Disruption of Rhino Demography by Poachers May Lead to Population Declines in Kruger National Park,South Africa

The onslaught on the World’s rhinoceroses continues despite numerous initiatives aimed at curbing it. When losses due to poaching exceed birth rates, declining rhino populations result. We used previously published estimates and growth rates for black rhinos (2008) and white rhinos (2010) together with known poaching trends at the time to predict population sizes and poaching rates in Kruger National Park, South Africa for 2013. Kruger is a stronghold for the south-eastern black rhino and southern white rhino. Counting rhinos on 878 blocks 3x3 km in size using helicopters, estimating availability bias and collating observer and detectability biases allowed estimates using the Jolly’s estimator. The exponential escalation in number of rhinos poached per day appears to have slowed. The black rhino estimate of 414 individuals (95% confidence interval: 343-487) was lower than the predicted 835 individuals (95% CI: 754-956). The white rhino estimate of 8,968 individuals (95% CI: 8,394-9,564) overlapped with the predicted 9,417 individuals (95% CI: 7,698-11,183). Density- and rainfall-dependent responses in birth- and death rates of white rhinos provide opportunities to offset anticipated poaching effects through removals of rhinos from high density areas to increase birth and survival rates. Biological management of rhinos, however, need complimentary management of the poaching threat as present poaching trends predict detectable declines in white rhino abundances by 2018. Strategic responses such as anti-poaching that protect supply from illegal harvesting, reducing demand, and increasing supply commonly require crime network disruption as a first step complimented by providing options for alternative economies in areas abutting protected areas.     

Polymorphic Variation in TIRAP Is Not Associated with Susceptibility to Childhood TB but May Determine Susceptibility to TBM in Some Ethnic Groups

Host recognition of mycobacterial surface molecules occurs through toll like receptors (TLR) 2 and 6. The adaptor protein TIRAP mediates down stream signalling of TLR2 and 4, and polymorphisms in the TIRAP gene (TIRAP) have been associated with susceptibility and resistance to tuberculosis (TB) in adults. In order to investigate the role of polymorphic variation in TIRAP in childhood TB in South Africa, which has one of the highest TB incidence rates in the world, we screened the entire open reading frame of TIRAP for sequence variation in two cohorts of childhood TB from different ethnic groups (Xhosa and mixed ancestry). We identified 13 SNPs, including seven previously unreported, in the two cohorts, and found significant differences in frequency of the variants between the two ethnic groups. No differences in frequency between individual SNPs or combinations were found between TB cases and controls in either cohort. However the 558C→T SNP previously associated with TB meningitis (TBM) in a Vietnamese population was found to be associated with TBM in the mixed ancestry group. Polymorphisms in TIRAP do not appear to be involved in childhood TB susceptibility in South Africa, but may play a role in determining occurrence of TBM.     

The host preferences of Nuttalliella namaqua (Ixodoidea: Nuttalliellidae): a generalist approach to surviving multiple host-switches

Nuttalliella namaqua has been described as a “living fossil” and the closest extant species to the ancestral tick lineage. It was previously proposed that the Nuttalliella lineage parasitized reptile-like mammals in the Permian and had to switch hosts several times due to mass or host lineage extinctions. Extant hosts include girdled lizards and murid rodents. The current study extends knowledge on the extant host range of N. namaqua using gut meal analysis of field collected specimens. Nymphs and females can parasitize a variety of reptiles that includes skinks, geckos and girdled lizards. Blood-meal from a hyrax was also detected in a specimen suggesting that N. namaqua could parasitize a broader range of mammals than the previously suggested murid rodents. Rather than being host specific, N. namaqua is proposed to be a generalist and the ability to switch and parasitize multiple hosts allowed it to survive multiple mass and host lineage extinctions.     

AN ADDITIONAL PUNCTATE SPECIES OF PYRAMIMONAS, P. FORMOSA, SP. NOV., AND ITS IMPACT ON THE SUBGENERA PUNCTATAE AND PYRAMIMONAS (PRASINOPHYCEAE, CHLOROPHYTA)

A new punctate species of Pyramimonas Schmarda from South Africa is described. This species is somewhat anomalous and, like P. chlorina Sym et Pienaar (subgenus Pyramimonas McFadden), has characters that bridge the divide between the subgenera Pyramimonas and Punctatae McFadden. Features of these two species, together with the lack of exclusive character sets for either subgenus derived from other species of these subgenera, lead to the conclusion that Punctatae now should be subsumed formally into the subgenus Pyramimonas.     

