Women who deliver by C-section are less likely to conceive subsequent children

Women who deliver their first child by cesarean section (C-section) are less likely to conceive a second child than those who deliver vaginally, despite being just as likely to plan a subsequent pregnancy, according to researchers. The team followed more than 2,000 women for three years after they delivered their first child.

Date:July 9, 2020

Source:Penn State

Women who deliver their first child by cesarean section (C-section) are less likely to conceive a second child than those who deliver vaginally, despite being just as likely to plan a subsequent pregnancy, according to Penn State College of Medicine researchers. The team followed more than 2,000 women for three years after they delivered their first child.


Kristen Kjerulff, professor of public health sciences, said that although previous studies showed that women who delivered by C-section were less likely to bear subsequent children, it was unclear to researchers whether this was due to maternal choice or a lower rate of conception.

The researchers followed women from before the birth of their first child and interviewed them every six months until three years after their first delivery. During each interview, they asked women to report how often they had unprotected intercourse in each of the previous six months.

Kjerulff and colleagues analyzed data from 2,021 women between the ages of 18 and 35 who provided data on unprotected intercourse and resulting conceptions for three years after their first birth. Nearly 600 of those women delivered their first child by C-section and those women were more likely to be older, overweight and obese, shorter, and more likely to have sought fertility advice, testing or treatment.

Approximately 69% of women who delivered by C-section conceived after unprotected intercourse compared to approximately 78% of women who delivered vaginally. Women who delivered by C-section also had a reduced likelihood of a live birth. The association remained after researchers accounted for maternal age, pre-pregnancy body mass index, time to conception of the first child, gestational weight gain, prior induced abortions, diabetes, hypertension, hospitalization during pregnancy and other factors.

Dr. Richard Legro, a coauthor of the manuscript published in JAMA Network Open and chair of the Department of Obstetrics and Gynecology at Penn State Health Milton S. Hershey Medical Center, says that controlling for intercourse was a key strength of the study and allowed the researchers to rule out trauma or lingering pain from C-section. Although the study didn't investigate the reasons for the decreased conception rate, he suspects there may be some physiological reasons.

"It's possible that pelvic or [fallopian] tubal scarring as a result of being exposed to open air and contaminants may affect subsequent attempts at getting pregnant," Legro said. "It is also possible that scar formation from the surgical wound in the uterus, though not in an area where pregnancies implant, may have lingering effects on the process of implantation."

Based on the findings from this study, Kjerulff and Legro recommend that women under 35 who fail to conceive after a year of unprotected intercourse following a C-section seek medical help. Legro noted the data from this study may be useful for physicians counseling women who elect to have C-sections.

"It's important that women who elect to have a C-section know that there is a chance they may have difficulty conceiving in the future," Legro said.

Journal Reference:
Kristen H. Kjerulff, Ian M. Paul, Carol S. Weisman, Marianne M. Hillemeier, Ming Wang, Richard S. Legro, John T. Repke. Association Between Mode of First Delivery and Subsequent Fecundity and Fertility. JAMA Network Open, 2020; 3 (4): e203076 DOI: 10.1001/jamanetworkopen.2020.3076

Bats offer clues to treating COVID-19

To combat COVID-19, we need to regulate our immune systems to resemble those of bats

HOLY PANDEMIC BATMAN, IT'S NOT WUHAN FLU
IT'S BAT FLU

Bats carry many viruses, including COVID-19, without becoming ill. Biologists are studying the immune system of bats to find potential ways to 'mimic' that system in humans.

Date:July 9, 2020

Source:University of Rochester

Bats are often considered patient zero for many deadly viruses affecting humans, including Ebola, rabies, and, most recently, the SARS-CoV-2 strain of virus that causes coronavirus.

Although humans experience adverse symptoms when afflicted with these pathogens, bats are remarkably able to tolerate viruses, and, additionally, live much longer than similar-sized land mammals.

What are the secrets to their longevity and virus resistance?

According to researchers at the University of Rochester, bats' longevity and capacity to tolerate viruses may stem from their ability to control inflammation, which is a hallmark of disease and aging. In a review article published in the journal Cell Metabolism, the researchers -- including Rochester biology professors Vera Gorbunova and Andrei Seluanov -- outline the mechanisms underlying bats' unique abilities and how these mechanisms may hold clues to developing new treatments for diseases in humans.

Why are bats 'immune' to viruses?

The idea for the paper came about when Gorbunova and Seluanov, who are married, were in Singapore in March before COVID-19 travel bans began. When the virus started to spread and Singapore went into lockdown, they were quarantined at the home of their colleague Brian Kennedy, director of the Centre for Healthy Aging at the National University of Singapore and co-author of the paper.

The three scientists, all experts on longevity in mammals, got to talking about bats. SARS-CoV-2 is believed to have originated in bats before the virus was transmitted to humans. Although bats were carriers, they seemed to be unaffected by the virus. Another perplexing factor: generally, a species' lifespan correlates with its body mass; the smaller a species, the shorter its lifespan, and vice versa. Many bat species, however, have lifespans of 30 to 40 years, which is impressive for their size.

"We've been interested in longevity and disease resistance in bats for a while, but we didn't have the time to sit and think about it," says Gorbunova, the Doris Johns Cherry Professor of Biology at Rochester. "Being in quarantine gave us time to discuss this, and we realized there may be a very strong connection between bats' resistance to infectious diseases and their longevity. We also realized that bats can provide clues to human therapies used to fight diseases."

