Cover crops: effect on sulfur availability in soybean

La elección de la especie de cultivo de cobertura (CC) a emplear puede afectar la disponibilidad de azufre (S) para el cultivo de soja (Glycine max (L.) Merr.) posterior. Así, el objetivo de este trabajo fue evaluar el efecto de avena (Avena sativa L.) y vicia (Vicia villosa Roth.) como CC y la fertilización azufrada sobre algunos parámetros que definen la disponibilidad de S y el rendimiento en el cultivo de soja posterior. Se realizaron tres ensayos de campo en distintas zonas del sudeste bonaerense donde se evaluó la combinación de tres niveles de CC (avena, vicia y un testigo sin CC) con dos niveles de fertilización azufrada en la soja (0 y 15 kg S ha-1). Se determinó el contenido de S-SO4-2 (0-60 cm) en el suelo a la siembra de la soja, el índice de verdor (IV) a inicio de floración (R1) y el rendimiento en grano. Los principales resultados del trabajo son: i) los CC acumularon entre 7 y 17 kg S ha-1, logrando reducir las pérdidas de S por lixiviación durante el barbecho invernal, ii) la vicia incrementó en promedio 28 kg S ha-1 su disponibilidad en el suelo a la siembra de la soja, respecto a la avena y al testigo, iii) el IV de la soja fue menor con antecesor avena que con vicia y el testigo, iv) no hubo respuesta en rendimiento a la fertilización con S, v) en dos de los tres sitios el CC de vicia redujo el rendimiento en grano de la soja, posiblemente por un efecto negativo sobre la nodulación y fijación biológica de nitrógeno, lo cual deberá ser corroborado en futuros trabajos.Selecting the cover crop (CC) specie may affect sulfur (S) availability for the succeeding soybean (Glycine max (L.) Merr.) crop. Thus, the objective of this work was to evaluate the effect of oat (Avena sativa L.) and vetch (Vicia villosa Roth.) as CC and S fertilization on some parameters that define S availability and yield in the succeeding soybean. Three field experiments were conducted in different areas of southeastern Buenos Aires province, where the combination of three levels of CC (oats, vetch, and a control without CC) with two levels of S fertilization (0 and 15 kg S ha-1) was evaluated in soybean. Determinations included: SO4 -2-S content in soil (0-60 cm) at soybean sowing, greenness index (IV) at the beginning of flowering (R1), and seed yield. The main results were: i) CC accumulated between 7 and 17 kg S ha-1, allowing reductions of S losses by leaching during the winter fallow, ii) vetch increased S availability in the soil at soybean planting by 28 kg S ha-1, compared to oat and the control, iii) soybean IV was lower when preceded by oat compared to vetch and the control, iv) there was no yield response to S fertilization, v) in two of the three sites vetch reduced soybean seed yield, possibly due to a negative effect on nodulation and biological nitrogen fixation, which should be tested in future works.Fil: Carciochi, Walter Daniel. Universidad Nacional de Mar del Plata. Facultad de Ciencias Agrarias; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata; ArgentinaFil: Contreras, Lucas E.. Universidad Nacional de Mar del Plata. Facultad de Ciencias Agrarias; ArgentinaFil: Crespo, Cecilia. Universidad Nacional de Mar del Plata. Facultad de Ciencias Agrarias; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata; ArgentinaFil: Barbieri, Pablo Andres. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata; Argentina. Instituto Nacional de Tecnología Agropecuaria. Centro Regional Buenos Aires Sur. Estación Experimental Agropecuaria Balcarce; Argentin

New Eruptive YSOs from SPICY and WISE

© Published under Creative Commons license CC BY-SA 4.0.This work presents four high-amplitude variable YSOs (≃3 mag at near-or mid-IR wavelengths) arising from the SPICY catalog. Three outbursts show a duration that is longer than 1 year, and are still ongoing. And additional YSO brightened over the last two epochs of NEOWISE observations and the duration of the outburst is thus unclear. Analysis of the spectra of the four sources confirms them as new members of the eruptive variable class. We find two YSOs that can be firmly classified as bona fide FUors and one object that falls in the V1647 Ori-like class. Given the uncertainty in the duration of its outburst, an additional YSO can only be classified as a candidate FUor. Continued monitoring and follow-up of these particular sources is important to better understand the accretion process of YSOs.Peer reviewe

