85 research outputs found

    Ventajas de la uniformización de objetos didácticos para la mejora de resultados docentes en un máster interuniversitario

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    El uso de entornos virtuales por parte de las universidades españolas está realmente consolidado, en ellos el docente puede poner a disposición de su alumnado diferentes tipos de objetos didácticos con los contenidos docentes de una determinada asignatura. Es evidente que el contenido de dichos objetos didácticos es importante para adquirir las competencias necesarias, pero también hay que poner atención al formato de los mismos. El presente trabajo pretende poner de manifiesto la importancia de la uniformización de objetos didácticos en la mejora de los resultados docentes. Este aspecto es especialmente relevante cuando se trata de estudios interuniversitarios, en los que intervienen docentes de diferentes universidades y con diferentes plataformas virtuales para generar y poner a disposición del alumnado el material didáctico. En particular se ha empleado la información disponible del Máster interuniversitario en Integridad y Durabilidad de Materiales, Componentes y Estructuras impartido conjuntamente por las Universidades de Oviedo, Cantabria y Burgos

    TEM study of defects versus growth orientations in heavily boron-doped diamond

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    International audienceHeavy boron-doping layer in diamond can be responsible for the generation of extended defects during the growth processes (Blank et al., Diam. Relat. Mater. 17, 1840 (2008) [1]). As claimed recently (Alegre et al., Appl. Phys. Lett. 105, 173103 (2014) [2]), boron pair interactions rather than strain-related misfit seems to be responsible for such dislocation generation. In the present work, electron microscopy observations are used to study the defects induced by heavy boron doping in different growth plane orientations. Facets of pyramidal Hillocks (PHs) and pits provide access to non-conventional growth orientations where boron atoms incorporation is different during growth. TEM analysis on FIB prepared lamellas confirm that also for those growth orientations, the generation of dislocations occurs within the heavily boron-doped diamond layers. Stacking faults (SFs) have been also observed by high resolution transmission electron microscopy (HREM). From the invisibility criteria, using weak beam (WB) observation, ½ [1-10] and 1/6 [11-2], Burger vectors have been identified. Their generation behavior confirms the mechanism reported by Alegre et al. where local in-plane strain effects induced at the growing surface of the diamond lattice by the neighboring of several boron atoms cause the generation of such extended defects

    Low-density colloid centrifugation removes bacteria from boar semen doses after spiking with selected species

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    [EN] Single-layer centrifugation (SLC) with a low-density colloid is an efficient method for removing contaminating microorganisms from boar semen while recovering most spermatozoa from the original sample. This study tested the performance of this technique, using 50-ml tubes, by spiking commercial semen doses prepared without antibiotics with selected bacterial species followed by storage at 17 °C. The doses were spiked up to 102/ml CFU (colony forming units) of the bacteria Burkholderia ambifaria, Pseudomonas aeruginosa, and Staphylococcus simulans. The semen was processed by SLC (15 ml of sample and 15 ml of colloid) with the colloid Porcicoll at 20% (P20) and 30% (P30), with a spiked control (CTL) and an unspiked control (CTL0), analyzing microbiology and sperm quality on days 0, 3 and 7. SLC completely removed B. ambifaria and S. simulans, considerably reducing P. aeruginosa and overall contamination (especially P30, ∼104 CFU/ml of total contamination on day 7, median). Sperm viability was lower in P20 and P30 samples at day 0, with higher cytoplasmic ROS. Still, results were similar in all groups on day 3 and reversed on day 7, indicating a protective effect of SLC (possibly directly by removal of damaged sperm and indirectly because of lower bacterial contamination). Sperm chromatin was affected by the treatment (lower DNA fragmentation and chromatin decondensation) and storage (higher overall condensation on day 7 as per chromomycin A3 and monobromobimane staining). In conclusion, SLC with low-density colloids can remove most bacteria in a controlled contamination design while potentially improving sperm quality and long-term storage at practical temperatures.S

    P24 75. Resultados a medio plazo de la revascularización transmiocárdica con láser y células madre

