6,014 research outputs found
Reactions effected by basic polymers and other studies of polymer reactivity.
Polystyrene has been chloromethylated and the resultant polymer converted by reaction with triethylamine into the polymeric quaternary ammonium chloride; this on basification gave a solution of poly(vinylbenzyltriethyl-ammonium hydroxide). Rate-constants for the hydrolysis of six straight-chain aliphatic esters with this polymeric alkali at 0° have been determined, also the corresponding rate-constants with sodium hydroxide. The values of u, the ratio of the former to the latter rate-constant for each ester, range from 0.73 to 1.05. The rates of hydrolysis with polymeric alkali thus do not differ greatly from those with sodium hydroxide. The actual differences are ascribed to the operation of two relatively minor factors: a salting-out effect in the vicinity of the polymeric hydroxide and a hydrophobic association of the alcoholic alkyl group of the ester with the hydrocarbon structures of the polycation. These effects are in opposition, the former decelerating and the latter accelerating reaction. These results are discussed in relation to considerable other work (carried out in these laboratories) and a coherent account is presented of the factors which influence reactions of various types effected with poly(vinylbenzyltriethylammonium hydroxide). A number of further reactions of poly(chloromethyl-styrene) have been investigated, particular attention having been given to the insertion of acetylacetone units in the polymer. Further work was devoted to attempts to incorporate this unit in a macromolecule by addition polymerization and by polycondensation. In the final section an evaluation of the utility of poly(vinylpyridine)s as basic reagents in organic chemistry is described. The copolymer of 2-vinylpyridine and styrene is effective in the dehydrobromination of 1-bromooctane to 1-octene. Very little isomerization accompanies the reaction, and it is thought that the reagent will prove of use in specific dehydrohalogenations
La contribución de la mujer en la economÃa rural de Castilla y León
La participación de la mujer en el tejido socioeconómico de las zonas rurales se ha visto frecuentemente infravalorada. Sin embargo, desde hace pocos años existe una clara conciencia por parte de los poderes públicos de que la inclusión de la mujer en las estrategias de dinamización socioeconómica del mundo rural es fundamental para fijar población y generar renta y empleo. El objetivo de este trabajo se centra en determinar la contribución económica de la mujer en el desarrollo del medio rural de la Comunidad Autónoma de Castilla y León. Para ello, se ha analizado la relación existente entre el grado de desarrollo de los municipios rurales y las caracterÃsticas socioeconómicas de las mujeres que los habitan. Para alcanzar tal fin, se han empleado tres tipos de técnicas multivariantes: el análisis de componentes principales, la regresión múltiple y el análisis de conglomerados. Los resultados alcanzados permiten afirmar que la participación económica y social de la mujer en el medio rural de Castilla y León se configura como una condición indispensable para alcanzar un mayor bienestar y nivel de desarrollo en esas zonas.Género, desarrollo rural, métodos cuantitativos, Castilla y León (España)., Agricultural and Food Policy, J16, O18, R23,
Results of a Professional Medical Counseling/surveillance in Preoperative Weight Loss
Background:Preoperative weight loss reduces the risk for complications after bariatric surgery.Objectives:To evaluate the effectiveness of a preoperative counseling program compared to general recommendations alone.Setting: Obesity Surgery Unit. Reina Sofia General University Hospital. Murcia (southeast Spain).Methods: Prospective, randomized controlled study including 162 patients. Participants were randomly assigned to our preoperative intensive behavioral/lifestyle program (Counseling Group:55, 78% women) or to receive general nutritional recommendations (Reference Group:49, 82% women). Primary endpoint was a between-group comparison of percent excess weight loss (%EWL) at 4 months.Results: Counseling Group: baseline Body Mass Index (BMI)1was 45.9±7.3kg/m2 when enrolled into the education program and reduced to to BMI2:43.2±5.6kg/m2 the day before the operation. After the motivational intervention, we got an average loss of 7.3±3.7kg of body weight and 12.4%EWL in 16 weeks.Reference Group: mean BMI1 was 45.5±7.3kg/m2. The day before surgery, BMI2 was: 46.1±6.1kg/m2. Over a period of 16 weeks the average weight gain was 1.8±1.1kg and -3%EWL (p=0.12). Weight gain was observed in 55% of these patients.The comparison of the mean %EWL in both groups did not reveal any statistically significant differences. Conclusions: The educational intervention was not statistically significant more effective than general nutritional recommendations in achieving weight loss
RAEGE: An Atlantic Network of Geodynamical Fundamental Stations
