Efecte de la freqüència d'incendis sobre l'estructura i composició de les comunitats vegetals a la península del Cap de Creus

L’efecte de la freqüència d’incendis sobre la dinàmica de les comunitats vegetals mediterrànies ha estat estudiada a la península del cap de Creus. S’han realitzat observacions en 24 parcel·les per percebre canvis en l’estructura i composició de les comunitats vegetals en funció de la freqüència de foc (de 1 a 5 incendis en una mateixa parcel·la) i de les estratègies regeneratives postincendi que presenten les espècies (rebrotació i germinació). Una elevada freqüència d’incendis va associada a una disminució de l’abundància de les espècies llenyoses rebrotadores obligades i de les espècies llenyoses germinadores obligades. D’aquestes últimes, les espècies del gènere Cistus acaben desapareixent a freqüències altes de foc. Les espècies rebrotadores facultatives es mantenen indiferents a la freqüència d’incendis, fet que els permet ser les dominants als estrats arbustius de les comunitats a freqüències elevades de foc. S’observa una tendència a l’increment d’espècies herbàcies, incloses les gramínies, a major números de focs. Brachypodium retusum és dominant en totes les àrees, demostrant una gran capacitat de colonització i regeneració postincendi. Aquests resultats suggereixen una transformació de les comunitats vegetals dominades per espècies arbustives llenyoses a estructures més simplificades dominades per herbàcies, establint-se un mecanisme de retroalimentació entre aquestes i el foc.

Nuclear factor I-C links platelet-derived growth factor and transforming growth factor beta1 signaling to skin wound healing progression.

Transforming growth factor beta (TGF-beta) and platelet-derived growth factor A (PDGFAlpha) play a central role in tissue morphogenesis and repair, but their interplay remain poorly understood. The nuclear factor I C (NFI-C) transcription factor has been implicated in TGF-beta signaling, extracellular matrix deposition, and skin appendage pathologies, but a potential role in skin morphogenesis or healing had not been assessed. To evaluate this possibility, we performed a global gene expression analysis in NFI-C(-/-) and wild-type embryonic primary murine fibroblasts. This indicated that NFI-C acts mostly to repress gene expression in response to TGF-beta1. Misregulated genes were prominently overrepresented by regulators of connective tissue inflammation and repair. In vivo skin healing revealed a faster inflammatory stage and wound closure in NFI-C(-/-) mice. Expression of PDGFA and PDGF-receptor alpha were increased in wounds of NFI-C(-/-) mice, explaining the early recruitment of macrophages and fibroblasts. Differentiation of fibroblasts to contractile myofibroblasts was also elevated, providing a rationale for faster wound closure. Taken together with the role of TGF-beta in myofibroblast differentiation, our results imply a central role of NFI-C in the interplay of the two signaling pathways and in regulation of the progression of tissue regeneration.

Proteomic and Metabolomic Analyses of Mitochondrial Complex I-deficient Mouse Model Generated by Spontaneous B2 Short Interspersed Nuclear Element (SINE) Insertion into NADH Dehydrogenase (Ubiquinone) Fe-S Protein 4 (Ndufs4) Gene.

Eukaryotic cells generate energy in the form of ATP, through a network of mitochondrial complexes and electron carriers known as the oxidative phosphorylation system. In mammals, mitochondrial complex I (CI) is the largest component of this system, comprising 45 different subunits encoded by mitochondrial and nuclear DNA. Humans diagnosed with mutations in the gene NDUFS4, encoding a nuclear DNA-encoded subunit of CI (NADH dehydrogenase ubiquinone Fe-S protein 4), typically suffer from Leigh syndrome, a neurodegenerative disease with onset in infancy or early childhood. Mitochondria from NDUFS4 patients usually lack detectable NDUFS4 protein and show a CI stability/assembly defect. Here, we describe a recessive mouse phenotype caused by the insertion of a transposable element into Ndufs4, identified by a novel combined linkage and expression analysis. Designated Ndufs4(fky), the mutation leads to aberrant transcript splicing and absence of NDUFS4 protein in all tissues tested of homozygous mice. Physical and behavioral symptoms displayed by Ndufs4(fky/fky) mice include temporary fur loss, growth retardation, unsteady gait, and abnormal body posture when suspended by the tail. Analysis of CI in Ndufs4(fky/fky) mice using blue native PAGE revealed the presence of a faster migrating crippled complex. This crippled CI was shown to lack subunits of the "N assembly module", which contains the NADH binding site, but contained two assembly factors not present in intact CI. Metabolomic analysis of the blood by tandem mass spectrometry showed increased hydroxyacylcarnitine species, implying that the CI defect leads to an imbalanced NADH/NAD(+) ratio that inhibits mitochondrial fatty acid β-oxidation.

