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Biomedical subjects

G Huber

Publications and source records attributed to G Huber.

At least 19 recordsLinked to original sources
PubMed2006

Reactivity, stability, and strength performance capacity in motor sports.

BACKGROUND: Racing drivers require multifaceted cognitive and physical abilities in a multitasking situation. A knowledge of their physical capacities may help to improve fitness and performance. OBJECTIVE: To compare reaction time, stability performance capacity, and strength performance capacity of élite racing drivers with those of age-matched, physically active controls. METHODS: Eight élite racing drivers and 10 physically active controls matched for age and weight were tested in a reaction and determination test requiring upper and lower extremity responses to visual and audio cues. Further tests comprised evaluation of one-leg postural stability on a two-dimensional moveable platform, measures of maximum strength performance capacity of the extensors of the leg on a leg press, and a test of force capacity of the arms in a sitting position at a steering wheel. An additional arm endurance test consisted of isometric work at the steering wheel at +30 degrees and -30 degrees where an eccentric threshold load of 30 N.m was applied. Subjects had to hold the end positions above this threshold until exhaustion. Univariate one way analysis of variance (alpha = 0.05) including a Bonferroni adjustment was used to detect group differences between the drivers and controls. RESULTS: The reaction time of the racing drivers was significantly faster than the controls (p = 0.004). The following motor reaction time and reaction times in the multiple determination test did not differ between the groups. No significant differences (p>0.05) were found for postural stability, leg extensor strength, or arm strength and endurance. CONCLUSIONS: Racing drivers have faster reaction times than age-matched physically active controls. Further development of motor sport-specific test protocols is suggested. According to the requirements of motor racing, strength and sensorimotor performance capacity can potentially be improved.

Adult↗
PubMed2005

"Safe" Coulomb excitation of 30Mg.

We report on the first radioactive beam experiment performed at the recently commissioned REX-ISOLDE facility at CERN in conjunction with the highly efficient gamma spectrometer MINIBALL. Using 30Mg ions accelerated to an energy of 2.25 MeV/u together with a thin (nat)Ni target, Coulomb excitation of the first excited 2+ states of the projectile and target nuclei well below the Coulomb barrier was observed. From the measured relative deexcitation gamma-ray yields the B(E2;0(+)gs-->2(+)1) value of 30Mg was determined to be 241(31)e2 fm4. Our result is lower than values obtained at projectile fragmentation facilities using the intermediate-energy Coulomb excitation method, and confirms the theoretical conjecture that the neutron-rich magnesium isotope 30Mg resides outside the "island of inversion."

Journal Article↗
PubMed2004

Diode pumping of a continuous-wave Pr3+-doped LiYF4 laser.

We report, for the first time to our knowledge, diode-pumped cw laser oscillation of Pr3+:LiYF4 in the red spectral range. The pump power is provided by a GaN laser diode emitting a maximum output power of 25 mW at a wavelength of approximately 442 nm. The Pr3+ laser emits 1.8 mW of output power at a 639.7-nm wavelength. Threshold pump power and slope efficiency in a nonoptimized setup are determined to be 5.5 mW and 24%, respectively.

Journal Article↗
PubMed2004

[Idiopathic psychosyndromes in the sight of Werner Janzarik].

In the 50 years of his scientific activity Werner Janzarik has also dealt with idiopathic psychosyndromes, the affective and schizophrenic psychoses. Our paper shows that the scientific work of Janzarik has essentially participated in the foundation of a scientific psychopathology of idiopathic psychosyndromes. In this connection Janzarik has used the whole spectrum of methods relevant for psychiatry in a very fruitful manner. It becomes evident that the step by step developed structural-dynamic concept of an anthropologically psychopathology represents today a substantial basis of a scientific psychiatry that presupposes understanding and knowledge of a comprehensive psychiatric experience related to patients. The transfer of his structural-dynamic approach to the idiopathic psychosyndromes turns out to be a new way of synopsis and integrated interpretation of the psychopathological and biological data relevant for psychiatry. His conclusive psychopathological concept certainly has, independently of its importance for psychiatric practice, a value on its own but must not dispense with psychiatric practice. The structural-dynamic design of Janzarik enables as scarcely an other concept manifold concretisations and transformations into empirically verifiable working hypotheses, also in the utilisation for the clinical psychiatry of idiopathic psychosyndromes and in reflecting their diagnostic and therapeutic aspects. The newly again recognisable tendency to a dividing up of our discipline into a somatic and a psychic position, into too much reductionistic and objectifying procedures of a biological psychiatry and one-sided psychonomic, anthropological, psychoanalytic and system-theoretical interpretations, proves the necessity and fruitfulness of the approach of Janzarik and its untimely character in a positive sense of great promise for the future, demonstrated just also in idiopathic psychosyndromes. The structural-dynamic way of consideration of idiopathic psychosyndromes, on the first sight, faced with the scientistic orientation of the contemporary psychiatry, appearing not useful, has meanwhile long ago on a large scale arrived at the research and practice of clinical psychiatry of affective and schizophrenic psychosyndromes.

