Showing papers by "University of Kiel published in 1983"

Tumours and hemihypertrophy associated with Wiedemann-Beckwith syndrome

Abstract: La frequence tumorale dans le syndrome de Wiedemann-Beckwith est de 7,5%, les tumeurs etant le plus souvent malignes. La frequence de l'hemihypertrophie est de 12,5% mais elle est de 40% chez les enfants porteurs de neoplasies

Benthic response to sedimentation events during autumn to spring at a shallow-water station in the Western Kiel Bight

Abstract: The response of the benthos to the break up of anoxia in the Kiel Bight (Western Baltic Sea), and to three succeeding events of “external” food supply, consisting of a settled autumn plankton bloom, resuspended matter and macrophyte input during winter, and of a sedimented spring phytoplankton bloom, is described on a community level. The first input of oxygen broke up anoxic conditions and made stored food resources available to decomposition. This “internal” food supply, mainly consisting of protein (folin positive matter), was followed by a drastic increase in heat production and ATP-biomass and caused a period of low redox potential, which lasted for several weeks. During this phase, a plankton bloom (dinoflagellates and diatoms) settled to the sea floor. Although there was an immediate response of benthic activity, this food input was not completely consumed by the strongly disturbed benthic community. During winter resuspended matter and the input of macrophyte debris caused another maximum in benthic activity and biomass despite the low temperature. The response to sedimentation of cells from a diatom bloom during mid March was also without any time lag and was consumed within 5–6 wk. A comparison of the amount of particles collected in a sediment trap with the increase of organic matter in the sediment demonstrated that the sediment collected four times (autumn) and seven to eight times (spring) more than measured by the sediment trap. Strong indications of food limitation of benthic activity were found. During autumn and winter these indications were caused more by physical than by biological processes. The three events of “external” food supply caused a temporary shift in the type of metabolism towards fermentation processes and reduced the redox potential. In spring the development of the benthic community was still being strongly influenced by the events of the preceding summer and autumn.

Long-term recording of monophasic action potentials from human endocardium.

Abstract: In 36 patients undergoing routine cardiac catheterization, a new “contact electrode” catheter technique was used to record monophasic action potentials (MAPs) from right atrial and right and left ventricular endocardial sites without the application of suction. Although of smaller amplitude, typically ranging from 15 to 40 mV, and of different reversal ratio (33 ± 3%), MAP recordings closely resembled transmembrane action potentials in configuration and duration. Continuous MAP recordings of stable amplitude and, during regular pacing, of constant duration (± 1% at 90% repolarization) could be made from the same endocardial site for test periods of 1 hour (n = 4), permitting direct evaluation of the effect of cycle length alterations on local myocardial repolarization. A linear relation was found between MAP duration and basic cycle length varying from 350 to 700 ms. These rate-dependent changes in MAP duration were caused by a change in the slow phase of repolarization (phase 2), whereas the slope of rapid repolarization (phase 3) was unaltered. Single premature MAPs or MAPs after a pause showed changes in both phases. No MAPs could be recorded in areas of infarcted, aneurysmal myocardium, indicating that local viable myocardium is a prerequisite for the generation of the monophasic signal. Thus, in human subjects this catheter permits safe, long-term recording of MAPs which, although of smaller amplitude than transmembrane action potentials, bear appropriate and predictable phase relations. Such recordings may be useful in evaluating changes in local myocardial electrical activity induced by pacing or resulting from myocardial disease, or both.

Raman study of anorthite, calcium Tschermak's pyroxene, and gehlenite in crystalline and glassy states

