Mitochondrial and nuclear genetic analyses of the tropical black-lip rock oyster (Saccostrea echinata) reveals population subdivision and informs sustainable aquaculture development

The black-lip rock oyster (Saccostrea echinata) has considerable potential for aquaculture throughout the tropics. Previous attempts to farm S. echinata failed due to an insufficient supply of wild spat; however, the prospect of hatchery-based aquaculture has stimulated renewed interest, and small-scale farming is underway across northern Australia and in New Caledonia. The absence of knowledge surrounding the population genetic structure of this species has raised concerns about the genetic impacts of this emerging aquaculture industry. This study is the first to examine population genetics of S. echinata and employs both mitochondrial cytochrome c oxidase subunit I gene (COI) and single nucleotide polymorphism (SNP) markers

Composition of objectively measured physical activity and sedentary behaviour participation across the school-day, influence of gender and weight status: cross-sectional analyses among disadvantaged Victorian school children

BACKGROUND: The after-school period has been described as the \u27critical window\u27 for physical activity (PA) participation. However, little is known about the importance of this window compared with the before and during-school period among socioeconomically disadvantaged children, and influence of gender and weight status. METHODS: 39 out of 156 (RR=25%) invited primary schools across 26 local government areas in Victoria, Australia, consented to participate with 856 children (RR=36%) participating in the wider study. The analysis sample included 298 Grade 4 and Grade 6 children (mean age: 11.2±1.1; 44% male) whom met minimum accelerometry wear-time criteria and had complete height, weight and health-behaviours questionnaire data. Accelerometry measured duration in daily light-intensity PA (LPA), moderate-to-vigorous PA (MVPA) and sedentary time (ST) was calculated for before-school=8-8:59, during-school=9:00-15:29 and after-school=15:30-18:00. Bivariate and multivariable linear regression analyses were conducted. RESULTS: During-school represented the greatest accumulation of LPA and MVPA compared with the before and after-school periods. Boys engaged in 102 min/day of LPA (95% CI 98.5 to 104.9) and 62 min/day of MVPA (95% CI 58.9 to 64.7) during-school; girls engaged in 103 min/day of LPA (95% CI 99.7 to 106.5) and 45 min/day of MVPA (95% CI 42.9 to 47.4). Linear regression models indicated that girls with overweight or obesity engaged in significantly less LPA, MVPA and more time in ST during-school. CONCLUSIONS: This study highlights the importance of in-school PA compared with after-school PA among socioeconomically disadvantage children whom may have fewer resources to participate in after-school PA

Healthy together Victoria and childhood obesity: a methodology for measuring changes in childhood obesity in response to a community-based, whole of system cluster randomized control trial

BACKGROUND: Healthy Together Victoria (HTV) - a complex \u27whole of system\u27 intervention, including an embedded cluster randomized control trial, to reduce chronic disease by addressing risk factors (physical inactivity, poor diet quality, smoking and harmful alcohol use) among children and adults in selected communities in Victoria, Australia (Healthy Together Communities). OBJECTIVES: To describe the methodology for: 1) assessing changes in the prevalence of measured childhood obesity and associated risks between primary and secondary school students in HTV communities, compared with comparison communities; and 2) assessing community-level system changes that influence childhood obesity in HTC and comparison communities. METHODS: Twenty-four geographically bounded areas were randomized to either prevention or comparison (2012). A repeat cross-sectional study utilising opt-out consent will collect objectively measured height, weight, waist and self-reported behavioral data among primary [Grade 4 (aged 9-10y) and Grade 6 (aged 11-12y)] and secondary [Grade 8 (aged 13-14y) and Grade 10 (aged 15-16y)] school students (2014 to 2018). Relationships between measured childhood obesity and system causes, as defined in the Foresight obesity systems map, will be assessed using a range of routine and customised data. CONCLUSION: This research methodology describes the beginnings of a state-wide childhood obesity monitoring system that can evolve to regularly inform progress on reducing obesity, and situate these changes in the context of broader community-level system change

Sleep duration and risk of obesity among a sample of Victorian school children

Abstract Background Insufficient sleep is potentially an important modifiable risk factor for obesity and poor physical activity and sedentary behaviours among children. However, inconsistencies across studies highlight the need for more objective measures. This paper examines the relationship between sleep duration and objectively measured physical activity, sedentary time and weight status, among a sample of Victorian Primary School children. Methods A sub-sample of 298 grades four (n = 157) and six (n = 132) Victorian primary school children (aged 9.2-13.2 years) with complete accelerometry and anthropometry data, from 39 schools, were taken from a pilot study of a larger state based cluster randomized control trial in 2013. Data comprised: researcher measured height and weight; accelerometry derived physical activity and sedentary time; and self-reported sleep duration and hypothesised confounding factors (e.g. age, gender and environmental factors). Results Compared with sufficient sleepers (67 %), those with insufficient sleep (<10 hrs/day) were significantly more likely to be overweight (OR 1.97, 95 % CI:1.11-3.48) or obese (OR 2.43, 95 % CI:1.26-4.71). No association between sleep and objectively measured physical activity levels or sedentary time was found. Conclusion The strong positive relationship between weight status and sleep deprivation merits further research though PA and sedentary time do not seem to be involved in the relationship. Strategies to improve sleep duration may help obesity prevention initiatives in the future

Systematics of RR Lyrae Statistical Parallax III: Apparent Magnitudes and Extinctions

