164 research outputs found

    Fake people, real effects : the presence of virtual onlookers can impair performance and learning

    Get PDF
    Can effects of social influence be elicited in virtual contexts, and if so, under which conditions can they be observed? Answering these questions has theoretical merit, as the answers can help broaden our understanding of the interaction mechanisms described by social psychology. The increasing popularity of immersive media in training applications, however, has made these questions of practical significance. Virtual reality (VR), in particular, is a weapon of choice in designing training and education simulations, as it can be used to generate highly realistic characters and environments. As a consequence, it is key to understand under which circumstances virtual ‘others’ can facilitate or impede performance and – especially – learning. In this study, we investigated the impact of virtual onlookers on an adapted Serial Reaction Time (SRT) task that was presented in VR. In each trial, participants responded to a series of spherical stimuli by tapping them with handheld controllers when they lit up. Depending on the experiment block, the sequence order was either the permutation of a fixed order (and therefore predictable given the first stimulus), or fully random (and therefore unpredictable). Participants were divided into three groups (audience variable), depending on the environment in which the task was set: a group without onlookers (none condition), a group with a computer-generated audience (CGI condition), and a group being watched by a prerecorded audience (filmed condition). Results showed that the presence of a virtual audience can hamper both overall performance and learning, particularly when the audience appears more realistic. This study further reinforces the notion that the effects of social influence transcend the physical presence of others, but rather extend to virtual audiences

    Oxidative Stress and NF-κB signaling are involved in LPS induced pulmonary dysplasia in chick embryos

    Get PDF
    Inflammation or dysbacteriosis-derived lipopolysaccharides (LPS) adversely influence the embryonic development of respiratory system. However, the precise pathological mechanisms still remain to be elucidated. In this study, we demonstrated that LPS exposure caused lung maldevelopment in chick embryos, including higher embryo mortality, increased thickness of alveolar gas exchange zone, and accumulation of PAS+ immature pulmonary cells, accompanied with reduced expression of alveolar epithelial cell markers and lamellar body count. Upon LPS exposure, pulmonary cell proliferation was significantly altered and cell apoptosis was inhibited as well, indicating a delayed progress of pulmonary development. LPS treatment also resulted in reduced CAV-1 expression and up-regulation of Collagen I, suggesting increased lung fibrosis, which was verified by Masson staining. Moreover, LPS induced enhanced Nrf2 expression in E18 lungs, and the increased reactive oxygen species (ROS) production was confirmed in MLE-12 cells in vitro. Antioxidant vitamin C restored the LPS induced down-regulation of ABCA3, SP-C and GATA-6 in MLE-12 cells. Furthermore, LPS induced activation of NF-κB signaling in MLE-12 cells, and the LPS-induced decrease in SP-C expression was partially abrogated by blocking NF-κB signaling with Bay-11-7082. Bay-11-7082 also inhibited LPS-induced increases of ROS and Nrf2 expression. Taken together, we have demonstrated that oxidative stress and NF-κB signaling are involved in LPS induced disruption of pulmonary cell development in chick embryos

    Ecological and Evolutionary Benefits of Temperate Phage: What Does or Doesn't Kill You Makes You Stronger

    Get PDF
    Infection by a temperate phage can lead to death of the bacterial cell, but sometimes these phages integrate into the bacterial chromosome, offering the potential for a more long-lasting relationship to be established. Here we define three major ecological and evolutionary benefits of temperate phage for bacteria: as agents of horizontal gene transfer (HGT), as sources of genetic variation for evolutionary innovation, and as weapons of bacterial competition. We suggest that a coevolutionary perspective is required to understand the roles of temperate phages in bacterial populations

    Dynamic interactions between the ground heat exchanger and environments in earth–air tunnel ventilation of buildings

