bluuebunny/crossref_metadata_2025 huggingface dataset:
The face module emerged in a deep convolutional neural network selectively deprived of face experience
Authors: Xu Shan , Zhang Yiyuan , Zhen Zonglei , Liu Jia
Published: July 2020

Can we recognize faces with zero experience on faces? This question is critical because it examines the role of experiences in the formation of domain-specific modules in the brain. Investigation with humans and non-human animals on this issue cannot easily dissociate the effect of the visual experience from that of the hardwired domain-specificity. Therefore the present study built a model of selective deprivation of the experience on faces with a representative deep convolutional neural network, AlexNet, by removing all images containing faces from its training stimuli. This model did not show significant deficits in face categorization and discrimination, and face-selective modules automatically emerged. However, the deprivation reduced the domain-specificity of the face module. In sum, our study provides undisputable evidence on the role of nature versus nurture in developing the domain-specific modules that domain-specificity may evolve from non-specific experience without genetic predisposition, and is further fine-tuned by domain-specific experience.
Integration of high-density genetic mapping with transcriptome analysis uncovers numerous agronomic QTL and reveals candidate genes for the control of tillering in sorghum
Authors: Govindarajulu Rajanikanth , Henderson Ashley N. , Xiao Yuguo , Chaluvadi Srinivasa R. , Mauro-Herrera Margarita , Siddoway Muriel L. , Whipple Clinton , Bennetzen Jeffrey L. , Devos Katrien M. , Doust Andrew N. , Hawkins Jennifer S.
Published: July 2020

Phenotypes such as branching, photoperiod sensitivity, and height were modified during plant domestication and crop improvement. Here, we perform quantitative trait locus (QTL) mapping of these and other agronomic traits in a recombinant inbred line (RIL) population derived from an interspecific cross betweenSorghum propinquumandSorghum bicolorinbred Tx7000. Using low-coverage Illumina sequencing and a bin-mapping approach, we generated ~1920 bin markers spanning ~875 cM. Phenotyping data were collected and analyzed from two field locations and one greenhouse experiment for six agronomic traits, thereby identifying a total of 30 QTL. Many of these QTL were penetrant across environments and co-mapped with major QTL identified in other studies. Other QTL uncovered new genomic regions associated with these traits, and some of these were environment-specific in their action. To further dissect the genetic underpinnings of tillering, we complemented QTL analysis with transcriptomics, identifying 6189 genes that were differentially expressed during tiller bud elongation. We identified genes such as Dormancy Associated Protein 1 (DRM1) in addition to various transcription factors that are differentially expressed in comparisons of dormant to elongating tiller buds and lie within tillering QTL, suggesting that these genes are key regulators of tiller elongation in sorghum. Our study demonstrates the usefulness of this RIL population in detecting domestication and improvement-associated genes in sorghum, thus providing a valuable resource for genetic investigation and improvement to the sorghum community.
A chromosome level genome ofAstyanax mexicanussurface fish for comparing population-specific genetic differences contributing to trait evolution
Authors: Warren Wesley C. , Boggs Tyler E. , Borowsky Richard , Carlson Brian M. , Ferrufino Estephany , Gross Joshua B. , Hillier LaDeana , Hu Zhilian , Keene Alex C. , Kenzior Alexander , Kowalko Johanna E. , Tomlinson Chad , Kremitzki Milinn , Lemieux Madeleine E. , Graves-Lindsay Tina , McGaugh Suzanne E. , Miller Jeff T. , Mommersteeg Mathilda , Moran Rachel L. , Peuß Robert , Rice Edward , Riddle Misty R. , Sifuentes-Romero Itzel , Stanhope Bethany A. , Tabin Clifford J. , Thakur Sunishka , Yoshiyuki Yamamoto , Rohner Nicolas
Published: July 2020

Identifying the genetic factors that underlie complex traits is central to understanding the mechanistic underpinnings of evolution. In nature, adaptation to severe environmental change, such as encountered following colonization of caves, has dramatically altered genomes of species over varied time spans. Genomic sequencing approaches have identified mutations associated with troglomorphic trait evolution, but the functional impacts of these mutations remain poorly understood. The Mexican Tetra,Astyanax mexicanus, is abundant in the surface waters of northeastern Mexico, and also inhabits at least 30 different caves in the region. Cave-dwellingA. mexicanusmorphs are well adapted to subterranean life and many populations appear to have evolved troglomorphic traits independently, while the surface-dwelling populations can be used as a proxy for the ancestral form. Here we present a high-resolution, chromosome-level surface fish genome, enabling the first genome-wide comparison between surface fish and cavefish populations. Using this resource, we performed quantitative trait locus (QTL) mapping analyses for pigmentation and eye size and found new candidate genes for eye loss such asdusp26. We used CRISPR gene editing inA. mexicanusto confirm the essential role of a gene within an eye size QTL,rx3, in eye formation. We also generated the first genome-wide evaluation of deletion variability that includes an analysis of the impact on protein-coding genes across cavefish populations to gain insight into this potential source of cave adaptation. The new surface fish genome reference now provides a more complete resource for comparative, functional, developmental and genetic studies of drastic trait differences within a species.
Copy numbers of 45S and 5S ribosomal DNA arrays lack meaningful correlation in humans
Authors: Hall Ashley N. , Turner Tychele N. , Queitsch Christine
Published: July 2020

