Harassment Origin for Kinematic Substructures in Dwarf Elliptical Galaxies?

We have run high resolution N-body models simulating the encounter of a dwarf galaxy with a bright elliptical galaxy. The dwarf absorbs orbital angular momentum and shows counter-rotating features in the external regions of the galaxy. To explain the core-envelope kinematic decoupling observed in some dwarf galaxies in high-density environments requires nearly head-on collisions and very little dark matter bound to the dwarf. These kinematic structures appear under rather restrictive conditions. As a consequence, in a cluster like Virgo ~1% of dwarf galaxies may present counter-rotation formed by harassment.Comment: 10 pages, 7 figures; Accepted for publication in Astronomy and Astrophysic

Análise do comportamento de lentes em vidro de sílica perante a utilização de radiação solar concentrada

CIES2020 - XVII Congresso Ibérico e XIII Congresso Ibero-americano de Energia SolarRESUMO: Este trabalho descreve os ensaios realizados com um simulador laboratorial de radiação solar concentrada com o objectivo de avaliar o comportamento de lentes em vidro de sílica quando sujeitas a elevados fluxos de radiação, e permitiu comparar o seu comportamento com o que foi demonstrado por lentes idênticas, mas fabricadas em vidro de borossilicato (BK-7) cujo preço é muito inferior. Os ensaios de irradiação das lentes atingiram durações de 60 minutos, durante os quais se procedeu à monitorização contínua da potência da radiação aplicada sobre cada lente e da temperatura nela gerada. Todas as lentes em vidro de sílica se comportaram bem, mas o mesmo não ocorreu com as lentes em vidro de borossilicato. No trabalho é aventada a hipótese de o comportamento negativo registado nas lentes em borossilicato ser provocado pelo facto de se ter usado a radiação emitida por uma lâmpada de arco de xénon que pode conter comprimentos de onda que estão ausentes na radiação solar, pelo que é proposto que nos futuros testes não se use um simulador de radiação solar.ABSTRACT: This work describes the tests conducted with a laboratory-scale high-flux solar simulator aiming to evaluate the performance of optical lenses made of silica glass when subjected to high-fluxes of radiation, and it allowed to compare their behaviour with the behaviour shown by lenses made of borosilicate glass (BK-7) which price is much lower. The irradiation tests reached durations up to 60 minutes, with continuous monitoring of the power irradiating each and of the temperature generated on it. All silica lenses have shown a good performance, contrarily to what was observed with the lenses made of borosilicate. In the work it is mentioned the possibility that the negative behaviour observed with the borosilicate lenses may be due to the fact that the radiation spectrum of a xenon arc lamp contains certain wavelengths that are not present in the solar radiation spectrum, and therefore it is suggested that future tests are conducted with real concentrated solar radiation and not with a simulator that artificially reproduces the solar energy distribution.info:eu-repo/semantics/publishedVersio

Obesidad de una población de escolares de Granada: evaluación de la eficacia de una intervención educativa