    Get PDF
    Earth–air tunnel ventilation is an energy efficient method of preheating or cooling of supply air to abuilding. The purposes of this study are to investigate the performance of earth–air heat exchangersunder varying soil and atmosphere conditions and the interactions between the heat exchanger andenvironments. A computer program has been developed for simulation of the thermal performance of anearth–air heat exchanger for preheating and cooling of supply air, taking account of dynamic variationsof climatic, load and soil conditions. The program solves equations for coupled heat and moisture transferin soil with boundary conditions for convection, radiation and evaporation/condensation that vary withthe climate both at the soil top surface and inside the heat exchanger. The importance of dynamic inter-actions between the heat exchanger, soil and atmosphere is illustrated from the comparison of the heattransfer rates through the heat exchanger. The predicted heat transfer rate varies with operating time anddecreases along the passage of air in the heat exchanger. Neglecting the interactions would significantlyover-predict the heat transfer rate and the amount of over-prediction increases with operating time

    Emergence of Variability in Isogenic Escherichia coli Populations Infected by a Filamentous Virus

    Get PDF
    The spread of epidemics not only depends on the average number of parasites produced per host, but also on the existence of highly infectious individuals. It is widely accepted that infectiousness depends on genetic and environmental determinants. However, even in clonal populations of host and viruses growing in homogeneous conditions, high variability can exist. Here we show that Escherichia coli cells commonly display high differentials in viral burst size, and address the kinetics of emergence of such variability with the non-lytic filamentous virus M13. By single-cell imaging of a virally-encoded fluorescent reporter, we monitor the viral charge distribution in infected bacterial populations at different time following infection. A mathematical model assuming autocatalytic virus replication and inheritance of bacterial growth rates quantitatively reproduces the experimental distributions, demonstrating that deterministic amplification of small host inhomogeneities is a mechanism sufficient to explain large and highly skewed distributions. This mechanism of amplification is general and may occur whenever a parasite has an initial phase of exponential growth within its host. Moreover, it naturally reproduces the shift towards higher virulence when the host is experimenting poor conditions, as observed commonly in host-parasite systems

    Interferon and Biologic Signatures in Dermatomyositis Skin: Specificity and Heterogeneity across Diseases

    Get PDF
    BACKGROUND: Dermatomyositis (DM) is an autoimmune disease that mainly affects the skin, muscle, and lung. The pathogenesis of skin inflammation in DM is not well understood. METHODOLOGY AND FINDINGS: We analyzed genome-wide expression data in DM skin and compared them to those from healthy controls. We observed a robust upregulation of interferon (IFN)-inducible genes in DM skin, as well as several other gene modules pertaining to inflammation, complement activation, and epidermal activation and differentiation. The interferon (IFN)-inducible genes within the DM signature were present not only in DM and lupus, but also cutaneous herpes simplex-2 infection and to a lesser degree, psoriasis. This IFN signature was absent or weakly present in atopic dermatitis, allergic contact dermatitis, acne vulgaris, systemic sclerosis, and localized scleroderma/morphea. We observed that the IFN signature in DM skin appears to be more closely related to type I than type II IFN based on in vitro IFN stimulation expression signatures. However, quantitation of IFN mRNAs in DM skin shows that the majority of known type I IFNs, as well as IFN g, are overexpressed in DM skin. In addition, both IFN-beta and IFN-gamma (but not other type I IFN) transcript levels were highly correlated with the degree of the in vivo IFN transcriptional response in DM skin. CONCLUSIONS AND SIGNIFICANCE: As in the blood and muscle, DM skin is characterized by an overwhelming presence of an IFN signature, although it is difficult to conclusively define this response as type I or type II. Understanding the significance of the IFN signature in this wide array of inflammatory diseases will be furthered by identification of the nature of the cells that both produce and respond to IFN, as well as which IFN subtype is biologically active in each diseased tissue

    The feasibility of a randomised controlled trial of physiotherapy for adults with joint hypermobility syndrome

