Modelling life history strategies with capture-recapture data: Evolutionary demography of the water skink Eulamprus tympanum

Matrix population models, elasticity analysis and loop analysis can potentially provide powerful techniques for the analysis of life histories. Data from a capture-recapture study on a population of southern highland water skinks (Eulamprus tympanum) were used to construct a matrix population model. Errors in elasticities were calculated by using the parametric bootstrap technique. Elasticity and loop analyses were then conducted to identify the life history stages most important to fitness. The same techniques were used to investigate the relative importance of fast versus slow growth, and rapid versus delayed reproduction. Mature water skinks were long-lived, but there was high immature mortality. The most sensitive life history stage was the subadult stage. It is suggested that life history evolution in E. tympanum may be strongly affected by predation, particularly by birds. Because our population declined over the study, slow growth and delayed reproduction were the optimal life history strategies over this period. Although the techniques of evolutionary demography provide a powerful approach for the analysis of life histories, there are formidable logistical obstacles in gathering enough high-quality data for robust estimates of the critical parameters.

General scales of community reaction to noise (dissatisfaction and perceived affectedness) are more reliable than scales of annoyance

General measures of reaction to noise, which assess the respondent's perceived affectedness or dissatisfaction, appear to be more valid and internally consistent than more narrow measures, such as specific assessment of noise annoyance. However, the test-retest reliability of general and specific measures has yet to be compared. As a part of the large-scale Sydney Airport Health Study, 97 respondents participated in the same interview twice, several weeks apart. Test-retest reliabilities were found to be significant (p

An overview of diversion strategies for Australian drug-related offenders

This paper provides a descriptive overview of options for diversion of drug-related offenders from the criminal justice system. Drug-related offences include drug offences (for example, possession of a prohibited substance); offences that are directly linked to intoxication (for example, drink-driving or assault); and offences committed to support drug use (for example, theft). After an offence has been detected by police, multiple opportunities for diversion occur throughout the criminal justice process. (a) Pre-arrest: when an offence is first detected, prior to a charge being laid. This is known as police diversion and includes fines, warnings and cautions, sometimes with educational information or referral to assessment and treatment. (b) Pre-trial: when a charge is made but before the matter is heard at court. Examples are treatment as a condition of bail, conferencing and prosecutor discretion. (c) Pre-sentence: a delay of sentence while assessment and treatment are sought. (d) Post-sentence: as part of sentencing, for example suspended sentences, drug courts, noncustodial sentences and circle sentencing. (e) Pre-release: prior to release from a sentence, on parole. Issues for diversion programmes include net widening, the ethics of coercion to treatment, the needs of families and intersectoral collaboration. A framework for diversion is presented in which increasingly treatment-focused and coercive diversion strategies are used as offenders' criminal careers and drug problems increase.

Modelling socially optimal land allocations for sugar cane growing in North Queensland: a linked mathematical programming and choice modelling study

A modelling framework is developed to determine the joint economic and environmental net benefits of alternative land allocation strategies. Estimates of community preferences for preservation of natural land, derived from a choice modelling study, are used as input to a model of agricultural production in an optimisation framework. The trade-offs between agricultural production and environmental protection are analysed using the sugar industry of the Herbert River district of north Queensland as an example. Spatially-differentiated resource attributes and the opportunity costs of natural land determine the optimal tradeoffs between production and conservation for a range of sugar prices.

Community structure of Quaternary coral reefs compared with Recent life and death assemblages

This paper assesses the reliability with which fossil reefs record the diversity and community structure of adjacent Recent reefs. The diversity and taxonomic composition of Holocene raised fossil reefs was compared with those of modern reef coral life and death assemblages in adjacent moderate and low-energy shallow reef habitats Of Madang Lagoon, Papua New Guinea. Species richness per sample area and Shannon-Wiener diversity (H') were highest in the fossil reefs, intermediate in the life assemblages, and lowest in the death assemblages. The taxonomic composition of the fossil reefs was most similar to the combination of the life and death assemblages from the modern reefs adjacent to the two fossil reefs. Depth zonation was recorded accurately in the fossil reefs. The Madang fossil reefs represent time-averaged composites of the combined life and death assemblages as they existed at the time the reef was uplifted. Because fossil reefs include overlapping cohorts from the life and death assemblages, lagoonal facies of fossil reefs are dominated by the dominant sediment-producing taxa, which are not necessarily the most abundant in the life assemblage. Rare or slow-growing taxa accumulate more slowly than the encasing sediments and are underrepresented in fossil reef lagoons. Time-averaging dilutes the contribution of rare taxa, rather than concentrating their contribution. Consequently, fidelity indices developed for mollusks in sediments yield low values in coral reef death and fossil assemblages. Branching corals dominate lagoonal facies of fossil reefs because they are abundant, they grow and produce sediment rapidly, and most of the sediment they produce is not exported. Fossil reefs distinguished kilometer-scale variations in community structure more clearly than did the modern life assemblages. This difference implies that fossil,reefs may provide a better long-term record of community structure than modern reefs. This difference also suggests that modern kilometer-scale variation in coral reef community structure may have been reduced by anthropogenic degradation, even in the relatively unimpacted reefs of Madang Lagoon. Holocene and Pleistocene fossil reefs provide a time-integrated historical record of community composition and may be used as long-term benchmarks for comparison with modern, degraded, nearshore reefs. Comparisons between fossil reefs and degraded modern reefs display gross changes in community structure more effectively than they demonstrate local extinction of rare taxa.