While there have been studies on the immune responses of bats and studies of bats' longevity, until their article, "no one has combined these two phenomena," Seluanov says.

Gorbunova and Seluanov have studied longevity and disease resistance in other exceptionally long-lived animals, including naked mole rats. One common theme in their research is that inflammation is a hallmark of the aging process and age-related diseases, including cancer, Alzheimer's, and cardiovascular disease. Viruses, including COVID-19, are one factor that can trigger inflammation.

"With COVID-19, the inflammation goes haywire, and it may be the inflammatory response that is killing the patient, more so than the virus itself," Gorbunova says. "The human immune system works like that: once we get infected, our body sounds an alarm and we develop a fever and inflammation. The goal is to kill the virus and fight infection, but it can also be a detrimental response as our bodies overreact to the threat."

Not so with bats. Unlike humans, bats have developed specific mechanisms that reduce viral replication and also dampen the immune response to a virus. The result is a beneficial balance: their immune systems control viruses but at the same time, do not mount a strong inflammatory response.

Why did bats acquire a tolerance for diseases?

According to the researchers, there are several factors that may contribute to bats having evolved to fight viruses and live long lives. One factor may be driven by flight. Bats are the only mammals with the ability to fly, which requires that they adapt to rapid increases in body temperature, sudden surges in metabolism, and molecular damage. These adaptations may also assist in disease resistance.

Another factor may be their environment. Many species of bats live in large, dense colonies, and hang close together on cave ceilings or in trees. Those conditions are ideal for transmitting viruses and other pathogens.

"Bats are constantly exposed to viruses," Seluanov says. "They are always flying out and bringing back something new to the cave or nest, and they transfer the virus because they live in such close proximity to each other."

Because bats are constantly exposed to viruses, their immune systems are in a perpetual arms race with pathogens: a pathogen will enter the organism, the immune system will evolve a mechanism to combat the pathogen, the pathogen will evolve again, and so on.

"Usually the strongest driver of new traits in evolution is an arms race with pathogens," Gorbunova says. "Dealing with all of these viruses may be shaping bats' immunity and longevity."

Can humans develop the same disease resistance as bats?

That's not an invitation for humans to toss their masks and crowd together in restaurants and movie theaters. Evolution takes place over thousands of years, rather than a few months. It has only been in recent history that a majority of the human population has begun living in close proximity in cities. Or that technology has enabled rapid mobility and travel across continents and around the globe. While humans may be developing social habits that parallel those of bats, we have not yet evolved bats' sophisticated mechanisms to combat viruses as they emerge and swiftly spread.

"The consequences may be that our bodies experience more inflammation," Gorbunova says.

The researchers also recognize that aging seems to play an adverse role in humans' reactions to COVID-19.

"COVID-19 has such a different pathogenesis in older people," Gorbunova says. "Age is one of the most critical factors between living and dying. We have to treat aging as a whole process instead of just treating individual symptoms."

The researchers anticipate that studying bats' immune systems will provide new targets for human therapies to fight diseases and aging. For example, bats have mutated or completely eliminated several genes involved in inflammation; scientists can develop drugs to inhibit these genes in humans. Gorbunova and Seluanov hope to start a new research program at Rochester to work toward that goal.

"Humans have two possible strategies if we want to prevent inflammation, live longer, and avoid the deadly effects of diseases like COVID-19," Gorbunova says. "One would be to not be exposed to any viruses, but that's not practical. The second would be to regulate our immune system more like a bat."
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Journal Reference:
Vera Gorbunova, Andrei Seluanov, Brian K. Kennedy. The World Goes Bats: Living Longer and Tolerating Viruses. Cell Metabolism, 2020; 32 (1): 31 DOI: 10.1016/j.cmet.2020.06.013

University of Rochester. "Bats offer clues to treating COVID-19: To combat COVID-19, we need to regulate our immune systems to resemble those of bats." ScienceDaily. ScienceDaily, 9 July 2020. .


Bats harbor a gene swiped from an ancient Ebola-like virus -- here's how they may use it

Study suggests that a gene encoding a viral protein has been carefully preserved in Myotis bats for millions of years

Some 18 million years ago, an ancestor of mouse-eared bats 'stole' genetic material from an ancient virus related to Ebola. The swiped genetic sequence -- a gene called VP35 -- has remained largely intact in the bats despite the passage of time, a new study finds. The research also sheds light on the gene's possible function in bats, suggesting that it may play a role in regulating the immune system's response to threats.

Date:July 24, 2018

Source:University at Buffalo

Some 18 million years ago, an ancestor of mouse-eared bats "stole" genetic material from an ancient virus related to Ebola.

The swiped genetic sequence -- a gene called VP35 -- has remained largely intact in the bats despite the passage of time, with few changes since it was co-opted, a new study finds. The research also sheds light on the gene's possible function in bats, suggesting that it may play a role in regulating the immune system's response to threats.

"We're using a multidisciplinary approach to understand the evolution, structure and function of a viral gene co-opted by a mammal," says Derek J. Taylor, PhD, an evolutionary biologist at the University at Buffalo. "From an evolutionary standpoint, it's rare that you can actually see a viral gene sequence like this that has remained intact in a mammalian host. Most of these things are eroded over time -- they get chopped up and shuffled around.

