386 research outputs found
Los manuscritos americanos de la Biblioteca Histórica "Marqués de Valdecilla" UCM
La Biblioteca Histórica de la Universidad Complutense de Madrid posee un pequeño conjunto de diecisiete manuscritos americanos, bien copiados en América o de tema americano. Entre ellos destacan algunas piezas excepcionales, como una copia de la Materia Medicinal de Francisco Hernández del siglo XVI, una crónica del noble indígena Fernando Alva Ixtlilxochitl del siglo XVII, o el conjunto de papeles relativos a la conspiración de La Guaira, de finales del siglo XVIII. Entre los manuscritos del siglo XX se encuentran desde un conjunto de documentos que la pedagoga cubana Carolina Poncet envió a Rafael Altamira, a copias de distintos trabajos académicos de la década de los años treinta. Las procedencias son variadas, destacando las seis del legado Francisco Guerra
Effect of the separated approximation of input data in the accuracy of the resulting PGD solution
The Proper Generalized Decomposition (PGD) requires separability of the input data (e.g. physical properties, source term, boundary conditions, initial state). In many cases the input data is not expressed in a separated form and it has to be replaced by some separable approximation. These approximations constitute a new error source that, in some cases, may dominate the standard ones (discretization, truncation…) and control the nal accuracy of the PGD solution.
In this work the relation between errors in the separated input data and the errors induced in the PGD solution is discussed. Error estimators proposed for homogenized problems and oscillation terms are adapted to asses the behaviour of the PGD errors resulting from approximated input data. The PGD is stable with respect to error in the separated data, with no critical amplification of the perturbations.
Interestingly, we identified a high sensitiveness of the resulting accuracy on the selection of the sampling grid used to compute the separated data. The separation has to be performed on the basis of values sampled at integration points: sampling at the nodes defining the functional interpolation results in an important loss of accuracy.
For the case of a Poisson problem separated in the spatial coordinates (a complex diffusivity function requires a separable approximation), the final PGD error is linear with the truncation error of the separated data. This relation is used to estimate the number of terms required in the separated data, that has to be in good agreement with the truncation error accepted in the PGD truncation (tolerance for the stoping criteria in the enrichment procedure). A sensible choice or the prescribed accuracy of the PGD solution has to be kept within the limits set by the errors in the separated input data
An error estimator for real-time simulators based on model order reduction
Model order reduction (MOR) is one of the most appealing choices for real-time simulation of non-linear solids. In this work a method is presented in which real time performance is achieved by means of the o-line solution of a (high dimensional) parametric problem that provides a sort of response surface or computational vademecum. This solution is then evaluated in real-time at feedback rates compatible with haptic devices, for instance (i.e., more than 1kHz). This high dimensional problem can be solved without the limitations imposed by the curse of dimensionality by employing Proper Generalized Decomposition (PGD) methods. Essentially, PGD assumes a separated representation for the essential eld of the problem. Here, an error estimator is proposed for this type of solutions that takes into account the non-linear character of the studied problems. This error estimator allows to compute the necessary number of modes employed to obtain an approximation to the solution within a prescribed error tolerance in a given quantity of interest
Estudio económico de la industria conservera del área de influencia riojano-navarra de la comarca de Calahorra
¿Cuál es la importancia a nivel regional de la existencia de empresas multinacionales? ¿Cómo afecta esta al desarrollo social económico y medioambiental de la zona? La existencia de grandes empresas a nivel nacional o incluso con actividad internacional, hacen a la zona afectada tratarse de una zona privilegiada en cuanto a trabajo y desarrollo local, pero ¿Cómo afecta el asentamiento de esta industria en otros aspectos como el social, económico o medioambiental?, en el caso de la industria conservera, como se relaciona esta con los productos de la zona propios, ¿Son necesarios recursos externos?La industria conservera riojana y navarra tienen una gran importancia dentro de las economías autonómica y foral respectivamente, ¿Es un sector muy interconectado con sus clientes y proveedores?, tras comentar todas estas cuestiones se estudiará el impacto de estas empresas con cifras proporcionadas por la base de datos SABI facilitadas por la propia universidad, se estudiara tanto sus cifras como evolución de las principales empresas, teniendo en cuenta el entorno de los últimos años (Crisis económica, expansión internacional de la industria…), en definitiva intentaremos dar respuesta a como afecta en un entorno local la existencia de un gran peso industrial (en este caso la industria conservera).<br /