Social structures, genetic structures and dispersal strategies in Australian rabbit (Oryctolagus cuniculus) populations

In this study, the pattern of movement of young male and female rabbits and the genetic structures present in adult male and female populations in four habitats was examined. The level of philopatry in young animals was found to vary between 18-90% for males and 32-95% for females in different populations. It was skewed, with more males dispersing than females in some but not all populations. Analysis of allozyme data using spatial autocorrelation showed that adult females from the same social group, unlike males, were significantly related in four of the five populations studied. Changes in genetic structure and rate of dispersal were measured before and during the recovery of a population that was artificially reduced in size. There were changes in the rate and distance of dispersal with density and sex. Subadults of both sexes moved further in the first year post crash (low density) than in the following years. While the level of dispersal for females was lower than that of the males for the first 3 years, thereafter (high density) both sexes showed similar, low levels of dispersal (20%). The density at which young animals switch behaviour between dispersal and philopatry differed for males and females. The level of genetic structuring in adult females was high in the precrash population, reduced in the first year post crash and undetectable in the second year. Dispersal behaviour of rabbits both affects the genetic structure of the population and changes with conditions. Over a wide range of levels of philopatry, genetic structuring is present in the adult female, but not the male population. Consequently, though genetic structuring is present, it does not lead to inbreeding. More long-distance movements are found in low-density populations, even though vacant warrens are available near birth warrens. The distances moved decreased as density increased. Calculation of the effective population size (N-e) shows that changes in dispersal distance offset changes in density, so that N-e remains constant.

Long-term disability after first-ever stroke and related prognostic factors in the Perth Community Stroke Study, 1989-1990

Background and Purpose-Few reliable estimates of the long-term functional outcome after stroke are available. This population-based study aimed to describe disability, dependency, and related independent prognostic factors at 5 years after,a first-ever stroke in patients in Perth, Western Australia. Methods-All individuals with a suspected acute stroke who were resident in a geographically defined region (population, 138 708) of Perth, Western Australia, were registered prospectively and assessed according to standardized diagnostic criteria over a period of 18 months in 1989 to 1990. Patients were followed up prospectively at 4 and 12 months and 5 years after the index event. Results-There were 370 cases of first-ever stroke, and 277 patients survived to 30 days. Of these early survivors, 152 (55%) were alive at 5 years, and among those who were neither institutionalized (n=146) nor disabled (n=129) at the time of their stroke, 21 (14%) were institutionalized in a nursing home, and 47 (36%) were disabled. The most important predictors of death or disability at 5 years were increasing age, baseline disability defined by a Barthel Index score of <20/20 (odds ratio [OR], 6.3; 95% confidence interval [CI], 2.7 to 14), moderate hemiparesis (OR, 2.7. 95% CI, 1.1 to 6.2), severe hemiparesis (OR, 4.5; 95% CI, 1.1 to 19), and recurrent stroke (OR, 9.4; 95% CI, 3.0 to 30). A low level of activity before the stroke was a significant predictor of institutionalization, and subsequent recurrent stroke was a consistent, independent predictor of institutionalization, disability, and death or institutionalization, increasing the odds of each of these 3 adverse outcomes by 5- to 15-fold. Conclusions-Among 30-day survivors of first-ever stroke, about half survive 5 years; of survivors, one third remain disabled, and I in 7 are in permanent institutional care. The major modifiable predictors of poor long-term outcome are a low level of activity before the stroke and subsequent recurrent stroke. Efforts to increase physical activity among the elderly and to prevent recurrent stroke in survivors of a first stroke are likely to reduce the long-term burden of cerebrovascular disease.

