195 research outputs found

    Pedometers and Aerobic Capacity: Evaluating an Elementary After-School Running Program

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    Childhood obesity affects 1 of every 6 youth in the United States. One contributing factor to this statistic is a lack of physical activity (PA). Demands related to accountability which are placed on educators to demonstrate academic achievement often result in resistance to allocating time during the school day for PA. One possible solution is to consider utilizing time after school to integrate PA programs. The purpose of this study was to assess the impact of a 12-week after-school pedometer-focused PA program on aerobic capacity and to examine the relationship between step count and aerobic capacity in elementary school aged children. A group of elementary students (n=24; 9.5±0.9 years) participated in a 12-week pedometer-focused PA program that included pretraining and posttraining fitness testing via the 20-meter version of the PACER test. Paired sample t-tests revealed significant differences between the pretest (M=21.0 laps, SD=9.9) and posttest (M=25.2 laps, SD=12.2) scores (t=4.04, P≤0.001). A Pearson correlation revealed no significant relationship between individual step count and the difference between PACER pre- and posttest (r=0.318, P=0.130). The program improved aerobic capacity, but an increase in pedometer-calculated step count was not a predictor

    The relative importance of physiologcal and behavioural adaptation in diving endotherms: a case study with Arctic Cormorants.

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    Extensive morphological and physiological adjustments are assumed to underpin the adaptations of diving birds to high thermoregulatory costs. However, the role of behavioral adaptations has received little consideration. We have assessed the relative importance of physiological and behavioral adjustments in aquatic endotherms by studying the case of the poorly insulated great cormorant (Phalacrocorax carbo) in two contrasting thermal environments: Normandy (water temperature 12°C) and Greenland (water temperature 5°C). Major differences were found in the feeding behavior of birds breeding in the two regions. Greenland birds showed a 70% reduction in time spent swimming relative to those in Normandy. Reduction in Greenland was achieved first by reducing time spent on the surface between dives and secondly by returning to land in between intensive bouts of diving. Total daily energy intake of cormorants was similar in both areas but prey capture rates in Greenland were 150% higher than those in Normandy. Our study shows that in a cold foraging environment, poorly insulated great cormorants significantly increase their foraging efficiency. To do this they rely on ecological adaptive patterns (minimization of time spent swimming in cold water and increased prey capture rates) far more than physiological adaptations (minimizing instantaneous costs). This finding supports predictions by Grémillet and Wilson (1999) that great cormorants can cope with a wide range of abiotic parameters despite their morphological handicaps, provided they can adjust their distribution to exploit dense prey patches

    A tropical bird in the Artic (The Cormorant paradox)

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    Seabirds, like all marine endotherms, have to compensate for the extensive cooling effect of water when diving. Alone among them, cormorants (Phalacrocoracidae) have a wettable plumage and are predicted to require disproportionately large amounts of food to balance heat losses. These piscivorous birds are thus thought to have a detrimental impact on fish stocks. However, we show here that even in great cormorants from Greenland, which dive in water at 3 to 7°C, daily food intake is lower than for well-insulated European seabirds. Despite their wettable plumage, cormorants thus appear to manage their energy budgets in a remarkably efficient way. Nevertheless, the specific foraging strategies which enable this performance make cormorants dependent on high prey density areas, a feature that should be taken into account by future management plans

    Projected distributions of Southern Ocean albatrosses, petrels and fisheries as a consequence of climatic change

