2,691 research outputs found
Nanoporous GaN by UV assisted electroless etching for sensor applications
GaN-based devices have demonstrated excellent performance for electronics and optoelectronics applications. In particular, these devices exhibit very good performance when operated at high temperatures and in harsh environments when compared to similar devices fabricated with conventional material systems. The good stability, durability and biocompatibility of the nitrides have also led to the development of GaN based chemical and biological gas sensors. These devices have been developed using Schottky diodes with platinum or palladium contacts on GaN and AlGaN/GaN structures [1-3] and showed high sensitivity. However, the response may be further improved if the effective surface área is increased, allowing a more efficient accumulation of the gas induced dipole layer [4]. In this paper fabrication and characterization of nanoporous GaN is presented as a fírst step for the fabrication of improved GaN gas sensors
Molecular characterization and morphology of Cochlodinium strangulatum, the type species of Cochlodinium, and Margalefidinium gen. nov. for C. polykrikoides and allied species (Gymnodiniales, Dinophyceae)
© The Author(s), 2017. This is the author's version of the work. It is posted here under a nonexclusive, irrevocable, paid-up, worldwide license granted to WHOI. It is made available for personal use, not for redistribution. The definitive version was published in Harmful Algae 63 (2017): 32-44, doi:10.1016/j.hal.2017.01.008.Photosynthetic species of the dinoflagellate genus Cochlodinium such as C. polykrikoides, one of the most harmful bloom-forming dinoflagellates, have been extensively investigated. Little is known about the heterotrophic forms of Cochlodinium, such as its type species, Cochlodinium strangulatum. This is an uncommon, large (~200 μm long), solitary, and phagotrophic species, with numerous refractile bodies, a central nucleus enclosed in a distinct perinuclear capsule, and a cell surface with fine longitudinal striae and a circular apical groove. The morphology of C. polykrikoides and allied species is different from the generic type. It is a bloom-forming species with single, two or four-celled chains, small cell size (25–40 μm long) with elongated chloroplasts arranged longitudinally and in parallel, anterior nucleus, eye-spot in the anterior dorsal side, and a cell surface smooth with U-shaped apical groove. Phylogenetic analysis based on LSU rDNA sequences revealed that C. strangulatum and C. polykrikoides/C. fulvescens formed two distally related, independent lineages. Based on morphological and phylogenetic analyses, the diagnosis of Cochlodinium is emended and C. miniatum is proposed as synonym of C. strangulatum. The new genus Margalefidinium gen. nov., and new combinations for C. catenatum, C. citron, C. flavum, C. fulvescens and C. polykrikoides are proposed.F.G. was supported by the Brazilian Conselho Nacional de Desenvolvimento Científico e Tecnológico [grant number BJT 370646/2013–14]. Support for M.L.R. and D.M.A. was provided through the Woods Hole Center for Oceans and Human Health, National Science Foundation [grant number OCE–1314642] and National Institute of Environmental Health Sciences [grant number 1–P01–ES021923–01]
Evolution Operators for Linearly Polarized Two-Killing Cosmological Models
We give a general procedure to obtain non perturbative evolution operators in
closed form for quantized linearly polarized two Killing vector reductions of
general relativity with a cosmological interpretation. We study the
representation of these operators in Fock spaces and discuss in detail the
conditions leading to unitary evolutions.Comment: Accepted for publication in Physical Review
Effects of gelatin origin, bovine-hide and tuna-skin, on the properties of compound gelatin-chitosan films
With the purpose to improve the physico-chemical performance of plain gelatin and chitosan films, compound gelatin-chitosan films were prepared. The effect of the gelatin origin (commercial bovine-hide gelatin and laboratory-made tuna-skin gelatin) on the physico-chemical properties of films was studied. The dynamic viscoelastic properties (elastic modulus G', viscous modulus, G″ and phase angle) of the film-forming solutions upon cooling and subsequent heating revealed that the interactions between gelatin and chitosan were stronger in the blends made with tuna-skin gelatin than in the blends made with bovine-hide gelatin. As a result, the fish gelatin-chitosan films were more water resistant (∼18% water solubility for tuna vs 30% for bovine) and more deformable (∼68% breaking deformation for tuna vs 11% for bovine) than the bovine gelatin-chitosan