Sex-biased differences in the effects of host individual, host population and environmental traits driving tick parasitism in red deer

AbstractThe structure and similarity of the parasite communities of fish can be evaluated at the component community (CC) and infracommunity (IC) levels. Both hierarchical levels have been used to assess parasite variations in fish at large (biogeographic) scales. However, studies evaluating the consistency between these two hierarchical levels at smaller geographical scales are scarce. In this study, the parasite assemblages of 124 Paralabrax humeralis collected by local fishermen by spear fishing at four sites (El Fierro, EF; P. Angamos, PA; Santa María, ISM; San Jorge, BSJ) in northern Chile were compared to assess the variability (or similarity) of their CCs and ICs at a limited geographical scale using multivariate analysis. At the IC level, discriminant analyses showed that P. humeralis parasite communities varied significantly among sites; 70% of ectoparasite ICs were correctly assigned to each site, but only 55% of helminth parasite ICs were correctly classified. At the CC level, the composition of parasite communities as assessed by correspondence analyses varied significantly between sites. Tagia sp., Neobenedenia sp. and Philometra sp. were associated with BSJ, ISM and PA, respectively; Corynosoma sp. and most digeneans were associated with both ISM and EF. Analysis of similarities (ANOSIM) showed significant variations in the degree of similarity between P. humeralis CCs from different sites, but not between ICs. Variations between CCs from different sites reflect fish population processes (e.g., population age, reproductive segregation) and the particular conditions of their respective habitats, whereas ICs reflect individual host movements. This study demonstrated that, when examined at a limited geographical scale, IC is better than CC at capturing the local pool of parasite assemblages when host populations are spatially segregated. Therefore, in this study, it is demonstrated that at a small geographic scale, CC variations are not reflected by IC, when host population is spatially segregated.

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A review of mathematical models of influenza A infections within a host or cell culture: lessons learned and challenges ahead

10.32920/14668812 ◽

2021 ◽

Author(s):

Catherine A. A. Beauchemin ◽

Andreas Handel

Keyword(s):

Public Health ◽

Cell Culture ◽

Mathematical Models ◽

Influenza A ◽

Influenza Infection ◽

Population Level ◽

Host Population ◽

Lessons Learned ◽

Infection Dynamics ◽

Individual Host

Most mathematical models used to study the dynamics of influenza A have thus far focused on the between-host population level, with the aim to inform public health decisions regarding issues such as drug and social distancing intervention strategies, antiviral stockpiling or vaccine distribution. Here, we investigate mathematical modeling of influenza infection spread at a different scale; namely that occurring within an individual host or a cell culture. We review the models that have been developed in the last decades and discuss their contributions to our understanding of the dynamics of influenza infections. We review kinetic parameters (e.g., viral clearance rate, lifespan of infected cells) and values obtained through fitting mathematical models, and contrast them with values obtained directly from experiments. We explore the symbiotic role of mathematical models and experimental assays in improving our quantitative understanding of influenza infection dynamics. We also discuss the challenges in developing better, more comprehensive models for the course of influenza infections within a host or cell culture. Finally, we explain the contributions of such modeling efforts to important public health issues, and suggest future modeling studies that can help to address additional questions relevant to public health.

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A review of mathematical models of influenza A infections within a host or cell culture: lessons learned and challenges ahead

10.32920/14668812.v1 ◽

2021 ◽

Author(s):

Catherine A. A. Beauchemin ◽

Andreas Handel

Keyword(s):

Public Health ◽

Cell Culture ◽

Mathematical Models ◽

Influenza A ◽

Influenza Infection ◽

Population Level ◽

Host Population ◽

Lessons Learned ◽

Infection Dynamics ◽

Individual Host

Most mathematical models used to study the dynamics of influenza A have thus far focused on the between-host population level, with the aim to inform public health decisions regarding issues such as drug and social distancing intervention strategies, antiviral stockpiling or vaccine distribution. Here, we investigate mathematical modeling of influenza infection spread at a different scale; namely that occurring within an individual host or a cell culture. We review the models that have been developed in the last decades and discuss their contributions to our understanding of the dynamics of influenza infections. We review kinetic parameters (e.g., viral clearance rate, lifespan of infected cells) and values obtained through fitting mathematical models, and contrast them with values obtained directly from experiments. We explore the symbiotic role of mathematical models and experimental assays in improving our quantitative understanding of influenza infection dynamics. We also discuss the challenges in developing better, more comprehensive models for the course of influenza infections within a host or cell culture. Finally, we explain the contributions of such modeling efforts to important public health issues, and suggest future modeling studies that can help to address additional questions relevant to public health.

