Researcher Questions Whether Powered Flight Appeared on Non-avialan Dinosaurs (Paleontology)

Francisco Serrano, from University of Malaga, refutes this conclusion published in 2020 in the absence of scientific evidence

Powered flight in animals -that uses flapping wings to generate thrust- is a very energetically demanding mode of locomotion that requires many anatomical and physiological adaptations. In fact, the capability to develop it has only appeared four times in the evolutionary history of animals: on insects, pterosaurs, birds and bats.

A research paper published in 2020 in the scientific journal Current Biology concluded that, apart from birds -the only living descendants of dinosaurs-, powered flight would have originated independently in other three groups of dinosaurs. A conclusion that makes a great impact, as it increases the number of vertebrates that would have developed this costly mode of locomotion, which, among dinosaurs, would no longer be an exclusive capability of birds.

The scientist of the Department of Ecology and Geology of the University of Malaga Francisco Serrano Alarcón has recently published an article in the same journal, questioning the idea that powered flight appeared multiple times among dinosaurs.

Imagen at the Beijing Museum of Natural History, China. © Stephanie Abramowicz (Natural History Museum of Los Angeles County).

The researcher of the UMA, member of the Dinosaur Institute (NHMLAC) of Los Angeles, refutes such conclusion in the absence of scientific evidence. As he remarks, the parameters used by the authors to determine flight capability do not allow differentiation between powered flight and passive flight, the latter being frequent in many more animal groups.

This new study, which he conducted along with the paleontologist Luis M. Chiappe, Vice-President for Research and Collections of the NHMLAC, compares the parameters measured on present animals with powered flight capability, such as birds and bats, and gliding animals, for example, flying squirrels or flying reptiles, among others. Moreover, they added new data on the capability to generate energy from muscles in addition to the data considered in the original study.

“Birds are a group of dinosaurs of which we have discovered 150-million-year-old fossils with fully developed wings. Among their closest non-avialan relatives, we have also found fossils with sufficiently developed wings that could provide them with some aerodynamic benefit, whether to glide between trees or get thrust to climb and jump over obstacles. But this does not mean that they could take off by flapping their wings or maintain a powered flight”, explains Francisco Serrano.

In short, both authors conclude that, although they cannot discount the possibility that powered flight appeared in other non-avialan dinosaurs, current evidence does not support the hypothesis suggested in the original paper by Pei et al (2020).

Featured image: Imagen at the Institute of Vertebrate Paleontology and Paleoanthropology in Beijing © F.J. Serrano. University of Malaga


Reference: FJ Serrano, LM Chiappe. 2021. Independent origins for powered flight in paravian dinosaurs? Current Biology 31(8), R370-R372, 2021. DOI: https://doi.org/10.1016/j.cub.2021.03.058 Link to paper

Provided by University of Malaga

Is Night Shift Really Helping You Sleep Better? (Science and Technology)

New BYU study finds that night shift functions don’t actually improve sleep.

How often have you laid in bed scrolling through news stories, social media or responding to a text? After staring at the screen, have you ever found that it is harder to fall asleep?

It’s widely believed that the emitted blue light from phones disrupts melatonin secretion and sleep cycles. To reduce this blue light emission and the strain on eyes, Apple introduced an iOS feature called Night Shift in 2016; a feature that adjusts the screen’s colors to warmer hues after sunset. Android phones soon followed with a similar option, and now most smartphones have some sort of night mode function that claims to help users sleep better.

Until recently, claims of better sleep due to Night Shift have been theoretical. However, a new study from BYU published in Sleep Health challenges the premise made by phone manufacturers and found that the Night Shift functionality does not actually improve sleep.

To test the theory, BYU psychology professor Chad Jensen and researchers from the Cincinnati Children’s Hospital Medical Center compared the sleep outcomes of individuals in three categories: those who used their phone at night with the Night Shift function turned on, those who used their phone at night without Night Shift and those who did not use a smartphone before bed at all.

