Culture

What The Study Did: This decision analytical model describes several key epidemiological features of imported coronavirus disease 2019 (COVID-19) cases in Wenzhou, China.

Authors: Xiaoqing Pan, Ph.D., of Shanghai Normal University, and Yan Lu, Ph.D., of Zhejiang University School of Medicine, in China, are the corresponding authors.

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

(doi:10.1001/jamanetworkopen.2020.6785)

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

What The Study Did: This survey study looked at how often cancer survivors in the United States and their spouses or partners stay in their jobs because of concerns about losing their health insurance.

Authors: Erin E. Kent, Ph.D., M.S., of the University of North Carolina in Chapel Hill, 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/jamaoncol.2020.0742)

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

One of the major concerns about the COVID-19 coronavirus pandemic has been the burden that cases will place on the health care system. A new study published April 23 in the journal Health Affairs found that the spread of the virus could cost hundreds of billions of dollars in direct medical expenses alone and require resources such as hospital beds and ventilators that may exceed what is currently available.

The findings demonstrate how these costs and resources can be cut substantially if the spread of COVID-19 coronavirus can be reduced to different degrees.

The study was led by the Public Health Informatics, Computational, and Operations Research (PHICOR) team at the City University of New York (CUNY) Graduate School of Public Health and Health Policy (CUNY SPH) along with the Infectious Disease Clinical Outcomes Research Unit (ID-CORE) at the Los Angeles Biomedical Research Institute, Harbor-UCLA Medical Center and Torrance Memorial Medical Center. The team developed a computer simulation model of the entire U.S. that could then simulate what would happen if different proportions of the population end up getting infected with the COVID-19 coronavirus. In the model, each infected person would develop different symptoms over time and, depending upon the severity of those symptoms, visit clinics, emergency departments, or hospitals. The resources each patient would require such as health care personnel time, medication, hospital beds, and ventilators would then be based on the health status of each patient. The model then tracks the resources involved, the associated costs, and the outcomes for each patient.

For example, if 20 percent of the U.S. population were to become infected with the COVID-19 coronavirus, there would be a median of 11.2 million hospitalizations and 1.6 million ventilators used, costing a median of $163.4 billion in direct medical costs during the course of the infection. The study shows that including direct medical costs for a year after hospital discharge increased the median cost to $214.5 billion. If 50 percent of the U.S. population were to get infected with the COVID-19 coronavirus, there would be 27.9 million hospitalizations, 4.1 million ventilators used and 156.2 million hospital bed days accrued, costing a median of $408.8 billion in direct medical costs during the course of the infection. This increases to 44.6 million hospitalizations, 6.5 million ventilators used and 249.5 million hospital bed days (general ward plus ICU bed days) incurred, costing a median of $654 billion during the course of the infection if 80 percent of the U.S. population were to get infected. The significant difference in medical costs when various proportions of the population get infected show the value of any strategies that could reduce infections and, conversely, the potential cost of simply letting the virus run its course.

"Some have suggested herd immunity strategies for this pandemic," explained Sarah Bartsch, project director at PHICOR and the study's lead author. "These strategies consist of allowing people to get infected until herd immunity thresholds are reached and the virus can no longer spread. However, our study shows that such strategies could come at a tremendous cost."

"This also shows what may occur if social distancing measures were relaxed and the country were to be 're-opened' too early," said CUNY SPH Professor Bruce Y. Lee, executive director of PHICOR and the study's senior author. "If the virus is still circulating and the infection rates surge as a result, we have to consider the resulting health care costs. Such costs will affect the economy as well because someone will have to pay for them. Any economic argument for re-opening the country needs to factor in health care costs."

The study shows how costly the COVID-19 coronavirus is compared to other common infectious diseases. For example, a single symptomatic COVID-19 coronavirus infection costs a median of $3,045 in direct medical costs during the course of the infection alone. This is four times higher than a symptomatic influenza case and 5.5 times higher than a symptomatic pertussis case. Factoring in the costs from longer lasting effects of the infection such as lung damage and other organ damage increased the median cost to $3,994.

"This is more evidence that the COVID-19 coronavirus is very different from the flu," said Bartsch. "The burden on the health care system and the resources needed are very different."

"Factoring in the costs incurred after the infection is over also adds to the costs. It is important to remember that for a proportion of the people who get infected, health care costs don't end when the active infection ends," Lee warned. "This pandemic will have its lasting effects and taking care of those who will suffer continuing problems is one of them."

A continuing concern is that the U.S. health care system will become overloaded with the surge of COVID-19 coronavirus cases and will subsequently not have enough person-power, ventilators, and hospital beds to accommodate the influx of patients. This study shows that even when only 20 percent of the population gets infected, the current number of available ventilators and ICU beds will not be suffient. According to the Society of Critical Care Medicine, there are approximately 96,596 ICU beds and 62,000 full-featured mechanical ventilators in U.S., substantially lower than what would be needed when only 20 percent of the population gets infected.

