J. Mateo Corbalan a Juan Facundo Quiroga

Lo felicita por sus triunfo

Search for associations containing young stars (SACY) VIII. An updated census of spectroscopic binary systems showing hints of non-universal multiplicity among these associations

We seek to update the spectroscopy binary fraction of the SACY (Search for Associations Containing Young stars) sample taking in consideration all possible biases in our identification of binary candidates, such as activity and rotation. Using high-resolution spectroscopic observations we have produced $\sim$1300 cross-correlation functions (CCFs) to disentangle the previously mentioned sources of contamination. The radial velocity values obtained were cross-matched with the literature and were used to revise and update the spectroscopic binary (SB) fraction in each of the SACY association. In order to better describe the CCF profile, we calculated a set of high-order cross-correlation features to determine the origin of the variations in radial velocities. We identified 68 SB candidates from our sample of 410 objects. Our results hint that the youngest associations have a higher SB fraction. Specifically, we found sensitivity-corrected SB fractions of $22 \substack{+15 \\ -11} \%$ for $\epsilon$~Cha , $31 \substack{+16 \\ -14} \%$ for TW Hya and $32 \substack{+9 \\ -8} \%$ for $\beta$~Pictoris, in contrast with the five oldest ($\sim 35-125$ Myr) associations we have sampled which are $\sim 10\%$ or lower. This result seems independent of the methodology used to asses membership to the associations. The new CCF analysis, radial velocity estimates and SB candidates are particularly relevant for membership revision of targets in young stellar associations. These targets would be ideal candidates for follow-up campaigns using high-resolution techniques in order to confirm binarity, resolve the orbits, and ideally calculate dynamical masses. Additionally, if the results on SB fraction in the youngest associations are confirmed, it could hint of non-universal multiplicity among SACY associations.Comment: The paper has been accepted in A&

Experiencia práctica de tipo interdisciplinar para manejo de dispositivos de potencia, instrumentación electrónica, sistemas microprocesadores e identificación paramétrica de sistemas dinámicos

El cambio en el entorno y en las dimensiones internas de las instituciones de educación superior provoca la necesidad de revisar el modelo educativo. Actualmente asistimos a la transformación de la Universidad provocada en gran medida por la revolución del conocimiento y las nuevas tecnologías de la información, que generan cambios tanto en el entorno como en los recursos internos disponibles en las universidades. El reto imperativo durante la próxima década es el cambio que debe producirse tanto en los productos que la Universidad ofrece (titulaciones, programas de postgrado, investigación, difusión, etc.) como en la forma en la que ofrece estos produ ctos, resultando necesario revisar los procesos docentes y haciéndose imperativa la introducción de la formación multidisciplinar. En este trabajo se presenta una experiencia práctica de tipo multidisciplinar, que aúna conceptos relacionados c on el manejo de herramientas de simulación basadas en Matlab y Simulink para el estudio de sistemas electrónicos digitales, analógicos y de potencia, así como el procesamiento de la señal y la identificación paramétrica de sistemas dinámicos. Se describirá el sistema con el que se trabajará (una máquina de inducción de 5 fases gobernada por un convertidor de potencia de 2 nivel es), para posteriormente definir su modelado empleando Matlab y Simulink y plantear los objetivos del trabajo de si mulación a realizar por los alumnos

Iluminación y confort en las aulas y laboratorios de carreras técnicas de grado universitario

El presente trabajo, analiza el grado de iluminación y confort, de laboratorios y aulas de carreras técnicas universitarias, de acuerdo al marco reglamentario nacional del factor de iluminación en espacios de trabajo, considerando a la actividad educativa incluida. Utilizando el protocolo aprobado por la Superintendencia de riesgos de trabajo, para la medición del factor de iluminación, tomando además las variaciones de temperatura y el factor del viento, como componentes del factor confort, necesario para una adecuada transmisión y adquisición de los contenidos didácticos

Heritage language anxiety and majority language anxiety among Turkish immigrants in the Netherlands