Project RAEGE (Red Atlantica de Estaciones Geodinamicas y Espaciales) intends to set up a Spanish-Portuguese network of four Geodetic Fundamental Stations in Yebes (1), Canary Islands (1), and A cores Islands (2), as part of the developments needed for the IVS VLBI2010 scenario. It is envisaged that each Geodetic Fundamental Station will be equipped with one radio telescope of VLBI2010 specifications (at least 12-m diameter, fast slewing speed, but also able to operate up to 40 GHz), one gravimeter, one permanent GNSS station, and, at least at the Yebes site, one SLR facility. The National Geographical Institute of Spain (IGN) has experience in VLBI, having been a member of the European VLBI Network since 1993 and being one of the founding institutions of the Joint Institute for VLBI in Europe (JIVE), and it has been participating in geodetic VLBI campaigns with the 14-m radio telescope in Yebes since 1995. A new 40-m radio telescope has been built and was recently put into operation. It regularly participates in IVS sessions. There is infrastructure available for the new stations at Yebes and the Canary Islands. An agreement between IGN, the Portuguese Geographical Institute (IGP), and the Regional Government of the A cores ensures that the RAEGE project can become a reality by 2013
Electrical and magnetic properties of FM/MgO/FM (FM = Co90Fe10, Fe20Ni80) heterostructures
In this paper we present the development and characterization of FM/MgO/FM (FM = Co90Fe10, Fe20Ni80) heterostructures. The magnetic order of the structures, magnetic anisotropy and interlayer exchange coupling were characterized by magnetization measurements. The influence of the substrate temperature during growth on the magnetic properties and topographical features of the bottom electrode was also explored. Higher values of the coercive field were achieved increasing the substrate temperature during deposition of the bottom electrode. Patterned magnetic tunnel junctions were grown on Si(1 0 0) and MgO(1 0 0). The junctions consist of square pillars with different areas (1600, 625, 100 and 25 μm2) fabricated by optical lithography. I(V) curves obtained with conducting atomic force microscopy of the patterned junctions were performed at room temperature in order to explore the reproducibility of the transport properties of the insulating barrier. The results show a more insulating behavior of the junctions grown on Si(1 0 0), with very good control and a high reproducibility of the transport properties of the MgO insulating barrier.Fil: Aviles Felix, Luis Steven. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte; Argentina. Comisión Nacional de Energía Atómica. Centro Atómico Bariloche; Argentina. Comisión Nacional de Energía Atómica. Gerencia del Área de Energía Nuclear. Instituto Balseiro; ArgentinaFil: Gonzalez Sutter, Jesus Ignacio. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte; Argentina. Comisión Nacional de Energía Atómica. Centro Atómico Bariloche; Argentina. Comisión Nacional de Energía Atómica. Gerencia del Área de Energía Nuclear. Instituto Balseiro; ArgentinaFil: Gomez, Javier Enrique. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte; Argentina. Comisión Nacional de Energía Atómica. Centro Atómico Bariloche; Argentina. Comisión Nacional de Energía Atómica. Gerencia del Área de Energía Nuclear. Instituto Balseiro; ArgentinaFil: Sirena, Martin. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte; Argentina. Comisión Nacional de Energía Atómica. Centro Atómico Bariloche; Argentina. Comisión Nacional de Energía Atómica. Gerencia del Área de Energía Nuclear. Instituto Balseiro; Argentin
Design and Validation of A Modular Instrument to Measure Torque and Energy Consumption in Industrial Operations
A modular torque measuring instrument capable of performing tapping torque tests (TTT) according to the ASTM D-5619 standard was designed, developed, and validated. With this new instrument, the performance of different lubricants can be evaluated in terms of frictional torque and energy consumption during tapping processes. This instrument can adapt onto any conventional milling machine or CNC machine and operate under various machining operations such as tapping, drilling, and other processes. To validate the design and performance of this new device, three commercially available lubricants were evaluated. From the three tested conditions, the results showed good repeatability, with consistent results throughout the different tests for each lubricant. The impact of such a proposed instrument ranges from academic use to industrial business use
Determinación del óptimo técnico y económico en una granja porcícola en Temascaltepec, Estado de México
Se estimó una función de producción cuadrática con rendimientos marginales decrecientes para determinar los óptimos técnico y económico en una granja porcina semitecnificada. El óptimo técnico o peso máximo en el animal fue de 162.17 kg con 74 unidades de alimento y el económico de 142.77 kg con 49 unidades de alimento; el precio de venta en pie fue de 16.0/kg. Cuando el costo del insumo variable es bajo en relación con el precio de venta del cerdo, la ganancia máxima se obtiene vendiendo los animales cercanos al punto de máxima producción; por el contrario, cuando el precio del insumo variable es alto, la ganancia máxima se obtiene si el peso del cerdo se aproxima a 66.79 kg
Application of Non-Destructive Techniques to the Recording and Modelling of Palaeolithic Rock Art
Characteristics of 107 Spanish healthcare registries and evaluation of the utilization thereof