"Of course, the actual capacity used will depend on the timing of when patients need them," said Bartsch. "But showing that there are orders of magnitude differences between what is currently available and what may be needed is concerning."

While health care professionals and public health officials have expressed concerns about ventilator and hospital bed shortages, the model can quantify in a more detailed manner what specifically will be required at different phases of the pandemic and what to expect when more people are infected.

The Arecibo Observatory in Puerto Rico is following an asteroid approaching Earth this week and while it poses no threat, it appears to know our planet is facing a pandemic.

"The small-scale topographic features such as hills and ridges on one end of asteroid 1998 OR2 are fascinating scientifically," says Anne Virkki, head of Planetary Radar at the observatory, "But since we are all thinking about COVID-19 these features make it look like 1998 OR2 remembered to wear a mask."

The National Science Foundation facility, which is managed by the University of Central Florida, has a team of experts who monitors near-Earth asteroids. This asteroid is in a special class of near-Earth asteroids called Potentially Hazardous Objects (PHOs).

PHOs are bigger than 140 meters (about 500 feet) and come within 5 million miles of Earth's orbit. No known PHO poses an immediate danger to the Earth, but observations like those conducted at the Arecibo Observatory are used to determine their future trajectories.

"The radar measurements allow us to know more precisely where the asteroid will be in the future, including its future close approaches to Earth," says Flaviane Venditti, a research scientist at the observatory. "In 2079, asteroid 1998 OR2 will pass Earth about 3.5 times closer than it will this year, so it is important to know its orbit precisely."

"Although this asteroid is not projected to impact Earth, it is important to understand the characteristics of these types of objects to improve impact-risk mitigation technologies," Virkki says.

The Arecibo data confirmed that 1998 OR2 is approximately 2 kilometers (1.2 miles) across in size and rotates once every 4.1 hours, as was suggested by observations made with optical telescopes. Should an asteroid be discovered that posed an impact threat to Earth, knowing such characteristics would be important for planning a response.

The team began observations on April 13 and will continue to collect data through April 23 when the asteroid will no longer be visible from the facility. The asteroid will make its closest approach to Earth on April 29 when it will still be 16 times farther than the distance to the Moon.

Although the pandemic has impacted operations around the world, Arecibo continues its important contributions to science and to planetary defense. Radio astronomy observations can largely be made remotely, with only limited on-site observing. However, planetary radar operations cannot be run fully remotely, requiring at least one radar operator and one scientist on site. The team of scientists and telescope operators on site have been adhering to health and safety guidelines, limiting the number of observing scientists at the telescope and wearing masks during the observations.

UCF manages the NSF facility under a cooperative agreement with Universidad Ana G. Méndez and Yang Enterprises, Inc. The Arecibo Planetary Radar Program is fully supported by NASA's Near-Earth Object Observations Program in NASA's Planetary Defense Coordination Office through grant no. 80NSSC19K0523 awarded to UCF. Arecibo has played a role in analyzing NEOs since the mid-90s, observing 60-120 objects per year. Congress made NEOs a priority when it directed NASA in 2005 to discover and characterize at least 90 percent of near-Earth objects larger than 140 meters by 2020.

Fishing for a living can seem so Zen - a time to be in the moment, just the fisher, the boat, the water.

Yet scientists are throwing a bit of shade on that perception, showing all the arrangements before and after the fish takes the bait - including the bait itself, in fact - must be considered to make effective and equitable policy about global fishing.

From the meals the fisher's family cooks to send along for the trip, to loans and rental agreements for boats and equipment, to access to markets, fishing extends fore and aft of the catching of fish. And ignoring those aspects puts effective and equitable policy at risk.

A more comprehensive look at the wider spectrum of activities, interactions, and relationships that comprise small-scale fishing operations, and what kinds of relationships better serve those who fish for a living in developing countries, is examined in "Governing the Commons Beyond Harvesting: An Empirical Illustration from Fishing" in this week's journal PLoS ONE.

"Much of the fisheries governance and management research has focused on understanding what happens on the water - how much people fish, the gear they use, and when and where - and how to constrain those choices with regulations. But decisions about how to fish are shaped by the incentives and relationships that characterize the livelihood activities taking place before and after fishing," said Abigail Bennett, Michigan State University (MSU) assistant professor of fisheries and wildlife and study co-author. "Much small-scale fishing in the world is collaborative by nature. And who you work together with to obtain a boat, loans and fishing permits constrain what and how you're able to fish. Opportunities for marketing fish after it's caught similarly have an influence on fishing.

"We have laid out a framework that brings into focus the interconnections between pre-harvest, harvest and post-harvest interactions. The point is to show that there is much more that is worth governing and making policy about beyond fishing itself."

Governance can have a huge impact. According to a 2012 study by the World Bank, Food and Agriculture of the United Nations, and WorldFish Center, small-scale fisheries account for about 90 percent of all the fishers in the world and contribute more than half of global catch. Much of that flows from small and often informal organizations.

Bennett notes that their importance can be more difficult to track and quantify because they're so widely dispersed and often are not formally organized.

