bluuebunny/crossref_metadata_2025_split huggingface dataset:
A model for COVID-19 with isolation, quarantine and testing as control measures
Authors: Aronna M.S. , Guglielmi R. , Moschen L.M. 
Published: May 2020

AbstractIn this article we propose a compartmental model for the dynamics of Coronavirus Disease 2019 (COVID-19). We take into account the presence of asymptomatic infections and the main policies that have been adopted so far to contain the epidemic: isolation (or social distancing) of a portion of the population, quarantine for confirmed cases and testing. We model isolation by separating the population in two groups: one composed by key-workers that keep working during the pandemic and have a usual contact rate, and a second group consisting of people that are enforced/recommended to stay at home. We refer to quarantine as strict isolation, and it is applied to confirmed infected cases.In the proposed model, the proportion of people in isolation, the level of contact reduction and the testing rate are control parameters that can vary in time, representing policies that evolve in different stages. We obtain an explicit expression for the basic reproduction numberin terms of the parameters of the disease and of the control policies. In this way we can quantify the effect that isolation and testing have in the evolution of the epidemic. We present a series of simulations to illustrate different realistic scenarios. From the expression ofand the simulations we conclude that isolation (social distancing) and testing among asymptomatic cases are fundamental actions to control the epidemic, and the stricter these measures are and the sooner they are implemented, the more lives can be saved. Additionally, we show that people that remain in isolation significantly reduce their probability of contagion, so risk groups should be recommended to maintain a low contact rate during the course of the epidemic.
Time courses of COVID-19 infection and local variation in socioeconomic and health disparities in England
Authors: Liu Shelley H. , Liu Bian , Li Yan , Norbury Agnes 
Published: May 2020

AbstractObjectiveTo identify factors associated with local variation in the time course of COVID-19 case burden in England.MethodsWe analyzed laboratory-confirmed COVID-19 case data for 150 upper tier local authorities, from the period from January 30 to May 6, 2020, as reported by Public Health England. Using methods suitable for time-series data, we identified clusters of local authorities with distinct trajectories of daily cases, after adjusting for population size. We then tested for differences in sociodemographic, economic, and health disparity factors between these clusters.ResultsTwo clusters of local authorities were identified: a higher case trajectory that rose faster over time to reach higher peak infection levels, and a lower case trajectory cluster that emerged more slowly, and had a lower peak. The higher case trajectory cluster (79 local authorities) had higher population density (p<0.001), higher proportion of Black and Asian residents (p=0.03; p=0.02), higher multiple deprivation scores (p<0.001), a lower proportions of older adults (p=0.005), and higher preventable mortality rates (p=0.03). Local authorities with higher proportions of Black residents were more likely to belong to the high case trajectory cluster, even after adjusting for population density, deprivation, proportion of older adults and preventable mortality (p=0.04).ConclusionAreas belonging to the trajectory with significantly higher COVID-19 case burden were more deprived, and had higher proportions of ethnic minority residents. A higher proportion of Black residents in regions belonging to the high trajectory cluster was not fully explained by differences in population density, deprivation, and other overall health disparities between the clusters.What is already known on this subject?Emerging evidence suggests that the burden of COVID-19 infection is falling unequally across England, with provisional data suggesting higher overall infection and mortality rates for Black, Asian, and mixed race/ethnicity individuals.What does this study add?We found that regions with greater socioeconomic deprivation and poorer population health measures showed a faster rise in COVID-19 cases, and reached higher peak case levels. Areas with a higher proportion of Black residents were more likely to show this kind of time course, even after adjusting for multiple co-occurring factors, including population density. This finding merits further investigation in terms of the intersecting vulnerability factors Black and other minority ethnic individuals face in England (e.g. proportion of people working in service and caring roles, and the role of structural discrimination), and has implications for the ongoing allocation of public health resources, in order to better mitigate such inequalities.
Use of the Spatial Access Ratio to Measure Geospatial Access to Emergency Surgical Services in California
Authors: Wan Neng , Lizotte Steven , Han Jiuying , Varghese Thomas , Nirula Raminder , McCrum Marta 
Published: May 2020

