Assessing the effects of attention and emotion on startle eyeblink modulation

Two experiments were conducted to assess simultaneously the effects of attentional and emotional processes on startle eyeblink modulation. In each experiment, participants were presented with a pleasant and an unpleasant picture. Half the participants were asked to attend to the pleasant picture and to ignore the unpleasant picture, whereas the reverse was the case for the other participants. Startle probes were presented at 3500 and 4500 ins after stimulus onset in Experiment I and at 250, 750, and 4450 ms after stimulus onset and 950 ms after stimulus offset in Experiment 2. Attentional processing affected startle eyeblink modulation and electrodermal responses in both experiments, However, effects of picture valence on startle eyeblink modulation were found only in Experiment 2. The results confirm the utility of startle eyeblink modulation as an index of attentional and emotional processing. They also illustrate that procedural characteristics, such as the nature of the lead intervals and how attention and emotion are operationalized, can determine whether emotional or attentional processes will be reflected in startle eyeblink.

Targeting of EBNA1 for rapid intracellular degradation overrides the inhibitory effects of the Gly-Ala repeat domain and restores CD8+T cell recognition

Epstein-Barr virus (EBV)-encoded nuclear antigen 1 (EBNA1) includes a unique glycine-alanine repeat domain that inhibits the endogenous presentation of cytotoxic T lymphocyte (CTL) epitopes through the class I pathway by blocking proteasome-dependent degradation of this antigen. This immune evasion mechanism has been implicated in the pathogenesis of EBV-associated diseases. Here, we show that cotranslational ubiquitination combined with N-end rule targeting enhances the intracellular degradation of EBNA1, thus resulting in a dramatic reduction in the half-life of the antigen. Using DNA expression vectors encoding different forms of ubiquitinated EBNA1 for in vivo studies revealed that this rapid degradation, remarkably, leads to induction of a very strong CTL response to an EBNA1-specific CTL epitope. Furthermore, this targeting also restored the endogenous processing of HLA class I-restricted CTL epitopes within EBNA1 for immune recognition by human EBV-specific CTLs. These observations provide, for the first time, evidence that the glycine-alanine repeat-mediated proteasomal block on EBNA1 can be reversed by specifically targeting this antigen for rapid degradation resulting in enhanced CD8+ T cell-mediated recognition in vitro and in vivo.

Effects of temporal association on recognition memory

The influence of temporal association on the representation and recognition of objects was investigated. Observers were shown sequences of novel faces in which the identity of the face changed as the head rotated. As a result, observers showed a tendency to treat the views as if they were of the same person. Additional experiments revealed that this was only true if the training sequences depicted head rotations rather than jumbled views: in other words, the sequence had to be spatially as well as temporally smooth. Results suggest that we are continuously associating views of objects to support later recognition, and that we do so not only on the basis of the physical similarity, but also the correlated appearance in time of the objects.

A Context Noise Model of Episodic Recognition Memory

Item noise models of recognition assert that interference at retrieval is generated by the words from the study list. Context noise models of recognition assert that interference at retrieval is generated by the contexts in which the test word has appeared. The authors introduce the bind cue decide model of episodic memory, a Bayesian context noise model, and demonstrate how it can account for data from the item noise and dual-processing approaches to recognition memory. From the item noise perspective, list strength and list length effects, the mirror effect for word frequency and concreteness, and the effects of the similarity of other words in a list are considered. From the dual-processing perspective, process dissociation data on the effects of length. temporal separation of lists, strength, and diagnosticity of context are examined. The authors conclude that the context noise approach to recognition is a viable alternative to existing approaches. (PsycINFO Database Record (c) 2008 APA, all rights reserved)

Interferon-gamma enhances cytotoxic T lymphocyte recognition of endogenous peptide in keratinocytes without lowering the requirement for surface peptide