The group devised ways to examine fishing operations beyond just measuring catch to understand factors influencing how fishers and other actors organize themselves even before they go out fishing by focusing on operations in two Mexican fishing villages, Rio Lagartos in Yucatan, and Bahia de Kino in Sonora.

In examining the activities affecting a fishing expedition, they focused on two common ways to manage - cooperatives, in which fishers ban together to pool resources, and the patron-client relationship, where fishers work for an individual fish buyer or single fishing business.

From there, they parsed the dynamics of each to figure out what qualities beyond catching a lot of fish made a fisher a good group member and what implications the two different groups might have for fishers' livelihoods and fisheries governance more generally.

"The role of trust is really important in creating and maintaining these relationships," Bennett said. "Fishing relationships revolve around so much more than fishing. It involves the fishers' whole lives and what they need to survive, and they can be exploited. It's messy but it's important to understand. We try to identify at least one signal in the noise to understand what drives the needs and relative stability."

In addition to Bennett, a member of MSU's Center for Systems Integration and Sustainability, the paper was written by Xavier Basurto of Duke University and Emilie Lindkvist and Maja Schluter of Stockholm University in Sweden.

Daniela Beckmann, Mirko Feldmann, Olena Shchyglo and Professor Denise Manahan-Vaughan from the Department of Neurophysiology of the Medical Faculty worked together for the study.

When sensory perception fades

The researchers studied the brain of mice that exhibit hereditary hearing loss, similar to age related hearing loss in humans. The scientists analysed the density of neurotransmitter receptors in the brain that are crucial for memory formation. They also researched the extent to which information storage in the brain's most important memory organ, the hippocampus, was affected.

Adaptability of the brain suffers

Memory is enabled by a process called synaptic plasticity. In the hippocampus, synaptic plasticity was chronically impaired by progressive hearing loss. The distribution and density of neurotransmitter receptors in sensory and memory regions of the brain also changed constantly. The stronger the hearing impairment, the poorer were both synaptic plasticity and memory ability.

"Our results provide new insights into the putative cause of the relationship between cognitive decline and age-related hearing loss in humans," said Denise Manahan-Vaughan. "We believe that the constant changes in neurotransmitter receptor expression caused by progressive hearing loss create shifting sands at the level of sensory information processing that prevent the hippocampus from working effectively", she adds.

The Kem Kem beds in Morocco are famous for the spectacular fossils found there, including at least four large-bodied non-avian theropods, several large-bodied pterosaurs and crocodilians.

Now, in a new geology and paleontology monograph, that reveals much more about the famous Kem Kem beds in Morocco, Dr. Nizar Ibrahim from the University of Detroit Mercy, Prof. Paul Sereno from the University of Chicago, and a team of international scholars from the United States, Europe and Morocco, have put together a comprehensive story that is published in the open-access journal ZooKeys.

The aim of the new research is to provide the international community with an in-depth review of the rocks and fossils of the region. It reviews the geology and paleontology of this famous but surprisingly understudied area, describing and formally naming the strata and summarizing all of the preserved life forms, from fragile plants and insects to massive dinosaurs. The monograph also paints a picture of life as it once was some 95 million years ago by describing the paleoenvironments of the region, and the unusual predator-dominated fauna.

In 1996 Prof. Sereno and colleagues introduced the informal term "Kem Kem beds" for this fossil-rich escarpment. In this monograph, the authors review the original tri-level proposal for the region by French geologist Choubert (his informal "trilogie mésocretacée") and propose the Kem Kem Group for the entire package of rock with two new names for the dinosaur-bearing layers based on the richest fossil sites, the Gara Sbaa and Douira formations.

The region is famous for the prodigious fossils found in all of these units, many derived from commercial fossil collecting, which obscures the precise location and level of the specimens. The monograph is the first work to pinpoint where many of the most important finds were made. Over the last 25 years in particular, paleontologists have brought to light a diverse array of new vertebrate fossils including at least four large-bodied non-avian theropods, several large-bodied pterosaurs, crocodilians, turtles and an array of sharks and bony fish.

To put a comprehensive story together on the Kem Kem, the authors of the monograph visited collections of Kem Kem fossils around the world and led many expeditions to the region. Fossil and geological data reviewed in the monograph is derived from a number of different sources. A University of Chicago-led major expedition in 1995 generated a wealth of geological and paleontological data, as did later expeditions involving teams from the University College Dublin, the University of Portsmouth, the Faculté des Sciences Aïn Chock, the Muséum national d'Histoire naturelle, the University Cadi Ayyad, the Museo Civico di Storia Naturale (Milan), and the University of Detroit Mercy.

One of the key features of the Kem Kem assemblage is the presence of several large-bodied theropods, a group of dinosaurs that includes all of the meat-eaters. Most famous among these from the Kem Kem include the sail-backed Spinosaurus and the sabre-toothed Carcharodontosaurus.

