showing 36 of ~574560 from 574555 documents
Muscle cross-sectional area and voluntary force production characteristics in elite strength- and endurance-trained athletes and sprinters
1989
Seven male elite strength-trained athletes (SA) from different weight categories, six elite sprinters (SPA) and seven elite endurance-trained athletes (EA) volunteered as subjects for examination of their muscle cross-sectional area (CSA), maximal voluntary isometric force, force-time and relaxation-time characteristics of the leg extensor muscles. The SA group demonstrated slightly greater CSA and maximal absolute strength than the SPA group, while the EA group demonstrated the smallest values both in CSA and especially in maximal strength (p<0.05). When the maximal forces were related to CSA of the muscles, the mean value for the SA group of 60.8±10.0 N·cm−2 remained slightly greater than…
Free amino acids in preterm and term milk from mothers delivering appropriate- or small-for-gestational-age infants.
1989
Free amino acids were quantitated in human milk collected during the first month postpartum from mothers of appropriate preterm (26-32 and 33-36 wk gestation) and term (small or appropriate-for-gestational-age) infants. Glutamic acid and taurine were the most abundant amino acids in all four groups at all stages of lactation. The ratio of essential to nonessential amino acids was higher in colostrum than in mature milk although the total amino acid level of mature milk was double that of the colostrum. Nonprotein amino acids amount to approximately 40% of the free-amino acid pool in colostrum. Differences in the content and changes in free-amino acid levels during lactation among the groups…
Photochemical versus aluminium chloride-catalyzed fries rearrangement of aryl hydrogen succinates. synthesis of 2(3H)-furanones
1989
The photochemical and aluminium chloride-catalyzed Fries rearrangement of a series of aryl hydrogen succinates3 a–f to the corresponding 4-oxoacids1 a–f are compared. Both approaches are complementary: the photochemical process is more general and becomes the method of choice for the succinoylation of phenols supporting alkoxy or hydroxy substituents, while the classical rearrangement is superior in the presence of alkyl or halogen substituents. These results are applied to the preparation of the 2(3H)-furanones2 a–f.
Stimulation of Serotonin-N-Acetyltransferase Activity in the Pineal Gland of the Mongolian Gerbil (Meriones unguiculatus) by Intracerebroventricular …
1989
There is ever-increasing evidence that intrapineal peptides have an important role in the modulation of pineal melatonin synthesis. In the pineal gland of the Mongolian gerbil (Meriones unguiculatus), we have previously shown the presence of VIP-immunoreactive nerve fibers as well as pinealocytic VIP receptors. To assess the functional significance of these findings, 10 microliters of a 1 microM or 1 nM solution of VIP were injected into the lateral ventricle of gerbils over a period of 10 min. Animals were killed 1.5 hr after injection, and the superficial pineal glands were excised and assayed for N-acetyltransferase (NAT) activity. Injection of the 1 microM VIP solution stimulated the NA…
false
1989
A series of combined main-chain side-group liquid-crystalline polymers was synthesized by melt polycondensation from trans-1,4-cyclohexanedicarboxylic acid, chloro-1,4-phenylene diacetate and 6-(4-methoxy-4′-biphenylyloxy)hexyl-1,4-phenylene diacetate. These polyesters combine the features of rigid-rod main-chain LC-polymers and of side-group LC-polymers. Polymers with small fractions of mesogenic side-groups (5 and 10 mol-%) have lower melting points than the parent polymer poly(chloro-1,4-phenylene 1,4-cyclohexanedicarboxylate) but are still liquid crystalline up to their decomposition at T ≥ 400°C. In polymers with larger fractions of mesogenic side-groups (50 and 100 mol-%) partial isom…
An Evanescent Field Optical Microscope
1989
We present a new form of optical microscope. An evanescent field is produced in the lower index medium of an ATR system and modulated by a sample deposited on the hypotenuse of the prism. A sharpened fiber optic probes this field and gives information about the topography of the surface.
