84 research outputs found
Empresaris immigrants en temps de crisi econòmica
El grup d'investigació egolab-GRAFO, del Departament d'Antropologia Social i Cultural, ha conclòs el projecte ITINERE (Perfils d'empresariat ètnic a Espanya CSO2009-07057). Aquesta recerca pretén realitzar un estudi a partir de diferents perfils d'empresariat immigrant o ètnic a Catalunya, així com una anàlisi de les seves xarxes personals de suport als emprenedors, tant locals com transnacionals.El grupo de investigación egolab-GRAFO, del Departamento de Antropología Social y Cultural, ha concluido el proyecto ITINERE (Perfiles de empresariado étnico en España CSO2009-07057). Esta investigación pretende realizar un estudio a partir de diferentes perfiles de empresariado inmigrante o étnico en Cataluña, así como un análisis de sus redes personales de apoyo a los emprendedores, tanto locales como transnacionales
Random lasing in Nd:LuVO4 crystal powder
Room temperature random lasing action is demonstrated for the first time in a low concentrated neodymium doped vanadate crystal powder. Laser threshold and emission efficiency are comparable to the ones obtained in stoichiometric borate crystal powders. The present investigation provides a complete picture of the random lasing characteristics of Nd-doped vanadate powder both in the spectral and temporal domain, together with a simplified model which accounts for the most relevant features of the random laser. © 2011 Optical Society of America.Peer Reviewe
Normalizing the gene dosage of Dyrk1A in a mouse model of Down syndrome rescues several Alzheimer's disease phenotypes
The intellectual disability that characterizes Down syndrome (DS) is primarily caused by prenatal changes in central nervous system growth and differentiation. However, in later life stages, the cognitive abilities of DS individuals progressively decline due to accelerated aging and the development of Alzheimer's disease (AD) neuropathology. The AD neuropathology in DS has been related to the overexpression of several genes encoded by Hsa21 including DYRK1A (dual-specificity tyrosine-(Y)-phosphorylation regulated kinase 1A), which encodes a protein kinase that performs crucial functions in the regulation of multiple signaling pathways that contribute to normal brain development and adult brain physiology. Studies performed in vitro and in vivo in animal models overexpressing this gene have demonstrated that the DYRK1A gene also plays a crucial role in several neurodegenerative processes found in DS. The Ts65Dn (TS) mouse bears a partial triplication of several Hsa21 orthologous genes, including Dyrk1A, and replicates many DS-like abnormalities, including age-dependent cognitive decline, cholinergic neuron degeneration, increased levels of APP and A?, and tau hyperphosphorylation. To use a more direct approach to evaluate the role of the gene dosage of Dyrk1A on the neurodegenerative profile of this model, TS mice were crossed with Dyrk1A KO mice to obtain mice with a triplication of a segment of Mmu16 that includes this gene, mice that are trisomic for the same genes but only carry two copies of Dyrk1A, euploid mice with a normal Dyrk1A dosage, and CO animals with a single copy of Dyrk1A. Normalizing the gene dosage of Dyrk1A in the TS mouse rescued the density of senescent cells in the cingulate cortex, hippocampus and septum, prevented cholinergic neuron degeneration, and reduced App expression in the hippocampus, A? load in the cortex and hippocampus, the expression of phosphorylated tau at the Ser202 residue in the hippocampus and cerebellum and the levels of total tau in the cortex, hippocampus and cerebellum. Thus, the present study provides further support for the role of the Dyrk1A gene in several AD-like phenotypes found in TS mice and indicates that this gene could be a therapeutic target to treat AD in DS.This work was supported by the Jerome Lejeune Foundation, Fundación Tatiana Pérez de Guzmán el Bueno and the Spanish Ministry of Economy and Competitiveness (PSI-2016-76194-R, AEI/FEDER, EU). The authors wish to express their gratitude to Mariona Arbonés for providing Dyrk1A +/− KO mice and to Eva García Iglesias for technical assistance
Energy Test of an Efficient Random Laser Emission Collecting System
The problem of light collection in random lasers (RLs) is addressed. As the radiation emitted by this system is Lambertian due to its spatial incoherence, a device based on an ellipsoidal revolution mirror is designed, developed, and tested in order to optimize the harvesting of the radiation emitted by the RL. The system provides a simple injection procedure of the emitted energy at the entrance of a multimode optical fiber. The results obtained show that the device has a net energy efficiency of 35%, close to the theoretically expected one. (C) The Authors. Published by SPIE under a Creative Commons Attribution 4.0 Unported LicenseThis work was supported by the Basque Government PIBA2018-24, Spanish Government MINECO under Project No. MAT2017-87035-C2-2-P (AEI/FEDER, UE), and Basque Country University (UPV/EHU) PPG17/07 and GIU17/01