"But VP35 is highly conserved. It's similar in all the bats we looked at, and the bat versions remain very close to what you see in modern Ebola and Marburg viruses. This conservation suggests that the gene has been preserved for an important purpose."

In Ebola and Marburg viruses today, the VP35 gene carries instructions for building a protein that blocks the immune response of infected animals, enabling disease to take hold. When scientists used artificial synthesis to create bat VP35 proteins in the lab, these proteins also acted as immune suppressors, but they were less potent than viral VP35s.

The study answers some important questions, but many mysteries remain. For example: Is the VP35 gene active in mouse-eared bats? Do mouse-eared bats produce any VP35 proteins? If the bats do make VP35 proteins, why is this beneficial?

"Our study explores VP35 function, but further research is needed to determine the specific evolutionary benefit," Taylor says. "Why has this gene been conserved for so long? We don't quite know the answer, and it's possible that VP35 has some other function in bats that we haven't yet discovered."

The study will be published in the journal Cell Reports on July 24, with Megan R. Edwards, PhD, of Georgia State University as first author. The project was led by Christopher F. Basler, PhD, of Georgia State; Daisy W. Leung, PhD, of the Washington University School of Medicine; and Taylor, a professor of biological sciences in the UB College of Arts and Sciences.

Similarities -- and differences -- in bats and in deadly viruses

To understand VP35's evolutionary history, the team compared VP35 sequences in 15 bat species from the genus Myotis (the mouse-eared bats), and used these sequences to reconstruct the archaic version of the gene that was first acquired by the bats' forebear some 18 million years ago.

This analysis showed that VP35 was strikingly similar across all 15 modern bats, modern Ebola and Marburg viruses, and the reconstructed ancestral gene. In other words: VP35 has changed very little in viruses and mouse-eared bats in the last 18 million years. Bolstering this conclusion, researchers discovered that the structure of a Myotis VP35 protein and an Ebola VP35 protein were alike in many ways.

Despite these resemblances, bat and viral forms of VP35 differ in function. Lab tests showed that bat VP35 helps to suppress production of an infection-fighting immune protein called interferon beta, but less effectively than Ebola and Marburg VP35s.

"How could a bat use a viral gene that normally suppresses interferon? While we don't know the exact answer, interferon is associated with inflammation, and it turns out that turning off the inflammation response is an important aspect of immune system function -- prolonged inflammation can be harmful in mammals," Taylor says. "So one possibility is that bats recruited a viral anti-inflammation gene to enhance control of inflammation."

Genetic theft: How it happens and why it matters

The new study was inspired in part by Taylor's prior work on VP35 and other "stolen" viral genes. Known as non-retroviral integrated RNA viral sequences (NIRVs), these co-opted genetic snippets are accidentally inserted into the genomes of infected hosts when a virus like Ebola or Marburg hijacks a host's genetic machinery to replicate.

NIRVs are a gold mine of information. Taylor, one of the first scientists to study them, calls them "scars of infection" and likens them to a "viral fossil record": You can investigate them to learn many fascinating things about the co-evolution of viruses and hosts.

In prior research, Taylor and colleagues used NIRVs to show that filoviruses -- the family housing Ebola and Marburg -- are ancient. The scientists also discovered that several mammals harbor the VP35 NIRV, which was originally acquired from archaic filoviruses that shared a common ancestor with Ebola and Marburg. Species that have this NIRV range from bats to hamsters, voles and wallabies.

The new project builds on this work by exploring VP35's modern function and showing that the gene has been meticulously conserved through evolution in mouse-eared bats.

"NIRVs can tell you something about the timescale of virus-host interactions, and they can tell you something about what types of hosts are being affected by a virus," Taylor says. "Now we're using them in this present study to inform functional studies. NIRVs are a fairly new area of study, and it's exciting to see what else we can learn from them."

Journal Reference:
Megan R. Edwards et al. Conservation of Structure and Immune Antagonist Functions of Filoviral VP35 Homologs Present in Microbat Genomes. Cell Reports, 2018 DOI: 10.1016/j.celrep.2018.06.045

University at Buffalo. "Bats harbor a gene swiped from an ancient Ebola-like virus -- here's how they may use it: Study suggests that a gene encoding a viral protein has been carefully preserved in Myotis bats for millions of years." ScienceDaily. ScienceDaily, 24 July 2018. .

Global wildlife surveillance could provide early warning for next pandemic

Experts propose decentralized system to monitor wildlife markets, other hotspots

Summary:Researchers propose a decentralized, global wildlife biosurveillance system to identify -- before the next pandemic emerges -- animal viruses that have the potential to cause human disease.

Date:July 9, 2020

Source:Washington University School of Medicine

The virus that causes COVID-19 probably originated in wild bats that live in caves around Wuhan, China, and may have been passed to a second animal species before infecting people, according to the World Health Organization. Many of the most devastating epidemics of recent decades -- including Ebola, avian influenza and HIV/AIDS -- were triggered by animal viruses that spilled over into people. Despite the ever-present danger of a new virus emerging and sparking a worldwide pandemic, there is no global system to screen for viruses in wild animals that eventually may jump to humans.
In a perspective article published July 9 in Science, a diverse group of infectious disease experts, ecologists, wildlife biologists and other experts argue that a decentralized global system of wildlife surveillance could -- and must - be established to identify viruses in wild animals that have the potential to infect and sicken people before another pandemic begins.

