99 research outputs found

    Comparative Population Genomics and Biophysical Modeling of Shrimp Migration in the Gulf of Mexico Reveals Current-Mediated Connectivity

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    The Gulf of Mexico experiences frequent perturbations, both natural and anthropogenic. To better understand the impacts of these events, we must inventory natural variability within the ecosystem, communities, species, and populations, and contextualize these findings in relation to physical features. Here, we present an integrated study of comparative population genomics and biophysical oceanography. Targeting three species of mesopelagic shrimp common to the Gulf of Mexico midwater (Acanthephyra purpurea, Systellaspis debilis, and Robustosergia robusta), we analyzed genetic diversity and population connectivity as proxies for species health and resilience, respectively. We also simulated a range of vertical migratory behaviors for the shrimp to infer the relationship between diel vertical migration and horizontal transmission between the Gulf of Mexico and the greater Atlantic Ocean. This study aims to establish biological baselines and characterize these values in terms of the prevailing oceanographic feature of the midwater: the Gulf Loop Current. Generally, the oplophorid species (A. purpurea and S. debilis) exhibit lower genetic diversity and higher interpopulation homogeneity compared to the sergestid (R. robusta). Biophysical simulations suggest the differences in vertical migratory regimes between these two groups have important implications for horizontal transport out of the Gulf of Mexico. Because of the difference in vertical migration patterns, access to the Gulf Loop Current varies across taxa and impacts inter-basin migration. Our findings suggest a negative correlation between surface abundance and genetic diversity in these three shrimp species. We hypothesize that this correlation may be due to the relationships between surface abundance and access to the fastest moving waters of the Gulf Loop Current

    The effects of a single whole-body cryotherapy exposure on physiological, performance and perceptual responses of professional academy soccer players following repeated sprint exercise

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    In professional youth soccer players, the physiological, performance and perceptual effects of a single whole body cryotherapy (WBC) session performed shortly after repeated sprint exercise were investigated. In a randomized, counter-balanced and crossover design, 14 habituated English Premier League academy soccer players performed 15 x 30 m sprints (each followed by a 10 m forced deceleration) on two occasions. Within 20 min of exercise cessation, players entered a WBC chamber (Cryo: 30 s at -60°C, 120 s at -135°C) or remained seated (Con) indoors in temperate conditions (~25°C). Blood and saliva samples, peak power output (countermovement jump) and perceptual indices of recovery and soreness were assessed pre-exercise and immediately, 2 h and 24 h post exercise. When compared to Con, a greater testosterone response was observed at 2 h (+32.5 ± 32.3 pg·ml-1, +21%) and 24 h (+50.4 ± 48.9 pg·ml-1, +28%) post-exercise (both P=0.002) in Cryo (trial x treatment interaction: P=0.001). No between trial differences were observed for other salivary (cortisol and testosterone/cortisol ratio), blood (lactate and Creatine Kinase), performance (peak power output) or perceptual (recovery or soreness) markers (all trial x treatment interactions: P>0.05); all of which were influenced by exercise (time effects: all P<0.05). A single session of WBC performed within 20 min of repeated sprint exercise elevated testosterone concentrations for 24 h but did not affect any other performance, physiological or perceptual measurements taken. While unclear, WBC may be efficacious for professional soccer players during congested fixture periods

    The Application of Novel Research Technologies by the Deep Pelagic Nekton Dynamics of the Gulf of Mexico (DEEPEND) Consortium

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    The deep waters of the open ocean represent a major frontier in exploration and scientific understanding. However, modern technological and computational tools are making the deep ocean more accessible than ever before by facilitating increasingly sophisticated studies of deep ocean ecosystems. Here, we describe some of the cutting-edge technologies that have been employed by the Deep Pelagic Nekton Dynamics of the Gulf of Mexico (DEEPEND; www.deependconsortium.org) Consortium to study the biodiverse fauna and dynamic physical-chemical environment of the offshore Gulf of Mexico (GoM) from 0 to 1,500 m

    Differences in Physiological Responses to Cardiopulmonary Exercise Testing in Adults With and Without Type 1 Diabetes: A Pooled Analysis

