showing 36 of ~574560 from 574555 documents
�ber die Minimall�sung der Poincar�-Perronschen Differenzengleichung
1991
This paper deals with a special class of solutions of the higher order linear difference equation. It is shown that the minimal solution of Poincare-Perron type equations can be expressed in terms of generalized continued fractions.
Age and Protein Restriction Followed by Balanced Refeeding Affect Pancreatic Digestive Enzyme Outputs and Turnover Times in Rats
1991
Outputs and turnover times of trypsinogen 2, chymotrypsinogen 1, lipase and amylase were determined in pancreatic juice of growing male Wistar rats at various times during protein restriction (5% protein) followed by balanced refeeding (20% protein). In control rats fed a 20% protein diet, trypsinogen 2, chymotrypsinogen 1 and amylase outputs increased progressively with age, those of lipase remained constant and the turnover times of the four hydrolases were shortened. With time, protein restriction induced the most rapid decrease in trypsinogen 2 output, followed by that of amylase, then by those of trypsinogen 1 and lipase. Compared with controls, protein restriction enhanced specific ra…
Anomalies from the Wess-Zumino-Witten action
1991
We show that the two most frequent expressions for the anomalous commutators can be both derived from quantities associated with the WZW model.
Parenchyma-sparing surgery for renal tumors
1991
Between 1969 und 1989 conservative surgery for kidney tumors was performed in 123 patients. In 49 patients there was an imperative indication for a parenchyma-sparing operation because nephrectomy would have made dialysis obligatory. Thirty-five of these 49 patients show no signs of tumor progression after a mean follow-up of 4.5 years. Known metastases were present in 3 of 6 patients who died as a result of their tumors. In two patients there was a recurrence after 1 and 5 years, respectively, requiring a second organ-preserving operation. In one further patient we suspect that multiple small tumor lesions may be present 2 years after the first operation. In 74 patients with a healthy cont…
The master two-loop two-point function. The general case
1991
Abstract We present a new calculation of the two-loop two-point function. Avoiding standard techniques such as Feynman parametrization and Wick rotation we end up with a simple double integral representation valid for arbitrary mass-cases. Numerical and analytical checks confirm our result.
What Bayesians Expect of Each Other
1991
Abstract Our goal is to study general properties of one Bayesian's subjective beliefs about the behavior of another Bayesian's subjective beliefs. We consider two Bayesians, A and B, who have different subjective distributions for a parameter θ, and study Bayesian A's expectation of Bayesian B's posterior distribution for θ given some data Y. We show that when θ can take only two values, Bayesian A always expects Bayesian B's posterior distribution to lie between the prior distributions of A and B. Conditions are given under which a similar result holds for an arbitrary real-valued parameter θ. For a vector parameter θ we present useful expressions for the mean vector and covariance matrix …
Interaction strength and shape difference for the h9/2 and h11/2 configurations in163Tm
1991
The strongly shape driving πh9/2[541]l/2− configuration with α=+1/2 exhibits some anomalous, and so far unexplained, features concerning the crossing frequency, ħωc, the aligned angular momentum, ix, and interaction strength, at the alignment of the first pair of i13/2 quasineutrons in several odd-Z rare earth-nuclei. The h9/2[541]1/2− and h11/2[523]7/2− bands have been studied in the stably deformed rare-earth nucleus163Tm to investigate these features. A difference in band crossing frequency of ∼ 80 keV between the two bands is found. Rotational bands built on these two configurations have been found to cross in the spin range I=25/2–29/2 ħ. Theγ-decay pattern between the two bands is est…
Proterozoic dykes of Salvador and Ilhéus-Olivença areas: a geological geoghemical comparison
1991
Polymer solution processing of (Bi, Pb)SrCaCuO
1991