The ribosomal DNA genes are tandemly arrayed in most eukaryotes and exhibit vast copy number variation. There is growing interest in integrating this variation into genotype-phenotype associations. Here, we explored a possible association of rDNA copy number variation with autism spectrum disorder and found no difference between probands and unaffected siblings. However, rDNA copy number estimates from whole genome sequencing are error-prone, so we sought to use pulsed-field gel electrophoresis, a classic gold-standard method, to validate rDNA copy number genotypes. The electrophoresis approach is not readily applicable to the human 45S arrays due to their size and location on five separate chromosomes; however, it should accurately resolve copy numbers for the shorter 5S arrays that reside on a single chromosome. Previous studies reported tightly correlated, concerted copy number variation between the 45S and 5S arrays, which should enable the validation of 45S copy number estimates with CHEF-gel-verified 5S copy numbers. Here, we show that the previously reported strong concerted copy number variation is likely an artifact of variable data quality in the earlier published 1000 Genomes Project sequences. We failed to detect a meaningful correlation between 45S and 5S copy numbers in the large, high-coverage Simons Simplex Collection dataset as well as in the recent high-coverage 1000 Genomes Project sequences. Our findings illustrate the challenge of genotyping repetitive DNA regions accurately and call into question the accuracy of recently published studies of rDNA copy number variation in cancers and aging that relied on diverse publicly available resources for sequence data.
Nuclear Pif1 is Post Translationally Modified and Regulated by Lysine Acetylation
Authors: Ononye Onyekachi E. , Sausen Christopher W. , Balakrishnan Lata , Bochman Matthew L.
Published: July 2020

InS. cerevisiae, the Pif1 helicase functions to impact both nuclear and mitochondrial DNA replication and repair processes. Pif1 is a 5’-3’ helicase, which preferentially unwinds RNA-DNA hybrids and resolves G-quadruplex structures. Further, regulation of Pif1 by phosphorylation negatively impacts its interaction with telomerase during double strand break repair. Here, we report that in addition to phosphorylation, Pif1 is also modified by lysine acetylation, which influences both its cellular and core biochemical activities. Using Pif1 overexpression toxicity assays, we determined that the acetyltransferase NuA4 (Esa1) and deacetylase Rpd3 are primarily responsible for dynamically acetylating nuclear Pif1. Mass spectrometry analysis revealed that Pif1 was modified throughout the protein’s sequence on the N-terminus (K118, K129), helicase domain (K525, K639, K725), and C-terminus (K800). Acetylation of Pif1 exacerbated its overexpression toxicity phenotype, which was alleviated upon deletion of its N-terminus. Biochemical assays demonstrated that acetylation of Pif1 stimulated its helicase activity, while maintaining its substrate preferences. Additionally, both the ATPase and DNA binding activities of Pif1 were stimulated upon acetylation. Limited proteolysis assays indicate that acetylation of Pif1 induces a conformational change that may account for its altered enzymatic properties. We propose an acetylation-based model for the regulation of Pif1 activities, addressing how this post translational modification can influence its role as a key player in a multitude of DNA transactions vital to the maintenance of genome integrity.
Oral Regeneration Is the Default Pathway Triggered by Injury inHydra
Authors: Cazet Jack , Juliano Celina
Published: July 2020

In animals capable of whole-body regeneration, a single bisection injury can trigger two different types of regeneration. Currently, it is not well understood how this adaptive response is transcriptionally regulated. We therefore comprehensively characterized transcript abundance and chromatin accessibility during two types of regeneration—oral and aboral regeneration—in the cnidarianHydra vulgaris. We found that there was an initial generalized response to injury that was not dependent on the type of structure being regenerated. Canonical Wnt signaling, which specifies oral tissue in cnidarians, was activated during this generalized response, likely through the direct upregulation of Wnt ligands by conserved injury-responsive transcription factors. As regeneration progressed, transcription diverged and Wnt signaling became restricted to oral regeneration. We found that TCF, the transcription factor downstream of Wnt signaling, was required for the initiation of oral and aboral-specific transcription, suggesting that the Wnt pathway is important for both types of regeneration. Finally, we found that Wnt signaling was also activated by puncture wounds and that removing pre-existing organizers induced these injuries to undergo ectopic head regeneration. Our work suggests that injuries activate an oral regeneration program, and that other regeneration outcomes are caused by signals from the surrounding tissue. Furthermore, these findings suggest that Wnt signaling may be part of an ancient and conserved metazoan wound response program predating the split of cnidarians and bilaterians.
Virulent disease epidemics can increase host density by depressing foraging of hosts
Authors: Penczykowski Rachel M. , Hall Spencer R. , Shocket Marta S. , Ochs Jessica Housley , Lemanski Brian C. P. , Sundar Hema , Duffy Meghan A.
Published: July 2020