AbstractBackgroundEmergency general surgery (EGS) diseases carry a substantial public health burden, accounting for over 3 million admissions annually. Due to their time-sensitive nature, ensuring adequate access to EGS services is critical for reducing patient morbidity and mortality. Travel-time alone, without consideration of resource supply and demand, may be insufficient to determine a regional health care system’s ability to provide timely access to EGS care. Spatial Access Ratio (SPAR) incorporates travel-time, as well as hospital-specific resources and capacity, to determine healthcare accessibility which may be more appropriate for surgical specialties. We therefore compared SPAR to travel-time in their ability to differentiate spatial access to EGS care for vulnerable populations.MethodsWe constructed a Geographic Information Science (GIS) platform using existing road networks, and mapped population location, race and socioeconomic characteristics, as well as all EGS-capable hospitals in California. We then compared the shortest travel time method to the gravity-based SPAR in their ability to identify disparities in spatial access for the population as a whole, and subsequently to describe socio-demographic disparities. Reduced spatial access was defined at > 60 minutes travel time, or lowest three classes of SPAR.Results283 EGS-capable hospitals were mapped, 142 (50%) of which had advanced resources. Using shortest travel time, 36.98M people (94.8%) were within 20-minutes driving time to any EGS capable hospital, and 33.49M (85.9%) to an advanced-resourced center. Only 166, 950 (0.4%) experienced prolonged (>60 minutes) travel time to any EGS-capable hospital, which increased to 1.05M (2.7%) for advanced-resources. Using SPAR, 11.5M (29.5%) of people had reduced spatial access to any EGS hospital, which increased to 13.9M (35.7%) when evaluating advanced-resource hospitals. The greatest disparities in spatial access to care were found for rural residents and Native Americans for both overall and advanced EGS services.ConclusionsWhile travel time and SPAR showed similar overall patterns of spatial access to EGS-capable hospitals, SPAR showed greater differentiation of spatial access across the state. Nearly one-third of California residents have limited or poor access to EGS hospitals, with the greatest disparities noted for Native American and rural residents. These findings argue for the use of gravity-based models such as SPAR that incorporate measures of population demand and hospital capacity when assessing spatial access to surgical services, and have implications for the allocation of healthcare resources to address disparities.
Regression Analysis of COVID-19 Spread in India and its Different States
Authors: Chauhan Poonam , Kumar Ashok , Jamdagni Pooja 
Published: May 2020

AbstractLinear and polynomial regression model has been used to investigate the COVID-19 outbreak in India and its different states using time series epidemiological data up to 26th May 2020. The data driven analysis shows that the case fatality rate (CFR) for India (3.14% with 95% confidence interval of 3.12% to 3.16%) is half of the global fatality rate, while higher than the CFR of the immediate neighbors i.e. Bangladesh, Pakistan and Sri Lanka. Among Indian states, CFR of West Bengal (8.70%, CI: 8.21–9.18%) and Gujrat (6.05%, CI: 4.90–7.19%) is estimated to be higher than national rate, whereas CFR of Bihar, Odisha and Tamil Nadu is less than 1%. The polynomial regression model for India and its different states is trained with data from 21st March 2020 to 19th May 2020 (60 days). The performance of the model is estimated using test data of 7 days from 20th May 2020 to 26th May 2020 by calculating RMSE and % error. The model is then used to predict number of patients in India and its different states up to 16th June 2020 (21 days). Based on the polynomial regression analysis, Maharashtra, Gujrat, Delhi and Tamil Nadu are continue to remain most affected states in India.
Fine-tuned spatiotemporal dynamics of sporophylls in movement-assisted dichogamy: a study onClerodendrum infortunatum
Authors: Mukhopadhyay Amritendu , Quader Suhel 
Published: May 2020

AbstractOver 70% of flowering plants are hermaphroditic, with male and female parts in the same flower. Hermaphroditism is cost-effective because a common investment in reward and attractive structures yields benefits through both male and female reproductive success. However, the advantage is accompanied by an increased risk of self-pollen deposition, which is disadvantageous for both self-compatible and self-incompatible species. Hermaphroditic plants reduce self-pollen deposition by separating sporophylls (male and female reproductive parts) either spatially (herkogamy) or temporally (dichogamy). In movement-assisted dichogamy, both sporophylls are involved in a coordinated motion, where they move in opposite directions. However, the effectiveness of this adaptation in reducing self-pollen deposition may be compromised at the point when the sporophylls cross each other and are close enough to interfere, resulting in a transition phase problem. The solution to this problem lies in the details of the spatiotemporal dynamics of the sporophylls in relation to their reproductive maturity. We studied these details across the floral lifetime of a protandrous shrubClerodendrum infortunatum(Lamiaceae), in rainforest fragments of the Western Ghats, India. We took photos of flowers at regular time intervals and measured sporophyll angles from the images. We also carried out a field experiment to determine stigma receptivity. The findings suggest that the effectiveness of dichogamy is maximised through two properties of the transition phase: physical resistance to self-pollen deposition by narrow stigma lobe opening, and chemical non-receptivity of the stigma during this phase. This study emphasises the importance of accessory adaptations in movement-assisted dichogamy to tackle the transition phase problem, which is inherent in this particular form of dichogamy.
Social media efficacy and workplace relationships
Authors: Snyder Jason , Cistulli Mark D. 
Published: May 2020

