Culture

Construction: How to turn 36 seconds into USD 5.4 billion

A team of researchers from Aarhus University have, for the first time ever, linked 40 years of productivity data from the construction industry with the actual work done. The results show that productivity in the construction industry has been declining since the 1970s. The results also explain the decline and how to achieve far more efficient construction in North America and Europe.

"This is a clear and cut business case and a helping hand for decision-makers in the construction industry: If the country's contractors are to make more money, they need to optimise processes."

This is how Hasse Neve, carpenter, MSc in Engineering, PhD and researcher in construction industry productivity at the Department of Engineering at Aarhus University, introduces the new study that, for the first time ever, links national productivity statistics in the construction industry with the efficiency of the actual work done on construction sites.

As it turns out, there is a statistically significant correlation between the two.

"Since 1972, we've continuously gotten less and less out of every hour of work. Construction sites have simply become less and less efficient because more time is spent on non-value adding work. Ultimately, this means that we spend more and more working hours on a single construction job. Therefore, our contractors do not earn as much money on construction as they could," says Hasse Neve.

The study has just been published in Construction Engineering and Management, one of the world's leading scientific journals for construction management.

Hasse Neve emphasises that it is primarily the construction management and not the builders who are responsible for and can influence how a building site operates, and thus how efficiently work is carried out. In general, everybody wants a good workflow and no waste:

"But to achieve this, the construction management team will need to use the right tools and competences and dedicate themselves to the task," he says and continues:

"The construction management team have the greatest influence on efficiency, and thereby on how much money is earned. And the way to increase efficiency is to use methods, tools and knowledge that already exist. Lean Construction tools are basically all about eliminating waste. It is therefore crucial that the construction management are trained in Lean Construction and that extra resources are added to both implementation and support throughout the project."

In the study, the research team used national productivity statistics from the construction industry and so-called work-sampling studies (observational studies of the work performed) from the US and Canada. The studies were carried out between 1972 and 2010. The reason that no Danish or European data were used is simply because not enough work-sampling studies have been completed in Denmark and Europe.

"Since the construction industry in North America isn't too different from its European or Danish counterparts, there's good reason to take these results seriously. If we're going to change the productivity development of the Danish construction industry, we need to focus on efficiency on construction sites," says Hasse Neve.

To illustrate the value that the construction industry could generate if more time was spent on value-adding work, Hasse has calculated what just 36 more seconds per hour (for builders) spent on generating value could mean for the construction industry's gross domestic product in the US and Canada: 5.4 billion dollars annually (approx. DKK 36 billion).

"Although there is a degree of uncertainty, this shows what a society could earn by simply spending one percentage point more time on value-adding work on construction sites. But the vast majority of sites can be optimised even more, thus the numbers could be huge," he says and continues:

"The results are of course based on North American data, but there is no doubt that the potential for the Danish construction industry is also significant. And that's a really fantastic thought. We have lots of tools and knowledge that can make construction processes far more efficient, so why not use them? Fundamentally, construction is about generating value. A good final product for the client and users, and an efficient process for contractors, so they can earn money.

And if you are unsure about how to get started?

"Then just call me," says the researcher with a smile.

Credit: 
Aarhus University

New study warns of misinformation about opt-out organ donation

A new study has warned of the power of a type of behaviour dubbed the 'lone wolf' effect which could result in people 'opting out' of supporting organ donation.

A behavioural study led by researchers from the University of Nottingham's School of Psychology and Nanyang Technological University's Department of Economics found that initial co-operation, encouraged by an opt-out policy, can be undermined by members of the public observing the actions of 'lone wolves'.

The study revealed that lone wolves unilaterally defect and publicly display their decision to opt out leading others to follow suit and do the same. This effect of lone wolves is a stronger social force for change than people following 'good shepherds' who are observed to register under an opt-in policy. Their findings have been published in Scientific Reports.

It has long been recognised that when it comes to making an organ donation decision, not everyone wishes to or can donate. People also may wish to donate, but don't, simply because they never got around to signing up. To help overcome this inertia, and redress the shortage in organs, some countries, including Wales and most recently, England, have introduced a change in law, to move from an opt-in system (where everyone is assumed to be a non-donor and registers to be a donors) to an opt-out system (where everyone is assumed to be a donor, unless they opt out.)

The policy in England is a so-called "soft opt-out" policy. This means that all adults in England (unless they are in one of the excluded groups), will be considered to have agreed to be an organ donor when they die unless they have recorded a decision not to donate (either by registering their decision on the NHS Organ Donor Register or telling their family and friends.) The system is a "soft opt-out" as relatives will still be consulted, before organ donation goes ahead.

Professor Eamonn Ferguson from the University of Nottingham said: "The opt-out system relies on people accepting the default of their organs being donated, unless they take action to confirm their decision not to donate. However, our research uncovered a disruptor to this called the 'lone wolf'.

If people know that others have decided to opt out, they are very likely also to do the same. In a world dominated by social media and instant messaging, this can sets up a negative cascade that quickly spreads.

This is important as much of the evidence for moving to opt-out is derived from population studies that cover time periods prior to the social media explosion."

The researchers devised economic games to model the organ donor decision. 213 people participated in games where they indicated their decision to register as a donor under opt-in, or opt-out. They examined the effect the feedback from others (akin to social media updates) had on people's decisions.

Associate Professor Jonathan Tan of Nanyang explains: "In theory, under an opt-out system where feedback is available, people are better off cooperating if they cannot get away with free-riding since others can observe them and opt out too. In practice, however, so long as there are lone wolves who unconditionally free-ride, this default system will lose its strategic power."

Professor Ferguson adds: "The results showed that when people decide not to follow an opt-out default or request, the effect on causing others to follow suit is very strong and much stronger than following people who are acting in accordance with an opt-in policy and registering.

We know that people follow others behaviour, but it is interesting that when everyone is requested to cooperate and help, people has a strong tendency to follow the example of a negative uncooperative influence (or lone wolf). Many people may decide to opt-out simply because others do. This may be because they think that others know something they don't or they don't want to be left behind.

