all, it shows that extreme events won't occur only at the end of the century, but are already taking place and will do so in the years to come." This is a cause for concern, since it means that the ancient plant remains stored in the permafrost soils can become exposed and broken down by microbes. The carbon contained within the plants is then released as carbon dioxide or methane, which exacerbates the greenhouse effect - a vicious circle.

For their study, Ingmar Nitze and his colleagues evaluated satellite images of the region surrounding Kotzebue and northwestern Alaska. In the pictures, the full and drained lakes can be easily distinguished. It is also clear when the lakes begin to drain. Winter 2017/2018 was the warmest in the region since continuous records began at the Kotzebue station in 1949. Accordingly, the experts had expected several lakes to drain. But they hadn't expected it to happen on this scale. "In the mild years 2005 and 2006, several lakes drained - but this time there were twice as many." And that's worrying, the experts warn, because at the same time it means the permafrost's potential to preserve large amounts of carbon is shrinking at an alarming rate.

Scientists warn of the social and environmental risks tied to the energy transition

A new international study by the ICTA-UAB and the McGill University (Canada)

 maps resistance movements' associated with green energy and fossil fuel projects

UNIVERSITAT AUTONOMA DE BARCELONA

Research News

 

IMAGE: DEMONSTRATION AGAINST HYDROPOWER UTILITY IN WINNIPEG, MANITOBA, CANADA (NOV 2019). view more 

CREDIT: DANIELA DEL BENE

To meet the most ambitious 1.5º C climate goal requires a rapid phaseout of fossil fuels and mass use of renewables. However, new international research by the Institute of Environmental Science and Technology of the Universitat Autònoma de Barcelona (ICTA-UAB) warns that green energy projects can be as socially and environmentally conflictive as fossil fuel projects. While renewable energies are often portrayed as being environmentally sustainable, this new study cautions about the risks associated with the green energy transition, arguing for an integrated approach that redesigns energy systems in favor of social equity and environmental sustainability. The research, which analyzes protests over 649 energy projects, has been recently published in the journal Environmental Research Letters.

The study, authored by an international group of researchers with a large presence of the ICTA-UAB and led by Dr. Leah Temper, from McGill University, draws on data from the Global Atlas of Environmental Justice (EJAtlas), an online database by ICTA-UAB that systematizes over 3000 ecological conflicts. The research examines what energy projects are triggering citizen mobilizations, the concerns being expressed as well as how different groups are impacted, and the success of these movements in stopping and modifying projects.

The study finds that conflicts over energy projects disproportionately impact rural and indigenous communities and that violence and repression against protesters was rife, with assassination of activists occurring in 65 cases, or 1 out of 10 cases studied. However, the study also points to the effectiveness of social protest in stopping and modifying energy projects, finding that over a quarter of projects facing social resistance turn out to be either cancelled, suspended, or delayed. Furthermore, it highlights how communities engage in collective action as a means of shaping energy futures and make claims for localization, democratic participation, shorter energy chains, anti-racism, climate-justice-focused governance, and Indigenous leadership.

According to Dr. Temper, "the study shows that the switch from fossil fuels to green energy is not inherently socially and environmentally benign and demonstrates how communities are standing up to demand a say in energy systems that works for them. These results call for action to ensure that the costs of decarbonization of our energy system do not fall on the most vulnerable members of our society." The study urges climate and energy policymakers to pay closer attention to the demands of collective movements to meaningfully address climate change and to move towards a truly just transition.

The study finds that amongst low-carbon energy projects, hydropower is the most socially and environmentally damag-ing, leading to mass displacement and high rates of violence. Out of the 160 cases of hydropower plants from 43 coun-tries studied, almost 85% of the cases are either high or medium intensity. Indigenous peoples are particularly at risk and are involved in 6 out of 10 cases. Co-author Dr. Daniela Del Bene, from ICTA-UAB, urges caution around large-scale renewables. "The case of hydropower dams shows that even less carbon-emitting technologies can cause severe im-pacts and lead to intense conflicts, including violence and assassinations of opponents. The energy transition is not only a matter of what technology or energy source to use but also of who controls and decides upon our energy systems", she says.

