High affinity binding of amyloid β-peptide to calmodulin: Structural and functional implications.

Amyloid β-peptides (Aβ) are a major hallmark of Alzheimer's disease (AD) and their neurotoxicity develop with cytosolic calcium dysregulation. On the other hand, calmodulin (CaM), a protein which plays a major multifunctional role in neuronal calcium signaling, has been shown to be involved in the regulation of non-amyloidogenic processing of amyloid β precursor protein (APP). Using fluorescent 6-bromoacetyl-2-dimethylaminonaphthalene derivatives of CaM, Badan-CaM, and human amyloid β(1-42) HiLyte™-Fluor555, we show in this work that Aβ binds with high affinity to CaM through the neurotoxic Aβ25-35 domain. In addition, the affinity of Aβ for calcium-saturated CaM conformation is approximately 20-fold higher than for CaM conformation in the absence of calcium (apo-CaM). Moreover, the value of Kd of 0.98 ± 0.11 nM obtained for Aβ1-42 dissociation from CaM saturated by calcium point out that CaM is one of the cellular targets with highest affinity for neurotoxic Aβ peptides. A major functional consequence of Aβ-CaM interaction is that it slowdowns Aβ fibrillation. The novel and high affinity interaction between calmodulin and Aβ shown in this work opens a yet-unexplored gateway to further understand the neurotoxic effect of Aβ in different neural cells and also to address the potential of calmodulin and calmodulin-derived peptides as therapeutic agents in AD

La repressió franquista al Vallès : Terrassa venjança, mort i resistència (1939-1945)

El treball sobre la repressió franquista a Terrassa, entre el 1939 i 1945, analitzarà: d'una banda, els mecanismes endegats per les elits locals (provincials i nacionals) per esclafar als republicans terrassenc i els nuclis de la resistència antifranquista per tal de garantir el control polític i social de la ciutat i, d'altra, els cost humà que va significar la Guerra Civil i, fonamentalment, la posterior repressió franquista (depurats, detinguts, empresonats, afusellats i exiliats empresonats a camps de concentració nazis). El treball inclou també un estudi de les víctimes del franquisme i dels esdeveniment més significatius de resistència antifranquist

Plantas hospedantes de Rhopalosiphum maidis (Fitch) (Homoptera: Aphididae) y su papel en el ciclo biológico del pulgón en Cataluña

Se evaluó el papel de las distintas plantas hospedantes de Rhopalosiphum maidis (Fitch) en el ciclo biológico anual de los dos cariotipos más comunes en Cataluña (2n = 8 y 2n = 10 cromosomas) mediante el seguimiento de poblaciones de pulgones en cereales de invierno y verano y en gramíneas espontáneas. Asimismo se registró la densidad de R. maidis en parcelas comerciales de maíz y se determinó el periodo de colonización mediante la instalación de una trampa de succión. Las gramíneas espontáneas juegan un papel fundamental en el ciclo biológico anual de ambos cariotipos. Los pulgones de cariotipo 2n = 10 pueden vivir sobre cebada durante el otoño, invierno y primavera, y sobre gramíneas adventicias, como Setaria sp. y Echinochloa crus-galli ((L.) P. Beauv.), en verano e inicios de otoño; la superposición del ciclo de estas gramíneas permite a los pulgones con este cariotipo cerrar su ciclo anual en ellas. En el caso de los pulgones de cariotipo 2n = 8, el sorgo es el principal hospedante de verano; la cañota constituye un hospedante básico en primavera y otoño, pudiendo actuar como hospedante en inviernos extremadamente cálidos. El periodo primaveral de colonización del maíz por R. maidis se produjo principalmente en mayo y duró hasta mediados de junio. El número de alados capturados en la trampa de succión, así como el de individuos hallados sobre plantas, fue muy bajo tanto en mayo como en junio. Los resultados obtenidos sugieren que el maíz no juega un papel relevante en el ciclo de R. maidis. Se analizan algunas de las posibles causas de este fenómeno.The role of the different host-plant of Rhopalosiphum maidis (Fitch) in the annual cycle of the most common karyotypes in Catalonia (2n = 8 and 2n = 10) was evaluated monitoring aphid populations on winter and summer cereals and wild grasses. Densi- ties of R. maidis in maize commercial fields were also recorded, and the period of aphid colonization was determined using a suction trap. Wild grasses play a main role in the annual biological cycle of both karyotypes. Aphids with 2n = 10 karyotype can live on barley through the autumn, winter and spring and on wild grasses, like Setaria sp. and Echinochloa crus-galli, in summer and beginning of autumn; the overlap of the cycle of these gramineae allows aphids with this karyotype complete their annual cycle on them. For aphids with 2n = 8 karyotype, sorghum is the main summer host whereas in spring and summer Johnson grass is, and it can be a winter host in extremely warm winters. The spring R. maidis colonization period of maize was mainly in May and lasted until mid June. Number of alates caught in the suction trap, as well as those on maize plants, were very low in may and June. Results achieved suggest that maize does not play a significant role in the annual cycle of R. maidis in Catalonia. Some reasons for that are discussed

Multiple scattering of light in optical diagnostics of dense sprays and other complex turbid media

