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M Values (m + value)
Selected AbstractsEffects of short-term training on insulin sensitivity and skeletal muscle glucose metabolism in Standardbred horsesEQUINE VETERINARY JOURNAL, Issue S36 2006L. STEWART-HUNT Summary Reasons for performing study: Increased insulin sensitivity occurs after a period of exercise training, but the mechanisms underlying this training-associated increase in insulin action have not been investigated. Objective: To examine the effects of short-term endurance training (7 consecutive days) and a subsequent period of inactivity (5 days) on whole body insulin sensitivity and GLUT-4 protein and the activities of glycogen synthase (GS) and hexokinase (HK) in skeletal muscle. It was hypothesised that training would increase insulin sensitivity in association with increased GLUT-4 protein and activities of GS and HK, but that these changes would be transient, returning to baseline after 5 days of inactivity. Methods: Seven mature Standardbred horses completed training consisting of 7 consecutive days of 45 min of treadmill exercise at a speed that elicited 55% of pretraining maximal aerobic capacity (VO2peak). Insulin sensitivity was determined by rate of glucose disposal (M) during the last 60 min of a 120 min euglycaemic-hyperinsulinaemic clamp (EHC) performed before (-2 days) and at 1 and 6 days following training. VO2peak was measured before (UT) and after (TR) training and the period of inactivity (IA). Results: Training resulted in a 9% increase in mean VO2peak (P<0.05) that was maintained following inactivity (IA). Mean M values were more than 2-fold higher (P<0.05) in TR than in UT. Mean M was also higher (P<0.05) in IA when compared to UT. GLUT-4 protien abundancewas more than 10-fold higher in TR and IA (P<0.001) than in UT. Pre-EHC GS activity and GS fractional velocity were increased (P<0.05) in TR when compared to UT and IA. Pre-EHC HK activity was increased (P<0.05) in IA when compared to UT and TR. Muscle glycogen was 66% lower (P<0.05) in TR than in UT and IA. Conclusions: Short-term training resulted in increases in whole body insulin sensitivity, and GLUT-4 protein content and glycogen synthase activity in skeletal muscle. The enhancements in insulin sensitivity, GLUT-4 protein and glycogen synthase activity were still evident after 5 days of inactivity. Potential relevance: Insulin resistance in equids has been associated with obesity and predisposition to laminitis. Regular physical activity may mitigate risk of these conditions via enhancement of insulin sensitivity and/or control of bodyweight. [source] Modulation of the Lifetime of Water Bound to Lanthanide Metal Ions in Complexes with Ligands Derived from 1,4,7,10-Tetraazacyclododecane Tetraacetate (DOTA)HELVETICA CHIMICA ACTA, Issue 5 2005Shanrong Zhang A series of di- and tetraamide derivatives of DOTA were synthesized, and their lanthanide(III) complexes were examined by multinuclear 1H-, 13C-, and 17O-NMR spectroscopy, and compared with literature data of similar, known complexes (Table). All ligands formed structures similar to the parent [LnIII(DOTA)], complexes, with four N-atoms and four O-atoms from DOTA and one O-atom from the inner-sphere water molecules. Interestingly, the lifetimes ,M of the inner-sphere, metal-bound water molecules vary widely, ranging from nano- to milliseconds, depending on the identity of the pendent amide side chains. In general, positively charged [LnIII(DOTA-tetraamide)]3+ complexes display the longest residence times (high ,M values), while complexes with additional charged functional groups on the extended amides display much smaller ,M values, even when the side groups are not directly coordinated to the central Ln3+ ions. The design of novel [LnIII(DOTA-tetraamide)]3+ complexes with a wide, tunable range of ,M values is of prime importance for the application of