109 research outputs found

    The Adoption of Formal HRM Practices by Small Firms in Africa

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    Several studies in the extant literature indicate that there is a significant relationship between Human Resource Management (HRM) practices and firm performance (Arthur, 1994; MacDuffie, 1995; Huselid, 1995; Guest et al. 2003). Huselid (1995) found that investments in high performance work systems were associated with greater productivity and corporate financial performance. The study by Guest et al. (2003) suggests a "positive association between the use of more HR practices and lower labour turnover and higher profitability".  Although a large majority of the studies were carried out in large companies, some support has been found for a positive association between HRM practices and performance in small and medium sized firms (Kotey & Slade, 2005). Key words: HRM, small firms, practice

    ANTICANCER ACTIVITY OF NATURAL HEALTH PRODUCTS (DANDELION ROOT & LONG PEPPER EXTRACTS); EXTENSIVE STUDY OF EFFICACY AND MECHANISM OF ACTION

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    The incidence of cancer worldwide is continuously on the rise, and the death toll associated with cancer, is constantly increasing. Available cancer therapy is unable to combat this ever-changing disease, and the severe side effects associated with various forms of therapy, indicate a serious need for the development of more effective and safer alternatives to currently available treatment. The use of natural health products in disease treatment has contributed to the development of over 75% of available chemotherapy. In this thesis, we study the potential anti-cancer effect of two natural health products, dandelion root and long pepper extracts. The major objectives of this work were to; - Evaluate the efficacy and mechanism of these extracts in various cancer models, - Assess any potential safety and toxicity issues associated with the use of these extracts and, - De-convolute and identify the pharmacologically active components that contribute to the anti-cancer activity of these extract Using standard biochemical and morphological assays, the induction of various programmed cell death processes was assessed, following treatment in cancer and non-cancer cell models, as well as in animal models. The results obtained indicate that dandelion root and long pepper extracts were efficacious in selectively inducing apoptosis and pro-death autophagy in various cancer cell models. Dandelion root extract rapidly activated the extrinsic pathway of apoptosis, a situation that was crucial to apoptosis induction in leukemia cells, but not required for colorectal cancer cells. Gene expression analysis showed that dandelion root extract efficiently targets multiple pathways to promote its anti-cancer activity. The generation of reactive oxygen species by long pepper extract treatment, appeared to be partially responsible for the induction of apoptosis in cancer cells. Furthermore, the lack of toxicity observed in animal models, on oral administration regimens of dandelion root and long pepper extracts, further confirm the safety of these extracts. Interestingly, the same regimen of oral administration of these extracts was successful in halting the growth of colon tumors in xenograft models. These findings provide scientific validation concerning the safe and effective use of natural health products as non-toxic and potentially more efficacious forms of therapy

    The Efficacy of Dandelion Root Extract in Inducing Apoptosis in Drug-Resistant Human Melanoma Cells

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    Notoriously chemoresistant melanoma has become the most prevalent form of cancer for the 25–29 North American age demographic. Standard treatment after early detection involves surgical excision (recurrence is possible), and metastatic melanoma is refractory to immuno-, radio-, and most harmful chemotherapies. Various natural compounds have shown efficacy in killing different cancers, albeit not always specifically. In this study, we show that dandelion root extract (DRE) specifically and effectively induces apoptosis in human melanoma cells without inducing toxicity in noncancerous cells. Characteristic apoptotic morphology of nuclear condensation and phosphatidylserine flipping to the outer leaflet of the plasma membrane of A375 human melanoma cells was observed within 48 hours. DRE-induced apoptosis activates caspase-8 in A375 cells early on, demonstrating employment of an extrinsic apoptotic pathway to kill A375 cells. Reactive Oxygen Species (ROS) generated from DRE-treated isolated mitochondria indicates that natural compounds in DRE can also directly target mitochondria. Interestingly, the relatively resistant G361 human melanoma cell line responded to DRE when combined with the metabolism interfering antitype II diabetic drug metformin. Therefore, treatment with this common, yet potent extract of natural compounds has proven novel in specifically inducing apoptosis in chemoresistant melanoma, without toxicity to healthy cells

    Public schools' characteristics and teacher turnover in Oman.

