1,421 research outputs found
Diseño de estructura de pavimento flexible de 2 kilómetros Lineales de calle por el método AASHTO 93 y drenaje menor, Juigalpa, Chontales
Presenta el diseño de la estructura de Pavimento y drenaje menor en algunas calles del Barrio Nuevo Amanecer y la Vía principal que conduce al Rastro Municipal, y a las nuevas instalaciones de la Sede de la Universidad Nacional de Ingeniería (UNI-RCJ), para proponer una Solución a la problemática y dificultades que afecta a pobladores de la zona
Self-organized nanopattrening of silicon surfaces by ion beam sputtering
In recent years Ion Beam Sputtering (IBS) has revealed itself as a powerful technique to induce surface nanopatterns with a large number of potential applications. These structures are produced in rather short processing times and over relatively large areas, for a wide range of materials, such as metals, insulators, and semiconductors. In particular, silicon has become a paradigmatic system due to its technological relevance, as well as to its mono-elemental nature, wide availability, and production with extreme flatness. Thus, this review focuses on the IBS nanopatterning of silicon surfaces from the experimental and the theoretical points of view. First, the main experimental results and applications are described under the light of the recently established evidence on the key role played by simultaneous impurity incorporation during irradiation, which has opened a new scenario for an improved understanding of the phenomenon. Second, the progress and state-of-art of the theoretical descriptions of the IBS nanopatterning process for this type of targets are discussed. We summarize the historical approach to IBS through simulation techniques, with an emphasis on recent information from Molecular Dynamics methods, and provide a brief overview of the earlier and most recent continuum models for pure and compound systems.This work has been partially supported by the Spanish Ministries of Science and Innovation (grants Nos. FIS2009-12964-C05-01, FIS2009-12964-C05-03, FIS2009-12964-C05-04, and BES-2010-036179) and of Economy and Competitiveness (grants Nos. FIS2012-38866-C05-01 and FIS2012-38866-C05-05, FIS2012-32349 and FIS2013-47949-C2-2). A.R.C. also acknowledges funding from SFRH/BPD/74095/2010 (Portugal) and from Juan de la Cierva program (Spain) under contract No. JCI-2012-14509.Publicad
Nonuniversality due to inhomogeneous stress in semiconductor surface nanopatterning by low-energy ion-beam irradiation
A lack of universality with respect to ion species has been recently established in nanostructuring of semiconductor surfaces by low-energy ion-beam bombardment. This variability affects basic properties of the pattern formation process, like the critical incidence angle for pattern formation, and has remained unaccounted for. Here, we show that nonuniform generation of stress across the damaged amorphous layer induced by the irradiation is a key factor behind the range of experimental observations, as the form of the stress field is controlled by the ion/target combination. This effect acts in synergy with the nontrivial evolution of the amorphous-crystalline interface. We reach these conclusions by contrasting a multiscale theoretical approach, which combines molecular dynamics and a continuum viscous flow model, with experiments using Xe+ and Ar+ ions on a Si(100) target. Our general approach can apply to a variety of semiconductor systems and conditions.This work has been partially supported by MICINN (Spain) Grant MAT2011-13333-E, and MINECO (Spain) Grants FIS2012-38866-C05-01, FIS2012-38866-C05-05, FIS2013-47949-C2-2-P and FIS2012-32349. TEM work has been conducted at LABMET laboratory, associated with Red de Laboratorios of CAM, Spain. A.M.-B. acknowledges support from MINECO, through FPI scolarship BES-2010-036179. A.R.C. acknowledges funding from Juan de la Cierva program (Spain) under Contract No. JCI-2012-14509.Publicad
Detección molecular de coronavirus bovino asociado al complejo respiratorio bovino en ganado de engorda del valle de Mexicali, Baja California, México
