3,037 research outputs found

    Cortisol Concentration as Predictor of Tobacco Initiation in Adolescents: Results From a Population-Based Swedish Cohort.

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    Abstract Purpose Stress potentiates the smoking reward, decreases the ability to resist smoking, and increases the risk of smoking relapse in adulthood. This study aimed to clarify if salivary cortisol, as an indicator of stress, may be prospectively associated with the onset and phenotype of tobacco use in adolescents. Methods This study was based on a cohort of Swedish adolescents, among whom saliva specimens were collected from a nested sample. We included adolescents with salivary cortisol measurements and without a history of tobacco use (n = 381, aged 13ā€“14 years). Quartiles of morning and afternoon cortisol concentration and cortisol area under the curve were considered as predictors. We categorized tobacco use according to the product mainly used: cigarette smoking, snus use, or either type of tobacco. For each product use, two outcomes were considered: initiation and duration of use. Poisson regression models were used to calculate rate ratios. Results A quartile increase in morning cortisol levels and cortisol area under the curve was consistently associated with a 1.2- to 1.4-fold increased risk of initiation of cigarette smoking snus use, or any tobacco use. Similar results were obtained examining the doseā€“response relationship and using the duration of use as outcome. No associations were apparent between afternoon cortisol concentration and any of the outcomes. All associations were similar between sexes. Conclusions Morning cortisol concentration, an indicator of hypothalamicā€“pituitaryā€“adrenal axis activation, is prospectively associated with tobacco use in adolescents. Whether this activation indicates the cumulative effect of stressors during the life course remains to be elucidated

    Sea anemones may thrive in a high CO2 world

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    Increased seawater pCO 2, and in turn 'ocean acidification' (OA), is predicted to profoundly impact marine ecosystem diversity and function this century. Much research has already focussed on calcifying reef-forming corals (Class: Anthozoa) that appear particularly susceptible to OA via reduced net calcification. However, here we show that OA-like conditions can simultaneously enhance the ecological success of non-calcifying anthozoans, which not only play key ecological and biogeochemical roles in present day benthic ecosystems but also represent a model organism should calcifying anthozoans exist as less calcified (soft-bodied) forms in future oceans. Increased growth (abundance and size) of the sea anemone (Anemonia viridis) population was observed along a natural CO 2 gradient at Vulcano, Italy. Both gross photosynthesis (P G) and respiration (R) increased with pCO 2 indicating that the increased growth was, at least in part, fuelled by bottom up (CO 2 stimulation) of metabolism. The increase of P G outweighed that of R and the genetic identity of the symbiotic microalgae (Symbiodinium spp.) remained unchanged (type A19) suggesting proximity to the vent site relieved CO 2 limitation of the anemones' symbiotic microalgal population. Our observations of enhanced productivity with pCO 2, which are consistent with previous reports for some calcifying corals, convey an increase in fitness that may enable non-calcifying anthozoans to thrive in future environments, i.e. higher seawater pCO 2. Understanding how CO 2-enhanced productivity of non- (and less-) calcifying anthozoans applies more widely to tropical ecosystems is a priority where such organisms can dominate benthic ecosystems, in particular following localized anthropogenic stress. Ā© 2012 Blackwell Publishing Ltd

    Impact of community-based interventions on condom use in the TłÄÆchĒ« region of Northwest Territories, Canada

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    <p>Abstract</p> <p>Background</p> <p>Since 2005, the TłÄÆchĒ« Community Services Agency (TCSA) in Canada's Northwest Territories (NT) has addressed rising rates of sexually transmitted infections (STI). In 2009, STI rates in the NT were ten times higher than the national rate and TłÄÆchĒ« regional rates were nearly four times that of the NT ā€“ 91 cases per 1000 people. We describe a social audit process that assessed the impact of an evidence-based community-led intervention.</p> <p>Methods</p> <p>A baseline survey of sexual health knowledge, attitudes and behaviours in 2006/07 provided evidence for a Community Action Research Team (CART) to develop and to put in place culturally appropriate interventions in the TłÄÆchĒ« region. A follow-up study in 2010 sought to assess the impact of CART activities on condom use and underlying conscious knowledge, attitudes, subjective norms, intention to change, sense of agency and discussions related to condom use and STI risks. We report the contrasts using Odds Ratios (OR) and 95% confidence intervals (CI).</p> <p>Results</p> <p>One in every three follow-up respondents (315/808) participated in at least one CART activity. Participation in highly ranked interventions was associated with increased condom use during the last sexual encounter (OR 1.45, 95%CI 1.07-1.98). Those exposed to three or more activities were more likely to talk openly about condoms (OR 2.08, 95%CI 1.41-3.28), but were also less likely to be monogamous (OR 0.49, 95%CI 0.29-0.90).</p> <p>Conclusions</p> <p>The measurable impact on condom use indicates a strong beginning for the TłÄÆchĒ« community intervention programmes. The interventions also seem to generate increased discussion, often a precursor to action. The TłÄÆchĒ« can use the evidence to improve and refocus their programming, increase knowledge and continue to improve safe condom use practices.</p

