bluuebunny/crossref_metadata_2025 huggingface dataset:
Solar dynamo cycle variations with a rotational period
Authors: Pipin V V
Published: January 2021

Using non-linear mean-field dynamo models, we calculate magnetic cycle parameters, such as the dynamo cycle period, the amplitude of the total magnetic energy and the Poynting flux luminosity from the surface, for solar analogues with rotation periods in the range of 1–30 d. We perform simulations for both kinematic and non-kinematic dynamo models. The kinematic dynamo models, which take into account the non-linear α-effect and the loss of the magnetic flux due to magnetic buoyancy, show a decrease of the magnetic cycle with the decrease of the stellar rotation period. Stars with a rotational period of fewer than 10 d show non-stationary long-term variations of magnetic activity. The non-kinematic dynamo models take into account the magnetic field feedback on the large-scale flow and heat transport inside the convection zone. They show the non-monotonic variation of the dynamo period with the rotation rate. The models for rotational periods fewer than 10 d show non-stationary evolution with a slight increase in the primary dynamo period with the increase of the rotation rate. The non-kinematic models show the growth of the dynamo-generated magnetic flux with the increase of the rotation rate. There is a dynamo saturation for a star rotating with a period of 2 d or less. The saturation of the magnetic activity parameters is accompanied by a depression of the differential rotation.
Distinct high-energy cutoff variation patterns in two Seyfert galaxies
Authors: Kang Jia-Lai , Wang Jun-Xian , Kang Wen-Yong
Published: January 2021

Investigating how the cut-off energy Ecut varies with X-ray flux and photon index Γ in individual active galactic nuclei (AGNs) opens a new window to probe the yet unclear coronal physics. So far Ecut variations have only been detected in several AGNs but different patterns have been reported. Here, we report new detections of Ecut variations in two Seyfert galaxies with multiple Nuclear Spectroscopic Telescope Array (NuSTAR) exposures. While in NGC 3227 Ecut monotonically increases with Γ, the Ecut–Γ relation exhibits a Λ shape in SWIFT J2127.4+5654 (Ecut increasing with Γ at Γ ≲ 2.05, but reversely decreasing at Γ ≳ 2.05), indicating more than a single underlying mechanism is involved. Meanwhile both galaxies show softer spectra while they brighten in X-ray, a common phenomenon in Seyfert galaxies. Plotting all seven AGNs with Ecut variations ever reported with NuSTAR observations in the Ecut–Γ diagram, we find they could be unified with the Λ pattern. Although the sample is small and SWIFT J2127.4+5654 is the only source with Γ varying across the break point thus the only one exhibiting the complete Λ pattern in a single source, the discoveries shed new light on the coronal physics in AGNs. Possible underlying physical mechanisms are discussed.
Pain and the Montreal Cognitive Assessment (MoCA) in Aging
Authors: Cardoso Josue , Apagueno Brandon , Lysne Paige , Hoyos Lorraine , Porges Eric , Riley Joseph L , Fillingim Roger B , Woods Adam J , Cohen Ronald , Cruz-Almeida Yenisel
Published: January 2021

Objective

The present study aimed to determine whether specific cognitive domains part of the Montreal Cognitive Assessment (MoCA) are significantly lower in community-dwelling older adults with chronic pain compared with older adults without pain and whether these domains would be associated with self-reported pain, disability, and somatosensory function.

Design

Secondary data analysis, cross-sectional.

Setting

University of Florida.

Subjects

Individuals over 60 years old enrolled in the Neuromodulatory Examination of Pain and mobility Across the Lifespan (NEPAL) study were included if they completed the MoCA and other study measures (n = 62). Most participants reported pain on most days during the past three months (63%).

Methods

Subjects underwent a health assessment (HAS) and a quantitative sensory testing (QST) session. Health/medical history, cognitive function and self-reported pain measures were administered during the HAS. Mechanical and thermal detection, and thermal pain thresholds were assessed during the QST session.

Results

Older adults with chronic pain had lower MoCA scores compared with controls on domains of executive function, attention, memory, and language (P < 0.05). The attention and language domains survived adjustments for age, sex, education, depression, and pain duration (P < 0.05). Attention was significantly associated with all pain characteristics including pain intensity and disability, while executive function was associated with mechanical detection (P < 0.05).

Conclusion

Our results support previous findings that individuals with chronic pain tend to show poorer cognitive functioning compared with pain-free controls in domains of attention and executive function. Our findings also extend these findings to community-dwelling older adults, who are already most vulnerable to age-related cognitive declines.
Preoperative Assessment of Geriatric Surgical Patients: Update on Clinical Scales Used for Elective General and Digestive Surgery
Authors: Gené Clara , Senti Sara , Parrales Mauricio , Troya José , Fernández-Llamazares Jaume , Julián Joan-Francesc , Parés David
Published: January 2021

Background:

Higher life expectancy in the general population entails a growing interest in the surgical management of diseases affecting elderly patients. Preoperative assessment when planning surgery needs to carefully evaluate physical and functional status of the patient. This review aims to describe the most commonly used scales in the evaluation of elderly patients scheduled for surgery and provides a useful tool to decide the scales that would be better to assess these specific patients.

