Ins1 (Cre) knock-in mice for beta cell-specific gene recombination.

AIMS/HYPOTHESIS: Pancreatic beta cells play a central role in the control of glucose homeostasis by secreting insulin to stimulate glucose uptake by peripheral tissues. Understanding the molecular mechanisms that control beta cell function and plasticity has critical implications for the pathophysiology and therapy of major forms of diabetes. Selective gene inactivation in pancreatic beta cells, using the Cre-lox system, is a powerful approach to assess the role of particular genes in beta cells and their impact on whole body glucose homeostasis. Several Cre recombinase (Cre) deleter mice have been established to allow inactivation of genes in beta cells, but many show non-specific recombination in other cell types, often in the brain. METHODS: We describe the generation of Ins1 (Cre) and Ins1 (CreERT2) mice in which the Cre or Cre-oestrogen receptor fusion protein (CreERT2) recombinases have been introduced at the initiation codon of the Ins1 gene. RESULTS: We show that Ins1 (Cre) mice induce efficient and selective recombination of floxed genes in beta cells from the time of birth, with no recombination in the central nervous system. These mice have normal body weight and glucose homeostasis. Furthermore, we show that tamoxifen treatment of adult Ins1 (CreERT2) mice crossed with Rosa26-tdTomato mice induces efficient recombination in beta cells. CONCLUSIONS/INTERPRETATION: These two strains of deleter mice are useful new resources to investigate the molecular physiology of pancreatic beta cells

Arresting bubble coarsening: A two-bubble experiment to investigate grain growth in presence of surface elasticity

Many two-phase materials suffer from grain-growth due to the energy cost which is associated with the interface that separates both phases. While our understanding of the driving forces and the dynamics of grain growth in different materials is well advanced by now, current research efforts address the question of how this process may be slowed down, or, ideally, arrested. We use a model system of two bubbles to explore how the presence of a finite surface elasticity may interfere with the coarsening process and the final grain size distribution. Combining experiments and modelling in the analysis of the evolution of two bubbles, we show that clear relationships can be predicted between the surface tension, the surface elasticity and the initial/final size ratio of the bubbles. We rationalise these relationships by the introduction of a modified Gibbs criterion. Besides their general interest, the present results have direct implications for our understanding of foam stability

Alteraciones fisarias tras radiación láser

Ante el auge actual de la radiación láser y al no encontrar bibliografía referente al posible efecto sobre el cartílago de crecimiento, hemos decidido hacer una valoración del mismo en un modelo experimental. Se utilizaron 50 ratas, estableciéndose cinco grupos de estudio de 10 animales cada uno, dependiendo de la dosis de radiación aplicada percutáneamente sobre la fisis femoral distal. Tras el estudio ultraestructural, histoquímico y morfométrico, hemos observado una serie de alteraciones indicadoras de un daño celular directo. Los hallazgos permiten concluir que este tipo de radiación está contraindicado absolutamente durante la fase de crecimiento óseo o en el esqueleto inmaduro.In view of the present importance of Laser Radiation, and due to the lack of references about its effects on the growth cartilage, we designed an experimental model in order to asses it. A total of 50 rats were used, establishing five groups of study at 10 animals each, depending on the dosis of radiation applied percutaneously on the distal femoral phisys. After the structural, histochemical and morphometric study, we observed a series of alterations indicating a direct celular damage at the physion. From the results, it is concluded that laser radiation should be on absolute contraindication during the phase of bone growth or in the inmature skeleton

Cycloidal Domains in the Magnetization Reversal Process of Ni80Fe20/Nd16Co84/Gd12Co88 Trilayers

The magnetization reversal of each individual layer in magnetic trilayers ( permalloy / Nd Co / Gd Co ) is investigated in detail with x-ray microscopy and micromagnetic calculations. Two sequential inversion mechanisms are identified. First, magnetic vortex-antivortex pairs move along the field direction while inverting the magnetization of magnetic stripes until they are pinned by defects. The vortex-antivortex displacements are reversible within a field interval which allows their controlled motion. Second, as the reversed magnetic field increases, cycloidal domains appear in the permalloy layer as a consequence of the dissociation of vortex-antivortex pairs due to pinning. The field range where magnetic vortices and antivortices are effectively guided by the stripe pattern is of the order of tens of mT for the Ni Fe layer, as estimated from the stability of cycloid domains in the sample

Un fragmento de cerámica ibérica con la figura de un ave en el yacimiento de San Sebastián (Tamarite de Litera, Huesca)

