Showing papers by "University of Kiel published in 1978"

Sand deserts during glacial maximum and climatic optimum

Abstract: THE past 20,000 yr have witnessed tremendous climatic changes, a glacial maximum at about 18,000 yr BP and a climatic optimum centred on about 6,000 yr BP, both of which mark extreme situations for the Quaternary. This paper attempts to show that active sand dunes were extensive 18,000 yr ago. Conversely, it seems that sand dunes were generally dormant 6,000 yr ago. Thus the former textbook concept1,2 of an arid climatic optimum and a pluvially active glacial maximum is reversed.

Responses of group IV afferent units from skeletal muscle to stretch, contraction and chemical stimulation

Abstract: In an attempt to differentiate between nociceptive group IV muscle receptors and “ergoceptive” ones, the discharges of single group IV fibres from skeletal muscle in response to local pressure, sustained stretch, repetitive contraction and intra-arterial injections of bradykinin, 5-hydroxytryptamine (5-HT), potassium, phosphate, and lactate were studied in anaesthetized cats.

Autoradiography and Epifluorescence Microscopy Combined for the Determination of Number and Spectrum of Actively Metabolizing Bacteria in Natural Waters

Abstract: A technique is described for the determination of bacterial numbers and the spectrum of actively metabolizing cells on the same microscopic preparation by a combined autoradiography/epifluorescence microscopy technique. Natural bacterial populations incubated with [3H]glucose were filtered onto 0.2-μm Nuclepore polycarbonate membranes. The filters were cut into quarters and fixed on the surface of glass slides, coated with NTB-2 nuclear track emulsion (Kodak), and exposed to the radiation. After processing, the autoradiographs were stained with acridine orange. A combination of overstaining on the slightly alkaline side and gradual destaining on the acid side of neutrality gave the best results. Epifluorescence microscopy revealed bright-orange fluorescent cells with dark-silver grains associated against a greenish-to-grayish background. Based on the standardization curves, detection of actually metabolizing cells was optimal when cells were incubated with 1 to 5 μCi of [3H]glucose per ml of sample for 4 h and the autoradiographs were exposed to NTB-2 emulsion at 7°C for 3 days. In water samples taken immediately above sandy sediments at beaches of the Kiel Fjord and the Kiel Bight (Baltic Sea, FRG), between 2.3 and 56.2% (average, 31.3%) of the total number of bacteria were actually metabolizing cells. Spearman rank correlation analysis revealed significant interrelationships between the number of active bacteria and the actual uptake rate of glucose.

Sedimentation of particulate matter during a phytoplankton spring bloom in relation to the hydrographical regime

Abstract: Data presented and discussed here were collected continuously during April/May 1975 in the Bornholm Basin of the Baltic Sea. Sedimentation rates of particulate matter were recorded with 5 multisample sediment traps from different depths in the water column at 2 positions 170 km apart. Current meter data collected during the same period and depths indicated that the positions remained hydrographically distinct during the investigation. Particulate matter from the euphotic zone including diatom cells formed the bulk of the material collected by all traps. This flux of organic particles to the bottom was unimpeded by the strong density stratification present in the water column. The upper traps always collected less material than lower ones. This paradox has been ascribed to diminishing current speeds with depth, concomitant with an increase in sinking rates of phytoplankton and phytodetritus. Both factors influence the sampling efficiency of sediment traps, which are thought to have underestimated actual sedimentation rates here. A time lag of 2 to 3 weeks in bloom development seemed responsible for the characteristic differences between the two positions. The phase of major sedimentation at one position covered about 18 days, and a distinct sequence in the composition of the material collected by the 6 glasses of each trap indicated phases of a progressively deteriorating phytoplankton population in the water column contributing the particulate material. A total of 6.2 g C m-2 in 34 days was recorded at this station. Apart from a trap situated in an oxygen deficient layer which collected 0.44 g C m-2 of zooplankton corpses, zooplankton mortality was overestimated by the traps. Large-scale sedimencation of “fresh” organic matter produced by the spring bloom is probably a regular feature in areas with low over-wintering zooplankton populations and, as such, possibly has a direct stimulatory effect on growth and reproduction of the benthos.