“In the whole sample, there were no differences across the three groups,” Jensen said. “Night Shift is not superior to using your phone without Night Shift or even using no phone at all.”

The study included 167 emerging adults ages 18 to 24 who use cell phones daily. They were asked to spend at least eight hours in bed and wore an accelerometer on their wrist to record their sleep activity. Individuals who were assigned to use their smartphone also had an app installed to monitor their phone use.

The measured sleep outcomes included total sleep duration, sleep quality, wake after sleep onset and the time it took to fall asleep.

After not finding significant differences in sleep outcomes across the three categories, the researchers split the sample into two separate groups: one which averaged about seven hours of sleep and another that slept less than six hours each night.

The group that got seven hours of sleep, which is closer to the recommended eight to nine hours a night, saw a slight difference in sleep quality based on phone usage. The individuals who did not use a phone before bed experienced superior sleep quality relative to both those with normal phone use and those using Night Shift.

Within the six-hour group, which had the least amount of sleep, there were no differences in sleep outcomes based on whether the participants used Night Shift or not.

“This suggests that when you are super tired you fall asleep no matter what you did just before bed,” explained Jensen. “The sleep pressure is so high there is really no effect of what happens before bedtime.”

The results suggest that it is not blue light alone that creates difficulty falling or staying asleep. The psychological engagement experienced when texting, scrolling and posting are also important factors that affect sleep outcomes.

“While there is a lot of evidence suggesting that blue light increases alertness and makes it more difficult to fall asleep, it is important to think about what portion of that stimulation is light emission versus other cognitive and psychological stimulations,” said Jensen.

Night Shift may make your screen darker, but Night Shift alone will not help you fall or stay asleep.

Featured image: Research from BYU psychology professor Chad Jensen found that using a cell phone in ‘Night Shift’ will not help a user fall or stay asleep.
Photo by Claire Moore/BYU Photo


Reference: Kara M. Duraccio, Kelsey K. Zaugg, Robyn C. Blackburn, Chad D. Jensen, Does iPhone night shift mitigate negative effects of smartphone use on sleep outcomes in emerging adults?, Sleep Health, 2021, , ISSN 2352-7218, https://doi.org/10.1016/j.sleh.2021.03.005. (https://www.sciencedirect.com/science/article/pii/S2352721821000607)


Provided by BYU

UCF Forensic Scientists Unlocking Unique Chemical Signatures In Tires (Forensic Science)

Skid marks left by cars are often analyzed for their impression patterns, but they often don’t provide enough information to identify a specific vehicle. UCF Chemistry Associate Professor Matthieu Baudelet and his forensics team at the National Center for Forensic Science, which was established at UCF in 1997, may have just unlocked a new way to collect evidence from those skid marks.

The team recently published a study in the journal Applied Spectroscopy that details how they are classifying the chemical profile of tires to link vehicles back to potential crime scenes.

“Tire evidence is often overlooked in forensics,” says Baudelet. “In cases of hit and runs or accidents involving multiple cars the chemical signature of the tires have the potential to be integral information to the investigation.”

The team used laser-induced breakdown spectroscopy (LIBS) on each sample. The technique focuses a laser onto the tire sample, which creates a microscopic plasma that emits light according to the chemical elements present. The spectroscopy comes in because it analyzes this light and matches it to the corresponding chemicals. It’s the same technique that instruments aboard the Mars rovers (Curiosity and Perseverance) use to determine what kinds of elements are found within the rocks of Mars.

“The process is as complicated as it is fun,” says Baudelet. “The whole idea is that tire evidence holds a lot of data. They have patterns, but these pattern impressions do not give all the answers. It became a question of ‘Can we use their chemical composition to obtain information from the tires?’”

