Showing papers by "University of Jyväskylä published in 1988"
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19 May 1988878 citations
TL;DR: The present results suggest that prolonged intensive strength training in elite athletes may influence the pituitary and possibly hypothalamic levels, lead to increased serum levels of testosterone, which may create more optimal conditions to utilize more intensive training leading to increased strength development.
Abstract: Neuromuscular and hormonal adaptations to prolonged strength training were investigated in nine elite weight lifters. The average increases occurred over the 2-yr follow-up period in the maximal neural activation (integrated electromyogram, IEMG; 4.2%, P = NS), maximal isometric leg-extension force (4.9%, P = NS), averaged concentric power index (4.1%, P = NS), total weight-lifting result (2.8%, P less than 0.05), and total mean fiber area (5.9%, P = NS) of the vastus lateralis muscle, respectively. The training period resulted in increases in the concentrations of serum testosterone from 19.8 +/- 5.3 to 25.1 +/- 5.2 nmol/l (P less than 0.05), luteinizing hormone (LH) from 8.6 +/- 0.8 to 9.1 +/- 0.8 U/l (P less than 0.05), follicle-stimulating hormone (FSH) from 4.2 +/- 2.0 to 5.3 +/- 2.3 U/l (P less than 0.01), and testosterone-to-serum sex hormone-binding globulin (SHBG) ratio (P less than 0.05). The annual mean value of the second follow-up year for the serum testosterone-to-SHBG ratio correlated significantly (r = 0.84, P less than 0.01) with the individual changes during the 2nd yr in the averaged concentric power. The present results suggest that prolonged intensive strength training in elite athletes may influence the pituitary and possibly hypothalamic levels, leading to increased serum levels of testosterone. This may create more optimal conditions to utilize more intensive training leading to increased strength development.
331 citations
TL;DR: The study shows that systems analysts' perceptions of information system failures can be largely accounted for by their professional and structural position in the systems development process and associated interests, which supports the view that a perception of IS failure is largely stakeholder-dependent.
212 citations
TL;DR: Methods and principles that help to analyze offices as systems of communicative action are explored and some research directions for the future are suggested.
Abstract: In this paper methods and principles that help to analyze offices as systems of communicative action are explored. In communicative action, office agents create commitments through symbolic means. A SAMPO (Speech-Act-based office Modeling aPprOach), which studies office activities as a series of speech acts creating, maintaining, modifying, reporting, and terminating commitments, is presented. The main steps and methods in the office system specification are outlined and their application illustrated through a simple example. In the final section advantages and disadvantages in the SAMPO are noted and some research directions for the future are suggested.
208 citations
TL;DR: In an effort to investigate the force-time characteristics during the acceleration phase of the sprint start, eight male sprinters were used as subjects as mentioned in this paper, and force time parameters were measured on a force platform.
Abstract: In an effort to investigate the force-time characteristics during the acceleration phase of the sprint start, eight male sprinters were used as subjects. Runs up to 3 m were analyzed from film, and force-time parameters were measured on a force platform. In a starting stance the reaction time of the group was .118 ± .016 s and the force production lasted .342 ± .022 s. The maximal resultant force at the moment of maximal horizontal force was 19.3 ± 2.2 N x kg1, and the direction of the force was 32 ± 7°. In the very last instant before leaving the blocks the velocity of the center of gravity was 3.46 ± .32 m x s−1. In the first contact after leaving the blocks there was a braking phase (.022 ± .005 s in duration) during which the average horizontal force was −153 ± 67 N. The braking phase was observed despite the body center of gravity being horizontally ahead by .13 ± . 05 m with respect to the first contact point. The percentage of deceleration in running velocity during that phase was 4.8 ± 2....
197 citations
TL;DR: Elongated tail ornaments in four species of whydahs Vidua, the forktailed flycatcher Tyrannus savana and the Asian paradise flycatchers Terpsiphone paradisi did not show higher geographical variation than the body size characters, suggesting that there is no line of equilibria for these ornamments.
