Effect of caffeine ingestion on fluid balance during exercise in the heat and during recovery

Background. The effect of ingestion of a common stimulant, caffeine, on fluid balance during exercise and recovery is not fully known. Objectives. To determine the effect of caffeine on fluid balance during exercise in the heat and during a 3-hour recovery period thereafter. Methods. In a randomised, controlled design, caffeine-naive participants (N=8) pedalled on a bike to achieve 2.5% baseline body mass loss in a hot environment in four separate conditions: with (C+) or without (C–) caffeine ingestion (6 mg/kg of body mass) prior to exercise, followed by (W+) or without (W–) 100% fluid replenishment (water) of the body mass loss during a 3-hour recovery period (yielding C+W+, C+W–, C–W+ and C–W–, respectively). Results. Mean (standard deviation) urine production was not different (p>0.05) regardless of rehydration status: 230 (162) mL (C+W–) v. 168 (77) mL (C–W–); and 713 (201) mL (C+W+) v. 634 (185) mL (C–W+). For the 3-hour recovery, caffeine ingestion caused higher hypohydration during rehydration conditions (p=0.02), but practically the mean difference in the loss of body mass was only 0.2 kg. Conclusion. In practical terms, there was no evidence that caffeine ingestion in moderation would impair fluid balance during prolonged exercise in the heat or during 3 hours of recovery

Differential roles of push and pull factors on escape for travel: Personal and social identity perspectives

© 2020 John Wiley & Sons Ltd This study examines the effects of push and pull motivations linked to an individual\u27s personal and social identities as key antecedents to escape for travel. In terms of push factors, escape for travel is driven from a personal identity perspective by the need for evaluation of self and regression and from a social identity perspective by the need for social interaction but not enhancement of kinship. Cultural motives that reflect personal identity positively influence escape for travel than destination pull factors linked to social identity. Overall, the study contributes to the existing knowledge on push and pull tourist motivations

The role of renal hypoperfusion in development of renal microcirculatory dysfunction in endotoxemic rats

To study the role of renal hypoperfusion in development of renal microcirculatory dysfunction in endotoxemic rats. Rats were randomized into four groups: a sham group (n = 6), a lipopolysaccharide (LPS) group (n = 6), a group in which LPS administration was followed by immediate fluid resuscitation which prevented the drop of renal blood flow (EARLY group) (n = 6), and a group in which LPS administration was followed by delayed (i.e., a 2-h delay) fluid resuscitation (LATE group) (n = 6). Renal blood flow was measured using a transit-time ultrasound flow probe. Microvascular perfusion and oxygenation distributions in the renal cortex were assessed using laser speckle imaging and phosphorimetry, respectively. Interleukin (IL)-6, IL-10, and tumor necrosis factor (TNF)-α were measured as markers of systemic inflammation. Furthermore, renal tissue samples were stained for leukocyte infiltration and inducible nitric oxide synthase (iNOS) expression in the kidney. LPS infusion worsened both microvascular perfusion and oxygenation distributions. Fluid resuscitation improved perfusion histograms but not oxygenation histograms. Improvement of microvascular perfusion was more pronounced in the EARLY group compared with the LATE group. Serum cytokine levels decreased in the resuscitated groups, with no difference between the EARLY and LATE groups. However, iNOS expression and leukocyte infiltration in glomeruli were lower in the EARLY group compared with the LATE group. In our model, prevention of endotoxemia-induced systemic hypotension by immediate fluid resuscitation (EARLY group) did not prevent systemic inflammatory activation (IL-6, IL-10, TNF-α) but did reduce renal inflammation (iNOS expression and glomerular leukocyte infiltration). However, it could not prevent reduced renal microvascular oxygenatio

A redox state-dictated signalling pathway deciphers the malignant cell specificity of CD40-mediated apoptosis

CD40, a member of the tumour necrosis factor receptor (TNFR) superfamily, has the capacity to cause extensive apoptosis in carcinoma cells, while sparing normal epithelial cells. Yet, apoptosis is only achieved by membrane-presented CD40 ligand (mCD40L), as soluble receptor agonists are but weakly pro-apoptotic. Here, for the first time we have identified the precise signalling cascade underpinning mCD40L-mediated death as involving sequential TRAF3 stabilisation, ASK1 phosphorylation, MKK4 (but not MKK7) activation and JNK/AP-1 induction, leading to a Bak- and Bax-dependent mitochondrial apoptosis pathway. TRAF3 is central in the activation of the NADPH oxidase (Nox)-2 component p40phox and the elevation of reactive oxygen species (ROS) is essential in apoptosis. Strikingly, CD40 activation resulted in down-regulation of Thioredoxin (Trx)-1 to permit ASK1 activation and apoptosis. Although soluble receptor agonist alone could not induce death, combinatorial treatment incorporating soluble CD40 agonist and pharmacological inhibition of Trx-1 was functionally equivalent to the signal triggered by mCD40L. Finally, we demonstrate using normal, ‘para-malignant’ and tumour-derived cells that progression to malignant transformation is associated with increase in oxidative stress in epithelial cells, which coincides with increased susceptibility to CD40 killing, while in normal cells CD40 signalling is cytoprotective. Our studies have revealed the molecular nature of the tumour specificity of CD40 signalling and explained the differences in pro-apoptotic potential between soluble and membrane-bound CD40 agonists. Equally importantly, by exploiting a unique epithelial culture system that allowed us to monitor alterations in the redox-state of epithelial cells at different stages of malignant transformation, our study reveals how pro-apoptotic signals can elevate ROS past a previously hypothesised ‘lethal pro-apoptotic threshold’ to induce death; an observation that is both of fundamental importance and carries implications for cancer therap

