853 resultados para Orientation sexuelle


Relevância:

20.00% 20.00%

Publicador:

Resumo:

Earlier initiation into more problematic drinking behaviour has been found to be associated with more problematic drinking later in life. Research has suggested that a lower future time perspective (and higher present time perspective) is associated with health-compromising behaviours such as problematic alcohol use in college student, University undergraduate and general population samples. This study used a cross-sectional design to examine whether consideration of future consequences (CFC), assessed by the Consideration of Future Consequences Scale, was significantly related to drinking behaviour in a large sample (n=707) of Northern Irish adolescents. Alcohol use was self-reported by means of a composite measure of drinking behaviour. Demographic data were also gathered. After controlling for year in school (proxy for age), sex and for clustering at school level, lower future orientation and higher present orientation were found to be significantly associated with more problematic self-reported drinking behaviour. These results extend recent findings of a significant relationship between a foreshortened future time perspective and more problematic self-reported drinking behaviour in a UK sample of University undergraduates, to a large UK sample of adolescents. Given the relationship between early-onset drinking and more problematic use in later life, health promotion interventions might explore using the CFC construct in targeting adolescent drinkers.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

For many years, orientation in migratory birds has primarily been studied in the laboratory. Although a laboratory-based setting enables greater control over environmental cues, the laboratory-based findings must be confirmed in the wild in free-flying birds to be able to fully understand how birds orient during migration. Despite the difficulties associated with following free-flying birds over long distances, a number of possibilities currently exist for tracking the long distance, sometimes even globe-spanning, journeys undertaken by migrating birds. Birds fitted with radio transmitters can either be located from the ground or from aircraft (conventional tracking), or from space. Alternatively, positional information obtained by onboard equipment (e.g., GPS units) can be transmitted to receivers in space. Use of these tracking methods has provided a wealth of information on migratory behaviors that are otherwise very difficult to study. Here, we focus on the progress in understanding certain components of the migration-orientation system. Comparably exciting results can be expected in the future from tracking free-flying migrants in the wild. Use of orientation cues has been studied in migrating raptors (satellite telemetry) and thrushes (conventional telemetry), highlighting that findings in the natural setting may not always be as expected on the basis of cage-experiments. Furthermore, field tracking methods combined with experimental approaches have finally allowed for an extension of the paradigmatic displacement experiments performed by Perdeck in 1958 on the short-distance, social migrant, the starling, to long-distance migrating storks and long-distance, non-socially migrating passerines. Results from these studies provide fundamental insights into the nature of the migratory orientation system that enables experienced birds to navigate and guide inexperienced, young birds to their species-specific winter grounds.

Relevância:

20.00% 20.00%

Publicador:

Relevância:

20.00% 20.00%

Publicador:

Resumo:

The metallo-phthalocyanines (MPcs) are an interesting group of organic semiconductor materials for applications such as large area solar cells due to their optoelectronic properties coupled with the possibility of easily and cheaply fabricating thin films of MPcs [1, 2]. As for organic semiconductors in general, many of the interesting properties of the MPcs such as magnetism, light absorption and charge transport, are highly anisotropic [2, 3]. To maximise the efficiency of a device based on these materials it is therefore important to study their molecular orientation in films and to assess the influence of different growth conditions and substrate treatments.
X-ray diffraction is a well established and powerful technique for studying texture (and hence molecular orientation) in crystalline materials, but it cannot provide any information about amorphous or nanocrystalline films. In electron paramagnetic resonance (EPR) spectroscopy the signal comes from the spin of unpaired electrons in the material. This technique therefore does not require the sample to be crystalline. It works for any sample with paramagnetic centres such as the MPcs where the unpaired electrons are contributed by the metal. In this paper we present a continuous-wave X-band EPR study using the anisotropy of the EPR spectrum of CuPc [4] to determine the orientation effects in different types of CuPc films. From these measurements we gain insight into the molecular arrangement of films with different spin concentrations, and apply our technique to the study of molecular orientation in photovoltaic cells.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Organic semiconductors have already found commercial applications in for example displays with organic light-emitting diodes (OLEDs) and great advances are also being made in other areas, such as organic field-effect transistors and organic solar cells. [1] The organic semicondutor group of materials known as metal phthalocyanines (MPc’s) is interesting for applications such as large area solar cells due to their optoelectronic properties coupled with the possibility of easily and cheaply fabricating thin films of MPc’s. [1, 2]

