Symmetry-Modelling of Rare Earth Compounds with Kramers Ions: II. Erbium(III) in Various Solids

The »truncated crystal field method« which allows determination of the microsymmetry of the crystal field around Kramers . ions is applied to erbium(III) in five different host crystals. The starting data for the calculations are taken from carefully interpreted optical spectra. In the first step, crystal field narameters for various assumed test symmetries are chosen in order to give the best fit to the splitting of the ground state multiplet. Then, a truncated crystal field calculation involving only a limited number of Stark levels is performed. The microsymmetry of the earth ion in the compounds is suggested in terms of the standard deviation between the calculated and experimental Stark splittings. All the calculations including the optimization of parameters have been performed on a personal computer. Tables of crystal field parameters and standard deviations are given for the following compounds with optical data taken from the literature: Er(C2H"S04h . 9H20, Er(IIJ) :LuP04, Er(III) : : HfSi04, Er(III) :LaC13and Er(III) :Y203

Symmetry-Modelling of Rare Earth Compounds with Kramers Ions: II. Erbium(III) in Various Solids

The »truncated crystal field method« which allows determination of the microsymmetry of the crystal field around Kramers . ions is applied to erbium(III) in five different host crystals. The starting data for the calculations are taken from carefully interpreted optical spectra. In the first step, crystal field narameters for various assumed test symmetries are chosen in order to give the best fit to the splitting of the ground state multiplet. Then, a truncated crystal field calculation involving only a limited number of Stark levels is performed. The microsymmetry of the earth ion in the compounds is suggested in terms of the standard deviation between the calculated and experimental Stark splittings. All the calculations including the optimization of parameters have been performed on a personal computer. Tables of crystal field parameters and standard deviations are given for the following compounds with optical data taken from the literature: Er(C2H"S04h . 9H20, Er(IIJ) :LuP04, Er(III) : : HfSi04, Er(III) :LaC13and Er(III) :Y203

Hypoxia Sensing and Responses in Parkinson's Disease.

Parkinson's disease (PD) is associated with various deficits in sensing and responding to reductions in oxygen availability (hypoxia). Here we summarize the evidence pointing to a central role of hypoxia in PD, discuss the relation of hypoxia and oxygen dependence with pathological hallmarks of PD, including mitochondrial dysfunction, dopaminergic vulnerability, and alpha-synuclein-related pathology, and highlight the link with cellular and systemic oxygen sensing. We describe cases suggesting that hypoxia may trigger Parkinsonian symptoms but also emphasize that the endogenous systems that protect from hypoxia can be harnessed to protect from PD. Finally, we provide examples of preclinical and clinical research substantiating this potential

The effects of weekly motivational phone calls on the amount of leisure sports activities and changes in physical fitness

Purpose: The purpose of this study is to investigate whether motivational weekly phone calls are able to promote overall and/or leisure physical activity levels and fitness in an urban population of Romania. Material: Sixty-five adult subjects (30 males and 35 females) were randomly selected and followed over the 8-month study period. Total physical activity and changes in body mass and body mass index (kg/m2) were recorded on a monthly basis. Fitness level was assessed by the participants themselves using three standardized motor tests: push-up test, 1-minute sit-up test and 3-minute step test. Results: The intervention resulted in an increase of physical activity level by approximately 70% in males and females aged 25-39 years. In those aged 40-49 years physical activity levels were enhanced by 77% in males and 18% in females. These changes were associated with improvements (25-31%; p < 0.01) in fitness levels. Changes in physical activity over the 8-month intervention period were negatively correlated with body mass index (r = - 0.721, p < 0.01). Conclusions: This study demonstrates that motivation by regular phone calls was highly effective in increasing leisure sports activities and improving fitness levels in young and middle-aged adults of both sexes

Classic Bioelectrical Impedance Vector Reference Values for Assessing Body Composition in Male and Female Athletes

Bioimpedance standards are well established for the normal healthy population and in clinical settings, but they are not available for many sports categories. The aim of this study was to develop reference values for male and female athletes using classic bioimpedance vector analysis (BIVA). In this study, 1556 athletes engaged in different sports were evaluated during their off-season period. A tetrapolar bioelectrical impedance analyzer was used to determine measurements of resistance (R) and reactance (Xc). The classic BIVA procedure, which corrects bioelectrical values for body height, was applied, and fat-free mass, fat mass, and total body water were estimated. In order to verify the need for specific references, classic bioelectrical values were compared to the reference values for the general male and female populations. Additionally, athletes were divided into three groups: endurance, velocity/power, and team sports. In comparison with the general healthy male and female populations, the mean vectors of the athletes showed a shift to the left on the R-Xc graph. Considering the same set of modalities, BIVA confidence graphs showed that male and female endurance athletes presented lower body fluids, fat mass, and fat-free mass than other sets of modalities. This study provides BIVA reference values for an athletic population that can be used as a standard for assessing body composition in male and female athletes

Influence of Inspiratory Muscle Training on Ventilatory Efficiency and Cycling Performance in Normoxia and Hypoxia

