A structured analysis of risk to important wildlife elements in three Australian Wildlife Conservancy sanctuaries

Where data and information are lacking, structured expert risk assessments can provide a powerful tool to progress natural resource planning. In many situations, practitioners make informal assessments of risk within small groups that typically constitute employees. In this study, we report on three small (in terms of experts) structured expert‐based risk assessment case studies conducted by expert employees of a not‐for‐profit organisation (Australian Wildlife Conservancy) to demonstrate the utility of the approach. The case studies were carried out for three wildlife sanctuaries managed by AWC: Faure Island, Karakamia and Paruna. The likelihood that a set of direct risk factors would cause management failure for sets of important wildlife elements in the three sanctuaries was elicited from the small group of ecological experts. The analysis was couched in terms of a management aim to not lose species from each wildlife element over the management period of 25 years with current management. The experts believed, in particular, that increasing temperature and decreasing water availability associated with climate change were likely to impact significantly upon the vegetation elements and water‐reliant fauna associated with the sanctuaries. Some vegetation elements were also thought likely to be at risk of over‐grazing, unsuitable fire regimes and, in some cases, disease. In addition to predation by exotic predators at one sanctuary, the experts identified additional direct risk factors for various fauna elements associated with expected changes to the vegetation elements, including reduction in food availability, nesting habitat, and generally important life media. From the risk analyses, a preliminary conceptual model was developed to underpin monitoring and to indicate areas for possible management intervention and research. The case studies demonstrate that even in a small workplace team, structured risk assessments can be efficiently accomplished and can provide expedient and transparent information that effectively captures and aggregates the views of the experts.     

Investigating the candidacy of a lipoteichoic acid-based glycoconjugate as a vaccine to combat Clostridium difficile infection

A lipoteichoic acid has recently been shown to be conserved in the majority of strains from Clostridium difficile and as such is being considered as a possible vaccine antigen. In this study we examine the candidacy of the conserved lipoteichoic acid by demonstrating that it is possible to elicit antibodies against C. difficile strains following immunisation of rabbits and mice with glycoconjugates elaborating the conserved lipoteichoic acid antigen. The present study describes a conjugation strategy that utilises an amino functionality, present at approximately 33 % substitution of the N-acetyl-glucosamine residues within the LTA polymer repeating unit, as the attachment point for conjugation. A maleimide-thiol linker strategy with the maleimide linker on the carboxyl residues of the carrier protein and the thiol linker on the carbohydrate was employed. Immunisation derived antisera from rabbits and mice, recognised all strains of C. difficile vegetative cells examined, despite an immune response to the linkers also being observed. These sera recognised live cells in an immunofluorescence assay and were also able to recognise the spore form of the bacterium. This study has illustrated that the LTA polymer is a highly conserved surface polymer of C. difficile that is easily accessible to the immune system and as such merits consideration as a vaccine antigen to combat C. difficile infection.     

The Positive and Negative Syndrome Scale (PANSS): A Three-Factor Model of Psychopathology in Marginally Housed Persons with Substance Dependence and Psychiatric Illness

Rates of psychopathology are elevated in marginalized and unstably housed persons, underscoring the need for applicable clinical measures for these populations. The Positive and Negative Syndrome Scale (PANSS) is a clinical instrument principally developed for use in schizophrenia to identify the presence and severity of psychopathology symptoms. The current study investigates whether a reliable and valid PANSS factor structure emerges in a marginally housed, heterogeneous sample recruited from the Downtown Eastside of Vancouver where substance use disorders and psychiatric illness are pervasive. Participants (n = 270) underwent structured clinical assessments including the PANSS and then were randomly assigned to either exploratory (EFA) or confirmatory factor analytic (CFA) subsamples. EFA pointed to a novel three factor PANSS. This solution was supported by CFA. All retained items (28 out of 30) load significantly upon hypothesized factors and model goodness of fit analyses are in the acceptable to good range. Each of the three first-order factor constructs, labeled Psychosis/Disorganized, Negative Symptoms/Hostility, and Insight/Awareness, contributed significantly to measurement of a higher-order psychopathology construct. Further, the latent structure of this 3-factor solution appears temporally consistent over one-year. This PANSS factor structure appears valid and reliable for use in persons with multimorbidity, including substance use disorders. The structure is somewhat distinct from existing solutions likely due to the unique characteristics of this marginally housed sample.     

Investigating the candidacy of LPS-based glycoconjugates to prevent invasive meningococcal disease: immunology of glycoconjugates with high carbohydrate loading

We investigated the immune responses of rabbits that were immunised with lipopolysaccharide (LPS)-based glycoconjugates by measuring the reactivity of the derived sera to a panel of selected wild-type and mutant strains of Neisseria meningitidis. In all cases, high titers of antibodies capable of recognising LPS elaborating the identical structure as presented on the immunising glycoconjugate were obtained, and in most cases the derived sera also recognised heterologous strains including wild-type, but at lower titers. However, although serum bactericidal antibodies were consistently obtained against strains elaborating the same LPS structure as the immunising antigen, this functional response was not observed against wild-type strains. We identified several potentially competing neo-epitopes that had been introduced via our conjugation strategies, which might compete with the conserved inner core oligosaccharide target region, thus reducing the antibody titers to epitopes which could facilitate bactericidal killing. This study has therefore identified key factors that are crucial to control in order to increase the likelihood of obtaining bactericidal antibodies to wild-type meningococcal cells with LPS-derived glycoconjugates. Glycoconjugates utilised in this study, have been found to contain epitopes that do not contribute to the derivation of antibodies that may facilitate bactericidal killing of wild-type strains and must be avoided in future LPS-based glycoconjugate preparations.     

