120 research outputs found
Relaxometría de Nanopartículas de Oxido de Hierro como medio de contraste en Imágenes de Resonancia Magnética
Membrane Dissolution in Distributed Architectures of P-Systems
The goal of this paper is twofold. Firstly, to survey in a systematic and uniform way the main results regarding the way membranes can be placed on processors in order to get a software/hardware simulation of P-Systems in a distributed environment. Secondly, we improve some results about the membrane dissolution problem, prove that it is connected, and discuss the possibility of simulating this property in the distributed model. All this yields an improvement in the system parallelism implementation since it gets an increment of the parallelism of the external communication among processors. Also, the number of processors grows in such a way that is notorious the increment of the parallelism in the application of the evolution rules and the internal communica-tionsstudy because it gets an increment of the parallelism in the application of the evolution rules and the internal communications. Proposed ideas improve previous architectures to tackle the communication bottleneck problem, such as reduction of the total time of an evolution step, increase of the number of membranes that could run on a processor and reduction of the number of processor
Distributed models in P-Systems architectures to reduce computation time
Membrane systems are computational equivalent to Turing machines. However, their distributed and massively parallel nature obtains polynomial solutions opposite to traditional non-polynomial ones. At this point, it is very important to develop dedicated hardware and software implementations exploiting those two membrane systems features. Dealing with distributed implementations of P systems, the bottleneck communication problem has arisen. When the number of membranes grows up, the network gets congested. The purpose of distributed architectures is to reach a compromise between the massively parallel character of the system and the needed evolution step time to transit from one configuration of the system to the next one, solving the bottleneck communication problem. The goal of this paper is twofold. Firstly, to survey in a systematic and uniform way the main results regarding the way membranes can be placed on processors in order to get a software/hardware simulation of P-Systems in a distributed environment. Secondly, we improve some results about the membrane dissolution problem, prove that it is connected, and discuss the possibility of simulating this property in the distributed model. All this yields an improvement in the system parallelism implementation since it gets an increment of the parallelism of the external communication among processors. Proposed ideas improve previous architectures to tackle the communication bottleneck problem, such as reduction of the total time of an evolution step, increase of the number of membranes that could run on a processor and reduction of the number of processors
Factores Asociados a Hemorragia Intraventricular En Neonatos Atendidos En Un Hospital de Segundo Nivel
Intraventricular hemorrhage (HIV) is a complication in neonates. It originates in the subependymal germinal matrix. This area is irrigated by a network of poorly differentiated vessels without a basement membrane. Also, it is fragile and vulnerable to the hemodynamic instability of cerebral blood flow. It is an important risk factor for periventricular leukomalacia, ventriculomegaly, and hydrocephalus. These neurological pathologies can generate sequelae in the pediatric population such as cerebral palsy (CP). Objective: To identify the factors associated with HIV in neonates treated in the early intervention program of the hospital of specialties of the child and the woman of the Secretary of Health of the State of Querétaro (HENMSESEQ). Material and Methods: Through the review of the clinical files, the factors associated with HIV present in the children attended to in the HENMSESEQ early intervention service were observed in 2015. Cases of HIV were corroborated by means of transfontanel ultrasound, statistical analysis with measures of central tendency, and comparison of the medians of children diagnosed with HIV and without diagnosis. Results: A group of 69 infants attended to in the early intervention program was studied. Out of them, 65.2% (45) were women and 34.3% (24) were men. They had a gestational age of 34.19 ± 4.22 weeks, birth weight of 2116.09 ± 859.36 g, and height of 44.06 ± 6.02 cm. Their stay in the Neonatal Intensive Care Unit (NICU) for the sample was 11.88 ± 16.84 days and they were 8.65 ± 12.20 days with invasive mechanical ventilation. There were 25 cases of HIV diagnosed by transfontanel ultrasound. Out of the 25 cases, 7 (10%) were HIV grade I, 14 (20%) II, 4 (5.7%) III, and no cases of grade IV were diagnosed. Using the Mann-Whitney U test, a difference was found between the groups of neonates diagnosed with HIV and without diagnosis in weeks of gestation, height, weight, APGAR, days of intubation, and days of stay in NICU
