bluuebunny/crossref_metadata_2025 huggingface dataset:
Peryton: a manual collection of experimentally supported microbe-disease associations
Authors: Skoufos Giorgos , Kardaras Filippos S , Alexiou Athanasios , Kavakiotis Ioannis , Lambropoulou Anastasia , Kotsira Vasiliki , Tastsoglou Spyros , Hatzigeorgiou Artemis G
Published: October 2020

We present Peryton (https://dianalab.e-ce.uth.gr/peryton/), a database of experimentally supported microbe-disease associations. Its first version constitutes a novel resource hosting more than 7900 entries linking 43 diseases with 1396 microorganisms. Peryton's content is exclusively sustained by manual curation of biomedical articles. Diseases and microorganisms are provided in a systematic, standardized manner using reference resources to create database dictionaries. Information about the experimental design, study cohorts and the applied high- or low-throughput techniques is meticulously annotated and catered to users. Several functionalities are provided to enhance user experience and enable ingenious use of Peryton. One or more microorganisms and/or diseases can be queried at the same time. Advanced filtering options and direct text-based filtering of results enable refinement of returned information and the conducting of tailored queries suitable to different research questions. Peryton also provides interactive visualizations to effectively capture different aspects of its content and results can be directly downloaded for local storage and downstream analyses. Peryton will serve as a valuable source, enabling scientists of microbe-related disease fields to form novel hypotheses but, equally importantly, to assist in cross-validation of findings.
Carbon nanotubes for flexible batteries: recent progress and future perspective
Authors: Zhu Sheng , Sheng Jian , Chen Yuan , Ni Jiangfeng , Li Yan
Published: October 2020

Flexible batteries, which maintain their functions potently under various mechanical deformations, attract increasing interest due to potential applications in emerging portable and wearable electronics. Significant efforts have been devoted to material synthesis and structural designs to realize the mechanical flexibility of various batteries. Carbon nanotubes (CNTs) have a unique one-dimensional (1D) nanostructure and are convenient to further assemble into diverse macroscopic structures, such as 1D fibers, 2D films and 3D sponges/aerogels. Due to their outstanding mechanical and electrical properties, CNTs and CNT-based hybrid materials are superior building blocks for different components in flexible batteries. This review summarizes recent progress on the application of CNTs in developing flexible batteries, from closed-system to open-system batteries, with a focus on different structural designs of CNT-based material systems and their roles in various batteries. We also provide perspectives on the challenges and future research directions for realizing practical applications of CNT-based flexible batteries.
Impact of Ventilator-associated Pneumonia on Cerebrospinal Fluid Inflammation During Immunosuppression After Subarachnoid Hemorrhage: A Pilot Study
Authors: Coelembier Clément , Venet Fabienne , Demaret Julie , Viel Sébastien , Lehot Jean-Jacques , Dailler Frédéric , Monneret Guillaume , Lukaszewicz Anne-Claire
Published: October 2020

Introduction:

Brain injuries can cause systemic immunosuppression, which in turn can lead to infections that adversely affect the injured brain and worsen clinical outcomes. This study aimed to investigate whether systemic infection, such as ventilator-associated pneumonia (VAP), induce intracranial inflammation in patients with subarachnoid hemorrhage (SAH).

Methods:

This prospective, observational study included 16 adults with SAH treated in the neuro-intensive care unit. Three paired cerebrospinal fluid samples (obtained from an external ventricular drain) and peripheral blood samples were obtained on days 1 to 3, 4 to 5, and 6 to 7 after SAH onset. Cell counts, cell phenotypes (monocyte HLA-DR, T regulatory cells, lymphocytes, and neutrophils), and inflammatory mediator levels were monitored.

Results:

Six patients developed VAP in the context of systemic immunosuppression demonstrated by a reduction in monocyte HLA-DR expression, lymphopenia, increased percentages of circulating T regulatory cells, and increased proportions of immature and immunosuppressive neutrophil subsets. During VAP, there was de novo recruitment of leukocytes into the cerebrospinal fluid, preferentially neutrophils, which exacerbated intracranial inflammation.

Conclusions:

VAP increased intracranial inflammatory responses in patients with SAH despite the occurrence of systemic immunosuppression. A better understanding of cell trafficking and their pleiotropic functions in brain injury is needed to define the optimal strategies for preventing infections in patients with SAH.
JMJD1C knockdown affects myeloid cell lines proliferation, viability, and gemcitabine/carboplatin-sensitivity
Authors: Schimek Vanessa , Björn Niclas , Pellé Lucia , Svedberg Anna , Gréen Henrik
Published: October 2020

Objectives

Chemotherapy-induced hematological toxicities are potentially life-threatening adverse drug reactions that vary between individuals. Recently, JMJD1C has been associated with gemcitabine/carboplatin-induced thrombocytopenia in non-small-cell lung cancer patients, making it a candidate marker for predicting the risk of toxicity. This study investigates if JMJD1C knockdown affects gemcitabine/carboplatin-sensitivity in cell lines.

