Variability of dynamic source parameters inferred from kinematic models of past earthquakes

We analyse the scaling and distribution of average dynamic source properties (fracture energy, static, dynamic and apparent stress drops) using 31 kinematic inversion models from 21 crustal earthquakes. Shear-stress histories are computed by solving the elastodynamic equations while imposing the slip velocity of a kinematic source model as a boundary condition on the fault plane. This is achieved using a 3-D finite difference method in which the rupture kinematics are modelled with the staggered-grid-split-node fault representation method of Dalguer & Day. Dynamic parameters are then estimated from the calculated stress-slip curves and averaged over the fault plane. Our results indicate that fracture energy, static, dynamic and apparent stress drops tend to increase with magnitude. The epistemic uncertainty due to uncertainties in kinematic inversions remains small (ϕ∼0.1 in log10 units), showing that kinematic source models provide robust information to analyse the distribution of average dynamic source parameters. The proposed scaling relations may be useful to constrain friction law parameters in spontaneous dynamic rupture calculations for earthquake source studies, and physics-based near-source ground-motion prediction for seismic hazard and risk mitigatio

Population genetics of Glossina palpalis palpalis from central African sleeping sickness foci

<p>Abstract</p> <p>Background</p> <p><it>Glossina palpalis palpalis </it>(Diptera: Glossinidae) is widespread in west Africa, and is the main vector of sleeping sickness in Cameroon as well as in the Bas Congo Province of the Democratic Republic of Congo. However, little is known on the structure of its populations. We investigated <it>G. p. palpalis </it>population genetic structure in five sleeping sickness foci (four in Cameroon, one in Democratic Republic of Congo) using eight microsatellite DNA markers.</p> <p>Results</p> <p>A strong isolation by distance explains most of the population structure observed in our sampling sites of Cameroon and DRC. The populations here are composed of panmictic subpopulations occupying fairly wide zones with a very strong isolation by distance. Effective population sizes are probably between 20 and 300 individuals and if we assume densities between 120 and 2000 individuals per km², dispersal distance between reproducing adults and their parents extends between 60 and 300 meters.</p> <p>Conclusions</p> <p>This first investigation of population genetic structure of <it>G. p. palpalis </it>in Central Africa has evidenced random mating subpopulations over fairly large areas and is thus at variance with that found in West African populations of <it>G. p. palpalis</it>. This study brings new information on the isolation by distance at a macrogeographic scale which in turn brings useful information on how to organise regional tsetse control. Future investigations should be directed at temporal sampling to have more accurate measures of demographic parameters in order to help vector control decision.</p

Treatment of chronic hepatitis C in patients unresponsive to interferon. Interest of re-treatment combining interferon induction therapy and ribavirin (a multicenter pilot study)

Aim About 45% of patients with chronic hepatitis C are unresponsive to the present reference treatment combining pegelated interferon plus ribavirin; before pegylated interferon was available the non-response rate was around 60%. This open multicenter pilot study, initiated before pegylated interferon became available, was designed to evaluate, in patients unresponsive to interferon monotherapy, the rate of biological and virological response and side-effects of the ribivirin- alpha 2b interferon combination. Methods The combination protocol was ribavirin (1 to 1.2 g/d) plus alpha 2b interferon at induction doses (9 MU/d the first week; 4.5 MU/d the eleven following weeks; 3 MU/2 days the 36 following weeks). Results Among the 27 included patients, 17 (63%) were viremia-negative (PCR) after 12 weeks of treatment, 9 (33%) were complete responders (undetectable viremia and normal transaminases) at the end of treatment (48 weeks) and of follow-up (72 weeks). Patients with non-1, non-4 genotypes who derived full benefit from this therapeutic strategy (6/7 (86%) were complete responders: 4/5 with genotype 3 and 2/2 with genotype 5). Quality-of-life was impaired during treatment, especially during the first 12 weeks of high-dose interferon therapy. Conclusion While waiting for new therapeutic possibilities, these good results suggest interferon induction at the beginning of treatment remains a valid option

Xpert MTB/RIF kit en el diagnóstico de tuberculosis de muestras no respiratorias

La detección rápida de M. tuberculosis (MTB) es uno de los objetivos de fundamentales de la OMS y el empleo de técnicas de amplificación de ácidos nucleicos es cada día mas habitual en los laboratorios avanzados, sin embargo la mayoría de estas técnicas están diseñadas para el estudio de MTB en muestras respiratorias y su funcionamiento es controvertido en muestras no respiratorias donde la carga bacilar es pobr

New Source of CP violation in B physics ?

In this talk we discuss how the down type left-right squark mixing in Supersymmetry can induce a new source of CP violation in the time dependent asymmtries in B --> phi K process. We use QCD improved factorization process to calculate the hadronic matrix element for the process and find the allowed parameter space for $\rho$ and $\phi$, the magnitude and phase of the down type LR(RL) squark mixing parameter $\delta^{bs}_{LR(RL)}$. In the same allowed regin we calculate the expected CP asymmtries in the $B \to \phi K^{*}$ process.Comment: 16 pages, Latex, 2 postscript figures, invited talk presented by N.G. Deshpande at the 9th Adriatic meeting, Dubrovnik, Croatia, 4-14 September, 2003. With updated reference

Interés del estudio de micobacterias atípicas y mezclas de micobacterias

Las Micobacterias atípicas constituyen desde hace tiempo un capìtulo importante en la patología infecciosa asi como la mezcla de micobacterias. El desarrollo de modernos sistemas de diagnóstico microbiológico han permitido un mejor aislamiento e identificación de estas especies, algunas de difícil crecimiento en los medios sólidos convencionales y de difícil tipificación por los métodos bioquímicos clásicos. Los nuevos medios de cultivo líquidos, la tecnología genética de amplificación y secuenciación y los sistemas cromatográficos de estudios de ácidos micólicos, han contribuido de forma importante a un mejor diagnóstico de estas especie