Baudelet and his graduate student, John Lucchi, started testing their idea by recreating skid marks in the laboratory using road materials like concrete and asphalt. By pressing a tire into the surface at the same velocity as a moving vehicle, a braking impression is made on the laboratory controlled “road” from the tire. This in turn gives the team a chance to analyze the chemical composition of the tire and the road material and make chemical comparisons.

Every tire is expected to have its own chemical signature and, as such, a unique, corresponding skid mark. One current challenge is identifying how elements on the road like oil, rainwater, and other cars interfere and change that signature. Baudelet says the National Center for Forensic Science has been working on overcoming these interference challenges with other evidence for years.

Now that the process shows promise, the team will focus on establishing statistical reliability. Standards for police evidence are justifiably high, so next steps involve reproducible, dependable protocols, Baudelet says. Ultimately, he would like to know his team’s work provided justice and closure to cases of hit-and-run and vehicle violence.

“We’re still working but so far we’ve made a lot of progress,” Baudelet says. “I feel that this can be a great supplementation to the methods currently being used in forensics and law enforcement.

Featured image: UCF Chemistry Associate Professor Matthieu Baudelet and graduate student John Lucchi collect a sample from a tire during their work at the National Center for Forensic Science. © UCF


Reference: Lucchi J, Gluck D, Rials S, Tang L, Baudelet M. Tire Classification by Elemental Signatures Using Laser-Induced Breakdown Spectroscopy. Applied Spectroscopy. February 2021. doi:10.1177/0003702821995585


Provided by UCF

Whats The Effect Of Nova Eruption On the Donor Star In A Cataclysmic Variable? (Planetary Science)

Cataclysmic variable stars are binary stars that consist of two components; a white dwarf primary, and a mass transferring secondary. The stars are so close to each other that the gravity of the white dwarf distorts the secondary, and the white dwarf accretes matter from the companion. Therefore, the secondary is often referred to as the donor star. The infalling matter, which is usually rich in hydrogen, forms in most cases an accretion disk around the white dwarf.

Schematic of a non-magnetic cataclysmic variable. A white dwarf (on the right) accretes matter through an accretion disk, fed by a Roche-lobe-filling main-sequence donor star (on the left). Matter from the donor star travels in a stream from the Lagrange point L1 and meets the accretion disk at a hot spot. The white dwarf has a mass of 0.8 M, its companion is a main sequence star of 0.5 M and their centres are separated by 1.64 R. © Philip D. Hall

As hydrogen accumulates on the white dwarf’s surface, the density and temperature at the base of the accreted layer rise. At some point, a critical mass is reached, and the accumulated layer explodes in a thermonuclear runaway— a nova. The binary system survives the explosion, mass accumulates once again on top of the white dwarf, and the nova recurs on a time-scale that depends on the accretion rate and on the white dwarf’s mass.

During and immediately after a nova eruption, the white dwarf’s luminosity is close to the Eddington limit. The companion is irradiated and heated to a surface temperature that is an order of magnitude hotter than its pre-eruption (main sequence) effective temperature. In 1988, Kovetz and colleagues studied the response of the companion to such irradiation and calculated the heat penetration into its atmosphere. They showed that as the heated layers expand, the donor overflows its Roche lobe more than in quiescence, and the mass transfer rate increases by orders of magnitude. Recently, Hillman and colleagues demonstrated that this irradiation-driven enhanced mass transfer may dominate the long term evolution of CVs over multiple nova cycles.

Now, Ginzburg and Quataert revisited the heating of the donor star by the hot white dwarf during and after a nova eruption using a combination of analytical arguments and experiments with the mesa stellar evolution code. They calculated the enhanced mass transfer rate following a nova and improve upon Kovetz et al. and Hillman et al. by refining their power-law scaling for how this rate depends on the irradiation temperature and on the donor’s mass. More importantly, they revise upwards the normalization of the mass transfer rate.