Affective Disorders, Psychotic↗
PubMed2003

Improved test of time dilation in special relativity.

An improved test of time dilation in special relativity has been performed using laser spectroscopy on fast ions at the heavy-ion storage-ring TSR in Heidelberg. The Doppler-shifted frequencies of a two-level transition in 7Li+ ions at v=0.064c have been measured in the forward and backward direction to an accuracy of Deltanu/nu=1 x 10(-9) using collinear saturation spectroscopy. The result confirms the relativistic Doppler formula and sets a new limit of 2.2 x 10(-7) for deviations from the time dilation factor gamma(SR)=(1-v2/c2)(-1/2).

Journal Article↗
PubMed2003

Stabilization of intracavity frequency-doubled lasers with type I phase matching.

We report a new method for stabilizing the power of intracavity frequency-doubled multimode lasers with type I phase matching. Such lasers usually show strong fluctuations of the output power caused by coupling of longitudinal laser modes in the nonlinear crystal. We eliminate these fluctuations by placing the gain medium and nonlinear crystal in specific locations in the laser cavity where the nonlinear coupling of different longitudinal modes is strongly reduced.

Journal Article↗
PubMed2003

Cluster calibration in mass spectrometry: laser desorption/ionization studies of atomic clusters and an application in precision mass spectrometry.

For accurate mass measurements and identification of atomic and molecular species precise mass calibration is mandatory. Recent studies with laser desorption/ionization and time-of-flight analysis of cluster ion production by use of fullerene and gold targets demonstrate the generation of atomic clusters for calibration purposes. Atomic ion results from the Penning trap mass spectrometer ISOLTRAP, in which a carbon cluster ion source has recently been installed, are presented as an application in the field of precision mass spectrometry.

Journal Article↗
PubMed2003

All-solid-state continuous-wave frequency-doubled Nd:YAG-BiBO laser with 2.8-W output power at 473 nm.

We report on a diode-pumped Nd:YAG laser with 4.6 W of linear polarized continuous-wave (cw) output power on the 4F3/2 --> 4I9/2 transitions at 946 nm. Three different crystals, cut for critical type I phase matching at room temperature, are used for the intracavity frequency doubling of the laser: 10-mm-long LiBaO5 (LBO), an 8-mm-long beta-BaB2O4 (BBO), and a 10.4-mm-long BiB3O6 (BiBO) grown by FEE GmbH. Up to 2.8 W of cw output power in the blue spectral range at 473 nm has been achieved with the BiBO crystal (2.1 W with BBO and 1.5 W with LBO).

Journal Article↗
PubMed2003

Anxiety scores before and after prenatal testing for congenital anomalies.

OBJECTIVE: Prenatal diagnosis has psychological effects on the pregnant woman. We studied the state of anxiety levels in 332 pregnant women presenting between the 12th and 20th week of gestation before and after prenatal examination with negative and positive prenatal findings. RESULTS: Prenatal examination produced a positive finding in 37 cases (11.1%). Both before and after prenatal examination pregnant women with a positive finding showed significantly higher anxiety-scales when compared to women with a negative result. After the examination state-anxiety levels were significantly reduced with a negative prenatal scan, whereas anxiety levels remained constant with a positive result. CONCLUSIONS: Prenatal testing for fetal anomalies presents an anxiety-inducing situation for the parents-to-be. If the results are negative, anxiety is reduced. Pregnant women who are confronted with a positive malformation scan show unchanged levels of anxiety after the examination.

Adult↗
PubMed2003

Alzheimer's disease proteins in cerebellar and hippocampal synapses during postnatal development and aging of the rat.