Methods

Lentiviral transduction-mediated shRNA knockdown of JMJD1C in the cell lines K562 and MEG-01 were performed using shRNA#32 and shRNA#33. The knockdown was evaluated using qPCR. Cell proliferation, viability, and gemcitabine/carboplatin-sensitivity were subsequently determined using cell counts, trypan blue, and the MTT assay.

Results

ShRNA#33 resulted in JMJD1C downregulation by 56.24% in K562 and 68.10% in MEG-01. Despite incomplete knockdown, proliferation (reduction of cell numbers by 61–68%, day 7 post-transduction) and viability (reduction by 21–53%, day 7 post-transduction) were impaired in K562 and MEG-01 cells. Moreover, JMJD1C knockdown reduced the gemcitabine IC50-value for K562 cells (P < 0.01) and MEG-01 cells (P < 0.05) compared to scrambled shRNA control transduced cells.

Conclusions

Our results suggest that JMJD1C is essential for proliferation, survival, and viability of K562 and MEG-01 cells. Further, JMJD1C also potentially affects the cells gemcitabine/carboplatin-sensitivity. Although further research is required, the findings show that JMJD1C could have an influential role for gemcitabine/carboplatin-sensitivity.
Maternal Mortality Due to Cardiac Disease in Pregnancy
Authors: KNYPINSKI JULIA , WOLFE DIANA S.
Published: October 2020

Maternal mortality worldwide has vastly improved over the last several decades. Unfortunately, maternal mortality in the United States has been increasing and now cardiovascular conditions are the leading case of maternal death. The calculation of maternal mortality ratios and pregnancy-related mortality ratios is accomplished by several different organizations and this data collection is often complex, tedious, and poorly understood. Here we review the history of maternal mortality in the United States and aim to better understand how this data are collected.
Vulvodynia
Authors: BARNABEI VANESSA M.
Published: October 2020

Vulvodynia is a heterogenous, chronic pain condition of unknown etiology that affects 7% to 15% of women. It affects sexual function and quality of life. Vulvodynia can be primary or secondary, localized or generalized, and spontaneous or provoked. Contributing factors for provoked vulvodynia might include vulvovaginal infections, low estrogen states, and underlying anxiety disorder. Generalized vulvodynia likely arises from underlying connective tissue or neurological dysfunction. Vulvodynia treatment must be individualized on the basis of the patient’s presentation and physical examination findings. Surgical excision of the vulvar vestibule has high success rates but other modalities showing success include pelvic floor physical therapy and cognitive-behavioral therapy.
Pregnancy and Congenital Heart Disease: A Brief Review of Risk Assessment and Management
Authors: CHAN ALICE , WOLFE DIANA S. , ZAIDI ALI N.
Published: October 2020

Cardiac disease is a leading cause of morbidity and mortality in pregnant women. An increased prevalence of the cardiovascular disease has been found in women of childbearing age, in which the responsibility of the treating physician extends to the mother and to the unborn fetus. As a result, care of these high-risk pregnant women with cardiovascular disease including those with congenital heart disease (CHD) require a team approach including specialists in maternal-fetal medicine, adult congenital cardiology, and obstetrical anesthesia. The human body undergoes significant amounts of physiological changes during this period of time and the underlying cardiac disease can affect both the mother and the fetus. Today, most female children born with CHD will reach childbearing age. For many women with complex CHD, carrying a pregnancy has a moderate to high risk for both the mother and her fetus. This chapter will review the epidemiology, risk factors, clinical presentation including common signs and symptoms, physiological changes in pregnancy, and the medical approach including cardiac medications, percutaneous interventions, and surgical procedures for pregnant women with CHD.
Relationship and Effects of Community Problems on Anxiety and Suicide
Authors: Lyu Juncheng , Ding Li , Zhang Jie
Published: October 2020

This study aimed to explore the relationship and the effects of community problems on anxiety and suicide. Data were from a case-control psychological autopsy study (392 suicides and 416 community living controls) carried out in 16 rural counties from three provinces in China. The World Health Organization Suicide Prevention–Multisite Intervention Study on Suicidal behaviors scale of community stress and problems and Spielberger State-Trait Anxiety Inventory were used to measure the community problems and trait anxiety. Spearman's correlation and multivariable regression methods were used to probe the effect of community problems on anxiety and suicide. There were 12 and 6 community problems correlated with anxiety (r
s = 0.169, p < 0.001) and suicide (r
s = 0.081, p = 0.022), respectively. Medical care, alcohol abuse, superstition, and job security were important community problems for anxiety and suicide. Community problems had stronger correlation with anxiety than suicide. It might be an effective method to reduce anxiety and suicide risk by solving different community problems.
Clinical and economic impact of bacterial resistance: an approach to infection control and antimicrobial stewardship solutions
Authors: Calbo Esther , Boix-Palop Lucía , Garau Javier
Published: October 2020

Purpose of review

The aim of this study was to describe the clinical and economic burden of bacterial antimicrobial resistance (AMR) and to provide an expert opinion on different approaches to fight it.

Recent findings

For several decades now, it has been known that AMR among human pathogens is related to high clinical and economic burden.