Life cycle assessment and life cycle cost of repairing surgical scissors

The International Journal of Life Cycle Assessment - The primary objective of this study was to evaluate the environmental impact and financial cost of repairing surgical scissors. We used life...     

Patterns of antral follicular wave dynamics and accompanying endocrine changes in cyclic and seasonally anestrous ewes treated with exogenous ovine follicle-stimulating hormone during the inter-wave interval

In the ewe, ovarian follicular waves emerge every 4 to 5 days and are preceded by a peak in FSH secretion. It is unclear whether large antral follicle(s) in a wave suppress the growth of other smaller follicles during the inter-wave interval, as is seen in cattle. In this study, anestrous (n = 6; experiment 1) and cyclic (n = 5; experiment 2) Western white face ewes were given ovine FSH (oFSH) (0.5 microg/kg; two s.c. injections, 8 h apart) during the growth phase (based on ultrasonography) of a follicular wave (wave 1). Control ewes (n = 5 and 6, respectively) received vehicle. In oFSH-treated ewes, serum FSH concentrations reached a peak (P < 0.05) by 12 h after oFSH treatment, and this induced FSH peak did not differ (P > 0.05) from the endogenous FSH peaks. In all ewes, emergence of follicular waves 1 and 2 was seen (P > 0.05). However, in oFSH-treated ewes, an additional follicular wave emerged approximately 0.5 days after treatment: during the interwave interval of waves 1 and 2 without delaying the emergence of wave 2. The growth characteristics and serum estradiol concentrations did not differ (P > 0.05) between oFSH-induced waves and waves induced by endogenous FSH peaks. We concluded that, unlike in cattle, the largest follicle of a wave in sheep has limited direct effect on the growth of other follicles induced by exogenous oFSH. In addition, the largest follicle of a wave may possibly not influence the rhythmicity of follicular wave emergence, as it does in cattle.     

Inhibiting ice recrystallization and optimization of cell viability after cryopreservation

The ice recrystallization inhibition activity of various mono- and disaccharides has been correlated with their ability to cryopreserve human cell lines at various concentrations. Cell viabilities after cryopreservation were compared with control experiments where cells were cryopreserved with dimethylsulfoxide (DMSO). The most potent inhibitors of ice recrystallization were 220?mM solutions of disaccharides; however, the best cell viability was obtained when a 200?mM d-galactose solution was utilized. This solution was minimally cytotoxic at physiological temperature and effectively preserved cells during freeze-thaw. In fact, this carbohydrate was just as effective as a 5% DMSO solution. Further studies indicated that the cryoprotective benefit of d-galactose was a result of its internalization and its ability to mitigate osmotic stress, prevent intracellular ice formation and/or inhibit ice recrystallization. This study supports the hypothesis that the ability of a cryoprotectant to inhibit ice recrystallization is an important property to enhance cell viability post-freeze-thaw. This cryoprotective benefit is observed in three different human cell lines. Furthermore, we demonstrated that the ability of a potential cryoprotectant to inhibit ice recrystallation may be used as a predictor of its ability to preserve cells at subzero temperatures.     

Varicella-zoster virus ORF63 inhibits apoptosis of primary human neurons

Virus-encoded modulation of apoptosis may serve as a mechanism to enhance cell survival and virus persistence. The impact of productive varicella-zoster virus (VZV) infection on apoptosis appears to be cell type specific, as infected human sensory neurons are resistant to apoptosis, yet human fibroblasts readily become apoptotic. We sought to identify the viral gene product(s) responsible for this antiapoptotic phenotype in primary human sensory neurons. Treatment with phosphonoacetic acid to inhibit viral DNA replication and late-phase gene expression did not alter the antiapoptotic phenotype, implicating immediate-early (IE) or early genes or a virion component. Compared to the parental VZV strain (rOKA), a recombinant virus unable to express one copy of the diploid IE gene ORF63 (rOkaΔORF63) demonstrated a significant induction of apoptosis in infected neurons, as determined by three methods: annexin V staining, deoxynucleotidyltransferase-mediated dUTP-biotin nick end label staining, and transmission electron microscopy. Furthermore, neurons transfected with a plasmid expressing ORF63 resisted apoptosis induced by nerve growth factor withdrawal. These results show that ORF63 can suppress apoptosis of neurons and provide the first identification of a VZV gene encoding an antiapoptotic function. As ORF63 is expressed in neurons during both productive and latent infection, it may play a significant role in viral pathogenesis by promoting neuron survival during primary and reactivated infections.