Showing papers by "University of Jyväskylä published in 1977"

Signal characteristics of EMG during fatigue.

Abstract: Electromyographic (EMG) activity of m. rectus femoris muscle was registered from young male and female subjects during maintained isometric knee extension at 60% of maximal voluntary contraction. The following EMG parameters were analyzed for the entire fatigue time: integrated EMG (IEMG), averaged motor unit potential (AMUP) and power spectral density function (PSDF). The results indicated a slight but continuous rise of IEMG during the fatigue period. AMUP showed sensitivity to fatigue with increase in amplitude, rise time, and number of spikes counted. PSDF was also easily affected by fatigue so that the total power density curve was shifted towards lower frequencies with a high frequency decay. The mean power frequency decreased linearily as a function of fatigue time. The findings suggest that in addition to natural recruitment of new motor units the fatigue is characterized by marked reduction in the conduction velocities of action potential along the used muscle fibers.

Changes in Motor Unit Activity and Metabolism in Human Skeletal Muscle during and after Repeated Eccentric and Concentric Contractions

Abstract: This study was designed to investigate electromyographic (EMG), muscle glycogen and blood lactate changes in quadriceps muscle group during repeated 40 maximal eccentric and concentric contractions, and to follow the recovery in EMG, muscle glycogen and serum creatine kinase values during a 4 day period following the work test. The subjects were normal males and the test order (eccentric or concentric) was randomly selected. The results indicated first, that the EMG parameters (IEMG, AMUP), muscle glycogen and blood lactate changed in a similar manner during the both fatigue loads. Despite the high tension work no selective depletion of glycogen could be observed in the slow or fast twitch muscle fibres in either type of work. The restoring of muscle glycogen occurred in a similar manner after the both fatigue loads, and no significant differences were present between eccentric and concentric works in the serum creatine kinase levels for a 2 days period. The eccentric work was associated with muscle soreness, which was strongest during the second day after the termination of the work test. The recovery of the EMG parameters were also delayed in eccentric fatigue. After concentric fatigue EMG-activity returned to normal values within 2 days.

Niche relations among dung-inhabiting beetles.

Abstract: The whole dung-inhabiting (adult) beetle community living in southern Finland was studied with reference to the seasonal (6 summer months), macrohabitat (open field, half-open pine forest and closed spruce forest) and successional (30 days) gradients. The material comprised 50 coprophagous and 129 carnivorous species, represented by 26,650 and 35,850 individuals, respectively. The most important characteristics of each species are given in an Appendix.In the coprophages the species-abundance relations fitted the lognormal distribution well, but in the carnivores the distribution was strikingly less even. A great number of other differences (see below) apparent between the two trophic groups were explained as the result of a difference in the degree of specialization, apart from the difference in their trophic position: coprophages are microhabitat (dung) and food specialists, while carnivores are microhabitat generalists (and therefore their "critical" niche space was not completely covered in this study).In the coprophages, two important species guilds were observed: the first occurred at the very geginning of the succession (mean position 2.5 days), and consisted mainly of true dung specialists; the second guild contained species with wider utilization along the successional dimension (mean position 6.5 days), and species of more generalist nature (saprophages). The utilization of carnivores along the successional gradient was more continuous, probably because of their more diversified food resources. The total niche width among the coprophages increased from early successional species to species occurring mainly later on, but was more constant in carnivores. The environmental dimensions proved to be totally independent of each other among the carnivores, while the coprophages showed a clear supplementary relationship along them. Among the carnivores, a spherical niche shape dominated, but among the coprophages elongated and disk-liked shapes were also well represented, especially in specialist species. In both groups, a significant positive correlation existed between niche width and dominance, but not between niche width and abundance. It is suggested that the patchy distribution and transient occurrence of suitable microhabitats contributes to the coexistence of many ecologically similar species.

Effects of 8 weeks' endurance training on skeletal muscle metabolism in 56–70-year-old sedentary men

Abstract: The effects of 8 weeks' endurance training on muscle metabolism at rest and after a submaximal bicycle ergometer exercise were studied in 31 previously sedentary men, aged 56–70. Training consisted of 3–5 one hour exercise bouts per week including walking-jogging, swimming, gymnastics and ball games. The effects of training were similar to those previously reported for younger men. Mean maximal oxygen uptake increased (11%), as did the resting values for muscle glycogen concentration, the enzymes representing aerobic energy metabolism (malate dehydrogenase, succinate dehydrogenase), and also some of the anaerobic enzymes (creatine phosphokinase, lactate dehydrogenase). Lactate production during submaximal work decreased. The enzyme activities were lower following acute exercise both before and after training.

