scholarly journals Host heterogeneity affects both parasite transmission to and fitness on subsequent hosts

2017 ◽  
Vol 372 (1719) ◽  
pp. 20160093 ◽  
Author(s):  
Jessica F. Stephenson ◽  
Kyle A. Young ◽  
Jordan Fox ◽  
Jukka Jokela ◽  
Joanne Cable ◽  
...  
Keyword(s):  
Poecilia Reticulata ◽  
Interactive Effects ◽  
Parasite Transmission ◽  
Disease Dynamics ◽  
Population Growth Rates ◽  
Transmission Parameters ◽  
The Relationship ◽  
Infectious Disease Dynamics ◽  
Lower Population ◽  
Transmission Speed

Infectious disease dynamics depend on the speed, number and fitness of parasites transmitting from infected hosts (‘donors’) to parasite-naive ‘recipients’. Donor heterogeneity likely affects these three parameters, and may arise from variation between donors in traits including: (i) infection load, (ii) resistance, (iii) stage of infection, and (iv) previous experience of transmission. We used the Trinidadian guppy, Poecilia reticulata , and a directly transmitted monogenean ectoparasite, Gyrodactylus turnbulli , to experimentally explore how these sources of donor heterogeneity affect the three transmission parameters. We exposed parasite-naive recipients to donors (infected with a single parasite strain) differing in their infection traits, and found that donor infection traits had diverse and sometimes interactive effects on transmission. First, although transmission speed increased with donor infection load, the relationship was nonlinear. Second, while the number of parasites transmitted generally increased with donor infection load, more resistant donors transmitted more parasites, as did those with previous transmission experience. Finally, parasites transmitting from experienced donors exhibited lower population growth rates on recipients than those from inexperienced donors. Stage of infection had little effect on transmission parameters. These results suggest that a more holistic consideration of within-host processes will improve our understanding of between-host transmission and hence disease dynamics. This article is part of the themed issue ‘Opening the black box: re-examining the ecology and evolution of parasite transmission’.

scholarly journals Parasite-induced plasticity in host social behaviour depends on sex and susceptibility

2019 ◽  
Vol 15 (11) ◽  
pp. 20190557 ◽  
Author(s):  
Jessica F. Stephenson
Keyword(s):  
Poecilia Reticulata ◽  
Parasite Infection ◽  
Behavioural Plasticity ◽  
Parasite Transmission ◽  
Disease Dynamics ◽  
Late Infection ◽  
Reciprocal Interactions ◽  
Host Sex ◽  
Mating Opportunities ◽  
Host Behaviour

Understanding the effects of parasites on host behaviour, of host behaviour on parasite infection, and the reciprocal interactions between these processes is vital to improving our understanding of animal behaviour and disease dynamics. However, behaviour and parasite infection are both highly variable within and between individual hosts, and how this variation affects behaviour–parasite feedbacks is poorly understood. For example, it is unclear how an individual's behaviour before infection might change once it becomes infected, or as the infection progresses, and how these changes depend on the host's parasite susceptibility. Here, using the guppy, Poecilia reticulata , and a directly transmitted ectoparasite, Gyrodactylus turnbulli , I show that parasite-induced behavioural plasticity depends on host sex and susceptibility. Among females, time spent shoaling (sociality), a behaviour that increases parasite transmission, did not depend on infection status (infected/not) or susceptibility. By contrast, male sociality in the absence of infection was negatively correlated with susceptibility, suggesting that the most susceptible males use behaviour to avoid infection. However, in late infection, when parasite transmission is most likely, male sociality and susceptibility became positively correlated, suggesting that susceptible males modify their behaviour upon infection potentially to increase transmission and mating opportunities. I discuss the implications of these patterns for disease dynamics.

scholarly journals House finches ( Carpodacus mexicanus ) balance investment in behavioural and immunological defences against pathogens

2013 ◽  
Vol 9 (1) ◽  
pp. 20120856 ◽  
Author(s):  
Maxine Zylberberg ◽  
Kirk C. Klasing ◽  
Thomas P. Hahn
Keyword(s):  
Reproductive Potential ◽  
Population Level ◽  
Carpodacus Mexicanus ◽  
Disease Dynamics ◽  
House Finches ◽  
Tissue Integrity ◽  
Defence Strategies ◽  
Immune Defences ◽  
The Relationship ◽  
Infectious Disease Dynamics

