Morphology and biomechanics of the nests of the Common Blackbird Turdus merula

Capsule Common blackbirds select different materials, with varying biomechanical properties, to construct different parts of their nest. Aims This study tested the hypothesis that outer components of a nest have a more structural role and so are stronger than materials used to line the cup. Methods Blackbird nests were measured prior to being dismantled to isolate structural components which were tested for mechanical strength and rigidity. Results Outer nest wall materials were significantly thicker, stronger and more rigid than materials in the inner structural wall or the cup lining. In the vertical plane materials used in the structural wall did not differ. By contrast, lining materials from the bottom of the nest cup were significantly thicker, stronger and more rigid than materials from the top of the cup. Conclusion Blackbirds use different materials in nest construction roles suited to their properties and so may be able to recognise the structural properties of these materials. Materials on the outside of the nest may have a key structural role during construction

National physical activity and sedentary behaviour policies in 76 countries: availability, comprehensiveness, implementation, and effectiveness

Background Evidence on current, national physical activity (PA) and sedentary behaviour (SB) policies is limited. We, therefore, analysed availability, comprehensiveness, implementation, and effectiveness of PA and SB policies internationally. Methods In this cross-sectional study, Global Observatory for Physical Activity (GoPA!) Country Contacts from 173 countries were asked to provide data on their national PA and SB policies by completing GoPA! Policy Inventory. Data were collected for 76 countries (response rate = 44%). Results Formal written policies for PA and SB were found in 92% (95% confidence interval [CI]: 86, 98) and 62% (95% CI: 50, 75) of countries, respectively. Sixty-two percent (95% CI: 51, 73) of countries have national PA guidelines, while 40% (95% CI: 29, 52) have SB guidelines. Fifty-two (95% CI: 40, 64) and 11% (95% CI: 3, 19) of countries have quantifiable national targets for PA and SB, respectively. The most represented ministries/departments involved in the promotion of more PA and/or less SB were in the sport (reported by 99% countries; 95% CI: 96, 100), health (97%; 95% CI: 94, 100), education (94%; 95% CI: 88, 100), and recreation and leisure (85%; 95% CI: 71, 99) sectors. The median score (0–10) for the comprehensiveness of PA and SB policies was 4 (95% CI: 4, 5) and 2 (95% CI: 2, 3), respectively. For PA and SB policy implementation it was 6 (95% CI: 5, 6). For the effectiveness of PA and SB policies it was 4 (95% CI: 3, 5) and 3 (95% CI: 2, 4), respectively. PA and SB policies were generally best developed in high-income countries and countries of European and Western-Pacific regions. Conclusions Most of the included countries have PA policies, but their comprehensiveness, implementation, and effectiveness are generally low-to-moderate. SB policies are less available, comprehensive, implemented, and effective than PA policies. PA and SB policies are better developed in high-income countries, compared with low- and lower-middle-income countries, and in countries of European and Western-Pacific regions, compared with other world regions. More investment is needed in development and implementation of comprehensive and effective PA and SB policies, particularly in low- and lower-middle-income countries

The descriptive epidemiology of total physical activity, muscle-strengthening exercises and sedentary behaviour among Australian adults - results from the National Nutrition and Physical Activity Survey

Background: The current Australia's Physical Activity and Sedentary Behaviour Guidelines recommend that adults engage in regular moderate-to-vigorous-intensity physical activity (MVPA) and strength training (ST), and minimise time spent in sedentary behaviours (SB). However, evidence about the specific individual and concurrent distribution of these behaviours in Australia is scarce. Therefore, the aim of this study was to determine the prevalence and sociodemographic correlates of MVPA, ST and SB in a national-representative sample of Australian adults. Methods: Data were collected using face-to-face interviews, as part of the National Nutrition and Physical Activity Survey 2011-12. The population-weighted proportions meeting the MVPA (≥150 min/week), ST (≥2 sessions/week) and combined MVPA-ST guidelines, and proportions classified as having 'low levels of SB' (<480 min/day) were calculated, and their associations with selected sociodemographic and health-related variables were assessed using multiple logistic regression analyses. This was also done for those at potentially 'high-risk', defined as insufficient MVPA-ST and 'high-sedentary' behaviour. Results: Out of 9345 participants (response rate = 77.0 %), aged 18-85 years, 52.6 % (95 % CI: 51.2 %-54.0 %), 18.6 % (95 % CI: 17.5 %-19.7 %) and 15.0 % (95 % CI: 13.9 %-16.1 %) met the MVPA, ST and combined MVPA-ST guidelines, respectively. Female gender, older age, low/medium education, poorer self-rated health, being classified as underweight or obese, and being a current smoker were independently associated with lower odds of meeting the MVPA, ST and combined MVPA-ST guidelines. A total of 78.9 % (95 % CI: 77.9 %-80.0 %) were classified as having low levels of SB. Females, older adults and those with lower education were more likely to report lower levels of SB, whilst those with poor self-rated health and obese individuals were less likely to report lower levels of SB (i.e. SB = ≥480 min/day). A total of 8.9 % (95 % CI: 8.1 %-9.6 %) were categorised as individuals at potentially 'high-risk'. Those with poorer self-rated health, obese individuals, those aged 25-44, and current smokers were more likely to be in the 'high risk' group. Conclusions: The large majority of Australian adults do not meet the full physical activity guidelines and/or report excessive SB. Our results call for public health interventions to reduce physical inactivity and SB in Australia, particularly among the subgroups at the highest risk of these unhealthy behaviours

