767 resultados para Migratory Shorebirds


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L’augment del nombre de persones estrangeres que s’ha produït al llarg dels darrers anys va comportar que l’any 2008 la Direcció General de Recursos i Règim Penitenciari (DGRRP a partir d’ara) plantegés al Centre d’Estudis Jurídics i Formació Especialitzada la necessitat de conèixer més en profunditat aquesta població i les seves característiques i necessitats específiques. Diversos interrogants concrets formaven part d’aquella demanda inicial i van quedar explícitament recollits en els objectius de la recerca que presentarem tot seguit. Un tema destacat va ser des del principi la constatació de les dificultats d’integració social de les persones estrangeres empresonades un cop acomplerta la pena, en el marc del complex context legal que regula l’estrangeria al nostre país. La finalitat d’aquesta recerca és donar un coneixement ampli i global de la realitat dels estrangers als centres penitenciaris catalans i de les seves possibilitats de futur, apuntant recomanacions que puguin ajudar la DGRRP a intervenir amb més eficàcia en aquest tema de gran actualitat i complexitat.

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El estudio recoge los perfiles de los extranjeros que se encuentran en las prisiones catalanas, cual ha sido su trayectoria migratoria hasta el momento actual, qué expectativas tienen respecto a su futuro, así como sus opiniones en relación a su situación en prisión y el trato que recibe por parte de las autoridades penitenciarias. También se analiza pormenorizadamente su situación administrativa y de regularización. El estudio termina con 29 recomendaciones para la mejora de todos los ámbitos de la intervención penitenciaria.

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El sarcoma de Ewing es el segundo tumor óseo infantil más frecuente y presenta una alta incidencia de enfermedad metastática. Este tipo de tumores presentan una traslocación génica característica que da origen a una proteína de fusión, normalmente EWS/FLI1. Esta proteína de fusión actúa como factor de transcripción aberrante regulando la expresión de diferentes genes implicados en la iniciación, mantenimiento y progresión del tumor. Nuestro grupo describió como uno de estos genes diana a la caveolina 1 (CAV1) describiendo además su papel determinante en el fenotipo maligno del sarcoma de Ewing, en la tumorigénesis y en la resistencia a apoptosis inducida por quimioterapia. Para investigar el papel concreto de CAV1 en el proceso metastático de este sarcoma, creamos un modelo de baja expresión de CAV1 en líneas celulares de sarcoma de Ewing y determinamos cambios en su capacidad migratoria, invasiva y metastática. En los ensayos in vitro hallamos una menor capacidad migratoria de las células knockdown de CAV1 y una reducción en la expresión de MMP9 y en la actividad de MMP2. La regulación de la actividad de MMP2 parece estar relacionada con la posible regulación que ejerce CAV1 en la función de MT1-MMP, proteína fundamental para la activación de MMP2. Por otro lado, en este estudio proponemos que CAV1 promueve la expresión de MMP9 tanto transcripcionalmente, regulando la vía de señalización ERK1/2, como a nivel post-transcripcional regulando la vía RSK1/rpS6. Además, en los ensayos de metástasis experimental in vivo las células knockdown de CAV1 presentaron una menor incidencia de metástasis pulmonar, hecho que correlacionó con una disminución en la expresión de SPARC, una proteína de adhesión importante en procesos metastáticos. En resumen, nuestros resultados evidencian la importancia de CAV1 en el proceso metastático del sarcoma de Ewing.

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Angiostrongylus costaricensis intermediate hosts are terrestrial mollusks mostly belonging to the Veronicellidae family. In the present investigation we focused on the mechanisms of larval expulsion from Sarasinula marginata infected with A. costaricensis. Twenty-five mollusks were individually infected with 5000 L1 and sacrificed at 30 min and 1, 2, 4, 6, and 8 h post-infection and at days 1, 2, 4, 5, 6, 8, 10, 11, 12, 14, 15, 16, 20, 21, 22, 25, 26, 28, and 30 post-infection; the mollusks were then fixed and stained. Diverse organs involved throughout the course of the migratory routes of larvae from oral penetration on were specified and the mechanisms of larval access to the fibromuscular layer through the kidney, rectum, and vascular system were defined. The elimination of L3, derived from oral and/or cutaneous infections, appears to depend on granulomas located close to the excretory ducts of mucous cells.