All else equal, parasites that harm host fitness should depress densities of their hosts. However, parasites that alter host traits may increase host density via indirect ecological interactions. Here, we show how depression of infected host foraging rate can produce such a hydra effect. Using a foraging assay, we quantified reduced foraging rates of a zooplankton host infected with a virulent fungal parasite. We then parameterized a dynamical model of hosts, parasites, and resources with this foraging function, showing how foraging depression can create a hydra effect. Mathematically, the hydra arose when increased resource productivity exceeded any increase in resource consumption per host. Therefore, the foraging-mediated hydra effect more likely emerged (1) for hosts which strongly control logistic-like resources and (2) during larger epidemics of moderately virulent parasites. We then analyzed epidemics from 13 fungal epidemics in nature. We found evidence for a foraging-mediated hydra effect: large outbreaks depressed foraging rate and correlated with increased densities of both algae and hosts. Therefore, depression of foraging rate of infected hosts can produce higher host densities even during epidemics of parasites that increase host mortality. Such hydras might prevent collapse of host populations but also could produce higher densities of infected hosts.
Mutational signatures and heterogeneous host response revealed via large-scale characterization of SARS-CoV-2 genomic diversity
Authors: Graudenzi Alex , Maspero Davide , Angaroni Fabrizio , Piazza Rocco , Ramazzotti Daniele
Published: July 2020

Abstract

To dissect the mechanisms underlying the inflation of variants in the SARS-CoV-2 genome, we present one of the largest up-to-date analyses of intra-host genomic diversity, which reveals that most samples present heterogeneous genomic architectures, due to the interplay between host-related mutational processes and transmission dynamics.

The deconvolution of the set of intra-host minor variants unveils the existence of non overlapping mutational signatures related to specific nucleotide substitutions, which prove that distinct hosts respond differently to SARS-CoV-2 infections, and which are likely ruled by APOBEC, Reactive Oxygen Species (ROS) and ADAR.

Thanks to a corrected-for-signaturesdN/dSanalysis we demonstrate that the mutational processes underlying such signatures are affected by purifying selection, with important exceptions. In fact, several mutations linked to low-rate mutational processes appear to transit to clonality in the population, eventually leading to the definition of new clonal genotypes and to a statistically significant increase of overall genomic diversity.

Importantly, the analysis of the phylogenetic model shows the presence of multiple homoplasies, due to mutational hotspots, phantom mutations or positive selection, and supports the hypothesis of transmission of minor variants during infections. Overall, the results of this study pave the way for the integrated characterization of intra-host genomic diversity and clinical outcome of SARS-CoV-2 hosts.
High-throughput cultivation of stable, diverse, fecal-derived microbial communities to model the intestinal microbiota
Authors: Aranda-Díaz Andrés , Ng Katharine Michelle , Thomsen Tani , Real-Ramírez Imperio , Dahan Dylan , Dittmar Susannah , Gonzalez Carlos Gutierrez , Chavez Taylor , Vasquez Kimberly S. , Nguyen Taylor H. , Yu Feiqiao Brian , Higginbottom Steven K. , Neff Norma F. , Elias Joshua E. , Sonnenburg Justin L. , Huang Kerwyn Casey
Published: July 2020

Mechanistic understanding of the impacts of the gut microbiota on human health has been hampered by limited throughput in animal models. To enable systematic interrogation of gut-relevant microbial communities, here we generated hundreds ofin vitrocommunities cultured from diverse stool samples in various media. Species composition revealed stool-derived communities that are phylogenetically complex, diverse, stable, and highly reproducible. Community membership depended on both medium and initial inoculum, with certain media preserving inoculum compositions. Different inocula yielded different community compositions, indicating their potential for personalized therapeutics. Communities were robust to freezing and large-volume culturing, enabling future translational applications. Defined communities were generated from isolates and reconstituted growth and composition similar to those of communities derived from stool inocula. Finally,in vitroexperiments probing the response to ciprofloxacin successfully predicted many changes observedin vivo, including the resilience and sensitivity of eachBacteroidesspecies. Thus, stool-derivedin vitrocommunities constitute a powerful resource for microbiota research.
Inflammation Drives Alternative First Exon usage to Regulate Immune Genes including a Novel Iron Regulated Isoform of Aim2
Authors: Robinson Elektra K. , Jagannatha Pratibha , Covarrubias Sergio , Cattle Matthew , Safavi Rojin , Song Ran , Viswanathan Kasthuribai , Shapleigh Barbara , Abu-Shumays Robin , Jain Miten , Cloonan Suzanne M. , Wakeland Edward , Akeson Mark , Brooks Angela N. , Carpenter Susan
Published: July 2020

Determining the layers of gene regulation within the innate immune response is critical to our understanding of the cellular responses to infection and dysregulation in disease. We identified a conserved mechanism of gene regulation in human and mouse via changes in alternative first exon (AFE) usage following inflammation, resulting in changes to isoform usage. Of these AFE events, we identified 50 unannotated transcription start sites (TSS) in mice using Oxford Nanopore native RNA sequencing, one of which is the cytosolic receptor for dsDNA and known inflammatory inducible gene,Aim2. We show that this unannotated AFE isoform ofAim2is the predominant isoform transcribed during inflammation and contains an iron-responsive element in its 5′UTR enabling mRNA translation to be regulated by iron levels. This work highlights the importance of examining alternative isoform changes and translational regulation in the innate immune response and uncovers novel regulatory mechanisms ofAim2.

