12 research outputs found

    Book-to-market ratio and returns on the JSE

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    Many firm-specific attributes or characteristics are understood to be proxies for what Fama and French (1992: p428) refer to as “the unnamed sources of risk”. Perhaps the most notorious of these is the size of the firm or its market value, first documented by Banz (1981). The relationship between size and average returns has become known as the “size effect”.KIM201

    Do exchange rates follow random walks? A variance ratio test of the Zambian foreignexchange market

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    The random-walk hypothesis in foreign-exchange rates market is one of the most researched areas, particularly in developed economies. However, emerging markets in sub-Saharan Africa have received little attention in this regard. This study applies Lo and MacKinlay’s (1988) conventional variance ratio test and Wright’s (2000) non-parametric ranks- and signs-based variance ratio tests to examine the validity of the random-walk hypothesis in the Zambian foreign-exchange market. The study utilises daily nominal United States dollar/Zambian kwacha (USD/ZMK) exchange-rate returns for data from August 2003 to December 2012. Both types of variance ratio tests reject the random-walk hypothesis over the data span. The implication is that technical and fundamental analysis can help traders and other investors to earn higher-than-average market returns.Key words: variance ratio tests, random-walk hypothesis, exchange rates, marketefficienc

    Natural and Vaccine-Mediated Immunity to Salmonella Typhimurium is Impaired by the Helminth Nippostrongylus brasiliensis

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    The impact of exposure to multiple pathogens concurrently or consecutively on immune function is unclear. Here, immune responses induced by combinations of the bacterium Salmonella Typhimurium (STm) and the helminth Nippostrongylus brasiliensis (Nb), which causes a murine hookworm infection and an experimental porin protein vaccine against STm, were examined. Mice infected with both STm and Nb induced similar numbers of Th1 and Th2 lymphocytes compared with singly infected mice, as determined by flow cytometry, although lower levels of secreted Th2, but not Th1 cytokines were detected by ELISA after re-stimulation of splenocytes. Furthermore, the density of FoxP3+ T cells in the T zone of co-infected mice was lower compared to mice that only received Nb, but was greater than those that received STm. This reflected the intermediate levels of IL-10 detected from splenocytes. Co-infection compromised clearance of both pathogens, with worms still detectable in mice weeks after they were cleared in the control group. Despite altered control of bacterial and helminth colonization in co-infected mice, robust extrafollicular Th1 and Th2-reflecting immunoglobulin-switching profiles were detected, with IgG2a, IgG1 and IgE plasma cells all detected in parallel. Whilst extrafollicular antibody responses were maintained in the first weeks after co-infection, the GC response was less than that in mice infected with Nb only. Nb infection resulted in some abrogation of the longer-term development of anti-STm IgG responses. This suggested that prior Nb infection may modulate the induction of protective antibody responses to vaccination. To assess this we immunized mice with porins, which confer protection in an antibody-dependent manner, before challenging with STm. Mice that had resolved a Nb infection prior to immunization induced less anti-porin IgG and had compromised protection against infection. These findings demonstrate that co-infection can radically alter the development of protective immunity during natural infection and in response to immunization

    A comparison of earnings per share and dividends per share as explanatory variables for share price.

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    Ekonomiese En BestuurswetenskappeOndernemingsbestuurPlease help us populate SUNScholar with the post print version of this article. It can be e-mailed to: [email protected]

    Does the ‘Liverpool Care Pathway’ facilitate an improvement in quality of care for dying cancer patients?

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    Background: The Liverpool Care Pathway for the Dying Patient (LCP) aims to transfer hospice principles of care for dying patients to other health-care sectors. This post-bereavement survey explored the LCP’s effectiveness in improving quality of care for cancer patients.methods: Postal self-completion questionnaires were sent to 778 next-of-kin to consecutive deceased patients who had died an ‘expected’ cancer death in a hospice and acute tertiary hospital.Results: Following exclusions (n=53), 255 of the 725 next-of-kin agreed to participate (35.2% response rate). Overall hospice participants reported the best quality of care, and hospital participants, for whom care was not supported by the LCP, reported the worst quality of care. Multivariate analysis showed the hospice was an independent predictor for patients being treated with dignity (OR 8.46) and receiving adequate family support (OR 7.18) (P<0.0001). Care supported by the LCP and the hospital specialist palliative care team were both associated with good family support, but neither was an independent predictor.Conclusions: From the bereaved relatives’ perspective, within the hospital, the LCP is effective in improving specific aspects of care, such as symptom control for dying patients. Further improvement is required, however, to attain the hospice standard of care
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