Concentrations of numerous hormones decrease with age. Some authors imply that a syndrome of partial endocrine deficiency may occur in the aging men. Among many lifestyle factors that influence hormonal status is physical activity. Especially interesting are relations between physical activity and the androgenic/estrogenic status of men. The aim of this study was to evaluate age-related changes of serum androgens, estradiol and SHBG in men presenting different levels of physical activity. Hormonal parameters were measured in a cohort of 387 healthy Caucasian men (aged from 24 to 72 years) from one administrative region of Poland. Their level of physical activity was determined by means of the International Physical Activity Questionnaire (IPAQ). We have found that contrary to SHBG concentration, total testosterone, free testosterone, bioavailable testosterone, calculated free testosterone and estradiol were negatively associated with age in the investigated subjects. Apart from estradiol, physical activity did not influence concentrations of the studied parameters. In younger (24-48 years), physically active males estradiol was significantly higher than in subjects characterized by a low level of physical activity. The situation was opposite in older males (48-72 years). In this age group low level of physical activity was associated with lower concentration of estradiol. Undertaking physical effort increased the decline of estradiol level with age., M. Slowinska-Lisowska, P. Jozkow, M. Medras., and Obsahuje bibliografii a bibliografické odkazy
The associativity of n-dimensional copulas in the sense of Post is studied. These copulas are shown to be just n-ary extensions of associative 2-dimensional copulas with special constraints, thus they solve an open problem of R. Mesiar posed during the International Conference FSTA 2010 in Liptovský Ján, Slovakia.
We used the aphid parasitoid Aphidius ervi reared in its host Acyrthosiphon pisum to examine if male sexual attractive responses can be conditioned to an odour (vanilla) that is not present in the natural environment. We used prior mating experience (exposure to females) as a non-conditioning stimulus and vanilla odour as a conditioning stimulus. The behavioural responses were tested in a glass Y-olfactometer just after eclosion (i.e., initial response) and after a training experience (i.e., trained response). During the 10-min training period individual males were allowed to copulate with a virgin female with or without vanilla odour present, or were exposed only to vanilla odour. Wing fanning was a recurrent behaviour which denoted increased sexual attraction to a volatile stimulus. Total time and time doing wing fanning in each olfactometer arm were determined. Vanilla odour, which initially did not elicit sexual-related behaviours, triggered strong sexual attractive responses when males were trained to females plus vanilla odour. Neither copulation only nor vanilla odour only treatments elicited such behaviours in trained males. The results are discussed in terms of parasitoid learning ability and its ecological consequences.
The upper dial-plate of the astronomical clock is an astrolabe controlled by a clockwork mechanism. It represents a stereographic projection of the celestial sphere from its North Pole onto the tangent plane passing through the South Pole. We give a survey of several astronomical mistakes that appeared on this dial throughout centuries., V letošním roce je orloji na Staroměstském náměstí v Praze právě 600 let. Před rokem 1979 byla na jeho astronomickém ciferníku nesprávně zakreslena kruhová oblast astronomické noci. V tomto článku se zmíníme o dalších významných kružnicích, jejichž rozměry a umístění na orloji by se daly ještě zlepšit., Michal Křížek, Pavel Křížek, Jakub Šolc., and Obsahuje bibliografii
The 2011 Nobel prize in physics was awarded to Saul Perlmutter, Brian Schmidt and Adam Reiss "for the discovery of the accelerating expansion of the Universe through observations of distant supernovae". It was expected that sooner or later the astronomy trio wil get this distinction because the authors and their teams have indeed achieved an epoch-making discovery. Writing the key papers in 1998 and 1999 required a good deal of courage from the authors, who literally risked their scientific reputation. The presented article highlights the deep roots of the discovery from the history of astronomy hence culminating to the XXth century., V říjnu 2011 oznámila komise pro udělování Nobelových cen, že Nobelovu cenu za fyziku získávají v r. 2011 tři astronomové (Saul Perlmutter, Brian P. Schmidt a Adam G. Reiss) za objev zrychlujícího se rozpínání vesmíru pomocí pozorování vzdálených supernov. V tomto případě se udělení ceny za zmíněné výzkumy vcelku očekávalo; šlo vlastně jen o to, kdy se tak stane. Jde totiž o vskutku epochální astronomický objev, i když napsat příslušné publikace v letech 1998 a 1999 vyžadovalo od autorů značnou odvahu - docela přitom riskovali svou vědeckou pověst. V článku poukazují na hluboké kořeny objevu v astronomické historii zejména od počátku 20. století., Jiří Grygar., and Obsahuje seznam literatury
