46 research outputs found
Irán y Arabia Saudí en Yemen
Este artículo analiza la implicación del régimen iraní en la guerra civil yemení como pretexto para la intervención saudí. Desde una perspectiva sociológica del poder, primero examinamos las motivaciones y los vínculos directos e indirectos entre los rebeldes hutíes y las élites iraníes. Luego usamos métodos cualitativos de investigación bibliográfica y análisis de fuentes periodísticas para examinar las razones de la decisión política de Arabia Saudí de intervenir en Yemen para extender el poder del príncipe bin Salmán y ampliar su apoyo popular. Podemos concluir que el papel de Irán en Yemen es insuficiente para entender a los hutíes como proxies. Por lo tanto, confirmamos que el príncipe saudí intensificó esta acusación para justificar la guerra y afirmar su posición dentro del sistema de poder interno
Guiding the humoral response against HIV-1 toward a MPER adjacent region by immunization with a VLP-formulated antibody-selected envelope variant
Preventive HIV-1 vaccine strategies rely on the elicitation of broadly neutralizing antibody (bNAb) responses, but their induction in vivo by vaccination remains challenging. Considering that the ability of an epitope to elicit effective humoral immunity depends on its exposure on the virion, we have used a reverse genetics approach to select variants from an HIV-1 AC10_29 randomly mutated envelope library that showed increased affinity for a selected bNAb (4E10 bNAb targeting the HIV-1 MPER region). Isolated envelope sequences were analyzed by deep-sequencing showing a small number of dominant changes, including the loss of four potential N-linked glycosylation sites and disruption of the V1/V2 loop. Accordingly, the dominant variant (LR1-C1), showed not only increased affinity for MPER bNAbs 4E10 and 2F5, but also higher affinity for an additional antibody targeting the V3 loop (447-52D) that could be a consequence of an open conformation tier 1-like Env. Furthermore, the amino acids specific for the selected variant are associated with an increased sensitivity for 4E10 and 2F5 antibodies. In vivo studies showed that sera from mice immunized with LR1-C1 viruses possessed an improved neutralizing activity compared to the wild-type AC10_29 env. While Virus Like Particles (VLPs) carrying this envelope were unable to induce detectable neutralizing activity in immunized rabbits, one animal showed antibody response to the 4E10-proximal region. Our data establish a novel approach that has the potential to yield HIV envelope immunogen sequences that direct antibody responses to specific envelope regions
Restauració d'una calaixera catalana de la segona meitat del segle XVIII
El procés de conservació-restauraciód’aquesta còmoda se’ns presentava com unrepte considerable a causa del deficient estatde conservació del moble i a les dificultatsderivades d’intervenir amb un grup moltnombrós d’alumnes. No obstant això el projecteera extraordinàriament apassionant considerantla notorietat i excel·lència de la peça, lespossibilitats de coordinar i dirigir amb èxitl’ampli equip humà i la nostra importantvinculació amb aquesta vila marinera
On the Synthesis and Chemical Behaviour of the Elusive Bis(hydrosulfido)-Bridged Dinuclear Rhodium(I) Complexes [{Rh(μ-SH)(CO)(PR3)}2]
11 páginas, 6 figuras, 5 tablas, 4 esquemas.Several bis(hydrosulfido)-bridged dinuclear rhodium(I) compounds, [{Rh(μ-SH)(L)2}2], have been prepared from rhodium(I) acetylacetonato complexes, [Rh(acac)(L)2], and H2S(g). Reaction of [Rh(acac){P(OPh)3}2] with H2S(g) affords the dinuclear bis(hydrosulfido)-bridged compound [{Rh(μ-SH){P(OPh)3}2}2] (1). However, reaction of complexes [Rh(acac)(CO)(PR3)] with H2S(g) gives the dinuclear compound [{Rh(μ-SH)(CO)(PR3)}2] (R=Cy, 2; R=Ph, 4) and the trinuclear cluster [Rh3(μ-H)(μ3-S)2(CO)3(PR3)3] (R=Cy, 3; R=Ph, 5). The selective synthesis of both type of compounds has been carried out by control of the H2S(g) concentration in the reaction media. The trinuclear hydrido–sulfido cluster [Rh3(μ-H)(μ3-S)2(CO)3(PPh3)3] (5) has been also obtained by reaction of [{Rh(μ-SH)(CO)(PPh3)}2] (4) with [Rh(acac)(CO)(PPh3)], proceeding through the trinuclear hydrosulfido–sulfido intermediate [Rh3(μ3-SH)(μ3-S)(CO)3(PPh3)3]. The molecular structures of complexes 1 and 3 have been determined by X-ray diffraction methods. Compound 1 is stable in solution, but complexes 2 and 4 slowly transform in solution into the trinuclear hydrido–sulfido clusters 3 and 5, respectively, with the release of H2S(g) in a reversible way. 1H NMR kinetic experiments for the transformation of 4 into 5 have revealed that this transformation follows second-order-type kinetic. The following activation parameters, ΔH≠=24±3 kJ mol−1 and of ΔS≠=−223±8 J K−1 mol−1, have been calculated from the determination of the second-order rate constants in the temperature range 30–45 °C. The large negative value of the activation entropy is consistent with an associative character of the rate-determining step. A plausible multistep mechanism based on the chemical behaviour of hydrosulfido–metal complexes and compatible with the kinetic behaviour has been proposed.The financial support from Ministerio de Educación y Ciencia (MEC/