Abstract: Raman spectra are reported for crystalline anorthite (An), calcium Tschermak's pyroxene (CaTs), gehlenite (Geh), and glasses of CaAl 2 Si 2 O 8 (An), CaAlAlSiO 6 (CaTs), and Ca 2 AlAlSiO 7 (Geh) composition. A small degree of Si-Al disorder in anorthite is indicated by the presence of weak Si-O-Si antisymmetric stretching modes in its spectrum. The spectrum of the glass of An composition closely resembles that of crystalline An. This correspondence indicates that the predominant species in An glass is composed of a random network of four-membered rings of TO 4 tetrahedra (where T = Si or Al). In the spectrum of glass CaTs composition the v s (T-O-T) band appears at lower frequency ( approximately 564 cm (super -1) ) than the v s (T-O-T) band of crystalline CaTs (651 cm (super -1) ). The v as (T-O-T) bands in the 900-1200 cm (super -1) region are also at lower frequencies and are relatively stronger than the v as (T-O-T) bands in the glass of An composition. The lower frequency of the v as (T-O-T) is due to an increase in Al/Si from 1 in An glass to 2 in CaTs glass. The increase in the relative intensity of the v as (T-O-T) bands is due to nonbridging oxygens. In the spectrum of glass of Geh composition the v s (T-0-T) band appears at lower frequency (552 cm (super -1) ) than in the spectrum of crystalline Geh (626 cm (super -1) ). The shift of the band toward lower frequencies in the spectrum of the glass of Geh composition indicates that most of the Al (super 3+) ions are tetrahedrally coordinated and act as network formers. A strong band at approximately 896 cm (super -1) in the spectrum of Geh glass is attributed to the presence of an appreciable amount of SiO (super 4-) 4 groups in the glass network.--Modified journal abstract.

Cimetidine-procainamide pharmacokinetic interaction in man: Evidence of competition for tubular secretion of basic drugs

Abstract: The hypothesis that basic drugs can compete for active tubular secretion by the kidney was tested in six healthy volunteers by comparing the single dose pharmacokinetics of oral procainamide before and during a daily dose of cimetidine. The area under the procainamide plasma concentration-time curve was increased by cimetidine by an average of 35% from 27.0±0.3 µg/ml·h to 36.5±3.4 µg/ml·h. The elimination half-life increased from an harmonic mean of 2.92 to 3.68 h. The renal clearance of procainamide was reduced by cimetidine from 347±46 ml/min to 196±11 ml/min. All these results were statistically significant (p<0.016). The area under the plasma concentration-time curve for n-acetylprocainamide was increased by a mean of 25% by cimetidine due to a significant (p<0.016) reduction in renal clearance from 258±60 ml/min to 197±59 ml/min. The data suggests that cimetidine inhibits the tubular secretion of both procainamide and n-acetylprocainamide, and, if so, represents the first documented evidence for this type of drug interaction in man. The clinical implications from this study necessitate dosage adjustments of procainamide in patients being concomitantly treated with cimetidine. The interaction is pertinent not only for basic drugs that are cleared by the kidney, but also for metabolites of basic drugs and endogenous substances which require active transport into the lumen of the proximal tubule of the kidney for their elimination.

Immunohistology and aetiology of histiocytic necrotizing lymphadenitis. Report of three instructive cases

Abstract: Three cases of histiocytic necrotizing lymphadenitis are reported. Two patients came from Vietnam and the third from Greece. In all cases there was infection with Yersinia enterocolitica of serogroup 9 or 3. Cervical lymph nodes were examined. Histologically, the characteristic necrosis developed in large foci of so-called T-associated plasma cells. Immunological analysis showed that these cells have characteristic markers of helper/inducer T cells, but do not express sheep erythrocyte receptors. The T-associated plasma cells perished by pyknosis and were then phagocytosed and digested by macrophages, which were present in large numbers. The necrotic areas were exclusively located in hyperplastic T regions. The B-cell system did not play a role in the reaction. T-associated plasma cells have been renamed ‘plasmacytoid T cells’ because they contain abundant rough endo-plasmic reticulum (‘plasmacytoid’) and show immunological features of T cells. It appears likely that plasmacytoid T cells are the counterparts of plasma cells of the B-cell system that secrete lymphokines instead of immunoglobulin.

Human dendritic reticulum cells of lymphoid follicles: their antigenic profile and their identification as multinucleated giant cells.

Abstract: The B-dependent areas of human lymphoid tissue contain non-lymphoid, non-phagocytic cells known as dendritic reticulum cells (DRC). These cells can be detected only very occasionally in routinely stained histologic sections. Recently we were able to overcome this limitation by preparing a monoclonal antibody, termed R 4/23, that reacts selectively with DRC. Thus by using an optimized immunoperoxidase method applied to frozen sections, it is possible to detect DRC in situ. To determine the antigenic profile of DRC, serial frozen sections of human tonsils were immunostained with R 4/23 and a large panel of other monoclonal antibodies or conventional antisera. In addition, touch imprints of tonsils and cytocentrifuge slides of cell suspensions with increased concentrations of DRC were immunostained with these reagents. DRC proved to be positive for μ, γ, α, κ and λ chains, complement component C3b, C3b receptors, C3d receptors, HLA-A,B,C antigens, human Ia-like antigens, common ALL antigen (cALLa), and antigens that are characteristic of the monocyte/macrophage lineages. DRC did not express δ chains, T cell antigens, or antigens that are expressed on interdigitating reticulum cells (IDC) and Langerhans cells. DRC in touch imprints and suspensions prepared from hyperplastic tonsils were found to be giant cells often with 10 or more nuclei. In certain cases of follicular hyperplasia and of centroblastic-centrocytic lymphoma, DRC with several nuclei were also detectable in situ.