A significant piece of Iberian painted pottery has been discovered at the San Sebastian site. It was hailed from research works developed to set up an Archaeological Charter of Aragon. The shard contains a drawn bird with an appearance like that of other vessels of the so-called AzailaAlloza-Alcorisa decorative style. Thus, it is new evidence that shows up the trade relationship, during 2nd and 1st centuries B.C. among pottery premises of Bajo Aragon, Teruel, and those of Southern part of La Litera, which is part of Eastern Aragon today and was named Western Illergetia in Antiquity. Damos a conocer un fragmento de cerámica ibérica pintada descubierto en el oppidum de San Sebastián en el transcurso de las investigaciones de la Carta Arqueológica de Aragón. En la escena que aparece sobre el mismo destaca la figura de un ave diseñada de manera similar a otras representadas en vasijas del estilo decorativo denominado Azaila-Alloza-Alcorisa. Constituye, en este caso, un nuevo testimonio de las relaciones e intercambios, en los siglos II y I a. C. entre los alfares del Bajo Aragón turolense y los del área meridional de la comarca de La Litera, en la actualidad parte del Aragón oriental, denominada Ilergecia Occidental en las fuentes antiguas

Actividades de ocio-tiempo libre y paseo fuera del hogar en ancianos de la provincia de Guadalajara

ObjetivoConocer cuáles son las actividades de ocio-tiempo libre y paseo diario en ancianos de la provincia de Guadalajara, en la hipótesis que éstas son susceptibles de mejorarse.DiseñoSe trata de un estudio descriptivo, transversal, de base poblacional.EmplazamientoEfectuado en el ámbito comunitario, en el marco de la atención primaria.ParticipantesPersonas mayores de 65 años, sin deterioro cognitivo y residentes en la comunidad, seleccionados de modo aleatorio a partir de bases de datos poblacionales. La muestra finalmente estudiada está compuesta en el medio rural por 192 varones y 196 mujeres. En el medio urbano por 172 varones y 220 mujeres.IntervencionesCada persona era entrevistada en su domicilio o en el centro de salud según sus preferencias mediante cuestionario, previamente sometido a estudio de estabilidad en las respuestas mediante coeficiente kappa test-retest. Efectuamos cribado de deterioro cognitivo mediante test de Pfeiffer.Resultados principalesCaminan menos de media hora al día en el medio rural un 43,6% (IC, 38,6-48,7) de los ancianos y el 34,4% (IC, 29,8-39,4) en el medio urbano. En el caso de los varones, un 24,7% (IC, 20,4-29,6) y en las mujeres el 51,4% (IC, 46,5-56,3). Las diferencias son significativas en ambos casos. No tienen aficiones en el medio rural un 12,1% (IC, 9,1-15,9) de los ancianos y el 9,4% (IC, 6,8-12,9) en el urbano. En el caso de los varones, un 11,3% (8,3-15,1) y el 10,1% (IC, 7,5-13,5) en las mujeres. No existen diferencias significativas.ConclusionesEs necesario fomentar las actividades de ocio-tiempo libre, pero sobre todo el paseo diario superior a media hora en las personas mayores de 65 años de la provincia de Guadalajara.ObjectiveTo find out what elderly people in the province of Guadalajara do in their leisure/free time and daily walking, in the supposition that these can be improved.DesignThis was a descriptive, crossover study based on a population-group.SettingAt community level, in the primary care context.ParticipantsPeople over 65 without cognitive deterioration and resident in the community, selected at random on the basis of population data bases. The sample finally studied was made up of 192 men and 196 women from the country-side, and 172 men and 220 women from an urban background.InterventionsEveryone was interviewed at home or the health centre according to their preferences through a questionnaire, which had undergone a stability study of the replies beforehand through the kappa test-retest coefficient. We screened cognitive deterioration through the Pfeiffer test.Main resultsIn the country, 43.6% of elderly people (CI: 38.6-48.7) walked under half an hour a day; in the urban context, 34.4% (CI: 29.8-39.4) did so. 24.7% of men (CI: 20.4-29.6) did so; and 51.4% of women (CI: 46.5-56.3). The differences were significant in the two cases. 12.1% (CI: 9.1-15.9) of elderly people in the country had no hobbies, and 9.4% (CI: 6.8-12.9) in the town. Among men and women, this broke down as 11.3% (CI: 8.3-15.1) and 10.1% (CI: 7.5-13.5), respectively. There were no significant differences.ConclusionsLeisure and free time activities among people over 65 in the province of Guadalajara must be fostered; but above all a daily walk for over half an hour must be encouraged