Abstract: In recent years several different kinds of sexual selection models have been developed, and tail ornaments in birds have frequently been used as an example of a sexually selected character where the models might apply. However, very little is known about intra- and interpopulation variation in ornament size. We have studied the elongated tail ornaments in four species of whydahs Vidua, the forktailed flycatcher Tyrannus savana and the Asian paradise flycatcher Terpsiphone paradisi. Ornaments were relatively longer in males with the longest tarsi (‘heterogony’ with positive allometry). Also, tail lengths were remarkably variable within each geographical area, the coefficient of variation (average = 11%) being three times as high as for body size characters. Models, with female preference of ornaments bearing no relation to male viability, usually generate lines of neutral equilibria. Thus, they predict extraordinary variation in ornaments between populations. However, elongated tail ornaments did not show higher geographical variation than the body size characters, suggesting that there is no line of equilibria for these ornaments.
165 citations
TL;DR: This article argues that information systems possess the potential to support authentic communicative interaction between organizational actors in such a way as to inspire criticism, to facilitate learning, and to raise the overall level of organizational competence.
152 citations
TL;DR: It is suggested that high intensity strengthening exercises may result in acute adaptive responses in both the neuromuscular and endocrine systems and Recording of muscle activation and muscle strength and analysis of certain serum hormone concentrations with sufficient frequency during the training process may be useful in optimizing and controlling the contents of individual training sessions and the full training program.
Abstract: Acute neuromuscular and endocrine adaptations to weight-lifting were investigated during two successive high intensity training sessions in the same day. Both the morning (I) (from 9.00 to 11.00 hours) and the afternoon (II) (from 15.00 hours to 17.00 hours) training sessions resulted in decreases in maximal isometric strength (p less than 0.01 and less than 0.05), shifts (worsening) in the force-time curve in the absolute scale (p less than 0.05 and ns.) and in decreases in the maximal integrated EMG (p less than 0.01 and less than 0.05) of the selected leg extensor muscles. Increases in serum total (p less than 0.05) and free testosterone (p less than 0.01) and in cortisol (p less than 0.01) concentrations were found during training session II. These were followed by decreases (p less than 0.001 and p less than 0.01 and ns.) in the levels of these hormones one hour after the termination of the session. The responses during the morning training session were different with regard to the decreases in serum total testosterone (p less than 0.05), free testosterone (ns.) and cortisol (p less than 0.05). Only slight changes were observed in the levels of luteinizing hormone and sex hormone-binding globulin during the training sessions. Increases (p less than 0.01) took place in somatotropin during both training sessions. The present findings suggest that high intensity strengthening exercises may result in acute adaptive responses in both the neuromuscular and endocrine systems. The diurnal variations may, however, partly mask the exercise-induced acute endocrinological adaptations in the morning.(ABSTRACT TRUNCATED AT 250 WORDS)
136 citations
TL;DR: Pavlovian conditioning of signal-centred action patterns and autonomic behaviour: a chronological analysis of function, and foraging decisions in starlings (Sturnus vulgaris L.).
135 citations
TL;DR: It is suggested that this family with 3 brothers with a myopathy that also affected their maternal grandfather and great‐uncle has an undescribed type of congenital myopathy, for which the name X‐linked myopathy with excessive autophagy is proposed.
Abstract: We report on 3 brothers with a myopathy that also affected their maternal grandfather and great-uncle. Characteristic features are onset in early childhood, very slow progression, normal life expectancy, weakness of proximal limb muscles, especially in the legs, elevation of serum creatine kinase, and no cardiac or intellectual involvement. In biopsy material muscle fibers are almost never necrotic but show excessive autophagic activity and exocytosis of the phagocytosed material. We suggest that this family has an undescribed type of congenital myopathy, for which we propose the name X-linked myopathy with excessive autophagy.
116 citations
TL;DR: The findings suggest that the turnover of endogenous androgens may increase during progressively intensified training without a change in serum total testosterone concentration and during the most stressful phases of training, the changes in serum androgen/cortisol ratios seem to be highly individual and may correlate with changes in muscular strength.
