24 research outputs found

    Studies of encephalitozoonosis in vervet monkeys (Cercopithecus pygerythrus) orally inoculated with spores of Encephalitozoon cuniculi isolated from dogs (Canis familiaris)

    Get PDF
    Encephalitozoonosis was induced in 35 of 38 vervet monkeys (Cercopithecus pygerythrus). They were either directly (orally) inoculated with Encephlitozoon cuniculi or indirectly exposed to this protozoan parasite. Cell-culture-grown spores of E. cuniculi, isolated from the kidneys of dogs with natural, fatal disease, were administered orally to 29 of these monkeys. Another 5 were exposed in utero by orally infecting pregnant females, and 3 were exposed to horizontal infection by nursing infected infants. Only one was given an intravenous inoculation of spores. The disease was induced in non-gravid and late-pregnant adults, immunocompetent infants, and in infants that were immunologically compromised by parenteral steroid administration, as well as in one infant that was immunologically immature because of its premature birth. The effects of age, dosage, post-inoculation (PI) interval, passage level of the parasite in cell culture and immunological status of the host were correlated with macroscopical and microscopical lesions. The experimentally induced infection was confirmed either by reisolation of the parasite in cell culture or by observation of spores in tissue sections. Both confirmatory methods were supported by serological examination. Reisolation of the organism in primary cell culture prepared from kidneys usually resulted in more frequent isolates and larger yields of spores from infants than from adult vervets. Infection with E. cuniculi invariably induced subclinical disease. Based on histology, lesions were minimal to moderately severe, depending on age, PI interval, and immunological status of the host. Alimentary tract infections were seen histologically as early as three days Pl. Subsequently, infections resulted in detectable lesions most consistently in the liver, kidneys and brain. Lesions in these organs were generally granulomatous and were similar to those found in canine encephalitozoonosis. In addition, multifocal interstitial pneumonitis and myocarditis as well as vasculitis and perivasculitis were seen in other tissues and organs. Infants had more severe and more widespread lesions than adults. Although lesions and spores were still present in the brain of one immunocompetent infant 36 weeks after initial infection, the disease in immunocompetent infants and adults is thought to be self-limiting. However, infection may persist. Immunological depression favoured increased growth and multiplication of the organism, and resulted in detection of more spores within inflammatory lesions as well as more intracellular colonies of the organism that were free of inflammatory reaction. Long-term growth of E. cuniculi in cell culture did not appear to alter its pathogenicity, nor did varying the numbers of spores (2 x 10⁶-3 x 10¹º) in the inoculum appear to influence the severity of the disease. Horizontal infection was readily established, and vertical transmission was demonstrated. Results of this study suggest that spores of E. cuniculi shed by dogs may become agents of latent infection and disease in vervets, and probably other nonhuman primates as well. It further seems probable that these spores may also be potential agents of latent zoonosis of man.The articles have been scanned in colour with a HP Scanjet 5590; 600dpi. Adobe Acrobat XI Pro was used to OCR the text and also for the merging and conversion to the final presentation PDF-format.lmchunu2014mn201

    Light and electron microscopical studies on canine encephalitozoonosis : cerebral vasculitis

    Get PDF
    Brain lesions in 2 natural cases of canine encephalitozoonosis were studied by light and electron microscopy. Granulomatous reactions, associated with small vessels and capillaries, partly originated from extensive perithelial cell proliferation which ultimately produced the epithelioid cell component. Diffuse glial reactions apparently occurred in relation to the vasculitis. Lymphoid cells infiltrated the epithelioid and glial cell inflammation. Encephalitozoon in all its reproductive stages was identified as the aetiological agent, and ultrastructurally differentiated from Nosema on the basis that a single nucleus was observed. Viable organisms were present only within endothelial cells. Macrophages containing dead spores were usually seen around parasitized vessels and, less frequently, in them neuropil. Organisms, whether viable or non-viable, were never seen extracellularly at the ultrastructural level. Selected histochemical stains and electron microscopy were used to differentiate between viable and non-viable spores. Vasculitis is demonstrated as the underlying lesion of canine encephalitozoonosism affecting the brain and is suggested to be the basic factor in the pathogenesis of this disease.The articles have been scanned in colour with a HP Scanjet 5590; 300dpi. Adobe Acrobat XI Pro was used to OCR the text and also for the merging and conversion to the final presentation PDF-format

    Being (im)polite: A forensic linguistic approach to interpreting a hate speech case

    Get PDF
    In a hate speech case a court might have to determine whether a person’s words were hurtful or harmful. Would it be possible to determine whether words are hurtful or harmful by using linguistics? This article offers a linguistic perspective on a court’s interpretation of the Equality Act in a hate speech case and focuses on speech acts and politeness. If the speech acts of a verbal exchange are studied and the levels of politeness are gauged, a court would be able to affi rm the hurtfulness or harmfulness of the speaker’s words. The article begins with a brief discussion on the potential role of the linguist in a courtroom; this is followed by a summary of the facts of the case. Then the court case is analysed and discussed in terms of speech acts and politeness. By employing principles in pragmatics the author reaches the same conclusion as the court.Afrikaans and Theory of Literatur

    The MeerKAT Galaxy Cluster Legacy Survey: I. Survey overview and highlights

    Get PDF
    Please abstract in the article.The South African Radio Astronomy Observatory (SARAO), the National Research Foundation (NRF), the National Radio Astronomy Observatory, US National Science Foundation, the South African Research Chairs Initiative of the DSI/NRF, the SARAO HCD programme, the South African Research Chairs Initiative of the Department of Science and Innovation.http://www.aanda.orghj2022Physic

    The SARAO MeerKAT 1.3 GHz Galactic Plane Survey

    Get PDF
    We present the SARAO MeerKAT Galactic Plane Survey (SMGPS), a 1.3 GHz continuum survey of almost half of the Galactic Plane (251○ ≤l ≤ 358○ and 2○ ≤l ≤ 61○ at |b| ≤ 1 5). SMGPS is the largest, most sensitive and highest angular resolution 1 GHz survey of the Plane yet carried out, with an angular resolution of 8″ and a broadband RMS sensitivity of ∼10–20 μJy beam−1. Here we describe the first publicly available data release from SMGPS which comprises data cubes of frequency-resolved images over 908–1656 MHz, power law fits to the images, and broadband zeroth moment integrated intensity images. A thorough assessment of the data quality and guidance for future usage of the data products are given. Finally, we discuss the tremendous potential of SMGPS by showcasing highlights of the Galactic and extragalactic science that it permits. These highlights include the discovery of a new population of non-thermal radio filaments; identification of new candidate supernova remnants, pulsar wind nebulae and planetary nebulae; improved radio/mid-IR classification of rare Luminous Blue Variables and discovery of associated extended radio nebulae; new radio stars identified by Bayesian cross-matching techniques; the realisation that many of the largest radio-quiet WISE H II region candidates are not true H II regions; and a large sample of previously undiscovered background H I galaxies in the Zone of Avoidance

    Classification of rainwater harvesting technologies

    No full text

    Current recovery for the RWG‐based method of moments

    No full text
    corecore