Most fossils in the Kem Kem region are discovered as isolated fragmentary pieces weathered from sandstones. Only four partial dinosaur skeletons or skulls have been recovered, which include the long-necked sauropod Rebbachisaurus garasbae and the theropods Deltadromeus agilis, Carcharodontosaurus saharicus and Spinosaurus aegyptiacus. These Kem Kem theropods are among the largest known dinosaurian predators on record reaching adult body lengths in excess of 12 meters.

"Given the continued input of new specimens and the continuing expansion of paleontological research, we predict that diversity in the Kem Kem Group will increase substantially in the coming decades. Based on our review of existing collections, this increase will include scores of taxa from the pond locality Oum Tkout including nonvertebrates, such as plants, insects, and ostracods, as well as an array of actinopterygian fish. We also anticipate a continuing trickle of new terrestrial vertebrates that will be named on better-preserved specimens that are diagnostic at present only at the familial level, including turtles and various kinds of archosaurs. As nearly half of the reptilian families listed are indeterminate, better-preserved specimens will offer future opportunities to recognize new reptilian genera", share the authors.

"In summary, the Kem Kem assemblage of non-vertebrates and vertebrates is likely to continue to show dramatic increase in diversity in the coming decades. Nonetheless, the array of taxa currently known, which extends from plants across a range of aquatic and terrestrial vertebrates, is sufficiently mature to allow a summary of the vertebrate
assemblage and a discussion of its paleoecological context", conclude the researchers.

In his earlier research, a famous paleontologist from the University of Chicago Prof. Paul Sereno has described many outstanding dinosaur discoveries, including new Cretaceous crocodilians from the Sahara and two new fanged vegetarian dinosaur dwarfs (called heterodontosaurids).

Recognition of the needs of wives and intimate partners in supporting the recovery of veterans and front-line emergency workers affected by post-traumatic stress disorder (PTSD) has been highlighted in a new study led by Flinders University.

Their contribution to trauma recovery, and their own need for support, are not well understood by military and emergency service organisations, healthcare providers and government, the researchers found when they interviewed 22 partners of Australian veterans, paramedics, fire and police officers.

"We looked at partners in these groups because of the occupational exposure to trauma they experience," says Flinders Behavioural Health researcher Professor Sharon Lawn, project lead and author of a new article published in Health and Social Care in the Community.

"The key finding was that partners feel invisible in recovery. They live with the trauma that their partners experience but are still not acknowledged by health services or professional organisations (such as Department of Veterans' Affairs, Police, etc) as a vital part of the person's support system."

Feeling invisible was the barrier respondents felt to receiving the support they crave, says co-investigator Paula Redpath, a consultant psychotherapist and discipline lead - Flinders Behavioural Health.

"The participants' key concerns were to protect their family unit and relationship with their partner, showing many ways in which they managed, coped and adapted to myriad changes brought by the PTSD," she says.

However, many perceive that the strength of their commitment to their relationship, their contribution to the recovery of the veteran, and to what they do every day for the family, is largely invisible to the organisations and healthcare providers available to these occupations, the researchers conclude.

The article, ' " Why do you stay?": The lived-experience of partners of Australian veterans and first responders with Posttraumatic Stress Disorder' (April 2020) by E Waddell, S Lawn, L Roberts, J Henderson, A Venning and P Redpath has been published by Wiley DOI 10.1111/hsc.12998

The research, funded by veteran support network The Road Home, used a qualitative phenomenological approach, and inductive thematic analysis was undertaken on data collected in 2017-2018 through individual interviews with a purposive sample of 22 partners of veterans, paramedics, fire and police officers living in Australia.

Behavioural Health, based at Flinders University, has developed a wide range of tools and outreach services to facilitate support for self-management, so that health professionals can become truly collaborative with people with chronic conditions.

Researchers have confirmed that neuropeptide somatostatin can improve cognitive function in the brain. A research group of Professor Seung-Hee Lee from the Department of Biological Sciences at KAIST found that the application of neuropeptide somatostatin improves visual processing and cognitive behaviors by reducing excitatory inputs to parvalbumin-positive interneurons in the cortex.

This study, reported at Science Advances on April 22nd (EST), sheds a new light on the therapeutics of neurodegenerative diseases. According to a recent study in Korea, one in ten seniors over 65 is experiencing dementia-related symptoms in their daily lives such like memory loss, cognitive decline, and motion function disorders. Professor Lee believes that somatostatin treatment can be directly applied to the recovery of cognitive functions in Alzheimer's disease patients.

Professor Lee started this study noting the fact that the level of somatostatin expression was dramatically decreased in the cerebral cortex and cerebrospinal fluid of Alzheimer's disease patients

Somatostatin-expressing neurons in the cortex are known to exert the dendritic inhibition of pyramidal neurons via GABAergic transmission. Previous studies focused on their inhibitory effects on cortical circuits, but somatostatin-expressing neurons can co-release somatostatin upon activation. Despite the abundant expression of somatostatin and its receptors in the cerebral cortex, it was not known if somatostatin could modulate cognitive processing in the cortex.