    Comparison of Two Methods for Measuring Sea Surface Temperature When Surfing

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    Nearshore coastal waters are among the most dynamic regions on the planet and difficult to sample from conventional oceanographic platforms. It has been suggested that environmental sampling of the nearshore could be improved by mobilising vast numbers of citizens who partake in marine recreational sports, like surfing. In this paper, we compared two approaches for measuring sea surface temperature (SST), an Essential Climate Variable, when surfing. One technique involved attaching a commercially-available miniature temperature logger (Onset UTBI-001 TidbiT v2) to the leash of the surfboard (tether connecting surfer and surfboard) and the second, attaching a surfboard fin (Smartfin) that contained an environmental sensor package. Between July 2017 and July 2018, 148 surfing sessions took place, 90 in the southwest UK and 58 in San Diego, California, USA. During these sessions, both Smartfin and leash sensors were deployed simultaneously. On the leash, two TidbiT v2 sensors were attached, one with (denoted LP) and one without (denoted LU) a protective boot, designed to shield the sensor from sunlight. The median temperature from each technique, during each surfing session, was extracted and compared along with independent water temperature data from a nearby pier and benthic logger, and matched with photosynthetically available radiation (PAR) data from satellite observations (used as a proxy for solar radiation during each surf). Results indicate a mean difference ( Ī“ ) of 0.13 Ā°C and mean absolute difference ( Ļµ ) of 0.14 Ā°C between Smartfin and LU, and a Ī“ of 0.04 Ā°C and an Ļµ of 0.06 Ā°C between Smartfin and LP. For UK measurements, we observed better agreement between methods ( Ī“=0.07 Ā°C and Ļµ=0.08 Ā°C between Smartfin and LU, and Ī“=0.00 Ā°C and Ļµ=0.03 Ā°C between Smartfin and LP) when compared with measurements in San Diego ( Ī“=0.22 Ā°C and Ļµ=0.23 Ā°C between Smartfin and LU, and Ī“=0.08 Ā°C and Ļµ=0.11 Ā°C between Smartfin and LP). Surfing SST data were found to agree well, in general, with independent temperature data from a nearby pier and benthic logger. Differences in SST between leash and Smartfin were found to correlate with PAR, both for the unprotected (LU) and protected (LP) TidbiT v2 sensors, explaining the regional differences in the comparison (PAR generally higher during US surfing sessions than UK sessions). Considering that the Smartfin is sheltered from ambient light by the surfboard, unlike the leash, results indicate the leash TidbiT v2 sensors warm with exposure to sunlight biasing the SST data positively, a result consistent with published tests on similar sensors in shallow waters. We matched all LU data collected prior to this study with satellite PAR products and corrected for solar heating. Results highlight the need to design temperature sensor packages that minimise exposure from solar heating when towed in the surface ocean

    Expanding Aquatic Observations through Recreation

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    Accurate observations of the Earth system are required to understand how our planet is changing and to help manage its resources. The aquatic environmentā€”including lakes, rivers, wetlands, estuaries, coastal and open oceansā€”is a fundamental component of the Earth system controlling key physical, biological, and chemical processes that allow life to flourish. Yet, this environment is critically undersampled in both time and space. New and cost-effective sampling solutions are urgently needed. Here, we highlight the potential to improve aquatic sampling by tapping into recreation. We draw attention to the vast number of participants that engage in aquatic recreational activities and argue, based on current technological developments and recent research, that the time is right to employ recreational citizens to improve large-scale aquatic sampling efforts. We discuss the challenges that need to be addressed for this strategy to be successful (e.g., sensor integration, data quality, and citizen motivation), the steps needed to realize its potential, and additional societal benefits that arise when engaging citizens in scientific sampling