Summary Sentence

Alternative first exon usage was the major splicing event observed in macrophages during inflammation, which resulted in the elucidation of a novel isoform and iron mediated regulatory mechanism of the protein coding gene,Aim2.
Discovery of Drug-like Ligands for the Mac1 Domain of SARS-CoV-2 Nsp3
Authors: Virdi Rajdeep S. , Bavisotto Robert V. , Hopper Nicholas C. , Vuksanovic Nemanja , Melkonian Trevor R. , Silvaggi Nicholas R. , Frick David N.
Published: July 2020

Small molecules that bind the SARS-CoV-2 non-structural protein 3 Mac1 domain in place of ADP-ribose could be useful as molecular probes or scaffolds for COVID-19 antiviral drug discovery because Mac1 has been linked to coronavirus’ ability to evade cellular detection. A high-throughput assay based on differential scanning fluorimetry (DSF) was therefore optimized and used to identify possible Mac1 ligands in small libraries of drugs and drug-like compounds. Numerous promising compounds included nucleotides, steroids, beta-lactams, and benzimidazoles. The main drawback to this approach was that a high percentage of compounds in some libraries were found to influence the observed Mac1 melting temperature. To prioritize DSF screening hits, the shapes of the observed melting curves and initial assay fluorescence were examined, and the results were compared with virtual screens performed using Autodock VINA. The molecular basis for alternate ligand binding was also examined by determining a structure of one of the hits, cyclic adenosine monophosphate, with atomic resolution.
Growth of tumor emboli within a vessel model reveals dependence on the magnitude of mechanical constraint
Authors: Kulwatno Jonathan , Gearhart Jamie , Gong Xiangyu , Herzog Nora , Getzin Matthew , Skobe Mihaela , Mills Kristen L.
Published: July 2020

Tumor emboli – aggregates of tumor cell within vessels – pose a clinical challenge as they are associated with increased metastasis and tumor recurrence. When growing within a vessel, tumor emboli are subject to a unique mechanical constraint provided by the tubular geometry of the vessel. Current models of tumor emboli use unconstrained multicellular tumor spheroids, which neglect this mechanical interplay. Here, we modelled a lymphatic vessel as a 200 μm-diameter channel in either a stiff or soft, bioinert agarose matrix, and we modelled colon or breast cancer tumor emboli with aggregates of HCT116 or SUM149PT cells, respectively. The stiff vessel model constrained the tumor emboli to the cylindrical geometry, which led to continuous growth of the emboli, in contrast to the growth plateau that unconstrained spheroids exhibit. Emboli morphology in the soft vessel model, however, was dependent on the magnitude of mechanical mismatch between the vessel matrix and the cell aggregates. In general, when the elastic modulus of the vessel was greater than the emboli (Eves/Eemb> 1), the emboli were constrained to grow within the vessel geometry, and when the elastic modulus of the vessel was less than the emboli (0 <Eves/Eemb< 1), the emboli bulged into the matrix. Inhibitors of myosin-related force generation decreased the elastic modulus and/or increased the stress relaxation of the tumor cell aggregates, effectively increasing the mechanical mismatch. The increased mechanical mismatch after drug treatment was correlated with increased confinement of tumor emboli growth along the vessel, which may translate to increased tumor burden due to the increased tumor volume within the diffusion distance of nutrients and oxygen.

INSIGHT BOX

The growth of tumor emboli—aggregates of tumor cells within vessels—is associated with aggressive cancer progression and metastasis. Models of their growth have not taken into account their biomechanical context, where radial expansion is constrained, but lengthwise expansion is free in the vessel. Here, we modelled the vessel geometry with a cylindrical microchannel in a hydrogel. In contrast to unconstrained or fully embedded aggregates, vessel-like constraint promotes growth of emboli in our model. The growth advantage is increased when the matrix is stiffened or actomyosin contractility weakened, both of which effectively increase the magnitude of mechanical constraint. This study sheds light on increased tumor burden in vessel-based growth and indicates a need to study tumor progression in similar environments.
Passive Monitoring of Physiological Data and Self-reported Symptoms to Detect Clusters of People with COVID-19
Authors: Quer Giorgio , Radin Jennifer M. , Gadaleta Matteo , Baca-Motes Katie , Ariniello Lauren , Ramos Edward , Kheterpal Vik , Topol Eric J. , Steinhubl Steven R
Published: July 2020

