1,980 research outputs found

    Simultaneous observations of haemolymph flow and ventilation in marine spider crabs at different temperatures: a flow weighted MRI study

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    In vivo magnetic resonance imaging (MRI) and angiography were applied to the marine spider crab Maja squinado for a study of temperature effects and thermal tolerance. Ventilation and haemolymph circulation were investigated during progressive cooling from 12°C to 2°C. The anatomical resolution of MR images from Maja squinado obtained with a standard spin echo sequence were suitable to resolve the structures of various internal organs. The heart of the animal could be depicted without movement artifacts. The use of a flow compensated gradient echo sequence allowed simultaneous observations of ventilation, reflected by water flow through the gill chambers as well as of haemolymph flow. Simultaneous investigation of various arteries was possible by use of flow weighted MRI. In addition to those accessible by standard invasive flow sensitive doppler sensors, flow changes in gill, leg arteries and the venous return could be observed. Both ventilation and haemolymph flow decreased during progressive cooling and changes in haemolymph flow varied between arteries. Haemolymph flow through the Arteria sternalis, some gill and leg arteries was maintained at low temperatures indicating a reduced thermal sensitivity of flow in selected vessels. In support of previous invasive studies of haemolymph flow as well as heart and ventilation rates, the results demonstrate that the operation of gills and the maintenance of locomotor activity are critical for cold tolerance. A shift in haemolymph flow between arteries likely occurs to ensure the functioning of locomotion and ventilation in the cold

    On the Correlation between National and International Law

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    The volume contains the revised contributions of a comparative German-Russian law seminar that took place in Kaliningrad from 15 to 19 September 2019 within the framework of the university partnership between the Philipps University Marburg and the Immanuel Kant Baltic Federal University Kaliningrad. The topic is the relationship between national and international law. In addition to introductory, dogmatic and conceptual foundations, concrete analyses of the relevant case law are presented, namely that of the German Federal Constitutional Court, the Constitutional Court of the Russian Federation, the Court of Justice of the European Union, the European Court of Human Rights, the International Court of Justice, the International Criminal Court, and the Court of the Eurasian Economic Union

    Solving Mixed--integer Control Problems by Sum Up Rounding With Guaranteed Integer Gap

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    Probleme der Optimalen Steuerung, die zeitabhaengige diskrete Entscheidungen beinhalten, haben in letzter Zeit zunehmend Beachtung gefunden, da sie in praktischen Anwendungen mit hohem Potential fuer Optimierung auftreten. Typische Beispiele sind die Wahl von Gaengen in Transport-Problemen oder Prozesse, in denen Ventile verwendet werden. Wir praesentieren Rundungsstrategien fuer direkte Methoden der optimalen Steuerung, die zu einer Approximation der Zielfunktion und Nebenbedingungen fuehren, deren Guete durch die Feinheit des Kontrolldiskretisierungsgitters abgeschaetzt werden kann. Erstmals wird gezeigt, dass eine endliche Anzahl von Umschaltungen sowohl im linearen wie im nichtlinearen Fall ausreicht, und dies bei Existenz von Pfad- und Kontrollbeschraenkungen. Ein numerisches Beispiel wird angegeben um die Methodik zu illustrieren

    Thermal acclimation to 4 or 10°C imparts minimal benefit on swimming performance in Atlantic cod ( Gadus morhua L.)

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    Thermal acclimation is frequently cited as a means by which ectothermic animals improve their Darwinian fitness, i.e. the beneficial acclimation hypothesis. As the critical swimming speed (U crit) test is often used as a proxy measure of fitness, we acclimated Atlantic cod (Gadus morhua) to 4 and 10°C and then assessed their U crit swimming performance at their respective acclimation temperatures and during acute temperature reversal. Because phenotypic differences exist between different populations of cod, we undertook these experiments in two different populations, North Sea cod and North East Arctic cod. Acclimation to 4 or 10°C had a minimal effect on swimming performance or U crit, however test temperature did, with all groups having a 10-17% higher U crit at 10°C. The swimming efficiency was significantly lower in all groups at 4°C arguably due to the compression of the muscle fibre recruitment order. This also led to a reduction in the duration of "kick and glide” swimming at 4°C. No significant differences were seen between the two populations in any of the measured parameters, due possibly to the extended acclimation period. Our data indicate that acclimation imparts little benefit on U crit swimming test in Atlantic cod. Further efforts need to identify the functional consequences of the long-term thermal acclimation proces

    Demonstration of immunochemical identity between the synaptic vesicle proteins synaptin and synaptophysin/p38

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    AbstractThe synaptic vesicle proteins synaptin and synaptophysin/p38 were shown to be immunochemically identical. Western immunoblot analysis of Triton X-100 extracts from rat brain showed that polyclonal polyspecific anti-synaptin antibodies and monoclonal antibody SY38 against synaptophysin both reacted with a band of 38 kDa. In two-dimensional immunoblots of chromaffin granule membranes from bovine adrenal medulla anti-synaptin and anti-synaptophysin antibodies also recognized the same component. Finally, in a Western immunoblotting experiment SY38 reacted with an immunoisolated synaptin antigen

    Probabilistic Two-way Clustering Approaches with Emphasis on the Maximum Interaction Criterion

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    We consider the problem of simultaneously and optimally clustering the rows and columns of a real-valued I x J data matrix X = (xi j) by corresponding row and columns partitions A = (A1; :::;Am) and B = (B1; :::;Bn), with given m and n. We emphasize the need to base the clustering method on a probabilistic model for the data and then to use standard methods from statistics (e.g., maximum likelihood, divergence) to characterize optimum two-way classifications. We survey some clustering criteria and algorithms proposed in the literature for various data types. Special emphasis is given to the maximum interaction clustering criterion proposed by the author in 1980. It can be shown that it results as the maximum likelihood clustering method under a two-way ANOVA model (with individual main effects, but cluster-specific interactions). After a simple data transformation (double-centering) well-known two-way SSQ clustering algorithms can directly be used for maximization
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