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    Teachers are the backbone of the educational systems and their turnover may threaten the whole educational system in any country. In Oman, teacher turnover is a neglected area of study and this article may help in shedding some light on teacher turnover phenomenon in Oman. The purpose of this study is to investigate the influence of school characteristics (e.g., school size, gender, time-shift, education type, and school location) on the turnover intentions of teachers in public schools in Oman. Survey questionnaires were used to collect data from 214 public schools in Oman. 142 schools from all educational regions in Oman were participated in this study. Data analyses tools for this study were descriptive statistics such as mean and standard deviation, in addition to independents t-test and analysis of variance. The study revealed that teacher intentions to transfer to other schools are influenced by almost all the studied school characteristics. Policy makers and human resource recruiters in Ministry of Education should be aware of teachers’ preferences for certain schools to avoid teachers’ shortage in non-preferred schools. Further studies about the influence of school time-shift and teachers’ intentions to quit or transfer are needed to affirm the results in this study. This is the first study about the influence of school characteristics on teacher turnover in public schools in Oman. Thus, the value of this study stems from the uniqueness of this study which may serve as an eye opening indicator about teacher turnover in Oman

    Novel Analogue of Colchicine Induces Selective Pro-Death Autophagy and Necrosis in Human Cancer Cells

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    Colchicine, a natural product of Colchicum autumnae currently used for gout treatment, is a tubulin targeting compound which inhibits microtubule formation by targeting fast dividing cells. This tubulin-targeting property has lead researchers to investigate the potential of colchicine and analogs as possible cancer therapies. One major study conducted on an analogue of allocolchicine, ZD 6126, was halted in phase 2 clinical trials due to severe cardio-toxicity associated with treatment. This study involves the development and testing of novel allocolchicine analogues that hold non-toxic anti-cancer properties. Currently we have synthesized and evaluated the anti-cancer activities of two analogues; N-acetyl-O-methylcolchinol (NSC 51046 or NCME), which is structurally similar to ZD 6126, and (S)-3,8,9,10-tetramethoxyallocolchicine (Green 1), which is a novel derivative of allocolchicine that is isomeric in the A ring. NSC 51046 was found to be non-selective as it induced apoptosis in both BxPC-3 and PANC-1 pancreatic cancer cells and in normal human fibroblasts. Interestingly, we found that Green 1 was able to modestly induce pro-death autophagy in these pancreatic cancer cells and E6-1 leukemia cells but not in normal human fibroblasts. Unlike colchicine and NSC 51046, Green 1 does not appear to affect tubulin polymerization indicating that it has a different molecular target. Green 1 also caused increased reactive oxygen species (ROS) production in mitochondria isolated from pancreatic cancer cells. Furthermore, in vivo studies revealed that Green 1 was well tolerated in mice. Our findings suggest that a small change in the structure of colchicine has apparently changed the mechanism of action and lead to improved selectivity. This may lead to better selective treatments in cancer therapy

    Organizational-level study of the impact of past turnover on future turnover in the Sultanate of Oman.

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    Turnover phenomena attracted researchers from all over the world for generations. Most of this research was directed towards turnover antecedents with a few scattered conceptual and empirical studies related to turnover consequences. The purpose of this study is to investigate the impact of past turnover on future turnover in public organizations, in addition to test the mediation role of organizational climate in this relationship. Public schools as separate identities were the best choice as the study sample. Data were collected through questionnaires from 142 public schools in all educational regions in Oman. Two-step structural equation modeling approach, and nested model comparison were used for data analysis. The results revealed that: (1) past turnover predicts future turnover, significantly; (2) organizational climate fails to mediate this relationship. The study added to the body of knowledge by confirming Staw’s hypothesis relating past turnover to future turnover in the Omani context. Human resource professionals and educational administration practitioners may play an important role in decreasing future turnover by tackling and decreasing past turnover, in addition to improving the relationship climate in schools. The study is limited to public schools in Oman and further studies about turnover consequences in the Arabic context are needed to affirm the results

    Advances in the Research and Development of Natural Health Products as Main Stream Cancer Therapeutics

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    Natural health products (NHPs) are defined as natural extracts containing polychemical mixtures; they play a leading role in the discovery and development of drugs, for disease treatment. More than 50% of current cancer therapeutics are derived from natural sources. However, the efficacy of natural extracts in treating cancer has not been explored extensively. Scientific research into the validity and mechanism of action of these products is needed to develop NHPs as main stream cancer therapy. The preclinical and clinical validation of NHPs would be essential for this development. This review summarizes some of the recent advancements in the area of NHPs with anticancer effects. This review also focuses on various NHPs that have been studied to scientifically validate their claims as anticancer agents. Furthermore, this review emphasizes the efficacy of these NHPs in targeting the multiple vulnerabilities of cancer cells for a more selective efficacious treatment. The studies reviewed here have paved the way for the introduction of more NHPs from traditional medicine to the forefront of modern medicine, in order to provide alternative, safer, and cheaper complementary treatments for cancer therapy and possibly improve the quality of life of cancer patients

