Now showing items 21-40 of 8885

    • Structural complexity of the co-chaperone SGTA: a conserved C-terminal region is implicated in dimerization and substrate quality control

      Martínez-Lumbreras, S.; Krysztofinska, E.M.; Thapaliya, A.; Spilotros, A.; Matak-Vinkovic, D.; Salvadori, E.; Roboti, P.; Nyathi, Yvonne; Muench, J.H.; Roessler, M.M.; et al. (2018-07-11)
      Protein quality control mechanisms are essential for cell health and involve delivery of proteins to specific cellular compartments for recycling or degradation. In particular, stray hydrophobic proteins are captured in the aqueous cytosol by a co-chaperone, the small glutamine-rich, tetratricopeptide repeat-containing protein alpha (SGTA), which facilitates the correct targeting of tail-anchored membrane proteins, as well as the sorting of membrane and secretory proteins that mislocalize to the cytosol and endoplasmic reticulum-associated degradation. Full-length SGTA has an unusual elongated dimeric structure that has, until now, evaded detailed structural analysis. The Cterminal region of SGTA plays a key role in binding a broad range of hydrophobic substrates, yet in contrast to the well-characterized N-terminal and TPR domains, there is a lack of structural information on the C-terminal domain. In this study, we present new insights into the conformation and organization of distinct domains of SGTA and show that the C-terminal domain possesses a conserved region essential for substrate processing in vivo. We show that the C-terminal domain region is characterized by α-helical propensity and an intrinsic ability to dimerize independently of the N-terminal domain. Based on the properties of different regions of SGTA that are revealed using cell biology, NMR, SAXS, Native MS, and EPR, we observe that its C-terminal domain can dimerize in the full-length protein and propose that this reflects a closed conformation of the substrate-binding domain. Our results provide novel insights into the structural complexity of SGTA and provide a new basis for mechanistic studies of substrate binding and release at the C-terminal region.
    • Effectiveness of pull-based print advertising with QR codes Role of consumer involvement and advertisement appeal

      Trivedi, Rohitkumar; Teichert, T.; Hardeck, D. (2019-12-12)
      Despite quick response (QR) codes’ prominence, little is known about their embedding in pullbased communications. This study aims to measure QR code effects in print advertising along five different stages of consumer decision making, using advertisement appeals with moderating effects of product category involvement. Data were derived from a German market research initiative with 326,212 consumer evaluations for 792 real print advertisements from 26 product categories. Multinomial logit models were used to investigate the effects of QR code presence on consumer reactions. QR codes steer purchase intention in a low-involvement product category if used alongside an emotional appeal. Advertisements for high-involvement products benefit if QR codes are combined with an overall informational appeal. QR codes do not enhance the persuasive effects of advertisements’ informational appeals in a low-involvement product category. The effects of QR codes on consumers’ responses cannot be analysed in isolation but depend on advertisement context. They interact with advertisements’ informational and emotional appeals and product category involvement. Marketers should not use QR codes indiscriminately but should carefully consider advertisement context. QR codes should be used alongside an emotional appeal if the marketer’s objective is to induce purchase intention in low-involvement settings. Advertisements for high-involvement products need to combine QR codes with an informational appeal. This study highlights the interplay of effects in print advertisements, which are typically considered push-based when they are combined with QR codes as pull-based communications in the digital marketing area.
    • Trust in Organizations

      Costa, Ana-Cristina (Elsevier, 2017)
    • Team Trust

      Costa, Ana-Cristina; Anderson, N.R. (Willey-Blackwell, 2017-03-23)
      This chapter seeks to clarify the definition of trust and its conceptualization specifically at the team or workgroup level, as well as discussing the similarities and differences between interpersonal and team level trust. Research on interpersonal trust has shown that individual perceptions of others trustworthiness and their willingness to engage in trusting behavior when interacting with them are largely history‐dependent processes. Thus, trust between two or more interdependent individuals develops as a function of their cumulative interaction. The chapter describes a multilevel framework with individual, team and organizational level determinants and outcomes of team trust. It aims to clarify core variables and processes underlying team trust and to develop a better understanding of how these phenomena operate in a system involving the individual team members, the team self and the organizational contexts in which the team operates. The chapter concludes by reviewing and proposing a number of directions for future research and future‐oriented methodological recommendations.
    • Trust at Work