Generalized kinetic analysis of ion-driven cotransport systems: a unified interpretation of selective ionic effects on Michaelis parameters.

Abstract: A major obstacle to the understanding of gradient-driven transport systems has been their apparently wide kinetic diversity, which has seemed to require a variety of ad hoc mechanisms. Ordinary kinetic analysis, however, has been hampered by one mathematically powerful but physically dubious assumption: that rate limitation occurs in transmembrane transit, so that ligand-binding reactions are at equilibrium. Simple models lacking that assumption turn out to be highly flexible and are able to describe most of the observed kinetic diversity in co- and counter-transport systems. Our “minimal” model of cotransport consists of a single transport loop linking six discrete states of a carrier-type molecule. The state transitions include one transmembrane charge-transport step, and one step each for binding of substrate and cosubstrate (driver ion) at each side of the membrane. The properties of this model are developed by sequential use of realisticexperimental simplifications and generalized numerical computations, focussed to create known effects of substrate, driver ion, and membrane potential upon the apparent Michaelis parameters (J max,K m ) of isotopic substrate influx. Specific behavior of the minimal model depends upon the arrangement of magnitudes of individual reaction constants among the whole set (12) in the loop. Well defined arrangements have been found which permit either increasing membrane potential or increasing external driverion selectively to reduce the substrateK m , elevateJ max, jointly raise bothK m andJ max, or lowerK m while raisingJ max. Other arrangements allow rising internal driver ion to act like either a competitive or a noncompetitive inhibitor of entry, or allow internal substrate to shut down (“transinhibit”) influx despite large inward driving forces. These findings obviate most postulates of special mechanisms in cotransport: e.g., stoichiometry changes, ion wells, carrier-mediated leakage, and gating —at least as explanations for existing transport kinetic data. They also provide a simple interpretation of certain kinds of homeostatic regulation, and lead to speculation that the observed diversity in cotransport kinetics reflects control-related selection of reaction rate constants, rather than fundamental differences of mechanism.

Encoding of visceral noxious stimuli in the discharge patterns of visceral afferent fibres from the colon

Abstract: Afferent fibres, in the inferior splanchnic nerves and lumbar white rami, which supply the colon and its mesentery in the cat, were investigated for their responses to distension and contraction of the colon and to local pressure applied to colon and its mesentery. 1) 63% (177 out of 287) of the axons had resting activity (median 0.3 imp/s). These axons were either unmyelinated (conduction velocity below 2 m/s) or thin myelinated (conduction velocity below 18 m/s). Most axons without resting activity (N=95 out of 106 axons) conducted at less than 1.4 m/s, and most were probably sympathetic efferents. 2) 76 out of 80 afferent units with resting activity (95%) and 8 out of 27 units without (30%) were excited by distension of the colon. The thresholds were largely at intraluminal pressures of around 25 mm Hg or higher. 3) Most afferent units (87%) responded with an increased steady state discharge throughout the distension with or without initial dynamic response. The rest of the afferent units responded only with a transient discharged to distension. 4) Most afferent units reacted in a graded manner to variable intraluminal pressures. 5) In only 43% of the distension-sensitive afferent units could mechanoreceptive sites be located on the wall of the colon or in the mesentery. The majority of the afferent units had one mechanoreceptive site only, some had two. 6) Afferent units reacting to colon distension were also excited by contraction of the colon. 7) The excitability spectrum of visceral afferent fibres in the inferior splanchnic nerves, which are activated by colon distension, suggests that these units are involved in visceral nociception from the colon.