Activin/TGFβ and BMP crosstalk determines digit chondrogenesis
AbstractThe progress zone (PZ) is a specialized area at the distal margin of the developing limb where mesodermal cells are kept in proliferation and undifferentiated, allowing limb outgrowth. At stages of digit morphogenesis the PZ cells can undergo two possible fates, either aggregate initiating chondrogenic differentiation to configure the digit blastemas, or to die by apoptosis if they are incorporated in the interdigital mesenchyme. While both processes are controlled by bone morphogenetic proteins (BMPs) the molecular basis for such contrasting differential behavior of the autopodial mesoderm remains unknown. Here we show that a well-defined crescent domain of high BMP activity located at the tip of the forming digits, which we termed the digit crescent (DC), directs incorporation and differentiation of the PZ mesenchymal cells into the digit aggregates. The presence of this domain does not correlate with an exclusive expression domain of BMP receptors and its abrogation by surgical approaches or by local application of BMP antagonists is followed by digit truncation and cell death. We further show that establishment of the DC is directed by Activin/TGFβ signaling, which inhibits Smad 6 and Bambi, two specific BMP antagonists expressed in the interdigits and progress zone mesoderm. The interaction between Activin/TGFβ and BMP pathways at the level of DC promotes the expression of the chondrogenic factor SOX9 accompanied by a local decrease in cell proliferation. Characteristically, the DC domain is asymmetric, it being extended towards the posterior interdigit. The presence of the DC is transitorily dependent of the adjacent posterior interdigit and its maintenance requires also the integrity of the AER
Activin/TGFβ and BMP crosstalk determines digit chondrogenesis
AbstractThe progress zone (PZ) is a specialized area at the distal margin of the developing limb where mesodermal cells are kept in proliferation and undifferentiated, allowing limb outgrowth. At stages of digit morphogenesis the PZ cells can undergo two possible fates, either aggregate initiating chondrogenic differentiation to configure the digit blastemas, or to die by apoptosis if they are incorporated in the interdigital mesenchyme. While both processes are controlled by bone morphogenetic proteins (BMPs) the molecular basis for such contrasting differential behavior of the autopodial mesoderm remains unknown. Here we show that a well-defined crescent domain of high BMP activity located at the tip of the forming digits, which we termed the digit crescent (DC), directs incorporation and differentiation of the PZ mesenchymal cells into the digit aggregates. The presence of this domain does not correlate with an exclusive expression domain of BMP receptors and its abrogation by surgical approaches or by local application of BMP antagonists is followed by digit truncation and cell death. We further show that establishment of the DC is directed by Activin/TGFβ signaling, which inhibits Smad 6 and Bambi, two specific BMP antagonists expressed in the interdigits and progress zone mesoderm. The interaction between Activin/TGFβ and BMP pathways at the level of DC promotes the expression of the chondrogenic factor SOX9 accompanied by a local decrease in cell proliferation. Characteristically, the DC domain is asymmetric, it being extended towards the posterior interdigit. The presence of the DC is transitorily dependent of the adjacent posterior interdigit and its maintenance requires also the integrity of the AER
Impact of a Gender-Neutral HPV Vaccination Program in Men Who Have Sex with Men (MSM)