Sprays and other industrially relevant turbid media can be quantitatively and qualitatively characterized using modern optical diagnostics. However, current laser based techniques generate errors in the dense region of sprays due to the multiple scattering of laser radiation e ected by the surrounding cloud of droplets. In most industrial sprays, the scattering of light occurs within the so-called intermediate scattering regime where the average number of scattering events is too great for single scattering to be assumed, but too few for the di usion approximation to be applied. An understanding and adequate prediction of the radiative transfer in this scattering regime is a challenging and non-trivial task that can significantly improve the accuracy and e ciency of optical measurements. A novel technique has been developed for the modelling of optical radiation propagation in inhomogeneous polydisperse scattering media such as sprays. The computational model is aimed to provide both predictive and reliable information, and to improve the interpretation of experimental results in spray diagnostics. Results from simulations are verified against the analytical approach and validated against the experiment by the means of homogeneous solutions of suspended polystyrene spheres. The ability of the technique to simulate various detection conditions, to di erentiate scattering orders and to generate real images of light intensity distributions with high spatial resolution is demonstrated. The model is used for the real case of planar Mie imaging through a typical hollow cone water spray. Versatile usage of this model is exemplified with its applications to image transfer through turbid media, correction of experimental Beer-Lambert measurements, the study of light scattering by single particles in the farfield region, and to simulate the propagation of ultra-short laser pulses within complex scattering media. The last application is fundamental for the development and testing of future optical spray diagnostics; particularly for those based on time-gating detection such as ballistic imaging.EThOS - Electronic Theses Online ServiceGBUnited Kingdo

La firma electrónica y su regulación en la Ley 59/2003, de 19 de diciembre, de Firma Electrónica

The new Law 59/2003, as a response to the need to award safety to communications in the Internet and to reinforce the existing legal frame, incorporates several innovations related to the regulation of the electronic signature. So it is created a new concept of electronic signature demanded by the sector, the electronic qualified signature, which is compared functionally to the manuscript signature; a series of guarantees are demanded to expiring for the devices of creation of electronic signature; it is included inside the modality of documentary evidence to the support in which the signed information appears; a special legitimation is demanded to solicitors of taking responsibility of the custody of such information; and, there is established a regime applicable to the performance of legal persons signatories

La autonomía del individuo en el ámbito sanitario. El deber de información y el consentimiento informado como derechos del paciente en la nueva Ley 41/2002, de 14 de noviembre

La Ley 41/2002, de 14 de noviembre, adopta el título significativo de Autonomía del paciente, que comporta la asunción por parte de los poderes públicos del principio bioético de la Autonomía, lo que constituye un avance decisivo en la conformación del sistema normativo sanitario español. Una de las consecuencias más inmediatas de este planteamiento es el reconocimiento informado del paciente, que, si bien ya había sido reconocido en la Ley General de Sanidad de 1986, en la nueva ley se explicita y desarrolla ampliamente, lo que permite a la autora de este estudio realizar un amplio y detallado análisis de los derechos y obligaciones de los pacientes, como consecuencia de la nueva ley

El rozamiento de las barras de control de una central nuclear como índice del mantenimiento predictivo

En caso de grandes niveles de quemado del combustible nuclear, pueden combarse los tubos guía de las barras de control de los reactores comerciales de agua a presión (Pressurized Water Reactor, PWR). En consecuencia, la caída de las barras de control podría dar lugar a una inserción parcial de alguna de ellas, quedando entonces no operativa. En el presente trabajo se propone la prevención temprana de este tipo de incidentes realizando un ensayo en el que se midan dos coeficientes de rozamiento asociados a la caída: el hidráulico y el de fricción de la barra con la pared interna del tubo guía. El coeficiente hidráulico apenas cambia con la curvatura del tubo guía, por lo que ésta solo puede detectarse gracias a la variación del coeficiente de fricción. También, se establece un modelo simplificado para describir la dinámica de la caída de las barras de control. Su validación se lleva a cabo confrontándolo con registros reales de ensayos de caída de barras en una central nuclear comercial. Finalmente, tomando de los registros de los ensayos el tiempo que transcurre hasta que la velocidad de caída alcanza su máximo, se ha encontrado que existe una relación lineal entre el inverso del cuadrado de dicho tiempo y el coeficiente de fricción de la barra con el interior del tubo guía

Discordant Supramolecular Fibres Reversibly Depolymerised by Temperature and Light

Synthetic stimuli responsive supramolecular polymers attract increasing interest for their ability to mimic the unique properties of natural assemblies. Here we focus on the well-studied benzene-1,3,5-tricarboxamide (BTA) motif, and substitute it with two (S)-3,7-dimethyloctyl groups and an azobenzene photoswitch. We demonstrate the UV (λ=365 nm) induced depolymerisation of the helical hydrogen-bonded polymers in methylcyclohexane (MCH) through circular dichroism and UV-vis spectroscopy in dilute solution (15 μm), and NMR and iPAINT super-resolution microscopy in concentrated solution (300 μm). The superstructure can be regenerated after thermal depolymerization, whilst repeated depolymerisation can be reversed without degradation by irradiating at λ=455 nm. Molecular dynamics simulations show that the most energetically favourable configuration for these polymers in MCH is a left-handed helical network of hydrogen-bonds between the BTA cores surrounded by two right-handed helices of azobenzenes. The responsiveness to two orthogonal triggers across a broad concentration range holds promise for use in, for example, photo-responsive gelation