scholarly journals Is Man the New Prospective Amplifying Host? Evolving Faces of SARS-CoV Dynamics and the Epidemiological Challenges

2021 ◽  
Vol 53 (02) ◽  
pp. 89-99
Author(s):  
Rina Tilak ◽  
Keyword(s):  
Large Scale ◽  
Evolutionary Dynamics ◽  
Reservoir Host ◽  
Intermediate Hosts ◽  
Highly Pathogenic ◽  
Digital Platforms ◽  
Disease Epidemiology ◽  
Underlying Causes ◽  
Human Coronaviruses

Introduction: The ongoing COVID-19 pandemic has wreaked havoc across the globe. Health systems are grappling with an unprecedented pressure, as the highly virulent SARS-CoV-2 strain is spreading unhinged, under a yet to be understood selection pressure. To understand the underlying causes, and the rapidly evolving disease epidemiology, we need to look closely and comprehend the evolutionary dynamics of the Human Coronaviruses or the HCoV. Methods: The research about this narrative review was conducted using digital platforms like PubMed/Medline, Semantic Scholar, medXiriv, Google Scholars, NIH, EMBL repository, John Hopkins CSSE COVID-19 Data, ResearchGate, and all the mentioned published work, peer-reviewed research articles, and data, have been accessed using the same. Results: The global rise in COVID-19 incidence and the declining trend witnessed in CFR clearly indicates rapid adaptability of the virus across a widespread population encompassing varied genetic make-up, race, diversity, and others. The last two decades have witnessed two HCoV related epidemics viz. the highly pathogenic Severe Acute Respiratory Syndrome Coronavirus or SARS-CoV and MERS-CoV. While both instances reflect the suspected role of bats as the common reservoir host, the differing intermediate hosts and subsequent spill over to humans is alarming. Conclusions: Through this review, we hypothesise that large-scale pandemics such as this, with alarming instances of differential case incidence patterns in widely varied climatic and geographical conditions put forth the rapid genetic adaptability of coronaviruses. This raises further concerns of a prospective “amplifying-host” in man keeping in mind the widely prevalent asymptomatic silent carriers of COVID-19 currently present across the globe.

scholarly journals A pan-coronavirus fusion inhibitor targeting the HR1 domain of human coronavirus spike

2019 ◽  
Vol 5 (4) ◽  
pp. eaav4580 ◽  
Author(s):  
Shuai Xia ◽  
Lei Yan ◽  
Wei Xu ◽  
Anurodh Shankar Agrawal ◽  
Abdullah Algaissi ◽  
...  
Keyword(s):  
Broad Spectrum ◽  
Inhibitory Activity ◽  
Target Site ◽  
Highly Pathogenic ◽  
Important Target ◽  
Medical Need ◽  
Pharmaceutical Properties ◽  
Human Coronaviruses ◽  
Bundle Structure

Continuously emerging highly pathogenic human coronaviruses (HCoVs) remain a major threat to human health, as illustrated in past SARS-CoV and MERS-CoV outbreaks. The development of a drug with broad-spectrum HCoV inhibitory activity would address this urgent unmet medical need. Although previous studies have suggested that the HR1 of HCoV spike (S) protein is an important target site for inhibition against specific HCoVs, whether this conserved region could serve as a target for the development of broad-spectrum pan-CoV inhibitor remains controversial. Here, we found that peptide OC43-HR2P, derived from the HR2 domain of HCoV-OC43, exhibited broad fusion inhibitory activity against multiple HCoVs. EK1, the optimized form of OC43-HR2P, showed substantially improved pan-CoV fusion inhibitory activity and pharmaceutical properties. Crystal structures indicated that EK1 can form a stable six-helix bundle structure with both short α-HCoV and long β-HCoV HR1s, further supporting the role of HR1 region as a viable pan-CoV target site.

