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University of Leeds news
Embargo: Wednesday 30 June, 7pm GMT
Bereavement care lacking for ethnic minorities
Grieving friends and relatives from ethnic minority backgrounds are suffering from a lack of appropriate help to cope with the loss of a loved one, especially during the COVID-19 pandemic, researchers say.
And the scarcity of data on the services that are available means providers do not know how support should be delivered to ensure they are suitable for different groups of people.
The researchers, led by the University of Leeds and the University of Sheffield, reviewed evidence on UK bereavement care for ethnic minority communities to determine how easy it was to access, what it looked like, and what the outcomes were.
They say people representing those communities need to be involved when services are developed and delivered to ensure that groups get the support they need.
Senior author and research co-lead Dr Matthew Allsop, from the School of Medicine, said: "The increased risks from covid-19 among minority ethnic groups prompted this review. We were keen to understand what research had been conducted that could inform how bereavement care should be delivered for people during the pandemic. We found a stark lack of evidence focusing on people from minority ethnic groups with only seven studies published over the last 25 years.
"The limited studies highlighted multiple challenges faced in accessing bereavement care. There is an urgent need for research and evidence to understand how bereavement support can be developed to ensure they meet the specific needs and preferences of different minority ethnic groups."
The team reviewed feedback about bereavement services between 1995 and 2020,which was provided by bereaved adults and children from UK ethnic minority populations, and people grieving the death of a person from an ethnic minority group.
Ethnic minorities include White minorities, such as Gypsy, Roma and Irish Traveller groups.
Services reviewed included hospital-based palliative care teams, hospital based neonatal teams, and community support.
Healthcare workers surveyed included doctors, nurses, chaplains and unspecified participants in UK neonatal units.
Seven studies were included, comprising 721 participants who completed surveys and took part in interviews and focus groups.
The review revealed a lack of awareness about bereavement care for ethnic minority communities among health professionals, while access to interpreters was variable, as was availability of psychological support. Two thirds of palliative care teams surveyed did not provide any form of bereavement support.
Support offered was not always needed or suitable for ethnic minority communities, with 17 or 18 participants in one study saying their family was their main source of support. Help from friends, neighbours and religious communities was also common. And one study showed personal faith and support from a religious leader was more important for bereaved people from a black Caribbean background than for people from white backgrounds.
One study revealed that other methods of support, like a memorial service, had a strong Christian theme, which may have precluded those from other faiths or cultures from attending.
Practical legal and financial support was often recognised to be needed rather than specialist interventions. One study showed black Caribbean respondents were more likely to be affected by these concerns than white respondents - and anxiety and depression was more prevalent among the black Caribbean respondents in this study.
One study described the significant financial difficulties experienced by half of the 19 Bangladeshi participants after a death, with trying to meet the costs of transporting the deceased back to Bangladesh given as an example.
Romany Gypsy and Traveller respondents described a cultural practice of not speaking about bereavement within the close-knit community, which researchers say can potentially increase the risk of poor mental health following significant loss or bereavement. Among this group there is reported stigma and shame associated with mental health illness, including bereavement related depression, resulting in a reluctance to seek formal support.
The paper, Bereavement care for ethnic minority communities: A systematic review of access to, models of, outcomes from, and satisfaction with, service provision, is published today in PLOS ONE.
The researchers say healthcare policy makers should now work with ethnic minority groups to design the most appropriate models and formats of bereavement care that meet their needs and preferences. This will improve the understanding of the role of family, friends and existing support systems, and begin to develop the evidence base underpinning current provision.
First author and research co-lead Dr Catriona Mayland, from the University of Sheffield, said: "There is a need to understand the role in bereavement care played by families, friends, faith and community-based support groups. Additionally, it is only by adopting a true partnership approach that we can understand what type, and in what way, bereavement care should be provided.
"This will enable better support for those experiencing grief from ethnic minority communities.'
Further information
For media enquiries contact University of Leeds press officer Lauren Ballinger via l.ballinger.leeds.ac.uk.
Partner institutions included University of Sheffield and Imperial College London.
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A new study by investigators from Brigham and Women's Hospital examines the associations between wealth mobility and long-term cardiovascular health. The multidisciplinary study borrowed methodology from the field of economics to analyze longitudinal changes in wealth. The team's results indicate that negative wealth mobility is associated with an increased risk of cardiovascular events, while positive wealth changes are associated with a decreased risk of cardiovascular events. Their results are published in JAMA Cardiology.

"Low wealth is a risk factor that can dynamically change over a person's life and can influence a person's cardiovascular health status," said Muthiah Vaduganathan, MD, MPH from the Brigham's Division of Cardiovascular Medicine. "So, it's a window of opportunity we have for an at-risk population. Buffering large changes in wealth should be an important focus for health policy moving ahead."

The retrospective study leveraged data from the RAND Health and Retirement Study (HRS). While wealth data is infrequently categorized in most studies, the HRS uniquely captures detailed information about both housing (primary residence, mortgages, home loans and more) and non-housing (vehicles, businesses, stocks, mutual funds, checking and savings accounts and more) wealth across multiple interviews. The study examined 5,579 adults 50 years or older with no cardiovascular health concerns at baseline. Between January 1992 and December 2016, the HRS research team collected data through interviews with participants about any new diagnoses they had received in terms of their overall health. For deceased participants, next of kin were interviewed and the National Death Index was consulted for additional information.

