Cis-acting elements, CArG-, E-, CCAAT- and TATA-boxes may be involved in sexually regulated gene transcription in Schistosoma mansoni

Schistosomes undergo various morphological and metabolic changes during their development, reflected in a finely tuned regulation of protein and/or gene expression. The mechanisms involved in the control of gene expression during the development of the parasite are not understood. Two actin genes had been previously cloned and observed to be differentially expressed during the maturation of the parasite. The SmAct gene contains four putative cis-regulatory elements (TATA-, CCAAT-, E- and CArG-boxes). Our objective was to investigate in greater detail the expression pattern of two actin genes and verify if the binding of nuclear proteins to the promoter elements of SmAct correlated with the expression profile observed. We detected little variation in the expression of actin genes during the first seven days of schistosomula culture in vitro. However, we observed significantly higher levels of expression in males compared to female adults. CArG and CCAAT elements bound to a greater extent and formed distinct complexes with male in comparison to female nuclear extracts. In contrast, female extracts bound weakly to the E-box probe while no binding was observed with male extracts. Taken together these results describe cis-acting elements that appear to be involved in sexually regulated gene expression in Schistosoma mansoni.

A novel reiterated family of transcribed oligo(A)-terminated, interspersed DNA elements in the genome of Trypanosoma cruzi

We report the molecular characterization of a novel reiterated family of transcribed oligo(A)-terminated, interspersed DNA elements in the genome of Trypanosoma cruzi. Steady-state level of transcripts of this sequence family appeared to be developmentally regulated, since only in the replicative forms the parasite showed expression of related sequences with a major band around 3 kb. The presence of frame shifts or premature stop codons predicts that transcripts are not translated. The sequence family also contains truncated forms of retrotransposons elements that may become potential hot spots for retroelement insertion. Sequences homologous to this family are interspersed at many chromosomes including the subtelomeric regions.

Rare earth elements and stable isotope geochemistry (δ13C and δ18O) of phosphorite deposits in the Gafsa Basin, Tunisia

Rare earth elements (REE) and stable isotope compositions (delta C-13 and delta O-18) of shark teeth and phosphatic coprolites were analyzed from the Lower Maastrichtian layers of the El Haria Formation and two sequences of the Paleocene-Eocene (P/E) Chouabine Formation in the Gafsa Basin (south western of Tunisia) in order to trace the sedimentological, climatic and oceanographic conditions. The REE chemistry and their distribution in the two archives are the same for each of the studied layers indicating that the coprolites and shark teeth experienced the same early diagenetic environments. However major differences occur between the Maastrichtian and the P/E reflecting changes in the depositional conditions. The Early Maastrichtian burial environment tended to be more anoxic with REE derived from reduced FeO. While in the P/E the REE patterns mimic the modern oxic-suboxic seawater, the REE source from remineralisation of organic coating could have more significance. The oxygen isotope compositions of the structural phosphates (delta O-18(PO4)) indicate a stable and warm climate during both studied time intervals. A small offset (-0.4 parts per thousand) in the delta O-18 value between the coprolites and shark teeth show minor thermal gradient between bottom and surface water. The pronounced negative shift of 34%. in delta C-13 values recorded in the upper part of the Chouabine Formation was ascribed to the Paleocene-Eocene boundary. At the same time the lack of negative change in the delta O-18 is explained by the semi-closed situation of the Gafsa Basin, which situation also played an important role in the evolution of the organic matters in the sediment resulting in the exceptional low delta C-13 values. (C) 2008 Elsevier B.V. All rights reserved.

Introducció als Sistemes d´Informació Geogràfica i creació d´una base de dades dels elements d´una xarxa de distribució d´aigua potable.

Aquest treball és una introducció als sistemes d'informació geogràfica, que consisteix en una breu descripció dels aspectes fonamentals dels sistemes d'informació geogràfica i en la creació d'una base de dades dels elements d'una xarxa de distribució d'aigua potable.

Cooperative binding of estrogen receptor to imperfect estrogen-responsive DNA elements correlates with their synergistic hormone-dependent enhancer activity.