Epidemiologic significance of Toxoplasma gondii infections in turkeys, ducks, ratites and other wild birds: 2009–2020

Parasitology ◽  
2020 ◽  
pp. 1-30 ◽  
Author(s):  
J. P. Dubey ◽  
F. H. A. Murata ◽  
C. K. Cerqueira-Cézar ◽  
O. C. H. Kwok ◽  
C. Su
Keyword(s):  
Genetic Diversity ◽  
Toxoplasma Gondii ◽  
Environmental Contamination ◽  
Migratory Birds ◽  
Avian Species ◽  
Clinical Disease ◽  
Birds Of Prey ◽  
Intermediate Hosts ◽  
Disease Epidemiology

Abstract Toxoplasma gondii infections are common in humans and animals worldwide. Wild and domestic avian species are important in the epidemiology of T. gondii infections because felids prey on them and excrete millions of oocysts in the environment, disseminating the infection. Herbivorous birds are also excellent sentinels of environmental contamination with T. gondii oocysts because they feed on the ground. Toxoplasma gondii infections in birds of prey reflect infections in intermediate hosts. Humans can become infected by consuming undercooked avian tissues. Here, the authors reviewed prevalence, persistence of infection, clinical disease, epidemiology and genetic diversity of T. gondii strains isolated from turkeys, geese, ducks, ratites and avian species (excluding chickens) worldwide 2009–2020. Genetic diversity of 102 T. gondii DNA samples isolated worldwide is discussed. The role of migratory birds in dissemination of T. gondii infection is discussed.

scholarly journals Development of a Whole-Virus ELISA for Serological Evaluation of Domestic Livestock as Possible Hosts of Human Coronavirus NL63

Viruses ◽  
2019 ◽  
Vol 11 (1) ◽  
pp. 43 ◽  
Author(s):  
Philip El-Duah ◽  
Benjamin Meyer ◽  
Augustina Sylverken ◽  
Michael Owusu ◽  
Lina Theresa Gottula ◽  
...  
Keyword(s):  
High Throughput Screening ◽  
Immunofluorescence Assay ◽  
Intermediate Hosts ◽  
Human Samples ◽  
Significant Difference ◽  
Domestic Livestock ◽  
Density Values ◽  
Human Coronaviruses ◽  
Testing Algorithm

Known human coronaviruses are believed to have originated in animals and made use of intermediate hosts for transmission to humans. The intermediate hosts of most of the human coronaviruses are known, but not for HCoV-NL63. This study aims to assess the possible role of some major domestic livestock species as intermediate hosts of HCoV-NL63. We developed a testing algorithm for high throughput screening of livestock sera with ELISA and confirmation with recombinant immunofluorescence assay testing for antibodies against HCoV-NL63 in livestock. Optimization of the ELISA showed a capability of the assay to significantly distinguish HCoV-NL63 from HCoV-229E (U = 27.50, p < 0.001) and HCoV-OC43 (U = 55.50, p < 0.001) in coronavirus-characterized sera. Evaluation of the assay with collected human samples showed no significant difference in mean optical density values of immunofluorescence-classified HCoV-NL63-positive and HCoV-NL63-negative samples (F (1, 215) = 0.437, p = 0.509). All the top 5% (n = 8) most reactive human samples tested by ELISA were HCoV-NL63 positive by immunofluorescence testing. In comparison, only a proportion (84%, n = 42) of the top 25% were positive by immunofluorescence testing, indicating an increased probability of the highly ELISA reactive samples testing positive by the immunofluorescence assay. None of the top 5% most ELISA reactive livestock samples were positive for HCoV-NL63-related viruses by immunofluorescence confirmation. Ghanaian domestic livestock are not likely intermediate hosts of HCoV-NL63-related coronaviruses.

How Trust Leads to Commitment on Microsourcing Platforms: Unraveling the Effects of Governance and Third-Party Mechanisms on Triadic Microsourcing Relationships

MIS Quarterly ◽  
2021 ◽  
Vol 45 (3) ◽  
pp. 1309-1348
Author(s):  
Wenbo Guo ◽  
◽  
Detmar Straub ◽  
Pengzhu Zhang ◽  
Zhao Cai ◽  
...  
Keyword(s):  
Large Scale ◽  
Transaction Cost Economics ◽  
Third Party ◽  
It Outsourcing ◽  
Governance Mechanisms ◽  
Holistic View ◽  
Digital Platforms ◽  
Triadic Relationships ◽  
Combining Data

