Subjective and predicted sleepiness while driving in young adults

Sleepiness is a significant contributor to car crashes and sleepiness related crashes have higher mortality and morbidity than other crashes. Young adult drivers are at particular risk for sleepiness related car crashes. It has been suggested that this is because young adults are typically sleepier than older adults because of chronic sleep loss, and more often drive at times of increased risk of acute sleepiness. This prospective study aimed to determine the relationship between predicted and perceived sleepiness while driving in 47 young-adult drivers over a 4-week period. Sleepiness levels were predicted by a model incorporating known circadian and sleep factors influencing alertness, and compared to subjective ratings of sleepiness during 25 18 driving episodes. Results suggested that young drivers frequently drive while at risk of crashing, at times of predicted sleepiness (>7% of episodes) and at times they felt themselves to be sleepy (>23% of episodes). A significant relationship was found between perceived and predicted estimates of sleepiness. However, the participants nonetheless drove at these times. The results of this study may help preventative programs to specifically target factors leading to increased sleepiness when driving (particularly time of day), and to focus interventions to stop young adults from driving when they feel sleepy. (c) 2005 Elsevier Ltd. All rights reserved.

Seasonal changes in the diel surfacing behaviour of the bimodally respiring turtle Rheodytes leukops

The purpose of this study was to determine whether a relationship existed between the diel surfacing trends of the bimodally respiring freshwater turtle Rheodytes leukops and daily fluctuations in specific biotic and abiotic factors: The, diel surfacing behaviour of adult R. leukops was recorded over four consecutive seasons (Austral autumn 2000 - summer 2001) within Marlborough Creek, central Queensland, Australia, using pressure-sensitive time-depth recorders. Additionally, diurnal variations in water temperature and aquatic Po-2 level, as well as the turtle's behavioural state (i.e., active versus resting), were monitored. In autumn and summer, surfacing frequency increased significantly during the daylight hours, with peak levels normally occurring around dawn (0500-0700) and. dusk (1700-1900). However, no consistent diel surfacing trend was recorded, for the turtles in winter or spring, owing to considerable variation among individual R. leukops. Diurnal surfacing trends recorded for R. leukops in, autumn and summer are attributed to periods of increased activity (possibly associated with foraging) during the daylight hours and not to daily variations in water temperature or aquatic Po-2 level. Turtles generally remained at a depth greater than 1 m throughout the day, where the effect of diel fluctuations in water temperature, (

A systematic review and meta-analysis of Northern Hemisphere season of birth studies in schizophrenia

Based on the epidemiological finding that individuals with schizophrenia tend to be born in winter/spring when compared to the general population, we examined (1) the strength and timing of this effect in Northern Hemisphere sites, and (2) the correlation between the season of birth effect size and latitude. Studies were located via electronic data sources, published citations, and letters to authors. Inclusion criteria were that studies specify the diagnostic criteria used, that studies specify the counts of schizophrenia and general population births for each month, and that subjects and the general population be drawn from the same birth years and catchment area. We extracted data from eight studies based on 126,196 patients with schizophrenia and 86,605,807 general population births and drawn from 27 Northern Hemisphere sites. Comparing winter/spring versus summer/autumn births, we found a significant excess for winter/spring births (pooled odds ratio = 1.07; 95% confidence interval 1.05, 1.08; population attributable risk = 3.3%). There was a small but significant positive correlation between the odds ratios for the season of birth comparison and latitude (r = 0.271, p < 0.005). Furthermore, the shape of the seasonality in schizophrenia births varied by latitude band. These variations may encourage researchers to generate candidate seasonally fluctuating exposures.

Adventitious root formation in cuttings of Backhousia citriodora F. Muell 2. Seasonal influences of temperature, rainfall, flowering and auxins on the stock plant

A 2-year study was carried out on established trees at two sites in southeastern Queensland, Australia, to identify environmental factors that influenced rooting of Backhousia citriodora from cuttings. Complex interactions of rainfall events above 20 mm from the preceding month and mean maximum temperature on stock plants resulted in a correlation with rooting success of r = 0.81 and 0.74 for sites at The University Of Queensland, Gatton Campus, and Cedar Glen, respectively. A more detailed investigation under controlled environmental conditions showed that maintaining stock plants at temperatures between 10 and 30degreesC had no direct effect on rooting capacity. However, temperature was correlated with growth, which may have an indirect effect on root formation. In spring floral initiation was found to only delay rooting and had no effect on the final rooting percentage. A series of seasonal experiments demonstrated that application of the auxins indole-3-acetic acid, indole-3-butyric acid and napthaleneacetic acid over a range of concentrations (1000-8000 mug/ml) did not significantly increase rooting compared to the control and there is no practical advantage in applying auxins. Seasonal results and the temperature experiment also suggest that under a glasshouse environment with higher temperatures in winter and an adequate supply of water, B. citriodora cuttings can be successfully rooted over the whole year. (C) 2004 Elsevier B.V. All rights reserved.