"It's impossible to know how often animal viruses spill over into the human population, but coronaviruses alone have caused outbreaks in people three times in the last 20 years," said co-author Jennifer A. Philips, MD, PhD, referring to the SARS, MERS and COVID-19 epidemics. Philips is an associate professor of medicine and co-director of the Division of Infectious Diseases at Washington University School of Medicine in St. Louis. "Even a decade ago it would have been difficult to conduct worldwide surveillance at the human-wildlife interface. But because of technological advances, it is now feasible and affordable, and it has never been more obvious how necessary it is."

Every animal has its own set of viruses, with some overlap across species. Often, an animal species and its viruses have lived together for so long that they've adapted to one another, and the viruses cause either no symptoms or only mild to moderate disease. But when different animal species that don't normally have much contact are brought together, viruses have the opportunity to jump from one species to another. Most viruses don't have the genetic tools to infect another species. But viruses with such tools can be lethal to a newly infected species with no natural immunity.

Human activity is making such spillover events more and more likely. As the population of the world continues to grow, the demand for natural resources skyrockets. People push into wild areas to make space for new homes and businesses, and to access resources to fuel their economies and lifestyles. Wild animals are caught and sold for consumption, or as exotic pets at wildlife markets, where diverse species are jumbled together under crowded and unsanitary conditions. Wild-animal parts are shipped around the world as trinkets or ingredients for traditional or alternative medicines.

And yet there is no international system set up to screen for disease-causing viruses associated with the movement of wildlife or wildlife products.

"In the lead up to this article, I spoke with friends and colleagues around the world who do wildlife research in Madagascar, Indonesia, Peru, Ecuador and asked them, 'Where do you take your samples for screening?'" said co-author Gideon Erkenswick, PhD, a postdoctoral research associate in Philips' lab. Erkenswick is also the director of Field Projects International, a nonprofit organization dedicated to the study and conservation of tropical ecosystems. "In almost every situation, the answer was 'Nowhere.' Locally, there is nobody with dedicated time and resources to do this work. To find new disease-causing viruses, we have to find willing foreign collaborators, then get samples out of the country, which is difficult and expensive."

Philips, Erkenswick, and colleagues in the Wildlife Disease Surveillance Focus Group that authored the Science paper, suggest the establishment of a global surveillance network to screen wild animals and their products at hotspots such as wildlife markets. The idea would be to have local teams of researchers and technicians extract viral genomes from animal samples, rapidly sequence them on site and upload the sequences to a central database in the cloud. The cost and size of the necessary scientific equipment has dropped in recent years, making such screening affordable even in resource-limited settings where most such hotspots are located.

"There's now a genetic sequencer available that is literally the size of a USB stick," Erkenswick said. "You could bring that and a few other supplies into a rainforest and analyze a sample for sequences associated with disease-causing viruses on site in a matter of hours. I mean, if you do chance upon something like the virus that causes COVID-19, do you really want to be collecting it, storing it, transporting it, risking further exposure, sample degradation, and adding months or years of delay, before you figure out what you've got? There are people with the expertise and skills to do this kind of work safely pretty much everywhere in the world, they just haven't been given the tools."

Once viral sequences are uploaded, researchers around the world could help analyze them to identify animal viruses that may be a threat to people and to develop a better understanding of the universe of viruses that thrive in different environments. By comparing genomic sequence data, researchers can identify what family an unknown virus belongs to and how closely it is related to any disease-causing viruses. They can also identify whether a virus carries genes associated with the ability to cause disease in people.

"By knowing the diversity out there, and tracking its evolution, we can ensure that we stay ahead of what's in wildlife populations and at the wildlife-human interface," Philips said. "In the past, before modern transportation, spillover events would have been local and spread slowly, giving people elsewhere time to respond. But now the world is so small that an event in one place puts the whole world at risk. This is not someone else's problem. It's everyone's problem."
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Story Source:

Materials provided by Washington University School of Medicine. Original written by Tamara Bhandari. Note: Content may be edited for style and length.


Journal Reference:
Mrinalini Watsa, Wildlife Disease Surveillance Focus Group. Rigorous wildlife disease surveillance. Science, 2020; 369 (6500): 145-147 DOI: 10.1126/science.abc0017


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Washington University School of Medicine. "Global wildlife surveillance could provide early warning for next pandemic: Experts propose decentralized system to monitor wildlife markets, other hotspots." ScienceDaily. ScienceDaily, 9 July 2020. .

No association found between exposure to mobile devices and brain volume alterations in adolescents

A new study of 2,500 Dutch children is the first to explore the relationship between brain volume and different doses of radiofrequency electromagnetic fields.

Date:July 9, 2020

Source:Barcelona Institute for Global Health (ISGlobal)

How does the use of mobile devices affect children's brains? A team from the Barcelona Institute for Global Health (ISGlobal), a centre supported by the "la Caixa" Foundation, has conducted the first epidemiological study to explore the relationship between brain volume in preadolescents -- more than 2,500 Dutch children -- and different doses of radiofrequency electromagnetic fields (RF-EMF). No association was found, although the authors did not rule out the possibility of an association between using mobile devices with a wireless Internet connection and smaller volume of the caudate nucleus.

The potential negative health consequences associated with children's use of mobile devices have been a matter of concern for some time. Exposure to RF-EMF is of particular interest, since the preadolescent brain is still developing and children will experience long periods of exposure to RF-EMF if they use mobile devices throughout their lives.