They first showed that a nova eruption irradiates and heats the donor star in a cataclysmic variable to high temperatures Tirr, causing its outer layers to expand and overflow the Roche lobe. They then, calculated the donor’s heating and expansion both analytically and numerically and found that irradiation drives enhanced mass transfer from the donor at a rate,

which reaches m• ∼ 10¯6 M yr¯1 at the peak of the eruption — about a thousand times faster than during quiescence. As the nova subsides and the white dwarf cools down, m• drops to lower values.

Finally, they discussed the decline of the mass transfer rate back to quiescence as the white dwarf cools down after a nova. They found that under certain circumstances, the decline halts and the mass transfer persists at a self-sustaining rate of m• ∼ 10¯7 M yr¯1 for up to ∼ 10³ yr after the eruption. At this rate, irradiation by the white dwarf’s accretion luminosity is sufficient to drive the mass transfer on its own.

Figure 1. The self-sustaining (bootstrapping) irradiation temperature Tirr ∝ m•^1/4 as a function of ΔrL ≡ rL – r(0), the difference between the donor’s Roche lobe rL and its non-irradiated radius r(0) © Ginzburg and Quataert

This ‘bootstrapping’ state may explain the high quiescent accretion rates (∼ m• ∼ 10¯7 M yr¯1) recently observed for the recurrent novae T Pyxidis (T Pyx) and IM Normae (IM Nor). If the self-sustaining rate is sufficiently high, the white dwarf can burn accreted hydrogen stably, potentially explaining long-lived supersoft X-ray sources with short orbital periods like RX J0537.7–7034 and 1E 0035.4–7230 as well.

Finally, they concluded that whether or not a system reaches the self-sustaining state is sensitive to the donor’s chromosphere structure, as well as to the orbital period change during nova eruptions.


Reference: Sivan Ginzburg, Eliot Quataert, “Novae heat their food: mass transfer by irradiation”, ArXiv, pp. 1-8, 2021. https://arxiv.org/abs/2104.11250


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Weight Loss Surgery Reduces Brain Pressure In Patients With Increasingly Common Neurological Condition (Neuroscience)

Weight loss surgery is more effective than dieting to reduce brain pressure that can cause blindness in patients with a neurological condition, finds a study led by the University of Birmingham and University Hospitals Birmingham NHS Foundation Trust (UHB).

Idiopathic Intracranial Hypertension (IIH) is a debilitating condition that raises pressure in the brain and can lead to chronic headaches and even permanent sight loss. The illness, which often leaves patients with a reduced quality of life, predominately affects women aged 25 to 36 and weight gain is a major risk factor of developing IIH and relapses of the disease.

Weight loss has been shown to be an effective treatment, with a reduction in body weight of between three to 15% inducing disease remission. However, maintaining weight loss is notoriously difficult, as most patients regain weight over a two to five year period.

In the first clinical trial of its kind, the research team set out to analyse whether bariatric surgery or a 12-month community weight management intervention (delivered through Weight WatchersTM) would be the most effective for reducing brain pressure in women with IIH.

The trial, supported by the National Institute for Health Research (NIHR), involved 66 women with IIH with an average age of 32 years and a body mass index (BMI) of 35 or more. Half underwent bariatric surgery, while the other half took part in Weight WatchersTM. Brain pressure was measured by lumbar puncture at the start and after 12 and 24 months.

The results, published today in JAMA Neurology, showed that bariatric surgery was significantly more effective than community weight management, with those having had surgery seeing an average intracranial pressure reduction of 25% after 12 months.

The results also showed that the surgery group lost on average 23Kg, as compared to losing 2kg in the Weight WatchersTM group at 12 months. This difference was greater at 24 months with 24% more weight lost in the surgery group as compared to Weight WatchersTM. This was because the bariatric surgery group continued to lose more weight over time (28Kg from the start of the study to 2 years), whilst the community weight management group had regained weight lost and, on average, were only 1kg lighter than at the start of the study.

