751 research outputs found

    Anxiety and Hysterical Symptoms in Schizophrenia

    Get PDF
    The existence of both anxiety and hysterical symptoms have been described in schizophrenic populations. Various explanations exist. The issue of whether such symptoms represent discrete clinical entities or are intrinsic to the schizophrenic process, requires further research.Keywords: Schizophrenia, Anxiety, HystericalSouth African Psychiatry Review - November 200

    Antigen Cross-Priming of Cell-Associated Proteins is Enhanced by Macroautophagy within the Antigen Donor Cell

    Get PDF
    Phagocytosis of dying cells constitutes an important mechanism of antigen capture for the cross-priming of CD8+ T cells. This process has been shown to be critical for achieving tumor and viral immunity. While most studies have focused on the mechanisms inherent in the dendritic cell that account for exogenous antigen accessing MHC I, several recent reports have highlighted the important contribution made by the antigen donor cell. Specifically, the cell stress and cell death pathways that precede antigen transfer are now known to impact cross-presentation and cross-priming. Herein, we review the current literature regarding a role for macroautophagy within the antigen donor cell. Further examination of this point of immune regulation is warranted and may contribute to a better understanding of how to optimize immunotherapy for treatment of cancer and chronic infectious disease

    Le " réseau " comme méthode d'approche des rapports sociaux dans les organisations

    Get PDF
    L'emploi de plus en plus répandu du terme de « réseau » dans les milieux scientifiques n'est pas sans relation avec les problèmes concrets de nos sociétés. Un exemple est donné à propos de la santé publique. Des mouvements de réseaux sont nécessaires pour réaliser ce qui est prévu dans le système. Ces réseaux peuvent être distingués en réseaux d'information, réseaux de consultation et réseaux d'instigation

    Thermal and colour data fusion for people detection and tracking

    Get PDF
    Thesis (MSc)--Stellenbosch University, 2014.ENGLISH ABSTRACT: In this thesiswe approach the problem of tracking multiple people individually in a video sequence. Automatic object detection and tracking is non-trivial as humans have complex and mostly unpredictable movements, and there are sensor noise and measurement uncertainties present. We consider traditional object detection methods and decide to use thermal data for the detection step. This choice is supported by the robustness of thermal data compared to colour data in unfavourable lighting conditions and in surveillance applications. A drawback of using thermal data is that we lose colour information, since the sensor interprets the heat emission of the body rather than visible light. We incorporate a colour sensor which is used to build features for each detected object. These features are used to help determine correspondences in detected objects over time. A problem with traditional blob detection algorithms, which typically consist of background subtraction followed by connected-component labelling, is that objects can appear to split or merge, or disappear in a few frames. We decide to add ‘dummy’ blobs in an effort to counteract these problems. We refrain from making any hard decisions with respect to the blob correspondences over time, and rather let the system decide which correspondences are more probable. Furthermore, we find that the traditional Markovian approach of determining correspondences between detected blobs in the current time step and only the previous time step can lead to unwanted behaviour. We rather consider a sequence of time steps and optimize the tracking across them. We build a composite correspondence model and weigh each correspondence according to similarity (correlation) in object features. All possible tracks are determined through this model and a likelihood is calculated for each. Using the best scoring tracks we then label all the detections and use this labelling as measurement input for a tracking filter. We find that the window tracking approach shows promise even though the data we us for testing is of poor quality and noisy. The system struggles with cluttered scenes and when a lot of dummy nodes are present. Nonetheless our findings act as a proof of concept and we discuss a few future improvements that can be considered.AFRIKAANSE OPSOMMING: In hierdie tesis benader ons die probleemomverskeiemense individueel in ’n video-opname op te spoor en te volg. Outomatiese voorwerp-opsporing en -volging is nie-triviaal, want mense het komplekse en meestal onvoorspelbare bewegings, en daar is sensor-ruis en metingonsekerhede teenwoordig. Ons neem tradisionele voorwerp-opsporing metodes in ag en besluit om termiese data te gebruik vir die opsporingstap. Hierdie keuse word ondersteun deur die robuustheid van termiese data in vergelyking met kleur data in ongunstige lig-kondisies en in sekuriteitstoepassings. Die nadeel van die gebruik van termiese data is dat ons kleur inligting verloor, aangesien die sensor die hitte vrystelling van die liggaam interpreteer, eerder as sigbare lig. Ons inkorporeer ’n kleur-sensor wat gebruik word om die kenmerke van elke gevolgde voorwerp te bou. Hierdie kenmerke word gebruik om te help om ooreenkomste tussen opgespoorde voorwerpe te bepaal met die verloop van tyd. ’n Probleem met die tradisionele voorwerp-opsporing algoritmes, wat tipies bestaan uit agtergrond- aftrekking gevolg deur komponent-etikettering, is dat dit kan voorkom asof voorwerpe verdeel of saamsmelt, of verdwyn in ’n paar rame. Ons besluit om ‘flous’-voorwerpe by te voeg in ’n poging om hierdie probleme teen te werk. Ons weerhou om enige konkrete besluite oor opgespoorde voorwerpe se ooreenkomste met die verloop van tyd te maak, en laat die stelsel eerder toe om te besluit watter ooreenkomste meer waarskynlik is. Verder vind ons dat die tradisionele Markoviaanse benadering vir die bepaling van ooreenkomste tussen opgespoorde voorwerpe in die huidige tydstap en die vorige een kan lei tot ongewenste gedrag. Ons oorweeg eerder ’n reeks van tydstappe, of ’n venster, en optimeer die volg van voorwerpe oor hulle. Ons bou ’n saamgestelde ooreenstemmingsmodel en weeg elke ooreenstemming volgens die ooreenkoms (korrelasie) tussen voorwerpe se kenmerke. Alle moontlike spore word deur hierdie model bepaal en ’n waarskynlikheid word bereken vir elkeen. Die spore met die beste tellings word gebruik om al die opsporings te nommeer, en hierdie etikettering word gebruik as meting-inset vir ’n volgingsfilter. Ons vind dat die venster-volg benadering belowend vaar selfs al is die invoerdata in ons toetse van swak gehalte en ruiserig. Die stelsel sukkel met besige tonele en wanneer baie flous-voorwerpe teenwoordig is. Tog dien ons bevindinge as ’n bewys van konsep en ons bespreek ’n paar verbeterings wat in die toekoms oorweeg kan word

