Sweet Road Trip

Postcard from Matthew Richard, during the Linfield College Semester Abroad Program at the University of Waikato in Hamilton, New Zealan

Putting conservation medicine into practice : examples from three endemic New Zealand bird species : a thesis presented in partial fulfilment of the requirements for the degree of Master of Science in Conservation Biology at Massey University

Conservation medicine is increasingly being viewed as an important component of conservation biology. While programmes focussing on wildlife health are generally limited to controlling the spread of infectious diseases, there is a need to evaluate the impacts of non-infectious diseases: in particular, a critical examination of invasive management practices is overdue. Marking or tagging animals for identification is one of the most common management tools employed by conservation managers, and yet their impacts have rarely been quantified. In the kakapo, Strigops habroptilus, metallic bands applied to the tarsus were implicated in joint problems in the banded leg; in contrast to this, subcutaneously implanted passive integrated transponders appear to be safe and effective in both adults and chicks. In the North Island robin, Petroica longipes, leg bands were directly implicated in leg injuries at a rate of 2% of adults per year. The most common injury was a result of the birds trapping their hallux (back toe) between a band and their leg; this forced the leg into a flexed position and resulted in tissue damage. To accurately interpret clinical pathology data collected in wildlife health assessments, reference ranges for haematological and biochemical data should be generated for each species. In the kakapo, blood samples from 1996 and 2002 allowed these references to be produced; however, this exercise highlighted limitations that are often underappreciated in conservation medicine. Many factors can influence the results: two of these being sample storage and laboratory processing methods. Many conservation programmes cannot collect, store and process samples in an ideal environment and, thus, comparisons between ideally generated reference ranges and data from individuals collected in the field may be spurious. Similarly, opportunistic carcass collection and post-mortem examination provides valuable identification of disease agents, but the findings are difficult to interpret in terms of their importance or prevalence within populations. The description of aspergillosis in a North Island robin is a case in point. The movement of animals for conservation purposes - translocations - is becoming widespread, and has the potential to introduce diseases into disease-free areas; the stitchbird, Notiomystis cincta, is currently the focus of conservation efforts that rely on translocations. Two poorly-understood diseases were examined: facial dermatitis and sub-lingual oral fistulas. The prevalence of facial dermatitis was influenced by season and sex, with males showing a higher prevalence of the condition than females during the breeding season. Histopathology, mite isolation and a therapeutic drug trial all suggest that a burrowing mite, Knemidocoptes spp is responsible for the condition. Sub-lingual oral fistulas are more widespread than previously thought, as they are not limited to birds with obvious tongue protrusions through the tissue deficit in the lower mandible. Evidence supports the hypothesis that these fistulas are acquired after fledging, and have a limited impact on bird productivity and survival

Audiovisual preservation strategies, data models and value-chains

This is a report on preservation strategies, models and value-chains for digital file-based audiovisual content. The report includes: (a)current and emerging value-chains and business-models for audiovisual preservation;(b) a comparison of preservation strategies for audiovisual content including their strengths and weaknesses, and(c) a review of current preservation metadata models, and requirements for extension to support audiovisual files

Inhomogeneity and Nonlinear Preheating

We investigated the possibility that nonlinear gravitational effects influence the preheating era after inflation, using numerical solutions of the inhomogeneous Einstein field equations. We compared our results to perturbative calculations and to solutions of the nonlinear field equations in a rigid (unperturbed) spacetime, in order to isolate gravitational phenomena. We confirm the broad picture of preheating obtained from the nonlinear field equations in a rigid background, but find gravitational effects have a measurable impact on the dynamics. The longest modes in the simulation grow much more rapidly in the relativistic calculation than with a rigid background. We used the Weyl tensor to quantify the departure from homogeneity in the universe. We saw no evidence for the sort of gravitational collapse that leads to the formation of primordial black holes.Comment: Talk given at Marcel Grossmann Meeting IX. 3 pages, 1 figur

Inequalities in diet and nutrition

The inequality of nutrition and obesity re-focuses concern on who in society is consuming the worst diet. Identification of individuals with the worst of dietary habits permits for targeting interventions to assuage obesity among the population segment where it is most prevalent. We argue that the use of fiscal interventions does not appropriately take into account the economic, social and health circumstances of the intended beneficiaries of the policy. This paper reviews the influence of socio-demographic factors on nutrition and health status and considers the impacts of nutrition policy across the population drawing on methodologies from both public health and welfare economics. The effects of a fat tax on diet are found to be small and while other studies show that fat taxes saves lives, we show that average levels of disease risk do not change much: those consuming particularly bad diets continue to do so. Our results also suggest that the regressivity of the policy increases as the tax becomes focused on products with high saturated fat contents. A fiscally neutral policy that combines the fat tax with a subsidy on fruit and vegetables is actually more regressive because consumption of these foods tends to be concentrated in socially undeserving households. We argue that when inequality is of concern, population-based measures must reflect this and approaches that target vulnerable populations which have a shared propensity to adopt unhealthy behaviours are appropriate

Experiments with calibrated digital sideband separating downconversion

This article reports on the first step in a focused program to re-optimize radio astronomy receiver architecture to better take advantage of the latest advancements in commercial digital technology. Specifically, an L-Band sideband-separating downconverter has been built using a combination of careful (but ultimately very simple) analog design and digital signal processing to achieve wideband downconversion of an RFI-rich frequency spectrum to baseband in a single mixing step, with a fixed-frequency Local Oscillator and stable sideband isolation exceeding 50 dB over a 12 degree C temperature range.Comment: 10 pages, 12 figures, to be published in PAS