Culture

A 30-year high in East African rainfall during 2018 and 2019 resulted in rising water levels and widespread flooding. The new study shows that emissions of methane - the second most important greenhouse gas - from flooded East African wetlands were substantially larger following these extreme rainfall events.

The study, led by Dr Mark Lunt from the University of Edinburgh's School of GeoSciences, used data from two different satellites in combination with an atmospheric model to evaluate methane emissions from East Africa. This included data from the European TROPOMI satellite instrument, launched in 2017, which provides information about atmospheric methane at unprecedented spatial resolution.

"Our study is one of the first times the new TROPOMI satellite data has been used to study regional methane emissions," says Dr Lunt. The satellite observed enhanced methane concentrations over East Africa during the anomalously wet months between October and December 2019.

Using these data, the authors found that, in the final three months of 2019, following a once in 30-year extreme rainfall event, emissions from East Africa were substantially larger than the same period in the previous year.

"The extra emissions were equivalent to the UK's annual total emissions of methane in just a three-month period" says Dr Lunt. Indeed, the authors found the additional emissions in 2019 were large enough to account for over a quarter of the global annual increase in methane emissions. The study shows these increased emissions were most likely to be from natural wetlands as a result of the additional rainfall.

According to the authors, the findings - published in the journal Environmental Research Letters - could be of significance for future methane emissions.

Prof. Paul Palmer, from the University of Edinburgh, who co-authored this work, said: "Climate models suggest that in the future there will be an increased frequency of these extreme rainfall events over East Africa. Our findings show that such a future scenario will have far-reaching consequences for global concentrations of atmospheric methane."

PULLMAN, Wash. - Fortune 500 firms with strong growth profiles are more susceptible to "cooking the books" than smaller, struggling companies, according to a recent study published in Justice Quarterly.

Researchers from Washington State University, Pennsylvania State University and Miami University examined the characteristics of more than 250 U.S. public corporations that were involved in financial securities fraud identified in Securities and Exchange Commission filings from 2005-2013. They were then compared to a control sample of firms that were not named in SEC fraud filings.

Clear trends emerged in the risk of fraud including corporations that were listed in the Fortune 500, traded on the New York Stock Exchange and had strong growth expectations.

"Prestigious companies, those that are household names, were actually more prone to engage in financial fraud, which was very surprising," said Jennifer Schwartz, WSU sociologist and lead author on the study. "We thought it would be companies that were struggling financially, that were nearing bankruptcy, but it was quite the opposite. It was the companies that thought they should be doing better than they were, the ones with strong growth imperatives--those were the firms that were most likely to cheat."

Corporate financial securities fraud involves attempts to manipulate financial markets in a business' favor by using faulty accounting practices, providing false or incomplete information or otherwise misrepresenting the company's financial status.

The researchers noted that this type of elite, white-collar crime is understudied especially when compared with street crime even though it has more wide-reaching consequences.

"What these companies were doing was essentially fudging the numbers, lying to investors, other companies and the SEC," said Schwartz. "Eventually, you have to make up for the money that was lost, that really never existed, so shareholders lose money, people lose retirement plans, people lose jobs. It's very, very damaging."

Schwartz and her co-authors decided to look at the time period around the global financial crisis that included the fraud scandals of WorldCom and Enron, and the subsequent regulatory Sarbanes-Oxley Act of 2002.

The goal was to identify the conditions at publicly traded companies in which there was a greater risk for fraud. The researchers found that companies with Fortune 500 status were represented nearly four times as often among the firms that had committed fraud than in the nonfraudulent control group. Likewise, firms that traded on NYSE were over-represented among fraudulent firms versus non-fraud - by nearly two to one, a higher rate than those that trade on other exchanges like the NASDAQ or OTC.

The study also revealed that fraud occurred more often in firms where the CEO was also the chair of the board, a potential connection that Schwartz and her colleagues are investigating further.

"We need to look more at corporate leadership arrangements, and the responsibility of individuals in creating the culture of the company itself," she said. "How can leaders encourage companies to be more successful not only in terms of profit or growth but also in terms of corporate social responsibility?"

PITTSBURGH, 2 February, 2021 - Researchers seeking to develop on-demand and behaviorally congruent HIV prevention options for people who practice anal sex are reporting the results of three early phase clinical trials of rectal microbicides at this week's HIV Research for Prevention (HIV R4P) Virtual Conference. The Phase I studies, led by the U.S. National Institutes of Health (NIH)-funded Microbicide Trials Network (MTN), found both of two gel-based products well-tolerated, with higher doses of the active drugs likely required to provide protection from HIV and other sexually transmitted infections (STIs). The results are being presented at the oral abstract session, Bottoms Up: New insights about rectal infections and HIV/STI prevention, on Wednesday, Feb. 3.

Rectal microbicides are topical products being developed and tested to reduce a person's risk of HIV and other STIs from anal sex. On-demand products refer to those that could be used around the time of sex, while behaviorally congruent rectal microbicides deliver anti-HIV drugs via products people may be already using as part of their sex routine. Researchers are interested in exploring these products as possible alternatives to systemic pre-exposure prophylaxis, or PrEP.