The research team demonstrated that the somatostatin treatment into the cerebral cortex could enhance visual processing and cognitive behaviors in mice. The research team combined behaviors, in vivo and in vitro electrophysiology, and electron microscopy techniques to reveal how the activation of somatostatin receptors in vivo enhanced the ability of visual recognition in animals. Interestingly, somatostatin release can reduce excitatory synaptic transmission to another subtype of GABAergic interneurons, parvalbumin (PV)-expressing neurons.

As somatostatin is a stable and safe neuropeptide expressed naturally in the mammalian brain, it was safe to be injected into the cortex and cerebrospinal fluid, showing a potential application to drug development for curing cognitive disorders in humans.

Professor Lee said, "Our research confirmed the key role of the neuropeptide SST in modulating cortical function and enhancing cognitive ability in the mammalian brain. I hope new drugs can be developed based on the function of somatostatin to treat cognitive disabilities in many patients suffering from neurological disorders."

Images from the Akatsuki spacecraft unveil what keeps Venus's atmosphere rotating much faster than the planet itself.

An international research team led by Takeshi Horinouchi of Hokkaido University has revealed that this 'super-rotation' is maintained near the equator by atmospheric tidal waves formed from solar heating on the planet's dayside and cooling on its nightside. Closer to the poles, however, atmospheric turbulence and other kinds of waves have a more pronounced effect. The study was published online in Science on April 23.

Venus rotates very slowly, taking 243 Earth days to rotate once around its axis. Despite this very slow rotation, Venus' atmosphere rotates westward 60 times faster than its planetary rotation. This super-rotation increases with altitude, taking only four Earth days to circulate around the entire planet towards the top of the cloud cover. The fast-moving atmosphere transports heat from the planet's dayside to nightside, reducing the temperature differences between the two hemispheres. "Since the super-rotation was discovered in the 1960s, however, the mechanism behind its forming and maintenance has been a long-standing mystery," says Horinouchi.

Horinouchi and his colleagues from the Institute of Space and Astronautical Science (ISAS, JAXA) and other institutes developed a new, highly precise method to track clouds and derive wind velocities from images provided by ultraviolet and infrared cameras on the Akatsuki spacecraft, which began its orbit of Venus in December 2015. This allowed them to estimate the contributions of atmospheric waves and turbulence to the super-rotation.

The group first noticed that atmospheric temperature differences between low and high latitudes are as small as it cannot be explained without a circulation across latitudes. "Since such circulation should alter the wind distribution and weaken the super-rotation peak, it also implies there is another mechanism which reinforces and maintains the observed wind distribution," Horinouchi explained. Further analyses revealed that the maintenance is sustained by the thermal tide -- an atmospheric wave excited by the solar heating contrast between the dayside and the nightside -- which provides the acceleration at low latitudes. Earlier studies proposed that atmospheric turbulence and the waves other than the thermal tide may provide the acceleration. However, the current study showed that they work oppositely to weakly decelerate the super-rotation at low latitude, even though they play an important role at mid- to high latitudes.

Their findings uncovered the factors that maintain the super-rotation while suggesting a dual circulation system that effectively transports heat across the globe: the meridional circulation that slowly transports heat towards the poles and the super-rotation that rapidly transports heat towards the planet's nightside.

"Our study could help better understand atmospheric systems on tidally-locked exo-planets whose one side always facing the central stars, which is similar to Venus having a very long solar day," Horinouchi added.

Another piece of the puzzle about the longevity of the corpus luteum in lynxes has been uncovered. Scientists at the Leibniz Institute for Zoo and Wildlife Research (Leibniz-IZW) and the Leibniz Institute for Molecular Pharmacology (Leibniz-FMP) discovered that selected anti-oxidative enzymes, especially the enzyme superoxide dismutase (SOD2), may play an important role to maintain the unusual longevity of the corpus luteum in lynxes. It is highly likely that SOD2 not only detoxifies the reactive oxygen radicals in the cells, but also inhibits programmed cell death. The results were recently published in the scientific journal Scientific Reports of the Nature Group.

In contrast to other felids, Eurasian lynx, Canada lynx and Iberian lynx can only become pregnant once a year within a short period of conception. This restriction in terms of reproductive period is particularly observed in animals that live in strongly seasonal habitats, e.g. in the north with long winters or in southern Europe with hot and dry summers. The restriction ensures that the young are born at the optimal time of year, increasing their chances of survival. For endangered species such as the Iberian lynx this restriction of the reproductive season is a challenge for breeding in human care. In 2004, the Iberian lynx conservation breeding programme was established on the Iberian Peninsula to support the survival of the Iberian lynx. If a female Iberian lynx does not become pregnant or lose their young in the breeding programme, she can only contribute to the breeding programme one year later. It is therefore remarkable that husbandry and breeding success has been improved to such an extent that currently about 40 animals from the breeding programme are being released into the wild every year to support the decimated wild population of only a few hundred animals.

