903 research outputs found

    Towards effective culvert design: Monitoring seasonal use and behavior by Mediterranean mesocarnivores

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    Drainage culverts are known to be used by a diverse number of species. To date, most studies looking at culvert usage have been restricted to the dry season. This seasonal bias has limited our understanding of how different species respond to culverts and, consequently, our ability to find effective ways to promote the use of culverts as aids to species movement. The main goal of this study was to examine the role of highway culverts for mesocarnivores throughout the year. We addressed (1) the seasonality of culvert use, (2) the relative importance of culvert structure, highway features, and surrounding landscape on culvert use, (3) the influence of the water depth and cover on culvert use, and (4) the effect of culvert structure on individual behavior. Fifteen culverts were monitored along 2 highways in southern Portugal using video-surveillance cameras and marble dust for 10 consecutive days per season. We used generalized linear mixed models to determine which factors most affected the culvert use and behavior by mesocarnivores. Our results highlight the effect of seasonality and water on culvert use. Culvert use was positively related with species activity throughout the year. All species (except otters (Lutra lutra)) were less likely to use culverts that contained water more than 3 cm deep or covering more than 70 % of the culvert base. Based on our results, future surveys and culvert retrofit design should address (1) the importance of seasonality in the interpretation of results and (2) the complementarity of culvert-specific features (water, ledges, and naturalization). © 2012 Springer Science+Business Media Dordrecht.Peer Reviewe

    Translaminar Pressure Difference and Ocular Perfusion Pressure in Glaucomatous Eyes with Different Optic Disc Sizes

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    Purpose: Intracranial pressure (ICP) and ocular perfusion pressure (OPP) are both involved with the pathogenesis of glaucoma. The orbital ICP determines a retrolaminar counter pressure that is antagonistic to the intraocular pressure (IOP). The purpose of this study is to evaluate whether the translaminar pressure difference (TLPD) and the OPP varies in glaucoma patients with different optic disc sizes. Methods: In this university hospital-based, observational, cross-sectional clinical study, all patients underwent an ophthalmic evaluation. Blood pressure, height, weight, and the results of retinal nerve fiber layer examination with optical coherence tomography examination were recorded. TLPD and OPP were calculated for each patient using proxy algorithms to attain indirect surrogate parameter values. Patients’ eyes were stratified into three quantiles according to optic disc sizes and the differences compared. Data from both eyes were used after using the appropriate correction for inter-eye dependency. Results: The sample consisted of 140 eyes of 73 patients with primary open-angle glaucoma and suspects. Patients with large disc size presented with higher TLPD as compared to those with average and small-sized discs (2.4 ± 4.5, 2.8 ± 3.8, and 3.7 ± 4.7 mmHg for first, second, and third tertile, respectively (P < 0.000). OPP did not vary according to the optic disc size. Conclusion: Glaucoma patients with larger optic discs have higher TLPD. The pathological significance of this finding warrants further investigation

    Predicting spectral features in galaxy spectra from broad-band photometry

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    We explore the prospects of predicting emission line features present in galaxy spectra given broad-band photometry alone. There is a general consent that colours, and spectral features, most notably the 4000 A break, can predict many properties of galaxies, including star formation rates and hence they could infer some of the line properties. We argue that these techniques have great prospects in helping us understand line emission in extragalactic objects and might speed up future galaxy redshift surveys if they are to target emission line objects only. We use two independent methods, Artifical Neural Neworks (based on the ANNz code) and Locally Weighted Regression (LWR), to retrieve correlations present in the colour N-dimensional space and to predict the equivalent widths present in the corresponding spectra. We also investigate how well it is possible to separate galaxies with and without lines from broad band photometry only. We find, unsurprisingly, that recombination lines can be well predicted by galaxy colours. However, among collisional lines some can and some cannot be predicted well from galaxy colours alone, without any further redshift information. We also use our techniques to estimate how much information contained in spectral diagnostic diagrams can be recovered from broad-band photometry alone. We find that it is possible to classify AGN and star formation objects relatively well using colours only. We suggest that this technique could be used to considerably improve redshift surveys such as the upcoming FMOS survey and the planned WFMOS survey.Comment: 10 pages 7 figures summitted to MNRA