"Income and wealth, while perhaps informally used interchangeably, actually provide different and complementary perspectives," said Sara Machado, PhD, an economist at the Department of Health Policy at the London School of Economics. "Income reflects money received on a regular basis, while wealth is more holistic, encompassing both assets and debts. Could paying off one's debt with a large relative wealth increase be important in promoting cardiovascular health, even without changes in income?"

For the purposes of this study, upward wealth mobility was defined as an increase of at least one wealth quintile and, similarly, downward wealth mobility was defined as a decrease of at least one quintile relative to peers of similar age. Participants who were in the same wealth quintile between interviews were classified as having stable wealth. Altogether, an increase in wealth was associated with protection against cardiovascular diseases and a decrease in wealth was associated with cardiovascular risk.

"Decreases in wealth are associated with more stress, fewer healthy behaviors, and less leisure time, all of which are associated with poorer cardiovascular health," said Andrew Sumarsono, MD from University of Texas Southwestern's Division of Hospital Medicine. "It is possible that the inverse is true and may help to explain our study's findings."

In terms of limitations, all interviews and reports of new diagnoses were self-reported by the participants. Additionally, there are many factors that influence general cardiovascular health, including certain environmental and socio-demographic variables. Some of these factors were not collected by the HRS and therefore were not considered in the study.

The research team hopes that the findings of their research can inform the future of health policy and medical literature.

"Wealth and health are so closely integrated that we can no longer consider them apart," said Vaduganathan. "In future investigations, we need to make dedicated efforts to routinely measure wealth and consider it a key determinant of cardiovascular health."

Research at Baylor College of Medicine, the Texas Heart Institute and collaborating institutions is moving a novel promising gene therapy to treat heart failure closer to the clinic.

Published in Science Translational Medicine, the study showed that knocking down the Hippo signaling pathway in cardiomyocytes in the hearts of pigs after they had a heart attack, resulted in heart tissue renewal and improved function when compared with pig hearts in which the Hippo signaling pathway was not modified. Given that the pig's heart is considered a valuable model to study the human heart, the findings suggest that this gene therapy may be useful in treating human heart failure.

Heart failure remains the leading cause of mortality in the western world, causing more deaths than all cancers combined. The best current treatment for heart failure is a heart transplant, but the number of hearts available for transplant is limited, underscoring the need for alternative treatments.

"One of the interests of my lab is to develop ways to heal heart muscle by studying pathways involved in heart development and regeneration," said corresponding author Dr. James Martin, professor and Vivian L. Smith Chair in Regenerative Medicine at Baylor and director of the Cardiomyocyte Renewal Lab at the Texas Heart Institute.

Previous work has shown that when patients are in heart failure there is an increase in the activity of the Hippo signaling pathway, which acts to inhibit heart repair. Earlier work from the Martin lab revealed that turning the Hippo signaling pathway off in a mouse model that mimics advanced human heart failure resulted in the murine hearts recovering their pumping function.

"Encouraged by these results, we took the next step by testing whether turning the Hippo signaling pathway off in pig hearts would also help the injured hearts recover," said first author Dr. Shijie Liu, a postdoctoral associate in the Martin lab.

An essential first translational step before taking the gene therapy to humans

In the current study the researchers modeled in the pig what happens in a human patient that has a heart attack and assessed the effect of gene therapy knockdown of the Hippo signaling pathway on heart recovery.

"Pigs with a heart attack present a condition that is similar to what you might find in a human patient who has a blockage in the main artery of the heart, which leads to myocardial infarction," Martin explained. "After myocardial infarction in the pigs, we administered the gene therapy, to turn off Hippo directly in heart of the pigs. Finally, we compared the effects of therapy or no therapy on heart function."

"We were excited by the results," Liu said. "Three months after we treated the pigs, those that received the gene therapy had improved their heart function, showed signs that their cardiomyocytes were regenerating, had less fibrosis or scarring and had evidence that new blood vessels had formed. The procedure was shown to be safe since the pigs tolerated the therapy very well."

"Our findings support our goal to move on to human clinical trials," Martin said. "This is a potentially transformational strategy to treat human heart failure. It taps into the healing capacity of the heart, promoting heart muscle self-repair and improved function, which can make a substantial difference in the lives of those who suffer a heart attack."

What The Study Did: National survey data were used to estimate how common psoriasis is among adults in the United States and how this has changed since 2003.

Authors: April W. Armstrong, M.D., M.P.H., of the University of Southern California in Los Angeles, is the corresponding author.

To access the embargoed study: Visit our For The Media website at this link https://media.jamanetwork.com/

(doi:10.1001/jamadermatol.2021.2007)

Editor's Note: The article includes conflicts of interest disclosures. Please see the article for additional information, including other authors, author contributions and affiliations, conflict of interest and financial disclosures, and funding and support.