Methods:

According to the PRISMA statement of publications published, we have carried out a systematic review focused on elderly patients who underwent surgical procedures in General and Surgery. Using Medline, Embase, and Cochrane library, a systematic search of the literature from 1992 to 2018 was performed. This enabled us to retrieve information from the selected articles on scales to evaluate medical fitness, functional status, or both, in the elderly or frail patients.

Results:

We reviewed 102 articles and selected the most frequently used assessment scales or indexes. After this extensive analysis, we selected 4 functional scales (Katz Index, Barthel Scale, Karnofsky Performance Score, and Vulnerable Elders Survey), 4 clinical scales (American Society of Anaesthesiologists Index, Charlson Comorbidity Index, Pfeiffer Test, and Physiological and Operative Severity Score for the enumeration of Mortality and Morbidity Scale) and finally, 2 mixed scales (American College of Surgeons National Surgical Quality Improvement Program Surgical Risk Calculator and Edmonton Frail Scale).

Conclusions:

No consensus on the use of a unified assessment scale for elderly patients exists. However, with this review, we provide a brief guideline about the most useful and used scales to perform a comprehensive assessment of geriatric patients undergoing surgery.
How far might plant-eating dinosaurs have moved seeds?
Authors: Perry George L. W.
Published: January 2021

Fossilized gut contents suggest that seeds consumed by dinosaurs may have remained intact in their stomachs, and since seed dispersal distance increases with body-mass in extant vertebrates, dinosaurs may have moved seeds long distances. I simulated seed dispersal by dinosaurs across body-masses from 1 × 10
1
to 8 × 10
4
kg using allometric random walk models, informed by relationships between (i) body-mass and movement speed, and (ii) body-mass and seed retention time. Seed dispersal distances showed a hump-shaped relationship with body-mass, reflecting the allometric relationship between maximum movement speed and body-mass. Across a range of assumptions and parameterizations, the simulations suggest that plant-eating dinosaurs could have dispersed seeds long distances.
Branching principles of animal and plant networks identified by combining extensive data, machine learning and modelling
Authors: Brummer Alexander B. , Lymperopoulos Panagiotis , Shen Jocelyn , Tekin Elif , Bentley Lisa P. , Buzzard Vanessa , Gray Andrew , Oliveras Imma , Enquist Brian J. , Savage Van M.
Published: January 2021

Branching in vascular networks and in overall organismic form is one of the most common and ancient features of multicellular plants, fungi and animals. By combining machine-learning techniques with new theory that relates vascular form to metabolic function, we enable novel classification of diverse branching networks—mouse lung, human head and torso, angiosperm and gymnosperm plants. We find that ratios of limb radii—which dictate essential biologic functions related to resource transport and supply—are best at distinguishing branching networks. We also show how variation in vascular and branching geometry persists despite observing a convergent relationship across organisms for how metabolic rate depends on body mass.
Task-dependent recruitment across ankle extensor muscles and between mechanical demands is driven by the metabolic cost of muscle contraction
Authors: Lai Adrian K. M. , Dick Taylor J. M. , Biewener Andrew A. , Wakeling James M.
Published: January 2021

The nervous system is faced with numerous strategies for recruiting a large number of motor units within and among muscle synergists to produce and control body movement. This is challenging, considering multiple combinations of motor unit recruitment may result in the same movement. Yet vertebrates are capable of performing a wide range of movement tasks with different mechanical demands. In this study, we used an experimental human cycling paradigm and musculoskeletal simulations to test the theory that a strategy of prioritizing the minimization of the metabolic cost of muscle contraction, which improves mechanical efficiency, governs the recruitment of motor units within a muscle and the coordination among synergist muscles within the limb. Our results support our hypothesis, for which measured muscle activity and model-predicted muscle forces in soleus—the slower but stronger ankle plantarflexor—is favoured over the weaker but faster medial gastrocnemius (MG) to produce plantarflexor force to meet increased load demands. However, for faster-contracting speeds induced by faster-pedalling cadence, the faster MG is favoured. Similar recruitment patterns were observed for the slow and fast fibres within each muscle. By contrast, a commonly used modelling strategy that minimizes muscle excitations failed to predict force sharing and known physiological recruitment strategies, such as orderly motor unit recruitment. Our findings illustrate that this common strategy for recruiting motor units within muscles and coordination between muscles can explain the control of the plantarflexor muscles across a range of mechanical demands.
The nature effect in motion: visual exposure to environmental scenes impacts cognitive load and human gait kinematics
Authors: Burtan D. , Joyce K. , Burn J. F. , Handy T. C. , Ho S. , Leonards U.
Published: January 2021

Prolonged exposure to urban environments requires higher cognitive processing resources than exposure to nature environments, even if only visual cues are available. Here, we explored the moment-to-moment impact of environment type on visual cognitive processing load, measuring gait kinematics and reaction times. In Experiment 1, participants (n= 20) walked toward nature and urban images projected in front of them, one image per walk, and rated each image for visual discomfort. Gait speed and step length decreased for exposure to urban as compared with nature scenes in line with gait changes observed during verbal cognitive load tasks. We teased apart factors that might contribute to cognitive load: image statistics and visual discomfort. Gait changes correlated with subjective ratings of visual discomfort and their interaction with the environment but not with low-level image statistics. In Experiment 2, participants (n= 45) performed a classic shape discrimination task with the same environmental scenes serving as task-irrelevant distractors. Shape discrimination was slower when urban scenes were presented, suggesting that it is harder to disengage attention from urban than from nature scenes. This provides converging evidence that increased cognitive demands posed by exposure to urban scenes can be measured with gait kinematics and reaction times even for short exposure times.
An agent-based model of the interrelation between the COVID-19 outbreak and economic activities
Authors: Kano Takeshi , Yasui Kotaro , Mikami Taishi , Asally Munehiro , Ishiguro Akio
Published: January 2021