Infection with parasites and pathogens is costly for hosts, causing loss of nutritional resources, reproductive potential, tissue integrity and even life. In response, animals have evolved behavioural and immunological strategies to avoid infection by pathogens and infestation by parasites. Scientists generally study these strategies in isolation from each other; however, since these defences entail costs, host individuals should benefit from balancing investment in these strategies, and understanding of infectious disease dynamics would benefit from studying the relationship between them. Here, we show that Carpodacus mexicanus (house finches) avoid sick individuals. Moreover, we show that individuals investing less in behavioural defences invest more in immune defences. Such variation has important implications for the dynamics of pathogen spread through populations, and ultimately the course of epidemics. A deeper understanding of individual- and population-level disease defence strategies will improve our ability to understand, model and predict the outcomes of pathogen spread in wildlife.

Interactive Effects of Acute Suicidal Affective Disturbance and Pain Persistence on Suicide Attempt Frequency and Lethality

Crisis ◽  
2019 ◽  
Vol 40 (6) ◽  
pp. 413-421 ◽  
Author(s):  
Megan L. Rogers ◽  
Thomas E. Joiner
Keyword(s):  
Suicide Attempt ◽  
Suicidal Behavior ◽  
Pain Perception ◽  
Suicide Attempts ◽  
Pain Tolerance ◽  
Self Report ◽  
Interactive Effects ◽  
Physical Pain ◽  
Affective Disturbance ◽  
The Relationship

Abstract. Background: Acute suicidal affective disturbance (ASAD) has been proposed as a suicide-specific entity that confers risk for imminent suicidal behavior. Preliminary evidence suggests that ASAD is associated with suicidal behavior beyond a number of factors; however, no study to date has examined potential moderating variables.  Aims: The present study tested the hypotheses that physical pain persistence would moderate the relationship between ASAD and (1) lifetime suicide attempts and (2) attempt lethality. Method: Students ( N = 167) with a history of suicidality completed self-report measures assessing the lifetime worst-point ASAD episode and the presence of a lifetime suicide attempt, a clinical interview about attempt lethality, and a physical pain tolerance task. Results: Physical pain persistence was a significant moderator of the association between ASAD and lifetime suicide attempts ( B = 0.00001, SE = 0.000004, p = .032), such that the relationship between ASAD and suicide attempts strengthened at increasing levels of pain persistence. The interaction between ASAD and pain persistence in relation to attempt lethality was nonsignificant ( B = 0.000004, SE = 0.00001, p = .765). Limitations: This study included a cross-sectional/retrospective analysis of worst-point ASAD symptoms, current physical pain perception, and lifetime suicide attempts. Conclusion: ASAD may confer risk for suicidal behavior most strongly at higher levels of pain persistence, whereas ASAD and pain perception do not influence attempt lethality.

Parenting Behaviors and Anxiety in Young Adults

2015 ◽  
Vol 36 (3) ◽  
pp. 170-176 ◽  
Author(s):  
Erin N. Stevens ◽  
Joseph R. Bardeen ◽  
Kyle W. Murdock
Keyword(s):  
Effortful Control ◽  
Parenting Behaviors ◽  
Protective Role ◽  
Anxiety Symptoms ◽  
Interactive Effects ◽  
Parental Overprotection ◽  
High Control ◽  
Development Of Anxiety ◽  
The Relationship

Parenting behaviors – specifically behaviors characterized by high control, intrusiveness, rejection, and overprotection – and effortful control have each been implicated in the development of anxiety pathology. However, little research has examined the protective role of effortful control in the relation between parenting and anxiety symptoms, specifically among adults. Thus, we sought to explore the unique and interactive effects of parenting and effortful control on anxiety among adults (N = 162). Results suggest that effortful control uniquely contributes to anxiety symptoms above and beyond that of any parenting behavior. Furthermore, effortful control acted as a moderator of the relationship between parental overprotection and anxiety, such that overprotection is associated with anxiety only in individuals with lower levels of effortful control. Implications for potential prevention and intervention efforts which specifically target effortful control are discussed. These findings underscore the importance of considering individual differences in self-regulatory abilities when examining associations between putative early-life risk factors, such as parenting, and anxiety symptoms.