Understanding Miro GTPases: Implications in the Treatment of Neurodegenerative Disorders

The Miro GTPases represent an unusual subgroup of the Ras superfamily and have recently emerged as important mediators of mitochondrial dynamics and for maintaining neuronal health. It is now well-established that these enzymes act as essential components of a Ca²⁺-sensitive motor complex, facilitating the transport of mitochondria along microtubules in several cell types, including dopaminergic neurons. The Miros appear to be critical for both anterograde and retrograde mitochondrial transport in axons and dendrites, both of which are considered essential for neuronal health. Furthermore, the Miros may be significantly involved in the development of several serious pathological processes, including the development of neurodegenerative and psychiatric disorders. In this review, we discuss the molecular structure and known mitochondrial functions of the Miro GTPases in humans and other organisms, in the context of neurodegenerative disease. Finally, we consider the potential human Miros hold as novel therapeutic targets for the treatment of such disease.     

Nuttalliella namaqua: a living fossil and closest relative to the ancestral tick lineage: implications for the evolution of blood-feeding in ticks

Ticks are monophyletic and composed of the hard (Ixodidae) and soft (Argasidae) tick families, as well as the Nuttalliellidae, a family with a single species, Nuttalliella namaqua. Significant biological differences in lifestyle strategies for hard and soft ticks suggest that various blood-feeding adaptations occurred after their divergence. The phylogenetic relationships between the tick families have not yet been resolved due to the lack of molecular data for N. namaqua. This tick possesses a pseudo-scutum and apical gnathostoma as observed for ixodids, has a leathery cuticle similar to argasids and has been considered the evolutionary missing link between the two families. Little knowledge exists with regard to its feeding biology or host preferences. Data on its biology and systematic relationship to the other tick families could therefore be crucial in understanding the evolution of blood-feeding behaviour in ticks. Live specimens were collected and blood meal analysis showed the presence of DNA for girdled lizards from the Cordylid family. Feeding of ticks on lizards showed that engorgement occurred rapidly, similar to argasids, but that blood meal concentration occurs via malpighian excretion of water. Phylogenetic analysis of the 18S nuclear and 16S mitochondrial genes indicate that N. namaqua grouped basal to the main tick families. The data supports the monophyly of all tick families and suggests the evolution of argasid-like blood-feeding behaviour in the ancestral tick lineage. Based on the data and considerations from literature we propose an origin for ticks in the Karoo basin of Gondwanaland during the late Permian. The nuttalliellid family almost became extinct during the End Permian event, leaving N. namaqua as the closest living relative to the ancestral tick lineage and the evolutionary missing link between the tick families.     

Randomized controlled trials of HIV/AIDS prevention and treatment in Africa: results from the Cochrane HIV/AIDS Specialized Register

Introduction

To effectively address HIV/AIDS in Africa, evidence on preventing new infections and providing effective treatment is needed. Ideally, decisions on which interventions are effective should be based on evidence from randomized controlled trials (RCTs). Our previous research described African RCTs of HIV/AIDS reported between 1987 and 2003. This study updates that analysis with RCTs published between 2004 and 2008.

Objectives

To describe RCTs of HIV/AIDS conducted in Africa and reported between 2004 and 2008.

Methods

We searched the Cochrane HIV/AIDS Specialized Register in September 2009. Two researchers independently evaluated studies for inclusion and extracted data using standardized forms. Details included location of trials, interventions, methodological quality, location of principal investigators and funders.

Results

Our search identified 834 RCTs, with 68 conducted in Africa. Forty-three assessed prevention-interventions and 25 treatment-interventions. Fifteen of the 43 prevention RCTs focused on preventing mother-to-child HIV transmission. Thirteen of the 25 treatment trials focused on opportunistic infections. Trials were conducted in 16 countries with most in South Africa (20), Zambia (12) and Zimbabwe (9). The median sample size was 628 (range 33-9645). Methods used for the generation of the allocation sequence and allocation concealment were adequate in 38 and 32 trials, respectively, and 58 reports included a CONSORT recommended flow diagram. Twenty-nine principal investigators resided in the United States of America (USA) and 18 were from African countries. Trials were co-funded by different agencies with most of the funding obtained from USA governmental and non-governmental agencies. Nineteen pharmaceutical companies provided partial funding to 15 RCTs and African agencies co-funded 17 RCTs. Ethical approval was reported in 65 trials and informed consent in 61 trials.

Conclusion

Prevention trials dominate the trial landscape in Africa. Of note, few principal investigators and funders are from Africa. These findings mirror our previous work and continue to indicate a need for strengthening trial research capacity in Africa.