"It's naïve to believe that oral products and other systemic delivery methods for PrEP will work for everyone," said Craig Hendrix, M.D., professor, Johns Hopkins University School of Medicine, who heads rectal microbicide research at the MTN. "There are some people who only want HIV prevention on-demand. They don't want drug in their body when they don't need it there. There are others who would like to have something that's behaviorally congruent, like a lube or a douche they're already using, but with a protective anti-HIV medication added. It's a matter of finding something that meets individual needs so that we can cover more people with products that work best for them."

The MTN-026 study, being presented by Craig Hoesley, M.D., professor, University of Alabama at Birmingham, evaluated the rectal safety of a gel containing 0.05 percent of the antiretroviral (ARV) drug dapivirine, as well as the levels of drug detected in blood, rectal fluid and rectal tissue after use. The gel formulation of dapivirine was originally developed for vaginal administration by the non-profit International Partnership for Microbicides (IPM), who also developed the monthly dapivirine vaginal ring that is advancing toward potential regulatory approvals for use by cisgender women to prevent HIV transmission. The MTN-026 study enrolled 27 HIV-negative cisgender and transgender men and women at sites in Thailand and the United States who were randomized to receive either dapivirine gel or a placebo (inactive) gel. While in the clinic, participants used an applicator to insert their assigned gel, first as a single dose, and then for seven consecutive
days following a two-week break. Study results showed that the gel was well-tolerated and acceptable to participants, with tissue concentrations suggesting a longer-acting formulation or a higher-dose gel would be required to provide effective protection from HIV transmission through anal sex.

A second study of dapivirine gel used as a rectal microbicide, MTN-033, being presented by Ken Ho, M.D., M.P.H., assistant professor, University of Pittsburgh School of Medicine, explored the safety and drug levels of the 0.05 percent dapivirine gel administered rectally with an applicator versus a lubricant (without an applicator) through anal sex with a simulated phallus. Given that using lube is a common practice during anal sex, researchers were interested in whether enough dapivirine could be delivered in this behaviorally congruent way to protect against HIV. The study, conducted at one clinical site in the United States with 16 HIV-negative cisgender men who have sex with men, found that after delivery of dapivirine gel as a rectal lube, drug levels in blood were a third of the levels observed after delivery with an applicator, which was more than expected based on prior studies of lube-based rectal gels. However, dapivirine did not remain in tissue long enough to provide sustained protection. Even so, researchers are encouraged by these results because they support the possibility of a medicated lube as a promising behaviorally congruent strategy for prevention of HIV transmission from anal sex.

The final rectal microbicide study, MTN-037, also being presented by Dr. Ho, evaluated the safety of a microbicide gel called PC-1005 for use in the rectum. Developed by the Population Council, PC-1005 is a multipurpose prevention technology gel that contains 0.002 percent MIV-150 (a potent ARV), 0.3 percent zinc acetate dihydrate (an anti-herpes simplex virus type 2, or HSV-2, agent) and 3 percent carrageenan (a potent anti-HIV agent and gellant). In laboratory and animal studies, PC-1005 was shown to be active against several STIs, including HIV, human papillomavirus (HPV) and HSV-2. MTN-037, which included 12 HIV-negative cisgender men and women at two sites in the United States, found that the gel was safe and well-tolerated with low systemic MIV-150 exposure. Through tissue sampling, researchers also concluded that a longer-acting formulation or higher dose of MIV-150 would be required to deliver an adequate amount of the drug for it to be effective at preventing the rectal transmission of HIV.

"Taken together, these studies show us that these drugs can be dosed rectally, including as an anal lube, get into the rectal tissue, and also provide evidence of virus suppression," concluded Dr. Hendrix. "As first in human trials, they represent a good starting point for optimizing the product formulations. We'll need some changes to make products like these viable, but they provide proof of principle that we can deliver an on-demand drug rectally."

Resurgent COVID-19 epidemics in the US in 2020 have been driven by adults aged 20-49, and in particular adults aged 35-49, before and after school reopening

Reproduction numbers for all age groups were controlled to well below one except for individuals aged 20-49

Across the US as a whole, the mobility trends indicate substantial initial declines in venue visits followed by a subsequent rebound for all age groups

Share of age groups among the observed COVID-19 deaths was remarkably constant

School reopening has not resulted in substantial increases in COVID-19 attributable deaths

As of October 2020, individuals aged 20-49 were the only groups sustaining COVID-19 transmission with reproduction numbers well above 1 in the US, according to the latest publication in Science today by the Imperial College COVID-19 Response team.

Following initial declines, numbers of COVID-19 cases started to rise again halfway through 2020 in the United States and Europe. In September the team published report 32, using age-specific mobility data from across the United states and linking these to age-specific COVID-19 mortality. Their findings pointed out that targeting interventions to adults aged 20-49 could facilitate safe reopening of schools and kindergartens.

The peer reviewed publication in Science today includes new data up to October 2020. The updated analysis of aggregated age-specific mobility data from more than 10 million individuals in the US, shows that 65 of 100 COVID-19 infections still originated from individuals aged 20-49 in the US.

Across the US as a whole, the mobility trends indicate substantial initial declines in venue visits (such as visit by an individual to locations like supermarkets and restaurants) followed by a subsequent rebound for all age groups. In contrast with the large fluctuations in the share of age groups among reported COVID-19 cases, the study describes the share of age groups among the observed COVID-19 deaths remarkably constant.

