A molecular contribution to the controversial taxonomical status of some freshwater snails (Caenogastropoda: Rissooidea, Cochliopidae) from the Central Andes desert to Patagonia

For over 40 years malacologists have been discussing the taxonomical status of Heleobia species, an enigmatic genus from Cochliopidae family (Caenogastropoda: Rissooidea). As with other rissooidean families, the considerable character convergence and the paucity of anatomical synapomorphies has proved to be a problem in resolving cochliopid phylogenetic relations and establishing the validity of several nominal cochliopid species. Here we present a molecular contribution to solve the taxonomical status of one of the most abundant Southern South America cochliopid genera which has many endemic species. We report molecular evidence that supports three of the four Heleobia groups described for this region, the "australis", "parchappii" and "piscium" groups. The fourth, the "hatcheri" group, belongs not to Heleobia but to a different genus which itself should not be considered as part of the family Cochliopidae but closely related to genus Potamolithus Pilsbry & Rush, 1896.

Auditories energètiques a edificis municipals de tipologia administrativa i d'ensenyament a l'any 2005 : mesures d'estalvi per augmentar la sostenibilitat ambiental i econòmica de les instal·lacions públiques municipals

En aquest document es tracta el tema energètic des de la vessant dels consums en edificis municipals i el tipus de model energètic que aquests tenen implementat. Per a poder portar a terme aquesta tasca s’han realitzat vàries auditories energètiques per conèixer els consums actuals dels edificis i el grau d’eficiència d’aquests, i finalment proposar mesures de millora de la gestió energètica dels edificis estudiats (edificis de la tipologia administrativa i d’ensenyament) i analitzar la possibilitat d’implantació d’energia solar, una font d’energia neta, barata i en concordança amb el medi ambient.

Desenvolupament de mesures per comparar transculturalment xarxes personals (USA i Estats Units)

Estudi elaborat a partir d’una estada a la Universitat de Florida durant Abril i Maig de 2006. “Application to Immigrant Populations in South Florida and Northeastern Spain" ha permès recollir les xarxes personals d’immigrants en els dos països mitjançant un qüestionari implementat amb un software desenvolupat ex professo per recollir i presentar visualment les dades. Es van revisar i assemblar les entrevistes i qüestionaris realitzats a Catalunya i a Estats Units (Miami i Nova York, especialment). Fins al moment s’han revisat i analitzat uns 450 casos. Un cop depurada i analitzada la informació obtinguda s’ha pogut disposar per primer cop de mesures globals pels diferents col•lectius estudiats. L'objectiu global del projecte és entendre les implicacions que les estructures de les xarxes personals tenen en relació a un conjunt de conductes (de salut, d'ús de la llengua, etx) i les autoconcepcions. En aquest sentit era necessari desenvolupar un seguit de mesures que permetessin comparar i documentar la variació de les estructures de les xarxes personals a diferents cultures, nivells socioeconòmics, gènere, religió, etc. i incorporar-les com a variables independents als models explicatius.En aquest moments s’està desenvolupant un índex basat en variables estructurals (número de components de la xarxa, densitat, grau d’intermediació, etc.) i variables de composició (proporció de persones diferents del país d’origen, entre d'altres). La idea és disposar d’un índex d’heterogeneïtat de la xarxa social comparable entre els diferents col•lectius. Malgrat que el treball continua, la principal conclusió a la que s’ha arribat és que al menys a Espanya a mida que passa el temps augmenta el nivell d’heterogeneïtat de les xarxes personals. És a dir, que desprès d’un ràpid procés de canvi i una fase de transnacionalitat la tendència és a reduir aquest nivell (pels costos socials i econòmics que comporta) depenent, naturalment, de factors com l’origen temporal (primera onada o successives), el tipus de col•lectiu i el sexe.