This also raises a very real risk that incorrect information about organ donation and the law change could lead large numbers of people to opt out. This is something that has not been documented before in academic research and we feel is important for the public to be aware, so they can be alert and on their guard for the influence of such information.

While we examined these effects in organ donation they have implications for other public health policies where defaults may be considered such as vaccinations, energy conservation and social distancing."

We would recommend harnessing the 'good shepherd' effect to help encourage registration as exemplified by recent evidence that posting about signing up to be a donor increased registration: the so called 'Facebook' effect.

If moving to an opt-out policy then strategies to ameliorate the 'lone wolf 'effect need to be considered. This could involve the use of moral norms to ameliorate the 'lone wolf 'as well as strategies to monitor social media and 'fake news' or negative stories about organ donation and ask people to question the validity of any information they see."

Credit: 
University of Nottingham

New biomarker for dementia diagnosis

image: Professor Arduino Mangoni, Head of Clinical Pharmacology at Flinders University, in his research laboratory in South Australia.

Image: 
Flinders University

Medical researchers in the UK and Australia have identified a new marker which could support the search for novel preventative and therapeutic treatments for dementia.

In an innovative new study, coordinated by Flinders University and University of Aberdeen, the researchers investigated the role of asymmetric dimethylarginine (ADMA), a blood marker associated with atherosclerosis and cardiovascular disease in epidemiological studies, on temporal changes in cognition in an established cohort of human ageing (the 1936 Aberdeen Birth Cohort).

Unlike other human ageing study cohorts, the 1936 Aberdeen Birth Cohort participants also underwent childhood intelligence tests at age 11, a key predictor of intelligence and health in old age.

Research has primarily focused on a set of abnormalities found in diseased brains. However, observational studies and clinical trials targeting these alterations have been disappointing, suggesting the urgent need to better understand the causes of dementia and identify novel markers of disease.

In the first longitudinal study, ADMA levels measured in the year 2000 (at participants' age 63 years) was associated with decline in cognitive performance assessments after four years, says Flinders University Professor Arduino Mangoni.

"Therefore the results of this study suggest, that ADMA, an easily measurable marker of atherosclerosis and cardiovascular risk, could be an early indicator of cognitive decline in old age - and possibly dementia," says Professor Mangoni, Head of Clinical Pharmacology at Flinders University.

Alzheimer's disease (AD), a neurodegenerative disorder characterised by a rapid decline in cognition and significant disability in old age, currently affects more than 342,000 Australians. This number is expected to increase to 400,000 in less than a decade.

The causes of late onset AD are largely unknown and despite extensive research, there is still no clear consensus on robust biomarkers to predict disease onset and progression and the response to therapies.

UK researcher Dr Deborah Malden says the results of the new study should be approached with caution and need further extensive investigations.

"We should be cautious about emphasising the results with the 93 participants' results here," she says.

"We would know much more after repeating this study in a large-scale cohort, potentially tens of thousands of individuals, and perhaps a genetic MR (Mendelian randomization) study," Dr Malden says.

Nevertheless, if the initial study findings are verified in large-scale testing, researchers hope the findings could pave the way for population-wide dementia risk stratification and perhaps future development of therapeutic strategies to reduce ADMA levels and/or slow the progression of cognitive decline in old age.

Credit: 
Flinders University

Basel study: Why lopinavir and hydroxychloroquine do not work on COVID-19

image: Treatment of a patient with Covid-19 in the intensive care unit of the University Hospital Basel.

Image: 
University Hospital Basel, Fabian Fiechter

Lopinavir is a drug against HIV, hydroxychloroquine is used to treat malaria and rheumatism. Until recently, both drugs were regarded as potential agents in the fight against the coronavirus SARS-CoV-2. A research group from the University of Basel and the University Hospital has now discovered that the concentration of the two drugs in the lungs of Covid-19 patients is not sufficient to fight the virus.

In February 2020, a Covid-19 patient cohort was established at the University and the University Hospital in Basel to prospectively monitor a range of diagnostic means and potential treatments for Covid-19, including the off-label use of hydroxychloroquine and lopinavir/ritonavir.

A research group prospectively monitored lopinavir plasma levels in Covid-19 patients. "Considering that substantial inflammation was observed in these patients, and previous studies have shown the inhibition of drug metabolism by systemic inflammation, we had the rationale to investigate the effect of inflammation on lopinavir and hydroxychloroquine plasma levels," states Professor Catia Marzolini, first author of the study and professor for experimental medicine at the University of Basel.

The authors included 92 patients in their study. Professor Parham Sendi, who is the co-leader of this study summarizes the main findings as follows: First, lopinavir plasma levels were more than two to threefold higher than typically observed in HIV patients. Hydroxychloroquine levels were with normal range. Second, there was a significant correlation between the inflammation marker levels in the blood and lopinavir plasma levels. Third, when the inflammation was blocked with the Interleukin-6 inhibitor Tocilizumab, lopinavir plasma levels were significantly lower than the ones in patients without Tozulizumab treatment.

These results clearly indicate that drug metabolism enzymes (cytochrome P450 3A) are inhibited by systemic inflammation. "Caution is advised when prescribing CYP3A4 substrates such as Lopinavir/ritonavir or any other drug with a narrow therapeutic index to Covid-19 patients because of the risk of elevated drug levels and related toxicities," the authors state.

Importantly, from the lopinavir and hydroxychloroquine concentrations in the plasma, the study group calculated the corresponding concentration in the lung compartment - the anatomic site of SARS-CoV-2 infection. The results strongly suggest that it is unlikely that both drugs reach sufficient concentrations to inhibit the virus replication in the lung.

WHO accepted the recommendation from the Solidarity Trial's International Steering Committee to discontinue the trial's hydroxychloroquine and lopinavir/ritonavir arms on 4 July 2020. Professor Manuel Battegay - co-leader of this study and head of the Division of Infectious Diseases and Hospital Epidemiology at the University Hospital in Basel - mentioned that the results provide important pharmacological and antiviral insights to the rationale of discontinuing the lopinavir/ritonavir arm. In fact, they add scientific reasoning why hydroxychloroquine and lopinavir are not effective against the SARS-CoV-2.

