bluuebunny/crossref_metadata_2025_split huggingface dataset:
Asymptomatic COVID-19 Have Longer Treatment Cycle Than Moderate Type of Confirmed Patients
Authors: Zhang Wei , Long Qinying , Huang Yanbiao , Chen Changju , Wu Jinhua , Hong Yang , Zhou Hourong , Wu Weidong 
Published: May 2020

ABSTRACTObjectivesA kind of pneumonia caused by unknown causes that occurred in Wuhan, Hubei, China in December 2019, was reported as a result of novel coronavirus infection on January 7, 2020, and then WHO named it COVID-19. To compare the difference of epidemiology and clinical characteristics between asymptomatic COVID-19 infections and moderate type of confirmed cases.MethodsRetrospective, single-center cohort study of COVID-19 involving 52 infections of both 26 asymptomatic and 26 moderate type of confirmed cases in the recovery stage at Guizhou Provincial Staff Hospital in Guiyang, China, from January 29, to March 31, 2020; final date of follow-up was April 22. This study was registered in Chinese Clinical Trial Registry Center. Documented the asymptomatic COVID-19 infections and moderate type of confirmed cases. Epidemiological, demographic, clinical, laboratory, radiological, and treatment data were collected and analyzed. Epidemiological and clinical characteristics of asymptomatic COVID-19 infections and moderate type of confirmed cases were compared.ResultsThe median treatment cycle of asymptomatic COVID-19 infections was 16 days (interquartile range, 11-20 days) and longer than 13 days (interquartile range, 10-15 days) of moderate type of confirmed cases (p=0.049). The median incubation period of asymptomatic COVID-19 infections was 10 days (interquartile range, 0-21 days), while the control group was 7 days (interquartile range, 1-15 days) (p=0.27). On the initial chest computerized tomography (CT) check, 18 (69.2%, 18/26) asymptomatic COVID-19 infections were no imaging changes, which was of no significance compared with 12 (46.2%, 12/26) patients with moderate type of confirmed patients (p=0.092).ConclusionsIn this single-center study, we found that asymptomatic COVID-19 infections have longer treatment cycle than those moderate type of confirmed cases.Key PointsIn this single-center case series involving 52 infections with asymptomatic and moderate type of COVID-19 cases, asymptomatic COVID-19 infections have longer treatment cycle than those moderate type of confirmed patients.
Identifying Explosive Epidemiological Cases with Unsupervised Machine Learning
Authors: Dolgikh Serge 
Published: May 2020

AbstractAn analysis of a combined dataset of epidemiological statistics of national and subnational jurisdictions, aligned at approximately two months after the first local exposure to Covid-19 with unsupervised machine learning methods such as PCA and deep autoencoder dimensionality reduction allows to clearly separate milder background cases from those with more rapid and aggressive onset of the epidemics. The analysis and findings of this study can be used in evaluation of possible epidemiological scenarios and as an effective modeling tool to design corrective and preventative measures to avoid developments with potentially heavy impact
Pathophysiological regulation of lung function by the free fatty acid receptor FFA4
Authors: Prihandoko Rudi , Kaur Davinder , Wiegman Coen H. , Alvarez-Curto Elisa , Donovan Chantal , Chachi Latifa , Ulven Trond , Tyas Martha R. , Euston Eloise , Dong Zhaoyang , Alharbi Abdulrahman Ghali M , Kim Richard , Lowe Jack G. , Hansbro Philip M. , Chung Kian Fan , Brightling Christopher E. , Milligan Graeme , Tobin Andrew B. 
Published: May 2020