The researchers find that in locations where novel highly-transmissible SARS-CoV-2 lineages have not yet established, additional interventions among adults aged 20-49, such as mass vaccination with transmission-blocking vaccines, could bring resurgent COVID-19 epidemics under control and avert deaths.

The work is presented in the latest report from Imperial's Department of Mathematics and the WHO Collaborating Centre for Infectious Disease Modelling within the MRC Centre for Global Infectious Disease Analysis, Abdul Latif Jameel Institute for Disease and Emergency Analytics (J-IDEA), Imperial College London.

Since the emergence of the new coronavirus (COVID-19) in December 2019, the Imperial College COVID-19 Response Team has adopted a policy of immediately sharing research findings on the developing pandemic.

Quotes from authors:

Dr Samir Bhatt, from Imperial College London, said: "This work is a big step in understanding how age affects the dynamics of COVID-19 epidemics. We would like thank in particular all epidemiologists at state Departments of Health who work tirelessly to update data on the evolving COVID19 epidemics. Without this effort, this study would not have been possible."

Dr Melodie Monod, from Imperial College London, said: "We find adults aged 20-49 are a main driver of the COVID-19 epidemic in the United State and are the only age groups contributing disproportionally to onward spread, relative to their population size. While children and teens contribute more to COVID19 spread since school closure mandates have been lifted in fall 2020, we find these dynamics have not changed substantially since school re-opening."

Dr Oliver Ratmann, from Imperial College London, said: "We believe this study is important because we demonstrate that adults aged 20-49 are the only age groups that have consistently sustained COVID-19 spread across the US, despite large variations in the scale and timing of local epidemics. Thus - at least where highly transmissible variants have not established - additional interventions targeting the 20-49 age group could bring resurgent epidemics under control and avert deaths."

By late summer 2020, the resurgence of COVID-19 in the United States was largely driven by adults between the ages of 20 and 49, a new study finds. The results indicate that in locations where novel highly transmissible SARS-CoV-2 lineages have not yet established, additional interventions among adults of these ages could bring resurgent COVID-19 epidemics under control and avert deaths. Following initial declines in the number of reported SARS-CoV-2 infections and deaths - a result largely attributed to non-pharmaceutical interventions - a resurgence in transmission of COVID-19 occurred in the United States and Europe beginning in August 2020. Understanding the age demographics that drove this is crucial. For example, between August and October 2020, school closure mandates were lifted in many United States locations. Whether the resurgent epidemics of SARS-CoV-2 during 2020 can be explained by students going back to school has been an open question. To help address this, Mélodie Monod et al. used detailed, longitudinal, and age-specific population mobility and COVID-19 mortality data to estimate how non-pharmaceutical interventions, changing contact intensities, age, and other factors interplayed. Part of the authors' approach involved analyzing aggregated, age-specific mobility trends from more than 10 million individuals' cell phones. The mobile device signals could be used to pinpoint the time, duration, and location of user visits to U.S. locations such as shops, parks, or universities. The authors incorporated this mobility data into a Bayesian contact-and-infection model. As of their last observation week in October 2020, and following evaluations of reproduction numbers - which consider secondary infections one infected person generates - and data on transmission chains, their results suggest school reopening did not result in substantial increases in COVID-19 attributable deaths. Instead, data suggest that SARS-CoV-2 transmission was sustained primarily by people in age groups 20-49. "[A]dults aged 20-49 naturally have most contacts to other adults aged 20 and above" and these, the authors say, are both more susceptible and more mobile than younger age groups. They conclude: "This study provides evidence that the resurgent COVID-19 epidemics in the US in 2020 have been driven by adults aged 20-49, and in particular adults aged 35-49, before and after school reopening."

Loess Plateau possesses a particular loess physiognomy with numerous ravines and slopes, and tableland is a typical landform in it. Together, the ununiform in both topographic undulation and land coverage compose the ununiform, complex underlying surface on Loess Plateau. This provides a special platform for research of turbulence above the complex underlying surface.

As the front-edge problem encountered in the atmospheric boundary layer thesis, the turbulence research for complex underlying surface has drawn extensive attention recently. Local similarity has already proven that under certain condition, theories of turbulence based on the uniform underlying surface can also be applied to which for the ununiform underlying surface. However, as there are still many inapplicable aspects for the complex underlying surface due to its complexity. For eddy-correlation technique, the basic principles of turbulence measurements are ensemble averages of certain space, time, and status, but it is impossible to set up massive equipment within a limited space and obtain all-state for turbulence eddy for a required period time while meeting the ensemble average. Therefore, this experiment bases on such assumption that the fluid field is steady and space are horizontally uniform by replacing the ensemble average with the average of a long-time measurement at one site. So it is necessary to regard the examination of ergodicity for the eddy-correlation technique as the precondition for the experimental research of turbulence in complex terrain of Loess Plateau tableland in its early stage.

Originated in statistic mechanics, the ergodic hypothesis, a principle of examination in microcosmic problem from macro-perspective, has been widely applied recently. Ergodicity theorem has given necessary and sufficient conditions for the stationary stochastic process to satisfy ergodicity. A few researches have revealled the ergodicity of turbulence from Navier-Stokes formula and qualitative researches. We have studied the ergodicity of turbulence measurements above uniform underlying surface. However, it is not researched how atmospheric stratification stability influences on the satisfaction of the ergodic hypothesis. Moreover, low-frequency processes are non-negligible in the estimation of turbulence flux. Under the existing observation conditions, what range of low-frequency processes can satisfy the ergodichy pothesis? These problems are imperative in the early stage of experimental research in turbulence and will be the basis of further researches.

