Potential Risk of Regional Disease Spread in West Africa through Cross-Border Cattle Trade

Background

Transboundary animal movements facilitate the spread of pathogens across large distances. Cross-border cattle trade is of economic and cultural importance in West Africa. This study explores the potential disease risk resulting from large-scale, cross-border cattle trade between Togo, Burkina Faso, Ghana, Benin, and Nigeria for the first time.

Methods and Principal Findings

A questionnaire-based survey of livestock movements of 226 cattle traders was conducted in the 9 biggest cattle markets of northern Togo in February-March 2012. More than half of the traders (53.5%) operated in at least one other country. Animal flows were stochastically simulated based on reported movements and the risk of regional disease spread assessed. More than three quarters (79.2%, range: 78.1–80.0%) of cattle flowing into the market system originated from other countries. Through the cattle market system of northern Togo, non-neighbouring countries were connected via potential routes for disease spread. Even for diseases with low transmissibility and low prevalence in a given country, there was a high risk of disease introduction into other countries.

Conclusions

By stochastically simulating data collected by interviewing cattle traders in northern Togo, this study identifies potential risks for regional disease spread in West Africa through cross-border cattle trade. The findings highlight that surveillance for emerging infectious diseases as well as control activities targeting endemic diseases in West Africa are likely to be ineffective if only conducted at a national level. A regional approach to disease surveillance, prevention and control is essential.     

Donor–Acceptor Shape Matching Drives Performance in Photovoltaics

While the demonstrated power conversion efficiency of organic photovoltaics (OPVs) now exceeds 10%, new design rules are required to tailor interfaces at the molecular level for optimal exciton dissociation and charge transport in higher efficiency devices. We show that molecular shape‐complementarity between donors and acceptors can drive performance in OPV devices. Using core hole clock (CHC) X‐ray spectroscopy and density functional theory (DFT), we compare the electronic coupling, assembly, and charge transfer rates at the interface between C₆₀ acceptors and flat‐ or contorted‐hexabenzocorone (HBC) donors. The HBC donors have similar optoelectronic properties but differ in molecular contortion and shape matching to the fullerene acceptors. We show that shape‐complementarity drives self‐assembly of an intermixed morphology with a donor/acceptor (D/A) ball‐and‐socket interface, which enables faster electron transfer from HBC to C₆₀. The supramolecular assembly and faster electron transfer rates in the shape complementary heterojunction lead to a larger active volume and enhanced exciton dissociation rate. This work provides fundamental mechanistic insights on the improved efficiency of organic photovoltaic devices that incorporate these concave/convex D/A materials.     

A species in decline: genetic diversity and conservation of the Victorian eastern barred bandicoot, Perameles gunnii

The eastern barred bandicoot, Perameles gunnii, has undergone a dramatic decline in distribution and abundance on the mainland of Australia during the twentieth century. In 1988 a captive breeding program was initiated to reduce the chance of extinction. With the extinction of the last wild mainland population in the early 1990s, reintroductions from captive-bred P. gunnii have met limited success, and currently only two extant populations persist in predator proof enclosures in the State of Victoria. With ~20 years of breeding, there are concerns that the genetic diversity within the breeding program has declined and may inhibit current and future success of the program. We have used ten nuclear microsatellite loci and sequencing of two partial mitochondrial genes (cytochrome oxidase I and ATPase 6) to determine genetic diversity within current Victorian P. gunnii. These diversity estimates are compared with historic samples from the captive breeding program dating back to 1995, historic samples from the last wild mainland population found at Hamilton in 1992 and contemporary Tasmanian wild populations. Results indicate that the captive P. gunnii population in the State of Victoria has lost significant genetic diversity through time. Genetic diversity is also reduced in populations at Hamilton Community Parklands and Mount Rothwell. Samples from the last wild population at Hamilton collected in 1992, along with samples from Tasmanian P. gunnii, had significantly greater genetic diversity than contemporary mainland populations. The results are discussed with reference to management options for maintaining genetic diversity within Victorian P. gunnii, including crossing Victorian and Tasmanian P. gunnii to increase genetic diversity, adaptability and evolutionary potential.     

Evidence for Enhanced Multisensory Facilitation with Stimulus Relevance: An Electrophysiological Investigation

Currently debate exists relating to the interplay between multisensory processes and bottom-up and top-down influences. However, few studies have looked at neural responses to newly paired audiovisual stimuli that differ in their prescribed relevance. For such newly associated audiovisual stimuli, optimal facilitation of motor actions was observed only when both components of the audiovisual stimuli were targets. Relevant auditory stimuli were found to significantly increase the amplitudes of the event-related potentials at the occipital pole during the first 100 ms post-stimulus onset, though this early integration was not predictive of multisensory facilitation. Activity related to multisensory behavioral facilitation was observed approximately 166 ms post-stimulus, at left central and occipital sites. Furthermore, optimal multisensory facilitation was found to be associated with a latency shift of induced oscillations in the beta range (14–30 Hz) at right hemisphere parietal scalp regions. These findings demonstrate the importance of stimulus relevance to multisensory processing by providing the first evidence that the neural processes underlying multisensory integration are modulated by the relevance of the stimuli being combined. We also provide evidence that such facilitation may be mediated by changes in neural synchronization in occipital and centro-parietal neural populations at early and late stages of neural processing that coincided with stimulus selection, and the preparation and initiation of motor action.     

