218 resultados para longitudinal analyses


Relevância:

20.00% 20.00%

Publicador:

Resumo:

Although intergroup contact is one of the most prominent interventions to reduce prejudice. the generalization of contact effects is still a contentious issue This research further examined the rarely studied secondary transfer effect (STE, Pettigrew, 2009) by which contact with a primary outgroup reduces prejudice toward secondary groups that are not directly involved in the contact Across 3 cross-sectional studies conducted in Cyprus (N = 1.653), Northern Ireland (N = 1,973). and Texas (N = 275) and 1 longitudinal study conducted in Northern Ireland (N = 411). the present research sought to systematically rule out alternative accounts of the STE and to investigate 2 potential mediating mechanisms (ingroup reappraisal and attitude generalization) Results indicated that, consistent with the STE. contact with a primary outgroup predicts attitudes toward secondary outgroups. over and above contact with the secondary outgroup, socially desirable responding. and prior attitudes Mediation analyses found strong evidence for attitude generalization but only limited evidence for ingroup reappraisal as an underlying process Two out of 3 tests of a reverse model, where contact with the secondary outgroup predicts attitudes toward the primary outgroup. provide further evidence for an indirect effect through attitude generalization Theoretical and practical implications of these results are discussed, and directions for future research are identified

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Aims To investigate secular trends in the incidence of Type 1 diabetes in Northern Ireland over the period 1989-2003. To highlight geographical variations in the incidence of Type 1 diabetes by producing disease maps and to compare incidence rates by relevant area characteristics.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Objective/background Our objective was to investigate glycaemic control in children with Type 1 diabetes in Scotland and to analyse the effect of changing 'conventional' insulin regimen strategies on outcome. DIABAUD 2 ( 1997 - 1998) (D2) demonstrated that average glycaemic control in young people with Type 1 diabetes in Scotland was poor, with mean HbA(1c) of 9.0%. Over 90% were then treated with a twice-daily insulin regimen. The aim of DIABAUD 3 ( 2002 2004) (D3) was to determine if control had improved, and to examine changes in insulin regimen and effects on glycaemic control.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Prokaryotes represent one-half of the living biomass on Earth, with the vast majority remaining elusive to culture and study within the laboratory. As a result, we lack a basic understanding of the functions that many species perform in the natural world. To address this issue, we developed complementary population and single-cell stable isotope (C-13)-linked analyses to determine microbial identity and function in situ. We demonstrated that the use of rRNA/mRNA stable isotope probing (SIP) recovered the key phylogenetic and functional RNAs. This was followed by single-cell physiological analyses of these populations to determine and quantify in situ functions within an aerobic naphthalene-degrading groundwater microbial community. Using these culture-independent approaches, we identified three prokaryote species capable of naphthalene biodegradation within the groundwater system: two taxa were isolated in the laboratory (Pseudomonas fluorescens and Pseudomonas putida), whereas the third eluded culture (an Acidovorax sp.). Using parallel population and single-cell stable isotope technologies, we were able to identify an unculturable Acidovorax sp. which played the key role in naphthalene biodegradation in situ, rather than the culturable naphthalene-biodegrading Pseudomonas sp. isolated from the same groundwater. The Pseudomonas isolates actively degraded naphthalene only at naphthalene concentrations higher than 30 mu M. This study demonstrated that unculturable microorganisms could play important roles in biodegradation in the ecosystem. It also showed that the combined RNA SIP-Raman-fluorescence in situ hybridization approach may be a significant tool in resolving ecology, functionality, and niche specialization within the unculturable fraction of organisms residing in the natural environment.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Two studies were carried out in England to investigate the role of essentialist national group definitions in determining the effect of national identification on prejudice towards immigrants, and asylum seekers in particular. It was expected that the relationship between national identification and prejudice would depend on the degree to which participants endorse an essentialist (`ethnic') definition of their nationality. Consistent with this, Study 1 (N=154) found that national identification is associated with negativity towards asylum seekers only among individuals who endorse an essentialist conception of the group, and shows no significant association with prejudice among those who reject such a conception. Study 2 (N=219) used a longitudinal design conducted over 6 weeks, allowing cross-lagged analysis of causality between essentialism, identification, and behavioural intentions towards asylum seekers. A causal effect of essentialism on willingness to support a group acting against asylum seekers was observed, with no significant causal effect in the reverse direction. The reverse causal direction was observed in the case of support for a group seeking to support asylum seekers, with intended behaviours determining essentialism. The results are discussed in terms of the importance of group definitions in the study of in-group affiliations and prejudice.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

The nonlinear amplitude modulation of longitudinal dust lattice waves (LDLWs) propagating in a dusty plasma crystal is investigated in a continuum approximation. It is shown that long wavelength LDLWs are modulationally stable, while shorter wavelengths may be unstable. The possibility for the formation and propagation of different envelope localized excitations is discussed. It is shown that the total grain displacement bears a (weak) constant displacement (zeroth harmonic mode), due to the asymmetric form of the nonlinear interaction potential. The existence of asymmetric envelope localized modes is predicted. The types and characteristics of these coherent nonlinear structures are discussed. (C) 2004 American Institute of Physics.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

The nonlinear aspects of longitudinal motion of interacting point masses in a lattice are revisited, with emphasis on the paradigm of charged dust grains in a dusty plasma (DP) crystal. Different types of localized excitations, predicted by nonlinear wave theories, are reviewed and conditions for their occurrence (and characteristics) in DP crystals are discussed. Making use of a general formulation, allowing for an arbitrary (e.g. the Debye electrostatic or else) analytic potential form phi(r) and arbitrarily long site-to-site range of interactions, it is shown that dust-crystals support nonlinear kink-shaped localized excitations propagating at velocities above the characteristic DP lattice sound speed v(0). Both compressive and rarefactive kink-type excitations are predicted, depending on the physical parameter values, which represent pulse- (shock-)like coherent structures for the dust grain relative displacement. Furthermore, the existence of breather-type localized oscillations, envelope-modulated wavepackets and shocks is established. The relation to previous results on atomic chains as well as to experimental results on strongly-coupled dust layers in gas discharge plasmas is discussed.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

A comprehensive nonlinear model is put forward for coupled longitudinal to transverse displacements in a horizontal dust mono-layer, levitated under the combined influence of gravity and an electric and/or magnetic sheath field. A set of coupled nonlinear evolution equations are obtained in a discrete description, and a pair of coupled (Boussinesq-like) PDEs are obtained in the continuum approximation. Finally, the amplitude modulation of the coupled modes is discussed, pointing out the importance of the coupling. All these results are generic, i.e. valid for any assumed form of the inter-grain interaction potential U and the sheath potential Phi.