Different strategies have been implemented to control the clinical and economic burden of AMR. Antimicrobial stewardship programmes (ASP), environmental cleaning and infection source control have been reported as the most effective interventions. There is a potential role for faecal microbiome transplant (FMT); however, long-term effectiveness and safety remain to be demonstrated. Another promising tool is to develop molecules to chelate or degrade residual antibiotics in the colon. Decolonization has demonstrated impact on methicillin-resistant Staphylococcus aureus (MRSA) infections, but there is limited evidence on the clinical impact and effectiveness of decolonization in MDR Gram-negative carriers.

A better assessment of AMR rates and the clinical and economic impact is needed. The epidemiology of AMR bacteria varies in different regions with MRSA, extended-spectrum beta-lactamase and carbapenamase-producing Enterobacterales being the most worrying. ASP and infection control have been increasingly demonstrated to impact on AMR rates. New approaches such as FMT and decolonization have still to demonstrate efficacy and safety.
Molecular MR Contrast Agents
Authors: Shuvaev Sergey , Akam Eman , Caravan Peter
Published: October 2020

Molecular magnetic resonance (MR) imaging utilizes molecular probes to provide added biochemical or cellular information to what can already be achieved with anatomical and functional MR imaging. This review provides an overview of molecular MR and focuses specifically on molecular MR contrast agents that provide contrast by shortening the T1 time. We describe the requirements for a successful molecular MR contrast agent and the challenges for clinical translation. The review highlights work from the last 5 years and places an emphasis on new contrast agents that have been validated in multiple preclinical models. Applications of molecular MR include imaging of inflammation, fibrosis, fibrogenesis, thromboembolic disease, and cancers. Molecular MR is positioned to move beyond detection of disease to the quantitative staging of disease and measurement of treatment response.
Heating of Hip Arthroplasty Implants During Metal Artifact Reduction MRI at 1.5- and 3.0-T Field Strengths
Authors: Khodarahmi Iman , Rajan Sunder , Sterling Robert , Koch Kevin , Kirsch John , Fritz Jan
Published: October 2020

Objectives

The aim of this study was to quantify the spatial temperature rises that occur during 1.5- and 3.0-T magnetic resonance imaging (MRI) of different types of hip arthroplasty implants using different metal artifact reduction techniques.

Materials and Methods

Using a prospective in vitro study design, we evaluated the spatial temperature rises of 4 different total hip arthroplasty constructs using clinical metal artifact reduction techniques including high-bandwidth turbo spin echo (HBW-TSE), slice encoding for metal artifact correction (SEMAC), and compressed sensing SEMAC at 1.5 and 3.0 T. Each MRI protocol included 6 pulse sequences, with imaging planes, parameters, and coverage identical to those in patients. Implants were immersed in standard American Society for Testing and Materials phantoms, and fiber optic sensors were used for temperature measurement. Effects of field strength, radiofrequency pulse polarization at 3.0 T, pulse protocol, and gradient coil switching on heating were assessed using nonparametric Friedman and Wilcoxon signed-rank tests.

Results

Across all implant constructs and MRI protocols, the maximum heating at any single point reached 13.1°C at 1.5 T and 1.9°C at 3.0 T. The temperature rises at 3.0 T were similar to that of background in the absence of implants (P = 1). Higher temperature rises occurred at 1.5 T compared with 3.0 T (P < 0.0001), and circular compared with elliptical radiofrequency pulse polarization (P < 0.0001). Compressed sensing SEMAC generated equal or lower degrees of heating compared with HBW-TSE at both field strengths (P < 0.0001).

Conclusions

Magnetic resonance imaging of commonly used total hip arthroplasty implants is associated with variable degrees of periprosthetic tissue heating. In the absence of any perfusion effects, the maximum temperature rises fall within the physiological range at 3.0 T and within the supraphysiologic range at 1.5 T. However, with the simulation of tissue perfusion effects, the heating at 1.5 T also reduces to the upper physiologic range. Compressed sensing SEMAC metal artifact reduction MRI is not associated with higher degrees of heating than the HBW-TSE technique.
Accessory and Incomplete Lung Fissures
Authors: Bayter Paula A. , Lee Gregory M. , Grage Rolf A. , Walker Christopher M. , Suster David I. , Greene Reginald E. , Gilman Matthew D. , Lanuti Michael , Stowell Justin T.
Published: October 2020

Objective:

This article reviews the anatomy, histology, and disease processes of pulmonary fissures, with emphasis on clinical implications of accessory and incomplete fissures.

Conclusion:

Accessory and incomplete pulmonary fissures are often overlooked during routine imaging but can have profound clinical importance. Knowledge of fissure anatomy could improve diagnostic accuracy and inform prognosis for oncologists, interventional pulmonologists, and thoracic surgeons.
Private Tour Guide to Pediatric Coronavirus Disease of 2019 and Multisystem Inflammatory Syndrome in Children in 10 Minutes
Authors: Foust Alexandra M. , Winant Abbey J. , Restrepo Ricardo , Liszewski Mark C. , Plut Domen , Lee Edward Y.
Published: October 2020