The Xenopus vitellogenin (vit) gene B1 estrogen-inducible enhancer is formed by two closely adjacent 13 bp imperfect palindromic estrogen-responsive elements (EREs), i.e. ERE-2 and ERE-1, having one and two base substitutions respectively, when compared to the perfect palindromic consensus ERE (GGTCANNNTGACC). Gene transfer experiments indicate that these degenerated elements, on their own, have a low or no regulatory capacity at all, but in vivo act together synergistically to confer high receptor- and hormone-dependent transcription activation to the heterologous HSV thymidine kinase promoter. Thus, the DNA region upstream of the vitB1 gene comprising these two imperfect EREs separated by 7 bp, was called the vitB1 estrogen-responsive unit (vitB1 ERU). Using in vitro protein-DNA interaction techniques, we demonstrate that estrogen receptor dimers bind cooperatively to the imperfect EREs of the vitB1 ERU. Binding of a first receptor dimer to the more conserved ERE-2 increases approximately 4- to 8-fold the binding affinity of the receptor to the adjacent less conserved ERE-1. Thus, we suggest that the observed synergistic estrogen-dependent transcription activation conferred by the pair of hormone-responsive DNA elements of the vit B1 ERU is the result of cooperative binding of two estrogen receptor dimers to these two adjacent imperfect EREs.

The ENCODE (ENCyclopedia Of DNA Elements) Project.

The ENCyclopedia Of DNA Elements (ENCODE) Project aims to identify all functional elements in the human genome sequence. The pilot phase of the Project is focused on a specified 30 megabases (approximately 1%) of the human genome sequence and is organized as an international consortium of computational and laboratory-based scientists working to develop and apply high-throughput approaches for detecting all sequence elements that confer biological function. The results of this pilot phase will guide future efforts to analyze the entire human genome.

La Intervenció psicopedagògica en el marc de les UEC : elements que afavoreixen un bon assessorament i una bona resposta educativa.

S'ha aprofundit en el camp de l'atenció a la diversitat que reben, i que poden rebre, els adolescents que fracassen en l'escolaritat reglada. Es fa un estudi de 4 unitats d'escolarització compartida i unes pràctiques a la Unitat Mèdico-Educativa de Sant Boi. Es plantegen alternatives per tal d'afavorir l'assessorament d'aquest centre i per a donar una bona resposta educativa a aquests alumnes en edat crítica.

La transposició de la Directiva 2001/29/CE sobre drets d'autor i l'impacte sobre les biblioteques i centres similars : elements per al debat

A Espanya encara tenim pendent la transposició de la Directiva 2001/29/CE "relativa a la armonización de determinados aspectos de los derechos de autor y derechos afines a los derechos de autor en la sociedad de la información", la qual suposarà una modificació del marc legal que regula aquesta matèria. En aquest article s'analitzen els aspectes de la Directiva que més poden afectar el desenvolupament dels serveis que ofereixen les biblioteques i centres similars, prestant atenció als punts que poden ser més conflictius a la llum de les dues propostes que fins al moment s'han plantejat.

Toxoplasma gondii: further studies on the subpellicular network

The association of the pellicle with cytoskeletal elements in Toxoplasma gondii allows this parasite to maintain its mechanical integrity and makes possible its gliding motility and cell invasion. The inner membrane complex (IMC) resembles the flattened membrane sacs observed in free-living protozoa and these sacs have been found to associate with cytoskeletal proteins such as articulins. We used immunofluorescence microscopy to characterise the presence and distribution of plateins, a sub-family of articulins, in T. gondii tachyzoites. A dispersed labelling of the whole protozoan body was observed. Electron microscopy of detergent-extracted cells revealed the presence of a network of 10 nm filaments distributed throughout the parasite. These filaments were labelled with anti-platein antibodies. Screening the sequenced T. gondii genome, we obtained the sequence of an IMC predicted protein with 25% identity and 42% similarity to the platein isoform alpha 1 present in Euplotes aediculatus, but with 42% identity and 55% similarity to that found in Euglena gracilis, suggesting strong resemblance to articulins.

Disseny d’un banc d’assaig d’efectes diferits en elements de formigó armat amb barres FRP

L'objectiu d'aquest projecte és el disseny dels bancs d'assaig necessaris per poder realitzar tres assajos de fisuració i deformació diferida al laboratori de resistència de materials de la UdGsobre provetes i bigues de formigó armat amb FRP i estudiar- ne el comportament. El primer assaig és el de fluència del formigó, on es sotmet una proveta a una compressió mantinguda en el temps. El segon assaig és un de tracció directa, on s'aplica una càrrega a tracció mantinguda en el temps en una proveta de formigó armat amb una barra FRP de reforç intern. El tercer és un assaig a flexió, on es carregarà una biga a flexió durant un període llarg de temps