On the other hand, wind, solar, and geothermal renewable energy projects, were the least conflictive and involved lower levels of repression than other projects.

According to co-author Sofia Avila, "conflicts around mega wind and solar power infrastructures are not about "blocking" climate solutions but rather about "opening" political spaces to build equitable approaches towards a low-carbon future. For example, in Mexico, long-lasting claims of injustice around an ambitious Wind Power Corridor in Oaxaca has spearheaded citizen debates around a just transition, while different proposals for cooperative and decentralized energy production schemes are emerging in the country."

According to Prof. Nicolas Kosoy, from McGill University, "participation and inclusiveness are key to resolving our socio-environmental crises. Both green and brown energy projects can lead to ecological devastation and social exclusion if local communities and ecosystems rights continue to be trampled upon."

The study argues that place-based mobilizations can point the way towards responding to the climate crisis while tackling underlying societal problems such as racism, gender inequality, and colonialism. According to Dr. Temper, addressing the climate crisis calls for more than a blind switch to renewables. Demand-side reduction is necessary but this needs to work in tandem with supply side approaches such as moratoria, and leaving fossil fuels in the ground are necessary. "Equity concerns need to be foremost in deciding on unminable and unburnable sites. Instead of creating new fossil fuel and green sacrifices zones, there is a need to engage these communities in redesigning just energy futures", she says.

###

During the coronavirus pandemic, radio has proved to be the medium of reference

So affirms an article by the researchers Emma Rodero and María Blanco-Hernández, in which they demonstrate the influence of radio in crisis situations and especially during the COVID-19 epidemic

UNIVERSITAT POMPEU FABRA - BARCELONA

Research News

 

Radio has always proved to be a medium that adapts easily to crisis situations. Throughout history, at times of major natural disasters and health emergencies, radio has played a leading role thanks to the fact that is the most universal, simplest and most accessible of media.

In the current crisis caused by covid-19, radio has again stood out as being an essential medium to stay informed, according to the study by Rodero (2020). The results indicate that radio is the medium that scores highest for its treatment of information about the pandemic.

The main goal of a recent article published in Index.comunicación by Emma Rodero, director of the UPF Media Psychology Lab at the Department of Communication, and María Blanco-Hernández, a researcher at the International University of La Rioja, was to demonstrate the influence of radio in crisis situations and describe the main initiatives that the medium is implementing relating to covid-19.

Thus, the authors have conducted a review of the state of affairs that has revealed the importance of radio in such situations. In addition, a detailed analysis of the information provided by the main domestic and international radio stations after the onset of the pandemic has allowed collating the most interesting initiatives implemented in each of them.

Increase in radio listening during the pandemic around the world

In Spain, the study by Rodero (2020) recorded an increase in radio consumption during the pandemic of almost one point. Most listeners tuned in between one and two hours a day; between 30 minutes and an hour and between two and three hours. The peak slot continued to be mornings, but due to lockdown, listening was more spread throughout the day, with increased listening especially in the afternoon and at midday. The broadcasters that experienced the highest increase were conventional general stations, while music stations suffered a decrease.

This upward trend in consumption during the pandemic has also been recorded in other countries. In the UK, Radiocentre has recorded an increase in commercial radio listening of 1 hour and 45 minutes. Broadcasters with a younger audience, like Fun Kids, have extended their broadcasting hours targeting children. The BBC puts increased consumption at 18%. In Italy, according to the Association of European Radios, the number of listeners has increased by 2.4%. In the United States there has been a 28% increase in consumption. In Chile, four out of five people heard the radio during the week, and two thirds did so daily. In Australia, listeners have heard an average of 1 hour and 46 minutes of radio a week during the pandemic and 72% of Australians are listening to as much or more radio during this crisis. In India, 82% of the population has been listening to radio during the pandemic with a 23% increase. In South Africa, a survey by the National Association of Broadcasters estimated at 36% the number of listeners who claim to be listening to more radio due to the pandemic.

