David J. Welch

Childhood Sleep Time and Long-Term Risk for Obesity: A 32-Year Prospective Birth Cohort Study

OBJECTIVE. Associations between short sleep duration and increased BMI have been found in children and adults. However, it is not known whether short sleep time during childhood has long-term consequences. We assessed the association between sleep time in childhood and adult BMI in a birth cohort. METHODS. Study members were a general-population birth cohort of 1037 participants (502 female) who were born in Dunedin, New Zealand, between April 1972 and March 1973. Parental reports of bedtimes and rising times collected at ages 5, 7, 9, and 11 years were used to estimate childhood sleep time. Linear regression analysis was used to analyze the association between childhood sleep time and BMI measured at 32 years of age. RESULTS. Shorter childhood sleep times were significantly associated with higher adult BMI values. This association remained after adjustment for adult sleep time and the potential confounding effects of early childhood BMI, childhood socioeconomic status, parental BMIs, child and adult television viewing, adult physical activity, and adult smoking. In logistic regression analyses, more sleep time during childhood was associated with lower odds of obesity at 32 years of age. This association was significant after adjustment for multiple potential confounding factors. CONCLUSIONS. These findings suggest that sleep restriction in childhood increases the long-term risk for obesity. Ensuring that children get adequate sleep may be a useful strategy for stemming the current obesity epidemic.

Does Childhood Television Viewing Lead to Attention Problems in Adolescence? Results From a Prospective Longitudinal Study

CONTEXT. There is controversy over whether childhood television viewing causes attention problems. The findings from cross-sectional and longitudinal studies have been mixed. To our knowledge, no longitudinal studies have assessed the impact of childrens television viewing on attention problems in adolescence. The objective of this study was to assess this association. DESIGN, PARTICIPANTS, AND SETTING. Study members were a general population birth cohort of 1037 participants (502 female) born in Dunedin, New Zealand, between April 1972 and March 1973. Parental estimates of childrens television-viewing time were obtained at ages 5, 7, 9, and 11 years. Self-, parent-, and teacher-reported attention problems in adolescence were obtained at ages 13 and 15 years. RESULTS. The mean of hours of television viewing during childhood was associated with symptoms of attention problems in adolescence. These associations remained significant after controlling for gender, attention problems in early childhood, cognitive ability at 5 years of age, and childhood socioeconomic status. This association was also independent of adolescent television viewing. CONCLUSIONS. Childhood television viewing was associated with attention problems in adolescence, independent of early attention problems and other confounders. These results support the hypothesis that childhood television viewing may contribute to the development of attention problems and suggest that the effects may be long-lasting.

Cannabis Smoking and Periodontal Disease Among Young Adults

CONTEXT Tobacco smoking is a recognized behavioral risk factor for periodontal disease (through its systemic effects), and cannabis smoking may contribute in a similar way. OBJECTIVE To determine whether cannabis smoking is a risk factor for periodontal disease. DESIGN AND SETTING Prospective cohort study of the general population, with cannabis use determined at ages 18, 21, 26, and 32 years and dental examinations conducted at ages 26 and 32 years. The most recent data collection (at age 32 years) was completed in June 2005. PARTICIPANTS A complete birth cohort born in 1972 and 1973 in Dunedin, New Zealand, and assessed periodically (with a 96% follow-up rate of the 1015 participants who survived to age 32 years). Complete data for this analysis were available from 903 participants (comprising 89.0% of the surviving birth cohort). MAIN OUTCOME MEASURE Periodontal disease status at age 32 years (and changes from ages 26 to 32 years) determined from periodontal combined attachment loss (CAL) measured at 3 sites per tooth. RESULTS Three cannabis exposure groups were determined: no exposure (293 individuals, or 32.3%), some exposure (428; 47.4%), and high exposure (182; 20.2%). At age 32 years, 265 participants (29.3%) had 1 or more sites with 4 mm or greater CAL, and 111 participants (12.3%) had 1 or more sites with 5 mm or greater CAL. Incident attachment loss between the ages of 26 and 32 years in the none, some, and high cannabis exposure groups was 6.5%, 11.2%, and 23.6%, respectively. After controlling for tobacco smoking (measured in pack-years), sex, irregular use of dental services, and dental plaque, the relative risk estimates for the highest cannabis exposure group were as follows: 1.6 (95% confidence interval [CI], 1.2-2.2) for having 1 or more sites with 4 mm or greater CAL; 3.1 (95% CI, 1.5-6.4) for having 1 or more sites with 5 mm or greater CAL; and 2.2 (95% CI, 1.2-3.9) for having incident attachment loss (in comparison with those who had never smoked cannabis). Tobacco smoking was strongly associated with periodontal disease experience, but there was no interaction between cannabis use and tobacco smoking in predicting the conditions occurrence. CONCLUSION Cannabis smoking may be a risk factor for periodontal disease that is independent of the use of tobacco.

