On the Radio Polarization Signature of Efficient and Inefficient Particle Acceleration in Supernova Remnant SN 1006

We present a radio polarization study of SN 1006, based on combined VLA and ATCA observations at 20 cm that resulted in sensitive images with an angular resolution of 10 arcsec. The fractional polarization in the two bright radio and X-ray lobes of the SNR is measured to be 0.17, while in the southeastern sector, where the radio and non-thermal X-ray emission are much weaker, the polarization fraction reaches a value of 0.6 +- 0.2, close to the theoretical limit of 0.7. We interpret this result as evidence of a disordered, turbulent magnetic field in the lobes, where particle acceleration is believed to be efficient, and a highly ordered field in the southeast, where the acceleration efficiency has been shown to be very low. Utilizing the frequency coverage of our observations, an average rotation measure of ~12 rad/m2 is determined from the combined data set, which is then used to obtain the intrinsic direction of the magnetic field vectors. While the orientation of magnetic field vectors across the SNR shell appear radial, a large fraction of the magnetic vectors lie parallel to the Galactic Plane. Along the highly polarized southeastern rim, the field is aligned tangent to the shock, and therefore also nearly parallel to the Galactic Plane. These results strongly suggest that the ambient field surrounding SN 1006 is aligned with this direction (i.e., from northeast to southwest) and that the bright lobes are due to a polar cap geometry. Our study establishes that the most efficient particle acceleration and generation of magnetic turbulence in SN 1006 is attained for shocks in which the magnetic field direction and shock normal are quasi-parallel, while inefficient acceleration and little to no generation of magnetic turbulence obtains for the quasi-perpendicular case.Comment: Accepted for publication in Astronomical Journa

A New Bispectral Test for Nonlinear Serial Dependence

Bispectrum, nonlinearity, time series analysis

Escritura poética de la historia de la Oda I, 37 de Q. Horacio Flaco

Fil: Assís de Rojo, M. Estela. Universidad Nacional de Tucumá

An Atomic and Molecular Study of the Interstellar Medium Around the SNR RCW 103

We report on the detection of HCO+ and 12CO emission in the rotational transition J=1-0 in the vicinity of the shock front at the southern border of the supernova remnant RCW 103, where previous infrared observations suggest an interaction with a molecular cloud. The observations were carried out with the Australian Millimeter Radiotelescope at Mopra. We observed a depletion of HCO+ behind the supernova shock front. In addition, we studied the interstellar medium over an extended region towards RCW 103 based on archival 21 cm HI line observations from the Australia Telescope Compact Array (ATCA) and the Parkes Telescope. No atomic gas is observed in emission in coincidence with the molecular feature. This absence is interpreted in terms of self absorption processes.Comment: accepted to be published in Publications of the Astronomical Society of Australi

Perception of neighborhood crime and drugs Increases cardiometabolic risk in Chilean adolescents

PURPOSE: Studies report an association between neighborhood risk and both obesity and cardiometabolic risk factors (CMR) among adolescents. Here we describe the effect of perceived neighborhood risk on adiposity and CMR among Chilean adolescents. METHODS: Participants were 523 low- to middle-income Chilean adolescents. We assessed neighborhood risk in early adolescence, adiposity in childhood and in early and later adolescence, and blood pressure and fasting glucose in later adolescence. Neighborhood risk profiles were estimated using latent profile analysis (LPA) and based on reported perceptions of crime and drug sales/use. Using linear and logistic regression, we examined the effect of neighborhood risk on adiposity and CMR. RESULTS: Mean age in early and later adolescence was 14 and 17 years, respectively. Participants were 52% male, with a mean BMI z-score of .67, and 8% met criteria for metabolic syndrome. LPA identified two neighborhood profiles: 61% low risk and 39% high risk. In later adolescence, being in the high risk profile predicted a higher BMI z-score, waist-to-height ratio, and fat mass index (p < .05). Adolescents in the high risk profile had three times greater odds of meeting criteria for metabolic syndrome (OR = 3.1, 95% CI: 1.5, 5.8) compared with those in the low risk profile. CONCLUSIONS: Our findings suggest that there are physiological responses to living in a neighborhood perceived as "risky," which may contribute to obesity and CMR even in adolescence. For Chilean neighborhoods with high crime and drugs, targeted public health interventions and policies for youth could be beneficial.This research was funded by R01HL088530 (NIH-NHLBI, PI: Gahagan); R01HD33487 (NIH-NICHD, PIs: Lozoff and Gahagan); R01DA021181 (NIH-NIDA, PI: Delva). The first author acknowledges D. Eastern Kang Sim for his support. All authors would like to thank the study participants for their on-going commitment to the project. (R01HL088530 - NIH-NHLBI; R01HD33487 - NIH-NICHD; R01DA021181 - NIH-NIDA

A revision of the Old World Black Nightshades (Morelloid clade of Solanum L., Solanaceae)

The Morelloid clade, also known as the black nightshades or ?Maurella? (Morella), is one of the 10 major clades within Solanum L. The pantropical clade consists of 75 currently recognised non-spiny herbaceous and suffrutescent species with simple or branched hairs with or without glandular tips, with a centre of distribution in the tropical Andes. A secondary centre of diversity is found in Africa, where a set of mainly polyploid taxa occur. A yet smaller set of species is found in Australasia and Europe, including Solanum nigrum L., the type of the genus Solanum. Due to the large number of published synonyms, combined with complex morphological variation, our understanding of species limits and diversity in the Morelloid clade has remained poor despite detailed morphological studies carried out in conjunction with breeding experiments. Here we provide the first taxonomic overview since the 19th century of the entire group in the Old World, including Africa, Asia, Australia, Europe and islands of the Pacific. Complete synonymy, morphological descriptions, distribution maps and common names and uses are provided for all 19 species occurring outside the Americas (i.e. Africa, Asia, Australia, Europe and islands of the Pacific). We treat 12 species native to the Old World, as well as 7 taxa that are putatively introduced and/or invasive in the region. The current knowledge of the origin of the polyploid species is summarised. A key to all of the species occurring in the Old World is provided, together with line drawings and colour figures to aid identification both in herbaria and in the field. Preliminary conservation assessments are provided for all species.Fil: Sarkinen, T.. University Of Edinburgh; Reino UnidoFil: Poczai, P.