High-frequency winter cooling and reef coral mortality during the Holocene climatic optimum

A detailed ecological, micro-structural and skeletal Sr/Ca study of a 3.42 m thick Goniopora reef profile from an emerged Holocene reef terrace at the northern South China Sea reveals at least nine abrupt massive Goniopora stress and mortality events occurred in winter during the 7.0-7.5 thousand calendar years before present (cal. ka BP) (within the Holocene climatic optimum). Whilst calculated Sr/Ca-SST (sea surface temperature) maxima during this period are comparable to those in the 1990s, Sr/Ca-SST minima are significantly lower, probably due to stronger winter monsoons. Such generally cooler winters, superimposed by further exceptional winter cooling on inter-annual to decadal scales, may have caused stress and mortality of the corals about every 50 years. Sea level rose by similar to 3.42 m during this period, with present sea-level reached at similar to 7.3 ka BP and a sea-level highstand of at least similar to 1.8 m occurred at similar to 7.0 ka. The results show that it took about 20-25 years for a killed Goniopora coral reef to recover. (C) 2004 Elsevier B.V. All rights reserved.

Seasonal patterns of growth, dehydrins and water-soluble carbohydrates in genotypes of Dactylis glomerata varying in summer dormancy

Background and Aims Summer dormancy in perennial grasses has been studied inadequately, despite its potential to enhance plant survival and persistence in Mediterranean areas. The aim of the present work was to characterize summer dormancy and dehydration tolerance in two cultivars of Dactylis glomerata (dormant 'Kasbah', non-dormant 'Oasis') and their hybrid using physiological indicators associated with these traits. Methods Dehydration tolerance was assessed in a glasshouse experiment, while seasonal metabolic changes which produce putative protectants for drought, such as carbohydrates and dehydrins that might be associated with summer dormancy, were analysed in the field. Key Results The genotypes differed in their ability to survive increasing soil water deficit: lethal soil water potential (ψ(s)) was -3(.)4 MPa for 'Kasbah' (although non-dormant), -1(.)3 MPa for 'Oasis', and -1(.)6 MPa for their hybrid. In contrast, lethal water content of apices was similar for all genotypes (approx. 0(.)45 g H2O g d. wt(-1)), and hence the greater survival of 'Kasbah' can be ascribed to better drought avoidance rather than dehydration tolerance. In autumn-sown plants, 'Kasbah' had greatest dormancy, the hybrid was intermediate and 'Oasis' had none. The more dormant the genotype, the lower the metabolic activity during summer, and the earlier the activity declined in spring. Decreased monosaccharide content was an early indicator of dormancy induction. Accumulation of dehydrins did not correlate with stress tolerance, but dehydrin content was a function of the water status of the tissues, irrespective of the soil moisture. A protein of approx. 55 kDa occurred in leaf bases of the most dormant cultivar even in winter. Conclusions Drought avoidance and summer dormancy are correlated but can be independently expressed. These traits are heritable, allowing selection in breeding programmes.

Adventitious root formation in Grevillea (Proteaceae), an Australian native species

Grevillea (Proteaceae) is a native Australian plant genus with high commercial value as landscape ornamentals. There has been limited research on the culture and propagation of Australian native species. The effect of indole-3-butyric acid (IBA) on the rooting of G. 'Royal Mantle' and G. 'Coastal Dawn' in winter, spring and summer was evaluated at University of Queensland Gatton, Southern Queensland in order to determine the rooting ability of this species in different seasons. Both Grevillea cultivars showed seasonal rooting. The more difficult-to-root G. 'Coastal Dawn' had a reduced response to IBA application than G. 'Royal Mantle'. Stem and leaf indole-3-acetic acid (IAA) levels were not different between cultivars, therefore rooting ability between the two cultivars does not appear to be due to the differences in endogenous IAA levels. (c) 2005 Elsevier B.V. All rights reserved.

