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.

scholarly journals Genetic diversity predicts pathogen resistance and cell-mediated immunocompetence in house finches

2005 ◽  
Vol 1 (3) ◽  
pp. 326-329 ◽  
Author(s):  
Dana M Hawley ◽  
Keila V Sydenstricker ◽  
George V Kollias ◽  
André A Dhondt
Keyword(s):  
Immune Responses ◽  
Severe Disease ◽  
Bacterial Pathogen ◽  
Mycoplasma Gallisepticum ◽  
Pathogen Resistance ◽  
Carpodacus Mexicanus ◽  
House Finches ◽  
Pathogen Challenge ◽  
Outbred Populations ◽  
The Relationship

Evidence is accumulating that genetic variation within individual hosts can influence their susceptibility to pathogens. However, there have been few opportunities to experimentally test this relationship, particularly within outbred populations of non-domestic vertebrates. We performed a standardized pathogen challenge in house finches ( Carpodacus mexicanus ) to test whether multilocus heterozygosity across 12 microsatellite loci predicts resistance to a recently emerged strain of the bacterial pathogen, Mycoplasma gallisepticum (MG). We simultaneously tested whether the relationship between heterozygosity and pathogen susceptibility is mediated by differences in cell-mediated or humoral immunocompetence. We inoculated 40 house finches with MG under identical conditions and assayed both humoral and cell-mediated components of the immune response. Heterozygous house finches developed less severe disease when infected with MG, and they mounted stronger cell-mediated immune responses to phytohaemagglutinin. Differences in cell-mediated immunocompetence may, therefore, partly explain why more heterozygous house finches show greater resistance to MG. Overall, our results underscore the importance of multilocus heterozygosity for individual pathogen resistance and immunity.

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’.

Carotenoid-based plumage coloration and aggression during molt in male house finches

Behaviour ◽  
2007 ◽  
Vol 144 (2) ◽  
pp. 165-178 ◽  
Author(s):  
William Medina-Jerez ◽  
Heather Adams ◽  
Kevin McGraw
Keyword(s):  
Male Dominance ◽  
Plumage Coloration ◽  
Visual Signal ◽  
Carpodacus Mexicanus ◽  
Plumage Color ◽  
House Finches ◽  
Clear Link ◽  
Access To Food ◽  
The Relationship ◽  
Male House

AbstractBirds often use colorful traits to mediate resource competitions, and typically individuals with bright or large patches of color are more competitive than or dominant to those with drab or small color patches. Male House Finches (Carpodacus mexicanus) are an exception, however, as drab males tend to be more aggressive than bright males during the breeding season and in winter. One hypothesis for this 'negatively correlated handicap' is that drab male house finches, being comparatively sexually unattractive and in poor health and condition, have more to gain by elevating aggression and increasing access to food and pursuit of (especially extra-pair) mates. It would seem important then to test this hypothesis during the period of molt, when birds are actively acquiring the foods and carotenoid pigments that make them colorful and a time in which there is a clear link between plumage color and nutrition/health in this species. We conducted two captive dominance experiments with male House Finches from the southwestern United States (their native range) to examine the relationship between carotenoid-based plumage coloration and aggression during molt. In the first experiment, where birds exhibited their natural, currently growing plumage color, we found that drab males were significantly more aggressive than bright males. However, when plumage colors were manipulated with art markers in a second experiment, color display was no longer significantly predictive of agonistic outcomes. These results suggest that: (1) drab male dominance is not an artifact in eastern US populations and instead is a conserved property of native and non-native House Finches, (2) like in our previous studies in winter, plumage color is correlated with dominance but does not serve as a visual signal of social status in this species, and (3) drab males should have a competitive advantage over access to important carotenoid-rich foods during molt, but apparently do not become as colorful because they do not adequately locate carotenoid-rich foods or do not use them efficiently for energetic or health reasons, which are perhaps exacerbated by elevated testosterone levels.

scholarly journals Multi-Scale Drivers of Immunological Variation and Consequences for Infectious Disease Dynamics