Level of asymmetric dimethylarginine (ADMA) is elevated and endothelial progenitor cells (EPC) and stem cells (SC) are decreased in patients undergoing renal transplantation (Tx) and may contribute to cardiovascular complications. We tested the hypothesis that ADMA, EPC and SC can be influenced with regular physical exercise early after Tx. Blood samples of ADMA, EPC, SC, adipocytokines and metabolic parameters were randomly obtained from 50 transplant patients before and 6 months after exercise program (Group I). Fifty age, sex HLA typing, duration of dialysis and immunosupression regimen-matched non exercising transplant were examined as controls (Group II). After 6 months, in Group I ADMA decreased (3.50±0.45 vs 2.11±0.35 μmol/l, P<0.01) and was lower comparing to Grou II (P<0.01), SC and EPC also decreased (2816±600 vs 2071±480 cells/ml resp. 194±87 to 125±67 cells/ml, P<0.02). Next changes in Group I: adiponectin (P<0.01), leptin (P<0.01), resistin (P<0.02). Visfatin, blood lipids, HbA1c, insulin and blood pressure were also influenced by training program (P<0.05)., V. Teplan, I. Králová Lesná, J. Piťha, A. Mahrová, J. Racek, I. Valkovský, A. Sekerková, M. Štollová., and Obsahuje bibliografii
A recently discussed cardiovascular risk factor, asymmetric dimethylarginine (ADMA), is known to act as an endogenous inhibitor of endothelial nitric oxide synthase. The aim of this study was to establish 1) the relationship between ADMA and ultrasonographically or biochemically determined endothelial dysfunction in children, and 2) the effect of folate supplementation on these parameters. The study cohort included 32 children with familial hypercholesterolemia (FH), 30 with diabetes mellitus type 1 (DM1) and 30 age-matched healthy children as the control group. Furthermore, twenty-eight randomly selected FH and DM1 children were re-examined after 3-months supplementation with folic acid. Baseline levels of ADMA and oxidized low density lipoproteins (oxLDL) were significantly higher in FH group than in DM1 and healthy children. Children in DM1 group had significantly lower concentration of homocysteine, but ADMA levels were normal. Folic acid supplementation significantly lowered homocysteine and hsCRP levels in both FH and DM1 group; however, ADMA and oxLDL concentrations remained unaltered. In conclusion, ADMA and oxLDL appear to be associated with endothelial dysfunction in children with FH. Administration of folic acid did not influence these markers in both FH and DM1 children., P. Jehlička ... [et al.]., and Obsahuje seznam literatury
We complement the recently introduced classes of lower and upper semilinear copulas by two new classes, called vertical and horizontal semilinear copulas, and characterize the corresponding class of diagonals. The new copulas are in essence asymmetric, with maximum asymmetry given by 1/16. The only symmetric members turn out to be also lower and upper semilinear copulas, namely convex sums of Π and M.
.
The gob side entry retaining with high water material is often used in coal mines. To study the stress evolution characteristics of surrounding rock and asymmetric support control technology of gob side entry retaining with high water material, the evolution law of stress and deformation of surrounding rock in gob side entry retaining during working face mining is studied by theoretical analysis, numerical simulation and field measurement. According to the stress variation of overlying strata during the mining process of the working face, the mechanical models before and after the basic roof fracture were established respectively. The stress and deformation of the filling body and the roof on the side of the filling body are larger, and the stress and deformation of the solid coal and the roof on the side of solid coal are smaller. The maximum stress is at 3 m away from the roadway. The first weighting step distance is 40 m and the periodic weighting step distance is 30 m. Based on the stress and deformation characteristics of the roadway surrounding, the roadway surrounding support is divided into filling bodyside, solid coal side, and middle part of roadway roof. The asymmetric support technology of "filling body+ double row hydraulic prop+ I-beam+ high-strength pretension anchor cable+ high-strength bolt" is proposed. The field engineering practice shows that the surrounding rock control effect of asymmetric support technology with high water material is good., Qiyuan Shan, Yongli Liu, Tao Li and Zhupeng Jin., and Obsahuje bibliografii