      Costa, Ana-Cristina; Ferrin, D.L.; Fulmer, C.A. (SAGE, 2018)
    • Analytical and experimental investigations of dam-break flows in triangular channels with wet-bed conditions

      Wang, B.; Liu, X.; Zhang, J.; Guo, Yakun; Chen, Y.; Peng, Y.; Liu, W.; Yang, S.; Zhang, F. (2020-05-19)
      Based on the method of characteristics, an analytical solution for the one-dimensional shallow-water equations is developed to simulate the instantaneous dam-break flows propagating down a triangular wet bed channel in this study. The internal relationships between the hydraulic properties associated with the dam-break flow are investigated through the comparisons with the well-known analytical solutions for rectangular channels. Meanwhile, laboratory experiments are conducted in a prismatic, horizontal and smooth flume with a triangular cross-section. The non-intrusive digital image processing is applied for obtaining water surface profiles and stage hydrographs. Results show that the dam-break flow propagation depends on the dimensionless parameter defined as the ratio of initial tailwater depth over reservoir head. has significant effect on the dam-break wave in the downstream flooded area. For , the water surface profiles in the reservoir for different at a given time remains similar. For ≥ 0.5, extra negative waves occur in the reservoir, leading to the water surface undulations. Undular bores are generated at the dam site and propagate downstream. Time evolution of dam-break flows under three different reservoir heads is similar for the same . The inception of water surface profile change is earlier when the reservoir head is larger. The analytical model shows satisfactory agreement with the experimental results though some errors exist between the analytical solution and measurements due to the formation of extra negative waves, jet and undular bores. The similarities and discrepancies between the hydraulics in the triangular and rectangular channels are identified analytically in terms of the profiles of water depth, velocity, discharge, bore height and wave-front celerity with . The presented solution could be applied to predict the effect of wet bed condition on the dam-break wave in triangular channels, while laboratory measurement data could be used for validating analytical and numerical models.
    • Numerical simulation of the hydraulic performances and flow pattern of swallow-tailed flip bucket

      Zhang, L.; Zhang, J.; Guo, Yakun; Peng, Y. (2020-05-14)
      In this study, the evolution process of the swallow-tailed flip bucket water nappe entering into the plunge pool is simulated by using the standard 𝑘-𝜀 turbulence model and the volume of fluid method. The effects of the upstream opening width ratio and downstream bucket angle on the flow pattern, the unit discharge distribution and the impact pressure distribution are studied. Based on the numerical results, the inner and outer jet trajectories are proposed by using the data. Results show that the longitudinal stretching length decreases with the increase of the upstream opening width ratio, and increases with the increase of the downstream bucket angle. The water nappe enters the plunge pool in a long strip shape. Thus, the unit discharge distribution of water nappe entry is consistent with the pressure distribution at the plunge pool bottom. The upstream opening width ratio and downstream bucket angle should be chosen as their intermediate values in order to have a uniform discharge distribution and to reduce the pressure peak at the plunge pool floor, which is effectively to avoid instability and destruction of plunge pool floor.
    • Can adults with autism spectrum disorders infer what happened to someone from their emotional response

      Cassidy, S.; Ropar, D.; Mitchell, Peter; Chapman, P. (2014-02)
      Can adults with autism spectrum disorders (ASD) infer what happened to someone from their emotional response? Millikan has argued that in everyday life, others' emotions are most commonly used to work out the antecedents of behavior, an ability termed retrodictive mindreading. As those with ASD show difficulties interpreting others' emotions, we predicted that these individuals would have difficulty with retrodictive mindreading. Sixteen adults with high-functioning autism or Asperger's syndrome and 19 typically developing adults viewed 21 video clips of people reacting to one of three gifts (chocolate, monopoly money, or a homemade novelty) and then inferred what gift the recipient received and the emotion expressed by that person. Participants' eye movements were recorded while they viewed the videos. Results showed that participants with ASD were only less accurate when inferring who received a chocolate or homemade gift. This difficulty was not due to lack of understanding what emotions were appropriate in response to each gift, as both groups gave consistent gift and emotion inferences significantly above chance (genuine positive for chocolate and feigned positive for homemade). Those with ASD did not look significantly less to the eyes of faces in the videos, and looking to the eyes did not correlate with accuracy on the task. These results suggest that those with ASD are less accurate when retrodicting events involving recognition of genuine and feigned positive emotions, and challenge claims that lack of attention to the eyes causes emotion recognition difficulties in ASD.
    • Using other minds as a window onto the world guessing what happened from clues in behaviour