PurposeWith the increase of social media usage in the workplace as a background, this paper specifically addresses social media efficacy's and social media privacy's impact on supervisor and subordinate trust, affective organizational commitment (AOC) and organizational citizenship behavior (OCB) through the theoretical lens of communication privacy management (CPM) theory.Design/methodology/approachAn online survey of 337 full- and part-time workers was conducted.FindingsPath models showed that social media efficacy positively influenced social media privacy which in turn impacted both supervisor trust and subordinate trust. Supervisor trust was positively related to AOC, while subordinate trust positively influenced OCB. t-tests revealed differences between workers who have social media relationships with supervisors and/or subordinates and those workers without such relationships.Practical implicationsIf workers believe they are adept at using social media, they will also be less concerned about the company's ability to infringe upon privacy through unwanted access to social media content. If social media efficacy drives perceptions of social media privacy and indirectly influences trust and organizational outcomes then it may be worthwhile for organizations to help enhance workers' feelings of social media efficacy through professional development programs.Originality/valueThis study is the first to extend research on workplace communication privacy into the realm of social media. Social media relationships also influence the work environment. These findings can be used as information in future research as well as policy development and professional development programs.
Affective events theory as a theoretical lens for improving the working environment of academics in developing economies
Authors: Ghasemy Majid , Erfanian Mahdiyeh , Gaskin James Eric 
Published: May 2020

PurposeThe rapid pace of progress in academic institutions in developing economies has created stressful and relatively toxic workplaces, resulting in different negative organizational outcomes indicating the need to transform universities into healthier academic workplaces. However, a review of the higher education literature in both developed and developing countries shows that the antecedents and consequences of academics' affective states has been a relatively unexplored area. Hence, our study aims at testing basic tenets of Affective Events Theory (AET) in a higher education context to address this issue.Design/methodology/approachThis is a quantitative study which applies CB-SEM methodology in analyzing the collected data from 2,324 academics in Malaysian higher education sector. We analyzed the data using EQS software package.FindingsOur results provided substantial support for the applicability and relevancy of AET in higher education domain. Specifically, welfare and supervisory support were identified as the two work environment features which significantly and equally contribute to academics' job satisfaction. In addition, the results showed that positive affect, in comparison with negative affect, was three times stronger in influencing academics' job satisfaction.Practical implicationsGiven the considerable role of positive affect in our study, higher education policy makers are urged to make relevant policies to transform universities into more emotionally safe workplaces. In addition, policies should be formulated in a way that encourages supervisory support and decreases workloads to ensure that the conflicts in general are reduced among academics.Originality/valueThis work is the first large-scale study testing the main tenets of AET in the higher education context. In addition, it addresses the problem of multivariate normality and solves this problem based on the robust methodology which corrects standard errors and fit indices, thereby providing more precise and unbiased results.
Size‐ and stage‐dependence in cause‐specific mortality of migratory brown trout
Authors: Nater Chloé R. , Vindenes Yngvild , Aass Per , Cole Diana , Langangen Øystein , Moe S. Jannicke , Rustadbakken Atle , Turek Daniel , Vøllestad Leif Asbjørn , Ergon Torbjørn 
Published: May 2020

AbstractEvidence‐based management of natural populations under strong human influence frequently requires not only estimates of survival but also knowledge about how much mortality is due to anthropogenic vs. natural causes. This is the case particularly when individuals vary in their vulnerability to different causes of mortality due to traits, life history stages, or locations.Here, we estimated harvest and background (other cause) mortality of landlocked migratory salmonids over half a century. In doing so, we quantified among‐individual variation in vulnerability to cause‐specific mortality resulting from differences in body size and spawning location relative to a hydropower dam.We constructed a multistate mark–recapture model to estimate harvest and background mortality hazard rates as functions of a discrete state (spawning location) and an individual time‐varying covariate (body size). We further accounted for among‐year variation in mortality and migratory behaviour and fit the model to a unique 50‐year time series of mark–recapture–recovery data on brown trout (Salmo trutta) in Norway.Harvest mortality was highest for intermediate‐sized trout, and outweighed background mortality for most of the observed size range. Background mortality decreased with body size for trout spawning above the dam and increased for those spawning below. All vital rates varied substantially over time, but a trend was evident only in estimates of fishers' reporting rate, which decreased from over 50% to less than 10% throughout the study period.We highlight the importance of body size for cause‐specific mortality and demonstrate how this can be estimated using a novel hazard rate parameterization for mark–recapture models. Our approach allows estimating effects of individual traits and environment on cause‐specific mortality without confounding, and provides an intuitive way to estimate temporal patterns within and correlation among different mortality sources.
Genetic background and thermal environment differentially influence the ontogeny of immune components during early life in an ectothermic vertebrate
Authors: Palacios Maria G. , Gangloff Eric J. , Reding Dawn M. , Bronikowski Anne M. 
Published: May 2020