Calreticulin enhances the secretory trafficking of a misfolded α-1-antitrypsin

α1-antitrypsin (AAT) regulates the activity of multiple proteases in the lungs and liver. A mutant of AAT (E342K) called ATZ forms polymers that are present at only low levels in the serum and induce intracellular protein inclusions, causing lung emphysema and liver cirrhosis. An understanding of factors that can reduce the intracellular accumulation of ATZ is of great interest. We now show that calreticulin (CRT), an endoplasmic reticulum (ER) glycoprotein chaperone, promotes the secretory trafficking of ATZ, enhancing the media:cell ratio. This effect is more pronounced for ATZ than with AAT and is only partially dependent on the glycan-binding site of CRT, which is generally relevant to substrate recruitment and folding by CRT. The CRT-related chaperone calnexin does not enhance ATZ secretory trafficking, despite the higher cellular abundance of calnexin-ATZ complexes. CRT deficiency alters the distributions of ATZ-ER chaperone complexes, increasing ATZ-BiP binding and inclusion body formation and reducing ATZ interactions with components required for ER-Golgi trafficking, coincident with reduced levels of the protein transport protein Sec31A in CRT-deficient cells. These findings indicate a novel role for CRT in promoting the secretory trafficking of a protein that forms polymers and large intracellular inclusions. Inefficient secretory trafficking of ATZ in the absence of CRT is coincident with enhanced accumulation of ER-derived ATZ inclusion bodies. Further understanding of the factors that control the secretory trafficking of ATZ and their regulation by CRT could lead to new therapies for lung and liver diseases linked to AAT deficiency.     

The new sequencer on the block: comparison of Life Technology’s Proton sequencer to an Illumina HiSeq for whole-exome sequencing

We assessed the performance of the new Life Technologies Proton sequencer by comparing whole-exome sequence data in a Centre d’Etude du Polymorphisme Humain trio (family 1463) to the Illumina HiSeq instrument. To simulate a typical user’s results, we utilized the standard capture, alignment and variant calling methods specific to each platform. We restricted data analysis to include the capture region common to both methods. The Proton produced high quality data at a comparable average depth and read length, and the Ion Reporter variant caller identified 96 % of single nucleotide polymorphisms (SNPs) detected by the HiSeq and GATK pipeline. However, only 40 % of small insertion and deletion variants (indels) were identified by both methods. Usage of the trio structure and segregation of platform-specific alleles supported this result. Further comparison of the trio data with Complete Genomics sequence data and Illumina SNP microarray genotypes documented high concordance and accurate SNP genotyping of both Proton and Illumina platforms. However, our study underscored the problem of accurate detection of indels for both the Proton and HiSeq platforms.     

Breeding distribution,population size and conservation of the Greyheaded Gull Larus cirrocephalus in southern Africa

Brooke, R.K., Allan, D.G., Cooper, J., Cyrus, D.P., Dean, W.R.J., Dyer, B.M., Martin, A.P. & Taylor, R.H. 1999. Breeding distribution, population size and conservation of the Greyheaded Gull Larus cirrocephalus in southern Africa. Ostrich 70 (3&4): 157–163.

The Greyheaded Gull Larus cirrocephalus occurs throughout southern Africa, both coastally and inland, and has bred at one time or another at 67 known localities since the 1860s. Most of these sites have been occupied by small numbers of birds, even single pairs, and for only one or a few years. The two principal breeding areas are the East Rand in Gauteng and Lake St Lucia in KwaZulu-Natal, both in South Africa. The next most important sites are Walvis Bay, Namibia and Lake Ngami, Botswana. The total southern African breeding population is estimated as about 2000 pairs. The Greyheaded Gull is not a threatened species in southern Africa, with 27 breeding sites supporting more than half the breeding population within formally conserved areas.     

A preliminary assessment of the habitat selection of two Palaearctic migrant passerine species in West Africa

We investigated the habitat selected by two Palaearctic migrants (Pied Flycatcher, Ficedula hypoleuca, Willow Warbler, Phylloscopus trochilus) in a patchy landscape in Ivory Coast and compared it with the habitat selection of Afrotropical species in the same foraging guilds. Transect counts were used to test the hypothesis that migrants use more open and more seasonal habitats and have a broader use of habitats compared with resident species. Habitats compared were, in order of decreasing tree density, gallery forest, an isolated forest and bush/tree savanna. The isolated forest had the most pronounced seasonal changes (deciduous trees) and was the one with the most diverse vegetation structure. The habitat where both migrants were most frequent was the isolated forest, and thus occurred in the habitat with the most pronounced seasonal change. Diversity of habitats selected was highest in migrants but in the Pied Flycatcher this was possibly an artefact due to subdominant individuals being excluded from the preferred habitat by territorial birds. Potential competition for habitat with Afrotropical species was found to be low.     

Migratory Masked Shrikes,Lanius nubicus staging at the desert edge: phenology,and sex- and age-related differences in body mass

Migratory Masked Shrikes (Lanius nubicus) were mist-netted during the spring and autumn migrations at Eilat, Israel. Nearly four times more shrikes were trapped during spring than in autumn. This could be explained by either the species assorting to loop migration, or a higher capture rate owing to poor body condition after crossing the Sahara in spring. In spring, no differences in phenology were observed between the sex- and age-groups. In contrast, in autumn juvenile males arrived significantly later than the rest of the population. Significant differences in wing chord length were found between the four sex and age classes (adult male, adult female, juvenile male, juvenile female) both in spring and autumn. However, significant differences in body mass were found only in autumn. In spring, in both sexes, wing length and body mass changed significantly with date of arrival. Masked Shrike in spring were lighter than in autumn. The results suggest that migration over desert is energetically costly and Eilat is a very important staging place for migratory Masked Shrikes.