Based on the analysis above, the possible main issues that influence accuracies in measurements of turbulences are the ergodicity of incomplete turbulences such as the unavoidable flows around bodies, especially for those on the Loess Plateau. So, the effects of Monin-Obukhov (M-O) stability on the ergodicity of different scale turbulence in surface layer are studied by applying turbulence data in the tableland of Loess Plateau in this paper. The main goal is to establish a proper scale for turbulence measurements and to improve the estimation accuracy on turbulence flux.

The comprehensive comparison of ergodicity for different-scale horizontal wind velocity, vertical wind velocity, and temperature turbulence under various stratification stability conditions fails to conclude a law of variation for turbulence measurement ergodicity with respect to the change of stratification stability. Turbulence measurement results show that with more steady turbulence signal, it can satisfy ergodicity more easily. Essentially, the steadiness of the turbulence signal is consistent with the uniformity of turbulence distribution. This means that during the single-point turbulence measurement, the more uniform the distribution of turbulence during a longtime interval, the higher the accuracy of the turbulence measurement can be. The steady turbulent field is more likely to appear on the Loess Plateau than on the flat underlying surface. The smallest-scale eddies inside the inertial sub-regionare unsteady since the intension of the energy region and the atmospheric stratification conditions affects the frequency and the waveband corresponding to the Kolmogorov energy cascade (fE(f)?f-2/3) part. For the large-scale eddies with a three-dimensional coherent structure, difference in energy spectrum will affect the position and energy size with corresponding frequency in the fE(f)?f-2/3 spectral coverage, and cause the ununiform distribution of eddies in the fE(f)?f-2/3 energy spectrum. However, as long as the measurement time of 1 h is long enough, though the distribution of the small-scale eddies is ununiform, statistically, they can satisfy ergodicity within certain stratification range, and it can be called as quasi-ergodicity.

The reseach suggests that ergodicity in turbulence measurement under the condition of loess plateau tableland complex terrain features following characteristics: (1) Whether the turbulence can satisfy ergodicity depends on the steadiness of various-scale turbulence distribution, and it does not show simple variation with the change of M-O stability. Generally, from the weakly stable stratification to the weakly unstable stratification, turbulence can satisfy ergodicity relatively easily. Under the condition of extremely stable stratification, turbulence does not readily satisfy ergodicity due to the change in large-scale, poor periodic temperature and wind velocity caused by turbulence intermittence. (2) The influence of terrain tends to result in a long-period steady turbulence coherent structure. Therefore, comparing with the flat underlying surface, relatively large-scale turbulence under the condition of complex terrain tends to satisfy ergodicity more easily. (3) For single-point turbulence measurement of 1h, though the small-scale turbulence can satisfy ergodicity, due to the difference in intensity in different locations of large-scale turbulence eddies, the small-scale eddies, with the scale of dozens of seconds, in the inertial sub-region is unsteady.

In sum, measurement of ergodicity can not only help understand if turbulence measurement can satisfy theory requirements, but can also help master the distribution of eddies with various scales in-depth and establish a sweeping scheme for problems such as lidar turbulence measurement. More importantly, ergodicity from single-point turbulence measurement features relatively significant differences with multipoint turbulence measurement. The structure of large-scale eddies, the distribution characteristic of small-scale eddies, and the difference in turbulence intensity and relevant flux for 1h and 30min oftime intervals and for various ergodicity conditions will be discussed with the 6 eddy-correlation system measurement in next essay.

Residential gardens are a poor substitute for native bushland and increasing urbanisation is a growing threat when it comes to bees, Curtin University research has found.

Published in 'Urban Ecosystems', the research looked at bee visits to flowers, which form pollination networks across different native bushland and home garden habitats.

Lead author, Forrest Foundation Scholar Miss Kit Prendergast, from Curtin's School of Molecular and Life Sciences said the findings highlight the need to prevent destruction of remaining bushland and preserve native vegetation, in order to protect sustainable bee communities and their pollination services.

"Our study involved spending hundreds of hours at 14 sites on the Swan Coastal Plain at Perth, Western Australia, recording which bees visited which flowers in the two types of habitats - gardens and native bushland," Miss Prendergast said.

"From these bee-plant interactions I was able to map pollination networks, which could be analysed to determine how 'healthy' each habitat was for bees and the pollination services it provided, as well as how much potential competition there was between different bee groups, such as between introduced European honeybees and native bee groups.

"We found residential gardens were structurally different to those in bushland remnants, and the increasing loss of these native areas for residential development could disrupt important bee-plant interactions."

Miss Prendergast said that while bushland remnants were more favourable environments for thriving pollination networks of bees and flowers, the chance of bee populations completely disappearing from an area was higher than in residential gardens.

"This suggests that, if disrupted for urban development, bee and plant populations in native bushland remnants would be even more prone to extinctions," Miss Prendergast said.

"The research shows the importance of bushland preservation to the survival and health of bee populations and the broader ecosystems.

