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The paper deals with sensitivity and reliability applications to numerical studies of an off-shore platform model. Structural parameters and sea conditions are referred to the Baltic jack-up drilling platform. The sudy aims at the influence of particular basic variables on static and dynamic response as well as the probability of failure due to water waves and wind loads. The paper presents the sensitivity approach to a generalized eigenvalue problem and evaluation of the performace functions. The first order time-invariant problems of structural reliability analysis are under concern
Celem pracy była ocena wpływu 36 godzinnego pozbawienia snu połączonego z umiarkowanym wysiłkiem fizycznym na częstość skurczów serca. Badanie przeprowadzono u 11 zdrowych mężczyzn o zainteresowaniach proobronnych (19±1 lat, BMI 21,5±0,7 kg/m2, VO2max 55±2 ml/kg/min). Pierwsze badanie przeprowadzono dzień przed rozpoczęciem testu (obciążenie wzrastało od 50W do 200W). Końcowy pomiar dokonano 2 godziny po objedzie po 36 godzinnym śnie i intensywnych ćwiczeniach. Stwierdzono zmniejszenie częstości skurczów serca oraz obniżenie stopnia zmęczenia według skali Borga. U młodych mężczyzn uczestniczących w badaniach 36 godzinnego pozbawienia snu połączonego z długotrwałym, umiarkowanym wysiłkiem fizycznym stwierdzono obniżenie częstości skurczów serca i subiektywnego postrzegania wysiłku fizycznego. Może to być rezultatem stymulacji adrenergicznej.
The study was designed to determine metabolic and hormonal responses to acute modification of body carbohydrate stores by exercise and subsequent meals and to find out whether the responses depend on the training status of subjects. Nine sedentary students and 10 endurance athletes took part in four experimental sessions. During control session, after overnight fast oxygen uptake and CO2 production were measured and blood glucose, free fatty acids (FFA), insulin (I), leptin (L), growth hormone (GH), testosterone (T), catecholamines, ACTH and cortisol were determined. The remaining sessions were preceded by 1.5 h exercise at 70% HRmax in the evening followed by 12-16 hrs fast till morning when subjects ate either high-carbohydrate (H-CHO) or low-carbohydrate (L-CHO) meal or fasted. Respiratory gases and blood samples were collected before and 2 hours after meal. In glycogen depleted subjects respiratory quotient (RQ), I, norepinephrine (NE) and L decreased, whilst other variables were unaltered. Changes in I and NE were greater in athletes than in sedentary subjects. After H-CHO RQ, blood glucose, I and NE increased and FFA, GH and T decreased. The latter effect was greater in athletes than in untrained subjects. After L-CHO, RQ was at the fasting level and FFA increased only in sedentary group. In both groups I increased and GH and T decreased. Neither meal affected L concentration. In conclusion, hormonal and metabolic changes observed after depleting carbohydrate stores resemble those occurring during starvation. Composition of the ingested meal affects postprandial metabolism, which additionally depends on the subjects’ training status.
Aim of this study was to elucidate the influence of carbohydrate store modification on exercise capacity and catecholamine thresholds. Nine sedentary students and 10 endurance athletes volunteered for the study consisting of four sessions in one-week intervals. During control session (C) subjects performed graded exercise till exhaustion with workload increasing by 50 Watts every 3 min after an overnight fast. Blood lactate and catecholamines were determined at rest, after each workload and at exhaustion. In the evening preceding each of the remaining three sessions subjects performed glycogen reducing exercise lasting 1.5 hrs at 70% HRmax. Till next morning they did not eat any meal but drank water. Two hours before exercise subjects were given either a high-carbohydrate (H-CHO) or a low-carbohydrate (L-CHO) meal of approx. 1000 kcal or remained fasted (F). Depletion of carbohydrate stores enhanced contribution of fat-derived energy substrates at submaximal workloads, but did not influence either maximal oxygen consumption, workload and lactate concentration or lactate threshold. Low carbohydrate availability resulted in elevated concentration of catecholamines only in untrained subjects. Ingestion of a meal either high or low in carbohydrates diminished those changes. Catecholamine thresholds were similar in all sessions and higher in athletes’ group.
Przeprowadzono badania poziomu hałasu wewnętrznego i zewnętrznego w 30 szkołach szczecińskich dobranych losowo. W 2/3 stwierdzono przekroczenie dopuszczalnych norm. W tych szkołach stwierdzono wyższe liczby dzieci z ubytkami słuchu oraz zaburzeniami psychicznymi.
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Plasma adrenomedullin response to maximal exercise in healthy subjects

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The aim of the study was to find out whether maximal exercise performed by healthy young men influences plasma adrenomedullin concentration (ADM) and is the peptide level related to the cardiovascular, metabolic and hormonal changes induced by exercise. Ten subjects (age 24 ± 1.0 yr) participated in the study. They performed graded bicycle ergometer exercise until exhaustion. Heart rate (HR) and blood pressure (BP) were measured throughout the test. Before and at the end of exercise venous blood samples were taken for [ADM], noradrenaline [NA], adrenaline [A], growth hormone [hGH], cortisol and lactate [LA] determination. Plasma [ADM] decreased during exercise from 1.71 ± 0.09 to 1.53 ± 0.10 pmol × l-1 (p< 0.01). This was accompanied by increases in plasma catecholamines and [hGH], while plasma cortisol level did not change. Positive correlation was found between the exercise-induced decreases in plasma ADM and diastolic BP. Blood [LA], systolic and mean BP at the end of exercise correlated negatively with plasma [ADM]. No significant interrelationships were found between plasma ADM, catecholamines or the other hormones measured. The present data suggests, that maximal exercise inhibits ADM secretion in young healthy men. Metabolic acidosis and a decrease in peripheral resistance might be involved in this effect.
The aim of the study was to find out whether prolonged exercise influences plasma adrenomedullin (ADM) concentration and whether it is related to the hormonal, metabolic and cardiovascular changes. Eighteen healthy subjects (age 25±1 yrs) were submitted to cycle exercise for 90 min at 70% of maximal oxygen uptake. Heart rate (HR) and blood pressure (BP) were measured continously. Before, at 30th min, and at the end of exercise venous blood samples were taken for [ADM], noradrenaline [NA], adrenaline [A], atrial natriuretic peptide [ANP], plasma renin activity PRA, interleukin-6 [IL-6] and lactate [LA] determination. Significant increases in plasma ADM and IL-6 were found at 90th min whereas other hormones were elevated already at 30th min of exercise. Positive correlations were ascertained between [ADM] and [NA] (r=0.47), [ANP] (r=0.35) or [IL-6] (r=0.35) and between exercise-induced increases in [ADM] and [NA] (r=0.38). PRA correlated positively with [NA] and [ANP]. Negative correlation was found between plasma [ADM] and diastolic BP. The present data suggest that increase in sympathetic nervous activity and cytokine induction during prolonged exercise may be involved in plasma ADM release and that increase in ADM and ANP secretion may be a compensatory mechanism against further elevation of blood pressure.
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