Aims and objectives: This study examines the language anxiety that occurs in immigrants’ daily lives when speaking the heritage language and the majority language, both in their host country and during visits to their home country. It compares the levels of heritage language anxiety and majority language anxiety across three generations of the Turkish immigrant community in the Netherlands and explores the link between immigrants’ language anxiety, and sociobiographical (i.e. generation, gender, education) and language background variables (i.e. age of acquisition, self-perceived proficiency, frequency of language use). Design: A Likert scale-based questionnaire was administered to 116 participants across three generations who reported their language anxiety levels when speaking the heritage language and the majority language in three social contexts (i.e. family, friendship and speaking with native speakers). Findings: Statistical analyses revealed that heritage language anxiety and majority language anxiety were prevalent in immigrants’ daily life, and that levels of both forms of anxiety differed across generations, and in different daily life situations. First- and second-generation immigrants typically experienced majority language anxiety, while second- and predominantly third-generation immigrants suffered from heritage language anxiety. Relationships emerged between language background variables and both forms of anxiety, but only in certain situations. These findings suggest that language background variables on their own may be insufficient to explain immigrant language anxiety in certain social contexts (i.e. within family). Rather than merely language background factors, a variety of other issues within social, cultural and national currents must be considered when examining language anxiety in the immigrant context. Implications: Taking an interdisciplinary approach that combines language contact and foreign language anxiety/second language anxiety research, this study suggests that the concept of foreign language anxiety/second language anxiety should be expanded beyond the confines of the classroom in order to include daily interactions immigrant or minority communities. Originality: This study contributes to the limited body of evidence on the topic of language anxiety in immigrant contexts and presents a new construct ‘majority language anxiety’

Atacamite Cu2Cl(OH)3: A model compound for the S = 1/2 sawtooth chain?

We present a combined experimental and theoretical study of the mineral atacamite Cu2Cl(OH)3.Based on ab initio band structure calculations, we derive a magnetic coupling scheme of essentially a S = 1/2 sawtooth chain. Experimentally, we fully characterize the long-range antiferromagnetically ordered state and field-induced behavior, here for H k b axis. Magnetic order is suppressed by magnetic fields of ∼ 20 T, while beginning at 31.5 T we observe a wide magnetization plateau at half of the saturation magnetization, Msat/2. Numerical calculations for the magnetization M(H) of the quantum sawtooth chain reveal a plateau at Msat/2, raising the issue of the understandingof its microscopic nature.Fil: Heinze, L.. Technische Universitat Carolo Wilhelmina Zu Braunschweig.; AlemaniaFil: Jeschke, H.. Okayama University; Japón. Goethe Universitat Frankfurt; AlemaniaFil: Metavitsiadis, A.. Technische Universitat Carolo Wilhelmina Zu Braunschweig.; AlemaniaFil: Reehuis, M.. Helmholtz-Zentrum Berlin für Materialien und Energie GmbH; AlemaniaFil: Feyerherm, R.. Helmholtz-Zentrum Berlin für Materialien und Energie GmbH; AlemaniaFil: Hoffmann, J. U.. Helmholtz-Zentrum Berlin für Materialien und Energie GmbH; AlemaniaFil: Wolter, A. U. B.. Leibniz Institute For Solid State And Materials Researc; AlemaniaFil: Ding, X.. Los Alamos National High Magnetic Field Laboratory; Estados UnidosFil: Zapf, V.. Los Alamos National High Magnetic Field Laboratory; Estados UnidosFil: Corvalán Moya, Carolina del Huerto. Comisión Nacional de Energía Atómica; Argentina. Los Alamos National High Magnetic Field Laboratory; Estados Unidos. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Weickert, F.. Los Alamos National High Magnetic Field Laboratory; Estados UnidosFil: Jaime, M.. Los Alamos National High Magnetic Field Laboratory; Estados UnidosFil: Rule, K. C.. Australian Nuclear Science And Technology Organisation; AustraliaFil: Menzel, D.. Technische Universitat Carolo Wilhelmina Zu Braunschweig.; AlemaniaFil: Valenti, R.. Goethe Universitat Frankfurt; AlemaniaFil: Brenig, W.. Technische Universitat Carolo Wilhelmina Zu Braunschweig.; AlemaniaFil: Süllow, S.. Technische Universitat Carolo Wilhelmina Zu Braunschweig.; Alemani

When reduced input leads to delayed acquisition: a study on the acquisition of clitic placement by Portuguese heritage speakers

This article examines the competence of heritage speakers of Portuguese living in Germany with respect to clitic placement in Portuguese by comparing their performance with that of monolingual speakers of the same age (7–15 years of age) in a test designed to elicit oral production data. The results of the study indicate that the heritage speakers go through stages in the acquisition of clitic placement that are similar to those of monolingual acquirers even though they take longer to attain the target grammar

Nutrition status of children in Latin America.

