Different Potentials (different + potential)

Distribution by Scientific Domains


Selected Abstracts


SNP discovery, expression and association analysis for the SDHD gene in pigs

JOURNAL OF ANIMAL BREEDING AND GENETICS, Issue 4 2007
S.E.F. Guimaraes
Summary The SDHD gene was examined for single nucleotide polymorphisms (SNP) as well as for expression changes in the Longissimus dorsi muscle of commercial pigs with different potential for growth. Three SNPs, including one previously described in the coding region and two new ones in the 3,-UTR, were found. The normalized expression of SDHD was correlated with growth, meat quality and sensory traits (p < 0.05). For the commercial pigs used in this study, as well as a Berkshire × Yorkshire resource population, the SNPs have been associated (p < 0.05) with: growth, carcass composition, meat quality and sensory traits. Despite the fact that the described SNPs were not significantly associated with the normalized expression values, the SDHD SNPs and expression were associated with growth and meat quality traits in pigs. [source]


Two-dimensional hydrogen-bonded networks in 1-(diaminomethylene)thiouron-1-ium nitrate and bis[1-(diaminomethylene)thiouron-1-ium] phosphonate monohydrate

ACTA CRYSTALLOGRAPHICA SECTION C, Issue 3 2009
Jan Janczak
Crystals of the title compounds, C2H7N4S+·NO3,, (I), and 2C2H7N4S+·HPO32,·H2O, (II), are built up from 1-(diaminomethylene)thiouron-1-ium cations and nitrate anions in (I), and from phosphonate anions and water molecules in (II). In both crystals, the cations and anions are linked together via N,H...O hydrogen bonds. The 1-(diaminomethylene)thiouron-1-ium cations exhibit a twisted conformation. Both arms of the cations are planar and are turned in opposite directions around the C,N bond involving the central N atom. Hydrogen-bonding interactions join oppositely charged units into layers in the nitrate salt and into double layers in the phosphonate monohydrate salt. In addition, the structures are stabilized by ,,, interactions between the delocalized , bonds of the cations. The significance of this study lies in the illustration of the differences between the supramolecular aggregations in the nitrate and phosphonate salts of a small organic molecule. The different geometries of the counter-ions and their different potential for hydrogen-bond formation results in markedly different hydrogen-bond arrangements. [source]


IgE-Mediated Asthma and Rhinitis I: A Role of Allergen Exposure?

BASIC AND CLINICAL PHARMACOLOGY & TOXICOLOGY, Issue 5 2002
Gunnar D. Nielsen
The IgE antibodies and associated cellular responses are responsible for the allergic airway diseases, allergic rhinitis and allergic asthma, which are increasing in societies with Western life style. Aeroallergens may have different potential to sensitize exposed subjects. Thus, there are only a limited number of important groups of aeroallergens, which are those from house dust mites, cockroaches, pets, pollens, and moulds. Allergy follows to a certain extent the pharmacological/toxicological paradigm of dose-response relationship. Unlike effects of pharmacologically and toxicologically active substances, allergens elicit their adverse effects in a two-stage process. In the first stage the immunologically naïve individual is sensitized to the allergen. In the second stage renewed exposure to the allergen elicits the disease response. Also, high concentrations of aeroallergens may induce immunological tolerance. The scientific literature suggests that many environmental factors contribute to the increase in sensitization and development of airway allergies. Nevertheless, the dose-response relationships apply (within certain limits) both to the sensitization itself and to the exacerbation of the diseases. This suggest that exposure reduction may be one of the methods for reduction of risk, in relation to control of the allergic airway diseases. [source]