New Eruptive YSOs from SPICY and WISE

This work presents four high-amplitude variable YSOs ($\simeq$ 3 mag at near- or mid-IR wavelengths) arising from the SPICY catalog. Three outbursts show a duration that is longer than 1 year, and are still ongoing. And additional YSO brightened over the last two epochs of NEOWISE observations and the duration of the outburst is thus unclear. Analysis of the spectra of the four sources confirms them as new members of the eruptive variable class. We find two YSOs that can be firmly classified as bona fide FUors and one object that falls in the V1647 Ori-like class. Given the uncertainty in the duration of its outburst, an additional YSO can only be classified as a candidate FUor. Continued monitoring and follow-up of these particular sources is important to better understand the accretion process of YSOs.Comment: 10 pages, 10 figures, Accepted for publication at the Journal of the Korean Astronomical Societ

New VVV Survey Globular Cluster Candidates in the Milky Way Bulge

© 2017 The American Astronomical Society. All rights reserved.It is likely that a number of Galactic globular clusters remain to be discovered, especially toward the Galactic bulge. High stellar density combined with high and differential interstellar reddening are the two major problems for finding globular clusters located toward the bulge. We use the deep near-IR photometry of the VISTA Variables in the Vía Láctea (VVV) Survey to search for globular clusters projected toward the Galactic bulge, and hereby report the discovery of 22 new candidate globular clusters. These objects, detected as high density regions in our maps of bulge red giants, are confirmed as globular cluster candidates by their color-magnitude diagrams. We provide their coordinates as well as their near-IR color-magnitude diagrams, from which some basic parameters are derived, such as reddenings and heliocentric distances. The color-magnitude diagrams reveal well defined red giant branches in all cases, often including a prominent red clump. The new globular cluster candidates exhibit a variety of extinctions (0.06 < A Ks < 2.77) and distances (5.3 < D < 9.5 kpc). We also classify the globular cluster candidates into 10 metal-poor and 12 metal-rich clusters, based on the comparison of their color-magnitude diagrams with those of known globular clusters also observed by the VVV Survey. Finally, we argue that the census for Galactic globular clusters still remains incomplete, and that many more candidate globular clusters (particularly the low luminosity ones) await to be found and studied in detail in the central regions of the Milky Way.Peer reviewedFinal Accepted Versio

Quality indicators in radiation oncology: proposal of the Spanish Society of Radiation Oncology (SEOR) for a continuous improvement of the quality of care in oncology.

Purpose Current cancer treatment options include surgical intervention, radiotherapy, and chemotherapy. The quality of the provision of each of them and their effective coordination determines the results in terms of benefit/risk. Regarding the radiation oncology treatments, there are not stabilised quality indicators to be used to perform control and continuous improvement processes for healthcare services. Therefore, the Spanish Society of Radiation Oncology has undertaken a comprehensive project to establish quality indicators for use with the information systems available in most Spanish healthcare services. Methods A two-round Delphi study examines consensus of several possible quality indicators (n = 28) in daily practice. These indicators were defined after a bibliographic search and the assessment by radiation oncology specialists (n = 8). They included aspects regarding treatment equipment, patient preparation, treatment, and follow-up processes and were divided in structure, process, and outcome indicators. Results After the evaluation of the defined quality indicators (n = 28) by an expert panel (38 radiation oncologist), 26 indicators achieved consensus in terms of agreement with the statement. Two quality indicators did not achieve consensus. Conclusions There is a high degree of consensus in Spanish Radiation Oncology specialists on which indicators in routine clinical practice can best measure quality. These indicators can be used to classify services based on several parameters (patients, equipments, complexity of the techniques used, and scientific research). Furthermore, these indicators allow assess our current situation and set improvements’ objectives.pre-print241 K