Nuclear receptor Rev-erb alpha (Nr1d1) functions in concert with Nr2e3 to regulate transcriptional networks in the retina.

The majority of diseases in the retina are caused by genetic mutations affecting the development and function of photoreceptor cells. The transcriptional networks directing these processes are regulated by genes such as nuclear hormone receptors. The nuclear hormone receptor gene Rev-erb alpha/Nr1d1 has been widely studied for its role in the circadian cycle and cell metabolism, however its role in the retina is unknown. In order to understand the role of Rev-erb alpha/Nr1d1 in the retina, we evaluated the effects of loss of Nr1d1 to the developing retina and its co-regulation with the photoreceptor-specific nuclear receptor gene Nr2e3 in the developing and mature retina. Knock-down of Nr1d1 expression in the developing retina results in pan-retinal spotting and reduced retinal function by electroretinogram. Our studies show that NR1D1 protein is co-expressed with NR2E3 in the outer neuroblastic layer of the developing mouse retina. In the adult retina, NR1D1 is expressed in the ganglion cell layer and is co-expressed with NR2E3 in the outer nuclear layer, within rods and cones. Several genes co-targeted by NR2E3 and NR1D1 were identified that include: Nr2c1, Recoverin, Rgr, Rarres2, Pde8a, and Nupr1. We examined the cyclic expression of Nr1d1 and Nr2e3 over a twenty-four hour period and observed that both nuclear receptors cycle in a similar manner. Taken together, these studies reveal a novel role for Nr1d1, in conjunction with its cofactor Nr2e3, in regulating transcriptional networks critical for photoreceptor development and function.

Estancia en el Departament de Emergencia y de Aceptación (DEA), estructura compleja de medicina y cirugía de 1º nivel del E.O. Ospedali Galliera, Génova

Proyecto de investigación elaborado a partir de una estancia en el Dipartamento di Emergencia e Accetazione del E.O. Ospedalli Galliera, Italia, entre marzo y octubre del 2006. En los últimos años ha habido un aumento de la población extranjera en los servicios sanitarios de urgencias. Este estudio se propone la observación de las modalidades de llegada en la urgencia de los Latinos, profundizando las manifestaciones, las expresiones de los trastornos y las descripciones de los síntomas por medio de entrevistas profundas llevada a cabo con una muestra de treinta latinoamericanos.

Indicadors de l'estructura sòcio-afectiva en el rendiment dels esports col·lectius

The present work carries out an analysis about which elements of the socioaffective structure take more importance for different male team sports coaches. Data obtaining carries out by using a survey applied directly by interview. In the first part, the interviewed coaches were asked to point out the indicators of the stated structure they considered more important, using a previous selection. In the second part, using a qualitative technique, the interviewed coaches were asked to explain own strategies to work, to control or to evaluate the indicators they pointed out as important in the first part. Analysis show that most of the coaches gave great importance to this structure (80% of the values are over 4 points on a top 5 points scale), and all of them had their own strategies to deal with the structure in their sports.

Gene flow among wild and domesticated almond species: insights from chloroplast and nuclear markers

Hybridization has played a central role in the evolutionary history of domesticated plants. Notably, several breeding programs relying on gene introgression from the wild compartment have been performed in fruit tree species within the genus Prunus but few studies investigated spontaneous gene flow among wild and domesticated Prunus species. Consequently, a comprehensive understanding of genetic relationships and levels of gene flow between domesticated and wild Prunus species is needed. Combining nuclear and chloroplastic microsatellites, we investigated the gene flow and hybridization among two key almond tree species, the cultivated Prunus dulcis and one of the most widespread wild relative Prunus orientalis in the Fertile Crescent. We detected high genetic diversity levels in both species along with substantial and symmetric gene flow between the domesticated P. dulcis and the wild P. orientalis. These results were discussed in light of the cultivated species diversity, by outlining the frequent spontaneous genetic contributions of wild species to the domesticated compartment. In addition, crop-to-wild gene flow suggests that ad hoc transgene containment strategies would be required if genetically modified cultivars were introduced in the northwestern Mediterranean.

El Bienestar del hogar y los funcionamientos elementales de la Infancia y juventud en edad escolar: aplicación de un Modelo de Estructura de Covarianza (MEC) al caso del departamento de Antioquia- Colombia

En la investigación planteo que el logro de las capacidades de los niños y jóvenes está sujeto a su entorno familiar, de manera que el bienestar del hogar en el espacio de los funcionamientos influye en los niveles de salud y de educación de los niños y jóvenes en edad escolar. La primera parte, es el marco basado en el enfoque de capacidades, donde se establece un soporte teórico entre el bienestar de la infancia y las capacidades. La segunda, es la aplicación de un Modelo de Estructura de Covarianza (MEC), aplicado al caso de Antioquia-Colombia. Palabras