The bovine respiratory complex (BRC) is the leading cause of disease and death in beef cattle worldwide. It is a multifactorial infectious syndrome caused by different viruses and bacteria that reduce the productive efficiency and cause economic losses. In Mexico, BRC has been reported in all regions where cattle are fattened; however, these reports lack information on the presence of bovine respiratory coronavirus (BCV). This makes it necessary to have reliable and accurate diagnostic tools for detecting the presence of BCV in beef cattle fattened in Mexico, in order to propose appropriate sanitary measures for their clinical management. In this work, a real-time-PCR molecular diagnostic platform (rt-PCR) was developed to amplify a fragment of the BCV S protein in nasal exudate samples. When applying the rt-PCR platform for BCV in seemingly healthy beef cattle with signs of respiratory disease associated to BRC, 19/50 (38 %) were found to be positive, confirming the presence of this virus in the cattle of the region. The results of this work constitute the first report on the presence of the BCV associated to the BRC in the cattle region of northwestern Mexico and establish the bases for future research about the role that this virus plays in the presentation of the pathology of the BRC in beef cattle exploitation systems in this region and across the country.El complejo respiratorio bovino (CRB) es la principal causa de enfermedad y muerte en el ganado de engorda en todo el mundo. Es un síndrome infeccioso multifactorial provocado por distintos virus y bacterias que disminuyen la eficiencia productiva y ocasionan pérdidas económicas. En México, el CRB se ha reportado en todas las regiones donde se engorda ganado; sin embargo, esos reportes carecen de información sobre la presencia del coronavirus respiratorio bovino (CVB), haciendo necesario contar con herramientas de diagnóstico confiables y precisas para detectar la presencia de CVB en el ganado que se engorda en México, para proponer las medidas sanitarias apropiadas para su manejo clínico. En este trabajo, se desarrolló una plataforma de diagnóstico molecular de PCR en tiempo real (rt-PCR) que amplifica un fragmento de la proteína S del CVB en muestras de exudado nasal. Al aplicar la plataforma rt-PCR para CVB en bovinos de engorda en aparente estado de salud y con signos de enfermedad respiratoria asociados a CRB se encontró que 19/50 (38 %) resultaron positivos, confirmando la presencia de ese virus en el ganado de la región. Los resultados de este trabajo significan el primer reporte sobre la presencia del CVB asociado al CRB en la región ganadera del noroeste de México y sienta las bases para futuras investigaciones sobre papel que juega este virus en la presentación de la patología del CRB en los sistemas de explotación de bovinos de engorda en nuestra región y el país
Competiciones de programación. Estímulo y salida laboral para los alumnos
Las competiciones de programación son un estímulo
importante para los alumnos de informática. Durante
los últimos años ha crecido el número de estas competiciones
en su mayoría promovidas por grandes empresas
con el propósito de reclutar alumnos brillantes.
La International Collegiate Programming Contest
es la más antigua de ellas, promovida por la ACM y
patrocinada por IBM. A la final mundial van los mejores
equipos de cada una de las más de 90 competiciones
regionales que tienen lugar por todo el mundo.
La regional en la que pueden participar las universidades
españolas es la Southwestern Europe Regional
Contest (España, Italia, Portugal, Suiza, Francia y Austria).
Esta regional fue organizada por la Escola Tècnica
Superior d’Enginyeria Informàtica de la Universitat
Politècnica de València en su edición de 2012 y lo será
también en 2013.
En este trabajo se presenta la experiencia de planificación
de una regional, tanto a nivel organizativo como
de planteamiento de los problemas para la competición.
Asimismo, se destaca la importancia de este
tipo de competiciones en cuanto al desarrollo de habilidades
y destrezas en los alumnos, pues su dedicación
a solucionar distintos tipos de problemas, combinando
conocimientos de matemáticas con técnicas algorítmicas,
les da una formación adicional que saben apreciar
las grandes empresas. Algunos alumnos de la ETSInf
que han participado en estas competiciones están en
proceso o ya han sido contratados por empresas del
sector como es Google.SUMMARY -- Programming contests are a good stimulus for computer
engineering students. These contests have experienced
an expansion during last years thanks to the interest
of big companies for hiring brilliant students.