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Bone substitute materials allowing trans-scaffold migration and in-scaffold survival of human bone-derived cells are mandatory for development of cell-engineered permanent implants to repair bone defects. In this study, we evaluated the influence on human bone-derived cells of the material composition and microstructure of foam scaffolds of calcium aluminate. The scaffolds were prepared using a direct foaming method allowing wide-range tailoring of the microstructure for pore size and pore openings. Human fetal osteoblasts (osteo-progenitors) attached to the scaffolds, migrated across the entire bioceramic depending on the scaffold pore size, colonized, and survived in the porous material for at least 6 weeks. The long-term biocompatibility of the scaffold material for human bone-derived cells was evidenced by in-scaffold determination of cell metabolic activity using a modified MTT assay, a repeated WST-1 assay, and scanning electron microscopy. Finally, we demonstrated that the osteo-progenitors can be covalently bound to the scaffolds using biocompatible click chemistry, thus enhancing the rapid adhesion of the cells to the scaffolds. Therefore, the different microstructures of the foams influenced the migratory potential of the cells, but not cell viability. Scaffolds allow covalent biocompatible chemical binding of the cells to the materials, either localized or widespread integration of the scaffolds for cell-engineered implants.

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Understanding the molecular aberrations involved in the development and progression of metastatic melanoma (MM) is essential for a better diagnosis and targeted therapy. We identified breast cancer suppressor candidate-1 (BCSC-1) as a novel tumor suppressor in melanoma. BCSC-1 expression is decreased in human MM, and its ectopic expression in MM-derived cell lines blocks tumor formation in vivo and melanoma cell proliferation in vitro while increasing cell migration. We demonstrate that BCSC-1 binds to Sox10, which down regulates MITF, and results in a switch of melanoma cells from a proliferative to a migratory phenotype. In conclusion, we have identified BCSC-1 as a tumor suppressor in melanoma and as a novel regulator of the MITF pathway.

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Dengue fever is the most important arbovirus infection found in tropical regions around the world. Dispersal of the vector and an increase in migratory flow between countries have led to large epidemics and severe clinical outcomes, such as dengue haemorrhagic fever and dengue shock syndrome. This study analysed the genetic variability of the dengue virus serotype 1 (DENV-1) in Brazil with regard to the full-length structural genes C/prM/M/E among 34 strains isolated during epidemics that occurred in the country between 1994-2011. Virus phylogeny and time of divergence were also evaluated with only the E gene of the strains isolated from 1994-2008. An analysis of amino acid differences between these strains and the French Guiana strain (FGA/89) revealed the presence of important nonsynonymous substitutions in the amino acid sequences, including residues E297 (Met→Thr) and E338 (Ser→Leu). A phylogenetic analysis of E proteins comparing the studied isolates and other strains selected from the GenBank database showed that the Brazilian DENV-1 strains since 1982 belonged to genotype V. This analysis also showed that different introductions of strains from the 1990s represented lineage replacement, with the identification of three lineages that cluster all isolates from the Americas. An analysis of the divergence time of DENV-1 indicated that the lineage circulating in Brazil emerged from an ancestral lineage that originated approximately 44.35 years ago.

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BACKGROUND: Long-term therapy with natalizumab increases the risk of progressive multifocal leukoencephalopathy (PML). OBJECTIVES: We present a patient study through therapy, the diagnosis of PML (after 29 infusions), plasma exchange (PE) and development of immune reconstitution inflammatory syndrome (IRIS). METHODS: Routine diagnostics, magnetic resonance imaging (MRI), immunological status (flow cytometry, T-cell migration assays and T-cell repertoire analysis), and brain biopsy with immunohistological analysis. RESULTS: CD49d decreased after 12 months of treatment. At PML diagnosis, CD49d expression and migratory capacity of T cells was low and peripheral T-cell receptor (TCR) complexity showed severe perturbations. The distribution of peripheral monocytes changed from CCR5+ to CCR7+. After PE some changes reverted: CD49d increased and overshot earliest levels, migratory capacities of T cells recovered and peripheral TCR complexity increased. With no clinical, routine laboratory or cerebrospinal fluid (CSF) changes, MRI 2 months after PE demonstrated progressive lesion development. Brain histopathology confirmed the presence of infiltrates indicative of IRIS without clinical signs, immunologically accompanied by CCR7/CCR5 recovery of peripheral monocytes. CONCLUSION: Natalizumab-associated immunological changes accompanying PML were reversible after PE; IRIS can occur very late, remain asymptomatic and be elusive to CSF analysis. Our study may provide insights into the changes under treatment with natalizumab associated with JC virus control.

