A quantitative assessment of shoot flammability for 60 tree and shrub species supports rankings based on expert opinion

Fire is an important ecological disturbance in vegetated ecosystems across the globe, and also has considerable impacts on human infrastructure. Vegetation flammability is a key bottom-up control on fire regimes, and on the nature of individual fires. Although New Zealand (NZ) historically had low fire frequencies, anthropogenic fires have considerably impacted indigenous vegetation as humans used fire extensively to clear forests. Few studies of vegetation flammability have been undertaken in NZ, and only one has compared the flammability of indigenous plants; this was a qualitative assessment derived from expert opinion. We addressed this knowledge gap by measuring the flammability of terminal shoots from a range of trees and shrubs found in NZ. We quantified shoot flammability of 60 indigenous and exotic species, and compared our experimentally derived ranking with expert opinion. The most flammable species was the invasive exotic shrub Ulex europaeus, followed by Eucalyptus viminalis, Pomaderris kumeraho, Dacrydium cupressinum, and Lophozonia menziesii. Our experimentally derived ranking was strongly correlated with expert opinion, lending support to both methods. Our results are useful to ecologists seeking to understand how fires have and will influence NZ’s ecosystems, and for fire managers identifying high-risk landscapes, and low flammability species for ‘green firebreaks’

Tear Fluid SIgA as a Noninvasive Biomarker of Mucosal Immunity and Common Cold Risk

PURPOSE: Research has not convincingly demonstrated the utility of saliva secretory immunoglobulin-A (SIgA) as a biomarker of upper respiratory tract infection (URTI) risk, and disagreement exists about the influence of heavy exercise ("open-window theory") and dehydration on saliva SIgA. Prompted by the search for viable alternatives, we compared the utility of tear and saliva SIgA to predict URTI prospectively (study 1) and assessed the influence of exercise (study 2) and dehydration (study 3) using a repeated-measures crossover design. METHODS: In study 1, 40 subjects were recruited during the common-cold season. Subjects provided tear and saliva samples weekly and recorded upper respiratory symptoms (URS) daily for 3 wk. Real-time PCR confirmed common-cold pathogens in 9 of 11 subjects reporting URS (82%). Predictive utility of tear and saliva SIgA was explored by comparing healthy samples with those collected during the week before URS. In study 2, 13 subjects performed a 2-h run at 65% V O2peak. In study 3, 13 subjects performed exercise heat stress to 3% body mass loss followed by overnight fluid restriction. RESULTS: Tear SIgA concentration and secretion rate were 48% and 51% lower, respectively, during URTI and 34% and 46% lower the week before URS (P 30%. Tear SIgA secretion rate >5.5 mug.min(-1) or no decrease of >30% predicted subjects free of URS in >80% of cases. Tear SIgA concentration decreased after exercise (-57%, P < 0.05) in line with the "open-window theory" but was unaffected by dehydration. Saliva flow rate decreased and saliva SIgA concentration increased after exercise and during dehydration (P < 0.05). CONCLUSIONS: Tear SIgA has utility as a noninvasive biomarker of mucosal immunity and common-cold risk

Climate Variability and Ross River Virus Transmission in Townsville Region, Australia 1985 to 1996

Background How climate variability affects the transmission of infectious diseases at a regional level remains unclear. In this paper, we assessed the impact of climate variation on the Ross River virus (RRv) transmission in the Townsville region, Queensland, north-east Australia. Methods Population-based information was obtained on monthly variations in RRv cases, climatic factors, sea level, and population growth between 1985 and 1996. Cross-correlations were computed for a series of associations between climate variables (rainfall, maximum temperature, minimum temperature, relative humidity and high tide) and the monthly incidence of RRv disease over a range of time lags. The impact of climate variability on RRv transmission was assessed using the seasonal auto-regressive integrated moving average (SARIMA) model. Results There were significant correlations of the monthly incidence of RRv to rainfall, maximum temperature, minimum temperature and relative humidity, all at a lag of 2 months, and high tide in the current month. The results of SARIMA models show that monthly average rainfall (β=0.0012, p=0.04) and high tide (β=0.0262, p=0.01) were significantly associated with RRv transmission, although temperature and relative humidity did not seem to have played an important role in the Townsville region. Conclusions Rainfall, and high tide were likely to be key determinants of RRv transmission in the Townsville region

