Segmented ball valve is easy to open and close

Segmented ball valve and flowmeter in the same spherical housing provide a valve that will handle large fluid volume without bulkiness and weight of blade valves or conventional ball valves. The valve is easily opened or closed and the flowmeter remains stationary, so errors are eliminated

Proton-neutron mass difference

Suppose all deviations from isotopic spin symmetry are due solely to electromagnetic effects. Then such things as the mass difference of charged and neutral π mesons, and the neutron-proton mass difference would have to be just electrodynamic

Aging is associated with positive responding to neutral information but reduced recovery from negative information

Studies on aging and emotion suggest an increase in reported positive affect, a processing bias of positive over negative information, as well as increasingly adaptive regulation in response to negative events with advancing age. These findings imply that older individuals evaluate information differently, resulting in lowered reactivity to, and/or faster recovery from, negative information, while maintaining more positive responding to positive information. We examined this hypothesis in an ongoing study on Midlife in the US (MIDUS II) where emotional reactivity and recovery were assessed in a large number of respondents (N = 159) from a wide age range (36–84 years). We recorded eye-blink startle magnitudes and corrugator activity during and after the presentation of positive, neutral and negative pictures. The most robust age effect was found in response to neutral stimuli, where increasing age is associated with a decreased corrugator and eyeblink startle response to neutral stimuli. These data suggest that an age-related positivity effect does not essentially alter the response to emotion-laden information, but is reflected in a more positive interpretation of affectively ambiguous information. Furthermore, older women showed reduced corrugator recovery from negative pictures relative to the younger women and men, suggesting that an age-related prioritization of well-being is not necessarily reflected in adaptive regulation of negative affect

A Theory of Challenge and Threat States in Athletes: a revised conceptualization

The Theory of Challenge and Threat States in Athletes (TCTSA) provides a psychophysiological framework for how athletes anticipate motivated performance situations. The purpose of this review is to discuss how research has addressed the 15 predictions made by the TCTSA, to evaluate the mechanisms underpinning the TCTSA in light of the research that has emerged in the last ten years, and to inform a revised TCTSA (TCTSA-R). There was support for many of the 15 predictions in the TCTSA, with two main areas for reflection identified; to understand the physiology of challenge and to re-evaluate the concept of resource appraisals. This re-evaluation informs the TCTSA-R which elucidates the physiological changes, predispositions, and cognitive appraisals that mark challenge and threat states. First, the relative strength of the sympathetic nervous system response is outlined as a determinant of challenge and threat patterns of reactivity and we suggest that oxytocin and neuropeptide Y are also key indicators of an adaptive approach to motivated performance situations and can facilitate a challenge state. Second, although predispositions were acknowledged within the TCTSA, how these may influence challenge and threat states was not specified. In the TCTSA-R it is proposed that one’s propensity to appraise stressors as a challenge that most strongly dictates acute cognitive appraisals. Third, in the TCTSA-R a more parsimonious integration of Lazarusian ideas of cognitive appraisal and challenge and threat is proposed. Given that an athlete can make both challenge and threat primary appraisals and can have both high or low resources compared to perceived demands, a 2x2 bifurcation theory of challenge and threat is proposed. This reflects polychotomy of four parts; high challenge, low challenge, low threat, and high threat. For example, in low threat, an athlete can evince a threat state but still perform well so long as they perceive high resources. Consequently, we propose suggestions for research concerning measurement tools and a reconsideration of resources to include social support. Finally, applied recommendations are made based on adjusting demands and enhancing resources.N/

Long-Term Effects of Experimental Carotid Stenosis on Hippocampal Infarct Pathology, Neurons and Glia and Amelioration by Environmental Enrichment

Hippocampal atrophy and pathology are common in ageing-related disorders and associated with cognitive impairment and dementia. We explored whether environmental enrichment (EE) ameliorated the pathological sequelae in the hippocampus subsequent to chronic cerebral hypoperfusion induced by bilateral common carotid artery stenosis (BCAS). Seventy-four male C57BL/6 J mice underwent BCAS or sham surgery. One-week after surgery, mice were exposed to three different degrees of EE; either standard housing conditions (std), limited 3-hour exposure to EE per day (3h) or full-time exposure to EE (full) for 3 months. Four months after surgery, the hippocampus was examined for the extent of vascular brain injury and neuronal and glial changes. Results showed that long-term BCAS induced strokes, most often in CA1 subfield, reduced 40-50% CA1 neurons (P<0.01) and increased microglia/macrophage in CA1-CA3 subfields (P<0.02). Remarkably, both 3h and full-time EE regimes attenuated hippocampal neuronal death and repressed recurrent strokes with complete prevention of larger infarcts in mice on full-time EE (P<0.01). Full-time EE also reduced astrocytic clasmatodendrosis and microglial/macrophage activation in all CA subfields. Our results suggest that exposure to EE differentially reduces long-term hypoperfusive hippocampal damage. The implementation of even limited EE may be beneficial for patients diagnosed with vascular cognitive impairment

Corticosterone and dopamine D2/D3 receptors mediate the motivation for voluntary wheel running in C57BL/6J mice

Physical exercise can improve cognition but whether this is related to motivation levels is unknown. Voluntary wheel running is a rewarding activity proposed as a model of motivation to exercise. To question the potential effects of exercise motivation on subsequent behaviour, we used a pharmacological approach targeting some reward mechanisms. The stress hormone corticosterone has rewarding effects mediated by activation of low affinity glucocorticoid receptors (GR). To investigate whether corticosterone synthesis motivates exercise via activation of GRs and subsequently, impacts on behaviour, we treated C57BL/6J mice acutely with the inhibitor of corticosterone synthesis metyrapone (35 mg/kg) or repeatedly with the GR antagonist mifepristone (30 mg/kg) prior to 1-h running wheel sessions. To investigate whether reducing motivation to exercise impacts on behaviour, we antagonised running-induced dopamine D2/D3 receptors activation with sulpiride (25 or 50 mg/kg) and assessed locomotor, anxietyrelated and memory performance after 20 running sessions over 4 weeks. We found that corticosterone synthesis contributes to running levels, but the maintenance of running behaviour was not mediated by activation of GRs. Intermittent exercise was not associated with changes in behavioural or cognitive performance. The persistent reduction in exercise levels triggered by sulpiride also had limited impact on behavioural performance, although the level of performance for some behaviours was related to the level of exercise. Altogether, these findings indicate that corticosterone and dopamine D2/D3 receptor activation contribute to the motivation for wheel running, but suggest that motivation for exercise is not a sufficient factor to alter behaviour in healthy mice

Manipulating cardiovascular indices of challenge and threat using resource appraisals

Challenge and threat reflect two distinct psychophysiological approaches to motivated performance situations. Challenge is related to superior performance in a range of tasks compared to threat, thus methods to promote challenge are valuable. In this paper we manipulate challenge and threat cardiovascular reactivity using only resource appraisals, without altering perceived task demands between challenge and threat conditions. Study 1 used a competitive throwing task and Study 2 used a physically demanding climbing task. In both studies challenge task instructions led to challenge cardiovascular reactivity and threat task instructions led to threat cardiovascular reactivity. In Study 1, participants who received challenge instructions performed better than participants who received threat instructions. In Study 2, attendance at the climbing task did not differ across groups. The findings have implications for stress management in terms of focusing on manipulating appraisals of upcoming tasks by promoting self-efficacy and perceived control and focusing on approach goals. Future research could more reliably assess the influence of similar task instructions on performance. © 2014 Elsevier B.V