Predation and Animal Populations : Lessons from Lemmings and Geese

Deborah Wilson, recipient of the Lorraine Allison Scholarship for 1997, has designed her doctoral research to answer the following two questions about lemming and goose population dynamics. First, do predators cause the lemming decline? And second, how does the lemming cycle affect predation on goose nest? To this end she experimentally protected an 11-hectare patch of tundra from predators, with a fence to deter large predatory mammals and monofilament fishing line overhead to deter predatory birds. The results of this experiment are reported along with the results of the second part of her study which emphasizes that a decline in abundance of one type of prey may have unexpected deleterious effects not only on its predators but also on other prey species. "These observations may be relevant when outbreaks of disease kill prey animals, or when wildlife managers attempt to remove introduced pest species. To be able to make predictions about the population dynamics of alternative prey, it is necessary to take into account spatial patterns, delayed effects, the foraging behaviour of predators, and interactions among different species of predators.

A study of the relationship between a child's achievement and adjustment in grades one and three.

Thesis (Ed.M.)--Boston Universit

Rapid assessment of tissue nitrogen in cultivated Gracilaria gracilis (Rhodophyta) and Ulva lactuca (Chlorophyta)

Tissue nitrogen content and thallus colour were quantified using a rapid assessment method based on the Pantone® matt uncoated formula guide for raft-cultivated Gracilaria gracilis Steentoft Irvine et Farnham at Saldanha Bay and tank-cultivated Ulva lactuca Linnaeus at Jacobsbaai in 2001 – 2002. A relationship between thallus colour and tissue nitrogen, as well as a transition between green-yellows and yellow-browns that occurs between 0.8 – 1.3 mg N per g tissue (Pantone® colours 460U – 455U) for Gracilaria were found, with the green-yellow colour indicating nitrogen-starved material and the yellow-browns indicating nitrogen-replete material. For Ulva a transition between green and yellow-green occurred at a tissue nitrogen content of between 1.5 – 1.7 mg N per g tissue (Pantone® colours 585U and 583U). This relationship can be used by seaweed farmers for cultivation management as a quick guide to determine nutritional status of the seaweeds, and as an indication of protein content when the seaweeds are used as feeds.Web of Scienc

Drug-Induced Bullous Sweet Syndrome with Multiple Autoimmune Features

Sweet syndrome (SS) (Acute Febrile Neutrophilic Dermatosis) has been reported in association with autoimmune phenomena including relapsing polychondritis, drug-induced lupus, and the development of antineutrophil cytoplasmic antibodies (ANCAs). However, a combination of these autoimmune features has not been reported. Herein, we report a case of drug-induced bullous SS with ocular and mucosal involvement, glomerulonephritis, and multiple autoimmune features including clinical polychondritis with antitype II collagen antibodies, ANCAs, antinuclear (HEp-2), and antihistone antibodies in a patient on hydralazine and carbamazepine

Intensity-dependence of exercise and active recovery in high-intensity interval training

Background: High-intensity interval training (HIIT) with interspersing active recovery is an effective mode of exercise training in cohorts ranging from athletes to patients. Here, we assessed the intensity-dependence of the intervals and active recovery bouts for permitting a sustainable HIIT protocol. Methods: 14 males completed 4x4-minute HIIT protocols where intensities of intervals ranged 80-100% of maximal oxygen uptake (VO2max) and active recovery ranged 60-100% of lactate (La-) threshold (LT). Blood La- measurements indicated fatigue, while tolerable duration of intervals indicated sustainability. Results: HIIT at 100% of VO2max allowed 44±10% [30-70%] completion, i.e. fatigue occurred after 7minutes:6seconds of the intended 16 minutes of high intensity, whereas HIIT at 95-80% of VO2max was 100% sustainable (p<0.01). Measured intensity did not differ from intended intensity across the protocols (p>0.05). Blood La- concentration [La-] increased to 9.3±1.4mM during HIIT at 100% of VO2max, whereas at 80-95% of VO2max stabilised at 2-6mM in an intensity-dependent manner (p<0.01 vs 100% of VO2max and p<0.05 vs baseline). Active recovery at 60-70% of LT during HIIT associated with steady-state blood [La-] peaking at 6-7mM, whereas at 80-100% of LT, blood [La-] accumulated to 10-13mM (p<0.05). After HIIT, active recovery at 80-90% of LT cleared blood [La-] 90% faster than at 60-70% of LT (p<0.05). Conclusions: To permit highest exercise stress during 4x4-minute HIIT, exercise intensity should be set to 95% of VO2max, whereas active recovery should be set to 60-70% of LT during HIIT and 80-90% of LT after HIIT to most efficiently prevent excess La- and aid recovery