films. The breaking strength of gelatin-chitosan films, whatever the gelatin origin, was higher than that of plain gelatin films. Bovine gelatin-chitosan films showed a significant lower water vapour permeability (WVP) than the corresponding plain films, whereas tuna gelatin-chitosan ones were only significantly less permeable than plain chitosan film. Complex gelatin-chitosan films behaved at room temperature as rubbery semicrystalline materials. In spite of gelatin-chitosan interactions, all the chitosan-containing films exhibited antimicrobial activity against Staphylococcus aureus, a relevant food poisoning. Mixing gelatin and chitosan may be a means to improve the physico-chemical performance of gelatin and chitosan plain films, especially when using fish gelatin, without altering the antimicrobial properties. © 2011 Elsevier Ltd.Peer Reviewe
Exploitation and Processing of Online Information for Annotating and Generating Texts Adapted to the User
La gran cantidad de información disponible en Internet está dificultando cada vez más que los usuarios puedan digerir toda esa información, siendo actualmente casi impensable sin la ayuda de herramientas basadas en las Tecnologías del Lenguaje Humano (TLH), como pueden ser los recuperadores de información o resumidores automáticos. El interés de este proyecto emergente (y por tanto, su objetivo principal) viene motivado precisamente por la necesidad de definir y crear un marco tecnológico basado en TLH, capaz de procesar y anotar semánticamente la información, así como permitir la generación de información de forma automática, flexibilizando el tipo de información a presentar y adaptándola a las necesidades de los usuarios. En este artículo se proporciona una visión general de este proyecto, centrándonos en la arquitectura propuesta y el estado actual del mismo.The great amount of available online information is making increasingly more and more difficult that users can assimilate such as volume of information, being this almost inconceivable without using Human Language Technologies (HLT) tools, for instance, information retrieval systems or automatic summarisers. The interest of this emerging project (and therefore its main goal) is precisely motivated by the need to define and create a HLT-based technological framework, able to process and semantically annotate all this information, allowing also the automatic generation of information, and making the type of information to be presented more flexible by adapting it to the users' needs. This article provides an overview of this project, focusing on the proposed architecture and its current status.Este proyecto ha sido financiado por la Universidad de Alicante a través del proyecto emergente “Explotación y tratamiento de la información disponible en Internet para la anotación y generación de textos adaptados al usuario” (GRE13-15) y su temática se enmarca en el contexto de los proyectos “DIIM2.0: Desarrollo de técnicas Inteligentes e Interactivas de Minería y Generación de Información sobre la Web 2.0” (PROMETEOII/2014/001) financiado por la Generalitat Valenciana y el proyecto “Técnicas de Deconstrucción en la Tecnologías del Lenguaje Humano” (TIN2012-31224) financiado por Ministerio de Economía y Competitividad del Gobierno de España
La importancia de la línea articular en la revisión de la artroplastia total de rodilla
Introducción: Uno de los retos de la cirugía de recambio de la artroplastia total de rodilla es la restauración
de la línea articular anatómica. El objetivo de este estudio es la evaluación clínica y radiológica y su relación
estadística con la posición de la línea articular en los recambios de artroplastia total de rodilla. Material y método:
Se estudiaron 25 pacientes intervenidos en nuestro servicio desde Enero 2002 a Diciembre de 2006 mediante
recambio protésico P.F.C. TC-3 Sigma (DePuy®). Se estudió la movilidad, estabilidad y la evaluación clínica según la
sociedad americana de la rodilla (AKS), en el estudio radiológico se estudió la distancia de la línea articular según
Hofmann y cols. A todos los pacientes se les realizó la encuesta de salud SF-36 en la revisión ambulatoria. Resultados:
18 pacientes (77%) presentaban una línea articular entre +4 mm y -4 mm respecto a la línea previa a la cirugía.
En 4 pacientes (16%) la línea articular era -4 mm, es decir, con desplazamiento proximal de la línea articular. En 3
pacientes (12%) la línea se situó +4 mm. Los pacientes que se encontraron en el grupo de -4 mm poseían una flexión
articular de 75°, frente a 90° del grupo +4mm y -4 mm y 88.33° del grupo +4mm (P<0.05). El AKS de los pacientes
con desplazamiento proximal (- 4mm) fue de 54.25, frente a 70.77 del grupo +4mm y -4 mm y 61 del grupo +4mm.