Response pattern of visceral afferent fibres, supplying the colon, upon chemical and mechanical stimuli

Abstract: In the cat responses of afferent fibres in the inferior splanchnic nerves which innervate the colon and its mesentery were investigated upon intra-arterial bolus injection of bradykinin, of KCl- and of hypertonic NaCl-solution and upon ischaemia of the colon. One hundred and twenty-five units were analyzed. 1) Seventy-seven from 96 units with resting activity (80%) and 7 from 29 units without (24%) were excited by bradykinin. The exictation was present both when the colon wall contracted and when the contractions were prevented or when the colon was paralytic. 2) Fifty-two from 82 units with resting activity (67%) and 4 from 21 units without (19%) responded to KCl with short-lasting, high-frequency bursts. Injections of hypertonic NaCl-solutions had only small effects on the afferent units. 3) The responses of the units to distension of the colon (see [3]) and to the chemical stimuli were highly correlated. 4) Afferent units which responded to distension of the colon and to bradykinin were also excited by partial or complete ischaemia of the colon (produced by occlusion of both mesenteric arteries or of only the inferior mesenteric artery). During ischaemia the activity in the afferents increased and became burst-like. The response to distension of the colon increased in some of the afferent units. 5) Blood pressure responses to colon distension and to local bradykinin application also increased during ischaemia. 6) The results indicate that visceral afferent fibres from the colon in the inferior splanchnic nerves may be functionally homogeneous and may encode noxious stimuli applied to the colon.

Regional geothermobarometry in the granulite facies terrane of South India

Abstract: In the southern part of the Archaean craton of South India, an approximately 3.4–2.9 b.y. old migmatite–gneiss terrane (Peninsular gneiss complex) has been subjected to granulite facies metamorphism about 2.6 b.y. ago. During this event, the extensive charnockite-khondalite zone of southern India developed. A younger metamorphism (Proterozoic?) led to retrogression of the charnockites and khondalites, mainly under the conditions of the amphibolite facies.The physical conditions of metamorphism have been evaluated by applying methods of geothermobarometry to the widespread charnockitic assemblages with garnet, orthopyroxene, clinopyroxene, plagioclase, and quartz. The interpretation of the P–T estimates includes a critical discussion of potential error sources, e.g. errors of the analytical data and the calibrations of the models, and takes into account the complex metamorphic history of the rocks and the kinetics of the mineral equilibria.P-T estimates were obtained for seven subareas from the rim compositions of the coexisting minerals: Shevaroy Hills 680±55°C—7·4±1 kb; Kollaimalai area 680±40°C—8·6± 1 kb; Nilgiri Hills 680±90°C—6·6±0.8kb (upland massif) and 705±60°C—9·3±0.8 kb (northern margin); Bhavani Sagar area 650±50°C—7·2± 1 kb; Sargur-Mysore area 690±60°C—7·6 kb; Bangalore-Kunigal-Satnur area 760±50°C—6 kb. Except for the last subarea, the P-T model data reflect the conditions of a late annealing stage probably related to the retrogressive metamorphism. Conditions near the peak of granulite facies metamorphism (730–800°C—6·5–9·5 kb) are recorded by the core compositions of the minerals. Although a rather uniform cooling history of the main part of the charnockite-khondalite terrane is suggested from the temperature data, differential uplift of smaller blocks is indicated by the regional variation of the pressure data.

Afferent and efferent axons in the medial and posterior articular nerves of the cat.

Abstract: The goal of this study is to determine the average numbers of afferent axons and postganglionic autonomic (sympathetic) efferent axons supplying the cat knee joint through the medial and posterior articular nerves. Interestingly, both nerves are composed primarily of unmyelinated axons. Only 20% of the axons in the medial articular nerve are myelinated, with the overwhelming majority, 80%, being unmyelinated. The posterior articular nerve has 78% unmyelinated and 22% myelinated axons. Neither nerve contains ventral root efferent axons. The sympathetic chain, in both nerves, contributes no myelinated and only 50% of the unmyelinated axons. The medial and posterior articular nerves are therefore predominantly afferent, since all myelinated and the remaining 50% of the unmyelinated axons arise from the dorsal root ganglion cell. The ratio of afferent unmyelinated to myelinated axons is 2:1. The roles of these afferent unmyelinated axons must now be considered in regard to joint kinesthetics and pain.

Altered polymorphonuclear leukocyte responses in psoriasis: chemotaxis and degranulation.