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    OBJECTIVE To investigate physiological responses to cardiopulmonary exercise (CPX) testing in adults with type 1 diabetes compared with age-, sex-, and BMI-matched control participants without type 1 diabetes.RESEARCH DESIGN AND METHODS We compared results from CPX tests on a cycle ergometer in individuals with type 1 diabetes and control participants without type 1 diabetes. Parameters were peak and threshold variables of VO2, heart rate, and power output. Differences between groups were investigated through restricted maximum likelihood modeling and post hoc tests. Differences between groups were explained by stepwise linear regressions (P < 0.05).RESULTS Among 303 individuals with type 1 diabetes (age 33 [interquartile range 22; 43] years, 93 females, BMI 23.6 [22; 26] kg/m2, HbA1c 6.9% [6.2; 7.7%] [52 (44; 61) mmol/mol]), VO2peak (32.55 [26.49; 38.72] vs. 42.67 ± 10.44 mL/kg/min), peak heart rate (179 [170; 187] vs. 184 [175; 191] beats/min), and peak power (216 [171; 253] vs. 245 [200; 300] W) were lower compared with 308 control participants without type 1 diabetes (all P < 0.001). Individuals with type 1 diabetes displayed an impaired degree and direction of the heart rate-to-performance curve compared with control participants without type 1 diabetes (0.07 [−0.75; 1.09] vs. 0.66 [−0.28; 1.45]; P < 0.001). None of the exercise physiological responses were associated with HbA1c in individuals with type 1 diabetes.CONCLUSIONS Individuals with type 1 diabetes show altered responses to CPX testing, which cannot be explained by HbA1c. Intriguingly, the participants in our cohort were people with recent-onset type 1 diabetes; heart rate dynamics were altered during CPX testing

    How are Research for Development Programmes Implementing and Evaluating Equitable Partnerships to Address Power Asymmetries?

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    The complexity of issues addressed by research for development (R4D) requires collaborations between partners from a range of disciplines and cultural contexts. Power asymmetries within such partnerships may obstruct the fair distribution of resources, responsibilities and benefits across all partners. This paper presents a cross-case analysis of five R4D partnership evaluations, their methods and how they unearthed and addressed power asymmetries. It contributes to the field of R4D partnership evaluations by detailing approaches and methods employed to evaluate these partnerships. Theory-based evaluations deepened understandings of how equitable partnerships contribute to R4D generating impact and centring the relational side of R4D. Participatory approaches that involved all partners in developing and evaluating partnership principles ensured contextually appropriate definitions and a focus on what partners value

    How are Research for Development Programmes Implementing and Evaluating Equitable Partnerships to Address Power Asymmetries?

    Get PDF
    The complexity of issues addressed by research for development (R4D) requires collaborations between partners from a range of disciplines and cultural contexts. Power asymmetries within such partnerships may obstruct the fair distribution of resources, responsibilities and benefits across all partners. This paper presents a cross-case analysis of five R4D partnership evaluations, their methods and how they unearthed and addressed power asymmetries. It contributes to the field of R4D partnership evaluations by detailing approaches and methods employed to evaluate these partnerships. Theory-based evaluations deepened understandings of how equitable partnerships contribute to R4D generating impact and centring the relational side of R4D. Participatory approaches that involved all partners in developing and evaluating partnership principles ensured contextually appropriate definitions and a focus on what partners value. The online version contains supplementary material available at 10.1057/s41287-023-00578-w. [Abstract copyright: © The Author(s) 2023.

    Women's views and postpartum follow-up in the CHIPS Trial (Control of Hypertension in Pregnancy Study).

