1,024 research outputs found
Asymptotically safe and free chiral theories with and without scalars
We unveil the dynamics of four dimensional chiral gauge-Yukawa theories
featuring several scalar degrees of freedom transforming according to distinct
representations of the underlying gauge group. We consider generalized
Georgi-Glashow and Bars-Yankielowicz theories. We determine, to the maximum
known order in perturbation theory, the phase diagram of these theories and
further disentangle their ultraviolet asymptotic nature according to whether
they are asymptotically free or safe. We therefore extend the number of
theories that are known to be fundamental in the Wilsonian sense to the case of
chiral gauge theories with scalars.Comment: ReVTeX, 28 pages, 14 figure
Gamma Ray Observatory, On Orbit Servicing
The feasibility of performing on-orbit servicing of the NASA Goddard Space Flight Center (GSFC) Gamma Ray Observatory (GRO) was initially addressed by TRW during the later portion of the Phase C development contract in 1981/82. The current post CDR GRO design reflects a capability for on-orbit changeout of the two Multimission Modular Spacecraft (MMS) modular power system (MPS) modules and the MMS communications and data handling (CADH) module via EVA. In addition, the design incorporates a capability for on-orbit refueling (OOR). The GRO design also incorporates a capability of EVA override operations for the deployment, restowage, and jettison of the GRO solar array and high-gain antenna appendages, the grapple fixture, and the electrical umbilical interface
Conceptual and methodological issues in family health and stress research
The present study examines relationships between family life events, family cohesion and adaptability and stress outcome for a sample of 1470 families. Several measures of each key variable are used in order to address both methodological and theoretical issues. Independent measures include demographic variables, life events and family cohesion and adaptability, measured by FACES II. Life events measures include events in 12 months, events in 3 years and events weighted for perception of stressfulness. Cohesion and adaptability are used as separate dimensions and together in family types. Measures of family type include individual and family symptomology, measured by the Family Health Status Inventory, and respondent\u27s life satisfaction;Analysis identified positive relationships between life events and outcome and between family cohesion and adaptability and outcome. The choice of the measure of stress outcome affects the relationship with all independent variables. Events weighted for stressfulness and events occurring within the longer time period are more strongly related to outcome than events during a shorter time. Of all the measures of family cohesion and adaptability, the difference between perceptions of present and ideal functioning on these dimensions is most highly related to outcome;A model is proposed linking demographic variables, life events and adaptability and cohesion with stress outcome. Family size affects the number of life events and family symptomology with larger families experiencing more events and childless families experiencing more symptoms. Family symptom scores were computed controlling for family size. The higher the number of family life events, the higher the degree of symptomology and the lower the level of life satisfaction. The mediating influence of cohesion and adaptability between life events and outcome varies according to the outcome measure used. In general, balanced levels of cohesion and adaptability, used together in family type, relate to lower levels of symptomology and higher levels of life satisfaction
Stopped-flow fluorescence kinetic studies of Glu-plasminogen Conformational changes triggered by AH-site ligand binding
AbstractBinding of 6-aminohexanoic acid to the AH-site, a weak lysine binding site in Glu-plasminogen, alters the conformation of the molecule. The kinetics of the binding and the accompanying conformational change are investigated at pH 7.8. 25°C. Changes of intrinsic protein fluorescence were measured as a function of time after rapid mixing in a stopped-flow apparatus. The results reflect a two-step reaction mechanism: Rapid association of Glu-plasminogen and 6-aminohexanoic acid (K1 = 44 mM) followed by the conformational change (k2 = 69 g−1 and k−2 = 3 g−1) with on overall dissociation constant K4 = 2.0 mM, Thus the conformational change is rather fast, t12 = 0.01 g. Its importance for the rates or Glu-plasminogen activation reactions is discussed
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