We sing the praises of the central limit theorem. Having previously removed all other possible causes of significant systematic error in the statistical parallax determination of RR Lyrae absolute magnitudes, we investigate systematic errors from two final sources of input data: apparent magnitudes and extinctions. We find corrections due to each of ~0.05 mag, i.e., ~1/2 the statistical error. However, these are of opposite sign and so roughly cancel. The apparent magnitude system that we previously adopted from Layden et al. was calibrated to the photometry of Clube & Dawe. Using Hipparcos photometry we show that the Clube & Dawe system is ~0.06 mag too bright. Extinctions were previously pinned to the HI-based map of Burstein & Heiles. We argue that A_V should rather be based on new COBE/IRAS dust-emission map of Schlegel, Finkbeiner & Davis. This change increases the mean A_V by ~0.05 mag. We find M_V=0.77 +/- 0.13 at [Fe/H]=-1.60 for a pure sample of 147 halo RR Lyraes, or M_V=0.80 +/- 0.11 at [Fe/H]=-1.71 if we incorporate kinematic information from 716 non-kinematically selected non-RR Lyrae stars from Beers & Sommer-Larsen. These are 2 and 3 sigma fainter than recent determinations of M_V from main sequence fitting of clusters using Hipparcos measurements of subdwarfs by Reid and Gratton et al. Since statistical parallax is being cleared of systematic errors and since the chance of a >2 sigma statistical fluctuation is <1/20, we conclude that these brighter determinations may be in error. In the course of three papers, we have corrected 6 systematic errors whose absolute values total 0.20 mag. Had these, contrary to the expectation of the central limit theorem, all lined up one way, they could have resolved the conflict in favor of the brighter determinations. In fact, the net change was only 0.06 mag.Comment: submitted to ApJ, 21 pages, 2 tables, 4 figure

Detecting glacial refugia in the Southern Ocean

Throughout the Quaternary, the continental‐based Antarctic ice sheets expanded and contracted repeatedly. Evidence suggests that during glacial maxima, grounded ice eliminated most benthic (bottom‐dwelling) fauna across the Antarctic continental shelf. However, paleontological and molecular evidence indicates most extant Antarctica benthic taxa have persisted in situ throughout the Quaternary. Where and how the Antarctic benthic fauna survived throughout repeated glacial maxima remain mostly hypothesised. If understood, this would provide valuable insights into the ecology and evolution of Southern Ocean biota over geological timescales. Here we synthesised and appraised recent studies and presented an approach to demonstrate how genetic data can be effective in identifying where and how Antarctic benthic fauna survived glacial periods. We first examined the geological and ecological evidence for how glacial periods influenced past species demography in order to provide testable frameworks for future studies. We outlined past ice‐free areas from Antarctic ice sheet reconstructions that could serve as glacial refugia and discussed how benthic fauna with pelagic or non‐pelagic dispersal strategies moved into and out of glacial refugia. We also reviewed current molecular studies and collated proposed locations of Southern Ocean glacial refugia on the continental shelf around Antarctica, in the deep sea, and around sub‐Antarctic islands. Interestingly, the proposed glacial refugia based on molecular data generally do not correspond to the ice‐free areas identified by Antarctic ice sheet reconstructions. The potential biases in sampling and in the choice of molecular markers in current literature are discussed, along with the future directions for employing testable frameworks and genomic methods in Southern Ocean molecular studies. Continued data syntheses will elucidate greater understanding of where and how Southern Ocean benthic fauna persisted throughout glacial periods and provide insights into their resilience against climate changes in the future

Future challenges in cephalopod research

We thank Anto´nio M. de Frias Martins, past President of the Unitas Malacologica and Peter Marko, President of the American Malacological Society for organizing the 2013 World Congress of Malacology, and the Cephalopod International Advisory Committee for endorsing a symposium held in honour of Malcolm R. Clarke. In particular, we would like to thank the many professional staff from the University of the Azores for their hospitality, organization, troubleshooting and warm welcome to the Azores. We also thank Malcolm Clarke’s widow, Dorothy, his daughter Zoe¨, Jose´ N. Gomes-Pereira and numerous colleagues and friends of Malcolm’s from around the world for joining us at Ponta Delgada. We are grateful to Lyndsey Claro (Princeton University Press) for granting copyright permissions.Peer reviewedPublisher PD

Can environmental DNA be used to detect first arrivals of the cane toad, Rhinella marina, into novel locations?

Eradicating invasive species is difficult, but success is more likely when populations are small after arrival. The cane toad, Rhinella marina, is an invasive pest species that threatens native fauna worldwide. Increasingly, environmental DNA (eDNA) is used as a technique to monitor the presence of invasive species given its power to detect low numbers of individuals. We aimed to investigate eDNA persistence in freshwater at three different temperatures (25, 30 and 35°C) and eDNA detection thresholds for R. marina using controlled experiments in aquaria. For the latter, two water volumes and two cane toad exposure times were used (800 or 200 L volume with 5 or 30 min exposure). A 15‐ml water sample was collected from each replicated aquaria and preserved with 5 ml Longmire's buffer. Environmental DNA was extracted and four technical quantitative PCR replicates were analyzed targeting the cane toad 16S rDNA mitochondrial gene. Environmental DNA decayed rapidly in water and was reliably detected for up to 3 days after cane toad removal, regardless of the temperature treatment. Also, cane toad eDNA was detected in the water after a 5‐min initial exposure of a single individual in 800 L of water. Under the physical parameters tested here, a positive detection means that a cane toad has been in contact with the water body between 1 and 3 days prior to the sampling event. The results of the present study show the importance of eDNA for determining the presence of a species that occurs at low abundance in a small water body, such as at the onset of a cane toad invasion

Reassortant Pandemic (H1N1) 2009 Virus in Pigs, United Kingdom

Surveillance for influenza virus in pigs in the United Kingdom during spring 2010 detected a novel reassortant influenza virus. This virus had genes encoding internal proteins from pandemic (H1N1) 2009 virus and hemagglutinin and neuraminidase genes from swine influenza virus (H1N2). Our results demonstrate processes contributing to influenza virus heterogeneity