    Network Service Orchestration: A Survey

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    Business models of network service providers are undergoing an evolving transformation fueled by vertical customer demands and technological advances such as 5G, Software Defined Networking~(SDN), and Network Function Virtualization~(NFV). Emerging scenarios call for agile network services consuming network, storage, and compute resources across heterogeneous infrastructures and administrative domains. Coordinating resource control and service creation across interconnected domains and diverse technologies becomes a grand challenge. Research and development efforts are being devoted to enabling orchestration processes to automate, coordinate, and manage the deployment and operation of network services. In this survey, we delve into the topic of Network Service Orchestration~(NSO) by reviewing the historical background, relevant research projects, enabling technologies, and standardization activities. We define key concepts and propose a taxonomy of NSO approaches and solutions to pave the way towards a common understanding of the various ongoing efforts around the realization of diverse NSO application scenarios. Based on the analysis of the state of affairs, we present a series of open challenges and research opportunities, altogether contributing to a timely and comprehensive survey on the vibrant and strategic topic of network service orchestration.Comment: Accepted for publication at Computer Communications Journa

    Increased animal production through the development of high-quality tropical forages

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    Animal production in the tropics and subtropics is based almost entirely on pastures. Cattle reared on pastures have a competitive advantage for export, eliminating the risks presented by the mad cow disease (bovine spongiform encephalopathy) and considerations related to animal welfare. To sustain all this huge pasture area and animal production, new cultivars of improved pastures must continuously be developed. Despite the great importance of tropical forage, breeding is a very recent activity worldwide. Only in the last 4 decades, have investments been made to develop new cultivars through selection within large germplasm collections and then through breeding. Since the 1980s Brazil invested in importing large germplasm banks and in hiring and training forage breeders, thus, today Brazil is the leader in tropical forage breeding and new high-quality forage cultivars are continuously being developed. For this to be possible, strong breeding programs and research teams must always be prioritized. Breeding is underway for the genera Brachiaria, Panicum, Pennisetum, Cynodon, Paspalum and important legumes as Arachis, Cajanus and Stylosanthes. The development of high-quality forages depends on the use of wide variability germplasm, knowledge of the biology of the species, as number and ploidy level of chromosomes and breeding methods, and the generation of a great number of hybrids to be evaluated. The main objective of any breeding program is to select and release a cultivar that will contribute to pasture diversification and an increase in animal production with resistance to the main pests and diseases. Another objective of breeding programs is to develop cultivars that will attend specific needs or have specific resistances to pests and diseases. To select for increased yield and increased quality combined is not always an easy task, but it is easier if the germplasm bank is large enough and representative of the natural variability of the species

    Seleção de progênies de Brachiaria decumbens utilizando diferentes intensidades de seleção.

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    As pastagens constituem no sistema pecuário Brasileiro de corte, a principal fonte de alimentação adotada para a produção animal. A utilização das mesmas cultivares comerciais no entanto, promoveu a formação de extensos monocultivos resultando em grandes riscos fitotécnicos e fitossanitários. Com base nessas informações, o presente trabalho teve por objetivo avaliar caracteres agronômicos e nutricionais de uma população de híbridos intraespecíficos de Brachiaria decumbens, a fim de predizer os ganhos de seleção para cada característica. Para isso, uma população de irmãos germanos de B. decumbens foi obtida por meio do cruzamento entre 75 híbridos sexuais com a cultivar apomítica Basilisk

    Application of hyperthermia induced by superparamagnetic iron oxide nanoparticles in glioma treatment