fast-responding, paramagnetic chemical-exchange-saturation-transfer (PARACEST) imaging agents used for the study of physiological and metabolic processes. [source] Tristimulus algorithm of colour matching for precoloured fibre blends based on the Stearns,Noechel modelCOLORATION TECHNOLOGY, Issue 2 2006L I Rong Prediction of the formula for matching a given colour standard by blending predyed fibres is of considerable importance to the textile industry. This kind of formulation lacks a computer-aided tool to assist colourists to find a good recipe to reproduce a target colour. In this study a tristimulus colour-matching algorithm based on the Stearns,Noechel model is proposed. This algorithm was run to predict recipes for 54 viscose blends. Colour differences between the original blend samples and the blend samples prepared according to the matched recipes were measured and expressed in CIELab 1976 units (D65 illuminant and 10° standard observer). Used in the classical way, in which the parameter M (the empirical constant in the Stearns,Noechel model) equals 0.09, the maximum colour difference is 2.16 CIELab units. The average computed colour difference is 0.69 CIELab units. It is demonstrated that the algorithm can be used in colour matching of fibre blends. A new method to acquire the set of M values is proposed in this study. [source] Rate and product studies in the solvolyses of methanesulfonic anhydride and a comparison with methanesulfonyl chloride solvolyses,JOURNAL OF PHYSICAL ORGANIC CHEMISTRY, Issue 6 2007Dennis N. Kevill Abstract The specific rates of solvolysis of methanesulfonic anhydride have been measured conductometrically at ,10,°C in 41 solvents. Use of the extended Grunwald,Winstein equation, with the NT scale of solvent nucleophilicity and the YOTs scale of solvent ionizing power, leads to sensitivity to changes in solvent nucleophilicity (, value) of 0.95 and a sensitivity to changes in solvent ionizing power (m value) of 0.61, with a multiple correlation coefficient (R) of 0.973. Product selectivity values (S) in binary hydroxylic solvents favor alcohol attack in EtOH,H2O (a value of 1.2 in 90% EtOH rising to 4.0 in 40% EtOH) and in MeOH,H2O (a value of 3.7 in 90% MeOH rising to 6.0 in 50% MeOH). In 2,2,2,-trifluoroethanol,H2O, the S values are much lower at about 0.1. Entropy of activation values are appreciably negative. Literature values for the specific rates of solvolysis of methanesulfonyl chloride have been extended to fluoroalcohol-containing solvents (titrimetric method) and, at 45.0,°C, for an overall 43 solvents values are obtained (using NT and YC1 scales) of 1.20 for , and of 0.52 for m (R,=,0.969). It is proposed that both substrates solvolyze by an SN2 pathway. Copyright © 2007 John Wiley & Sons, Ltd. [source] HOW DO THE SIGNAL DETECTION INDICES REACT TO FREQUENCY CONTEXT BIAS FOR INTENSITY SCALING?JOURNAL OF SENSORY STUDIES, Issue 1 2001HYE-SEONG LEE ABSTRACT Stimulus frequency context effects were noted for stimuli with positive, negative and no skew, using aqueous NaCl stimuli of different concentrations as a model system and orange juice stimuli with added amounts of sucrose as a beverage system. The hypothesis that analysis by signal detection ,m values, rather than individually rated intensity values, would result in the absence of the context effect, was not confirmed. [source] An asteroseismic study of the , Cephei star , Ophiuchi: constraints on global stellar parameters and core overshootingMONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY, Issue 4 2007M. Briquet ABSTRACT We present a seismic study of the , Cephei star , Ophiuchi. Our analysis is based on the observation of one radial mode, one rotationally split ,= 1 triplet and three components of a rotationally split ,= 2 quintuplet for which the m values were well identified by spectroscopy. We identify the radial mode as fundamental, the triplet