Dung beetles (Coleoptera: Scarabaeidae: Aphodiinae) of the Mpala Research Centre and environs, Laikipia District, Kenya

The dung beetle fauna of the subfamily Aphodiinae occurring in the Laikipia District of Kenya was surveyed. In total, 14 genera and 29 species were found and these taxa are placed in identification keys. Known generic distributions are provided and species collection data listed

Exploring conformational energy landscape of glassy disaccharides by CPMAS 13C NMR and DFT/GIAO simulations. II. Enhanced molecular flexibility in amorphous trehalose

This paper deals with the comparative use of the chemical shift surfaces to simulate experimental 13C CPMAS data on amorphous solid state disaccharides, paying particular attention to -1-1 linkage of trehalose, to -1,4 linkage between pyranose rings (lactose) and to linkage implying a furanose ring (sucrose). The combination of molecular mechanics with DFT/GIAO ab-initio methods provides reliable structural information on the conformational distribution in the glass. The results are interpreted in terms of an enhanced flexibility that trehalose experiences in amorphous solid state compared to the other sugars. An attempt to relate this property to the balance between intra- and inter-molecular hydrogen bonding network in the glass is presented

Critical fluctuations and breakdown of Stokes-Einstein relation in the Mode-Coupling Theory of glasses

We argue that the critical dynamical fluctuations predicted by the mode-coupling theory (MCT) of glasses provide a natural mechanism to explain the breakdown of the Stokes-Einstein relation. This breakdown, observed numerically and experimentally in a region where MCT should hold, is one of the major difficulty of the theory, for which we propose a natural resolution based on the recent interpretation of the MCT transition as a bona fide critical point with a diverging length scale. We also show that the upper critical dimension of MCT is d_c=8.Comment: Proceedings of the workshop on non-equilibrium phenomena in supercooled fluids, glasses and amorphous materials (17-22 September, 2006, Pisa

An integrated approach using M. truncatula to identify loci/genes controlling nutritional and physiological quality of legume seeds

An integrated approach using M. truncatula to identify loci/genes controlling nutritional and physiological quality of legume seeds

The kinetic fragility of liquids as manifestation of the elastic softening

We show that the fragility $m$, the steepness of the viscosity and relaxation time close to the vitrification, increases with the degree of elastic softening, i.e. the decrease of the elastic modulus with increasing temperature, in universal way. This provides a novel connection between the thermodynamics, via the modulus, and the kinetics. The finding is evidenced by numerical simulations and comparison with the experimental data of glassformers with widely different fragilities ($33 \le m \le 115$), leading to a fragility-independent elastic master curve extending over eighteen decades in viscosity and relaxation time. The master curve is accounted for by a cavity model pointing out the roles of both the available free volume and the cage softness. A major implication of our findings is that ultraslow relaxations, hardly characterised experimentally, become predictable by linear elasticity. As an example, the viscosity of supercooled silica is derived over about fifteen decades with no adjustable parameters.Comment: 7 pages, 6 figures; Added new results, improved the theoretical sectio

Is Adipose Tissue a Place for Mycobacterium tuberculosis Persistence?

BACKGROUND: Mycobacterium tuberculosis, the etiological agent of tuberculosis (TB), has the ability to persist in its human host for exceptionally long periods of time. However, little is known about the location of the bacilli in latently infected individuals. Long-term mycobacterial persistence in the lungs has been reported, but this may not sufficiently account for strictly extra-pulmonary TB, which represents 10–15% of the reactivation cases. METHODOLOGY/PRINCIPAL FINDINGS: We applied in situ and conventional PCR to sections of adipose tissue samples of various anatomical origins from 19 individuals from Mexico and 20 from France who had died from causes other than TB. M. tuberculosis DNA could be detected by either or both techniques in fat tissue surrounding the kidneys, the stomach, the lymph nodes, the heart and the skin in 9/57 Mexican samples (6/19 individuals), and in 8/26 French samples (6/20 individuals). In addition, mycobacteria could be immuno-detected in perinodal adipose tissue of 1 out of 3 biopsy samples from individuals with active TB. In vitro, using a combination of adipose cell models, including the widely used murine adipose cell line 3T3-L1, as well as primary human adipocytes, we show that after binding to scavenger receptors, M. tuberculosis can enter within adipocytes, where it accumulates intracytoplasmic lipid inclusions and survives in a non-replicating state that is insensitive to the major anti-mycobacterial drug isoniazid. CONCLUSIONS/SIGNIFICANCE: Given the abundance and the wide distribution of the adipose tissue throughout the body, our results suggest that this tissue, among others, might constitute a vast reservoir where the tubercle bacillus could persist for long periods of time, and avoid both killing by antimicrobials and recognition by the host immune system. In addition, M. tuberculosis-infected adipocytes might provide a new model to investigate dormancy and to evaluate new drugs for the treatment of persistent infection

Effets de la Deltamethrine et d'une solution d'extrait de graines de "Neem" sur les populations de Plutella xylostella (L.) (Lep.: Yponomeutidae) et de Cotesia plutellae (Hym.:Braconidae) dans la zone périurbaine de Cotonou au Bénin

Une comparaison entre des applications de deltaméthrine et une solution d'extrait d'amande de Neem a été effectuée dans la zone péri urbaine de Cotonou, sur des populations de Plutella xylostella (L.). Sur les parcelles traitées à la deltaméthrine, on observe des populations du oraageur dix fois supérieures à celles présentes sur les parcelles traitées au Neem. Le nombre de choux commercialisables issus des parcelles traitées au Neem est 1.5 fois supérieur à celui produit par celles traitées avec le pyréthrinoïde. L'influence de ces applications a également été observée sur les populations de Cotesia plutellae (Kurdjumov), unique parasitoïde de la Teigne. Il semble que ces populations ne soient ni génées par les applications d'extrait de Neem, ni par celles de deltaméthrine

Comparative Effects Of Deltamethrin And Neem Kernel Solution Treatments On Diamondback Moth And Cotesia Plutellae (Hym., Braconidae) Parasitoid Populations In The Cotonou Peri-Urban Area In Benin

A comparison between deltamethrin and Neem kernel solution treatments on Plutella xylostella (L.) populations was made in the Cotonou peri-urban area. Diamondback moth populations were 10 times larger in deltamethrin plots, than in Neem plots after treatment. The number of marketable cabbages from Neem-treated plots was 1.5 times greater than the number from deltamethrin-treated plots. There was no apparent effect of either treatments on Cotesia plutellae (Kurdjumov) populations, the only parasitoid of the pest that was present in the area. (Résumé d'auteur