Abstract A simple polymer processing route to the 110 K phase (Bi, Pb) 2 Sr 2 Ca 2 Cu 3 O 10+δ superconductor has been developed. The influence of the polymer to metal starting ratio, as well as the sintering temperature and time on the quality of the resulting superconducting powders has been studied by XRD, a.c. susceptibility and resistivity measurements. Microstructure of ceramic compacts has been studied by SEM, and qualitatively analysed by EDS for compositional homogeneity. The results indicate that the polymer synthesis route described here may offer a good alternative to the conventional solid state preparation methods towards attaining homogeneous 110 K superconductor powder withi…
Production properties ofD 0,D +,D *+ andD s + in 230 GeV/c? ? andK ?-Cu interactions
1991
We have studied the hadronic production of charmed mesons in the NA 32 experiment at CERN. A special trigger together with a high resolution vertex detector consisting of charge coupled devices and silicon microstrip detectors allowed the selection of very clean samples of charmed mesons. We have collected 852 fully reconstructed decays: 60D + →K + K −π+, 543D°→K −π+ andK −π+π−π+ as well as 249D +→K −π+π+ (or charge conjugate). 147 mesons out of our $${{D^0 } \mathord{\left/ {\vphantom {{D^0 } {\bar D^0 }}} \right. \kern-\nulldelimiterspace} {\bar D^0 }}$$ sample were produced via chargedD * state. For all charmed mesons we determine the total production cross-section and study thex F andp …
Vector supersymmetry in the universal bundle
1991
Abstract We present a vector supersymmetry for Witten-type topological gauge theories, and examine its algebra in terms of a superconnection formalism. When covariant constraints on the supercurvature are chosen, a correspondence is established with the universal bundle construction of Atiyah and Singer. The vector supersymmetry represents a certain shift operator in the curvature of the universal bundle, and can be used to generate the hierarchy of observables in these theories. This formalism should lead to the construction of vector supergravity theories, and perhaps to the gravitational analogue of the universal bundle.
Partially competitive inhibition of intestinal baclofen absorption by beta-alanine, a nonessential dietary aminoacid.
1991
In situ intestinal absorption of baclofen in the rat in the presence of beta-alanine has been investigated. Through the perfusion of 0.50 mM baclofen solutions containing variable concentrations of the aminoacid (from 5 to 100 mM), a partially competitive inhibition of baclofen absorption was characterized: absorption rate pseudoconstants of the spasmolytic drug decrease as beta-alanine concentration increases, until a limiting value is obtained (36.8 per cent of that found for baclofen alone). A computer method was developed in order to calculate parameters governing baclofen absorption in the presence of beta-aminoacid, with the following results: Vm = 11.22 mM h-1; Km = 7.42 mM; Ki = 2.4…
Low-temperature phosphorescence of 1,4-benzodiazepines
1991
Abstract A highly sensitive method for the low-temperature phosphorescence determination of a series of 1,4-benzodiazepines has been developed. Oxazepam has been used as a test molecule to study the effects of instrumental parameters, such as time decay, gate time, excitation and emission slits, and ordinate, on the phosphorescence spectra. The corresponding analytical parameters have been established for different concentration levels. Under the best sensitivity conditions a limit of detection of 16 parts per trillion (ppt) for oxazepam, 3.8 ppt for medazepam, 2 ppt for prazepam, 5 × 10 −3 ppt for diazepam, and 0.09 ppt for lorazepam could be obtained. The proposed method is thus the most …
Topological field theory
1991
Charakterisierung von Kettengeometrien �ber semilokalen Algebren
1991
Chain geometries over semilocal rings are characterized as special touching structures possessing a distinguished group of automorphisms fixing two distant points.
Lorenz character of the Doppler-broadened far-infrared laser
1991
The dynamic behavior of an optically pumped Doppler-broadened single-mode far-infrared laser is theoretically investigated in detail and compared with that of the simpler Lorenz–Haken laser. Through the analysis of phase diagrams, three-dimensional attractor’s projections, intensity maps, and the different terms of the laser equations, the analogies and the differences between the two models are determined. Optical pumping and Doppler broadening, present in this far-infrared laser model, can be approximately incorporated into a Lorenz–Haken model with effective parameters. These results represent a further step toward the understanding of the Lorenz-like behavior observed in recent years in…
Ocular pseudomyasthenia: report of a case with a pineal region tumor.
