Analyzing library collections with starfield visualizations

This paper presents a qualitative and formative study of the uses of a starfield-based visualization interface for analysis of library collections. The evaluation process has produced feedback that suggests ways to significantly improve starfield interfaces and the interaction process to improve their learnability and usability. The study also gave us clear indication of additional potential uses of starfield visualizations that can be exploited by further functionality and interface development. We report on resulting implications for the design and use of starfield visualizations that will impact their graphical interface features, their use for managing data quality and their potential for various forms of visual data mining. Although the current implementation and analysis focuses on the collection of a physical library, the most important contributions of our work will be in digital libraries, in which volume, complexity and dynamism of collections are increasing dramatically and tools are needed for visualization and analysis

Experiences with starfield visualizations for analysis of library collections

This paper presents a qualitative and formative study of the uses of a starfield-based visualization interface for analysis of library collections. The evaluation process has produced feedback that suggests ways to significantly improve starfield interfaces and the interaction process to improve their learnability and usability. The study also gave us clear indication of additional potential uses of starfield visualizations that can be exploited by further functionality and interface development. We report on resulting implications for the design and use of starfield visualizations that will impact their graphical interface features, their use for managing data quality and their potential for various forms of visual data mining. Although the current implementation and analysis focuses on the collection of a physical library, the most important contributions of our work will be in digital libraries, in which volume, complexity and dynamism of collections are increasing dramatically and tools are needed for visualization and analysis

Evidence for intermediate-age stellar populations in early-type galaxies from K-band spectroscopy

The study of stellar populations in early-type galaxies in different environments is a powerful tool for constraining their star formation histories. This study has been traditionally restricted to the optical range, where dwarfs around the turn-off and stars at the base of the RGB dominate the integrated light at all ages. The near-infrared spectral range is especially interesting since in the presence of an intermediate-age population, AGB stars are the main contributors. In this letter, we measure the near-infrared indices NaI and D$_{\rm CO}$ for a sample of 12 early-type galaxies in low density environments and compare them with the Fornax galaxy sample presented by Silva et al. (2008). The analysis of these indices in combination with Lick/IDS indices in the optical range reveals i) the NaI index is a metallicity indicator as good as C4668 in the optical range, and ii) D$_{\rm CO}$ is a tracer of intermediate-age stellar populations. We find that low-mass galaxies in low density environments show higher NaI and D$_{\rm CO}$ than those located in Fornax cluster, which points towards a late stage of star formation for the galaxies in less dense environments, in agreement with results from other studies using independent methods.Comment: 7 pages, 3 figures, accepted for publication in ApJ

Generation of micro-sized PDMS particles by a flow focusing technique for biomicrofluidics applications

Polydimethylsiloxane (PDMS), due to its remarkable properties, is one of the most widely used polymers in many industrial and medical applications. In this work, a technique based on a flow focusing technique is used to produce PDMS spherical particles with sizes of a few microns. PDMS precursor is injected through a hypodermic needle to form a film/reservoir over the needle's outer surface. This film flows towards the needle tip until a liquid ligament is steadily ejected thanks to the action of a coflowing viscous liquid stream. The outcome is a capillary jet which breaks up into PDMS precursor droplets due to the growth of capillary waves producing a micrometer emulsion. The PDMS liquid droplets in the solution are thermally cured into solid microparticles. The size distribution of the particles is analyzed before and after curing, showing an acceptable degree of monodispersity. The PDMS liquid droplets suffer shrinkage while curing. These microparticles can be used in very varied technological fields, such as biomedicine, biotechnology, pharmacy, and industrial engineering.The authors acknowledge the financial support provided by Fundação para a Ciência e a Tecnologia (FCT), COMPETE and FEDER through the Projects PTDC/SAU-ENB/116929/2010, EXPL/EMS-SIS/2215/2013, PTDC/QEQ-FTT/4287/2014 and fellowship SFRH/BD/89077/2012. Partial support from the spanish Ministry of Science and Education (Grant No. DPI2013-46485), Junta de Extremadura (Grant No. GR10047), and “la Caixa” Foundation (predoctoral grant) is gratefully acknowledged too. Finally, we thank Jos e M. Montanero for his helpful suggestions and discussion on the results.info:eu-repo/semantics/publishedVersio

Resultados organizacionales y formación

Es común aceptar el valor de la formación de los empleados de cara a la mejora de la competitividad de las empresas, especialmente en una economía cada vez más abierta y avanzada tecnológicamente como es la actual. Son muchos los trabajos que han analizado empíricamente la relación entre formación de empleados y resultados organizacionales sin embargo, la evidencia empírica respecto del efecto positivo de la formación en el rendimiento de las empresas no es concluyente. Con el objetivo de dar una explicación a la ambigüedad observada en esta relación, planteamos el estudio de la formación y su efecto en los resultados de la empresa desde la perspectiva institucional. Apoyándonos en este marco teórico explicativo, se constata que hay factores de contexto que actúan como presiones para las empresas de cara a la decisión de realizar acciones formativas, lo que nos permitirá exponer una explicación a la controvertida y débil relación observada entre formación y resultados de la empresa.Currently, training is widely accepted as an important tool to help firms to improve their human resources and so increase its competitiveness. Despite the relationship between training and organizational results having been largely assessed, most empirical studies show paradoxical effects. The main purpose of this paper is to explore possible theories which could explain said results, and with this in mind, a different approach, the institutional theory, has been used to study the relationship between training and organizational results

