389 research outputs found

    Finding Your Literature Match -- A Recommender System

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    The universe of potentially interesting, searchable literature is expanding continuously. Besides the normal expansion, there is an additional influx of literature because of interdisciplinary boundaries becoming more and more diffuse. Hence, the need for accurate, efficient and intelligent search tools is bigger than ever. Even with a sophisticated search engine, looking for information can still result in overwhelming results. An overload of information has the intrinsic danger of scaring visitors away, and any organization, for-profit or not-for-profit, in the business of providing scholarly information wants to capture and keep the attention of its target audience. Publishers and search engine engineers alike will benefit from a service that is able to provide visitors with recommendations that closely meet their interests. Providing visitors with special deals, new options and highlights may be interesting to a certain degree, but what makes more sense (especially from a commercial point of view) than to let visitors do most of the work by the mere action of making choices? Hiring psychics is not an option, so a technological solution is needed to recommend items that a visitor is likely to be looking for. In this presentation we will introduce such a solution and argue that it is practically feasible to incorporate this approach into a useful addition to any information retrieval system with enough usage.Comment: Contribution to the proceedings of the colloquium Future Professional Communication in Astronomy II, 13-14 April 2010, Cambridge, Massachusetts. 11 pages, 4 figures

    Metal-based gels: Synthesis, properties, and applications

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    This review covers various aspects of recent developments on the design, the synthesis, the characterization of gels that: (i) are formed in the presence of metal ions (metallogels); (ii) are based on coordination complexes as gelators. Particular attention is devoted to systems that show recognition and sensing properties towards different analytes

    Utilidad de la reconstrucción tridimensional con tomografía computarizada en Traumatología y Ortopedia

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    La reconstrucción tridimensional es una nuev a técnica diagnóstica introducida en cirugía ortopédica y traumatología. Está indicada en algunas fracturas de acetábulo, columna y pelvis porque facilita una visión desde diferente s ángulos y en determinadas lesiones congénitas donde es imprescindible una correcta evaluación preoperatoria. Presentamo s dos paciente s con fracturas acetabulares, otro con lesión me - tastásica en columna lumbar y otro con hipoplasia del arco neural de cuarta vértebra lumbar. La reconstrucción tridimensional fue útil para el definitivo diagnóstico en los cuatro pacientes.Three dimensional images is a new technique introduced in orthopaedic surgery and traumatology. It's indicated for some fractures of the acetabulum, spine or pelvic girdle becaus e supply a vision from differents angles and in determinated congenital damage s who is indispensable an accurate evaluation before the surgery. We presented two patients with acetabular fractures, other with a metastasi c tumour in lumbar spine and anothe r with a hipoplasti c neural arch in a lumbar vertebra. The thre e dimensional reconstruction was useful for the definitive diagnostic in the four patients

    The High Time Resolution Universe Survey - V: Single-pulse energetics and modulation properties of 315 pulsars

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    We report on the pulse-to-pulse energy distributions and phase-resolved modulation properties for catalogued pulsars in the southern High Time Resolution Universe intermediate-latitude survey. We selected the 315 pulsars detected in a single-pulse search of this survey, allowing a large sample unbiased regarding any rotational parameters of neutron stars. We found that the energy distribution of many pulsars is well-described by a log-normal distribution, with few deviating from a small range in log-normal scale and location parameters. Some pulsars exhibited multiple energy states corresponding to mode changes, and implying that some observed "nulling" may actually be a mode-change effect. PSRJ1900-2600 was found to emit weakly in its previously-identified "null" state. We found evidence for another state-change effect in two pulsars, which show bimodality in their nulling time scales; that is, they switch between a continuous-emission state and a single-pulse-emitting state. Large modulation occurs in many pulsars across the full integrated profile, with increased sporadic bursts at leading and trailing sub-beam edges. Some of these high-energy outbursts may indicate the presence of "giant pulse" phenomena. We found no correlation with modulation and pulsar period, age, or other parameters. Finally, the deviation of integrated pulse energy from its average value was generally quite small, despite the significant phase-resolved modulation in some pulsars; we interpret this as tenuous evidence of energy regulation between distinct pulsar sub-beams.Comment: Before full MNRAS publication, supplementary material is available temporarily at http://dl.dropbox.com/u/22076931/supplementary_material.pd

    Coordination Chemistry and Sensing Properties Towards Anions and Metal Ions of a Simple Fluorescent Urea

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    The coordination and sensing properties towards anions and transition metal ions of the simple novel fluorescent urea 1-(2-aminophenyl)-3-(naphthalen-1)-yl)urea (L) were investigated in solution, and in the solid state. An electron donating amine group in the molecular skeleton of L decreased the acidity of the urea NHs that are usually deprotonated by basic anions and allowed for a good degree of affinity towards fluoride in DMSO-d6-0.5 %H2O. Moreover, the amine moiety acted as a further binding group for metal ions. Indeed, L was able to bind Zn2+ both in solution and in the solid state, and to respond to the presence of this metal ion in MeCN with an enhancement of the fluorescence emission. Although solution studies evidenced the formation of a 1 : 1 complex of L with Zn2+, complexes with a 2 : 1 ligand-to-metal stoichiometry were isolated in the solid state. DFT calculations helped to clarify the stability reasons behind these results

    A pilot study of occupational exposure to ultrafine particles during 3D printing in research laboratories

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    Introduction3D printing is increasingly present in research environments, and could pose health risks to users due to air pollution and particulate emissions. We evaluated the nanoparticulate emissions of two different 3D printers, utilizing either fused filament fabrication with polylactic acid, or stereolithography (SLA) with light curing resin. MethodsNanoparticulate emissions were evaluated in two different research environments, both by environmental measurements in the laboratory and by personal sampling. ResultsThe SLA printer had higher nanoparticulate emissions, with an average concentration of 4,091 parts/cm(3), versus 2,203 particles/cm(3) for the fused filament fabrication printer. The collected particulate matter had variable morphology and elemental composition with a preponderance of carbon, sulfur and oxygen, the main byproducts. DiscussionOur study implies that when considering the health risks of particulate emissions from 3D printing in research laboratories, attention should be given to the materials used and the type of 3D printer
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