433 resultados para Cohn, LeopoldCohn, LeopoldLeopoldCohn


Relevância:

10.00% 10.00%

Publicador:

Resumo:

Catadiscus pomaceae sp. n. from the intestine of the prosobranch mollusc Pomacea canaliculata (Lamarck, 1801), is described. The host snail was collected from a lenitic biotope belonging to the Riachuelo basin (Corrientes province, Argentina) during 1985-1986. So far the species of the genus Catadiscus Cohn, 1904 have been recorded in amphibians and reptiles. This is the first instance of a species of that genus parasitizing a mollusc.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

This thesis suggests to carry on the philosophical work begun in Casati's and Varzi's seminal book Parts and Places, by extending their general reflections on the basic formal structure of spatial representation beyond mereotopology and absolute location to the question of perspectives and perspective-dependent spatial relations. We show how, on the basis of a conceptual analysis of such notions as perspective and direction, a mereotopological theory with convexity can express perspectival spatial relations in a strictly qualitative framework. We start by introducing a particular mereotopological theory, AKGEMT, and argue that it constitutes an adequate core for a theory of spatial relations. Two features of AKGEMT are of particular importance: AKGEMT is an extensional mereotopology, implying that sameness of proper parts is a sufficient and necessary condition for identity, and it allows for (lower- dimensional) boundary elements in its domain of quantification. We then discuss an extension of AKGEMT, AKGEMTS, which results from the addition of a binary segment operator whose interpretation is that of a straight line segment between mereotopological points. Based on existing axiom systems in standard point-set topology, we propose an axiomatic characterisation of the segment operator and show that it is strong enough to sustain complex properties of a convexity predicate and a convex hull operator. We compare our segment-based characterisation of the convex hull to Cohn et al.'s axioms for the convex hull operator, arguing that our notion of convexity is significantly stronger. The discussion of AKGEMTS defines the background theory of spatial representation on which the developments in the second part of this thesis are built. The second part deals with perspectival spatial relations in two-dimensional space, i.e., such relations as those expressed by 'in front of, 'behind', 'to the left/right of, etc., and develops a qualitative formalism for perspectival relations within the framework of AKGEMTS. Two main claims are defended in part 2: That perspectival relations in two-dimensional space are four- place relations of the kind R(x, y, z, w), to be read as x is i?-related to y as z looks at w; and that these four-place structures can be satisfactorily expressed within the qualitative theory AKGEMTS. To defend these two claims, we start by arguing for a unified account of perspectival relations, thus rejecting the traditional distinction between 'relative' and 'intrinsic' perspectival relations. We present a formal theory of perspectival relations in the framework of AKGEMTS, deploying the idea that perspectival relations in two-dimensional space are four-place relations, having a locational and a perspectival part and show how this four-place structure leads to a unified framework of perspectival relations. Finally, we present a philosophical motivation to the idea that perspectival relations are four-place, cashing out the thesis that perspectives are vectorial properties and argue that vectorial properties are relations between spatial entities. Using Fine's notion of "qua objects" for an analysis of points of view, we show at last how our four-place approach to perspectival relations compares to more traditional understandings.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