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    Given the major ongoing influence of environmental change on the oceans, there is a need to understand and predict the future distributions of marine species in order to plan appropriate mitigation to conserve vulnerable species and ecosystems. In this study we use tracking data from seven large seabird species of the Southern Ocean (black‐browed albatross Thalassarche melanophris, grey‐headed albatross T. chrysostoma, northern giant petrel Macronectes halli, southern giant petrel M. giganteus, Tristan albatross Diomedea dabbenena, wandering albatross D. exulans and white‐chinned petrel Procellaria aequinoctialis, and on fishing effort in two types of fisheries (characterised by low or high‐bycatch rates), to model the associations with environmental variables (bathymetry, chlorophyll‐a concentration, sea surface temperature and wind speed) through ensemble species distribution models. We then projected these distributions according to four climate change scenarios built by the Intergovernmental Panel for Climate Change for 2050 and 2100. The resulting projections were consistent across scenarios, indicating that there is a strong likelihood of poleward shifts in distribution of seabirds, and several range contractions (resulting from a shift in the northern, but no change in the southern limit of the range in four species). Current trends for southerly shifts in fisheries distributions are also set to continue under these climate change scenarios at least until 2100; some of these may reflect habitat loss for target species that are already over‐fished. It is of particular concern that a shift in the distribution of several highly threatened seabird species would increase their overlap with fisheries where there is a high‐bycatch risk. Under such scenarios, the associated shifts in distribution of seabirds and increases in bycatch risk will require much‐improved fisheries management in these sensitive areas to minimise impacts on populations in decline

    Do early warning indicators consistently predict nonlinear change in long-term ecological data?

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    1. Anthropogenic pressures, including climate change, are causing nonlinear changes in ecosystems globally. The development of reliable early warning indicators (EWIs) to predict these changes is vital for the adaptive management of ecosystems and the protection of biodiversity, natural capital and ecosystem services. Increased variance and autocorrelation are potential early warning indicators and can be readily estimated from ecological time series. Here, we undertook a comprehensive test of the consistency between early warning indicators and nonlinear abundance change across species, trophic levels and ecosystem types. 2. We tested whether long-term abundance time series of 55 taxa (126 data sets) across multiple trophic levels in marine and freshwater ecosystems showed (i) significant nonlinear change in abundance ‘turning points’ and (ii) significant increases in variance and autocorrelation (‘early warning indicators’). For each data set, we then quantified the prevalence of three cases: true positives (early warning indicators and associated turning point), false negatives (turning point but no associated early warning indicators) and false positives (early warning indicators but no turning point). 3. True positives were rare, representing only 9% (16 of 170) of cases using variance, and 13% (19 of 152) of cases using autocorrelation. False positives were more prevalent than false negatives (53% vs. 38% for variance; 47% vs. 40% for autocorrelation). False results were found in every decade and across all trophic levels and ecosystems. 4. Time series that contained true positives were uncommon (8% for variance; 6% for autocorrelation), with all but one time series also containing false classifications. Coherence between the types of early warning indicators was generally low with 43% of time series categorized differently based on variance compared to autocorrelation. 5. Synthesis and applications. Conservation management requires effective early warnings of ecosystem change using readily available data, and variance and autocorrelation in abundance data have been suggested as candidates. However, our study shows that they consistently fail to predict nonlinear change. For early warning indicators to be effective tools for preventative management of ecosystem change, we recommend that multivariate approaches of a suite of potential indicators are adopted, incorporating analyses of anthropogenic drivers and process-based understanding

    Prioritising public health: a qualitative study of decision making to reduce health inequalities