FEDER) is gratefully acknowledged (Project CTQ2006-03973/BQU).Peer reviewe
Ecosystemic urbanism, keys for the resilience and liveability of metropolitan areas
La actual emergencia climática y los impactos del cambio global plantean la necesidad de realizar una transición ecológica en las próximas décadas. Las ciudades y metrópolis deben ser las protagonistas de esa transición y para ello deben replantear su modelo urbano.
Las ciudades deberán adaptarse a impactos ambientales que ya son una realidad, que afectan a ecosistemas y a la población, y que agravan la desigualdad social.
El Plan Director Urbanístico de la Área Metropolitana de Barcelona (PDU metropolitano) plantea un enfoque del urbanismo basado en el análisis del metabolismo urbano, y que permita vincular ecosistemas, urbes y flujos de materia y energía. Esta es la perspectiva global que permitirá superar la actual crisis ecológica. El artículo se centra en los aspectos más innovadores del PDU en cuanto a resiliencia y habitabilidad aplicadas al urbanismo. En concreto se focaliza en la ordenación de espacios como:
La estructura azul, pensando en el ciclo integral del agua.
El mosaico agroforestal como forma más resiliente de los espacios abiertos
Las membranas, espacios de conexión e intercambio en el borde urbano
Las avenidas metropolitanas y los ejes verdes en el cambio de paradigma de los flujos urbanos. La rehabilitación de los tejidos urbanos desde una perspectiva energética y climática.
El presente artículo demuestra que cuando la forma permite que se desarrollen los procesos deseados, el territorio se vuelve más resiliente. En conclusión, entender la mutabilidad y el dinamismo de la forma en función de cómo cambian las necesidades del territorio es entender su capacidad evolutiva en relación con su equilibrio y resiliencia, en tanto que el territorio es un ecosistema.The current climate emergency and the impacts of global change pose the necessity in the next decades of an ecological transition. Cities and metropolitan areas must lead this transition by rethinking their urban model.
Cities shall face environmental impacts, already present in our daily life. Those impacts affect natural ecosystems and a large amount of population, causing social inequality.
The Metropolitan Urban Master Plan of Barcelona (PDU) suggests an urban planning approach based on the metabolism analysis, and which allows linking ecosystems, cities, and energy and matter flows. This global perspective is the cornerstone to overcome the current ecological crisis. Therefore, this paper is focused on the most innovative aspects of the PDU in terms of urban resil- ience and liveability. Specifically, it focuses on the planning of the following spaces:
Blue infrastructure, taking into consideration the water cycle.
Agroforestry mosaic, as a great form of resilient open space.
Membranes, as connection and exchange areas at the urban periphery.
Metropolitan avenues and green corridors’ role in the paradigm shift of urban flows.
Urban rehabilitation and renovation with an energetic and climatic perspective.
This paper demonstrates that when form grants the development of the desired processes, the territory becomes more resilient. In conclusion, understanding the mutability and dynamism of the form according to the changing needs of the territory leads to understand its evolving capacity, regarding its rebalance and resilience, as long as the territory is in fact an ecosystem
Introducción al derecho, septiembre 2013
Recurs d'aprenentatge de la Universitat Oberta de Catalunya.Recurso de aprendizaje de la "Universitat Oberta de Catalunya".Learning resource of the "Universitat Oberta de Catalunya"
Introducció al dret, setembre 2013
Recurs d'aprenentatge de la Universitat Oberta de Catalunya.Recurso de aprendizaje de la "Universitat Oberta de Catalunya".Learning resource of the "Universitat Oberta de Catalunya"