Credit: 
University of Basel

A balancing act between immunity and longevity

image: PUF60 mediates a yin-yang like balance between immunity and longevity.

Image: 
Raymond Laboy

As we age, the immune system gradually becomes impaired. One aspect of this impairment is chronic inflammation in the elderly, which means that the immune system is constantly active and sends out inflammatory substances. Such chronic inflammation is associated with multiple age-related diseases including arthritis and Alzheimer's disease, and impaired immune responses to infection. One of the questions in ageing research is whether chronic inflammation is a cause of ageing, or a consequence of the ageing process itself? Scientists in the laboratory of Director Adam Antebi at the Max Planck Institute for Biology of Ageing in Cologne, Germany have found evidence suggesting that increased inflammation causes the ageing process to speed up, and that there is a fine balance between maintaining immune system function and longevity.

From their work in the tiny roundworm, Caenorhabditis elegans, the scientists discovered a change in an evolutionarily conserved gene called PUF60, which made the worms long lived but at the same time dampened the immune response. Worms with this change lived about 20% longer than normal worms, but when they were infected with certain bacteria, they succumbed more quickly to the infection. This means that an overactive immune system also has a price: it shortens life span. Conversely, a less active immune system pays off as longer life span - as long as the animal does not die from an infection.

How does PUF60 regulate this fine balance between a maintained immune system and longevity? PUF60 works as a so-called "splicing factor", and is involved in the removal (or "splicing out") of segments in the ribonucleic acid, RNA. This process is essential to generate functional proteins.

The scientists found that the genetically changed PUF60 perturbs this process and alters the regulation of other genes that are involved in immune functions. "We're excited by this finding because it implicates a very fundamental process in the cell to immunity," says Adam Antebi. "These observations of course raise further questions. Notably pinpointing how PUF60 activity affects immunity and longevity, and how these two processes are balanced will be central to understanding the relationship between inflammation and ageing."

Credit: 
Max-Planck-Gesellschaft

Study shows that aerosol box used to protect healthcare workers during COVID

A new study shows that certain aerosol boxes of a similar type to those that have been manufactured and used in hospitals in the UK and around the world in order to protect healthcare workers from COVID-19 can actually increase exposure to airborne particles that carry the virus, and thus casts doubt on their usefulness.

The authors - who include Drs Peter Chan, Joanna Simpson and colleagues, Intensive Care and Anaesthesia Specialists at Eastern Health, Melbourne, VIC, Australia - say that "the consequences of promotion of such untested devices include either a false sense of security using these devices, or paradoxical increase in healthcare workers exposure to COVID-19". The study is published in Anaesthesia (a journal of the Association of Anaesthetists).

The danger posed to frontline health workers exposed to infectious COVID-19 is significant. The sickest COVID-19 patients often need to be placed onto a ventilator, which is also when the risk to the health worker of exposure to virus is potentially at its greatest. This has created a race to manufacture aerosol containment devices including improvised protection strategies and devices for use during tracheal intubation. This has taken on even greater urgency in the last week, with a global "second wave" becoming more likely, and a recent open letter to the World Health Organization from 239 global scientists in 32 countries warning that we have probably been severely underestimating the amount of COVID-19 spread through fine aerosol droplets over large distances. On Wednesday, July 8, WHO formally acknowledged this emerging evidence regarding potential spread of COVID-19 through these tiny droplets.

Aerosol boxes have been promoted by multiple worldwide news organisations in print, television, online and across social media (see examples below) as not only a quick and simple solution to protecting frontline workers but also an example of private industries stepping up production to support frontline healthcare workers. However, these devices were produced outside the normal regulatory framework, and thus were never clinically tested or validated for effectiveness and safety. They were subsequently heavily promoted in the media and on social media. Yet despite this heavy promotion, no international guideline on personal protective equipment (PPE) has ever endorsed their use.

In recent months there have been increasing concerns from the medical community that these devices might be either not helping, or potentially exposing frontline medical staff to unforeseen harm, but as this could not be proven, the devices continued to be used across the globe. In this new study, Drs Chan and Simpson and colleagues partnered with Ascent Vision Technologies, a Melbourne-based engineering company, to test the effectiveness of varying methods of aerosol containment, including the so-called aerosol box (see links to photos below), which various private companies have offered their services to manufacture.

The study was carried out in a self-contained intensive care unit room at Box Hill Hospital, Melbourne, using seven adult volunteers (four male, three female), who took turns in random order acting as the patient or the doctor (the person performing the intubation). The study simulated exposure of the doctor to airborne particles sized 0.3 - 5.0 microns using five aerosol containment methods (aerosol box; sealed box with and without suction; vertical drape; and horizontal drape) compared with no intervention. As each of the seven volunteers did all six trials (the five interventions plus no intervention), the study generated 42 sets of results.

To simulate aerosolisation, the patient volunteer held a bottle of fluid just under their mouth, and coughed every 30 seconds. Over five minutes particle detection devices were used to count different sized particles and assess particle spread.

Compared with no device use, the aerosol box surprisingly showed an increase in airborne particle exposure of all sizes over 5 minutes. Assuming that COVID-19 particles act in the same way as the fluid used in this simulation, the results of this study suggest that this aerosol box was increasing exposure to COVID-19 particles, in some cases by a factor of 5 times or more.

The authors say: "We were surprised to find airborne particle contamination of the doctor increased substantially using the aerosol box compared with all other devices and with no device use. Spikes of airborne particles were clearly seen, coinciding with patient coughing. We believe that these represent particles escaping from the arm access holes in the aerosol box."

They add: "The race to generate sustainable equipment to protect healthcare workers during intubation procedures in patients with suspected or proven COVID-19, particularly in settings where PPE supply is limited, has flooded the scientific community and social media with a variety of novel devices meant to contain potentially infectious aerosols produced by patients. Evidence for the safety and efficacy of these devices is lacking."