1991
A case presenting with clinical features of ocular myasthenia and a false-positive edrophonium test is reported. Brain CT and MRI scan revealed a pineal region tumor histologically verified as germinoma. We recommend evaluating patients with clinical features of myasthenia gravis (MG) confined to the ocular muscles for intracranial mass lesions.
Die Änderungen der Fußmaße unter einem extremen Ausdauerlauf
1991
55 (including 13 women) of 110 starters of a 1000-km-ultra long distance run reached their goal after 20 days of daily running 50 km. As a consequence of the burden of running 500 km the flat feet form is diminished, which might be caused by an increased reactive muscular tonus. The increase of foot length and breadth measures between the 9th and 16th day, however, demonstrates the opposite effect, when a "physiological limit" of circa 500 km is exceeded.
On the universal bundle for gravity
1991
Abstract We construct a supergravity type theory based on a superspace whose odd directions consist of a vector, together with a scalar representing a topological BRST shift symmetry. As such, the resulting theory is a theory of topological gravity. The gravitino is interpreted as a ghost field for this shift symmetry and plays the usual role of gauge field for local supersymmetry. Our construction is within the bundle of frames approach to superspace where covariant torsion constraints are analyzed, and we find that the resulting theory contains additional fields which are not present in existing theories of topological gravity. In particular, a minimal solution exists which contains a BRS…
Scaled factorial moments and split-bin correlation functions. A thermodynamic model comparison
1991
Abstract We compare the scaled factorial moments to the recently proposed split-bin correlation functions, using the thermodynamic model for heavy ion collisions that was recently demonstrated to exhibit power-law growth of the scaled factorial moments as a function of bin size. We find that the split-bin correlation functions are superior for experimental use, as they are intensitive to fictitious correlations due to limited resolving power. In addition, after correction for non-flat single-particle distributions, the split-bin correlation functions provide an unambiguous signal for correlations. As a result, they may provide more powerful evidence for new phenomena like fractal structure …
φ, ϱ, and ω production in pU, OU and SU reactions at 200 GeV per nucleon
1991
Abstract Low mass muon pair production at high P T and low X F studied in pU, OU and SU 200 GeV per nucleon react ions. When energy density or projectile mass are increased, φ production is enhanced as compared with the yield of muon pairs in the mass continuum (1.7 M μμ c 2 ), whereas the production of ω and ϱ, experimentally unresolved, remains approximately constant. This φ enhancement is in agreement with predictions based on quark-gluon plasma formation and, together with the previously reported J/Ψ suppression, puts severe constraints on a purely hadronic description of nucleus-nucleus collisions.
Pharmacokinetics and bioavailability of diclofenac in the rat.
