Intragroup diffuse light in compact groups of galaxies - II. HCG 15, 35 and 51

This continuing study of intragroup light in compact groups of galaxies aims to establish new constraints to models of formation and evolution of galaxy groups, specially of compact groups, which are a key part in the evolution of larger structures, such as clusters. In this paper we present three additional groups (HCG 15, 35 and 51) using deep wide-field B- and R-band images observed with the LAICA camera at the 3.5-m telescope at the Calar Alto observatory (CAHA). This instrument provides us with very stable flat-fielding, a mandatory condition for reliably measuring intragroup diffuse light. The images were analysed with the OV_WAV package, a wavelet technique that allows us to uncover the intragroup component in an unprecedented way. We have detected that 19, 15 and 26 per cent of the total light of HCG 15, 35 and 51, respectively, are in the diffuse component, with colours that are compatible with old stellar populations and with mean surface brightness that can be its low as 28.4 B mag arcsec(-2). Dynamical masses, crossing times and mass-to-light ratios were recalculated using the new group parameters. Also tidal features were analysed using the wavelet technique.

When group members admit to being conformist: The role of relative intragroup status in conformity self-reports

Five studies examined the hypothesis that people will strategically portray the self as being more g-roup influenced the more junior they feel within the group. Among social psychologists (Study 1), ratings of self-conformity by g-roup members were greater when the status of the participant was low than when it was high. These effects were replicated in Studies 2, 3, and 4 in which relative intragroup status was manipulated. In Study 3, the authors found junior group members described themselves as more conformist than senior members when they were addressing an ingroup audience, but when they were addressing an outgroup audience the effect disappeared. Furthermore, junior members (but not senior members) rated themselves as more conformist when they were led to believe their responses were public than when responses were private (Study 5). The discussion focuses on the strategic processes underlying low-status group members' self-reports of group influence and the functional role of conformity in groups.

Intergroup processes in intragroup contexts: The roles of group status, group identification and communication in diverse work teams

The present research examines employee identification and communication in organisations. In Study 1, 2229 soldiers from a military organisation completed measures of perceived status and strength of identification with their unit, employment category and their brigade. As predicted, the status of a key organisational group influenced reactions to different organisational groups: full-time soldiers evaluated their work unit and the organisation as being lower in status and identified less strongly with both of these groups than part-time soldiers. The second study extended these findings to a different research context: a large psychiatric hospital undergoing downsizing and restructuring. Surprisingly, there were no differences in survivors' and victims' levels of identification with organisational groups. Instead, and consistent with Study 1, there was evidence to suggest that employees adjusted their patterns of identification and perceptions of group status through a compensatory mechanism that maximised opportunities for selfenhancement and positive distinctiveness. In the third study, employees from a public hospital (N = 142) rated communication from double ingroup members (same work unit/same occupational group) more favourably than communication from partial group members (same work unit/different occupational group). These results are considered in terms of their practical implications for identity management in organisations.

Collectively coping with contact: The role of intragroup support in dealing with the challenges of intergroup mixing in residential contexts

The social identity approach to stress has shown how intragroup support processes shape individuals' responses to stress across health care, workplace, and community settings. However, the issue of how these 'social cure' processes can help cope with the stress of intergroup contact has yet to be explored. This is particularly important given the pivotal role of intergroup threat and anxiety in the experience of contact as well as the effect of contact on extending the boundaries of group inclusion. This study applies this perspective to a real-life instance of residential contact in a divided society. Semi-structured interviews with 14 Catholic and 13 Protestant new residents of increasingly mixed areas of Belfast city, Northern Ireland, were thematically analysed. Results highlight that transitioning to mixed communities was fraught with intergroup anxiety, especially for those coming from 'single identity' areas. Help from existing residents, especially when offered by members of other religious denominations, signalled a 'mixed community ethos' to new residents, which facilitated adopting and sharing this identity. This shared identity then enabled them to deal with unexpected intergroup threats and provided resilience to future sectarian division. New residents who did not adopt this shared identity remained isolated, fearful, and prone to negative contact.

Developing transactive memory systems : theoretical contributions from a social identity perspective

Transactive memory system (TMS) theory explains how expertise is recognized and coordinated in teams. Extending current TMS research from a group information-processing perspective, our article presents a theoretical model that considers TMS development from a social identity perspective. We discuss how two features of communication (quantity and quality) important to TMS development are linked to TMS through the group identification mechanism of a shared common team identity. Informed by social identity theory, we also differentiate between intragroup and intergroup contexts and outline how, in multidisciplinary teams, professional identification and perceived equality of status among professional subgroups have a role to play in TMS development. We provide a theoretical discussion of future research directions aimed at testing and extending our model.

Digital videos in financial accounting: A sociocognitive approach to learning

Understanding the important concepts necessary to undertake the preparation of consolidated financial statements has proven challenging for many accounting undergraduate students. As a result, the development of multimedia modelling concepts such as acquisition analysis, business combination valuation entries, reacquisition entries and intragroup transactions were embedded within an e-learning environment. The principle of modelling, derived from social cognitive theory, was applied to the design of the multimedia. A study was conducted to gauge the effectiveness of the approach and consider student perceptions with regard to learning through this approach. Quantitative data were collected from accounting undergraduate students (n= 464) enrolled across three different cohorts including international campuses (n=386), an Australian campus (n=49) and a distance education cohort (n=29). Analyses were undertaken to show significant differences between these cohorts. This research paper presents findings that indicate a positive and significant association between the number of times the videos were accessed, and the assignment score (p<0.05) was evident, suggesting that students that referred to the videos relatively frequently were able to utilise the knowledge gained from the videos to assist them in completing the assignment.

GMRT observations of the group Holmberg 124: Evolution by tidal forces and ram pressure?

