Giraffe translocation population viability analysis

Most populations of giraffes have declined in recent decades, leading to the recent IUCN decision to upgrade the species to Vulnerable status, and some subspecies to Endangered. Translocations have been used as a conservation tool to re-introduce giraffes to previously occupied areas or establish new populations, but guidelines for founding populations are lacking. To provide general guidelines for translocation projects regarding feasibility, we simulated various scenarios of translocated giraffe populations to identify viable age and sex distributions of founding populations using population viability analysis (PVA) implemented in Vortex software. We explored the parameter space for demography and the genetic load, examining how variation in founding numbers and sex ratios affected 100 yr probability of population extinction and genetic diversity. We found that even very small numbers of founders (N ≤ 10 females) can appear to be successful in the first decades due to transient positive population growth, but with moderate population growth rate and moderate genetic load, long-term population viability (probability of extinction 95% genetic diversity of the source population in an isolated population, 50 females and 5 males are recommended to compose the founding population. Sensitivity analyses revealed first-year survival and reproductive rate were the simulation parameters with the greatest proportional influence on probability of extinction and genetic diversity. These simulations highlight important considerations for translocation success and data gaps including true genetic load in wild giraffe populations

Building a locally diploid genome and transcriptome of the diatom Fragilariopsis cylindrus

The genome of the cold-adapted diatom Fragilariopsis cylindrus is characterized by highly diverged haplotypes that intersperse its homozygous genome. Here, we describe how a combination of PacBio DNA and Illumina RNA sequencing can be used to resolve this complex genomic landscape locally into the highly diverged haplotypes, and how to map various environmentally controlled transcripts onto individual haplotypes. We assembled PacBio sequence data with the FALCON assembler and created a haplotype resolved annotation of the assembly using annotations of a Sanger sequenced F. cylindrus genome. RNA-seq datasets from six different growth conditions were used to resolve allele-specifc gene expression in F. cylindrus. This approach enables to study differential expression of alleles in a complex genomic landscape and provides a useful tool to study how diverged haplotypes in diploid organisms are used for adaptation and evolution to highly variable environments

Parasite diversity and ecology in a model species, the guppy (Poecilia reticulata) in Trinidad

The guppy (Poecilia reticulata) is a model species in ecology and evolution. Many studies have examined effects of predators on guppy behaviour, reproduction, survival strategies, feeding and other life-history traits, but few have studied variation in their parasite diversity. We surveyed parasites of 18 Trinidadian populations of guppy, to provide insight on the geographical mosaic of parasite variability, which may act as a source of natural selection acting on guppies. We found 21 parasite species, including five new records for Trinidad. Spatial variation in parasite diversity was significantly higher than that of piscine predators, and significant variation in parasite richness among individuals and populations was correlated with: (i) host size, (ii) snail species richness, and (iii) the distance between populations. Differences in parasite species richness are likely to play an important, yet underestimated role in the biology of this model species of vertebrate ecology and evolution

Diagnosis and management of antiretroviral-therapy failure in resource-limited settings in sub-Saharan Africa: challenges and perspectives.

Despite the enormous progress made in scaling up antiretroviral therapy (ART) in sub-Saharan Africa, many challenges remain, not least of which are the identification and management of patients who have failed first-line therapy. Less than 3% of patients are receiving second-line treatment at present, whereas 15-25% of patients have detectable viral loads 12 months or more into treatment, of whom a substantial proportion might have virological failure. We discuss the reasons why virological ART failure is likely to be under-diagnosed in the routine health system, and address the current difficulties with standard recommended second-line ART regimens. The development of new diagnostic tools for ART failure, in particular a point-of-care HIV viral-load test, combined with simple and inexpensive second-line therapy, such as boosted protease-inhibitor monotherapy, could revolutionise the management of ART failure in resource-limited settings

Rapid Urine-Based Screening for Tuberculosis to Reduce AIDS-Related Mortality in Hospitalized Patients in Africa (STAMP) Trial Protocol

Trial protocol for the STAMP trial- a multi-country (Malawi and South Africa) individually randomised clinical trial to determine the impact on early mortality of the addition of rapid, urine-based TB screening to the standard of care TB screening in HIV-infected patients requiring admission to medical wards in hospitals in southern Africa

Interleukin-5 Potentiates Sulfidopeptide Leukotriene Production by Human Eosinophils

Interleukin-5 (IL-5) has been shown to be a selective eosinophil growth and differentiation factor. In the present study, the effect of recombinant human IL-5 on human eosinophil sulfidopeptide leukotriene production was investigated. IL-5 did not affect leukotriene synthesis in unstimulated eosinophils. However, IL-5 potentiated leukotriene synthesis by eosinophils stimulated with serum treated zymosan (STZ) or the calcium ionophore A23187 by 69% and 135%, respectively. The priming effect of IL-5 was dose dependent, with significant stimulation occurring at 1 000 U/ml for STZ and 100-1 000 U/ml for A23187. Pre-incubation with IL-5 did not increase leukotriene synthesis further

Breast enlargement in Malawian males on the standard first line antiretroviral therapy regimen: Case reports and review of the literature

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Pharmacokinetics of Antituberculosis Drugs in HIV-Positive and HIV-Negative Adults in Malawi

Limited data address the impact of HIV co-infection on the pharmacokinetics of anti-tuberculosis drugs in Sub-Saharan Africa. 47 Malawian adults underwent rich pharmacokinetic sampling at 0-0.5-1-2-3-4-6-8 and 24 hours post-dose. 51% were male; mean age was 34 years. 65% were HIV-positive with a mean CD4 count of 268 cells/μL. Anti-tuberculosis drugs were administered as fixed-dose combinations (rifampicin150mg/isoniazid75mg/pyrazinamide400mg/ethambutol275mg) according to recommended weight bands. Plasma drug concentrations were determined by high-performance liquid chromatography (rifampicin and pyrazinamide) or liquid chromatography-mass spectrometry (isoniazid and ethambutol). Data were analysed by non-compartmental methods and analysis of variance of log-transformed summary parameters. Pharmacokinetic parameters were: rifampicin Cmax 4.129 (2.474-5.596)μg/mL, AUC0-24 21.32 (13.57-28.60)μg/mL*h, half-life 2.45 (1.86-3.08)h; isoniazid Cmax 3.97 (2.979-4.544)μg/mL, AUC0-24 22.5 (14.75-34.59)μg/mL*h, half-life 3.93 (3.18-4.73)h.; pyrazinamide Cmax 34.21 (30.00-41.60)μg/mL, AUC0-24 386.6 (320.0-463.7)μg/mL*h, half-life 6.821 (5.71-8.042)h; ethambutol Cmax 2.278 (1.694-3.098)μg/mL, AUC0-24 20.41 (16.18-26.27)μg/mL*h, half-life 7.507 (6.517-8.696)h. Isoniazid PK data analysis suggested that around two-thirds were slow acetylators. Dose, weight and weight-adjusted dose were not significant predictors of PK exposure probably due to weight-banded dosing. In this first pharmacokinetic study of tuberculosis drugs in Malawian adults, measures of pharmacokinetic exposure were comparable with other studies for all first line drugs except for rifampicin, for which Cmax and AUC0-24 were notably lower. Contrary to some earlier observations, HIV status did not significantly affect AUC of any of the drugs. Increasing the dose of rifampicin could be beneficial in African adults, irrespective of HIV status. Current co-trimoxazole prophylaxis was associated with an increase in half-life of isoniazid of 41% (p=0.022). Possible competitive interactions between isoniazid and sulphamethoxazole mediated by the N-acetyltransferase pathway should therefore be explored further