What The Study Did: This survey study investigated the association between general surgery resident grit, which was defined as perseverance and passion for long-term goals, and burnout and thoughts of attrition and suicide.

Authors: Karl Y. Bilimoria, M.D., M.S., of Northwestern University in Chicago, is the corresponding author.

To access the embargoed study: Visit our For The Media website at this link https://media.jamanetwork.com/

(doi:10.1001/jamasurg.2021.2378)

Editor's Note: The article includes conflict of interest and funding/support disclosures. Please see the article for additional information, including other authors, author contributions and affiliations, conflict of interest and financial disclosures, and funding and support.

Boston - Data has historically shown that the majority of patients insured through Medicaid, as well as the uninsured, seek inpatient hospital care and services at safety-net hospitals. The Affordable Care Act expanded Medicaid to increase access to public insurance options for low-income individuals and families, as well as improve access to specialty medical care services. Results of a new study led by researchers at Boston Medical Center (BMC) show, however, that this expansion did not lead patients receiving care at safety-net hospitals to transfer their care to non-safety-net hospitals.

Published in JAMA Network Open, the national data review showed that discharges from safety-net hospitals were higher among Black and Hispanic patients living in higher-poverty zip codes compared to White patients in states that expanded Medicaid.

"While we thought that the expansion of Medicaid might lead some racial/ethnic minority patients to transfer their care to non-safety-net hospitals, where specialty care services can often be more accessible, our study results demonstrate that was not the case," said Karen Lasser, MD, MPH, an internal medicine physician at BMC who is the study's lead author.

Discharge data from 11 states that expanded Medicaid (NY, PA, NJ, KY, IL, IA, AR. CO, AZ, CA and OR) and six that did not expand Medicaid (TX, WI, FL, GA, NC and VA) between 2017 and 2021 were included in this study. This large data set included nearly 83 percent of the Hispanic population in the United States. Hospitals in the top quartile of the number of discharges among Medicaid and/or uninsured patients in 2012 were identified as safety-net hospitals. The data were grouped by age (26-64 years and over 65 years, with older individuals serving as a comparison group), zip code-poverty level, and race/ethnicity.

During the study period, the 17 states had a total of 18,289,417 Medicaid-covered and uninsured patient discharges- 59.4 percent of the discharges were in states with expanded Medicaid and 40.6 percent in non-expansion states. Among patients between 26-64 years old in expansion states, discharges at safety-net hospitals were higher among Black and Hispanic patients (38.5 percent and 39.2 percent, respectively) compared to white patients (22.6 percent), and these discharges occurred among patients from zip codes with higher poverty levels. The data did not show any systematic changes in safety-net hospitalizations among Medicaid-insured or uninsured patients in either expansion or non-expansion states, as well as among all subgroups by race/ethnicity and zip code-level poverty.

"Our study results could indicate that some patients with Medicaid are satisfied with their care and benefit from the services, such as case management and medical interpretation, available at many safety-net hospitals," added Lasser, professor of medicine and public health at Boston University Schools of Medicine and Public Health. "However, we need to improve our understanding of what drives these patients to make decisions about where they receive care, and just as important, address the underlying structural racism that may play a role in these decisions."

Politicians use emotional resources in their speeches in parliament depending on the type of debate and use emotive rhetoric strategically and selectively, mainly to attract voters. This is one of the main conclusions of a study published in the journal American Political Science Review (APSR) involving Toni Rodon, a professor with the UPF Department of Political and Social Sciences and member of the Research Group on Institutions and Political Actors, together with Moritz Osnabrügge (Durham University, as first author) and Sara B. Hobolt (London School of Economics and Political Science).

"Our research provides evidence that incentives to attract voters differ systematically depending on the type of debate"

In recent years, much research has been done showing that emotions are important in politics and that the use of emotive rhetoric, based on positive or negative language, is common during election campaigns. Research has also been conducted within political parties regarding the stance adopted and the dissent expressed in parliamentary debates, but when and why politicians use emotive rhetoric in their legislative speeches has been studied less, and is now elaborated on by the authors in their work.

Emotive language usually refers to a style of communication that arouses an emotional response from the listener, thus evoking positive or negative reactions that go beyond the specific meaning of the word or phrase used. So, it can be a powerful tool to convince people of the validity of a particular message, and from the point of view of electoral competition, there is evidence linking emotion-eliciting appeals with the electoral success of certain political formations.

Analysis of two million speeches in the House of Commons and in the Dáil Éireann

The analysis included in article covers two million speeches delivered in the House of Commons and in the Dáil Éireann, the lower houses of parliament of Great Britain and Ireland, respectively. Specifically, a million parliamentary speeches, i.e., all those that were delivered in the House of Commons between 2001 and 2019, and a further one million speeches delivered in the Dáil Éireann between 2002 and 2013.

The authors chose the British Parliament because it is one of the oldest in the world, an ideal institutional environment for studying these kinds of speeches. "We focused on the House of Commons because it is the more powerful of the two legislative chambers in the UK and the debates held there differ in terms of their profile and the size of the audience, which has allowed us to compare emotive rhetoric across different types of debate", the authors assert. In a second stage, the study of the speeches delivered in the lower house of the Irish parliament has allowed confirming and generalizing their findings.