As of July 2020, COVID-19 caused by SARS-COV-2 is spreading worldwide, causing severe economic damage. While minimizing human contact is effective in managing outbreaks, it causes severe economic losses. Strategies to solve this dilemma by considering the interrelation between the spread of the virus and economic activities are urgently needed to mitigate the health and economic damage. Here, we propose an abstract agent-based model of the COVID-19 outbreak that accounts for economic activities. The computational simulation of the model recapitulates the trade-off between the health and economic damage associated with voluntary restraint measures. Based on the simulation results, we discuss how the macroscopic dynamics of infection and economics emerge from individuals’ behaviours. We believe our model can serve as a platform for discussing solutions to the above-mentioned dilemma.
Analytical continuation of two-dimensional wave fields
Authors: Assier Raphaël C. , Shanin Andrey V.
Published: January 2021

Wave fields obeying the two-dimensional Helmholtz equation on branched surfaces (Sommerfeld surfaces) are studied. Such surfaces appear naturally as a result of applying the reflection method to diffraction problems with straight scatterers bearing ideal boundary conditions. This is for example the case for the classical canonical problems of diffraction by a half-line or a segment. In the present work, it is shown that such wave fields admit an analytical continuation into the domain of two complex coordinates. The branch sets of such continuation are given and studied in detail. For a generic scattering problem, it is shown that the set of all branches of the multi-valued analytical continuation of the field has a finite basis. Each basis function is expressed explicitly as a Green’s integral along so-called double-eight contours. The finite basis property is important in the context of coordinate equations, introduced and used by the authors previously, as illustrated in this article for the particular case of diffraction by a segment.
Psychophysical study of the moon illusion in paintings and landscape photos
Authors: Kovács Zoltán , Udvarnoki Zoltán , Papp Eszter , Horváth Gábor
Published: January 2021

The moon illusion is a visual deception when people perceive the angular diameter of the Moon/Sun near the horizon larger than that of the one higher in the sky. Some theories have been proposed to explain this illusion, but not any is generally accepted. Although several psychophysical experiments have been performed to study different aspects of the moon illusion, their results have sometimes contradicted each other. Artists frequently display(ed) the Moon/Sun in their paintings. If the Moon/Sun appears near the horizon, its painted disc is often exaggeratedly large. How great is the magnitude of moon illusion of painters? How different are the size enlargements of depicted lunar/solar discs? To answer these questions, we measured these magnitudes on 100 paintings collected from the period of 1534–2017. In psychophysical experiments, we also investigated the moon illusion of 10 test persons who had to estimate the size of the lunar/solar disc on 100 paintings and 100 landscape photographs from which the Moon/Sun was retouched. Compared to the lunar/solar disc calculated from reference distances estimated by test persons in paintings, painters overestimated the Moon's size on average
Q
 = 2.1 ± 1.6 times, while the Sun was painted
Q
 = 1.8 ± 1.2 times larger than the real one, where
Q
 = 
r
painted
/
r
real
is the ratio of the radii of painted (
r
painted
) and real (
r
real
) Moons/Suns. In landscape photos, test persons overestimated the Moon's size
Q
 = 1.6 ± 0.4 times and the Sun was assumed
Q
 = 1.7 ± 0.5 times larger than in reality, where
Q
 = 
r
test
/
r
real
is the ratio of the radius
r
test
estimated by the test persons and the real radius
r
real
of Moons/Suns. The majority of the magnitude of moon illusion
Q
 = 1.6, 1.7, 1.8, 2.1, 2.8, 2.9 measured by us are larger than the
Q
-values 1.1, 1.2, 1.3, 1.4, 1.5, 1.6, 1.8 obtained in previous psychophysical experiments due to methodological differences.
M-theory, black holes and cosmology
Authors: Kallosh Renata
Published: January 2021

This paper is dedicated to Michael J. Duff on the occasion of his 70th birthday. I discuss some issues of M-theory/string theory/supergravity closely related to Mike’s interests. I describe a relation between STU black hole entropy, the Cayley hyperdeterminant, the Bhargava cube and a three-qubit Alice–Bob–Charlie triality symmetry. I shortly describe my recent work with Gunaydin, Linde and Yamada on M-theory cosmology (Gunaydin
et al.
2020 M-theory cosmology, octonions, error-correcting codes (
http://arxiv.org/abs/2008.01494
)), inspired by the work of Duff with Ferrara and Borsten, Levay, Marrani
et al.
Here, we have seven-qubits, a party including Alice, Bob, Charlie, Daisy, Emma, Fred and George. Octonions and Hamming error-correcting codes are at the base of these models. They lead to seven benchmark targets of future cosmic microwave background missions looking for primordial gravitational waves from inflation. I also show puzzling relations between the fermion mass eigenvalues in these cosmological models, the exceptional Jordan eigenvalue problem and black hole entropy. The symmetry of our cosmological models is illustrated by beautiful pictures of a Coxeter projection of the root system of E7.
Differences in Quaternary co-divergence reveals community-wide diversification in the mountains of southwest China varied among species
Authors: Wan Tao , Oaks Jamie R. , Jiang Xue-Long , Huang Huateng , Knowles L. Lacey
Published: January 2021