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    OBJECTIVE: To compare women's views about blood pressure (BP) control in CHIPS (Control of Hypertension In Pregnancy Study) (NCT01192412). DESIGN: Quantitative and qualitative analysis of questionnaire responses. SETTING: International randomised trial (94 sites, 15 countries). POPULATION/SAMPLE: 911 (92.9%) women randomised to 'tight' (target diastolic blood pressure, 85mmHg) or 'less tight' (target diastolic blood pressure, 100mmHg) who completed questionnaires. METHODS: A questionnaire was administered at ∌6-12 weeks postpartum regarding post-discharge morbidity and views about trial participation. Questionnaires were administered by the site co-ordinator, and contact was made by phone, home or clinic visit; rarely, data was collected from medical records. Quantitative analyses were Chi-square or Fisher's exact test for categorical variables, mixed effects multinomial logistic regression to adjust for confounders, and p<0.001 for statistical significance. NVivo software was used for thematic analysis of women's views. MAIN OUTCOME MEASURES: Satisfaction, measured as willingness to have the same treatment in another pregnancy or recommend that treatment to a friend. RESULTS: Among the 533 women in 'tight' (N=265) vs. 'less tight' (N=268) control who provided comments for qualitative analysis, women in 'tight' (vs. 'less tight') control made fewer positive comments about the amount of medication taken (5 vs. 28 women, respectively) and intensity of BP monitoring (7 vs. 17, respectively). However, this did not translate into less willingness to either have the same treatment in another pregnancy (434, 95.8% vs. 423, 92.4%, respectively; p=0.14) or recommend that treatment to a friend (435, 96.0% and 428, 93.4%, respectively; p=0.17). Importantly, although satisfaction remained high among women with an adverse outcome, those in 'tight' control who suffered an adverse outcome (vs. those who did not) were not consistently less satisfied, whereas this was not the case among women in 'less tight' control among whom satisfaction was consistently lower for the CHIPS primary outcome (p<0.001), severe hypertension (p≀0.01), and pre-eclampsia (p<0.001). CONCLUSIONS: Women in 'tight' (vs. 'less tight') control were equally satisfied with their care, and more so in the face of adverse perinatal or maternal outcomes

    Influence of gestational age at initiation of antihypertensive therapy: Secondary analysis of CHIPS trial data (control of hypertension in pregnancy study).

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    For hypertensive women in CHIPS (Control of Hypertension in Pregnancy Study), we assessed whether the maternal benefits of tight control could be achieved, while minimizing any potentially negative effect on fetal growth, by delaying initiation of antihypertensive therapy until later in pregnancy. For the 981 women with nonsevere, chronic or gestational hypertension randomized to less-tight (target diastolic blood pressure, 100 mm Hg), or tight (target, 85 mm Hg) control, we used mixed-effects logistic regression to examine whether the effect of less-tight (versus tight) control on major outcomes was dependent on gestational age at randomization, adjusting for baseline factors as in the primary analysis and including an interaction term between gestational age at randomization and treatment allocation. Gestational age was considered categorically (quartiles) and continuously (linear or quadratic form), and the optimal functional form selected to provide the best fit to the data based on the Akaike information criterion. Randomization before (but not after) 24 weeks to less-tight (versus tight) control was associated with fewer babies with birth weight 48 hours (Pinteraction=0.354). For the mother, less-tight (versus tight) control was associated with more severe hypertension at all gestational ages but particularly so before 28 weeks (Pinteraction=0.076). In women with nonsevere, chronic, or gestational hypertension, there seems to be no gestational age at which less-tight (versus tight) control is the preferred management strategy to optimize maternal or perinatal outcomes

    Surface Ocean Dispersion Observations From the Ship-Tethered Aerostat Remote Sensing System

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    Oil slicks and sheens reside at the air-sea interface, a region of the ocean that is notoriously difficult to measure. Little is known about the velocity field at the sea surface in general, making predictions of oil dispersal difficult. The Ship-Tethered Aerostat Remote Sensing System (STARSS) was developed to measure Lagrangian velocities at the air-sea interface by tracking the transport and dispersion of bamboo dinner plates in the field of view of a high-resolution aerial imaging system. The camera had a field of view of approximately 300 × 200 m and images were obtained every 15 s over periods of up to 3 h. A series of experiments were conducted in the northern Gulf of Mexico in January-February 2016. STARSS was equipped with a GPS and inertial navigation system (INS) that was used to directly georectify the aerial images. A relative rectification technique was developed that translates and rotates the plates to minimize their total movement from one frame to the next. Rectified plate positions were used to quantify scale-dependent dispersion by computing relative dispersion, relative diffusivity, and velocity structure functions. STARSS was part of a nested observational framework, which included deployments of large numbers of GPS-tracked surface drifters from two ships, in situ ocean measurements, X-band radar observations of surface currents, and synoptic maps of sea surface temperature from a manned aircraft. Here we describe the STARSS system and image analysis techniques, and present results from an experiment that was conducted on a density front that was approximately 130 km offshore. These observations are the first of their kind and the methodology presented here can be adopted into existing and planned oceanographic campaigns to improve our understanding of small-scale and high-frequency variability at the air-sea interface and to provide much-needed benchmarks for numerical simulations
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