5 research outputs found

    Yoga to Decrease the Stress Response: Gentle Yoga Encourages Faster Decline in Salivary Cortisol Concentrations Following Participation in TSST

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    Short-term, activation of the human stress response system is beneficial as it prepares the body to deal with stressors at hand (McEwen & Stellar, 1993). If this system is overactive or chronically active however, it can negatively impact health and longevity (Cohen, Janicki-Deverts, & Miller, 2007). According to a review conducted by Ross & Thomas (2010) implementation of a yoga practice has been shown to down-regulate the stress response system. The present study aimed to expand on current research involving yoga for stress reduction by exploring whether participation in gentle yoga could decrease the stress response more quickly than naturally occurs after psychological stress exposure. Participants were exposed to a psychological stress test, then randomly assigned to take part in a gentle yoga sequence or watch a neutral video. Analyses through independent sample t-tests indicated faster decline in salivary cortisol concentrations from initial stress response for participants that took part in gentle yoga. Results suggest participation in a gentle yoga practice helps decrease the stress response more quickly than occurs naturally following psychological stress exposure

    Comparative Functional Dynamics Studies on the Enzyme Nano-bio Interface

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    Citation: Thomas, S. E., Comer, J., Kim, M. J., Marroquin, S., Murthy, V., Ramani, M., … DeLong, R. K. (2018, August 8). Comparative functional dynamics studies on the enzyme nano-bio interface. https://doi.org/10.2147/IJN.S152222Comparative functional dynamics studies on the enzyme nano-bio interface Spencer E Thomas,1,2,* Jeffrey Comer,1,* Min Jung Kim,1 Shanna Marroquin,1 Vaibhav Murthy,1 Meghana Ramani,1 Tabetha Gaile Hopke,2 Jayden McCall,1 Seong-O Choi,1 Robert K DeLong1 1Nanotechnology Innovation Center of Kansas State, Department of Anatomy and Physiology, College of Veterinary Medicine, Kansas State University, Manhattan, KS, USA; 2Department of Biomedical Science, Missouri State University, Springfield, MO, USA *These authors contributed equally to this work Introduction: Biomedical applications of nanoparticles (NPs) as enzyme inhibitors have recently come to light. Oxides of metals native to the physiological environment (eg, Fe, Zn, Mg, etc.) are of particular interest—especially the functional consequences of their enzyme interaction. Materials and methods: Here, Fe2O3, zinc oxide (ZnO), magnesium oxide (MgO) and nickel oxide (NiO) NPs are compared to copper (Cu) and boron carbide (B4C) NPs. The functional impact of NP interaction to the model enzyme luciferase is determined by 2-dimensional fluorescence difference spectroscopy (2-D FDS) and 2-dimensional photoluminescence difference spectroscopy (2-D PLDS). By 2-D FDS analysis, the change in maximal intensity and in 2-D FDS area under the curve (AUC) is in the order Cu~B4C>ZnO>NiO>>Fe2O3>MgO. The induced changes in protein conformation are confirmed by tryptic digests and gel electrophoresis. Results: Analysis of possible trypsin cleavage sites suggest that cleavage mostly occurs in the range of residues 112–155 and 372–439, giving a major 45 kDa band. By 2-D PLDS, it is found that B4C NPs completely ablate bioluminescence, while Cu and Fe2O3 NPs yield a unique bimodal negative decay rate, -7.67×103 and -3.50×101 relative light units respectively. Cu NPs, in particular, give a remarkable 271% change in enzyme activity. Molecular dynamics simulations in water predicted that the surfaces of metal oxide NPs become capped with metal hydroxide groups under physiological conditions, while the surface of B4C becomes populated with boronic acid or borinic acid groups. These predictions are supported by the experimentally determined zeta potential. Thin layer chromatography patterns further support this conception of the NP surfaces, where stabilizing interactions were in the order ionic>polar>non-polar for the series tested. Conclusion: Overall the results suggest that B4C and Cu NP functional dynamics on enzyme biochemistry are unique and should be examined further for potential ramifications on other model, physiological or disease-relevant enzymes. Keywords: 2-dimensional fluorescence difference, 2-D FDS, AUC, corrected light intensity emitted, emission wavelength, excitation wavelength, wavelength of max intensity, RL

    A Meta-Analysis of Expressive Writing on Positive Psychology Variables and Traumatic Stress

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    Emotional expression has been shown to be benficial for promoting both positive psychological and physical health outcomes. Unfortunately, inhibiting emotions can lead to impairments in physical and psychological health. James Pennebaker showed that expressive writing is an effective form of emotional expression, and he and others have used expressive writing as an experimental manipulation to gauge its effectiveness in treating a wide variety of health-related and psychological outcomes. While many studies have been conducted that examine the effectiveness of expressive writing across such outcomes, a considerable amount of these studies tend to neglect necessary considerations such as power and meaningfulness of respective effect sizes. Four previous meta-analyses have been conducted that examine expressive writing's affect on psychological outcomes, however, these studies focus on the experimental versus control group effect size. Thus, our meta-analysis sought to examine the effectiveness of an expressive writing intervention on only the experimental conditions in studies measuring posttraumatic growth, posttraumatic stress, and quality of life using random effects models. Results indicated a small overall effect size for posttraumatic stress and negligible to small effect sizes for posttraumatic growth and quality of life. Implications for future research design and interpretation of published research are discussed

    Have psychologists increased reporting of outliers in response to the reproducibility crisis?

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    Psychology is currently experiencing a "renaissance" where the replication and reproducibility of published reports are at the forefront of conversations in the field. While researchers have worked to discuss possible problems and solutions, work has yet to uncover how this new culture may have altered reporting practices in the social sciences. As outliers and other errant data points can bias both descriptive and inferential statistics, the search for these data points is essential to any analysis using these parameters. We quantified the rates of reporting of outliers and other data within psychology at two time points: 2012 when the replication crisis was born, and 2017, after the publication of reports concerning replication, questionable research practices, and transparency. A total of 2235 experiments were identified and analyzed, finding an increase in reporting from only 15.7% of experiments in 2012 to 25.0% in 2017. We investigated differences across years given the psychological field or statistical analysis that experiment employed. Further, we inspected whether data exclusions mentioned were whole participant observations or data points, and what reasons authors gave for stating the observation was deviant. We conclude that while report rates are improving overall, there is still room for improvement in the reporting practices of psychological scientists which can only aid in strengthening our science
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