Senior author Alex Sinclair, Professor of Neurology at the University of Birmingham and Neurology lead of the Idiopathic Intracranial Hypertension Service at UHB, said: “A link between weight and IIH has long been observed but, until now, there has been no robust evidence that weight loss can reduce brain pressure.

“We have shown that weight loss achieved through bariatric surgery is significantly more therapeutic than community weight loss management interventions both in the short and longer term to treat IIH brain pressure.

“Whilst we recognise that bariatric surgery may not be an appropriate approach for all patients with IIH and increased weight, it is important to now have the evidence that a surgical approach can lead to significant sustained disease remission.”

First author Miss Susan Mollan, Director of Ophthalmic Research at UHB, added: “We hope that as a consequence of this research, current NHS and NICE guidance can change to include bariatric surgery as a treatment for women with IIH and a BMI greater than 35 when appropriate and in line with the patient’s best interests and wishes.

“Weight stigma is a major barrier to patient care in IIH. We also hope this research will prompt discussion and education around weight management to ensure this sensitive topic is approached with care and dignity.”

Co-author James Mitchell, Lecturer in Neurology at the University of Birmingham, added: “Weight regain is often driven by biology rather than willpower, and obesity is a chronic relapsing disease that requires lifelong treatment. Therefore, it’s essential that patients are given appropriate support to achieve weight loss and further work is done to ensure they have good access to weight management services.”


Reference

  • Mollan et al (April, 2021). ‘Bariatric surgery versus community weight management intervention for the treatment of idiopathic intracranial hypertension (IIH:WT): A randomized clinincal trial.’ JAMA Neurology. DOI: 10.1001/jamanerol.2021.0659

Provided by University of Birmingham

Mayo Researchers Question Effectiveness of mRNA COVID-19 Vaccines for Solid Organ Transplant Patients (Medicine)

A small study from Mayo Clinic researchers raises the concern that some transplant patients may have a limited immune response after being vaccinated for COVID-19 with an mRNA vaccine. Their findings are published as a letter to the editor in the American Journal of Transplantation.

The letter covers seven organ transplant recipients diagnosed with COVID-19 at Mayo Clinic in Florida six to 44 days after receiving either of the mRNA COVID-19 vaccines that have been authorized for emergency use by the Food and Drug Administration. Two patients had received one dose, and five patients had received both doses.

COVID-19 infection was confirmed in all patients with a polymerase chain reaction nasal swab test. The study team, led by Hani Wadei, M.D., a Mayo Clinic Transplant Center nephrologist, reports that five of the patients had severe enough infection to be hospitalized and three required oxygen when discharged.

Dr. Wadei and his team tested the blood of patients who had received a solid organ for spike antibodies to COVID-19, which would be the type of antibody generated by the vaccine. Of the six patients who were tested, antibodies to the spike protein were found in only one. That patient had received both mRNA vaccine doses 44 days prior and had a low titer of anti-spike antibody. Using available vaccination data, Dr. Wadei and his team estimated that the infection rate in vaccinated solid organ transplant recipients was 10 times higher than the general population ― 0.6% versus 0.05%.

“This study is eye-opening for the transplant community,” says Dr. Wadei. “Our study suggests that transplant patients don’t have the same immune response as the general population. They got infected after getting vaccinated and lifting protective measures, thinking they were immune to the virus.”

The researchers note that transplant patients were excluded from current vaccine studies. Another vaccine, based around an adenovirus vector and authorized for use by the FDA, was not reviewed by Mayo researchers in this study, as it was not available to Mayo patients.

“Care should still be implemented in vaccinated solid organ transplant immunocompromised patients until we have better vaccine strategies,” says Dr. Wadei. “All individuals, especially transplant patients, should continue to follow protective measures, such as social distancing, mask-wearing and regular hand hygiene.”