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MULTIPLE PARASITISM OF ARMORED COCCIDS (HOMOPTERA) BY HOST-REGULATIVE APHELINIDS (HYMENOPTERA); ECTOPARASITES VERSUS ENDOPARASITES

The Canadian Entomologist ◽

10.4039/ent103857-6 ◽

1971 ◽

Vol 103 (6) ◽

pp. 857-872 ◽

Cited By ~ 11

Author(s):

S. E. Flanders

Keyword(s):

Host Population ◽

Statistical Analyses ◽

Low Density ◽

Field Observations ◽

Host Individual ◽

The Family

AbstractWhen a host-regulative ectoparasite and a host-regulative endoparasite compete for the same host population (multiple parasitism) the former largely replaces the latter when the host’s density is high, the ectoparasite then being relatively numerous and the endoparasite scarce. However, after the ectoparasite has reduced the host population to a low density the converse is true, the endoparasite being more numerous. This difference is an effect of the endoparasite being able to operate at lower host densities; an essential adaptation if it is to survive competition with a host-regulative ectoparasitic population. The above conclusions are based (1) on the statistical analyses of numerous population samples of ectoparasitic and endoparasitic species of the family Aphelinidae (Chalcidoidea: Hymenoptera) imported into California while inhabiting host coccids (Diaspididae: Homoptera); (2) on field observations by the writer and the reports of others on the numerical status of such hosts and their specific parasites in gardens and orchards in various countries, those in which the species are indigenous as well as in those where they are exotic; (3) on the principles of multiple parasitism as elucidated by Harry S. Smith; and (4) on multiple parasitism by an ectoparasite and a host-specific endoparasite being characterized by the ectoparasite always destroying the endoparasite when both are attacking the same host individual and the endoparasite replacing the ectoparasite when populations of both are subsisting on a low density host population.

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Scale-dependent effects of geography, host ecology, and host genetics, on species composition and co-occurrence in a stickleback parasite metacommunity

10.1101/672410 ◽

2019 ◽

Cited By ~ 1

Author(s):

Daniel I. Bolnick ◽

Emlyn J. Resetarits ◽

Kimberly Ballare ◽

Yoel E. Stuart ◽

William E. Stutz

Keyword(s):

Parasite Species ◽

Species Distributions ◽

Host Population ◽

Threespine Stickleback ◽

Population Characteristics ◽

Parasite Communities ◽

Individual Host ◽

Host Ecology ◽

Using Data ◽

Lake Size

ABSTRACTA core goal of ecology is to understand the abiotic and biotic variables that regulate species distributions and community composition. A major obstacle is that the rules governing species distribution can change with spatial scale. Here, we illustrate this point using data from a spatially nested metacommunity of parasites infecting a metapopulation of threespine stickleback fish from 34 lakes on Vancouver Island, British Columbia. Parasite communities differ among host individuals within each host population and between host populations. The distribution of each parasite taxon depends, to varying degrees, on individual host traits (e.g., mass, diet) and on host population characteristics (e.g., lake size, mean diet). However, in most cases, a given parasite was regulated by different factors at the host-individual and host-population scales, contributing to scale-dependent patterns of parasite-species co-occurrence.

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Ecological impacts of the microsporidian parasite Pleistophora mulleri on its freshwater amphipod host Gammarus duebeni celticus

Parasitology ◽

10.1017/s0031182005007754 ◽

2005 ◽

Vol 131 (3) ◽

pp. 331-336 ◽

Cited By ~ 23

Author(s):

N. J. FIELDING ◽

C. MacNEIL ◽

N. ROBINSON ◽

J. T. A. DICK ◽

R. W. ELWOOD ◽

...

Keyword(s):

