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Functional Understanding (functional + understanding)

Distribution by Scientific Domains
Life Sciences40%

Selected Abstracts

Functional changes in astroglial cells in epilepsy

GLIA, Issue 5 2006
Devin K. Binder
Abstract Epilepsy comprises a group of disorders characterized by the periodic occurrence of seizures, and pathologic specimens from patients with temporal lobe epilepsy demonstrate marked reactive gliosis. Since recent studies have implicated glial cells in novel physiological roles in the CNS, such as modulation of synaptic transmission, it is plausible that glial cells may have a functional role in the hyperexcitability characteristic of epilepsy. Indeed, alterations in distinct astrocyte membrane channels, receptors and transporters have all been associated with the epileptic state. This review integrates the current evidence regarding astroglial dysfunction in epilepsy and the potential underlying mechanisms of hyperexcitability. Functional understanding of the cellular and molecular alterations of astroglia-dependent hyperexcitability will help to clarify the physiological role of astrocytes in neural function as well as lead to the identification of novel therapeutic targets. © 2006 Wiley-Liss, Inc. [source]

The lower esophageal sphincter strength in patients with gastroesophageal reflux before and after laparoscopic Nissen fundoplication

DISEASES OF THE ESOPHAGUS, Issue 1 2007
J. H. Schneider
SUMMARY., Lower esophageal sphincter pressure (LESP) and sphincter strength (LESS) were measured before and after short and floppy laparoscopic Nissen fundoplication (LNF) in 38 patients with severe gastro-esophageal reflux disease (GERD). These patients were compared with a control group of 23 healthy volunteers. GERD was assessed by stationary manometry, 24-h pH recordings and endoscopy. LESS was verified by motorized pull-back of an air-filled balloon catheter from the stomach into the esophagus. The catheter assembly was well tolerated by all study participants. LESP increased significantly after operation from 8 mmHg to 14 mmHg (75% of normal values; P < 0.0001), but compared to the control group, LESP (22 mmHg) decreased significantly (P < 0.002). In the control group and in patients with GERD, LESP and LESS showed excellent correlation (r = 0.97, r = 0.94, respectively). After LNF, LESS increased significantly from 0.6 to 1.6 N (P < 0.0001), about 166%. We conclude that the measurement of LESS is able to explain the discrepancy between satisfactory NF operation and the distinct increase of postoperative LESP. The evaluation of LESS is a helpful tool in assessing functional understanding of laparoscopic Nissen fundoplication with a short and floppy wrap. [source]

Translating networked learning: un-tying relational ties

JOURNAL OF COMPUTER ASSISTED LEARNING, Issue 2 2008
J.G. Enriquez
Abstract This article explores the social network of learning beyond a functional understanding of social relations. It describes and interprets the realities of networked learning within a particular postgraduate course in an English university setting. It draws attention to some of the limitations of the increasing interest in the use of social network analysis (SNA) alongside content analysis of recent studies in the field of networked learning. In particular, SNA has been used to analyse response relations among participants in online discussions in terms of, for example, density and centrality. It argues for a different approach to a network of learning, focusing on the relational effects of multiple technical and social arrangements and engagements beyond the response relations the online environment is able to capture and store. This approach emphasizes network processes rather than network structures. [source]

The Role of Chemistry in the Energy Challenge

CHEMSUSCHEM CHEMISTRY AND SUSTAINABILITY, ENERGY & MATERIALS, Issue 2 2010
Robert Schlögl Prof.
Chemistry with its key targets of providing materials and processes for conversion of matter is at the center stage of the energy challenge. Most energy conversion systems work on (bio)chemical energy carriers and require for their use suitable process and material solutions. The enormous scale of their application demands optimization beyond the incremental improvement of empirical discoveries. Knowledge-based systematic approaches are mandatory to arrive at scalable and sustainable solutions. Chemistry for energy, "ENERCHEM" contributes in many ways already today to the use of fossil energy carriers. Optimization of these processes exemplified by catalysis for fuels and chemicals production or by solid-state lightning can contribute in the near future substantially to the dual challenge of energy use and climate protection being in fact two sides of the same challenge. The paper focuses on the even greater role that ENERCHEM will have to play in the era of renewable energy systems where the storage of solar energy in chemical carries and batteries is a key requirement. A multidisciplinary and diversified approach is suggested to arrive at a stable and sustainable system of energy conversion processes. The timescales for transformation of the present energy scenario will be decades and the resources will be of global economic dimensions. ENERCHEM will have to provide the reliable basis for such technologies based on deep functional understanding. [source]

Munc18-1 as a key regulator of neurosecretion

JOURNAL OF NEUROCHEMISTRY, Issue 1 2010
Gayoung A. Han
J. Neurochem. (2010) 115, 1,10. Abstract Munc18-1 plays essential roles in neurosecretion by interacting with syntaxin-1 and controlling the formation of the soluble N -ethylmaleimide-sensitive factor attachment protein receptors (SNARE) complex. At least three important functions of Munc18-1 have been proposed: (i) molecular chaperone of syntaxin-1 for appropriate localization and expression of syntaxin-1, (ii) priming/stimulation of the SNARE-mediated membrane fusion, and (iii) docking of large dense-core vesicles to the plasma membrane. Similarly, at least two different binding modes have been proposed for the interaction between Munc18-1 and syntaxin-1: (i) binary binding to a ,closed' conformation of syntaxin-1, and (ii) binding to the N-terminal peptide of syntaxin-1, which is thought to enable an interaction with the quaternary SNARE complex and/or further stabilize the binary interaction between Munc18-1 and closed syntaxin-1. Recent structural analyses have identified critical Munc18-1 residues implicated in these different modes of binding. These have recently been tested functionally in rescue experiments using Munc18-1 null neurons, chromaffin cells and Munc18-1/-2 knockdown PC12 cells, allowing remarkable progress to be made in the structural/functional understanding of Munc18-1. In this review, we summarize these recent advances and attempt to propose an updated model of the pleiotropic functions of Munc18-1 in neuroexocytosis. [source]