131 research outputs found

    Who is to blame? The relationship between ingroup identification and relative deprivation is moderated by ingroup attributions

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    Contradictory evidence can be found in the literature about whether ingroup identification and perceived relative deprivation are positively or negatively related. Indeed, theoretical arguments can be made for both effects. It was proposed that the contradictory findings can be explained by considering a hitherto unstudied moderator: The extent to which deprivation is attributed to the ingroup. It was hypothesised that identification would only have a negative impact on deprivation, and that deprivation would only have a negative impact on identification, if ingroup attributions are high. To test this, attributions to the ingroup were experimentally manipulated among British student participants (N = 189) who were asked about their perceived deprivation vis-à-vis German students, yield ing support for the hypotheses

    The Reproducibility of Blood Acid Base Responses in Male Collegiate Athletes Following Individualised Doses of Sodium Bicarbonate: A Randomised Controlled Crossover Study

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    Background: Current evidence suggests sodium bicarbonate (NaHCO3) should be ingested based upon the individualised alkalotic peak of either blood pH or bicarbonate (HCO3−) because of large inter-individual variations (10–180 min). If such a strategy is to be practical, the blood analyte response needs to be reproducible. Objective: This study aimed to evaluate the degree of reproducibility of both time to peak (TTP) and absolute change in blood pH, HCO3− and sodium (Na+) following acute NaHCO3 ingestion. Methods: Male participants (n = 15) with backgrounds in rugby, football or sprinting completed six randomised treatments entailing ingestion of two doses of 0.2 g·kg−1 body mass (BM) NaHCO3 (SBC2a and b), two doses of 0.3 g·kg−1 BM NaHCO3 (SBC3a and b) or two control treatments (CON1a and b) on separate days. Blood analysis included pH, HCO3− and Na+ prior to and at regular time points following NaHCO3 ingestion over a 3-h period. Results: HCO3− displayed greater reproducibility than pH in intraclass correlation coefficient (ICC) analysis for both TTP (HCO3− SBC2 r = 0.77, P = 0.003; SBC3 r = 0.94, P < 0.001; pH SBC2 r = 0.62, P = 0.044; SBC3 r = 0.71, P = 0.016) and absolute change (HCO3− SBC2 r = 0.89, P < 0.001; SBC3 r = 0.76, P = 0.008; pH SBC2 r = 0.84, P = 0.001; SBC3 r = 0.62, P = 0.041). Conclusion: Our results indicate that both TTP and absolute change in HCO3− is more reliable than pH. As such, these data provide support for an individualised NaHCO3 ingestion strategy to consistently elicit peak alkalosis before exercise. Future work should utilise an individualised NaHCO3 ingestion strategy based on HCO3− responses and evaluate effects on exercise performance

    Optimizing the diagnostic power with gastric emptying scintigraphy at multiple time points

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    <p>Abstract</p> <p>Background</p> <p>Gastric Emptying Scintigraphy (GES) at intervals over 4 hours after a standardized radio-labeled meal is commonly regarded as the gold standard for diagnosing gastroparesis. The objectives of this study were: 1) to investigate the best time point and the best combination of multiple time points for diagnosing gastroparesis with repeated GES measures, and 2) to contrast and cross-validate Fisher's Linear Discriminant Analysis (LDA), a rank based Distribution Free (DF) approach, and the Classification And Regression Tree (CART) model.</p> <p>Methods</p> <p>A total of 320 patients with GES measures at 1, 2, 3, and 4 hour (h) after a standard meal using a standardized method were retrospectively collected. Area under the Receiver Operating Characteristic (ROC) curve and the rate of false classification through jackknife cross-validation were used for model comparison.</p> <p>Results</p> <p>Due to strong correlation and an abnormality in data distribution, no substantial improvement in diagnostic power was found with the best linear combination by LDA approach even with data transformation. With DF method, the linear combination of 4-h and 3-h increased the Area Under the Curve (AUC) and decreased the number of false classifications (0.87; 15.0%) over individual time points (0.83, 0.82; 15.6%, 25.3%, for 4-h and 3-h, respectively) at a higher sensitivity level (sensitivity = 0.9). The CART model using 4 hourly GES measurements along with patient's age was the most accurate diagnostic tool (AUC = 0.88, false classification = 13.8%). Patients having a 4-h gastric retention value >10% were 5 times more likely to have gastroparesis (179/207 = 86.5%) than those with ≤10% (18/113 = 15.9%).</p> <p>Conclusions</p> <p>With a mixed group of patients either referred with suspected gastroparesis or investigated for other reasons, the CART model is more robust than the LDA and DF approaches, capable of accommodating covariate effects and can be generalized for cross institutional applications, but could be unstable if sample size is limited.</p

    Individual Differences in Sound-in-Noise Perception Are Related to the Strength of Short-Latency Neural Responses to Noise

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    Important sounds can be easily missed or misidentified in the presence of extraneous noise. We describe an auditory illusion in which a continuous ongoing tone becomes inaudible during a brief, non-masking noise burst more than one octave away, which is unexpected given the frequency resolution of human hearing. Participants strongly susceptible to this illusory discontinuity did not perceive illusory auditory continuity (in which a sound subjectively continues during a burst of masking noise) when the noises were short, yet did so at longer noise durations. Participants who were not prone to illusory discontinuity showed robust early electroencephalographic responses at 40–66 ms after noise burst onset, whereas those prone to the illusion lacked these early responses. These data suggest that short-latency neural responses to auditory scene components reflect subsequent individual differences in the parsing of auditory scenes