The International Collegiate Programming Contest
is the oldest one, promoted by ACM and sponsored by
IBM. The ACM-ICPC World Final takes place every
year, only the best teams can participate, which are selected
from the ones who compete in the more than 90
regional contests celebrated around the world. Spanish
universities can participate in the Southwestern Europe
Regional Contest (Spain, Italy, Portugal, France and
Austria). The 2012 edition of this regional contest took
place in Valencia, organised by the School of Computer
Engineering at the Universitat Politècnica de València.
The 2013 edition will be organised in Valencia as
well.
In this paper it is presented the experience of planning
a regional contest, both from the point of view of
organisation as from posing the problems. Additionally,
it is pointed out the value of this sort of programming
contests as they foster the development of some
abilities and skills in students, because the time they
spend solving problems where the knowledge of mathematical
concepts and of algorithmic techniques is
very important. This fact gives students a special training
very appreciated by big software companies. Some
former students from ETSInf who participated in
international programming contests were hired or are
in process of being hired by Google
Early Stepdown From Echinocandin to Fluconazole Treatment in Candidemia: A Post Hoc Analysis of Three Cohort Studies
[Background] There are no clear criteria for antifungal de-escalation after initial empirical treatments. We hypothesized that early de-escalation (ED) (within 5 days) to fluconazole is safe in fluconazole-susceptible candidemia with controlled source of infection.[Methods] This is a multicenter post hoc study that included consecutive patients from 3 prospective candidemia cohorts (2007–2016). The impact of ED and factors associated with mortality were assessed.[Results] Of 1023 candidemia episodes, 235 met inclusion criteria. Of these, 54 (23%) were classified as the ED group and 181 (77%) were classified as the non-ED group. ED was more common in catheter-related candidemia (51.9% vs 31.5%; P = .006) and episodes caused by Candida parapsilosis, yet it was less frequent in patients in the intensive care unit (24.1% vs 39.2%; P = .043), infections caused by Nakaseomyces glabrata (0% vs 9.9%; P = .016), and candidemia from an unknown source (24.1% vs 47%; P = .003). In the ED and non-ED groups, 30-day mortality was 11.1% and 29.8% (P = .006), respectively. Chronic obstructive pulmonary disease (odds ratio [OR], 3.97; 95% confidence interval [CI], 1.48–10.61), Pitt score > 2 (OR, 4.39; 95% CI, 1.94–9.20), unknown source of candidemia (OR, 2.59; 95% CI, 1.14–5.86), candidemia caused by Candida albicans (OR, 3.92; 95% CI, 1.48–10.61), and prior surgery (OR, 0.29; 95% CI, 0.08–0.97) were independent predictors of mortality. Similar results were found when a propensity score for receiving ED was incorporated into the model. ED had no significant impact on mortality (OR, 0.50; 95% CI, 0.16–1.53).[Conclusions] Early de-escalation is a safe strategy in patients with candidemia caused by fluconazole-susceptible strains with controlled source of bloodstream infection and hemodynamic stability. These results are important to apply antifungal stewardship strategies.This research forms part of an activity that has received funding from EIT Health. EIT Health is supported by the European Institute of Innovation and Technology (EIT), a body of the European Union that receives support from the European Union´s Horizon 2020 Research and Innovation Program. This study has been cofunded by the European Regional Development Fund. E. M.-G. (PI18/01061), P. P.-A. (“Rio Hortega” contract CM18/00132), M. F.-R. (“Miguel Servet” contract CP18/00073), and C. G.-V. (FIS PI18/01061) have received research grants from the Ministerio de Sanidad y Consumo, Instituto de Salud Carlos III.Peer reviewe
Programa de desarrollo de sistemas integrales de infraestructura y movilidad colectiva. Nuevas formas de movilidad para la vida