BACKGROUND: Establishing the genetic basis of phenotypes such as skeletal dysplasia in model organisms can provide insights into biologic processes and their role in human disease. METHODS: We screened mutagenized mice and observed a neonatal lethal skeletal dysplasia with an autosomal recessive pattern of inheritance. Through genetic mapping and positional cloning, we identified the causative mutation. RESULTS: Affected mice had a nonsense mutation in the thyroid hormone receptor interactor 11 gene (Trip11), which encodes the Golgi microtubule-associated protein 210 (GMAP-210); the affected mice lacked this protein. Golgi architecture was disturbed in multiple tissues, including cartilage. Skeletal development was severely impaired, with chondrocytes showing swelling and stress in the endoplasmic reticulum, abnormal cellular differentiation, and increased cell death. Golgi-mediated glycosylation events were altered in fibroblasts and chondrocytes lacking GMAP-210, and these chondrocytes had intracellular accumulation of perlecan, an extracellular matrix protein, but not of type II collagen or aggrecan, two other extracellular matrix proteins. The similarities between the skeletal and cellular phenotypes in these mice and those in patients with achondrogenesis type 1A, a neonatal lethal form of skeletal dysplasia in humans, suggested that achondrogenesis type 1A may be caused by GMAP-210 deficiency. Sequence analysis revealed loss-of-function mutations in the 10 unrelated patients with achondrogenesis type 1A whom we studied. CONCLUSIONS: GMAP-210 is required for the efficient glycosylation and cellular transport of multiple proteins. The identification of a mutation affecting GMAP-210 in mice, and then in humans, as the cause of a lethal skeletal dysplasia underscores the value of screening for abnormal phenotypes in model organisms and identifying the causative mutations.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Background The PEmb-QoL is a validated 40-item questionnaire to quantify health-related quality of life in patients having experienced pulmonary embolism (PE). It covers six health dimensions: frequency of complaints, activities of daily living limitations, work-related problems, social limitations, intensity of complaints, and emotional complaints. Originally developed in Dutch and English, we sought to prospectively validate the psychometric properties of a French version of the PEmb-QoL.MethodsWe performed a forward and backward translation of the English version of the PEmb-QoL into French. French-speaking consecutive adult patients with an acute, objectively confirmed PE admitted to the emergency department of a Swiss university hospital between 08/2009 and 09/2011 were recruited telephonically. We used standard psychometric tests and criteria to evaluate the acceptability, reliability, and validity of the French version of the PEmb-QoL. We also performed an exploratory factor analysis.ResultsOverall, 102 patients were enrolled in the study. The French version of the PEmb-QoL showed good reliability (internal consistency, item¿total and inter-item correlations), reproducibility (test-retest reliability), and validity (convergent, discriminant) in French-speaking patients with PE. The exploratory factor analysis suggested three underlying dimensions: limitations in daily activity (items 4b-m, 5a-d), symptoms (items 1a-h and 7), and emotional complaints (items 9a-f and j).ConclusionWe successfully validated the French version of the PEmb-QoL questionnaire in patients with PE. Our results show that the PEmb-QoL is a valuable tool for assessing health-related quality of life after PE in French-speaking patients.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Spondyloepimetaphyseal dysplasia with joint laxity, leptodactylic type (lepto-SEMDJL, aka SEMDJL, Hall type), is an autosomal dominant skeletal disorder that, in spite of being relatively common among skeletal dysplasias, has eluded molecular elucidation so far. We used whole-exome sequencing of five unrelated individuals with lepto-SEMDJL to identify mutations in KIF22 as the cause of this skeletal condition. Missense mutations affecting one of two adjacent amino acids in the motor domain of KIF22 were present in 20 familial cases from eight families and in 12 other sporadic cases. The skeletal and connective tissue phenotype produced by these specific mutations point to functions of KIF22 beyond those previously ascribed functions involving chromosome segregation. Although we have found Kif22 to be strongly upregulated at the growth plate, the precise pathogenetic mechanisms remain to be elucidated.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Infectious and inflammatory diseases have repeatedly shown strong genetic associations within the major histocompatibility complex (MHC); however, the basis for these associations remains elusive. To define host genetic effects on the outcome of a chronic viral infection, we performed genome-wide association analysis in a multiethnic cohort of HIV-1 controllers and progressors, and we analyzed the effects of individual amino acids within the classical human leukocyte antigen (HLA) proteins. We identified >300 genome-wide significant single-nucleotide polymorphisms (SNPs) within the MHC and none elsewhere. Specific amino acids in the HLA-B peptide binding groove, as well as an independent HLA-C effect, explain the SNP associations and reconcile both protective and risk HLA alleles. These results implicate the nature of the HLA-viral peptide interaction as the major factor modulating durable control of HIV infection.

Relevância:

10.00% 10.00%

Publicador:

Relevância:

10.00% 10.00%

Publicador:

