228 research outputs found

    Seeing the world through others’ minds: inferring social context from behaviour

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    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

    Eigenvalue sensitivity minimisation for robust pole placement by the receptance method

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    The problem of robust pole placement in active structural vibration control by the method of receptance is considered in this paper. Expressions are derived for the eigenvalue sensitivities to parametric perturbations, which are subsequently minimised to improve performance robustness of the control of a dynamical system. The described approach has application to a vibrating system where variations are present due to manufacturing and material tolerances, damages and environment variabilities. The closed-loop eigenvalue sensitivities are expressed as a linear function of the velocity and displacement feedback gains, allowing their minimisation with carefully calculated feedback gains. The proposed algorithm involves curve fitting perturbed frequency response functions, FRFs, using the rational fraction polynomial method and implementation of a polynomial fit to the individual estimated rational fraction coefficients. This allows the eigenvalue sensitivity to be obtained entirely from structural FRFs, which is consistent with the receptance method. This avoids the need to evaluate the M,C,K matrices which are typically obtained through finite element modelling, that produces modelling uncertainty. It is also demonstrated that the sensitivity minimisation technique can work in conjunction with the pole placement and partial pole placement technique using the receptance method. To illustrate the working of the proposed algorithm, the controller is first implemented numerically and then experimentally

    Evidence of exposure to Rickettsia felis in Australian patients

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    AbstractRickettsia felis is an emerging zoonosis, causing flea-borne spotted fever (FBSF). Serological diagnosis is typically confounded by cross-reactivity with typhus group rickettsiae and prior to the development of specific serological methods, cases of FBSF in Australia were misdiagnosed.Patient sera tested between August 2010 and December 2013 and known to be seropositive to R. typhi by immunofluorescence antibody testing (IFAT) were subsequently retested against R. felis using an R. felis-specific IFAT. Sera of 49 patients were of a sufficient quality to be included in re-analysis. A classification of FBSF and murine typhus (MT) was attributed to fourteen and seven patients respectively, based on a minimum four-fold higher antibody titre to R. felis than to R. typhi and vice versa. Twenty-eight patients were classified as indeterminate for either R. felis or R. typhi (antibody titres within two-fold of one another).Historically, it is likely that Australian patients clinically ill with FBSF were misdiagnosed. It is important that medical practitioners consider FBSF as part of their differential diagnoses, and obtain relevant history with regard to patient's exposure to domestic pets and their fleas. Australian microbiology diagnostic laboratories should include serological testing for R. felis as part of the diagnostic panel for febrile diseases. Veterinarians are encouraged to increase their awareness of this emerging zoonosis and advocate flea control in pets

    Recruitment of Antigen Presenting Cells to Skin Draining Lymph Node From HPV16E7-Expressing Skin Requires E7-Rb Interaction.

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    "High-risk" human papillomaviruses (HPV) infect keratinocytes of squamous epithelia. The HPV16E7 protein induces epithelial hyperplasia by binding Rb family proteins and disrupting cell cycle termination. Murine skin expressing HPV16E7 as a transgene from a keratin 14 promoter (K14.E7) demonstrates epithelial hyperplasia, dysfunctional antigen presenting cells, ineffective antigen presentation by keratinocytes, and production of immunoregulatory cytokines. Furthermore, grafted K14.E7 skin is not rejected from immunocompetent non-transgenic recipient animals. To establish the contributions of E7, of E7-Rb interaction and of epithelial hyperplasia to altered local skin immunity, K14.E7 skin was compared with skin from K14.E7 mice heterozygous for a mutant Rb unable to bind E7 (K14.E7xRbΔL/ΔL mice), that have normoplastic epithelium. Previously, we demonstrated that E7-speicfic T cells do not accumulate in K14.E7xRbΔL/ΔL skin grafts. Here, we further show that K14.E7xRbΔL/ΔL skin, like K14.E7 skin, is not rejected by immunocompetent non-transgenic animals. There were fewer CD11b+ antigen presenting cells in skin draining lymph nodes from animals recipient of K14.E7xRbΔL/ΔL grafts, when compared with animals receiving K14.E7 grafts or K5mOVA grafts. Maturation of migratory DCs derived from K14.E7xRbΔL/ΔL grafts found in the draining lymph nodes is significantly lower than that of K14.E7 grafts. Surprisingly, K14.E7xRbΔL/ΔL keratinocytes, unlike K14.E7 keratinocytes, are susceptible to E7 directed CTL-mediated lysis in vitro. We conclude that E7-Rb interaction and its associated epithelial hyperplasia partially contribute to the suppressive local immune responses in area affected by HPV16E7 expression