    Expanding aquatic observations through recreation

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    This is the final version. Available on open access from Frontiers Media via the DOI in this recordAccurate observations of the Earth system are required to understand how our planet is changing and to help manage its resources. The aquatic environment-including lakes, rivers, wetlands, estuaries, coastal and open oceans-is a fundamental component of the Earth system controlling key physical, biological, and chemical processes that allow life to flourish. Yet, this environment is critically undersampled in both time and space. New and cost-effective sampling solutions are urgently needed. Here, we highlight the potential to improve aquatic sampling by tapping into recreation. We draw attention to the vast number of participants that engage in aquatic recreational activities and argue, based on current technological developments and recent research, that the time is right to employ recreational citizens to improve large-scale aquatic sampling efforts. We discuss the challenges that need to be addressed for this strategy to be successful (e.g., sensor integration, data quality, and citizen motivation), the steps needed to realize its potential, and additional societal benefits that arise when engaging citizens in scientific sampling.UK National Centre for Earth ObservationSmartfin/Lostbird FoundationDefr

    Comparison of a Smartfin with an Infrared Sea Surface Temperature Radiometer in the Atlantic Ocean

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    This is the final version. Available on open access from MDPI via the DOI in this recordThe accuracy and precision of satellite sea surface temperature (SST) products in nearshore coastal waters are not well known, owing to a lack of in-situ data available for validation. It has been suggested that recreational watersports enthusiasts, who immerse themselves in nearshore coastal waters, be used as a platform to improve sampling and fill this gap. One tool that has been used worldwide by surfers is the Smartfin, which contains a temperature sensor integrated into a surfboard fin. If tools such as the Smartfin are to be considered for satellite validation work, they must be carefully evaluated against state-of-the-art techniques to quantify data quality. In this study, we developed a Simple Oceanographic floating Device (SOD), designed to float on the ocean surface, and deployed it during the 28th Atlantic Meridional Transect (AMT28) research cruise (September and October 2018). We attached a Smartfin to the underside of the SOD, which measured temperature at a depth of āˆ¼0.1 m, in a manner consistent with how it collects data on a surfboard. Additional temperature sensors (an iButton and a TidbiT v2), shaded and positioned a depth of āˆ¼1 m, were also attached to the SOD at some of the stations. Four laboratory comparisons of the SOD sensors (Smartfin, iButton and TidbiT v2) with an accurate temperature probe (Ā±0.0043 K over a range of 273.15 to 323.15 K) were also conducted during the AMT28 voyage, over a temperature range of 290ā€“309 K in a recirculating water bath. Mean differences (Ī“), referenced to the temperature probe, were removed from the iButton (Ī“=0.292 K) and a TidbiT v2 sensors (Ī“=0.089 K), but not from the Smartfin, as it was found to be in excellent agreement with the temperature probe (Ī“=0.005 K). The SOD was deployed for 20 min periods at 62 stations (predawn and noon) spanning 100 degrees latitude and a gradient in SST of 19 K. Simultaneous measurements of skin SST were collected using an Infrared Sea surface temperature Autonomous Radiometer (ISAR), a state-of-the-art instrument used for satellite validation. Additionally, we extracted simultaneous SST measurements, collected at slightly different depths, from an underway conductivity, temperature and depth (CTD) system. Over all 62 stations, the mean difference (Ī“) and mean absolute difference (Ļµ) between Smartfin and the underway CTD were āˆ’0.01 and 0.06 K respectively (similar results obtained from comparisons between Smartfin and iButton and Smartfin and TidbiT v2), and the Ī“ and Ļµ between Smartfin and ISAR were 0.09 and 0.12 K respectively. In both comparisons, statistics varied between noon and predawn stations, with differences related to environmental variability (wind speed and sea-air temperature differences) and depth of sampling. Our results add confidence to the use of Smartfin as a citizen science tool for evaluating satellite SST data, and data collected using the SOD and ISAR were shown to be useful for quantifying near-surface temperature gradients.European Space AgencyLost Bird Projec

    Population weighted raster maps can communicate findings of social audits: examples from three continents

