Long-Term Optical Monitoring of Eta Carinae. Multiband light curves for a complete orbital period

The periodicity of 5.5 years for some observational events occurring in Eta Carinae manifests itself across a large wavelength range and has been associated with its binary nature. These events are supposed to occur when the binary components are close to periastron. To detect the previous periastron passage of Eta Car in 2003, we started an intensive, ground-based, optical, photometric observing campaign. We continued observing the object to monitor its photometric behavior and variability across the entire orbital cycle. Our observation program consisted of daily differential photometry from CCD images, which were acquired using a 0.8 m telescope and a standard BVRI filter set at La Plata Observatory. The photometry includes the central object and the surrounding Homunculus nebula. We present up-to-date results of our observing program, including homogeneous photometric data collected between 2003 and 2008. Our observations demonstrated that Eta Car has continued increasing in brightness at a constant rate since 1998. In 2006, it reached its brightest magnitude (V ~ 4.7) since about 1860s. The object then suddenly reverted its brightening trend, fading to V = 5.0 at the beginning of 2007, and has maintained a quite steady state since then. We continue the photometric monitoring of Eta Car in anticipation of the next "periastron passage", predicted to occur at the beginning of 2009.Comment: Accepted by A&A. The paper contains 3 figures and 2 table

Status of low-energy accelerator-based BNCT worldwide and in Argentina

Existing and active low-energy Accelerator-Based BNCT programs worldwide will be reviewed and compared. In particular, the program in Argentina will be discussed which consists of the development of an Electro-Static-Quadrupole (ESQ) Accelerator-Based treatment facility. The facility is conceived to operate with the deuteron-induced reactions 9Be(d,n)10B and 13C(d,n)14N at 1.45 MeV deuteron energy, as neutron sources. Neutron production target development status is specified. The present status of the construction of the new accelerator development laboratory and future BNCT centre is shown.Fil: Cartelli, Daniel Enrique. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Comisión Nacional de Energía Atómica; Argentina. Universidad Nacional de San Martín. Escuela de Ciencia y Tecnología; ArgentinaFil: Capoulat, Maria Eugenia. Comisión Nacional de Energía Atómica; Argentina. Universidad Nacional de San Martín. Escuela de Ciencia y Tecnología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Baldo, M.. Comisión Nacional de Energía Atómica; ArgentinaFil: Suárez Sandín, J. C.. Comisión Nacional de Energía Atómica; ArgentinaFil: Igarzabal, M.. Comisión Nacional de Energía Atómica; ArgentinaFil: del Grosso, Mariela Fernanda. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Comisión Nacional de Energía Atómica; ArgentinaFil: Valda, A. A.. Comisión Nacional de Energía Atómica; Argentina. Universidad Nacional de San Martín. Escuela de Ciencia y Tecnología; ArgentinaFil: Canepa, N.. Comisión Nacional de Energía Atómica; ArgentinaFil: Gun, M.. Comisión Nacional de Energía Atómica; ArgentinaFil: Minsky, Daniel Mauricio. Comisión Nacional de Energía Atómica; Argentina. Universidad Nacional de San Martín. Escuela de Ciencia y Tecnología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Conti, G.. Comisión Nacional de Energía Atómica; ArgentinaFil: Erhardt, J.. Comisión Nacional de Energía Atómica; ArgentinaFil: Somacal, Héctor Rubén. Comisión Nacional de Energía Atómica; Argentina. Universidad Nacional de San Martín. Escuela de Ciencia y Tecnología; ArgentinaFil: Bertolo, A. A.. Comisión Nacional de Energía Atómica; ArgentinaFil: Bergueiro, J.. Comisión Nacional de Energía Atómica; ArgentinaFil: Gaviola, P. A.. Comisión Nacional de Energía Atómica; ArgentinaFil: Kreiner, Andres Juan. Comisión Nacional de Energía Atómica; Argentina. Universidad Nacional de San Martín. Escuela de Ciencia y Tecnología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin

Converting simulated total dry matter to fresh marketable yield for field vegetables at a range of nitrogen supply levels

Simultaneous analysis of economic and environmental performance of horticultural crop production requires qualified assumptions on the effect of management options, and particularly of nitrogen (N) fertilisation, on the net returns of the farm. Dynamic soil-plant-environment simulation models for agro-ecosystems are frequently applied to predict crop yield, generally as dry matter per area, and the environmental impact of production. Economic analysis requires conversion of yields to fresh marketable weight, which is not easy to calculate for vegetables, since different species have different properties and special market requirements. Furthermore, the marketable part of many vegetables is dependent on N availability during growth, which may lead to complete crop failure under sub-optimal N supply in tightly calculated N fertiliser regimes or low-input systems. In this paper we present two methods for converting simulated total dry matter to marketable fresh matter yield for various vegetables and European growth conditions, taking into consideration the effect of N supply: (i) a regression based function for vegetables sold as bulk or bunching ware and (ii) a population approach for piecewise sold row crops. For both methods, to be used in the context of a dynamic simulation model, parameter values were compiled from a literature survey. Implemented in such a model, both algorithms were tested against experimental field data, yielding an Index of Agreement of 0.80 for the regression strategy and 0.90 for the population strategy. Furthermore, the population strategy was capable of reflecting rather well the effect of crop spacing on yield and the effect of N supply on product grading

Detection of high-velocity material from the wind-wind collision zone of Eta Carinae across the 2009.0 periastron passage