AbstractIncreased prevalence of inflammatory airway diseases including asthma and chronic obstructive pulmonary disease (COPD) together with a significant number of patients being inadequately controlled by current frontline treatments means that there is a need to define novel therapeutic targets for these conditions1. Here we investigate a member of the G protein-coupled receptor (GPCR) family, FFA4, which responds to free circulating fatty acids, including dietary omega-3 fatty acids found in fish oils2–4. Although usually associated with metabolic responses linked with food intake, we show that FFA4 is expressed in the lung where it is coupled to Gq/11-signalling. Activation of FFA4 by drug-like agonists produced relaxation of murine airway smooth muscle mediated, at least in part, by the release of the prostaglandin PGE2that subsequently acts on EP2prostanoid receptors. In normal mice, activation of FFA4 resulted in a decrease in lung resistance. Importantly, in acute and chronic ozone models of pollution-mediated inflammation, and in house-dust mite and cigarette smoke-induced inflammatory disease, FFA4 agonists acted to reduce airway resistance, whilst this response was absent in mice lacking expression of FFA4. The expression profile of FFA4 in human lung was very similar to that observed in mice and the response to FFA4/FFA1 agonists similarly mediated human airway smooth muscle relaxation. Hence, our study provides evidence that pharmacological targeting of lung FFA4, and possibly combined activation of FFA4 and FFA1, hasin vivoefficacy that might have therapeutic value in the treatment of bronchoconstriction associated with inflammatory airway diseases such as asthma and COPD.
Cardiac MRI in common marmosets revealing age-dependency of cardiac function
Authors: Moussavi Amir , Mietsch Matthias , Drummer Charis , Behr Rüdiger , Mylius Judith , Boretius Susann 
Published: May 2020

The aim of this study was to establish a feasible and robust magnetic resonance imaging protocol for the quantitative assessment of cardiac function in marmosets and to present normal values of cardiac function across different ages from young adult, middle-aged, to very old clinically healthy animals.Cardiac MRI of 33 anesthetized marmosets at the age of 2-15 years was performed at 9.4 T using IntraGate-FLASH that operates without any ECG-triggering and breath holding. Normalized to post-mortem heart weight, the left ventricular end-diastolic volume (LV-EDV) was significantly reduced in older marmosets. The LV end-systolic volume (LV-ESV) and the LV stroke volume (LV-SV) showed a similar trend while the LV ejection fraction (LV-EF) and wall thickening remained unchanged. Similar observations were made for the right ventricle. Moreover, the total ventricular myocardial volume was lower in older monkeys while no significant difference in heart weight was found.In conclusion, IntraGate-FLASH allowed for quantification of left ventricular cardiac function but seems to underestimate the volumes of the right ventricle. Although less strong and without significant sex differences, the observed age related changes were similar to previously reported findings in humans supporting marmosets as a model system for age related cardiovascular human diseases.
AlteredN-glycan composition impacts flagella mediated adhesion inChlamydomonas reinhardtii
Authors: Xu Nannan , Oltmanns Anne , Zhao Longsheng , Girot Antoine , Karimi Marzieh , Hoepfner Lara , Kelterborn Simon , Scholz Martin , Beißel Julia , Hegemann Peter , Bäumchen Oliver , Liu Luning N. , Huang Kaiyao , Hippler Michael 
Published: May 2020

AbstractFor the unicellular algaChlamydomonas reinhardtii, the presence ofN-glycosylated proteins on the surface of two flagella is crucial for both cell-cell interaction during mating and flagellar surface adhesion. It is unknown whether the composition ofN-glycans attached to respective proteins is important for these processes. To this end, we examined severalC. reinhardtiiinsertional mutants and a CRIPSR/Cas9 knockout mutant of xylosyltransferase 1A, all possessing alteredN-glycan compositions. Taking advantage of atomic force microscopy and micropipette force measurements, our data revealed that reduction inN-glycan complexity impedes the adhesion force required for binding the flagella to surfaces. In addition, polystyrene bead binding and transport is impaired. Notably, assembly, Intraflagellar Transport and FMG-1B transport into flagella are not affected by alteredN-glycosylation. Thus, we conclude that properN-glycosylation of flagellar proteins is crucial for adheringC. reinhardtiicells onto surfaces, indicating thatN-glycans mediate surface adhesion via direct surface contact.
Widening the bottleneck: Heterologous expression, purification, and characterization of theKtedonobacter racemiferminimal type II polyketide synthase inEscherichia coli
Authors: Klein Joshua G. , Wu Yang , Kokona Bashkim , Charkoudian Louise K. 
Published: May 2020