Mass measurements of very high accuracy by time-of-flight ion cyclotron resonance of ions injected into a penning trap
1989
Abstract The possibility of absolute mass measurements using time-of-flight detection of ion cyclotron resonance on ions injected into a Penning trap has been demonstrated. Resolving powers of 2 million have been achieved, with accuracies of about 0.5 ppm. Absolute accuracy is obtained by direct observation of the sum frequency of the cyclotron and the magnetron motions through the use of an azimuthal quadrupole r.f. field to transform initial magnetron motion into cyclotron motion. Imperfections of the Penning trap leading to systematic errors are discussed. The system has been designed specifically to measure the masses of radionuclides produced at the on-line isotope separator ISOLDE. Wi…
Cooling and slowing of trapped antiprotons below 100 meV
1989
Electron cooling of trapped antiprotons allows their storage at energies 10 million times lower than is available in any antiproton storage ring. More than 60 000 antiprotons with energies from 0 to 3000 eV are stored in an ion trap from a single pulse of 5.9-MeV antiprotons from LEAR. Trapped antiprotons maintain their initial energy distribution over a storage lifetime exceeding 50 h unless allowed to collide with a cold buffer gas of trapped electrons, where- upon they cool dramatically to 1 eV in tens of seconds. The cooled antiprotons can be stacked into a harmonic potential well suited for long-term storage and precision measurements.
Training volume, androgen use and serum creatine kinase activity.
1989
Serum creatine kinase (CK) activities were investigated in elite male strength athletes (n = 20) during normal weight training and bodybuilding training (one training session per day), during high volume strength training (two sessions per day) and during strength training (one session per day) with the use of high dose synthetic androgens (five athletes in each subgroup). The findings demonstrated that the increase in serum CK was highest in the subgroup using androgens. These results suggest that strength training with the use of androgenic steroids leads to higher serum CK activities than normal strength training.
The Sports Club as a Social Organization in Finland
1989
The voluntary sports movement began in Finland in the late 1800s concomitantly with the industrialization of the country. Due to the political, ethnic and emancipatory interests the sports movement has particular configurations still valid at present and embodied in the separate national organizations for workers, Finnish-Swedish people and women. The national survey on sports clubs as social organizations was carried out in 1987. The data were collected by mail from the sample of clubs (n 835). The survey was focused on the prime components of the internal system of sports clubs — ideology, membership, program, resources and administration — but also on the interaction between this interna…
Lung Compartmentalization of Increased TNF Releasing Ability by Mononuclear Phagocytes in Pulmonary Sarcoidosis
1989
The TNF is a monokine with cytotoxic and tumor-necrosing activities; in addition, TNF may play a role in inflammatory processes. The present study evaluates spontaneous and LPS-mediated release of TNF by AMs and autologous peripheral BMs of normal subjects and patients with pulmonary sarcoidosis. A recently developed cytotoxicity assay, specific for detection of TNF activity, was applied. This study demonstrates that (1) unstimulated mononuclear phagocytes released low levels of TNF with no differences between groups; (2) when effector cells were stimulated with LPS, AMs from patients with active pulmonary sarcoidosis released more TNF than AMs recovered from normal subjects and from patien…
Structure of the neutron-rich nucleus 37 94 rb57
1989
A level scheme has been established for 37 94 Rb57 based on studies at the fission-product separator JOSEF ofγγ coincidences following theβ- decay of94Kr. For the 190.7 keV level a half-life of 2.5(8) ns has been determined through the centroid-shift method. The majorβ-decay branch of94Kr proceeds with log ft=3.7 into the 988.4 keV state in94Rb. This transition must be of the 0+→1+ GT type involving the transitionνg7/2→πg9/2. IBFFM calculations have been performed for94Rb, starting from the parametrization used in the previous IBM investigations for the isotope93Rb and the isotone96Y. A theoretical interpretation of the low-lying levels including propositions for the spins is given in a com…
QCD Jets at HERA II.O(? s 2 ) four-jet cross-sections
1989
We present exact expressions for theO(α s 2 ) tree graph four-jet cross-sections in neutral current and charged current deep inelasticep scattering initiated by quarks, antiquarks and gluons including lepton polarization effects. Using helicity amplitudes the partonic cross-sections are given in concise form including all colour, flavour and statistical factors. We explicate the electroweak coupling dependence and state how the partonic cross-sections are folded with the respective parton densities to obtain theep jet cross-sections toO(α s 2 ). We present some numerical results for the neutral current one-photon exchange case. We elaborate on the cut dependence of the jet rates and present…
Electromagnetic properties of neutrinos in a medium
1989
We show that, contrary to the situation in the vacuum, a Majorana neutrino can have electric and magnetic dipole moments in a medium. This is because of new contributions, equal for a particle and its antiparticle, that can arise only in a material background. For Dirac neutrinos, these contributions make the magnitudes of the dipole moments of the particle and the antiparticle unequal. We discuss the conditions which give rise to such effects, with particular attention to the role played by the discrete symmetries {ital C}, {ital P}, and {ital T}.