Effect of Eight Weeks' Physical Training on Muscle and Connective Tissue of the M. Vastus Lateralis in 69-year-old Men and Women

Abstract: Five one-hour exercise periods a week for 8 weeks included walking-jogging, swimming, gymnastics and ballgames for 26 healthy male and female 69-year-old pensioners. The mean maximal oxygen uptake of the men increased from 28.9 ml-kg-1-min-1 before training to 32.0 ml-kg-1-min-1 after training and for the women from 27.9 to 31.3 ml-kg-1-min-1. Muscle malate dehydrogenase activity was increased while that for lactate dehydrogenase decreased or remained the same. The activity of these enzymes was higher in the male both before and after training when compared with the female. However, the percentage number of slow twitch muscle fibers was nearly the same in both groups. Prolyl hydroxylase activity was increased after training especially in the female subjects. These results show that endurance-type training leads to an enhanced capacity for aerobic metabolism in older subjects and that collagen metabolism in skeletal muscles is affected by physical training.

A Contribution to the Categories of Social Time and the Economy of Time

Abstract: The article strives to demonstrate the centrality of the category of social time (a) in people's daily lives, (b) as a methodological tool in the study of social process, and (c) as a means towards the planned development and management of advanced societies. Social time has two aspects: rhythm of life and available total time. The article shows that in advanced societies total time and its rational allocation are central in the development of society and individual personality. The nature of social time in less developed societies is also reviewed as well as the historical development of time awareness and the problems of the research on time budget. The article is based on the conceptions about the nature of the economy of time that emerged from reading Marx's Grundrisse.

Occurrence and Heterogeneity of Chymotrypsin Inhibitors in Vegetative Tissues of Barley

Abstract: Inhibitors of chymotrypsin and the alkaline proteinase of Aspergillus oryzae were present in the shoots of barley seedlings and weak activities were also detected in the shoot tops of 6-week-old plants. Treatments which induce inhibitor formation in tomato and potato leaves had no effect when tested on mature leaves, seedlings, or young tillers of barley. Fractionation experiments with isoelectric focusing showed that the barley leaves contained several proteinase inhibitors acting on both chymotrypsin and the Aspergillus proteinase, and one inhibitor which acted only on the Aspergillus enzyme. All of these inhibitors were different from the five Aspergillus proteinase inhibitors which are abundant in the endosperm of resting seeds. Two chymotrypsin inhibitors with weaker activity on the Aspergillus proteinase were present in rootlets and also in embryos of resting seeds. These inhibitors were different from both the endospermal inhibitors and the inhibitors present in young leaves.

Peptidases in germinating barley grain: properties, localization and possible functions.

Abstract: Barley grain contains about 10% insoluble reserve proteins. When the grain germinates the reserve proteins are hydrolysed to amino acids and transported to the growing tissues of the seedling. In the resting grain most of the reserve proteins are 'packed' into the non-living storage tissue, the starchy endosperm. During germination the internal pH of the starchy endosperm is about 5, and it contains high activities of proteinases (secreted by the living aleurone cells) and carboxypeptidases, all with pH optima between 4 and 6. As a whole the starchy endosperm of a germinating grain resembles a giant secondary lysosome. Adjacent to the starchy endosperm is a specialized absorptive and processing tissue, the scutellum. This organ contains very high activities of the 'acid carboxypeptidases' and also two 'alkaline peptidase': a leucine aminopeptidase and a dipeptidase, both pH optima at 8 to 10. The high peptidase activities in the scutellum suggest that the hydrolysis products of the reserve proteins are absorbed from the starchy endosperm as a mixture of amino acids and small peptides, which are hydrolysed to amino acids in the scutellum before transport to the growing seedling tissues.

Effect of endurance training on the capacity of red and white skeletal muscle of mouse to oxidize carboxyl-14C-labelled palmitate

Abstract: Three groups of mice were trained for 1, 4 and 5 months according to different running programs on a motor driven treadmill and the fatty acid oxidation capacity (FAO) and the activities of some enzymes of energy metabolism (cytochrome c oxidase, malate dehydrogenase, triosephosphate dehydrogenase, and lactate dehydrogenase) were determined from m. quadriceps femoris (MQF). Endurance training increased the FAO [5-month training 4 days/week, 30 min/day 22% (p less than 0.05); 1-month training, 7 days/week, 150 min/day 37% (p less than 0.001); 4-month training, 5 days/week, 60 min/day 24% (p less than 0.05)]. The activities of cytochrome c oxidase and malate dehydrogenase increased approx. 30% (p less than 0.001) whereas triosephosphate dehydrogenase and lactate dehydrogenase activities were not prominently influenced by training. The predominantly red part of MQF of untrained animals oxidized palmitate four times faster than the predominantly white part. The activities of cytochrome c oxidase and malate dehydrogenase were two times higher showing pronounced FAO in the red part. Endurance training increased the FAO and activities of oxidative enzymes in the red and white parts and in the whole muscle relatively equally resulting in similar differences between the muscle types after training. The absolute increase in the FAO of the red muscle was, however, manyfold when compared in chemical units to the white muscle.