AbstractEnzyme assemblies such as type II polyketide synthases (PKSs) produce a wide array of bioactive secondary metabolites. While the molecules produced by type II PKSs have found remarkable success in the clinic, the biosynthetic prowess of these enzymes has been stymied by: 1) the inability to reconstitute the bioactivity of the minimal PKS enzymesin vitroand 2) limited exploration of type II PKSs from diverse phyla. Towards filling this unmet need, we expressed, purified, and characterized the ketosynthase chain length factor (KSCLF) and acyl carrier protein (ACP) fromKtedonobacter racemifer. UsingE. colias a heterologous host, we obtained soluble proteins in titers representing significant improvements over previous KSCLF heterologous expression efforts. Characterization of these enzymes reveals thatKrACP has self-malonylating activity. Sedimentation velocity analytical ultracentrifugation (SV-AUC) analysis ofholo-KrACP andKrKSCLF indicates that these enzymes do not interactin vitro, suggesting that the acylated state of these proteins might play an important role in facilitating biosynthetically relevant interactions. Given the potential impact of obtaining soluble core type II PKS biosynthetic enzymes to enablein vitrocharacterization studies, these results lay important groundwork for optimizing the interaction betweenKrKSCLF andKrACP and exploring the biosynthetic potential of other non-actinomycete type II PKSs.
Changes in RT-PCR-positive SARS-CoV-2 rates in adults and children according to the epidemic stages
Authors: Levy Corinne , Basmaci Romain , Bensaid Philippe , Bru Cécile Bost , Coinde Edeline , Dessioux Emmanuelle , Fournial Cécile , Gashignard Jean , Haas Hervé , Hentgen Véronique , Huet Frédéric , Lalande Muriel , Martinot Alain , Pons Charlotte , Romain Anne Sophie , Ursulescu Nicoleta , Sage François Vie Le , Raymond Josette , Béchet Stéphane , Toubiana Julie , Cohen Robert 
Published: May 2020

AbstractAimTo describe the trends of RT-PCR positive SARS-CoV-2 rates in children and adults according to the time of COVID-19 epidemic.MethodsIn this prospective multicenter study involving 45 pediatric units, we collected the results of nasopharyngeal swabs in France from March 2, 2020 to April 26, 2020.ResultsDuring the study period, 52,588 RT-PCR tests for SARS-CoV-2 were performed, 6,490 in children and 46,098 in adults. The risk ratio of RT-PCR positive SARS-CoV-2 tests for adults compared to children was 3.5 (95% CI [3.2;3.9]) for the whole study period. These rates varied according to the time of the epidemic and were higher at the peak. The lower rates of positive test in children persisted during the surveillance period but varied according to the time in the epidemic.ConclusionThe rate of positive RT-PCR positive SARS-CoV-2 tests for children was always less than that for adults but vary according to the epidemic stage.
The impact of adaptive mosquito behavior and insecticide-treated nets on malaria prevalence
Authors: Ngonghala Calistus N. , Wairimu Josephine , Adamski Jesse , Desai Hardik 
Published: May 2020

AbstractMalaria prevalence in sub-Saharan Africa remains high. Kenya for example, records about 3.5 million new cases and 11 thousand deaths each year [1]. Most of these cases and deaths are among children under five. The main control method in malaria endemic regions has been through the use of pyrethroid-treated bed nets. Although this approach has been fairly successful, the gains are threatened by mosquito-resistance to pyrethroids, physical and chemical degradation of ITNs that reduce their efficacy, inconsistent and improper use by humans, etc. We present a model to investigate the effects of insecticide-treated bed-net use and mosquito-resistance and adaptation to pyrethroids used to treat bed nets on malaria prevalence and control in malaria endemic regions. The model captures the development and loss of resistance to insecticides, the effects of bed-net use on malaria control in a setting where proper and consistent use is not guaranteed, as well as differentiated biting of human hosts by resistant and sensitive mosquitoes. Important thresholds, including the basic reproduction number R0, and two parameter groupings that are important for disease control and for establishing the existence of endemic equilibria to the model are calculated. Furthermore, a global sensitivity analysis is carried out to identify important parameters such as insecticide treated bed-net coverage, insecticide treated bed-net efficacy, the maximum biting rate of resistant mosquitoes, etc., that drive the system and that can be targeted for disease control. Threshold levels of bed-net coverage and bed-net efficacy required for containing the disease are identified and shown to depend on the type of insecticide-resistance. For example, when mosquito-resistance to insecticides is not permanent and is acquired only through recruitment and the efficacy of insecticide-treated nets is 90%, about 70% net coverage is required to contain malaria. However, for the same insecticide-treated net efficacy, i.e., 90%, approximately 93% net coverage is required to contain the disease when resistance to insecticides is permanent and is acquired through recruitment and mutation in mosquitoes. The model exhibits a backward bifurcation, which implies that simply reducing R0 slightly below unity might not be enough to contain the disease. We conclude that appropriate measures to reduce or eliminate mosquito-resistance to insecticides, ensure that more people in endemic areas own and use insecticide-treated nets properly, and that the efficacy of these nets remain high most of the times, as well as educating populations in malaria endemic areas on how to keep mosquito densities low and minimize mosquito bites are important for containing malaria.
Going by the Numbers : Learning and Modeling COVID-19 Disease Dynamics
Authors: Basu Sayantani , Campbell Roy H. 
Published: May 2020