The mountains of southwest China (MSWC) is a biodiversity hotspot with highly complex and unusual terrain. However, with the majority of studies focusing on the biogeographic consequences of massive mountain building, the Quaternary legacy of biodiversity for the MSWC has long been overlooked. Here, we took a statistical comparative phylogeography approach to examine factors that shaped community-wide diversification. With data from 30 vertebrate species, the results reveal spatially concordant genetic structure, and temporally clustered co-divergence events associated with river barriers during severe glacial cycles. This indicates the importance of riverine barriers in the phylogeographic history of the MSWC vertebrate community. We conclude that the repeated glacial cycles are associated with co-divergences that are themselves structured by the heterogeneity of the montane landscape of the MSWC. This orderly process of diversification has profound implications for conservation by highlighting the relative independence of different geographical areas in which some, but not all species in communities have responded similarly to climate change and calls for further comparative phylogeographic investigations to reveal the connection between biological traits and divergence pulses in this biodiversity hotspot.
Prior Bariatric Surgery in COVID-19 Positive Patients May Be Protective
Authors: Jenkins Megan , Maranga Gabrielle , Wood G. Craig , Petrilli Christopher M. , Ren-Fielding Christine
Published: January 2021

Introduction

Patients infected with novel COVID-19 virus have a spectrum of illnesses ranging from asymptomatic to death. Data has shown that age, gender and obesity are strongly correlated with poor outcomes in COVID-19 positive patients. Bariatric surgery is the only treatment that provides significant, sustained weight loss in the severely obese. We look at whether prior bariatric surgery correlates with increased risk of hospitalization and outcome severity after COVID-19 infection.

Methods

A cross-sectional retrospective analysis of a COVID-19 database from a single, NYC-based, academic institution was conducted. A cohort of COVID-19 positive patients with a history of bariatric surgery (n=124) were matched in a 4:1 ratio to a control cohort of COVID-19 positive patients who were eligible for bariatric surgery (BMI ≥40 kg/m2 or BMI ≥35 kg/m2 with a comorbidity) (n=496). A comparison of outcomes, including mechanical ventilation requirements and deceased at discharge, was done between cohorts using Chi-square test or Fisher’s exact test. Additionally, overall length of stay and duration of time in ICU were compared using Wilcoxon Rank Sum test. Conditional logistic regression analyses were done to determine both unadjusted (UOR) and adjusted odds ratios (AOR).

Results

A total of 620 COVID-19 positive patients were included in this analysis. The categorization of bariatric surgeries included 36% Roux-en-Y Gastric Bypass (RYGB, n=45), 35% laparoscopic adjustable gastric banding (LAGB, n=44), and 28% laparoscopic sleeve gastrectomy (LSG, n=35). The body mass index (BMI) for the bariatric group was 36.1 kg/m2 (SD=8.3), which was significantly lower than the control group, 41.4 kg/m2 (SD=6.5) (p<0.0001). There was also less burden of diabetes in the bariatric group (32%) compared to the control group (48%) (p=0.0019). Patients with a history of bariatric surgery were less likely to be admitted through the emergency room (UOR=0.39, p=0.0001), less likely to have had a ventilator used during the admission (UOR=0.42, p=0.028), had a shorter length of stay in both the ICU (p=0.033) and overall (UOR=0.44, p=0.0002), and were less likely to be deceased at discharge compared to the control group (OR=0.42, p=0.028).

Conclusion

A history of bariatric surgery significantly decreases the risk of emergency room admission, mechanical ventilation, prolonged ICU stay, and death in patients with COVID-19.
Hospitalization as reliable indicator of second wave COVID-19 pandemic in eight European countries
Authors: Allieta Mattia , Sebastiano Davide Rossi
Published: January 2021

Time dependent reproduction number (Rt) is one of the most popular parameters to track the impact of COVID-19 pandemic. However, especially at the initial stages, Rt can be highly underestimated because of remarkable differences between the actual number of infected people and the daily incidence of people who are tested positive. Here, we present the analysis of daily cumulative number of hospitalized (HP) and intensive care unit (ICU) patients both in space and in time in the early phases of second wave COVID-19 pandemic across eight different European countries, namely Austria, Belgium, Czech Republic, France, Italy, Portugal, Spain, and United Kingdom. We derive simple model equations to fit the time dependence of these two variables where exponential behavior is observed. Growth rate constants of HP and ICU are listed, providing country-specific parameters able to estimate the burden of SARS-COV-2 infection before extensive containment measures take place. Our quantitative parameters, fully related to hospitalizations, are disentangled from the capacity range of the screening campaign, for example the number of swabs, and they cannot be directly biased by the actual number of infected people. This approach can give an array of reliable indicators which can be used by governments and healthcare systems to monitor the dynamics of COVID-19 epidemic.
Prediction of COVID-19 Pandemic of Top Ten Countries in the World Establishing a Hybrid AARNN LTM Model
Authors: Gahan Padmabati , Pattnaik Monalisha , Nayak Agnibrata , Roul Monee Kieran
Published: January 2021