VIRAC: The VVV Infrared Astrometric Catalogue

© 2017 The Authors. Published by Oxford University Press on behalf of the Royal Astronomical Society. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted reuse, distribution, and reproduction in any medium, provided the original work is properly cited.We present VIRAC version 1, a near-infrared proper motion and parallax catalogue of the VISTA Variables in the Via Lactea (VVV) survey for 312 587 642 unique sources averaged across all overlapping pawprint and tile images covering 560 deg 2 of the bulge of the MilkyWay and southern disc. The catalogue includes 119 million high-quality proper motion measurements, of which 47 million have statistical uncertainties below 1 mas yr -1. In the 11 < K s < 14 magnitude range, the high-quality motions have a median uncertainty of 0.67 mas yr -1. The catalogue also includes 6935 sources with quality-controlled 5s parallaxes with a median uncertainty of 1.1 mas. The parallaxes show reasonable agreement with the Tycho- Gaia Astrometric Solution, though caution is advised for data with modest significance. The SQL data base housing the data is made available via the web. We give example applications for studies of Galactic structure, nearby objects (low-mass stars and brown dwarfs, subdwarfs, white dwarfs) and kinematic distance measurements of young stellar objects. Nearby objects discovered include LTT 7251 B, an L7 benchmark companion to a G dwarf with over 20 published elemental abundances, a bright L subdwarf, VVV 1256-6202, with extremely blue colours and nine new members of the 25 pc sample. We also demonstrate why this catalogue remains useful in the era of Gaia. Future versions will be based on profile fitting photometry, use the Gaia absolute reference frame and incorporate the longer time baseline of the VVV extended survey.Peer reviewedFinal Published versio

Extreme infrared variables from UKIDSS-I. A concentration in star-forming regions

We present initial results of the first panoramic search for high-amplitude near-infrared variability in theGalactic plane.We analyse the widely separated two-epoch K-band photometry in the fifth and seventh data releases of the UKIDSS Galactic plane survey.We find 45 stars with δK > 1 mag, including two previously known OH/IR stars and a Nova. Even though the midplane is not yet included in the data set, we find the majority (66 per cent) of our sample to be within known star-forming regions (SFRs), with two large concentrations in the Serpens OB2 association (11 stars) and the Cygnus-X complex (12 stars). Sources in SFRs show spectral energy distributions that support classification as young stellar objects (YSOs). This indicates that YSOs dominate the Galactic population of high-amplitude infrared variable stars at low luminosities and therefore likely dominate the total high-amplitude population. Spectroscopic follow up of the DR5 sample shows at least four stars with clear characteristics of eruptive premain- sequence variables, two of which are deeply embedded. Our results support the recent concept of eruptive variability comprising a continuum of outburst events with different timescales and luminosities, but triggered by a similar physical mechanism involving unsteady accretion. Also, we find what appears to be one of the most variable classical Be stars. © 2014 The Authors Published by Oxford University Press on behalf of the Royal Astronomical Society

Extreme infrared variables from UKIDSS – II. An end-of-survey catalogue of eruptive YSOs and unusual stars

We present a catalogue of 618 high amplitude infrared variable stars (1 < DeltaK < 5 mag) detected by the two widely separated epochs of 2.2 um data in the UKIDSS Galactic plane survey, from searches covering 1470 deg^2. Most were discovered by a search of all fields at 30 < l < 230 deg. Sources include new dusty Mira variables, three new CV candidates, a blazar and a peculiar source that may be an interacting binary system. However, c. 60 per cent are YSOs, based on spatial association with star forming regions at distances ranging from 300 pc to over 10 kpc. This confirms our initial result in Contreras Pena et al.(Paper I) that YSOs dominate the high amplitude infrared variable sky in the Galactic disc. It is also supported by recently published VVV results at 295 < l < 350 deg. The spectral energy distributions of the YSOs indicate class I or flat spectrum systems in most cases, as in the VVV sample. A large number of variable YSOs are associated with the Cygnus X complex and other groups are associated with the North America/Pelican nebula, the Gemini OB1 molecular cloud, the Rosette complex, the Cone nebula, the W51 star forming region and the S86 and S236 HII regions. Most of the YSO variability is likely due to variable/episodic accretion on timescales of years, albeit usually less extreme than classical FUors and EXors. Luminosities at the 2010 WISE epoch range from c. 0.1 Lsun to 10^3 Lsun but only rarely exceed 10^2.5 Lsun