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    Gliomas are a group of heterogeneous primary central nervous system (CNS) tumors arising from the glial cells. Malignant gliomas account for a majority of malignant primary CNS tumors and are associated with high morbidity and mortality. Glioblastoma is the most frequent and malignant glioma, and despite the recent advances in diagnosis and new treatment options, its prognosis remains dismal. New opportunities for the development of effective therapies for malignant gliomas are urgently needed. Magnetic hyperthermia (MHT), which consists of heat generation in the region of the tumor through the application of magnetic nanoparticles subjected to an alternating magnetic field (AMF), has shown positive results in both preclinical and clinical assays. The aim of this review is to assess the relevance of hyperthermia induced by magnetic nanoparticles in the treatment of gliomas and to note the possible variations of the technique and its implication on the effectiveness of the treatment. We performed an electronic search in the literature from January 1990 to October 2010, in various databases, and after application of the inclusion criteria we obtained a total of 15 articles. In vitro studies and studies using animal models showed that MHT was effective in the promotion of tumor cell death and reduction of tumor mass or increase in survival. Two clinical studies showed that MHT could be applied safely and with few side effects. Some studies suggested that mechanisms of cell death, such as apoptosis, necrosis, and antitumor immune response were triggered by MHT. Based on these data, we could conclude that MHT proved to be efficient in most of the experiments, and that the improvement of the nanocomposites as well as the AMF equipment might contribute toward establishing MHT as a promising tool in the treatment of malignant gliomas

    The Viscacha survey - II: Structure of star clusters in the Magellanic Clouds periphery

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    We provide a homogeneous set of structural parameters of 83 star clusters located at the periphery of the Small Magellanic Cloud (SMC) and the Large Magellanic Cloud (LMC). The clusters’ stellar density and surface brightness profiles were built from deep, AO assisted optical images, and uniform analysis techniques. The structural parameters were obtained from King and Elson et al. model fittings. Integrated magnitudes and masses (for a subsample) are also provided. The sample contains mostly low surface brightness clusters with distances between 4.5 and 6.5 kpc and between 1 and 6.5 kpc from the LMC and SMC centres, respectively. We analysed their spatial distribution and structural properties, comparing them with those of inner clusters. Half-light and Jacobi radii were estimated, allowing an evaluation of the Roche volume tidal filling. We found that: (i) for both MCs, the tidal radii are on average larger than those of inner clusters; (ii) the core radii dispersion tends to be greater for LMC clusters located towards the southwest, with position angles of ∼200 degrees and about ∼5 degrees from the LMC centre, i.e., those LMC clusters nearer to the SMC; (iii) the analysis of clusters with ages available revealed that the core radius evolution is similar to the one of inner clusters; (iv) Roche volumes are overfilled for SMC clusters with galactocentric distances closer than 3 kpc.Fil: Santos, Joao F. C.. Universidad de La Serena; Chile. Universidade Federal de Minas Gerais; BrasilFil: Maia, Francisco. Universidade Federal do Rio de Janeiro; BrasilFil: Dias, Bruno. Millennium Institute of Astrophysics; Chile. Universidad Andrés Bello; ChileFil: de O. Kerber, Leandro. Universidade Estadual de Santa Cruz; BrasilFil: Piatti, Andres Eduardo. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Bica, Eduardo. Universidade Federal do Rio Grande do Sul; BrasilFil: Angelo, Mateus S.. Centro Federal de Educacao Tecnológica de Minas Gerais; BrasilFil: Minniti, Dante. Universidad Andrés Bello; Chile. Millennium Institute of Astrophysics; Chile. Vatican Observatory; ItaliaFil: Pérez Villegas, Angeles. Universidade de Sao Paulo; BrasilFil: Roman Lopes, Alexandre. Universidad de La Serena; ChileFil: Westera, Pieter. Universidad Federal Do Abc; BrasilFil: Fraga, Luciano. Laboratorio Nacional de Astrofísica; BrasilFil: Quint, Bruno. Gemini Observatory; ChileFil: Sanmartim, David. Carnegie Institution of Washington; Chil
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