5,556 research outputs found
Flux-cutting and flux-transport effects in type-II superconductor slabs in a parallel rotating magnetic field
The magnetic response of irreversible type-II superconductor slabs subjected
to in-plane rotating magnetic field is investigated by applying the circular,
elliptic, extended-elliptic, and rectangular flux-line-cutting critical-state
models. Specifically, the models have been applied to explain experiments on a
PbBi rotating disk in a fixed magnetic field , parallel to the flat
surfaces. Here, we have exploited the equivalency of the experimental situation
with that of a fixed disk under the action of a parallel magnetic field,
rotating in the opposite sense. The effect of both the magnitude of the
applied magnetic field and its angle of rotation upon the
magnetization of the superconductor sample is analyzed. When is smaller
than the penetration field , the magnetization components, parallel and
perpendicular to , oscillate with increasing the rotation angle. On
the other hand, if the magnitude of the applied field, , is larger than
, both magnetization components become constant functions of at
large rotation angles. The evolution of the magnetic induction profiles inside
the superconductor is also studied.Comment: 12 pages, 29 figure
Effect of solidification rate on pore connectivity of aluminium foams and its consequences on mechanical properties
This study evaluates the influence of solidification rate on the generation and control of pore connectivity of closed-cell aluminium foams. Additionally, it gives the experimental support to evaluate and model the effect of this pore connectivity on the mechanical properties. A collection of AlSi10 foams produced via powder metallurgy route, with porosities between 0.65 and 0.85, were examined. During production, applied heating conditions were the same in all cases but the cooling conditions were varied in order to promote different solidification rates in a wide range (from -1 to -15 K/s). Structural characterisation was performed by gas pycnometry and X- ray microtomography while the mechanical properties were evaluated by microhardness measurements and uniaxial compression tests. Results showed a clear reduction of pore connectivity when increasing the solidification rate. The consequence is a prominent improvement of the foam strength over the one expected from just the matrix refinement. Further analysis on this relationship between the pore connectivity and the mechanical properties, has allowed to propose a correction to the theoretical model for collapse strength in closed cell foams to consider such contribution and predict more accurate results
Relación entre calidad y coste de la prescripción farmacológica en atención primaria
ObjetivoAnalizar la prescripcion farmaceutica de los medicos generales (MG) segun un sistema de indicadores cualitativos y evaluar la relacion de estos con el gasto global de prescripcion farmaceutica por habitante.DisenoEstudio descriptivo, retrospectivo.EmplazamientoAtencion primaria.Mediciones y resultados principalesSe evalua la prescripcion farmaceutica de 285 MG de 32 equipos de atencion primaria, siendo la prescripcion individual de cada medico la unidad de analisis. La prescripcion se clasifico en 3 categorias segun su valor intrinseco (%VIF): bajo (. 75%), medio (76–79%) y alto (. 80%). Como trazadores de hiperprescripcion fueron seleccionados: DHD antibioticos (AB), DHD antiinflamatorios no esteroides (AINE) y DHD antiulcerosos (ULC), y como trazadores de seleccion: %DHD cefalosporinas tercera generacion/DHD cefalosporinas totales (CEF3.aG), %DHD quinolonas amplio espectro/DHD quinolonas totales (QAP), %DHD AINE/DHD (AINE + analgesicos) (ANAL). Los indicadores cuantitativos estudiados fueron: gasto total/poblacion asignada (GPA), coste/receta farmacos de eficacia dudosa y coste/DDD de AB, AINE y ULC. Se aplico el analisis de variancia, incluyendo la prueba de Scheffe para comparaciones multiples y la correlacion lineal de Pearson. Un 26% de las prescripciones tenia un %VIF < 75%, mientras que el 34% lo tenia > 80%. Las medias de DHD AB entre las categorias de VIF eran diferentes (p < 0,0001), al igual que las de DHD de AINE (p < 0,0001) y ULC (p = 0,007), observandose un menor consumo de AB, AINE y ULC en las prescripciones con VIF mas alto. Las CEF3aG, asi como ANAL presentan diferencias significativas con las 3 categorias de VIF (p < 0,0001 y p = 0,041) a diferencia del QAP (p = 0,18). El GPA es menor entre los MG cuyas prescripciones tenian el %VIF mas alto; en cambio, el coste/receta y el coste DDD no presentaron diferencias significativas segun categorias de %VIF.ConclusionesLos medicos con mejor perfil cualitativo segun estos indicadores presentan un menor gasto por habitante. En cambio, no se observan diferencias en el coste por receta ni en el coste/tratamiento entre los distintos medicos. Por tanto, las intervenciones deben priorizar la mejora de la calidad de la prescripcion farmaceutica antes que promover unicamente el cambio al farmaco de menor coste.ObjectivesWith a system of qualitative indicators, to analyse the pharmaceutical prescription of general practitioners (GPs), and to evaluate the relationship of these indicators to the overall pharmaceutical prescription expenditure per inhabitant.DesignRetrospective descriptive study.SettingPrimary care.Measurements and main resultsThe drugs prescription of 285 GPs from 32 primary care teams was evaluated, with the individual prescription of each doctor as the unit of analysis. The prescription was classified in 3 categories according to its intrinsic value (IV): low (. 