The researchers are calling on further studies to test for vaccine efficacy in transplant patients, examine post-vaccine infection rate and identify methods to boost the vaccine-related immune response in these patients. The next step in their research is to test all vaccinated solid organ transplant recipients at Mayo Clinic in Florida for anti-spike antibodies, with the goal of expanding studies to additional transplant patients at Mayo’s other campuses in Arizona and Minnesota.

Other authors on the paper are Thomas Gonwa, M.D.Juan Carlos Leoni Moreno, M.D.Sadia Shah, M.D.Nabeel Aslam, M.D.; and Leigh Speicher, M.D. ― all from Mayo Clinic.

For the full author list and disclosure information, see the published paper.

Wadei, H.M., Gonwa, T.A., Leoni, J.C., Shah, S.Z., Aslam, N. and Speicher, L.L. (2021), COVID‐19 infection in Solid Organ Transplant Recipients after SARS‐CoV‐2 vaccination. American Journal of Transplantation. Accepted Author Manuscript. https://doi.org/10.1111/ajt.16618


Provided by Mayo Clinic


About Mayo Clinic

Mayo Clinic is a nonprofit organization committed to innovation in clinical practice, education and research, and providing compassion, expertise and answers to everyone who needs healing. Visit the Mayo Clinic News Network for additional Mayo Clinic news. For information on COVID-19, including Mayo Clinic’s Coronavirus Map tracking tool, which has 14-day forecasting on COVID-19 trends, visit the Mayo Clinic COVID-19 Resource Center.

A New Way Of Rapidly Counting and Identifying Viruses (Medicine)

A Lancaster University professor has introduced a new concept for rapidly analysing for the presence of a virus from colds to coronaviruses.

Based on analysing chemical elements the methodology, which has been adapted from an analytical technique used to identify metallic nanoparticles, is able to detect the presence of viruses within just 20 seconds.

Although the tests would need to be performed in a lab, it could be used to quickly identify whether people admitted to hospitals have been infected by a virus – enabling clinicians to decide treatments and also whether to admit patients into isolation wards.

The proposed technique, called ‘Single virus inductively coupled plasma mass spectroscopy’ (SV ICP-MS) analysis, can be used to quickly determine families of viruses. However, although the concept can identify that someone has a type of coronavirus for example, it would not be able to determine the type of coronavirus, or variants. Additional tests would still be required to find out the specific virus someone was infected with.

While SV ICP-MS is not an alternative for tests developed to specifically identify types of Covid-2 infections, it could be used to discriminate if viruses from one family, such as coronaviruses, are present or not. If a virus is found to be present, more specific testing would be needed.

The concept, developed by Professor Claude Degueldre, from Lancaster University’s Department of Engineering, uses diluted samples of fluids, such as nasal mucus or saliva, from patients. A plasma torch is used to atomise and ionise the virus particles. Measurements of intensities for selected masses of the elements from the viruses provide rapid results to show the presence of a virus or not. This process works on DNA and RNA virus types within seconds.

Complementary analysis such as existing sequencing techniques can be tested to complete the identification, though they can take up to two days.

Another key benefit is the ability to test a large number of samples quickly.

Professor Degueldre said: “What we are proposing here is not a new Covid test but is a new concept to rapidly find out if there are viruses present. This would be useful if people are ill but it is not known if they have a virus or another health condition that is making them sick. This concept would inform the clinical team whether or not there is a virus to inform early treatment actions and other measures such as the need for isolation. More detailed tests would still be required to discover the exact viral infection, but results from these take longer.

“Another application for the concept is to test water samples from sewage systems or down flow in rivers. The results would enable public health experts to identify areas of cities that have viral outbreaks”.

The concept is still at an early stage and further research and experiments are needed to further develop the process.

The technique has been outlined in the paper ‘Single virus inductively coupled plasma mass spectroscopy analysis: A comprehensive study’, which has been published by the journal Talanta.