      Pillai, D.; Sheppard, E.; Ropar, D.; Marsh, L.; Pearson, A.; Mitchell, Peter (2014-10)
      It has been proposed that mentalising involves retrodicting as well as predicting behaviour, by inferring previous mental states of a target. This study investigated whether retrodiction is impaired in individuals with Autism Spectrum Disorders (ASD). Participants watched videos of real people reacting to the researcher behaving in one of four possible ways. Their task was to decide which of these four “scenarios” each person responded to. Participants’ eye movements were recorded. Participants with ASD were poorer than comparison participants at identifying the scenario to which people in the videos were responding. There were no group differences in time spent looking at the eyes or mouth. The findings imply those with ASD are impaired in using mentalising skills for retrodiction.
    • Processing of Spontaneous Emotional Responses in Adolescents and Adults with Autism Spectrum Disorders Effect of Stimulus Type

      Cassidy, S.; Mitchell, Peter; Chapman, P.; Ropar, D. (2015-10)
      Recent research has shown that adults with autism spectrum disorders (ASD) have difficulty interpreting others' emotional responses, in order to work out what actually happened to them. It is unclear what underlies this difficulty; important cues may be missed from fast paced dynamic stimuli, or spontaneous emotional responses may be too complex for those with ASD to successfully recognise. To explore these possibilities, 17 adolescents and adults with ASD and 17 neurotypical controls viewed 21 videos and pictures of peoples' emotional responses to gifts (chocolate, a handmade novelty or Monopoly money), then inferred what gift the person received and the emotion expressed by the person while eye movements were measured. Participants with ASD were significantly more accurate at distinguishing who received a chocolate or homemade gift from static (compared to dynamic) stimuli, but significantly less accurate when inferring who received Monopoly money from static (compared to dynamic) stimuli. Both groups made similar emotion attributions to each gift in both conditions (positive for chocolate, feigned positive for homemade and confused for Monopoly money). Participants with ASD only made marginally significantly fewer fixations to the eyes of the face, and face of the person than typical controls in both conditions. Results suggest adolescents and adults with ASD can distinguish subtle emotion cues for certain emotions (genuine from feigned positive) when given sufficient processing time, however, dynamic cues are informative for recognising emotion blends (e.g. smiling in confusion). This indicates difficulties processing complex emotion responses in ASD.
    • Being Sherlock Holmes Can we sense empathy from a brief sample of behaviour

      Wu, W.; Sheppard, E.; Mitchell, Peter (2016-02)
      Mentalizing (otherwise known as ‘theory of mind’) involves a special process that is adapted for predicting and explaining the behaviour of others (targets) based on inferences about targets’ beliefs and character. This research investigated how well participants made inferences about an especially apposite aspect of character, empathy. Participants were invited to make inferences of self‐rated empathy after watching or listening to an unfamiliar target for a few seconds telling a scripted joke (or answering questions about him/herself or reading aloud a paragraph of promotional material). Across three studies, participants were good at identifying targets with low and high self‐rated empathy but not good at identifying those who are average. Such inferences, especially of high self‐rated empathy, seemed to be based mainly on clues in the target's behaviour, presented either in a video, a still photograph or in an audio track. However, participants were not as effective in guessing which targets had low or average self‐rated empathy from a still photograph showing a neutral pose or from an audio track. We conclude with discussion of the scope and the adaptive value of this inferential ability.
    • How Easy is it to Read the Minds of People with Autism Spectrum Disorder?

      Sheppard, E.; Pillai, D.; Wong, G.T-L.; Ropar, D.; Mitchell, Peter (2016-04)
      How well can neurotypical adults’ interpret mental states in people with ASD? ‘Targets’ (ASD and neurotypical) reactions to four events were video-recorded then shown to neurotypical participants whose task was to identify which event the target had experienced. In study 1 participants were more successful for neurotypical than ASD targets. In study 2, participants rated ASD targets equally expressive as neurotypical targets for three of the events, while in study 3 participants gave different verbal descriptions of the reactions of ASD and neurotypical targets. It thus seems people with ASD react differently but not less expressively to events. Because neurotypicals are ineffective in interpreting the behaviour of those with ASD, this could contribute to the social difficulties in ASD.
    • Seven- to 11-Year-Olds' Developing Ability to Recognize Natural Facial Expressions of Basic Emotions