The prevalence of overweight and obesity is rapidly increasing among Latin American children, posing challenges for current healthcare systems and increasing the risk for a wide range of diseases. To understand the factors contributing to childhood obesity in Latin America, this paper reviews the current nutrition status and physical activity situation, the disparities between and within countries and the potential challenges for ensuring adequate nutrition and physical activity. Across the region, children face a dual burden of undernutrition and excess weight. While efforts to address undernutrition have made marked improvements, childhood obesity is on the rise as a result of diets that favour energy-dense, nutrient-poor foods and the adoption of a sedentary lifestyle. Over the last decade, changes in socioeconomic conditions, urbanization, retail foods and public transportation have all contributed to childhood obesity in the region. Additional research and research capacity are needed to address this growing epidemic, particularly with respect to designing, implementing and evaluating the impact of evidence-based obesity prevention interventions

High-risk HPV infection after five years in a population-based cohort of Chilean women

<p>Abstract</p> <p>Background</p> <p>The need to review cervical cancer prevention strategies has been triggered by the availability of new prevention tools linked to human papillomavirus (HPV): vaccines and screening tests. To consider these innovations, information on HPV type distribution and natural history is necessary. This is a five-year follow-up study of gynecological high-risk (HR) HPV infection among a Chilean population-based cohort of women.</p> <p>Findings</p> <p>A population-based random sample of 969 women from Santiago, Chile aged 17 years or older was enrolled in 2001 and revisited in 2006. At both visits they answered a survey on demographics and sexual history and provided a cervical sample for HPV DNA detection (GP5+/6+ primer-mediated PCR and Reverse line blot genotyping). Follow-up was completed by 576 (59.4%) women; 45 (4.6%) refused participation; most losses to follow-up were women who were unreachable, no longer eligible or had missing samples. HR-HPV prevalence increased by 43%. Incidence was highest in women < 20 years of age (19.4%) and lowest in women > 70 (0%); it was three times higher among women HR-HPV positive versus HPV negative at baseline (25.5% and 8.3%; OR 3.8, 95% CI 1.8-8.0). Type-specific persistence was 35.3%; it increased with age, from 0% in women < 30 years of age to 100% in women > 70. An enrollment Pap result ASCUS or worse was the only risk factor for being HR-HPV positive at both visits.</p> <p>Conclusions</p> <p>HR-HPV prevalence increased in the study population. All HR-HPV infections in women < 30 years old cleared, supporting the current recommendation of HR-HPV screening for women > 30 years.</p

Association between anthropometric indices and cardiometabolic risk factors in pre-school children

ABSTRACT: The world health organization (WHO) and the Identification and prevention of dietary- and lifestyle-induced health effects in children and infants- study (IDEFICS), released anthropometric reference values obtained from normal body weight children. This study examined the relationship between WHO [body mass index (BMI) and triceps- and subscapular-skinfolds], and IDEFICS (waist circumference, waist to height ratio and fat mass index) anthropometric indices with cardiometabolic risk factors in pre-school children ranging from normal body weight to obesity. Methods: A cross-sectional study with 232 children (aged 4.1 ± 0.05 years) was performed. Anthropometric measurements were collected and BMI, waist circumference, waist to height ratio, triceps- and subscapular-skinfolds sum and fat mass index were calculated. Fasting glucose, fasting insulin, homeostasis model analysis insulin resistance (HOMA-IR), blood lipids and apolipoprotein (Apo) B-100 (Apo B) and Apo A-I were determined. Pearson’s correlation coefficient, multiple regression analysis and the receiver-operating characteristic (ROC) curve analysis were run. Results: 51 % (n = 73) of the boys and 52 % (n = 47) of the girls were of normal body weight, 49 % (n = 69) of the boys and 48 % (n = 43) of the girls were overweight or obese. Anthropometric indices correlated (p 0.68 to AUC < 0.76). Conclusions: WHO and IDEFICS anthropometric indices correlated similarly with fasting insulin and HOMA-IR. The diagnostic accuracy of the anthropometric indices as a proxy to identify children with insulin resistance was similar. These data do not support the use of waist circumference, waist to height ratio, triceps- and subscapular- skinfolds sum or fat mass index, instead of the BMI as a proxy to identify pre-school children with insulin resistance, the most frequent alteration found in children ranging from normal body weight to obesity