Caracterización agronómica, fenológica, cualitativa y molecular de la colección nuclear de cebadas españolas

El presente proyecto planteaba el paso siguiente a la construcción, por nosotros mismos, de la Colección Nuclear de Cebadas Españolas, que es una representación esquemática de la variabilidad genética de las cebadas ancestralmente cultivadas en nuestro país. Para la explotación completa de estos materiales autóctonos en el Programa Nacional de Mejora de Cebadas, que estamos llevando a cabo los grupos integrantes de este proyecto, se realizó el mismo, que ha comprendido los objetivos siguientes: - Caracterización agronómica, mediante ensayos de campo en ambientes contrastantes y representativos, incluyendo la evaluación de respuestas a factores productores de estreses bióticos y abióticos. - Caracterización fenológica, mediante ensayos en invernadero con protocolos desarrollados por nosotros, para identificar la respuesta de estos genotipos a la vernalización y el fotoperiodo. - Caracterización maltero-cervecera/pienso, mediante análisis de cebada y malta. - Caracterización molecular, mediante el uso de marcadores SSRs y STS.

La dispersió Møller i els inicis de l’electrodinàmica quàntica: treball de recerca per al mestratge en Història de les Ciències

S’hi analitza la deducció teòrica i la contrastació experimental originals de la dispersió electró-electró (dispersió Møller, 1932), amb l’objectiu d’esbrinar quin paper van tenir en el desenvolupament de l’electrodinàmica quàntica. S’hi mostra que Christian Møller (1904-1980) va deduir la fórmula que du el seu nom mitjançant la noció de correspondència, evitant així els problemes que plantejava una incipient teoria quàntica de camps. La fórmula només va assolir el seu estatus actual d’aplicació paradigmàtica de l’electrodinàmica quàntica després de la Segona Guerra Mundial, un cop la teoria va haver superat aquests problemes a través del procés de renormalització. El treball aclareix d’aquesta manera un episodi clau en el desenvolupament d’una de les teories fonamentals de la física del segle XX.

PET Molecular Imaging of Hypoxia in Ischemic Stroke: An Update.

Hypoxia, a condition of insufficient oxygen availability to support metabolism, occurs when the vascular supply is interrupted, as in stroke. The identification of the hypoxic and viable tissue in stroke as compared with irreversible lesions (necrosis) has relevant implications for the treatment of ischemic stroke. Traditionally, imaging by positron emission tomography (PET), using 15O-based radiotracers, allowed the measurement of perfusion and oxygen extraction in stroke, providing important insights in its pathophysiology. However, these multitracer evaluations are of limited applicability in clinical settings. More recently, specific tracers have been developed, which accumulate with an inverse relationship to oxygen concentration and thus allow visualizing the hypoxic tissue non invasively. These belong to two main groups: nitroimidazoles, and among these the 18F-Fluoroimidazole (18F-FMISO) is the most widely used, and the copper-based tracers, represented mainly by Cu-ATSM. While these tracers have been at first developed and tested in order to image hypoxia in tumors, they have also shown promising results in stroke models and preliminary clinical studies in patients with cardiovascular disorders, allowing the detection of hypoxic tissue and the prediction of the extent of subsequent ischemia and clinical outcome. These tracers have therefore the potential to select an appropriate subgroup of patients who could benefit from a hypoxia-directed treatment and provide prognosis relevant imaging. The molecular imaging of hypoxia made important progress over the last decade and has a potential for integration into the diagnostic and therapeutic workup of patients with ischemic stroke.

Ab initio modeling and molecular dynamics simulation of the alpha 1b-adrenergic receptor activation.

This work describes the ab initio procedure employed to build an activation model for the alpha 1b-adrenergic receptor (alpha 1b-AR). The first version of the model was progressively modified and complicated by means of a many-step iterative procedure characterized by the employment of experimental validations of the model in each upgrading step. A combined simulated (molecular dynamics) and experimental mutagenesis approach was used to determine the structural and dynamic features characterizing the inactive and active states of alpha 1b-AR. The latest version of the model has been successfully challenged with respect to its ability to interpret and predict the functional properties of a large number of mutants. The iterative approach employed to describe alpha 1b-AR activation in terms of molecular structure and dynamics allows further complications of the model to allow prediction and interpretation of an ever-increasing number of experimental data.

