1,568 research outputs found

    Behavior of tumors under nonstationary theraphy

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    We present a model for the interaction dynamics of lymphocytes-tumor cells population. This model reproduces all known states for the tumor. Futherly,we develop it taking into account periodical immunotheraphy treatment with cytokines alone. A detailed analysis for the evolution of tumor cells as a function of frecuency and theraphy burden applied for the periodical treatment is carried out. Certain threshold values for the frecuency and applied doses are derived from this analysis. So it seems possible to control and reduce the growth of the tumor. Also, constant values for cytokines doses seems to be a succesful treatment.Comment: 6 pages, 7 figure

    Comprehensive transient-state study for CARMENES-NIR high thermal stability

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    CARMENES has been proposed as a next-generation instrument for the 3.5m Calar Alto Telescope. Its objective is finding habitable exoplanets around M dwarfs through radial velocity measurements (m/s level) in the near-infrared. Consequently, the NIR spectrograph is highly constraint regarding thermal/mechanical requirements. As a first approach, the thermal stability has been limited to \pm 0.01K (within year period) over a working temperature of 243K. This can be achieved by means of several temperature-controlled rooms. The options considered to minimise the complexity of the thermal design are here presented, as well as the transient-state thermal analyses realised to make the best choice

    First detection of thermal radio jets in a sample of proto-brown dwarf candidates

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    We observed with the JVLA at 3.6 and 1.3 cm a sample of 11 proto-brown dwarf candidates in Taurus in a search for thermal radio jets driven by the most embedded brown dwarfs. We detected for the first time four thermal radio jets in proto-brown dwarf candidates. We compiled data from UKIDSS, 2MASS, Spitzer, WISE and Herschel to build the Spectral Energy Distribution (SED) of the objects in our sample, which are similar to typical Class~I SEDs of Young Stellar Objects (YSOs). The four proto-brown dwarf candidates driving thermal radio jets also roughly follow the well-known trend of centimeter luminosity against bolometric luminosity determined for YSOs, assuming they belong to Taurus, although they present some excess of radio emission compared to the known relation for YSOs. Nonetheless, we are able to reproduce the flux densities of the radio jets modeling the centimeter emission of the thermal radio jets using the same type of models applied to YSOs, but with corresponding smaller stellar wind velocities and mass-loss rates, and exploring different possible geometries of the wind or outflow from the star. Moreover, we also find that the modeled mass outflow rates for the bolometric luminosities of our objects agree reasonably well with the trends found between the mass outflow rates and bolometric luminosities of YSOs, which indicates that, despite the "excess" centimeter emission, the intrinsic properties of proto-brown dwarfs are consistent with a continuation of those of very low mass stars to a lower mass range. Overall, our study favors the formation of brown dwarfs as a scaled-down version of low-mass stars.Comment: 18 pages, 8 figures, 14 tables, accepted by the Astrophysical Journa

    Preparation, characterization and catalytic activity towards green reactions of sulfonic functionalized SBA-15

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    Acidic heterogeneous catalysts based on the anchorage of sulfonic groups on SBA-15 mesoporous silica were synthesized. In a first synthesis step, samples containing mercapto groups were prepared by co-condensation of tetraethylorthosilicate with 3-mercaptopropyltrimethoxysilane, in presence of ethylene-propylene block copolymer as mesoporous silica structure director. In other samples, mercapto groups were introduced by post-functionalization of the traditional calcined SBA-15. In a second step, these mercapto groups were oxidized in order to get sulfonic acid groups on the surface. Characterization of the samples was carried out by N2 adsorption-desorption, FTIR, XPS and acid-base titration. Spectroscopic techniques showed that the effective incorporation of sulfonic groups depends on the synthesis methodology used. In turn, the SBA-15 post-synthesis functionalization produces changes in structural characteristics like a decrease in BET surface and changes in the pore size distribution. The as-prepared materials were tested as acid catalysts in the alkylation of isobutane with 1-butene, and in the esterification of free fatty acids with methanol. The results obtained show a lack of activity in the alkylation reaction which can be associated with the formation and stabilization of the intermediate carbocation species.Centro de Investigación y Desarrollo en Ciencias Aplicada

    Snakebites mapping in municipalities of the Coffee Triangle Region in Colombia using Geographic Information Systems (GIS)

