1,075 research outputs found

    Self and peer-ratings of self-esteem and cardiovascular reactivity to laboratory stressors in cadets

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    Past research has indicated that self-esteem has multiple dimensions. It has been suggested that defensive high self-esteem makes one vulnerable to ego-threat and might be reflected in discrepancies between peer- and self-ratings. The purpose of this study was to observe how self- and peer-rated self-esteem affect cardiovascular reactivity to ego-threatening stressors (cold pressor and toughness-challenging interview) in nineteen military college cadets. High/low groups of self-esteem were formed based on peer- and self-ratings. Cadets in the low self-rating group showed evidence of a mixed (myocardial and vascular) response; cadets in the high peer-rating group showed higher myocardial and lower vascular reactivity. Cadets with high peer- /low self-ratings (defensive high self-esteem) had a greater blood pressure increase during interview preparation than participants with high peer-/high self-ratings. The present findings suggest that secure high self-esteem, as reflected by agreement between self- and peer-ratings, may be the only way to ensure low vulnerability to stress

    Students’ Perspective of Self-Guided Simulation Training on Process in the Initial Phase of Private Pilot Flight Training: A Preliminary Review

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    As the demand for flight training increases, self-guided training methods for students can be explored to determine their effect on environment for learning. A series of self-guided simulation training scenarios, aimed at assisting initial private pilot students, were created to be used on Advanced Aviation Training Devices (AATD). A pilot study was conducted where participants, using an AATD, followed a lesson plan with detailed instructions and then were evaluated by an instructor. In addition to evaluation scores, participants were given surveys on their perceptions of the experience overall and how prepared they felt for each evaluation. This preliminary study was conducted to determine student perception of self-guided training, the effectiveness of this type of training, and if there is any impact on the number of flight hours required prior to passing their private pilot pre-solo stage check

    Ventilatory requirements of quadriceps resistance training in people with COPD and healthy controls.

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    BACKGROUND: It is proposed that resistance training (RT) does not activate the cardiopulmonary system to the same extent as whole-body exercise. This is important for patients with chronic obstructive pulmonary disease (COPD) who are ventilatory limited. OBJECTIVE: The aim was to assess the ventilatory response to an isokinetic quadriceps RT program in people with COPD and healthy controls. DESIGN: Observational. REGISTRATION NUMBER: ISRCTN22764439. SETTING: Outpatient, university teaching hospital. PARTICIPANTS AND OUTCOME MEASURES: People with COPD (n=14) and healthy controls (n=11) underwent breath-by-breath analysis of their ventilation during an RT session (five sets of 30 maximal knee extensions at 180°/sec). Subjects performed a maximal cycle ergometry test (CET) at baseline. Peak ventilation (VE; L/min) and oxygen consumption (VO2; mL/kg/min) were collected. The same system measured VO2 and VE during the RT session. Parameters are presented as a percentage of the maximal CET. Isokinetic workload, symptom scores, heart rate (HR), and oxygen saturation were documented post-training. RESULTS: People with COPD worked at higher percentages of their maximal capacity than controls (mean range between sets 1-5 for VO2 =49.1%-60.1% [COPD], 45.7%-51.43% [controls] and for VE =57.6%-72.2% [COPD], 49.8%-63.6% [controls]), although this was not statistically significant (P>0.1 in all cases). In absolute terms, the difference between groups was only significant for actual VO2 on set 2 (P<0.05). Controls performed more isokinetic work than patients with COPD (P<0.05). Median Borg symptom scores after RT were the same in both groups (3 breathlessness, 13 exertion), no de-saturation occurred, and both groups were training at ≄65% of their maximum HR. CONCLUSION: No statistically significant differences were found between people with COPD and healthy controls for VO2 and VE achieved during training. The symptoms associated with training were within acceptable limits

    Associations of Vitamin D with Inter- and Intra-Muscular Adipose Tissue and Insulin Resistance in Women with and without Polycystic Ovary Syndrome

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    Low vitamin D and insulin resistance are common in polycystic ovary syndrome (PCOS) and associated with higher inter- and intra-muscular adipose tissue (IMAT). We investigated associations between vitamin D, IMAT and insulin resistance in a cross-sectional study of 40 women with PCOS and 30 women without PCOS, and pre- and post-exercise in a 12-week intervention in 16 overweight participants (10 with PCOS and six without PCOS). A non-classical body mass index (BMI) threshold was used to differentiate lean and overweight women (BMI ≄ 27 kg/mÂČ). Measurements included plasma 25-hydroxyvitamin D (25OHD), insulin resistance (glucose infusion rate (GIR; mg/mÂČ/min), fasting glucose and insulin, and glycated haemoglobin), visceral fat, mid-thigh IMAT (computed tomography) and total body fat (dual-energy X-ray absorptiometry). Women with both PCOS and low 25OHD levels had the lowest GIR (all p < 0.05). Higher IMAT was associated with lower 25OHD (B = -3.95; 95% CI -6.86, -1.05) and GIR (B = -21.3; 95% CI -37.16, -5.44) in women with PCOS. Overweight women with pre-exercise 25OHD ≄30 nmol/L had significant increases in GIR, and decreases in total and visceral fat (all p < 0.044), but no associations were observed when stratified by PCOS status. Women with PCOS and low 25OHD levels have increased insulin resistance which may be partly explained by higher IMAT. Higher pre-training 25OHD levels may enhance exercise-induced changes in body composition and insulin resistance in overweight women