The role of dogs in transmission of gastrointestinal parasites in a remote tea-growing community in northeastern India

The prevalence and risk factors associated with canine gastrointestinal parasitic zoonoses and the role of dogs in the mechanical transmission of human Ascaris infection was examined in three tea estates in Assam, India. Nearly all (99%) dogs harbored one or more zoonotic species of gastrointestinal parasites, with hookworm infection being most common (94%). Parasitic stages presumed to be host-specific for humans such as Ascaris spp. (31%), Trichuris trichiura (25%), and Isospora belli (2%) were also recovered from dog feces. A polymerase chain reaction-linked restriction fragment length polymorphism technique was used to differentiate the species of Ascaris eggs in dog feces. The results of this study demonstrate the role of the dog as a significant disseminator and environmental contaminator of Ascaris lumbricoides in communities where promiscuous defecation by humans occurs.

Ten-year survival after first-ever stroke in the Perth Community Stroke Study

Background and Purpose-Very few studies have provided information regarding long-term prognosis after stroke. We aimed to determine the absolute and relative survival over 10 years among patients with first-ever stroke from a population-based study in Perth, Western Australia. Methods-For a 12-month period beginning February 1989, all individuals with a suspected acute stroke or transient ischemic attack who were resident in a geographically defined and representative region of Perth, Western Australia, were registered prospectively and assessed according to standardized diagnostic criteria. Patients with a definite first-ever stroke were followed up prospectively at 4 months, 12 months, 5 years, and 10 years after the index event. Results-A total of 251 patients with first-ever stroke were registered, and 244 (97%) were followed up at 10 years, by which time 197 (79%; 95% confidence interval [CI], 74 to 84) had died. The major causes of death were the direct effects of the initial stroke (27%; 95% CI, 21 to 33) and cardiovascular disease (26%; 95% CI, 20 to 32). Among 1-year survivors of stroke, the average annual case fatality was 4.8%, which was 2.3 (95% CI, 1.9 to 2.7) times greater than for the general population of the same age and sex. Conclusions-One in 5 patients with first-ever stroke survived to 10 years. The average annual case fatality was 4.8% between years 1 and 10 after stroke, which was twice that expected for the general population. Vascular disease is the major cause of death among long-term survivors of stroke.

Humans, dogs and parasitic zoonoses - Unravelling the relationships in a remote endemic community in Northeast India using molecular tools

Canine parasitic zoonoses pose a continuing public health problem, especially in developing countries and communities that are socioeconomically disadvantaged. Our study combined the use of conventional and molecular epidemic, logical tools to determine the role of dogs in transmission of gastrointestinal (GI) parasites such as hookworms, Giardia and Ascaris in a parasite endemic teagrowing community in northeast India. A highly sensitive and specific molecular tool was developed to detect and differentiate the zoonotic species of canine hookworm eggs directly from faeces. This allowed epidemiological screening of canine hookworm species in this community to be conducted with ease and accuracy. The zoonotic potential of canine Giardia was also investigated by characterising Giardia duodenalis recovered from humans and dogs living in the same locality and households at three different loci. Phylogenetic and epidemiological analysis provided compelling evidence to support the zoonotic transmission of canine Giardia. Molecular tools were also used to identify the species of Ascaris egg present in over 30% of dog faecal samples. The results demonstrated the role of dogs as a significant disseminator and environmental contaminator of Ascaris lumbricoides in communities where promiscuous defecation practices exist. Our study demonstrated the usefulness of combining conventional and molecular parasitological and epidemiological tools to help solve unresolved relationships with regards to parasitic zoonoses.

Epidemiological and molecular evidence supports the zoonotic transmission of Glardia among humans and dogs living in the same community

Giardia duodenalis isolates recovered from humans and clogs living in the same locality in a remote tea-growing community of northeast India were characterized at 3 different loci; the SSU-rDNA, elongation factor 1-alpha (ef1-alpha) and triose phosphate isomerase (tpi) gene. Phylogenetic analysis of the SSU-rDNA and ef1-alpha genes provided poor genetic resolution of the isolates within various assemblages, stressing the importance of using multiple loci when inferring genotypes to Giardia. Analysis of the tpi gene provided better genetic resolution and placed canine Giardia isolates within the genetic groupings of human isolates (Assemblages A and B). Further evidence for zoonotic transmission was supported by epidemiological data showing a highly significant association between the prevalence of Giardia in humans and presence of it Giardia-positive dog in the same household (odds ratio 3.01, 95%) CI, 1.11, 8.39, P = 0.0000).