The aim of this study was to analyse the influence of inspiratory muscle training (IMT) on ventilatory efficiency, in normoxia and hypoxia, and to investigate the relationship between ventilatory efficiency and cycling performance. Sixteen sport students (23.05 +/- 4.7 years; 175.11 +/- 7.1 cm; 67.0 +/- 19.4 kg; 46.4 +/- 8.7 ml·kg-1·min-1) were randomly assigned to an inspiratory muscle training group (IMTG) and a control group (CG). The IMTG performed two training sessions/day [30 inspiratory breaths, 50% peak inspiratory pressure (Pimax), 5 days/week, 6-weeks]. Before and after the training period subjects carried out an incremental exercise test to exhaustion with gas analysis, lung function testing, and a cycling time trial test in hypoxia and normoxia. Simulated hypoxia (FiO2 = 16.45%), significantly altered the ventilatory efficiency response in all subjects (p < 0.05). Pimax increased significantly in the IMTG whereas no changes occurred in the CG (time group, p < 0.05). Within group analyses showed that the IMTG improved ventilatory efficiency (VE/VCO2 slope; EqCO2VT2) in hypoxia (p < 0.05) and cycling time trial performance [WTTmax (W); WTTmean (W); PTF(W)] (p < 0.05) in hypoxia and normoxia. Significant correlations were not found in hypoxia nor normoxia found between ventilatory efficiency parameters (VE/VCO2 slope; LEqCO2; EqCO2VT2) and time trial performance. On the contrary the oxygen uptake efficiency slope (OUES) was highly correlated with cycling time trial performance (r = 0.89; r = 0.82; p < 0.001) under both conditions. Even though no interaction effect was found, the within group analysis may suggest that IMT reduces the negative effects of hypoxia on ventilatory efficiency. In addition, the data suggest that OUES plays an important role in submaximal cycling performance.(VLID)3080991Version of recor

Regulation of plasma volume in male lowlanders during 4 days of exposure to hypobaric hypoxia equivalent to 3500 m altitude.

Acclimatization to hypoxia leads to a reduction in plasma volume (PV) that restores arterial O &lt;sub&gt;2&lt;/sub&gt; content. Findings from studies investigating the mechanisms underlying this PV contraction have been controversial, possibly as experimental conditions were inadequately controlled. We examined the mechanisms underlying the PV contraction evoked by 4 days of exposure to hypobaric hypoxia (HH) in 11 healthy lowlanders, while strictly controlling water intake, diet, temperature and physical activity. Exposure to HH-induced an ∼10% PV contraction that was accompanied by a reduction in total circulating protein mass, whereas diuretic fluid loss and total body water remained unchanged. Our data support an oncotically driven fluid redistribution from the intra- to the extravascular space, rather than fluid loss, as the mechanism underlying HH-induced PV contraction. Extended hypoxic exposure reduces plasma volume (PV). The mechanisms underlying this effect are controversial, possibly as previous studies have been confounded by inconsistent experimental conditions. Here, we investigated the effect of hypobaric hypoxia (HH) on PV in a cross-over study that strictly controlled for diet, water intake, physical activity and temperature. Eleven males completed two 4-day sojourns in a hypobaric chamber, one in normoxia (NX) and one in HH equivalent to 3500 m altitude. PV, urine output, volume-regulating hormones and plasma protein concentration were determined daily. Total body water (TBW) was determined at the end of both sojourns by deuterium dilution. Although PV was 8.1 ± 5.8% lower in HH than in NX after 24 h and remained ∼10% lower thereafter (all P &lt; 0.002), no differences were detected in TBW (P = 0.17) or in 24 h urine volumes (all P &gt; 0.23). Plasma renin activity and circulating aldosterone were suppressed in HH during the first half of the sojourn (all P &lt; 0.05) but thereafter similar to NX, whereas no differences were detected for copeptin between sojourns (all P &gt; 0.05). Markers for atrial natriuretic peptide were higher in HH than NX after 30 min (P = 0.001) but lower during the last 2 days (P &lt; 0.001). While plasma protein concentration was similar between sojourns, total circulating protein mass (TCP) was reduced in HH at the same time points as PV (all P &lt; 0.03). Despite transient hormonal changes favouring increased diuresis, HH did not enhance urine output. Instead, the maintained TBW and reduced TCP support an oncotically driven fluid redistribution into the extravascular compartment as the mechanism underlying PV contraction

Brain regions essential for improved lexical access in an aged aphasic patient: a case report

BACKGROUND: The relationship between functional recovery after brain injury and concomitant neuroplastic changes is emphasized in recent research. In the present study we aimed to delineate brain regions essential for language performance in aphasia using functional magnetic resonance imaging and acquisition in a temporal sparse sampling procedure, which allows monitoring of overt verbal responses during scanning. CASE PRESENTATION: An 80-year old patient with chronic aphasia (2 years post-onset) was investigated before and after intensive language training using an overt picture naming task. Differential brain activation in the right inferior frontal gyrus for correct word retrieval and errors was found. Improved language performance following therapy was mirrored by increased fronto-thalamic activation while stability in more general measures of attention/concentration and working memory was assured. Three healthy age-matched control subjects did not show behavioral changes or increased activation when tested repeatedly within the same 2-week time interval. CONCLUSION: The results bear significance in that the changes in brain activation reported can unequivocally be attributed to the short-term training program and a language domain-specific plasticity process. Moreover, it further challenges the claim of a limited recovery potential in chronic aphasia, even at very old age. Delineation of brain regions essential for performance on a single case basis might have major implications for treatment using transcranial magnetic stimulation