Estimating the abundance of eastern grey kangaroos (Macropus giganteus) in south-eastern New South Wales, Australia

To provide an estimate of kangaroo numbers for harvest management, a survey was designed for an area of 29500 km(2) encompassing the agricultural and grazing lands of the Braidwood, Cooma, Goulburn, Gundagai and Yass Rural Lands Protection Board (RLPB) districts in south-east New South Wales. An aerial survey using a helicopter was considered more efficient than ground survey because of the size of the area, relatively high relief and dense tree cover, and the need for regular monitoring. Tree cover and landscape relief was used to stratify the five RLPB districts into areas of probable high, medium and low kangaroo density. Kangaroo density estimated from helicopter surveys conducted in the Northern Tablelands of New South Wales was used to suggest densities and thereby allocate survey effort in each stratum. A survey comprising 735 km of transect line was conducted in winter 2003 with a target precision of 20%. The survey returned an estimate of 286600 32300 eastern grey kangaroos for the whole of the proposed south-east New South Wales kangaroo-management zone. In 2004, a trial harvest of slightly less than 15% of this estimate was taken. Success of the trial will be determined by the impact of harvesting on the population's dynamics, by landholder and industry participation, and by the capacity to monitor population size, harvest offtake and compliance with regulations.

Factors affecting female reproductive success and the survival of pouch young in the threatened brush-tailed rock-wallaby, Petrogale penicillata

Knowledge of factors affecting the survival of individuals and their reproductive success is essential for threatened species management, but studies assessing these factors are lacking for many threatened rock-wallaby species. In this study we investigated the factors influencing the breeding performance of females and the survival of pouch young in a wild colony of the threatened brush-tailed rock-wallaby. Individuals were trapped between October 2000 and April 2004. More than 50% of the females in the colony were breeding below their full potential and giving birth to only one offspring per year. Most females within the colony bred in synchrony, with a substantial birth peak evident during autumn. Pouch young born in autumn left the pouch during spring and were weaned during summer and autumn when forage was most abundant. Pouch young born during the autumn birth peak or in winter had a substantially higher probability of surviving through to pouch emergence than those born during spring or summer. This study provides demographic parameters that may be used in population models and for comparison with other populations, particularly those that are small and declining. To optimise reproductive success in reintroduction programs, females in good condition and with small pouch young should be released at the end of the wettest season.

Risk taking from the participant's perspective: The case of driving and accident risk

Although perceived health risk plays a prominent role in theories of health behavior. its empirical role in risk taking is less clear. In Study 1 (N = 129), 2 measures of drivers' risk-taking behavior were found to be unrelated to self-estimates of accident concern but to be related to self-ratings of driving skill and the perceived thrill of driving. In Study 2 (N = 405), out of a wide range of potential influences, accident concern had the weakest relationship with risk taking. The authors concluded that although health risk is a key feature in many theories of health behavior and a central focus for researchers and policy makers, it may not be such a prominent factor for those actually taking the risk.

A bloom of Lyngbya majuscula in Shoalwater Bay, Queensland, Australia: An important feeding ground for the green turtle (Chelonia mydas)

Lyngbya majuscula, a toxic cyanobacterium, was observed blooming during June-July (winter) 2002 in Shoalwater Bay, Queensland, Australia, an important feeding area for a large population of green turtles (Chelonia mydas). The bloom was mapped and extensive mats of L majuscula were observed overgrowing seagrass beds along at least 18 km of coast, and covering a surface area of more than I I km(2). Higher than average rainfall preceded the bloom and high water temperatures in the preceding summer may have contributed to the bloom. In bloom samples, lyngbyatoxin A (LA) was found to be present in low concentration (26 mu g kg(-1) (dry weight)), but debromoaplysiatoxin (DAT) was not detected. The diet of 46 green turtles was assessed during the bloom and L. majuscula was found in 51% of the samples, however, overall it contributed only 2% of the animals' diets. L. majuscula contribution to turtle diet was found to increase as the availability of the cyanobacterium increased. The bloom appeared to have no immediate impact on turtle body condition, however, the presence of a greater proportion of damaged seagrass leaves in diet in conjunction with decreases in plasma concentrations of sodium and glucose could suggest that the turtles may have been exposed to a Substandard diet as a result of the bloom. This is the first confirmed report of L. majuscula blooming in winter in Shoalwater Bay, Queensland, Australia and demonstrates that turtles consume the toxic cyanobacterium in the wild, and that they are potentially exposed to tumour promoting compounds produced by this organism. (c) 2005 Elsevier B.V. All rights reserved.

Hazard detection in older adult drivers

Older adults make up an increasing propordon of automobile drivers in Australia. Despite the fact that older drivers generally drive much less than younger drivers, there is a disdnct increase in accidents, fatalides and injuries in drivers over age 65 (per actual kilometres driven). Accurate means of screening older adults to idendfy those at increased risk of motor vehicle accidents have proved elusive. Neuropsychological assessment and clinical examinadon are not well-correlated with accident risk. On-road tesdng, which is more highly correlated with accident risk, is expensive and dme-consuming, as well as being less suitable as a screening process. Hazard percepdon methods have been used as an effecdve screening method for idendfying younger adults at increased risk of accidents. A brief video-based hazard percepdon screening test involving footage of genuine traffic hazards for use on older individuals will be presented.