Myopathic form of arthrogryposis and microcirculation lesion.
1989
A microvascular lesion characterized by extensive platelet aggregation, thrombosis, vascular damage with hemorrhages was found in the muscle of a 2-month-old boy with a myopathic form of the arthrogryposis syndrome. The lesion morphologically resembled the vascular leakage seen in immunologically mediated tissue injury. A degradative effect of proteases released during platelet and neutrophil aggregation on the muscle and joints is suggested.
Immunonephelometric determination of the apolipoprotein A-II.
1989
A fully mechanized immunonephelometric method is described for the rapid and specific determination of apolipoprotein A-II in serum. The method utilizes commercially available sheep antiserum against human apolipoprotein A-II. Nephelometry was performed with the Behring Nephelometer Analyzer (BNA). A single determination can be performed in 12 minutes, requiring 10 microliters sample volume. The measuring range is about 0.08 to 1.25 g/l apolipoprotein A-II. Precision is characterized by intra-assay coefficients of variation of 3.37%, 3.93% and 4.49% for apolipoprotein A-II concentrations of 1.22 g/l, 0.376 g/l and 0.185 g/l, and inter-assay coefficients of variation of 4.27% for an apolipop…
El comportamiento de los estudiantes universitarios
1989
International audience
Notas sobre la historiografia del pensamiento economico en España. Siglos XVIII y XIX
1989
El propósito de estas notas es ofrecer una descripción escueta de la literatura dedicada al pensamiento económico en España, publicada desde las I Jornadas (Madrid, febrero 1974), para que —siguiendo las indicaciones de los organizadores de estas III Jornadas— pueda servir de marco, referencia o acicate en el debate subsiguiente a las comunicaciones. Es una descripción improvisada e incompleta, que espero mejorar con la ayuda de los asistentes. Concluiré la relación con unas reflexiones generales que me ha sugerido el análisis de dicha literatura.
Chemical and spectroscopical evidence for an electron‐transfer mechanism in the reaction of arenesulfonyl chlorides with anions
1989
The reaction of amide and amidate anions 2 with p-toluenesulfonyl chloride (1) under different reaction conditions gives rise to the total or partial reduction of the acyl halide to p-toluenesulfinic acid (5) and acylation compounds in variable amounts depending on the crowding at the anionic center. This indicates that a Single-Electron Transfer (SET) mechanism is involved in the reactions of 1 with anions. Unpaired electron species are detected by ESR in the course of the reactions.
Solution of controversy over 1583-keV levels inPb204
1989
Data from {sup 204}Pb({ital p},{ital p}{prime}){sup 204}Pb conversion-electron and gamma-ray experiments, together with previous results, prove the existence of two levels (0{sup +} and 2{sup +}) at 1583-keV excitation energy in {sup 204}Pb. Modified values (limits) of the {rho}{sub 21}{sup 2} and {ital X}{sub 211} are 0.0013{lt}{rho}{sub 21}{sup 2}{lt}0.015 and {ital X}{sub 211}{gt}0.073. New experimental evidence indicates that all the three observed excited {ital O}{sup +} states in {sup 204}Pb can be explained as belonging to the four-neutron-hole valence space and, therefore, there is no clear candidate for the proton 2p-2h intruder state in this nucleus.
Ultrasonic B-scans of the facial/oral periodontium in pigs.