Abstract

An understudied aspect of vertebrate ecoimmunology has been the relative contributions of environmental factors (E), genetic background (G) and their interaction (G × E) in shaping immune development and function. Environmental temperature is known to affect many aspects of immune function and alterations in temperature regimes have been implicated in emergent disease outbreaks, making it a critical environmental factor to study in the context of immune phenotype determinants of wild animals.

We assessed the relative influences of environmental temperature, genetic background and their interaction on first‐year development of innate and adaptive immune defences of captive‐born garter snakes Thamnophis elegans using a reciprocal transplant laboratory experiment. We used a full‐factorial design with snakes from two divergent life‐history ecotypes, which are known to differ in immune function in their native habitats, raised under conditions mimicking the natural thermal regime—that is, warmer and cooler—of each habitat.

Genetic background (ecotype) and thermal regime influenced innate and adaptive immune parameters of snakes, but in an immune‐component specific manner. We found some evidence of G × E interactions but no indication of adaptive plasticity with respect to thermal environment. At the individual level, the effects of thermal environment on resource allocation decisions varied between the fast‐ and the slow‐paced life‐history ecotypes. Under warmer conditions, which increased food consumption of individuals in both ecotypes, the former invested mostly in growth, whereas the latter invested more evenly between growth and immune development.

Overall, immune parameters were highly flexible, but results suggest that other environmental factors are likely more important than temperature per se in driving the ecotype differences in immunity previously documented in the snakes under field conditions. Our results also add to the understanding of investment in immune development and growth during early postnatal life under different thermal environments. Our finding of immune‐component specific patterns strongly cautions against oversimplification of the highly complex immune system in ecoimmunological studies. In conjunction, these results deepen our understanding of the degree of immunological flexibility wild animals present, information that is ever more vital in the context of rapid global environmental change.
Attack and aggregation of a major squash pest: Parsing the role of plant chemistry and beetle pheromones across spatial scales
Authors: Brzozowski Lauren J. , Gardner Jeffrey , Hoffmann Michael P. , Kessler André , Agrawal Anurag A. , Mazourek Michael 
Published: May 2020

Abstract

Successful management of insect crop pests requires an understanding of the cues and spatial scales at which they function to affect rates of attack of preferred and non‐preferred host plants. A long‐standing conceptual framework in insect–plant ecology posits that there is hierarchical structure spanning host location, acceptance and attack that could be exploited for integrated pest management.

We investigated how plant‐ and insect‐derived chemical cues affect successive decisions of host choice in aggregating insects, and tested predictions in the Cucurbita pepo–Acalymma vittatum system. Acalymma vittatum is an aggregating specialist beetle pest that strongly prefers zucchini (C. p. pepo) to summer squash (C. p. ovifera), two independent domesticates of C. pepo. We hypothesized that subspecies‐specific plant traits, especially volatile cues, interact with the male‐produced aggregation pheromone to amplify beetle preference for C. p. pepo.

Differential beetle attack of C. pepo subspecies in the field is not determined by plant traits that affect host finding or differential aggregation due to pheromones: across two years, beetles had strong density‐dependent attraction to both subspecies when male beetles were feeding, and no interactions between plant volatiles and the male‐produced pheromone were detected. In the absence of male pheromone emission, beetles were equally unattracted to plants with or without beetle feeding.

In contrast, plant traits that mediate insect acceptance appear to underlie differences in preference. At a local scale, beetles did not accept and emigrated from C. p. ovifera compared to C. p. pepo. Distinct volatile emissions were observed between subspecies, but further work is needed to identify if these volatiles promote emigration.

Synthesis and applications. By dissecting pest preference during successive host choice decisions, we isolated a trait with implications for pest management. Beetles on cucurbits can be managed by employing cultivars with differential susceptibility (e.g. trap cropping), and the mechanistic knowledge presented here informs best practices and limitations for on‐farm applications. More broadly, pest management in diversified cropping systems can be enhanced through understanding how plant preference gradients affect herbivore movement and behaviour, and plant breeders can target traits to reduce herbivory in such systems.