Alzheimer's dementia may be considered a synaptic disease of central neurons: the loss of synapses, reflected by early cognitive impairments, precedes the appearance of extra cellular focal deposits of beta-amyloid peptide in the brain of patients. Distinct immunocytochemical patterns of amyloid precursor proteins (APPs) have previously been demonstrated in the synapses by ultrastructural analysis in the cerebellum and hippocampus of adult rats and mice. Now we show that during postnatal development and during aging in these structures, the immunocytochemical expression of APPs increases in the synapses in parallel with the known up-regulation of total APPs brain levels. Interestingly, as shown previously in the adult rodents, the presenilins (PSs) 1 and 2, which intervene in APPs metabolism, exhibit a synaptic distribution pattern similar to that of APPs with parallel quantitative changes throughout life. In the brain tissue, single and double immunocytochemistry at the ultrastructural level shows co-localisation of APPs and PSs in axonal and dendritic synaptic compartments during postnatal synaptogenesis, adulthood and aging. In addition, double-labelling immunocytofluorescence detects these proteins close to synaptophysin at the growth cones of developing cultured neurons. Thusly, the brain expression of APPs and PSs appears to be regulated synchronously during lifespan in the synaptic compartments where the proteins are colocated. This suggests that PS-dependent processing of important synaptic proteins such as APPs could intervene in age-induced adjustments of synaptic relationships between specific types of neurons.

Aging↗
PubMed2003

The influence of gestational age on depressive reactions, stress and anxiety of pregnant women and their partners in relation to prenatal diagnosis.

Prenatal diagnosis is usually performed in the early weeks of gestation in order to avoid medical and emotional maternal risks in the event of fetal malformation. This study examines emotions such as depression, stress and anxiety in pregnant women and their partners with regard to the week of gestation in which the prenatal diagnosis was made. In total, 452 pregnant women (between 7 and 40 weeks' gestation) and 274 partners participated in this study. The pregnant women were divided into four groups of 113 subjects each according to length of pregnancy (group 1 = 7-15 weeks' gestation, group 2 = 16-18 weeks' gestation, group 3 = 19-23 weeks' gestation and group 4 = 24-40 weeks' of gestation). Depression, stress and Spielberger state-trait anxiety levels were measured before the prenatal examination, and stress and state anxiety were assessed after prenatal examination. Statistical analysis was performed using analysis of variance (ANOVA). After the prenatal examination, the mean values of state anxiety (p = 0.032) and stress (p = 0.030) showed statistically significant differences in the pregnant women. Their partners only showed statistically significant differences in the stress values (p = 0.048) after examination. In conclusion, emotional stress related to the prenatal diagnosis seems to be largely independent of gestational age. Ultrasound scans give the parents-to-be a clearer image of their unborn child, as their perception of the fetus is transformed from that of an anonymous object into an individual.

Analysis of Variance↗
PubMed2002

Normal values of fetal ductus venosus blood flow waveforms during the first stage of labor.

OBJECTIVE: To present normal values of fetal ductus venosus blood flow waveforms during the first stage of labor during and between contractions. MATERIALS AND METHODS: Seventy-eight women between the 37th and 41st weeks of gestation were included in the study. At distinct stages of cervical dilation, blood flow velocity waveforms of the fetal ductus venosus during and between contractions were visualized in fetuses with a normal non-stress test. The pulsatility index for veins, peak velocity index for veins and fetal heart rate were calculated off-line. The means +/- standard deviations (SD) during and between contractions were compared using the Wilcoxon test. RESULTS: Ductus venosus blood flow velocity waveforms were visualized during 331 contractions and 375 episodes of uterine quiescence in 74 of 78 fetuses (95%) during normal labor. The mean +/- standard deviation values of pulsatility and peak velocity indices for veins during contractions were 1.66 +/- 0.85 (median: 1.56, range: 0.29-4.69) and 1.46 +/- 0.65 (median: 1.34, range: 0.26-3.13), respectively. Between contractions the values were 0.48 +/- 0.19 (median: 0.46, range: 0.14-1.00) for the pulsatility index and 0.44 +/- 0.18 (median: 0.42, range: 0.14-1.00) for the peak velocity index for veins. These differences during and between contractions were highly significant (P-value < 0.0001), whereas the fetal heart rate showed no significant differences. CONCLUSION: There are significant differences in fetal ductus venosus blood flow waveforms during and between labor contractions. Further studies should evaluate whether these normal values of the fetal ductus venosus are beneficial for risk evaluation in fetuses with an abnormal non-stress test and/or intrauterine growth restriction.

Adult↗
PubMed2002

[Psychopathology - an exhausted mine?].