Hypothalamic and Extrahypothalamic Distribution of Somatostatin-immunoreactive Elements in the Rat Brain

Abstract: Using a highly sensitive antibody to somatostatin, its hypothalamic and extrahypothalamic distribution in the rat was re-examined by light microscopic immunohistochemistry (PAP-method). The scattered somatostatin-producing perikarya occur in multiple layers within the subependymal neuropil surrounding the third ventricle. They supply with short-distance projections the following hypothalamic nuclei: 1) preoptic nuclei (especially their suprachiasmatic and medial components), 2) the peripheral zones of the suprachiasmatic nuclei, 3) the ventromedial and 4) arcuate nuclei, and 5) the ventral premammillary nuclei. Furthermore, the following long-distance projections have been observed: In a rostral direction (A1) rostral of the anterior commissure to the lamina terminalis, (A2) to the OVLT, (A3) to the olfactory tubercle, and (A4) rostrally and caudally by-passing the anterior commissure to the dorsal part of the stria terminalis.

Regeneration of Mesophyll Protoplasts Isolated from Dihaploid Clones of Solanum tuberosum

Abstract: Protoplasts have been isolated from leaves of shoot cultures of six dihaploid clones of Solanum tuberosum L. (2n = 2x = 24). In the KM medium (Kao and Michayluk 1975), sustained cell divisions were obtained in up to 50% of the plated protoplasts of four clones, whereas only a few divisions occurred in the other two clones. The first mitosis appeared 2–8 days after plating, dependent on the clones. In the clones showing sustained cell divisions, a protoplast titre of about 5 × 103 per ml turned out to be optimal. The culture conditions for protoplasts of one of the poorly growing clones, clone H2 140, have been improved using modified KM media, plating at a concentration of as high as 5 × 104 cells per ml, and subsequent diluting at intervals 5 days. The dilutions were carried out with media containing 0.25% agar. Up to 60% of the plated protoplasts underwent divisions within 10 days under these conditions. After about 15 days, the regenerants were transferred onto media inducing organogenesis. Shoots and roots were formed on modified media MS (Murashige and Skoog 1962) and B5 (Gamborg et al. 1968). Plants have been regenerated in four of the investigated clones. Countings of chromosomes revealed a satisfactory stability of the karyotype in shoot culture and protoplast regeneration.

Fluctuations and interactions of bacterial activity in sandy beach sediments and overlying waters

Abstract: Fluctuations and interactions of the following microbiological variables and sediment properties were investigated on samples from sandy beaches of the Baltic Sea: bacterial number and biomass, net uptake and respiration rate of 14C-glucose (U), concentration of natural free dissolved glucose and fructose, actual uptake rate and turnover time of glucose, sand-grain size and shape, water and organic matter content of the sediment. Spearman rank correlation analysis demonstrated significant relationships between cell number, biomass and actual uptake rate of glucose. The concentration of natural glucose varied with sand-grain shape, and the uptake rates of glucose were inversely correlated with the water content of the sediment. In the overlying water, cell number and/or biomass were significantly correlated with both concentration and uptake rates of glucose. Partial correlation analysis, however, indicates that, in the water overlying the sediment at least one of the standing crop variables (bacterial number or biomass) is independently variable with uptake activity. The sediment bacterial standing crop does not necessarily reflect metabolic activity. Various significant interactions were noted between mainly sediment properties (water content, organic matter content, grain size) and variables in the water above (cell number, biomass, concentration and uptake rates of glucose).

The ISEE 1 and 2 Medium Energy Particles Experiment

Abstract: We describe the medium energy particles experiment (MEPE) on-board ISEE 1 and 2. The MEPE consists of the WIM instrument on ISEE 1 and the KED instrument on ISEE 2. Both instruments employ solid-state detectors and magnetic analysis to measure the angular, energy, and intensity distributions of protons (ions) above 24 keV and electrons above 20 keV. The WIM instrument also includes a composition measurement employing ?E by E and time-of-flight techniques. Three-parameter analysis is performed above 250 keV/nucleon, and single parameter analysis is performed above 125 keV/nucleon for helium through oxygen. Three-dimensional angular distributions are obtained through the use of a scan platform in the WIM instrument and multiple detector heads in the KED instrument. A variety of operational modes are used to optimize data collection from both instruments. Resolutions up to 128 channels in energy, 192 samples over the unit sphere in angle, and 0.095 s in time are available.