Adaptation of labour relations, formats and content

Radio stations have had to adapt to the new situation with professionals working from home and schedules modified to include content on the coronavirus. As in other crises, listening has increased, and the medium is helping to alleviate the psychological effects of the pandemic.

The study reflects some specific cases of adaptation such as that of Cadena Cope, "where between just 20 and 30% of workers have attended the workplace in person", or the case of the United Kingdom "where community radio stations have innovated and improved their ingenuity presenting programmes, providing entertainment and information". It also cites the case of Ràdio UNDAV (National University of Avellaneda) in Argentina, which has created a procedure manual for radio operators explaining the technical mechanisms through which to perform tasks remotely. In the field of music, one of the initiatives that has had greatest reach in Spain is the proposal by Jordi Cruz of Cadena 100. The idea was to use the song entitled Resistiré (I will resist) by Dúo Dinámico (1988) as the anthem of the pandemic, in order to raise the spirits of all citizens.

The study concludes that the technical simplicity of radio has been an ally in allowing the stations to continue broadcasting regularly. Radios worldwide have responded with all kinds of initiatives. Many have dedicated special programmes or podcasts to the pandemic, some with up-to-date information, others reviewing the history or the causes of the pandemic, others reflecting the reality and its effects, and others with a clear mission to help clear up doubts about the disease.

This central role of radio is also seen in the number of initiatives that different stations around the world have organized, such as competitions and acts of solidarity to help all those affected. Once again, as has happened at other times of emergency in history, radio is playing a major role.

###

Related works:

Emma Rodero-Antón, María Blanco-Hernández (2020), "El papel de la radio en situaciones de crisis. Iniciativas en la pandemia del coronavirus", Index.comunicación, nº 10 (3), páginas 193-213.

Emma Rodero (2020), "La radio: el medio que mejor se comporta en las crisis. Hábitos de escucha, consumo y percepción de los oyentes de radio durante el confinamiento por el Covid-19", El profesional de la información, 29(3), 1-15.

e-Repositori-UPF: https://repositori.upf.edu/handle/10230/44567

Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.

Pronouns matter -- pronoun use conveys inclusivity

In her doctoral dissertation, Laura Hekanaho investigates attitudes towards English third person singular pronouns; the use of pronouns is very politicized

UNIVERSITY OF HELSINKI

Research News

 

IMAGE: ANOTHER PRONOUN-RELATED ISSUE PERTAINS TO NONBINARY PEOPLE: WHAT PRONOUNS SHOULD BE USED TO REFER TO PEOPLE WHO ARE NOT 'HE' OR 'SHE'? EVEN THOUGH BEING NONBINARY IS NOT A NEW... view more 

CREDIT: PEXELS / SHARON MCCUTCHEON

In her doctoral dissertation, Laura Hekanaho investigates attitudes towards English third person singular pronouns. The use of pronouns is very politicised.

Laura Hekanaho takes an in-depth look at two main problems caused by gendered pronouns ('he', 'she'): the use of singular pronouns in generic contexts, and pronominal references to nonbinary individuals. What connects these pronouns is their relevance to gender-fair language use; who is allowed representation in language?

Generic references to people no longer rely on the masculine pronoun

The problem with generic references has been the choice of pronoun when referring to people in general but using a singular construction (e.g., 'A child loves his/her/their mother.'). Traditionally, such expressions have used the 'he' pronoun, a practice which has been shown to be problematic in previous research.

"This is a broader phenomenon related to language and society, where masculinity has often been set as the norm," Hekanaho says. Most languages have words like 'spokesman', 'fireman' and so on. In present-day English, other alternatives are commonly used, singular 'they' being the most common generic pronoun.

