Rotating Stars and the Formation of Bipolar Planetary Nebulae II: Tidal Spin-up

We present new binary stellar evolution models that include the effects of tidal forces, rotation, and magnetic torques with the goal of testing Planetary Nebulae (PNe) shaping via binary interaction. We explore whether tidal interaction with a companion can spin up the AGB envelope. To do so we have selected binary systems with main sequence masses of 2.5 \Mo and of 0.8 \Mo and evolve them allowing initial separations of 5, 6, 7, and 8 AU. The binary stellar evolution models have been computed all the way to the PNe formation phase or until Roche lobe overflow (RLOF) is reached, whatever happens first. We show that with initial separations of 7 and 8 AU, the binary avoids entering into RLOF, and the AGB star reaches moderate rotational velocities at the surface ($\sim 3.5$ and $\sim 2$ \kms respectively) during the inter-pulse phases, but after the thermal pulses it drops to a final rotational velocity of only $\sim 0.03$ \kms. For the closest binary separations explored, 5 and 6 AU, the AGB star reaches rotational velocities of $\sim 6$ and $\sim 4$ \kms respectively when the RLOF is initiated. We conclude that the detached binary models that avoid entering the RLOF phase during the AGB will not shape bipolar PNe, since the acquired angular momentum is lost via the wind during the last two thermal pulses. This study rules out tidal spin-up in non-contact binaries as a sufficient condition to form bipolar PNe.Comment: 25 pages, 3 figures, accepted by The Astrophysical Journa

Injectable and Spatially Patterned Microporous Annealed Particle (MAP) Hydrogels for Tissue Repair Applications.

Spatially patterned hydrogels are becoming increasingly popular in the field of regenerative medicine and tissue repair because of their ability to guide cell infiltration and migration. However, postfabrication technologies are usually required to spatially pattern a hydrogel, making these hydrogels difficult to translate into the clinic. Here, an injectable spatially patterned hydrogel is reported using hyaluronic acid (HA)-based particle hydrogels. These particle hydrogels are sequentially loaded into a syringe to form a pattern and, once injected, they maintain the pattern. The applicability of this hydrogel in a wound healing skin model, a subcutaneous implant model, as well as a stroke brain model is examined and distinct patterning in all models tested is shown. This injectable and spatially patterned hydrogel can be used to create physical or biochemical gradients. Further, this design can better match the scaffold properties within the physical location of the tissue (e.g., wound border vs wound center). This allows for better design features within the material that promote repair and regeneration

Counterfactual thinking in everyday life situations: Temporal order effects and social norms.

Razonamiento contrafáctico en situaciones de la vida diaria: Efectos de
 orden temporales y normas sociales. El razonamiento contrafáctico es la
 comparación de una situación fáctica con una alternativa simulada. Cuando
 las personas imaginan cómo las cosas podrían haber sido diferentes, tienden
 a deshacer mentalmente el último suceso de una secuencia de
 acontecimientos independientes previos a un resultado. Se presentan dos
 experimentos que examinan este fenómeno que ha sido denominado el
 efecto de orden temporal. El primer experimento, con 132 participantes,
 examinó el efecto de variar el número de eventos de la vida diaria en el
 efecto de orden temporal. Los resultados muestran que en situaciones
 cotidianas, es necesario un número suficiente de sucesos para que efecto se
 produzca. El segundo experimento, con 177 participantes, examinó una
 posible relación entre el efecto de orden temporal con un efecto diferente: la
 tendencia a cambiar eventos controlables que son excepcionales respecto a
 las normas interpersonales de conducta. Los resultados muestran que la
 posición en una secuencia temporal de sucesos independientes afecta a la
 facilidad para cambiar esos eventos excepcionales. Los resultados se
 discuten en términos de normas sociales

Sobre la restauració fluviali la complexitat dels rius efímers: algunes consideracions crítiques

En aquest article s"analitzen les actuacions de restauració fluvial dutes a terme a la Confederació Hidrogràfica del Xúquer entre 2008 i 2009, especialment les intervencions de restauració geomorfològica, la qual cosa ens permet una sèrie de consideracions crítiques sobre les obres. Es fan també algunes reflexions teòriques sobre els canvis ambientals i antròpics esdevinguts al llarg del segle XX i les implicacions que tenen sobre la restauració fluvial, en la mesura que aporten complexitat i incertesa a la restauració. En particular s"analitzen algunes actuacions de restauració que comprometen la connectivitat hidrològica i sedimentària, que són especialment febles en rius efímers. This paper presents a critical review of the geomorphological river restoration works carried out in the Júcar River Basin between 2008 and 2009, considering the impacts on the hydro-geomorphic systems. The scope of the environmental and anthropogenic changes occurred in the Mediterranean rivers throughout the twentieth century adds considerable complexity and uncertainty to the restoration actions. In particular several considerations are done about some restoration works that compromise the hydrological and sediment connectivity, which are particularly weak in ephemeral rivers