    Association of psychological flexibility with engagement in pulmonary rehabilitation following an acute exacerbation of chronic obstructive pulmonary disease

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    This study aimed to investigate (a) the association between psychological flexibility and engagement in pulmonary rehabilitation within 8 weeks following hospitalisation for an acute exacerbation of chronic obstructive pulmonary disease (AECOPD) and (b) how psychological (in)flexibility presents in this context. A mixed-methods study was conducted. Psychological flexibility during an AECOPD was assessed using The Acceptance and Action Questionnaire-II (AAQ-II) (n = 41) and the Engaged Living Scale (ELS) (n = 40). Engagement in post-AECOPD pulmonary rehabilitation was then recorded. Twenty-three patients also participated in cognitive interviews. Psychological flexibility was associated with a greater chance of accepting a pulmonary rehabilitation referral following an AECOPD. Small numbers prohibited analysis on attendance or completion. An AAQ-II score of 11 translated to a 60 (37–82)% probability of accepting a referral to pulmonary rehabilitation and an ELS score of 73 was associated with a 68 (46–91)% probability of accepting. Four themes were extracted from interviews: (1) family values, (2) self as abnormal, (3) ‘can’t do anything’ versus ‘I do what I can’ and (4) disability, and related emotions, as barriers to action. Randomised clinical trials are needed to evaluate interventions designed to increase psychological flexibility (i.e. acceptance and commitment therapy) to support acceptance of pulmonary rehabilitation post-AECOPD

    Association of psychological flexibility with engagement in pulmonary rehabilitation following an acute exacerbation of chronic obstructive pulmonary disease

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    This study aimed to investigate (a) the association between psychological flexibility and engagement in pulmonary rehabilitation within 8 weeks following hospitalisation for an acute exacerbation of chronic obstructive pulmonary disease (AECOPD) and (b) how psychological (in)flexibility presents in this context. A mixed-methods study was conducted. Psychological flexibility during an AECOPD was assessed using The Acceptance and Action Questionnaire-II (AAQ-II) (n = 41) and the Engaged Living Scale (ELS) (n = 40). Engagement in post-AECOPD pulmonary rehabilitation was then recorded. Twenty-three patients also participated in cognitive interviews. Psychological flexibility was associated with a greater chance of accepting a pulmonary rehabilitation referral following an AECOPD. Small numbers prohibited analysis on attendance or completion. An AAQ-II score of 11 translated to a 60 (37–82)% probability of accepting a referral to pulmonary rehabilitation and an ELS score of 73 was associated with a 68 (46–91)% probability of accepting. Four themes were extracted from interviews: (1) family values, (2) self as abnormal, (3) ‘can’t do anything’ versus ‘I do what I can’ and (4) disability, and related emotions, as barriers to action. Randomised clinical trials are needed to evaluate interventions designed to increase psychological flexibility (i.e. acceptance and commitment therapy) to support acceptance of pulmonary rehabilitation post-AECOPD

    Use of Functional Near-Infrared Spectroscopy to Predict and Measure Cochlear Implant Outcomes: A Scoping Review

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    Outcomes following cochlear implantation vary widely for both adults and children, and behavioral tests are currently relied upon to assess this. However, these behavioral tests rely on subjective judgements that can be unreliable, particularly for infants and young children. The addition of an objective test of outcome following cochlear implantation is therefore desirable. The aim of this scoping review was to comprehensively catalogue the evidence for the potential of functional near infrared spectroscopy (fNIRS) to be used as a tool to objectively predict and measure cochlear implant outcomes. A scoping review of the literature was conducted following the PRISMA extension for scoping review framework. Searches were conducted in the MEDLINE, EMBASE, PubMed, CINAHL, SCOPUS, and Web of Science electronic databases, with a hand search conducted in Google Scholar. Key terms relating to near infrared spectroscopy and cochlear implants were used to identify relevant publications. Eight records met the criteria for inclusion. Seven records reported on adult populations, with five records only including post-lingually deaf individuals and two including both pre- and post-lingually deaf individuals. Studies were either longitudinal or cross-sectional, and all studies compared fNIRS measurements with receptive speech outcomes. This review identified and collated key work in this field. The homogeneity of the populations studied so far identifies key gaps for future research, including the use of fNIRS in infants. By mapping the literature on this important topic, this review contributes knowledge towards the improvement of outcomes following cochlear implantation