How should nonbinary individuals be referred to who are neither she nor he?

Another pronoun-related issue pertains to nonbinary people: what pronouns should be used to refer to people who are not 'he' or 'she'? Even though being nonbinary is not a new phenomenon, the linguistic needs of nonbinary individuals have only received broader attention in recent years. In English, many nonbinary individuals have started using 'they' as their personal pronoun, but some prefer neopronouns such as 'ze' and 'xe' (e.g., 'Chris loves zir coffee black.').

English pronouns have become politicised

English pronouns have been politicised in many ways, evoking a multitude of emotions and opinions, which have an effect on what pronouns are used and how.

"For this reason, in my doctoral dissertation I have investigated not only pronoun usage, but also their acceptability and attitudes towards pronouns."

Hekanaho's doctoral thesis is based on a questionnaire survey with 1,128 respondents, of whom 79 were nonbinary and the rest were women or men. Most of the respondents spoke English as their native language, but some were native speaker of Finnish or Swedish.

The results illustrated the importance of pronouns on a number of levels. In generic use, the respondents preferred singular 'they', above all for its gender-inclusive nature. On the other hand, using 'he' or 'she' alone was considered gender exclusive, while the combination of 'he or she' was more acceptable, although not as popular as 'they'. In fact, inclusivity appears to be the deciding factor in the use of generic pronouns.

Nonbinary pronouns polarise opinions the most

"Many cisgender respondents strongly opposed nonbinary pronouns, finding them strange and unnecessary. Due to its familiarity, 'they' was, however, considered to be a better option than neopronouns."

However, behind the opposition to nonbinary pronouns lie ideological reasons that go beyond the perceived strangeness of pronouns. The existence of nonbinary identities, and consequently nonbinary pronouns, challenges the fairly established idea of gender being a binary concept. As such, attitudes towards these pronouns also reflect gender ideologies, as was evident in the data.

The nonbinary participants also described their relationship with pronouns. The majority reported using 'they' as their own pronoun, and only few preferred neopronouns. The importance of pronouns to identity was highlighted in the responses. When other people use a nonbinary individual's correct pronouns, this is a sign of respect and indicates that the speaker acknowledges and accepts nonbinary identities. In contrast, refusing to use nonbinary pronouns is disrespectful, indicating that the person rejects the validity of nonbinary identities.

"Language use does matter, since it's not only about the words and pronouns we use, but also about the values we communicate through our language use. Inclusive and respectful language can, for example, make the lives of minorities easier."

###

Laura Hekanaho, MA, will defend her doctoral thesis entitled 'Generic and Nonbinary Pronouns: Usage, Acceptability and Attitudes' on 8 December at 15.00 at the Faculty of Arts, University of Helsinki.

The public examination will be held online via Zoom. Link: https://helsinki.zoom.us/j/68523161534?pwd=YzFCejN3ZlFCVGx0WnBIcTVLdVpSQT09#success passcode: 190190

Early human landscape modifications discovered in Amazonia

No evidence of extensive savannah formations during the current Holocene period

UNIVERSITY OF HELSINKI

Research News

 

IMAGE: AERIAL VIEW OF A RESEARCH SITE CALLED SEVERINO CALAZANS. view more 

CREDIT: MARTTI PÄRSSINEN

In 2002 Professor Alceu Ranzi (Federal University of Acre) and Prof. Martti Parssinen (University of Helsinki) decided to form an international research team to study large geometric earthworks, called geoglyphs, at the Brazilian state of Acre in South-western Amazonia. Soon it appeared that a pre-colonial civilization unknown to international scholars built there geometric ceremonial centers and sophisticated road systems. This civilization flourished in the rainforest 2,000 years ago. The discovery supported Prof. William Balee´s (Tulane University) theory of early human impacts on the current Amazonian tropical forest composition that radically altered the notion of the pristine Amazon rainforest.

