Detection of an optical filament in the Monogem Ring

The Monogem Ring is a huge bright soft X-ray enhancement with a diameter of ~ 25\degr. This 0.3 kpc distant structure is a peculiar Galactic supernova remnant in that it is obviously visible only in X-rays, due to its expansion into a region of extremely low ambient density: hence, practically no optical emission or a neutral HI shell was expected to be detectable. - Here we report on the discovery of a very faint arc-like nebula on a POSS II R film copy, at the south-eastern borders of the MR. Spectroscopy revealed this filament to have a very large [SII]$\lambda$ 6716+6731/Halpha ratio of up to ~ 1.8, indicating shock excitation, and a low density of N_e <100 cm^{-3}. There is no hint of [OIII] emission in the spectra. On deep wide-field direct images in Halpha and in [SII] the nebula appears as a ~ 20 arcmin long, thin (~ 1 arcmin), structured filament, stretching N-S. We believe that this filament belongs to the MR and became visible due to the interaction of the expanding remnant with a mild density increase in the interstellar medium. Only one other possible optical filament of the MR has been reported in the literature, but no spectrum was provided.Comment: 6 pages, 4 figures, of which 2 in jpeg format and degraded because of size constraints. Accepted for publication in A&

Role of surface microgeometries on electron escape probability and secondary electron yield of metal surfaces

The influence of microgeometries on the Secondary Electron Yield (SEY) of surfaces is investigated. Laser written structures of different aspect ratio (height to width) on a copper surface tuned the SEY of the surface and reduced its value to less than unity. The aspect ratio of microstructures was methodically controlled by varying the laser parameters. The results obtained corroborate a recent theoretical model of SEY reduction as a function of the aspect ratio of microstructures. Nanostructures - which are formed inside the microstructures during the interaction with the laser beam - provided further reduction in SEY comparable to that obtained in the simulation of structures which were coated with an absorptive layer suppressing secondary electron emission

The Luminous Type Ic SN 1992ar at z=0.145

We present spectroscopic and photometric observations of SN1992ar, the more distant SN in the Calan/Tololo Survey. We compare its spectrum with those of nearby Type Ia and Ic SNe and conclude that the latter type is a better match to SN 1992ar. Using K-corrections based on the spectra of well observed Type Ic and Ia SNe we compute different possible rest frame light curves of SN 1992ar and compare them with those of representative SNe of each type observed in the nearby universe. From the photometry and the spectra, we are able to conclude that SN 1992ar cannot be matched by any known example of a Type Ia SN. Even though the data set collected is fairly complete (one spectrum and 10 photometric points), it is not possible to decide whether SN 1992ar was a fast Type Ic SN, like SN 1994I, or a slow one, like SN 1983V. The absolute V magnitudes at maximum implied by each of these possibilities are -19.2 and -20.2, respectively. The latter would make SN 1992ar one of the brightest SNe on record. SN 1992ar, hence, illustrates the problem of contamination faced by the high z Type Ia SNe samples whose luminosity distances are used to determine the cosmological parameters of the Universe. We present observational criteria to distinguish the two SN types when the SiII 6355 line is redshifted out of the sensitivity range of typical CCD detectors, and discuss the effect that these luminous Type Ic SNe would have on the measured cosmological parameters, if not removed from the High-z Type Ia SN samples.Comment: 40 pages, 9 figures. Accepted for publication in Astrophysical Journa

A photo-ionized canopy for the shock-excited Criss-Cross Nebula

Aims. We study a new broad well-defined arc of optical nebulosity close to the cloud-shock interacting Criss-Cross Nebula, derive the basic physical properties of the former and revise those of the latter, and compare both objects to simulations of cloud-shock interactions from the literature. Methods. Deep optical, partly wide-field, images were used to reveal the intricate morphology and overall extent of the nebulosities. Optical spectroscopy enabled us to uncover their nature. Results. The two nebulosities obviously are physically linked, but are of different type; the Criss-Cross Nebula is, as was shown also in an earlier paper, excited via a slow shock from the expanding Orion-Eridanus Bubble, but the broad arc is definitely photo-ionized. The source for ionizing photons appears to be hot gas in this bubble. Some results of simulations of interactions of SNRs with interstellar clouds available from the literature bear a striking resemblance to our nebulae, which appear to represent an example - unrivalled in closeness and clarity - for an early to medium stage in the destruction of an isolated cloud over-run by a highly evolved SNR. Thereby the Criss-Cross Nebula is, when seen from the SNR, the rear disrupted part of the original small cloud, whereas the arc probably is its yet rather intact front part.Comment: 6 pages, 3 figures. Figures degraded because of size constraints. Accepted for publication in A&

Stress-Softening Formulae of Polymer Bearings

The motivation for this work was the absence of closed form solutions that can reasonably describe the axial deformation behaviour of stress-softening polymer bearings. In this paper, new closed form solutions that exhibit Mullins phenomenon are developed. We show that the apparent Young modulus depends on the shape factor and the minimal infinitesimal strain. We furthermore found that, in a nonlinear deformation, the shape factor plays an important role in stress softening. The solutions are design friendly and are consistent with expected results

Nutritional status of children and adolescents hospitalized at the pediatric surgery unit