75%), medium (76–79%) and high (. 80%). Selected as tracers of over-prescription were: daily dose per inhabitant (DDI) of antibiotics (AB), DDI of non-steroid anti-inflammatory drugs (NSAID), and DDI of ulcer drugs (ULC). Selected as tracers of selection were: % DDI third-generation cephalosporins/DDI total cephalosporins; % DDI broad-spectre quinolones/DDI total quinolones; and % DDI NSAID/DDI NSAID plus analgesics. Quantitative indicators studied were: total expenditure per allocated population, cost per drugs prescription of doubtful efficacy, and cost per daily dose of AB, NSAID and ULC. Variance analysis, including the Scheffe test for multiple comparisons and Pearson's linear correlation, was applied. 26% of the prescriptions had an IV below 75%, and 34% had an IV above 80%. The means of DDI of AB among the categories of IV were different (p < 0.0001), as were those of DDI of NSAID (p < 0.0001) and of ULC (p = 0.007). Lower consumption of AB, NSAID and ULC was found in prescriptions with the highest IV %. The third-generation cephalosporins and the NSAID + analgesics showed significant differences in the three IV categories (p < 0.0001 and p = 0.041), unlike broad-spectrum quinolones (p = 0.18). The total expenditure per allocated population was less for GPs whose prescriptions had the highest IV %; whereas the cost per prescription and cost per daily dose showed no significant differences for IV categories.ConclusionsThe doctors with the best qualitative profile on these indicators had less expenditure per inhabitant. However, no differences were found in the cost per prescription or cost per treatment between doctors. Therefore, interventions must prioritise improving drug prescription quality rather than just promoting changes to lower-cost drugs
Detection of a multi-shell planetary nebula around the hot subdwarf O-type star 2MASS J19310888+4324577
(Abridged) The origin of hot subdwarf O-type stars (sdOs) remains unclear
since their discovery in 1947. Among others, a post-Asymptotic Giant Branch
(post-AGB) origin is possible for a fraction of sdOs. We are involved in a
comprehensive ongoing study to search for and to analyze planetary nebulae
(PNe) around sdOs with the aim of establishing the fraction and properties of
sdOs with a post-AGB origin. We use deep Halpha and [OIII] images of sdOs to
detect nebular emission and intermediate resolution, long-slit optical
spectroscopy of the detected nebulae and their sdO central stars. These data
are complemented with other observations for further analysis of the detected
nebulae. We report the detection of an extremely faint, complex PN around 2MASS
J19310888+4324577 (2M1931+4324), a star classified as sdO in a binary system.
The PN shows a bipolar and an elliptical shell, whose major axes are oriented
perpendicular to each other, and high-excitation structures outside the two
shells. WISE archive images show faint, extended emission at 12 and 22 microns
in the inner nebular regions. The internal nebular kinematics is consistent
with a bipolar and a cylindrical/ellipsoidal shell, in both cases with the main
axis mainly perpendicular to the line of sight. The nebular spectrum only
exhibits Halpha, Hbeta and [OIII]4959,5007 emission lines, but suggests a very
low-excitation ([OIII]/Hbeta = 1.5), in strong contrast with the absence of
low-excitation emission lines. The spectrum of 2M1931+4324 presents narrow,
ionized helium absorptions that confirm the previous sdO classification and
suggest an effective temperature >= 60000 K. The binary nature of 2M1931+4324,
its association with a complex PN, and several properties of the system provide
strong support for the idea that binary central stars are a crucial ingredient
in the formation of complex PNe.Comment: 8 pages, 7 figures, accepted in Astronomy and Astrophysic
Limits on the Electromagnetic and Weak Dipole Moments of the Tau-Lepton in E_6 Superstring Models
We obtain limits on the electromagnetic and weak dipole moments of the
tau-lepton in the framework of a Left-Right symmetric model (LRSM) and a class
of inspired models with an additional neutral vector boson .
Using as an input the data obtained by the L3 and OPAL Collaborations for the
reaction , we get a stringent limit on the LRSM
mixing angle , , which in
turn induces bounds on the tau weak dipole moments which are consistent with
the bounds obtained recently by the DELPHI and ALEPH Collaborations from the
reaction . We also get similar bounds for the weak
dipole moments of the tau lepton in the framework of superstring models.Comment: 18 pages, 5 figure
Associations Between Body Composition and Movements During Gait in Women.