Most previous research on this subject has separately assessed the association between brain development and different RF-EMF sources, without finding clear associations. The new study, published in Environment International, aimed to investigate brain volume alterations using an integrative approach that considered multiple sources of RF-EMF. This approach allowed a more comprehensive assessment of the possible impact of RF-EMF exposure on the adolescent brain.

The study used data on more than 2,500 children aged 9-12 years from the Generation R Study, a birth cohort based in Rotterdam, the Netherlands. Parents completed a questionnaire on their children's use of mobile devices. RF-EMF doses to the brain from different sources were estimated and grouped according to three exposure patterns: telephone calls, screen activities, and other environmental factors such as mobile telephone antennas. Magnetic resonance imaging (MRI) scans were used to determine the volume of various parts of the brain.

The authors found no association between alterations in total or lobe-specific brain volume and overall RF-EMF dose. Nor was brain volume associated with the use of mobile devices for telephone calls, which are the primary contributors of RF-EMF exposure to the brain. However, a link was found between smaller volume of the caudate nucleus -- a brain structure involved in memory and coordination of movements -- and RF-EMF dose from the use of devices with screens (mobile phones, tablets and laptops) with a wireless Internet connection.

"The main objective of the study was to determine whether there were any associations between exposure to RF-EMF and brain volumes," commented ISGlobal researcher Alba Cabré, lead author of the study. "Our findings show that this is not the case. The possible association between the RF-EMF dose received through the use of these devices for screen activities and the volume of the caudate nucleus is a secondary finding for which we currently have no explanation. When you surf the Internet on a mobile phone, tablet or laptop using a wireless connection, the brain's exposure to RF-EMF is much lower than it is when you make phone calls, for example, because of the distance between the device and your head. In any case, this result should be interpreted with great caution, since the influence of other factors and the possibility of a chance finding cannot be ruled out."

RF-EMF Exposure or Use-Related Factors?

One possible explanation for the findings, besides the brain's exposure to RF-EMF, is the influence of social or individual factors related to certain uses of mobile devices. ISGlobal researcher Mònica Guxens, coordinator of the study, commented: "We cannot rule out the possibility that brain alterations may somehow be related to the way in which children use mobile devices." She added: "More research is needed on mobile communication devices and their possible associations with brain development, regardless of whether the relationship is due to RF-EMF exposure or other factors related to the use of these devices."

The average overall whole-brain dose of RF-EMF was estimated at 84.3 mJ/kg/day. The highest overall lobe-specific dose was estimated in the temporal lobe (307.1 mJ/kg/day). Both doses are well below the maximum values recommended by the International Commission on Non-Ionising Radiation Protection (ICNIRP).

Journal Reference:
Alba Cabré-Riera, Hanan El Marroun, Ryan Muetzel, Luuk van Wel, Ilaria Liorni, Arno Thielens, Laura Ellen Birks, Livia Pierotti, Anke Huss, Wout Joseph, Joe Wiart, Myles Capstick, Manon Hillegers, Roel Vermeulen, Elisabeth Cardis, Martine Vrijheid, Tonya White, Martin Röösli, Henning Tiemeier, Mònica Guxens. Estimated whole-brain and lobe-specific radiofrequency electromagnetic fields doses and brain volumes in preadolescents. Environment International, 2020; 142: 105808 DOI: 10.1016/j.envint.2020.105808

Study says inhalers OK to use amid COVID-19 concerns

Researchers find that the benefits of inhalers for asthma sufferers outweigh the risks of contracting coronavirus, following concerns raised after WHO warned that steroids could reduce immunity.

Date:July 9, 2020   Source:University of Huddersfield

The benefits of using inhalers and nebulisers containing steroids outweigh the risks despite warnings to the contrary during the COVID-19 pandemic, a study by University of Huddersfield researchers has found.

A warning issued by WHO in March advised that steroids used in inhalers and nebulisers could have a negative effect on a user's immunity system, leaving them more susceptible to COVID-19. The concern was that regular steroid use could leave users vulnerable to contracting the virus, or developing a more severe version than non-users.

WHO's cautionary note caused worry for people with asthma or chronic obstructive pulmonary disease (COPD), leaving them unsure about whether they could keep using inhalers and nebulisers or not. The British Thoracic Society had reported that demand for inhalers had jumped by 400%, leading to shortages in the UK, following WHO's announcement.

However, Dr Hamid Merchant and Dr Syed Shahzad Hasan from the University of Huddersfield commissioned research into the use of steroids and risk of infections, especially viral infections of the upper respiratory tract. That included previous outbreaks of SARS, as well as the COVID-19 pandemic.

"It confused a lot of people," says Dr Hasan. "After the WHO advice, people thought that continuous use of steroids would leave them at a greater risk of contracting the virus or developing more than a mild version of CoViD-19."

Inhaled corticosteroids (ICS) and oral corticosteroids (OCS) are prescribed to help asthma sufferers and those with COPD, with inhalers used to prevent attacks.

The study has been published in Respiratory Medicine, having assessed evidence and findings from a range of bodies including the British Thoracic Society and the National Institute for Health and Care Excellence (NICE). The other authors in the study included Toby Capstick (a consultant pharmacist on respiratory medicine at Leeds Teaching Hospitals NHS Trust), Syed Tabish Zaidi (Associate Professor in Pharmacy at the University of Leeds) and Chia Siang Kow (a clinical pharmacist from Malaysia).