Abstract: Endocrine and neuromuscular effects of prolonged strength training were investigated in 21 strength-trained male subjects during the course of a 24-week progressive strength training and during a subsequent detraining period of 12 weeks. Maximal isometric leg extensor force increased by 19% (P less than 0.001) during the first 20 weeks, followed by a plateau during the 4 latest weeks of training. During the course of the training period, no systematic change was found in serum testosterone concentrations, but there was a decreasing tendency in the concentrations of free testosterone (NS), 17-OH-progesterone (NS), androstenedione (P less than 0.05), dehydroepiandrosterone (P less than 0.05), cortisol (P less than 0.01), transcortin (CBG) (P less than 0.05), and in the cortisol/CBG ratio (P less than 0.05). The last 4 weeks of training were characterized by significant correlations between the individual changes in maximal isometric force and the changes in serum free testosterone concentrations (r = 0.60, P less than 0.01). The changes in the ratios of free testosterone to cortisol (r = 0.73, P less than 0.001), total testosterone to cortisol (r = 0.83, P less than 0.001), and 17-OH-progresterone to cortisol (r = 0.62, P less than 0.01) also correlated with the changes in maximal force. The findings suggest that the turnover of endogenous androgens may increase during progressively intensified training without a change in serum total testosterone concentration. Prolonged intensive strength training may also lead to changes in the concentrations of serum cortisol and transcortin. During the most stressful phases of training, the changes in serum androgen/cortisol ratios seem to be highly individual and may correlate with changes in muscular strength.
TL;DR: During a short period of intense strength training the changes especially in serum testosterone concentrations indicate the magnitude of physiologic stress of training, but these changes do not, however, necessarily directly imply the changes in performance capacity.
Abstract: Daily adaptive responses in the neuromuscular and endocrine systems to a 1-week very intensive strength training period with two training sessions per day were investigated in eight elite weight lifters. The morning and the afternoon sessions resulted in acute decreases (P less than 0.05-0.01) in maximal isometric strength and in the maximal neural activation (iEMG) of the leg extensor muscles, but the basic levels remained unaltered during the entire training period. Significant (P less than 0.05-0.01) acute increases in serum total and free testosterone levels were found during the afternoon sessions. During the 1-week training period, serum total and free testosterone concentrations decreased gradually (P less than 0.05-0.001) as observed in the basic morning values before the sessions, but after 1 day of rest serum total and free testosterone reached (P less than 0.01 and 0.05) the pretraining level. The sessions resulted also in acute changes (P less than 0.05-0.01) in serum cortisol and somatotropin concentrations, but the basic morning levels did not change during the training period. The present findings suggest that during a short period of intense strength training the changes especially in serum testosterone concentrations indicate the magnitude of physiologic stress of training. The acute changes in serum hormone concentrations during a period of a few days do not, however, necessarily directly imply the changes in performance capacity. A longer period of follow-up lasting a few weeks is probably needed if an individual trainability status of a strength athlete is to be evaluated on the basis of the hormone determinations.
TL;DR: On considere l'equation elliptique d'ordre 2: L(u)=Σ i,f=1 n ∂ 1 (a ij ∂ ju )=0 ou les coefficients a ij sont des fonctions C 1 dans un domaine D de R n.
Abstract: On considere l'equation elliptique d'ordre 2: L(u)=Σ i,f=1 n ∂ 1 (a ij ∂ ju )=0 ou les coefficients a ij sont des fonctions C 1 dans un domaine D de R n
TL;DR: It is concluded that intensive running with an anaerobic response causes an increase in the concentrations of beta-E + beta-LPH and ACTH in plasma in endurance athletes, whereas slight aerobic exercise did not elicit any response.
TL;DR: The hypothesis stating that microtine social organization is an opportunistic strategy reacting phenotypically to changing environmental – especially food – conditions is supported.
Abstract: The social organization of Clethrionomys glareolus Schreber was studied by live trapping in an enclosure of 0.8 ha in Central Finland between the years 1982–1986. The enclosure consisted of three habitats: abandoned field, brushwood, and moist spruce heath forest.
The population density increased from 50 voles ha−1 in 1982 and 1983 to 150 ha−1 in 1984 and 1985. In the summer of 1986 the population crashed to almost zero. In the summer of 1984 after winter breeding the number of breeding females grew to 22 compared with 6–7 in previous years. In 1984 the mature females changed from territorial to group behaviour.
During the high population density in 1984 and 1985 breeding stopped already in late July – early August, thus preventing any fence effect.
The present study supports the hypothesis stating that microtine social organization is an opportunistic strategy reacting phenotypically to changing environmental – especially food – conditions.