The novel COVID-19 global pandemic has become a public health emergency of international concern affecting 215 countries and territories around the globe. As of 28 November 2020, it has caused a pandemic outbreak with a total of more than 6,171,5119 confirmed infections and more than 1,44,4235 confirmed deaths reported worldwide. The main focus of this paper is to generate LTM real-time out of sample forecasts of the future COVID-19 confirmed and death cases respectively for the top ten profoundly affected countries including for the world. To solve this problem we introduced a novel hybrid approach AARNN model based on ARIMA and ARNN forecasting model that can generate LTM (fifty days ahead) out of sample forecasts of the number of daily confirmed and death COVID-19 cases for the ten countries namely USA, India, Brazil, Russia, France, Spain, UK, Italy, Argentina, Colombia and also for the world respectively. The predictions of the future outbreak for different countries will be useful for the effective allocation of health care resources and will act as early-warning system for health warriors, corporate leaders, economists, government/public-policy makers, and scientific experts.
Empty Streets, Speeding and Motor Vehicle Collisions during Covid-19 Lockdowns: Evidence from Northern Ireland
Authors: Vandoros Sotiris , Papailias Fotis
Published: January 2021

Covid-19 and lockdowns have had spillover effects on other health outcomes. Motor vehicle collisions (MVC) are likely to have been affected by the pandemic due to, among others, less traffic volume and speeding on empty streets. This paper studies the impact of the pandemic on MVCs in Northern Ireland. Using monthly data on injuries and deaths, we find a steep decline in slight and serious injuries compared to what would have been expected in the absence of the pandemic. However, we find no effect on the number of deaths. Based on data from speeding tickets, a plausible explanation for the differential effect on the number of injuries and deaths is speeding on empty streets during the pandemic.
COVID-HEART: Development and Validation of a Multi-Variable Model for Real-Time Prediction of Cardiovascular Complications in Hospitalized Patients with COVID-19
Authors: Shade Julie K. , Doshi Ashish N. , Sung Eric , Popescu Dan M. , Minhas Anum S. , Gilotra Nisha A. , Aronis Konstantinos N. , Hays Allison G. , Trayanova Natalia A.
Published: January 2021

Cardiovascular (CV) manifestations of COVID-19 infection carry significant morbidity and mortality. Current risk prediction for CV complications in COVID-19 is limited and existing approaches fail to account for the dynamic course of the disease. Here, we develop and validate the COVID-HEART predictor, a novel continuously-updating risk prediction technology to forecast CV complications in hospitalized patients with COVID-19. The risk predictor is trained and tested with retrospective registry data from 2178 patients to predict two outcomes: cardiac arrest and imaging-confirmed thromboembolic events. In repeating model validation many times, we show that it predicts cardiac arrest with an average median early warning time of 18 hours (IQR: 13-20 hours) and an AUROC of 0.92 (95% CI: 0.91-0.92), and thromboembolic events with a median early warning time of 72 hours (IQR: 12-204 hours) and an AUROC of 0.70 (95% CI: 0.67-0.73). The COVID-HEART predictor is anticipated to provide tangible clinical decision support in triaging patients and optimizing resource utilization, with its clinical utility potentially extending well beyond COVID-19.
Rejuveinix Mitigates Sepsis-Associated Oxidative Stress in the Brain of Mice: Clinical Impact Potential in COVID-19 and Nervous System Disorders
Authors: Uckun Fatih M. , Tuzcu Mehmet , Gitterle Marcus , Volk Michael , Sahin Kazim
Published: January 2021

Here, we demonstrate that our anti-sepsis and COVID-19 drug candidate Rejuveinix (RJX) substantially improves the survival outcome in the LPS-GalN animal model of sepsis and multi-organ failure. One hundred (100) percent (%) of untreated control mice remained alive throughout the experiment. By comparison, 100% of LPS-GalN injected mice died at a median of 4.6 hours. In contrast to the invariably fatal treatment outcome of vehicle-treated control mice, 40% of mice treated with RJX (n=25) remained alive with a 2.4-fold longer median time survival time of 10.9 hours (Log-rank X2=20.60, P<0.0001). Notably, RJX increased the tissue levels of antioxidant enzymes SOD, CAT, and GSH-Px, and reduced oxidative stress in the brain. These findings demonstrate the clinical impact potential of RJX as a neuroprotective COVID-19 and sepsis drug candidate.
The impact of vitamin D supplementation on mortality rate and clinical outcomes of COVID-19 patients: A systematic review and meta-analysis
Authors: Nikniaz Leila , Akbarzadeh Mohammad Amin , Hosseinifard Hossein , Hosseini Mohammad-Salar
Published: January 2021

Background

Several studies have suggested the positive impact of vitamin D on patients infected with SARS-CoV-2. This systematic review aims to evaluate the effects of vitamin D supplementation on clinical outcomes and mortality rate of COVID-19 patients.