"We found there is strong evidence that the benefits of continuing with steroids outweighs the risk," declares Dr Merchant.

"There is a risk that the immune system goes down, and there is a chance of acquiring infections but the benefits of continuing with steroids throughout were higher than the risks. We concluded by saying that the patients should continue their regular medicines including steroids."

Journal Reference:
Syed Shahzad Hasan, Toby Capstick, Syed Tabish Razi Zaidi, Chia Siang Kow, Hamid A. Merchant. Use of corticosteroids in asthma and COPD patients with or without COVID-19. Respiratory Medicine, 2020; 170: 106045 DOI: 10.1016/j.rmed.2020.106045

CRIMINAL CAPITALISM

Scientists trace the origin of our teeth from the most primitive jawed fish

Scientists have digitally 'dissected', for the first time, the most primitive jawed fish fossils with teeth found near Prague more than 100 years ago. The results show that their teeth have surprisingly modern features.

Date:July 9, 2020

Source:European Synchrotron Radiation Facility

The origin of our teeth goes back more than 400 million years back in time, to the period when strange armoured fish first developed jaws and began to catch live prey. We are the descendants of these fish, as are all the other 60,000 living species of jawed vertebrates -- sharks, bony fish, amphibians, reptiles, birds and mammals. An international team of scientists led by Uppsala University (Sweden), in collaboration with the ESRF, the European Synchrotron (France), the brightest X-ray source, has digitally 'dissected', for the first time, the most primitive jawed fish fossils with teeth found near Prague more than 100 years ago. The results, published today in Science, show that their teeth have surprisingly modern features.

Teeth in current jawed vertebrates reveal some consistent patterns: for example, new teeth usually develop on the inner side of the old ones and then move outwards to replace them (in humans this pattern has been modified so that new teeth develop below the old ones, deep inside the jawbone). There are, however, several differences between bony fish (and their descendants the land animals) and sharks; for example the fact that sharks have no bones at all, their skeleton is made of cartilage, and neither the dentine scales nor the true teeth in the mouth attach to it; they simply sit in the skin. In bony fish and land animals, the teeth are always attached to jaw bones. In addition, whilst sharks shed their worn-out teeth entire, simply by detaching them from the skin, bony fish and land animals shed theirs by dissolving away the tooth bases.

This diversity raises many questions about the origin of teeth. Until now, researchers have focused on fossils of a group of ancient fish that lived about 430 to 360 million years ago, called the arthrodires, which were the only stem jawed vertebrates in which teeth were known. However, they struggled to understand how they could have evolved into the teeth of modern vertebrates, as arthrodire teeth are so different in position and mode of tooth addition in comparison to bony fish and sharks.

Scanning the most primitive jawed fishes

A team from Uppsala University, Charles University (Czech Republic), Natural History Museum in London (UK), National Museum in Prague (Czech Republic) and the ESRF, the European Synchrotron (France) set out to determine whether this peculiar type of dentition was really ancestral to ours, or just a specialised offshoot off the lineage leading towards modern jawed vertebrates.

With this aim, they turned to the acanthothoracids, another early fish group that are believed to be more primitive than the arthrodires and closely related to the very first jawed vertebrates. The problem with acanthothoracids is that their fossils are rare and always incomplete. The very finest of them come from the Prague Basin in the Czech Republic, from rocks that are just over 400 million years old, and were collected at the turn of the last century. They have proved difficult to study by conventional techniques because the bones cannot be freed from the enclosing rock, and have therefore never been investigated in detail.

The researchers used the unique properties of the ESRF, the world's brightest X-ray source and the synchrotron microtomography ID19's beamline, to visualise the internal structure of the fossils in 3D without damaging them. At the ESRF, an 844 metre-ring of electrons travelling at the speed of light emits high-powered X-ray beams that can be used to non-destructively scan matter, including fossils.

"The results were truly remarkable, including well-preserved dentitions that nobody expected to be there" says Valéria Vaškaninová, lead author of the study and scientist from Uppsala University. Follow-up scans at higher resolution allowed the researchers to visualize the growth pattern and even the perfectly preserved cell spaces inside the dentine of these ancient teeth.

Like arthrodires, the acanthothoracid dentitions are attached to bones. This indicates that bony fish and land animals retain the ancestral condition in this regard, whereas sharks are specialized in having teeth that are only attached to the skin -- in contrast to the common perception that sharks are primitive living vertebrates. Again, like arthrodires, the teeth of acanthothoracids were not shed.

More different from arthrodires than expected

In other ways, however, acanthothoracid dentitions are fundamentally different from those of arthrodires. Like sharks, bony fish and land animals, acanthothoracids only added new teeth on the inside; the oldest teeth were located right at the jaw margin. In this respect, the acanthothoracid dentitions look remarkably modern.

"To our surprise, the teeth perfectly matched our expectations of a common ancestral dentition for cartilaginous and bony vertebrates." explains Vaškaninová.

The tooth-bearing bones also carry small non-biting dentine elements of the skin on their outer surfaces, a character shared with primitive bony fish but not with arthrodires. This is an important difference because it shows that acanthothoracid jaw bones were located right at the edge of the mouth, whereas arthrodire jaw bones lay further in. Uniquely, one acanthothoracid (Kosoraspis) shows a gradual shape transition from these dentine elements to the neighboring true teeth, while another (Radotina) has true teeth almost identical to its skin dentine elements in shape. This may be evidence that the true teeth had only recently evolved from dentine elements on the skin.