Traditional screening for COVID-19 typically includes survey questions about symptoms, travel history, and sometimes temperature measurements. We explored whether longitudinal, personal sensor data can help identify subtle changes which may indicate an infection, such as COVID-19. To do this we developed an app that collects smartwatch and activity tracker data, as well as self-reported symptoms and diagnostic testing results from participants living in the US. We assessed whether symptoms and sensor data could differentiate COVID-19 positive versus negative cases in symptomatic individuals. Between March 25 and June 7, 2020, we enrolled 30,529 participants, of whom 3,811 reported symptoms, 54 reported testing positive for COVID-19, and 279 negative. We found that a combination of symptom and sensor data resulted in an AUC=0.80 [0.73 – 0.86] which was significantly better (p < 0.01) than a model which just considered symptoms alone (AUC=0.71 [0.63 – 0.79]) in the discrimination between symptomatic individuals positive or negative for COVID-19. Such orthogonal, continuous, passively captured data may be complementary to virus testing that is generally a one-off, or infrequent, sampling assay.
Reopening universities during the COVID-19 pandemic: A testing strategy to minimize active cases and delay outbreaks
Authors: Rennert Lior , Kalbaugh Corey A. , Shi Lu , McMahan Christopher
Published: July 2020

Background

University campuses present an ideal environment for viral spread and are therefore at extreme risk of serving as a hotbed for a COVID-19 outbreak. While active surveillance throughout the semester such as widespread testing, contact tracing, and case isolation, may assist in detecting and preventing early outbreaks, these strategies will not be sufficient should a larger outbreak occur. It is therefore necessary to limit the initial number of active cases at the start of the semester. We examine the impact of pre-semester NAT testing on disease spread in a university setting.

Methods

We implement simple dynamic transmission models of SARS-CoV-2 infection to explore the effects of pre-semester testing strategies on the number of active infections and occupied isolation beds throughout the semester. We assume an infectious period of 3 days and vary R0 to represent the effectiveness of disease mitigation strategies throughout the semester. We assume the prevalence of active cases at the beginning of the semester is 5%. The sensitivity of the NAT test is set at 90%.

Results

If no pre-semester screening is mandated, the peak number of active infections occurs in under 10 days and the size of the peak is substantial, ranging from 5,000 active infections when effective mitigation strategies (R0 = 1.25) are implemented to over 15,000 active infections for less effective strategies (R0 = 3). When one NAT test is mandated within one week of campus arrival, effective (R0 = 1.25) and less effective (R0 = 3) mitigation strategies delay the onset of the peak to 40 days and 17 days, respectively, and result in peak size ranging from 1,000 to over 15,000 active infections. When two NAT tests are mandated, effective (R0 = 1.25) and less effective (R0 = 3) mitigation strategies delay the onset of the peak through the end of fall semester and 20 days, respectively, and result in peak size ranging from less than 1,000 to over 15,000 active infections. If maximum occupancy of isolation beds is set to 2% of the student population, then isolation beds would only be available for a range of 1 in 2 confirmed cases (R0 = 1.25) to 1 in 40 confirmed cases (R0 = 3) before maximum occupancy is reached.

Conclusion

Even with highly effective mitigation strategies throughout the semester, inadequate pre-semester testing will lead to early and large surges of the disease and result in universities quickly reaching their isolation bed capacity. We therefore recommend NAT testing within one week of campus return. While this strategy is sufficient for delaying the timing of the outbreak, pre-semester testing would need to be implemented in conjunction with effective mitigation strategies to reduce the outbreak size.
Predicted effects of summer holidays and seasonality on the SARS-Cov-2 epidemic in France
Authors: Duchemin Louis , Paris Mathilde , Boussau Bastien
Published: July 2020

1

The SARS-CoV-2 epidemic in France has had a large death toll. It has not affected all regions similarly, since the death rate can vary several folds between regions where the epidemic has remained at a low level and regions where it got an early burst. The epidemic has been slowed down by a lockdown that lasted for almost eight weeks, and individuals can now move between metropolitan French regions without restriction. In this report we investigate the effect on the epidemic of summer holidays, during which millions of individuals will move between French regions. Additionally, we evaluate the effect of strong or weak seasonality and of several values for the reproduction number on the epidemic, in particular on the timing, the height and the spread of a second wave. To do so, we extend a SEIR model to simulate the effect of summer migrations between regions on the number and distribution of new infections. We find that the model predicts little effect of summer migrations on the epidemic, because the number of migrating infectious individuals are low as a consequence of the lockdown. However, all the reproduction numbers above 1.0 and the seasonality parameters we tried result in a second epidemic wave, with a peak date that can vary between October 2020 and April 2021. If the sanitary measures currently in place manage to keep the reproduction number below 1.0, the second wave will be avoided. If they keep the reproduction number at a low value, for instance at 1.1 as in one of our simulations, the second wave is flattened and could be similar to the first wave.
COVID-19 presenting as anosmia and dysgeusia in New York City emergency departments, March - April, 2020
Authors: Wang Tina Z. , Sell Jessica , Weiss Don , Lall Ramona
Published: July 2020

Background

Increasing evidence has been emerging of anosmia and dysgeusia as frequently reported symptoms in COVID-19. Improving our understanding of these presenting symptoms may facilitate the prompt recognition of the disease in emergency departments and prevent further transmission.