TL;DR: The results show that the BMs in slow muscle are much more collagenous than those in fast muscle which contains, on the contrary, a higher concentration of laminin, which seems only partly to be explained by the higher capillarization of slow twitch muscle fibers.
Abstract: The changes in the biochemical composition of basement membrane (BM) in slow-twitch (m. soleus, MS) and fast-twitch (m. rectus femoris, MRF) skeletal muscles of rats were studied during aging and life-time endurance training (treadmill running). The concentrations of the 7S domain of type IV collagen and of the P2 fragment of laminin were determined with radioimmunoassays in the muscles of rats aged 1, 2, 4, 10, and 24 months. The concentration of type IV collagen was higher in MS than in MRF and increased significantly with age. At older ages, the concentration tended to be higher in the MS of trained than untrained rats. The concentration of laminin was significantly higher in MRF than in MS, especially in old age. Consequently, the ratio of type IV collagen to laminin was significantly higher in MS than in MRF, the difference increasing with advancing age. The results show that the BMs in slow muscle are much more collagenous than those in fast muscle which contains, on the contrary, a higher concentration of laminin. This difference seems only partly to be explained by the higher capillarization of slow twitch muscle fibers. Aging and training seem further to distinguish the composition of the BM in slow and fast muscle.
TL;DR: In this article, the authors evaluated the explosive strengths of young and adult male athletes by a vertical jumping and a ball-throwing test, and found that the young athletes ranged in age from 10 to 16 years representing seven different sports events: track and field, apparatus gymnastics, basketball, ice hockey, orienteering, skiing, and wrestling.
Abstract: The explosive strengths of young (n = 361) and adult (n = 10) male athletes were evaluated by a vertical jumping and a ball-throwing test. The young athletes ranged in age from 10 to 16 years representing seven different sports events: track and field, apparatus gymnastics, basketball, ice hockey, orienteering, skiing, and wrestling. The adult subjects were volleyball players. Weighted vertical counter-movement jumps were performed on a platform connected to an electronic unit which calculated the height of the rise of the body's center of gravity. For the stationary ball throwing test, horizontal throwing velocity was measured for balls of different masses by an electrical apparatus. In addition to the new jumping and throwing tests a subgroup of 48 track and field athletes were measured doing jump and reach, standing broad jump, and throwing distance tests. The new jumping test was found to give reliable results from 11–12 years of age and older while the throwing test results were reliable at ...
TL;DR: It is concluded that blood lactate production in prepubescent boys is related to serum testosterone level and muscle type II fibre area, indicating the role of maturation and training.
Abstract: Blood lactate production and recovery from anaerobic exercise were investigated in 19 trained (AG) and 6 untrained (CG) prepubescent boys. The exercises comprised 3 maximal test performances; 2 bicycle ergometer tests of different durations (15 s and 60 s), and running on a treadmill for 23.20±2.61 min to measure maximal oxygen uptake. Blood samples were taken from the fingertip to determine lactate concentrations and from the antecubital vein to determine serum testosterone. Muscle biopsies were obtained from vastus lateralis. Recovery was passive (seated) following the 60 s test but that following the treadmill run was initially active (10 min), and then passive. Peak blood lactate was highest following the 60 s test (AG, 13.1±2.6 mmol·l−1 and CG, 12.8±2.3 mmol·l−1). Following the 15 s test and the treadmill run, peak lactate values were 68.7 and 60.6% of the 60 s value respectively. Blood lactate production was greater (p<0.001) during the 15s test (0.470±0.128 mmol·l−1·s−1) than during the 60s test (0.184±0.042 mmol·l−1·s−1). Although blood lactate production was only nonsignificantly greater in AG, the amount of anaerobic work in the short tests was markedly greater (p<0.05-0.01) in AG than CG. Muscle fibre area (type II%) and serum testosterone were positively correlated (p<0.05) with blood lactate production in both short tests. Blood lactate elimination was greater (p<0.001) at the end of the active recovery phase than in the next (passive) phase. It is concluded that blood lactate production in prepubescent boys is related to serum testosterone level and muscle type II fibre area, indicating the role of maturation and training. Submaximal exercise is likely to increase blood lactate removal during recovery.