High and low profile legislative debates: two different styles of discourse

The article which, based on an analysis of how politicians use emotive rhetoric in parliament, contributes to the understanding of political competition and legislative behaviour, underlines differences with regard to incentives that legislators have according to the type of debate. "Our research provides evidence that incentives to attract voters differ systematically depending on the type of debate", the authors suggest. Thus, in high-profile legislative debates, parliamentarians have more incentives to use emotive rhetoric to attract the attention of a wider audience, which they capture by using more emotive political content and language.

It could be said that PMQs is the debate to which citizens are most exposed, and this gives incentives for MPs to use more emotive language.

In the House of Commons, this is the case of Prime Minister's Questions (PMQs), a debate held weekly. It is a convention during which the prime minister answers questions from MPs, especially the leader of the opposition. It is the parliamentary highlight of the week, broadcast live and covered extensively by the media.

It could be said that PMQs is the debate to which citizens are most exposed, and this gives incentives for MPs to use more emotive language. Other high-profile debates are the Queen's Speech, which take place annually at the start of each new year of parliament (at which the Queen reads the government's main priorities, and which also involves the prime minister and the opposition leader) or the Dáil Leaders' Questions, which are put to the Irish prime minister.

Conversely, in low-profile legislative debates, which are not so avidly followed and generate less expectation, politicians mostly address their colleagues in parliament, and therefore emotional rhetoric is less pronounced.

A new application to measure emotive rhetoric

The study presents a new methodological application to measure emotive rhetoric, and it does so by combining the Affective Norms for English Words (ANEW) dictionary, with word-embedding techniques that enables creating a dictionary specific to the field. Thus, the new tool categorizes emotional and neutral words via ANEW and also identifies new words used in parliamentary speeches to broaden these two categories.

Word Clouds of Emotive and Neutral Words

For example, some of the neutral words incorporated by the authors are "walkway", "diameter", "metres" and "radiators" and some of the emotional words, "appalling", "empathy", "horrific" and "admiration". With regard to areas where we find a higher average level of emotive rhetoric there is "fabric of society", "social groups" and "welfare and quality of life", and the areas where we find a lower level of emotive rhetoric, "political system" and "economy". "Our measurement technique more accurately captures the emotive use of language in a political environment", the researchers assert.

The authors conclude their work with a reminder: although emotive parliamentary speeches may have positive implications, with increased public interest in the activities of their representatives and in politics in general, there is the risk of negative consequences: "Emotive rhetoric may also increase polarization and may favour politicians who prioritize emotional appeals over competent, coherent policy, and can harm the quality of deliberation and at the same time the quality of democratic representation", they warn.

Cambridge scientists have identified 200 approved drugs predicted to work against COVID-19 - of which only 40 are currently being tested in COVID-19 clinical trials.

In a study published today in Science Advances, a team led by researchers at the University of Cambridge's Milner Therapeutics Institute and Gurdon Institute used a combination of computational biology and machine learning to create a comprehensive map of proteins that are involved in SARS-CoV-2 infection - from proteins that help the virus break into the host cell to those generated as a consequence of infection. By examining this network using artificial intelligence (AI) approaches, they were able to identify key proteins involved in infection as well as biological pathways that might be targeted by drugs.

To date, the majority of small molecule and antibody approaches for treating COVID-19 are drugs that are either currently the subject of clinical trials or have already been through clinical trials and been approved. Much of the focus has been on several key virus or host targets, or on pathways - such as inflammation - where a drug treatment could be used as an intervention.

The team used computer modelling to carry out a 'virtual screen' of almost 2,000 approved drugs and identified 200 approved drugs that could be effective against COVID-19. Forty of these drugs have already entered clinical trials, which the researchers argue supports the approach they have taken.

When the researchers tested a subset of those drugs implicated in viral replication, they found that two in particular - an antimalarial drug and a type of medicine used to treat rheumatoid arthritis - were able to inhibit the virus, providing initial validation of their data-driven approach.

Professor Tony Kouzarides, Director of the Milner Therapeutics Institute, who led the study, said: "By looking across the board at the thousands of proteins that play some role in SARS-CoV-2 infection - whether actively or as a consequence of infections - we've been able to create a network uncovering the relationship between these proteins.

"We then used the latest machine learning and computer modelling techniques to identify 200 approved drugs that might help us treat COVID-19. Of these, 160 had not been linked to this infection before. This could give us many more weapons in our armoury to fight back against the virus."

Using artificial neural network analysis, the team classified the drugs depending on the overarching role of their targets in SARS-CoV-2 infection: those that targeted viral replication and those that targeted the immune response. They then took a subset of those involved in viral replication and tested them using cell lines derived from humans and from non-human primates.

Of particular note were two drugs, sulfasalazine (used to treat conditions such as rheumatoid arthritis and Crohn's disease) and proguanil (and antimalarial drug), which the team showed reduced SARS-CoV-2 viral replication in cells, raising the possibility of their potential use to prevent infection or to treat COVID-19.