    Get PDF
    © Queen’s Printer and Controller of HMSO 2016. Background: Joint hypermobility syndrome (JHS) is a heritable disorder associated with laxity and pain in multiple joints. Physiotherapy is the mainstay of treatment, but there is little research investigating its clinical effectiveness. Objectives: To develop a comprehensive physiotherapy intervention for adults with JHS; to pilot the intervention; and to conduct a pilot randomised controlled trial (RCT) to determine the feasibility of conducting a future definitive RCT. Design: Patients’ and health professionals’ perspectives on physiotherapy for JHS were explored in focus groups (stage 1). A working group of patient research partners, clinicians and researchers used this information to develop the physiotherapy intervention. This was piloted and refined on the basis of patients’ and physiotherapists’ feedback (stage 2). A parallel two-arm pilot RCT compared ‘advice’ with ‘advice and physiotherapy’ (stage 3). Random allocation was via an automated randomisation service, devised specifically for the study. Owing to the nature of the interventions, it was not possible to blind clinicians or patients to treatment allocation. Setting: Stage 1 – focus groups were conducted in four UK locations. Stages 2 and 3 – piloting of the intervention and the pilot RCT were conducted in two UK secondary care NHS trusts. Participants: Stage 1 – patient focus group participants (n = 25, three men) were aged > 18 years, had a JHS diagnosis and had received physiotherapy within the preceding 12 months. The health professional focus group participants (n = 16, three men; 14 physiotherapists, two podiatrists) had experience of managing JHS. Stage 2 – patient participants (n = 8) were aged > 18 years, had a JHS diagnosis and no other musculoskeletal conditions causing pain. Stage 3 – patient participants for the pilot RCT (n = 29) were as for stage 2 but the lower age limit was 16 years. Intervention: For the pilot RCT (stage 3) the advice intervention was a one-off session, supplemented by advice booklets. All participants could ask questions specific to their circumstances and receive tailored advice. Participants were randomly allocated to ‘advice’ (no further advice or physiotherapy) or ‘advice and physiotherapy’ (an additional six 30-minute sessions over 4 months). The physiotherapy intervention was supported by a patient handbook and was delivered on a one-to-one patient–therapist basis. It aimed to increase patients’ physical activity through developing knowledge, understanding and skills to better manage their condition. Main outcome measures: Data from patient and health professional focus groups formed the main outcome from stage 1. Patient and physiotherapist interview data also formed a major component of stages 2 and 3. The primary outcome in stage 3 related to the feasibility of a future definitive RCT [number of referrals, recruitment and retention rates, and an estimate of the value of information (VOI) of a future RCT]. Secondary outcomes included clinical measures (physical function, pain, global status, self-reported joint count, quality of life, exercise self-efficacy and adverse events) and resource use (to estimate cost-effectiveness). Outcomes were recorded at baseline, 4 months and 7 months. Results: Stage 1 – JHS is complex and unpredictable. Physiotherapists should take a long-term holistic approach rather than treating acutely painful joints in isolation. Stage 2 – a user-informed physiotherapy intervention was developed and evaluated positively. Stage 3 – recruitment to the pilot RCT was challenging, primarily because of a perceived lack of equipoise between advice and physiotherapy. The qualitative evaluation provided very clear guidance to inform a future RCT, including enhancement of the advice intervention. Some patients reported that the advice intervention was useful and the physiotherapy intervention was again evaluated very positively. The rate of return of questionnaires was low in the advice group but reasonable in the physiotherapy group. The physiotherapy intervention showed evidence of promise in terms of primary and secondary clinical outcomes. The advice arm experienced more adverse events. The VOI analysis indicated the potential for high value from a future RCT. Such a trial should form the basis of future research efforts. Conclusion: A future definitive RCT of physiotherapy for JHS seems feasible, although the advice intervention should be made more robust to address perceived equipoise and subsequent attrition. Trial registration: Current Controlled Trials ISRCTN29874209. Funding: This project was funded by the National Institute for Health Research (NIHR) Health Technology Assessment programme and will be published in full in Health Technology Assessment; Vol. 20, No. 47. See the NIHR Journals Library website for further project information
    • …
    corecore