ELEMENTOS PARA ESTABLECER POLÍTICAS DE INGRESO Y PERMANENCIA EN CARRERAS DE LAS CIENCIAS EXACTAS Y NATURALES

Una de las problemáticas que actualmente enfrenta el sistema universitario argentino radica en las bajas tasas de retención en la etapa inicial de los estudios superiores. La misma constituye una muestra de la desarticulación de niveles en el sistema educativo nacional y se ha convertido en uno de los objetivos a mejorar tanto por parte de las universidades como de la Secretaría de Políticas Universitarias de la Nación. Los colegios de enseñanza media dependientes de universidades nacionales son una potencial herramienta de articulación Universidad - Escuela Media que puede y debe ser mejor aprovechada. Con la intención de reflexionar sobre la temática planteada se describen las exigencias de ingreso a algunas facultades cuya oferta de carreras se inicia con asignaturas de las ciencias exactas y naturales. Las estrategias de ingreso desarrolladas por estas instituciones indican que la Universidad se está haciendo cargo de las falencias de la escuela media asumiendo el ingreso como una asignatura inicial de sus carreras. Aún así, también demuestran que la desarticulación no es sólo vertical

Engagement of civil engineer students in the first academic year

Stronger student engagement or improved student engagement are common instructional objectives expressed by Higher Educational Institutions. They aim, in particular, at reducing the early dropouts of Science, technology, engineering, and mathematics (STEM) studies and to involve students in their own learning process. This paper presents training resources and materials recently incorporated to the Calculus course of the first year of the Civil Engineering Bachelor at the Escola Tècnica Superior d’Enginyers de Camins Canals i Ports de Barcelona, in order to motivate and encourage students towards independent learning in mathematical topics. One of these tools is a series of specific thematic math videos. They have different aims and scopes. On the one hand, they connect basic concepts of the Calculus course with relevant topics of Civil Engineering. On the other hand, they propose and state contextualized problems (pertaining to Civil Engineering) which are solved stepwise using Calculus tools and procedures. Moreover, there are different kinds of videos, namely: motivational, audiovisual workshops and audiovisual laboratories. Producing and editing workshop videos required the cooperation of professors and also last year students in Civil Engineering. Being the speakers actual students, these videos convey to the target audience (first year students) a sensation of proximity and a potential easiness. Much more than if they were presented by a lecturer. Initially, all of these videos were only accessible through the Civil Engineering School web portal, CaminsOpenCourseWare. Currently, the three collections of videos are already displayed on the YouTube channel, which provides more flexibility for access and allows controlling displays. They are also integrated into the web platform of the Calculus course, which allows students being immediately updated.Postprint (published version

Regional workshop to use the findings from operations research to increase the access, quality and integration of contraceptive services in Latin America and the Caribbean

In October 2007, the Frontiers in Reproductive Health (FRONTIERS) program held a three-day regional workshop in La Antigua, Guatemala, to disseminate results of its operations research projects. During the workshop, participants received contraceptive technology updates, and learned about effective strategies tested by FRONTIERS to increase access to the IUD and vasectomy; and about integration of family planning with postpartum, postabortion, and PMTCT. Researchers discussed study results, program managers explained how they were used, and practitioners talked about implementing the interventions—a combination of perspectives that successfully transmitted the message that the interventions were not difficult to apply, could have a great impact, and, as one participant wrote on the evaluation form, that “small changes could lead to great results.” Participants prepared plans, outlined in this report, to put into practice lessons learned at the workshop

Thermodiffusion in Ternary Mixtures of Water/Ethanol/Triethylene Glycol: First Report on the DCMIX3-Experiments Performed on the International Space Station

We report on thermodiffusion experiments conducted on the International Space Station ISS during fall 2016. These experiments are part of the DCMIX (Diffusion and thermodiffusion Coefficients Measurements in ternary Mixtures) project, which aims at establishing a reliable data base of non-isothermal transport coefficients for selected ternary liquid mixtures. The third campaign, DCMIX3, focuses on aqueous systems with water/ethanol/triethylene glycol as an example, where sign changes of the Soret coefficient have already been reported for certain binary subsystems. Investigations have been carried out with the SODI (Selectable Optical Diagnostics Instrument) instrument, a Mach-Zehnder interferometer set up inside the Microgravity Science Glovebox in the Destiny Module of the ISS. Concentration changes within the liquids have been monitored in response to an external temperature gradient using phase-stepping interferometry. The complete data set has been made available in spring 2017. Due to additionally available measurement time, it was possible to collect a complete data set at 30∘C and an almost complete data set at 25∘C, which significantly exceeds the originally envisaged measurements at a single temperature only. All samples could be measured successfully. The SODI instrument and the DCMIX experiments have proven reliable and robust, allowing to extract meaningful data even in case of unforeseen laser instabilities. First assessments of the data quality have revealed six out of 31 runs with some problems in image contrast and/or phase step stability that will require more sophisticated algorithms. This publication documents all relevant parameters of the conducted experiments and also events that might have an influence on the final results. The compiled information is intended to serve as a starting point for all following data evaluations