Marine Fisheries Management in a Changing Climate: A Review of Vulnerability and Future Options

Marine capture fisheries are an important source of protein globally, with coastal and oceanic fish providing a rich source of essential fatty acids, vitamins, and minerals. Fisheries also support economies and important social structures in many nations, particularly developing nations (Allison et al., 2009). Marine fisheries are under increasing threat from climate change, with climate change now identified as the latest threat to the worlds fast declining fish stocks (UNEP, 2008; Cochrane et al., 2009). Marine fisheries will be exposed to increasing sea surface temperatures, ocean acidification, sea level rise, increasing storm intensity and altered ocean circulation, and rainfall patterns that will affect target species through a range of direct and indirect mechanisms. The sensitivity of fish stocks to these changes will determine the range of potential impacts to life cycles, species distributions, community structure, productivity, connectivity, organism performance, recruitment dynamics, prevalence of invasive species, and access to marine resources by fishers. Many fisheries are already experiencing changes in target species diversity and abundance, species distribution, and habitat area, as well as loss of fishing effort due to intensifying storms (Johnson and Marshall, 2007; Hobday et al., 2008; UNEP, 2008). Using a vulnerability assessment framework, we examine the level of vulnerability of marine fisheries to climate change and the factors that will temper vulnerability, such as adaptive capacity. Assessing fisheries vulnerability to climate change is essential to prioritize systems in greatest need of intervention, understand the drivers of vulnerability to identify future research directions, and more importantly, to review current fisheries management with the view to develop management responses that will be effective in securing the future sustainability of marine fisheries.

Evaluating catch and mitigating risk in a multispecies, tropical, inshore shark fishery within the Great Barrier Reef World Heritage Area

Small-scale and artisanal fisheries for sharks exist in most inshore, tropical regions of the world. Although often important in terms of food security, their low value and inherent complexity provides an imposing hurdle to sustainable management. An observer survey of a small-scale commercial gill-net fishery operating within the Great Barrier Reef World Heritage area revealed at least 38 species of elasmobranch were present in the catch. Of the total elasmobranch catch, 95% was 25 species of Carcharhiniformes from the families Carcharhinidae, Hemigaleidae and Sphyrnidae. Individual species were captured in a variety of ways by the fishery, often with strongly biased sex ratios and in a variety of life stages (e.g. neonates, juveniles, adult). Despite this, the main carcharhiniform taxa captured could be qualitatively categorised into four groups based on similar catch characteristics, body size and similarities in life history: small coastal ( 2000 mm); and hammerheads. Such groupings can potentially be useful for simplifying management of complex multispecies fisheries. The idiosyncrasies of elasmobranch populations and how fisheries interact with them provide a challenge for management but, if properly understood, potentially offer underutilised options for designing management strategies.

Programming obesity and poor fitness: the long-term impact of childhood television.

Objective: To assess whether the long‐term effects of childhood television viewing on BMI and cardiorespiratory fitness are mediated by adult viewing.

Personality and perception of tinnitus

Objectives: Tinnitus has high prevalence and a wide range of etiologies and of impacts on sufferers. Our objective was to develop understanding of the role of personality in the perception of tinnitus in the general population. As a theoretical basis for this, we combined elements of a general model of signal detection with the ideas of ignition (development) and promotion (neural transmission) of tinnitus, and considered plausible roles for personality factors within this conceptual framework. Design: We interviewed a birth cohort of 970 people aged 32 yr sampled from the general population. On the basis of questioning, we divided them into three groups, those without tinnitus, those with occasional tinnitus (including those with transient tinnitus of very brief duration), and those who experienced tinnitus most of the time. We also established how annoying or distressing the tinnitus was, and assessed personality using the Multidimensional Personality Questionnaire. Results: Tinnitus was experienced rarely by 38.2% and half the time or more by 6.8% of those studied. Men and women did not differ in the amount of tinnitus reported, but women were more likely to find it annoying. People from lower socioeconomic backgrounds were more likely to report tinnitus. People with tinnitus were more socially withdrawn, reactive to stress, alienated, and less Self-Controlled. People who were more annoyed by tinnitus were more socially withdrawn, and men were more stress reactive and alienated. Conclusions: Our interpretation of the findings is that personality influences the persistence of tinnitus by influencing the tendency to be aware of it. Consideration of personality factors may improve the ability to tailor tinnitus therapies, and the concept of awareness may benefit treatment outcomes by showing tinnitus sufferers a means of internalizing the locus of control over their symptoms.

