153 research outputs found
Fresh Activity in Old Systems: Radio AGN in Fossil Groups of Galaxies
We present the first systematic 1.4 GHz Very Large Array radio continuum
survey of fossil galaxy group candidates. These are virialized systems believed
to have assembled over a gigayear in the past through the merging of galaxy
group members into a single, isolated, massive elliptical galaxy and featuring
an extended hot X-ray halo. We use new photometric and spectroscopic data from
SDSS Data Release 7 to determine that three of the candidates are clearly not
fossil groups. Of the remaining 30 candidates, 67% contain a radio-loud
(L_1.4GHz > 10^23 W Hz^-1) active galactic nucleus (AGN) at the center of their
dominant elliptical galaxy. We find a weak correlation between the radio
luminosity of the AGN and the X-ray luminosity of the halo suggesting that the
AGN contributes to energy deposition into the intragroup medium. We only find a
correlation between the radio and optical luminosity of the central elliptical
galaxy when we include X-ray selected, elliptically dominated non-fossil
groups, indicating a weak relationship between AGN strength and the mass
assembly history of the groups. The dominant elliptical galaxy of fossil groups
is on average roughly an order of magnitude more luminous than normal group
elliptical galaxies in optical, X-ray, and radio luminosities and our findings
are consistent with previous results that the radio-loud fraction in elliptical
galaxies is linked to the stellar mass of a population. The current level of
activity in fossil groups suggests that AGN fueling continues long after the
last major merger. We discuss several possibilities for fueling the AGN at the
present epoch.Comment: Accepted for publication in A
Left Ventricular Flow Analysis: Novel Imaging Biomarkers and Predictors of Exercise Capacity in Heart Failure.
Background:
Cardiac remodeling, after a myocardial insult, often causes progression to heart failure. The relationship between alterations in left ventricular blood flow, including kinetic energy (KE), and remodeling is uncertain. We hypothesized that increasing derangements in left ventricular blood flow would relate to (1) conventional cardiac remodeling markers, (2) increased levels of biochemical remodeling markers, (3) altered cardiac energetics, and (4) worsening patient symptoms and functional capacity.
Methods:
Thirty-four dilated cardiomyopathy patients, 30 ischemic cardiomyopathy patients, and 36 controls underwent magnetic resonance including 4-dimensional flow, BNP (brain-type natriuretic peptide) measurement, functional capacity assessment (6-minute walk test), and symptom quantification. A subgroup of dilated cardiomyopathy and control subjects underwent cardiac energetic assessment. Left ventricular flow was separated into 4 components: direct flow, retained inflow, delayed ejection flow, and residual volume. Average KE throughout the cardiac cycle was calculated.
Results:
Patients had reduced direct flow proportion and direct-flow average KE compared with controls (P<0.0001). The residual volume proportion and residual volume average KE were increased in patients (P<0.0001). Importantly, in a multiple linear regression model to predict the patient’s 6-minute walk test, the independent predictors were age (β=−0.3015; P=0.019) and direct-flow average KE (β=0.280, P=0.035; R2 model, 0.466, P=0.002). In contrast, neither ejection fraction nor left ventricular volumes were independently predictive.
Conclusions:
This study demonstrates an independent predictive relationship between the direct-flow average KE and a prognostic measure of functional capacity. Intracardiac 4-dimensional flow parameters are novel biomarkers in heart failure and may provide additive value in monitoring new therapies and predicting prognosis.This study was supported by the British Heart Foundation [grant number FS/12/14/29354 to VMS]; Medical Research Council (ATH); Oxford British Heart Foundation Centre of Research Excellence (ATH and SN); Sir Henry Dale Fellowship from the Wellcome Trust and the Royal Society (098436/Z/12/B to CTR); National Institute for Health Research Oxford Biomedical Research Centre Programme (SN and SGM); Swedish Research Council (PD and TE); the Swedish Heart and Lung Foundation [grant number 20140398 to CJC]. The research leading to these results has received funding from the European Union's Seventh Framework Programme (FP7/2007-2013) under grant agreement 310612 to TE
Una mirada longitudinal : ¿Es el ?Docentia? útil para la evaluación del profesorado universitario?