Methods

We examined a cross-sectional cohort using New York City emergency department syndromic surveillance data for March and April 2020. Emergency department visits for anosmia and/or dysgeusia were identified and subsequently matched to the Electronic Clinical Laboratory Reporting System to determine testing results for SARS-CoV-2.

Results

Of the 683 patients with anosmia and/or dysgeusia included, SARS-CoV-2 testing was performed for 232 (34%) and 168 (72%) were found to be positive. Median age of all patients presenting with anosmia and/or dysgeusia symptoms was 38, and 54% were female. Anosmia and/or dysgeusia was the sole complaint of 158 (23%) patients, of whom 35 were tested for SARS-CoV-2 and 23 (66%) were positive. While the remaining patients presented with at least one other symptom, nearly half of all patients (n=334, 49%) and more than a third of those who tested positive (n=62, 37%) did not have any of the CDC-established symptoms used for screening of COVID-19 such as fever, cough, shortness of breath, or sore throat.

Conclusions and Relevance

Anosmia and/or dysgeusia have been frequent complaints among patients presenting to emergency departments during the COVID-19 pandemic, and, while only a small proportion of patients ultimately underwent testing for SARS-CoV-19, the majority of patients tested have been positive. Anosmia and dysgeusia likely represent underrecognized symptoms of COVID-19 but may have important future implications in disease diagnosis and surveillance.
Long-term PM2.5 exposure and depressive symptoms in China: a quasi-experimental study
Authors: Xue Tao , Guan Tianjia , Zheng Yixuan , Geng Guannan , Zhang Qiang , Yao Yao , Zhu Tong
Published: July 2020

Background

Air pollutants, particularly fine particulate matters (PM2.5) have been associated with mental disorder such as depression. Clean air policy (CAP, i.e., a series of emission-control actions) has been shown to reduce the public health burden of air pollutions. There were few studies on the health effects of CAP on mental health, particularly, in low-income and middle-income countries (LMICs). We investigated the association between a stringent CAP and depressive symptoms among general adults in China.

Methods

We used three waves (2011, 2013 and 2015) of the China Health and Retirement Longitudinal Study (CHARLS), a prospective nationwide cohort of the middle-aged and older population in China. We assessed exposure to PM2.5 through a satellite-retrieved dataset. We implemented a difference-in-differences (DID) approach, under the quasi-experimental framework of the temporal contrast between 2011 (before the CAP) and 2015 (after the CAP), to evaluate the effect of CAP on depressive symptoms. The association was further explored using a mixed-effects model of the three waves. To increase the interpretability, the estimated impact of PM2.5 was compared to that of aging, an established risk factor for depression.

Findings

Our analysis included 15,954 participants. In the DID model, we found a 10-μg/m3 reduction of PM2.5 concentration was associated with a 4.14% (95% CI: 0.41–8.00%) decrement in the depressive score. The estimate was similar to that from the mixed-effects model (3.63% [95% CI, 2.00–5.27%]). We also found improved air quality during 2011-2015 offset the negative impact from 5-years’ aging.

Interpretation

The findings suggest that implementing CAP may improve mental wellbeing of adults in China and other LMICs.

Funding

National Natural Science Foundation and Ministry of Science and Technology of China, and Energy Foundation.
COVID-19 incidence trends between April and June 2020: A global analysis
Authors: Amanor-Boadu Vincent , Ross Kara
Published: July 2020

The study sought to investigate how the number of confirmed cases of COVID-19 have evolved in the most recent three months across the world, and what insights the trends may provide about the second half of the pandemic’s first year using a situation analysis approach based on national income, temperature, trade intensity with China, and location defined by longitude and latitude. The study confirmed the negative relationship between COVID-19 cases and temperature. It contributed to the resolution of the conflicting results about latitude after organizing it into a categorical variable instead of its continuous form. This approach works because the average temperature in the 15°S to 15°N region remains similar to the average temperatures in both the Above 15°N region and the Below 15°S region during their summer months because the 15°S to 15°N region does not experience the marked seasonal changes in temperature. Given the negative association between temperature and case numbers, this suggests that countries in the 15°S to 15°N region might continue exhibiting the low numbers they have thus far exhibited through the second half of this year, even as numbers climb in the Below 15°S region. To succeed, their policymakers must control importation of the disease by implementing effective testing, quarantining, and contact tracing for people entering their borders. Policymakers in countries Below 15°S region may manage their inherent risks by applying lessons learned from countries in the Above 15°N region during these past months. Such preventative measures may allow the world to avoid the drastic lockdown policies and facilitate rapid global economic recovery from this pandemic.
Comparative conventional extraction methods of ethanolic extracts of Clinacanthus nutans leaves on antioxidant activity and toxicity
Authors: Chuah Pei Ni , Nyanasegaram Dhalini , Yu Ke-Xin , Mohamed Razik Rasny , Al-Dhalli Samer , Kue Chin Siang , Shaari Khozirah , Ng Chean Hui
Published: July 2020

Purpose

The purpose of this paper is to evaluate the antioxidant activity and toxicity of Clinacanthus nutans leaves from three conventional extraction methods, i.e. maceration, Soxhlet and magnetic stirring.