Tire Treadwear — A Comprehensive Evaluation of the Factors: Generic Type, Aspect Ratio, Tread Pattern, and Tread Composition Part I: Introduction and Details on the Organization of the Program

1986 ◽  
Vol 14 (4) ◽  
pp. 201-218 ◽  
Author(s):  
A. G. Veith
Keyword(s):  
Aspect Ratio ◽  
Comprehensive Evaluation ◽  
Test Method ◽  
Interactive Effects ◽  
Data Analyses ◽  
Main Effect ◽  
Systematic Determination ◽  
Relationship Of ◽  
The Relationship

Abstract This four-part series of papers addresses the problem of systematic determination of the influence of several tire factors on tire treadwear. Both the main effect of each factor and some of their interactive effects are included. The program was also structured to evaluate the influence of some external-to-tire conditions on the relationship of tire factors to treadwear. Part I describes the experimental design used to evaluate the effects on treadwear of generic tire type, aspect ratio, tread pattern (groove or void level), type of pattern (straight rib or block), and tread compound. Construction procedures and precautions used to obtain a valid and functional test method are included. Two guiding principles to be used in the data analyses of Parts II and III are discussed. These are the fractional groove and void concept, to characterize tread pattern geometry, and a demonstration of the equivalence of wear rate for identical compounds on whole tread or multi-section tread tires.

scholarly journals Simulation of leaf curl disease dynamics in chili for strategic management options

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Buddhadeb Roy ◽  
Shailja Dubey ◽  
Amalendu Ghosh ◽  
Shalu Misra Shukla ◽  
Bikash Mandal ◽  
...  
Keyword(s):  
Disease Risk ◽  
Virus Transmission ◽  
Host Population ◽  
High Rate ◽  
Disease Dynamics ◽  
Model Framework ◽  
Management Options ◽  
Transmission Parameters ◽  
Vector Population ◽  
Leaf Curl

AbstractLeaf curl, a whitefly-borne begomovirus disease, is the cause of frequent epidemic in chili. In the present study, transmission parameters involved in tripartite interaction are estimated to simulate disease dynamics in a population dynamics model framework. Epidemic is characterized by a rapid conversion rate of healthy host population into infectious type. Infection rate as basic reproduction number, R0 = 13.54, has indicated a high rate of virus transmission. Equilibrium population of infectious host and viruliferous vector are observed to be sensitive to the immigration parameter. A small increase in immigration rate of viruliferous vector increased the population of both infectious host and viruliferous vector. Migrant viruliferous vectors, acquisition, and transmission rates as major parameters in the model indicate leaf curl epidemic is predominantly a vector -mediated process. Based on underlying principles of temperature influence on vector population abundance and transmission parameters, spatio-temporal pattern of disease risk predicted is noted to correspond with leaf curl distribution pattern in India. Temperature in the range of 15–35 °C plays an important role in epidemic as both vector population and virus transmission are influenced by temperature. Assessment of leaf curl dynamics would be a useful guide to crop planning and evolution of efficient management strategies.

scholarly journals Haplotype Explorer: an infection cluster visualization tool for spatiotemporal dissection of the COVID-19 pandemic

2021 ◽  
Author(s):  
Tetsuro Kawano-Sugaya ◽  
Koji Yatsu ◽  
Tsuyoshi Sekizuka ◽  
Kentaro Itokawa ◽  
Masanori Hashino ◽  
...  
Keyword(s):  
Functional Limitations ◽  
Time Dependent ◽  
Network Visualization ◽  
Disease Dynamics ◽  
Accession Number ◽  
Haplotype Networks ◽  
Virus Serotype ◽  
Serotype 1 ◽  
Cluster Visualization ◽  
Infectious Disease Dynamics

Abstract Summary Many of software for network visualization are available, but existing software have not been optimized to infection cluster visualization, especially the current worldwide invasion of COVID-19 since 2019. To reach the spatiotemporal understanding of epidemics, we have developed Haplotype Explorer. In Haplotype Explorer, users can explore the network interactively with metadata like accession number, locations, and collection dates. Time dependent transition of the network can be exported as continuous sections for making a movie. Here, we introduce features and products of Haplotype Explorer, demonstrating time-dependent snapshots and a movie of haplotype networks inferred from total of 4,282 SARS-CoV-2 genomes. Abstract The worldwide eruption of COVID-19 that began in Wuhan, China in late 2019 reached 10 million cases by late June 2020. In order to understand the epidemiological landscape of the COVID-19 pandemic, many studies have attempted to elucidate phylogenetic relationships between collected viral genome sequences using haplotype networks. However, currently available applications for network visualization are not suited to understand the COVID-19 epidemic spatiotemporally due to functional limitations, that motivated us to develop Haplotype Explorer, an intuitive tool for visualizing and exploring haplotype networks. Haplotype Explorer enables to dissect epidemiological consequences via interactive node filters and provides the perspective on infectious disease dynamics depend on regions and time, such as introduction, outbreak, expansion, and containment. Here, we demonstrate the effectiveness of Haplotype Explorer by showing features and an example of visualization. The demo using SARS-CoV-2 genomes are available at https://github.com/TKSjp/HaplotypeExplorer/blob/master/Example/. There are several examples using SARS-CoV-2 genomes and Dengue virus serotype 1 E-genes sequence.

