The antenna DSA 3 and its potential use for Radio Astronomy

The European Space Agency (ESA) will inaugurate its third Deep Space Antenna (DSA 3) by the end of 2012. DSA 3 will be located in Argentina near the city of Malarg"ue in the Mendoza province. While the instrument will be primarily dedicated to communications with interplanetary missions, the characteristics of its antenna and receivers will also enable standalone leading scientific contributions, with a high scientific-technological return. We outline here scientific proposals for a radio astronomical use of DSA 3.Comment: 4 pages, submitted as Proceedings for the BAA

Growth and bacterial dynamics of beef calves during transition from milk/pasture to a high-concentrate diet added with tannins or medium-chain fatty acids

Context. Rumen fermentation modulation with feed additives during the transition period to high-concentrate diets might help to avoid bacterial dysbiosis. Aims. Assessing the effects of the addition of tannins and medium-chain fatty acids (MCFA) to the adaptation diet of beef calves to a high-concentrate ration on the rate of intake, animal performance and rumen bacterial composition. Methods. Eighteen 7-month-old beef calves were abruptly weaned and transitioned over a 28-day period from a milk/grass regime to one of the following diets: a non-supplemented high-concentrate diet plus wheat straw, both given ad libitum (C); C plus 20 g/kg of a 65:35 chestnut and quebracho tannin extract; and C plus 6 g/kg of a commercial mixture of MCFA. Concentrate and straw rate of intake were recorded. Rumen fluid was collected on Days 0, 1, 7, 14, 21 and 28 at 0, 3, 6 and 9 h after feeding to characterise rumen fermentation. Samples from 0 h were analysed to assess the bacterial population using Ion Torrent sequencing. Key results. The rate of intake of concentrates and straw, as well as daily gains and final weights, were similar (P > 0.05) among diets. The addition of tannins or MCFA did not modify (P = 0.98) the rumen bacterial population, which was affected by sampling day (P < 0.001). The additives inclusion did not affect relative abundances of the main bacterial taxa (P < 0.05), most of them differing across days (P < 0.001). Diversity indexes (Shannon and richness) declined over sampling days (P < 0.05), although some genera emerged after concentrate inclusion. Conclusions. At the doses used in the present experiment, tannins and MCFA did not exert any effect on intake, animal performance and bacterial population. Abrupt transition to high-concentrate diets modified the rumen environment and bacterial community, indicating bacterial adaptation to new environmental conditions. Implications. Abrupt transition of 7-month-old calves from milk/pasture to a high-concentrate diet did not impair rumen microbiota or performance; therefore, the use of feed additives seems unnecessary. © 2021 CSIRO. All rights reserved

Closing the dark photon window to thermal dark matter

The nature of dark matter remains a central question in particle physics, cosmology, and astrophysics. The prevailing hypothesis postulates that dark matter consists of particles that interact only weakly with Standard Model particles. However, the knowledge of dark matter properties beyond these interactions is limited. This study explores a scenario involving a dark photon as a mediator between dark matter and the Standard Model, akin to the photon's role in electromagnetism. Recent cosmological and experimental evidence impose constraints on this scenario, focusing on results from direct detection experiments such as PICO-60, XENON-1T, and PANDAX-4T. The results reveal severe constraints, effectively closing the window for laboratory searches for dark photons as mediators between the Standard Model and the dark sector (dark electrons) in the secluded dark matter scenario. The findings underscore the need for alternative explanations and offer fresh perspectives on the ongoing quest to understand dark matter and its interactions since they are nearly independent of the dark electron fraction content for the total dark matter. This analysis significantly narrows down the parameter space for thermal dark matter scenarios involving a dark photon portal, reinforcing the urgency of exploring alternative models and designing new experiments to unravel the mysteries surrounding the nature of dark matter.Comment: 11 pages, 5 figure

Quantum State During and after O(4)O(4)-Symmetric Bubble Nucleation with Gravitaional Effects

We extend our previous analysis of the quantum state during and after $O(4)$-symmetric bubble nucleation to the case including gravitational effects. We find that there exists a simple relationship between the case with and without gravitational effects. In a special case of a conformally coupled scalar field which is massless except on the bubble wall, the state is found to be conformally equivalent to the case without gravity.Comment: 31 pages plain Tex file, uuencoded postscript figure file is available from [email protected] upon request, KUNS126

Hispanic ethnicity and survival in pediatric acute lymphocytic leukemia (all) patients in Florida

Introduction: Pediatric cancer mortality rates have drastically declined according to analyzed population-based surveillance data; however, incidences of most childhood cancers continue to rise. Recent studies have indicated an association between ethnicity/race and cancer survival. Florida's ethnically/racially diverse population and surging pediatric cancer incidence characterize the state as an ideal setting to study the association between ethnicity/race and pediatric cancer survival. Objective: To determine whether or not an association exists between Hispanic ethnicity and cancer survival in a Floridian population of pediatric patients with Acute Lymphocytic Leukemia (ALL). Methods: We will use data from participants 18 years or younger of Florida Cancer Data System (FCDS). Cox-proportional hazard regression was used to assess independent association between Hispanic ethnicity and time to death (time interval from diagnose of ALL to the last patient contact, as recorded in the database). Survival status (death or alive) was assessed at the date of last contact. Those who are alive at last contact were then censored. Results: In the unadjusted model, ethnicity was not associated with risk of death (HR= 0.87, 95% CI=0.73 - 1.04). After adjustment for sex, race, age at diagnosis, insurance status, geographic area, and immunophenotype) the results showed again no association between Hispanic ethnicity and survival (HR = 1.19, 95% CI=0.82 - 1.72). Conclusions: We found no evidence for differences in survival based on ethnic status. Potential difference in racial-survival disparities in pediatric ALL within various geographic regions might depend on Hispanic ancestries or cancer type. Further research on the topic is still deemed necessary as to clarify the nature of the association between ethnicity and cancer survival