El desenvolupament curricular de l’Educació Física a Primària i Secundària: una anàlisi des de la perspectiva del professorat
L’estudi analitza el desenvolupament curricular de l’àrea d’Educació Física respecte a tres elements bàsics del currículum (finalitats, continguts i metodologia). Per assolir els objectius de l’estudi, les dades quantitatives i qualitatives van ser recollides mitjançant l’aplicació d’una enquesta postal i el desenvolupament de grups de discussió. Els resultats mostren que els/les docents d’Educació Física troben dificultats per desenvolupar les prescripcions dictades pel currículum oficial. Tanmateix, les dades indiquen clares diferències entre el professorat de primària i secundària respecte a la prioritat de les finalitats educatives, la selecció de continguts i la forma de treballar-los. Per tant, els resultats d’aquest estudi demostren la idea que les manifestacions del professorat sobre el desenvolupament del currículum en Educació Física estarien en part determinades per les prescripcions i valors que envolten el currículum oficial de cada una de les etapes, on aquest exerceix la seva tasca educativa
Magnetic and microstructural analysis of palladium nanoparticles with different capping systems
Palladium nanoparticles capped with different protective systems in a size range between 1.2 and 2.4 nm have been obtained by varying the preparation chemical method. Magnetization curves for all the samples show hysteresis loops, evidencing a ferromagnetic or a permanent magnetism in the nanoparticles. The microstructure of the nanoparticles has been analyzed by x-ray absorption and transmission electron microscopy. The nature of the magnetic behavior found for all these Pd nanoparticles (NPs) is different depending on their sizes and structural features and is explained on the basis of two different suggested mechanisms. The particles protected by means of a surfactant (tetralkylammonium salts), present a ferromagnetic order related to the factors increasing the density of states just below the Fermi level. Whereas, when the nanoparticles are stabilized by covalent bonds with protective species (thiol derivatized alkane chains or surface oxidized Pd NPs), the increase of the 4d density of holes, localized by the bonded atoms (S or O), is giving rise to the observed ferromagneticlike behavio
Haloalkalitolerant Actinobacteria with capacity for anthracene degradation isolated from soils close to areas with oil activity in the State of Veracruz, Mexico
The use of native strains of microorganisms from soils is an excellent option for bioremediation. To our knowledge, until now there has been no other group working on the isolation of Actinobacteria from contaminated soils in Mexico. In this study, samples of soils close to areas with oil activity in the State of Veracruz, Mexico, were inoculated for the isolation of Actinobacteria. The strains isolated were characterized morphologically, and the concentrations of NaCl and pH were determined for optimal growth. Strain selection was performed by the detection of a phylogenetic marker for Actinobacteria located at the 23S rRNA gene, followed by species identification by sequencing the 16S rRNA gene. Several haloalkalitolerant Actinobacteria were isolated and identified as: Kocuria rosea, K. palustris, Microbacterium testaceum, Nocardia farcinica and Cellulomonas denverensis. Except for C. denverensis, the biomass of all strains increased in the presence of anthracene. The strains capacity to metabolize anthracene (at 48 h), determined by fluorescence emission, was in the range of 46–54%. During this time, dihydroxy aromatic compounds formed, characterized by attenuated total reflectance Fourier transform infrared spectroscopy bands of 1205 cm–1 and 1217 cm–1. Those Actinobacteria are potentially useful for the bioremediation of saline and alkaline environments contaminated with polycyclic aromatic hydrocarbon compounds. [Int Microbiol 2016; 19(1):15-26]Keywords: Kocuria · Microbacterium · haloalkalitolerant Actinobacteria · anthracene degradation · State of Veracruz, Mexic
