4,169 research outputs found

    Upogebia deltaura (Crustacea: Thalassinidea) in Clyde Sea maerl beds, Scotland

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    Burrows inhabited by Upogebia deltaura (Crustacea: Thalassinidea) were studied over a two-year period on two maerl beds at 10 m below Chart Datum (CD) in the Clyde Sea area, Scotland. Labelled burrows proved to be stable features on each ground, with animals able to withstand the impacts of scallop dredging and storm disturbance by re-building the damaged upper sections of their burrows. Resin casts excavated using an air-lift showed that these burrows were inhabited by single individuals. Burrows were deeper, larger and more complicated than was previously thought typical for U. deltaura and other members of the genus. Mapping of burrow systems revealed average densities of 2.9 ind m-2 with up to ten openings m-2. These elusive animals were the deepest burrowing megafauna (to 68 cm) and the most abundant large crustaceans within the maerl bed habitat

    The impact of Rapido trawling for scallops, Pecten jacobaeus (L.), on the benthos of the Gulf of Venice

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    Rapido trawls are used to catch sole around the coast of Italy and to catch scallops in the northern Adriatic Sea but little is known about the environmental impact of this gear. Benthic surveys of a commercial scallop ground using a towed underwater television (UWTV) sledge revealed an expansive area of level, sandy sediment at 25 m characterized by high population densities of scallops (2.82 m-2 Aequipecten opercularis but fewer Pecten jacobaeus) together with ophiuroids, sponges, and the bivalve Atrina fragilis. Rapido trawls were filmed in action for the first time, providing information on the selectivity and efficiency of the gear together with its impact on the substratum and on the benthos. The trawls worked efficiently on smooth sand with ca. 44% catch rate for Pecten jacobaeus, of which 90% were >7 cm in shell height. Most organisms in the path of the trawl passed under or through the net; on average by-catch species only formed 19% of total catch by weight. Of the 78 taxa caught, lethal mechanical damage varied from 50% in soft-bodied organisms such as tunicates. A marked plot surveyed using towed UWTV before, then 1 and 15 h after fishing by Rapido trawl showed clear tracks of disturbed sediment along the trawl path where infaunal burrow openings had been erased. Abundant, motile organisms such as Aequipecten showed no change in abundance along these tracks although scavengers such as Inachus aggregated to feed on damaged organisms. There were significant decreases in the abundance of slow-moving/sessile benthos such as Pecten, Holothuria, and Atrina. Juvenile pectinids were abundant on the shells of Atrina. The introduction of a scheme of areas closed to trawling would protect highly susceptible organisms such as Atrina and enhance the chances of scallop recruitment to adjacent areas of commercial exploitation

    Acute exercise and appetite-regulating hormones in overweight and obese individuals: A meta-analysis

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    In lean individuals, acute aerobic exercise is reported to transiently suppress sensations of appetite, suppress blood-concentrations of acylated ghrelin (AG) and increase glucagon-like peptide-1 (GLP-1) and peptide-YY (PYY). Findings in overweight/obese individuals have yet to be synthesised. In this systematic review and meta-analysis, we quantified the effects acute exercise has on AG, total PYY and GLP-1 in overweight/obese individuals. The potential for body mass index (BMI) to act as a moderator for AG was also explored. Six published studies (73 participants, 78% male, mean BMI: 30.6 kg.m-2) met the inclusion criteria. Standardised mean differences (SMD) and standard errors were extracted for AG, total PYY and GLP-1 concentrations in control and exercise trials and synthesised using a random effects meta-analysis model. BMI was the predictor in a meta-regression for AG. Exercise moderately suppressed AG area-under-the-curve concentrations (pooled SMD -0.34, 95%CI: -0.53 to -0.15). The magnitude of this reduction was greater for higher mean BMIs (pooled meta-regression slope: -0.04 SMD/kg.m-2 (95%CI: -0.07 to 0.00)). Trivial SMDs were obtained for total PYY (0.10, 95%CI: -0.13 to 0.31) and GLP-1 (-0.03, 95%CI: -0.18 to 0.13). This indicates that exercise in overweight/obese individuals moderately alters AG in a direction that could be associated with decreased hunger and energy intake. (PROSPERO registration: CRD42014006265)