A global systematic scoping review of studies analysing indicators, development, and content of national-level physical activity and sedentary behaviour policies

Background: National policy approaches to physical activity (PA) promotion and sedentary behaviour (SB) reduction are needed to address rising rates of non-communicable diseases. Understanding the policy process and impact through robust research and evaluation is crucial for facilitating successful reforms in national health policy. This scoping review, therefore, aimed to map the evidence on indicators, development, and content of national PA and/or SB policies globally. Methods: A systematic search of academic and grey literature was conducted through six bibliographic databases, Google, and websites of three large organisations for PA promotion. Results: Out of 24,872 screened documents, 203 publications from 163 studies were selected. The selected studies investigated PA/SB policies in 168 countries worldwide, and we provided summary results for each of the countries. Overall, 69, 29, and 2% of the analyses of national PA/SB policies were conducted for high-, middle-, and low-income countries, respectively. Twenty-two percent of the studies mentioned SB policies as part of their analysis, with only one study focusing solely on assessing SB policies. Operational definitions of policy were found in only 13% of publications. Only 15% of the studies used a conceptual or theoretical framework. A large variety of methods were used for data collection and analysis of PA/SB policy. Conclusions: We found that PA policy research is much more developed than it was considered several years ago. Research around SB policies is still in its infancy, but it seems to have experienced some positive progress in the last few years. Three key issues were identified that should be addressed in further research: [i] there is a lack of PA/SB policy research in low- and middle-income countries, which is an important limitation of the current body of evidence; [ii] the definition of policy varied significantly across studies, and most studies did not rely on any theoretical framework, which may impede cross-study comparisons; and [iii] studies have used a variety of methods to analyse policy, which may also cause problems with comparability. Future PA/SB policy research should aim towards a clearer conceptualisation of policy, greater reliance on existing theoretical frameworks, and the use and further development of standardised methods for PA/SB policy analysis

Too much sitting and all-cause mortality: is there a causal link?

Background: Sedentary behaviours (time spent sitting, with low energy expenditure) are associated with deleterious health outcomes, including all-cause mortality. Whether this association can be considered causal has yet to be established. Using systematic reviews and primary studies from those reviews, we drew upon Bradford Hill's criteria to consider the likelihood that sedentary behaviour in epidemiological studies is likely to be causally related to all-cause (premature) mortality. Methods: Searches for systematic reviews on sedentary behaviours and all-cause mortality yielded 386 records which, when judged against eligibility criteria, left eight reviews (addressing 17 primary studies) for analysis. Exposure measures included self-reported total sitting time, TV viewing time, and screen time. Studies included comparisons of a low-sedentary reference group with several higher sedentary categories, or compared the highest versus lowest sedentary behaviour groups. We employed four Bradford Hill criteria: strength of association, consistency, temporality, and dose-response. Evidence supporting causality at the level of each systematic review and primary study was judged using a traffic light system depicting green for causal evidence, amber for mixed or inconclusive evidence, and red for no evidence for causality (either evidence of no effect or no evidence reported). Results: The eight systematic reviews showed evidence for consistency (7 green) and temporality (6 green), and some evidence for strength of association (4 green). There was no evidence for a dose-response relationship (5 red). Five reviews were rated green overall. Twelve (67 %) of the primary studies were rated green, with evidence for strength and temporality. Conclusions: There is reasonable evidence for a likely causal relationship between sedentary behaviour and all-cause mortality based on the epidemiological criteria of strength of association, consistency of effect, and temporality