Design/methodology/approach

Total flavonoid content (TFC) and phenolic content (TPC) were determined using colorimetric method of aluminum chloride and Folin-Ciocalteu (FC) assay, respectively. Antioxidant property of C. nutans was evaluated using 2,2'-diphenyl-1-pierylhydrazyl (DPPH) free radical scavenging assay. Cytotoxic activity of C. nutans against brine shrimp was evaluated based on LC50 (lethality concentration) after 24 h exposure to the plant extract.

Findings

The highest TPC of C. nutans was observed with Soxhlet extraction method (98.87 ± 10.43 mg of gallic acid equivalents (GAE/g) followed by maceration (68.77 ± 2.45 mg of GAE/g) and magnetic stirring (46.75 ± 2.45 mg of GAE/g). Interestingly, remarkable highest TFC was observed with magnetic stirring (568.90 ± 4.85 mg of rutin equivalent (RE)/g) followed by maceration (249.60 ± 2.79 mg of RE/g) and Soxhlet (174.8 ± 1.74 mg of RE/g). On the other hands, the extract obtained using maceration method showed the highest antioxidant activity (IC50: 14.18 mg/mL compared to ascorbic acid 144.36 µg/mL). Cytotoxicity of C. nutans from all extraction methods showed similar LC50 values with maceration (3.81 mg/mL), Soxhlet (2.61 mg/mL) and magnetic stirring (4.56 mg/mL), respectively.

Originality/value

Both phenolic and flavonoids are responsible for the antioxidant activity, of C. nutans extracts. Based on Meyer's toxicity index, all extracts were nontoxic (LC50>1 mg/mL).
Factors driving indebtedness among small- and medium-sized dairy companies
Authors: Mazzoleni Alberto , Pollonini Enrica
Published: July 2020

Purpose

We developed a model to demonstrate how multiple interrelated aspects of a firm influence its recourse to third-party financing, which frequently depends on the characteristics of each food production chain.

Design/methodology/approach

We conducted an empirical research on a relevant sample of small- and medium-sized Italian dairy firms. Our research methodology is inspired by the grounded theory (Glaser and Strauss, 1967).

Findings

Our findings illustrated that firm indebtedness is the result of intertwined variables, linked to different firm dimensions, including growth, financial structure and economic dynamics.

Research limitations/implications

A portion of the analysed phenomenon is not explained using the sample and econometric tools.

Practical implications

There are practical implications for the decision-makers in a firm (in particular, the managers and the shareholders) as the model allows to evaluate the influence of a set of mutually interdependent firm variables for the indebtedness level.

Originality/value

First, we considered the recourse to third-party financing within the context of the systems theory (Millová and Blatný, 2015) and from the perspective of linked causes and mutually connected variables. Second, our research focussed on a well-defined food chain and on features of firms operating in this context. Last, our model considered the impact of the recent economic crisis, which motivated us to review the existing models.
Innovation within the food companies: how creative partnerships may conduct to better performances?
Authors: Ferraris Alberto , Vrontis Demetris , Belyaeva Zhanna , De Bernardi Paola , Ozek Hande
Published: July 2020

Purpose

This is one of the first empirical studies aimed at analyzing the interrelation between creative partnerships (CPs), absorptive (AC), knowledge application (KA) capacities and innovation performance in food companies.

Design/methodology/approach

We tested this on a sample of 112 Italian medium-sized food firms that established CPs through a partial least square (PLS) structural equation model (SEM) approach.

Findings

Results are in favor of an important role of CPs in the innovation process of food firms analyzed only if combined with the development of the two internal capacities investigated (AC and KA).

Research limitations/implications

Implications are provided in order to stimulate new and more forms of collaboration between CIs and food firms as well as more empirical studies on this topic.

Originality/value

Few studies in food companies keep into account the role of internal capacities that firms have to build with the aim of acquiring external knowledge through partnerships, in particular in the specific context of CPs. These specific kinds of partnerships are becoming increasingly important because they provide key nonoverlapping knowledge and propose new creative methods, ways and answers that differentiate the innovation process of food firms.
Impact of uncertainty on foreign exchange market stability: based on the LT-TVP-VAR model
Authors: Liu Jingshan
Published: July 2020

Purpose

The purpose of this study is to investigate the effects of uncertainty, namely, macroeconomic uncertainty (MU) and financial uncertainty (FU) on foreign exchange market stability, specifically on foreign exchange market pressure (EMP) and jump risk (RJV).

Design/methodology/approach

The latent threshold time-varying parameter VAR (LT-TVP-VAR) econometric approach is used in estimations to solve structural breaks.