El Docentia es el modelo propuesto por ANECA, y asumido por las universidades españolas para la evaluación de la calidad docente. Uno de los problemas del modelo que se viene detectando es su escasa capacidad para diferenciar al profesorado entre las distintas categorÃas posibles, con un sesgo muy acentuado hacia la calificación de ?Excelente?. Esto afecta al prestigio del modelo: primero, si la gran mayorÃa del profesorado es ?Excelente?, no se verá reflejado el profesorado que realmente destaca sobre el conjunto y, segundo, afecta a su capacidad para orientar al profesorado hacia la mejora de su docencia. En el presente estudio examinamos la capacidad discriminativa del modelo en base a la experiencia de su implementación en la Universidad de La Laguna (Docentia-ULL). Hemos simulado el resultado de la evaluación cambiando el modelo en dos sentidos. Por un lado, los pesos de las dimensiones y sub-dimensiones, asà como de los topes de cada criterio, para primar la valoración del compromiso del profesorado con la formación y la innovación educativa, frente al mero cumplimiento de las obligaciones docentes. Por otro lado, los resultados de satisfacción del alumnado y de los responsables académicos pasan a actuar como requisito independiente de los méritos del docente en la evaluación. Además, se ha elevado el mÃnimo necesario de estas dimensiones para obtener una valoración ?Favorable?, ?Muy Favorable? o ?Excelente?. Los resultados mostraron que la disminución del peso en la evaluación de las obligaciones docentes frente a la formación e innovación produjo una distribución de la calificación del profesorado más centrada hacia las categorÃas intermedias. Además se compara con resultados reales obtenidos después de la implantación del modelo alternativo elegido a raÃz de las simulaciones. Se discuten las implicaciones de este tipo de mejoras en la evaluación de la calidad docente y del desempeño del profesorado en la universidad española
Interrogating marine virus-host interactions and elemental transfer with BONCAT and nanoSIMS-based methods
While the collective impact of marine viruses has become more apparent over the last decade, a deeper understanding of virus-host dynamics and the role of viruses in nutrient cycling would benefit from direct observations at the single-virus level. We describe two new complementary approaches - stable isotope probing coupled with nanoscale secondary ion mass spectrometry (nanoSIMS) and fluorescence-based biorthogonal non-canonical amino acid tagging (BONCAT) - for studying the activity and biogeochemical influence of marine viruses. These tools were developed and tested using several ecologically relevant model systems (Emiliania huxleyi/EhV207, Synechococcus sp. WH8101/Syn1, and Escherichia coli/T7). By resolving carbon and nitrogen enrichment in viral particles, we demonstrate the power of nanoSIMS tracer experiments in obtaining quantitative estimates for the total number of viruses produced directly from a particular production pathway (by isotopically labeling host substrates). Additionally, we show through laboratory experiments and a pilot field study that BONCAT can be used to directly quantify viral production (via epifluorescence microscopy) with minor sample manipulation and no dependency on conversion factors. This technique can also be used to detect newly synthesized viral proteins. Together these tools will help fill critical gaps in our understanding of the biogeochemical impact of viruses in the ocean
The Relationship between Zinc Intake and Serum/Plasma Zinc Concentration in Children: A Systematic Review and Dose-Response Meta-Analysis
Recommendations for zinc intake during childhood vary widely across Europe. The EURRECA project attempts to consolidate the basis for the definition of micronutrient requirements, taking into account relationships among intake, status and health outcomes, in order to harmonise these recommendations. Data on zinc intake and biomarkers of zinc status reported in randomised controlled trials (RCTs) can provide estimates of dose-response relationships which may be used for underpinning zinc reference values. This systematic review included all RCTs of apparently healthy children aged 1–17 years published by February 2010 which provided data on zinc intake and biomarkers of zinc status. An intake-status regression coefficient was calculated for each individual study and calculated the overall pooled and SE using random effects meta-analysis on a double log scale. The pooled dose-response relationship between zinc intake and zinc status indicated that a doubling of the zinc intake increased the serum/plasma zinc status by 9%. This evidence can be utilised, together with currently used balance studies and repletion/depletion studies, when setting zinc recommendations as a basis for nutrition policies
Double beta decay in deformed nuclei
A brief review of theoretical results for the double-beta decay and the double-electron capture in heavy deformed nuclei is presented. The ββ half life of 160Gd is evaluated using an extended version of the pseudo SU(3) model. While the 2ν mode is forbidden when the most probable occupations are considered, states with different occupation numbers can be mixed through the pairing interaction. The amount of this mixing is calculated using perturbation theory. The possibility of observingthe ββ decay in 160Gd is discussed for both the 2ν and 0ν modes.Facultad de Ciencias Exacta
Empresas biotecnológicas y divulgación de la ciencia. El caso de las pymes biotecnológicas asentadas en parques biotecnológicos de AndalucÃa
Biotech companies cannot ignore the social interest they arouse in this age of knowledge; this interest raises expectations and fears, and meeting the demand created is not only the responsibility of government agencies. To analyse the situation this paper focuses on 32 SMEs based in four Technology Parks in Andalusia. We use a variety of methods to examine their presence in the local newspapers in their respective provinces; what areas their websites cover and find the opinion of their managers on various aspects of their communications. The results revealed an absence of dialogue between society and these firms. It might be necessary for SMEs to integrate disclosure mechanisms within their communication strategies and their CSR; however, their executives did not repudiate the public as an audience, but have not found the tools to bridge this gap.<br><br>Las empresas biotecnológicas no pueden desestimar que el interés social por esa franja de conocimiento es muy alto, genera expectativas y recelos, y cubrir esa demanda no solo compete a los organismos públicos. Para comprobar cuál es su realidad enfocamos en este trabajo a las 32 pymes asentadas en cuatro parques tecnológicos de AndalucÃa. Utilizamos metodologÃas variadas para comprobar cómo es su presencia en los periódicos locales de referencia en sus respectivas provincias; qué ámbitos cubren sus sitios web y cuál es la opinión de sus gestores sobre diferentes aspectos de su comunicación. Los resultados nos llevan a concluir que no existe diálogo entre la sociedad y estas empresas, paso ineludible para que las pymes integren mecanismos de divulgación como elementos de su comunicación y de su RSC; sin embargo, sus ejecutivos no repudian a la ciudadanÃa como público, si bien no han localizado las herramientas que solucionen tal desconexión
- …