ABSTRACTThe COrona VIrus Disease (COVID-19) pandemic caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV2) has resulted in a challenging number of infections and deaths worldwide. In order to combat the pandemic, several countries worldwide enforced mitigation measures in the forms of lockdowns, social distancing and disinfection measures. In an effort to understand the dynamics of this disease, we propose a Long Short Term Memory (LSTM) based model. We train our model on nearly four months of cumulative COVID-19 cases and deaths. Our model can be adjusted based on the parameters in order to provide predictions as needed. We provide results at both the country and county levels. We also perform a quantitative comparison of mitigation measures in various counties in the United States based on the rate of difference of a short and long window parameter of the proposed LSTM model. The analyses provided by our model can provide valuable insights based on the trends in the rate of infections and deaths. This can also be of help for countries and counties deciding on mitigation and reopening strategies. We believe that the results obtained from the proposed method will contribute to societal benefits for a current global concern.
The iron-responsive genome of the chitonAcanthopleura granulata
Authors: Varney Rebecca M. , Speiser Daniel I. , McDougall Carmel , Degnan Bernard M. , Kocot Kevin M. 
Published: May 2020

ABSTRACTMolluscs biomineralize structures that vary in composition, form, and function, prompting questions about the genetic mechanisms responsible for their production and the evolution of these mechanisms. Chitons (Mollusca, Polyplacophora) are a promising system for studies of biomineralization because they build a range of calcified structures including shell plates and spine- or scale-like sclerites. Chitons also harden the calcified teeth of their rasp-like radula with a coat of iron (as magnetite). Here we present the genome of the West Indian fuzzy chitonAcanthopleura granulata, the first from any aculiferan mollusc. TheA. granulatagenome contains homologs of many biomineralization genes identified previously in conchiferan molluscs. We expected chitons to lack genes previously identified from pathways conchiferans use to make biominerals like calcite and nacre because chitons do not use these materials in their shells. Surprisingly, theA. granulatagenome has homologs of many of these genes, suggesting that the ancestral mollusc had a more diverse biomineralization toolkit than expected. TheA. granulatagenome has features that may be specialized for iron biomineralization, including a higher proportion of genes regulated directly by iron than other molluscs.A. granulataalso produces two isoforms of soma-like ferritin: one is regulated by iron and similar in sequence to the soma-like ferritins of other molluscs, and the other is constitutively translated and is not found in other molluscs. TheA. granulatagenome is a resource for future studies of molluscan evolution and biomineralization.SIGNIFICANCE STATEMENTChitons are molluscs that make shell plates, spine- or scale-like sclerites, and iron-coated teeth. Currently, all molluscs with sequenced genomes lie within one major clade (Conchifera). Sequencing the genome of a representative from the other major clade (Aculifera) helps us learn about the origins and evolution of molluscan traits. The genome of the West Indian Fuzzy Chiton,Acanthopleura granulata, reveals chitons have homologs of many genes other molluscs use to make shells, suggesting all molluscs share some shell-making pathways. The genome ofA. granulatahas more genes that may be regulated directly by iron than other molluscs, and chitons produce a unique isoform of a major iron-transport protein (ferritin), suggesting that chitons have genomic specializations that contribute to their production of iron-coated teeth.
Transient resting-state network dynamics in cognitive ageing
Authors: Tibon Roni , Tsvetanov Kamen , Price Darren , Nesbitt David ,   Cam-CAN, Henson Richard 
Published: May 2020

AbstractIt is important to maintain cognitive function in old age, yet the neural substrates that support successful cognitive ageing remain unclear. One factor that might be crucial, but has been overlooked due to limitations of previous data and methods, is the ability of brain networks to flexibly reorganise and coordinate over a millisecond time-scale. Magnetoencephalography (MEG) provides such temporal resolution, and can be combined with Hidden Markov Models (HMMs) to characterise transient neural states. We applied HMMs to resting-state MEG data from a large cohort (N=594) of population-based adults (aged 18-88), who also completed a range of cognitive tasks. Using multivariate analysis of neural and cognitive profiles, we found that decreased occurrence of “lower-order” brain networks, coupled with increased occurrence of “higher-order” networks, was associated with both increasing age and impaired fluid intelligence. These results favour theories of age-related reductions in neural efficiency over current theories of age-related functional compensation.
Presence of a resident species aids invader evolution
Authors: Lachapelle Josianne , Bestion Elvire , Jackson Eleanor E , Schaum C-Elisa 
Published: May 2020