Methods

A comprehensive search was conducted through the databases of PubMed, Scopus, Web of Knowledge, Embase, Ovid, and The Cochrane Library with no limitation in time and language, until December 16, 2020. The results were screened based on their accordance with the subject. Two independent reviewers selected the eligible studies and the outcomes of interest were extracted. Using the Joanna Briggs Institute (JBI) Critical Appraisal Tools for Randomized Controlled Trials (RCTs) and Quasi-Experimental Studies, the remaining results were appraised critically. Statistical analysis was performed using the Comprehensive Meta-Analysis (CMA) software version 2.0.

Results

Of the 2311 results, 1305 duplicated results were removed. After screening the titles, abstracts, and the full-text articles of the remaining records, four studies and 259 patients were enrolled, including 139 patients in vitamin D intervention groups. In three of the studies, the patients’ survival and mortality rate were evaluated. The pooled analysis of these studies showed a significantly lower mortality rate among the intervention groups (10.56%) compared with the control groups (23.88%) (OR = 0.264, 95% CI = 0.099–0.708, p-value = 0.008). Two of the studies reported the clinical outcomes based on the World Health Organization’s Ordinal Scale for Clinical Improvement (OSCI) score for COVID-19, where both of them showed a significant decrease in OSCI score in the vitamin D intervention groups. Additionally, One study reported a lower rate of intensive care unit (ICU) admission, and one study reported a significant decrease in serum levels of Fibrinogen.

Conclusion

Prescribing vitamin D supplementation to patients with COVID-19 infection seems to decrease the mortality rate, the severity of the disease, and serum levels of the inflammatory markers. Further studies are needed to determine the ideal type, dosage and duration of supplementation.
Antithrombotic Therapy in COVID-19: Systematic Summary of Ongoing or Completed Randomized Trials
Authors: Talasaz Azita H. , Sadeghipour Parham , Kakavand Hessam , Aghakouchakzadeh Maryam , Kordzadeh-Kermani Elaheh , Van Tassell Benjamin W. , Gheymati Azin , Ariannejad Hamid , Hosseini Seyed Hossein , Jamalkhani Sepehr , Sholzberg Michelle , Monreal Manuel , Jimenez David , Piazza Gregory , Parikh Sahil A. , Kirtane Ajay , Eikelboom John W. , Connors Jean M. , Hunt Beverley J. , Konstantinides Stavros V. , Cushman Mary , Weitz Jeffrey I. , Stone Gregg W. , Krumholz Harlan M. , Lip Gregory Y.H. , Goldhaber Samuel Z. , Bikdeli Behnood
Published: January 2021

Endothelial injury and microvascular/macrovascular thrombosis are common pathophysiologic features of coronavirus disease-2019 (COVID-19). However, the optimal thromboprophylactic regimens remain unknown across the spectrum of illness severity of COVID-19. A variety of antithrombotic agents, doses and durations of therapy are being assessed in ongoing randomized controlled trials (RCTs) that focus on outpatients, hospitalized patients in medical wards, and critically-ill patients with COVID-19. This manuscript provides a perspective of the ongoing or completed RCTs related to antithrombotic strategies used in COVID-19, the opportunities and challenges for the clinical trial enterprise, and areas of existing knowledge, as well as data gaps that may motivate the design of future RCTs.
The Effect of Frames on COVID-19 Vaccine Hesitancy
Authors: Palm Risa , Bolsen Toby , Kingsland Justin T.
Published: January 2021

In order to control the spread of infectious diseases such as COVID-19, it will be important to develop a communication strategy to counteract “vaccine hesitancy”. This paper reports the results of a survey experiment testing the impacts of several types of message content: the safety and efficacy of the vaccine itself, the likelihood that others will take the vaccine, and the possible role of politics in promoting the vaccine. In an original survey of 1123 American M-Turk respondents, we provided six different information conditions suggesting the safety and efficacy of the vaccine, the lack of safety/efficacy of the vaccine, the suggestion that most others would take the vaccine, the suggestion that most others would not take the vaccine, the suggestion that the vaccine is being promoted to gain greater control over individual freedom, and the suggestion that it is being rushed for political motivations. We compared the responses for those in the treatment groups with a control group who received no additional information. In comparison to the control group, those who received information about the safety/efficacy of the vaccine were more likely to report that they would take the vaccine, those who received information that others were reluctant to take the vaccine were more likely to report that they themselves would not take it, that other Americans would not take it, and that it was not important to get the vaccine, and those who received information about political influences on vaccine development expressed hesitancy to take it. Communication of effective messages about the vaccine will be essential for public health agencies that seek to promote vaccine take-up.
Scaling up: understanding movement from individual differences to population-level dispersal
Authors: Edelsparre Allan H. , Hefley Trevor J. , Rodríguez Marco A. , Fitzpatrick Mark J. , Sokolowski Marla B.
Published: January 2021

