The construction of the Diama dam on the Senegal river, the Manantali dam on the Bafing river, Mali and the ensuing ecological changes have led to a massive outbreak of Schistosoma mansoni in Northern Senegal, associated with high intensity of infections, due to intense transmission, and the creation of new foci of S. haematobium. Data on the vectorial capacity of Biomphalaria pfeifferi from Nd...

The extent of microsatellite size homoplasy, as well as its effect on several population genetics statistics, was investigated in natural populations using the single-strand conformation polymorphism (SSCP) method. The analysis was conducted using 240 individuals from 13 populations of the freshwater snail Bulinus truncatus at a GT(n)CT(m) compound microsatellite locus. We showed that SSCP can ...

Silvio Berlusconi has dominated Italian political life since he was first elected prime minister in 1994. He has been the third longest-serving prime minister of Italy, after Benito Mussolini and Giovanni Giolitti, and, as of May 2011, he was the longest-serving current leader of a G8 country. This political longevity is often difficult to understand for foreign political analysts. The former I...

Schistosoma mattheei ova were collected from cattle in different localities in South Africa and after hatching, miracidia were used to infest Bulinus (Physopsis) globosus. Cercariae harvested from these snails were used to infest the definitive host Praomys (Mastomys) coucha and eggs from the resulting female S. mattheei were collected. These ova were compared with a Schistosoma haematobium X S...

This study was carried out to investigate the potential use of the herb Pulicaria crispa in the biological control of different developmental stages of Bulinus truncatus, a major snail intermediate host of urinary schistosomiasis. Age-dependent susceptibilities of mature adult snails, immature snails, juveniles, and one-day old egg masses to aqueous extracts of Pulicaria crispa leaves collected...

Helisoma duryi is a planorbid snail, which has been suggested as biological control agent against the intermediate hosts of schistosomiasis. This snail species has been present in a sugar estate in northern Tanzania since 1972. In January 1981 a snail survey was done in this area in order to determine the distribution and abundance of H. duryi relative to other freshwater snail species. The dis...

We introduce the Hamming ball sampler, a novel Markov chain Monte Carlo algorithm, for efficient inference in statistical models involving high-dimensional discrete state spaces. The sampling scheme uses an auxiliary variable construction that adaptively truncates the model space allowing iterative exploration of the full model space. The approach generalizes conventional Gibbs sampling schemes...

Formation of the early vertebrate embryo depends on a Brachyury/Wnt autoregulatory loop within the posterior mesodermal progenitors. We show that exogenous retinoic acid (RA), which dramatically truncates the embryo, represses expression of the zebrafish brachyury ortholog no tail (ntl), causing a failure to sustain the loop. We found that Ntl functions normally to protect the autoregulatory lo...

Crutchfield et al. observed that noise truncates period-doubling cascade and induces chaos. To date, however, very little low-dimensional chaos has been unambiguously identified experimentally. This discrepancy stimulates us to reexamine the noisy logistic map. We find that noise can indeed induce chaos. However, this is not associated with the main 2n cascade. We identify three basic condition...