Factorial validity and measurement invariance across gender groups of the German version of the Interpersonal Reactivity Index

The Interpersonal Reactivity Index (IRI) is the most widely used measure of empathy, but its factorial validity has been questioned. The present research investigates the factorial validity of the German adaptation of the IRI, the "Saarbrücker Persönlichkeitsfragebogen SPF-IRI". Confirmatory Factor Analyses (CFA) and Exploratory Structural Equation Modeling (ESEM) were used to test the theoretically predicted four-factor model. Across two subsamples ESEM outperformed CFA. Substantial cross-loadings were evident in ESEM. Measurement invariance (MI) across gender groups was tested using ESEM in the combined sample. Strict MI (invariant factor loadings, intercepts, residuals) could be established, and variances and covariances were also equal. Differences for latent means were evident. Women scored higher on fantasy, empathic concern, and personal distress. No significant differences were found for perspective taking. Mean differences were due to real differences on latent variables and not a result of measurement bias. Results support the factorial validity of the German SPF-IRI. The heterogeneity of empathy and the unclear differentiation between cognitive and emotional aspects might be a source for the unclear differentiation of scales

Is the Public willing to help the Nigerian Police during the Boko Haram crisis? A look at moderating factors.

This paper sought the opinion of 200 Nigerians on their willingness to cooperate with the Police during the Boko Haram crisis. Public perceptions of Police effectiveness during the crisis, residence location, gender and religious affiliation were used as moderators. Data was analysed using an explanatory factor analysis and structural equation modelling. Results indicated a strong association between perceived effectiveness and willingness to report to the Police with respondents who question the effectiveness of the Police being less likely to be willing to report criminal activity about Boko Haram. Further to this, the impact of religion on willingness to report was at least partially mediated by perceived effectiveness of the Police with the results showing that Christian respondents perceived the Police as less effective. Females and those living in the North were significantly less willing to report criminal activity to the Police The findings are then discussed in relation to the BH crises and directions for future research are given

Why do People Worry and Ruminate? Investigating Factors that Maintain Repetitive Negative Thought

The overarching aim of this research was to understand factors implicated in the maintenance of rumination and worry, conceptualised as a transdiagnostic process of repetitive negative thought (RNT), through the use of cross-sectional, prospective, and experimental research designs. Rumination and worry have been repeatedly implicated in the development and maintenance of various forms of psychopathology, in particular, depression and anxiety disorders. Given the negative outcomes for mood and psychopathology, there is a need for a better understanding of vulnerability factors that maintain this unconstructive thinking. Based on a review of the literature, an integrative theoretical model was developed and tested using structural equation modelling. Using cross-sectional data, the model was tested in a large sample of adults (n = 506). Of the broad range of proximal and distal vulnerability factors examined, only neuroticism and beliefs about the function of repetitive thought remained significantly associated with RNT once current symptoms were statistically controlled. Emotional abuse and abstract processing were indirectly associated with RNT. Following on from this, a prospective study examined which of these vulnerability factors prospectively predicted change in RNT over six to eight weeks. Only neuroticism and the specific belief that repetitive thought aids instrumental understanding predicted change in RNT, after controlling for depression and anxiety symptoms. Next, two experimental studies were conducted to explore the causal relationship between RNT and the belief that RNT aids insight and understanding, by experimentally manipulating this appraisal and measuring the impact on state RNT. Whilst methodological issues with the first experimental study precluded clear conclusions being drawn about the nature of the relationship, the second experimental study demonstrated that participants manipulated to believe that RNT is helpful for increasing insight and understanding had greater levels of state RNT after exposure to a stressor, relative to participants manipulated to believe that RNT is unhelpful. Finally, in order to see whether rumination has any consequences that may potentially reinforce its further use, an experimental study was conducted to manipulate processing mode (abstract rumination versus concrete thinking) and examine the effect on a range of outcomes relating to insightfulness and avoidance. Whilst rumination did not lead to increased insight, it did afford more justification for avoidance, relative to concrete thinking. The clinical and theoretical implications of these findings are discussed with respect to existing theories of repetitive negative thought

Integrative DNA Methylation and Gene Expression Analyses Identify DNA Packaging and Epigenetic Regulatory Genes Associated with Low Motility Sperm

In previous studies using candidate gene approaches, low sperm count (oligospermia) has been associated with altered sperm mRNA content and DNA methylation in both imprinted and non-imprinted genes. We performed a genome-wide analysis of sperm DNA methylation and mRNA content to test for associations with sperm function. (NCBI 1788). There was a trend among altered expression of these epigenetic regulatory genes and RPMM DNA methylation class.Using integrative genome-wide approaches we identified CpG methylation profiles and mRNA alterations associated with low sperm motility