They conclude: "This study demonstrates that devices such as the aerosol box we tested - which is typical of designs used worldwide - confer minimal to no benefit in containing aerosols during an aerosol-generating procedure and may increase rather than decrease airborne particle exposure. The use of any aerosol containment device has been eliminated from our intubation protocols until their safety can be properly established."

Dr Chan adds: "If this box were a sold as a product, and therefore regulated, it would likely need to be immediately recalled due to a potential infection risk to the healthcare worker. Unfortunately, because these devices have been donated and are not regulated in any way, healthcare workers might be continuing to increase their exposure to COVID-19 while thinking they are protecting themselves."

Credit: 
AAGBI

New research shows that laser spectral linewidth is classical-physics phenomenon

New ground-breaking research from the University of Surrey could change the way scientists understand and describe lasers - establishing a new relationship between classical and quantum physics.

In a comprehensive study published by the journal Progress in Quantum Electronics, a researcher from Surrey, in partnership with a colleague from Karlsruhe Institute of Technology and Fraunhofer IOSB in Germany, calls into question 60 years of orthodoxy surrounding the principles of lasers and the laser spectral linewidth - the foundation for controlling and measuring wavelengths of light.

In the new study, the researchers find that a fundamental principle of lasers, that the amplification of light compensates for the losses of the laser, is only an approximation. The team quantify and explain that a tiny excess loss, which is not balanced by the amplified light but by normal luminescence inside the laser, provides the answer to the spectral linewidth of the laser.

One of these loss mechanisms, the outcoupling of light from the laser, produces the laser beam used in vehicle manufacturing, telecommunications, laser surgery, GPS and so much more.

Markus Pollnau, Professor in Photonics at the University of Surrey, said: "Since the laser was invented in 1960, the laser spectral linewidth has been treated as the stepchild in the descriptions of lasers in textbooks and university teaching worldwide, because its quantum-physical explanation has placed extraordinary challenges even for the lecturers.

"As we have explained in this study, there is a simple, easy-to-understand derivation of the laser spectral linewidth, and the underlying classical physics proves the quantum-physics attempt of explaining the laser spectral linewidth hopelessly incorrect. This result has fundamental consequences for quantum physics."

Credit: 
University of Surrey

Global COVID-19 registry finds strokes associated with COVID-19 are more severe, have worse outcomes and higher mortality

DALLAS, July 10, 2020 -- Acute ischemic strokes (AIS) associated with COVID-19 are more severe, lead to worse functional outcomes and are associated with higher mortality , according to new research published yesterday in Stroke, a journal of the American Stroke Association, a division of the American Heart Association.

In "Characteristics and Outcomes in Patients with COVID-19 and Acute Ischemic Stroke: The Global COVID-19 Stroke Registry," researchers analyzed data on patients with COVID-19 and AIS treated at 28 health care centers in 16 countries this year and compared them to patients without COVID-19 from the Acute Stroke Registry and Analysis of Lausanne (ASTRAL) Registry, from 2003 to 2019. Researchers sought to determine the clinical characteristics and outcomes of patients with COVID-19 and AIS.

Between January 27, 2020 to May 19, 2020, there were 174 patients hospitalized with COVID-19 and AIS. Each COVID-19 patient with AIS was matched and compared to a non-COVID-19 AIS patient based on a set of pre-specified factors including age, gender and stroke risk factors (hypertension, diabetes, atrial fibrillation, coronary artery disease, heart failure, cancer, previous stroke, smoking, obesity and dyslipidemia). The final analysis included 330 patients total.

In both patient groups, stroke severity was estimated with the National Institute of Health Stroke Scale (NIHSS), and stroke outcome was assessed by the modified Rankin score (mRS). When AIS patients with COVID-19 were compared to non-COVID-19 patients:

COVID-19 patients had more severe strokes (median NIHSS score of 10 vs. 6, respectively);

COVID-19 patients had higher risk for severe disability following stroke (median mRS score 4 vs. 2, respectively); and

COVID-19 patients were more likely to die of AIS.

The researchers noted there are several potential explanations for the relationship between COVID-19-associated strokes and increased stroke severity: "The increased stroke severity at admission in COVID-19-associated stroke patients compared to the non-COVID-19 cohort may explain the worse outcomes. The broad, multi-system complications of COVID-19, including acute respiratory distress syndrome, cardiac arrhythmias, acute cardiac injury, shock, pulmonary embolism, cytokine release syndrome and secondary infection, probably contribute further to the worse outcomes including higher mortality in these patients. ... The association highlights the urgent need for studies aiming to uncover the underlying mechanisms and is relevant for prehospital stroke awareness and in-hospital acute stroke pathways during the current and future pandemics."

Credit: 
American Heart Association

Invention: "Nanocage" tool untangles (molecular) spaghetti

video: This 17-second animation shows a new tool--called a "nanocage"--that can catch and straighten out molecule-sized tangles of polymers. It works a bit like pulling a wad of thread through a needle hole--opening a new way to create custom materials that have never been made before.

Image: 
Schneebeli Lab/UVM

A team of scientists at the University of Vermont have invented a new tool--they call it a "nanocage"--that can catch and straighten out molecule-sized tangles of polymers.

Once a knotty polymer strand--whether made of protein or plastic--is pulled open "then we can activate just the polymers we want, while leaving the rest alone, " says UVM chemist Severin Schneebeli who led the new research. This tool--that works a bit like pulling a wad of thread through a needle hole--"opens a new way to create custom materials that have never been made before," he says. These might include nanoscale pill coatings that wrap around single molecules of medicine or new industrial products assembled from precisely arranged strands of plastic at the atomic scale.

The tool, composed of molecular edges with special "shape-directing" hydrogen bonds--and thousands of times smaller than a pinhead--can select out shorter strands of a polymer, leaving longer ones behind, demonstrating that the nanocage can be used to selectively find particular sizes of molecules in a soup of material. "It's selective and that's never been done before," Schneebeli says. This research is the first time that science has been able distinguish and activate different size polymer chains in a lab--opening the door to new possibilities for precision chemistry.

The new research was published in the June edition of the journal Chem.