    'I'm not X, I just want Y': formulating 'wants' in interaction

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    This article provides a conversation analytic description of a two-part structure, ‘I don’t want X, I want/just want Y’. Drawing on a corpus of recordings of family mealtimes and television documentary data, I show how speakers use the structure in two recurrent environments. First, speakers may use the structure to reject a proposal regarding their actions made by an interlocutor. Second, speakers may deliver the structure following a co-interactant’s formulation of their actions or motivations. Both uses decrease the likelihood of challenge in third-turn position. When responding to multi-unit turns speakers routinely deal with the last item first. The value of ‘I want Y’ is to formulate an alternative sense of agency which undermines the preceding turn and shifts the trajectory of the ongoing sequence. The article contributes to work in discursive psychology as I show how speakers may formulate their ‘wants’ in the service of sequentially unfolding social interaction

    Are we missing the target? Are we aiming too low? What are the aerobic exercise prescriptions and their effects on markers of cardiovascular health and systemic inflammation in patients with knee osteoarthritis? A systematic review and meta-analysis

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    Objectives We systemically reviewed published studies that evaluated aerobic exercise interventions in patients with knee osteoarthritis (OA) to: (1) report the frequency, intensity, type and time (FITT) of exercise prescriptions and (2) quantify the changes in markers of cardiovascular health and systemic inflammation. Data sources PubMed, CINAHL, Scopus; inception to January 2019. Eligibility criteria Randomised clinical trials (RCT), cohort studies, case series. Design We summarised exercise prescriptions for all studies and calculated effect sizes with 95% CIs for between-group (RCTs that compared exercise and control groups) and within-group (pre-post exercise) differences in aerobic capacity (VO2), heart rate (HR), systolic blood pressure (SBP), diastolic blood pressure (DBP) and inflammatory markers (interleukin-6 (IL-6), tumour necrosis factor-alpha). We pooled results where possible using random effects models. Results Interventions from 49 studies were summarised; 8% (4/49) met all FITT guidelines; 16% (8/49) met all or most FITT guidelines. Fourteen studies (10 RCTs) reported at least one marker of cardiovascular health or systemic inflammation. Mean differences (95% CI) indicated a small to moderate increase in VO2(0.84 mL/min/kg; 95% CI 0.37 to 1.31), decrease in HR (-3.56 beats per minute; 95% CI -5.60 to -1.52) and DBP (-4.10 mm Hg; 95% CI -4.82 to -3.38) and no change in SBP (-0.36 mm Hg; 95% CI -3.88 to 3.16) and IL-6 (0.37 pg/mL; 95% CI -0.11 to 0.85). Within-group differences were also small to moderate. Conclusions In studies of aerobic exercise in patients with knee OA, very few interventions met guideline-recommended dose; there were small to moderate changes in markers of cardiovascular health and no decrease in markers of systemic inflammation. These findings question whether aerobic exercise is being used to its full potential in patients with knee OA. PROSPERO registration number CRD42018087859

    Diagnosis and Decision-Making in Telemedicine

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    This article provides an analysis of the skills that health professionals and patients employ in reaching diagnosis and decision-making in telemedicine consultations. As governmental priorities continue to emphasize patient involvement in the management of their disease, there is an increasing need to accurately capture the provider–patient interactions in clinical encounters. Drawing on conversation analysis of 10 video-mediated consultations in 3 National Health Service settings in England, this study examines the interaction between patients, General Practitioner (GPs), nurses, and consultants during diagnosis and decision-making, with the aim to identify the range of skills that participants use in the process and capture the interprofessional communication and patient involvement in the diagnosis and decision-making phases of telemedicine consultations. The analysis shows that teleconsultations enhance collaborative working among professionals and enable GPs and nurses to develop their skills and actively participate in diagnosis and decision-making by contributing primary care–specific knowledge to the consultation. However, interprofessional interaction may result in limited patient involvement in decisionmaking. The findings of this study can be used to inform training programs in telemedicine that focus on the development of effective skills for professionals and the provision of information to patients

    A semi-Markov model for stroke with piecewise-constant hazards in the presence of left, right and interval censoring.

