Variable gamma-ray emission from the Be/X-ray transient A0535+26?

We present a study of the unidentified gamma-ray source 3EG J0542+2610. This source is spatially superposed to the supernova remnant G180.0-1.7, but its time variability makes unlikely a physical link. We have searched into the EGRET location error box for compact radio sources that could be the low energy counterpart of the gamma-ray source. Although 29 point-like radio sources were detected and measured, none of them is strong enough as to be considered the counterpart of a background gamma-ray emitting AGN. We suggest that the only object within the 95 % error box capable of producing the required gamma-ray flux is the X-ray transient A0535+26. We show that this Be/accreting pulsar can produce variable hadronic gamma-ray emission through the mechanism originally proposed by Cheng & Ruderman (1989), where a proton beam accelerated in a magnetospheric electrostatic gap impacts the transient accretion disk.Comment: 6 pages, 3 figures, Astronomy & Astrophysics in pres

Spectrophotometric determination of the deltamethrin

In the province of Corrientes is found highest production of indoor plants from all Argentina, specially in the northeast of this province. This is because the low frequency orthelack of frosts, allowing a lower cost in the production, since heating is not needed. In this type of cultive is commonly used thedeltamethrin, as the result of this, the validation of a simple method comparable with the gas chromatography for the determination of this Pesticide on both, irrigation and consumption water, was studied. In this work, a spectrophotometric method is proposed for the determination of deltamethrin inirrigation water from the area of flower crops located in the Department of Concepción in the province of Corrientes. Deltamethrin solutions in a range from 0,025 to 1 mg/L on irrigation water were prepared. The absorbance spectrum was scanned between 200 and 400 nm. The maximum absorbance was found at 220 nm. A calibration curve in the range from 0.025 to 1 mg/L, responded to A = (0.3246± 0.0224) C + (0.0096 ± 0.0068) with R2 = 0.998. The % RSD was 0.961 indicating good repeatability for the analytical procedure. The accuracy in the recovery experience was 99.0 - 109.6%. The statistical comparison using the t-test and the F-test indicates that there are no significant differences between GC and spectrophotometric methods, with a confidence level of 95%. The specificity and intermediate accuracy tests were satisfactory.Fil: Gimenez, L. I.. Universidad Nacional del Nordeste. Facultad de Ciencias Exactas Naturales y Agrimensura. Departamento de Química; ArgentinaFil: Michellod, A. M. M.. Universidad Nacional del Nordeste. Facultad de Ciencias Exactas Naturales y Agrimensura. Departamento de Química; ArgentinaFil: Jorge, M. J.. Universidad Nacional del Nordeste. Facultad de Ciencias Exactas Naturales y Agrimensura. Departamento de Química; ArgentinaFil: Pila, Andrea Natalia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Nordeste. Instituto de Modelado e Innovación Tecnológica. Universidad Nacional del Nordeste. Facultad de Ciencias Exactas Naturales y Agrimensura. Instituto de Modelado e Innovación Tecnológica; ArgentinaFil: Bordón, Alexander Germán. Universidad Nacional del Nordeste. Facultad de Ciencias Exactas Naturales y Agrimensura. Departamento de Química; ArgentinaFil: Profeta, Mariela Inés. Universidad Nacional del Nordeste. Facultad de Ciencias Exactas Naturales y Agrimensura. Departamento de Química; ArgentinaFil: Romero, Jorge Marcelo. Universidad Nacional del Nordeste. Facultad de Ciencias Exactas Naturales y Agrimensura. Departamento de Química; ArgentinaFil: Jorge, Nelly Lidia. Universidad Nacional del Nordeste. Facultad de Ciencias Exactas Naturales y Agrimensura. Departamento de Química; Argentin