"These findings change our whole understanding of the origin of teeth" says co-author Per Ahlberg, professor at Uppsala University. And he adds: "Even though acanthothoracids are among the most primitive of all jawed vertebrates, their teeth are in some ways far more like modern ones than arthrodire dentitions. Their jawbones resemble those of bony fish and seem to be directly ancestral to our own. When you grin at the bathroom mirror in the morning, the teeth that grin back at you can trace their origins right back to the first jawed vertebrates."


Journal Reference:
Valéria Vaškaninová, Donglei Chen, Paul Tafforeau, Zerina Johanson, Boris Ekrt, Henning Blom, Per Erik Ahlberg. Marginal dentition and multiple dermal jawbones as the ancestral condition of jawed vertebrates. Science, 2020 DOI: 10.1126/science.aaz9431

European Synchrotron Radiation Facility. "Scientists trace the origin of our teeth from the most primitive jawed fish." ScienceDaily. ScienceDaily, 9 July 2020. 

PREHISTORIC FISH PIC
https://plawiuk.blogspot.com/2020/07/fossil-of-giant-70m-year-old-fish-found.html

New evidence of long-term volcanic, seismic risks in northern Europe

An ancient European volcanic region may pose both a greater long-term volcanic risk and seismic risk to northwestern Europe than scientists had realized, geophysicists report. The densely populated area is centered in the Eifel region of Germany, and covers parts of Belgium, the Netherlands, France and Luxembourg.

Date:July 9, 2020

Source:University of California - Los Angeles

An ancient European volcanic region may pose both a greater long-term volcanic risk and seismic risk to northwestern Europe than scientists had realized, geophysicists report in a study in the Geophysical Journal International.

The scientists are not predicting that a volcanic eruption or earthquake is imminent in the densely populated area, which is centered in the Eifel region of Germany, and covers parts of Belgium, the Netherlands, France and Luxembourg. But the study revealed activity that is uncommon for the region.

"Our findings suggest this region is an active volcanic system, and much more seismically active than many of the faults in Europe between the Eifel volcanic region and the Alps," said Paul Davis, a UCLA research professor of geophysics and a senior author of the study.

Davis and his co-authors report subtle, unusual movements in the surface of the Earth, from which they conclude the Eifel volcanic region remains seismically active. The region has a long history of volcanic activity, but it has been dormant for a long time; scientists think the last volcanic eruption there was some 11,000 years ago.

The geophysicists report that the land surface in that region is lifting up and stretching apart, both of which are unusual in Europe. Although the uplift is only a fraction of an inch per year, it is significant in geological terms, Davis said.

The geophysicists analyzed global positioning system data from across Western Europe that showed subtle movements in the Earth's surface. That enabled them to map out how the ground is moving vertically and horizontally as the Earth's crust is pushed, stretched and sheared.

The dome-like uplift they observed suggests those movements are generated by a rising subsurface mantle plume, which occurs when extremely hot rock in the Earth's mantle becomes buoyant and rises up, sending extremely hot material to the Earth's surface, causing the deformation and volcanic activity. The mantle is the geological layer of rock between the Earth's crust and its outer core.

Corné Kreemer, the study's lead author, is a research professor at the University of Nevada, Reno's Nevada Bureau of Mines and Geology. He said many scientists had assumed that volcanic activity in the Eifel was a thing of the past, but the study indicates that no longer seems to be the case.

"It seems clear that something is brewing underneath the heart of northwest Europe," he said.

The Eifel volcanic region houses many ancient volcanic features, including circular lakes known as maars -- which are remnants of violent volcanic eruptions, such as the one that created Laacher See, the largest lake in the area. The explosion that created Laacher See is believed to have occurred approximately 13,000 years ago, with an explosive power similar to that of the spectacular 1991 Mount Pinatubo eruption in the Philippines.

The researchers plan to continue monitoring the area using a variety of geophysical and geochemical techniques to better understand potential risks.

The research was supported by the Royal Dutch Academy of Sciences, the United States Geological Survey, the National Earthquake Hazard Reduction Program and NASA.


University of California - Los Angeles. "New evidence of long-term volcanic, seismic risks in northern Europe." ScienceDaily. ScienceDaily, 9 July 2020. .

Skull of two million year-old giant dormouse reconstructed

A researcher has digitally pieced together fossilized fragments from five giant dormouse skulls to reconstruct the first known complete skull of the species, which was roughly the size of a cat.

Date:July 9, 2020

Source:University of York

A PhD student has produced the first digital reconstruction of the skull of a gigantic dormouse, which roamed the island of Sicily around two million years ago.

In a new study, the student from Hull York Medical School, has digitally pieced together fossilised fragments from five giant dormouse skulls to reconstruct the first known complete skull of the species.

The researchers estimate that the enormous long-extinct rodent was roughly the size of a cat, making it the largest species of dormouse ever identified.

The digitally reconstructed skull is 10 cm long -- the length of the entire body and tail of many types of modern dormouse.

PhD student Jesse Hennekam said: "Having only a few fossilised pieces of broken skulls available made it difficult to study this fascinating animal accurately. This new reconstruction gives us a much better understanding of what the giant dormouse may have looked like and how it may have lived."

