A key aim in epidemiology is to understand how pathogens spread within their host populations. Central to this is an elucidation of a pathogen's transmission dynamics. Mathematical models have generally assumed that either contact rate between hosts is linearly related to host density (density-dependent) or that contact rate is independent of density (frequency-dependent), but attempts to confi...

Different methods have been evaluated for manufacturing the porous Ti6Al4V alloys according to decreasing stress shielding phenomenon and increasing mechanical compatibility between the metallic components and the host tissue. For this purpose, in this work Ti6Al4V alloy chips were pressed under 400 MPa pressure and then samples were categorized and heated into two groups at 1000 and 1150℃ unde...

Different methods have been evaluated for manufacturing the porous Ti6Al4V alloys according to decreasing stress shielding phenomenon and increasing mechanical compatibility between the metallic components and the host tissue. For this purpose, in this work Ti6Al4V alloy chips were pressed under 400 MPa pressure and then samples were categorized and heated into two groups at 1000 and 1150℃ unde...

I used a host-visitor modeling framework to examine the interaction between the treehopper Publilia conca6a and ants in the genus Formica. In particular, I tested the functional relationship between ant tending, the spatial distribution of treehoppers, and treehopper density. The per-capita density of ants at each host plant was a decreasing function of treehopper density, distance from the ant...

Host density thresholds are a fundamental component of the population dynamics of pathogens, but empirical evidence and estimates are lacking. We studied host density thresholds in the dynamics of ectoparasitic sea lice (Lepeophtheirus salmonis) on salmon farms. Empirical examples include a 1994 epidemic in Atlantic Canada and a 2001 epidemic in Pacific Canada. A mathematical model suggests dyn...

Pathogens have important effects on host life-history traits, but the magnitude of these effects is often strongly context-dependent. The outcome of an interaction between a host and an infectious agent is often associated with the level of stress experienced by the host. Ranavirus causes disease and mortality in amphibian populations in various locations around the world, but most known cases ...

striped rice stem borer, chilo suppressalis (lepidoptera: pyralidae) is one of the major pests in north part of iran which causes serious damage. the last larval instar overwinters in the stem of weeds around the fields. regarding the importance of weeds as overwintering habitat, population density of larvae was studied in three areas; low-, mid-, and up-lands of mazandaran province and also on...

The feral Soay sheep (Ovis aries L.) population on Hirta, St Kilda, is host to a diverse component parasite community, but previous parasitological studies of the population have only focussed on the metazoan species. This paper reports the first epidemiological study of the protozoan species comprising Cryptosporidium parvum, Giardia duodenalis and 11 species of Eimeria in Soay sheep across 3 ...