1989
In vitro ultrasonic scans of the oral/facial periodontium of pigs were obtained using a special experimental design and with the help of a newly developed ultrasonic measuring and analysis system. These two-dimensional images distinguish themselves from the one-dimensional RF-echograms and A-scans in that they enable the viewer to have a quick overview of the relationship between different interfaces in a scanned sector. A selection of ultrasonic B-scans proves that the scanned tissues such as gingiva, bone, periodontal ligament, tooth surface and even structures of the inner part of the tooth may be clearly imaged and distinctly differentiated. Furthermore, we demonstrate with manipulation…
Conditioned orienting (alpha) and delayed behavioral and evoked neural responses during classical conditioning
1989
A differentiation of short-latency (alpha) and long-latency (delayed) classically conditioned behavioral and evoked neural (hippocampal) responses was attempted. Further, facilitation and retardation of these responses were studied in an experimental design in which 10 paired conditioning sessions either preceded (CC-CO group) or followed (CO-CC group) 10 randomly unpaired presentations of conditioned stimuli (CS) and unconditioned stimuli (UCS). A 2024-ms tone (1000 Hz) was delivered directly through a miniature earphone to the left ear, eliciting an orienting head movement ('alpha' response) to the left. The unconditioned stimulus (UCS) was a direct 1024-ms stimulation of the lateral hypo…
An unusual translocation associated with recurrent spontaneous abortions
1989
The authors report a case of 11;17 translocation associated with recurrent spontaneous abortions, and request contact with colleagues who have observed similar cases.
DEFECTIVE JEJUNAL BRUSH BORDER Na+/H+ EXCHANGE IN LETHAL FAMILIAN PROTRACTED DIARRHOEA
1989
The clinical spectrum of disease associated with the recently described defect in jejunal brush border membrane (BBM) Na+/H+ exchange remains poorly defined. We describe a further, lethal case of protracted diarrhoea in a child from a family in whom 2 previous siblings died of protracted diarrhoea at 2 and 11 months. The patient, a boy, was born at term weighing 2.9 kg and was admitted at 6d with profuse watery diarrhoea, severe dehydration and metabolic acidosis. Parenteral nutrition was started but the diarrhoea persisted, and he developed severe necrotising enterocolitis requiring an ileostomy. A high-output secretory diarrhoea persisted during nil by mouth (ileostomy fluid mmol/l: Na+ 1…
Multiphoton-ionization transition amplitudes and the Keldysh approximation.
1989
The Keldysh approximation to treat the multiphoton ionization of atoms is reconsidered. It is shown that, if one consistently uses the hypothesis under which the approximation should be valid (essentially, that of a weak, short-range binding potential), a Keldysh-like term results as an approximation to the first term of a uniformly convergent series in powers of the binding potential. No cancellation occurs when higher-order terms are taken into account. This result allows one to consider the Keldysh approximation as a well-defined theoretical model, without implying, however, that it is adequate to describe multiphoton ionization of real atoms.
Fast orthometalation reactions at a binuclear dirhodium(II) complex. Synthesis, crystal structure and reactivity of Rh2(O2CCH3)3[(C6H4)PPh2]·(HO2CCH3…
1989
Abstract From the reaction of Rh2(O2CCH3)4(MeOH)2, in hot acetic acid with PPh3 the monometalated intermediate Rh2(O2CCH3)3[(C6H4)PPh2](HO2CCH3)2 has been isolated and characterized by an X-ray study. This compound rapidly reacts with an excess of PPh3 in dichloromethane at room temperature to give Rh2(O2CCH3)2-[(C6H4)PPh2]2(PPh3)2 with a head-to-tail structure. The same procedure at higher temperatures gives a mixture of this compound and another doubly metalated compound with a head-to-head structure.
Survival strategies of the crab spider Thomisus onustus Walckenaer 1806 (Chelicerata, Arachnida, Thomisidae).
1989
The initial energy supply of emerging spiderlings is relatively meagre, so survival without feeding on insects during a spell of bad weather is limited to a period of a few days or weeks. During our investigations, spiderlings of Thomisus onustus (Arachnida, Thomisidae) were kept on different diets. There was a significant difference in survival rate between spiderlings that were starved or fed on pollen, “nectar”, or Drosophila. The results showed that pollen and nectar can be a source of energy for spiders for an extensive period. This demonstrates another way in which spiders may survive starvation when insect prey is lacking and thus ensure the survival of a whole population.
La Distribution de la matiere organique dans la formation de Noto, roche-mere du bassin de Ragusa (Sicile)
1989
Congenital hyperthyroidism with reciprocal translocation t(1;17)(q25;q21)
1989
The authors report a case of 1;17 translocation and request contact with colleagues who have observed similar cases.
Effects of modelling on children's pretend play.