Dr Namshik Han, Head of Computational Research and AI at the Milner Therapeutics Institute, added: "Our study has provided us with unexpected information about the mechanisms underlying COVID-19 and has provided us with some promising drugs that might be repurposed for either treating or preventing infection. While we took a data-driven approach - essentially allowing artificially intelligent algorithms to interrogate datasets - we then validated our findings in the laboratory, confirming the power of our approach.

"We hope this resource of potential drugs will accelerate the development of new drugs against COVID-19. We believe our approach will be useful for responding rapidly to new variants of SARS-CoV2 and other new pathogens that could drive future pandemics."

Predicting the potential effects of coral loss on fish communities globally is a fundamental task, especially considering that reef fishes provide protein to millions of people. A new study led by the University of Helsinki predicts how fish diversity will respond to declines in coral diversity and shows that future coral loss might cause a more than 40% reduction in reef fish diversity globally.

Corals increasingly bleach and often die when the water warms. What happens to fish if there are no alternative reefs to swim to? The few fish species that feed on corals will inevitably starve, but the rest might find alternative rocky habitat to persist. As yet, it has been hard to do the larger-scale studies that can project what fish will remain in a world without corals. A new study led by Giovanni Strona at the University of Helsinki finds that global projections of fish diversity without corals are as low as small-scale experiments suggest.

An international team of marine biologist started by mapping tropical fish and coral diversity across the world's oceans for every square degree latitude and longitude. These unprecedented maps showed what marine biologists have long known, fish and coral diversity vary widely, with many more species in the Indo-Pacific "coral triangle" than in the western Atlantic and eastern Pacific. Marine diversity hotspots have been long explained by the way that latitude, habitat, temperature, and geography affect speciation and extinction rates among corals and fishes alike. After controlling for factors that drive diversity in general, the authors found that areas with diverse corals still tended to have more diverse fishes, suggesting that coral diversity begets fish diversity.

"This is not particularly surprising given that corals provide a unique food source for some species, as well a three-dimensional habitat that many species use for shelter. And the fish that depend on corals may be prey for fish that don't depend directly on corals," says the lead author Giovanni Strona from the University of Helsinki.

After fitting the line between coral diversity and fish diversity, the authors did a simple thought experiment. They anticipated global coral extirpation by extrapolating the fish vs corals association down to the point where no coral species were left. That extrapolation suggested that around 40% of the world's tropical reef fishes are likely to disappear should corals disappear. As shown in smaller scale experiments, this is a much bigger loss than those species known to depend directly or even indirectly on coral, suggesting that coral reef food webs will begin to unravel if corals do go extinct. This unravelling is expected to be more intense some places than others. The Central Pacific is expected to lose more than 60% of its reef fish, compared with only 10% in the Western Atlantic.

"We first devised a statistical model to disentangle the effect of environment, biogeography and history on fish and coral diversity that accurately predicting local-scale fish diversity as a response to several environmental variables such as water temperature, pH and salinity and coral diversity," Strona explains.

"Besides offering a way to predict fish diversity under novel environmental conditions, the approach offered a tool to explore how fish diversity will vary in response to changes in coral diversity", continues Valeriano Parravicini, a co-leader of the study at the University of Perpignan.

"For anyone who has enjoyed snorkeling on a coral reef, or for the millions of people that depend on reef fishes for food, this thought experiment should be concerning. But it also inspires greater efforts to conserve and restore coral reefs. The benefits of doing so would extend far beyond corals, to fish and other organisms that depend directly or indirectly on corals," says Kevin Lafferty, Senior Scientist with the U.S. Geological Survey, at the University of California, Santa Barbara.

By the beginning of April 2021, the number of people infected during the COVID-19 pandemic had risen to more than 130 million people of whom more than 2.8 million died. The SARS-CoV-2 virus responsible for COVID-19 is transmitted particularly by droplets or aerosols emitted when an infected person speaks, sneezes or coughs. This is how the viruses and other pathogens spread through the environment and transmit infectious diseases when they are inhaled by someone else.

The capacity of these particles to remain suspended in the air and to spread in the environment depends largely on the size and nature of the air flow generated by the expiration of air. As with other airborne infectious diseases such as tuberculosis, common flu or measles, the role played by fluid dynamics is key to predicting the risk of infection by inhaling these particles in suspension.

In a coughing event that lasts for 0.4 seconds and has a maximum exhaled air speed of 4.8 m/s, the flow first generates a turbulent stream of air that is hotter and more humid than that of the environment. Once the expiration is over, the stream turns into a puff of air that rises because of flotation and its lack of weight while it dissipates.

The particles transported by this flow form clouds, the trajectories of which depend on their size. The dynamics of the largest particles are governed by gravity and describe parabolas with a clear horizontal limit. Despite their limited ability to remain in suspension and the limited horizontal scope, the viral load can be high because they are large (diameters larger than 50 microns).