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Peri-urban infestations with triatomine bugs, their sources and their dynamics have rarely been investigated. Here, we corroborated the reported occurrence of Triatoma infestans in a peri-urban area and in neighbouring rural houses in Pampa del Indio, in the Argentine Chaco, and identified its putative sources using spatial analysis and demographic questionnaires. Peri-urban householders reported that 10% of their premises had triatomines, whereas T. infestans was collected by timed manual searches or community-based surveillance in only nine (3%) houses. Trypanosoma cruzi-infected T. infestans and Triatoma sordida were collected indoors only in peri-urban houses and were infected with TcV and TcI, respectively. The triatomines fed on chickens, cats and humans. Peri-urban infestations were most frequent in a squatter settlement and particularly within the recently built mud houses of rural immigrants, with large-sized households, more dogs and cats and more crowding. Several of the observed infestations were most likely associated with passive bug transport from other sources and with active bug dispersal from neighbouring foci. Thus, the households in the squatter settlement were at a greater risk of bug invasion and colonisation. In sum, the incipient process of domestic colonisation and transmission, along with persistent rural-to-urban migratory flows and unplanned urbanisation, indicate the need for active vector surveillance and control actions at the peri-urban interface of the Gran Chaco.

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A l’atmosfera hi trobem radionúclids de la sèrie del 238U com el 222Rn, 210Pb i 210Po. L’objectiu principal d’aquest estudi és determinar el contingut i distribució de 210Pb en plomes d’aus migratòries i estudiar el seu potencial ús com a traçador de corrents migratòries, gràcies a que les plomes són estructures útils per a realitzar estudis de biomonitorització. Per a realitzar l’estudi s’ha escollit com a espècie migratòria el falciot comú (Apus apus). Els resultats mostren que el 210Pb no es distribueix uniformement entre individus adults i joves, ni entre les diferents plomes de l’ala dels ocells. La major concentració de 210Pb es troba en les plomes primàries dels individus adults i en l’hemibandera externa de la ploma. Les concentracions de 210Pb oscil·len entre els 43 i 1065 Bq·kg-1, amb una concentració mitjana de 586 Bq·kg-1. El fet de detectar 210Pb només en les plomes primàries de l’ala implica que la incorporació de 210Pb a l’ocell és via adsorció del 210Pb present a l’atmosfera. Es pot afirmar que el 210Pb present a l’atmosfera és arrossegat per les ales de les aus i queda adsorbit a les plomes.

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The mucosal epithelia of the digestive tract acts as a selective barrier, permeable to ions, small molecules and macromolecules. These epithelial cells aid the digestion of food and absorption of nutrients. They contribute to the protection against pathogens and undergo continuous cell renewal which facilitates the elimination of damaged cells. Both innate and adaptive defence mechanisms protect the gastrointestinal-mucosal surfaces against pathogens. Interaction of microorganisms with epithelial cells triggers a host response by activating specific transcription factors which control the expression of chemokines and cytokines. This host response is characterized by the recruitment of macrophages and neutrophils at the site of infection. Disruption of epithelial signalling pathways that recruit migratory immune cells results in a chronic inflammatory response. The adaptive defence mechanism relies on the collaboration of epithelial cells (resident sampling system) with antigen-presenting and lymphoid cells (migratory sampling system); in order to obtain samples of foreign antigen, these samples must be transported across the barriers without affecting the integrity of the barrier. These sampling systems are regulated by both environmental and host factors. Fates of the antigen may differ depending on the way in which they cross the epithelial barrier, i.e. via interaction with motile dendritic cells or epithelial M cells in the follicle-associated epithelium.