Estudi hidrodinàmic per elements finits de diferents pales simètriques per a la impulsió a rem en banc fix

Actualment l’esport del rem només s’entén com a activitat de lleure o esport de competició.Dins del rem, hi ha una gran varietat de disciplines esportives; totes coincideixen en l’impuls d’una embarcació mitjançant un sistema de palanques simple. Es diferencien en dos grans grups: el banc mòbil i el banc fix. El banc mòbil disposa d’un seient sobre rodes que permet aprofitar la força de les cames per la impulsió, en canvi, en el banc fix, no hi ha desplaçament del seient, el que implica el treball del tors i braços. Un dels punts que tenen en comú tot el banc fix, és el disseny del seu rem; a diferènciadel banc mòbil on la pala pot tenir el disseny que es vulgui. En banc fix la pala del rem ha de ser simètrica i alineada amb la canya del rem. L’objectiu d’aquest projecte és l’anàlisi hidrodinàmic de diferents models de pales simètriques per tal de determinar el model més eficient, des del punt de vista hidrodinàmic, per a la impulsió de l’embarcació de banc fix. Així, es simularan virtualment diferents models de pales simètriques disponibles en el mercat com models prototipus amb un programa de dinàmica de fluids computacional. L’anàlisi dels resultats determinarà el model més eficient. En la realització del projecte, l’estudi hidrodinàmic es realitzarà de manera virtual a partir de la utilització de programes comercials de dinàmica de fluids. Així com també programes de disseny 3D i programes de mallat que siguin compatibles amb el programa de simulació a utilitzar. En el disseny s’utilitzaran programes com Autocad i Rhinoceros, després, en funció del disseny, utilitzarem un programa d’elements finits anomenat ICEM ANSYS que mallarà la geometria emprada. Finalment, la simulació s’efectuarà amb el programa ANSYS CFX. L’estudi no preveu el càlcul de resistència mecànica dels models ni la seva construcció

Conceptualising 'precarious prosperity' - Empirical and Theoretical Elements for Debate

Empirical studies have recently pointed towards a socio-structural category largely overlooked in social inequality research: the dynamic positions of households adjacent to those of the poor and yet not representing those of the established, more prosperous positions in society. These results suggest that the population in this category fluctuates into and out of poverty more often than moving into and out of secure prosperity. This category - still lacking theoretical conceptualization - is characterized by both precariousness and a certain degree of prosperity; despite a restricted and uncertain living standard it holds a range of opportunities for action. We seek analytical elements to conceptualize 'precarious prosperity' for comparative empirical research by subjecting various concepts of social inequality research to critical scrutiny. We then operationally define 'precarious prosperity' to screen for this population in three countries. Based on qualitative interviews with households in precarious prosperity, we present first analyses of perceptions and household strategies that underline the relevance of the concept in different countries.

Regulatory elements involved in the post-transcriptional control of stage-specific gene expression in Trypanosoma cruzi: a review

Trypanosoma cruzi, a protozoan parasite that causes Chagas disease, exhibits unique mechanisms for gene expression such as constitutive polycistronic transcription of protein-coding genes, RNA editing and trans-splicing. In the absence of mechanism controlling transcription initiation, organized subsets of T. cruzi genes must be post-transcriptionally co-regulated in response to extracellular signals. The mechanisms that regulate stage-specific gene expression in this parasite have become much clearer through sequencing its whole genome as well as performing various proteomic and microarray analyses, which have demonstrated that at least half of the T. cruzi genes are differentially regulated during its life cycle. In this review, we attempt to highlight the recent advances in characterising cis and trans-acting elements in the T. cruzi genome that are involved in its post-transcriptional regulatory machinery.

Modelització numèrica d’un sistema de descàrrega d’una columna de la catedral d Girona mitjançant el mètode dels elements finits (anàlisi no lineal)

Aquest projecte consisteix en aplicar el càlcul no lineal en la modelització volumètricanumèrica de l’estructura del sistema de descàrrega d’una columna del claustre de lacatedral de Girona mitjançant el mètode dels elements finits. A la Universitat de Gironas’ha fet diferents estudis del claustre de la catedral de Girona però sempre simulant uncomportament lineal de les característiques dels materials. El programa utilitzat és la versió docent del programa ANSYS disponible al Dept.d’EMCI i l’element emprat ha sigut el SOLID65. Aquest element permet introduircaracterístiques de no linealitat en els models i és adequat per a anàlisi no lineald’elements com la pedra de Girona