Two Types of K⁺ Channel Subunit, Erg1 and KCNQ2/3, Contribute to the M-Like Current in a Mammalian Neuronal Cell

The potassium M current was originally identified in sympathetic ganglion cells, and analogous currents have been reported in some central neurons and also in some neural cell lines. It has recently been suggested that the M channel in sympathetic neurons comprises a heteromultimer of KCNQ2 and KCNQ3 (Wang et al., 1998) but it is unclear whether all other M-like currents are generated by these channels. Here we report that the M-like current previously described in NG108–15 mouse neuroblastoma x rat glioma cells has two components, “fast” and “slow”, that may be differentiated kinetically and pharmacologically. We provide evidence from PCR analysis and expression studies to indicate that these two components are mediated by two distinct molecular species of K+ channel: the fast component resembles that in sympathetic ganglia and is probably carried byKCNQ2/3 channels, whereas the slow component appears to be carried by merg1a channels. Thus, the channels generating M-like currents in different cells may be heterogeneous in molecular composition

In California and Europe, a New Dawn for Corporate Climate Disclosure

The Securities and Exchange Commission (SEC) is expected to finalize a new rule this month to cover required corporate climate disclosures by public-reporting companies. But the bigger news is that California Gov. Gavin Newsom (D) has announced that he will soon sign into law two climate change disclosure bills passed by the state Legislature

Achievement Goal Promotion at University: Social Desirability and Social Utility of Mastery and Performance Goals

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Magnetic and Metal-Insulator Transitions in beta-Na0.5CoO2 and gamma-K0.5CoO2 -NMR and Neutron Diffraction Studies-

Co-oxides beta-Na0.5CoO2 and gamma-K0.5CoO2 have been prepared by the Na de-intercalation from alpha-NaCoO2 and by the floating-zone method, respectively. It has been found that successive phase transitions take place at temperatures Tc1 and Tc2 in both systems. The appearance of the internal magnetic field at Tc1 with decreasing temperature T indicates that the antiferromagnetic order exists at T < Tc1, as in gamma-Na0.5CoO2. For beta-Na0.5CoO2, the transition temperatures and the NMR parameters determined from the data taken for magnetically ordered state are similar to those of gamma-Na0.5CoO2, indicating that the difference of the stacking ways of the CoO2 layers between these systems do not significantly affect their physical properties. For gamma-K0.5CoO2, the quantitative difference of the physical quantities are found from those of beta- and gamma-Na0.5CoO2. The difference between the values of Tci (i = 1 and 2) of these systems might be explained by considering the distance between CoO2 layers.Comment: 8 pages, 14 figures, 1 Tabl

IC immunity modeling process validation using on-chip measurements

International audienceDeveloping integrated circuit (IC) immunity models and simulation flow has become one of the major concerns of ICs suppliers to predict whether a chip will pass susceptibility tests before fabrication and avoid redesign cost. This paper presents an IC immunity modeling process including the standard immunity test applied to a dedicated test chip. An on-chip voltage sensor is used to characterize the radio frequency interference propagation inside the chip and thus validate the immunity modeling process

Bisphosphonates alter trabecular bone collagen cross-linking and isomerization in beagle dog vertebra

Changes in organic matrix may contribute to the anti-fracture efficacy of anti-remodeling agents. Following one year of treatment in beagle dogs, bisphosphonates alter the organic matrix of vertebral trabecular bone, while raloxifene had no effect. These results show that pharmacological suppression of turnover alters the organic matrix component of bone. INTRODUCTION: The collagen matrix contributes significantly to a bone's fracture resistance yet the effects of anti-remodeling agents on collagen properties are unclear. The goal of this study was to assess changes in collagen cross-linking and isomerization following anti-remodeling treatment. METHODS: Skeletally mature female beagles were treated for one year with oral doses of vehicle (VEH), risedronate (RIS; 3 doses), alendronate (ALN; 3 doses), or raloxifene (RAL; 2 doses). The middle dose of RIS and ALN and the lower dose of RAL approximate doses used for treatment of post menopausal osteoporosis. Vertebral trabecular bone matrix was assessed for collagen isomerization (ratio of alpha/beta C-telopeptide [CTX]), enzymatic (pyridinoline [PYD] and deoxypyridinoline [DPD]), and non-enzymatic (pentosidine [PEN]) cross-links. RESULTS: All doses of both RIS and ALN increased PEN (+34-58%) and the ratio of PYD/DPD (+14-26%), and decreased the ratio of alpha/beta CTX (-29-56%) compared to VEH. RAL did not alter any collagen parameters. Bone turnover rate was significantly correlated to PEN (R = -0.664), alpha/beta CTX (R = 0.586), and PYD/DPD (R = -0.470). CONCLUSIONS: Bisphosphonate treatment significantly alters properties of bone collagen suggesting a contribution of the organic matrix to the anti-fracture efficacy of this drug class.The authors thank Dr. Keith Condon, Diana Jacob, Mary Hooser, and Lauren Waugh for histological preparation. This work was supported by NIH Grants AR047838 and AR007581 and research grants from The Alliance for Better Bone Health (Procter & Gamble Pharmaceuticals and sanofi-aventis), and Lilly Research Laboratories, as well as an unrestricted grant from Eli Lilly to INSERM. Merck and Co. kindly provided the alendronate. This investigation utilized an animal facility constructed with support from Research Facilities Improvement Program Grant Number C06 RR10601-01 from the National Center for Research Resources, National Institutes of Health

SMEs and Certified Management Standards: The Effect of Motives and Timing on Implementation and Commitment

Existing research on certifiable management standards (CMS) and corporate social responsibility (CSR) tends to focus on large companies and is characterised by disagreement about the role of these standards as drivers of CSR. We contribute to the literature by shifting the analytical focus to the behaviour of small and medium-sized enterprises (SMEs) that subscribe to multiple CSR related standards. We argue that, in respect of motive and commitment, SMEs are not as different from large companies as the literature suggests, as they are guided by similar institutional and economic motives. Results, based on ISO 9001, ISO 14001 and OHSAS 18001 certified SMEs in Greece, demonstrate that later adopters are more susceptible to coercive and mimetic motives and are less likely to commit fully to the CMS requirements, while earlier adopters react to normative motives and considerations of internal efficiency gains and tend to carry out CMS requirements with greater diligence

Fréchet mean and pp-mean on the unit circle: decidability, algorithm, and applications to clustering on the flat torus

International audienceThe center of mass of a point set lying on a manifold generalizes the celebrated Euclidean centroid, and is ubiquitous in statistical analysis in non Euclidean spaces. In this work, we give a complete characterization of the weighted $p$-mean of a finite set of angular values on $S^1$ , based on a decomposition of $S^1$ such that the functional of interest has at most one local minimum per cell. This characterization is used to show that the problem is decidable for rational angular values-a consequence of Lindemann's theorem on the transcendence of π, and to develop an effective algorithm parameterized by exact predicates. A robust implementation of this algorithm based on multi-precision interval arithmetic is also presented, and is shown to be effective for large values of n and $p$. We use it as building block to implement the $k$-means and $k$-means++ clustering algorithms on the flat torus, with applications to clustering protein molecular conformations. These algorithms are available in the Structural Bioinformatics Library (http://sbl.inria.fr). Our derivations are of interest in two respects. First, efficient p-mean calculations are relevant to develop principal components analysis on the flat torus encoding angular spaces-a particularly important case to describe molecular conformations. Second, our two-stage strategy stresses the interest of combinatorial methods for $p$-means, also emphasizing the role of numerical issues