Internet-based medical education: a realist review of what works, for whom and in what circumstances

http://creativecommons.org/licenses/by/2.0

Continuously Tuneable Critical Current in Superconductor-Ferromagnet Multilayers

We demonstrate that the critical current of superconducting Nb/Ni multilayers can be continuously tuned by up to a factor of three during magnetization reversal of the Ni films under an applied in-plane magnetic field. Our observations are in reasonably good agreement with a model of vortex pinning by Bloch domain walls that proliferate in the samples during magnetization reversal, whereby each vortex interacts with at most one wall in any of the Ni layers. Our model suggests ways in which the controllable pinning effect could be significantly enhanced, with important potential applications in tuneable superconducting devices

Entrepreneurs’ age, institutions, and social value creation goals: a multi-country study

This study explores the relationship between an entrepreneur's age and his/her social value creation goals. Building on the lifespan developmental psychology literature and institutional theory, we hypothesize a U-shaped relationship between entrepreneurs’ age and their choice to create social value through their ventures, such that younger and older entrepreneurs create more social value with their businesses while middle age entrepreneurs are relatively more economically and less socially oriented with their ventures. We further hypothesize that the quality of a country’s formal institutions in terms of economic, social, and political freedom steepen the U-shaped relationship between entrepreneurs’ age and their choice to pursue social value creation as supportive institutional environments allow entrepreneurs to follow their age-based preferences. We confirm our predictions using multilevel mixed-effects linear regressions on a sample of over 15,000 entrepreneurs (aged between 18 and 64 years) in 45 countries from Global Entrepreneurship Monitor data. The findings are robust to several alternative specifications. Based on our findings, we discuss implications for theory and practice, and we propose future research directions

The effects of alcohol consumption, psychological distress and smoking status on emergency department presentations in New South Wales, Australia

BACKGROUND: Despite clear links between risky alcohol consumption, mental health problems and smoking with increased morbidity and mortality, there is inconclusive evidence about how these risk factors combine and if they are associated with increased attendance at emergency departments. This paper examines the population-level associations and interactions between alcohol consumption, psychological distress and smoking status with having presented to an emergency department in the last 12 months. METHODS: This study uses data from a representative sample of 34,974 participants aged 16 years and over from the New South Wales Population Health Survey, administered between 2002 and 2004. Statistical analysis included univariate statistics, cross-tabulations, and the estimation of prevalence rate ratios using Cox's proportional hazard regression model. RESULTS: Results show that high-risk alcohol consumption, high psychological distress and current smoking were all significantly and independently associated with a greater likelihood of presenting to an emergency department in the last year. Presenting to an emergency department was found to be three times more likely for women aged 30 to 59 years with all three risk factors and ten times more likely for women aged 60 years or more who reported high risk alcohol consumption and high psychological distress than women of these age groups without these risk factors. For persons aged 16 to 29 years, having high-risk alcohol consumption and being a current smoker doubles the risk of presenting to an emergency department. CONCLUSION: The combination of being a high-risk consumer of alcohol, having high psychological distress, and being a current smoker are associated with increased presentations to emergency departments, independent of age and sex. Further research is needed to enhance recognition of and intervention for these symptoms in an emergency department setting in order to improve patient health and reduce future re-presentations to emergency departments

Ecological implications of a flower size/number trade-off in tropical forest trees

Peer reviewedPublisher PD

Binary and Millisecond Pulsars at the New Millennium

We review the properties and applications of binary and millisecond pulsars. Our knowledge of these exciting objects has greatly increased in recent years, mainly due to successful surveys which have brought the known pulsar population to over 1300. There are now 56 binary and millisecond pulsars in the Galactic disk and a further 47 in globular clusters. This review is concerned primarily with the results and spin-offs from these surveys which are of particular interest to the relativity community.Comment: 59 pages, 26 figures, 5 tables. Accepted for publication in Living Reviews in Relativity (http://www.livingreviews.org