Filtering through the plethora of radiologic studies generated in response to the coronavirus disease of 2019 (COVID-19) pandemic can be time consuming and impractical for practicing thoracic radiologists with busy clinical schedules. To further complicate matters, several of the imaging findings in the pediatric patients differ from the adult population. This article is designed to highlight clinically useful information regarding the imaging manifestations of pediatric COVID-19 pneumonia, including findings more unique to pediatric patients, and multisystem inflammatory syndrome in children.
Conceptual developments in sperm competition: a very brief synopsis
Authors: Parker Geoff A.
Published: October 2020

The past half century has seen the development of the field of post-ejaculatory sexual selection, the sequel to sexual selection for mate-acquisition (pre-ejaculatory) described by Darwin. In richness and diversity of adaptations, post-ejaculatory selection rivals that of pre-ejaculatory sexual selection. Anisogamy—and hence two sexes—likely arose by primeval gamete competition, and sperm competition remains a major force maintaining high sperm numbers. The post-ejaculatory equivalent of male–male competition for matings, sperm competition was an intense ancestral form of sexual selection, typically weakening as mobility and internal fertilization developed in many taxa, when some expenditure became diverted into pre-ejaculatory competition. Sperm competition theory has been relatively successful in explaining variation in relative testes size and sperm numbers per ejaculate and is becoming more successful in explaining variation in sperm phenotype. Sperm competition has generated many other male adaptations such as seminal fluid proteins that variously modify female reproduction towards male interests, and copulatory plugs, prolonged copulations and post-ejaculatory guarding behaviour that reduce female remating probability, many of which result in sexual conflict. This short survey of conceptual developments is intended as a broad overview, mainly as a primer for new researchers.

This article is part of the theme issue ‘Fifty years of sperm competition'.
Evolutionary insight from a humble fly: sperm competition and the yellow dungfly
Authors: Simmons Leigh W. , Parker Geoff A. , Hosken David J.
Published: October 2020

Studies of the yellow dungfly in the 1960s provided one of the first quantitative demonstrations of the costs and benefits associated with male and female reproductive behaviour. These studies advanced appreciation of sexual selection as a significant evolutionary mechanism and contributed to the 1970s paradigm shift toward individual selectionist thinking. Three behaviours in particular led to the realization that sexual selection can continue during and after mating: (i) female receptivity to remating, (ii) sperm displacement and (iii) post-copulatory mate guarding. These behaviours either generate, or are adaptations to sperm competition, cryptic female choice and sexual conflict. Here we review this body of work, and its contribution to the development of post-copulatory sexual selection theory.

This article is part of the theme issue ‘Fifty years of sperm competition’.
Within-ejaculate sperm competition
Authors: Sutter Andreas , Immler Simone
Published: October 2020

Sperm competition was defined by Geoff Parker 50 years ago as the competition between sperm from two or more males over the fertilization of a set of eggs. Since the publication of his seminal paper, sperm competition has developed into a large field of research, and many aspects are still being discovered. One of the relatively poorly understood aspects is the importance of selection and competition among sperm within the ejaculate of a male. The sheer number of sperm present in a male's ejaculate suggests that the competition among sibling sperm produced by the same male may be intense. In this review, we summarize Parker's theoretical models generating predictions about the evolution of sperm traits under the control of the haploid gamete as opposed to the diploid male. We review the existing evidence of within-ejaculate competition from a wide range of fields and taxa. We also discuss the conceptual and practical hurdles we have been facing to study within-ejaculate sperm competition, and how novel technologies may help in addressing some of the currently open questions.

This article is part of the theme issue ‘Fifty years of sperm competition’.
Selfish genetic elements and male fertility
Authors: Verspoor Rudi L. , Price Tom A. R. , Wedell Nina
Published: October 2020

Selfish genetic elements (SGEs) are diverse and near ubiquitous in Eukaryotes and can be potent drivers of evolution. Here, we discuss SGEs that specifically act on sperm to gain a transmission advantage to the next generation. The diverse SGEs that affect sperm often impose costs on carrier males, including damaging ejaculates, skewing offspring sex ratios and in particular reducing sperm-competitive success of SGE-carrying males. How males and females tolerate and mitigate against these costs is a dynamic and expanding area of research. The intense intra-genomic conflict that these selfish elements generate could also have implications for male fertility and spermatogenesis more widely.

This article is part of the theme issue ‘Fifty years of sperm competition’.
Sexual selection after gamete release in broadcast spawning invertebrates
Authors: Evans Jonathan P. , Lymbery Rowan A.
Published: October 2020

Broadcast spawning invertebrates offer highly tractable models for evaluating sperm competition, gamete-level mate choice and sexual conflict. By displaying the ancestral mating strategy of external fertilization, where sexual selection is constrained to act after gamete release, broadcast spawners also offer potential evolutionary insights into the cascade of events that led to sexual reproduction in more ‘derived’ groups (including humans). Moreover, the dynamic reproductive conditions faced by these animals mean that the strength and direction of sexual selection on both males and females can vary considerably. These attributes make broadcast spawning invertebrate systems uniquely suited to testing, extending, and sometimes challenging classic and contemporary ideas in sperm competition, many of which were first captured in Parker's seminal papers on the topic. Here, we provide a synthesis outlining progress in these fields, and highlight the burgeoning potential for broadcast spawners to provide both evolutionary and mechanistic understanding into gamete-level sexual selection more broadly across the animal kingdom.

