Galaxy Orbits for Galaxy Clusters in Sloan Digital Sky Survey and 2dF Galaxy Redshift Survey

We present the results of a study for galaxy orbits in galaxy clusters using a spectroscopic sample of galaxies in Sloan Digital Sky Survey (SDSS) and 2dF Galaxy Redshift Survey (2dFGRS). We have determined the member galaxies of Abell clusters covered by these surveys using the galaxies' redshift and positional data. We have selected 10 clusters using three criteria: the number of member galaxies is greater than or equal to 40, the spatial coverage is complete, and X-ray mass profile is available in the literature. We derive the radial profile of the galaxy number density and velocity dispersion using all, early-type, and late-type galaxies for each cluster. We have investigated the galaxy orbits for our sample clusters with constant and variable velocity anisotropies over the clustercentric distance using Jeans equation. Using all member galaxies, the galaxy orbits are found to be isotropic within the uncertainty for most of sample clusters, although it is difficult to conclude strongly for some clusters due the large errors and the variation as a function of the clustercentric distance in the calculated velocity anisotropies. We investigated the orbital difference between early-type and late-type galaxies for four sample clusters, and found no significant difference between them.Comment: 59 pages, 21 figures. To appear in ApJ. Paper with high resolution figures are available at http://astro.kias.re.kr/~hshwang/papers/orbit.pd

Substructure lensing in galaxy clusters as a constraint on low-mass sterile neutrinos in tensor-vector-scalar theory: The straight arc of Abell 2390

Certain covariant theories of the modified Newtonian dynamics paradigm seem to require an additional hot dark matter (HDM) component - in the form of either heavy ordinary neutrinos or more recently light sterile neutrinos (SNs) with a mass around 11eV - to be relieved of problems ranging from cosmological scales down to intermediate ones relevant for galaxy clusters. Here we suggest using gravitational lensing by galaxy clusters to test such a marriage of neutrino HDM and modified gravity, adopting the framework of tensor-vector-scalar theory (TeVeS). Unlike conventional cold dark matter (CDM), such HDM is subject to strong phase-space constraints, which allows one to check cluster lens models inferred within the modified framework for consistency. Since the considered HDM particles cannot collapse into arbitrarily dense clumps and only form structures well above the galactic scale, systems which indicate the need for dark substructure are of particular interest. As a first example, we study the cluster lens Abell 2390 and its impressive straight arc with the help of numerical simulations. Based on our results, we outline a general and systematic approach to model cluster lenses in TeVeS which significantly reduces the calculation complexity. We further consider a simple bimodal lens configuration, capable of producing the straight arc, to demonstrate our approach. We find that such a model is marginally consistent with the hypothesis of 11eV SNs. Future work including more detailed and realistic lens models may further constrain the necessary SN distribution and help to conclusively assess this point. Cluster lenses could therefore provide an interesting discriminator between CDM and such modified gravity scenarios supplemented by SNs or other choices of HDM.Comment: 22 pages, 14 figures, 2 tables; minor changes to match accepted versio

Sildenafil citrate (Viagra) treatment of sexual dysfunction in a schizophrenic patient

SummaryA high frequency of sexual dysfunction occurs in treated and untreated patients with schizophrenia. Unfortunately, no effective therapy for this problem is currently available. We present a case of a 26-year-old patient with paranoid schizophrenia, who suffered from lack of desire and erection, and was successfully treated with sildenafil citrate (Viagra). This case illustrates the complex character of sexual dysfunction in male schizophrenic patients.</jats:p

Tratamiento de disfunción sexual en un paciente esquizofrénico con citrato de sildenafilo (Viagra®)

ResumenEn los pacientes con esquizofrenia tratados y no tratados se produce una frecuencia alta de disfunción sexual. Por desgracia, no se dispone en la actualidad de terapia efectiva para este problema. Presentamos el caso de un paciente de 26 años con esquizofrenia paranoide que sufría falta de deseo y erección y fue tratado con éxito con citrato de sildenafilo (Viagra). Este caso ilustra el complejo carácter de la disfunción sexual en los pacientes esquizofrénicos varones.</jats:p

Combined clozapine-lithium treatment for schizophrenia and schizoaffective disorder

SummaryThree adolescent and two adult patients suffering from chronic excited psychoses (either schizophrenia or schizoaffective disorder) resistant to traditional neuroleptics and clozapine were treated with combined clozapine-lithium. Improvement was assessed with the Positive and Negative Symptoms Scale, the Brief Psychiatric Rating Scale and the Clinical Global Impressions, administered before and during combined clozapine-lithium treatment. All patients demonstrated a significant improvement with this combination. There was no occurrence of agranulocytosis, neuroleptic malignant syndrome or other clinically significant adverse effects.</jats:p

Tratamiento combinado de clozapina y litio para la esquizofrenia y el trastorno esquizoafectivo

ResumenTres adolescentes y dos pacientes adultos que sufrían psicosis crónicas con excitación (esquizofrenia o trastorno esquizoafectivo) resistentes a los neurolépticos tradicionales y a la clozapina recibieron tratamiento con una combinación de clozapina y litio. La mejoría se evaluó con la Escala de Síntomas Positivos y Negativos, la Escala de Evaluación Psiquiátrica Breve y las Impresiones Clínicas Globales, administradas antes y durante el tratamiento combinado de clozapina y litio. Todos los pacientes demostraron una mejoría significativa con esta combinación. No se produjo agranulocitosis, síndrome neuroléptico maligno u otros efectos adversos significativos clínicamente.</jats:p