913 resultados para SUPERINFECTION EXCLUSION


Relevância:

20.00% 20.00%

Publicador:

Resumo:

Amblycipitidae Day, 1873 is an Asian family of catfishes (Siluriformes) usually considered to contain 28 species placed in three genera: Amblyceps (14 spp.), Liobagrus (12 spp.) and Xiurenbagrus (2 spp.). Morphology-based systematics has supported the monophyly of this family, with some authors placing Amblycipitidae within a larger group including Akysidae, Sisoridae and Aspredinidae, termed the Sisoroidea. Here we investigate the phylogenetic relationships among four species of Amblyceps, six species of Liobagrus and the two species of Xiurenbagrus with respect to other sisoroid taxa as well as other catfish groups using 6100 aligned base pairs of DNA sequence data from the rag1 and rag2 genes of the nuclear genome and from three regions (cyt b, COL ND4 plus tRNA-His and tRNA-Ser) of the mitochondrial genome. Parsimony and Bayesian analyses of the data indicate strong support for a diphyletic Amblycipitidae in which the genus Amblyceps is the sister group to the Sisoridae and a clade formed by genera Liobagrus and Xiurenbagrus is the sister group to Akysidae. These taxa together form a well supported monophyletic group that assembles all Asian sisoroid taxa, but excludes the South American Aspredinidae. Results for aspredinids are consistent with previous molecular studies that indicate these catfishes are not sisoroids, but the sister group to the South American doradoid catfishes (Auchenipteridae + Doradidae). The redefined sisoroid clade plus Bagridae, Horabagridae and (Ailia + Laides) make up a larger monophyletic group informally termed "Big Asia." Likelihood-based SH tests and Bayes Factor comparisons of the rag and the mitochondrial data partitions considered separately and combined reject both the hypothesis of amblycipitid monophyly and the hypothesis of aspredinid inclusion within Sisoroidea. This result for amblycipitids conflicts with a number of well documented morphological synapomorphies that we briefly review. Possible nomenclatural changes for amblycipitid taxa are noted.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Both absolute molecular weight and molecular sizes (radius of gyration and hydrodynamic radius) of a vinyl-type polynorbornene eluting from size-exclusion chromatography columns were determined by combined with a static and dynamic laser light scattering detector. The hydrodynamic radius of polymer fraction eluting from size-exclusion chromatography columns was obtained from dynamic laser light scattering measurements at only a single angle of 900 by introducing a correction factor. According to the scaling relationship between molecular sizes and molecular weight and the ratio between radius of gyration and hydrodynamic radius, the vinyl-type polynorbornene took a random coil conformation in 1,2,4-trichlorobenzene at 150 degreesC.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

The collapse process of porphyrin monolayers at the air-water interface was studied by Brewster angle microscopy and by compression-recompression isotherms. It was found that the start of collapse observed by BAM is accordant with that measured by compression-recompression isotherms. The behavior of mixed monolayers was studied also and the results showed that porphyrin islands were excluded from mixed monolayers at 35mN/m.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

The thesis examines cultural processes underpinning the emergence, institutionalisation and reproduction of class boundaries in Limerick city. The research aims to bring a new understanding to the contemporary context of the city’s urban regeneration programme. Acknowledging and recognising other contemporary studies of division and exclusion, the thesis creates a distinctive approach which focuses on uncovering the cultural roots of inequality, educational disadvantage, stigma and social exclusion and the dynamics of their social reproduction. Using Bateson’s concept of schismogenesis (1953), the thesis looks to the persistent, but fragmented culture of community and develops a heuristic ‘symbolic order of the city’. This is defined as “…a cultural structure, the meaning making aspect of hierarchy, the categorical structures of world understanding, the way Limerick people understand themselves, their local and larger world” (p. 37). This provides a very different departure point for exploring the basis for urban regeneration in Limerick (and everywhere). The central argument is that if we want to understand the present (multiple) crises in Limerick we need to understand the historical, anthropological and recursive processes underpinning ‘generalised patterns of rivalry and conflict’. In addition to exploring the historical roots of status and stigma in Limerick, the thesis explores the mythopoesis of persistent, recurrent narratives and labels that mark the boundaries of the city’s identities. The thesis examines the cultural and social function of ‘slagging’ as a vernacular and highly particularised form of ironic, ritualised and, often, ‘cruel’ medium of communication (often exclusion). This is combined with an etymology of the vocabulary of Limerick slang and its mythological base. By tracing the origins of many normalised patterns of Limerick speech ‘sayings’, which have long since forgotten their roots, the thesis demonstrates how they perform a significant contemporary function in maintaining and reinforcing symbolic mechanisms of inclusion/exclusion. The thesis combines historical and archival data with biographical interviews, ethnographic data married to a deep historical hermeneutic analysis of this political community.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Science Foundation Ireland (05/PICA/B802/EC07, 07/SRC/B1158 and 12/RC/227505); Irish Research Council (Enterprise Partnership Scheme (IRSCET-Clarochem-2010-02)); University College Cork (UCC 2013 Strategic Research Fund); Clarochem (Ireland) Ltd

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Findings are presented from a longitudinal study of over 1,500 adolescents. Some were engaged in interventions aimed at reducing social disaffection. Participants completed measures of social-identification, academic self-concept and motivation, and social, emotional and behavioural difficulties. Consistent with our previous research, developmental trends in identity and self-concept were found - adolescents became more negative about some school-based factors and more positive about aspects of identity. Trends were less clear in the 120 adolescents receiving interventions. Findings demonstrate the importance of psychology in work with young people. [Source: (2008) 'Invited Address, IUPsyS Invited Symposium, Invited Symposium, Symposium, Paper Session, Poster Session', International Journal of Psychology, 43:3, 348 - 527]

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Gel filtration on soft gels has been employed for over 40 years for the separation, desalting and molecular weight estimation of peptides and proteins. Technical improvements have given rise to high-performance size-exclusion chromatography (HPSEC) on rigid supports, giving more rapid run times and increased resolution. Initially, these packings were more suitable for the separation of proteins than of peptides, but supports that operate in the fractionation range

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Fifty-one young people aged 14�15 years considered to be at a high-risk of substance abuse and exhibiting antisocial behavior, primarily because they longer attended mainstream school, participated in this research by completing a questionnaire to measure drug use and delinquent behaviour. The findings suggest that many of them may have already developed a high propensity to drug abuse and antisocial behaviour compared with their peers in mainstream education. As they were all excluded from school, they were not accessing school based prevention programmes delivered to their contemporaries at school suggesting that additional and specialized resources are required to fully meet their needs.