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    <p>Abstract</p> <p>Background</p> <p>Maps can portray trends, patterns, and spatial differences that might be overlooked in tabular data and are now widely used in health research. Little has been reported about the process of using maps to communicate epidemiological findings.</p> <p>Method</p> <p>Population weighted raster maps show colour changes over the study area. Similar to the rasters of barometric pressure in a weather map, data are the health occurrence ā€“ a peak on the map represents a higher value of the indicator in question. The population relevance of each sentinel site, as determined in the stratified last stage random sample, combines with geography (inverse-distance weighting) to provide a population-weighted extension of each colour. This transforms the map to show population space rather than simply geographic space.</p> <p>Results</p> <p>Maps allowed discussion of strategies to reduce violence against women in a context of political <it>sensitivity</it> about quoting summary indicator figures. <it>Time-series maps</it> showed planners how experiences of health services had deteriorated despite a reform programme; where in a country HIV risk behaviours were improving; and how knowledge of an economic development programme quickly fell off across a region. <it>Change maps</it> highlighted where indicators were improving and where they were deteriorating. Maps of <it>potential impact of interventions</it>, based on multivariate modelling, displayed how partial and full implementation of programmes could improve outcomes across a country. <it>Scale</it> depends on context. To support local planning, district maps or local government authority maps of health indicators were more useful than national maps; but multinational maps of outcomes were more useful for regional institutions. Mapping was useful to illustrate in which districts enrolment in religious schools ā€“ a <it>rare occurrence</it> - was more prevalent.</p> <p>Conclusions</p> <p>Population weighted raster maps can present social audit findings in an accessible and compelling way, increasing the use of evidence by planners with limited numeracy skills or little time to look at evidence. Maps complement epidemiological analysis, but they are not a substitute. Much less do they substitute for rigorous epidemiological designs, like randomised controlled trials.</p

    Effect of resting pressure on the estimate of cerebrospinal fluid outflow conductance

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    <p>Abstract</p> <p>Background</p> <p>A lumbar infusion test is commonly used as a predictive test for patients with normal pressure hydrocephalus and for evaluation of cerebrospinal fluid (CSF) shunt function. Different infusion protocols can be used to estimate the outflow conductance (<it>C</it><sub>out</sub>) or its reciprocal the outflow resistance (<it>R</it><sub>out</sub>), with or without using the baseline resting pressure, <it>P</it><sub>r</sub>. Both from a basic physiological research and a clinical perspective, it is important to understand the limitations of the model on which infusion tests are based. By estimating <it>C</it><sub>out</sub> using two different analyses, with or without <it>P</it><sub>r</sub>, the limitations could be explored. The aim of this study was to compare the <it>C</it><sub>out</sub> estimates, and investigate what effect <it>P</it><sub>r</sub>had on the results.</p> <p>Methods</p> <p>Sixty-three patients that underwent a constant pressure infusion protocol as part of their preoperative evaluation for normal pressure hydrocephalus, were included (age 70.3 Ā± 10.8 years (mean Ā± SD)). The analysis was performed without (<it>C</it><sub>excl Pr</sub>) and with (<it>C</it><sub>incl Pr</sub>) P<sub>r</sub>. The estimates were compared using Bland-Altman plots and paired sample <it>t</it>-tests (<it>p </it>< 0.05 considered significant).</p> <p>Results</p> <p>Mean <it>C</it><sub>out</sub> for the 63 patients was: <it>C</it><sub>excl Pr </sub>= 7.0 Ā± 4.0 (mean Ā± SD) Ī¼l/(s kPa) and <it>C</it><sub>incl Pr</sub> = 9.1 Ā± 4.3 Ī¼l/(s kPa) and <it>R</it><sub>out</sub> was 19.0 Ā± 9.2 and 17.7 Ā± 11.3 mmHg/ml/min, respectively. There was a positive correlation between methods (r = 0.79, n = 63, <it>p </it>< 0.01). The difference, Ī”<it>C</it><sub>out</sub>= -2.1 Ā± 2.7 Ī¼l/(s kPa) between methods was significant (<it>p </it>< 0.01) and Ī”<it>R</it><sub>out </sub>was 1.2 Ā± 8.8 mmHg/ml/min). The Bland-Altman plot visualized that the variation around the mean difference was similar all through the range of measured values and there was no correlation between Ī”<it>C</it><sub>out </sub>and <it>C</it><sub>out</sub>.</p> <p>Conclusions</p> <p>The difference between <it>C</it><sub>out </sub>estimates, obtained from analyses with or without <it>P</it><sub>r</sub>, needs to be taken into consideration when comparing results from studies using different infusion test protocols. The study suggests variation in CSF formation rate, variation in venous pressure or a pressure dependent <it>C</it><sub>out </sub>as possible causes for the deviation from the CSF absorption model seen in some patients.</p
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