(p<0.05). Discusión: Los resultados de este estudio nos muestran la importancia de la planificación pre y peroperatoria
acompañado de una depurada técnica quirúrgica para la localización de las referencias anatómicas y colocación
de los implantes conservando la altura de la interlinea articular.Introduction: One of the challenges of surgery replacement total knee arthroplasty is the restoration of
the line anatomical articulation. The aim of this study is to assess clinical and radiological and their statistical relationship
with the position of line articulating in revision total knee arthroplasty. Materials and methods: We studied
25 consecutive patients in our hospital from January 2002 to December 2006 through prosthetic replacement PFC TC-
3 Sigma (DePuy®). We studied the mobility, stability and clinical evaluation according to the American Knee Society
index (AKS), in the radiological study explored the anatomic axis of the knee and the distance from the line as articulate
Hofmann y cols. Results: 18 patients (77%) presented a articular line between +4 mm and 4 mm respect to the
line prior to surgery, 4 patients (16%) presented - 4 mm from de previous articular line, showed a shift toward the line
of proximal joint, and 3 patients (12%) presented +4 mm displacement. Patients who were found in the group -4 mm
had 75 ° flexion, compared with 90 of the group +4mm and -4 mm and 88.33 mm +4 ° group (P <0.05), The AKS
index of patients with displacement proximal (- 4mm) was 54.25, compared with 70.77 of the group +4mm and 4 mm
and 61 mm +4 group (p <0.05). Discussion: Satisfactory results of this study show the importance of planning pre
and peroperatoria and a refined surgical technique for tracing the anatomical references and placement of implants in
correct articular line
Neutralization Susceptibility of African Swine Fever Virus Is Dependent on the Phospholipid Composition of Viral Particles
AbstractIn this study we have investigated the generation of African swine fever (ASF) virus variants resistant to neutralizing antibodies after cell culture propagation. All highly passaged ASF viruses analyzed were resistant to neutralization by antisera from convalescent pigs or antibodies generated against individual viral proteins which neutralized low-passage viruses. A molecular analysis of neutralizable and nonneutralizable virus isolates by sequencing of the genes encoding for neutralizing proteins revealed that the absence of neutralization of high-passage viruses is not due to antigenic variability of critical epitopes. A comparative analysis of phospholipid composition of viral membranes between low- and high-passage viruses revealed differences in the relative amount of phosphatidylinositol in these two groups of viruses, independent of the cells in which the viruses were grown. Further purification of low- and high-passage viruses by Percoll sedimentation showed differences in the phospholipid composition identical to those found with the partially purified viruses and confirmed the susceptibility of these viruses to neutralization. The incorporation of phosphatidylinositol into membranes of high-passage viruses rendered a similar neutralization susceptibility to low-passage viruses, in which this is a major phospholipid. In contrast, other phospholipids did not interfere with high-passage virus neutralization, suggesting that phosphatidylinositol is essential for a correct epitope presentation to neutralizing antibodies. Additionally, the removal of phosphatidylinositol from a low-passage virus by a specific lipase transformed this virus from neutralizable to nonneutralizable. These data constitute clear evidence of the importance of the lipid composition of the viral membranes for the protein recognition by antibodies and may account in part for the past difficulties in reproducibly demonstrating ASF virus-neutralizing antibodies by using high-passage viruses
Catalytic hydroprocessing of lignin β-O-4 ether bond model compound phenethyl phenyl ether over ruthenium catalysts
The catalytic hydroprocessing of phenethyl phenyl ether (PPE), a model compound of one of the most significant ether linkages within lignin structure, β-O-4, has been studied. Reactions were carried out using two ruthenium-based catalysts, supported on different materials: 3.8 wt.% Ru/C and 3.9 wt.% Ru/Al2O3. Aiming at studying the reaction mechanism, experiments were carried out at 150 °C and 25 bar in H2 atmosphere, with varying feed to catalyst mass ratios and reaction time. Differences between the relative importance of the steps of the mechanism were observed when using those two catalysts. The most significant finding was the predominance of the cleavage of Cβ-O bonds compared to the cleavage of the Caryl-O when using Ru/Al2O3 as catalyst; whereas with Ru/C, the two routes were nearly equivalent. It has been observed that the kinetic model describes the general tendencies of consumption and formation of the different products, but some over/under estimation of concentrations occurs. Finally, the effect of temperature was also explored by carrying out reactions at 100 and 125 °C, observing that decreasing temperature from 150 to 125 or 100 °C favored the dimer hydrogenation route versus the hydrogenolysis of the ether bonds
Managing summaries for mobile devices
