Superparasitism refers to the oviposition behavior of parasitoid females who lay their eggs in an already parasitized host. This often yields intense competition among larvae that are sharing the same host. Why would a female oviposit in such hostile habitat instead of looking for a better quality, unparasitized host? Here we present a continuous-time model of host-parasitoid interaction and di...

Maedi-Visna Virus (MVV) seroprevalence and its relationship with housing and mode of rearing of replacement ewe-lambs was investigated in 38 non-randomly selected sheep-flocks in Spain. They included extensive lamb-producing Manchega cross-bred flocks raised almost permanently at pasture, semi-intensive Latxa dairy flocks housed 2-8 months/year and intensively raised Assaf dairy flocks housed m...

During the second outbreak of avian influenza H5N1 in Thailand, probable horizontal transmission among tigers was demonstrated in the tiger zoo. Sequencing and phylogenetic analysis of those viruses showed no differences from the first isolate obtained in January 2004. This finding has implications for influenza virus epidemiology and pathogenicity in mammals.

1. Studies of variability in host resistance to disease generally emphasize variability in susceptibility given exposure, neglecting the possibility that hosts may vary in behaviours that affect the risk of exposure. 2. In many insects, horizontal transmission of baculoviruses occurs when larvae consume foliage contaminated by the cadavers of virus-infected conspecific larvae; so, host behaviou...

TO THE EDITOR—The recent publication by Price et al [1] uses novel methods to illustrate the complex dynamics involved in nosocomial transmission of Staphylococcus aureus through the use of wholegenome sequencing. However, the claim that patient-to-patient transmission is a rare occurrence is not well justified by the presented data. The authors report 7 of 37 (18.7%) patient-to patient transmi...

The aim of this review is to summarise and evaluate the data available about the aetiology of scrapie in naturally affected sheep flocks, particularly data concerning the possible transmission of infection between related animals. The author examines data taken from various relevant studies carried out over the last thirty years. The main conclusions are that scrapie is an infectious disease wi...

Earthquakes hit urban centres in Europe infrequently, but occasionally with disastrous effects. Obtaining an unbiased view of seismic hazard (and risk) is therefore very important. In principle, the best way to test probabilistic seismic hazard assessments (PSHAs) is to compare them with observations that are entirely independent of the procedure used to produce PSHA models. Arguably, the most ...

Serological inspection of Simian T-lymphotropic Virus Type 1 was conducted for a wild colony of Macaca fuscata, which was captured in the middle Honshu, Japan. The increase of positive rate after the juvenile stage with the positive rate reaching 100% (or 35/35) in youngster and adult stages, was observed. This finding suggests that, in contrast with human T-lymphotropic Virus Type 1, horizonta...

This paper focuses on homeopaths' strategies to popularise homeopathy from 1850 to 1870. I argue that homeopaths created a space for homeopathy in Mexico City in the mid-nineteenth century by facilitating patients' access to medical knowledge, consultation and practice. In this period, when national and international armed conflicts limited the diffusion and regulation of academic medicine, hom...

A huge variety of Arthropod species is infected with endosymbiotic Wolbachia bacteria that manipulate their host's reproduction to invade populations. In addition to vertical transmission from mother to offspring through the egg cytoplasm, it has been demonstrated through phylogenetic analyses and natural transfer experiments that horizontal transmission of Wolbachia (i.e. contagion) can occur ...