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    <p>Abstract</p> <p>Background</p> <p>The public health system in England is currently facing dramatic change. Renewed attention has recently been paid to the best approaches for tackling the health inequalities which remain entrenched within British society and across the globe. In order to consider the opportunities and challenges facing the new public health system in England, we explored the current experiences of those involved in decision making to reduce health inequalities, taking cardiovascular disease (CVD) as a case study.</p> <p>Methods</p> <p>We conducted an in-depth qualitative study employing 40 semi-structured interviews and three focus group discussions. Participants were public health policy makers and planners in CVD in the UK, including: Primary Care Trust and Local Authority staff (in various roles); General Practice commissioners; public health academics; consultant cardiologists; national guideline managers; members of guideline development groups, civil servants; and CVD third sector staff.</p> <p>Results</p> <p>The short term target- and outcome-led culture of the NHS and the drive to achieve "more for less", combined with the need to address public demand for acute services often lead to investment in "downstream" public health intervention, rather than the "upstream" approaches that are most effective at reducing inequalities. Despite most public health decision makers wishing to redress this imbalance, they felt constrained due to difficulties in partnership working and the over-riding influence of other stakeholders in decision making processes. The proposed public health reforms in England present an opportunity for public health to move away from the medical paradigm of the NHS. However, they also reveal a reluctance of central government to contribute to shifting social norms.</p> <p>Conclusions</p> <p>It is vital that the effectiveness and cost effectiveness of all new and existing policies and services affecting public health are measured in terms of their impact on the social determinants of health and health inequalities. Researchers have a vital role to play in providing the complex evidence required to compare different models of prevention and service delivery. Those working in public health must develop leadership to raise the profile of health inequalities as an issue that merits attention, resources and workforce capacity; and advocate for central government to play a key role in shifting social norms.</p

    A translational framework for public health research

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    &lt;p&gt;&lt;b&gt;Background&lt;/b&gt;&lt;/p&gt; &lt;p&gt;The paradigm of translational medicine that underpins frameworks such as the Cooksey report on the funding of health research does not adequately reflect the complex reality of the public health environment. We therefore outline a translational framework for public health research.&lt;/p&gt; &lt;p&gt;&lt;b&gt;Discussion&lt;/b&gt;&lt;/p&gt; &lt;p&gt;Our framework redefines the objective of translation from that of institutionalising effective interventions to that of improving population health by influencing both individual and collective determinants of health. It incorporates epidemiological perspectives with those of the social sciences, recognising that many types of research may contribute to the shaping of policy, practice and future research. It also identifies a pivotal role for evidence synthesis and the importance of non-linear and intersectoral interfaces with the public realm.&lt;/p&gt; &lt;p&gt;&lt;b&gt;Summary&lt;/b&gt;&lt;/p&gt; &lt;p&gt;We propose a research agenda to advance the field and argue that resources for 'applied' or 'translational' public health research should be deployed across the framework, not reserved for 'dissemination' or 'implementation'.&lt;/p&gt

    Assessing the impact of a new health sector pay system upon NHS staff in England

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    <p>Abstract</p> <p>Background</p> <p>Pay and pay systems are a critical element in any health sector human resource strategy. Changing a pay system can be one strategy to achieve or sustain organizational change. This paper reports on the design and implementation of a completely new pay system in the National Health Service (NHS) in England. 'Agenda for Change' constituted the largest-ever attempt to introduce a new pay system in the UK public services, covering more than one million staff. Its objectives were to improve the delivery of patient care as well as enhance staff recruitment, retention and motivation, and to facilitate new ways of working.</p> <p>Methods</p> <p>This study was the first independent assessment of the impact of Agenda for Change at a local and national level. The methods used in the research were a literature review; review of 'grey' unpublished documentation provided by key stakeholders in the process; analysis of available data; interviews with key national informants (representing government, employers and trade unions), and case studies conducted with senior human resource managers in ten NHS hospitals in England</p> <p>Results</p> <p>Most of the NHS trust managers interviewed were in favour of Agenda for Change, believing it would assist in delivering improvements in patient care and staff experience. The main benefits highlighted were: 'fairness', moving different staff groups on to harmonized conditions; equal pay claim 'protection'; and scope to introduce new roles and working practices.</p> <p>Conclusion</p> <p>Agenda for Change took several years to design, and has only recently been implemented. Its very scale and central importance to NHS costs and delivery of care argues for a full assessment at an early stage so that lessons can be learned and any necessary changes made. This paper highlights weaknesses in evaluation and limitations in progress. The absence of systematically derived and applied impact indicators makes it difficult to assess impact and impact variations. Similarly, the lack of any full and systematic evaluation constrained the overall potential for Agenda for Change to deliver improvements to the NHS.</p
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