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    ObjetivoAnalizar los resultados a medio plazo de la revascularización transmiocárdica con láser en combinación con células madre en pacientes con angina refractaria.MétodosDesde junio de 2007 hasta diciembre de 2009 se seleccionaron 19 pacientes (16 hombre y 3 mujeres) con enfermedad coronaria difusa y angina refractaria a tratamiento médico (clase III: 12 pacientes, clase IV: 7 pacientes). En todos ellos se realizó cirugía de revascularización transmiocárdica con láser en combinación con implantación de células madre de médula ósea autóloga.ResultadosLa edad media fue de 65 ± 8,5 años. La media de intervencionismos percutáneos por pacientes previos a la cirugía fue de 3,3 (rango 0-7). Ocho pacientes fueron intervenidos previamente de cirugía coronaria. No hubo efectos adversos asociados al procedimiento. No hubo mortalidad quirúrgica. El número medio de canales creados fue de 19, con un recuento celular por mililitro de: células totales mononuclares (1.660 x 106), CD34+ (9,8 x 106), y CD133+ (4,6 x 106). La mediana de estancia hospitalaria fue de 6 días. El seguimiento medio fue de 19 meses (rango 1-30). En el seguimiento un paciente falleció 24 meses tras la cirugía por insuficiencia cardíaca. En el último seguimiento 11 pacientes estaban en clase I, 5 en clase II y 3 en clase III.Tres pacientes requirieron nuevo cateterismo debido a empeoramiento de su angina.ConclusionesLa cirugía transmiocárdica con láser en combinación con inyección de células madre es un procedimiento seguro y clínicamente efectivo en pacientes con enfermedad coronaria difusa y angina refractaria a tratamiento médico

    Functional traits driving species role in the structure of terrestrial vertebrate scavenger networks

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    Species assemblages often have a non-random nested organization, which in vertebrate scavenger (carrion-consuming) assemblages is thought to be driven by facilitation in competitive environments. However, not all scavenger species play the same role in maintaining assemblage structure, as some species are obligate scavengers (i.e., vultures) and others are facultative, scavenging opportunistically. We used a database with 177 vertebrate scavenger species from 53 assemblages in 22 countries across five continents to identify which functional traits of scavenger species are key to maintaining the scavenging network structure. We used network analyses to relate ten traits hypothesized to affect assemblage structure with the “role” of each species in the scavenging assemblage in which it appeared. We characterized the role of a species in terms of both the proportion of monitored carcasses on which that species scavenged, or scavenging breadth (i.e., the species “normalized degree”), and the role of that species in the nested structure of the assemblage (i.e., the species “paired nested degree”), therefore identifying possible facilitative interactions among species. We found that species with high olfactory acuity, social foragers, and obligate scavengers had the widest scavenging breadth. We also found that social foragers had a large paired nested degree in scavenger assemblages, probably because their presence is easier to detect by other species to signal carcass occurrence. Our study highlights differences in the functional roles of scavenger species and can be used to identify key species for targeted conservation to maintain the ecological function of scavenger assemblages.Generalitat Valenciana SEJI/2018/024, APOSTD/2019/016, CIDEGENT/ 2020/030, ACIF/2019/056Ministerio de Educación y Cultura CI-2017-32149, FJCI-2015-25632, IJC2018-036642-I, YC-2019-027216-I, RYC-2015-19231, RYC-2017-2273, GL2012-40013-C02-01/02, CGL2015- 66966-C2-1-R, CGL2015-66966-C2-1-R2, CGL2017-89905-R, RTI2018-099609-B-C21, RTI2018-099609-B-C22Govern de les Illes Balears PD/039/201National Science Centre in Poland 2013/08/M/ NZ9/00469, 2016/22/Z/NZ8/00Slovenian Research Agency P4-0059US Department of Energy DE- EM000439USA National Science Foundation #1255913California Department of Fish & Wildlife P0880013Junta de Andalucía RNM-192

    Effects of dexmedetomidine on subthalamic local field potentials in parkinson's disease

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    Background: Dexmedetomidine is frequently used for sedation during deep brain stimulator implantation in patients with Parkinson's disease, but its effect on subthalamic nucleus activity is not well known. The aim of this study was to quantify the effect of increasing doses of dexmedetomidine in this population. Methods: Controlled clinical trial assessing changes in subthalamic activity with increasing doses of dexmedetomidine (from 0.2 to 0.6 μg kg-1 h-1) in a non-operating theatre setting. We recorded local field potentials in 12 patients with Parkinson's disease with bilateral deep brain stimulators (24 nuclei) and compared basal activity in the nuclei of each patient and activity recorded with different doses. Plasma levels of dexmedetomidine were obtained and correlated with the dose administered. Results: With dexmedetomidine infusion, patients became clinically sedated, and at higher doses (0.5-0.6 μg kg-1 h-1) a significant decrease in the characteristic Parkinsonian subthalamic activity was observed (P<0.05 in beta activity). All subjects awoke to external stimulus over a median of 1 (range: 0-9) min, showing full restoration of subthalamic activity. Dexmedetomidine dose administered and plasma levels showed a positive correlation (repeated measures correlation coefficient=0.504; P<0.001). Conclusions: Patients needing some degree of sedation throughout subthalamic deep brain stimulator implantation for Parkinson's disease can probably receive dexmedetomidine up to 0.6 μg kg-1 h-1 without significant alteration of their characteristic subthalamic activity. If patients achieve a 'sedated' state, subthalamic activity decreases, but they can be easily awakened with a non-pharmacological external stimulus and recover baseline subthalamic activity patterns in less than 10 min
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