Effects of temperature on the discharges of muscle spindles and tendon organs.

Abstract: 1 In anaesthetized cats the effects of temperature on the nervous outflow from skeletal muscle via thick myelinated afferent fibres were studied Single unit recordings were made from afferents of muscle spindles and tendon organs during slow and fast temperature changes of the medial gastrocnemius muscle which was deefferented by ventral root section and prestretched to a tension of 100 p 2 Group I afferent units from muscle spindles were activated by warming and depressed by cooling, the effect of warming being much more pronounced than that of cooling Afferents from secondary spindle endings with a high background discharge behaved similar to Ia fibres, whereas those with a low initial discharge rate showed an activation by cooling and a depression (mostly to cessation of firing) by warming The discharges of group I afferents from tendon organs varied; an activation by warming was the most frequently observed reaction 3 Some of the afferents from muscle spindles and tendon organs showed signs of a dynamic sensitivity to thermal stimulation, but in general the dynamic component in the responses to temperature changes was only small 4 The results suggest that the afferent outflow via thick myelinated fibres from a resting, moderately prestretched muscle strongly depends on temperature At raised intramuscular temperatures (about 42°C) the nervous outflow is characterized by an increased activity in all of the I a and many of the I b afferents, while the majority of group II spindle afferents will be depressed In contrast, in a cold muscle (about 29°C) the nervous outflow via afferents from primary spindle endings will be reduced, while the net activity from secondary spindle endings will be increased and no marked changes are expected to occur in the discharges of I b fibres

The ISEE 1 and 2 medium energy particles experiment

Abstract: We describe the medium energy particles experiment (MEPE) on-board ISEE 1 and 2. The MEPE consists of the WIM instrument on ISEE 1 and the KED instrument on ISEE 2. Both instruments employ solid-state detectors and magnetic analysis to measure the angular, energy, and intensity distributions of protons (ions) above 24 keV and electrons above 20 keV. The WIM instrument also includes a composition measurement employing ?E by E and time-of-flight techniques. Three-parameter analysis is performed above 250 keV/nucleon, and single parameter analysis is performed above 125 keV/nucleon for helium through oxygen. Three-dimensional angular distributions are obtained through the use of a scan platform in the WIM instrument and multiple detector heads in the KED instrument. A variety of operational modes are used to optimize data collection from both instruments. Resolutions up to 128 channels in energy, 192 samples over the unit sphere in angle, and 0.095 s in time are available.

The complexity of immunohistochemical staining pattern of hodgkin and sternberg‐reed cells—demonstration of immunoglobulin, albumin, α1‐antichymotrypsin and lysozyme

Abstract: The immunoperoxidase-bridge technique was applied to 103 lymph-node and spleen biopsies from Hodgkin's disease to detect intracytoplasmic immunoglobulin (Clg). The plasma cells that stained positively for gamma, mu, alpha, or delta chains varied greatly in number from case to case, depending somewhat on the histologic type of the disease. Hodgkin (H) and Sternberg-Reed (SR) cells that stained for gamma chains were the most frequent, followed by those positive for delta chains. H and SR cells positive for mu or alpha chains were usually sparse. In 11 cases gamma and delta chains were present simultaneously in single cells. No other combination of heavy-chain classes could be found in H and SR cells. In five cases of the lymphocytic-depletion type, the Clg was restricted to one heavy-chain class and one light-chain type. Gamma-chain subtypes were determined in a total of 24 cases. In the cases with one light-chain type and in four other cases, only gamma, chains were present in the H and SR cells. In many cases the proportion of H and SR cells positive for each gamma-chain subclass was not the same as that of the surrounding plasma cells. Variable numbers of H and SR cells showed unequivocal positivity for albumin in 12, alpha1-antichymotrypsin in 12, and lysozyme in one out of the 44 cases tested. In 21 out of these 44 cases only Clg could be detected. The findings presented here are discussed in relation to the possible monocytoid/macrophage or lymphoid B-cell nature of H and SR cells. Our data provide evidence for both a lymphatic and a macrophage origin of H and SR cells. It is not possible to reconcile these data on the basis of present knowledge.