In contrast, the smallest particles (with diameters shorter than 50 microns) are transported by the action of air flow. These aerosols are capable of remaining in suspension for longer times and they spread over a greater area. The largest particles remain in the air for a few seconds while the smallest can remain suspended for up to a few minutes, Even though their viral load is smaller, these aerosols can get through face masks and be moved from room to room, for example, through ventilation systems. The retention percentage of face masks decreases when the particles are smaller.

The behaviour of the particle cloud depends on the size of the particles and can be complicated by the effects of evaporation, which gradually reduces the diameter of the droplets.

With the support of the Consortium of University Services of Catalonia, the research group form the URV's Department of Mechanical Engineering, led by Alexandre Fabregat and Jordi Pallarés, in conjunction with researchers from the University of the State of Utah and the University of Illinois, has used high-performance numerical simulations to study in unprecedented detail the process of aerosol dispersion generated by a cough or a sneeze. The level of detail was so high that they needed considerable calculation power and numerous processors of a supercomputer working at the same time.

The results indicate that the plume of air produced by the expiration carries particles of less than 32 microns above the height of emission, which generates a cloud that has a great capacity to remain in suspension and be dispersed by air currents over a significant distance. The largest particles have a limited scope which is not changed by the effect of evaporation during the displacement to the ground. Assuming the habitual viral loads for infectious diseases, the results were used to draw a map of the concentration of viral particles around the infected person after they had coughed or sneezed.

This research has been published as two scientific articles in the journal Physics of Fluids with the titles "Direct numerical simulation of the turbulent flow generated during a violent expiratory event" and "Direct numerical simulation of turbulent dispersion of evaporative aerosol clouds produced by an intense expiratory event". Both articles were featured on the front cover because of their scientific impact.

Language distinguishes us humans; we learn it through experience and social interactions. Especially in the first year of life, human vocalizations change dramatically, becoming more and more language-like. In our closest relatives, non-human primates, language development was previously thought to be largely predetermined and completed within the first few weeks after birth. In a behavioral study now published, researchers from the German Primate Center, the University of Tübingen and the Rockefeller University New York were able to show that the infantile development of vocalizations in common marmosets also includes an extended flexible phase, without which language development in humans would not be possible. The common marmoset is therefore a suitable animal model to better understand the evolution of early infant speech development (Science Advances).

Human language changes dramatically in the first year after birth. It evolves from preverbal, not-yet-language-like calls such as laughter or crying, to pre-linguistic vocalizations, to a babbling phase in which utterances become increasingly language-like and complex. Here, several factors are considered particularly critical for vocal development, including maturation, learning, and early social interactions with parents.

In contrast, it was assumed for decades that phonation in monkeys develops exclusively as a result of physical growth and maturation and that it is independent of learning processes or external factors such as social interaction. For example, previous studies showed that deafness or social isolation due to the absence of parents has little or no effect on the vocal development of nonhuman primates, and that vocal development in most monkey species is completed within a few weeks after birth, so these animals appear to be equipped with the adult vocal repertoire by the juvenile stage. "One of the reasons for these findings is probably that previous work on voice development in non-human primates has mainly focused on the first weeks after birth and ignored possible changes associated with later growth in the following months until adulthood," says Yasemin Gültekin, first author of the study and a scientist at the German Primate Center.

A team led by Yasemin Gültekin and Steffen Hage from the German Primate Center - Leibniz Institute for Primate Research, The Rockefeller University New York and the University of Tübingen closely studied the sound development of common marmosets, a social primate species, from early infancy until sexual maturity at 15 months of age. During this period, the vocalization behavior of the animals kept at the Rockefeller University was recorded with microphones every month. In total, nearly 150,000 vocalizations of six marmosets were thus recorded and analyzed. "Our results show that, similar to the first months of human life, the vocalization behavior of marmosets changes through different developmental stages from the first weeks after birth to adulthood," says Kurt Hammerschmidt, who analyzed the data of the study at the German Primate Center.

The team found that all species-specific vocalization types were already present in the first month after birth and that their developmental changes in acoustic structure can be largely explained by physical maturation. These results are in agreement with previous work suggesting that the acoustic structure of vocalizations is innate and does not require learning through auditory or social feedback. "While changes in acoustic structure could be explained mainly by physical growth or maturation, we found that the way these vocalizations are used flexibly during development points to experiential learning mechanisms, which are one of the key features in human language development," says Gültekin, lead author of the study.

"Our work provides an important building block to better understand the evolutionary foundations of early human language development. It sets the stage for future studies on how social interactions can influence speech development," concludes Yasemin Gültekin.

Significantly higher rates of child intensive care admissions for unintentional cannabis poisonings have been seen following legalization of the drug in Canada.

Researchers from The Hospital for Sick Children (SickKids), based in Toronto, found a four-fold increase in unintentional poisonings in children under the age of 12 and a three-fold increase in intensive care admissions for severe cannabis poisoning in the first two years following cannabis legalization.

However, the overall number of visits per month for cannabis intoxications to the SickKids Emergency Department (ED) remained consistent when comparing the pre- and post-legalization periods. The findings were published in the peer-reviewed journal Clinical Toxicology.