IS research has extensively examined the role of trust in client-vendor relationships, as well as the role of governance in information technology (IT) outsourcing, but little research has been carried out on the latest manifestation of outsourcing—namely, microsourcing, i.e., the sourcing of smaller scale projects. To extend the literature on the traditional IT outsourcing literature—a stream that largely focuses on medium-to-large scale offline projects—we investigate how to develop trust and commitment in a triadic microsourcing relationship which includes the microsourcer, the microsourcee, and the microsourcing platform (MP). We draw on transaction cost economics (TCE) to theorize a model specifically adapted to the microsourcing phenomenon to scrutinize the influences of formal contractual mechanisms, relational mechanisms, and third-party mechanisms. Combining data from a matched sample of microsourcers and microsourcees on the leading Chinese MP, Zbj.com, the paper deploys degree-symmetric modeling (DSM) for construct conceptualization, measurement, and data analysis. DSM is consistent with the holistic view used to develop the research model for triadic relationships. Findings confirm that the MP is critical in delivering governance mechanisms to ensure the development of triadic trust and commitment. The results suggest that researchers and practitioners should pay closer attention to triadic trust and commitment building through proper governance mechanisms in the online microsourcing marketplace. We argue that this work could be extended to other online digital platforms that involve multiple transacting parties.

scholarly journals Genome-wide analyses of human noroviruses provide insights on evolutionary dynamics and evidence of coexisting viral populations evolving under recombination constraints

2021 ◽  
Vol 17 (7) ◽  
pp. e1009744
Author(s):  
Kentaro Tohma ◽  
Cara J. Lepore ◽  
Magaly Martinez ◽  
Juan I. Degiuseppe ◽  
Pattara Khamrin ◽  
...  
Keyword(s):  
Phylogenetic Trees ◽  
Large Scale ◽  
Evolutionary Dynamics ◽  
Structural Proteins ◽  
Genomic Information ◽  
Human Noroviruses ◽  
Genome Wide ◽  
Genomic Regions ◽  
Genome Information

Norovirus is a major cause of acute gastroenteritis worldwide. Over 30 different genotypes, mostly from genogroup I (GI) and II (GII), have been shown to infect humans. Despite three decades of genome sequencing, our understanding of the role of genomic diversification across continents and time is incomplete. To close the spatiotemporal gap of genomic information of human noroviruses, we conducted a large-scale genome-wide analyses that included the nearly full-length sequencing of 281 archival viruses circulating since the 1970s in over 10 countries from four continents, with a major emphasis on norovirus genotypes that are currently underrepresented in public genome databases. We provided new genome information for 24 distinct genotypes, including the oldest genome information from 12 norovirus genotypes. Analyses of this new genomic information, together with those publicly available, showed that (i) noroviruses evolve at similar rates across genomic regions and genotypes; (ii) emerging viruses evolved from transiently-circulating intermediate viruses; (iii) diversifying selection on the VP1 protein was recorded in genotypes with multiple variants; (iv) non-structural proteins showed a similar branching on their phylogenetic trees; and (v) contrary to the current understanding, there are restrictions on the ability to recombine different genomic regions, which results in co-circulating populations of viruses evolving independently in human communities. This study provides a comprehensive genetic analysis of diverse norovirus genotypes and the role of non-structural proteins on viral diversification, shedding new light on the mechanisms of norovirus evolution and transmission.

The Role of Sense of Direction and Other Factors During Navigation in a Large-Scale, Unconstrained Environment

2013 ◽  
Author(s):  
Elisabeth J. Ploran ◽  
Ericka Rovira ◽  
James C. Thompson ◽  
Raja Parasuraman
Keyword(s):  
Large Scale ◽  
Sense Of Direction

Magnetic Properties of xCeO2•(50 − x) PbO•50B2O3 Glasses and Glass Ceramics

2017 ◽  
Vol 13 (1) ◽  
pp. 4486-4494 ◽  
Author(s):  
G.El Damrawi ◽  
F. Gharghar
Keyword(s):  
Magnetic Properties ◽  
Large Scale ◽  
Glass Ceramics ◽  
Magnetic Behavior ◽  
Crystal Formation ◽  
Dual Roles ◽  
Effective Agent ◽  
Ordered Structures ◽  
Essential Change