In order to understand why lynxes can only become pregnant once a year and how a new cycle is induced, it is necessary to study the mechanism of female reproduction. After the ovulation of egg cells, corpora lutea - hormone glands - are formed on the ovaries. They produce the hormone progesterone which prevents a new ovulation, an effect also used in the contraceptive pill. If a corpus luteum regresses at the end of the cycle or after birth, a new cycle can start. As the Leibniz-IZW reproduction team found out in previous studies, the lynx corpora lutea remain present and active for several years, they persist. "We suspect that the longevity of the corpus luteum and their release of progesterone are responsible for the strong seasonality of lynx reproduction," explains Beate Braun, scientist of the Department of Reproduction Biology at Leibniz-IZW.

Until now it was unclear how the longevity of the corpus luteum comes about. The scientists have now succeeded in solving part of this mystery. "We could show that anti-oxidative enzymes, especially superoxide dismutase (SOD2), is likely to contribute in a significant way to the regulation of corpus luteum longevity," says Beate Braun. The research team investigated ten anti-oxidative enzymes in fresh and older, at least one year old, corpora lutea of Iberian lynxes (Lynx pardinus) and Eurasian lynxes (Lynx lynx). The scientists recorded for different stages of the corpus luteum which enzyme was being produced, present and active. "The expression profiles of SOD2 showed remarkable differences between older corpora lutea of lynxes, fresh lynx corpora lutea and the corpora lutea of the domestic cat," explains Braun. SOD2 was conspicuous in the older lynx corpus luteum with very high expression and enzyme activity, whereas it played a subordinate role in the domestic cat in all corpus luteum stages. "We suspect that SOD2 in the older, long-lived/persistent, lynx corpora lutea has a classic anti-oxidative effect by transforming poisonous reactive oxygen radicals," says Katarina Jewgenow, head of the Department of Reproductive Biology. "During that process, SOD2 produces hydrogen peroxide, which is then broken down and converted into water by other enzymes. In addition, the hydrogen peroxide can function as a signaling molecule that protects the corpus luteum from programmed cell death and thus ensures its survival for several years," adds Jewgenow.

These new findings contribute to a better understanding of lynx reproduction and provide an important basis for further investigations into the regulation of corpus luteum development and longevity. The aim is to elucidate the complex mechanisms of female reproduction in lynxes step by step and provide lasting support for the conservation breeding of lynxes in human care through the use of assisted reproduction techniques such as ovulation induction and artificial insemination.

Kadir Dede and Dr. Enno Ohlebusch at Ulm University in Germany have devised a method for constructing pan-genome subgraphs at different granularities without having to wait hours and days on end for the software to process the entire genome. Scientists will now be able to create visualizations of pan-genomes on different scales much more rapidly.

The research article "Dynamic construction in pan-genome structures", was published in De Gruyter's open access journal Open Computer Science.

In order to analyze specific parts of a genome, scientists must be able to "see" the parts they are investigating, and this requires a large amount of processing power and time. The Computational Pan-Genomics Consortium encourages researchers to ensure that all information within a data structure is easily accessible for human eyes by visualization support on different scales. However, a pan-genome graph can have thousands to millions of nodes, which are not very easy for human eyes to visualize.

In an experiment, Dede and Ohlebusch used 10 human genomes and computed a graph that contains part of the large repetitive central exon of the human MUC5AC gene. Formerly, researchers had to create an entire index structure of the genomes, which takes about 8.5 hours and requires 38.5 GB of memory. Using the method developed by Dede and Ohlebusch, the researcher simply has to compute two bit-vectors (on which the construction of the subgraph is based) and the subgraph ? containing the reference path and its ?-neighborhood.

Instead of over eight hours, the software constructed the subgraph (including the computation of the bitvectors, which requires about 10 minutes) in only 24.5 minutes and required 39.6 GB of main memory; the subgraph itself required merely 15 KB of memory.

"Based on solid theory, Dede and Ohlebusch present a new method for the flexible and efficient exploration of suspicious genomic regions, highlighting for example pathogenic genes that distinguish new variants of a virus from all previously known genomes," said Prof. Dr. Jens Stoye, head of the Genome Informatics team, Faculty of Technology, Bielefeld University.

The open access paper can be found here: https://doi.org/10.1515/comp-2020-0018

Quantum computing is increasingly becoming the focus of scientists in fields such as physics and chemistry, and industrialists in the pharmaceutical, airplane, and automobile industries. Globally, research labs at companies like Google and IBM are spending extensive resources on improving quantum computers, and with good reason. Quantum computers use the fundamentals of quantum mechanics to process significantly greater amounts of information much faster than classical computers. It is expected that when error-corrected and fault-tolerant quantum computation is achieved, scientific and technological advancement will occur at an unprecedented scale.