NATURE KNOWS

The abilities of the nanocage are new to science--but not to nature. For billions of years, life has evolved ways to select just the bit of a protein or other biological knot that it wants to untie and turn on--what scientists call "functionalize." But people have had a hard time doing the same thing. "Despite plenty of examples in biology," the UVM scientists write, "efficient and selective modification of man-made polymers is still difficult."

Whether altering biological strands, like DNA, or industrial materials, like plastics, the new tetrahedron-shaped tool promises to let scientists do what nature already does well. "It took years of hard work in the lab to assemble this tetrahedron before we could test it," says Mona Sharafi, the lead author on the new study, and post-doctoral researcher at the Unversity of Vermont who came to the United States from Iran. "It's entirely man-made" she says, "but inspired by nature."

POTENT POLYMERS

The word polymer comes from a pair of Greek words that mean "many parts." And polymers are just that: materials made from huge molecules comprised of many repeating parts. They're found in many everyday products. Some are natural, like rubber and shellac. Many are synthetic, and are used to produce much of the material in everyday life -- from shopping bags to diapers, clothing to water pipes. Polymers can be found in tidy long strings at the molecular level--or they can be tied up in godawful knots like a billion strands of micro-spaghetti

Nature has had eons to figure out how to both synthesize these huge molecules--biopolymers, like DNA--and how to edit and activate selected portions. People have gotten pretty good at making new synthetic polymers--but not so good at selecting and editing them. Many scientists and engineers--working on new applications for renewable energy (e.g., next-generation solar cells), precision medicine (like delivery of cancer drugs to targeted parts of the body) and advanced electronics (including flexible devices)--would like to have greater control and efficiency working with what the UVM team call "functional polymers with complex topologies." With support from the National Science Foundation and the National Institutes of Health (which supported the computational studies, directed by UVM chemist Jianing Li), the research on the nanocage provides a new tool to do so-- "to untie the knot, opening polymers that would have been inaccessible before," say UVM's Mona Sharafi. "We have opened something big."

Credit: 
University of Vermont

Fast-spreading mutation helps common flu subtype escape immune response

Strains of a common subtype of influenza virus, H3N2, have almost universally acquired a mutation that effectively blocks antibodies from binding to a key viral protein, according to a study from researchers at Johns Hopkins Bloomberg School of Public Health.

The results have implications for flu vaccine design, according to the researchers. Current flu vaccines, which are "seasonal vaccines" designed to protect against recently circulating flu strains, induce antibody responses mostly against a different viral protein called hemagglutinin.

The new mutation, described in the study published online June 29 in PLOS Pathogens, was first detected in the 2014-2015 flu season in some H3N2 flu strains, and evidently is so good at boosting flu's ability to spread that it is now present in virtually all circulating H3N2 strains. Recent flu seasons, in which H3N2 strains have featured prominently, have been relatively severe compared to historical averages.

The mutation alters a viral protein called neuraminidase, and the researchers found in their study that this alteration paradoxically reduces the ability of flu virus to replicate in a type of human nasal cell that it normally infects. However, the researchers also found evidence that the mutation more than compensates for this deficit by setting up a physical barrier that hinders antibodies from binding to neuraminidase.

"These findings tell us that flu vaccines focusing on the hemagglutinin protein are leaving the virus openings to evolve and evade other types of immunity," says study senior author Andrew Pekosz, PhD, professor and vice chair of the Department of Molecular Microbiology and Immunology at the Bloomberg School.

Every year, influenza viruses sicken millions of people around the world, killing several hundred thousands. The diversity of flu strains and their ability to mutate rapidly--two strains infecting the same host can even swap genes--have made flu viruses an especially difficult target for vaccine designers. Although scientists are working towards a universal vaccine that will protect long-term against most flu variants, current flu vaccines are designed to protect against only a short list of recently circulating strains. Any mutation that occurs in these circulating strains and appears to improve their ability to spread is naturally of interest to flu virologists.

The goal of the study was to understand better the workings of the new H3N2 mutation. Scientists have known that it alters the flu virus's neuraminidase protein in a way that provides an attachment point, close to neuraminidase's active site, for a sugar-like molecule called a glycan. But how the presence of a glycan at that location on the neuraminidase protein improves the virus's ability to infect hosts and spread hasn't been clear.

Pekosz and first author Harrison Powell, PhD, a graduate student in his laboratory at the time of the study, compared the growth, in laboratory cells, of typical H3N2 strains that have the glycan-attachment mutation to the growth of the same flu strains without the mutation. They found that the mutant versions grew markedly more slowly in human cells from the lining of the nasal passages--a cell type that a flu virus would initially infect.

The researchers found the likely reason for this slower growth: the glycan-attracting mutation hinders the activity of neuraminidase. The protein is known to serve as a crucial flu enzyme whose functions include clearing a path for the virus through airway mucus, and enhancing the release of new virus particles from infected cells.

It wasn't entirely unexpected that the addition of a moderately bulky glycan molecule near the enzyme's active site would have this effect. But it left unexplained how that would benefit the virus.

The scientists solved the mystery by showing that the glycan blocks antibodies that would otherwise bind to or near the active site of the neuraminidase enzyme.

Neuraminidase, especially its active site, is considered one of the most important targets for the immune response to a flu infection. It is also the target of flu drugs such as Tamiflu (oseltamivir). Thus it makes sense that a mutation protecting that target confers a net benefit to the virus, even if it means that the neuraminidase enzyme itself works less efficiently.

The finding highlights the potential for flu viruses to evade therapies, seasonal vaccines, and the ordinary immune response, Pekosz says, and points to the need for targeting multiple sites on the virus to reduce the chance that single mutations can confer such resistance.

The researchers have been following up their findings with studies of how the new mutation affects the severity of flu, how it has spread so rapidly among H3N2 strains, and how these altered flu strains have adapted with further mutations.

"Neuraminidase antigenic drift of influenza A virus H3N2 clade 3c.2a viruses alters virus replication, enzymatic activity and inhibitory antibody binding" was written by Harrison Powell and Andrew Pekosz.