Los dispositivos móviles han cambiado notablemente la forma en la que los usuarios acceden a la información disponible en Internet. Estos dispositivos permiten un acceso instantáneo desde cualquier lugar, pero tienen una serie de limitaciones importantes sobre los ordenadores personales. Su limitada pantalla, así como en ocasiones la limitada capacidad de recepción de la información, dado el coste, hacen que la selección de información a acceder sea todavía más importante. La generación automática de resúmenes multi-documentos es una alternativa de interés que es el objeto de este artículo. Así en este artículo se presentan y evalúan un modelo de generación automática de resúmenes, junto con un sistema de recuperación de información basado en pasajes.Mobile devices have significantly changed the way users access the information available on Internet. These devices allow instant access anytime and anywhere, but they have a number of important limitations with respect to personal computers. The limited screen space and, sometimes, the limited capacity to receive the information, make the selection of information even more important. Automatic summary generation from multi-document summarization is an interesting alternative which is the subject of this paper. Therefore, in this article is presented and evaluated a model of automatic summarization with an information retrieval system based on passages.Investigación realizada gracias a la financiación de los proyectos: DIIM2.0 (PROMETEOII/2014/001) de la Generalitat Valenciana; TIN2015-65100-R, DIGITY (TIN2015-65136-C2-2-R) del Ministerio de Economía y Competitividad y SAM (FP7-611312) de la Unión Europe
Genetics and biology of Anastrepha fraterculus: Research supporting the use of the sterile insect technique (SIT) to control this pest in Argentina
Two species of true fruit flies (taxonomic family Tephritidae) are considered pests of fruit and vegetable production in Argentina: the cosmopolitan Mediterranean fruit fly (Ceratitis capitata Wiedemann) and the new world South American fruit fly (Anastrepha fraterculus Wiedemann). The distribution of these two species in Argentina overlaps north of the capital, Buenos Aires. Regarding the control of these two pests, the varied geographical fruit producing regions in Argentina are in different fly control situations. One part is under a programme using the sterile insect technique (SIT) for the eradication of C. capitata, because A. fraterculus is not present in this area. The application of the SIT to control C. capitata north of the present line with the possibility of A. fraterculus occupying the niche left vacant by C. capitata becomes a cause of much concern. Only initial steps have been taken to investigate the genetics and biology of A. fraterculus. Consequently, only fragmentary information has been recorded in the literature regarding the use of SIT to control this species. For these reasons, the research to develop a SIT protocol to control A. fraterculus is greatly needed. In recent years, research groups have been building a network in Argentina in order to address particular aspects of the development of the SIT for Anastrepha fraterculus. The problems being addressed by these groups include improvement of artificial diets, facilitation of insect mass rearing, radiation doses and conditions for insect sterilisation, basic knowledge supporting the development of males-only strains, reduction of male maturation time to facilitate releases, identification and isolation of chemical communication signals, and a good deal of population genetic studies. This paper is the product of a concerted effort to gather all this knowledge scattered in numerous and often hard-toaccess reports and papers and summarize their basic conclusions in a single publication.Fil: Cladera, Jorge Luis. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Instituto Nacional de Tecnología Agropecuaria. Centro de Investigación en Ciencias Veterinarias y Agronómicas. Instituto de Genética; ArgentinaFil: Vilardi, Juan Cesar. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Ecología, Genética y Evolución de Buenos Aires. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Ecología, Genética y Evolución de Buenos Aires; Argentina. Universidad de Buenos Aires. Facultad de Cs.exactas y Naturales. Departamento de Ecología, Genética y Evolución. Genética de Población Aplicadas; ArgentinaFil: Juri, Marianela Lucia. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Ecología, Genética y Evolución de Buenos Aires. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Ecología, Genética y Evolución de Buenos Aires; Argentina. Instituto Nacional de Tecnología Agropecuaria. Centro de Investigación en Ciencias Veterinarias y Agronómicas. Instituto de Genética; Argentina. Universidad de Buenos Aires. Facultad de Cs.exactas y Naturales. Departamento de Ecología, Genética y Evolución. Genética de Población Aplicadas; ArgentinaFil: Paulin, Laura Elisa. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Ecología, Genética y Evolución de Buenos Aires. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Ecología, Genética y Evolución de Buenos Aires; Argentina. Universidad de Buenos Aires. Facultad de Cs.exactas y Naturales. Departamento de Ecología, Genética y Evolución. Genética de Población Aplicadas; ArgentinaFil: Giardini, M. Cecilia. Instituto Nacional de Tecnología Agropecuaria. Centro de Investigación en Ciencias Veterinarias y Agronómicas. Instituto de Genética; ArgentinaFil: Gómez Cendra, Paula Valeria. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Ecología, Genética y Evolución de Buenos Aires. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Ecología, Genética y Evolución de Buenos Aires; Argentina. Universidad de Buenos Aires. Facultad de Cs.exactas y Naturales. Departamento de Ecología, Genética y Evolución. Genética de Población Aplicadas; ArgentinaFil: Segura, Diego Fernando. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Instituto Nacional de Tecnología Agropecuaria. Centro de Investigación en Ciencias Veterinarias y Agronómicas. Instituto de Genética; ArgentinaFil: Lanzavecchia, Silvia Beatriz. Instituto Nacional de Tecnología Agropecuaria. Centro de Investigación en Ciencias Veterinarias y Agronómicas. Instituto de Genética; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin
- …