754 research outputs found
Regulation of Human Cystic Fibrosis Transmembrane Conductance Regulator (Cftr) by Serum- and Glucocorticoid-Inducible Kinase (Sgk1)
Background: Serum- and glucocorticoid-inducible kinase-1 (SGK1) increases CFTR Cl currents in Xenopus oocytes by an unknown mechanism. Because SGK increases the plasma membrane expression of other ion channels, the goal of this paper was to test the hypothesis that SGK1 stimulates CFTR Cl currents by increasing the number of CFTR Cl channels in the plasma membrane. Methods: CFTR Cl currents were measured in Xenopus oocytes by the two-electrode voltage clamp technique, and CFTR in the plasma membrane was determined by laser scanning confocal microscopy. Results: wt-SGK1 stimulated CFTR Cl currents by 42% and increased the amount of CFTR in the plasma membrane by 35%. A kinase-dead SGK mutant (K127N) had a dominant-negative effect on CFTR, reducing CFTR Cl currents by 38%. In addition, deletion of the C-terminal PDZ-interacting motif (SGK1-ΔSFL) increased CFTR Cl currents by 108%. Thus, SGK1-ΔSFL was more effective than wt-SGK1 in stimulating CFTR Cl currents. Neither wt-SGK nor the K127N mutant had any effect on Cl currents in oocytes when expressed alone in the absence of CFTR. Conclusion: SGK1 stimulates CFTR Cl currents in Xenopus oocytes by increasing the number of channels in the plasma membrane. Moreover, the effect of SGK may be mediated by protein-protein interactions involving the PDZ interacting motif
Superconducting Cosmc Strings and Primordial Magnetic Fields
We consider grand unified theories with superconducting cosmic strings and
which admit the mechanism for generating primordial magnetic fields recently
discussed by Vachaspati. We show that these models are severely constrained by
cosmological arguments. Quite generically, either stable springs or vortons
will form. Provided the mass per unit length of the strings is sufficiently
large, these stable configurations will overclose the Universe.Comment: BROWN-HET-830, 14 pages, use phyzz
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Dialogue Modelling and the Remit of Core Grammar
In confronting the challenge of providing formal models of dialogue, with its plethora of fragments and rich variation in modes of context-dependent construal, it might seem that linguists face two types of methodological choice: either (a) conversation employs dialogue-specific mechanisms, for which a grammar specific to such activity must be constructed; or (b) variation arises due to independent parsing/production systems which invoke a process-neutral grammar. However, as dialogue research continues to develop, there are intermediate possibilities, and in this paper we discuss the approach developed within Dynamic Syntax (DS, Kempson et al. 2001, Cann et al. 2005), a grammar framework within which, not only the parser, but indeed “syntax” itself are just a single mechanism allowing the progressive construction of semantic representations in context. Here we take as a case study the set of phenomena classifiable as clarifications, reformulations, fragment requests and corrections accompanied by extensions, and argue that though these may seem to be uniquely constitutive of dialogue, they are grounded in the mechanisms of apposition equivalently usable in monologue for presenting reformulations, extensions, self-corrections etc
The in vitro effects of resistin on the innate immune signaling pathway in isolated human subcutaneous adipocytes
Context: Obesity-associated inflammation is a contributory factor in the pathogenesis of type 2 diabetes mellitus (T2DM); the mechanisms underlying the progression to T2DM are unclear. The adipokine resistin has demonstrated pro-inflammatory properties in relation to obesity and T2DM.
Objective: To characterize resistin expression in human obesity and address the role of resistin in the innate immune pathway. Furthermore, examine the influence of lipopolysaccharide, recombinant human resistin (rhResistin), insulin and rosiglitazone in human adipocytes. Finally, analyze the effect of rhResistin on the expression of components of the NF-κB pathway and insulin signaling cascade.
Methods: Abdominal subcutaneous adipose tissue was obtained from patients undergoing elective liposuction surgery (n = 35, aged: 36-49 yr; BMI: 26.5 ± 5.9 kg/m2). Isolated adipocytes were cultured with rhResistin (10-50 ng/ml). The level of cytokine secretion from isolated adipocytes was examined by ELISA. The effect of rhResistin on protein expression of components of the innate immune pathway was examined by Western blot.
Results: In-vitro studies demonstrated that antigenic stimuli increase resistin secretion (P < 0.001) from isolated adipocytes. Pro-inflammatory cytokine levels were increased in response to rhResistin (P < 0.001); this was attenuated by rosiglitazone (P < 0.01). When examining components of the innate immune pathway, rhResistin stimulated Toll-like receptor-2 protein expression. Similarly, mediators of the insulin signaling pathway, phosphospecific JNK1 and JNK2, were upregulated in response to rhResistin.
