1,193 research outputs found
Instream Measures in einer alpinen Schwallstrecke â eine erste Bilanz von der Hasliaare
In der Hasliaare in Innertkirchen wurden im Winter 2014/15 auf einer 300 m langen Flussstrecke fischökologische Aufwertungsmassnahmen in Form von Instream Measures (direkt im FliessgewĂ€sser, innerhalb der DĂ€mme) umgesetzt. Aus ökologischer Sicht lag der Hauptfokus auf dem Schaffen von Habitaten fĂŒr Jungfischstadien der heimischen Forelle (Salmo trutta), da diese in der mit Buhnen kanalisierten Strecke bei AbflĂŒssen grösser als 20 mÂł/s fehlen. In der Planungsphase mussten erstens die dynamischen Anforderungen eines Gebirgsflusses berĂŒcksichtigt werden. Zweitens musste bei der ökologischen Aufwertung das Schwall/ Sunk-Abflussregime beachtet werden, drittens sollte der Aufwand in einem akzeptablen VerhĂ€ltnis zum ökologischen Mehrwert stehen und nicht zuletzt mussten die AnsprĂŒche von vielen verschiedenen Akteuren berĂŒcksichtigt werden. Als Massnahmen wurde eine Kombination aus Belebtsteingruppen, Wurzelstöcken, FischunterstĂ€nden und abgeknickten Buhnen realisiert. Im Sommer und Herbst 2015 erfolgte eine erste Erfolgskontrolle, bei der die fischökologischen Verbesserungen aufgezeigt werden konnten
Tentative Reference Acts? âRecognitional Demonstrativesâ as Means of Suggesting Mutual Knowledge â or Overriding a Lack of It
In an explorative study on German oral corpus data we investigate recognitional use of proximal demonstratives as a means of explicit speaker-hearer interaction shaping the discourse structure. We show that recognitionals mark tentative reference acts in that speakers suggest - or pretend - mutual knowledge of the referent, at the same time appealing to the hearers to accept the reference. Hearers may tacitly or explicitly accept the referential act or deny it asking for clarification, in the latter case making speakers change the intended local discourse topic. On these grounds we argue against a differentiation between recognitional and indefinite demonstratives, subsuming both as kinds of recognitional use under âpretendedâ cognitive proximity
GPCR-OKB: the G protein coupled receptor oligomer knowledge base
Rapid expansion of available data about G Protein Coupled Receptor (GPCR) dimers/oligomers over the past few years requires an effective system to organize this information electronically. Based on an ontology derived from a community dialog involving colleagues using experimental and computational methodologies, we developed the GPCR-Oligomerization Knowledge Base (GPCR-OKB). GPCR-OKB is a system that supports browsing and searching for GPCR oligomer data. Such data were manually derived from the literature. While focused on GPCR oligomers, GPCR-OKB is seamlessly connected to GPCRDB, facilitating the correlation of information about GPCR protomers and oligomers
Current Perspective on the Location and Function of Gamma- Aminobutyric Acid (GABA) and its Metabolic Partners in the Kidney.
Gamma-aminobutyric acid (GABA) is an inhibitory neurotransmitter located in the mammalian central nervous system, which binds to GABAA and GABAB receptors to mediate its neurological effects. In addition to its role in the CNS, an increasing number of publications have suggested that GABA might also play a role in the regulation of renal function. All three enzymes associated with GABA metabolism; glutamic acid decarboxylase, GABA ?-oxoglutarate transaminase (GABA-T) and succinic semialdehyde dehydrogenase (SSADH) have been localised to the kidney providing the necessary machinery for localised GABA synthesis and metabolism. Moreover GABA receptors have been localised to both tubular and vascular structures in the kidney, and GABA is excreted in urine (~3 ?M) in humans. Despite the collective evidence describing the presence of a GABA system in the kidney, the precise function of such a system requires further clarification. Here we provide an overview of the current renal GABA literature and provide novel data that indicates GABA can act at contractile pericyte cells located along vasa recta capillaries in the renal medulla to potentially regulate medullary blood flow
Influx of Calcium through L-type Calcium Channels in Early Postnatal Regulation of Chloride Transporters in the Rat Hippocampus
During the early postnatal period, GABAB receptor activation facilitates L-type calcium current in rat hippocampus. One developmental process that L-type current may regulate is the change in expression of the K+Clâ co-transporter (KCC2) and N+K+2Clâ co-transporter (NKCC1), which are involved in the maturation of the GABAergic system. The present study investigated the connection between L-type current, GABAB receptors, and expression of chloride transporters during development. The facilitation of L-type current by GABAB receptors is more prominent in the second week of development, with the highest percentage of cells exhibiting facilitation in cultures isolated from 7 day old rats (37.5%). The protein levels of KCC2 and NKCC1 were investigated to determine the developmental timecourse of expression as well as expression following treatment with an L-type channel antagonist and a GABAB receptor agonist. The time course of both chloride transporters in culture mimics that seen in hippocampal tissue isolated from various ages. KCC2 levels increased drastically in the first two postnatal weeks while NKCC1 remained relatively stable, suggesting that the ratio of the chloride transporters is important in mediating the developmental change in chloride reversal potential. Treatment of cultures with the L-type antagonist nimodipine did not affect protein levels of NKCC1, but significantly decreased the upregulation of KCC2 during the first postnatal week. In addition, calcium current facilitation occurs slightly before the large increase in KCC2 expression. These results suggest that the expression of KCC2 is regulated by calcium influx through L-type channels in the early postnatal period in hippocampal neurons
GPCRTree: online hierarchical classification of GPCR function
Background: G protein-coupled receptors (GPCRs) play important physiological roles transducing extracellular signals into intracellular responses. Approximately 50% of all marketed drugs target a GPCR. There remains considerable interest in effectively predicting the function of a GPCR from its primary sequence. Findings: Using techniques drawn from data mining and proteochemometrics, an alignment-free approach to GPCR classification has been devised. It uses a simple representation of a protein's physical properties. GPCRTree, a publicly-available internet server, implements an algorithm that classifies GPCRs at the class, sub-family and sub-subfamily level. Conclusion: A selective top-down classifier was developed which assigns sequences within a GPCR hierarchy. Compared to other publicly available GPCR prediction servers, GPCRTree is considerably more accurate at every level of classification. The server has been available online since March 2008 at URL: http://igrid-ext.cryst.bbk.ac.uk/gpcrtree
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