The heterotrimeric G-protein complex modulates light sensitivity in arabidopsis thaliana seed germination

Release of dormancy and induction of seed germination are complex traits finely regulated by hormonal signals and environmental cues such as temperature and light. The Red (R):Far-Red (FR) phytochrome photoreceptors mediate light regulation of seed germination. We investigated the possible involvement of heterotrimeric G-protein complex in the phytochrome signaling pathways of Arabidopsis thaliana seed germination. Germination rates of null mutants of the alpha (Gα) and beta (Gβ) subunits of the G-protein (Atgpa1-4 and agb1-2, respectively) and the double mutant (agb1-2/gpa1-4) are lower than the wildtype (WT) under continuous or pulsed light. The Gα and Gβ subunits play a role in seed germination under hourly pulses of R lower than 0.1 μmol m -2 s -1 whereas the Gβ subunit plays a role in higher R fluences. The germination of double mutants of G-protein subunits with phyA-211 and phyB-9 suggests that AtGPA1 seems to act as a positive regulator of phyA and probably phyB signaling pathways, while the role of AGB1 is ambiguous. The imbibition of seeds at 4°C and 35°C alters the R and FR light responsiveness of WT and G-protein mutants to a similar magnitude. Thus, Gα and Gβ subunits of the heterotrimeric G-protein complex modulate light induction of seed germination by phytochromes and are dispensable for the control of dormancy by low and high temperatures prior to irradiation. We discuss the possible indirect role of the G-protein complex on the phytochrome-regulated germination through hormonal signaling pathways.Fil: Botto, Javier Francisco. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Investigaciones Fisiológicas y Ecológicas Vinculadas a la Agricultura. Universidad de Buenos Aires. Facultad de Agronomía. Instituto de Investigaciones Fisiológicas y Ecológicas Vinculadas a la Agricultura; ArgentinaFil: Ibarra, Silvia Elizabeth. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Investigaciones Fisiológicas y Ecológicas Vinculadas a la Agricultura. Universidad de Buenos Aires. Facultad de Agronomía. Instituto de Investigaciones Fisiológicas y Ecológicas Vinculadas a la Agricultura; ArgentinaFil: Jones, Alan M.. University of North Carolina; Estados Unido

Computerized clinical decision support systems for chronic disease management: A decision-maker-researcher partnership systematic review

<p>Abstract</p> <p>Background</p> <p>The use of computerized clinical decision support systems (CCDSSs) may improve chronic disease management, which requires recurrent visits to multiple health professionals, ongoing disease and treatment monitoring, and patient behavior modification. The objective of this review was to determine if CCDSSs improve the processes of chronic care (such as diagnosis, treatment, and monitoring of disease) and associated patient outcomes (such as effects on biomarkers and clinical exacerbations).</p> <p>Methods</p> <p>We conducted a decision-maker-researcher partnership systematic review. We searched MEDLINE, EMBASE, Ovid's EBM Reviews database, Inspec, and reference lists for potentially eligible articles published up to January 2010. We included randomized controlled trials that compared the use of CCDSSs to usual practice or non-CCDSS controls. Trials were eligible if at least one component of the CCDSS was designed to support chronic disease management. We considered studies 'positive' if they showed a statistically significant improvement in at least 50% of relevant outcomes.</p> <p>Results</p> <p>Of 55 included trials, 87% (n = 48) measured system impact on the process of care and 52% (n = 25) of those demonstrated statistically significant improvements. Sixty-five percent (36/55) of trials measured impact on, typically, non-major (surrogate) patient outcomes, and 31% (n = 11) of those demonstrated benefits. Factors of interest to decision makers, such as cost, user satisfaction, system interface and feature sets, unique design and deployment characteristics, and effects on user workflow were rarely investigated or reported.</p> <p>Conclusions</p> <p>A small majority (just over half) of CCDSSs improved care processes in chronic disease management and some improved patient health. Policy makers, healthcare administrators, and practitioners should be aware that the evidence of CCDSS effectiveness is limited, especially with respect to the small number and size of studies measuring patient outcomes.</p

Charge distribution over dust particles configured with size distribution in a complex plasma

A theoretical kinetic model describing the distribution of charge on the dust particles configured with generalized Kappa size distribution in a complex plasma has been developed. The formulation is based on the manifestation of uniform potential theory with an analytical solution of the master differential equation for the probability density function of dust charge; the number and energy balance of the plasma constituents are utilized in writing the kinetic equations. A parametric study to determine the steady state plasma parameters and the charge distribution corresponding to a size distribution of dust grains in the complex plasma has been made; the numerical results are presented graphically. The charge distribution is seen sensitive to the population of small grains in the particle size distribution and thus in contrast to symmetrical distribution of charge around a mean value for uniform sized grains, the charge distribution in the present case peaks around lower charge