[EN] A major challenge in human papillomavirus (HPV) vaccine programs is the universal gender-neutral recommendation, as well as estimation of its long-term effect. The objective of this study is to predict the added benefit of male vaccination, especially in men who have sex with men (MSM), and to analyze the impact of the program on society. We propose a mathematical model of the HPV infection based on a network paradigm. Data from Spain allowed constructing the sexual network. HPV force of infection was taken from literature. Different scenarios using variable vaccine coverage in both males and females were studied. Strong herd immunity is shown in the heterosexual population, with an important decrease of HPV 6/11 infections both in men and in unvaccinated women with an only-women vaccination at 14 years of age. No impact of this program occurred in the infection incidence in MSM. This group would only benefit from a vaccination program that includes males. However, the impact at short term would be lower than in heterosexual men. The protection of MSM can only be achieved by direct vaccination of males. This may have important consequences for public health.This paper has been supported by the Spanish Ministerio de Economía, Industria y Competitividad (MINECO), the Agencia Estatal de Investigación (AEI) and Fondo Europeo de Desarrollo Regional (FEDER UE) grant MTM2017-89664-P. This paper has been supported by the European Union through the Operational Program of the [European Regional Development Fund (ERDF)/European Social Fund (ESF)] of the Valencian Community 2014¿2020. Files: GJIDI/2018/A/010 and GJIDI/2018/A/009Diez-Domingo, J.; Sánchez-Alonso, V.; Villanueva Micó, RJ.; Acedo, L.; Tuells, J. (2021). Impact of a Gender-Neutral HPV Vaccination Program in Men Who Have Sex with Men (MSM). International Journal of Environmental research and Public Health (Online). 18(3):1-11. https://doi.org/10.3390/ijerph18030963S11118
On the Elimination of Infections Related to Oncogenic Human Papillomavirus: an Approach using a Computational Network Model
[EN] Cervical cancer is the fourth most common malignancy in women worldwide, although it is preventable with prophylactic HPV vaccination. HPV transmission-dynamic models can predict the potential for the global elimination of cervical cancer. The random network model is a new approach that allows individuals to be followed, and to implement a given vaccination policy according to their clinical records. We developed an HPV transmission-dynamic model on a lifetime sexual partners network based on individual contacts, also accounting for the sexual behavior of men who have sex with men (MSM). We analyzed the decline in the prevalence of HPV infection in a scenario of 75% and 90% coverage for both sexes. An important herd immunity effect for men and women was observed in the heterosexual network, even with 75% coverage. However, HPV infections are persistent in the MSM population, with sustained circulation of the virus among unvaccinated individuals. Coverage around 75% of both sexes would be necessary to eliminate HPV-related conditions in women within five decades. Nevertheless, the variation in the decline in infection in the long term between a vaccination coverage of 75% and 90% is relatively small, suggesting that reaching coverage of around 70-75% in the heterosexual network may be enough to confer high protection. Nevertheless, HPV elimination may be achieved if men's coverage is strictly controlled. This accurate representation of HPV transmission demonstrates the need to maintain high HPV vaccination coverage, especially in men, for whom the cost-effectiveness of vaccination is questioned.This work has been supported by the Spanish Ministerio de Economia, Industria y Competitividad (MINECO), the Agencia Estatal de Investigacion (AEI) and Fondo Europeo de Desarrollo Regional (FEDER UE), grant MTM2017-89664-P. Authors also wish to acknowledge Maria Giovanna Ferrario, Victor Latorre, and the Medical Statistics Consulting team (Valencia, Spain) for their collaboration in writing this manuscript.Muñoz-Quiles, C.; Diez-Domingo, J.; Acedo, L.; Sánchez-Alonso, V.; Villanueva Micó, RJ. (2021). On the Elimination of Infections Related to Oncogenic Human Papillomavirus: an Approach using a Computational Network Model. Viruses. 13(5):1-12. https://doi.org/10.3390/v13050906S11213
Aplicabilidad de las zeolitas como regulador de fraguado
El presente trabajo propone sustituir la proporción que corresponde al yeso en un cemento pórtland por zeolita natural, a fin de regular el fraguado de la pasta en condiciones más o menos similares a las ordinarias, y obtener igualmente resistencias mecánicas aceptables. Los criterios seguidos en esta investigación tienen su base en la propiedad de las zeolitas como intercambiadores iónicos, mediante la cual pueden saturarse de agua rápidamente, controlando la humedad de la pasta, y neutralizando así la reacción del C3A con el Ca(OH)2; de este modo, “ralentizan” el fraguado durante un período de tiempo lo suficientemente adecuado como para facilitar la hidratación óptima de los silicatos, principalmente los bicálcicos, con la formación de variedades secundarias más estables, como la tobermorita. Las resistencias mecánicas obtenidas en esta investigación alcanzaron los 59,3 Mpa a los 28 días. Asimismo, los ensayos para la determinación de los tiempos de inicio y final de fraguado arrojaron resultados de 95 y 135 minutos, respectivamente, mientras que la expansión resultó igual a cero en todos los casos.
