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

The economics of a temporary VAT cut

1. The rate of VAT has been cut temporarily to 15%, with a return to 17.5% in place for the end of 2009. The government has predicted that this will increase consumer spending by about 0.5%. Much of the analysis of this tax cut has been critical of the policy and concluded that the government's estimates of the impact on spending are over-optimistic. The source of this criticism is a misunderstanding of the mechanism through which the tax cut will have an impact. In fact, we believe the government's estimates are overly-pessimistic. 2. There are two mechanisms through which the temporary VAT cut might affect spending: first, it will increase spending power, making households feel as if they have more income. This mechanism is likely to be small partly because the tax cut increases income only for one year, and so the increase in total lifetime resources is very small, and partly because the lost revenue will have to be paid back. 3. However, the second (often ignored) mechanism is likely to be much more important. This second mechanism is the effect that the tax cut will have through changing the price of goods bought in 2009 compared to 2010: the cost of goods bought in 2009 has fallen compared to goods bought in 2010 and this change in prices gives an incentive to bring forward consumer spending to this year, rather than waiting until next. 4. Economic evidence on households' willingness to move spending from one year into an earlier (or later) year suggests that a 1% fall in the price today will translate into a 1% increase in spending. Since roughly only half of goods purchased are subject to VAT, the cut in the rate by 2.5% is like a cut in prices today by 1.25% and we would expect this to boost spending by about 1.25% over what it would otherwise be. 5. Of course, this issue of what the spending would otherwise be is crucial: we will not now know what spending in 2009 would have been without the cut in VAT and even with the VAT cut, spending is likely to decline. Our point is simply that economic analysis shows that the cut in VAT will make the situation significantly less bad than it might otherwise have been. 6. A natural comparison to the fiscal stimulus of a cut in VAT is a monetary stimulus through a cut in the interest rate: both make the price of spending today low compared to next year - an interest rate cut makes saving less attractive than current spending, as does the cut in VAT. The 1.25% fall in prices due to the cut in VAT reduces the price of spending today by more than a 1% point cut in the interest rate. It is surprising that some commentators have labeled the former as "small", while the latter would typically be considered a large cut. 7. There is however a difference between cutting interest rates and cutting VAT: a cut in interest rates penalises savers, whose spending power falls, and rewards borrowers. By contrast, the cut in VAT increases the spending power of savers (as well as borrowers) and this seems a fairer way to stimulate the economy.

Why do home owners work longer hours?

This paper uses a structural model to address the question of why home-owners with large mortgage debt work longer hours than those without such debt. We consider whether this is due to lower net wealth or to capital market imperfections, including mortgage constraints that depend on current earnings and, therefore, labour supply choices. We show that the need to meet current mortgage commitments can generate the observed correlation, and this impact of current commitments arises from the institutional borrowing constraints. We also show that labour supply as a function of household debt is highly nonlinear: those with greater debt are more likely to face binding borrowing constraints and their labour supply is more variable.

Charged Fermions Below 100 GeV

How light can a fermion be if it has unit electric charge? We revisit the lore that LEP robustly excludes charged fermions lighter than about 100 GeV. We review LEP chargino searches, and find them to exclude charged fermions lighter than 90 GeV, assuming a higgsino-like cross section. However, if the charged fermion couples to a new scalar, destructive interference among production channels can lower the LEP cross section by a factor of 3. In this case, we find that charged fermions as light as 75 GeV can evade LEP bounds, while remaining consistent with constraints from the LHC. As the LHC collects more data, charged fermions in the 75-100 GeV mass range serve as a target for future monojet and disappearing track searches.Comment: 35 pages, 11 figures, 2 table