PUVA-treatment of urticaria pigmentosa.

Abstract: Treatment of urticaria pigmentosa (UP) has been unsatisfactory. The patients' complaints of itching, swelling and increased skin sensitivity are well known and distressing and are unrelieved by local or systemic remedies. We have treated io patients suffering from UP with oral 8-methoxypsoralen (8-MOP) followed by long wave ultraviolet irradiation (UVA). The treatment schedule currently used for the treatment of psoriasis was adopted (Wolff ef al., 1975). All patients showed typical generalized cutaneous involvement of late onset (except patient 10). None of them were of the telangiectasia macularis eruptiva perstans type. All diagnoses were confirmed by biopsy (except patient 10). The patients received 05-0-8 mg/kg 8-MOP 2 h prior to UVA irradiation (Waldmann PUVA 4000). PUVA was given 4 times a week until no wealing could be produced by mechanical irradiation of the skin (Darier's sign). The data relevant to treatment are summarized in Table i. Treatment with PUVA resulted in generalized tanning and loss of Darier's sign. While the hyperpigmented macules overlying the mast cell infiltrates showed some persistence, wealing and dermographism following physical trauma could no longer be provoked. The padents unanimously noted rehef from itching and physical distress.

The functional and structural border between the CSF- and blood-milieu in the circumventricular organs (organum vasculosum laminae terminalis, subfornical organ, area postrema) of the rat.

Abstract: The present study continues a previous investigation on the median eminence (EM) (Krisch et al., 1978). In rats with high levels of neurohormones (LHRH, vasopressin) a limited immunohistochemical labeling of perivascular tanycyte processes can be observed surrounding capillaries in the marginal region of the organum vasculosum laminae terminalis (OVLT) and in the inner part of the subfornical organ (SFO). This labeling extends from the perivascular space a short distance along the tanycyte processes. By conventional electron microscopy and by freeze-etching, tight junctions are demonstrated at a distance from the capillary lumen which corresponds to the borderline of the immunohistochemical labeling of perivascular tanycyte processes in light microscopic preparations. The tight junctions are arranged in several parallel and helical rows and correspond to those found in the median eminence. Consequently, the immunohistochemical labeling the OVLT and in the SFO marks the intercellular cleft. In the circumventricular organs the immunostaining labels the extension of the perivascular space characterized by the hemal milieu. The perivascular space is separated off by tight junctions from the CSF-milieu of the adjacent neuropil. Furthermore, the present study demonstrates tight junctions in the marginal region of the area postrema (AP) between the perivascular processes of the tanycytes.

Improved extended-x-ray-absorption fine-structure (EXAFS) studies applied to the investigation of Cu-O, Cu-N, and Cu-Br bond lengths

Abstract: Extended-x-ray-absorption fine-structure spectra in the region of the $\mathrm{Cu} K$ edge are presented for Cu, CuO, ${\mathrm{Cu}}_{2}$O, CuS${\mathrm{O}}_{4}$, CuS${\mathrm{O}}_{4}$\ifmmode\cdot\else\textperiodcentered\fi{}5${\mathrm{H}}_{2}$O, Cu${(\mathrm{OH})}_{2}$, Cu(N${\mathrm{O}}_{3}$)\ifmmode\cdot\else\textperiodcentered\fi{}3${\mathrm{H}}_{2}$O, ${[\mathrm{C}\mathrm{u}{(\mathrm{N}{\mathrm{H}}_{3})}_{4}]}^{2+}$, and Cu${\mathrm{Br}}_{2}$. By the usual Fourier-analysis method, bond lengths for Cu-O, Cu-N, and Cu-Br are determined. Further, a back-transformation into real space is used which allows us to check the consistency of the evaluation for the whole energy range investigated. The advantages of this evaluation are: bond lengths can be taken from regions of high accuracy of the experimental data, the $k$ dependence of the phase shifts can be checked and this presentation gives a criterion on how to fit the reference energy necessary for the energy-momentum conversion. The bond lengths determined with this method agree to within 0.02 \AA{}A with reliable x-ray diffraction data.