Findings

The relationship of uncertainties and China's foreign exchange market stability is latent threshold nonlinear dynamic time-varying. In China's renminbi (RMB) appreciation stage, both MU and FU weaken the appreciation pressure of RMB. Moreover, MU and FU significantly increase the RJV, while MU significantly affects the RJV of the foreign exchange market. In the RMB depreciation stage, both MU and FU strengthen the EMP.

Research limitations/implications

Findings based on data in China's foreign exchange market can be considered for other global markets in future research.

Practical implications

An increase in MU and FU has a negative effect on foreign exchange stability. Regulators can prevent the economic system uncertainty shocks on foreign exchange market stability through observation and judgment of MU and FU, which helps prevent and relieve financial risks. Investors can reduce foreign exchange risk as the exchange rate rebounds after hedging behavior during high uncertainty periods.

Originality/value

The effect of MU on the foreign exchange market stability is greater than that of FU, regardless of whether EMP or RJV occurs in the foreign exchange market.
Blockchain in general management and economics: a systematic literature review
Authors: Alkhudary Rami , Brusset Xavier , Fenies Pierre
Published: July 2020

Purpose

This paper aims to provide a systematic review of the literature addressing blockchain technology (BT) in general management and economics (GME).

Design/methodology/approach

A systematic literature review methodology is used to collect and analyze the literature.

Findings

Three clusters of research are identified, namely, law, economy and innovation. The use of BT in law areas fosters the registration of intellectual property (IP) rights, although conflict between some of BT applications and regulatory frameworks is present. Research on cryptocurrencies is of high interest to the economy today. In the innovation cluster, BT improves security, traceability and transparency in operations over supply chains. However, BT has many technical imperfections that hinder its wide adoption. Furthermore, the need for the full commitment of all business actors complicates its implementation. Research on BT is still at a nascent stage. Conceptual papers dominate the literature (18 theories are discussed). Eight main future research directions are described. For example, the relationship between the use of BT in supply chains and competitive advantage is not established; and quality standards for BT platforms are not developed.

Research limitations/implications

The review is restricted to academic journals in the fields of GME, which limits the extent of the conclusions.

Originality/value

The paper synthesizes 47 studies published in academic journals, avoiding misleading claims and inaccurate information insofar as possible; and provides a spectrum of descriptive statistics and qualitative meta-synthesis analysis of the current literature.
Moving drug discoveries beyond the valley of death: the role of innovation ecosystems
Authors: Calza Francesco , Ferretti Marco , Panetti Eva , Parmentola Adele
Published: July 2020

Purpose

The paper aims to explore the nature of initiatives and strategies of inter-organizational cooperation to cross the valley of death in the biopharma industry.

Design/methodology/approach

The authors conducted an exploratory case study analysis in the Biopharma Innovation Ecosystem in Greater Boston Area (USA), which is one of the oldest, and most successful IE in the US, specialized in the Biopharma domain, by conducting a round of expert interviews with key informants in the area, chosen as representatives of the different types of actors engaged in the drug development processes at different stages.

Findings

Main findings suggest that cooperation can contribute to surviving the valley of death by reducing the barriers within the drug development pipeline through the promotion of strategic relationships among actors of different nature, including the establishment of government-led thematic associations or consortia, agreements between university and business support structures, proximity to venture capitalist and the promotion of a general culture of academic entrepreneurship within universities.

Originality/value

The authors believe that this paper contributes to the literature by shedding light on the nature of the specific cooperative initiative the barriers in drug development and help to survive the valley of the death.
Career self-efficacy and education abroad: implications for future global workforce
Authors: Arghode Vishal , Heminger Sarah , McLean Gary N.
Published: July 2020

Purpose

This study aims to explore how career self-efficacy shapes an individual’s career decisions and how learning and development interventions, including participation in education abroad, might play a role in career choice.

Design/methodology/approach

The authors used the following databases to review the literature on career self-efficacy: Academic Search Premier, Education Resources Information Center and ProQuest. The following key search terms were used in the search: career self-efficacy, career choice and education abroad. The titles of the identified articles were first reviewed for relevance, followed by the abstract, before further review for inclusion suitability.

Findings

Findings suggest career self-efficacy plays a vital role in career decision-making, generating interests and deciding career goals. By improving career self-efficacy among college students, career interests can be reshaped. Findings evidence a relationship between education abroad and career competencies and career development.

Research limitations/implications

The review offers an invaluable pathway to breed ideas and thoughts about research in the career self-efficacy domain. While education abroad itself may be a useful intervention in the development of a student’s career self-efficacy, among other characteristics and skills, a further empirical study is necessary to determine the extent to which this is true. Using or creating an accurate scale for the measurement of career self-efficacy among undergraduate students is critical to determine a reliable and valid measure, as is controlling for potential differences in self-efficacy between students who self-select for high impact endeavors such as education abroad and those who do not.

Practical implications

Noting that practices in international education support collaboration between career services offices and study abroad offices, the authors point to the importance of interventions that intentionally and explicitly incorporate the career self-efficacy construct.

Originality/value

Findings evidence a relationship between education abroad and career competencies and career development, through research examining connections to career self-efficacy and education abroad is noticeably scarce. The paper explores the above relationship.