321 research outputs found

    Application of aerospace-generated technology to water pollution and other public sector problems Quarterly report, 1 Dec. 1968 - 28 Feb. 1969

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    Aerospace-generated technology considered for solving 22 specific problems in water pollutio

    The Importance of Campos Ecosystem as a World Food Producer and as a Provider of Ecosystem Services

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    The Campos ecosystem represent one of the largest grassland areas on the world, with great biodiversity in plants and animals. It contributes to improve world food security, based on ruminant livestock production, providing animal protein to feed more than 160.000.000 people. The research agenda for Campos ecosystem demands attention on the productivity and increasing variability phenomena, overgrazing, biodiversity standards and water contamination among other factors. It provides services including genetic resources, carbon storage, control of soil erosion, nutrient recycling, water production with low nutrient concentration and pest control. Overall, there is available technology to improve long-term livestock productivity and preserve current environmental indicators and improve sustainability, contributing to supply increasing world food demand

    Introducción al estudio de la propiedad horizontal

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    Fil: Bendersky, Mario J. Universidad de Buenos Aires. Facultad de Derecho. Cátedra Derecho Civil IV. Buenos Aires, ArgentinaFil: Bendersky, Mario J. Universidad de Buenos Aires. Facultad de Ciencias Económicas. Cátedra Derecho Privado. Buenos Aires, ArgentinaSUMARIO: \nI: NOCION. ll: TERMINOLOGIA. lll: BREVES ANTECEDENTES HISTORICOS. IV: LEGISLACION COMPARADA. V: IMPORTANCIA DEL lNSTITUTO Y VENTAJAS QUE REPORTA lV: NATURALEZA JURIDICA. VII: LA CUESTION EN EL CODIGO CIVIL. LA LEY 13512 FUENTES- NORMAS QUE DEROGA\

    An Infrared Imaging Method for High-Throughput Combinatorial Investigation of Hydrogenation-Dehydrogenation and New Phase Formation of Thin Films

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    We have developed an infrared imaging setup enabling in situ infrared images to be acquired, and expanded on capabilities of an infrared imaging as a high-throughput screening technique, determination of a critical thickness of a Pd capping layer which significantly blocks infrared emission from below, enhancement of sensitivity to hydrogenation and dehydrogenation by normalizing raw infrared intensity of a Mg thin film to an inert reference, rapid and systematic screening of hydrogenation and dehydrogenation properties of a Mg–Ni composition spread covered by a thickness gradient Pd capping layer, and detection of formation of a Mg2Si phase in a Mg thin film on a thermally oxidized Si substrate during annealing

    Competition and Selection Among Conventions

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    In many domains, a latent competition among different conventions determines which one will come to dominate. One sees such effects in the success of community jargon, of competing frames in political rhetoric, or of terminology in technical contexts. These effects have become widespread in the online domain, where the data offers the potential to study competition among conventions at a fine-grained level. In analyzing the dynamics of conventions over time, however, even with detailed on-line data, one encounters two significant challenges. First, as conventions evolve, the underlying substance of their meaning tends to change as well; and such substantive changes confound investigations of social effects. Second, the selection of a convention takes place through the complex interactions of individuals within a community, and contention between the users of competing conventions plays a key role in the convention's evolution. Any analysis must take place in the presence of these two issues. In this work we study a setting in which we can cleanly track the competition among conventions. Our analysis is based on the spread of low-level authoring conventions in the eprint arXiv over 24 years: by tracking the spread of macros and other author-defined conventions, we are able to study conventions that vary even as the underlying meaning remains constant. We find that the interaction among co-authors over time plays a crucial role in the selection of them; the distinction between more and less experienced members of the community, and the distinction between conventions with visible versus invisible effects, are both central to the underlying processes. Through our analysis we make predictions at the population level about the ultimate success of different synonymous conventions over time--and at the individual level about the outcome of "fights" between people over convention choices.Comment: To appear in Proceedings of WWW 2017, data at https://github.com/CornellNLP/Macro