This article is part of the theme issue ‘Fifty years of sperm competition’.
Within-population sperm competition intensity does not predict asymmetry in conpopulation sperm precedence
Authors: Garlovsky Martin D. , Yusuf Leeban H. , Ritchie Michael G. , Snook Rhonda R.
Published: October 2020

Postcopulatory sexual selection can generate evolutionary arms races between the sexes resulting in the rapid coevolution of reproductive phenotypes. As traits affecting fertilization success diverge between populations, postmating prezygotic (PMPZ) barriers to gene flow may evolve. Conspecific sperm precedence is a form of PMPZ isolation thought to evolve early during speciation yet has mostly been studied between species. Here
,
we show conpopulation sperm precedence (CpSP) between
Drosophila montana
populations. Using Pool-seq genomic data we estimate divergence times and ask whether PMPZ isolation evolved in the face of gene flow. We find models incorporating gene flow fit the data best indicating populations experienced considerable gene flow during divergence. We find CpSP is asymmetric and mirrors asymmetry in non-competitive PMPZ isolation, suggesting these phenomena have a shared mechanism. However, we show asymmetry is unrelated to the strength of postcopulatory sexual selection acting within populations. We tested whether overlapping foreign and coevolved ejaculates within the female reproductive tract altered fertilization success but found no effect. Our results show that neither time since divergence nor sperm competitiveness predicts the strength of PMPZ isolation. We suggest that instead cryptic female choice or mutation-order divergence may drive divergence of postcopulatory phenotypes resulting in PMPZ isolation.

This article is part of the theme issue ‘Fifty years of sperm competition’.
Sperm competition and fertilization mode in fishes
Authors: Fitzpatrick John L.
Published: October 2020

Sperm competition is a powerful selective force that has shaped sexual traits throughout animal evolution. Yet, how fertilization mode (i.e. external versus internal fertilization) influences the scope and potential for sperm competition to act on ejaculates remains unclear. Here, I examine how fertilization mode shapes ejaculatory responses to sperm competition in fishes, a diverse group that constitute the majority of vertebrate biological diversity. Fishes are an ideal group for this examination because they exhibit a wide range of reproductive behaviours and an unparalleled number of transitions in fertilization mode compared to any other vertebrate group. Drawing on data from cartilaginous and bony fishes, I first show that rates of multiple paternity are higher in internally than externally fertilizing fishes, contrary to the prevailing expectation. I then summarize how sperm competition acts on sperm number and quality in internally and externally fertilizing fishes, highlighting where theoretical predictions differ between these groups. Differences in how ejaculates respond to sperm competition between fertilization modes are most apparent when considering sperm size and swimming performance. Clarifying how fertilization mode influences evolutionary responses in ejaculates will inform our understanding of ejaculate evolution across the animal tree of life.

This article is part of the theme issue ‘Fifty years of sperm competition’.
Sperm and alternative reproductive tactics: a review of existing theory and empirical data
Authors: Kustra Matthew C. , Alonzo Suzanne H.
Published: October 2020

Males that exhibit alternative reproductive tactics (ARTs) often differ in the risk of sperm competition and the energetic trade-offs they experience. The resulting patterns of selection could lead to between-tactic differences in ejaculate traits. Despite extensive research on male ARTs, there is no comprehensive review of whether and what differences in sperm traits exist between male ARTs. We review existing theory on ejaculate evolution relevant to ARTs and then conduct a comprehensive vote-counting review of the empirical data comparing sperm traits between males adopting ARTs. Despite the general expectation that sneaker males should produce sperm that are more competitive (e.g. higher quality or performance), we find that existing theory does not predict explicitly how males adopting ARTs should differ in sperm traits. The majority of studies find no significant difference in sperm performance traits between dominant and sneaker males. However, when there is a difference, sneaker males tend to have higher sperm performance trait values than dominant males. We propose ways that future theoretical and empirical research can improve our understanding of the evolution of ejaculate traits in ARTs. We then highlight how studying ejaculate traits in species with ARTs will improve our broader knowledge of ejaculate evolution.

This article is part of the theme issue ‘Fifty years of sperm competition’.
The role of female reproductive fluid in sperm competition
Authors: Gasparini Clelia , Pilastro Andrea , Evans Jonathan P.
Published: October 2020

The role of non-gametic components of the ejaculate (seminal fluid) in fertility and sperm competitiveness is now well established. Surprisingly, however, we know far less about female reproductive fluid (FRF) in the context of sexual selection, and insights into male–FRF interactions in the context of sperm competition have only recently emerged. Despite this limited knowledge, evidence from taxonomically diverse species has revealed insights into the effects of FRF on sperm traits that have previously been implicated in studies of sperm competition. Specifically, through the differential effects of FRF on a range of sperm traits, including chemoattraction and alterations in sperm velocity, FRF has been shown to exert positive phenotypic effects on the sperm of males that are preferred as mating partners, or those from the most compatible or genetically diverse males. Despite these tantalizing insights into the putative sexually selected functions of FRF, we largely lack a mechanistic understanding of these processes. Taken together, the evidence presented here highlights the likely ubiquity of FRF-regulated biases in fertilization success across a diverse range of taxa, thus potentially elevating the importance of FRF to other non-gametic components that have so far been studied largely in males.