Now, the team published an article in Antiquity demonstrating that the earthwork-building civilization had a much longer human history behind it than was expected. The team members demonstrate that humans have regularly used fire to clear small open patches in the rainforest. These activities started quite soon after the last Ice Age ended thousands of years before the first geoglyphs were constructed. Thanks to the charcoal the humans left in the Amazonian soil during the last 10 000 years, it was possible to measure systematically carbon-13 isotope values of many samples. By using these values taken from archaeologically dated charcoal it was possible to estimate past vegetation and precipitation. The results published in Antiquity indicate that the forest main vegetation and precipitation have remained quite unchanged during the last ten thousand years until the 20th century. No evidence of drier periods or natural/artificial savannah formations were observed before the current colonization started to penetrate into the southwestern Amazonia from the turn of the 19th and 20th centuries onward. Hence, the authors argue that the theories of extensive savannah formations in the South-western Amazonia during the current Holocene period are based on a false interpretation of the connection between charcoal accumulation and natural fires due to drier climatic periods. These interpretations have not taken into account the millennial human presence in Amazonia.

Alceu Ranzi says that "it is possible that opening patches were aimed to attract large mammals such as giant sloths and mastodons until the megafauna disappeared forever. In addition, ash and charcoal fertilized the soil and open areas were prepared for the growing of palms fruits, vegetables and root plants useful for human subsistence." Martti Parssinen adds that "it is probably not a coincidence that today southwestern Amazonia is considered one of the most important centers of domestication: cassava/manioc, squash, chili-pepper and peach palm seem to have been domesticated there almost 10 000 years ago. In every case, domestication processes left important fingerprints on Amazonian forest composition. Therefore there is no such thing as virgin rainforest."

In general, the study shows that indigenous peoples of the Amazon have been able to use their environment in a sustainable manner. Parssinen says that "there is no indication that large areas of Holocene forest would have been deforested before the second half of the 20th century. Deforestation is a current phenomenon."

###

Martti Parssinen, William Balee and Alceu Ranzi are the authors of the current article. In addition, archaeologist Antonia Barbosa from the Superintendencia do Instituto do Patrimonia Historico e Artistico Nacional no Acre is the fourth author. The Academy of Finland financed the project and the Finnish Cultural and Academic Institute in Madrid also contributed to the project. In Brazil the research was authorized by Instituto do Patrimonio Historico e Artistico Nacional (IPHAN).

Ultrasensitive transistor for herbicide detection in water

INSTITUTE OF INDUSTRIAL SCIENCE, THE UNIVERSITY OF TOKYO

Research News

 

IMAGE: UNIVERSITY OF TOKYO RESEARCHERS HAVE FABRICATED A TINY ELECTRONIC SENSOR THAT CAN DETECT VERY LOW LEVELS OF A COMMONLY USED WEED KILLER IN DRINKING WATER. view more 

CREDIT: INSTITUTE OF INDUSTRIAL SCIENCE, THE UNIVERSITY OF TOKYO

A new polymer-based, solid-state transistor can more sensitively detect a weed killer in drinking water than existing hydrogel-based fluorescence sensor chips. The details were published in Chemistry-A European Journal.

The sensor is a specially designed organic thin-film transistor based on semiconducting molecules of carboxylate-functionalized polythiophene (P3CPT). What's special about this particular device is that, unlike other conjugated polymer-based sensors, this one is a solid-state device that can conduct an electric current when placed inside a fluid.

The device, designed by Tsuyoshi Minami of The University of Tokyo's Institute of Industrial Science and colleagues, works by adding copper ions, which bind to the P3CPT molecules. When the device is placed in water that contains even the smallest amount of the herbicide glyphosate, the copper ions leave the P3CPT molecules to attach to the glyphosate molecules. This causes a detectable reduction in the flow of electric current through the device. Glyphosate is a commonly used weed killer in agriculture, and there are concerns that its presence in drinking water can be harmful to human health.

