Measurement of the thorium-228 activity in solutions cavitated by ultrasonic sound

We show that cavitation of a solution of thorium-228 in water does not induce its transformation at a faster rate than the natural radioactive decay. We measured the activity of a thorium-228 solution in water before, and after, it was subjected to a cavitation at 44 kHz and $250$W for 90 minutes in order to observe any change in the thorium half-life. The results were compared to the original activity of the sample and we observed no change. Our results and conclusions conflict with those in a recent paper by F. Cardone et. al. [Phys. Lett. A 373 (2009) 1956-1958].Comment: 6 pages, 1 figure, 2 tables, v1 submitted to Physics Letters A. v2: minor corrections, change caption for tables (include comment for counter efficiency with uncertainty) and symbols for beta-alph

Alternativas tecnológicas para el desarrollo sostenible de la producción láctea en áreas con distintos grados de restricciones edafoclimáticas del NE de la Provincia de Santa Fe.

El objetivo del trabajo, es disponer de información local respecto a las características de los sistemas lecheros y la calidad de la leche que se obtiene en el NE de la Provincia de Santa Fe, y desarrollar nuevas alternativas tecnológicas para mejorar la productividad e incrementar el valor agregado de los productos lácteos. Se relevó información (2013- 2015), sobre la dieta ofrecida al rodeo lechero, y se analizó la leche cruda para determinar el perfil de los ácidos grasos, en establecimientos de producción lechera ubicados: Norte del departamento San Justo, Sur del departamento Vera, departamento General Obligado, y Norte del departamento San Javier. Se seleccionaron cultivares de alfalfa con adaptación sitio específica, con ensayos en las localidades de Calchaquí y Vera y Pintado (departamentos Vera y San Justo). Se utilizó un diseño experimental de bloques completos aleatorizados con 4 repeticiones. Se implantaron 40 cultivares de alfalfa, pertenecientes a los grados de reposo invernal 6, 7, 8, 9 y 10. La variedad con mayor producción en Calchaquí (1° corte) fue Sirosal (4.135 kg MS/ha.) y en Vera y Pintado, variedad Brava GS (2.093 kg MS/ha.). En el 2do corte, la variedad de mayor producción en ambos sitios fue Brava GS, con 3.435 kg MS/ha. Calchaquí y 3.585 kg MS/ha. en Vera y Pintado. Los cultivares WL 1058, Trinidad 87, CW 194 Premium, ProINTA Monarca y WL 818 manifestaron una producción semejante en ambos ambientes, mientras que los cultivares Sirosal, WL 919, Aurora, Sardi, Pampa Flor, CW 809, P 30 y Verdor muestran elevada interacción genotipo x ambiente. Se observó que los productores adoptan las mismas pasturas y cultivos que la región pampeana, con menor productividad. Con producciones < 500 lts/día en promedio, 80% de los productores utilizan alfalfa y predomina el cultivo de sorgo tanto forrajero como granífero. Entre 1000 a 2000 lts/día, y >2000 lts/día, el 100% siembra alfalfa, y verdeos de maíz, sorgo forrajero y granífero, y moha. Con mayores escalas de producción (>1000 lts/día), aumenta el uso de silaje y de concentrados. Es bajo el porcentaje de utilización de semillas de algodón. El valor máximo obtenido de CLA en leche cruda de la zona de la cuenca pampeana corresponde a un valor de 1.41 mg/100g, mientras que en dicha zona se observa valor máximode CLA de 2.24 mg/100g.publishedVersio

New Physics searches in a low threshold scintillating argon bubble chamber measuring coherent elastic neutrino-nucleus scattering in reactors

The sensitivity to New Physics of a low threshold scintillating argon bubble chamber measuring coherent elastic neutrino-nucleus scattering in reactors is reported. Namely, light scalar mediators, sterile neutrino oscillations, unitarity violation, and non-standard interactions are studied. The results indicate that this detector could be able to set stronger constraints than current limits set by the recent COHERENT measurements. Considering the best scenario, a 100 kg detector located 30 m from a 2000 MW$_{th}$ reactor, a sterile neutrino search would cover most of the space parameter allowed from the reactor anti-neutrino anomaly fit. Unitarity violation studies could set constraints on $\alpha_{11}$ more stringent than the current oscillation experiments fit. A low threshold argon detector with very low backgrounds has the potential to explore New Physics in different scenarios and set competitive constraints