Conclusion: Resistin may participate in more than one mechanism to influence pro-inflammatory cytokine release from human adipocytes; potentially via the integration of NF-κB and JNK signaling pathways
Impaired perception of facial motion in autism spectrum disorder
Copyright: © 2014 O’Brien et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.This article has been made available through the Brunel Open Access Publishing Fund.Facial motion is a special type of biological motion that transmits cues for socio-emotional communication and enables the discrimination of properties such as gender and identity. We used animated average faces to examine the ability of adults with autism spectrum disorders (ASD) to perceive facial motion. Participants completed increasingly difficult tasks involving the discrimination of (1) sequences of facial motion, (2) the identity of individuals based on their facial motion and (3) the gender of individuals. Stimuli were presented in both upright and upside-down orientations to test for the difference in inversion effects often found when comparing ASD with controls in face perception. The ASD group’s performance was impaired relative to the control group in all three tasks and unlike the control group, the individuals with ASD failed to show an inversion effect. These results point to a deficit in facial biological motion processing in people with autism, which we suggest is linked to deficits in lower level motion processing we have previously reported
Measuring the State of Disaster Philanthropy 2015: Data to Drive Decisions
Jointly produced by Foundation Center and the Center for Disaster Philanthropy, Measuring the State of Disaster Philanthropy 2015: Data to Drive Decisions analyzes funding trends for disasters and humanitarian crises in 2013. In addition to examining U.S. foundation funding, this second annual report integrates other disaster-related funding data, including bilateral and multilateral aid, corporate giving, and online giving, to paint a more detailed picture of how institutional philanthropy is situated within the broader disaster funding landscape. Collectively, this report, along with the dashboard and mapping platform, provides donors, practitioners, and other stakeholders with in-depth information on funding flows for disasters and humanitarian crises. Explore more at disasterphilanthropy.org
Brain structural covariance networks in obsessive-compulsive disorder: a graph analysis from the ENIGMA Consortium.
Brain structural covariance networks reflect covariation in morphology of different brain areas and are thought to reflect common trajectories in brain development and maturation. Large-scale investigation of structural covariance networks in obsessive-compulsive disorder (OCD) may provide clues to the pathophysiology of this neurodevelopmental disorder. Using T1-weighted MRI scans acquired from 1616 individuals with OCD and 1463 healthy controls across 37 datasets participating in the ENIGMA-OCD Working Group, we calculated intra-individual brain structural covariance networks (using the bilaterally-averaged values of 33 cortical surface areas, 33 cortical thickness values, and six subcortical volumes), in which edge weights were proportional to the similarity between two brain morphological features in terms of deviation from healthy controls (i.e. z-score transformed). Global networks were characterized using measures of network segregation (clustering and modularity), network integration (global efficiency), and their balance (small-worldness), and their community membership was assessed. Hub profiling of regional networks was undertaken using measures of betweenness, closeness, and eigenvector centrality. Individually calculated network measures were integrated across the 37 datasets using a meta-analytical approach. These network measures were summated across the network density range of K = 0.10-0.25 per participant, and were integrated across the 37 datasets using a meta-analytical approach. Compared with healthy controls, at a global level, the structural covariance networks of OCD showed lower clustering (P < 0.0001), lower modularity (P < 0.0001), and lower small-worldness (P = 0.017). Detection of community membership emphasized lower network segregation in OCD compared to healthy controls. At the regional level, there were lower (rank-transformed) centrality values in OCD for volume of caudate nucleus and thalamus, and surface area of paracentral cortex, indicative of altered distribution of brain hubs. Centrality of cingulate and orbito-frontal as well as other brain areas was associated with OCD illness duration, suggesting greater involvement of these brain areas with illness chronicity. In summary, the findings of this study, the largest brain structural covariance study of OCD to date, point to a less segregated organization of structural covariance networks in OCD, and reorganization of brain hubs. The segregation findings suggest a possible signature of altered brain morphometry in OCD, while the hub findings point to OCD-related alterations in trajectories of brain development and maturation, particularly in cingulate and orbitofrontal regions
ISSCR standards for the use of human stem cells in basic research.
The laboratory culture of human stem cells seeks to capture a cellular state as an in vitro surrogate of a biological system. For the results and outputs from this research to be accurate, meaningful, and durable, standards that ensure reproducibility and reliability of the data should be applied. Although such standards have been previously proposed for repositories and distribution centers, no widely accepted best practices exist for laboratory research with human pluripotent and tissue stem cells. To fill that void, the International Society for Stem Cell Research has developed a set of recommendations, including reporting criteria, for scientists in basic research laboratories. These criteria are designed to be technically and financially feasible and, when implemented, enhance the reproducibility and rigor of stem cell research
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