AbstractPhytoplankton populations are intrinsically large and genetically variable, and interactions between species in these populations shape their physiological and evolutionary responses. Yet, evolutionary responses of microbial organisms in novel environments are investigated almost exclusively through the lens of species colonising new environments on their own, and invasion studies are often of short duration. Although exceptions exist, neither type of study usually measures ecologically relevant traits beyond growth rates. Here, we experimentally evolved populations of fresh- and seawater phytoplankton as monocultures (the green algaeChlamydomonas moewusiiandOstreococcus tauri, each colonising a novel, unoccupied salinity) and co-cultures (invading a novel salinity occupied by a resident species) for 200 generations. Colonisers and invaders differed in extinction risks, phenotypes (e.g. size, primary production rates) and strength of local adaptation: invaders had systematically lower extinction rates and broader salinity and temperature preferences than colonisers – regardless of the environment that the invader originated from. We emphasise that the presence of a locally adapted species has the potential to alter the invading species’ eco-evolutionary trajectories in a replicable way across environments of differing quality, and that the evolution of small cell size and high ROS tolerance may explain high invader fitness. To predict phytoplankton responses in a changing world, such interspecific relationships need to be accounted for.
Poultry farmer response to disease outbreaks in smallholder farming systems
Authors: Delabouglise Alexis , Le Thanh Nguyen Thi , Ai Xuyen Huynh Thi , Nguyen-Van-Yen Benjamin , Tuyet Phung Ngoc , Lam Ha Minh , Boni Maciej F. 
Published: May 2020

AbstractAvian influenza outbreaks have been occurring on smallholder poultry farms in Asia for two decades. Farmer responses to these outbreaks can slow down or accelerate virus transmission. We used a longitudinal survey of 53 small-scale chicken farms in southern Vietnam to investigate the impact of outbreaks with disease-induced mortality on harvest rate, vaccination, and disinfection behaviors. We found that in small broiler flocks (≤16 birds/flock) the estimated probability of harvest was 56% higher when an outbreak occurred, and 214% higher if an outbreak with sudden deaths occurred in the same month. Vaccination and disinfection were strongly positively correlated with flock size and farm size, respectively. Small-scale farmers – the overwhelming majority of poultry producers in low-income countries – tend to rely on rapid sale of birds to mitigate losses from diseases. As depopulated birds are sent to markets or trading networks, this reactive behavior has the potential to enhance onward transmission.One sentence summaryA cohort study of fifty three small-scale poultry farms in southern Vietnam reveals that when outbreaks occur with symptoms similar to highly pathogenic avian influenza, farmers respond by sending their chickens to market early, potentially exacerbating the effects of the outbreak.
Examining Blunted Initial Response to Reward and Recent Suicidal Ideation in Children and Adolescents Using Event-Related Potentials: Failure to Conceptually Replicate Across Two Independent Samples
Authors: Gallyer Austin J. , Burani Kreshnik , Mulligan Elizabeth M. , Santopetro Nicholas , Dougherty Sean P. , Jeon Min Eun , Nelson Brady D. , Joiner Thomas E. , Hajcak Greg 
Published: May 2020

AbstractA recent study by Tsypes and colleagues (2019) found that children with recent suicidal ideation had blunted neural reward processing, as measured by the reward positivity (RewP), compared to matched controls, and that this difference was driven by reduced neural responses to monetary loss, rather than to reward. Here, we aimed to conceptually replicate and extend these findings in two samples (n= 264, 27 with suicidal ideation; andn= 314, 49 with suicidal ideation at baseline) of children and adolescents (11 to 15 years and 8 to 15 years, respectively). Results from both samples showed no evidence that children and adolescents with suicidal ideation have abnormal reward or loss processing, nor that reward processing predicts suicidal ideation two years later. The results highlight the need for greater statistical power, as well as continued research examining the neural underpinnings of suicidal thoughts and behaviors.