The sub-arcsecond hard X-ray structure of loop footpoints in a solar flare

The newly developed X-ray visibility forward fitting technique is applied to Reuven Ramaty High Energy Solar Spectroscopic Imager (RHESSI) data of a limb flare to investigate the energy and height dependence on sizes, shapes, and position of hard X-ray chromospheric footpoint sources. This provides information about the electron transport and chromospheric density structure. The spatial distribution of two footpoint X-ray sources is analyzed using PIXON, Maximum Entropy Method, CLEAN and visibility forward fit algorithms at nonthermal energies from $\sim 20$ to $\sim 200$ keV. We report, for the first time, the vertical extents and widths of hard X-ray chromospheric sources measured as a function of energy for a limb event. Our observations suggest that both the vertical and horizontal sizes of footpoints are decreasing with energy. Higher energy emission originates progressively deeper in the chromosphere consistent with downward flare accelerated streaming electrons. The ellipticity of the footpoints grows with energy from $\sim 0.5$ at $\sim 20$ keV to $\sim 0.9$ at $\sim 150$ keV. The positions of X-ray emission are in agreement with an exponential density profile of scale height $\sim 150$~km. The characteristic size of the hard X-ray footpoint source along the limb is decreasing with energy suggesting a converging magnetic field in the footpoint. The vertical sizes of X-ray sources are inconsistent with simple collisional transport in a single density scale height but can be explained using a multi-threaded density structure in the chromosphere.Comment: 7 pages, 7 figures, submitted to Ap

Avaliação algimétrica e sinérgica em cães tratados pela levomepromazina, induzidos pelo tiopental e mantidos pelo sevofluorano, pré-tratados ou não pelo butorfanol

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Evaluation of microbial contamination of air in two haematology departments equipped with ventilation systems with different filtration devices

Background. Nosocomial infections (NI) are above all due to health-care workers practices, but also the contamination of the environment could lead to their rise in health-care facilities. Introduction. In the last years, the incidence of NI has increased due to a substantial rise in the number of immuno-compromised patients. These patients are often gathered in hospital areas declared at ?high risk? of infection such as Hematology and Bone Marrow Transplant ward. In this study, we evaluated microbial contamination of the air in two divisions with high risk patients, focusing on the validity of the air system with correla- tion to the presence or not of the HEPA absolute filters. Methods. An environmental surveillance study has been carried out in two Divisions of Haematology, in two different Hospitals. Investigations have been performed by sampling air and by analyzing bacterial and fungal growth on microbiology plates after an incubation period. Results. Unit A, without HEPA filters in the ventilation systems, showed a gradual increase in the bacterial load 20 and 60 days after cleaning of the ventilation system. Mycetes and Aspergilli were not present in basal conditions, at 20 or 60 days after decontamination. Unit B, equipped with HEPA filters placed at the inlet vents, showed extremely low values of the bacterial load either in basal conditions or upon inspection 60 days after cleaning. No mycetes were present. Discussion. From the results obtained, it was evident that fol- lowing the cleaning operation, the quality of the air is excellent in both types of equipment, since no mycetes were present and the bacterial load was inf. 20 CFU/mc in all the sites tested. However, although in subsequent controls mycetes were absent in both types of equipment, a great difference in the suspended bacterial load was found: Unit B was close to sterility whereas in Unit A a progressive increase was observed

AntarctiCor: Solar Coronagraph in Antarctica for the ESCAPE Project

The Antarctica solar coronagraph –AntarctiCor– for the “Extreme Solar Coronagraphy Antarctic Program Experiment” –ESCAPE– comprises an internally-occulted coronagraph based on the externally-occulted ASPIICS coronagraph for the ESA formation-flying PROBA-3 mission. This paper describes the AntarctiCor design for ground-based observations from the DomeC Antarctica plateau of the polarized broad-band (591 nm ± 5 nm) K-corona and of the narrowband (FWHM = 0.5 nm), polarized emission of the coronal green-line at 530.3 nm. The science goal of these observations is to map the topology and dynamics of the coronal magnetic field, addressing coronal heating and space weather questions

anorectal involvement is frequent in limited systemic sclerosis

The gastrointestinal tract, particularly the oesophagus, is affected in about half of all patients with systemic sclerosis. Only a few studies so far have dealt with the anorectal tract. We studied the anal function using anorectal manometry in 12 patients with limited systemic sclerosis. We also studied the oesophageal function. For the oesophagus, we measured the difference between intragastric and oesophageal pressure, while for the anorectal tract we investigated the maximum resting pressure, the maximum voluntary squeeze effort and the rectoanal inhibitory reflex. Maximum resting pressure and maximum voluntary squeeze effort were found to be decreased in all patients. The rectoanal inhibitory reflex was abnormal in four patients. Statistical analysis showed a significant correlation between maximum resting pressure and maximum voluntary squeeze effort. No correlation was found between oesophageal and anorectal involvement. Anorectal dysfunction is common in patients with limited systemic sclerosis. We suggest that these patients should have an evaluation of their anorectal function including anorectal manometry