Many of the properties of organic semiconductors, such as magnetism, light absorption and charge transport, show orientational anisotropy. [2, 3] To maximise the efficiency of a device based on these materials it is therefore important to study the molecular orientation in films and to assess the influence of different growth conditions and substrate treatments. X-ray diffraction is a well established and powerful technique for studying texture (and hence molecular orientation)_in crystalline materials, but cannot provide any information about amorphous or nanocrystalline films. In this paper we present a continuous wave X-band EPR study using the anisotropy of the CuPc EPR spectrum [4] to determine the orientation effects in different types of CuPc films. From these measurements we also gain insight into the molecular arrangement of films of CuPc mixed with the isomorphous H2Pc and with C60 in films typical of real solar cell systems.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

This paper introduces the paired comparison model as a suitable approach for the analysis of partially ranked data. For example, the Inglehart index, collected in international social surveys to examine shifts in post-materialistic values, generates such data on a set of attitude items. However, current analysis methods have failed to account for the complex shifts in individual item values, or to incorporate subject covariates. The paired comparison model is thus developed to allow for covariate subject effects at the individual level, and a reparameterization allows the inclusion of smooth non-linear effects of continuous covariates. The Inglehart index collected in the 1993 International Social Science Programme survey is analysed, and complex non-linear changes of item values with age, level of education and religion are identified. The model proposed provides a powerful tool for social scientists.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Three studies demonstrated that the moral judgments of religious individuals and political conservatives are highly insensitive to consequentialist (i.e., outcome-based) considerations. In Study 1, both religiosity and political conservatism predicted a resistance toward consequentialist thinking concerning a range of transgressive acts, independent of other relevant dispositional factors (e.g., disgust sensitivity). Study 2 ruled out differences in welfare sensitivity as an explanation for these findings. In Study 3, religiosity and political conservatism predicted a commitment to judging “harmless” taboo violations morally impermissible, rather than discretionary, despite the lack of negative consequences rising from the act. Furthermore, non-consequentialist thinking style was shown to mediate the relationship religiosity/conservatism had with impermissibility judgments, while intuitive thinking style did not. These data provide further evidence for the influence of religious and political commitments in motivating divergent moral judgments, while highlighting a new dispositional factor, non-consequentialist thinking style, as a mediator of these effects.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

The current study sought to elaborate and test a theoretical proposition that introjective personality functioning, which has been implicated in various psychological difficulties (e.g., self-critical depression, obsessive-compulsive disorder), has an emotional foundation in the self-conscious emotion of shame and is supported by dissociation. Moreover, introjective functioning was predicted to be associated with reduced interpersonal intimacy. To test the model, a Web-based survey design using path analysis was used. Three hundred and fifteen university students were assessed with measures of self-conscious emotions (i.e., shame, guilt, and embarrassment), introjective (self-definition) and anaclitic (relational) personality style, pathological dissociation, and interpersonal intimacy. Introjective personality was found to be associated with increased shame and reduced interpersonal intimacy. However, the path between pathological dissociation and introjective functioning was not significant. The results are discussed with reference to the moderating influence of introjective functioning between shame and reduced interpersonal intimacy.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Animals can call on a multitude of sensory information to orient and navigate. In some cases they may calibrate these cues against each other to establish the most accurate information available. One such cue is the pattern of polarized light in the sky, which may be used as a geographical reference to calibrate other cues in the compass mechanism. Mammals, however, have not been shown to use this cue, even though they do calibrate a magnetic compass with sunset. In this paper we demonstrate that bats use polarization cues at sunset to calibrate a magnetic compass, subsequently used for orientation during a homing experiment. It is thus the only mammal known so far to make use of the polarization pattern in the sky. This is an intriguing finding as currently there is no clear understanding of how this cue is perceived in this taxon and has general implications for the sensory biology of mammalian vision.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

The ways in which fish use space in nature are described, distinguishing between movements within a home range, dispersal and directed migration, as are the mechanisms that determine how fish use space. The external stimuli to which fish respond, how they use these cues to find their way around and the role of hormones in migration are also covered. An account is then given of how movement and orientation change with age, the evidence for inherited differences in these aspects of behaviour and environmental effects on development of space use patterns. The benefits that accrue to fish from moving in particular ways are described, as are adverse consequences of such movements, in the form of energetic costs and exposure to predators and pathogens. The ways in which benefits and costs are balanced against each other are discussed, with special reference to diurnal vertical migration. Although cultured fish usually inhabit confined spaces, their natural patterns of orientation and movement can cause a number of problems in aquaculture and some of these are described. Such problems are amenable to biological solutions and these are considered in the final section of this chapter, which also looks at the potential for using what is known about how fish move about to improve the effectiveness of general husbandry practices.