El análisis de redes en el estudio de la colaboración científica

El análisis de redes sociales es una herramienta que se usa cada vez más para determinar las relaciones entre los diferentes elementos bibliográficos que componen un trabajo científico. Desde tiempo atrás, las asociaciones entre coautores y entre sus instituciones y países de adscripción, se toman como una formar de medir las colaboraciones en ciencia. En nuestra presentación examinamos cómo el análisis de redes sociales se emplea para lograr una interpretación más acertada de estas relaciones tomando como ejemplo las colaboraciones bilaterales entre los países latinoamericanos.Social network analysis is a tool used increasingly by bibliometricians to determine the relationships between the different bibliographical elements present in a scientific paper. The associations between coauthors or between the institutions or countries they represent, have long been used as an manifestation of collaboration in science. In this presentation we look at how social network analysis is employed to assist in the interpretation of these relationships using examples taken from our work on bilateral collaborations between countries in Latin America

Colaboración científica de la Universidad Nacional Autónoma de México (UNAM) y su política institucional

The aim of the present study is to analyze the patterns of research collaboration of the National University of Mexico (UNAM) in mainstream literature in relation to its science policy. Sixty percent of the collaborative studies in science of the UNAM registered in the Web of Science from 1999 to 2002 involved only national institutions; the corresponding figure for the social sciences, arts and humanities was 87%. In both cases articles published in international collaboration received more citations on average than those involving only national institutions. Significant levels of coauthorship were found between the UNAM research centres and local institutions in those areas of the country where the UNAM has implemented a policy of decentralization of research activity. Little collaboration was found between institutes of the UNAM in the different research areas, as well as few publications in journals outside their own research areas. Both findings suggest a low level of participation in multi and interdisciplinary projects.El presente trabajo tiene por objetivo principal analizar los patrones de la colaboración en la producción científica de la Universidad Nacional Autónoma de México (UNAM) en revistas de corriente principal en términos de la política científica institucional. La colaboración en los trabajos en ciencias registrados en el Web of Science entre 1999 y 2002, demuestra que el 60% de publicaciones involucran solamente instituciones nacionales y en ciencias sociales, artes y humanidades, el 87%. En ambos casos los artículos en colaboración internacional recibieron más citas que los trabajos puramente nacionales. El análisis reveló niveles significativos de publicaciones en co-autoría entre las sedes foráneas de la UNAM y las instituciones locales, pero un bajo nivel de colaboración entre dependencias de la UNAM en diferentes disciplinas, así como escasas publicaciones en revistas fuera de su campo disciplinario. Estos resultados sugieren poca colaboración en proyectos multi e interdisciplinarios, por lo menos entre las diferentes instituciones de la propia UNAM

Colaboración científica entre países de la región latinoamericana

An analysis of the scientific collaboration among Latin American countries registered between 1975 and 2004 in the Science Citation Index database, Web of Science online version, revealed a steady increase in the number of publications, more marked in the last decade, as well as in the percentages that these represent in the total number of publications authored by regional scientists. Differences were found between countries in the magnitude of these increases, the smaller countries showing the highest levels of collaboration, especially with respect to those publications also involving scientists from institutions outside the Latin American region. The most common subject areas of intra-regional collaboration were Biology, Health, Physics, and Chemistry. Participating institutions from outside the region in intra-regional co-authorship were most commonly European (40% of cases) and North American (38%). The impact of papers as measured by a normalized h-index, involving scientists from outside the region was greater than that found for all intra-regional publications. The dominant bilateral regional collaboration was between Brazil and Argentina which in recent years has focused on topics in the Health Sciences and Astronomy. A detailed analysis of Physics papers showed that institutions from Brazil and Argentina are the most productive in intra-regional collaborations and Condensed Matter, the most studied subject.Un análisis de la colaboración científica entre los países de América Latina a través de documentos registrados de 1975-2004 en el Science Citation Index versión Web of Science, revela un aumento paulatino en el número total de trabajos principalmente en la última década, así como en los porcentajes de éstos del total de publicaciones registradas por la región. La magnitud de estos aumentos varía; los países más pequeños mostraron los niveles más altos de colaboración, en especial aquellas colaboraciones intra-regionales que involucran países fuera de la región. Los temas más abordados por el esfuerzo intra-regional son de las áreas de la Biología, la Salud, la Física, y la Química. En cuanto a la participación de los países fuera de la región en las colaboraciones intra-regionales, el 40% corresponden a países europeos y el 38% a América del Norte. El impacto de los trabajos intra-regionales con la presencia de por los menos un país de fuera de la región calculado a través de un índice h normalizado, fue superior al impacto de los trabajos en colaboración intra-regional en su conjunto. La colaboración Brasil-Argentina domina las colaboraciones bilaterales intra-regionales que en la última década se han enfocado a temas en las Ciencias de la Salud y Astronomía. Las instituciones brasileñas y argentinas son las más productivas en el área de Física y la categoría de mayor contribución en las colaboraciones intra-regionales, es la Materia Condensada

Radio continuum observations of Class I protostellar disks in Taurus: constraining the greybody tail at centimetre wavelengths