    Exercise and insulin resistance in PCOS: muscle insulin signalling and fibrosis

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    OBJECTIVE:Mechanisms of insulin resistance in polycystic ovary syndrome (PCOS) remain ill-defined, contributing to sub-optimal therapies. Recognising skeletal muscle plays a key role in glucose homeostasis we investigated early insulin signalling, its association with aberrant transforming growth factor ÎČ (TGFÎČ) regulated tissue fibrosis. We also explored the impact of aerobic exercise on these molecular pathways. METHODS:A secondary analysis from a cross-sectional study was undertaken in women with (n=30) or without (n=29) PCOS across lean and overweight BMIs. A subset of participants with (n=8) or without (n=8) PCOS who were overweight completed 12-weeks of aerobic exercise training. Muscle was sampled before and 30 min into a euglycaemic-hyperinsulinaemic clamp pre- and post-training. RESULTS:We found reduced signalling in PCOS of mechanistic target of rapamycin (mTOR). Exercise training augmented but did not completely rescue this signalling defect in women with PCOS. Genes in the TGFÎČ signalling network were upregulated in skeletal muscle in the overweight women with PCOS but were unresponsive to exercise training except for genes encoding LOX, collagen 1 and 3. CONCLUSIONS:We provide new insights into defects in early insulin signalling, tissue fibrosis, and hyperandrogenism in PCOS-specific insulin resistance in lean and overweight women. PCOS-specific insulin-signalling defects were isolated to mTOR, while gene expression implicated TGFÎČ ligand regulating a fibrosis in the PCOS-obesity synergy in insulin resistance and altered responses to exercise. Interestingly, there was little evidence for hyperandrogenism as a mechanism for insulin resistance

    Chemical dispersants can suppress the activity of natural oil-degrading microorganisms

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    Author Posting. © The Author(s), 2015. This is the author's version of the work. It is posted here by permission of National Academy of Sciences for personal use, not for redistribution. The definitive version was published in Proceedings of the National Academy of Sciences of the United States of America 112 (2015): 14900-14905, doi:10.1073/pnas.1507380112.During the Deepwater Horizon oil well blowout in the Gulf of Mexico, the application of 7 million liters of chemical dispersants aimed to stimulate microbial crude oil degradation by increasing the bioavailability of oil compounds. However, the effects of dispersants on oil biodegradation rates are debated. In laboratory experiments, we simulated environmental conditions comparable in the hydrocarbon-rich, 1100m deep, plume that formed during the Deepwater Horizon discharge. The presence of dispersant significantly altered the microbial community composition through selection for potential dispersant-degrading Colwellia, which also bloomed in situ in Gulf deep-waters during the discharge. In contrast, oil addition lacking dispersant stimulated growth of natural hydrocarbon-degrading Marinobacter. Dispersants did not enhance heterotrophic microbial activity or hydrocarbon oxidation rates. Extrapolating this comprehensive data set to real world scenarios questions whether dispersants stimulate microbial oil degradation in deep ocean waters and instead highlights that dispersants can exert a negative effect on microbial hydrocarbon degradation rates.This research was supported by a grant from BP/the Gulf of Mexico Research Initiative to support the "Ecosystem Impacts of Oil and Gas Inputs to the Gulf (ECOGIG)” consortium. PMM also acknowledges funding from the National Science Foundation (OCE-1057683)

    A global model of the response of tropical and sub-tropical forest biodiversity to anthropogenic pressures

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    Habitat loss and degradation, driven largely by agricultural expansion and intensification, present the greatest immediate threat to biodiversity. Tropical forests harbour among the highest levels of terrestrial species diversity and are likely to experience rapid land-use change in the coming decades. Synthetic analyses of observed responses of species are useful for quantifying how land use affects biodiversity and for predicting outcomes under land-use scenarios. Previous applications of this approach have typically focused on individual taxonomic groups, analysing the average response of the whole community to changes in land use. Here, we incorporate quantitative remotely sensed data about habitats in, to our knowledge, the first worldwide synthetic analysis of how individual species in four major taxonomic groups—invertebrates, ‘herptiles’ (reptiles and amphibians), mammals and birds—respond to multiple human pressures in tropical and sub-tropical forests. We show significant independent impacts of land use, human vegetation offtake, forest cover and human population density on both occurrence and abundance of species, highlighting the value of analysing multiple explanatory variables simultaneously. Responses differ among the four groups considered, and—within birds and mammals—between habitat specialists and habitat generalists and between narrow-ranged and wide-ranged species
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