Dripping Faucet Dynamics Clarified by an Improved Mass-Spring Model

An improved mass-spring model for a dripping faucet is presented. The model is constructed based on the numerical results which we recently obtained from fluid dynamical calculations. Both the fluid dynamical calculations and the present mass-spring model exhibit a variety of complex behavior including transition to chaos in good agreement with experiments. Further, the mass-spring model reveals fundamental dynamics inherent in the dripping faucet system.Comment: 17 pages, 17 figure

PtRu nanoparticles supported on noble carbons for ethanol electrooxidation

In this work, three cytosine derived nitrogen doped carbonaceous materials (noble carbons, NCs) with different atomic C/N ratios and porous networks have been synthesized and used as supports for PtRu electrocatalysts in the ethanol oxidation reaction (EOR) for clean hydrogen production. Both, the metal phase and the carbon support play critical roles in the electrocatalysts final performance. Lower NPs size distribution was obtained over supports with low atomic C/N ratios (i.e., 4 and 6) and defined porosity (i.e., 1701 m2 g−1 for PtRu/CNZ and 1834 m2 g−1 for PtRu/CLZ, respectively). In contrast, a lower C/N ratio and poor porous network (i.e., 65 m2 g−1, PtRu/CLK) led to the largest particle size and fostered an increase of the alloying degree between Pt and Ru NPs (i.e., 3 for C/N ~ 6 and 28 for C/N ~ 3). Electrochemical active surface area was found to increase with decreasing NPs size and the alloy extent, due to a higher availability of Pt active sites. Accelerated degradation tests showed that PtRu/NCs outperform similar to PtRu NPs on commercial carbon pointing at the stabilizing effect of NCs. PtRu/CNZ exhibited the best electrochemical performance (i.e., 69.1 mA mgPt−1), outperforming PtRu/CLZ and PtRu/CLK by 3- and 9-fold, respectively, due to a suitable compromise between particle sizes, degree of alloy, textural properties and elemental composition. Best anodes were scaled-up to a proton exchange membrane cell and PtRu/CNZ was proved to provide the best electrocatalytic activity (262 mA cm−2 and low energy requirements), matching the values obtained by the state of the art of EOR electrocatalysts

Influence of climate change and human activities on the organic and inorganic composition of peat during the ‘Little Ice Age’ (El Payo mire, W Spain)

Acknowledgements We are grateful to Ana Moreno, Mariano Barriendos and Gerardo Benito who kindly provided us data included in Figure 5a. We also want to thank the two anonymous reviewers for their constructive comments. Funding This work was funded by the projects HAR2013-43701-P (Spanish Economy and Competitiveness Ministry) and CGL2010-20672 (Spanish Ministry of Science and Innovation). This research was also partially developed with Xunta de Galicia funding (grants R2014/001 and GPC2014/009). N Silva-Sánchez is currently supported by an FPU pre-doctoral grant (AP2010-3264) funded by the Spanish Government.Peer reviewedPostprin

Identificación molecular de bacterias asociadas a la filosfera de plantas de arroz (Oryza sativa L), mediante técnicas de cultivo microbiano

Las plantas albergan una gran diversidad de microorganismos, como hongos, bacterias, etc., que interactúan con ella y tienen una funcionalidad que va desde la patogenicidad, hasta la protección de la misma. Se ha estudiado parte de esta diversidad microbiana a nivel de la filosfera en plantas de Oryza sativa (L) “arroz”; mediante microbiología molecular se ha caracterizado siete especies bacterianas entre las cuales sobresalieron especies Uncultured, es decir no cultivadas, además de Bacillus amyloliquefafaciens, Enterobacter asburiae, Klebsiella pneumoniae y Pantoea sp., todas ellas con un alto porcentaje de identidad; asimismo, mediante metagenómica dirigida se caracterizó trecientos ochenta y cinco especies bacterianas, de las que sobresalen pertenecen a los generos Bacillus, Rhizobium, Pseudomonas, Mycobacterium, Nocardioides, Clostridium, Methylobacterium y Pantoea. Las faamilias que más destacan son Enterobacteriaceae, Rhizobiaceae, Microbacteriaceae, Bacillaceae, Flavobacteriaceae, Pseudomonadaceae, Nocardiaceae, Mycobacteriaceae, Clostridiaceae y Methylobacteriaceae; no se encontró Burkholderia glumae