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  • 1
    Electronic Resource
    Electronic Resource
    On the current-voltage relationship in auroral breakups and westwards-travelling surges (1997)
    Springer
    Annales geophysicae 14 (1997), S. 1265-1273 
    Details
    ISSN: 0992-7689
    Source: Springer Online Journal Archives 1860-2000
    Topics: Geosciences , Physics
    Notes: Abstract Auroral precipitating electrons pass through an acceleration region before entering the atmosphere. Regardless of what produces it, a parallel electric field is assumed to cause the acceleration. It is well known that from kinetic theory an expression for the corresponding upward field-aligned current can be calculated, which under certain assumptions can be linearized to j‖ = KV. The K constant, referred to as the Lyons-Evans-Lundin constant, depends on the source density and thermal energy of the magnetospheric electrons; it is an important parameter in magnetosphere-ionosphere coupling models. However, the K parameter is still rather unknown, and values are found in a wide range of 10−8–10−10Sim−2. In this study, we investigated how the type of auroral structure affects the K values. We look at onset and westwards-travelling surge (WTS) events and make comparisons with earlier results from observations of more stable auroral arcs. A new analysis technique for studying those magnetospheric parameters using ground-based measurements is introduced. Electron density measurements are taken with the EISCAT radar, and through an inversion technique the flux-energy spectra are calculated. Source densities, thermal energies and potential drops are estimated from fittings of accelerated Maxwellian distributions. With this radar technique we have the possibility to study the changes of the mentioned parameters during the development of onsets and the passage of surges over EISCAT. The study indicates that the linearization of the full Knight formulation holds even for the very high potential drops and thermal temperatures found in the dynamic onset and WTS events. The values of K are found to be very low, around 10−11Sm−2 in onset cases as well as WTS events. The results may establish a new technique where ionospheric measurements are used for studying the ionosphere-magnetosphere coupling processes.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s00585-996-1265-2
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  • 2
    Electronic Resource
    Electronic Resource
    Bone mineral density in patients with prostatic cancer treated with orchidectomy and with estrogens (1995)
    Springer
    Calcified tissue international 57 (1995), S. 97-99 
    Details
    ISSN: 1432-0827
    Keywords: Bone mineral density ; Bone mineral content ; Prostatic cancer ; Endocrine treatment
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Notes: Abstract Bone mineral density (BMD) and bone mineral content (BMC) were measured in the femoral neck area, trochanteric area and Wards triangle, and in the distal radius of the left forearm before and after 1 year of endocrine treatment in 27 patients with prostatic cancer. Eleven of the patients were treated with orchidectomy and 16 with combined oral and intramuscular estrogens. The patients were free from metastases during the entire observation period. In the orchidectomized patients, BMD and BMC of the distal radius decreased significantly following treatment, whereas no changes were observed in the estrogen-treated patients. These preliminary results demonstrate that estrogens may protect bone in male subjects also and may merit further investigations on larger groups of patients.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00298427
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    Paper (German National Licenses)
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  • 3
    Electronic Resource
    Electronic Resource
    Smoothelin in adult and developing human arteries and myocardium (1999)
    Springer
    Histochemistry and cell biology 112 (1999), S. 291-299 
    Details
    ISSN: 1432-119X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract  The aim of this investigation was to study, with immunohistochemical methods, the distribution of the novel cytoskeletal protein smoothelin in human cardiovascular tissues, the possible changes during the development of the cardiovascular system and its correlation to the intermediate filament proteins desmin and vimentin. Smoothelin was detected in smooth muscle cells of the fetal coronary arteries. In very young subjects (up to 3 months of age), only a few cells in the media of the elastic arteries contained smoothelin, whereas it was present in most smooth muscle cells in the muscular arteries. In individuals older than 1 year, most smooth muscle cells in the media of all blood vessels contained smoothelin. In vessels with a developed intima, smoothelin was present in a variable proportion of the smooth muscle cells. With few exceptions, smoothelin was more frequently detected than desmin in medial smooth muscle cells. Smoothelin and vimentin were codistributed in the smooth muscle cells of the media in most vessels. In the cardiomyocytes (fetal to adult age), the smoothelin antibody detected epitopes located at the Z-disc level but not in the intercalated discs. In conclusion, smoothelin is more widely distributed in the muscular arteries than in the elastic arteries early in life, and thus exhibits a variable distribution during postnatal development of vascular tissues. In the adult, smoothelin is detected in the media of most vascular smooth muscle cells, both in muscular and elastic arteries, and is not necessarily codistributed with either desmin or vimentin. Evidence that smoothelin is present in human striated cardiomyocytes is also presented.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s004180050450
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  • 4
    Electronic Resource
    Electronic Resource
    Three-Dimensional Ultrasonic Crack Detection in Anisotropic Materials (1997)
    Springer
    Research in nondestructive evaluation 9 (1997), S. 59-79 
    Details
    ISSN: 1432-2110
    Source: Springer Online Journal Archives 1860-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: Abstract. The scattering of probe-generated ultrasonic fields incident upon a strip-like crack in an anisotropic half-space is discussed. In the situation considered, two possibly coinciding probes are attached to the surface of the half-space. One is transmitting waves incident upon the crack and the other one is receiving the scattered waves. An electric signal response is calculated via an electromechanical reciprocity relation. For a crack far away from the probes and the surface, an approximate expression is calculated. Several numerical examples are presented for an isotropic and a transversely isotropic solid. The results are presented as A-, B-, and C-scans.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/PL00003890
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  • 5
    Electronic Resource
    Electronic Resource
    Brain monoaminergic and neuropeptidergic variations in human aging (1996)
    Springer
    Journal of neural transmission 103 (1996), S. 101-115 
    Details
    ISSN: 1435-1463
    Keywords: Human brain ; aging ; monoamines ; neuropeptide Y ; somatostatin ; corticotropin-releasing factor ; HPLC
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The effect of age on the monoamines 5-hydroxytryptamine (5-HT), noradrenaline (NA) and dopamine (DA), their metabolites 5-hydroxyindoleacetic acid (5-HIAA), homovanillic acid (HVA), 3,4-dihydr-oxyphenylacetic acid (DOPAC), and the 5-HT precursor 5-hydroxy-L-tryptophan (5-HTP), together with the peptides neuropeptide Y (NPY), somatostatin (SOM), and corticotropin-releasing factor (CRF), was studied in frontal cortex, gyrus cinguli and hypothalamus from 23 healthy control subjects, aged 16–75 years. After correcting for postmortem interval, significant decreases in gyrus cinguli NA, NPY and CRF, and hypothalamic DA, HVA, and 5-HIAA concentrations were obtained with advancing age. The involvement of the monoaminergic system in several functional abnormalities appearing in senescence is suggested. Furthermore, evidence is given of the participation of the peptidergic systems in the aging process.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01292620
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    Paper (German National Licenses)
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