This article is part of the theme issue ‘Fifty years of sperm competition'.
Temporal dynamics of competitive fertilization in social groups of red junglefowl (Gallus gallus) shed new light on avian sperm competition
Authors: Carleial Rômulo , McDonald Grant C. , Spurgin Lewis G. , Fairfield Eleanor A. , Wang Yunke , Richardson David S. , Pizzari Tommaso
Published: October 2020

Studies of birds have made a fundamental contribution to elucidating sperm competition processes, experimentally demonstrating the role of individual mechanisms in competitive fertilization. However, the relative importance of these mechanisms and the way in which they interact under natural conditions remain largely unexplored. Here, we conduct a detailed behavioural study of freely mating replicate groups of red junglefowl,Gallus gallus, to predict the probability that competing males fertilize individual eggs over the course of 10-day trials. Remating frequently with a female and mating last increased a male's probability of fertilization, but only for eggs ovulated in the last days of a trial. Conversely, older males, and those mating with more polyandrous females, had consistently lower fertilization success. Similarly, resistance to a male's mating attempts, particularly by younger females, reduced fertilization probability. After considering these factors, male social status, partner relatedness and the estimated state of male extragonadal sperm reserves did not predict sperm competition outcomes. These results shed new light on sperm competition dynamics in taxa such as birds, with prolonged female sperm storage and staggered fertilizations.

This article is part of the theme issue ‘Fifty years of sperm competition’.
Of mice and women: advances in mammalian sperm competition with a focus on the female perspective
Authors: Firman Renée C.
Published: October 2020

Although initially lagging behind discoveries being made in other taxa, mammalian sperm competition is now a productive and advancing field of research. Sperm competition in mammals is not merely a ‘sprint-race’ between the gametes of rival males, but rather a race over hurdles; those hurdles being the anatomical and physiological barriers provided by the female reproductive tract, as well as the egg and its vestments. With this in mind, in this review, I discuss progress in the field while focusing on the female perspective. I highlight ways by which sperm competition can have positive effects on female reproductive success and discuss how competitive outcomes are not only owing to dynamics between the ejaculates of rival males, but also attributable to mechanisms by which female mammals bias paternity toward favourable sires. Drawing on examples across different species—from mice to humans—I provide an overview of the accumulated evidence which firmly establishes that sperm competition is a key selective force in the evolution of male traits and detail how females can respond to increased sperm competitiveness with increased egg resistance to fertilization. I also discuss evidence for facultative responses to the sperm competition environment observed within mammal species. Overall, this review identifies shortcomings in our understanding of the specific mechanisms by which female mammals ‘select’ sperm. More generally, this review demonstrates how, moving forward, mammals will continue to be effective animal models for studying both evolutionary and facultative responses to sperm competition.

This article is part of the theme issue ‘Fifty years of sperm competition’.
Social status and ejaculate composition in the house mouse
Authors: Bayram Helen L. , Franco Catarina , Brownridge Philip , Claydon Amy J. , Koch Natalie , Hurst Jane L. , Beynon Robert J. , Stockley Paula
Published: October 2020

Sperm competition theory predicts that males should tailor ejaculates according to their social status. Here, we test this in a model vertebrate, the house mouse (Mus musculus domesticus), combining experimental data with a quantitative proteomics analysis of seminal fluid composition. Our analyses reveal that both sperm production and the composition of proteins found in seminal vesicle secretions differ according to social status. Dominant males invested more in ejaculate production overall. Their epididymides contained more sperm than those of subordinate or control males, despite similar testes size between the groups. Dominant males also had larger seminal vesicle glands than subordinate or control males, despite similar body size. However, the seminal vesicle secretions of subordinate males had a significantly higher protein concentration than those of dominant males. Moreover, detailed proteomic analysis revealed subtle but consistent differences in the composition of secreted seminal vesicle proteins according to social status, involving multiple proteins of potential functional significance in sperm competition. These findings have significant implications for understanding the dynamics and outcome of sperm competition, and highlight the importance of social status as a factor influencing both sperm and seminal fluid investment strategies.

This article is part of the theme issue ‘Fifty years of sperm competition’.
Anxiety Levels among Healthcare Professionals during Covid-19 Pandemic: A Multifactorial Study
Authors: Malik Arif , Hafeez Muhammad Mansoor , Waquar Sulayman , Rana Muhammad Asim , Alam Rabail
Published: October 2020

The current study focuses on psychological stress level among doctors, estimated by calculating anxiety score. For the assessment of anxiety levels, the GAD-7 scale was used. Chi-Square test and Odd ratios were calculated among the exposed and not exposed groups involved in the management of COVID-19 patients. Results revealed increased anxiety levels in the exposed group. Besides, the availability of personal protective equipment’s and stress from the family to quit the job were the substantial contributing factors that increased anxiety. Based on the results, it is proposed that the concern administrative authorities should consider these findings to facilitate medical healthcare professionals.
White blood cells and severe COVID-19: a Mendelian randomization study
Authors: Sun Yitang , Zhou Jingqi , Ye Kaixiong
Published: October 2020