Objetivos: El objeto del presente trabajo es estudiar la prevalencia de la obesidad y el sobrepeso en una población de escolares y verificar la efectividad de la intervención educativa desarrollada sobre esos alumnos en términos de mejora de los valores percentilados del índice de masa corporal. Material: La población valorada está compuesta por 977 escolares de entre 9 y 17 años de edad, pertenecientes a 13 centros educativos públicos de la ciudad de Granada y de su provincia (España). Metodología: Se trata de un estudio longitudinal, analítico, multicéntrico y observacional de cohortes, desarrollado en tres fases. En primer lugar, valoración del estado nutricional, mediante técnicas antropométricas (peso, talla e índice de masa corporal, seis pliegues cutáneos y cuatro perímetros corporales) así como la presión arterial. Una segunda fase en la que se desarrolló la intervención educativa sobre la alimentación y el ejercicio físico. En la fase final se evaluó la efectividad de la intervención. Resultados: Se encontró una mayor prevalencia de obesidad en las chicas de entre 12 y 13 años (15,1%). En los chicos, la prevalencia de obesidad fue inferior hasta los 13 años, aunque después mostraron un creciente incremento de dicha prevalencia (12,6%). Se produjo una reducción significativa de los valores de IMC en los dos sexos, aunque más significativa entre las chicas. Conclusiones: Existe un incremento alarmante en la prevalencia de sobrepeso y obesidad entre la población valorada. La reducción significativa de las puntuaciones en el IMC confirma la efectividad de la intervención educativa desarrollada.Objectives: The objective of this research was to study the prevalence of obesity and excess weight in a population of school children and adolescents, and to verify the effectiveness of an educational intervention, as reflected in the variation of their body mass index values. Materials: The population sample was composed of 977 school children and adolescents from 9 to 17 years of age, belonging to 13 public elementary schools and high schools in the city and province of Granada (Spain). Methodology: This longitudinal cohort study was analytical, muticentric, and observational. It was carried out in three phases. The first phase involved the evaluation of the nutritional state of the sample population by means of anthropometric measurements (weight, height, body mass index, six skin folds and four body perimeters) as well as arterial blood pressure. The second phase entailed an educational intervention focusing on good nutritional habits and physical exercise. The third and final phase evaluated the effectiveness of the intervention. Results: A higher obesity prevalence (15.1%) was found in school girls between 12 and 13. In the case of boys, obesity prevalence was lower up to age 13 though afterwards, it progressively increased (12.6%). The educational intervention produced an important reduction in body mass index values in both sexes though this reduction was more significant in young females. Conclusions: There is a currently an alarming increase in obesity and overweight prevalence among the population evaluated in this study. The significant reduction in body mass index values resulting from this research confirmed the effectiveness of the educational intervention to reduce excess weight

Measurement of Atmospheric Neutrino Oscillations with the ANTARES Neutrino Telescope

The data taken with the ANTARES neutrino telescope from 2007 to 2010, a total live time of 863 days, are used to measure the oscillation parameters of atmospheric neutrinos. Muon tracks are reconstructed with energies as low as 20 GeV. Neutrino oscillations will cause a suppression of vertical upgoing muon neutrinos of such energies crossing the Earth. The parameters determining the oscillation of atmospheric neutrinos are extracted by fitting the event rate as a function of the ratio of the estimated neutrino energy and reconstructed flight path through the Earth. Measurement contours of the oscillation parameters in a two-flavour approximation are derived. Assuming maximum mixing, a mass difference of $\Delta m_{32}^2=(3.1\pm 0.9)\cdot 10^{-3}$ eV$^2$ is obtained, in good agreement with the world average value.Comment: 9 pages, 5 figure

Lithium and boron in calcified tissues of vicuna and its relation to the chronic exposure by water ingestion in the Andean lithium triangle

Vicuna is a wild, endangered species of Andean camelid living in the hyperarid Andean plateau. In the central part of the plateau, the Lithium Triangle defines a zone with lithium‐rich salt pans. Brine pools naturally form within the salt pans, and the adaptation strategy of vicuna consists of drinking from brine pools. Together with reporting the first chemical data on vicuna bones and teeth, we analyzed lithium, boron, and arsenic in water and brines, with the aim of assessing their relation to chronic exposure by water ingestion. We collected and analyzed bones of vicuna specimens lying in an Andean salt pan, together with brine and water samples. Brine and water samples are highly saline and contain large amounts of lithium, boron, and arsenic. Lithium (13.50–40 mg kg–1 ) and boron (40–46.80 mg kg–1 ), but not arsenic, were found in the vicuna bones and teeth. Based on our results and on previously reported data on human tissues in the Andes, we conducted statistical assessments of the relationships between lithium and boron in body tissues and water samples, and discuss their environmental significance in the context of the Lithium Triangle.Fil: López Steinmetz, Romina Lucrecia. Universidad Nacional de Jujuy. Instituto de Ecorregiones Andinas. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Salta. Instituto de Ecorregiones Andinas; Argentina. Universidad Nacional de Jujuy. Instituto de Geología Minera; ArgentinaFil: Fong, Shao Bing. University of Melbourne; AustraliaFil: Boyer, Emile. Universite de Rennes I; FranciaFil: López Steinmetz, Lorena Cecilia. Universidad Nacional de Córdoba. Instituto de Investigaciones Psicológicas. - Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Investigaciones Psicológicas; ArgentinaFil: Tejerina, Norberto Elio. Universidad Nacional de Jujuy. Instituto de Geología Minera; ArgentinaFil: Meuric, Vincent. Universite de Rennes I; Franci