Credit: 
Johns Hopkins Bloomberg School of Public Health

COVID-19 can be transmitted in the womb, reports pediatric infectious disease journal

July 10, 2020 - A baby girl in Texas - born prematurely to a mother with COVID-19 - is the strongest evidence to date that intrauterine (in the womb) transmission of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) can occur, reports The Pediatric Infectious Disease Journal, the official journal of The European Society for Paediatric Infectious Diseases. The journal is published in the Lippincott portfolio by Wolters Kluwer.

The findings "suggest in utero transmission" of COVID-19 from an infected mother to her infant, according to the case report by Julide Sisman, MD, and colleagues of The University of Texas Southwestern Medical Center, Dallas.

"Numerous infants have now been delivered to pregnant women diagnosed with SARS-CoV-2, with the majority of these infants without respiratory illness or positive molecular evidence for SARS-CoV-2," comments Amanda S. Evans, MD, one of the lead authors of the new study. "Our study is the first to document intrauterine transmission of the infection during pregnancy, based on immunohistochemical and ultrastructural evidence of SARS-CoV-2 infection in the fetal cells of the placenta."

First Documented Intrauterine Transmission of COVID-19

The authors report on an infant delivered to a mother diagnosed with COVID-19, who also had type 2 diabetes. The infant was born at 34 weeks' gestation after the mother had premature rupture of the membranes. The baby was born "large for gestational age" (LGA) - an important complication in infants of diabetic mothers. She was treated in the neonatal ICU due to prematurity and possible SARS-CoV-2 exposure.

The infant appeared initially healthy, with normal breathing and other vital signs. On the second day of life, she developed fever and relatively mild breathing problems. "It is unlikely that the respiratory distress observed in this infant was due to prematurity since it did not start until the second day of life," the researchers write.

The baby tested positive for SARS-CoV-2 infection at 24 and 48 hours after birth. She was treated with supplemental oxygen for several days but did not need mechanical ventilation. COVID-19 tests remained positive for up to 14 days. At 21 days, the mother and infant were sent home in good condition.

The researchers examined the placenta, which showed signs of tissue inflammation. In addition, specialized tests documented the presence of coronavirus particles as well as a protein (SARS-CoV-2 nucleocapsid protein) specific for the COVID-19 virus in fetal cells of the placenta. Together, these findings confirmed that the infection was transmitted in the womb, rather than during or after birth.

Although data on COVID-19 remain very limited, "Intrauterine transmission of SARS-CoV-2 appears to be a rare event," Dr. Sisman and colleagues conclude. They highlight several urgent priorities for further research, including the mechanisms and risk factors of in utero SARS-CoV-2 transmission and the outcomes of congenital COVID-19 in infants.

"We wanted to be very careful of our interpretation of this data, but now is an even more important time for pregnant women to protect themselves from COVID-19," comments Dr. Evans. She adds, "The CDC has thoughtful guidance on ways to reduce risk of infection." (See https://www.cdc.gov/coronavirus/2019-ncov/need-extra-precautions/pregnancy-breastfeeding.html)

Two additional case reports in PIDJ also describe "vertical" transmission of SARS-Co-V2 from mother to infant occurring under different circumstances. Together, the three cases highlight the important but difficult distinction between virus transmission occurring before or during/after delivery (intrauterine versus intrapartum), according to a commentary led by George K. Siberry, MD, of the US Agency for International Development and Associate Chief Editor of PIDJ. Dr. Siberry and coauthors write: "As these cases illustrate, evaluation for vertical - and especially intrauterine - SARS-CoV-2 infection can be challenging, and assessment is often limited by lack of optimal testing of appropriate specimens obtained at specific timepoints."

Credit: 
Wolters Kluwer Health

Gender bias in evaluating surgical residency faculty members may be decreasing

video: Dr. Adam Shellito, MD (PGY-4)

Image: 
American College of Surgeons

CHICAGO (July 10, 2020): In the male-dominated field of surgery, female faculty of training programs tend to receive lower scores than male faculty on their teaching evaluations, which are important for career advancement, past research has found. Now a new study suggests progress in this apparent gender bias: Among 21 U.S. general surgery residency programs, female faculty scored slightly better overall than male faculty did on teaching evaluations performed by surgeons-in-training, even in programs with the fewest women, the authors report. The study is published as an "article in press" on the Journal of the American College of Surgeons website in advance of print.

These results were unexpected, according to the researchers, because a 2018 study found that female surgical faculty often received lower scores than male faculty did on teaching evaluations,1 and other study findings also show a negative bias against female faculty in academic medicine.2,3

"Hopefully, based on our results, we're seeing a shift in attitudes and perceptions of surgical residents about women in surgery and women as educators so that all surgeons are graded on an equal scale," said lead study author Adam Shellito, MD, a fourth-year surgical resident at Harbor-UCLA Medical Center in Torrance, Calif. "This shift will hopefully allow women to reach higher academic positions and leadership positions in surgery."

Nationwide, less than 21 percent of surgeons are women.4 Even fewer women hold leadership roles in surgery, with women representing only 18 percent of directors of general surgery residency programs.5

For residency program faculty, teaching evaluations are important because the results help determine promotions and tenure, said senior investigator Kristine Calhoun, MD, FACS, associate professor, University of Washington School of Medicine, Seattle.

Multi-institutional study

The study was conducted by members of the Surgery Educators Workgroup, a research collaboration of general surgery residency programs from across the United States. In their data analysis from 21 participating programs, the investigators included only full-time faculty who worked with general surgery residents. They also sent surveys to the program directors to gather information about each program, such as the sex-based composition of both residents and faculty.

Although all the programs require their residents to anonymously complete faculty teaching evaluations online after each surgical rotation, the evaluation tools varied greatly, Dr. Shellito noted. Therefore, the researchers created a composite score for each faculty member. They divided the total number of points a person received by the total possible points for that evaluation tool over the one-year study period from July 2018 to June 2019. For each faculty member and institution, the researchers calculated the percentage score from a maximum 100 percent.

The general surgery programs surveyed varied widely, from 14 to 77 residents and 14 to 155 teaching faculty per program, the researchers reported. Although nearly half (47 percent) of the residents were female, women made up only 28 percent of the faculty.