as p1 and the quintuplet as g1. Our non-local thermodynamic equilibrium abundance analysis results in a metallicity and CNO abundances in full agreement with the most recent updated solar values. With X,[0.71, 0.7211] and Z,[0.009, 0.015], and using the Asplund et al. mixture but with a Ne abundance about 0.3 dex larger, the matching of the three independent modes enables us to deduce constrained ranges for the mass (M= 8.2 ± 0.3 M,) and central hydrogen abundance (Xc= 0.38 ± 0.02) of , Oph and to prove the occurrence of core overshooting (,ov= 0.44 ± 0.07). We also derive an equatorial rotation velocity of 29 ± 7 km s,1. Moreover, we show that the observed non-equidistance of the ,= 1 triplet can be reproduced by the second-order effects of rotation. Finally, we show that the observed rotational splitting of two modes cannot rule out a rigid rotation model. [source] Schisandrin B stereoisomers protect against hypoxia/reoxygenation-induced apoptosis and associated changes in the Ca2+ -induced mitochondrial permeability transition and mitochondrial membrane potential in AML12 hepatocytesPHYTOTHERAPY RESEARCH, Issue 11 2009Po Yee Chiu Abstract The effects of the schisandrin B stereoisomers, (±), -schisandrin [(±), -Sch] and (,)schisandrin B [(,)Sch B], on hypoxia/reoxygenation-induced apoptosis were investigated in AML12 hepatocytes. Changes in cellular reduced glutathione (GSH) levels, Ca2+ -induced mitochondrial permeability transitions (MPTs) and mitochondrial membrane potentials (,,m values) were also examined in (±), -Sch- and (,)Sch B-treated cells, without or with hypoxia/reoxygenation challenge. The (±), -Sch/(,)Sch B pretreatments (2.5,5.0 µm) protected against hypoxia/reoxygenation-induced apoptosis in AML12 cells in a concentration-dependent manner, with the (,)Sch B effect being more potent. Drug antiapoptotic effects were further evidenced by suppression of hypoxia/reoxygenation-induced mitochondrial cytochrome c release and subsequent cleavage of caspase 3 and poly-ADP-ribose polymerase by (,)Sch B pretreatment. Whereas hypoxia/reoxygenation challenge increased the extent of Ca2+ -induced MPT pore opening, and ,,m, in AML12 hepatocytes, cytoprotection afforded by (±), -Sch/(,)Sch B pretreatment against hypoxia/reoxygenation-induced apoptosis was associated with a decreased sensitivity to Ca2+ -induced MPT and an increased ,,m in both unchallenged and challenged cells, compared with the drug-free control. The results indicate that (±), -Sch/(,)Sch B pretreatment protected against hypoxia/reoxygenation-induced apoptosis in AML12 hepatocytes and that the cytoprotection afforded by (±), -Sch/(,)Sch B may at least in part be mediated by a decrease in sensitivity to Ca2+ -induced MPT, which may in turn result from enhancement of cellular GSH levels by drug pretreatments. Copyright © 2009 John Wiley & Sons, Ltd. [source] 1-(,- d -Erythrofuranosyl)adenosineACTA CRYSTALLOGRAPHICA SECTION C, Issue 4 2010Paul C. Kline The title compound, also known as ,-erythroadenosine, C9H11N5O3, (I), a derivative of ,-adenosine, (II), that lacks the C5, exocyclic hydroxymethyl (,CH2OH) substituent, crystallizes from hot ethanol with two independent molecules having different conformations, denoted (IA) and (IB). In (IA), the furanose conformation is OT1,E1 (C1,- exo, east), with pseudorotational parameters P and ,m of 114.4 and 42°, respectively. In contrast, the P and ,m values are 170.1 and 46°, respectively, in (IB), consistent with a 2E,2T3 (C2,- endo, south) conformation. The N -glycoside conformation is syn (+sc) in (IA) and anti (,ac) in (IB). The crystal structure, determined to a resolution of 2.0,Å, of a cocrystal of (I) bound to the enzyme 5,-fluorodeoxyadenosine synthase from Streptomyces cattleya shows the furanose ring in a near-ideal OE (east) conformation (P = 90° and ,m = 42°) and the base in an anti (,ac) conformation. [source] | |||||||||||||