DOI: 10.1016/j.talanta.2021.122211

Featured image: Professor Claude Degueldre © Lancaster University


Provided by Lancaster University

New Testing Strategy Can Speed Up COVID-19 Test Results for Healthcare Workers (Medicine)

In The Journal of Molecular Diagnostics investigators share a new methodology for testing pooled samples that maximizes the proportion of samples resolved after a single round of testing

Fast turnaround of COVID-19 test results for healthcare workers is critical. Investigators have now developed a COVID-19 testing strategy that maximizes the proportion of negative results after a single round of testing, allowing prompt notification of results. The method also reduces the need for increasingly limited test reagents, as fewer additional tests are required. Their strategy is described in The Journal of Molecular Diagnosticspublished by Elsevier.

There is an urgent need to reduce the spread of COVID-19 transmission in hospitals and care facilities and to maintain adequate levels of staffing. Group testing strategies with pooled samples have been proposed to increase capacity; however, the currently used strategies are slow.

“One of the main hurdles to initiating a comprehensive hospital staff testing program is the large number of staff requiring testing and the rapid turnaround times that would be required to make any screening strategy successful,” explained lead investigators Graeme Black, DPhil, and John Henry McDermott, MD, both from the Division of Evolution and Genomic Sciences, School of Biological Sciences, University of Manchester, Manchester, UK. “Using the method we have developed, any laboratory could adapt their testing scheme based on the current throughput and the current prevalence of infection in the population, facilitating a data-driven testing strategy.”

Traditional Dorfman sequential (DS) pooling combines multiple samples and, if a pool test returns positive, all of the constituent samples undergo further testing. In a healthcare setting, this means that even individuals who ultimately test negative for COVID-19 will have to isolate. The investigators developed a nonadaptive combinatorial (NAC) pooling approach that tests the same sample in several simultaneously assayed pools. The algorithm assumes initially that each sample is positive. It then attempts to disprove this assumption by finding a well in which the sample has been placed that has tested as negative. Then another algorithm is used to find positive wells that contain a single sample on the list of the remaining potentially positive samples. Indeterminate samples are retested.

To establish a suitable limit of detection for pooling, nasopharyngeal samples of known SARS-CoV-2 status were placed in two pools, each containing 14 SARS-CoV-2 negative samples and one SARS-CoV-2 positive sample, with the positive samples at differing viral loads. Pooling matrices were generated for 700, 350, and 250 samples, with each sample assigned to 2, 4, and 5 wells, respectively. The samples were also tested in a DS testing scheme. The efficacy of each matrix was tested under different SARS-CoV-2 prevalence levels of 0.1%, 3%, 7%, and 10% of the population.

All NAC matrices performed well at low prevalence levels, with an average of 585 tests saved per assay in the 700 sample matrix. In simulations of low-to-medium prevalence levels (0.1% – 3%), which is the prevalence expected in an asymptomatic healthcare worker population, all the NAC matrices required fewer retests than the DS testing scheme. However, as the population prevalence increased, the performance of each matrix deteriorated.

“Pooling becomes increasingly useful as the population prevalence of SARS-CoV-2 decreases,” Prof. Black and Dr. McDermott observed. “Initially the most conservative matrix, 250 samples, should be used to determine the prevalence level. As the prevalence falls, the use of less tolerant but higher throughput assays could be used, such as the 700 sample pool.”

The matrices and system to decode the results are freely available (www.samplepooling.com) and laboratories can choose the matrix that best suits their current population prevalence and sample size, facilitating a context-specific, relatively low cost data-driven testing approach.

“Many high-throughput testing schemes for SARS-CoV-2 detection have been developed over the past year. We illustrate the potential power that adaptable automated, innovative mathematical approaches have to increase COVID-19 diagnostic capability in a safe manner. Such an approach could reach far greater numbers, save lives, and be delivered in a sustainable way. Undoubtedly, this has considerable relevance to other future population-based screening approaches,” Prof. Black and Dr. McDermott concluded.