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Desde el año 2012, en el grupo Conservació-Restauració del Patrimoni de la Facultat de Belles Arts, Universitat de Barcelona (Grup de Recerca Consolidat 2014- 16 SGR 459G reconocido porla Generalitat de Catalunya), se está desa rrollando un proyecto de investigación sobre el uso de nuevos procedimientos de limpieza mecánica y consolidación de documento gráfico mediante fibrasde celulosa. La limpieza mecánica más extendida en documento gráfico se realiza con gomas. El procedimiento, apesar de habitual, comporta riesgos potenciales para el soporte y para los elementos sustentados albasarse en mecanismos de fricción y/o abrasión que pueden ultrapasar la suciedad. Así, modificaciónde textura y/o brillo (Pearlstein et al., 1982; Sterlini, 1995), cambios en las propiedades físicas(James & Cohn, 1997; Mclnnis, 1980) y alteraciones químicas y/o mecánicas a largo plazo (DaudinSchotteet al., 2010; Moffatt & Laver, 1981; Moy, 2007; Silverman & Irwin, 2009) son los riesgos habitualmente referidos en la literatura. Para minimizar estos inconvenientes y como posible alternativa, se está eva luando la limpieza conmicroproyección de fibras de celulosa como alternativa a las gomas. Una de las principales ventajasprincipales de este procedimiento radica en el hecho de que el agente de limpieza es altamente compatible con la obra ya que tiene una composición muy similar. Por lo tanto, su empleo podríareducir la posibilidad de afectar negativamente la estabilidad química de la pieza a corto o largo plazo.Hasta el momento se han realizado ensayos comparativos entre gomas y microproyección para la limpieza de grabados calcográficos con resultados satisfactorios en eficacia y preservación de la obra a corto y medio plazo (Iglesias-Campos et al., 2014a; Iglesias-Campos & Ruiz-Recasens, 2014 enprensa; Iglesias-Campos, et al., 2014 en prensa). Paralelamente se realizan ensayos de envejecimiento artificial con los que comparar los posibles efectos en el tiempo entre ambas técnicas.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Desde el año 2012, en el grupo Conservació-Restauració del Patrimoni de la Facultat de Belles Arts, Universitat de Barcelona (Grup de Recerca Consolidat 2014- 16 SGR 459G reconocido porla Generalitat de Catalunya), se está desa rrollando un proyecto de investigación sobre el uso de nuevos procedimientos de limpieza mecánica y consolidación de documento gráfico mediante fibrasde celulosa. La limpieza mecánica más extendida en documento gráfico se realiza con gomas. El procedimiento, apesar de habitual, comporta riesgos potenciales para el soporte y para los elementos sustentados albasarse en mecanismos de fricción y/o abrasión que pueden ultrapasar la suciedad. Así, modificaciónde textura y/o brillo (Pearlstein et al., 1982; Sterlini, 1995), cambios en las propiedades físicas(James & Cohn, 1997; Mclnnis, 1980) y alteraciones químicas y/o mecánicas a largo plazo (DaudinSchotteet al., 2010; Moffatt & Laver, 1981; Moy, 2007; Silverman & Irwin, 2009) son los riesgos habitualmente referidos en la literatura. Para minimizar estos inconvenientes y como posible alternativa, se está eva luando la limpieza conmicroproyección de fibras de celulosa como alternativa a las gomas. Una de las principales ventajasprincipales de este procedimiento radica en el hecho de que el agente de limpieza es altamente compatible con la obra ya que tiene una composición muy similar. Por lo tanto, su empleo podríareducir la posibilidad de afectar negativamente la estabilidad química de la pieza a corto o largo plazo.Hasta el momento se han realizado ensayos comparativos entre gomas y microproyección para la limpieza de grabados calcográficos con resultados satisfactorios en eficacia y preservación de la obra a corto y medio plazo (Iglesias-Campos et al., 2014a; Iglesias-Campos & Ruiz-Recasens, 2014 enprensa; Iglesias-Campos, et al., 2014 en prensa). Paralelamente se realizan ensayos de envejecimiento artificial con los que comparar los posibles efectos en el tiempo entre ambas técnicas.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Tutkielman tarkoituksena on tutkia Mika Waltarin romaanin Neljä päivänlaskua (1949) lajityypin hahmottumista kertojahahmojen luotettavuuden kautta. Neljä päivänlaskua on aikaisemmissa tutkimuksissa tulkittu Waltarin omaelämäkerrallisena päiväkirjaromaanina ja tätä tulkintaa tukevat romaanin lukuisat paratekstit ja Neljän päivänlaskun Waltarin elämään viittaava kertomus. Tutkielman tavoitteena on osoittaa, että romaani pitää sisällään aineksia paljon monipuolisempaan tarkasteluun. Motiivina on haastaa suomalainen kirjallisuushistoria ja aiemmat Waltari-tutkimukset osoittamalla, että Neljä päivänlaskua on jo aikakaudelleen poikkeuksellinen suomalainen romaani ja se on maamme ensimmäisiä postmodernistisia ja metafiktiivisiä romaaneja. Neljässä päivänlaskussa on kaksi erilaista kertojahahmoa, joista jälkimmäinen erottuu siten, että hänen kerrontatapansa on lähes pelkästään loppuviitteiden merkitsemistä. Ensimmäinen kertojahahmo kertoo fantastisia aineksia sisältävän kertomuksen kokemistaan kummallisuuksista ja kirjoittamisesta. Jälkimmäinen kertoja kommentoi tätä kerrontaa korostetun epäpätevästi ja epätieteellisesti. Yhdessä kertojahahmot tuottavat varsin metafiktiivisen romaanikokonaisuuden. Kun Neljää päivänlaskua pidetään yleisesti Sinuhe egyptiläisen työpäiväkirjana, niin tutkielmani osoittaa, että näiden romaanien välillä on vahva yhteys, mutta se ei perustu niiden tekijä Waltariin. Romaanien todellisuudet limittyvät toisiinsa, ne käyvät dialogia keskenään ja toistavat samantapaista kertomusta, joissa fakta ja fiktio sekoittuvat erottamattomasti. Neljän päivänlaskun ja Sinuhe egyptiläisen yhteyttä voi luonnehtia postmodernistiseksi. Keskeisiä teoreettisia käsitteitä ovat metafiktio ja postmodernismi. Tutkielmassa keskeisiä teoreetikkoja ovat Mika Hallila, Sari Salin ja Dorrit Cohn, sekä väittelykumppaneita ovat lukuisat Waltari-tutkijat, kuten Markku Envall ja Panu Rajala. Lajityypin ja kertojahahmojen luotettavuuden analysointi tuo tutkielmaan monia elementtejä, jotka tukevat teoreettista viitekehystä. Kun romaanin lajityyppi hahmottuu postmodernismin kautta, tutkimuskysymykseen vastaaminen yllättää: sillä ei ole väliä, pitääkö Neljän päivänlaskun kertojia luotettavina. Matka tähän toteamukseen osoittautui tärkeäksi, ei määränpää.