Muscle damage and inflammation following a three-day trail run.

Thesis (M.Med.Sc.)-University of KwaZulu-Natal, 2012.Introduction The physiological effects of single and multiday road running races have been studied extensively and include the occurrence of rhabdomyolysis, reflected by significantly increased urinary myoglobin (uMb), as well as increased concentrations of serum creatine phosphokinase (CPK), high sensitivity C-reactive protein (hsCRP), cortisol and cardiac troponin-T (cTnT), dehydration and compromised renal function. Furthermore, in hyperthermic athletes, a positive relationship has been noted between hyperthermia, muscle damage, dehydration and pacing. The physiological effects of a multiday trail run of similar duration to single day road races, however, are unknown. The side-effects of the use of statin medication for hypercholesterolaemia include muscle fatigue, cramping and increased muscle damage. These have been found to be aggravated in endurance athletes and it has been reported that females, especially when being medicated from a young age, are more susceptible to these side-effects. Objectives 1. To investigate the effect of a three-day trail run on systemic and urinary markers of muscle damage and inflammation in recreational runners and to establish the association of dehydration and hyperthermia with these markers. 2. To observe the effect of the three day trail run on systemic and urinary markers of muscle damage and inflammation on an additional hypercholesterolaemic female athlete using statin medication in combination with a lipid uptake inhibitor. Method Firstly, an observational cohort study was conducted on 19 recreational male (n=6) and female (n=13) athletes during a 95km trail run over three days. Pre-and post-stage and 24 and 72 h post-race concentrations of serum CPK, hsCRP, cortisol, cTnT, and osmolality (sOsm) as well as uMb, changes in body mass, delayed onset muscle soreness (DOMS) and thigh circumference (TC) were measured. Continuous recordings of heart rate (HR) and intestinal temperature (Tintest ) were made throughout each stage. In addition, a case report is included on one trained female endurance athlete currently being treated for familial hypercholesterolaemia with 20 mg Aspavor and 10 mg Ezetrol daily and not included in the above cohort, to investigate the degree of muscle damage and inflammation she experienced as a result of participation in the three-day event. Results: Heart rate ranged between 77 and 83% age-predicted-maximum (APmax) and Tintest between 36.1 and 40.2 ºC during the three stages. Significant rises in mean serum CPK, hsCRP, sOsm and blood neutrophil count reached peak concentrations of 1 488U/L, 8.91mg/l, 298mosm/L and 10.21 10^9/L (p≤0.001), respectively. No evidence of elevations in uMb and cTnT were detected. The stage-induced increments in DOMS correlated positively with CPK, r=0.71; 95% CI [0.62, 0.78]. TC decreased significantly post S1post and S2post (p≤0.05) and a maximum mean body mass loss of 3.09% (±1.04%) occurred during S2. There was no significant difference between nonsteroidal anti-inflammatory drug (NSAID) users and non-users in terms of serum CPK, hsCRP, cortisol, post race DOMS scores, running times, TC or sOsm (p>0.05). The post-pre change in sOsm during each stage correlated inversely with the changes in % body mass, r = -0.36, 95% CI [-0.57,-0.094] and the pooled data examining the relationship between the change of sOsm and change in serum CPK for the three stages (n=57), revealed an insignificant positive correlation (r= 0.034, 95% CI [-0.228, 0.291]. The maximum Tintest ranged between 38.3 º C and 40.2 º C and only exceeded 40º C in two of the 12 athletes monitored. The relationship between the change in Tintest and serum CPK was insignificant (p>0.05) for the 11 individuals from whom complete sets of data were available (r= 0.24, 95% CI [-0.42, 0.734]. In the hypercholesterolaemic athlete, the maximum serum CPK (665U/L), hsCRP (1.9mg/Ll) and cortisol (845nmol/L) concentrations corresponded with undetected uMb despite a maximum body mass loss of 4.5% Conclusion: Three consecutive days of 95km trail running resulted in low markers of muscle damage and inflammation, when compared to results obtained in previous single day road races of similar duration despite the maintenance of a heart rate above 77% APmax, Tintest rising above 39o C and mean body mass decrement of >2.0%. The unchanged concentrations of serum cTnT and uMb confirmed the low values of the markers of muscle damage and inflammation. An insignificant positive correlation between muscle damage and dehydration was noted. Furthermore the daily use of 0.4 mg/kg Atorvastatin in combination with 10mg Ezetrol did not result in the subject experiencing subjective myalgia, cramps, fatigue or increased markers of muscle damage following her participation in the trail run

Intensified future heat extremes linked with increasing ecosystem water limitation

Heat extremes have severe implications for human health, ecosystems, and the initiation of wildfires. While they are mostly introduced by atmospheric circulation patterns, the intensity of heat extremes is modulated by terrestrial evaporation associated with soil moisture availability. Thereby, ecosystems provide evaporative cooling through plant transpiration and soil evaporation, which can be reduced under water stress. While it has been shown that regional ecosystem water limitation is projected to increase in the future, the respective repercussions on heat extremes remain unclear. In this study, we use projections from 12 Earth system models to show that projected changes in heat extremes are amplified by increasing ecosystem water limitation in regions across the globe. We represent the ecosystem water limitation with the ecosystem limitation index (ELI) and quantify temperature extremes through the differences between the warm-season mean and maximum temperatures. We identify hotspot regions in tropical South America and across Canada and northern Eurasia where relatively strong trends towards increased ecosystem water limitation jointly occur with amplifying heat extremes. This correlation is governed by the magnitude of the ELI trends and the present-day ELI which denotes the land–atmosphere coupling strength determining the temperature sensitivity to evaporative cooling. Many regions where ecosystem functioning is predominantly energy-limited or transitional in the present climate exhibit strong trends towards increasing the water limitation and simultaneously experience the largest increases in heat extremes. Sensitivity of temperature excess trends to ELI trends is highest in water-limited regions, such that in these regions relatively small ELI trends can amount to drastic temperature excess trends. Therefore, considering the ecosystem's water limitation is key for assessing the intensity of future heat extremes and their corresponding impacts.</p

Ion exchanges in apatites. Effects on composition and properties

The modification of the composition of apatites materials can be made by several processes corresponding to ion exchange reactions which can conveniently be adapted to current coatings and ceramics and are an alternative to the set up of new synthesis methods. In addition to high temperature thermal treatments, which allow to virtually replace partly or totally monovalent OH- anion of stoichiometric hydroxyapatite by any halogen ion or carbonate, aqueous processes corresponding to dissolution-reprecipitation reactions have also been proposed and used. The most interesting possibilities are however provided by aqueous ion exchange reactions involving nanocrystalline apatites. These apatites are characterised by the existence on the crystal surface of a hydrated layer of loosely bound mineral ions which can be easily exchanged in solution. This layer offers a possibility to trap mineral ions and possibly active molecules which can modify the apatite properties. Such processes are involved in mineralised tissues and could be used in biomaterials for the release of active mineral species

Recommendations for increasing replicability in psychology

Replicability of findings is at the heart of any empirical science. The aim of this article is to move the current replicability debate in psychology towards concrete recommendations for improvement. We focus on research practices but also offer guidelines for reviewers, editors, journal management, teachers, granting institutions, and university promotion committees, highlighting some of the emerging and existing practical solutions that can facilitate implementation of these recommendations. The challenges for improving replicability in psychological science are systemic. Improvement can occur only if changes are made at many levels of practice, evaluation, and reward. Copyright © 2013 John Wiley &amp; Sons, Ltd. </jats:p