Las redes sociales de la economía social
A partir del trabajo de campo en curso llevado a cabo en Cataluña (proyecto de investigación ENCLAVE - CSO2012-32635), se sugiere la existencia de al menos tres tipos de los llamados "empresarios sociales": los profesionales desplazados por los recortes en el gasto público en los sectores de la salud, los servicios sociales y la cooperación; las cooperativas y las asociaciones tradicionales, re-etiquetados como "empresarios sociales" o "empresas sociales" (conversos) y, por último, los que gozan de apoyo institucional público y privado para el desarrollo de sus iniciativas sociales o ambientales (elegidos). Con el fin de contrastar algunas de las hipótesis que plantea la literatura sobre los emprendedores sociales (a saber, su capacidad para movilizar recursos locales y lograr la participación de una amplia gama de actores para el logro de sus fines), se recogieron redes personales de casos de emprendedores sociales con la ayuda de EgoNet (http:// sourceforge.net/projects/egonet) utilizando un generador múltiple de nombres para obtener datos sobre personas relacionadas con la iniciativa. Las redes personales de estos tres tipos se resumieron mediante "grafos agrupados"(http://visone.info/wiki/index.php/Personal_networks_%28tutorial%29, los cuales presentan diferentes características para cada tipo, en términos de equilibrio entre lazos fuertes y débiles de apoyo a la iniciativa empresarial. Sostenemos que este nuevo escenario en el que nuevos y viejos actores se esfuerzan por presentarse a sí mismos con las etiquetas disponibles difícilmente puede entenderse sólo en términos de las motivaciones sociales, como sugiere la literatura. Por último, se presenta una conceptualización del campo del "empresariado social" como consecuencia del avance del neoliberalismo y la reducción del gasto público destinado a las clases medias y populares en Europa a partir de la crisis financiera
Random Laser Action in Nd:YAG Crystal Powder Jon
This work explores the room temperature random stimulated emission at 1.064 mu m of a Nd:YAG crystal powder (Neodymium-doped yttrium aluminum garnet) in a very simple pump configuration with no assistance from an internal mirror. The laser threshold energy as a function of pump beam area and pump wavelength has been measured, as well as the temporal dynamics of emission pulses. The absolute energy of stimulated emission and the absolute laser slope efficiency have been measured by using a method proposed by the authors. The results show a surprising high efficiency that takes the low Nd3+ ion concentration of the crystal powder into account.This work has been partially supported by the Spanish Ministerio de Economia y Competitividad, MINECO project MAT2013-48246-C2-2-P, the Basque Country Government, project IT-943-16, and Saiotek S-PE11UN072 and S-PC13UN017
Influence of Upconversion Processes in the Optically-Induced Inhomogeneous Thermal Behavior of Erbium-Doped Lanthanum Oxysulfide Powders
The efficient infrared-to-visible upconversion emission present in Er-doped lanthanum oxysulfide crystal powders is used as a fine thermal sensor to determine the influence of upconversion processes on the laser-induced thermal load produced by the pump laser and to assess the potentialities of this material in order to obtain anti-Stokes laser-induced cooling. The analysis of the upconversion emission and excitation spectra as well as the decay curves indicates that energy transfer upconversion is the main mechanism responsible for the green (S-4(3/2)) and red (F-4(9/2)) upconversion luminescence. The dependence on temperature of the intensity ratio of upconversion emission from thermally-coupled H-2(11/2) and S-4(3/2) levels of Er3+ in the 240-300 K temperature range has been used to estimate a relative sensitivity of 1.09 x 10(-2) K-1. Thermal measurements performed on the powder samples by using a thermal infrared camera exhibit a very inhomogeneous heat distribution at the sample surface due to the random distribution of the pumping energy inside the sample as well as to the random properties of the thermal field. The analysis of both spectroscopic and thermal measurements show that after a transient heating induced by the background absorption, cooling of discrete regions by means of anti-Stokes processes can be observed.This work was supported by the Spanish Government under project MAT2013-48246-C2-2-P and Basque Country Government IT-943-16. Macarena Barredo-Zuriarrain acknowledges an FPI grant from the Spanish Government
Prenatal, but not Postnatal, Curcumin Administration Rescues Neuromorphological and Cognitive Alterations in Ts65Dn Down Syndrome Mice
Background: The cognitive dysfunction in Down syndrome (DS) is partially caused by deficient neurogenesis during fetal stages. Curcumin enhances neurogenesis and learning and memory.