EstrellaNueva: an open-source software to study the interactions and detection of neutrinos emitted by supernovae

Supernovae emit large fluxes of neutrinos which can be detected by detectors on Earth. Future tonne-scale detectors will be sensitive to several neutrino interaction channels, with thousands of events expected if a supernova emerges in the galaxy neighborhood. There is a limited number of tools to study the interaction rates of supernova neutrinos, although a plethora of available supernova models exists. EstrellaNueva is an open-source software to calculate expected rates of supernova neutrinos in detectors using target materials with typical compositions, and additional compositions can be easily added. This software considers the flavor transformation of neutrinos in the supernova through the adiabatic Mikheyev--Smirnov--Wolfenstein effect, and their interaction in detectors through several channels. Most of the interaction cross sections have been analytically implemented, such as neutrino-electron and neutrino-proton elastic scattering, inverse beta decay, and coherent elastic neutrino-nucleus scattering. This software provides a link between supernova simulations and the expected events in detectors by calculating fluences and event rates to ease any comparison between theory and observation. It provides a simple and standalone tool to explore many physics scenarios offering an option to add analytical cross sections and define any target material

Prevalencia de síntomas depresivos en mujeres perimenopáusicas docentes de primaria de bachillerato

ResumenAntecedentes: La depresi&oacute;n es la primera causa de a&ntilde;os saludables de vida perdidos en todo el mundo; los cambios hormonales de la menopausia parecen incrementarla susceptivilidad para desarrollar este estado.[J&aacute;uregui-D&uacute;ran IE, D&iacute;as Mart&iacute;nes LA. Prevalencia de s&iacute;ntomas depresivos&nbsp; en mujeres perimenop&aacute;usicas docentes de primaria de bachillerato. mEDunab 2005;8:65-70].Palabras clave: Menopausia, depresi&oacute;n, CES-D

Physicochemical characterization and antimicrobial properties of rhamnolipids produced by Pseudomonas aeruginosa 47T2 NCBIM 40044

7 pages, 2 figures, 3 tables.-- PMID: 12474254 [PubMed].-- Available online Dec 3, 2002.Pseudomonas aeruginosa 47T2, grown in submerged culture with waste frying oil as a carbon source, produced a mixture of rhamnolipids with surface activity. Up to 11 rhamnolipid homologs (Rha-Rha-C8-C10; Rha-C10-C8/Rha-C8-C10;Rha-Rha-C8-C12:1; Rha-Rha-C10-C10; Rha-Rha-C10-C12:1; Rha-C10-C10; Rha-Rha-C10-C12/Rha-Rha-C12-C10; Rha-C10-C12:1/Rha-C12:1-C10; Rha-Rha-C12:1-C12; Rha-Rha-C10-C14:1; Rha-C10-C12/Rha-C12-C10) were isolated from cultures of P. aeruginosa 47T2 from waste frying oil and identified by HPLC-MS analysis. This article deals with the production, isolation, and chemical characterization of the rhamnolipid mixture RL47T2. The physicochemical and biological properties of RL47T2 as a new product were also studied. Its surface tension decreased to 32.8 mN/m; and the interfacial tension against kerosene to 1 mN/m. The critical micellar concentration for RL47T2 was 108.8 mg/mL. The product showed excellent antimicrobial properties. Antimicrobial activity was evaluated according to the minimum inhibitory concentration (MIC), the lowest concentration of an antimicrobial agent that inhibits development of visible microbial growth. Low MIC values were found for bacteria Serratia marcescens (4 g/mL), Enterobacter aerogenes (8 g/mL), Klebsiella pneumoniae (0.5 g/mL), Staphylococcus aureus and Staphylococcus epidermidis (32 g/mL), Bacillus subtilis (16 g/mL), and phytopathogenic fungal species: Chaetonium globosum (64 g/mL), Penicillium funiculosum (16 g/mL), Gliocadium virens (32 g/mL) and Fusarium solani (75 g/mL).Finnancial support by the CIRIT and CICYT; Grant Number: 199956R 00024, PPQ-2000-0105-P4-03, REN 2001-3224.Peer reviewe