Occupational exposure to blood borne pathogens among healthcare workers and preventative strategies

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When do conservation planning methods deliver? Quantifying the consequences of uncertainty

The rapid global loss of biodiversity has led to a proliferation of systematic conservation planning methods. In spite of their utility and mathematical sophistication, these methods only provide approximate solutions to real-world problems where there is uncertainty and temporal change. The consequences of errors in these solutions are seldom characterized or addressed. We propose a conceptual structure for exploring the consequences of input uncertainty and oversimpli?ed approximations to real-world processes for any conservation planning tool or strategy. We then present a computational framework based on this structure to quantitatively model species representation and persistence outcomes across a range of uncertainties. These include factors such as land costs, landscape structure, species composition and distribution, and temporal changes in habitat. We demonstrate the utility of the framework using several reserve selection methods including simple rules of thumb and more sophisticated tools such as Marxan and Zonation. We present new results showing how outcomes can be strongly affected by variation in problem characteristics that are seldom compared across multiple studies. These characteristics include number of species prioritized, distribution of species richness and rarity, and uncertainties in the amount and quality of habitat patches. We also demonstrate how the framework allows comparisons between conservation planning strategies and their response to error under a range of conditions. Using the approach presented here will improve conservation outcomes and resource allocation by making it easier to predict and quantify the consequences of many different uncertainties and assumptions simultaneously. Our results show that without more rigorously generalizable results, it is very dif?cult to predict the amount of error in any conservation plan. These results imply the need for standard practice to include evaluating the effects of multiple real-world complications on the behavior of any conservation planning method.

Improving diagnosis and oral vaccination strategies against bovine tuberculosis

In this work peptide antigens [ESAT-6,p45 in water (1ml, 1mg/ml)] have been adsorbed onto 10mg inorganic substrates (hydroxyapatite (MHA P201;P120, CHA), polystyrene, calcium carbonate and glass microspheres) and in vitro release characteristics were determined. The aim of formulation was to enhance the interaction of peptides with antigen presenting cells and to achieve rapid peptide release from the carrier compartment system in a mildly acidic environment. Hydroxyapatite microparticle P201 has a greater surface area and thus has the largest peptide adsorption compared to the P120. CHA gave a further higher adsorption due to larger surface area than that available on microparticles. These particles were incorporated into the BOVIGAMTM assay to determine if they improve the sensitivity. After overnight incubation the blood plasma was removed and the amount of IFN-g in each plasma sample was estimated. CHA and MHA P201 gave a significantly higher immune response at low peptide concentration compared to the free peptide, thus indicating that these systems can be used to evaluate Tuberculosis (TB) amongst cattle using the BOVIGAMTM assay. Badgers are a source of TB and pass infection to cattle. At the moment vaccination against TB in badgers is via the parenteral route and requires a trained veterinary surgeon as well as catching the badgers. This process is expensive and time consuming; consequently an oral delivery system for delivery of BCG vaccines is easier and cheaper. The initial stage involved addition of various surfactants and suspending agents to disperse BCG and the second stage involved testing for BCG viability. Various copolymers of Eudragit were used as enteric coating systems to protect BCG against the acidic environment of the stomach (SGF, 0.1M HCl pH 1.2 at 37oC) while dissolving completely in the alkaline environment of the small intestine (SIF, IM PBS solution pH 7.4 at 37oC). Eudragit L100 dispersed in 2ml PBS solution and 0.9ml Tween 80 (0.1%w/v) gave the best results remaining intact in SGF loosing only approximately 10-15% of the initial weight and dissolving completely within 3 hours. BCG was incorporated within the matrix formulation adjusted to pH 7 at the initial formulation stage containing PBS solution and Tween 80. It gave viability of x106 cfu/ml at initial formulation stage, freezing and freeze-drying stages. After this stage the matrix was compressed at 4 tons for 3 mins and placed in SGF for 2 hours and then in SIF until dissolved. The BCG viability dropped to x106 cfu/ml. There is potential to develop it further for oral delivery of BCG vaccine.

Community involvement in urban nature conservation : case studies of the Urban Wildlife Group 1980-85

The effectiveness of the strategies employed by the Urban Wildlife Group (a voluntary conservation organisation) to provide and manage three urban nature parks has been evaluated, using a multiple methods methodology. Where the level of community interest and commitment to a project is high, the utilisation of the community nature park strategy (to maximise benefits to UWG and the community) is warranted. Where the level of interest and commitment of the local community is low, a strategy designed to encourage limited involvement of the community is most effective and efficient. The campaign strategy, whereby the community and UWG take direct action to oppose a threat of undesirable development on a nature park, is assessed to be a sub-strategy, rather than a strategy in its own right. Questionnaire surveys and observations studies have revealed that urban people appreciate and indeed demand access to nature parks in urban areas, which have similar amenity value to that provided by countryside recreation sites. Urban nature parks are valued for their natural character, natural features (trees, wild flowers) peace and quiet, wildlife and openness. People use these sites for a mixture of informal and mainly passive activities, such as walking and dog walking. They appear to be of particular value to children for physical and imaginative play. The exact input of time and resources that UWG has committed to the projects has depended on the level of input of the local authority. The evidence indicates that the necessary technical expertise needed to produce and manage urban nature parks, using a user-oriented approach is not adequately provided by local authorities. The methods used in this research are presented as an `evaluation kit' that may be used by practitioners and researchers to evaluate the effectiveness of a wide range of different open spaces and the strategies employed to provide and manage them.

Endothelial Nox4 NADPH oxidase enhances vasodilatation and reduces blood pressure in vivo

Objective- Increased reactive oxygen species (ROS) production is involved in the pathophysiology of endothelial dysfunction. NADPH oxidase-4 (Nox4) is a ROS-generating enzyme expressed in the endothelium, levels of which increase in pathological settings. Recent studies indicate that it generates predominantly hydrogen peroxide (H O ), but its role in vivo remains unclear. Methods and Results- We generated transgenic mice with endothelium-targeted Nox4 overexpression (Tg) to study the in vivo role of Nox4. Tg demonstrated significantly greater acetylcholine- or histamine-induced vasodilatation than wild-type littermates. This resulted from increased H O production and H O -induced hyperpolarization but not altered nitric oxide bioactivity. Tg had lower systemic blood pressure than wild-type littermates, which was normalized by antioxidants. Conclusion- Endothelial Nox4 exerts potentially beneficial effects on vasodilator function and blood pressure that are attributable to H O production. These effects contrast markedly with those reported for Nox1 and Nox2, which involve superoxide-mediated inactivation of nitric oxide. Our results suggest that therapeutic strategies to modulate ROS production in vascular disease may need to separately target individual Nox isoforms. © 2011 American Heart Association, Inc.