Charging kinetics of dust particles in a non-Maxwellian Lorentzian plasma

Charging kinetics of uniformly dispersed spherical dust particles in a non-Maxwellian plasma, characterized by a Lorentzian (κ) distribution function of electrons/ions has been developed; the formulation is based on the uniform potential theory, applicable to the dust particles characterized by a size distribution function. Owing the openness character of the complex plasmas, the charging kinetics has been developed on the basis of number and energy balance of the plasma constituents along with the charge balance over the dust particles; the neutrality of the complex plasma is a consequence of the number balance of electrons/ions and charge balance on the dust particles. A more rigorous approach, proposed by Mott-Smith and Langmuir [Phys. Rev. 28, 727 (1926)] has been adopted to derive the expressions for the electron/ion accretion current over the dust surface and corresponding mean energy in a non-Maxwellian Lorentzian plasma. Further the formulation has been implemented to determine the secondary electron emission (SEE) from the spherical dust particles in such plasmas. The departure of the results for the Lorentzian plasma, from that in the case of Maxwellian plasma has been graphically illustrated and discussed. It is seen that the Lorentzian nature of the plasma and the inclusion of the collective effect of the dust particles significantly affects the dust charge and other plasma parameters; the formulation and understanding of the charging kinetics in a Lorentzian plasma have implications for both the physics (e.g. grain growth and disruption) and the dynamics of dust in laboratory and space environment, when the dimension of the plasma are much larger than the diffusion length

Efficient utilization of multilayer graphene towards thermionic convertors

In this paper a comprehensive model to investigate the thermionic emission from few layer graphene (FLG) structures operating at finite temperature (7) and its feasibility towards thermionic energy conversion scheme as cathode, has been proposed. Taking into account the stacking dependent energy dispersion for the evaluation of density of states of Fermionic electrons and Fowler's treatment of the electron emission, the analytical expressions for the thermionic flux from ABA/ABC stacked FLG surfaces have been derived and shown to be an increasing function of number of constituent layers (N). In contrast to the usual RD law (alpha T-2) thermionic flux -temperature scaling, ABA and ABC stacked FLG have been identified to display alpha T-3 and alpha T1+2/N temperature scaling. Utilizing the competence of FLGs to deliver substantial thermionic flux in fabricating the FLG based cathodes, an appropriate operating regime for the constituent parameters of the thermionic convertors (TCs) describing efficient energy conversion, has been specified. As a remarkable feature, FLG based cathodes provide flexibility to operate TC at low cathode (and high anode) temperature, with a sustained optimum efficacy (equal to the monolayer graphene). As an illustrative case, a TC configured with FLG based cathode (N = 10, ABA stacking, similar to 900 K) and low work function (Cesium coated) metallic anode (2.0 V, 400 K) has been identified to display similar to 55% of the conversion efficiency (equivalent to similar to 2% of the Carnot efficiency). On the basis of analytical formulation, appropriately tuned FLG based cathode operating at low temperature, is proposed as a promising contrivance in achieving efficient energy conversion of heat into electrical power. (C) 2017 Elsevier Masson SAS. All rights reserved

Prediction of viscosity of multicomponent liquid mixtures

113-123Viscosities of three quaternary, viz. n-hexadecane + n-tetradecane + n-hexane + 2-bromobutane (I), n-hexadecane + carbon tetrachloride + benzene + n-hexane (II) and n-hexadecane + n-tetradecane + 4-methylcyclohexanone + n-hexane (III) and eleven ternary liquid mixtures (IA-D, IIA-D and IIIA-C) have been evaluated theoretically, using various empirical relations (Frenkel, Kendall-Munroe, Bingham and Additive relations) applicable to binary mixtures. The theoretical values of viscosity of these mixtures are compared with the experimental viscosities given in literature. The results of calculation show that the viscous behaviour of these liquid mixtures having constituent components with likelihood of better interactions with each other, can be best explained by Frenkel relation as it takes into account all the possible major interactions. Still better results by Frenkel relation are obtained when some small molecules like CCl4 is one of the components of the mixture (II) which can take up interstitial positions resulting in enhanced interaction. The presence of planar molecules, like benzene with its 3t-electron cloud above and below the ring, certainly inhibits the interaction between the components to some extent and results in somewhat ideal behaviour of mixtures. This is evident for some systems where Kendall-Munroe and Additive relations give better results than those given by Frenkel relation. The presence of substituent and polar groups on one of the components affects the extent of interaction more than when they are present in a cyclic molecule than on a straight chain hydrocarbon. Thus, the presence of bromine in system (I) and the ternary mixtures still allows interaction to a greater extent since in the possible compact structure 2-bromobutane can fit with bromine protruding out. However, the presence of polar and substituent groups in cyclic molecule (4-methylcyclohexanone) does not allow interaction and also inhibits the interaction of other components resulting in ideal mixing and thus better