2019 ◽  
Vol 59 (5) ◽  
pp. 1129-1137 ◽  
Author(s):  
Daniel J Becker ◽  
Cynthia J Downs ◽  
Lynn B Martin
Keyword(s):  
Infectious Disease ◽  
Host Defense ◽  
Disease Ecology ◽  
Landscape Heterogeneity ◽  
Population Level ◽  
Immune Defense ◽  
Model Systems ◽  
Disease Dynamics ◽  
Multi Scale ◽  
Infectious Disease Dynamics

Abstract The immune system is the primary barrier to parasite infection, replication, and transmission following exposure, and variation in immunity can accordingly manifest in heterogeneity in traits that govern population-level infectious disease dynamics. While much work in ecoimmunology has focused on individual-level determinants of host immune defense (e.g., reproductive status and body condition), an ongoing challenge remains to understand the broader evolutionary and ecological contexts of this variation (e.g., phylogenetic relatedness and landscape heterogeneity) and to connect these differences into epidemiological frameworks. Ultimately, such efforts could illuminate general principles about the drivers of host defense and improve predictions and control of infectious disease. Here, we highlight recent work that synthesizes the complex drivers of immunological variation across biological scales of organization and scales these within-host differences to population-level infection outcomes. Such studies note the limitations involved in making species-level comparisons of immune phenotypes, stress the importance of spatial scale for immunology research, showcase several statistical tools for translating within-host data into epidemiological parameters, and provide theoretical frameworks for linking within- and between-host scales of infection processes. Building from these studies, we highlight several promising avenues for continued work, including the application of machine learning tools and phylogenetically controlled meta-analyses to immunology data and quantifying the joint spatial and temporal dependencies in immune defense using range expansions as model systems. We also emphasize the use of organismal traits (e.g., host tolerance, competence, and resistance) as a way to interlink various scales of analysis. Such continued collaboration and disciplinary cross-talk among ecoimmunology, disease ecology, and mathematical modeling will facilitate an improved understanding of the multi-scale drivers and consequences of variation in host defense.

scholarly journals The Relationship between Suicidality and Socio-Demographic Variables, Physical Disorders, and Psychiatric Disorders: Results from the Singapore Mental Health Study 2016

2021 ◽  
Vol 18 (8) ◽  
pp. 4365
Author(s):  
Kundadak Ganesh Kudva ◽  
Edimansyah Abdin ◽  
Janhavi Ajit Vaingankar ◽  
Boon Yiang Chua ◽  
Saleha Shafie ◽  
...  
Keyword(s):  
Mental Health ◽  
Suicidal Ideation ◽  
Psychiatric Disorders ◽  
Population Level ◽  
Risk Groups ◽  
Epidemiological Survey ◽  
Health Study ◽  
Physical Disorders ◽  
Mental Health Study ◽  
The Relationship

Suicidality encompasses suicidal ideation, plans, and attempts. This paper aims to establish associations between suicidality and sociodemographic variables, physical disorders, and psychiatric disorders. The Singapore Mental Health Study 2016 was a population-level epidemiological survey, which determined the prevalence of physical disorders, psychiatric disorders, and suicidality. Questionnaires were used to determine socio-demographic information. A total of 6216 respondents were interviewed. Lifetime prevalence of suicidal ideation, planning, and attempts were 7.8%, 1.6%, and 1.6%, respectively. All components of suicidality were more likely in those with major depressive disorder, bipolar disorder, generalized anxiety disorder, alcohol use disorder, and chronic pain. Suicidal ideation and attempts were more likely in those with diabetes. Age above 65, being male, and a monthly household income of ≥ SGD 10,000 were associated with a lower likelihood of suicidal ideation. These findings indicate that there are high-risk groups for whom suicidality is a concern, and for whom interventions may be needed.

scholarly journals PDE limits of stochastic SIS epidemics on networks

2020 ◽  
Vol 8 (4) ◽  
Author(s):  
F Di Lauro ◽  
J-C Croix ◽  
L Berthouze ◽  
I Z Kiss
Keyword(s):  
Network Inference ◽  
Mean Field ◽  
Population Level ◽  
Death Process ◽  
Disease Dynamics ◽  
Epidemic Outbreak ◽  
Numerical Tests ◽  
Mean Field Models ◽  
Stochastic Epidemic ◽  
Fokker Planck Equations