    Extracellular superoxide dismutase (SOD3) regulates oxidative stress at the vitreoretinal interface

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    Oxidative stress is a pathogenic feature in vitreoretinal disease. However, the ability of the inner retina to manage metabolic waste and oxidative stress is unknown. Proteomic analysis of antioxidants in the human vitreous, the extracellular matrix opposing the inner retina, identified superoxide dismutase-3 (SOD3) that localized to a unique matrix structure in the vitreous base and cortex. To determine the role of SOD3, Sod3-/- mice underwent histological and clinical phenotyping. Although the eyes were structurally normal, at the vitreoretinal interface Sod3-/- mice demonstrated higher levels of 3-nitrotyrosine, a key marker of oxidative stress. Pattern electroretinography also showed physiological signaling abnormalities within the inner retina. Vitreous biopsies and epiretinal membranes collected from patients with diabetic vitreoretinopathy (DVR) and a mouse model of DVR showed significantly higher levels of nitrates and/or 3-nitrotyrosine oxidative stress biomarkers suggestive of SOD3 dysfunction. This study analyzes the molecular pathways that regulate oxidative stress in human vitreous substructures. The absence or dysregulation of the SOD3 antioxidant at the vitreous base and cortex results in increased oxidative stress and tissue damage to the inner retina, which may underlie DVR pathogenesis and other vitreoretinal diseases

    Optical Coherence Tomography Angiography Findings in Dengue-Related Maculopathy:A Case Report

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    The ophthalmic manifestations of dengue fever include a visually impairing maculopathy, where patients are left with a central or paracentral relative scotoma. The authors present a case of a 26-year-old female patient returning from Thailand with unilateral reduction in visual acuity and a central scotoma associated with dengue fever. The authors report the use of the optical coherence tomography angiography (OCTA) as a noninvasive imaging platform to demonstrate its value in showing the persistent changes corresponding to the functional central scotoma in dengue-related maculopathy, which often cannot be visualized clinically or by standard OCT and fundus fluorescein angiography

    Diagnostic techniques for inflammatory eye disease: past, present and future: a review

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    Investigations used to aid diagnosis and prognosticate outcomes in ocular inflammatory disorders are based on techniques that have evolved over the last two centuries have dramatically evolved with the advances in molecular biological and imaging technology. Our improved understanding of basic biological processes of infective drives of innate immunity bridging the engagement of adaptive immunity have formed techniques to tailor and develop assays, and deliver targeted treatment options. Diagnostic techniques are paramount to distinguish infective from non-infective intraocular inflammatory disease, particularly in atypical cases. The advances have enabled our ability to multiplex assay small amount of specimen quantities of intraocular samples including aqueous, vitreous or small tissue samples. Nevertheless to achieve diagnosis, techniques often require a range of assays from traditional hypersensitivity reactions and microbe specific immunoglobulin analysis to modern molecular techniques and cytokine analysis. Such approaches capitalise on the advantages of each technique, thereby improving the sensitivity and specificity of diagnoses. This review article highlights the development of laboratory diagnostic techniques for intraocular inflammatory disorders now readily available to assist in accurate identification of infective agents and appropriation of appropriate therapies as well as formulating patient stratification alongside clinical diagnoses into disease groups for clinical trials
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