"This has implications for the conservation of wild bee populations in this biodiversity hotspot, and suggests removal of remnant native vegetation for residential development could disrupt the balance and integrity of local ecosystems and lead to extinctions."

Co-authored by Professor Jeff Ollerton from the University of Northampton, the full paper, 'Plant-pollinator networks in Australian urban bushland remnants are not structurally equivalent to those in residential gardens', can be found online.

Researchers have shown how disposable face masks could be recycled to make roads, in a circular economy solution to pandemic-generated waste.

Their study shows that using the recycled face mask material to make just one kilometre of a two-lane road would use up about 3 million masks, preventing 93 tonnes of waste from going to landfill.

Developed by researchers at RMIT University in Melbourne, Australia, the new road-making material is a mix of shredded single-use face masks and processed building rubble designed to meet civil engineering safety standards.

Analysis shows the face masks help to add stiffness and strength to the final product, designed to be used for base layers of roads and pavements.

The study published in the journal Science of the Total Environment is the first to investigate potential civil construction applications of disposable surgical face masks.

The use of personal protective equipment (PPE) has increased dramatically during the COVID-19 pandemic, with an estimated 6.8 billion disposable face masks being used across the globe each day.

First author Dr Mohammad Saberian said multidisciplinary and collaborative approaches were now needed to tackle the environmental impact of COVID-19, particularly the risks associated with the disposal of used PPE.

"This initial study looked at the feasibility of recycling single-use face masks into roads and we were thrilled to find it not only works, but also delivers real engineering benefits," Saberian said.

"We hope this opens the door for further research, to work through ways of managing health and safety risks at scale and investigate whether other types of PPE would also be suitable for recycling."

Making roads with masks

Roads are made of four layers: subgrade, base, sub-base and asphalt on top. All the layers must be both strong and flexible to withstand the pressures of heavy vehicles and prevent cracking.

Processed building rubble - known as recycled concrete aggregate (RCA) - can potentially be used on its own for the three base layers.

But the researchers found adding shredded face masks to RCA enhances the material while simultaneously addressing environmental challenges on two fronts: PPE disposal and construction waste.

Construction, renovation and demolition account for about half the waste produced annually worldwide, and in Australia, about 3.15 million tons of RCA is added to stockpiles each year rather than being reused.

The study identified an optimal mixture - 1% shredded face masks to 99% RCA - that delivers on strength while maintaining good cohesion between the two materials.

The mixture performs well when tested for stress, acid and water resistance, as well as strength, deformation and dynamic properties, meeting all the relevant civil engineering specifications.

While the experimental study was conducted with a small amount of unused surgical face masks, other research has investigated effective methods for disinfecting and sterilising used masks.

A comprehensive review of disinfection technologies found 99.9% of viruses could be killed with the simple "microwave method", where masks are sprayed with an antiseptic solution then microwaved for one minute.

In related work, the RMIT researchers have also investigated the use of shredded disposable face masks as an aggregate material for making concrete, with promising preliminary findings.

Professor Jie Li leads the RMIT School of Engineering research team, which focuses on recycling and reusing waste materials for civil construction.

Li said the team was inspired to look at the feasibility of blending face masks into construction materials after seeing so many discarded masks littering their local streets.

"We know that even if these masks are disposed of properly, they will go to landfill or they'll be incinerated," he said.

"The COVID-19 pandemic has not only created a global health and economic crisis but has also had dramatic effects on the environment.

"If we can bring circular economy thinking to this massive waste problem, we can develop the smart and sustainable solutions we need."

Optical waveguides suspended in air are capable to beat free-space laser beams in light-analyte interaction even without complex dispersion engineering. This phenomenon has been predicted more than 20 years ago, yet never observed in experiment.

In a new paper published in Light Science & Application, a team of scientists, led by Professor Jana Jágerská from Department of Science and Technology, UiT The Arctic University of Norway, and co-workers have devised a mid-infrared free standing solid core optical waveguide which pushes the light interaction with the surrounding air beyond what has been reported up until now: 107 % interaction strength compared to that of a free-space beam has been demonstrated.

"The guided mode of our thin waveguide resembles a free-space beam: it is strongly de-localized and travels predominantly in air. But, at the same time, it is still bound to the chip and can be guided along a pre-defined e.g. spiral waveguide path."

This is a significant achievement from the perspective of basic research but also an important step towards practical applications in on-chip gas sensing. Thanks to the high air-confinement of the guided mode, the waveguide not only improves upon the light-analyte interaction, but the guided light also experiences minimal overlap with the solid waveguide core material. This means that the guided mode is only marginally disturbed by material or structural imperfections, which suppresses undesired loss, scattering or reflections. The waveguide hence delivers transmission nearly free from spurious etalon fringes, which are of utmost importance for applications in trace gas spectroscopy.

"The main killer of precision of TDLAS instruments are [spectral] fringes, and integrated nanophotonic components typically produce plenty of them. Our chips are different. The theoretical reflections on the waveguide facets are as low as 0.1 %, and spurious fringes in transmission are therefore suppressed to below the noise level."