Increasing evidence shows that white blood cells are associated with the risk of coronavirus disease 2019 (COVID-19), but the direction and causality of this association are not clear. To evaluate the causal associations between various white blood cell traits and the COVID-19 susceptibility and severity, we conducted two-sample bidirectional Mendelian Randomization (MR) analyses with summary statistics from the largest and most recent genome-wide association studies. Our MR results indicated causal protective effects of higher basophil count, basophil percentage of white blood cells, and myeloid white blood cell count on severe COVID-19, with odds ratios (OR) per standard deviation increment of 0.75 (95% CI: 0.60-0.95), 0.70 (95% CI: 0.54-0.92), and 0.85 (95% CI: 0.73-0.98), respectively. Neither COVID-19 severity nor susceptibility was associated with white blood cell traits in our reverse MR results. Genetically predicted high basophil count, basophil percentage of white blood cells, and myeloid white blood cell count are associated with a lower risk of developing severe COVID-19. Individuals with a lower genetic capacity for basophils are likely at risk, while enhancing the production of basophils may be an effective therapeutic strategy.
Modelling SARS-CoV-2 transmission in a UK university setting
Authors: Hill Edward M. , Atkins Benjamin D. , Keeling Matt J. , Tildesley Michael J. , Dyson Louise
Published: October 2020

Around 40% of school leavers in the UK attend university and individual universities generally host thousands of students each academic year. Bringing together these student communities during the COVID-19 pandemic may require strong interventions to control transmission. Prior modelling analyses of SARS-CoV-2 transmission within universities using compartmental modelling approaches suggest that outbreaks are almost inevitable.

We constructed a network-based model to capture the interactions of a student population in different settings (housing, social and study). For a single academic term of a representative campus-based university, we ran a susceptible-latent-infectious-recovered type epidemic process, parameterised according to available estimates for SARS-CoV-2. We investigated the impact of: adherence to (or effectiveness of) isolation and test and trace measures; room isolation of symptomatic students; and supplementary mass testing.

With all adhering to test, trace and isolation measures, we found that 22% (7% - 41%) of the student population could be infected during the autumn term, compared to 69% (56% - 76%) when assuming zero adherence to such measures. Irrespective of the adherence to isolation measures, on average a higher proportion of students resident on-campus became infected compared to students resident off-campus. Room isolation generated minimal benefits. Regular mass testing, together with high adherence to isolation and test and trace measures, could substantially reduce the proportion infected during the term compared to having no testing.

Our findings suggest SARS-CoV-2 may readily transmit in a university setting if there is limited ad-herence to nonpharmaceutical interventions and/or there are delays in receiving test results. Following isolation guidance and effective contact tracing curbed transmission and reduced the expected time an adhering student would spend in isolation.
COVID-19 in a Rural Health System in New York – Case Series and an Approach to Management
Authors: Kedar Eyal , Scott Regina , Soule Daniel , Lovelett Carly , Tower Kyle , Broughal Kylie , Jaremczuk Daniel , Mohaddes Sara , Rainey-Spence Imre , Atkinson Timothy
Published: October 2020

Background

Many rural hospitals and health systems in the U.S. lack sufficient resources to treat COVID-19. We developed a system for managing inpatient COVID-19 hospital admissions in St. Lawrence County, an underserved rural county which is the largest county in New York State.

Methods

We used a hub and spoke system to route COVID-19 patients in the St. Lawrence Health System to its flagship hospital. We assembled a small clinical team to manage admitted COVID-19 patients and to stay abreast of a quickly changing body of literature and standard of care. We subsequently completed a review of clinical data for patients who were treated by our inpatient COVID-19 treatment team between March 20 and May 22, 2020.

Results

Twenty COVID-19 patients were identified. Sixteen patients (80%) met NIH criteria for severe or critical disease. One patient died. No patients were transferred to other hospitals.

Conclusions

During the first two months of the pandemic, we were able to manage hospitalized COVID-19 patients in our rural community. Development of similar treatment models in other rural areas should be considered.
Aging and COVID-19 mortality: A demographic perspective
Authors: Sasson Isaac
Published: October 2020

Demographers have emphasized the importance of age in explaining the spread and impact on mortality of COVID-19. However, the relationship between COVID-19 with age should be contextualized in relation to other causes of death. This study set out to compare the age pattern of COVID-19 mortality with other major causes of death and across countries, and to use these regularities to impute age-specific death counts in countries with partial data. Using US vital Statistics, the COVID-19 mortality doubling time in a Gompertz context was compared with 65 major causes of death. COVID-19 fatality and mortality doubling times were similarly compared within and between 27 countries, using harmonized demographic databases of confirmed COVID-19 cases and deaths. Several findings are supported by the empirical evidence. First, COVID-19 mortality increases exponentially with age at a Gompertz rate near the median of aging-related causes of death, as well as pneumonia and influenza. Second, COVID-19 mortality levels are 2.8 to 8.2 times higher than pneumonia and influenza across the adult age range. Third, the relationship between both COVID-19 fatality and mortality with age varies considerably across countries. Fourth, COVID-19 deaths by age are imputed for Israel as a case in point. In conclusion, the increase in COVID-19 mortality with age resembles the population rate of aging. Country differences in the age pattern of COVID-19 fatality and mortality may point to differences in underlying population health, standards of clinical care, and data quality. This study underscores the need to contextualize the age pattern of COVID-19 mortality in relation to other causes of death.
Melatonin is significantly associated with survival of intubated COVID-19 patients
Authors: Ramlall Vijendra , Zucker Jason , Tatonetti Nicholas
Published: October 2020

Background

Respiratory distress requiring intubation is the most serious complication associated with coronavirus disease 2019 (COVID-19).