First observations of oblique ionospheric sounding chirp signal in Mexico

The results of the first experiment of oblique ionospheric sounding (OIS) chirp signal reception in Mexico are reported. Maximal and Lowest Observed Frequencies variations were studied under the quiet Space Weather conditions. The diurnal ionospheric variations by OIS signal confirm the results based on GNSS data in the Mexican region. The best HF radio propagation conditions along the considered path are during morning and daytime hours. The multi-hop propagation is frequent. The interlayer propagation modes are present at nighttime

Impact of previous tobacco use with or without cannabis on first psychotic experiences in patients with first-episode psychosis

Objective: There is high prevalence of cigarette smoking in individuals with first-episode psychosis (FEP) prior to psychosis onset. The purpose of the study was to determine the impact of previous tobacco use with or without cannabis on first psychotic experiences in FEP and the impact of this use on age of onset of symptoms, including prodromes. Methods: Retrospective analyses from the naturalistic, longitudinal, multicentre, “Phenotype-Genotype and Environmental Interaction. Application of a Predictive Model in First Psychotic Episodes (PEPs)” Study. The authors analysed sociodemographic/clinical data of 284 FEP patients and 231 matched healthy controls, and evaluated first psychotic experiences of patients using the Symptom Onset in Schizophrenia Inventory. Results: FEP patients had significantly higher prevalence of tobacco, cannabis, and cocaine use than controls. The FEP group with tobacco use only prior to onset (N = 56) had more sleep disturbances (42.9% vs 18.8%, P = 0.003) and lower prevalence of negative symptoms, specifically social withdrawal (33.9% vs 58%, P = 0.007) than FEP with no substance use (N = 70), as well as lower prevalence of ideas of reference (80.4% vs 92.4%, P = 0.015), perceptual abnormalities (46.4% vs 67.4%, P = 0.006), hallucinations (55.4% vs 71.5%, P = 0.029), and disorganised thinking (41.1% vs 61.1%, P = 0.010) than FEP group with previous tobacco and cannabis use (N = 144). FEP patients with cannabis and tobacco use had lower age at first prodromal or psychotic symptom (mean = 23.73 years [SD = 5.09]) versus those with tobacco use only (mean = 26.21 [SD = 4.80]) (P = 0.011). Conclusions: The use of tobacco alone was not related to earlier age of onset of a first psychotic experience, but the clinical profile of FEP patients is different depending on previous tobacco use with or without cannabis. © 2021 The Author

Assessment of Chemical Inhibitor Addition to Improve the Gas Production from Biowaste

The coexistence of sulphate-reducing bacteria and methanogenic archaea in the reactors during the anaerobic digestion from sulphate-containing waste could favor the accumulation of sulfide on the biogas, and therefore reduce its quality. In this study, the effect of sulphate-reducing bacteria inhibitor (MoO−2 4 ) addition in a two phase system from sulphate-containing municipal solid waste to improve the quality of the biogas has been investigated. The results showed that although SRB and sulphide production decreased, the use of inhibitor was not effective to improve the anaerobic digestion in a two phase system from sulphate-containing waste, since a significant decrease on biogas and organic matter removal were observed. Before MoO−2 4 addition the average values of volatile solid were around 12 g/kg, after 5 days of inhibitor use, those values did exceed to 28 g/kg. Molybdate caused acidification in the reactor and it was according to decrease in the pH values. In relation to microbial consortia, the effect of inhibitor was a decrease in Bacteria (44%; 60% in sulphate-reducing bacteria) and Archaea (38%) population