Abstract Stochastic epidemic models on networks are inherently high-dimensional and the resulting exact models are intractable numerically even for modest network sizes. Mean-field models provide an alternative but can only capture average quantities, thus offering little or no information about variability in the outcome of the exact process. In this article, we conjecture and numerically demonstrate that it is possible to construct partial differential equation (PDE)-limits of the exact stochastic susceptible-infected-susceptible epidemics on Regular, Erdős–Rényi, Barabási–Albert networks and lattices. To do this, we first approximate the exact stochastic process at population level by a Birth-and-Death process (BD) (with a state space of $O(N)$ rather than $O(2^N)$) whose coefficients are determined numerically from Gillespie simulations of the exact epidemic on explicit networks. We numerically demonstrate that the coefficients of the resulting BD process are density-dependent, a crucial condition for the existence of a PDE limit. Extensive numerical tests for Regular, Erdős–Rényi, Barabási–Albert networks and lattices show excellent agreement between the outcome of simulations and the numerical solution of the Fokker–Planck equations. Apart from a significant reduction in dimensionality, the PDE also provides the means to derive the epidemic outbreak threshold linking network and disease dynamics parameters, albeit in an implicit way. Perhaps more importantly, it enables the formulation and numerical evaluation of likelihoods for epidemic and network inference as illustrated in a fully worked out example.

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 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

scholarly journals Investigating hot-Jupiter inflated radii with hierarchical Bayesian modelling

2018 ◽  
Vol 616 ◽  
pp. A76 ◽  
Author(s):  
Marko Sestovic ◽  
Brice-Olivier Demory ◽  
Didier Queloz
Keyword(s):  
Large Fraction ◽  
Population Level ◽  
Mass Range ◽  
Hierarchical Bayesian ◽  
Incident Flux ◽  
Hot Jupiters ◽  
Probabilistic Relation ◽  
Relationship Of ◽  
The Relationship ◽  
Level Analysis

Context. As of today, hundreds of hot Jupiters have been found, yet the inflated radii of a large fraction of them remain unexplained. A number of mechanisms have been proposed to explain these anomalous radii, however most of these can only work under certain conditions and may not be sufficient to explain the most extreme cases. It is still unclear whether a single mechanism can sufficiently explain the entire distribution of radii, or whether a combination of these mechanisms is needed. Aims. We seek to understand the relationship of radius with stellar irradiation and mass and to find the range of masses over which hot Jupiters are inflated. We also aim to find the intrinsic physical scatter in their radii, caused by unobservable parameters, and to constrain the fraction of hot Jupiters that exhibit inflation. Methods. By constructing a hierarchical Bayesian model, we inferred the probabilistic relation between planet radius, mass, and incident flux for a sample of 286 gas giants. We separately incorporated the observational uncertainties of the data and the intrinsic physical scatter in the population. This allowed us to treat the intrinsic physical scatter in radii, due to latent parameters such as the heavy element fraction, as a parameter to be inferred. Results. We find that the planetary mass plays a key role in the inflation extent and that planets in the range ~0.37−0.98  MJ show the most inflated radii. At higher masses, the radius response to incident flux begins to decrease. Below a threshold of 0.37 ± 0.03  MJ we find that giant exoplanets as a population are unable to maintain inflated radii ≿1.4  RJ but instead exhibit smaller sizes as the incident flux is increased beyond 106 W m−2. We also find that below 1  MJ, there is a cut-off point at high incident flux beyond which we find no more inflated planets, and that this cut-off point decreases as the mass decreases. At incident fluxes higher than ~1.6 × 106 W m−2 and in a mass range 0.37−0.98  MJ, we find no evidence for a population of non-inflated hot Jupiters. Our study sheds a fresh light on one of the key questions in the field and demonstrates the importance of population-level analysis to grasp the underlying properties of exoplanets.

scholarly journals Pathogen resistance and immunocompetence covary with social status in house finches (Carpodacus mexicanus)

2007 ◽  
Vol 21 (3) ◽  
pp. 520-527 ◽  
Author(s):  
D. M. HAWLEY ◽  
C. S. JENNELLE ◽  
K. V. SYDENSTRICKER ◽  
A. A. DHONDT
Keyword(s):  
Social Status ◽  
Pathogen Resistance ◽  
Carpodacus Mexicanus ◽  
House Finches
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