    Efficient Induction of Extrinsic Cell Death by Dandelion Root Extract in Human Chronic Myelomonocytic Leukemia (CMML) Cells

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    BACKGROUND: Chronic Myelomonocytic Leukemia (CMML) is a heterogeneous disease that is not only hard to diagnose and classify, but is also highly resistant to treatment. Available forms of therapy for this disease have not shown significant effects and patients rapidly develop resistance early on in therapy. These factors lead to the very poor prognosis observed with CMML patients, with median survival duration between 12 and 24 months after diagnosis. This study is therefore centered around evaluating the selective efficacy of a natural extract from dandelion roots, in inducing programmed cell death in aggressive and resistant CMML cell lines. METHODOLOGY/PRINCIPAL FINDINGS: To confirm the induction of programmed cell death in three human CMML cell lines, nuclear condensation and externalization of the phosphatidylserine, two main characteristics of apoptosis, were detected using Hoechst staining and annexin-V binding assay. The induction of another mode of cell death, autophagy, was determined using a monodansylcadaverine (MDC) stain, to detect the formation of autophagy vacuoles. The results from this study indicate that Dandelion Root Extract (DRE) is able to efficiently and selectively induce apoptosis and autophagy in these cell lines in a dose and time dependent manner, with no significant toxicity on non-cancerous peripheral blood mononuclear cells. More importantly, we observed early activation of initiator caspase-8, which led to mitochondrial destabilization and the induction of autophagy, suggesting that DRE acts through the extrinsic pathway of apoptosis. The inability of DRE to induce apoptosis in dominant-negative FADD cells, confirms the mechanism of action of DRE in in vitro models of CMML. CONCLUSION: The results from this study indicate that natural products, in particular Dandelion Root Extract, have great potential, as non-toxic and effective alternatives to conventional modes of chemotherapy available today

    Multi-dimensional knowledge of malaria among Nigerian caregivers: implications for insecticide-treated net use by children

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    Abstract Background Poor malaria knowledge can negatively impact malaria control programmes. This study evaluates knowledge distribution in the domains of causation, transmission, vulnerability, symptoms, and treatment of malaria. It assesses the association between a caregiver’s knowledge about malaria and ownership and use of insecticide-treated nets (ITNs) by children. Methods Some 1939 caregivers of young children were recruited through a school-based survey in two Nigerian states. A 20-item, multi-dimensional survey instrument was developed and used to rank each caregiver’s knowledge in five dimensions (cause, transmission, vulnerability, symptoms, treatment of malaria). Scores for each domain were used to create an aggregate knowledge score for each caregiver. The outcome measures were ITN ownership, and ITN use the night and week before the study. Regression models were used to evaluate the relationship between caregiver’s knowledge (individual domains and aggregate score) and ownership and use of ITN after controlling for likely confounders. Results The main predictor of ITN use was ITN ownership (r = 0.653; p < 0.001); however, ownership only explains 43 % of variance in net use. Total knowledge index for the study population was significantly associated with both ITN ownership (r = 0.122; p = 0.001) and use (r = 0.095; p = 0.014). The spectrum of caregiver’s knowledge of malaria and its causes captured in the various domains was, however, found to be poor. Fifty percent of the respondents knew that malaria is transmitted by female mosquitoes and 65 % still believe that too much exposure to the sun is a risk factor for malaria. Knowledge of populations most vulnerable to malaria (83 %) and knowledge of malaria transmission (32 %) were the domains with the highest and lowest average correct answers. Conclusions There is a need to improve ITN coverage in Nigeria as ITN ownership was associated with ITN use. Additionally, treating knowledge as a multi-dimensional phenomenon revealed that a lot of misperceptions about malaria still exist. Distribution of ITNs through the public/private sector may need to be augmented with tailored behavioural change communication to dispel myths and improve the multi-dimensional knowledge of malaria in the local population.http://deepblue.lib.umich.edu/bitstream/2027.42/134666/1/12936_2016_Article_1557.pd
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