The enormous prehistoric dormouse is an example of island gigantism -- a biological phenomenon in which the body size of an animal isolated on an island increases dramatically.






The palaeontological record shows that many weird and wonderful creatures once roamed the Italian islands. Alongside the giant dormouse, Sicily was also home to giant swans, giant owls and dwarf elephants.

Jesse's PhD supervisor, Dr Philip Cox from the Department of Archaeology at the University of York and Hull York Medical School, said: "While Island dwarfism is relatively well understood, as with limited resources on an island animals may need to shrink to survive, the causes of gigantism are less obvious.


"Perhaps, with fewer terrestrial predators, larger animals are able to survive as there is less need for hiding in small spaces, or it could be a case of co-evolution with predatory birds where rodents get bigger to make them less vulnerable to being scooped up in talons."

Jesse spotted the fossilised fragments of skull during a research visit to the Palermo Museum in Italy, where a segment of rock from the floor of a small cave, discovered during the construction of a motorway in northwest Sicily in the 1970s, was on display.

"I noticed what I thought were fragments of skull from an extinct species embedded in one of the cave floor segments," Jesse said. "We arranged for the segment to be sent to Basel, Switzerland for microCT scanning and the resulting scans revealed five fragmented skulls of giant dormice present within the rock."





The reconstruction is likely to play an important role in future research directed at improving understanding of why some small animals evolve larger body sizes on islands, the researchers say.

"The reconstructed skull gives us a better sense of whether the giant dormouse would have looked similar to its normal-sized counterparts or whether its physical appearance would have been influenced by adaptations to a specific environment," Jesse explains.

"For example, if we look at the largest living rodent -- the capybara -- we can see that it has expanded in size on a different trajectory to other species in the same family."

Jesse is also using biomechanical modelling to understand the feeding habits of the giant dormouse.

"At that size, it is possible that it may have had a very different diet to its smaller relatives," he adds.

Journal Reference:

Jesse J. Hennekam, Victoria L. Herridge, Loïc Costeur, Carolina Di Patti, Philip G. Cox. Virtual Cranial Reconstruction of the Endemic Gigantic Dormouse Leithia melitensis (Rodentia, Gliridae) from Poggio Schinaldo, Sicily. Open Quaternary, 2020; 6 DOI: 10.5334/oq.79

University of York. "Skull of two million year-old giant dormouse reconstructed." ScienceDaily. ScienceDaily, 9 July 2020. .


ILLUSTRATIONS ALICE IN WONDERLAND CHAPTER VII
https://www.cs.cmu.edu/~rgs/alice-VII.html

New study detects ringing of the global atmosphere

Date:July 7, 2020

Source:University of Hawaii at Manoa

A ringing bell vibrates simultaneously at a low-pitched fundamental tone and at many higher-pitched overtones, producing a pleasant musical sound. A recent study, just published in the Journal of the Atmospheric Sciences by scientists at Kyoto University and the University of Hawaii at Manoa, shows that the Earth's entire atmosphere vibrates in an analogous manner, in a striking confirmation of theories developed by physicists over the last two centuries.

In the case of the atmosphere, the "music" comes not as a sound we could hear, but in the form of large-scale waves of atmospheric pressure spanning the globe and traveling around the equator, some moving east-to-west and others west-to-east. Each of these waves is a resonant vibration of the global atmosphere, analogous to one of the resonant pitches of a bell. The basic understanding of these atmospheric resonances began with seminal insights at the beginning of the 19th century by one of history's greatest scientists, the French physicist and mathematician Pierre-Simon Laplace. Research by physicists over the subsequent two centuries refined the theory and led to detailed predictions of the wave frequencies that should be present in the atmosphere. However, the actual detection of such waves in the real world has lagged behind the theory.

Now in a new study by Takatoshi Sakazaki, an assistant professor at the Kyoto University Graduate School of Science, and Kevin Hamilton, an Emeritus Professor in the Department of Atmospheric Sciences and the International Pacific Research Center at the University of Hawaii at Manoa, the authors present a detailed analysis of observed atmospheric pressure over the globe every hour for 38 years. The results clearly revealed the presence of dozens of the predicted wave modes.

The study focused particularly on waves with periods between 2 hours and 33 hours which travel horizontally through the atmosphere, moving around the globe at great speeds (exceeding 700 miles per hour). This sets up a characteristic "chequerboard" pattern of high and low pressure associated with these waves as they propagate.

"For these rapidly moving wave modes, our observed frequencies and global patterns match those theoretically predicted very well," stated lead author Sakazaki. "It is exciting to see the vision of Laplace and other pioneering physicists so completely validated after two centuries."

But this discovery does not mean their work is done.

"Our identification of so many modes in real data shows that the atmosphere is indeed ringing like a bell," commented co-author Hamilton. "This finally resolves a longstanding and classic issue in atmospheric science, but it also opens a new avenue of research to understand both the processes that excite the waves and the processes that act to damp the waves."

So let the atmospheric music play on!

Journal Reference:
Takatoshi Sakazaki, Kevin Hamilton. An Array of Ringing Global Free Modes Discovered in Tropical Surface Pressure Data. Journal of the Atmospheric Sciences, 2020; 77 (7): 2519 DOI: 10.1175/JAS-D-20-0053.1

University of Hawaii at Manoa. "New study detects ringing of the global atmosphere." ScienceDaily. ScienceDaily, 7 July 2020. .