1991
Diclofenac sodium is a widely used drug with interesting absorption and disposition features when administered to laboratory animals. The present study was undertaken to assess the pharmacokinetics of the drug after iv and gastrointestinal dosing to rats. Renal excretion of unchanged drug was negligible, but biliary excretion of the drug (unchanged and conjugated) was detected in bile duct-cannulated rats; it accounted for 27.2 and 31.2% of the total dose following iv and intraduodenal administration, respectively. Most of the drug excreted in the bile was conjugated diclofenac; unchanged drug accounted for only 4.7 and 5.4% of total diclofenac excreted in the bile after iv and intraduodena…
Anxiety and coping dispositions as predictors of the visual interaction between mother and child
1991
Abstract The “model of coping modes” distinguishes four dispositionally determined patterns of behavior (coping modes) which become apparent in stressful situations: repression, sensitization, nondefensiveness, and high anxiety. Following from this model, the present study is aimed at assessing associations between coping modes and children's looking behavior towards their mothers in a moderately stress-inducing laboratory setting. The visual exchange of 63 mothers and their eight- to 14-year-old children was observed during a ten-minute planning period for a Punch and Judy show which the child had to later perform. A close visual orientation toward the mother was registered for sensitizers…
Neue N-Arylsubstituierte 2,6-Difluorbenzamidine
1991
Abstract Addition of various anilines as their p -toluenesulfonic salts to 2,6-difluorobenzonitrileleads to N -aryl-2,6-difluorobenzamidinium- p -toluenesulfonates bearing N -aryl substituentsas follows: (2-fluorophenyl)-, (3-fluorophenyl)-, (4-fluorophenyl)-, (2-chlorophenyl)-, (3-chlorophenyl)-and (4-chlorophenyl)-. The corresponding N -aryl-2,6-difluorobenzamidineswere isolated as free bases. The characterization of the new compounds was done byIR, 1 H NMR and mass spectrometry.
The probability of prompt and delayed fission of muonic237Np
1991
Fission fragments from the reaction237Np(μ−,γ,f) have been measured in coincidence with muonic X-rays. The efficiency of the fission fragment detector is determined from (μ−,γ,f)-data of the same experiment. The total fission probability perμ-stopPt has been measured as well as the fission probabilities Pf of the non-radiative muonic (3d→1s)- and (2p→1s)-transitions; the latter has been divided into two parts leading to different mean excitation energiesE:P t =(54±17)%,P f (3d→1s)=(41±21)%,P f (2p→1s,E=6.218 MeV)=(61±19)%, andP f (2p→1s,E=6.525 MeV)=(57±18)%. The influence of the muon on the fission barrier is discussed. The fission probability after muon capture is compared with a calculat…
Das Körpermuskelkompartiment und seine Beziehungen zu Nahrungsaufnahme und Blutchemie unter einer extremen Ausdauerbelastung
1991
Untersuchungsgegenstand sind die Veranderungen des anthropometrisch erfasten Muskelkompartiments und seiner Beziehungen zu den korrelierenden blutchemischen und ernahrungsphysiologischen Kenngrosen bei 42 Teilnehmern und 13 Teilnehmerinnen eines 1000-km-Ultralangstreckenlaufs, der in 20 Tagesetappen von jeweils 50 km zu bewaltigen war. Differenziert nach Korperfraktionen folgt auf einen initialen Muskelmasseanstieg eine Abflachung bis zum 12. Tag und bleibt dann stabil. Die aktive Korpersubstanz nimmt zunachst geringfugig ab und steigt nach Laufmitte wieder an. Bei Abnahme samtlicher korrigierter Muskeldurchmesser zeigte lediglich der Oberschenkeldurchmesser eine anabole Entwicklung, dessen…
Effects of cadmium on the biochemical composition of the freshwater crayfishProcambarus clarkii (Girard, 1852)
1991
Lake Albufera of Valencia (Spain) and the surrounding rice field waters are subjected to very heavy loads of sewage and toxic residues. Among these residues include heavy metals which have been deposited from the many urban and waste waters in this area. The American red crayfish, Procambarus clarkii from Albufera Lake has high resistance to heavy metals. The authors have also found that P. clarkii shows a high capacity for cadmium accumulation in experimental conditions and natural conditions since crayfish collected in this area contained considerable amounts of cadmium in several tissues even after 15 days of depuration in clean water. Since the physiological changes that take place when…
Pointwise regularity of solutions to nonlinear double obstacle problems
1991
Chromosomal polymorphism and patterns of viability in natural populations of Drosophila melanogaster from cellar and vineyard.