Genetic and environmental variation in perceived exertion and heart rate during bicycle ergometer work

Abstract: The relative contributions of heredity and environment to the variance in heart rate (HR) and rating of perceived exertion (RPE) during the bicycle ergometer work were studied with 14 pairs of male (6 monozygous (MZ) and 8 dizygous (DZ)) and 22 pairs of female (8 MZ and 14 DZ) twins ranging in age from 11 to 20 years. The results showed for both sexes that no significant differences in the intrapair variances of HR and RPE could be observed between the MZ and DZ twin samples. Thus it was concluded that in contrast to several other parameters of the measurements of the physical work capacity HR and RPE are not influenced to any significant degree by the genetic factors.

States of 167 Ho from the decay of neutron rich nuclide 167 Dy

Abstract: Theβ −-decay of 66 167 Dy produced through the fast neutron reaction170Er(n, α)167Dy has been investigated by using several kinds of detectors and a high-capacity two-parameter recording system. The half-life andβ −-decay energy of167Dy were determined to beT 1/2 = 6.20 ± 0.08min andQ β-=2.35±0.06, respectively. The observed level scheme of 67 167 Ho (completely unknown previously) contains 12 states, among them a 6.0±0.1 μsM2 isomer at 259.3 keV. On the basis of theoretical and systematic considerations combined with multipole determinations, the following Nilsson model assignments are proposed for the lowest states of167Ho: 0 keV (7−/2 [523]), 259.3 keV (3+/2[411]), 319.8 keV (5/2 3+/2[411]), 392.5 keV (1+/2[411]), 410.0 keV (3/2 1+/2[411]), 569.7 keV (3−/2{7−/2[523], 2+}). Theβ-decay proceeds mainly to the proposed gamma-vibrational state at 569.7 keV with an anomalously low logft value 5.4, indicating similarity between the microscopic structures of this state and the famous ¦K 0−2¦ gamma vibration of165Ho.

1H and 13C n.m.r. spectra of dichloro(trans-2-chlorovinyl)arsine

Abstract: Proton and carbon magnetic resonance spectra of Lewisite or dichloro(trans-2-chlorovinyl)arsine have been measured and the results are compared with the n.m.r. spectral parameters of other trans-1,2-substituted ethylenes. The coupling constants can be rationalized by substituent electronegativity. The chemical shifts show an unusually large paramagnetic effect from the AsCl2 group.

Properties of isomeric states and the ?d 3/2-vi 13/2 multiplet in194Au

Abstract: The level structure of194Au has been studied by observing prompt and delayedγ-rays following194Pt(p,n) and195Pt(p,2n) reactions. The conversion electron andγ-ray spectra from the decay of the 0.42s (10−) and 0.60s (5+) isomers at 476 keV and 107.4 keV, respectively, have been measured using the He-jet method. The half-lives of the 6+ (278.2 keV, 1.1±0.4 ns), 7+ (224.6 keV, 2.6±0.2 ns) and 8+ (406.8 keV, 2.9±0.4 ns) members of theπd3/2-vi13/2 multiplet have been obtained from the time distributions between cyclotron beam pulses andγ-rays depopulating these levels. A calculation made assuming a pure two-particle configuration for the multiplet predicts very well theB(E2) values for the transitions between the levels of this multiplet but the calculatedB(M1) values are not in agreement with experimental results.

Three nuclei n.m.r. spectroscopy of dimethoate compounds. A large solvent effect on the 31PSC1H vicinal coupling

Abstract: Proton, phosphorus and carbon magnetic resonance spectra of dimethoate, dimethoxon, des-N-methyldimethoate, ω-hydroxydimethoate, trimethyldithiophosphate and O,O-dimethyldithiophosphate in different solvents have been measured. Most of the n.m.r. parameters were characteristic of the structural environment of the corresponding nucleus and solvent-independent. However, in the amide structures dimethoate, dimethoxon, des-N-methyldimethoate and ω-hydroxydimethoate the 31PSC1H vicinal coupling showed an unusually large solvent effect of a 2.3 to 6.5 Hz decrease when CDCI3 was replaced by acetone-d6 or DMSO-d6.