Proceeding from the considerations of European psychiatrists that trends in the contemporary psychiatry seem to underestimate or even neglect the psychopathological approach, resulting in a threatening loss of clinical-psychiatric competence, this critical review deals with the reasons and arguments, why our discipline does still need the phenomenological PP for diagnostics and therapy, practice and research. Only the PP under discussion is able to meet the demand of clinical psychiatry to provide a reasonably reliable description of symptoms and syndromes, upon which rational diagnosis and adequate prevention and treatment can be based. The overly objectifying psychiatry of Kraepelin has been overcome by the descriptive-analytic and understanding PP in the direction of Jaspers and Schneider, aiming more at the elucidation of the patients' own inner experiences than at the observation of behaviour and expression. It is shown that important concepts, findings and results of the classical and recent psychiatry could be obtained by means of the PP, developed by representatives of the German speaking clinical psychiatry and psychology. PP has to take the lead previous to all other basic sciences, relevant for our discipline, also because it is not a self-contained theory, but an open approach, based on methodological reflection, showing ways for research. If the maxime "phenomenology is prior to genesis and interpretation" is ignored, or, if this PP is confused with and mistaken for philosophical phenomenology, the results of such a procedure must be doubtful. An intense training and thorough adoption of PP, the "phenomenological attitude" of the physician is urgently demanded as well by German speaking as recently also by anglophone psychiatrists. The substantial influence of the "phenomenological attitude" on psychology and sociology of clinical practice, on the atmosphere of a psychiatric hospital and the style and kind of psychiatric research, due to the fact that the psychopathologist can do practical and scientific work only with the patient and in very close relation with the patient, is also meaningful in order to avoid faulty developments. In this connection the dependence of psychiatry of political and sociological conditions and its susceptibility for ideologies is discussed and illustrated by some pertinent examples of the last decades.

Clinical Competence↗
PubMed2001

Critical geometry of two-dimensional passive scalar turbulence.

Passive scalars advected by a magnetically driven two-dimensional turbulent flow are analyzed using methods of statistical topography. The passive tracer concentration is interpreted as the height of a random surface, and the scaling properties of its contour loops are analyzed. Various exponents that describe the loop ensemble are measured and compared to a scaling theory. This leads to a geometrical criterion for the intermittency of scalar fluctuations.

Journal Article↗
PubMed2001

Preimplantation genetic diagnosis in Germany - ethical responsibility and law.

Preimplantation diagnosis (PGD) can be judged as early or brought forward prenatal diagnosis and brings up the ethical question in Germany whether potential selection of embryos and intentional killing of a human conceptus, showing a defect not or almost not compatible with life, is reconcilable with human dignity. Whereas prenatal diagnosis and its consequences are socially accepted in Germany, PGD is not compatible with the Embryo Protection Law and is still under debate since >5 years. On the other hand abortion is not subject to prosecution because the legal status of the mother outweighs that of the embryo or fetus. Here the conflict of two legally protected rights - the embryo's worth of protection and the woman's family planning - are accepted and form the basis of the potential decision of the prospective mother to carry the fetus to term or not. An obvious and deep contradiction of assessment is present between the legal requirements for the regulation of abortions in its amendment of 1995 and the Embryo Protection Law which exists unchanged since 1991. The killing of an embryo or fetus in vivo is not subject to prosecution although it is illegal, whereas the discard of an embryo in vitro after PGD was performed, also illegal, is subject to prosecution.

Journal Article↗
PubMed2001

[The psychopathology of delusion, the principle of psychonomy and biological theory of delusion].

The psychopathology of the delusional experiences of schizophrenic patients is analyzed on the basis of a sample of 119 drug-naive patients and 502 patients of the Bonn-Schizophrenia-Study. The phenomenology, the forms and themes of delusion, the delusional certainty, the impact on behaviour ("Realitätsbedeutung"), the levels of development of delusional perception and the meaning of the psychological working-up of the primordial delusional experiences ("Wahnarbeit") are described. The structure-dynamic and the 'gestalt'-psychological approaches of Janzarik and Kisker try to derive the phenomenon of delusional psychoses from the psychonomy of the emotional connections, as far as they cannot be explained as immediate symptoms of a somatic illness. [7]. The present study also shows that subjective experiences of schizophrenic patients, suffering from delusions, largely develop psychonomically according to the rules of the psychic motivational dynamic, and that the share of the comprehensible working-up and assimilation with regard to the "schizophrenic end-phenomena" [16] has been considered too little by the traditional psychiatry. But, there are in the view of the basic symptom concept, especially in process active stages, hints at a higher share of the somatic component as to the structure of delusional syndromes. Looking at the processes, determined by the psychic causality on the one side, and at the boundaries of "genetic understanding" [39] in the delusional psychosis on the other side, we tried to answer the question to what extent the delusional psychosis can be understood according to the "principle of psychonomy" [5,6], and, in what respect it seems to be "apsychonomic" and thereby presumably somatically founded. The inquiry yields starting points for a biological hypothesis of delusion, compatible with a multidimensional conception, that reveals understandable connections between delusion and biography and shows the reach of the "principle of psychonomy".

Delusions↗