Bleaching susceptibility of aquarium corals collected across northern Australia

Abstract There are a wide range of Scleractinian corals that are collected for the global reef aquarium market, often from non-reefal environments. The sustainability of coral harvesting is potentially threatened by increasing anthro- pogenic disturbances and climate change, though it is unknown to what extent many commonly harvested corals are susceptible to environmental change, or actually bleach during marine heatwaves. In this study, we experimentally tested the temperature sensitivity and bleaching suscepti- bility of six coral species (Homophyllia australis, Micro- mussa lordhowensis, Catalaphyllia jardinei, Trachyphyllia geoffroyi, Duncanopsammia axifuga, and Euphyllia glab- rescens), which are important components of the aquarium coral fisheries across northern Australia, in Western Aus- tralia, the Northern Territory, and/or Queensland. Inter- specific differences were evident in the temperature sensitivity and bleaching susceptibility among the study species. Homophyllia australis, and M. lordhowensis were found to be particularly susceptible to elevated temperatures, whereby all corals subjected to elevated temperatures died within the course of the experimental treatment (75 d). Catalaphyllia jardinei and E. glabrescens also exhibited significant increases in mortality when exposed to elevated temperatures, though some of the corals did survive, and C. jardinei mostly died only after exposure to elevated temperatures. The other species (T. geoffroyi and D. axifuga) exhibited marked bleaching when exposed to elevated temperatures, but mortality of these corals was similar to that of conspecifics held at ambient temperatures. This study highlights the potential for envi- ronmental change to impact the sustainability and viability of Australian coral harvest fisheries. More importantly, this study highlights the need for specific and targeted in situ monitoring for important stocks of coral fishery target species, to assess their vulnerability to fishery and fishery- independent effects

The Spitzer Warm Mission Science Prospects

After exhaustion of its cryogen, the Spitzer Space telescope will still have a fully functioning two-channel mid-IR camera that will have sensitivities better than any other ground or space-based telescopes until the launch of JWST. This document provides a description of the expected capabilities of Spitzer during its warm mission phase, and provides brief descriptions of several possible very large science programs that could be conducted. This information is intended to serve as input to a wide ranging discussion of the warm mission science, leading up to the Warm Mission Workshop in June 2007

Demographic associations with stage of readiness to screen for colorectal cancer

Objective: To describe the distribution of a population in southern urban Adelaide in terms of readiness to screen for colorectal cancer (CRC) by Faecal Occult Blood Test (FOBT) or colonoscopy according to the stages in the Transtheoretical Model (TTM) of behaviour change and to compare the stages according to demographic variables. Methods: A random sample of 664 South Australians aged 50 to 74 were surveyed in June 2006. Chi-squared analyses were performed to determine if statistically significant differences on demographic variables existed between participants at different stages of readiness to screen

Adaptation to different salinities exposes functional specialization in the intestine of the sea bream (Sparus aurata L.)

The processing of intestinal fluid, in addition to a high drinking rate, is essential for osmoregulation in marine fish. This study analyzed the long-term response of the sea bream (Sparus aurata L.) to relevant changes of external salinity (12, 35 and 55p.p.t.), focusing on the anterior intestine and in the less-often studied rectum. Intestinal water absorption, epithelial HCO3– secretion and gene expression of the main molecular mechanisms (SLC26a6, SLC26a3, SLC4a4, atp6v1b, CFTR, NKCC1 and NKCC2) involved in Cl– and HCO3– movements were examined. The anion transporters SLC26a6 and SLC26a3 are expressed severalfold higher in the anterior intestine, while the expression of Atp6v1b (V-type H+-ATPase β-subunit) is severalfold higher in the rectum. Prolonged exposure to altered external salinity was without effect on water absorption but was associated with concomitant changes in intestinal fluid content, epithelial HCO3– secretion and salinity-dependent expression of SLC26a6, SLC26a3 and SLC4a4 in the anterior intestine. However, the most striking response to external salinity was obtained in the rectum, where a 4- to 5-fold increase in water absorption was paralleled by a 2- to 3-fold increase in HCO3– secretion in response to a salinity of 55p.p.t. In addition, the rectum of high salinity-acclimated fish shows a sustained (and enhanced) secretory current (Isc), identified in vitro in Ussing chambers and confirmed by the higher expression of CFTR and NKCC1 and by immunohistochemical protein localization. Taken together, the present results suggest a functional anterior–posterior specialization with regard to intestinal fluid processing and subsequently to salinity adaptation of the sea bream. The rectum becomes more active at higher salinities and functions as the final controller of intestinal function in osmoregulation

Exploring the Validity of the Continuum of Resistance Model for Discriminating Early from Late and Non-uptake of Colorectal Cancer Screening: Implications for the Design of Invitation and Reminder Letters.

This item is under embargo for a period of 12 months from the date of publication, in accordance with the publisher's policy.Background The continuum of resistance model contends that respondents lie at one end of a continuum and non-respondents at the other with respect to factors demonstrated to impact on screening participation. Purpose The aim of this study was to explore the validity of this model for the prediction of participation in colorectal cancer screening. Method People aged 50 to 74 years were asked to complete a survey (n = 1,250). Eligible respondents (n = 376, 30 %) were invited to complete a faecal occult blood test (FOBT). The cutoff period for the determination of participation rates was 12 weeks, with a reminder sent at 6 weeks. Results FOBTs were returned by n = 196 people (132 within 6 weeks, 64 following a reminder). Participation was generally influenced by the same variables in both the first 6 weeks and the second 6 weeks, consistent with the continuum of resistance model. These variables were having known someone with bowel cancer and the social cognitive factor, perceptions of barriers to screening. There is a suggestion, however, that other factors may be differentially associated with early, late and non-participants. Conclusion Participation in screening appears somewhat consistent with the continuum of resistance model in that early and late participants respond to some of the same factors. This suggests that the same messages are relevant to early, late and non-screeners, but further consideration of what other factors may be influencing discrete stages of readiness to participate is necessary.This work was supported by a National Health and Medical Research Council Grant number 324717