Quantum spin fluctuations in the dipolar Heisenberg-like rare earth pyrochlores

The magnetic pyrochlore oxide materials of general chemical formula R2Ti2O7 and R2Sn2O7 (R = rare earth) display a host of interesting physical behaviours depending on the flavour of rare earth ion. These properties depend on the value of the total magnetic moment, the crystal field interactions at each rare earth site and the complex interplay between magnetic exchange and long-range dipole-dipole interactions. This work focuses on the low temperature physics of the dipolar isotropic frustrated antiferromagnetic pyrochlore materials. Candidate magnetic ground states are numerically determined at zero temperature and the role of quantum spin fluctuations around these states are studied using a Holstein-Primakoff spin wave expansion to order 1/S. The results indicate the strong stability of the proposed classical ground states against quantum fluctuations. The inclusion of long range dipole interactions causes a restoration of symmetry and a suppression of the observed anisotropy gap leading to an increase in quantum fluctuations in the ground state when compared to a model with truncated dipole interactions. The system retains most of its classical character and there is little deviation from the fully ordered moment at zero temperature.Comment: Latex2e, 18 pages, 4 figures, IOP forma

Production of PHB from Chicory Roots - Comparison of Three Cupriavidus necator Strains

Chicory roots from hydroponic salad cultivation are an abundant food residue in Navarra (Spain) that are underutilized to date. Aiming at a holistic utilization of resources, we report here the first process using chicory root hydrolysate for the production of poly([R]-3-hydroxybutyrate) (PHB). The polymer can be used for packaging material made for the locally produced vegetables. In the first step, we developed a pre-treatment process to obtain a hydrolysate, which contained 34 g L-1 sugars and 0.7 g L-1 total Kjeldahl nitrogen. This hydrolysate was used as fermentation substrate for three PHB-producing strains. Cupriavidus necator DSM 428 reached a dry biomass concentration of 11.3 g L-1 with a PHB content of 66 % in dry mass within 5 days. C. necator DSM 531 yielded 3.5 g L-1 dry biomass containing 46 % PHB within the same period. C. necator DSM 545 was superior over the other two in that 14.0 g L-1 of biomass containing 78 % PHB after only 3 days were obtained. These results show that even within the same species, the productivities on natural substrates are very different. The produced polymers were extracted using chloroform, and several thermo-physical parameters are in good accordance with published data. Overall, our holistic approach and the encouraging results prove that chicory roots are a viable fermentation substrate for PHB-production.This work was conducted as a part of the LEAD-ERA Project CARBIO, which was financed by the Basque Goverment and co-financed by the European Regional Development Fund (ERDF) of the European Union

MEGARA main optics opto-mechanics

MEGARA is the future integral-field and multi-object spectrograph for the GTC 10.4m telescope located in the Observatorio del Roque de los Muchachos in La Palma. INAOE is a member of the MEGARA Consortium and it is in charge of the Optics Manufacturing work package. In addition to the manufacturing of 73 elements, the work package includes the opto-mechanics i.e. the opto-mechanical design, manufacture, tests and integration of the complete assembly of the main optics composed by the collimator and camera subsystems. MEGARA passed the Optics Detailed Design Review in May 2013 and will have the Detailed Design Review of the complete instrument early 2014. Here we describe the detailed design of the collimator and camera barrels. We also present the finite elements models developed to simulate the behavior of the barrel, sub-cells and other mechanical elements. These models verify that the expected stress fields and the gravitational displacements on the lenses are compatible with the optical quality tolerances. The design is finished and ready for fabrication

Resolving Vega and the inclination controversy with CHARA/MIRC

Optical and infrared interferometers definitively established that the photometric standard Vega (alpha Lyrae) is a rapidly rotating star viewed nearly pole-on. Recent independent spectroscopic analyses could not reconcile the inferred inclination angle with the observed line profiles, preferring a larger inclination. In order to resolve this controversy, we observed Vega using the six-beam Michigan Infrared Combiner on the Center for High Angular Resolution Astronomy Array. With our greater angular resolution and dense (u,v)-coverage, we find Vega is rotating less rapidly and with a smaller gravity darkening coefficient than previous interferometric results. Our models are compatible with low photospheric macroturbulence and also consistent with the possible rotational period of ~0.71 days recently reported based on magnetic field observations. Our updated evolutionary analysis explicitly incorporates rapid rotation, finding Vega to have a mass of 2.15+0.10_-0.15 Msun and an age 700-75+150 Myrs, substantially older than previous estimates with errors dominated by lingering metallicity uncertainties (Z=0.006+0.003-0.002).Comment: Accepted for publication in ApJ Letter