Emission continua of rare gas plasmas

Abstract: Photoionization cross sections of rare gases have been calculated by using the scaled Thomas-Fermi method, including polarization effects. Absorption coefficients have been derived for bound-free transitions in thermal plasmas of 6000 K to 30000 K, for a wavelength range from 300 A to 10000 A.

A new multisample sediment trap

Abstract: A sediment trap is described which can be used in open ocean moorings or as a freefloating version. With this sediment trap, 8 successive samples of settled particulate material can be obtained. The collecting interval can be set to any appropriate time period.

Tidal Friction in the Solid Earth: Loading Tides Versus Body Tides

Abstract: Astronomical as well as palaeontological evidence suggests a secular retardation of the Earth’s rotation, which is attributed to tidal friction, i. e., mainly to the nonequilibrium and imperfectly fluid response of the Earth’s oceans, as well as to the imperfectly elastic response of the solid Earth to tidal forces. Estimates of the rotational energy dissipated in the oceans show that the oceanic term probably accounts for most of the dissipated energy (Pekeris and Accad, 1969; Pariiskii et al., 1972; Kuznetsov, 1972; Brosche and Sundermann, 1972; Hender-shott, 1972), although the exact share between both, the oceanic dissipation and the dissipation within the solid Earth, is not known. This is attributed to insufficiencies in the knowledge of the marine tides in the open oceans, and to the fact that nothing is known about the rheological mechanism of tidal dissipation within the solid Earth. Measurements of tidal gravity variations at the Earth’s surface, as well as precise observations of the tidal effect on satellite orbits have not yet revealed reliable results on imperfectly elastic body tides of the Earth. Model calculations give also only rough estimations of the tidal energy dissipated within the Earth, mainly because no information is available on the specific tidal dissipation function, i. e., the quality factor Q within the Earth.

The functional and structural border of the neurohemal region of the median eminence.

Abstract: In stressed rats the tanycytes of the ventrolateral wall of the third ventricle exhibit by light microscopic immunohistochemistry a positive staining for neurohormones which is distinctly limited to the distal perivascular end of the tanycyte process. Since by electron microscopic immuncytochemistry the tanycyte cytoplasm does not show any reaction product, the light microscopic reaction most likely results from a labeling of the intercellular space in the direct vicinity of the subendothelial cleft. Whether this subendothelial space is permeable to neurohormones was tested by injection of HRP1. In the region of the arcuate nucleus 30 min after intravenous application, the marker is affixed to the membranes of the perivascular tanycyte processes in the subendothelial cleft of capillaries possessing non-fenestrated endothelia. Occasionally, HRP penetrates for a short distance between the tanycytes. Then the labeling of the intercellular cleft ends abruptly. Here, several parallel ridges of tight junctions between the perivascular distal tanycyte processes are found by the freeze-etching technique. Since HRP cannot reach the subendothelial clefts of this region by passing through capillary walls due to the presence of a blood-brain barrier, it is suggested that the marker penetrates from the median eminence this far via the subendothelial extracellular space. It is prevented from spreading further by the tight junctions of the perivascular tanycyte endings. The same way may be taken by the neurohormones. Hence, a border area exists adjacent to the dorsolateral aspect of the neurohemal region of the median eminence where the tanycytes isolate the neuropil from the cerebrospinal fluid not only by their apical tight junctions, but also by basal tight junctions from the subendothelial cleft. This communicates with the perivascular space of the portal vessels.

The Structure of the Nervous System

Abstract: The building blocks of the nervous system are the nerve cells, also called neurons. It is estimated that the human brain possesses 25 billion cells. Like all animal cells, each neuron is bounded by a cell membrane that encloses the contents of the cell—that is, the cytoplasm (cell fluid) and the nucleus. The size and shape of these neurons vary widely, but the structural plan always includes certain elements (Fig. 1-1): a cell body, or soma, and the processes from this cell body, namely an axon (neurite), and usually several dendrites. The neuron diagrammed in Fig. 1-1 has one axon and four dendrites.

