47 resultados para duck
Resumo:
This paper reexamines the potential impact of the English-only movement on linguistic minorities and Anglos' perceptions of their own and minority groups' language vitality. Of particular interest is the Hispanic population-the fastest growing minority in the U.S. Communication scholars have paid only scant attention to the English-only movement and how it affects the social and communication climate for Latinos. However, literature reviews prepared for the American Psychological Association and for the Teachers of English to Speakers of Other Languages (in 1991 and 1995, respectively) concluded that English-only initiatives have negative consequences for limited-English proficiency groups. Revisiting this still-growing issue in the light of more recent studies across disciplines and media reports, we examine how Anglo support for English-only policies limits the use, promotion, and salience of minority languages like Spanish in institutional settings and in the linguistic landscape and suggest directions for future research.
Resumo:
A new cloud-point extraction and preconcentration method, using a cationic, surfactant, Aliquat-336 (tricaprylyl-methy;ammonium chloride), his-been developed for the determination of cyanobacterial toxins, microcystins, in natural waters. Sodium sulfate was used to induce phase separation at 25 degreesC. The phase behavior of Aliquat-336 with respect to concentration of Na2SO4 was studied. The cloud-point system revealed a very high phase volume ratio compared to other established systems of nonionic, anionic, and cationic surfactants: At pH 6-7, it showed an outstanding selectivity in ahalyte extraction for anionic species. Only MC-LR and MC-YR, which are known to be predominantly anionic, were extracted (with averaged recoveries of 113.9 +/- 9% and 87.1 +/- 7%, respectively). MC-RR, which is likely to be amphoteric at the above pH range, was. not cle tectable in.the extract. Coupled to HPLC/UV separation and detection, the cloud-point extraction method (with 2.5 mM Aliquat-336 and 75 mM Na2SO4 at 25 degreesC) offered detection limits of 150 +/- 7 and 470 +/- 72 pg/mL for MC-LR and MC-YR, respectively, in 25 mL of deionized water. Repeatability of the method was 7.6% for MC-LR and 7.3% for MC-YR: The cloud-point extraction process can be. completed within 10-15 min with no cleanup steps required. Applicability of the new method to the determination of microcystins in real samples was demonstrated using natural surface waters, collected from a local river and a local duck pond spiked with realistic. concentrations of microcystins. Effects of salinity and organic matter (TOC) content in the water sample on the extraction efficiency were also studied.
Resumo:
The present research focused on responses of low-status group members to a merger with a high-status group. A study was conducted (N = 153) in which the alignment of the leader for the merged group (ingroup vs. outgroup) and leader behavior (equality, outgroup favoritism, ingroup favoritism, complementarity) were manipulated. The authors predicted that the leader, by his or her behavior, would play an important role in defining the new relationship between premerger groups. Overall, low-status ingroup leaders were evaluated more positively than high-status outgroup leaders. Ingroup leaders were evaluated more favorably and were more likely to engender a common identity in the merged group than were outgroup leaders when leaders behaved in an ingroup-favoring or complementary fashion. In contrast, evaluations of ingroup and outgroup leaders did not differ when the leader stressed equality or was outgroup favoring. The findings demonstrate the important role leaders can play in accentuating or de-emphasizing premerger status differences.
Resumo:
Industrial relations research that attempts to grapple with individuals' union-related sentiments and activities often draws on one of two traditions of psychological research—the individual-level factors tradition (for example, personality and attitude-behaviour relations) and the social context tradition (for example, frustration-aggression and relative deprivation). This paper provides an overview of research conducted from within these traditions to explain union-related phenomena and identifies some of the limitations that arise as a consequence of a shared tendency to treat people in an atomistic fashion. The paper argues for an understanding of the psychological processes that underpin group-based action. To this end, it elaborates a theoretical framework based on social identity theory and self-categorisation theory that would allow us to examine the dynamic interplay between the individual, their cognitions and their environment. The paper concludes with a brief discussion of a specific case of union mobilisation, to indicate how this theoretical framework might aid empirical analysis.
Resumo:
Asurvey-based field study was conducted with 232 members and nonmembers of the National Tertiary Education Union to investigate the psychological processes underpinning union support. Drawing on value-expectancy models and social identity/self-categorisation theory, this study investigated the role that both individual and grouprelated factors play in predicting attitudinal and behavioural support for the union. Variables investigated included instrumental and ideological attitudes, perceptions of a normative climate of union-support, and perceptions of higher education being under threat. Further to support for previous findings for the role of instrumental and ideological attitudes it was found that the perceived workplace norm had the anticipated direct effect on behaviour and evaluation and also moderated the behavioural expression of ideological and instrumental attitudes. The perception of threat to employment and higher education also directly impacted on behaviour and moderated the behavioural expression of ideological beliefs. The implications of these findings for collective action research will he discussed.
Resumo:
This study proposes gaining a new understanding of group development by considering the integrative and the punctuated equilibrium models of group development as complementary rather than competing. We hypothesized that we would observe both punctuated equilibrium and linear progression in content-analyzed data from 25 simulated project teams, albeit on different dimensions. We predicted changes in time awareness and in task and pacing activity in line with the punctuated equilibrium model and changes in structure and process on task and socioemotional dimensions in line with the integrative model. Results partially supported predictions for both models.
