OCT evaluation of visible and subthreshold retinal photocoagulation using 532nm laser

Presentation Purpose:We conducted a study to determine if the spectral domain optical coherence tomography (SD-OCT) could be used as a tool to assess effective delivery of threshold and subthreshold laser burns created using 532nm green wavelength laser. Methods:10 patients planned for panretinal photocoagulation (PRP) for proliferative diabetic retinopathy were included in this study. Before initiating the full PRP, a row of moderately white laser burns as used for conventional PRP was created using 532 nm laser set at threshold power for 0.1 second with 300 microns spot size. Further rows of laser burns were created by altering the duration and power settings on the laser device. The area of the retina irradiated with laser was imaged using the Topcon SD-OCT within a few minutes of laser treatment. Results:Laser burns created using threshold power were seen on the OCT scan in all cases as a homogenous diffuse increase in reflectivity extending across the full thickness of retina (Fig 1). Retinal burns created by lowering the duration of laser pulse to 0.01s were barely visible ophthalmoscopically but were clearly detectable on the OCT scan as a localised, well-defined area of increased tissue reflectivity (Fig 2). Conclusions:OCT is a useful to tool to assess the delivery of laser burns created using the 532 nm green laser. Burns of a subthreshold intensity that may not be visible ophthalmoscopically result in retinal changes that are clearly detectable on OCT imaging. Further studies would be needed to assess the clinical effectiveness of subthreshold laser treatment for retinal vascular diseases using the 532 nm green laser.

Minority influence and innovation:antecedents, processes and consequences

Social groups form an important part of our daily lives. Within these groups pressures exist which encourage the individual to comply with the group’s viewpoint. This influence, which creates social conformity, is known as ‘majority influence’ and is the dominant process of social control. However, there also exists a ‘minority influence’, which emerges from a small subsection of the group and is a dynamic force for social change. Minority Influence and Innovation seeks to identify the conditions under which minority influence can prevail, to change established norms, stimulate original thinking and help us to see the world in new ways. With chapters written by a range of expert contributors, areas of discussion include: •processes and theoretical issues •the factors which affect majority and minority influence •interactions between majority and minority group members This book offers a thorough evaluation of the most important current developments within this field and presents consideration of the issues that will be at the forefront of future research. As such it will be of interest to theorists and practitioners working in social psychology. This book offers a thorough evaluation of the most important current developments within this field and presents consideration of the issues that will be at the forefront of future research. As such it will be of interest to theorists and practitioners working in social psychology.

Majority and minority influence using the afterimage paradigm:a series of attempted replications

Five experiments are reported which attempt to replicate Moscovici and Personnaz's (1980) study that showed that a minority, but not a majority, produced a perceptual conversion in a task involving afterimage judgments. Given the theoretical importance of the study, a number of replications were conducted which were designed to test four explanations. The experiments also address a methodological issue that had not been previously examined, namely within-phase effects. Afterimage shifts were found for a majority and minority source only when there were more trials after-influence compared to pre-influence. In all the experiments there was a consistent within-phase effect showing afterimages gradually shifted toward the complementary color of green. These results suggest that afterimage shifts are due to a within-phase effect of afterimages progressively moving to the complementary color of green and to subject suspiciousness. The experiments therefore call into the question the validity of the paradigm as an appropriate test of conversion theory.

Minority influence and argument generation

The theories of Moscovici (1980) and Nemeth (1986) concerning the cognitive processes underlying minority influence are examined in an argument generation paradigm. While Moscovici (1980) argues that minority influence increases the generation of arguments for and against the minority position, Nemeth (1986) proposes that minorities induce divergent thinking which leads to the generation of a wider range of arguments which are more original. In the first study, subjects read a minority text and then generated arguments concerning the minority issue within a specified time. The second study was similar to the first and included a condition where minority influence followed partial sensory deprivation (being placed in a dark, soundproof room for 45 minutes) which was predicted to decrease cognitive effort. Contrary to Moscovici, in neither study was there evidence that a minority led to more arguments being generated compared to a control condition (no influence). However, in one study, a minority led to more arguments being generated in the minority than in the majority direction. However, as predicted by Nemeth, in both studies a minority resulted in a wider range of arguments being generated than those proposed in the minority's message and these were rated by independent judges as being more original. Finally, as predicted, partial sensory deprivation led to a narrower range of arguments which were focused more upon issues raised in the minority text.