Evaluations ranged from one to 29 questions, for a total of 291 questions among all programs. In total, there were 20,187 evaluations of 1,177 faculty, according to the article.

Surprising results

Contrary to what the researchers anticipated, female faculty had significantly higher composite evaluation scores on average--90.6 percent versus 89.5 percent for male faculty. Because the difference was small, Dr. Shellito said they would classify the scores as an equalization between sexes.

The researchers also analyzed the results between quartiles of programs with the highest versus the lowest numbers of female faculty, female residents, and both. They found that residents at the programs with fewer women on the faculty and/or residency staff rated female faculty higher overall than male faculty.

This result also surprised the researchers, Dr. Calhoun said. They hypothesized multiple reasons for this finding, she said, including that in programs with few women on the faculty, residents may not have wanted to single them out with poor evaluations, that the female faculty were actually better educators, or that as more women become surgical residents, there is increased awareness of gender bias.

Among North American general surgery residents, 41 percent were women in 2018,6 a 5 percent increase from the previous year,7 according to the Association of American Medical Colleges.

Regardless of the educator's sex, this study's results showed a high satisfaction rate of surgical residents with their teaching faculty, which Dr. Calhoun called "a powerful finding."

Another finding confirms the importance of their research, Dr. Shellito stated. "More than 75 percent of program directors that we surveyed agree that faculty evaluations are important to the residency program or the institution," he said.

He cautioned, however, that their results suggesting a lack of overt gender bias may not apply to the entire country because more than half of the par

Credit: 
American College of Surgeons

Farmers' climate change conundrum: Low yields or revenue instability

ITHACA, N.Y. - Climate change will leave some farmers with a difficult conundrum, according to a new study by researchers from Cornell University and Washington State University: Either risk more revenue volatility, or live with a more predictable decrease in crop yields.

As water shortages and higher temperatures drive down crop yields in regions that depend heavily on seasonal snow, the choice to use more drought-tolerant crop varieties comes at a cost, according to model projections detailed in the paper "Water Rights Shape Crop Yield and Revenue Volatility Tradeoff for Adaptation in Snow Dependent Systems," published June 10 in Nature Communications.

The study examined the Yakima River Basin in Washington, where a complex combination of snow, reservoirs and water rights controls the availability of irrigation water. That water dictates the success of some of the U.S.' largest producers of wheat, corn, potatoes, pears, cherries, grapes, apples and hops. With proper snowfall and melt, total agricultural productivity in the basin can reach more than $4 billion a year.

The research team sought to quantify climate change's direct and indirect effects on irrigated agriculture in the basin. Researchers also wanted to know if drought-resistant crop varieties could help recover productivity during times of drought.

Climate risk modeling is a specialty of Patrick Reed, the Joseph C. Ford Professor of Engineering at Cornell's School of Civil and Environmental Engineering. In this collaborative study, Reed's group built on prior research at Washington State University that developed a modeling platform connecting crop growth and development, land-surface hydrology and river-system processes. The model simulates dam operations and prioritizes the allocation of water among different sectors within the Yakima River Basin.

The team found that higher water stress and temperatures led to lower crop yield, as anticipated, said Keyvan Malek, a postdoctoral researcher in Reed's group and lead author of the study.

"However, the models show that year-to-year variability in expected crop yields goes down because the difference between the best and worst case yields is reduced," said Malek. "While this is not a positive result, year-to-year fluctuations in crop yield revenue are strongly important in how crop insurance programs balance revenue fluctuations."

The team then used its model to explore the potential of new drought-tolerant crop varieties, which are expected to improve annual yields under climate change. The results showed that although those varieties could significantly improve the average yield, farmers could also experience much higher revenue volatility from crop production.

"Typical and best-case annual yields are much higher," said Jennifer Adam, Berry Distinguished Professor of Engineering at Washington State University and co-author of the study. "But climate change still is likely to cause severe droughts where current water management institutions in the Yakima River Basin simply cannot provide enough water, and there are severe worst-case crop failures."

The researchers argue that the best outcomes for crop yield and revenue volatility must be through a simultaneous improvement in crop varieties - for example, by preserving agrobiodiversity - and in water systems, such as through improvements in water-governing institutions and infrastructure.

It is important to carefully capture a snow-dependent region's specific management constraints while being innovative with climate adaptation strategies, the researchers said.

"Otherwise, systems may unintentionally strike the wrong balance as they trade off improving average yields and farmers' revenue volatility," Reed said.

Credit: 
Cornell University

Commentary in Pediatrics: Children don't transmit Covid-19, schools should reopen in fall

image: Based on one new and three recent studies, the authors of a commentary in Pediatrics conclude that children rarely transmit Covid-19, either among themselves or to adults. Based on the evidence, the authors recommend that schools reopen in the fall, since staying home can adversely affect children's development.

Image: 
www.vperemen.com / CC BY-SA

A commentary published in the journal Pediatrics, the official peer-reviewed journal of the American Academy of Pediatrics, concludes that children infrequently transmit Covid-19 to each other or to adults and that many schools, provided they follow appropriate social distancing guidelines and take into account rates of transmission in their community, can and should reopen in the fall.

The authors, Benjamin Lee, M.D. and William V. Raszka, Jr., M.D., are both pediatric infectious disease specialists on the faculty of the University of Vermont's Larner College of Medicine. Dr. Raszka is an associate editor of Pediatrics.

The authors of the commentary, titled "COVID-19 Transmission and Children: The Child Is Not to Blame," base their conclusions on a new study published in the current issue of Pediatrics, "COVID-19 in Children and the Dynamics of Infection in Families," and four other recent studies that examine Covid-19 transmission by and among children.

--In the new Pediatrics study, Klara M. Posfay-Barbe, M.D., a faculty member at University of Geneva's medical school, and her colleagues studied the households of 39 Swiss children infected with Covid-19. Contact tracing revealed that in only three (8%) was a child the suspected index case, with symptom onset preceding illness in adult household contacts.