Peroxisome proliferator-activated receptor structures: ligand specificity, molecular switch and interactions with regulators.

Peroxisome proliferator-activated receptors (PPARs) compose a family of nuclear receptors that mediate the effects of lipidic ligands at the transcriptional level. In this review, we highlight advances in the understanding of the PPAR ligand binding domain (LBD) structure at the atomic level. The overall structure of PPARs LBD is described, and important protein ligand interactions are presented. Structure-activity relationships between isotypes structures and ligand specificity are addressed. It is shown that the numerous experimental three-dimensional structures available, together with in silico simulations, help understanding the role played by the activating function-2 (AF-2) in PPARs activation and its underlying molecular mechanism. The relation between the PPARs constitutive activity and the intrinsic stability of the active conformation is discussed. Finally, the interactions of PPARs LBD with co-activators or co-repressors, as well as with the retinoid X receptor (RXR) are described and considered in relation to PPARs activation.

Molecular estimation of dispersal for ecology and population genetics

The dispersal process, by which individuals or other dispersing agents such as gametes or seeds move from birthplace to a new settlement locality, has important consequences for the dynamics of genes, individuals, and species. Many of the questions addressed by ecology and evolutionary biology require a good understanding of species' dispersal patterns. Much effort has thus been devoted to overcoming the difficulties associated with dispersal measurement. In this context, genetic tools have long been the focus of intensive research, providing a great variety of potential solutions to measuring dispersal. This methodological diversity is reviewed here to help (molecular) ecologists find their way toward dispersal inference and interpretation and to stimulate further developments.

Aplicación de técnicas de citogenética molecular para la detección de aneuploidía y clastogenicidad en células humanas expuestas a arsénico

Los objetivos de esta investigación son: a) Determinar la potencialidad genotóxica de diversos compuestos de arsénico (incluyendo inorgánicos y sus formas metiladas) con el ensayo de micronúcleos utilizando cultivos de células humanas; y b)Estudiar la posible acción aneugénica y clastogénica de los compuestos analizados, determinando el origen de los micronúcleos inducidos mediante la técnica FISH, utilizando sondas pancentroméricas.

Molecular variation at a candidate gene implicated in the regulation of fire ant social behavior

The fire ant Solenopsis invicta and its close relatives display an important social polymorphism involving differences in colony queen number. Colonies are headed by either a single reproductive queen (monogyne form) or multiple queens (polygyne form). This variation in social organization is associated with variation at the gene Gp-9, with monogyne colonies harboring only B-like allelic variants and polygyne colonies always containing b-like variants as well. We describe naturally occurring variation at Gp-9 in fire ants based on 185 full-length sequences, 136 of which were obtained from S. invicta collected over much of its native range. While there is little overall differentiation between most of the numerous alleles observed, a surprising amount is found in the coding regions of the gene, with such substitutions usually causing amino acid replacements. This elevated coding-region variation may result from a lack of negative selection acting to constrain amino acid replacements over much of the protein, different mutation rates or biases in coding and non-coding sequences, negative selection acting with greater strength on non-coding than coding regions, and/or positive selection acting on the protein. Formal selection analyses provide evidence that the latter force played an important role in the basal b-like lineages coincident with the emergence of polygyny. While our data set reveals considerable paraphyly and polyphyly of S. invicta sequences with respect to those of other fire ant species, the b-like alleles of the socially polymorphic species are monophyletic. An expanded analysis of colonies containing alleles of this clade confirmed the invariant link between their presence and expression of polygyny. Finally, our discovery of several unique alleles bearing various combinations of b-like and B-like codons allows us to conclude that no single b-like residue is completely predictive of polygyne behavior and, thus, potentially causally involved in its expression. Rather, all three typical b-like residues appear to be necessary.