Between the Devil and the Deep Blue Sea: The Role of the Amundsen Sea Continental Shelf in Exchanges Between Ocean and Ice Shelves

The Amundsen Sea is a key region of Antarctica where ocean, atmosphere, sea ice, and ice sheet interact. For much of Antarctica, the relatively warm water of the open Southern Ocean (a few degrees above freezing) does not reach the Antarctic continental shelf in large volumes under current climate conditions. However, in the Amundsen Sea, warm water penetrates onto the continental shelf and provides heat that can melt the underside of the area’s floating ice shelves, thinning them. Here, we discuss how the ocean’s role in melting has come under increased scrutiny, present 2014 observations from the Amundsen Sea, and discuss their implications, highlighting aspects where understanding is still incomplete

Sub-Sets of Cancer Stem Cells Differ Intrinsically in Their Patterns of Oxygen Metabolism

PMCID: PMC3640080This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited

Ocean glider observations of iceberg-enhanced biological production in the northwestern Weddell Sea:Iceberg enhanced production

Icebergs affect local biological production around Antarctica. We used an ocean glider to observe the effects of a large iceberg that was advected by the Antarctic Slope Current along the continental slope in the northwestern Weddell Sea in early 2012. The high-resolution glider data reveal a pronounced effect of the iceberg on ocean properties, with oxygen concentrations of (13 ± 4) μmol kg−1 higher than levels in surrounding waters, which are most likely due to positive net community production. This response was confined to three areas of water in the direct vicinity of the iceberg track, each no larger than 2  km2. Our findings suggest that icebergs have an impact on Antarctic production presumably through local micronutrient injections, on a scale smaller than typical satellite observations of biological production in the Southern Ocean

Composition of bird nests is a species-specific characteristic

Bird nests represent an extended phenotype of individuals expressed during reproduction and so exhibit variability in composition, structure and function. Descriptions of nests based on qualitative observations suggest that there is interspecific variation in size and composition but there are very few species in which this has been confirmed. For these species, data of the amounts of different materials indicate that nest construction behaviour is plastic and affected by a variety of factors, such as prevailing temperature, geographic location, and availability of materials. The lack of data on nest composition is hampering our understanding of how nests achieve their various functions and how different species solve the problem of building a nest that will accommodate incubation and allow successful hatching of eggs. This study deconstructed nests of four species of the Turdidae, four species of the Muscicapidae, and six species of the Fringillidae and quantified the size of the nests and their composition. These data were used to test: (1) whether nest size correlated with adult bird mass; (2) whether it was possible to distinguish between species on the basis of their nest composition; and (3) whether, within a species, it was possible to distinguish between the cup lining and the rest of the nest based on composition. Most but not all nest dimensions correlated with bird mass. Principal component analysis revealed species differences based on nest composition and discriminant analysis could distinguish cup lining from the outer nest based on material composition. Intraspecific variation in composition varied among species and in general fewer types of material were found in the cup lining than the outer nest. These data provide insight into how nests are constructed by the different species and in conjunction with studies of the mechanical, thermal and hydrological properties of a nest, will begin to reveal how and why individual species select particular combinations of materials to build a nest

Glacial meltwater identification in the Amundsen Sea

Pine Island Ice Shelf, in the Amundsen Sea, is losing mass because of warm ocean waters melting the ice from below. Tracing meltwater pathways from ice shelves is important for identifying the regions most affected by the increased input of this water type. Here, optimum multiparameter analysis is used to deduce glacial meltwater fractions from water mass characteristics (temperature, salinity, and dissolved oxygen concentrations), collected during a ship-based campaign in the eastern Amundsen Sea in February–March 2014. Using a one-dimensional ocean model, processes such as variability in the characteristics of the source water masses on shelf and biological productivity/respiration are shown to affect the calculated apparent meltwater fractions. These processes can result in a false meltwater signature, creating misleading apparent glacial meltwater pathways. An alternative glacial meltwater calculation is suggested, using a pseudo–Circumpolar Deep Water endpoint and using an artificial increase in uncertainty of the dissolved oxygen measurements. The pseudo–Circumpolar Deep Water characteristics are affected by the under ice shelf bathymetry. The glacial meltwater fractions reveal a pathway for 2014 meltwater leading to the west of Pine Island Ice Shelf, along the coastline