Notes for editors
The article is “A Nonadaptive Combinatorial Group Testing Strategy to Facilitate Health Care Worker Screening during the Severe Acute Respiratory Syndrome Coronavirus-2 (SARS-CoV-2) Outbreak,” by John H. McDermott, Duncan Stoddard, Peter J. Woolf, Jamie M. Ellingford, David Gokhale, Algy Taylor, Leigh A.M. Demain, William G. Newman, and Graeme Black (https://doi.org/10.1016/j.jmoldx.2021.01.010). It appears online in advance of The Journal of Molecular Diagnostics, volume 23, issue 5 (May 2021) published by Elsevier.

The article is openly available at https://www.jmdjournal.org/article/S1525-1578(21)00031-3/fulltext.

Featured image: Proposed testing approach for healthcare worker screening. A single round of group testing via a nonadaptive combinatorial scheme is used as an initial high-throughput screen. In this example, this screen can confirm the status of 335 samples (96%). The 15 indeterminate samples are then determined via monoplex testing rather than a second group testing round being implemented (Credit: The Journal of Molecular Diagnostics).


Provided by Elsevier

Researchers Say Prescribing Opioids for Pain Relief after Knee Surgery is Unnecessary (Medicine)

A new study by Henry Ford Health System published in Arthroscopy: The Journal of Arthroscopic and Related Surgery may signal a first step toward eliminating the use of opioids to relieve pain after knee surgery.

A novel multimodal pain management protocol developed at Henry Ford can bring about immediate pain relief for knee injury patients without using powerful opioids like morphine, codeine, and oxycodone.

Jildeh Toufic © HFHS

“Orthopedic surgeons can now perform meniscal knee surgery without the need for prescribing opioids whatsoever,” said Toufic Jildeh, M.D., chief resident at Henry Ford’s Department of Orthopaedic Surgery and the study’s lead researcher. “We believe this non-opioid approach can be replicated for other types of orthopedic surgeries.”

In what has been labeled as a serious national crisis by the U.S. Department of Health, nearly 10 million Americans misused prescription pain relievers in 2019 and more than 50 thousand people died as a result of opioid-related overdoses. Dr. Jildeh points to the study’s findings as an important first step in the effort to reduce and eliminate the use of addictive opioids to manage pain following other types of surgeries as well.

“When patients learned they can undergo surgery without the need to take opioids to manage their pain, they were excited,” said Dr. Jildeh.

Dr. Jildeh said the reliance on prescribing non-opioids for severe pain relief is part of the health system’s broader initiative launched in 2016 to reduce the number of opioid pills and patches. In 2019, the State of Michigan enacted new laws regulating the prescribing and dispensing of controlled substances including opioid painkillers. From 1999 to 2016, Michigan saw a 17% increase in fatal prescription drug and opioid overdoses.

Studies have shown that patients can become addicted to their opioid pain control medications after various types of surgery including meniscus knee surgery. “Our non-opioid approach is our response to advancing better practices for pain management for our patients,” Dr. Jildeh said.

From the study’s 61 patients, 30 received opioids for pain control and 31 received a non-opioid regimen such as anti-inflammatories, acetaminophen and muscle relaxers. Researchers reported pain scores from the non-opioid group were equivalent to those of the opioid group and there were no significant differences in side effects between the two groups.

“Patients were given the option to ask for opioids if they felt as if their pain was not in control, and we reported that none of the patients in our nonopioid cohort asked for opioids,” said Dr. Jildeh.

The non-opioid approach has become the standard of care for managing pain after meniscus surgery for many surgeons at Henry Ford.


Reference: Toufic R. Jildeh, Kelechi R. Okoroha et al., “Multimodal Nonopioid Pain Protocol Provides Equivalent Pain Versus Opioid Control Following Meniscus Surgery: A Prospective Randomized Controlled Trial”, Anthroscopy, 2021. DOI: https://doi.org/10.1016/j.arthro.2021.02.043


Provided by Henry Ford Health System