    Minimizing Variability of Cascade Impaction Measurements in Inhalers and Nebulizers

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    The purpose of this article is to catalogue in a systematic way the available information about factors that may influence the outcome and variability of cascade impactor (CI) measurements of pharmaceutical aerosols for inhalation, such as those obtained from metered dose inhalers (MDIs), dry powder inhalers (DPIs) or products for nebulization; and to suggest ways to minimize the influence of such factors. To accomplish this task, the authors constructed a cause-and-effect Ishikawa diagram for a CI measurement and considered the influence of each root cause based on industry experience and thorough literature review. The results illustrate the intricate network of underlying causes of CI variability, with the potential for several multi-way statistical interactions. It was also found that significantly more quantitative information exists about impactor-related causes than about operator-derived influences, the contribution of drug assay methodology and product-related causes, suggesting a need for further research in those areas. The understanding and awareness of all these factors should aid in the development of optimized CI methods and appropriate quality control measures for aerodynamic particle size distribution (APSD) of pharmaceutical aerosols, in line with the current regulatory initiatives involving quality-by-design (QbD)

    Neuropsychological function is related to irritable bowel syndrome in women with premenstrual syndrome and dysmenorrhea

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    Background There is increasing evidence demonstrating the co-occurrence of primary dysmenorrhea (PD), premenstrual syndrome (PMS), and irritable bowel syndrome (IBS) in women. This study aimed to investigate whether women who have symptoms of IBS in addition to PD and PMS also report more severe or frequent menstruation-associated symptoms and psychological complications compared to women with PD and PMS alone. Methods The study group included 182 female University students aged 18–25 years. IBS was diagnosed using the Rome III criteria. The severity of PMS and PD was determined using a 10-point visual analog scale and PSST (Premenstrual Syndrome Screening Tool), respectively. Neuropsychological functions including cognitive function, depression score, anxiety score, stress, insomnia, daytime sleepiness, quality of life and personality were assessed using standard questionnaires. Results Of the 182 young females, 31 (17.0%) had IBS. Average days of bleeding during the menstrual cycle and mean pain severity on the PSST scale were significantly greater in the group with IBS compared to the non-IBS group (p < 0.01). The non-IBS individuals scored more favorably than the women with IBS with respect to severity of depression, insomnia, daytime sleepiness (p < 0.05). The PSST scores were significantly correlated with scores for depression (r = 0.29; p < 0.001), anxiety (r = 0.28; p < 0.001), stress (r = 0.32; p < 0.001), insomnia (r = 0.34; p < 0.001) and daytime sleepiness (r = 0.31; p < 0.001); while, they were negatively correlated with cognitive abilities (r = − 0.20; p = 0.006) and quality of life (r = − 0.42; p < 0.001). Linear regression analysis showed that the PSST scores were possibly significant factors in determining the scores for depression, anxiety, stress, quality of life, insomnia and daytime sleepiness (p < 0.05). Conclusion IBS is related to psychological comorbidities, in particular depression, sleep problems and menstrual-associated disorders. IBS may exacerbate the features of PMS which should be taken into account in the management of PMS

    Strain induced martensite formation in PM nickel steels

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    Powder metallurgy (PM) nickel steels are often selected because they have high strength, high impact resistance and good abrasion resistance. The microstructure of slowly cooled PM nickel steels typically contains pearlite, bainite, martensite and a fair volume fraction of retained austenite. Since volume diffusion is really low at conventional sintering temperatures [1120- 1150uC (2050-2100uF)], nickel rich areas are usually found where prior admixed nickel particles were located, i.e. at the surface of iron particles and in sintering necks. Therefore, there is a discrepancy between the rather low mechanical properties of austenite and the high strength of PM nickel steel. Hence, the hypotheses that stress induced or strain induced martensite formation takes place during mechanical testing have been investigated. Results show that martensite forms during mechanical testing, and its final volume fraction is proportional to nickel content. \ua9 2013 Institute of Materials, Minerals and Mining.Peer reviewed: YesNRC publication: Ye

    Effects of additions of nickel nanoparticles on sintering response of PM hybrid low alloy steels

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    Addition of pure elements to powder mixes can cause the formation of heterogeneous microstructures in powder metallurgy (PM) parts upon sintering. For instance, it has been shown that additions of nickel particles to an iron powder form nickel rich areas (NRAs), since nickel has low diffusivity in iron at conventional sintering temperature [ 3c1121\ub0C (2050\ub0F)]. Thus, the present work is aimed at determining if addition of a small quantity of carbon coated nickel nanoparticles to a PM hybrid low alloy steel premix could result in a more homogeneous distribution of nickel in sintered parts. It also characterises the effect of this addition on microstructures and mechanical properties. Grain boundary and volume diffusion coefficients of nickel nanoparticles have been determined using Suzuoka's equation and wavelength dispersive X-ray spectrometry maps. Results show that addition of nanoparticles initiates lattice diffusion at lower temperature and produces less NRA. \ua9 2013 Institute of Materials, Minerals and Mining.Peer reviewed: YesNRC publication: Ye
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