Localized nodular tenosynovitis: a case description

Se describe una afección dolorosa localizada en la zona del carpo del miembro torácico izquierdo. Con características físicas peculiares, habiéndose llegado al diagnóstico definitivo mediante estudios complementarios, siendo el histopatológico el que determino que se trataba de una tenosinovitis nodular localizada (TNL) de los tendones de los músculos extensor carpo radial y flexor digital común.It describes a painful affection localized on the area of the carpus of the left forelimb with peculiar physical characteristics, having arrived to a definite diagnosis through out to the complementary studies being the histopathologic which determined that it was a localized nodular tenosynovitis on the tendons of the extensor radial carpus and common digital flexor muscles.Facultad de Ciencias Veterinaria

Regularized energy-dependent solar flare hard x-ray spectral index

The deduction from solar flare X-ray photon spectroscopic data of the energy dependent model-independent spectral index is considered as an inverse problem. Using the well developed regularization approach we analyze the energy dependency of spectral index for a high resolution energy spectrum provided by Ramaty High Energy Solar Spectroscopic Imager (RHESSI). The regularization technique produces much smoother derivatives while avoiding additional errors typical of finite differences. It is shown that observations imply a spectral index varying significantly with energy, in a way that also varies with time as the flare progresses. The implications of these findings are discussed in the solar flare context.Comment: 13 pages; 5 figures, Solar Physics in pres

Local re-acceleration and a modified thick target model of solar flare electrons

The collisional thick target model (CTTM) of solar hard X-ray (HXR) bursts has become an almost 'Standard Model' of flare impulsive phase energy transport and radiation. However, it faces various problems in the light of recent data, particularly the high electron beam density and anisotropy it involves.} {We consider how photon yield per electron can be increased, and hence fast electron beam intensity requirements reduced, by local re-acceleration of fast electrons throughout the HXR source itself, after injection.} {We show parametrically that, if net re-acceleration rates due to e.g. waves or local current sheet electric (${\cal E}$) fields are a significant fraction of collisional loss rates, electron lifetimes, and hence the net radiative HXR output per electron can be substantially increased over the CTTM values. In this local re-acceleration thick target model (LRTTM) fast electron number requirements and anisotropy are thus reduced. One specific possible scenario involving such re-acceleration is discussed, viz, a current sheet cascade (CSC) in a randomly stressed magnetic loop.} {Combined MHD and test particle simulations show that local ${\cal E}$ fields in CSCs can efficiently accelerate electrons in the corona and and re-accelerate them after injection into the chromosphere. In this HXR source scenario, rapid synchronisation and variability of impulsive footpoint emissions can still occur since primary electron acceleration is in the high Alfv\'{e}n speed corona with fast re-acceleration in chromospheric CSCs. It is also consistent with the energy-dependent time-of-flight delays in HXR features.Comment: 8 pages, 2 figure

High metastatic potential melanoma in a three-year-old bitch

El objetivo de este trabajo es presentar un caso de un melanoma con altísimo potencial metastásico en una perra Rottweiler de tres años. La exploración clínica reveló un nódulo de 1,5 cm en un labio vulvar con linfadenomegalia inguinal superficial ipsilateral y otro nódulo similar en la encía. Se realizó el diagnóstico citológico de melanoma. Las radiografías de tórax revelaron imágenes pulmonares compatibles con metástasis. Se practicó la eutanasia. En la necropsia se observaron nódulos negros, firmes, desde 2 milímetros hasta varios centímetros de diámetro, de localización múltiple, comprometiendo la mayor parte de los órganos. Se formuló un diagnóstico histopatológico de melanoma maligno de tipo celular mixto. Resulta llamativa la edad de presentación en este caso al igual que la agresividad de su comportamiento.The aim of this report is to present a case of a highly metastatic melanoma in a three-year-old Rottweiler bitch. Physical examination revealed a 1.5 cm round gingival and similar vulvar nodules and superficial inguinal lymphadenomegaly. Melanoma was first diagnosed on cytological examination. Thoracic radiographies revealed pulmonary metastasis. The dog was euthanatized and black, firm nodules from 2 mm to several centimetres were observed in most organs at necropsy. Mixed cell type malignant melanoma was diagnosed by histopathology. The early age of presentation and the aggressive behaviour of the tumor were the unusual features in this report.Facultad de Ciencias Veterinarias (FCV