Abstract: SUMMARY Chemotactic activities of circulating polymorphonuclear leukocytes (PMN) were determined in twenty patients with psoriasis and twenty healthy control persons. After serial dilution of the complement split product C5a and the formylated tripeptide f-met-Ieu-phe (FMLP), chemotaxis profiles showed that PMN migration toward both chemotaxins was significantly increased in psoriasis. In addition, PMN from psoriatic patients responded to chemotaxins at much lower concentrations compared with controls. The liberation of (lysosomal) β-glucuronidase was also determined in cytochalasin B-treated cells confronted with increased concentrations of the chemotaxins. Secretion of this marker enzyme started at lower concentrations in PMN derived from psoriatic patients. Our observations demonstrate migratory and secretory hyper-responsiveness of PMN from psoriatic patients. This may play a role in perpetuating the psoriatic tissue reaction.

Plasmacytoid T-cell clusters in non-specific lymphadenitis

Abstract: The occurrence and morphology of Lymphoblastennester (clusters of lymphoblasts) were analyzed in 500 unselected cases of nonspecific lymphadenitis. Sixty-eight cases showed such clusters, which consist of uniform-looking medium-sized cells. Based on the results of recent immunologic investigations, these cells may be interpreted as T-cells with plasmacytoid features ("plasmacytoid T-cells', PTC). PTC were usually located near venules in the pulp, but not in the generally hyperplastic T-nodules. There was usually no relation to hyperplasia of B-regions (follicles). Although occasional mitotic figures and basophilic blast cells were found at the edges of PTC clusters, it is possible that PTC develop through transformation of T-lymphocytes. PTC often showed pyknotic nuclei and a tendency to perish, suggesting that they are end cells. Necrotic cells were phagocytosed by macrophages, which occasionally caused a starry sky pattern like that seen in germinal centers. Sometimes there were also a few interdigitating reticulum cells in the clusters. The function of PTC is still obscure; they might secrete lymphokines.

Internalization versus compliance: Differential processes underlying minority influence and conformity

Abstract: Two experiments investigated whether minority influence and conformity operate by the same or by different processes. It was predicted that subjects who were simultaneously exposed to a majority and a minority opinion would move towards the minority in private but towards the majority in public. The results of Experiment 1 supported this hypothesis. Experiment 2 investigated three hypotheses predicting that (1) the above interaction would be replicated, (2) minorities would trigger more arguments and counter-arguments, and (3) cognitive activity would mediate internalization but not compliance. Hypotheses 1 and 3 were supported. The second hypothesis was not supported. However, minorities were found to trigger more arguments and fewer counter-arguments than majorities. The results were interpreted as supporting the dual process model.

Ecophysiology of lichens in the dry valleys of Southern Victoria Land, Antarctica

Abstract: CO2 exchange was measured in three cryptoendolithic lichen samples from the ice-free mountains of Southern Victoria Land. Optimum temperature for net photosynthesis at different light intensities ranged from below 2°C to about 7°C; the upper compensation point ranged from 5°C to 15.7°C, and the lower compensation point could be estimated in two samples as being between-6°C and-8°C. Dark respiration rates were higher than those of net photosynthesis. The results indicate that these cryptoendolithic lichens are not more adapted to low temperatures than are crustose lichens from coastal Antarctica. Calculations show that optimum temperatures for photosynthesis may not be reached in the natural environment. Photosynthetic rates were low, but they increased when samples were split into smaller pieces, permitting gas exchange through broken rock surfaces. In nature, when gas exchange is possible only through the intact rock crust, these apparent rates are probably even lower.

Identification of new Sialic Acids Derived from Glycoprotein of Bovine Submandibular Gland

Abstract: Improvements in the isolation procedure and the analytical equipment enabled the detection of seven novel sialic acids in bovine submandibular gland glycoprotein: N-acetyl-8-O-acetylneuraminic acid, N-acetyl-8,9-di-O-acetylneuraminic acid, N-acetyl-7,8,9-tri-O-acetylneuraminic acid, N-glycoloyl-7-O-acetylneuraminic acid, N-glycoloyl-7,9-di-O-acetylneuraminic acid, N-glycoloyl-8,9-di-O-acetylneuraminic acid, and N-glycoloyl-7,8,9-tri-O-acetylneuraminic acid. There are also indications for the presence of N-glycoloyl-8-O-acetylneuraminic acid. In addition, the sialic acids already known to occur in this tissue, namely N-acetylneuraminic acid, N-acetyl-7-O-acetylneuraminic acid, N-acetyl-9-O-acetylneuraminic acid, N-acetyl-7,9-di-O-acetylneuraminic acid, N-glycoloyl-neuraminic acid, and N-glycoloyl-9-O-acetylneuraminic acid could be identified. Sialic acids were released from the mucin by mild acid hydrolysis and prefractionated on a Dowex 2X8 anionexchange column (formate form) by elution with a 00.6 M gradient of formic acid. The four pools of sialic acids obtained in this way were each further fractionated by column chromatography on cellulose with n-butanol/n-propanol/water (1/2/1, v/v/v) as eluent. By this procedure, N-acetylneuraminic acid, N-acetyl-7-O-acetylneuraminic acid, N-acetyl-9-O-acetylneuraminic acid, N-glycoloylneuraminic acid, and N-glycoloyl-9-O-acetylneuraminic acid were obtained in pure form. The other sialic acids could be enriched sufficiently in different fractions for structural identification. Analyses of sialic acids were carried out by one-dimensional and two-dimensional thin-layer chromatography, gas-liquid chromatography, gas-liquid chromatography, and gas-liquid chromatographymass spectrometry.