Keratinocytes expressing the human papillomavirus (HPV) type 16 E7 protein, as a transgene driven by the K14 promoter, form a murine model of HPV-mediated epithelial cancers in humans. Our previous studies have shown that K14E7 transgenic skin grafts onto syngeneic mice are not susceptible to immune destruction despite the demonstrated presence of a strong, systemic CTL response directed against the E7 protein. Consistent with this finding, we now show that cultured, E7 transgenic keratinocytes (KC) express comparable endogenous levels of E7 protein to a range of CTL-sensitive E7-expressing cell lines but are not susceptible to CTL-mediated lysis in vitro . E7 transgenic and non-transgenic KC are susceptible to conventional mechanisms of CTL-mediated lysis, including perforin and Fas/FasL interaction when an excess of exogenous peptide is provided. The concentration of exogenous peptide required to render a cell susceptible to lysis was similar between KC and other conventional CTL targets (e.g. EL-4), despite large differences in H-2D(b) expression at the cell surface. Furthermore, exposure of KC to IFN-gamma increased H-2D(b) expression, but did not substantially alter the exogenous peptide concentration required to sensitize cells for half maximal lysis. In contrast, the lytic sensitivity of transgenic KC expressing endogenous E7 is modestly improved by exposure to IFN-gamma. Thus, failure of CTL to eliminate KC expressing endogenous E7, and by inference squamous tumours expressing E7, may reflect the need for a sustained, local inflammatory environment during the immune effector phase.

Emotion in the workplace: The new challenge for managers

Emotions in workplace settings and emotional intelligence are hot topics in management today. Leading business journals such as Fortune and Harvard Business Review have featured articles on emotional intelligence. But there is more to emotions in the workplace than just emotional intelligence. The aim of this article is to acquaint managers with intriguing new research that examines both emotional intelligence and the broader issue of emotion, which has been shown to play a powerful role in workplace settings. We show that this research has a strong potential for practical application in organizations within many broad human-resource functions such as selection, performance management, and training, as well as implications for more narrow domains like customer service. We conclude that the study of emotions in organizational settings has provided new and important insights into the way in which people in organizations behave, and we offer advice for managers to enable them to develop and to maintain a positive emotional climate in their organizations.

The role of affect and affective congruence in perceptions of leaders: an experimental study

Based on the idea that emotional exchanges determine symbolic meanings in interpersonal exchanges, we hypothesized that displays of positive and congruent affect determine members' ratings of leaders in a simulated performance appraisal context. To test the hypotheses, 537 participants viewed videotapes of four male and female leaders giving positive and negative feedback, and with facial expressions of affect that were either congruent or incongruent with the verbal message that they were delivering. Results supported hypotheses that positive and message-congruent leader affect results in more positive member ratings of the leader, assessed using a seven-item measure of members' perceptions of the leader's negotiating latitude. The least positive ratings of negotiating latitude were given when positive feedback was delivered with negative facial affect. (C) 2002 Elsevier Science Inc. All rights reserved.

Emotion and attribution of intentionality in leader-member relationships

In this article, we present a model of emotions and attributions of intentionality within the leader-member relationship. The model is predicated on two central ideas. The first is that leadership is intrinsically an emotional process, where leaders display emotion and attempt to evoke emotion in their members. The second is that leadership is a process of social interaction and is therefore appropriately defined in terms of social, psychological theories such as the attribution theory. Our focus is on the perspective of members, not the leaders. Specifically, members' attributions about their leader's intentions influence how the members evaluate, interpret, and eventually label the leader's influence attempts as either true or pseudo transformational leadership. These attributions are determined by and themselves influence the members' emotions. We describe each of the elements of the model and conclude with a discussion of the implications of the model for theory, research, and practice. (C) 2002 Elsevier Science Inc. All rights reserved.

Interaction between natural and sexual selection during the evolution of mate recognition

The interaction between natural and sexual selection is central to many theories of how mate choice and reproductive isolation evolve, but their joint effect on the evolution of mate recognition has not, to my knowledge, been investigated in an evolutionary experiment. Natural and sexual selection were manipulated in interspecific hybrid populations of Drosophila to determine their effects on the evolution of a mate recognition system comprised of cuticular hydrocarbons (CHCs). The effect of natural selection in isolation indicated that CHCs were costly for males and females to produce. The effect of sexual selection in isolation indicated that females preferred males with a particular CHC composition. However, the interaction between natural and sexual selection had a greater effect on the evolution of the mate recognition system than either process in isolation. When natural and sexual selection were permitted to operate in combination, male CHCs became exaggerated to a greater extent than in the presence of sexual selection alone, and female CHCs evolved against the direction of natural selection. This experiment demonstrated that the interaction between natural and sexual selection is critical in determining the direction and magnitude of the evolutionary response of the mate recognition system.