Led by Dr Yaron Finkelstein, Staff Physician, Paediatric Emergency Medicine and Clinical Pharmacology and Toxicology at SickKids, the study compared cannabis-related ED visits, hospitalizations and intensive care unit (ICU) admissions at SickKids during pre- and post-legalization periods to analyze the unintentional impacts of the legislation.

"While uncommon in adults, cannabis intoxication can have significant negative impacts on young children including behavioural changes, seizures, respiratory depression, problems with coordination and balance, and even coma. As different formulations of cannabis continue to be legalized, it is important for everyone who has cannabis in their home, to be aware of the potential harms to children and ensure cannabis products are safely stored," notes Finkelstein, Senior Scientist, Child Health Evaluative Sciences at SickKids.

Measuring admissions for cannabis intoxication to SickKids over a 12-year period, from January 1, 2008 to December 31, 2019, the study identified that a higher proportion of children were admitted to the ICU following legalization (13.6% vs. 4.7%, respectively).

The study determined that the increases in severe intoxications from cannabis were primarily due to exposure of young children to cannabis edibles, which have become increasingly accessible and popular. Edible cannabis products are both highly concentrated and visually attractive to young children - leading to ingestion as the most consequential route of paediatric exposures. Inconsistencies and difficulties in determining the exact formulation and potency of the edible ingested can also make it challenging for health-care providers to anticipate the severity and length of the effects of cannabis exposure.

The study team, including researchers and trainees from across SickKids, hopes that by raising awareness of the potential dangers of unintentional cannabis poisonings, the findings will encourage the public to be even more careful when storing cannabis products within the home, particularly edibles that can often be mistaken by children for regular food and candy.

"As the COVID-19 pandemic has presented more opportunities for families to be at home, it is even more important to ensure that substances, such as cannabis, are stored out of the reach of young children. There are simple actions everyone can take to help prevent unintentional poisonings and keep children safe, including keeping cannabis products in a locked container, away from other food and drinks" adds Finkelstein, who is also a Professor, Departments of Paediatrics and Pharmacology and Toxicology at the University of Toronto.

A McGill-led study has shown that the size of the Maya population in the lowland city of Itzan (in present-day Guatemala) varied over time in response to climate change. The findings, published recently in Quaternary Science Reviews, show that both droughts and very wet periods led to important population declines.

These results are based on using a relatively new technique involving looking at stanols (organic molecules found in human and animal faecal matter) taken from the bottom of a nearby lake. Measurements of stanols were used to estimate changes in population size and to examine how they align with information about climate variability and changes in vegetation drawn from other biological and archaeological sources.

By using the technique, the researchers were able to chart major Maya population changes in the area over a period starting 3,300 years before the present (BP). They were also able to identify shifts in settlement patterns that took place over the course of hundreds of years that are associated with changes in land use and agricultural practices.

They discovered, moreover, that the land had been settled earlier than previously suggested by archaeological evidence.

New tool provides surprising information about human presence in Maya lowlands

The evidence from faecal stanols suggests that humans were present on the Itzan escarpment about 650 years before the archaeological evidence confirms it. It also shows that that the Maya continued to occupy the area, albeit in smaller number, after the so-called "collapse" between 800-1000 AD, when it had previously been believed that drought or warfare caused the entire population to desert the area. There is further evidence of a large population spike around the same time as a historical record of refugees fleeing the Spanish attack of 1697 AD on the last Maya stronghold in the southern Maya lowlands (Nojpeten, or modern-day Flores in Guatemala) - something that had not been known before.

Estimates of ancient population size in the Maya lowlands have traditionally been obtained through ground inspection and excavation. To reconstruct population dynamics, archaeologists locate, map, and count residential structures, and they excavate them to establish dates of occupation. They compare population trends at the site and regional levels. And they then use techniques such as pollen analysis and indicators of soil erosion into lakes to reconstruct the ecological changes that took place at the same time.

"This research should help archaeologists by providing a new tool to look at changes that might not be seen in the archaeological evidence, because the evidence may never have existed or may have since been lost or destroyed," said Benjamin Keenan, a PhD candidate in the Department of Earth and Planetary Sciences at McGill, and the first author on the paper. "The Maya lowlands are not very good for preserving buildings and other records of human life because of the tropical forest environment."

Maya population size affected by both droughts and wet periods

The faecal stanol from the sediment in Laguna Itzan confirms that the Maya population in the area declined due to drought at three different periods; between 90-280 AD, between 730-900 AD and during the much less well studied drought between 1350-950 BC. The researchers also found that the population declined during a very wet period from 400--210 BC, something which has received little attention until now. The population decline in response to both dry and wet periods shows that there were climatic effects on population at both climate extremes, and not only during dry periods.

"It is important for society generally to know that there were civilisations before us that were affected by and adapted to climate change," said Peter Douglas, an assistant professor in the Department of Earth and Planetary Sciences and the senior author on the paper. "By linking evidence for climate and population change we can begin to see a clear link between precipitation and the ability of these ancient cities to sustain their population."