Kenyaite; synthesis and properties

Abstract: Hydrous sodium silicate, synthesis from aqueous suspensions containing SiO 2 and NaOH with SiO 2 /NaOH ratios ranging from 5 to 20 and H 2 O/NaOH ratios from 50 to 500 at 100-150 degrees C. Transformation: magadiite --> kenyaite --> quartz. Formation of kenyaite at 100 degrees C requires several months; reaction times decreased at higher temperatures but quartz forms rapidly. Synthetic kenyaites form spherical aggregates of well-developed plates. Intracrystalline reactivity. Through exchange of protons for the interlayer sodium ions, kenyaite is transformed into a crystalline silicic acid.--Modified journal abstract.

Dimensions of the great arteries, semilunar valve roots, and right ventricular outflow tract during growth: normative angiocardiographic data.

Abstract: Systolic and diastolic diameters of the right and left pulmonary arteries (RPAD, LPAD), descending thoracic aorta (DTAD), right ventricular infundibulum (RVID), and pulmonary and aortic valve roots at the proximal, commissural and distal levels were estimated from angiocardiograms in 24 infants, children, and adolescents without heart disease, and correlated with body surface area (BSA), stroke volume (SV), cardiac output (CO), and ventricular volumes. The relationships between cardiovascular diameters and BSA were better expressed by a power function than by the other functions tried. We obtained different exponents for pulmonary and aortic valve annuli and the more distally measured great arteries (RPAD, LPAD, and DTAD), suggesting different growth patterns. The right ventricular infundibular shortening fraction (RVISF) was weakly correlated with BSA (r = -0.328), and the values obtained indicated constancy during normal growth. There was a direct proportional relationship between the pulmonary valve annulus diameter and the cube root of the right ventricular volume (r = 0.952), as well as between SV and cross-sections of the right pulmonary artery (RPAC; r = 0.916), left pulmonary artery (LPAC; r = 0.878) and descending thoracic aorta (r = 0.962). RPAC and LPAC were strongly correlated (r = 0.940), the RPAC being significantly larger than the LPAC.

The Modern Current Regime Across the Greenland-Scotland Ridge

Abstract: The Greenland-Scotland ridge system is not only a topographical boundary between the basins of the Norwegian-Greenland seas and the basins of the mid-latitude North Atlantic, but it also plays a decisive role in the location of the zone separating water masses of different climatological origin. This is readily demonstrated in Figure 1 showing the ridge system to be an area of strong temperature contrasts. The most important water masses merging there are characterized in Figure 2 by means of their temperature and salinity characteristics. The two extremes are Atlantic waters with high salinities and high temperatures originating from south of the ridge and Polar waters with low temperatures and low salinities relating their origin to surface waters influenced by melting and run-off into the Polar Sea. The two Arctic waters (intermediate and deep) received their relatively high salinities from Atlantic waters and have obtained their low temperatures from cooling in the Greenland-Norwegian seas.

Specification-Oriented Semantics for Communicating Processes

Abstract: We are aiming at a classification of semantical models for Communicating Processes that will enable us to recommend certain models which are just detailed enough for particular applications But before such an aim can be fully realised, more sophisticated models of processes should be studied

Influence of Soil Reaction and Organic Matter on The Solubility of Heavy Metals in Soils

Abstract: The solubility behaviour of heavy metals determines mobility, leaching, availability, and toxicity of these elements in soils. In model experiments the solubility of Cu, Zn, Cd and Pb was investigated in equilibrium solutions of different soil samples under varying conditions.