Cerium oxide in borate glasses of composition xCeO2·(50 − x)PbO·50B2O3 plays an important role in changing both microstructure and magnetic behaviors of the system. The structural role of CeO2 as an effective agent for cluster and crystal formation in borate network is clearly evidenced by XRD technique. Both structure and size of well-formed cerium separated clusters have an effective influence on the structural properties. The cluster aggregations are documented to be found in different range ordered structures, intermediate and long range orders are the most structures in which cerium phases are involved. The nano-sized crystallized cerium species in lead borate phase are evidenced to have magnetic behavior.  The criteria of building new specific borate phase enriched with cerium as ferrimagnetism has been found to keep the magnetization in large scale even at extremely high temperature. Treating the glass thermally or exposing it to an effective dose of ionized radiation is evidenced to have an essential change in magnetic properties. Thermal heat treatment for some of investigated materials is observed to play dual roles in the glass matrix. It can not only enhance alignment processes of the magnetic moment but also increases the capacity of the crystallite species in the magnetic phases. On the other hand, reverse processes are remarked under the effect of irradiation. The magnetization was found to be lowered, since several types of the trap centers which are regarded as defective states can be produced by effect of ionized radiation. 

The Impact of Quantitative Easing on Emerging Markets – Literature Review

e-Finanse ◽  
2018 ◽  
Vol 14 (4) ◽  
pp. 67-76
Author(s):  
Piotr Bartkiewicz
Keyword(s):  
Emerging Markets ◽  
Large Scale ◽  
Empirical Literature ◽  
Quantitative Easing ◽  
Methodological Choices ◽  
The Subject ◽  
Methodological Approaches ◽  
The Impact ◽  
Sufficient Precision

AbstractThe article presents the results of the review of the empirical literature regarding the impact of quantitative easing (QE) on emerging markets (EMs). The subject is of interest to policymakers and researchers due to the increasingly larger role of EMs in the world economy and the large-scale capital flows occurring after 2009. The review is conducted in a systematic manner and takes into consideration different methodological choices, samples and measurement issues. The paper puts the summarized results in the context of transmission channels identified in the literature. There are few distinct methodological approaches present in the literature. While there is a consensus regarding the direction of the impact of QE on EMs, its size and durability have not yet been assessed with sufficient precision. In addition, there are clear gaps in the empirical findings, not least related to relative underrepresentation of the CEE region (in particular, Poland).

Age Advantages of Emotional Experience during the COVID-19 Pandemic are Robust, but Diminished Compared to Pre-pandemic Conditions

2020 ◽  
Author(s):  
Rui Sun ◽  
Disa Sauter
Keyword(s):  
Older Adults ◽  
Large Scale ◽  
Negative Emotion ◽  
Emotional Experience ◽  
Negative Emotions ◽  
Older Individuals ◽  
Selection Strategies ◽  
Scale Test ◽  
Prolonged Stress

Getting old is generally seen as unappealing, yet aging confers considerable advantages in several psychological domains (North &amp; Fiske, 2015). In particular, older adults are better off emotionally than younger adults, with aging associated with the so-called “age advantages,” that is, more positive and less negative emotional experiences (Carstensen et al., 2011). Although the age advantages are well established, it is less clear whether they occur under conditions of prolonged stress. In a recent study, Carstensen et al (2020) demonstrated that the age advantages persist during the COVID-19 pandemic, suggesting that older adults are able to utilise cognitive and behavioural strategies to ameliorate even sustained stress. Here, we build on Carstensen and colleagues’ work with two studies. In Study 1, we provide a large-scale test of the robustness of Carstensen and colleagues’ finding that older individuals experience more positive and less negative emotions during the COVID-19 pandemic. We measured positive and negative emotions along with age information in 23,629 participants in 63 countries in April-May 2020. In Study 2, we provide a comparison of the age advantages using representative samples collected before and during the COVID-19 pandemic. We demonstrate that older people experience less negative emotion than younger people during the prolonged stress of the COVID-19 pandemic. However, the advantage of older adults was diminished during the pandemic, pointing to a likely role of older adults use of situation selection strategies (Charles, 2010).

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