    What patients with bipolar disorder and major depressive disorder perceive as adverse life events precipitating a current major depressive episode

    Get PDF
    BACKGROUND : Adverse life events (ALEs) as precipitants of a major depressive episode (MDE) have been the subject of many studies. These studies indicate an increase in ALEs in the 6 months preceding an MDE. OBJECTIVES : The study examined what participants, suffering from major depressive disorder (MDD) or bipolar disorder (BD), perceived as the precipitating ALE of a current MDE. The severity and categories of ALEs were compared between these two patient groups. METHODS : Consenting, adult inpatients were sourced from Weskoppies Hospital, Steve Biko Academic Hospital, Tshwane District Hospital, Denmar Psychiatric Hospital and Vista Clinic in the Pretoria area. A semi-structured questionnaire was used to obtain demographic data and the diagnosis. Information regarding the course of the disorder, including the number of previous MDEs and the age at which the first MDE occurred, was also obtained. The perceived precipitating ALE was detailed for each participant. A severity value referred to as a Life Change Unit Score (LCU score), based on the Recent Life Changes Questionnaire (RLCQ) by Miller and Rahe, was then assigned to each participant’s perceived precipitant. RESULTS : Of the 64 participants, 12.7 % were experiencing a first MDE. In those participants who had experienced prior episodes the average number (standard deviation (SD)) of previous episodes was 3.86 (2.46). The mean approximate age (SD) at first onset of an MDE was 24.81 (10.9) years. The BD group had significantly more previous MDEs than the MDD group. Although the average LCU scores were higher in the BD group than the MDD group this did not reach statistical significance. Therefore, this study could not find a difference in the severity of the perceived precipitants between the BD group and MDD group. However, when the LCU scores were analysed within subcategories of the RLCQ, it was found that participants with BD perceived significantly more problems associated with the workplace as precipitants of a current MDE than individuals with MDD. CONCLUSION : Most participants could link an ALE to the onset of a current MDE. The study did not find a differential response to ALEs between patients with BD and MDD. The severity of the social precipitants did not differ significantly between the two groups. The notion of a ‘kindling effect’ could not be supported by the outcome of this study. Because some study participants experienced ALEs not accounted for by the RLCQ, a more comprehensive assessment instrument may be more appropriate for similar studies.http://www.sajp.org.za/index.php/sajphb201
    corecore