Evolutionary experiments on mate recognition in the Drosophila serrata species complex

It is becoming increasingly apparent that at least some aspects of the evolution of mate recognition may be amenable to manipulation in evolutionary experiments. Quantitative genetic analyses that focus on the genetic consequences of evolutionary processes that result in mate recognition evolution may eventually provide an understanding of the genetic basis of the process of speciation. We review a series of experiments that have attempted to determine the genetic basis of the response to natural and sexual selection on mate recognition in the Drosophila serrata species complex. The genetic basis of mate recognition has been investigated at three levels: (1) between the species of D. serrata and D. birchii using interspecific hybrids, (2) between populations of D. serrata that are sympatric and allopatric with respect to D. birchii, and (3) within populations of D. serrata. These experiments suggest that it may be possible to use evolutionary experiments to observe important events such as the reinforcement of mate recognition, or the generation of the genetic associations that are central to many sexual selection models.

Interspecific variation in plumage colour among birds: species recognition or light environment?

The traditional explanation for interspecific plumage colour variation in birds is that colour differences between species are adaptations to minimize the risk of hybridization. Under this explanation, colour differences between closely related species of birds represent reproductive character displacement. An alternative explanation is that interspecific variation in plumage colour is an adaptive response to variation in light environments across habitats. Under this explanation, differences in colour between closely related species are a product of selection on signal efficiency. We use a comparative approach to examine these two hypotheses, testing the effects of sympatry and habitat use, respectively, on divergence in male plumage colour. Contrary to the prediction of the Species Isolation Hypothesis, we find no evidence that sympatric pairs of species are consistently more divergent in coloration than are allopatric pairs of species. However, in agreement with the Light Environment Hypothesis, we find significant associations between plumage coloration and habitat use. All of these results remain qualitatively unchanged irrespective of the statistical methodology used to compare reflectance spectra, the body regions used in the analyses, or the exclusion of areas of plumage not used in sexual displays. Our results suggest that, in general, interspecific variation in plumage colour among birds is more strongly influenced by the signalling environment than by the risk of hybridization.

Enhancing the immunogenicity and modulating the fine epitope recognition of antisera to a helical group A streptococcal peptide vaccine candidate from the M protein using lipid-core peptide technology

A conserved helical peptide vaccine candidate from the M protein of group A streptococci, p145, has been described. Minimal epitopes within p145 have been defined and an epitope recognized by protective antibodies, but not by autoreactive T cells, has been identified. When administered to mice, p145 has low immunogenicity. Many boosts of peptide are required to achieve a high antibody titre (> 12 800). To attempt to overcome this low immunogenicity, lipid-core peptide technology was employed. Lipid-core peptides (LCP) consist of an oligomeric polylysine core, with multiple copies of the peptide of choice, conjugated to a series of lipoamino acids, which acts as an anchor for the antigen. Seven different LCP constructs based on the p145 peptide sequence were synthesized (LCP1-->LCP7) and the immunogenicity of the compounds examined. The most immunogenic constructs contained the longest alkyl side-chains. The number of lipoamino acids in the constructs affected the immunogenicity and spacing between the alkyl side-chains increased immunogenicity. An increase in immunogenicity (enzyme-linked immunosorbent assay (ELISA) titres) of up to 100-fold was demonstrated using this technology and some constructs without adjuvant were more immunogenic than p145 administered with complete Freund's adjuvant (CFA). The fine specificity of the induced antibody response differed for the different constructs but one construct, LCP4, induced antibodies of identical fine specificity to those found in endemic human serum. Opsonic activity of LCP4 antisera was more than double that of p145 antisera. These data show the potential for LCP technology to both enhance immunogenicity of complex peptides and to focus the immune response towards or away from critical epitopes.

Genetic constraints on the evolution of mate recognition under natural selection

Field populations of Drosophila serrata display reproductive character displacement in cuticular hydrocarbons (CHCs) when sympatric with Drosophila birchii. We have previously shown that the naturally occurring pattern of reproductive character displacement can be experimentally replicated by exposing field allopatric populations of D. serrata to experimental sympatry with D. birchii. Here, we tested whether the repeated evolution of reproductive character displacement in natural and experimental populations was a consequence of genetic constraints on the evolution of CHCs. The genetic variance-covariance (G) matrices for CHCs were determined for populations of D. serrata that had evolved in either the presence or absence of D. birchii under field and experimental conditions. Natural selection on mate recognition under both field and experimental sympatric conditions increased the genetic variance in CHCs consistent with a response to selection based on rare alleles. A close association between G eigenstructure and the eigenstructure of the phenotypic divergence (D) matrix in natural and experimental populations suggested that G matrix eigenstructure may have determined the direction in which reproductive character displacement evolved during the reinforcement of mate recognition.