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En el marc de la recerca sobre identitats i nova ciutadania, l’objecte d’aquest treball és reconèixer elements clau dels processos d’identificació nacional a Catalunya en la població nouvinguda, i identificar els factors que n'afavoreixen la seva vinculació comunitària. La recerca s'ha desenvolupat en un primer bloc analitzant la perspectiva sociològica entorn a la idea d’identitat, així com l’evolució del discurs identitari a Catalunya, a fi de continuar desenvolupant amb profunditat el debat sobre identitat i nació en relació al fet migratori i la diversitat social existent. En un segon bloc d’anàlisi, la recerca fixa la mirada a una dotzena de casos treballats a través d’històries de vida de diverses realitats migratòries del nostre país corresponents a les diverses onades del segle XX, tant d’immigració espanyola com d'immigració de fora de l'Estat espanyol. La voluntat d’aquest segon bloc és extreure experiències socials d’interpretacions individuals que assenyalin quins elements permeten o dificulten la mobilitat social, quines experiències tenen valor identitari i de quin tipus, i quins fenòmens esdevenen rellevants en la configuració d’espais de referència i identificació nacional a nivell individual. Finalment s’incorpora un apartat d’entrevistes en profunditat a diversos actors socials i polítics rellevants a fi de reconèixer aquells elements que centren el discurs de la “nova cultura pública comuna”. L’objectiu és interrelacionar el discurs polític i filosòfic actual amb l’experiència biogràfica de les persones, assenyalant aquells elements que han estat significatius per a la seva identitat com a catalans i catalanes o, ans al contrari, que no han afavorit una situació en aquests termes. En aquest sentit la pregunta que vincula aquest espai de reflexió és: Quins elements afavoreixen la identificació nacional englobant la diversitat social existent i quins mecanismes d'adhesió hi podrien funcionar?

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No podem pensar en una tradició musical llatinoamericana si no és a partir de la relació i confrontació de les cultures indígenes, africanes i europees, enteses des de la colonització fins a corrents immigratoris posteriors. El que es coneix com a nacionalisme musical va molt més enllà de les limitades barreres d'una nació o de la utilització de melodies i ritmes trets del folklore; consisteix en tot un procés de difusió i d'assimilació que sí que ens fa possible parlar d'unes produccions sonores pròpies, en aquest cas argentines, cubanes o brasileres. Enmig d'aquest context, els compositor llatinoamericans de música culta han hagut de fer una difícil elecció entre la música europea i la dels seus propis països, elecció que mitjançant aquest treball m'agradaria destacar.

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Afro-Palearctic migrant species are exposed to parasites at both breeding and over-wintering grounds. The house martin Delichon urbicum is one such migratory species facing high instances of blood parasite infection. In an attempt to determine whether breeding European house martins harbour similar blood parasite communities to populations breeding in North Africa, birds were sampled at their breeding grounds in Switzerland and Algeria. Moreover, haemosporidian prevalence and parasite communities were compared to published data sets on Spanish and Dutch breeding populations. This study furthermore wanted to establish whether co-infection with multiple genera or lineages of parasites had negative effects on host body condition. Breeding house martins caught in Algeria showed a higher prevalence of avian haemosporidian parasites than did European populations. Swiss house martins showed a prevalence comparable to that of Spanish and Dutch populations. There were slight differences in the haemosporidian community between European and North-African populations in terms of composition and abundance of each lineage. Similar to the Dutch house martins, but in contrast to the Spanish population, infection status and number of genera of parasites infecting single hosts did not inFLuence Swiss house martin body condition.

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In a weighted spatial network, as specified by an exchange matrix, the variances of the spatial values are inversely proportional to the size of the regions. Spatial values are no more exchangeable under independence, thus weakening the rationale for ordinary permutation and bootstrap tests of spatial autocorrelation. We propose an alternative permutation test for spatial autocorrelation, based upon exchangeable spatial modes, constructed as linear orthogonal combinations of spatial values. The coefficients obtain as eigenvectors of the standardised exchange matrix appearing in spectral clustering, and generalise to the weighted case the concept of spatial filtering for connectivity matrices. Also, two proposals aimed at transforming an acessibility matrix into a exchange matrix with with a priori fixed margins are presented. Two examples (inter-regional migratory flows and binary adjacency networks) illustrate the formalism, rooted in the theory of spectral decomposition for reversible Markov chains.