scholarly journals Auditors, Underwriters, and Firm Owners’ Interaction in an IPO Environment: The Case of OECD Nations

2021 ◽  
Vol 13 (11) ◽  
pp. 6281
Author(s):  
Sheela Sundarasen ◽  
Kamilah Kamaludin ◽  
Izani Ibrahim ◽  
Usha Rajagopalan ◽  
Nevi Danila
Keyword(s):  
Positive Impact ◽  
Common Law ◽  
Civil Law ◽  
Least Square ◽  
Interactive Effects ◽  
Cross Sectional ◽  
Key Stakeholders ◽  
Research Findings ◽  
Firm Owners ◽  
The Relationship

This study explores the effects of interactions among key stakeholders, i.e., auditors, underwriters, and firm owners on IPOs’ first-day returns in selected OECD nations. It also examines the alteration effects of legal origin (Common law and Civil law) on the relationship between the interacted key stakeholders and IPOs’ first-day returns. A total of four thousand one hundred and sixty-four IPOs from twenty-eight OECD nations are included in this study. Since it is cross-sectional data, a two-stage least square regression is applied. The empirical outcomes indicate that, in general, the interacted reputable underwriters and auditors have a positive impact on IPOs’ first-day return. The relationship is modified between common law and civil law nations, whereby in civil law nations, no significance is demonstrated except for the interaction between the reputable auditors and underwriters. In the common law nation, interactions between reputable auditors and ownership retention have an impact on IPOs’ first-day return. The research findings provide outlooks into an IPO framework for issuers, investors, and regulators. Issuers may want to weigh carefully the costs and benefits of hiring credible auditors and underwriters when going public as they act as signaling agents. As for the investors, they should take into consideration the involvement of reputable underwriters and auditors and the degree to which the IPO firms retain ownership, as the interactive effects give clear signals on firm valuation and IPOs’ first-day returns. Regulators may find the findings informative concerning the creation of a more organized regulatory and financial system that could lead to a deeper and more open financial market.

scholarly journals Real-time forecasting of infectious disease dynamics with a stochastic semi-mechanistic model

Epidemics ◽  
2018 ◽  
Vol 22 ◽  
pp. 56-61 ◽  
Author(s):  
Sebastian Funk ◽  
Anton Camacho ◽  
Adam J. Kucharski ◽  
Rosalind M. Eggo ◽  
W. John Edmunds
Keyword(s):  
Infectious Disease ◽  
Real Time ◽  
Mechanistic Model ◽  
Disease Dynamics ◽  
Infectious Disease Dynamics

Interactive effects of leader justice and support for safety on safety performance

2014 ◽  
Vol 1 (3) ◽  
pp. 296-315 ◽  
Author(s):  
Benjamin R. Kaufman and ◽  
Konstantin P. Cigularov ◽  
Peter Chen ◽  
Krista Hoffmeister ◽  
Alyssa M. Gibbons ◽  
...  
Keyword(s):  
Organizational Justice ◽  
Safety Performance ◽  
Interactive Effects ◽  
Safety Practices ◽  
Content Type ◽  
Fair Treatment ◽  
Leader Support ◽  
Safety Interventions ◽  
The Relationship ◽  
Practical Implications

Purpose – The purpose of this paper is to examine the main and interactive effects of general and safety-specific leader justice (SSLJ) (i.e. fair treatment) and leader support for safety (LSS) on safety performance. Design/methodology/approach – Two independent samples of construction workers rate their leaders with regards to fair treatment and support for safety and report their own safety performance in a survey. Findings – In both studies, LSS significantly moderated relationships of both general and SSLJ with safety performance. In Study 1, the strength of relationship between general leader justice and safety performance increases while LSS is increased. Similar pattern was found for the relationship between SSLJ and safety performance in Study 2. Practical implications – Safety interventions targeting leadership should consider training for leader safety practices that are perceived as supportive and fair. Originality/value – The research is unique in its examination of leader justice in a safety-specific context and its interactive effects with LSS on safety performance. The present research helps to extend the reach of organizational justice theory's nomological network to include safety.

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