OBJECTIVE: To evaluate the nutritional status, duration of hospital stay and clinical specialties of patients hospitalized in the Pediatric Surgery Unit of São Paulo Hospital, UNIFESP-EPM. METHODS: This cross-sectional retrospective study enrolled 749 children and adolescents of both genders admitted to the Pediatric Surgery Unit during the period of August 2007 to July 2008. The following data were collected: anthropometric variables, duration of hospital stay and surgical procedures. For nutritional status classification, the Z score for body mass index (Z BMI) and height-for-age (Z H/A) were used according to the World Health Organization growth chart (WHO, 2007). The children were classified according to the surgical procedures performed. Results were compared by ANOVA followed by Bonferroni multiple comparisons test, being significant p<0.05. Statistical analysis was carried out through STATA 8.0 software. RESULTS: Patients' mean age was seven years old (0 to 18), 59% were males and 18% had ear, neck or throat surgery. Among the hospitalized patients, 66% had appropriated height for age, 43% were eutrophic and 31% obese/overweight. The malnourished patients presented longer hospital stay than the obese/overweight patients (7.2 versus 4.1 days; p=0,035). Infants had prolonged hospital stay (p=0,006) and less Z BMI values in comparison to the other age groups. (p=0,001). Infants that needed cardiac surgery presented lower Z BMI in relation to the others (p=0,002). CONCLUSIONS: The patients profile in the Pediatric Surgery Unit followed the nutritional pattern observed in Brazil, with increasing prevalence of obesity together with malnutrition. However, malnutrition is still an aggravating factor for prolonged hospital stayOBJETIVO: Avaliar o estado nutricional, o tempo de internação e as especialidades clínicas de pacientes internados na enfermaria de Cirurgia Pediátrica do Hospital São Paulo da UNIFESP-EPM. MÉTODOS: Estudo transversal retrospectivo, com 749 crianças e adolescentes de ambos os gêneros acompanhados por equipe interdisciplinar durante o período de agosto de 2007 a julho de 2008. Foram coletados dados antropométricos, dias de internação e procedimento cirúrgico segundo a especialidade. Para a classificação do estado nutricional, utilizou-se o escore Z do índice de massa corporal (Z IMC) e da estatura/idade (Z E/I) segundo a curva da Organização Mundial de Saúde (OMS, 2007). As crianças foram classificadas segundo diagnóstico estabelecido previamente à cirurgia. Utilizou-se o programa STATA 8.0 para análise dos dados e aplicou-se o teste ANOVA e comparações múltiplas de Bonferroni, considerando-se significante p<0,05. RESULTADOS: A mediana de idade foi sete anos (0 a 18), predominando o gênero masculino (59%) e as internações para cirurgia otorrinolaringológica (18%). Dos pacientes internados, 66% tinham estatura adequada para idade, 43% eutróficos e 31% obesos/sobrepeso. Os pacientes desnutridos permaneceram mais dias internados quando comparados aos obesos/sobrepeso (7,2 versus 4,1 dias; p=0,035). Os lactentes apresentaram maior tempo de internação (p=0,006) e menor valor de Z IMC, comparados aos outros grupos etários (p=0,001). Os lactentes com programação de cirurgia cardíaca apresentaram Z IMC menor em relação às demais especialidades (p=0,002). CONCLUSÕES: O perfil dos pacientes internados condiz com a atual transição nutricional, aumento da prevalência de obesidade concomitante à desnutrição. Entretanto, a desnutrição ainda constitui fator agravante para a permanência hospitalarUNIFESP-EPM Departamento de Pediatria Disciplina de NutrologiaUNIFESP-EPM Programa de Pós-Graduação em Ciências da NutriçãoUNIFESP, EPM, Depto. de Pediatria Disciplina de NutrologiaUNIFESP, EPM Programa de Pós-Graduação em Ciências da NutriçãoSciEL

A Performance and Resource Consumption Assessment of Secure Multiparty Computation

In recent years, secure multiparty computation (SMC) advanced from a theoretical technique to a practically applicable technology. Several frameworks were proposed of which some are still actively developed. We perform a first comprehensive study of performance characteristics of SMC protocols using a promising implementation based on secret sharing, a common and state-of-the-art foundation. Therefor, we analyze its scalability with respect to environmental parameters as the number of peers, network properties -- namely transmission rate, packet loss, network latency -- and parallelization of computations as parameters and execution time, CPU cycles, memory consumption and amount of transmitted data as variables. Our insights on the resource consumption show that such a solution is practically applicable in intranet environments and -- with limitations -- in Internet settings

March1-dependent modulation of donor MHC II on CD103+ dendritic cells mitigates alloimmunity.

In transplantation, donor dendritic cells (do-DCs) initiate the alloimmune response either by direct interaction with host T cells or by transferring intact donor MHC to host DCs. However, how do-DCs can be targeted for improving allograft survival is still unclear. Here we show CD103+ DCs are the major do-DC subset involved in the acute rejection of murine skin transplants. In the absence of CD103+ do-DCs, less donor MHC-II is carried to host lymph nodes, fewer allogenic T cells are primed and allograft survival is prolonged. Incubation of skin grafts with the anti-inflammatory mycobacterial protein DnaK reduces donor MHC-II on CD103+DCs and prolongs graft survival. This effect is mediated through IL-10-induced March1, which ubiquitinates and decreases MHC-II levels. Importantly, in vitro pre-treatment of human DCs with DnaK reduces their ability to prime alloreactive T cells. Our findings demonstrate a novel therapeutic approach to dampen alloimmunity by targeting donor MHC-II on CD103+DCs