Objectives: We aimed to test the ability of curcumin to rescue the neuromorphological and cognitive alterations of the Ts65Dn (TS) mouse model of DS when administered prenatally or during early postnatal stages, and to evaluate whether these effects were maintained several weeks after the treatment.
Methods: To evaluate the effects of prenatal curcumin administration, 65 pregnant TS females were subcutaneously treated with curcumin (300 mg/kg) or vehicle from ED (Embryonic Day) 10 to PD (Postnatal Day) 2. All the analyses were performed on their TS and Control (CO) male and female progeny. At PD2, the changes in neurogenesis, cellularity, and brain weight were analyzed in 30 TS and CO pups. The long-term effects of prenatal curcumin were evaluated in another cohort of 44 TS and CO mice between PD30 and PD45. The neuromorphological effects of the early postnatal administration of curcumin were assessed on PD15 in 30 male and female TS and CO pups treated with curcumin (300 mg/kg) or vehicle from PD2 to PD15. The long-term neuromorphological and cognitive effects were assessed from PD60 to PD90 in 45 mice. Data was compared by ANOVAs.
Results: Prenatal administration of curcumin increased the brain weight (+45%, P < 0.001), the density of BrdU (bromodeoxyuridine)- (+150%, P < 0.001) and DAPI (4',6-diamidino-2-phenylindole)- (+38%, P = 0.005) positive cells, and produced a long-term improvement of cognition in TS (+35%, P = 0.007) mice with respect to vehicle-treated mice. Postnatal administration of curcumin did not rescue any of the short- or long-term altered phenotypes of TS mice.
Conclusion: The beneficial effects of prenatal curcumin administration to TS mice suggest that it could be a therapeutic strategy to treat DS cognitive disabilities.This study was supported by the “Fondazione Generali e Assicurazioni Generali”, Italy; Fundación Tatiana Pérez de Guzmán el Bueno, IDIVAL (NVAL 19/23), and the Spanish Ministry of Economy and Competitiveness (PSI-2016-76194-R, AEI/FEDER, EU)
Cerebellar alterations in a model of Down syndrome: The role of the Dyrk1A gene
Down syndrome (DS) is characterized by a marked reduction in the size of the brain and cerebellum. These changes play an important role in the motor alterations and cognitive disabilities observed in this condition. The Ts65Dn (TS) mouse, the most commonly used model of DS, reflects many DS phenotypes, including alterations in cerebellar morphology. One of the genes that is overexpressed in both individuals with DS and TS mice is DYRK1A/Dyrk1A (dual-specificity tyrosine-(Y)-phosphorylation regulated kinase 1A), which has been implicated in the altered cerebellar structural and functional phenotypes observed in both populations. The aim of this study was to evaluate the effect of Dyrk1A on different alterations observed in the cerebellum of TS animals. TS mice were crossed with Dyrk1A +/- KO mice to obtain mice with a triplicate segment of Mmu16 that included Dyrk1A (TS +/+/+), mice with triplicate copies of the same genes that carried only two copies of Dyrk1A (TS +/+/-), euploid mice that expressed a normal dose of Dyrk1A (CO +/+) and CO animals with a single copy of Dyrk1A (CO +/-). Male mice were used for all experiments. The normalization of the Dyrk1A gene dosage did not rescue the reduced cerebellar volume. However, it increased the size of the granular and molecular layers, the densities of granular and Purkinje cells, and dendritic arborization. Furthermore, it improved the excitatory/inhibitory balance and walking pattern of TS +/+/- mice. These results support the hypothesis that Dyrk1A is involved in some of the structural and functional cerebellar phenotypes observed in the TS mouse model.This work was supported by grants from the Jerome Lejeune
Foundation and Fundación Tatiana Pérez de Guzmán el Bueno and the Spanish
Ministry of Economy and Competitiveness (PSI-2016-76194-R, AEI/FEDER, EU) and
“Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas
(CIBERNED, CB06/05/0037)” from Spain
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