Case Report: Prone Positioning and Nasal High Flow Oxygen Therapy - An Alternative Strategy to Invasive and Non-Invasive Ventilation in a Case of Severe Acute Respiratory Distress Syndrome
Acute respiratory distress syndrome (ARDS) is associated with high rates of mortality, which is directly attributed to the pulmonary inflammatory response then compromising gaseous exchange. This case study describes the successful management of a 63-year-old male with severe ARDS who received a strategy which involved the following interventions: Nasal High Flow Oxygen (NHFO) therapy, and prone positioning. It is thought that this strategy improved the lung volume at end expiration to an extent that the patient was able to avoid both noninvasive (NIV) and invasive mechanical ventilation (MV) (and their known associated risks). There is limited evidence describing the use of NHF therapy in patients with ARDS. The use of prone positioning has been demonstrated to significantly improve 28-day mortality in patients with severe ARDS with a PaO2/FiO2< 150 mmHg. The authors acknowledge that until such time that controlled clinical trials considering the efficacy of strategy are conducted it would be premature to recommend it forall suchcases. The prone position is a promising therapy for patients with spontaneous ventilation with high-flow oxygen therapy; controlled and randomized studies should be done to demonstrate its safety and efficacy
Bioactives Overproduction through Operational Strategies in the Ichthyotoxic Microalga Heterosigma akashiwo Culture
The red tide-forming microalga Heterosigma akashiwo has been associated with massive events of fish deaths, both wild and cultured. Culture conditions are responsible for the synthesis or accumulation of some metabolites with different interesting bioactivities. H. akashiwo LC269919 strain was grown in a 10 L bubble column photobioreactor artificially illuminated with multi-coloured LED lights. Growth and production of exopolysaccharides, polyunsaturated fatty acids (PUFAs), and carotenoids were evaluated under different culture modes (batch, fed-batch, semicontinuous, and continuous) at two irradiance levels (300 and 700 µE·s−1·m−2). Continuous mode at the dilution rate of 0.2·day−1 and 700 µE·s−1·m−2 provided the highest production of biomass, PUFAs (132.6 and 2.3 mg·L−1·day−1), and maximum fucoxanthin productivity (0.16 mg·L−1·day−1). The fed-batch mode accumulated exopolysaccharides in a concentration (1.02 g·L−1) 10-fold over the batch mode. An extraction process based on a sequential gradient partition with water and four water-immiscible organic solvents allowed the isolation of bioactive fucoxanthin from methanolic extracts of H. akashiwo. Metabolites present in H. akashiwo, fucoxanthin and polar lipids (i.e., eicosapentaenoic acid (EPA)), or probably such as phytosterol (β-Sitosterol) from other microalgae, were responsible for the antitumor activity obtained.This research was funded by the General Secretariat of Universities, Research and Technology of the Andalusian Government (grant: P18-RT-2477) and the State Research Agency (grants PID2019-109476RB-C22) of the Spanish Ministry of Science, Innovation and Universities
Modificaciones en el planteamiento docente de la asignatura Fundamentos Químicos de la Ingeniería Civil del Grado en Ingeniería Civil
Es un problema actual la falta de motivación de los estudiantes del grado en Ingeniería Civil, especialmente en las asignaturas básicas. En esta red se ha planteado un cambio tanto de programa como de metodología docente para el caso de Fundamentos Químicos de la Ingeniería Civil, a fin de mejorar los resultados del aprendizaje de los estudiantes. Se ha realizado en primer lugar una investigación de los programas y metodologías docentes utilizados en otras universidades españolas para materias equivalentes y los resultados de esa búsqueda, junto con el estudio y la reflexión sobre la aplicabilidad de nuevas metodologías docentes ha dado lugar a una propuesta de metodología/programa que se pretende implementar en el curso 1016-17 y seguir analizando de forma crítica para mejorarlo. Se propone el uso de la metodología del aprendizaje basado en proyectos para la selección de materiales óptimos para una obra de Ingeniería Civil, y el desarrollo, a partir de la información obtenida por los alumnos y modulada por el equipo docente tendrá como resultado la adquisición de todas las competencias y cubrirá todos los descriptores incluidos en la memoria verificada del grado
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