Introductory quantum physics courses using a LabVIEW multimedia module

COMPUTER APPLICATIONS IN ENGINEERING EDUCATION, Issue 2 2007
Ismael Orquín
Abstract We present the development of a LabVIEW multimedia module for introductory Quantum Physics courses and our experience in the use of this application as an educational tool in learning methodologies. The program solves the time-dependent Schrödinger equation (TDSE) for arbitrary potentials. We describe the numerical method used for solving this equation, as well as some mathematical tools employed to reduce the calculation time and to obtain more accurate results. As an illustration, we present the evolution of a wave packet for three different potentials: the repulsive barrier potential, the repulsive step potential, and the harmonic oscillator. This application has been successfully integrated in the learning strategies of the course Quantum Physics for Engineering at the Polytechnic University of Valencia, Spain. © 2007 Wiley Periodicals, Inc. Comput Appl Eng Educ. 15: 124,133, 2007; Published online in Wiley InterScience (www.interscience.wiley.com); DOI 10.1002/cae.20100 [source]


Electrochemical Reduction of Oxygen on Carbon Supported Pt and Pt/Ru Fuel Cell Electrodes in Alkaline Solutions

FUEL CELLS, Issue 4 2003
E.H. Yu
Abstract A study of O2 reduction in 1 M NaOH solution at gas diffusion electrodes made from carbon supported Pt and Pt/Ru catalysts is reported. Two Tafel regions were observed for both the Pt and Pt/Ru electrodes. Although the same mechanism was suggested for oxygen reduction on both Pt and Pt/Ru catalysts, the O2 reduction activity was lower on Ru. Electrochemical Impedance Spectroscopy (EIS) analysis was carried out at different potentials and showed the significant contribution of diffusion on the reaction process and kinetics. The effect of methanol on O2 reduction was investigated in solutions containing various concentrations of methanol. The electrode performance deteriorated with increasing methanol concentration because of a mixed cathode potential. The methanol tolerance, i. e., the methanol concentration which polarises the O2 reduction reaction for O2 reduction, at the Pt/C electrode with a Pt loading of 1.2 mg cm,2 is 0.2 M methanol in 1 M NaOH. [source]


Optimisation of gradient HPLC analysis of phenolic compounds and flavonoids in beer using a CoulArray detector

JOURNAL OF SEPARATION SCIENCE, JSS, Issue 15-16 2004
Lucie, ehová
Abstract A method was developed for simultaneous analysis of natural antioxidants in beer using multichannel electrochemical detection with a CoulArray detector, which enables selective and sensitive antioxidant detection in gradient HPLC and facilitates the identification of analytes based on the ratios of signals recorded at different potentials applied to the detection cells arranged in series. The separation conditions were optimised for 27 phenolic compounds including derivatives of benzoic and cinnamic acids, flavones, and a few related glycosides identified in beer samples. Separation selectivities of 11 columns with different stationary phase chemistries were compared, and the pH and gradient programs were optimised for the individual columns to provide best resolution and high number of resolved peaks, using the window-diagram approach. The effects of pH on the sensitivity of electrochemical coulometric detection were considered in the optimisation approach. The optimised conditions were applied to the analysis of real beer samples. [source]


Effects of field reorganisation on the spatial variability of runoff and erosion rates in vineyards of Northeastern Spain

LAND DEGRADATION AND DEVELOPMENT, Issue 1 2010
M. C. Ramos
Abstract This study analyses the spatial variability of runoff and erosion rates in vineyards due to mechanisation works. Runoff samples were collected at three positions in two plots after 33 erosive events in three years (2001, 2003, 2004) with different rainfall patterns. Three replications were considered at each position. Soil properties were evaluated in order to analyse its relationship with runoff and erosion rates. Runoff and erosion rates were, on average, higher in the levelled plot (HD), ranging between 8·4 and 34·3 per cent, than in the non-levelled plot (LD) ranging between 8·2 and 24·1 per cent. Mean sediment concentration in runoff ranged between 6 and 8,g,L,1 in the HD plot and about 4·6,g,L,1 in the LD plot, but with high differences within the plot. In the HD plot, runoff-rainfall rates were significantly higher (at 95 per cent level) in the upper part of the slope and decreased along the slope, while in the LD plot, differences in runoff rates were not significant and similar to those observed in the less disturbed areas of the HD plot. The higher susceptibility to soil sealing in areas where the original topsoil was removed conditioned runoff rates. In the lower part of the HD plot runoff rates were, on average, 20 per cent lower than in the upper part of the slope. In those positions runoff rates up to 79 per cent were recorded. Organic matter content and water retention capacity at different potentials are the soil characteristics related to the differences on runoff and erosion rates in the resulting soils. Copyright © 2009 John Wiley & Sons, Ltd. [source]