We report new radio continuum and 21 cm HI observations using the Giant Metrewave Radio Telescope (GMRT) of the group Holmberg 124 ( Ho 124) comprising four late-type galaxies, namely NGC 2820, Mrk 108, NGC 2814 and NGC 2805. The three galaxies, NGC 2820, Mrk 108 and NGC 2814 which are closely located in the sky plane have clearly undergone tidal interactions as seen from the various morphological tidal signatures and debris. Moreover we note various features in the group members which we believe might be due to ram pressure. In this paper, we describe four interesting results emerging from our observations: a) detection of the tidal radio continuum bridge at 330 MHz connecting the galaxies NGC 2820+ Mrk 108 with NGC 2814. The radio bridge was discovered at 1465 MHz by van der Hulst & Hummel ( 1985, A& A, 150, 17). We find that the bridge has a fairly steep spectrum with a spectral index alpha(S proportional to nu(alpha)) of - 1.8(-0.2)(+0.3) which is much steeper than the - 0.8 quoted by van der Hulst & Hummel ( 1985); b) detection of other tidal features like the tilted HI and radio continuum disk of NGC 2814, a HI streamer and a radio continuum tail arising from the south of NGC 2814. We also report the detection of a possible tidal dwarf galaxy in HI; c) sharp truncation in the HI distribution in the south of NGC 2820 and in the HI and radio continuum distribution in the north of NGC 2814. The optical disks in both the cases look undisturbed. As pointed out by Davis et al. ( 1997, AJ, 114, 613), ram pressure affects different components of the interstellar medium to varying degrees. Simple estimates of pressure in different components of the interstellar medium ( radio continuum, Ha and HI) in NGC 2820 indicate that ram pressure will significantly influence HI; d) detection of a large one-sided HI loop to the north of NGC 2820. No radio continuum emission or Ha emission is associated with the HI loop. We discuss various scenarios for the origin of this loop including a central starburst, ram pressure stripping and tidal interaction. We do not support the central starburst scenario since the loop is not detected in ionized gas. Using the upper limit on X-ray luminosity of Ho 124 (Mulchaey et al. 2003, ApJS, 145, 39), we estimate an upper limit on the intragroup medium (IGrM) density of 8.8 x 10(-4) cm(-3). For half this electron density, we estimate the ram pressure force of the IGrM to be comparable to the gravitational pull of the disk of NGC 2820. Since tidal interaction has obviously influenced the group, we suggest that the loop could have formed by ram pressure stripping if tidal effects had reduced the surface density of HI in NGC 2820. From the complex observational picture of Ho 124 and the numerical estimates, we suggest that the evolution of the Ho 124 group may be governed by both tidal forces due to the interaction and the ram pressure due to motion of the member galaxies in the IGrM and that the IGrM densities should not be too low (i.e. >= 4 x 10(-4)). However this needs to be verified by further observations.

Avaliação da S(+) cetamina no tratamento da dor neuropática e qualidade de vida em portadores de hanseníase

A dor neuropática é uma síndrome dolorosa crônica, que ocorre muito frequentemente em pacientes com hanseníase, de difícil tratamento. Objetivou-se avaliar o efeito terapêutico da S(+)-cetamina na dor neuropática e qualidade de vida em portadores de hanseníase atendidos em ambulatórios em São Luís - MA. Estudo experimental tipo ensaio clínico, prospectivo, aleatório, duplamente cego, controlado por placebo, com 34 pacientes distribuídos aleatoriamente em um dois grupos, cetamina e placebo por três meses e randomizados por numeração sequenciada. A dor foi avaliada por meio de escala analógica visual (EAV) nas seis visitas quinzenais (1, 2, 3, 4, 5 e 6), e pelo inventário DN4, na visita 1 e 6, com distribuição da S(+)-cetamina e o analgésico de resgate e avaliado os efeitos adversos em cada visita. Realizou-se a coleta de 15mL de sangue para exames de segurança na visita 1 e 6 e para quantificação de citocinas plasmáticas IL-1, IL-6 e TNFα, nas visitas 1, 2, 4 e 6. Foi também, avaliada a qualidade de vida por meio do questionário WHOQOL-Bref nas visitas 1 e 6. Os resultados demostraram predominância do sexo feminino, idade de 18 a 29 anos, pardos, solteiros, renda de 2 a 4 salários mínimos; e média de 7,782,21 anos de estudo. Na avaliação da dor pela EAV os dois grupos apresentaram uma redução dos escores médios de dor ao longo do tempo, e mostrou significância estatística p < 0,05. Entretanto não foi observada diferença estatística para os escores de dor entre os grupos e também, em relação ao uso do medicamento analgésico (codeína) de resgate. Houve redução significante nos escore de DN4 no grupo placebo em relação às avaliações iniciais e finais comparadas à cetamina, ainda os escores iniciais do DN4 foram significativamente menores no grupo placebo, nas avaliações de antes e depois do uso da S(+)-cetamina. Na avaliação da qualidade de vida nos domínios físico, psicológico, relações sociais e meio ambiente, não se observou diferença estatisticamente significante entre os grupos estudados. Os valores de IL-1, IL-6 e TNF-α, em quatro coletas do soro dos grupos cetamina e placebo não mostraram diferença estatisticamente significante tanto na avaliação intragrupo ao longo das visitas, como entre os grupos. Em relação aos efeitos adversos, houve um predomínio estatisticamente significante no grupo cetamina especialmente para tontura, alteração visual e outros efeitos. Conclui-se que a S(+)-cetamina por via oral na dose utilizada em pacientes com hanseníase e dor neuropática não se mostrou superior ao placebo em relação ao efeito analgésico e no impacto na qualidade de vida.