--In a recent study in China, contact tracing demonstrated that, of the 68 children with Covid-19 admitted to Qingdao Women's and Children's Hospital from January 20 to February 27, 2020, 96% were household contacts of previously infected adults. In another study of Chinese children, nine of 10 children admitted to several provincial hospitals outside Wuhan contracted Covid-19 from an adult, with only one possible child-to-child transmission, based on the timing of disease onset.

--In a French study, a boy with Covid-19 exposed over 80 classmates at three schools to the disease. None contracted it. Transmission of other respiratory diseases, including influenza transmission, was common at the schools.

--In a study in New South Wales, nine infected students and nine staff across 15 schools exposed a total of 735 students and 128 staff to Covid-19. Only two secondary infections resulted, one transmitted by an adult to a child.

"The data are striking," said Dr. Raszka. "The key takeaway is that children are not driving the pandemic. After six months, we have a wealth of accumulating data showing that children are less likely to become infected and seem less infectious; it is congregating adults who aren't following safety protocols who are responsible for driving the upward curve."

Rising cases among adults and children in Texas childcare facilities, which have seen 894 Covid-19 cases among staff members and 441 among children in 883 child care facilities across the state, have the potential to be misinterpreted, Dr. Raszka said. He has not studied the details of the outbreak.

"There is widespread transmission of Covid-19 in Texas today, with many adults congregating without observing social distancing or wearing masks," he said. "While we don't yet know the dynamics of the outbreak, it is unlikely that infants and children in daycare are driving the surge. Based on the evidence, it's more plausible that adults are passing the infection to the children in the vast majority of cases."

Additional support for the notion that children are not significant vectors of the disease comes from mathematical modeling, the authors say. Models show that community-wide social distancing and widespread adoption of facial cloth coverings are far better strategies for curtailing disease spread, and that closing schools adds little. The fact that schools have reopened in many Western European countries and in Japan without seeing a rise in community transmissions bears out the accuracy of the modeling.

Reopening schools in a safe manner this fall is important for the healthy development of children, the authors say. "By doing so, we could minimize the potentially profound adverse social, developmental, and health costs that our children will continue to suffer until an effective treatment or vaccine can be developed and distributed, or failing that, until we reach herd immunity," the paper concludes.

Credit: 
University of Vermont

More than meets the eye

The ability to recognize faces is a complex neurocognitive skill with important social implications. The disorder, which, according to some estimates, affects more than 2 percent of the population, can lead to isolation and anxiety and impair personal and work relationships.

The traditional view of face blindness--prosopagnosia in scientific parlance--has held that the disorder arises from deficits in visual perception. Under that view, individuals with face blindness are unable to visually distinguish the features of faces presented side by side and unable to determine whether the faces are the same or not.

Now a new study led by researchers at Harvard Medical School and the VA Boston Healthcare System shows that face blindness may arise from deficits beyond visual perception and appears to involve glitches in retrieving various contextual cues from memory.

The results, published July 5 ahead of print in the journal Cortex, suggest that the traditional view of face blindness as a purely visual perceptual disorder may be reductive, the researchers said. Further, they reveal that successful facial recognition requires recollection, or the recall of relevant contextual details about a person, such as their name or profession.

The new findings can help explain a mystifying discrepancy in face blindness research: People with the condition often fail to visually identify familiar faces, but many also perform normally on visual-perception tests.

"This inconsistency has always hinted that there may be other factors at play that go beyond visual perception," said study senior author Joseph DeGutis, HMS assistant professor of psychiatry at VA Boston. "Our findings suggest that one important deficit beyond perception is face recollection."

The ability to recognize a face requires two forms of memory: Recollection and familiarity. Recollection is the retrieval of contextual information upon seeing a face--a fellow shopper greeting you in the store and you recognizing them as the person you met through work a few weeks back. Familiarity, on the other hand, is a fuzzier "feeling of knowing" without any contextual information, the researchers explained. Think of the fellow shopper looking vaguely familiar but without any of the relevant details that tell you how you know them.

The findings can help inform the design of techniques to boost face recognition in people with developmental prosopagnosia--a form of face blindness that is not caused by brain injury, poor vision or neurodevelopmental disorders like autism.

"Our results underscore that prosopagnosia is a far more complex disorder that is driven by more than deficits in visual perception," said study first author Anna Stumps, a researcher in the Boston Attention Learning Laboratory at VA Boston. "This finding can help inform the design of new training approaches for people with face blindness."

The research team is currently working to design one such experimental program in the VA Boston laboratory where the work was conducted.

The study involved 6o people, ages 18 to 65, half of whom had lifelong face blindness.

The participants were asked to perform a series of facial-recognition tasks by studying and then identifying sets of faces that the participants had not seen prior to the study.

Participants were asked to study 60 faces shown on a computer screen, one at a time. The participants were then shown a scramble of 120 faces--some of them already seen during the study session and some completely new.

To tease out the differences in recognition memory between participants with and without face blindness, DeGutis and colleagues measured their degree of confidence in classifying each face as "old" or "new" on a scale of 1 to 6. Correctly identifying a face as old with high confidence reflects the use of recollection, the researchers said, whereas correctly identifying a face as old with less confidence reflects the use of familiarity.

Compared with participants who had face blindness, people without it were significantly more confident that they had seen these faces before. However, those with face blindness were still able to correctly identify many of the faces they had seen before, although with less confidence. In other words, when trying to recognize a face, participants with face blindness relied on familiarity, the vague sense of knowing or having seen someone before without specific contextual information. In contrast, individuals without face blindness relied on recollection.

Taken together, these findings suggest that people with face blindness use different memory processes for face recognition.

The results, the researchers said, demonstrate that successful face recognition requires more than a vague familiarity with a face--a sense of having seen a face before but without recalling any other details to "place" the face. Memory researchers call this inability to identify a familiar face out of context "butcher-on-the-bus" phenomenon. Though everyone experiences this from time to time, for people with true face blindness this can happen frequently, as often as multiple times a day.

"Our findings suggest that people with developmental prosopagnosia use a different memory system when trying to learn and remember faces and that system is less optimally suited for the task of recognizing faces," DeGutis said.

Credit: 
Harvard Medical School