El objetivo de este trabajo es explorar las relaciones entre los parámetros acelerométricos de la marcha y la composición corporal en mujeres sanas. Para conseguirlo se realice un estudio transversal con una muestra de 112 mujeres adultas sanas (64,1 ± 8,6 años). Las participantes caminaron una distancia de 20 metros con un acelerómetro triaxial situado a la altura de la cuarta vértebra lumbar. La prueba se repitió tres veces y se utilizó la media de los tres ensayos para el análisis. También se evaluaron indicadores clínicos (Timed Up and Go Test, prueba de los seis minutos marcha y perímetro de cintura) y la composición corporal (bioimpedancia). Los porcentajes de grasa corporal total y en miembros inferiores se correlacionaron fuertemente con la aceleración media en eje vertical y el valor mínimo de módulo vector de las aceleraciones. En mujeres mayores de 71 años, la proporción de grasa corporal total y de miembros inferiores determina los movimientos del cuerpo durante la marcha. Por tanto, la cantidad de masa grasa está relacionada con la estabilidad en la marcha de las personas mayoresThe aim of this paper is to explore the relationships between gait parameters and body composition in healthy women. A cross-sectional study with a sample composed of 112 healthy adult women (64.1 ± 8.6 years). The subjects walked a distance of 20 meters with a triaxial accelerometer attached at the fourth lumbar vertebra. The test was repeated three times and the mean of the three trials was used for the analysis. Clinical indicators (Timed Up and Go Test, 6-Minute Walk Test and waist perimeter) and body composition (bioimpedance) were also evaluated. Total body and lower limb fat mass percentages were strongly correlated with the average acceleration in vertical axis and the minimum value of module vector of the accelerations. In women over the age of 71, the percentage of total body fat and lower limbs determines body movements during gait. Therefore, the amount of fat mass is related to the stability in the gait of the elderl
Effect of diet on live weight and egg weight of backyard hens during the rainy season
The objective was to determine the effect of diet on live weight (LW) and egg weight (EW) of backyard hens (BH) during the rainy season in the Bajío region of the state of Michoacán, Mexico. Seventeen municipalities were sampled, where 101 BH (six hens/municipality) were captured and weighed and 101 eggs (six eggs/municipality) were harvested and weighed. The crops of the captured hens were removed Post-sacrifice, the organic content/crop (OCC) was classified and weighed by components, to later perform chemical compositional analysis. Data were analysed using generalised linear models and the differences between municipalities were obtained by the method of least squares means. The weight of the OCC (36.4 ± 22.4 g) was affected by the municipality (P<0.001), but not by the LW of the BH (P>0.05). Commercial feed (8.1 ± 6.0 g), grains: maize and sorghum (13.9 ± 13.5 g) kitchen waste (1.5 ± 2.9 g), herbaceous (0.6 ± 0.9 g) and insects (0.3 ± 0.7 g) were found in the crop. According to the commercial feed (COF) component, two feeding systems (FS) were identified: traditional FS, without COF and nontraditional FS, with COF. The diets of both FS were similar (P>0.05) in nutritional composition and do not meet the nutritional requirements of the hens. The LW (1.567 ± 0.316 kg) and EW (51.3 ± 1.0 g) of the BH cannot be completely attributed to the diet consumed during the rainy season
Morbilidad Asistida y morbilidad real por infecciones respiratorias agudas
ResumenEl presente trabajo aborda el estudio de la morbilidad por Infecciones Respiratorias Agudas (IRA) en áreas del municipio Lisa en Ciudad Habana, así como en localidades del municipio Isla de la Juventud (Cuba), con objeto de caracterizar algunos aspectos de la morbilidad por demanda de consultae identificar la morbilidad real. Alrededor del 90% de las consultas por IRA fueron por primera vez y en general la razón de éstas, respecto al seguimiento fue de 5,3. A través de la búsqueda activa de enfermos se obtuvieron las tasas de morbilidad real (TMR) entre valores de 110,4 y 163,4 casos por 1000 habitantes, que fueron muy superiores a las tasas de morbilidad por demanda de consulta (TMDC) en iguales periodos de tiempo. Resultado de la división de ambas tasas se obtuvo el«índice de morbilidad real» (IMR) cuyo cociente osciló entre 5 y 15, aproximadamente. Una alta proporción (47,6%) de enfermos refirieron no haber solicitado atención médica. Estos resultados permiten hacer estimaciones aproximadas del comportamiento real de las IRA en el universo de estudio y establecer bases para un nuevo programa de control, perfeccionando ademcis la vigilancia epidemiolóigica en la atención primaria de salud.SummaryThe present work presents the study of morbidity due to acute respiratory infections (ARI) in areas of the town of Lisa in Ciudad Habana, and Isla Juventud (Cuba), to caracterise different aspects of morbidity measured by health care attendance and to measure true morbidity. About 90% of consultations for ARI were first-time consultations, while their ratio to further consultations was 5.3. True morbidity rates (TMR), obtained trough active research, ranged from 110.4 to 163.4 cases per 1000 inhabitants, considerably higher than morbidity rates measured by primary care consultations (MRPCC) in the same time period. The true morbidity index (TMI), as measured by the ratio of the two previous rates, ranged from 5 to 15. Ahigh proportion (47.6%) of cases reported no medical careattendance. These results provide approximate estimates of true morbidity in the study area, and allow the establishment of a new control program, also improving epidemiologic surveillance within primary care activities
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