1989
The effects of modelling on pretend play were studied in children between 2.6 and 3.6 years of age by examining changes both in the action and language-based expressions of pretending. Three modelled scenes were demonstrated with the same realistic toys used by the child in the pre-modelling phase. The results gave support to the idea of the effectiveness of modelling. The effects of the modelled scenes were clearest among children whose pre-modelling play consisted of object-centred actions including few of pretending. The post-modelling play of this subgroup showed better quality of action and language categories and integration measures. Among the decentred players no significant action …
Effects of an ultra-long-distance (1000 km) race on lipid metabolism
1989
The influence was examined of ultra-long-distance running (1000 km race lasting 20 days) on changes in serum lipids. The 110 participants received two types of diet, a conventional Western diet and a wholesome vegetarian diet. Of the 55 finishers the serum concentration of total cholesterol, low density lipoprotein (LDL)-cholesterol, apolipoprotein B and triglycerides decreased significantly during the first 8 days of the run, but rose again towards the end of the race without reaching pre-race levels. The high density lipoprotein (HDL)-cholesterol increased initially but decreased in the final days of the run. The values for apolipoprotein A-I were not correlated with HDL-cholesterol. The …
Microscopic s-wave optical potential for slow pions scattered by a nucleus.
1989
We have done a microscopic calculation of the {ital s}-wave optical potential for the pion-nucleus system at low energies, 0{le}{ital T}{sub {pi}}{le}100 MeV, using a description based on hadronic degrees of freedom. We have obtained, separately, the real and imaginary parts of the optical potential coming from one-body and two-body processes. We have also separated the imaginary part of the potential associated to absorption and to quasielastic channels. We find that the imaginary part of the absorption channel is independent of the energy (within the range of energies considered here) in agreement with a recent empirical determination. We compare our results with phenomenological potentia…
Trisomy 12 and translocation (7;9) in an ovarian immature teratoma.
1989
We report a case of an immature malignant ovarian teratoma with peritoneal implants diagnosed in an 18-year-old woman. The tumor was brought into remission after surgery (three laparotomies) and adjuvant chemotherapy. A residual peritoneal implant showed a mature epithelial and glial configuration. Histologically, the neuroectodermal component was dominant in the original tumor as well as in the metastases, being confirmed by immunohistochemistry and electron microscopy. A stem cell line has been obtained with cell culture, having a germ cell character and a yolk sac configuration. This line possessed a trisomy 12 and a translocation (7;9) similar to other chromosomal abnormalities describe…
Ciclosporin and thyroid-stimulating immunoglobulins in endocrine orbitopathy.
1989
The study investigated whether ciclosporin (C) affected the thyroid-stimulating immunoglobulins (TSI) in serum of patients with endocrine orbitopathy (EO). The effect of C was compared with that of prednisone (P). Fifteen patients with EO classes III-V received C (n = 7) or P (n = 8). In addition to the immunosuppressants, five patients with Graves' disease in each group received methimazole (MMI). The stimulation of the cAMP levels in the medium of thyrocyte cultures was determined as a parameter of TSI. The TSI levels were markedly lowered in both groups during and after therapy. C group: before therapy 6.2 pmol/ml +/- 1.63 (100%, mean +/- SEM), during treatment 4.6 pmol/ml +/- 2.28 (74%)…
Chromatin structure of transposon Tn903 cloned into a yeast plasmid
1989
Transposon Tn903 contains the APH gene for kanamycin resistance, which is active in yeast [A. Jiménez and J. Davies (1980) Nature (London) 287, 869-871] and is flanked by two inverted repeats (IR) 1057 bp long. When plasmid pAJ50, carrying Tn903 and the 2-microns circle origin of replication, is cloned into Saccharomyces cerevisiae, nucleosomes are assembled in vivo on the prokaryotic DNA of the transposon. Indirect end labeling revealed that three nucleosomes are preferentially positioned on symmetrical sequences from both IRs. DNase I digestion also confirmed that the chromatin structure is symmetrical in both IRs. This suggests that sequence determinants are decisive for chromatin struct…
Prévisions des dépenses d'éducation prioritaire à l'horizon 2000 dans les pays en développement
1989
Référence interne : 89080; L'objet de ce rapport est de fournir une évaluation chiffrée de la dépense publique que devraient supporter les pays en développement pour satisfaire la demande d'éducation primaire qui est prévue en l'an 2000, et d'estimer également le coût qu'impliquerait la généralisation de l'enseignement primaire à cette même époque.