Magnetic Differences on GEM - direct observation of closest R...R approach in rare-earth phosphate glasses

Rare-earth (R) phosphate glasses have shown great promise in the laser and optoelectronics industry. Their structure plays an important role in their physical characteristics, with the R...R closest approach affecting their optical and magnetic properties. A novel characterisation method for amorphous materials which makes use of magnetic field effects has enabled the first direct experimental evidence of nearest neighbour R...R separation in these materials

Lenticel hydration alters the susceptibility of apple fruit to infection by Phlyctema vagabunda

Bull’s eye rot, caused by Phlyctema vagabunda, is an important postharvest rot of apples. A combination of laboratory and field trials were conducted to examine the relationship between infection and status of apple lenticels. Fruit were hydrated and then inoculated, and climatic factors were compared with inoculations and natural infections in the field. In laboratory trials it was shown that increased lenticel density and size led to more infections. Hydration distended lenticel diameter, and dehydration contracted lenticels. A strong relationship with wind run, leaf wetness and temperature were shown to be important for laboratory inoculations of monthly harvested fruit, natural infections in trap fruit experiments, and monthly field inoculations. It was hypothesised that high wind run (> c. 240 km/day) reduced fruit susceptibility by promoting lenticel closure, and when lenticels were open, temperature limited the formation of an infection stroma. If the stroma did not form, postharvest expression of disease was negligible. Leaf wetness over 28 days was also an important factor for infection, probably because of the effect on micro-crack formation and resealing of lenticels during maturation by components of the cuticle. From these results, pre-harvest application of compounds that close lenticels could provide some control of bull’s eye rot without the need for fungicides

A922 Sequential measurement of 1 hour creatinine clearance (1-CRCL) in critically ill patients at risk of acute kidney injury (AKI)

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Change in dominance determines herbivore effects on plant biodiversity

Herbivores alter plant biodiversity (species richness) in many of the world’s ecosystems, but the magnitude and the direction of herbivore effects on biodiversity vary widely within and among ecosystems. One current theory predicts that herbivores enhance plant biodiversity at high productivity but have the opposite effect at low productivity. Yet, empirical support for the importance of site productivity as a mediator of these herbivore impacts is equivocal. Here, we synthesize data from 252 large-herbivore exclusion studies, spanning a 20-fold range in site productivity, to test an alternative hypothesis—that herbivore-induced changes in the competitive environment determine the response of plant biodiversity to herbivory irrespective of productivity. Under this hypothesis, when herbivores reduce the abundance (biomass, cover) of dominant species (for example, because the dominant plant is palatable), additional resources become available to support new species, thereby increasing biodiversity. By contrast, if herbivores promote high dominance by increasing the abundance of herbivory-resistant, unpalatable species, then resource availability for other species decreases reducing biodiversity. We show that herbivore-induced change in dominance, independent of site productivity or precipitation (a proxy for productivity), is the best predictor of herbivore effects on biodiversity in grassland and savannah sites. Given that most herbaceous ecosystems are dominated by one or a few species, altering the competitive environment via herbivores or by other means may be an effective strategy for conserving biodiversity in grasslands and savannahs globally

Demography and condition of bushtail possum : A thesis submitted in partial fulfilment of the requirements for the Degree of Master of Applied Science at Lincoln University

Necropsy data were collected from brushtail possum (Trichosurus vulpecula) populations in forest habitat at Waihaha, and in farm habitat at Hohotaka, both in the central North Island of New Zealand. A major control operation reduced the Hohotaka population by 89% in 1988, and low population numbers were maintained thereafter by smaller annual operations. Finite rates of increase, calculated from birth and mortality data, were approximately unity for all three populations. Possums at Waihaha were in better morphological and physiological condition, and had lower birth and mortality rates and an older age structure, than those at Hohotaka. The contribution of spring breeding to the population was higher at Waihaha and Hohotaka post-poisoning than at Hohotaka pre-poisoning. After poisoning at Hohotaka, a morphological index of survivors' condition increased, but a fat-related index declined. Birth and mortality rates increased, male and female age structures became younger, and adult sex ratios became increasingly male biased (due in part to male-biased birth ratios). The usefulness of these results for predicting the demographic response of possum populations to sustained control of this pest in other areas is discussed

Impacts of deer on Kaimanawa beech forests : a thesis presented in partial fulfilment of the requirements for the degree of Doctor of Philosophy in Ecology at Massey University, Palmerston North, New Zealand

Extensive mountain beech (Nothofagus solandri var. cliffortioides) canopy collapse has been apparent for decades in the Kaimanawa Region, central North Island of New Zealand. In most other unlogged mountain beech forests prolific seedling regeneration follows canopy collapse, but in the central North Island regeneration has been impeded by red (Cervus elaphus) and sika deer (Cervus nippon) browsing. The primary objective of this study was to determine relative impacts on mountain beech regeneration of red and sika deer, and the impacts of deer in general on Kaimanawa Region beech forest composition. Previous international research has shown that herbivores can drastically modify seedling species composition, but the ongoing consequences of herbivory for canopy composition and competitive interactions between plants on a landscape-scale are still poorly understood. This PhD uses short and long-term monitoring of vegetation to examine the effects of herbivory on forest regeneration and successional processes. In an attempt to restore mountain beech regeneration, high intensity deer culling was initiated in October 1998 to reduce deer densities. A further objective of this study was to determine the effect of deer culling on deer densities and mountain beech seedling growth. Data from 20 m x 20 m permanent plots are used to relate the impacts of sika and red deer to changes in mountain, red (Nothofagus fusca) and silver (Nothofagus menziesii) beech forest composition and regeneration. Plots were established on randomly located transects over two decades ago and were re-measured periodically since. Mountain beech seedling abundance is compared among areas with different sika deer colonisation histories to determine impacts of sika deer over time. Comparisons are also made with areas outside the region, where no sika deer were present. At ten subjectively located sites, paired fenced and unfenced plots were established in a high-intensity deer culling area between 1997 and 1999, to monitor benefits of deer culling for mountain beech seedling growth. To provide comparisons, paired plots were also established at eleven sites in areas with low- and medium-intensity deer culling. Results show that sika deer have widespread impacts on Kaimanawa beech (Nothogagus spp.) forest regeneration and composition. Where sika deer have been dominant over red deer for more than a decade, mountain beech seedling regeneration has been suppressed in comparison to areas without sika deer. This is particularly evident at stands which had low occupancy by trees, and where prolific seedling regeneration is expected due to increased nutrient and light availability. Mountain beech forest composition in the Kaimanawa Region has undergone shifts towards browse-tolerant and browse-resistant species over the last two decades. In red and silver beech forests there was an increase in the stem densities of species of small trees that are unpalatable to deer. Analysis of seedling densities indicates that deer-palatable Weinmannia racemosa and Griselinia littoralis trees were failing to recruit into the >75 cm height class. In the southern part of the Kaimanawa study area understorey composition shifted over two decades towards browse-tolerant turf forming herb, fern, grass and bryophyte communities, which may have been due to the presence of deer. Analysis of seedling growth rates from paired fenced and unfenced plots provides strong evidence that mountain beech seedling growth increased once deer browsing was removed through fencing, and to a lesser extent following reductions in deer abundance through high-intensity deer culling. I established two experiments to examine the relationships between herbivory and competition between mountain beech seedlings and other turf-forming plant species. These experiments showed that the composition of turf communities had little effect on mountain beech seedling establishment, but their complete removal increased mountain beech seedling growth and survivorship. There was no immediate compositional response of turf communities to the removal of deer browsing, so the reversibility of deer-induced impacts are unclear