Mean field baryon magnetic moments and sumrules

New developments have spurred interest in magnetic moments ($\mu$-s) of baryons. The measurement of some of the decuplet $\mu$-s and the findings of new sumrules from various methods are partly responsible for this renewed interest. Our model, inspired by large colour approximation, is a relativistic self consistent mean field description with a modified Richardson potential and is used to describe the $\mu$-s and masses of all baryons with up (u), down (d) and strange (s) quarks. We have also checked the validity of the Franklin sumrule (referred to as CGSR in the literature) and sumrules of Luty, March-Russell and White. We found that our result for sumrules matches better with experiment than the non-relativistic quark model prediction. We have also seen that quark magnetic moments depend on the baryon in which they belong while the naive quark model expects them to be constant.Comment: 7 pages, no figure, uses epl.cl

Activation of Ciona sperm motility: phosphorylation of dynein polypeptides and effects of a tyrosine kinase inhibitor

A high molecular mass dynein ATPase polypeptide and a 18–20 kDa dynein light chain of Ciona sperm flagella are phosphorylated during in vivo activation of motility or in vitro activation of motility by incubation with cyclic AMP. A similar level of phosphorylation of these proteins is obtained by incubation of washed, demembranated spermatozoa with catalytic subunit of cyclic AMP-dependent protein kinase, under conditions where there is no activation of motility until a supernatant component is added. Therefore, phosphorylation of these dynein polypeptides is not sufficient for activation of motility. Activation of motility in vitro by incubation with cyclic AMP can be completely inhibited by a random copolymer of glutamate and tyrosine that inhibits tyrosine kinase activity. Under these conditions, much of the protein phosphorylation associated with activation of motility is also inhibited. These new results suggest that regulation of motility of these spermatozoa may involve a multicomponent kinase cascade rather than a simple phosphorylation of a protein ‘switch’ by the cyclic AMP-dependent kinase. A 53 kDa axonemal phosphoprotein band, identified as band M1, shows the strongest correlation with activation of motility in these experiments

Phase transition between non-extremal and extremal Reissner-Nordstr\"om black holes

We discuss the phase transition between non-extremal and extremal Reissner-Nordstr\"om black holes. This transition is considered as the $T \to 0$ limit of the transition between the non-extremal and near-extremal black holes. We show that an evaporating process from non-extremal black hole to extremal one is possible to occur, but its reverse process is not possible to occur because of the presence of the maximum temperature. Furthermore, it is shown that the Hawking-Page phase transition between small and large black holes unlikely occurs in the AdS Reissner-Nordstr\"om black holes.Comment: 12 pages, 6 figures, version to appear in MPL

Control of beam propagation in optically written waveguides beyond the paraxial approximation

Beam propagation beyond the paraxial approximation is studied in an optically written waveguide structure. The waveguide structure that leads to diffractionless light propagation, is imprinted on a medium consisting of a five-level atomic vapor driven by an incoherent pump and two coherent spatially dependent control and plane-wave fields. We first study propagation in a single optically written waveguide, and find that the paraxial approximation does not provide an accurate description of the probe propagation. We then employ coherent control fields such that two parallel and one tilted Gaussian beams produce a branched waveguide structure. The tilted beam allows selective steering of the probe beam into different branches of the waveguide structure. The transmission of the probe beam for a particular branch can be improved by changing the width of the titled Gaussian control beam as well as the intensity of the spatially dependent incoherent pump field.Comment: 10 pages, 9 figure

Behaviour of the EAS Age Parameter in the Knee Energy Region

Analyzing simulated EAS events generated with the CORSIKA code, the characteristics of lateral distribution of electrons in EAS around the knee energy region of the primary energy spectrum have been studied and compared with experimental observations. The differences between the EGS4 and the NKG output of CORSIKA in respect to electron radial density distribution have been investigated. The relation between lateral and longitudinal age parameters has been studied after introducing the notion of the local age parameter that reflects the profile of the lateral distribution of electrons in EAS. The present analysis motivates the inclusion of the lateral shower age in a multiparameter study of EAS to extract information on hadronic interactions and primary composition.Comment: Talk presented at XVI International Symposium on Very High Energy Cosmic Ray Interactions (ISVHECRI 2010), Batavia, IL, USA (28 June - 2 July 2010). 4 pages, 5 figure

An Equilibrium Model of Health Insurance Provision and Wage Determination

We investigate the e_ect of employer-provided health insurance on job mobility rates and economic welfare. In particular, we develop and estimate an equilibrium model of wage and health insurance determination that yields implications that are empirically observed. Namely, not all jobs provide health insurance and jobs with insurance pay higher wages than those without insurance. Using data from the 1990 to 1993 panels of the Survey of Income and Program Participation, we find that jobs that do provide health insurance last almost five times longer than jobs that do not. While this implies that the mobility rate for jobs without insurance is significantly higher than the mobility rate for jobs with insurance, this di_erence is welfare enhancing since jobs with health insurance are more productive jobs. Furthermore, simulations reveal that decreasing the health insurance premium paid by employers increases the steady state health insurance coverage rate, decreases the unemployment rate, but may or may not lead to productivity gains in the economy.HEALTH INSURANCE; EQUILIBRIUM MODELS; WAGE BARGAINING; JOB MOBILITY

A survey of announcement effects on foreign exchange returns

Researchers have long studied the reaction of foreign exchange returns to macroeconomic announcements in order to infer changes in policy reaction functions and foreign exchange micro­structure, including the speed of market reaction to news and how order flow helps impound public and private information into prices. These studies have often been disconnected, however; and this article critically reviews and evaluates the literature on announcement effects on foreign exchange returns.Foreign exchange