Interspecific Interactions ◽

Parasite Burden ◽

Parasite Prevalence ◽

Abdominal Muscle ◽

Host Population ◽

Ecological Impacts ◽

Activity Level ◽

Microsporidian Parasite ◽

Individual Host ◽

Invasive Amphipod

The microsporidian parasite, Pleistophora mulleri, infects the abdominal muscle of the freshwater amphipod Gammarus duebeni celticus. We recently showed that P. mulleri infection was associated with G. d. celticus hosts being more vulnerable to predation by the invasive amphipod Gammarus pulex. Parasitized G. d. celticus also had a reduced ability to prey upon other co-occurring amphipods. We suggested the parasite may have pervasive influences on host ecology and behaviour. Here, we examine the association between P. mulleri parasitism and parameters influencing individual host fitness, behaviour and interspecific interactions. We also investigate the relationship between parasite prevalence and host population structure in the field. In our G. d. celticus study population, P. mulleri prevalence was strongly seasonal, ranging from 8·5% in summer to 44·9% in winter. The relative abundance of hosts with the heaviest parasite burden increased during summer, which coincided with high host mortality, suggesting that parasitism may regulate host abundance to some degree. Females were more likely to be parasitized than males and parasitized males were paired with smaller females than unparasitized males. Parasitism was associated with reduction in the host's activity level and reduced both its predation on the isopod Asellus aquaticus and aggression towards precopula pairs of the invasive G. pulex. We discuss the pervasive influence of this parasite on the ecology of its host.

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Interactions between malaria parasites infecting the same vertebrate host

Parasitology ◽

10.1017/s0031182000080227 ◽

1988 ◽

Vol 96 (3) ◽

pp. 607-639 ◽

Cited By ~ 86

Author(s):

T. L. Richie

Keyword(s):

Field Studies ◽

Host Population ◽

Host Cells ◽

Laboratory Animals ◽

Cross Resistance ◽

Laboratory Studies ◽

Cross Sectional ◽

Species Complexes ◽

Individual Host ◽

The Tropics

SUMMARYSeveral species of malarial protozoans commonly parasitize the same host population and often the same individual host. This paper reviews the evidence for interactions among such host-sharing parasites. Field studies measuring the cross-sectional prevalence of malarial species often record fewer mixed infections than expected by chance, suggesting that one parasite has excluded another or suppressed its parasitaemia to undetectable levels. Prevalences may vary reciprocally between seasons, with one species increasing in prevalence while another decreases, despite parallel increases in the transmission rates of both, again suggesting suppression of one species by another. However, longitudinal studies of individual hosts indicate that malarial parasites may also favourably affect the host environment for each other, perhaps due to their depressive effect on the immune system: this is shown by the recrudescence of a latent malarial species immediately before or after the parasitic wave of another species. The suppression hypothesis is supported by data derived from the simultaneous inoculation of twoPlasmodiumspecies into laboratory animals; many studies have shown that one or both species are suppressed. This may be mediated by competition for host cells or nutrients, or by heterologous immunity. However, the suppressed species rebounds after the other species has abated, and may show a prolonged infection. Experimental evidence that one species can facilitate the recrudescence of another is minimal, but this may reflect the paucity of investigations of this phenomenon. Laboratory studies show only minor cross-resistance between host-sharing species, which is consistent with the hypothesis that their co-occurrence has led to antigenic divergence or that species showing strong heterologous resistance cannot co-exist in the same host population. Such complementarity occurs not only with the host immune response but also with many other life-history characteristics of host-sharing parasites, such as host cell preference. I conclude that malarial species have been important in each other's evolution, particularly in the tropics where multi-species complexes are common.

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Vocalizations in red deer (Cervus elaphus), sika deer (Cervus nippon), and red × sika hybrids

Journal of Zoology ◽

10.1017/s0952836998001149 ◽

1998 ◽

Vol 244 (1) ◽

pp. 123-134 ◽

Cited By ~ 1

Author(s):

A. M. Long ◽

N.P. Moore ◽

T. J. Hayden

Keyword(s):

Cervus Elaphus ◽

Red Deer ◽

Sika Deer ◽

Cervus Nippon

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The deer of the island of Lampedusa (Pelagian Archipelago, Italy): literary references and osteological evidence

Archives of Natural History ◽

10.3366/anh.2002.29.1.51 ◽

2002 ◽

Vol 29 (1) ◽

pp. 51-66 ◽

Cited By ~ 7

Author(s):

MARCO MASSETP ◽

BRUNO ZAVA

Keyword(s):

Nineteenth Century ◽

Cervus Elaphus ◽

Red Deer ◽

Scientific Literature ◽

Taxonomic Relationships

During the nineteenth century, scientific literature and official reports recorded the occurrence of a population of red deer, Cervus elaphus, on the island of Lampedusa (Pelagian Archipelago, Italy). Osteological specimens collected by the zoologist Enrico Hillier Giglioli towards the end of the century confirmed these references. Since cervids are not found among the fossil fauna of the island, the red deer must have been introduced by man although we do not yet know precisely when. The former existence of the species on Lampedusa is discussed by comparison of literary material and bone evidence. The population's probable origins and its taxonomic relationships with other Mediterranean red deer populations are also analysed.

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