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    Objective: We sought to develop epidemiological maps using geographical information systems (GIS) for the incidence of reported venomous snakebites in the Coffee-Triangle region of Colombia, between 2007 and 2011. Methods: Surveillance cases data (2007-2011) were used to estimate annual incidence rates of snakebites (cases/100,000 pop) to develop the first maps in the 53 municipalities of this region (departments Caldas, Quindío, Risaralda). The GIS software used was Kosmo Desktop 3.0RC1®. Thirty thematic maps were developed according to municipalities and years. Results: A total of 617 cases were reported (56.08% from Caldas, 32.58% from Risaralda and 11.35% from Quindío), for a cumulated regional rate of 25. 25 cases/100,000 pop (35.43 for Caldas, 21.86 for Risaralda and 12.81% for Quindío). The highest cumulated rate was reported in the less developed and more rural municipality of one department (Pueblo Rico, Risaralda) with 265.64 cases/100,000 pop. Between 2007 and 2011, a considerable increase was seen in the rates. At Pueblo Rico, Risaralda, there was a change from 41.04 cases/100,000pop in 2007 up to 63.11 cases/100,000pop in 2011 (1.54 times higher). From Caldas, Samaná showed a high variation from 19.47 to 77.7 (3.99 times higher). Conclusions: Morbidity of snakebites is highly concentrated in one department (Caldas). Use of GIS-based epidemiological maps allows guiding decisions-taking for prevention and control of public health problems that still represents a significant issue in the region and the country, such as snakebites

    Snakebites mapping in municipalities of the Coffee Triangle Region in Colombia using Geographic Information Systems (GIS)

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    Objective: We sought to develop epidemiological maps using geographical information systems (GIS) for the incidence of reported venomous snakebites in the Coffee-Triangle region of Colombia, between 2007 and 2011. Methods: Surveillance cases data (2007-2011) were used to estimate annual incidence rates of snakebites (cases/100,000 pop) to develop the first maps in the 53 municipalities of this region (departments Caldas, Quindío, Risaralda). The GIS software used was Kosmo Desktop 3.0RC1®. Thirty thematic maps were developed according to municipalities and years. Results: A total of 617 cases were reported (56.08% from Caldas, 32.58% from Risaralda and 11.35% from Quindío), for a cumulated regional rate of 25. 25 cases/100,000 pop (35.43 for Caldas, 21.86 for Risaralda and 12.81% for Quindío). The highest cumulated rate was reported in the less developed and more rural municipality of one department (Pueblo Rico, Risaralda) with 265.64 cases/100,000 pop. Between 2007 and 2011, a considerable increase was seen in the rates. At Pueblo Rico, Risaralda, there was a change from 41.04 cases/100,000pop in 2007 up to 63.11 cases/100,000pop in 2011 (1.54 times higher). From Caldas, Samaná showed a high variation from 19.47 to 77.7 (3.99 times higher). Conclusions: Morbidity of snakebites is highly concentrated in one department (Caldas). Use of GIS-based epidemiological maps allows guiding decisions-taking for prevention and control of public health problems that still represents a significant issue in the region and the country, such as snakebites

    Magnetic properties of permalloy antidot arrayfabricated by interference lithography

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    The interference laser lithography and ion-beam sputtering have been reported. Magneto-optical Kerr effect magnetometry indicated that the sample exhibits four-fold anisotropic behaviour, i.e. different magnetization loops were observed when the external magnetic field was applied along either x-or y-axis, or along the array diagonal. Broadband ferromagnetic resonance measurements revealed a rich variety of different magnetization configurations in the unsaturated state that can be controlled by the orientation of the external magnetic field. Micromagnetic simulations have been performed to explain the observed results. On the contrary, in the saturated regime the system demonstrated almost isotropic magnetic behaviour that improves with external field increase. The obtained results show the potential of interference lithography for the fabrication of large area antidot arrays. (C) 2019 Author(s).The Portuguese team acknowledges the Network of Extreme Conditions Laboratories-NECL and Portuguese Foundation of Science and Technology (FCT) support through the projects NORTE-01-0145-FEDER-022096, MIT-EXPL/IRA/0012/2017, POCI-01-0145-FEDER-031302, EXPL/IF/01191/2013 (D.N.), EXPL/IF/00541/2015 (S.A.B.), EXPL/IF/00981/2013 (G.N.K). D.N., G.N.K., C.R and R.M. acknowledge the support by the European Union Horizon 2020 Research and Innovation Programme under Marie Sklodowska-Curie Grant Agreement EU H2020-MSCA-RISE-2016 (No 734801). The Spanish team acknowledges the support from Spanish MINECO through the grant FIS2016-76058 (AEI/FEDER, UE). A.H.-R. acknowledges the support from European Union's Horizon 2020 research and innovation program under the Marie Sklodowska-Curie Action (reference H2020-MSCA-IF-2016-746958). G.N.K. and O.V.D. acknowledge the support from European Cooperation in Science and Technology (COST) project CA16218 "NANOCOHYBRI.