TL;DR: In this article, the energy levels of even 110-116 pd nuclei have been studied from β-decays of odd-odd 110−116 Rh isotopes produced at the on-line isotope separator IGISOL.
TL;DR: It is shown that a diverse soil animal community enhances the activity of soil microbes, and may thereby accelerate decomposition in raw coniferous forest soil.
Abstract: The effect of diverse soil fauna (Collembola, Acari, Enchytraeidae, Nematoda) on decomposition of dead organic matter was studied in microcosms containing (1) birch leaf litter, (2) raw humus of coniferous forest and (3) litter on humus. Total respiration (CO2 evolution) was monitored weekly, and mass loss, length of fungal hyphae (total and metabolically active) and survival of animal populations were checked at the end of weeks 12 and 21–22 from the start of experiment. Animal populations established themselves well during the incubation. At the end of the experiment some replicates containing litter had microarthropod densities of up to 500 specimens per microcosm, corresponding to a field population of 200 000 m−2. The soil animals had a positive influence on total respiration in all substrates. By the end of experiment 32.0%, 22.6% and 14.6% more CO2 had evolved in the presence of animals in litter, litter + humus and humus alone, respectively. There was clear trend towards a higher mass loss in the presence of animals, though it was significant in litter only. Our results showed that a diverse soil animal community enhances the activity of soil microbes, and may thereby accelerate decomposition in raw coniferous forest soil.
TL;DR: The dynamics of hot matter produced in ultrarelativistic heavy-ion collisions is studied with a cascade simulation and the putative quark-gluon plasma with independent globs of high-density matter is model.
Abstract: The dynamics of hot matter produced in ultrarelativistic heavy-ion collisions is studied with a cascade simulation. We model the putative quark-gluon plasma with independent globs of high-density matter. The hadronic phase is treated by explicit tracking of pion coordinates. We find that the pions make 0--2 collisions with globs and 1--3 collisions with other pions, under conditions expected for heavy ions at collider energies. The entropy increases by about 20% during the phase transition. The transverse momentum in the final state is almost entirely due to the momentum with which pions are emitted from the globs, except at extremely high densities where the hydrodynamic expansion of the pure plasma phase is significant.
TL;DR: The fauna affected the humification process positively in the litter + humus and in humus alone, i.e. relatively more humic substances than total C were liberated from the materials in the presence of animals.
Abstract: To examine the role of a community of soil animals in N-mineralization and C fluxes in dead organic matter, we established a microcosm system with substrates composed of: (a) birch leaf litter; (b) raw coniferous humus; and (c) litter on humus. Every 3–4 wks the substrates were irrigated with distilled water, and the amounts of NO5-N, NH4-N, total-N and total-C (as well as humic substances at one recording) in the leachates were analyzed. At the end of the experiment, water-soluble and exchangeable forms of N were measured in the test materials. The differences in the release of N were clear both between the replicates with and without soil animals and between the different forms of N. From wk 10 onwards the fauna enhanced significantly the leaching of total-N and NH4-N from the humus alone. The release of total-N from the litter alone was also increased by the fauna. The presence of animals did not significantly affect any form of K.CIextractable N. The amounts of total C in the leachates increased significantly in almost all samples when the fauna was involved. In addition, the fauna affected the humification process positively in the litter + humus and in humus alone, i.e. relatively more humic substances than total C were liberated from the materials in the presence of animals.
TL;DR: In this article, a steady-state nonlinear parabolic-type model, which simulates the multiphase heat transfer during solidification in continuous casting, is presented and a detailed solution algorithm is presented.
Abstract: In this paper a steady-state nonlinear parabolic-type model, which simulates the multiphase heat transfer during solidification in continuous casting, is presented. An enthalpy formulation is used and we apply a FE-method in space and an implicit Euler method in time. A detailed solution algorithm is presented. We compute the temperature distributions in the strand when the boundary conditions (mold/spray cooling) on the strand surface are known. The numerical model gives thereby a good basis for the testing of new designs of continuous-casting machines. An application of the model to continuous casting of billets is presented.
TL;DR: To examine whether the geographical size differences between mainland and Gotland Coal Tits are genetic or environmental, transplanted eggs between the two populations are transplanted.