      Kang, K.; Anthoney, L.; Mitchell, Peter (2017-09)
      Being able to recognize facial expressions of basic emotions is of great importance to social development. However, we still know surprisingly little about children’s developing ability to interpret emotions that are expressed dynamically, naturally, and subtly, despite real-life expressions having such appearance in the vast majority of cases. The current research employs a new technique of capturing dynamic, subtly expressed natural emotional displays (happy, sad, angry, shocked, and disgusted). Children aged 7, 9, and 11 years (and adults) were systematically able to discriminate each emotional display from alternatives in a five-way choice. Children were most accurate in identifying the expression of happiness and were also relatively accurate in identifying the expression of sadness; they were far less accurate than adults in identifying shocked and disgusted. Children who performed well academically also tended to be the most accurate in recognizing expressions, and this relationship maintained independently of chronological age. Generally, the findings testify to a well-developed ability to recognize very subtle naturally occurring expressions of emotions.
    • How accurately can other people infer your thoughts - And does culture matter?

      Valanides, C.; Sheppard, E.; Mitchell, Peter (2017-11)
      This research investigated how accurately people infer what others are thinking after observing a brief sample of their behaviour and whether culture/similarity is a relevant factor. Target participants (14 British and 14 Mediterraneans) were cued to think about either positive or negative events they had experienced. Subsequently, perceiver participants (16 British and 16 Mediterraneans) watched videos of the targets thinking about these things. Perceivers (both groups) were significantly accurate in judging when targets had been cued to think of something positive versus something negative, indicating notable inferential ability. Additionally, Mediterranean perceivers were better than British perceivers in making such inferences, irrespective of nationality of the targets, something that was statistically accounted for by corresponding group differences in levels of independently measured collectivism. The results point to the need for further research to investigate the possibility that being reared in a collectivist culture fosters ability in interpreting others’ behaviour.
    • Judging personality from a brief sample of behaviour: detecting where others stand on trait continua

      Wu, W.; Sheppard, E.; Mitchell, Peter (2017-11)
      Trait inferences occur routinely and rapidly during social interaction, sometimes based on scant or fleeting information. In this research, participants (perceivers) made inferences of targets' big‐five traits after briefly watching or listening to an unfamiliar target (a third party) performing various mundane activities (telling a scripted joke or answering questions about him/herself or reading aloud a paragraph of promotional material). Across three studies, when perceivers judged targets to be either low or high in one or more dimensions of the big‐five traits, they tended to be correct, but they did not tend to be correct when they judged targets as average. Such inferences seemed to vary in effectiveness across different trait dimensions and depending on whether the target's behaviour was presented either in a video with audio, a silent video, or just in an audio track—perceivers generally were less often correct when they judged targets as average in each of the big‐five traits across various information channels (videos with audio, silent videos, and audios). Study 3 replicated these findings in a different culture. We conclude with discussion of the scope and the adaptive value of this trait inferential ability.
    • Seeing the world through others minds Inferring social context from behaviour

      Teoh, Y.; Wallis, E.; Stephen, I.D.; Mitchell, Peter (2017-02)
      Past research tells us that individuals can infer information about a target’s emotional state and intentions from their facial expressions (Frith & Frith, 2012), a process known as mentalising. This extends to inferring the events that caused the facial reaction (e.g. Pillai, Sheppard, & Mitchell, 2012; Pillai et al., 2014), an ability known as retrodictive mindreading. Here, we enter new territory by investigating whether or not people (perceivers) can guess a target’s social context by observing their response to stimuli. In Experiment 1, perceivers viewed targets’ responses and were able to determine whether these targets were alone or observed by another person. In Experiment 2, another group of perceivers, without any knowledge of the social context or what the targets were watching, judged whether targets were hiding or exaggerating their facial expressions; and their judgments discriminated between conditions in which targets were observed and alone. Experiment 3 established that another group of perceivers’ judgments of social context were associated with estimations of target expressivity to some degree. In Experiments 1 and 2, the eye movements of perceivers also varied between conditions in which targets were observed and alone. Perceivers were thus able to infer a target’s social context from their visible response. The results demonstrate an ability to use other minds as a window onto a social context that could not be seen directly.
    • Dissociating neural signatures of mental state retrodiction and classification based on facial expressions