    Objetivos del proyecto ECOPHYN: Ecofisiología de la alimentación y la nutrición del pulpo común

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    Trabajo presentado en el XXV FOROACUI Foro de los recursos marinos y de la acuicultura de las rías gallegas, celebrado en Pontevedra (España) del 05 al 06 de junio de 2022.Los pulpos tienen un papel relevante en las cadenas tróficas de los ecosistemas marinos de todo el mundo, representando un recurso pesquero de gran importancia y una especie prometedora para la acuicultura. El pulpo común, Octopus vulgaris, es la especie de pulpo con mayor interés comercial en todo el mundo; sin embargo, la producción pesquera no será suficiente para cubrir la demanda del mercado en un futuro próximo. En este contexto, los esfuerzos se han dirigido a la producción sostenible de esta especie tanto desde la acuicultura como desde la pesca. En los últimos años se han producido avances relevantes en estos ámbitos, entre los que se encuentran las aportaciones de nuestros grupos de investigación, que han despejado el camino para una mejor comprensión de su papel en el medio natural, la pesca y la futura producción acuícola de esta especie. La alimentación y la nutrición son factores clave para entender los requisitos ecofisiológicos de los pulpos tanto en el campo como en condiciones de cultivo. De hecho, nuestros estudios previos identificaron un importante desconocimiento en su fisiología nutricional, lo que todavía dificulta su producción acuícola y la comprensión de su papel como depredador en los sistemas marinos. También hay que tener en cuenta que la mayor parte de los conocimientos sobre su fisiología y comportamiento se han obtenido básicamente de individuos subadultos y adultos y que existe mucha menos información sobre la fase de transición entre las paralarvas planctónicas y las fases bentónicas, la fase juvenil, en el medio natural y en condiciones de cultivo, debido a las dificultades para obtener estas primeras fases de vida en cantidades suficientes. El presente proyecto pretende abordar esta falta de conocimiento, estudiando la ecofisiología de la alimentación y la nutrición en O. vulgaris a lo largo de su desarrollo, con especial énfasis en estas fases tempranas antes mencionadas. Nuestra hipótesis general de trabajo propone que la mejora del conocimiento de la fisiología nutricional de esta especie tendrá un impacto significativo en la futura gestión y desarrollo de este recurso comercial. Más concretamente, nuestra propuesta pretende profundizar en la digestión, metabolismo y nutricion del pulpo mediante la caracterización de los ritmos endógenos, el proceso de digestión, las vías metabólicas, el microbioma, la firma isotópica y la microquímica, así como la identificación de biomarcadores vinculados a la respuesta inmune, la salud y el bienestar en tejidos seleccionados del pulpo. Esta investigación se llevará a cabo a lo largo del desarrollo del pulpo, utilizando diferentes enfoques y las técnicas más recientes, incluidas las herramientas "ómicas". La generación de este nuevo conocimiento sentará las bases para una mejora en la explotación racional de este recurso tanto a nivel de su acuicultura y bienestar animal como para el conocimiento del papel de la especie en su medio natural

    Efecto de amortiguamiento térmico de una barrera verde de Arundo donax como elemento de bioclimatización en edificios

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    Among the main environmental impacts of the operation of residential buildings are those due to greenhouse gases generation as a result of electric consumption of air conditioning systems. The use of vegetation systems in residential buildings represents an alternative to reduce this energy consumption. Green vegetation systems barriers are often used as protection against winds, but recently they are also being used as acoustic dampers. This work explores their use as thermal insulation systems for buildings. Specifically, we report the behavior of an Arundo donax green barrier as a bioclimatic element. The results are analyzed based on indoor and outdoor temperature measurement in prototype buildings, in function of the green barrier presence. Additionally Arundo donax transpiration under extreme environmental conditions was determined.Entre los principales impactos ambientales derivados de la operación de edificios habitacionales está la generación de gases de efecto invernadero resultante del consumo eléctrico de sistemas de climatización. El uso de sistemas de vegetación representa una alternativa para disminuir dicho consumo energético. Las barreras verdes son sistemas de vegetación empleados como protección contra el viento, aunque recientemente se ha explorado su uso como sistemas de amortiguación acústica. En este trabajo se analiza su posible aplicación como sistemas de aislamiento térmico para edificios. En específico, se reporta el comportamiento de una barrera verde de Arundo donax como elemento de bioclimatización. Los resultados se analizan a partir de las temperaturas medidas en el interior y exterior de edificios prototipo, en función de la presencia de una barrera verde. Adicionalmente se determinó la traspiración del Arundo donax en condiciones ambientales extremas
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