Palabras claves: zeolitas, yeso, fraguado, cemento, resistencia
ABSTRACT
This work proposes to substitute the proportion of gypsum on cement by natural zeolite, in order to regulate the forged of the mortar under conditions more or less similar to the ordinary ones, and to obtain high mechanical strength. The approaches used in this investigation have been focused on the zeolites property as ion-exchanger, by means of which it can be quickly saturated itself with water, controlling the humidity inside mortar, and neutralizing the reaction of both, the C3A and Ca(OH)2; this way, zeolites diminishes the forged speed during an appropriate time in which it allows the complete hydrate of the silicates, mainly the belite, with the formation of secondary more stable varieties, as tobermorite. The mechanical strength obtained in this investigation reached 59,3 Mpa at 28 days. Also, the tests for the determination of the times of starting-final forged have reported results of 95 and 135 minutes, while the volume stability was similar to zero in all the cases.
Key words: zeolites, gypsum, forged, cement, strengt
Estudio de la exclusión social a través de registros de datos de servicios sociales : análisis a partir de la herramienta SiSo
Este artículo tiene como objetivo identificar los factores relativos a la exclusión social atendiendo a cuatro niveles de gravedad entre la población usuaria de programas de inclusión social. Para ello, se realiza un análisis de la base de datos perteneciente a la herramienta SiSo de valoración de las situaciones de dificultad social en el eje inclusión/exclusión. Dicha herramienta se emplea desde el año 2017 en la valoración y el estudio de casos en los servicios sociales de primer nivel en Castilla-La Mancha. En el momento de realizar este artículo, se han valorado un total de 18.968 unidades familiares. Para ello, se recurre a análisis bivariables con los que identificar las principales características en seis dimensiones o ámbitos vitales. Asimismo, los resultados recogen la adecuación del análisis de componentes principales a los respectivos ámbitos vitales. Finalmente, el apartado de resultados recoge un análisis multinomial para determinar su importancia según los niveles de dificultad analizados. Las conclusiones del artículo son relevantes para la segmentación en el primer nivel de atención de los servicios sociales según los niveles de dificultad, con repercusiones en la precisión de necesidades y en la intervención conjunta con otros sistemas de protección social.This article aims to identify factors associated with social exclusion among users of social inclusion programs according to four levels of severity. To this end, the SiSo tool was used to assess situations of social hardship on the inclusion/exclusion spectrum. This tool has been used since 2017 to evaluate and study cases in first level or primary care social services in the region of Castilla-La Mancha, Spain. At the time of writing, a total of 18,968 family units have been assessed. Bivariate analyses were performed to identify the main characteristics of users in six dimensions or life domains. The results show that principal component analysis is suitable for identifying the variables in the respective domains. Finally, a multinomial analysis was performed to determine the importance of the variables according to levels of hardship. The findings can be useful for segmenting family units and defining social services interventions by level of hardship, as well as for conducting joint interventions with other social protection systems
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