Methods

In this retrospective study, we used survival analysis to determine whether or not mortality following intubation was associated with hormone exposure in patients treated at New York Presbyterian/ Columbia University Irving Medical Center. Here, we report the overall hazards ratio for each hormone for exposure before and after intubation for intubated and mechanically ventilated patients.

Results

Among the 189,987 patients, we identified 948 intubation periods across 791 patients who were diagnosed with COVID-19 or infected with SARS-CoV2 and 3,497 intubation periods across 2,981 patients who were not. Melatonin exposure after intubation was statistically associated with a positive outcome in COVID-19 (demographics and comorbidities adjusted HR: 0.131, 95% CI: 7.76E-02 - 0.223, p-value = 8.19E-14) and non-COVID-19 (demographics and comorbidities adjusted HR: 0.278, 95% CI: 0.142 - 0.542, p-value = 1.72E-04) intubated patients. Additionally, melatonin exposure after intubation was statically associated with a positive outcome in COVID-19 patients (demographics and comorbidities adjusted HR: 0.127, 95% CI: 6.01E-02 - 0.269, p-value = 7.15E-08).

Conclusions

Melatonin exposure after intubation is significantly associated with a positive outcome in COVID-19 and non-COVID-19 patients. Additionally, melatonin exposure after intubation is significantly associated with a positive outcome in COVID-19 patients requiring mechanical ventilation. While our models account for many covariates, including clinical history and demographics, it is impossible to rule out confounding or collider biases within our population. Further study into the possible mechanism of this observation is warranted.
Life course air pollution exposure and cognitive decline: modelled historical air pollution data and the Lothian Birth Cohort 1936
Authors: Russ Tom C. , Cherrie Mark P. C. , Dibben Chris , Tomlinson Sam , Reis Stefan , Dragosits Ulrike , Vieno Massimo , Beck Rachel , Carnell Ed , Shortt Niamh K. , Muniz-Terrera Graciela , Redmond Paul , Taylor Adele M. , Clemens Tom , van Tongeren Martie , Agius Raymond M , Starr John M. , Deary Ian J. , Pearce Jamie R.
Published: October 2020

Background

Air pollution has been consistently linked with dementia and cognitive decline. However, it is unclear whether risk is accumulated through long-term exposure or whether there are sensitive/critical periods. A key barrier to clarifying this relationship is the dearth of historical air pollution data.

Objective

To demonstrate the feasibility of modelling historical air pollution data and using them in epidemiological models.

Methods

Using the EMEP4UK atmospheric chemistry transport model, we modelled historical fine particulate matter (PM2.5) concentrations for the years 1935, 1950, 1970, 1980, and 1990 and combined these with contemporary modelled data from 2001 to estimate life course exposure in 572 participants in the Lothian Birth Cohort 1936 with lifetime residential history recorded. Linear regression and latent growth models were constructed using cognitive ability (IQ) measured by the Moray House Test at the ages of 11, 70, 76, and 79 years to explore the effects of historical air pollution exposure. Covariates included sex, IQ at age 11 years, social class, and smoking.

Results

Higher air pollution modelled for 1935 (when participants would have been in utero) was associated with worse change in IQ from age 11-70 years (β=-0.006, SE=0.002, P=0.03) but not cognitive trajectories from age 70-79 years (P>0.05). There was no support for other critical/sensitive periods of exposure or an accumulation of risk (all P>0.05).

Conclusions

The life course paradigm is essential in understanding cognitive decline and this is the first study to examine life course air pollution exposure in relation to cognitive health.
Three-month outcomes in hospitalized COVID-19 patients
Authors: Savarraj Jude PJ , Burkett Angela B , Hinds Sarah N , Paz Atzhiry S , Assing Andres , Juneja Shivanki , Colpo Gabriela Delevati , Torres Luis F , Gusdon Aaron , McCullough Louise , Choi H Alex
Published: October 2020

COVID-19 is an ongoing pandemic with a devastating impact on public health. Acute neurological symptoms have been reported after a COVID-19 diagnosis, however there is no data available on the long-term neurological symptoms. Using a prospective registry of hospitalized COVID-19 patients, we assessed the neurological assessments (including functional, cognitive and psychiatric assessments) of several hospitalized patients at 3 months. Our main finding is that 71% of the patients still experienced neurological symptoms at 3 months and the most common symptoms being fatigue (42%) and PTSD (29%). 64% of the patients report pain symptoms we well. Cognitive symptoms were found in 12%. Our preliminary findings suggests the importance of investigating long-term and rationalizes the need for further studies investigating the neurologic outcomes after COVID-19.