We report near-IR spectroscopic observations of the Eta Carinae massive binary system during 2008-2009 using VLT/CRIRES. We detect a strong, broad absorption wing in He I 10833 extending up to -1900 km/s across the 2009.0 spectroscopic event. Archival HST/STIS ultraviolet and optical data shows a similar high-velocity absorption (up to -2100 km/s) in the UV resonance lines of Si IV 1394, 1403 across the 2003.5 event. UV lines from low-ionization species, such as Si II 1527, 1533 and C II 1334, 1335, show absorption up to -1200 km/s, indicating that the absorption with v from -1200 to -2100 km/s originates in a region markedly faster and more ionized than the nominal wind of the primary star. Observations obtained at the OPD/LNA during the last 4 spectroscopic cycles (1989-2009) also display high-velocity absorption in He I 10833 during periastron. Based on the OPD/LNA dataset, we determine that material with v < -900 km/s is present in the phase range 0.976 < phi < 1.023 of the spectroscopic cycle, but absent in spectra taken at phi < 0.947 and phi > 1.049. Therefore, we constrain the duration of the high-velocity absorption to be 95 to 206 days (or 0.047 to 0.102 in phase). We suggest that the high-velocity absorption originates from shocked gas in the wind-wind collision zone, at distances of 15 to 45 AU in the line-of-sight to the primary star. Using 3-D hydrodynamical simulations of the wind-wind collision zone, we find that the dense high-velocity gas is in the line-of-sight to the primary star only if the binary system is oriented in the sky so that the companion is behind the primary star during periastron, corresponding to a longitude of periastron of omega ~ 240 to 270 degrees. We study a possible tilt of the orbital plane relative to the Homunculus equatorial plane and conclude that our data are broadly consistent with orbital inclinations in the range i=40 to 60 degrees.Comment: 18 pages, 15 figures, accepted for publication in A&A; high-resolution PDF version available also at http://www.mpifr.de/staff/jgroh/etacar.htm

Instrumentation for fluorescence lifetime measurement using photon counting

We describe the evolution of HORIBA Jobin Yvon IBH Ltd, and its time-correlated single-photon counting (TCSPC) products, from university research beginnings through to its present place as a market leader in fluorescence lifetime spectroscopy. The company philosophy is to ensure leading-edge research capabilities continue to be incorporated into instruments in order to meet the needs of the diverse range of customer applications, which span a multitude of scientific and engineering disciplines. We illustrate some of the range of activities of a scientific instrument company in meeting this goal and highlight by way of an exemplar the performance of the versatile DeltaFlex instrument in measuring fluorescence lifetimes. This includes resolving fluorescence lifetimes down to 5 ps, as frequently observed in energy transfer, nanoparticle metrology with sub-nanometre resolution and measuring a fluorescence lifetime in as little as 60 μs for the study of transient species and kinetics

Health Care Disparities in Radiology: A Primer for Resident Education

© 2018 Elsevier Inc. As the population of the United States grows increasingly diverse, health care disparities become vital to understand and mitigate. The ethical and financial implications of how groups of Americans gain access to health care have evolved into some of today\u27s most challenging socioeconomic problems. Educators in radiology are just beginning to tackle the concepts of health care disparities, unconscious bias, and cultural competency. In July 2017, the Accreditation Council for Graduate Medical Education required that all trainees and teaching faculty of accredited training programs receive training and experience in new areas of quality improvement to include an understanding of health care disparities as part of the core competencies. To our knowledge, there is no centralized curriculum regarding health care disparities for radiology residents and fellows. Many programs, in fact, have yet to introduce the concept to their trainees, who may have difficulty recognizing that this is even a problem affecting radiology. This manuscript serves as a primer for radiology trainees on health care disparities, with the goal of defining major concepts and providing examples of how variable access to radiological care can have substantial impact on patient outcomes

The Association of Program Directors in Radiology Well-Being 2019 Survey: Identifying Residency Gaps and Offering Solutions

© 2019 American College of Radiology Purpose: The Well-Being subcommittee of the Association of Program Directors in Radiology (APDR) Common Program Requirements (CPR) Ad Hoc Committee and the APDR Academic Output Task Force jointly conducted a study of APDR members’ current level of understanding and implementation of the 2017 ACGME CPR regarding well-being. Methods: A survey instrument consisting of 10 multiple-choice and open-ended questions was distributed to the 322 active members of the APDR. The survey focused on three main content areas: APDR member knowledge of the 2017 CPR, composition of department well-being curricula, and residency well-being innovations. Results: In all, 121 members (37.6%) responded to the survey. Of those, 67% rated their knowledge of requirements as incomplete. Responses also indicated that 74% of departments have not implemented a comprehensive well-being curriculum; 53% of programs do not offer the mandated self-screening tool; 15% of respondents do not offer residents protected time for medical, mental health, and dental appointments; and 42% do not offer their trainees access to an institutional mental health clinic. Survey comments offer numerous individual well-being initiatives from across the membership. Conclusions: The results of the APDR Well-Being Survey indicate that many programs have substantial work remaining to achieve ACGME compliance. Well-being innovations were included in an effort to share best practices

A Program Director\u27s Guide to Cultivating Diversity and Inclusion in Radiology Residency Recruitment

Diversity and inclusion are vital elements to the success of any group. Indeed, evidence from the business world indicates that a group\u27s overall talent level is a function of its collective cognitive diversity. The ability to effectively problem solve, innovate, and adapt to change all depend to a large degree on the biases and life experiences of an organization\u27s constituent members. As other industries have come to embrace this principle, their recruitment strategies have included placing a premium on employees who can think differently from one another. The benefits of diversity and inclusion have been touted in the medical literature and on social media sites in recent years. The radiology Twitter community often discusses the nuances of diversity and how it benefits all stakeholders in a radiology department. In essence, a diverse group allows for collaboration among colleagues with dissimilar experiences and perspectives, increasing the odds for discovery of new concepts and innovation (Fig 1) (1). Patients may stand to benefit the most, as diversity among practicing physicians is believed to be a key component of improving access and reducing disparities to health care in the United States (2,3)