Baseline data of four insecticides with different modes of action for Anastrepha fraterculus and Ceratitis capitata (Diptera: Tephritidae)

La mosca de la fruta del Mediterráneo, Ceratitis capitata (Wiedemann), y la mosca sudamericana de los frutos, Anastrepha fraterculus (Wiedemann) son plagas de gran importancia económica en Argentina y el mundo. Una de las formas de control es el uso de insecticidas en pulverizaciones totales o en cebos. El uso reiterado de un determinado producto ejerce una fuerte presión de selección, pudiendo ocasionar la aparición de resistencia. El objetivo de este trabajo fue determinar el dato de nivel básico de cuatro insecticidas con diferentes mecanismos de acción mediante bioensayos en laboratorio. Los productos utilizados fueron formulaciones comerciales de ciantraniliprol, clorpirifos, lambdacialotrina y spinosad. La concentración letal media se estimó mediante un análisis de la curva dosis-respuesta. Para ciantraniliprol y clorpirifós los machos y las hembras de ambas especies fueron igualmente susceptibles. Para lambdacialotrina se detectaron diferencias entre las dos especies; la CL50 de A. fraterculus (0,058 y 0,074 para machos y hembras respectivamente) fue menor que la de C. capitata (0,523 y 0,624 para machos y hembras respectivamente). Para spinosad, los machos de A. fraterculus fueron igualmente susceptibles que los machos y las hembras de C. capitata. Estos resultados generan valores de referencia para Argentina y evidencian la necesidad de completar este tipo de estudios con evaluaciones de poblaciones naturales sobre las cuales se ejerce control químico así como con ensayos en campo y semi-campo. Asimismo muestran la necesidad de completar este tipo de estudios con evaluaciones de los niveles de ingesta en las distintas concentraciones.The Mediterranean fruit fly, Ceratitis capitata (Wiedemann), and the South American fruit fly, Anastrepha fraterculus (Wiedemann) are pests of major economic importance in Argentina and worldwide. One way to control them is the use of insecticide in sprays or baits. The repeated use of a particular product exerts a strong selection pressure and can lead to development of resistance. The aim of this study was to determine baseline data of four insecticides with different mechanisms of action through laboratory bioassays. The products used were commercial formulations of cyantraniliprole, chlorpyrifos, lambdacyalothrin and spinosad. The mean lethal concentration was estimated by a dose-response curve analysis. Cyantraniliprole and chlorpyrifos were equally susceptible for males and females of both species. For lambdacyalothrin differences between the two species were detected; LC50 of A. fraterculus (0.058 and 0.074 for males and females respectively) was lower than that of C. capitata (0.523 and 0.624 for males and females respectively). For spinosad, A. fraterculus males were equally susceptible than males and females of C. capitata. These results generate reference values for Argentina and demonstrate the need to complete these studies with field evaluations of natural populations on which chemical control is exercised as well as with field and semi-field trials. It also shows the need to complete these studies in which the intake at different concentrations is measured.Fil: Paez Jerez, P. G.. Universidad Nacional de Tucumán. Facultad de Agronomía y Zootecnia. Cátedra. Terapéutica Vegetal; ArgentinaFil: Carrizo, B. N.. Instituto Nacional de Tecnología Agropecuaria. Centro Regional Tucumán-Santiago del Estero. Estación Experimental Agropecuaria Famaillá; ArgentinaFil: Musse, R.. Universidad Nacional de Tucumán. Facultad de Agronomía y Zootecnia. Cátedra. Terapéutica Vegetal; ArgentinaFil: Varela, E.. Universidad Nacional de Tucumán. Facultad de Agronomía y Zootecnia. Cátedra. Terapéutica Vegetal; ArgentinaFil: Armiñana, A.. Universidad Nacional de Tucumán. Facultad de Agronomía y Zootecnia. Cátedra. Terapéutica Vegetal; ArgentinaFil: Milla, F.. Instituto Nacional de Tecnología Agropecuaria. Centro Nacional de Investigaciones Agropecuarias. Centro de Investigación de Ciencias Veterinarias y Agronómicas. Instituto de Genética; ArgentinaFil: Vera, Maria Teresa. Universidad Nacional de Tucumán. Facultad de Agronomía y Zootecnia. Cátedra. Terapéutica Vegetal; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: de la Vega, M. H.. Universidad Nacional de Tucumán. Facultad de Agronomía y Zootecnia. Cátedra. Terapéutica Vegetal; Argentin