But, building quantum computers for large-scale computation is proving to be a challenge in terms of their architecture. The basic units of a quantum computer are the "quantum bits" or "qubits." These are typically atoms, ions, photons, subatomic particles such as electrons, or even larger elements that simultaneously exist in multiple states, making it possible to obtain several potential outcomes rapidly for large volumes of data. The theoretical requirement for quantum computers is that these are arranged in two-dimensional (2D) arrays, where each qubit is both coupled with its nearest neighbor and connected to the necessary external control lines and devices. When the number of qubits in an array is increased, it becomes difficult to reach qubits in the interior of the array from the edge. The need to solve this problem has so far resulted in complex three-dimensional (3D) wiring systems across multiple planes in which many wires intersect, making their construction a significant engineering challenge.

A group of scientists from Tokyo University of Science, Japan, RIKEN Centre for Emergent Matter Science, Japan, and University of Technology, Sydney, led by Prof Jaw-Shen Tsai, proposes a unique solution to this qubit accessibility problem by modifying the architecture of the qubit array. "Here, we solve this problem and present a modified superconducting micro-architecture that does not require any 3D external line technology and reverts to a completely planar design," they say. This study has been published in the New Journal of Physics.

The scientists began with a qubit square lattice array and stretched out each column in the 2D plane. They then folded each successive column on top of each other, forming a dual one-dimensional array called a "bi-linear" array. This put all qubits on the edge and simplified the arrangement of the required wiring system. The system is also completely in 2D. In this new architecture, some of the inter-qubit wiring--each qubit is also connected to all adjacent qubits in an array--does overlap, but because these are the only overlaps in the wiring, simple local 3D systems such as airbridges at the point of overlap are enough and the system overall remains in 2D. As you can imagine, this simplifies its construction considerably.

The scientists evaluated the feasibility of this new arrangement through numerical and experimental evaluation in which they tested how much of a signal was retained before and after it passed through an airbridge. Results of both evaluations showed that it is possible to build and run this system using existing technology and without any 3D arrangement.

The scientists' experiments also showed them that their architecture solves several problems that plague the 3D structures: they are difficult to construct, there is crosstalk or signal interference between waves transmitted across two wires, and the fragile quantum states of the qubits can degrade. The novel pseudo-2D design reduces the number of times wires cross each other, thereby reducing the crosstalk and consequently increasing the efficiency of the system.

At a time when large labs worldwide are attempting to find ways to build large-scale fault-tolerant quantum computers, the findings of this exciting new study indicate that such computers can be built using existing 2D integrated circuit technology. "The quantum computer is an information device expected to far exceed the capabilities of modern computers," Prof Tsai states. The research journey in this direction has only begun with this study, and Prof Tsai concludes by saying, "We are planning to construct a small-scale circuit to further examine and explore the possibility."

Falling visibility in three major African cities reveals that air pollution has increased significantly over the last 45 years - leaving citizens facing further short-term increases in man-made pollution due to increasing urbanization and economic development, a new study reveals.

Africa is not well-equipped with air quality monitoring, so scientists have used visibility data for capital cities in Ethiopia, Kenya and Uganda as a substitute measurement.

They discovered a significant reduction in visibility since the 1970s, where Nairobi shows the greatest loss (60%), compared to Kampala (56%) and Addis Ababa (34%) - due to increased particulate matter (PM) emissions from vehicles and energy generation.

Correspondingly, PM pollution levels in the three cities are estimated to have increased by 182%, 162% and 62% respectively since the 1970s to the current period.

University of Birmingham experts published their findings in Environmental Research Letters. They are now calling for a systematic approach to understand the causes and effects of air pollution in urban East Africa - allowing improvements in air quality to co-exist with sustainable future economic development.

Report co-author Dr. Ajit Singh commented: "Evidence indicates that ambient air quality in urban African locations is often poor, because of high rates of urbanisation and population growth leading to large-scale construction, increased energy use, vehicle emissions and industrialisation.

"PM air pollution is a major concern in East Africa because of its impact on human health. There are few air quality monitoring networks, resulting in little long-term air quality data, but visibility measured at major cities can be used as a proxy for PM pollution.

"We're tremendously proud of our work in East Africa and the analysis techniques we developed to study Nairobi, Kampala and Addis Ababa are translatable to other parts of the world where air quality data is limited."

The Birmingham team's work is funded by the UK Department for International Development (DFID) through the East Africa Research Fund (EARF) grant 'A Systems Approach to Air Pollution (ASAP) East Africa' and Digital Air Quality (DAQ) - East Africa funded via EPSRC Global Challenges Research Fund.

Co-author Dr. William Avis commented: "Air pollution poses a major health, economic and social threat to cities around the world - inextricably linked to how we plan, manage and live in urban areas. East Africa is no exception to this, but lacks robust air quality data."

Co-author and ASAP lead Professor Francis Pope said: "We need to understand the causes and effects of air pollution in these three cities, which are rapidly developing and will likely experience further increases in PM. Poor air quality acts as a brake on development through increasing expenditure on health, loss of labour productivity, and the impact of illness on education.

"To date, no studies have been able to assess the role of socio-economic factors upon the evolution of air pollution in East Africa. Our work provides data that helps us understand this relationship and provides a much needed baseline for East African urban air quality that can help assess future air quality improvement interventions in the region."