The scientists found that the device was so sensitive that it could detect as low as 0.26 parts per million of glyphosate in drinking water. The team compared their new device to a conventional fluorescence sensor chip, which was only capable of detecting down to 0.95 parts per million of glyphosate. To put this into perspective, the maximum allowable amount of glyphosate in drinking water, according to the United States Environmental Protection Agency, is 0.7 parts per million.

The scientists believe that the sensitivity of their device boils down to interactions occurring within individual polymer molecules and between neighbouring ones. Commonly used fluorescence sensors depend solely on interactions occurring within individual molecules.

"Our device could be a novel solid-state platform for sensing target molecules in aqueous media," says Minami. The researchers are currently working on further developing their polythiophene-based sensors.

###

About Institute of Industrial Science (IIS), the University of Tokyo

Institute of Industrial Science (IIS), the University of Tokyo is one of the largest university-attached research institutes in Japan.

More than 120 research laboratories, each headed by a faculty member, comprise IIS, with more than 1,000 members including approximately 300 staff and 700 students actively engaged in education and research. Our activities cover almost all the areas of engineering disciplines. Since its foundation in 1949, IIS has worked to bridge the huge gaps that exist between academic disciplines and real-world applications.

Disclaimer: AAAS and EurekAlert! are not responsible for the accu

Octogenarian snapper found in WA becomes oldest tropical reef fish by two decades

An 81-year-old midnight snapper caught off the coast of Western Australia has taken the title of the oldest tropical reef fish recorded anywhere in the world

AUSTRALIAN INSTITUTE OF MARINE SCIENCE

Research News

 

IMAGE: A RED SNAPPER view more 

CREDIT: DAN BAYLEY

An 81-year-old midnight snapper caught off the coast of Western Australia has taken the title of the oldest tropical reef fish recorded anywhere in the world.

The octogenarian fish was found at the Rowley Shoals--about 300km west of Broome--and was part of a study that has revised what we know about the longevity of tropical fish.

The research identified 11 individual fish that were more than 60 years old, including a 79-year-old red bass also caught at the Rowley Shoals.

Australian Institute of Marine Science (AIMS) Fish Biologist Dr Brett Taylor, who led the study, said the midnight snapper beat the previous record holder by two decades.

"Until now, the oldest fish that we've found in shallow, tropical waters have been around 60 years old," he said.

"We've identified two different species here that are becoming octogenarians, and probably older."

Dr Taylor said the research will help us understand how fish length and age will be affected by climate change.

"We're observing fish at different latitudes--with varying water temperatures--to better understand how they might react when temperatures warm everywhere," he said.

The study involved four locations along the WA coast, as well as the protected Chagos Archipelago in the central Indian Ocean.

It looked at three species that are not targeted by fishing in WA; the red bass (Lutjanus bohar), midnight snapper (Macolor macularis), and black and white snapper (Macolor niger).

Co-author Dr Stephen Newman, from the WA Department of Primary Industries and Regional Development, said long-lived fish were generally considered more vulnerable to fishing pressure.

"Snappers make up a large component of commercial fisheries in tropical Australia and they're also a key target for recreational fishers," he said.

"So, it's important that we manage them well, and WA's fisheries are among the best managed fisheries in the world."

Marine scientists are able to accurately determine the age of a fish by studying their ear bones, or 'otoliths'.

Fish otoliths contain annual growth bands that can be counted in much the same way as tree rings.

Dr Taylor said the oldest red bass was born during World War I.

"It survived the Great Depression and World War II," he said.

"It saw the Beatles take over the world, and it was collected in a fisheries survey after Nirvana came and went."

"It's just incredible for a fish to live on a coral reef for 80 years."

###

The research is published in the journal Coral Reefs.

Funding was provided by the Bertarelli Foundation and contributed to the Bertarelli Programme in Marine Science.