Crecimiento del empleo y estructura espacial: el caso de las provincias españolas. 1999 y 2004

En este documento se presenta un estudio acerca de cómo variables de estructura económica y de estructura espacial afectan el crecimiento del empleo en 50 provincias españolas entre los años 1999 y 2004. Para ello, se realiza una estimación global que abarca los sectores de manufacturas y de servicios. Los resultados evidencian economías de urbanización, pero ambigüedad para las economías de localización. Además, variables de estructura espacial como los índices de centralización y concentración resultaron no ser significativos, mientras que el porcentaje de empleo disperso y en subcentros explican ampliamente el modelo además de alcanzar su signo esperado

Organització nuclear dels gens que codifiquen per a les proteïnes làcties en cèlules epitelials mamàries en diferents estadis de desenvolupament

Estudi realitzat a partir d’una estada al Institut National de la Recherche Agronomique (INRA), a França, entre 2006 i 2008. En el ultims anys, estudis realitzats en diferents tipus cel•lulars han pogut determinar l’importància de l’organització nuclear en el control i regulació gènica. S’han realizat diferents experiments per tal de determinar si la posició dels gens de les proteïnes làcties en el nucli interfàsic de cel•lules epitelials mamaries és important per regular la seva expressió. Els gens de les proteïnes de la llet s’expressen a la glàndula mamaria durant la lactació en resposta a les hormones lactogèniques (majoritàriament prolactina i glucocorticoids). Mitjançant la tècnica de FISH (fluorescent in situ hibridization) en 3D s’ha caracteritzat la localització nuclear del gens WAP (whey acidic protein) i les caseïnes en cèl•lules epitelials mamaries de ratolí (HC11) cultivades en l’absència i presencia d’hormones lactogèniques. En absència d’hormones, els dos gens estan distribuïts dins del nucli de forma no aleatòria, el gen WAP es troba localitzat en l’interior del nucli, mentre que les caseïnes es troben localitzades prop de la perifèria nuclear. L’estimulació hormonal indueix un canvi significatiu en la distància dels dos gens a la perifèria nuclear. Així mateix, la posició del locus de la caseïna en relació al seu territori cromosòmic (CT) 5 està correlacionada amb la inducció hormonal i per tant amb la seva activació transcripcional, mentre que la posició del gen WAP amb relació al seu CT11 sembla més determinada pel context cromosòmic del gen. Per últim, no s’han trobat diferencies en la localització dels gens en relació a l'heterocromatina del centròmer, descrit com a compartiment repressiu, entre les cèl•lules estimulades amb hormones i les que no. En els dos casos s’ha trobat un gran percentatge de gens que no estan associats als centròmers.

Hand exposure in diagnostic nuclear medicine with 18F- and 99mTc-labelled radiopharmaceuticals - Results of the ORAMED project

Workers performing preparation and administration of radiopharmaceuticals in NM departments are likely to receive high local skin doses to the hands which may even surpass the dose limit of 500 mSv whenever radiation protection standards are insufficient. A large measurement campaign was organised within the framework of the ORAMED project to determine the dose distribution across the hands received during preparation and administration of 18F- and 99mTc-labelled radiopharmaceuticals. The final data, collected over almost 3 years, include 641 measurements from 96 workers in 30 NM departments from 6 European countries. Results have provided levels of reference doses for the considered standard NM diagnostic procedures (mean maximum normalised skin dose of 230 μSv/GBq, 430 μSv/GBq, 930 μSv/GBq and 1200 μSv/GBq for the administration of 99mTc, preparation of 99mTc, administration of 18F and preparation of 18F, respectively). Finger dose was analysed as a function of the potential parameters of influence showing that shielding is the most efficient means of radiation protection to reduce skin dose. An appropriate method for routine monitoring of the extremities is also proposed: the base of the index finger of the non-dominant hand is a suitable position to place the ring dosemeter, with its sensitive part oriented towards the palm side; its reading may be multiplied by a factor of 6 to estimate the maximum local skin dose. Finally, results were compared to earlier published data, which correspond mostly to individual works with a reduced number of workers and measurements.

Superfamily of steroid nuclear receptors: positive and negative regulators of gene expression.

The nuclear hormone receptor superfamily is characterized by an impressive functional diversity of its members despite a remarkable overall structural unity. A variety of ligands bind specifically to them and these receptors control gene networks that have profound effects on growth, development, and homeostasis. The ligand-receptor complexes recognize transcriptional enhancer DNA sequences, the hormone response elements, resulting in induction or repression of gene activity. The similarity between all these hormone response enhancer elements, as well as between the receptors themselves, indicates a conserved general strategy for the hormonal control of transcription by steroids. The activated receptors bind to responsive promoters and most likely mediate the assembly of stage- and tissue-specific transcription factor complexes that stimulate or inhibit gene expression.