Exercise-induced whole-body dehydration does not affect airway responsiveness in athletes but may impair small airway function

Exercise-induced bronchoconstriction (EIB) is the transient narrowing of the airways that occurs during or shortly after strenuous exercise. Loss of water from the airway surface, due to the conditioning of large volumes of air during exercise, is the main physiological stimulus for EIB. We proposed that exercise-induced whole-body dehydration would interfere with hydration of the airways and, consequently, increase the risk and/or severity of EIB. We also investigated the effects of whole-body dehydration on resting lung function

Implications of moderate altitude training for sea level endurance in elite distance runners

Elite distance runners participated in one of two studies designed to investigate the e ects of mod- erate altitude training (inspiratory partial pressure of oxygen »115±125 mmHg) on submaximal, maximal and supramaximal exercise performance following return to sea-level. Study 1 (New Mexico, USA) involved 14 subjects who were assigned to a 4-week altitude training camp (1500±2000 m) whilst 9 performance-matched subjects continued with an identical training programme at sea-level (CON). Ten EXP subjects who trained at 1640 m and 19 CON subjects also participated in study 2 (Krugersdorp, South Africa). Selected metabolic and cardiorespiratory parameters were determined with the subjects at rest and during exercise 21 days prior to (PRE) and 10 and 20 days following their return to sea- level (POST). Whole blood lactate decreased by 23% (P < 0.05 vs PRE) during submaximal exercise in the EXP group only after 20 days at sea-level (study 1). However, the lactate threshold and other measures of running economy remained unchanged. Similarly, su- pramaximal performance during a standardised track session did not change. Study 2 demonstrated that hypoxia per se did not alter performance. In contrast, in the EXP group supramaximal running velocity de- creased by 2% (P < 0.05) after 20 days at sea-level. Both studies were characterised by a 50% increase in the frequency of upper respiratory and gastrointestinal tract infections during the altitude sojourns, and two male subjects were diagnosed with infectious mononucleosis following their return to sea-level (study 1). Group mean plasma glutamine concentrations at rest decreased by 19% or 143 (74) lM (P < 0.001) after 3 weeks at alti- tude, which may have been implicated in the increased incidence of infectious illness

Geochemistry of cold seeps - Fluid sources and systematics

Emanation of fluids at cold seeps, mud volcanoes, and other types of submarine seepage structures is a typical phenomenon occurring at continental margins worldwide. They represent pathways along which volatiles and solutes are recycled from deeply buried sediments into the global ocean, and hence they may be considered as a potentially important link in global geochemical cycles. In this contribution we present geochemical data from various geological and tectonic settings such as the Gulf of Cadiz, the convergent margin off Central America, and/or the Black Sea and provide approaches how to systemize available data sets. Clay-mineral dewatering plays a central role in terms of fluid-mobilization from greater depth, however, resulting cold seep fluids are typically very different from each other and cover a large range of geochemical signatures. This is is due to variations in control parameters such as the type and thickness of the sediment cover, thermal conditions, extension of fluid pathways, and the potential for secondary overprinting. For example, freshened fluids emanating at cold seeps off Costa Rica indicate dewatering and related geochemical reactions in subducting sediments, while fluids sampled at mud volcanoes in the Gulf of Cadiz provide evidence for a high-temperature fluid source originating in the underlying oceanic basement. The latter finding provides evidence for a hydrological connection between buried oceanic crust and the water column even at old crustal ages. Varius geochemical tracers were proposed in the past to decipher relevant processes in the subsurface. In a recent systematic study, Scholz et al. [1] demonstrated the general use of Li, reflecting the temperature-dependent isotope fractionation during early diagenetic Li uptake and burial diagenetic Li release from sediments. However, additional approaches are required in order to provide robust geochmical interpretations of cold seep fluids

Effect of terbutaline on hyperpnoea-induced bronchoconstriction and urinary club cell protein 16 in athletes

This article is made available through the Brunel Open Access Publishing Fund and is distributed by the Creative Commons CC-BY 3.0 license, under which all are free to reuse or distribute the article under the condition that this original publication must be cited.Repeated injury of the airway epithelium caused by hyperpnoea of poorly conditioned air has been proposed as a key factor in the pathogenesis of exercise-induced bronchoconstriction (EIB) in athletes. In animals, the short-acting β2-agonist terbutaline has been shown to reduce dry airflow-induced bronchoconstriction and the associated shedding of airway epithelial cells. Our aim was to test the efficacy of inhaled terbutaline in attenuating hyperpnoea-induced bronchoconstriction and airway epithelial injury in athletes. Twenty-seven athletes with EIB participated in a randomized, double-blind, placebo-controlled, crossover study. Athletes completed an 8-min eucapnic voluntary hyperpnoea (EVH) test with dry air on two separate days 15 min after inhaling 0.5 mg terbutaline or a matching placebo. Forced expiratory volume in 1 s (FEV1) and urinary concentration of the club cell (Clara cell) protein 16 (CC16, a marker of airway epithelial perturbation) were measured before and up to 60 min after EVH. The maximum fall in FEV1 of 17 ± 8% (SD) on placebo was reduced to 8 ± 5% following terbutaline (P < 0.001). Terbutaline gave bronchoprotection (i.e., post-EVH FEV1 fall <10%) to 22 (81%) athletes. EVH caused an increase in urinary excretion of CC16 in both conditions (P < 0.001), and terbutaline significantly reduced this rise (pre- to postchallenge CC16 increase 416 ± 495 pg/μmol creatinine after placebo vs. 315 ± 523 pg/μmol creatinine after terbutaline, P = 0.016). These results suggest that the inhalation of a single therapeutic dose of terbutaline offers significant protection against hyperpnoea-induced bronchoconstriction and attenuates acute airway epithelial perturbation in athletes.World Anti Doping Agenc