Limited ecological population connectivity suggests low demands on self-recruitment in a tropical inshore marine fish (Eleutheronema tetradactylum: Polynemidae)

The diversity of geographic scales at which marine organisms display genetic variation mirrors the biophysical and ecological complexity of dispersal by pelagic larvae. Yet little is known about the effect of larval ecology on genetic population patterns, partly because detailed data of larval ecology do not yet exist for most taxa. One species for which this data is available is Eleutheronema tetradactylum, a tropical Indo‐West Pacific shorefish. Here, we use a partial sequence mitochondrial cytochrome oxidase subunit 1 (COI) marker and five microsatellite loci to survey the genetic structure of E. tetradactylum across northern Australia. Structure was found throughout the range and isolation by distance was strong, explaining approximately 87 and 64% of the genetic variation in microsatellites and mtDNA, respectively. Populations separated by as little as 15 km also showed significant genetic structure, implying that local populations are mainly insular and self‐seeding on an ecological time frame. Because the larvae of E. tetradactylum have lower swimming performance and poor orientation compared with other tropical fishes, even modest larval abilities may permit self‐recruitment rather than passive dispersal.

Personality influences on change in smoking behavior.

OBJECTIVE To investigate associations between personality traits in early adulthood (and changes in them) and change in smoking status. DESIGN Prospective, longitudinal study of a general-population birth cohort. MAIN OUTCOME MEASURES We measured smoking at ages 18, 26, and 32, and personality at ages 18 and 26 using the Multidimensional Personality Questionnaire (Tellegen & Waller, in press). We assessed personalitys ability to predict future smoking, and assessed how changes in personality traits relate to change in smoking status. RESULTS Higher aggression and alienation at age 18 predicted smoking at 26; higher self-control and traditionalism at age 18 predicted nonsmoking at 26; and higher alienation at age 26 predicted persistence of smoking to age 32. Personality change between 18 and 26 was associated with change in smoking behavior; those who stopped smoking decreased more than others in negative emotionality and increased more in constraint. CONCLUSION These findings suggest that interventions fostering personality change may be effective in reducing smoking and indicate appropriate targets for such antismoking interventions in young people. In particular, high alienation predicted smoking persistence, perhaps due to resistance to existing antismoking messages; we discuss approaches that may overcome this.

Genetic population structure of grey mackerel Scomberomorus semifasciatus in northern Australia

This study used mtDNA sequence and microsatellite markers to elucidate the population structure of Scomberomorus semifasciatus collected from 12 widespread sampling locations in Australia. Samples (n = 544) were genotyped with nine microsatellite loci, and 353 were sequenced for the control (384 bp) and ATPase (800 bp) mtDNA gene regions. Combined interpretation of microsatellite and mtDNA data identified four genetic stocks of S. semifasciatus: Western Australia, north-west coast of the Northern Territory, Gulf of Carpentaria and the eastern coast of Queensland. Connectivity among stocks across northern Australia from the Northern Territory to the eastern coast of Queensland was high (mean F(ST) = 0·003 for the microsatellite data and Φ(ST) = 0·033 and 0·009 for control region and ATPase, respectively) leading to some uncertainty about stock boundaries. In contrast, there was a clear genetic break between the stock in Western Australia compared to the rest of northern Australia (mean F(ST) = 0·132 for the microsatellite data and Φ(ST) = 0·135 and 0·188 for control region and ATPase, respectively). This indicates a restriction to gene flow possibly associated with suboptimal habitat along the Kimberley coast (north Western Australia). The appropriate scale of management for this species corresponds to the jurisdictions of the three Australian states, except that authorities in Queensland and Northern Territory should co-ordinate the management of the Gulf of Carpentaria stock.