The researchers compared changes in pollution to population growth and GDP statistics - finding increased PM levels linked to increases in national GDP and populations in all three study cities.

They also discovered distinct variations in seasonal visibility, which are largely explained by changing PM sources and sinks in rainy and dry seasons. Visibility was lowest during the dry months and highest in wet months. At all study sites, visibility was higher on Sundays - due to reduced traffic and industrial emissions.

Two specific cell types in the nose have been identified as likely initial infection points for COVID-19 coronavirus. Scientists discovered that goblet and ciliated cells in the nose have high levels of the entry proteins that the COVID-19 virus uses to get into our cells. The identification of these cells by researchers from the Wellcome Sanger Institute, University Medical Centre Groningen, University Cote d'Azur and CNRS, Nice and their collaborators, as part of the Human Cell Atlas Lung Biological Network, could help explain the high transmission rate of COVID-19.

Reported today (23rd April) in Nature Medicine, this first publication with the Lung Biological Network is part of an ongoing international effort to use Human Cell Atlas data to understand infection and disease. It further shows that cells in the eye and some other organs also contain the viral-entry proteins. The study also predicts how a key entry protein is regulated with other immune system genes and reveals potential targets for the development of treatments to reduce transmission.

Novel coronavirus disease - COVID-19 - affects the lungs and airways. Patient's symptoms can be flu-like, including fever, coughing and sore throat, while some people may not experience symptoms but still have transmissible virus. In the worst cases, the virus causes pneumonia that can ultimately lead to death. The virus is thought to be spread through respiratory droplets produced when an infected person coughs or sneezes, and appears to be easily transmitted within affected areas. So far the virus has spread to more than 184 countries and claimed more than 180,000 lives*.

Scientists around the world are trying to understand exactly how the virus spreads, to help prevent transmission and develop a vaccine. While it is known that the virus that causes COVID-19 disease, known as SARS-CoV-2, uses a similar mechanism** to infect our cells as a related coronavirus that caused the 2003 SARS epidemic, the exact cell types involved in the nose had not previously been pinpointed.

To discover which cells could be involved in COVID-19 transmission, researchers analysed multiple Human Cell Atlas§ (HCA) consortium datasets of single cell RNA sequencing, from more than 20 different tissues of non-infected people. These included cells from the lung, nasal cavity, eye, gut, heart, kidney and liver. The researchers looked for which individual cells expressed both of two key entry proteins that are used by the COVID-19 virus to infect our cells.

Dr Waradon Sungnak, the first author on the paper from Wellcome Sanger Institute, said: "We found that the receptor protein - ACE2 - and the TMPRSS2 protease that can activate SARS-CoV-2 entry are expressed in cells in different organs, including the cells on the inner lining of the nose. We then revealed that mucus-producing goblet cells and ciliated cells in the nose had the highest levels of both these COVID-19 virus proteins, of all cells in the airways. This makes these cells the most likely initial infection route for the virus."

Dr Martijn Nawijn, from the University Medical Center Groningen in the Netherlands, said, on behalf of the HCA Lung Biological Network: "This is the first time these particular cells in the nose have been associated with COVID-19. While there are many factors that contribute to virus transmissibility, our findings are consistent with the rapid infection rates of the virus seen so far. The location of these cells on the surface of the inside of the nose make them highly accessible to the virus, and also may assist with transmission to other people."

The two key entry proteins ACE2 and TMPRSS2 were also found in cells in the cornea of the eye and in the lining of the intestine. This suggests another possible route of infection via the eye and tear ducts, and also revealed a potential for fecal-oral transmission.

When cells are damaged or fighting an infection, various immune genes are activated. The study showed that ACE2 receptor production in the nose cells is probably switched on at the same time as these other immune genes.

The work was carried out as part of the global Human Cell Atlas consortium which aims to create reference maps of all human cells to understand health and disease. More than 1,600 people across 70 countries are involved in the HCA community, and the data is openly available to scientists worldwide.

Dr Sarah Teichmann, a senior author from the Wellcome Sanger Institute and co-chair of the HCA Organising Committee, said: "As we're building the Human Cell Atlas it is already being used to understand COVID-19 and identify which of our cells are critical for initial infection and transmission. This information can be used to better understand how coronavirus spreads. Knowing which exact cell types are important for virus transmission also provides a basis for developing potential treatments to reduce the spread of the virus."

The global HCA Lung Biological Network continues to analyse the data in order to provide further insights into the cells and targets likely to be involved in COVID-19, and to relate them to patient characteristics.

Professor Sir Jeremy Farrar, Director of Wellcome, said: "By pinpointing the exact characteristics of every single cell type, the Human Cell Atlas is helping scientists to diagnose, monitor and treat diseases including COVID-19 in a completely new way. Researchers around the world are working at an unprecedented pace to deepen our understanding of COVID-19, and this new research is testament to this. Collaborating across borders and openly sharing research is crucial to developing effective diagnostics, treatments and vaccines quickly, ensuring no country is left behind."