1,892 research outputs found

    A Comparative Study of Path Performance Metrics Predictors

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    peer reviewedUsing quality-of-service (QoS) metrics for Internet traffic is expected to improve greatly the performance of many network enabled applications, such as Voice-over-IP (VoIP) and video conferencing. However, it is not possible to constantly measure path performance metrics (PPMs) such as delay and throughput without interfering with the network. In this work, we focus on PPMs measurement scalability by considering machine learning techniques to estimate predictive models from past PPMs observations. Using real data collected from PlanetLab, we provide a comparison between three different predictors: AR(MA) models, Kalman filters and support vector machines (SVMs). Some predic- tors use delay and throughput jointly to take advantage of the possible relationship between PPMs, while other predictors consider PPMs individually. Our current results illustrate that the best performing model is an individual SVM specific to each time series. Overall, delay can be predicted with very good accuracy while accurate forecasting of throughput remains an open problem

    Ossification of the roof of the porus trigeminus with duplicated abducens nerve.

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    Ossification of parts of the intracranial dura mater is common and is generally accepted as an age-related finding. Additionally, duplication of the abducens nerve along its course to the lateral rectus muscle is a known, although uncommon anatomical variant. During routine cadaveric dissection, an ossified portion of dura mater traveling over the trigeminal nerve\u27s entrance (porus trigeminus) into the middle cranial fossa was observed unilaterally. Ipsilaterally, a duplicated abducens nerve was also observed, with a unique foramen superolateral to the entrance of Dorello\u27s canal. To our knowledge, there has been no existing report of a simultaneous ossified roof of the porus trigeminus with an ipsilateral duplicated abducens nerve. Herein, we discuss this case and the potential clinical and surgical applications. We believe this case report will be informative for the skull base surgeon in the diagnosis of neuralgic pain in the frontomaxillary, andibular, orbital, and external and middle ear regions

    Ectopic Pituitary Adenoma Presenting as a Clival Mass.

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    Pituitary adenomas are well described in the literature and are frequently observed and treated in clinical practice by neurosurgeons. On the other hand, ectopic adenomas are a diagnostic enigma; a good understanding of anatomy and radiological characteristics is crucial for the successful management of such pathologies. In this paper, we describe the case of a 77-year-old woman who presented with a clival mass invading the left cavernous sinus; we also discuss the associated diagnostic techniques, approaches, imaging options, and characteristics

    Coercivity and squareness enhancement in ball-milled hard magnetic-antiferromagnetic composites

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    This article may be downloaded for personal use only. Any other use requires prior permission of the author and the American Institute of Physics.The room-temperature coercivity,HC, and squareness, MR/MS (remanence/saturation magnetizations), of permanent magnet,SmCo5powders have been enhanced by ball milling with antiferromagnetic NiO (with Néel temperature, TN=590 K). This enhancement is observed in the as-milled state. However, when the milling of SmCo5 is carried out with an antiferromagnet with TN below room temperature (e.g., for CoO, TN=290 K), the coercivity enhancement is only observed at low temperatures after field cooling through TN. The ferromagnetic-antiferromagnetic exchange coupling induced either by local heating during milling(SmCo5+NiO) or field cooling (SmCo5+CoO) is shown to be the origin of the HC increase

    Improved Detection of Enterotoxigenic Escherichia coli among Patients with Travelers' Diarrhea, by Use of the Polymerase Chain Reaction Technique

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    This study sought to determine whether a specific polymerase chain reaction (PCR) for enterotoxigenic Escherichia coli (ETEC) toxins after chaotropic extraction of DNA from stool would increase the detection of ETEC over that of conventional oligonucleotide probe hybridization of 5 E. coli colonies per stool sample (a standard method). By DNA hybridization, 29 (21%) of 140 patients were positive for ETEC, and 59 (42%) of 140 were positive for ETEC when PCR was used. Sensitivity of the PCR assay was confirmed through spiked stool experiments to be ∼100-1000 ETEC colonies per sample. Specificity of the assay was determined by showing an absence of ETEC by the PCR technique in a subgroup of 48 subjects and by confirming the presence of ETEC DNA of positive samples by dot blot procedure. PCR technique detected significantly more ETEC infections in these subjects than did the hybridization method (P < .0001

    Glycine-betaine-derived ionic liquids: Synthesis, characterization and ecotoxicological evaluation

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    Ionic Liquids (ILs) are generically regarded as environmentally "harmless" and thus, assumed as "non-toxic". However, due to the endless design possibilities, their ecotoxicological profile is still poorly known. An accurate knowledge on the toxicity of a substance is required, under the scope of environmental regulation worldwide, before their application and commercialization. Knowledge on the relationship between the chemical structure and toxic effects is essential for the future design of more biocompatible solvents. Focusing on the use of ILs as base lubricants, lubricant additives, or even as potential working fluids for absorption heat pumps, the knowledge on its environmental impact is of great importance, due to the possibility of spills. In this specific context, four analogues of glycine-betaine-based ILs (AGB-ILs) and four glycine-betaine based ILs (GB-ILs) were synthesized and characterized. Their ecotoxicity was assessed using representatives of two trophic levels in aquatic ecosystems, the bacteria Allivibrio fischeri (commonly used as a screening test organism) and the microalgae Raphidocelis subcapitata (as an alternative test organism that has been proven very sensitive to several IL families). The microalgae were more sensitive than the bacteria, hence, following a precautionary principle, we recommend considering the toxicity towards microalgae as an indicator in future studies regarding the focused ILs. Although four of the studied ILs were derived from a natural amino acid, all were considered hazardous for the aquatic environment, disproving the primary theory that all ILs derived from natural compounds are benign. Furthermore, the modification in the structure of anion and the cation can lead to the increase of toxicity.publishe