This optical waveguide fits therefore very well into the prospect of a future miniature trace gas sensors. Sensitive and selective integrated sensors based on the reported waveguide chips would not only down scale the dimensions of existing trace gas analysers, but also allow for microlitre sensing volumes and deployment in distributed sensors networks, leading to new applications in environmental monitoring, biology, medicine, as well as industrial process control.

The COVID-19 pandemic has upended many parts of daily life, one of them being our work life. Research carried out by the Universitat Oberta de Catalunya (UOC) has studied the factors that help make efficient work teams. The explanation is multidimensional and multilevel.

"Inspiring leadership builds employees' resilience and willingness to undertake new challenges," said Pilar Ficapal Cusi, professor at the UOC's Faculty of Economics and Business and one of the authors of the study, which was published in the Journal of Cleaner Production.

Viewed from the group and organizational perspective, "the shared vision, the team's belief in its own creative effectiveness, the ability to reflect openly about how their members connect to adapt to new circumstances and assuredness in participation are key elements that lead to effective performance," she added.

The study analysed 654 work teams, with a total of 3,190 employees, in different companies based in Spain. 57% were women and 43% were men. The group size ranged between 3 and 10 members, and the average age was around 37. The questionnaires were completed between April 2016 and December 2017.

According to Mihaela Enache Zegheru, also a professor at the UOC's Faculty of Economics and Business and another of the study's authors, together with professor Joan Torrent Sellens, said: "The results show that leadership that tends to be a source of inspiration and motivation for achieving results is essential for driving the team's perceived performance." All three are members of the UOC's i2TIC research group.

According to the research, setting realistic goals is also important for the group to function well. "The members need clearly defined and accepted goals. These goals should also be attainable but challenging and encourage a shared vision," continued Enache Zegheru.

The research also looked at companies, showing that organizations that foster collaborative work environments that stimulate creativity and innovation improve their teams' performance. In addition, organizational practices that encourage open communication and the team members' involvement in decision-making processes may contribute to triggering and developing creative potential.

The pros and cons of telecommuting

Although the questionnaires were answered before the current pandemic, the researchers draw some conclusions from their analysis and from other previous studies that may be applicable to the current situation, particularly as regards telecommuting, an option that has become more popular as a means for preventing the spread of SARS-CoV-2.

The authors explained: "Telecommuting is effective for achieving short-term cost reductions or productivity improvements. However, it has also been shown that processes based on creativity or innovation experience greater difficulties in the distance work context."

The researchers also warned that although telecommuting has advantages such as time flexibility, reduced mobility and greater work efficiency, the constant use of technologies leads to an overabundance of information which, if it is more than the employee can effectively cope with, generates negative effects such as work overload, technostress, fatigue, and conflicts between work and home life.

Ficapal Cusi said: "Within the current work context, under severe pressure from the health crisis, it is important that the team develops mechanisms for coping with potentially stressful environments, accepting challenges and collectively developing creative and innovative ideas."

In Enache Zegheru's opinion, "the leader plays an important role here. In this context, leadership that is task-oriented but also supports and motivates the team contributes to the group's effective performance".

Employees must also feel supported by the organization. Indeed, according to the authors, "a good fit between each of the team members' abilities, expectations and needs, and an appropriate balance between work demands and work resources are essential for employees' well-being".

Researchers at Lund University in Sweden have discovered the individual traits of fungi, and how their hyphae - that is, the fungal threads that grow in soil - behave very differently as they navigate through the earth's microscopic labyrinths.

The study was performed in a lab environment, and the underground system constructed synthetically from silicone. Using a microscope, researchers were able to follow seven species and compare their behaviour. How do they react when the maze they grow in turns sharply and forces the hyphae to grow in the direction it came from? What happens when a large space opens up in front of them?

"Under a microscope, their behaviour becomes much more personal than you can ever imagine. They become individual characters", says Edith Hammer, one of the researchers behind the study.

The research team discovered that the fungi use different strategies when they grow and form their structures, the so-called mycelium. The different characteristics have led the researchers to give the various fungi nicknames such as "the soldier", the marathon runner" and "the snake".

The soldier gained its name because it grows with great force, and plows down obstacles in its path, yet it does not get very far. The marathon runner, on the other hand, sends out hypha that act like 'lone fighters', and grow quite far before giving up their search for food. However, this requires that they do not encounter tough obstacles, as this is their weak spot. Unlike the marathon runner, the snake specializes in weaving and growing around obstacles.

Examples of obstacles that the hyphae may encounter, and that can delay and confuse them, are zigzag patterns, sharp angles and rounded corners. The study shows that some species simply stop when they end up in a corner.

The research is unique because it is the first time that the behaviour of individual hyphae in multiple species has been studied in parallel and in detail. Previous studies have often focused on the mycelium as a whole, as they have not been able to distinguish the behaviour of individual hyphae.

So far, however, important pieces of the puzzle are missing on how microscopic soil structures affect the behaviour of fungi, in order for the research to have practical applications in agriculture.

A greater exposure to air pollution at the very start of life was associated with a detrimental effect on people's cognitive skills up to 60 years later, the research found.

Researchers at the University of Edinburgh tested the general intelligence of more than 500 people aged approximately 70 years using a test they had all completed at the age of 11 years.

The participants then repeated the same test at the ages of 76 and 79 years.

A record of where each person had lived throughout their life was used to estimate the level of air pollution they had experienced in their early years.