Dispersal is fundamental to life on our planet. Dispersal facilitates colonization of continents and islands. Dispersal mediates gene flow among populations, and influences the rate of spread of invasive species. Theory suggests that individuals consistently differ in dispersal propensity, however determining the relative contributions of environmental factors to individual and population-level dispersal, represent a major challenge to understand the spread of organisms. To address this, we conducted a field experiment usingDrosophila melanogaster.As proxies for individuals with different dispersal propensities, we used wildtype strains of flies with natural variants of theforaginggene, known to influence dispersal in laboratory and field experiments. These included flies withforsalleles known to be less dispersive, flies with theforRalleles which are more dispersive flies as well as an outbred population established from field collected flies. We released approximately 6000 flies of each strain in an experimental arena (100 m × 100 m) in the field and our recaptures were used to determine dispersal of flies over time. To estimate environmental effects on dispersal, we measured temperature, wind direction and wind speed. Using partial-differential equations we combined ecological diffusion with advection to estimate dispersal rates and responses to wind. We found that temperature effects elicited a similar response in high and low dispersal lab strains with dispersal rate increasing with temperature most rapidly at temperatures above 18°C. This was in contrast to outbred flies which remained unresponsive to temperature changes. We also detected a response to wind with advection rates increasing linearly with wind speed for all flies in general. Our results suggest that response to temperature and wind can minimize known differences in behavioural predispositions to disperse. Our results also suggest that the direction and magnitude of wind may play a key role in the colonization and distribution of fly populations. Our findings therefore have implications for forecasting the spread of pests and invasive species as well as pathogens and vectors of disease. Our findings further contribute to the understanding of how the environment can modify behavioural predispositions and to influence population-level dispersal in fly populations in particular and insect species in general.
Epigenetic analysis of Paget’s disease of bone identifies differentially methylated loci that predict disease status
Authors: Diboun Ilhame , Wani Sachin , Ralston Stuart H , Albagha Omar M E
Published: January 2021

Paget’s Disease of Bone (PDB) is characterized by focal increases in disorganized bone remodeling. This study aims to characterize PDB associated changes in DNA methylation profiles in patients’ blood. Meta-analysis of data from the discovery and replication set, comprising of 116 PDB cases and 130 controls, revealed significant differences in DNA methylation at 14 CpG sites, 4 CpG islands, and 6 gene-body regions. These loci, including two characterized as functional through eQTM analysis, were associated with functions related to osteoclast differentiation, mechanical loading, immune function, and viral infection. A multivariate classifier based on discovery samples was found to discriminate PDB cases and controls from the replication with a sensitivity of 0.84, specificity of 0.81, and an area under curve of 92.8%. In conclusion, this study has shown for the first time that epigenetic factors contribute to the pathogenesis of PDB and may offer diagnostic markers for prediction of the disease.
Encoding-linked pupil response is modulated by expected and unexpected novelty: Implications for memory formation and neurotransmission
Authors: Kafkas Alex
Published: January 2021

Whether a novel stimulus is expected or unexpected may have implications for the kind of ensuing encoding and the type of subsequent memory. Pupil response was used in the present study to explore the way expected and unexpected stimuli are encoded and whether encoding-linked pupil response is modulated by expectation. Participants first established a contingency relationship between a series of symbols and the type of stimulus (man-made or natural) that followed each one. At encoding, some of the target stimuli violated the previously established relationship (i.e., unexpected), while the majority conformed to this relationship (i.e., expected). Expectation at encoding had opposite effects on familiarity and recollection, the two types of memory that support recognition, and modulated differently the way pupil responses predicted subsequent memory. Encoding of unexpected novel stimuli was associated with increased pupil dilation as a predictor of subsequent memory type and strength. In contrast, encoding of expected novel stimuli was associated with decreased pupil response (constriction), which was predictive of subsequent memory type and strength. The findings support the close link between pupil response and memory formation, but critically indicate that this is modulated by the type of novelty as defined by expectation. These novel findings have important implications for the encoding mechanisms involved when different types of novelty are detected and is proposed to indicate the operation of different neurotransmitters in memory formation.
Proton receptors regulate synapse-specific reconsolidation in the amygdala
Authors: Koffman Erin E , Kruse Charles M , Singh Kritika , Naghavi FarzanehSadat , Egbo Jennifer , Boateng Sandra , Houdi BA Mark , Lin Boren , Debiec Jacek , Du Jianyang
Published: January 2021

When an extinction procedure is performed within the reconsolidation window, the original aversive memory can be replaced by one that is less traumatic. Recent studies revealed that carbon dioxide (CO2) inhalation during retrieval enhances memory lability. However, the effects of CO2inhalation on the central nervous system can be extensive, and there is lack of evidence suggesting that the effects of CO2are selective to a reactivated memory. We discovered that CO2inhalation paired with memory retrieval potentiates the specific aversive memory trace, resulting in greater memory lability. The specific effects of CO2depend on acid-sensing ion channels (ASICs), the proton receptors that are involved in synaptic transmission and plasticity in the amygdala. In addition, CO2inhalation alters memory lability via synaptic plasticity at selectively targeted synapses. Overall, our results suggest that inhaling CO2during the retrieval event increases the lability of an aversive memory through a synapse-specific reconsolidation process.
Inferring differential subcellular localisation in comparative spatial proteomics using BANDLE
Authors: Crook Oliver M. , Davies Colin T. R. , Breckels Lisa M. , Christopher Josie A. , Gatto Laurent , Kirk Paul D.W. , Lilley Kathryn S.
Published: January 2021