Emergence of heterogeneity and political organization in information exchange networks

We present a simple model of the emergence of the division of labor and the development of a system of resource subsidy from an agent-based model of directed resource production with variable degrees of trust between the agents. The model has three distinct phases, corresponding to different forms of societal organization: disconnected (independent agents), homogeneous cooperative (collective state), and inhomogeneous cooperative (collective state with a leader). Our results indicate that such levels of organization arise generically as a collective effect from interacting agent dynamics, and may have applications in a variety of systems including social insects and microbial communities.Comment: 10 pages, 6 figure

Alignment of patient and primary care practice member perspectives of chronic illness care: a cross-sectional analysis

Polly H. Noel and Luci K. Leykum are with the South Texas Veterans Health Care System, 7400 Merton Minter Blvd, San Antonio, TX 78229, USA -- Polly H. Noel, Ray F. Palmer, Raquel L. Romero, Luci K. Leykum, Holly J. Lanham, and Krista W. Bowers are with the Department of Medicine, University of Texas Health Science Center at San Antonio, 7703 Floyd Curl Dr, San Antonio, TX 78229, USA -- Michael L. Parchman is with the MacColl Center for Healthcare Innovation, Group Health Research Institute, Group Health Cooperative, 1730 Minor Ave 1600, Seattle, WA 98101, USA -- Holly J. Leykum is with the The McCombs School of Business, The University of Texas at Austin, 2110 Speedway, Stop B6000, Austin, TX 78712, USA -- John E. Zeber is with the Central Texas Veterans Health Care System, 1901 S. 1st St, Temple, TX 76504, USA and Scott and White Healthcare Center for Applied Health Research, 2401 S. 31st St, Temple, TX 76508, USABackground: Little is known as to whether primary care teams’ perceptions of how well they have implemented the Chronic Care Model (CCM) corresponds with their patients’ own experience of chronic illness care. We examined the extent to which practice members’ perceptions of how well they organized to deliver care consistent with the CCM were associated with their patients’ perceptions of the chronic illness care they have received. Methods: Analysis of baseline measures from a cluster randomized controlled trial testing a practice facilitation intervention to implement the CCM in small, community-based primary care practices. All practice “members” (i.e., physician providers, non-physician providers, and staff) completed the Assessment of Chronic Illness Care (ACIC) survey and adult patients with 1 or more chronic illnesses completed the Patient Assessment of Chronic Illness Care (PACIC) questionnaire. Results: Two sets of hierarchical linear regression models accounting for nesting of practice members (N = 283) and patients (N = 1,769) within 39 practices assessed the association between practice member perspectives of CCM implementation (ACIC scores) and patients’ perspectives of CCM (PACIC). ACIC summary score was not significantly associated with PACIC summary score or most of PACIC subscale scores, but four of the ACIC subscales were consistently associated with PACIC summary score and the majority of PACIC subscale scores after controlling for patient characteristics. The magnitude of the coefficients, however, indicates that the level of association is weak. Conclusions: The ACIC and PACIC scales appear to provide complementary and relatively unique assessments of how well clinical services are aligned with the CCM. Our findings underscore the importance of assessing both patient and practice member perspectives when evaluating quality of chronic illness care.Information, Risk, and Operations Management (IROM)[email protected]

Cosmology constraints from shear peak statistics in Dark Energy Survey Science Verification data

Shear peak statistics has gained a lot of attention recently as a practical alternative to the two-point statistics for constraining cosmological parameters. We perform a shear peak statistics analysis of the Dark Energy Survey (DES) Science Verification (SV) data, using weak gravitational lensing measurements from a 139 deg² field. We measure the abundance of peaks identified in aperture mass maps, as a function of their signal-to-noise ratio, in the signal-to-noise range 04 would require significant corrections, which is why we do not include them in our analysis. We compare our results to the cosmological constraints from the two-point analysis on the SV field and find them to be in good agreement in both the central value and its uncertainty. We discuss prospects for future peak statistics analysis with upcoming DES data