BACKGROUND: The information concerning the currently existing healthcare registries in our country is not readily accessible, is scarce and some are not well-known, possibly being underused in comparison to their many potential uses. This study is aimed at evaluating the characteristics of the Spanish Healthcare registries and the utilization thereof, especially in Healthcare technology assessment. METHODS: Descriptive, cross-sectional study of the Spanish Healthcare registries within the 1997-2002 period. These registries were identified by means ofa bibliographic databases search and by way of a survey of Scientific Societies and Central and Autonomic Healthcare Administration. Another bibliographic databases search was conducted of the publications which use data from the healthcare registries included and have been evaluated by applying the scientific evidence quality criteria. RESULTS: A total of 107 healthcare registries were identified, most of which of local or regional coverage (71%), preferably were under Autonomic government authority (64.5%). The areas showing the largest number of registries identified were those related to death statistics (16.8%) and cancer (15.9%). A total of 298 publications were retrieved which analyze data produced by the registries identified, most of which are devoted to the study of the frequency and distribution of the events recorded (58.1%) and less frequently to the conducting of healthcare technology assessment studies (24.4%). CONCLUSIONS: The critical evaluation of the publications made it possible to identify some elements related to the analysis methodology and design which would heighten the quality of the healthcare technology assessment. Healthcare registries in Spain have developed recently and to differing degrees. Important areas without any records and improvement elements related to the use of healthcare registries for healthcare technology assessment were detected. It would be advisable to avail of a register of registries which would provide relevant, up-dated information thereon. Fundamento:La información sobre los registros sanitarios exis-tentes en nuestro país es poco accesible y escasa y algunos son pococonocidos, pudiendo estar infrautilizados en relación con sus múlti-ples usos potenciales. El objetivo de este trabajo es evaluar las carac-terísticas de los Registros Sanitarios españoles y su utilización, espe-cialmente en Evaluación de Tecnologías Sanitarias.Métodos:Estudio descriptivo transversal de los Registros Sanita-rios españoles entre 1997 y 2002. La identificación de los registros serealizó a través de búsqueda bibliográfica y mediante encuesta a Socie-dades Científicas y Administración sanitaria central y autonómica. Seha realizado una búsqueda bibliográfica específica de las publicacio-nes que utilizan datos de los registros sanitarios incluidos y se han eva-luado aplicando los criterios de calidad de la evidencia científica.Resultados:Se han identificado 107 registros sanitarios, prefe-rentemente de cobertura local o regional (71%) y dependientes en sumayoría de la Administración autonómica (64,5%). Las áreas conmayor número de registros identificados corresponden a la mortali-dad (16,8%) y al cáncer (15,9%). Se han recuperado 298 publicacio-nes que analizan datos producidos por los registros identificados, delas que la mayoría se dedican al estudio de la frecuencia y distribuciónde los eventos registrados (58,1%) y con menor frecuencia a la reali-zación de estudios de evaluación de tecnologías sanitarias (24,4%).Conclusiones: La evaluación crítica de las publicaciones ha per-mitido identificar algunos elementos relacionados con el diseño y lametodología de análisis que incrementarían la calidad de los estudiosde evaluación de tecnologías sanitarias.Los registros sanitarios enEspaña han tenido un desarrollo desigual y reciente. Se han detecta-do áreas relevantes sin registros y elementos de mejora relacionadoscon la utilización de los registros sanitarios para estudios de evalua-ción de tecnologías sanitarias. Sería recomendable contar con unregistro de registros que proporcionara información relevante yactualizada sobre los mismo
Exploring Campylobacter seasonality across Europe (2008-2016) using The European Surveillance System TESSy
Background: Campylobacteriosis is the most commonly reported food-borne infection in the European Union, with an annual number of cases estimated at around 9 million. In many countries, campylobacteriosis has a striking seasonal peak during early/ mid-summer. In the early 2000s, several publications reported on campylobacteriosis seasonality across Europe and associations with temperature and precipitation. Subsequently, many European countries have introduced new measures against this foodborne disease. Aim: To examine how the seasonality of campylobacteriosis varied across Europe from 2008–16, to explore associations with temperature and precipitation, and to compare these results with previous studies. We also sought to assess the utility of the European Surveillance System TESSy for cross-European seasonal analysis of campylobacteriosis. Methods: Ward’s Minimum Variance Clustering was used to group countries with similar seasonal patterns of campylobacteriosis. A two-stage multivariate meta-analysis methodology was used to explore associations with temperature and precipitation. Results: Nordic countries had a pronounced seasonal campylobacteriosis peak in mid-to late summer (weeks 29–32), while most other European countries had a less pronounced peak earlier in the year. The United Kingdom, Ireland, Hungary and Slovakia had a slightly earlier peak (week 24). Campylobacteriosis cases were positively associated with temperature and, to a lesser degree, precipitation. Conclusion: Across Europe, the strength and timing of campylobacteriosis peaks have remained similar to those observed previously. In addition, TESSy is a useful resource for cross-Euro-pean seasonal analysis of infectious diseases such as campylobacteriosis, but its utility depends upon each country’s reporting infrastructure
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