4 research outputs found
Detection of equine herpesvirus-4 and physiological stress patterns in young Thoroughbreds consigned to a South African auction sale
BACKGROUND : The prevalence of equine herpesvirus types-1 and -4 (EHV-1 and -4) in South African Thoroughbreds
at auction sales is currently undefined. Commingling of young Thoroughbreds from various populations together
with physiological stress related to their transport and confinement at a sales complex, may be associated with
shedding and transmission of EHV-1 and -4. This prospective cohort study sampled 90 young Thoroughbreds
consigned from eight farms, originating from three provinces representative of the South African Thoroughbred
breeding demographic to a sales complex. Nasal swabs for quantitative real-time polymerase chain reaction
(qPCR) assay to detect EHV-1 and -4 nucleic acid and blood samples for enzyme-linked immunosorbent assay
for EHV-1 and -4 antibodies were collected from all horses on arrival and departure. Additional nasal swabs for
qPCR were obtained serially from those displaying pyrexia and, or nasal discharge. Daily faecal samples were
used for determination of faecal glucocorticoid metabolite (FGM) concentrations as a measurement of physiological
stress and these values were modelled to determine the factors best explaining FGM variability.
RESULTS : EHV-4 nucleic acid was detected in 14.4 % and EHV-1 from none of the animals in the study population.
Most (93.3 %) and very few (1.1 %) of this population showed antibodies indicating prior exposure to EHV-4 and
EHV-1 respectively. Pyrexia and nasal discharge were poor predictors for detecting EHV-4 nucleic acid. The horses’
FGM concentrations increased following arrival before decreasing for most of the remaining study period including the
auction process. Model averaging showed that variation in FGM concentrations was best explained by days post-arrival
and transport duration.
CONCLUSIONS : In this study population, sales consignment was associated with limited detection of EHV-4 nucleic
acid in nasal secretions, with most showing prior exposure to EHV-4 and very few to EHV-1. The physiological stress
response shown by most reflected the combination of stressors associated with transport and arrival and these are
key areas for future investigation into management practices to enhance health and welfare of young Thoroughbreds
during sales consignment.Racing South Africa (Pty) Ltd, the
Equine Research Centre and Departments of Companion Animal Clinical
Studies and Production Animal Clinical Studies, Faculty of Veterinary Science,
University of Pretoria, South Africa.http://www.biomedcentral.com/bmcvetresam201
Multiple Geographic Origins of Commensalism and Complex Dispersal History of Black Rats
The Black Rat (Rattus rattus) spread out of Asia to become one of the world's worst agricultural and urban pests, and a reservoir or vector of numerous zoonotic diseases, including the devastating plague. Despite the global scale and inestimable cost of their impacts on both human livelihoods and natural ecosystems, little is known of the global genetic diversity of Black Rats, the timing and directions of their historical dispersals, and the risks associated with contemporary movements. We surveyed mitochondrial DNA of Black Rats collected across their global range as a first step towards obtaining an historical genetic perspective on this socioeconomically important group of rodents. We found a strong phylogeographic pattern with well-differentiated lineages of Black Rats native to South Asia, the Himalayan region, southern Indochina, and northern Indochina to East Asia, and a diversification that probably commenced in the early Middle Pleistocene. We also identified two other currently recognised species of Rattus as potential derivatives of a paraphyletic R. rattus. Three of the four phylogenetic lineage units within R. rattus show clear genetic signatures of major population expansion in prehistoric times, and the distribution of particular haplogroups mirrors archaeologically and historically documented patterns of human dispersal and trade. Commensalism clearly arose multiple times in R. rattus and in widely separated geographic regions, and this may account for apparent regionalism in their associated pathogens. Our findings represent an important step towards deeper understanding the complex and influential relationship that has developed between Black Rats and humans, and invite a thorough re-examination of host-pathogen associations among Black Rats
Economic Valuation for Information Security Investment: A Systematic Literature Review
Research on technological aspects of information security risk is a well-established area and familiar territory for most information security professionals. The same cannot be said about the economic value of information security investments in organisations. While there is an emerging research base investigating suitable approaches measuring the value of investments in information security, it remains difficult for practitioners to identify key approaches in current research. To address this issue, we conducted a systematic literature review on approaches used to evaluate investments in information security. Following a defined review protocol, we searched several databases for relevant primary studies and extracted key details from the identified studies to answer our research questions. The contributions of this work include: a comparison framework and a catalogue of existing approaches and trends that would help researchers and practitioners navigate existing work; categorisation and mapping of approaches according to their key elements and components; and a summary of key challenges and benefits of existing work, which should help focus future research efforts