Las poblaciones urbanas padecen diversos problemas ambientales, de salud, segregación y pérdida de espacios públicos, derroche energético, ruido, así como altas inversiones de tiempo y dinero. Estas situaciones poseen un denominador común: una tecnología inadecuada llamada automóvil unipersonal. Buscamos intervenir tecnológicamente el contexto de las ciudades mediante un sistema de movilidad público, eficiente, no invasivo, silencioso, de bajo costo, saludable y ecológico. En este trabajo presentamos diferentes soluciones, con la intención de ir llevando esta tecnología hacia su transferencia tecnológica.ITESO, A.C.CoecytjalIngenieros Sin Frontera
Aulas develadas 3: la práctica, con investigación, se cambia
Este tercer libro de la colección “Aulas develadas: La práctica, con investigación, se cambia”, producto de las investigaciones de aula adelantadas por docentes de la Universidad del Norte, con el apoyo del Centro para la Excelencia Docente (CEDU) en el programa Círculo de Escritura, lo componen seis capítulos que recopilan los resultados de trabajos realizados por docentes de las áreas Ciencia política y Relaciones internacionales, Matemáticas, Psicología e Ingeniería. Confiamos en que los hallazgos que aquí se presentan sean de interés para los lectores y puedan ser compartidos de manera amplia entre distintos públicos
HCV-coinfection is related to an increased HIV-1 reservoir size in cART-treated HIV patients: a cross-sectional study
In HIV-1/HCV-coinfected patients, chronic HCV infection leads to an increased T-lymphocyte immune activation compared to HIV-monoinfected patients, thereby likely contributing to increase HIV-1 reservoir that is the major barrier for its eradication. Our objective was to evaluate the influence of HCV coinfection in HIV-1 viral reservoir size in resting (r) CD4+ T-cells (CD25-CD69-HLADR-). Multicenter cross-sectional study of 97 cART-treated HIV-1 patients, including 36 patients with HIV and HCV-chronic co-infection without anti-HCV treatment, 32 HIV patients with HCV spontaneous clearance and 29 HIV-monoinfected patients. rCD4+ T-cells were isolated and total DNA was extracted. HIV viral reservoir was measured by Alu-LTR qPCR. Differences between groups were calculated with a generalized linear model. Overall, 63.9% were men, median age of 41 years and Caucasian. Median CD4+ and CD8+ T-lymphocytes were 725 and 858 cells/mm 3 , respectively. CD4+ T nadir cells was 305 cells/mm 3 . Proviral HIV-1 DNA size was significantly increased in chronic HIV/HCV-coinfected compared to HIV-monoinfected patients (206.21 ± 47.38 vs. 87.34 ± 22.46, respectively; P = 0.009), as well as in spontaneously clarified HCV co-infected patients when compared to HIV-monoinfected individuals (136.20 ± 33.20; P = 0.009). HIV-1/HCV co-infected patients showed a larger HIV-1 reservoir size in comparison to HIV-monoinfected individuals. This increase could lead to a greater complexity in the elimination of HIV-1 reservoir in HIV-1/HCV-coinfected individuals, which should be considered in the current strategies for the elimination of HIV-1 reservoir.Financial support was provided by the Instituto de Salud Carlos III to VB (PI15CIII/00031), by the Spanish Ministry of Economy and Competitiveness to MC
(SAF2016–78480-R) and The SPANISH AIDS Research Network RD16CIII/0002/0001, RD16CIII/0002/0002
and RD16/0025/0013 - ISCIII – FEDER. MRLP is supported by ISCIII - Subdirección General de Evaluacion and European Funding for Regional Development (FEDER) (PIE 13/00040 and RD12/0017/0017 RETIC de
SIDA). C.P. is supported by the Portuguese Fundação para a Ciência e Tecnologia (FCT) (grant number SFRH/
BPD/77448/2011 is part of the EDCTP2 programme supported by the European Union). V.B., A.F.R. and N.R.
are supported by the Miguel Servet programme from Fondo de Investigación Sanitaria (ISCIII) (grant number CP13/00098, CP14/CIII/00010 and CP14/00198, respectively)
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