The research also suggests that the Maya people may have adapted to environmental issues such as soil degradation and nutrient loss by using techniques such as the application of human waste (also known as night soil) as a fertiliser for crops. This is suggested by a relatively low amount of fecal stanols in the lake sediment at a time when there is archaeological evidence for the highest human populations. One explanation for this is that human waste was applied to soils as fertilizer and therefore the stanols were not washed into the lake.

Increasing our understanding of cellular processes requires information about the types of biomolecules involved, their locations, and their interactions. This requires the molecules to be labeled without affecting physiological processes (bioorthogonality). This works when the markers are very quickly and selectively coupled using small molecules and "click chemistry". In the journal Angewandte Chemie, a team of researchers has now introduced a novel type of click reaction that is also suitable for living cells and organisms.

As an example, labeling biomolecules allows for the localization and characterization of tumors when an antibody that binds to specific molecules in the tumor cells is injected. A dye is then also injected. The antibodies and the dye are both equipped with small molecular groups that have almost no influence on cellular processes. When they encounter their counterpart, they bind immediately and specifically to each other with no side reactions--as easily as the two parts clicking together. This is where the term click chemistry comes from. The dye only remains attached to tumor cells, making them detectable.

The most well-known click chemistry reaction is the azide-alkyne reaction. An azide group reacts with an alkyne group to form a five-membered ring. However, this reaction requires a toxic copper catalyst, making it unsuitable for living systems. An alternative is the use of cyclic alkynes, in which the triple bond is under so much strain that the reaction works without a catalyst. Yet, the cycle can be unsuitable for some applications.

A team headed by Justin Kim at the Dana-Farber Cancer Institute and Harvard Medical School (Boston, USA) has now developed an alternative click reaction with linear, terminal alkynes, which works rapidly and is catalyst-free under complex physiological conditions. After a precise analysis of the electronic interactions in alkynes and tests with a variety of substituents, the team found that certain alkynes with halogens on both sides of the triple bond are reactive enough. The trick was to balance the different influences of the individual substituents so that the alkynes were sufficiently activated (push-pull activation) to react without a catalyst while remaining safe from attack by cellular components. For the other half of the click unit the team chose to use N,N-dialkylhydroxylamines (organic compounds containing both nitrogen and oxygen) instead of the conventional azides. The resulting reaction products (enamine-N-oxides) are biocompatible.

These new click reactions (retro-Cope eliminations) are very fast. The products are formed regioselectively, and the components are sufficiently stable and can easily be introduced to biomolecules. This broadens the spectrum of bioorthogonal coupling reactions for cellular labeling in living systems.

Plants play an essential role in curbing climate change, absorbing about one-third of the carbon dioxide emitted from human activities and storing it in soil so it doesn't become a heat-trapping gas. Extreme weather affects this ecosystem service, but when it comes to understanding carbon uptake, floods are studied far less than droughts - and they may be just as important, according to new research.

In a global analysis of vegetation over more than three decades, Stanford University researchers found that photosynthesis - the process by which plants take up carbon dioxide from the atmosphere - was primarily influenced by floods and heavy rainfall nearly as often as droughts in many locations. The paper, published in Environmental Research Letters on June 29, highlights the importance of incorporating plant responses to heavy rainfall in modeling vegetation dynamics and soil carbon storage in a warming world.

"These wet extremes have basically been ignored in this field and we're showing that researchers need to rethink it when designing schemes for future carbon accounting," said senior study author Alexandra Konings, an assistant professor of Earth system science in Stanford's School of Earth, Energy & Environmental Sciences (Stanford Earth). "Specific regions might be much more important for flood impacts than previously thought."

More photosynthesis in combination with other factors can enable greater amounts of carbon to be stored in the soil over the long term, according to the researchers. To estimate the presence of photosynthesis, they analyzed plant greenness according to publicly available satellite data from 1981 to 2015.

Because the field of carbon accounting is dominated by research on drought impacts, the co-authors were surprised to find that photosynthesis was affected by flooding so frequently - in about half the regions in the analysis. While drought is known to decrease photosynthesis, wet extremes can either decrease or accelerate the process.

"I think the drought side is probably something that many of us understand clearly because we can see soils drying out - we know that plants need water to be able to function normally," said lead study author Caroline Famiglietti, a PhD student in Earth system science.

Using statistical analysis, the researchers divided the globe into regions and isolated periods during which the plants' photosynthetic activity wouldn't have resulted from other factors, such as temperature or sunlight changes. They then used several long-term soil moisture datasets to determine which locations were more sensitive to extreme wet events than to extreme dry events and found that many regions in central Mexico, eastern Africa and northern latitudes should be targeted for further investigation.

"Everything that is observed in this master dataset reflects the behavior of the broader climate system," Famiglietti said. "This paper identified something surprising, but it didn't answer all the questions we still have."

In a warmer world, extreme weather is projected to become more intense, extensive and persistent, but the mechanisms controlling drought responses in plants are much better understood than extreme wet responses. The findings suggest an opportunity to address "a big component of the uncertainty in future climate change and its links to ecosystem carbon storage," according to Konings.

"If we can better understand these processes, we can improve modeling and better prepare for the future," Famiglietti said.