We present deep 1.8 cm (16 GHz) radio continuum imaging of seven young stellar objects in the Taurus molecular cloud. These objects have previously been extensively studied in the sub-mm to NIR range and their SEDs modelled to provide reliable physical and geometrical parametres.We use this new data to constrain the properties of the long-wavelength tail of the greybody spectrum, which is expected to be dominated by emission from large dust grains in the protostellar disk. We find spectra consistent with the opacity indices expected for such a population, with an average opacity index of beta = 0.26+/-0.22 indicating grain growth within the disks. We use spectra fitted jointly to radio and sub-mm data to separate the contributions from thermal dust and radio emission at 1.8 cm and derive disk masses directly from the cm-wave dust contribution. We find that disk masses derived from these flux densities under assumptions consistent with the literature are systematically higher than those calculated from sub-mm data, and meet the criteria for giant planet formation in a number of cases.Comment: submitted MNRA

Physical activity, additional breast cancer events, and mortality among early-stage breast cancer survivors: findings from the WHEL Study

ObjectiveResearch suggests that physical activity is associated with improved breast cancer survival, yet no studies have examined the association between post-diagnosis changes in physical activity and breast cancer outcomes. The aim of this study was to determine whether baseline activity and 1-year change in activity are associated with breast cancer events or mortality.MethodsA total of 2,361 post-treatment breast cancer survivors (Stage I-III) enrolled in a randomized controlled trial of dietary change completed physical activity measures at baseline and one year. Physical activity variables (total, moderate-vigorous, and adherence to guidelines) were calculated for each time point. Median follow-up was 7.1 years. Outcomes were invasive breast cancer events and all-cause mortality.ResultsThose who were most active at baseline had a 53% lower mortality risk compared to the least active women (HR = 0.47; 95% CI: 0.26, 0.84; p = .01). Adherence to activity guidelines was associated with a 35% lower mortality risk (HR = 0.65, 95% CI: 0.47, 0.91; p < .01). Neither baseline nor 1-year change in activity was associated with additional breast cancer events.ConclusionsHigher baseline (post-treatment) physical activity was associated with improved survival. However, change in activity over the following year was not associated with outcomes. These data suggest that long-term physical activity levels are important for breast cancer prognosis

AMI radio continuum observations of young stellar objects with known outflows

We present 16 GHz (1.9 cm) deep radio continuum observations made with the Arcminute Microkelvin Imager (AMI) of a sample of low-mass young stars driving jets. We combine these new data with archival information from an extensive literature search to examine spectral energy distributions (SEDs) for each source and calculate both the radio and sub-mm spectral indices in two different scenarios: (1) fixing the dust temperature (Td) according to evolutionary class; and (2) allowing Td to vary. We use the results of this analysis to place constraints on the physical mechanisms responsible for the radio emission. From AMI data alone, as well as from model fitting to the full SED in both scenarios, we find that 80 per cent of the objects in this sample have spectral indices consistent with freefree emission. We find an average spectral index in both Td scenarios, consistent with freefree emission. We examine correlations of the radio luminosity with bolometric luminosity, envelope mass and outflow force, and find that these data are consistent with the strong correlation with envelope mass seen in lower luminosity samples. We examine the errors associated with determining the radio luminosity and find that the dominant source of error is the uncertainty on the opacity index, beta. We examine the SEDs for variability in these young objects, and find evidence for possible radio flare events in the histories of L1551 IRS 5 and Serpens SMM 1

Beliefs About Medication and Uptake of Preventive Therapy in Women at Increased Risk of Breast Cancer: Results From a Multicenter Prospective Study

Introduction Uptake of preventive therapies for breast cancer is low. We examined whether women at increased risk of breast cancer can be categorized into groups with similar medication beliefs, and whether belief group membership was prospectively associated with uptake of preventive therapy. Patients and Methods Women (n = 732) attending an appointment to discuss breast cancer risk were approached; 408 (55.7%) completed the Beliefs About Medicines and the Perceived Sensitivity to Medicines questionnaires. Uptake of tamoxifen at 3 months was reported in 258 (63.2%). The optimal number of belief groups were identified using latent profile analysis. Results Uptake of tamoxifen was 14.7% (38/258). One in 5 women (19.4%; 78/402) reported a strong need for tamoxifen. The model fit statistics supported a 2-group model. Both groups held weak beliefs about their need for tamoxifen for current and future health. Group 2 (38%; 154/406 of the sample) reported stronger concerns about tamoxifen and medicines in general, and stronger perceived sensitivity to the negative effects of medicines compared with group 1 (62%; 252/406). Women with low necessity and lower concerns (group 1) were more likely to initiate tamoxifen (18.3%; 33/180) than those with low necessity and higher concerns (group 2) (6.4%; 5/78). After adjusting for demographic and clinical factors, the odds ratio was 3.37 (95% confidence interval, 1.08-10.51; P = .036). Conclusion Uptake of breast cancer preventive therapy was low. A subgroup of women reported low need for preventive therapy and strong medication concerns. These women were less likely to initiate tamoxifen. Medication beliefs are targets for supporting informed decision-making

Personality traits and mental disorders

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