Effect of potential on the corrosion behavior of a new titanium alloy for dental implant applications in fluoride media

MATERIALS AND CORROSION/WERKSTOFFE UND KORROSION, Issue 2 2004
A. M. Al-Mayouf
Abstract The effect of fluoride ion concentration and pH on the corrosion behavior of TCA (60 Ti 10 Ag 30 Cu), which is a new Ti alloy with low melting point, pure Titanium (Ti), and TAV (TiAl6V4) was examined using open circuit potential (OCP) and electrochemical impedance spectroscopy (EIS) at different potentials. Results show that the corrosion resistance of TCA and Ti decrease at anodic potentials compared with results obtained at OCP. At one potential the corrosion resistance decrease depends on NaF concentration and pH. TAV shows less resistance against corrosion in fluoride containing saliva. TCA has potentials more positive than Ti and TAV due to surface enrichment of Cu and Ag as Ti dissolves which accelerates the cathodic reaction. Fluoride ion may not hinder the growth of oxide layers on the surfaces of the electrodes. It will have influence on the properties of the oxide layer causing them to be not protective against corrosion in acid media containing fluoride ions. [source]


A three-dimensional Brownian motor, realised with symmetric optical lattices

PHYSICA STATUS SOLIDI (B) BASIC SOLID STATE PHYSICS, Issue 5 2009
Anders Kastberg
Abstract A three-dimensional Brownian motor is realised using lasercooled caesium atoms trapped in a system of two static, and individually symmetric, optical lattices; a so-called double optical lattice. Isotropic fluctuations, emanating from light scattering, are rectified, and the diffusion of the ensemble of atoms is biased, with a resulting constant velocity that is controllable both in direction and magnitude. The working principle of the Brownian motor can be seen as a pulsation between two different potentials, both symmetric but around different points. The correlation between interferometric spatial offsets, and imbalance in optical pumping rates, leads to a spatio-temporal asymmetry sufficient for generating a controlled, directed motion (© 2009 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source]


Electrophysiological properties of BK channels in Xenopus motor nerve terminals

THE JOURNAL OF PHYSIOLOGY, Issue 1 2004
Xiao-Ping Sun
Single channel properties of Ca2+ -activated K+ (BK or Maxi-K) channels have been investigated in presynaptic membranes in Xenopus motoneurone,muscle cell cultures. The occurrence and density of BK channels increased with maturation/synaptogenesis and was not uniform: highest at the release face of bouton-like synaptic varicosities in contact with muscle cells, and lowest in varicosities that did not contact muscle cells. The Ca2+ affinity of the channel (Kd= 7.7 ,m at a membrane potential of +20 mV) was lower than those of BK channels that have been characterized in other terminals. Hill coefficients varied between 1.5 and 2.8 at different potentials and open probability increased e-fold per 16 mV change in membrane potential over a range of [Ca2+]i from 1 ,m to 1 mm. The maximal activation rate of ensembled single BK channel currents was in the submillisecond range at ,+20 mV. The activation rate increased ,10-fold in response to a [Ca2+]i increase from 1 to 100 ,m, but increased only ,2-fold with a voltage change from +20 to +130 mV. The fastest activation kinetics of BK channels in cell-attached patches resembled that in inside-out patches with [Ca2+]i of 100 ,m or more, suggesting that many BK channels are located very close to calcium channels. Given the low Ca2+ affinity and rapid Ca2+ binding/unbinding properties, we conclude that BK channels in this preparation are adapted to play an important role in regulation of neurotransmitter release, and they are ideal reporters of local [Ca2+] at the inner membrane surface. [source]