The steady-state localisation of proteins provides vital insight into their function. These localisations are context specific with proteins translocating between different sub-cellular niches upon perturbation of the subcellular environment.Differential localisation, that is a change in the steady-state subcellular location of a protein, provides a step towards mechanistic insight of subcellular protein dynamics. Aberrant localisation has been implicated in a number of pathologies, thusdifferential localisationmay help characterise disease states and facilitate rational drug discovery by suggesting novel targets. High-accuracy high-throughput mass spectrometry-based methods now exist to map the steady-state localisation and re-localisation of proteins. Here, we propose a principled Bayesian approach, BANDLE, that uses these data to compute the probability that a protein differentially localises upon cellular perturbation, as well quantifying the uncertainty in these estimates. Furthermore, BANDLE allows information to be shared across spatial proteomics datasets to improve statistical power. Extensive simulation studies demonstrate that BANDLE reduces the number of both type I and type II errors compared to existing approaches. Application of BANDLE to datasets studying EGF stimulation and AP-4 dependent localisation recovers well studied translocations, using only two-thirds of the provided data. Moreover, we potentially implicate TMEM199 with AP-4 dependent localisation. In an application to cytomegalovirus infection, we obtain novel insights into the rewiring of the host proteome. Integration of high-throughput transcriptomic and proteomic data, along with degradation assays, acetylation experiments and a cytomegalovirus intcractome allows us to provide the functional context of these data.
Astrocyte-derived thrombospondin induces cortical synaptogenesis in a sex-specific manner
Authors: Mazur Anna , Bills Ean H. , Henderson Brandon J. , Risher W. Christopher
Published: January 2021

The regulation of synaptic connectivity in the brain is vital to proper functioning and development of the central nervous system (CNS). Formation of neural networks in the CNS has been shown to be heavily influenced by astrocytes, which secrete factors, including thrombospondin (TSP) family proteins, that promote synaptogenesis. However, whether this process is different between males and females has not been thoroughly investigated. In this study, we found that cortical neurons purified from newborn male rats showed a significantly more robust synaptogenic response compared to female-derived cells when exposed to factors secreted from astrocytes. This difference was driven largely by the neuronal response to TSP2, which increased synapses in male neurons while showing no effect on female neurons. Blockade of endogenous 17β-estradiol production with letrozole normalized the TSP response between male and female cells, indicating a level of regulation by estrogen signaling. Our results suggest that TSP-induced synaptogenesis is critical for the development of male but not female cortical synapses, contributing to sex differences in astrocyte-mediated synaptic connectivity.
Neural Correlates of a Trance Process and Alternative States of Consciousness in a Traditional Healer
Authors: Rogerson Rebecca G. , Barnstaple Rebecca , DeSouza Joseph F.X.
Published: January 2021

Trance processes are a form of altered states of consciousness (ASC) widely reported across cultures. Entering these states is often linked to auditory stimuli such as singing, chanting, or rhythmic drumming. While scientific research into this phenomenon is relatively nascent, there is emerging interest in investigating the neural correlates of altered states of consciousness such as trance. This report aims to add to this field of ASC through exploring how the perception of an experiencedSangoma--traditional South African healer--entering a trance process correlates to BOLD signal modulation with auditory stimuli. Functional MRI data were analyzed using a General Linear model comparing music versus no music condition multiplied by the percept of experiencing trance (High or Low). Positive BOLD activation was shown in auditory cortex in both hemispheres during a trance process. Other brain regions tightly correlated to trance perception were right parietal, right frontal, and area prostriata (P<0.05, Bonferroni corrected). Orbitofrontal cortex (part of the Default Mode Network) was negatively activated and most correlated with music when trance was high, showing the largest differential between high and low trance perception. This is the first study to directly correlate BOLD signal variations in an expert subject’s percept of trance onset and intensity, providing insight into the neural signature and dynamics of this unique form of ASC. Future studies should examine in greater detail perception of trance processes in expert subjects, adding other neuroimaging modalities to further investigate how these brain regions are modulated by trance expertise.
Medium-throughput zebrafish optogenetic platform identifies deficits in subsequent neural activity following brief early exposure to cannabidiol and Δ-9-tetrahydrocannabinol
Authors: Kanyo Richard , Amin Md Ruhul , Locskai Laszlo F. , Bouvier Danika D. , Olthuis Alexandria M. , Allison W. Ted , Ali Declan W.
Published: January 2021

In the light of legislative changes and the widespread use of cannabis as a recreational and medicinal drug, delayed effects of cannabis upon brief exposure during embryonic development are of high interest as early pregnancies often go undetected. Here, zebrafish embryos were exposed to cannabidiol (CBD) and Δ-9-tetrahydrocannabinol l (THC) until the end of gastrulation (1-10 hours post-fertilization) and analyzed later in development (4-5 days post-fertilization). In order to measure neural activity, we implemented CaMPARI (Calcium-Modulated Photoactivatable Ratiometric Integrator) and optimized the protocol for a 96-well format complemented by locomotor analysis. Our results revealed that neural activity was decreased by CBD more than THC. At higher doses, both cannabinoids could dramatically reduce neural activity and locomotor activity. Interestingly, the decrease was more pronounced when CBD and THC were combined. At the receptor level, CBD-mediated reduction of locomotor activity was partially prevented using cannabinoid type 1 and 2 receptor inhibitors. Overall, we report that CBD toxicity occurs via two cannabinoid receptors and is synergistically enhanced by THC exposure to negatively impact neural activity late in larval development. Future studies are warranted to reveal other cannabinoids and receptors involved in this pathway to understand the subsequent health implications of cannabis consumption on fetal development.