      Kang, K.; Schneider, D.; Schweinberger, S.R.; Mitchell, Peter (2018-08-22)
      Posed facial expressions of actors have often been used as stimuli to induce mental state inferences, in order to investigate 'Theory of Mind' processes. However, such stimuli make it difficult to determine whether perceivers are using a basic or more elaborated mentalizing strategy. The current study used as stimuli covert recordings of target individuals who viewed various emotional expressions, which caused them to spontaneously mimic these expressions. Perceivers subsequently judged these subtle emotional expressions of the targets: in one condition ('classification') participants were instructed to classify the target's expression (i.e. match it to a sample) and in another condition ('retrodicting') participants were instructed to retrodict (i.e. infer which emotional expression the target was viewing). When instructed to classify, participants showed more prevalent activations in event-related brain potentials (ERPs) at earlier and mid-latency ERP components N170, P200 and P300-600. By contrast, when instructed to retrodict participants showed enhanced late frontal and fronto-temporal ERPs (N800-1000), with more sustained activity over the right than the left hemisphere. These findings reveal different cortical processes involved when retrodicting about a facial expression compared to merely classifying it, despite comparable performance on the behavioral task.
    • Modelling the executive components involved in processing false belief and mechanical/intentional sequences

      Tsuji, H.; Mitchell, Peter (2019-06)
      To understand the executive demands of the false-belief (FB) task relative to an alternative theory-of-mind (or mechanical causality) task, picture sequencing, the present study used path analyses. One hundred and sixty-six children between 3 and 6 years old completed the FB and picture-sequencing tasks, three executive function tasks (updating, inhibition, and shifting), and the receptive language test. The model with the best fit indicated that FB performance had a direct contribution from shifting of attention and inhibitory control, which was independent of the significant contribution made by picture sequencing. This model indicates that FB inference requires more executive processing than picture sequencing, which is used as an alternative task to measure theory of mind. Statement of contribution What is already known on this subject? The majority of researchers use the false-belief task to assess mentalizing ability in young children. Sources of information used in various different mentalizing tasks require different levels of cognitive demand. Many executive functions (EFs) are involved in children's judgements of false belief. What does this study add? A statistical model was created to compare processing requirements of false-belief and picture-sequencing tasks. The model supported the claim that the false-belief task involves considerably more than just mentalizing. Shifting the focus of attention was an EF that was found to be a key component of performance in the false-belief task.
    • Accurate inferences of others thoughts depend on where they stand on the empathic trait continuum

      Wu, W.; Mitchell, Peter (2019-10)
      This research explores the possibility that a person's (perceiver's) prospects of making a correct inference of another person's (target's) inner states depends on the personal characteristics of the target, potentially relating to how readable they are. Twenty-seven targets completed the Empathy Quotient (EQ) and were classified as having low, average or high EQ. They were unobtrusively videoed while thinking of an event of happiness, gratitude, anger and sadness. After observing targets thinking of such a past event, fifty-two perceivers (participants) in Study 1 were asked to infer what the target was thinking, and fifty perceivers in Study 2 were asked to rate the target's expression – positive or negative. Results suggested that (1) perceivers' accuracy in detecting targets' thoughts depended on which EQ group the target belonged to, and (2) target readability is not a proxy measure for level of target expressiveness. In other words, something about EQ status renders targets more or less easy to read in a way that is not simply explained by expressive people being more readable. We conclude with discussion of the importance of the target's trait as well as situation they experience in determining how accurately a perceiver might infer their inner states.
    • Is there a link between autistic people being perceived unfavorably and having a mind that is difficult to read?

      Alkhaldi, R.S.; Sheppard, E.; Mitchell, Peter (2019-10)
      The link between autistic people having a mind that is difficult to read (by neurotypical participants) and being perceived unfavorably was investigated. Videoed Autistic and neurotypical targets from Sheppard et al. (PLOS ONE 7(11):e49859, 2016) were scored for how readable they were when reacting to a distinctive greeting from the experimenter. These videos were presented to new groups of perceivers (neurotypical adults) who rated neurotypical targets more socially favorably than autistic targets irrespective of whether details of the experimenter’s greeting were concealed (Study 1) or disclosed (Study 2). Target readability correlated with ratings of target favorability (r = .58 and r = .63), independent of target diagnosis. Perceivers might rate targets unfavorably because they experience difficulty reading them, though other interpretations of the correlation are also possible.