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    This paper presents a parametric method of fitting semi-Markov models with piecewise-constant hazards in the presence of left, right and interval censoring. We investigate transition intensities in a three-state illness-death model with no recovery. We relax the Markov assumption by adjusting the intensity for the transition from state 2 (illness) to state 3 (death) for the time spent in state 2 through a time-varying covariate. This involves the exact time of the transition from state 1 (healthy) to state 2. When the data are subject to left or interval censoring, this time is unknown. In the estimation of the likelihood, we take into account interval censoring by integrating out all possible times for the transition from state 1 to state 2. For left censoring, we use an Expectation-Maximisation inspired algorithm. A simulation study reflects the performance of the method. The proposed combination of statistical procedures provides great flexibility. We illustrate the method in an application by using data on stroke onset for the older population from the UK Medical Research Council Cognitive Function and Ageing Study

    Rapid processing of PET list-mode data for efficient uncertainty estimation and data analysis

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    In this technical note we propose a rapid and scalable software solution for the processing of PET list-mode data, which allows the efficient integration of list mode data processing into the workflow of image reconstruction and analysis. All processing is performed on the graphics processing unit (GPU), making use of streamed and concurrent kernel execution together with data transfers between disk and CPU memory as well as CPU and GPU memory. This approach leads to fast generation of multiple bootstrap realisations, and when combined with fast image reconstruction and analysis, it enables assessment of uncertainties of any image statistic and of any component of the image generation process (e.g., random correction, image processing) within reasonable time frames (e.g., within five minutes per realisation). This is of particular value when handling complex chains of image generation and processing. The software outputs the following: (1) estimate of expected random event data for noise reduction; (2) dynamic prompt and random sinograms of span-1 and span-11 and (3) variance estimates based on multiple bootstrap realisations of (1) and (2) assuming reasonable count levels for acceptable accuracy. In addition, the software produces statistics and visualisations for immediate quality control and crude motion detection, such as: (1) count rate curves; (2) centre of mass plots of the radiodistribution for motion detection; (3) video of dynamic projection views for fast visual list-mode skimming and inspection; (4) full normalisation factor sinograms. To demonstrate the software, we present an example of the above processing for fast uncertainty estimation of regional SUVR (standard uptake value ratio) calculation for a single PET scan of ¹⁸F-florbetapir using the Siemens Biograph mMR scanner

    Alternative Metabolic Strategies are Employed by Endurance Runners of Different Body Sizes; Implications for Human Evolution

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    OBJECTIVE: A suite of adaptations facilitating endurance running (ER) evolved within the hominin lineage. This may have improved our ability to reach scavenging sites before competitors, or to hunt prey over long distances. Running economy (RE) is a key determinant of endurance running performance, and depends largely on the magnitude of force required to support body mass. However, numerous environmental factors influence body mass, thereby significantly affecting RE. This study tested the hypothesis that alternative metabolic strategies may have emerged to enable ER in individuals with larger body mass and poor RE. METHODS: A cohort of male (n = 25) and female (n = 19) ultra-endurance runners completed submaximal and exhaustive treadmill protocols to determine RE, and V̇O2Max. RESULTS: Body mass was positively associated with sub-maximal oxygen consumption at both LT1 (male r=0.66, p<0.001; female LT1 r=0.23, p=0.177) and LT2 (male r=0.59, p=0.001; female r=0.23, p=0.183) and also with V̇O2Max (male r=0.60, p=0.001; female r=0.41, p=0.046). Additionally, sub-maximal oxygen consumption varied positively with V̇O2Max in both male (LT1 r=0.54, p=0.003; LT2 r=0.77, p<0.001) and female athletes (LT1 r=0.88, p<0.001; LT2 r=0.92, p<0.001). CONCLUSIONS: The results suggest that, while individuals with low mass and good RE can glide economically as they run, larger individuals can compensate for the negative effects their mass has on RE by increasing their capacity to consume oxygen. The elevated energy expenditure of this low-economy high-energy turnover approach to ER may bring costs associated with energy diversion away from other physiological processes, however
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