    Bibliografía

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    Se reseñan los siguientes libros: * La Nueva Gramática de la Real Academia. — Sus innovaciones y salvedades. * Leyes psicológicas de la Evolución de los Pueblos, por G. Le Bon, págs. 220; Daniel Jorro, editor, Madrid. * El estudio y la enseñanza de la Historia, por B. A. Hinsdale, profesor de la Universidad de Michigan; ps. 466; Daniel Jorro, editor, Madrid. * La Foi laique, por Ferdinando Buisson; ps. 334; Hachette y Cía., editor, París. * Laboratoire de Psycologie expérimentale de Rome. Contributi Psicologici, recueil de 23 mémoires. * Esquisse d’une éducation de l’attention, París, F. Alean, 137 págs., por Van Biervliet. * La genése des instincts. Etude expérimentale, 1 Vol. in 16, 327, págs. Flamarión, París 1912, por Hachet Souplet. * Les regles esthétiques et les lois du sentimente, por H. Dussanze; París, Alean, 1911. Págs. 541. * The Carnegie Foundation for the advancement of Teaching. Medical Education in Europe, 357 págs. * Antropo-sociologia. (Vulgarización enciclopédica de sus elementos), por Alejandro Güichot y Sierra, I tomo. Editado por Artes Gráficas, Sevilla, 1911. * La Psicología étnica e la Scienza eugenistica, por Enrique Morselli, Génova, 7 de Mayo de 1912. * La vida, su valor y su significación, por Rodolfo Eucken, profesor de Filosofía de la Universidad de Jena; págs. 280, Daniel Jorro, Madrid. * Die Geschichte der Erziehung in soziologischer und geistesgeschichtlicher Beleuchtung, por P. Barth. Leipzig, O. B. Beisland, editor (1811). Páginas, VII 620. * L’Educazione dei sensi, por Evaristo Marzili; S. Lapi, editor, Cittá del Castello (1912). Páginas: XII-207. * Mapa Escolar de la Provincia de Entre Ríos. * Los diputados de Buenos Aires en las cortes de Cádiz y el nuevo sistema de gobierno económico de América, por el doctor E. del Valle Iberlucea, profesor de las dos universidades; pág. 266. Martín García editor. * Contribución al estudio de los niños débiles y retardados en edad escolar, por Hamiiton Cassinelli, tesis para optar al título de doctor en medicina, pág. 217. * Álgebra, por E. Lafférriére, pág. 561. Cabaut y Cía. editores. Buenos Aires.Facultad de Ciencias Jurídicas y Sociale

    Fundamental aspects and first application

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    Low-temperature storage to slow down degradation is accepted by the film conservation community. Still, this solution prohibits public access, is price-sensitive, has high energy costs, and there are concerns about their effects on the physical stability and material lifetime. In this research, a smart solution is developed based on the selective capture of acetic acid produced by the cellulose acetate polymer. This innovative approach is based on Metal-Organic Frameworks (MOFs) for acetic acid adsorption, specifically a highly selective porous iron(III) based MOF, MIL-100(Fe), which was synthesized using a green approach. The stability of MIL-100(Fe), under acetic acid exposure, was demonstrated by accelerated aging experiments, with no noticeable changes in crystallinity and/or porosity as deduced from powder X-ray diffraction analysis, infrared spectroscopy, thermogravimetric analysis, nitrogen porosimetry, and electron microscopy. Compatibility tests with the artefacts were performed to prove the safety of the MIL-100(Fe) to the artefacts. A field application in a demonstration prototype (smart box) was performed at Institut Valencià de Cultura. A recently developed hybrid model provided recommendations on the quantity of adsorbents to use in the smart box. Good agreement was observed between the model predictions and the in-field experimental results, which validated the model application. The model predicted that the new adsorbent (5% of the film's weight, replaced every 10 years, at 16°C or 22°C) extends the film's lifetime equivalently to cold storage (5°C). Finally, environmental impact assessment and life cycle analysis were performed to compare the two preservation approaches. The new approach based on this Fe-MOF yielded an average reduction of carbon footprint related to movie film preservation of about 50% considering the current European Union (EU) energy mix and about 40% considering the 2030 EU energy mix (where a transition towards renewable energy is expected). The proposed innovative technology represents a robust solution towards efficient and more sustainable film preservation while significantly contributing to moving toward climate transition objectives in the culture heritage sector.publishersversionpublishe
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