Locomotor performance of sand lizards (Lacerta agilis): effects of predatory pressure and parasite load

Locomotor performance affects foraging efficiency, predator avoidance and consequently fitness. Agility and speed determine the animal's social status and reflect its condition. In this study, we test how predatory pressure and parasite load influences locomotor performance of wild specimens of the sand lizard Lacerta agilis. Animals were chased on a 2-metre racetrack. Lizards with autotomy ran significantly faster than lizards with an intact tail, but there was no significant difference in running speed between individuals with fresh caudal autotomy and regenerated tails. Parasite presence and load, age and sex had no significant effect on speed. Our results indicate that autotomy either alters locomotory behaviour or that individuals with autotomised tails were those that previously survived contact with predators, and therefore represented a subgroup of the fastest individuals. Therefore, in general, predatory pressure but not parasites affected locomotor performance in lizards.     

Outcome assessment of a dedicated HIV positive health care worker clinic at a central hospital in Malawi: a retrospective observational study

Background

Malawi has one of the world''s lowest densities of Health Care Workers (HCW) per capita. This study evaluates outcomes of a dedicated HCW HIV clinic in Malawi, created at Zomba Central Hospital in January 2007.

Methods and Findings

Retrospective cohort data was analyzed comparing HCW clinic patient baseline characteristics and treatment outcomes at 18 months after inception, against those attending the general HIV clinic. In-depth interviews and focus group discussions were conducted to explore perceptions of patients and caregivers regarding program value, level of awareness and barriers for uptake amongst HCW. 306 patients were enrolled on antiretroviral therapy (ART) in the HCW HIV clinic, 6784 in the general clinic. Significantly (p<0.01) more HCW clients were initiated on ART on the basis of CD4 as opposed to WHO Stage 3/4 (36% vs.23%). Significantly fewer HCW clients defaulted (6% vs.17%), and died (4% vs.12%). The dedicated HCW HIV clinic was perceived as important and convenient in terms of reduced waiting times, and prompt and high quality care. Improved confidentiality was an appreciated quality of the HCW clinic however barriers included fear of being recognized.

Conclusions/Significance

Outcomes at the HCW clinic appear better compared to the general HIV clinic. The strategy of dedicated clinics to care for health providers is a means of HIV impact mitigation within human resource constrained health systems in high prevalence settings.     

Isolation and characterization of hemolymph clotting factors in Drosophila melanogaster by a pullout method

Clotting is critical in limiting loss of hemolymph and initiating wound healing in insects as well as in vertebrates. Clotting is also an important immune defense, quickly forming a secondary barrier to infection, thereby immobilizing, and possibly killing bacteria directly. Here, we describe methods to assess clotting and to extract the clot from Drosophila larval hemolymph by using aggregation of paramagnetic beads. The validity of the assay was demonstrated by characterization of mutants. We show that clotting occurs in the absence of phenoloxidase and that the Drosophila clot binds bacteria. We also describe a pullout assay to purify the clot as a whole, free from entrapped hemocytes and cellular debris. Proteins subsequently identified by mass spectrometry include both predicted and novel clot proteins. Immune induction has been shown for three of the latter, namely Tiggrin and two unknown proteins (GC15825 and CG15293) that we now propose function in hemolymph clotting. The most abundant clot protein is Hemolectin, and we confirm that hemolectin mutant larvae show clotting defects.