    Risk-of-bias assessment of the randomized clinical trials and systematic reviews on surgical treatments for breast cancer-related lymphedema : A mapping review

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    Altres ajuts: acords transformatius de la UABBreast cancer treatment is the principal cause of lymphedema in the upper extremities. Breast cancer-related lymphedema (BCRL) treatments were previously based on conservative therapy; surgical treatments are alternative options that could be highly beneficial, especially for patients who are not responsive to conservative therapy. The main aim of this study was to describe and critically assess the risk of bias of randomized clinical trials (RCTs) and systematic reviews (SRs) on surgical treatment for BCRL. We conducted an evidence mapping review according to the methodology proposed by Global Evidence Mapping (GEM). An update was done for our previous systematic search in MEDLINE, EMBASE, CENTRAL (Cochrane), and Epistemonikos from the year 2000 onward. We assessed the risk of bias for the RCTs and SRs using the RoB-2 and ROBIS tools, respectively. Two surgical RCTs and eight SRs were found among the 47 surgical studies that met the eligibility criteria. The overall risk-of-bias assessments of these studies were rated as some concerns (six outcomes) and high risk (three outcomes) for the measured outcomes among the RCTs and as a high risk of bias (five studies) and low risk (three studies) for the included SRs. The overall evidence in the literature on surgical treatment for BCRL is low, as there are few published RCTs and SRs, and the risk-of-bias assessment for the majority was rated as high risk of bias or with some concerns. High-quality studies are needed to improve evidence-based decision-making by surgeons and patients

    Light propagation in non-trivial QED vacua

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    Within the framework of effective action QED, we derive the light cone condition for homogeneous non-trivial QED vacua in the geometric optics approximation. Our result generalizes the ``unified formula'' suggested by Latorre, Pascual and Tarrach and allows for the calculation of velocity shifts and refractive indices for soft photons travelling through these vacua. Furthermore, we clarify the connection between the light velocity shift and the scale anomaly. This study motivates the introduction of a so-called effective action charge that characterizes the velocity modifying properties of the vacuum. Several applications are given concerning vacuum modifications caused by, e.g., strong fields, Casimir systems and high temperature.Comment: 13 pages, REVTeX, 3 figures, to appear in Phys. Rev.

    Energy spectra, wavefunctions and quantum diffusion for quasiperiodic systems

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    We study energy spectra, eigenstates and quantum diffusion for one- and two-dimensional quasiperiodic tight-binding models. As our one-dimensional model system we choose the silver mean or `octonacci' chain. The two-dimensional labyrinth tiling, which is related to the octagonal tiling, is derived from a product of two octonacci chains. This makes it possible to treat rather large systems numerically. For the octonacci chain, one finds singular continuous energy spectra and critical eigenstates which is the typical behaviour for one-dimensional Schr"odinger operators based on substitution sequences. The energy spectra for the labyrinth tiling can, depending on the strength of the quasiperiodic modulation, be either band-like or fractal-like. However, the eigenstates are multifractal. The temporal spreading of a wavepacket is described in terms of the autocorrelation function C(t) and the mean square displacement d(t). In all cases, we observe power laws for C(t) and d(t) with exponents -delta and beta, respectively. For the octonacci chain, 0<delta<1, whereas for the labyrinth tiling a crossover is observed from delta=1 to 0<delta<1 with increasing modulation strength. Corresponding to the multifractal eigenstates, we obtain anomalous diffusion with 0<beta<1 for both systems. Moreover, we find that the behaviour of C(t) and d(t) is independent of the shape and the location of the initial wavepacket. We use our results to check several relations between the diffusion exponent beta and the fractal dimensions of energy spectra and eigenstates that were proposed in the literature.Comment: 24 pages, REVTeX, 10 PostScript figures included, major revision, new results adde
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