Inspiratory muscle training enhances pulmonary O2 uptake kinetics and high-intensity exercise tolerance in humans

Fatigue of the respiratory muscles during intense exercise might compromise leg blood flow, thereby constraining oxygen uptake (VO2) and limiting exercise tolerance. We tested the hypothesis that inspiratory muscle training (IMT) would reduce inspiratory muscle fatigue, speed VO2 kinetics and enhance exercise tolerance. Sixteen recreationally active subjects (mean ± SD, age 22 ± 4 yr) were randomly assigned to receive 4 wk of either pressure threshold IMT [30 breaths twice daily at ~50% of maximum inspiratory pressure (MIP)] or sham treatment (60 breaths once daily at ~15% of MIP). The subjects completed moderate-, severe- and maximal-intensity "step" exercise transitions on a cycle ergometer before (Pre) and after (Post) the 4-wk intervention period for determination of VO2 kinetics and exercise tolerance. There were no significant changes in the physiological variables of interest after Sham. After IMT, baseline MIP was significantly increased (Pre vs. Post: 155 ± 22 vs. 181 ± 21 cmH2O; P < 0.001), and the degree of inspiratory muscle fatigue was reduced after severe- and maximal-intensity exercise. During severe exercise, the VO2 slow component was reduced (Pre vs. Post: 0.60 ± 0.20 vs. 0.53 ± 0.24 l/min; P < 0.05) and exercise tolerance was enhanced (Pre vs. Post: 765 ± 249 vs. 1,061 ± 304 s; P < 0.01). Similarly, during maximal exercise, the VO2 slow component was reduced (Pre vs. Post: 0.28 ± 0.14 vs. 0.18 ± 0.07 l/min; P < 0.05) and exercise tolerance was enhanced (Pre vs. Post: 177 ± 24 vs. 208 ± 37 s; P < 0.01). Four weeks of IMT, which reduced inspiratory muscle fatigue, resulted in a reduced VO2 slow-component amplitude and an improved exercise tolerance during severe- and maximal-intensity exercise. The results indicate that the enhanced exercise tolerance observed after IMT might be related, at least in part, to improved VO2 dynamics, presumably as a consequence of increased blood flow to the exercising limbs

Flood management consideration in sustainability appraisal and strategic environmental assessment in England and Scotland

The impact of flood events in the UK has drawn attention to limitations associated with traditional flood defence regimes. In recognition of this there has been a significant level of advocacy for a systems based approach which assumes a greater role for spatial planning. This paper considers the extent to which strategic assessment contributes toward the consideration of flooding within spatial planning. The paper draws on four cases from England and Scotland. Specific attention is given to the nature of flood management approaches considered in assessment and the recommendations presented. The research indicates that assessment practice is dominated by probabilistic calculations of flood risk and typically replicates national policy and guidance on flood management. It is argued that there exists potential for assessment to foster more nuanced and tailored consideration of flood management by including multiple perspectives, such as management of the whole system, risk and vulnerability, resilience and adaptation

Altered expression of glutamate signaling, growth factor, and glia genes in the locus coeruleus of patients with major depression.

Several studies have proposed that brain glutamate signaling abnormalities and glial pathology have a role in the etiology of major depressive disorder (MDD). These conclusions were primarily drawn from post-mortem studies in which forebrain brain regions were examined. The locus coeruleus (LC) is the primary source of extensive noradrenergic innervation of the forebrain and as such exerts a powerful regulatory role over cognitive and affective functions, which are dysregulated in MDD. Furthermore, altered noradrenergic neurotransmission is associated with depressive symptoms and is thought to have a role in the pathophysiology of MDD. In the present study we used laser-capture microdissection (LCM) to selectively harvest LC tissue from post-mortem brains of MDD patients, patients with bipolar disorder (BPD) and from psychiatrically normal subjects. Using microarray technology we examined global patterns of gene expression. Differential mRNA expression of select candidate genes was then interrogated using quantitative real-time PCR (qPCR) and in situ hybridization (ISH). Our findings reveal multiple signaling pathway alterations in the LC of MDD but not BPD subjects. These include glutamate signaling genes, SLC1A2, SLC1A3 and GLUL, growth factor genes FGFR3 and TrkB, and several genes exclusively expressed in astroglia. Our data extend previous findings of altered glutamate, astroglial and growth factor functions in MDD for the first time to the brainstem. These findings indicate that such alterations: (1) are unique to MDD and distinguishable from BPD, and (2) affect multiple brain regions, suggesting a whole-brain dysregulation of such functions

BEATLES HERITAGE IN LIVERPOOL AND ITS ECONOMIC AND CULTURAL SECTOR IMPACT: A REPORT FOR LIVERPOOL CITY COUNCIL

This report and the underlying research were undertaken by three research institutes based in the University of Liverpool and Liverpool John Moores University: the Institute of Popular Music at the University of Liverpool; the European Institute of Urban Affairs at Liverpool John Moores University; and the Institute of Cultural Capital, a department jointly supported by both universities, established after the 2008 European Capital of Culture. The report is based on interviews with a snowball sample of the Beatles industry in Liverpool across Core, Semiperiphery and Periphery stakeholders. Interviews were supplemented by data from literature, prior work and regional economic data

On the mechanism by which dietary nitrate improves human skeletal muscle function.

Inorganic nitrate is present at high levels in beetroot and celery, and in green leafy vegetables such as spinach and lettuce. Though long believed inert, nitrate can be reduced to nitrite in the human mouth and, further, under hypoxia and/or low pH, to nitric oxide. Dietary nitrate has thus been associated favorably with nitric-oxide-regulated processes including blood flow and energy metabolism. Indeed, the therapeutic potential of dietary nitrate in cardiovascular disease and metabolic syndrome-both aging-related medical disorders-has attracted considerable recent research interest. We and others have shown that dietary nitrate supplementation lowers the oxygen cost of human exercise, as less respiratory activity appears to be required for a set rate of skeletal muscle work. This striking observation predicts that nitrate benefits the energy metabolism of human muscle, increasing the efficiency of either mitochondrial ATP synthesis and/or of cellular ATP-consuming processes. In this mini-review, we evaluate experimental support for the dietary nitrate effects on muscle bioenergetics and we critically discuss the likelihood of nitric oxide as the molecular mediator of such effects