Chemographic relationships in sapphirine-bearing rocks from Sonapahar, Assam, India

Abstract: Silica-deficient rocks in which sapphirine coexists with cordierite, gedrite, chondrodite, spinel, corundum and phlogopite in various parageneses, occur in association with cordierite-garnet-sillimanitebearing granulitic gneisses in a Precambrian metamorphic terrain displaying amphibolite-granulite transition facies. Brucite coexists with spinel and corundum and its unusual stability in this environment has been attributed to its significant fluorine content. Kornerupine occurs as armoured relics within cordierite in one sample of the sapphirine-spinel-cordierite-phlogopite-bearing rock. Sapphirines (X Mg 0.77 to 0.92) plot near the 7∶9∶3 composition.X Mg varies in the order: chondrodite and brucite>gedrite>cordierite >phlogopite>sapphirine>spinel.

Vacuum ultraviolet reflectivity and band structure of SrTiO 3 and BaTiO 3

Abstract: The room temperature near-normal incidence reflectance spectra for SrTiO3 and BaTiO3 have been measured in the energy region 10 to 32 eV. The optical constants for the region 0 to 32eV have been derived from a Kramers-Kronig analysis by including earlier measurements for the low energy region. For SrTiO3 five peaks in the Ti3d derived conduction band density of states have been found on the basis of experimental data only, neglecting excitonic effects. The energies of these peaks are in excellent agreement with peaks in the density of states calculated by Mattheiss. The results for BaTiO3 could not be interpreted as unambiguously in such a scheme. Alternatively, some of the transitions could be interpreted as being due to core level excitons.

Uptake of glucose by bacteria in the sediment

Abstract: A method is described for the incubation of undisturbed sediment cores under in situ conditions with the addition of low concentrations of 14C-glucose. Data are presented for respiration, gross uptake and actual uptake rate of glucose by bacteria in sandy, wave-washed beaches of the Baltic Sea. On the average, the bacteria respired 8% of the total glucose taken up. The gross uptake measured was between 2.3×10-3 and 6.8×10-3 μg 14C-glucose g sediment-1 (dry weight) h-1 (average 4.7×10-3 μg g-1 h-1). Minima in the gross uptake rate corresponded with maxima in the concentration of natural free dissolved glucose. For the actual uptake rate, however, very similar uptake rates were calculated for the sediments examined (between 1.4×10-1 and 1.9×10-1 μg glucose g-1 h-1, average 1.7×10-1 μg g-1 h-1).

Somatic cell hybridization of Vicia faba+Petunia hybrida

Abstract: Isolated protoplasts of Vicia faba and Petunia hybrida have been fused by the action of Ca++, high pH and, occasionally, PEG. The heterokaryotic stage frequently endured mitotic divisions. Only one cell was found with apparently fusing nuclei. Another heterokaryon showed asynchronous phases in the nuclear cycle. Three hybrid tissues have been identified 50 and 60 days after fusion. One of them could be propagated, is 9 months old and still rapidly proliferating. The fusion hybrids contained predominantly nuclei or chromosomes of one or the other species and a few chromosomes of the second parent. These observations were assigned to chromosome elimination which has been conclusively seen in cells containing nuclei of Petunia-type and one or two chromosomes of Vicia left in the cytoplasm. Breakage of chromosomes was the only type of chromosome mutations found in hybrid tissue.

On the distribution of low salinity intermediate waters around the faroes

Abstract: The observed distribution and the spreading of low salinity waters of arctic and subarctic origin is discussed for the central Iceland-Faroe ridge and for the area around the Faroe Islands. After sinking along the polar front northwest of the Faroes the low salinity water spreads over the northern Faroe slope and into the Faroe-Shetland channel at intermediate levels. The amount of intermediate water leaving the Faroe-Bank channel into the northeastern Atlantic is small compared to its availability in the Faroe-Shetland channel, hence supporting the hypothesis of a re-circulation for the area east of the Faroes. The observations of intermediate water furthermore show no direct flow across the central Iceland-Faroe ridge but they reveal that mixing processes over the sill and advection of waters from the Faroe-Bank channel outflow determine the hydrographic structure of the southwestern flank of the Iceland-Faroe ridge.