The team used statistical models to analyse the relationship between a person's exposure to air pollution and their thinking skills in later life.

They also considered lifestyle factors, such as socio-economic status and smoking.

Findings showed exposure to air pollution in childhood had a small but detectable association with worse cognitive change between the ages of 11 and 70 years.

This study shows it is possible to estimate historical air pollution and explore how this relates to cognitive ability throughout life, researchers say.

Dr Tom Russ, Director of the Alzheimer Scotland Dementia Research Centre at the University of Edinburgh, said: "For the first time we have shown the effect that exposure to air pollution very early in life could have on the brain many decades later. This is the first step towards understanding the harmful effects of air pollution on the brain and could help reduce the risk of dementia for future generations."

Researchers say until now it has not been possible to explore the impact of early exposure to air pollution on thinking skills in later life because of a lack of data on air pollution levels before the 1990s when routine monitoring began.

For this study researchers used a model called the EMEP4UK atmospheric chemistry transport model to determine pollution levels -- known as historical fine particulate matter (PM2.5) concentrations -- for the years 1935, 1950, 1970, 1980, and 1990. They combined these historical findings with contemporary modelled data from 2001 to estimate life course exposure

The participants were part of the Lothian Birth Cohort 1936 study, a group of individuals who were born in 1936 and took part in the Scottish Mental Survey of 1947.

Since 1999, researchers have been working with the Lothian Birth Cohorts to chart how a person's thinking power changes over their lifetime.

To evaluate the chemical composition of food from a physiological point of view, it is important to know the functions of the receptors that interact with food ingredients. These include receptors for bitter compounds, which first evolved during evolution in bony fishes such as the coelacanth. What 400 million years of evolutionary history reveal about the function of both fish and human bitter receptors was recently published in the journal Genome Biology and Evolution by a team of researchers led by the Leibniz Institute for Food Systems Biology at the Technical University of Munich and the University of Cologne.

Evolutionarily, bitter receptors are a relatively recent invention of nature compared to other chemoreceptors, such as olfactory receptors. Their function of protecting vertebrates from consuming potentially toxic substances has long been scientifically recognized. More recent are observations that bitter receptors have other functions beyond taste perception. These include roles in defense against pathogenic bacteria, in metabolic regulation, and possibly also functions as sensors for endogenous metabolites and hormones.

Coelacanth and zebrafish in comparison

The team of scientists led by biologists Sigrun Korsching of the University of Cologne and Maik Behrens of the Leibniz Institute for Food Systems Biology now provides further evidence to support this hypothesis. In their current study, the team compared two original bitter receptor types from the coelacanth (Latimeria chalumnae) with four others from the zebrafish (Danio rerio) phylogenetically, functionally and structurally. To this end, the research team conducted, among other experiments, extensive functional studies using an established cell-based test system as well as a computer-based modeling approach. The goal was to gain a deep insight into the evolutionary history of bitter receptors in order to learn more about their functions.

As the study results show, both fish species possess, amongst others, a pair of homologous bitter receptor genes that presumably arose from a primordial gene. In this regard, the bitter recognition spectra of these fish receptors were largely identical despite 400 million years of separate evolution, according to the results of the functional studies. "What is particularly exciting about our results is that the original fish receptors recognized substances in the cellular test system which are still detected by human bitter receptors to date. These include bile acids," says co-author Antonella Di Pizio of the Leibniz Institute.

Over 400 million years of selection pressure

"So there must have been selective pressure at least until humans evolved, that means human bitter receptors can still detect the same bitter substances as a bony fish did over 400 million years ago," concludes taste researcher Maik Behrens. Sigrun Korsching adds, "This speaks for one or more important functions of bitter receptors, even during human evolution."

"Coelacanths are carnivores. Therefore, one could speculate that the existence of a bitter receptor variant that mainly recognizes steroid hormones and bile acids protects against the consumption of poisonous fish, which can contain not only bile acids but also highly potent neurotoxins in their liver and gallbladder. For example, the poisonous puffer fish Arothron hispidus lives in the same waters as the coelacanth," says Maik Behrens. "In humans and also in zebrafish, however, it is questionable whether such a receptor variant would have been preserved from an evolutionary point of view if it did not have other functions inside the body. Another argument in favor of such extraoral functions is that bitter receptors are also found on human organs such as the heart, brain or thyroid gland," Behrens added. One goal of his research is to help understand the effects of bitter substances on a systems biological level, regardless of whether they entered the body through food or whether they belong to the body's own substances.

A process that releases iron in response to stress may contribute to heart failure, and blocking this process could be a way of protecting the heart, suggests a study in mice published today in eLife.

People with heart failure often have an iron deficiency, leading some scientists to suspect that problems with iron processing in the body may play a role in this condition. The study explains one way that iron processing may contribute to heart failure and suggests potential treatment approaches to protect the heart.

"Iron is essential for many processes in the body including oxygen transport, but too much iron can lead to a build-up of unstable oxygen molecules that can kill cells," says first author Jumpei Ito, who was a Research Associate at the School of Cardiovascular Medicine and Sciences, King's College London, UK, at the time the study was carried out, and is now a visiting scientist based at Osaka Medical College, Japan. "We already knew that iron metabolism undergoes changes in heart failure, but it was unclear whether these changes are helpful or harmful."