Majority and minority influence using the afterimage paradigm:a replication with an unambiguous blue slide

This study re-examines the afterimage paradigm which claims to show that a minority produces a conversion in a task involving afterimage judgements (more private influence than public influence) as opposed to mere compliance produced by a majority. Subsequent failures to replicate this finding have suggested that the changes in the afterimages could be attributed to increased attention due to an ambiguous stimulus coupled with subject suspiciousness. This study attempted to replicate the original experiment but with an unambiguous stimulus in order to remove potential biases. The results showed shifts in afterimages consistent with the increased attention hypothesis for a minority and majority and these were unaffected by the level of suspiciousness reported by the subjects. Additional data shows that no shifts were found in a no-influence control condition showing that shifts were related to exposure to a deviant source and not to response repetition.

The effects of ingroup-outgroup membership on minority influence when group membership is determined by a trivial categorisation

Two experiments are reported which investigate the influence of ingroup and outgroup minority influence where group membership was determined according to a trivial dimension. The results of the first experiment replicate an earlier study and show that an ingroup minority has significantly more influence than an outgroup minority. In the second study the connotations associated with membership of the ingroup and outgroup (positive/negative) were experimentally manipulated. When ingroup/outgroup membership was associated with a positive/negative image respectively, the ingroup minority had the most influence. However, when ingroup/outgroup membership was associated with a negative/positive image, as predicted, an outgroup minority had more influence than an ingroup minority. These results are interpreted as supporting an intergroup analysis of minority influence processes.

Minority influence and social categorization:a replication

The effects of ingroup and outgroup minorities upon public and private levels of influence was examined. The results show that whilst ingroup minorities have greater influence in public, outgroup minorities can have as much, if not more influence than ingroup minorities when responses are made in private. These results are consistent with previous research and support the social identijkation model of social influence.

Minority influence and 'trivial' social categorization

This experiment examines ingroup and outgroup minority influence when group membership was determined by a trivial categorization. The results show that ingroup minorities had more public influence than outgroup minorities when the categorization was trivial and when subjects also believed that they were similar to their ingroup. However, no differences were found when group membership was not associated with similarity. These results are interpreted as supporting the social identification model of social influence.

A management tool for developing the relationships between large purchasing organisations and small ethnic minority suppliers

Purpose: The purpose of this paper is to scrutinise the characteristics of the relationship between large purchasing organisations (LPOs) and ethnic minority suppliers (EMSs) engaging with supplier diversity programmes and provide an assessment and developmental framework for such organisations. Design/methodology/approach: Having considered an array of purchaser-supplier relationship frameworks in relevant streams of literature, the paper draws on Lamming et al.'s framework to advance a tool for assessing and developing the relationship between LPOs and EMSs. Findings: The submitted relationship assessment and development framework brings in sharp focus the characteristics of the relationship between LPO and EMS, providing a systematic way to examine the inter-organisational context within which EMS development takes place. Research limitations/implications: The framework submitted could signpost future research in this field, which should take a longitudinal, processual approach. This is necessary to provide opportunities to examine the dynamics underlying the development of potent LPO-EMS relationships in a variety of settings, including negative instances. Practical implications: The paper has implications for corporate policy making and practice in this arena. Assessing the potency of LPOs-EMSs relationships by applying the proffered tool can help both parties engage with supplier diversity, to develop fruitful relationships that enhance their competitiveness. Social implications: The latter can have social implications, as EMSs often operate in and employ people from disadvantaged communities. Originality/value: The framework advanced in this article constitutes a novel tool that highlights the areas in which LPOs and EMSs should channel their efforts, in order to develop a potent relationship between them, which underpins the development of EMSs' supply capabilities. © Emerald Group Publishing Limited.