1991
Two neighbouring natural populations of Drosophila melanogaster have been analysed, one from a cellar habitat and the other from a vineyard outside. An extensive study of inversion polymorphism in the two populations has been carried out. Furthermore, the relationship between inversion polymorphism and the viability of the second chromosome has been studied. The data regarding the total frequency of inversion-carrying chromosomes indicate a lower frequency in the cellar population than in the vineyard population. Some possibilities that could explain the behaviour of the chromosomes from the cellar in relation to the peculiar environment of this habitat are discussed. New endemic inversions…
Some Detrimental Effects of Negative Mood on Individuals' Ability to Solve Resource Dilemmas
1991
This research examined the effects of induced mood on subjects' problem-solving behavior In an initial study, an experimenter induced one of three emotions (happiness, sadness, or anger) or no emotion in subjects. Shortly thereafter a second experimenter asked each subject to solve a resource dilemma problem. Subjects in the sad and angry mood conditions were less successful (i.e., they were more likely to deplete limited resources, and they achieved less profit) than subjects in the happy or neutral mood condition. Performance of subjects in positive moods did not differ from that of subjects in neutral moods. In a second study, the effect of a sad mood leading to less success than a neut…
Ein neues captorhinomorphes reptil aus dem thüringischen rotliegend (Unter-Perm; Ost-Deutschland)
1991
Thuringothyris mahlendorffae n.gen. n.sp. is described on the basis of the skull roof, palate, stapes and much of the postcranial skeleton from the Upper Rotliegend (Tambach-Schichten) of the Thuringian Forest in eastern Germany. The new taxon shows both protorothyridid and some captorhinid features. The interrelationships of the »Protorothyrididae«, primitive Captorhinidae, and earliest Diapsida are reviewd. The tetrapod material is used to reassess the biostratigraphic position of the fossil-bearing horizon.
Atypical facial porokeratosis of Mibelli
1991
Summary An atypical case of porokeratosis of Mibelli that was localized to the face is reported.
How singular are black hole interiors?
1991
Abstract Ori has recently shown that an astronaut approaching the inner horizon of a black hole is not necessarily torn apart by tidal forces. This raises anew the possibility of astronavigation through black holes, perhaps to other universes. We re-examine this question in the light of hypotheses about probable conditions in the black hole core.
Jump-diffusion models of German stock returns
1991
This paper discusses the statistical properties of jump-diffusion processes and reports on parameter estimates for the DAX stock index and 48 German stocks with traded options. It is found that a Poisson-type jump-diffusion process can explain the high levels of kurtosis and skewness of observed return distributions of German stocks. Furthermore, we demonstrate that the return dynamics of the DAX include a statistically significant jump component except for a few sample subperiods. This finding is seen to be inconsistent with asset pricing models assuming that the jump component of the stock's return is unsystematic and diversifiable in the market portfolio.
Isolation and characterization of Saccharomyces cerevisiae mutants resistant to aculeacin A
1991
Aculeacin A is a lipopeptide that inhibits beta-glucan synthesis in yeasts. A number of Saccharomyces cerevisiae mutants resistant to this antibiotic were isolated, and four loci (ACR1, ACR2, ACR3, and ACR4) whose products are involved in the sensitivity to aculeacin A of yeast cells were defined. Mutants containing mutations in the four loci were also resistant to echinocandin B, another member of this lipopeptide family of antibiotics. In contrast, acr1, acr3, and acr4 mutants were resistant to papulacandin B (an antibiotic containing a disaccharide linked to two fatty acid chains that also inhibits beta-glucan synthesis), but acr2 mutants were susceptible to this antibiotic. This result …
Use of Social Reference Groups in Sport Policy Making
1991
Based on reference group theory the purpose of the present study was to determine how sport political decision-makers acted while making decisions, and which reference groups and backgrounds they selected for supporting their behavior. Furthermore, the aim was to find out how the reference group strategy of decision-makers had changed since the middle of the 1970's (Olin, 1982). A sample of 1788 officials and appointed representatives from 167 cities in Finland were selected for the study. The results indicated that the reference groups and backgrounds the majority of the decision-makers chose as bases for their decision behavior in order of descending importance were: the city officials p…