Supernova remnants and gamma-ray sources

A review of the possible relationship between gamma-ray sources and supernova remnants (SNRs) is presented. Particular emphasis is given to the analysis of the observational status of the problem of cosmic ray acceleration at SNR shock fronts. All positional coincidences between SNRs and unidentified gamma-ray sources listed in the Third EGRET Catalog at low Galactic latitudes are discussed on a case by case basis. For several coincidences of particular interest, new CO(J=1-0) and radio continuum maps are shown, and the mass content of the SNR surroundings is determined. The contribution to the gamma-ray flux observed that might come from cosmic ray particles (particularly nuclei) locally accelerated at the SNR shock fronts is evaluated. We discuss the prospects for future research in this field and remark on the possibilities for observations with forthcoming gamma-ray instruments.Comment: Final version of a review article, to appear in the Physics Reports (82 pages, 31 figures). Figures requiring high quality are just too large and too many to be included here. Please download them from http://www.angelfire.com/id/dtorres/down3.htm

Understanding Radiocarpal Rotation Through In Vivo Pronation and Supination of the Hand: A Single Case Study

Background: Studies have not clearly defined the motion of the distal radius in relation to the carpus in vivo. We hypothesized that 1) with the hand fixed by grasping a handle to prevent hand and wrist motion, the resulting load in torsion generated by extrinsic muscle in vivo would create motion at the radiocarpal joint; and 2) the motion measured will be between the distal radius and the proximal row of the carpus. Methods: The data was acquired from the senior author external to our institution; in the current study, we quantify the resulting radiocarpal motion. A K-wire was placed into the second metacarpal, and a second wire was placed in the distal radius. The shoulder was abducted to 90° and the hand was pronated, held stationary gripping a fixed object. The forearm was pronated and supinated to simulate radiocarpal rotation. Photographs were obtained at three points: 1) initial position showing the wire in vertical alignment; 2) same perspective in maximum internal radiocarpal rotation; and 3) same perspective in maximum external radiocarpal rotation. ImageJ (open source) was used to quantify the angle between the wires. Results: Superimposition of the three photographs in vivo allowed us to approximate two angle measurements. The measurements with maximal internal and external rotations were 16° and 24°, respectively. Conclusions: Radiocarpal rotation should be considered in addition to flexion and extension motions and radial ulnar deviations when treating degenerative changes in the wrist

G337.2+0.1: a new X-ray supernova remnant?

We present evidence supporting a SNR origin for the radio source G337.2+0.1, which was discovered along the line of sight to the Norma spiral arm in the MOST 843-MHz radio survey. The radio source is spatially superposed to the unidentified ASCA source AX J1635.9-4719. An analysis of this latter source reveals that its X-ray spectrum, extended nature, and non-variable flux are consistent with what is expected for a SNR. In addition, we have used HI-line observations of the region to look for any effect of the presumed remnant on the ISM. We have found a well-defined minimum centered at the position of the radio source in the velocity range of ~ -25 to -19 km s-1. This feature appears as a sharp absorption dip in the spectrum that might be produced when the continuum emission from the SNR candidate is absorbed by foreground gas. Hence we have used it to constrain the distance to the source, which seems to be a young (age ~ a few 103 yr) and distant (d ~ 14 kpc) SNR. G337.2+0.1 and AX J1635.9-4719 would be the radio/X-ray manifestations of this remnant.Facultad de Ciencias Astronómicas y GeofísicasInstituto Argentino de Radioastronomí

Geología y estructura de las ultramafitas de Tapo y Acobamba (Tarma, Perú). Removilización tectónica andina de un segmento ofiolítico pre-andino

Los cuerpos de serpentinitas con asociaciones menores de rocas máficas han sido interpretados como una intrusión de un magma ultrabásico profundo que se instala en forma de sills y diques en el seno de un conjunto metasedimentario de bajo grado atribuído al precámbrico, incluido en las unidades del Complejo del Marañón (Grandin et al., 1977 y referencias incluidas; Grandin y Zegarra, 1979). El emplazamiento del conjunto ultramáfico esta representado por varias etapas, primero la intrusión pre-tectónica en sills elongados en una secuencia sedimentaria de edad precámbrica y posteriormente los cuerpos gabroicos (íbidem). También se han interpretado los cuerpos ultramáficos como una inyección de tipo diapírico en secuencias del Paleozóico Superior (Megard et al., 1996