To learn more about the role of iron metabolism in heart failure, Ito and colleagues studied mice lacking a protein called the nuclear receptor coactivator 4 (NCOA4), which is necessary to release iron stored in cells when the body's iron levels are low. They found that these mice developed less severe changes associated with heart failure compared to mice with NCOA4. Specifically, the NCOA4-deficient mice did not develop excessive levels of iron or a build-up of unstable oxygen molecules that can lead to cell death in heart failure.

A compound called ferrostatin-1 inhibits the release of stored iron and reduces the accumulation of unstable oxygen molecules. Further experiments by the team showed that treating mice with NCOA4 with ferrostatin-1 can reduce the amount of cell death in heart failure. "Our results suggest that the release of iron can be detrimental to the heart," Ito says. "It can lead to unstable oxygen levels, death in heart cells and ultimately heart failure."

More studies are now needed to understand each step in the process that releases iron and to test whether inhibiting this process could be beneficial to people with heart failure.

"Patients with heart failure who are iron deficient are currently treated with iron supplements, which previous studies have shown reduces their symptoms," adds senior author Kinya Otsu, the British Heart Foundation Professor of Cardiology at King's College London. "While our work does not contradict those studies, it does suggest that reducing iron-dependent cell death in the heart could be a potential new treatment strategy for patients."

Trees are by far the tallest organisms on Earth. Height growth is made possible by a specialized vascular system that conducts water from the roots to the leaves with high efficiency, while simultaneously providing stability. The so-called xylem, also known as wood, is a network of hollow cells with extremely strong cell walls that reinforce the cells against the mechanical conflicts arising from growing tall. These walls wrap around the cells in filigree band and spiral patterns. So far, it is only partly known, how these patterns are created. Scientists from the Max Planck Institute for Molecular Plant Physiology in Golm/Potsdam and from Wageningen University and their colleagues study the formation of such reinforced and patterned cell walls.

Plants take up water from the soil via the roots and transport it through a vascular system, the so-called xylem, into the canopy. The xylem is a network of tubular cell wall containers that are formed by living xylem cells during plant growth. Before their death, the cells actively organize the deposition of an exceptionally strong wall - the so-called secondary wall - into band and spiral patterns. After that, the cells dissolve and vacate their interior, and lignify the walls to further provide strength, resilience, and waterproof to these structures. Due to this, xylem cells provide both, an efficient water transportation system and plant stability.

The major load-bearing component of xylem walls is cellulose. To allow the cellulose to form these visually impressive band patterns, it needs the help of various proteins. These include so-called microtubules - small, tubular protein structures that are part of the cytoskeleton - which provide the molecular 'tracks' for the cell-wall-producing machinery. This machinery moves along the microtubules like an asphalt paver and continuously deposits wall material on the outside of the cells. The microtubules thus act like an instruction manual for cell wall synthesis. Despite much research into the general formation of cell walls, it has not yet been clear how the microtubule cytoskeleton is reorganized into such filigree patterns during secondary wall formation.

Arabidopsis with xylem cells

"One problem in elucidating these mechanisms has been the deep-tissue localization of the xylem, being buried underneath many cell layers. Due to this, it cannot be observed directly. We are using a genetic engineering approach to make this process visible under the microscope", explains René Schneider from the Max Planck Institute for Molecular Plant Physiology. The researchers used Arabidopsis thaliana (thale cress), an inconspicuous weed and model plant for research, and modified it in that way, that all its cells can be forced to form xylem and thus secondary cell walls. "For this purpose, we have equipped our plants with a 'gene switch'. This makes it possible to trigger the mechanism of xylem development from the outside in a targeted manner. By that, all cells in the plant are becoming xylem cells, particularly the ones at the surface which are easy to study with high-resolution microscopy", Schneider describes. With this method, it is possible for the first time to observe xylem cells and their wall patterns as they develop.

Using this new tool, the researchers describe which processes drive the rearrangement of the microtubules during xylem formation. They developed an automatic imaging method and observed that the microtubule bands and spirals form simultaneously over the entire cell surface and the resulting pattern is further adjusted until an orderly distribution of bands is achieved. During this process, the microtubules in the gaps are continuously broken down while they are growing in the bands.

The re-arrangement into parallel, evenly spaced bands takes about one to two hours and is maintained for the remaining time. The entire transformation process of a cell to become a proper xylem cell requires several days in total. With the help of their observation in plants and by using computer simulations, the team of scientists was also able to identify a protein complex, KATANIN, which turned out to be involved in the timely and orderly formation of secondary walls.

Based on these findings, Dr. René Schneider will further pursue the research question of how exactly the patterns of secondary walls are formed in plants. Therefore, he is supported by the German Research Foundation (DFG) under the renowned Emmy-Noether-Program to establish a research group at the University of Potsdam. The research group is funded with 1.3 million Euros and will use in-vivo (in living plants), in-vitro (in the laboratory; outside the plant), as well as computer-based methods to further explore the genetics and biophysics of cell wall pattern formation. The group's work is not only of interest for plant research, but could also contribute to the adaptation of plants to the future climate, since the survival of trees in a changing climate depends largely on the adaptability of xylem vessels. The identification of proteins and associated genes that adapt the vascular system to environmental conditions could help to identify or even genetically engineer more climate-resistant plant species.