Abstract: Geographic variation in morphological characters of birds has usually been assumed to be shaped by natural selection leading to phenotypes that reflect genetic differences adapted to local conditions. However, James (1983) transplanted eggs of the Red-winged Blackbird Agelaius phoeniceus between nests in different populations and found that a considerable part of the differences in nestling development was attributable to environmental factors. This important experiment indicates that we cannot take for granted that morphological differences have a genetic basis, without further evidence. Whether morphological character displacement between allopatric and sympatric populations can be accepted as evidence for evolutionary effects ofinterspecific competition is a hotly debated issue (e.g., Grant, 1975; Strong et al., 1979; Connell, 1980; Grant and Abbott, 1980; Arthur, 1982). There are several problems in demonstrating that morphological changes have in fact evolved in response to interspecific competition, since geographical differences in natural selection attributable, for example, to predation and food quality may also have caused the changes. However, even if the alternative explanations can be rejected with field experiments or other conclusive data, the possibility that morphological changes have arisen without any genetic changes remains to be tested. The population of Coal Tits (Parus ater) on the island of Gotland in the Baltic Sea is one of the best studied cases of niche expansion with associated morphological changes in the absence of putative competitors. Alerstam et al. (1974) compared the population densities and the use of foraging sites of tits in the coniferous forests on the island of Gotland and on the adjacent Swedish mainland. On the mainland, two other tit species, the Willow Tit Parus montanus and the Crested Tit Parus cristatus coexist with the Coal Tit. The Coal Tit is smaller in size and forages on the outer needle-bearing twigs of spruce (Picea abies) and pine (Pinus silvestrist, while the two larger species forage in the inner tree parts. On Gotland, in the absence ofthe two larger species, the Coal Tit has expanded its use of foraging sites to the inner tree parts, and the population density has increased to correspond to the combined density of the three species on the mainland (for further data see Alatalo et al. [1986]). Moreover, the Gotland Coal Tits have increased in body size, and as result they resemble the absent species (U. M. Norberg and R. A. Norberg, pers. comm.; Gustafsson, 1988). The hypothesis that interspecific competition is underlying these geographical changes has been corroborated by field experiments in Central Sweden, where Coal Tits were found to increase their use of inner tree parts after Willow and Crested Tits had been removed from flocks (Alatalo et al., 1985). To examine whether the geographical size differences between mainland and Gotland Coal Tits are genetic or environmental, we transplanted eggs between the two populations. This experiment is particularly relevant in light of the many lines of evidence supporting the possibility that interspecific competition has had evolutionary consequences for these populations.
TL;DR: Chloride, total organic chlorine (TOCl) and chlorophenols have been measured in bottom sediment layers of seven lakes in Central Finland as mentioned in this paper, and the amounts increase markedly in 20th century layers and are much higher below than above the pulp mills.
TL;DR: The results indicated that the muscle strength and muscle endurance of middle-aged employees was systematically lower among those with high muscular load compared to those with low load at work.
Abstract: Muscle strength and muscle endurance in groups with different occupational muscular load was studied among 60 women and 69 men. The mean age of the subjects was 52.0 ± 3.4 years. Isometric grip and trunk strength were measured on dynamometers, and dynamic muscle endurance by sit-ups. A job analysis was done with the AET method including the assessment of intensity, duration and type of muscular work of each subject. According to the job analysis, the subjects were classified into groups with low or high muscular load at work. The maximal isometric hand grip strength of women with a load classified as long duration of static or dynamic load on the hands at work was 86 and 88%, respectively of the strength of those with a load of short duration. The women with high intensity in static work had a grip strength of 86% of those with low intensity. These differences in strength among women between the high and low load groups were statistically significant (P < 0.05). No other statistically significant differences in muscle strength or muscle endurance between the high and low work load groups were found, although the high work load group had systematically the lowest muscle strength and muscle endurance in almost all comparisons. Muscle strength and muscle endurance was, however, not a discriminating factor between the group classifications of static and dynamic work. The results indicated that the muscle strength and muscle endurance of middle-aged employees was systematically lower among those with high muscular load compared to those with low load at work.
TL;DR: In this paper, surface natural humic water samples free of industrial and domestic inputs were analyzed directly by high-performance liquid chromatography on a TSK gel size-exclusion column system with u.v. detection at 280 nm.