Resumo:
Recently, there has been much speculation about the impact of international media coverage of Australia's position on Indigenous people, migrants and asylum seekers on other nations' images of Australia. In this experiment we examined whether there was any basis for such concerns by considering the short-term impact of negative TV coverage of Australians on Canadian viewers. A questionnaire provided baseline data on Canadian students' perceptions of Australians and Australian race relations. Four months later, the students were assigned to one of three conditions that varied media contact with Australians. Students viewed one of two television programs (about right-wing political independent, Pauline Hanson, and her emotive criticisms of Aborigines and Asian immigrants or about an ethnically-mixed group of young Australians and their positive sense of cultural identity), or they viewed no program (no contact control). Results indicated that both positive and negative media coverage of Australians affected Canadians' views of Australia in the short-term. In particular, negative coverage (of Hanson) promoted less favourable views of Australians and Australian race relations over time and relative to the positive media and no media control conditions. The media's role in shaping international images is discussed.
Resumo:
This experiment examined members' evaluations of a group leader and the group in contexts where a superordinate group comprised two subgroups and the group leader was aligned with one or other subgroup. The design varied group leader (ingroup, outgroup) and leader behavior (ingroup favoring, outgroup favoring) as well as the broader comparative context (intragroup, intergroup). Across a number of measures, results indicated a consistent Group Leader x Leader Behavior interaction that was independent of comparative context. Although group members were most satisfied with an ingroup leader who favored the ingroup, ingroup leaders were perceived positively irrespective of their behavior Outgroup leaders who unexpectedly favored the other subgroup were also perceived positively. However, outgroup leaders who favored their own subgroup were perceived as less fair and as more biased than other leaders. They also engendered less identification with the superordinate group and a less unified perception of the group. Results demonstrate the importance of social identity concerns to leadership in nested group contexts and emphasize the fact that perceptions of leader fairness and concern for the common group mediate responses to the superordinate category. Copyright (C) 2003 John Wiley Sons, Ltd.
Resumo:
The focus of the present work is the well-known feature of the probability density function (PDF) transport equations in turbulent flows-the inverse parabolicity of the equations. While it is quite common in fluid mechanics to interpret equations with direct (forward-time) parabolicity as diffusive (or as a combination of diffusion, convection and reaction), the possibility of a similar interpretation for equations with inverse parabolicity is not clear. According to Einstein's point of view, a diffusion process is associated with the random walk of some physical or imaginary particles, which can be modelled by a Markov diffusion process. In the present paper it is shown that the Markov diffusion process directly associated with the PDF equation represents a reasonable model for dealing with the PDFs of scalars but it significantly underestimates the diffusion rate required to simulate turbulent dispersion when the velocity components are considered.
Resumo:
Previous research indicates that people who are highly identified with their groups tend to remain committed to them under threat. This study examines the generalizability, of this effect to (a) a real-life context involving the perception that others view the ingroup (Australians) as intolerant of minorities and (b) various dimensions of social identification. The sample comprised 213 respondents to a random mail survey. Perceived threat was inversely related to self-stereotyping (i.e. perceptions of self-ingroup similarity), but only for individuals with weak subjective ties to other group members. Threat perceptions were also predictive of enhanced judgments of within-group variability on threat-relevant dimensions, particularly for individuals with weaker ingroup ties. Various strategies for coping with a threatened social identity are linked to different facets of social identification.
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A questionnaire was distributed on the Australian republic issue to examine the interplay between norms and relevance of the issue to the group on voting intentions. Supporters of an Australian republic (N = 188) indicated the level of support for a republic within their peer Group, the relevance of the republic issue to the group, and measures designed to assess voting intentions and other attitude outcomes. Analysis revealed an interaction between normative support and relevance of the issue to the group. On the measure of intention, increasing normative support was associated with increased intention to vote in an attitude-consistent way at both relevance levels, but the effect was heightened when the issue was highly relevant to the group. On the outcomes of willingness to express opinion and perceived personal importance of the republic issue, normative support had a positive effect only when the issue was highly relevant to the group. Mediation analyses revealed that the impact of normative support and group relevance on intention were mediated through perceived personal importance of the republic issue.
Resumo:
Many marine reptiles and birds possess extrarenal salt glands that facilitate the excretion of excess sodium and chloride ions accumulated as a consequence of living in saline environments. Control of the secretory activity of avian salt glands is under neural control, but little information is available on the control of reptilian salt glands. Innervation of the lingual salt glands of the salt water crocodile, Crocodylus porosus, was examined in salt water-acclimated animals using histological methods. Extensive networks of both cholinergic and adrenergic nerve fibres were identified close to salt-secreting lobules and vasculature. The identification of both catecholamine-containing and cholinergic neurons in the salt gland epithelium and close to major blood vessels in the tissue suggests the action of the neurotransmitters on the salt-secreting epithelium itself and the rich vascular network of the lingual salt glands.
Resumo:
Many viruses including HIV, hepatitis C and hepatitis B, have an outer lipid envelope which maintains inserted viral peptides in the “correct” functional conformation and orientation. Disruption of the lipid envelope by most solvents destroys infectivity and often results in a loss of antigenicity. This communication outlines a novel approach to viral inactivation by specific solvent delipidation which modifies the whole virion rendering it non-infective, but antigenic. Duck hepatitis B virus (DHBV) was delipidated using a diisopropylether (DIPE) and butanol mixture and residual infectivity tested by inoculation into day-old ducks. Delipidation completely inactivated the DHBV (p < 0.001). Delipidated DHBV was then used to vaccinate ducks. Three doses of delipidated DHBV induced anti-DHBs antibody production and prevented high dose challenge infection in five out of six ducks. In comparison, five of six ducks vaccinated with undelipidated DHBV and four of four ducks vaccinated with glutaraldehyde inactivated DHBV were unprotected (p < 0.05). Although this solvent system completely inactivated DHBV, viral antigens were retained in an appropriate form to induce immunity. Delipidation of enveloped viruses with specific organic solvents has potential as the basis for development of vaccines.