1,720,955 research outputs found
The implications of chemical contamination in food: a surveillance and probabilistic human health risk assessment of heavy metal accumulation in food
No full textThesis (Doctor of Philosophy Environmental Health) -- Central University of Technology, 2022Food safety risks remain paramount in designing effective detection and surveillance systems. The globalisation of trade and environmental factors play a significant role in safeguarding against emerging and existing food safety risks from the food production chain to the consumer level. Targeted and routine human health risk assessments are critical in measuring exposure amongst populations. The study of chemical toxicity in the food industry is fundamental and needs to be supported by rigorous toxicological studies. This will improve the quality of food products offered by the food industry and ultimately benefit consumers. Contaminants such as heavy metals can cause adverse human health effects and thus need regulation through adequate legislative interventions and proper monitoring standards supported by curated scientific data. The study aimed to review the key drivers of chemical pollutants influencing contamination in food and their applicable surveillance methods. Then, measure the heavy metal contamination in the Bloemfontein fresh-produce markets. In this study, the first step in the research process included the extensive review of literature which aimed at establishing foundational information based on existing research. This was achieved through a rigorous literature review which framed the research questions and objectives. This study applied an experimental research strategy and encompassed a quantitative research method. Trace metal assessment was carried out in eighteen vegetable samples of six different vegetable types namely: Spinacia oleracea, Beta vulgaris, Daucus carota, Allium, Brassica oleracea, and Solanum Lycopersicum. The Inductively Coupled Plasma Optical Emissions Spectrometer (ICP-OES) was used to determine the concentration of heavy metals in selected vegetables, then measured against the Codex Alimentarius standards for metals in foodstuffs. In addition, probabilistic human health risk assessments were conducted to determine the hazard quotient and hazard index for the non-carcinogenic effects of the selected vegetables. Literature enquiry revealed that the food industry has been gravitating towards using mechanised systems with intelligent algorithms to meet the demand for safe food more cost-effectively. Therefore, the adoption of intelligent systems has shown significant benefits in controlling potential contaminants, thus reducing the burden of disease and economic loss. Findings further revealed that bioremediation studies should be intensified to cover a broad spectrum of contaminants such as heavy metals, pesticides, fertilizers, antibiotics, and microbial contaminants. As such, it should also consider the remediation of biological contaminants at the points of food production, processing, and supply chain. The concentration of cadmium in spinach, tomato, cabbage, and onion was reported to exceed the maximum permissible limits set by the Codex Alimentarius for metals in foodstuffs. However, the estimated daily intake and hazard quotients were less than a unit. Moreover, the hazard index shows that none of the studied metals (As, Cu, Pb, Cd) had values greater than 1. This demonstrated that there are no anticipated adverse health effects. The Target Hazard Quotient (THQ) in order of exposure for all vegetable types was ranked as follows: As > Cd > Cu > Pb. Based on the findings of this study, precautions should be taken to control the accumulation of cadmium in spinach, tomato, cabbage, and onions due to potentially adverse effects. Most developing nations rely on agricultural produce; therefore, there must be investments in sustainable technologies and research to understand and predict the leading food contaminants. Future studies will incorporate more essential and nonessential metals in the analysis. Additionally, vegetable samples will be collected directly from agricultural land which is the beginning of the food production chain. Toxicological studies are known to be sensitive and difficult due to timelines. This creates a challenge regarding the correlation between chemicals and human health outcomes through epidemiological investigations to assess the risks. To date, no significant study apart from laboratory-controlled research yields any substantial results concerning human exposure and health outcomes. Therefore, there are still gaps regarding the types of chemical toxicants and their subsequent human health effects. This calls for rapid policy adoption on persistent pollutants due to the lack of immediate results of human health deterioration
Communicable disease surveillance by environmental health practitioners : Ekurhuleni mMetropolitan Municipality
Get PDFM.Tech. (Environmental Health)Abstract: Communicable diseases are a long-standing global concern. This study described Environmental Health practices relating to communicable disease surveillance in the Ekurhuleni Metropolitan Municipality (EMM). This research is driven by the need for Environmental Health Practitioners (EHPs) to comply with the regulations defining the scope of practice for Environmental Health. Section 5 outlines the role of EHPs in the surveillance of communicable diseases. The extent to which EHPs investigate the existence of communicable disease and the actual practices these EHPs follow, is a fundamental question in public health. Therefore, the specific objective of this study is to assess the knowledge, evaluate the practices, determine the EHPs’ perceptions and finally, recommend standard operating procedures (SOPs) for communicable disease surveillance (CDS). This study is descriptive in nature and encompasses quantitative methods. The total population includes 95 EHPs, consisting of senior EHPs and Environmental Health Managers. Data was collected through a structured self-administered questionnaire which was hand delivered to the interested participants. Based on the results, there are no standard operating procedures regarding the surveillance of communicable diseases, which could possibly lead to inconsistent practices within the EMM. The level of knowledge contributed to EHPs perception of communicable disease surveillance and their performance of this function. Based on the results, there is a likelihood that provisions of the regulations are not optimally adhered to. These results may facilitate the establishment of a comprehensive approach in addressing CDS. This approach should guide policy formulation by the national government and aid in CDS through training and establishment of SOPs
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Get PDF“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Get PDFWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Dispelling the Myths Behind First-author Citation Counts
Get PDFWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
koamabayili/VECTRON-author-checklist: VECTRON author checklist
No full textWe have done our best to complete the author checklist relating to the use of animals in the hut study. Note that the objective for the hut study was to evaluate the IRS treatment applications for residual efficacy against Anopheles mosquitoes, including the local An. coluzzii mosquito population. Cows were only used to attract mosquitoes into the huts and no tests were carried out directly on the cows. The author checklist is intended for use with studies where experiments are carried out on animals, which is why we have had such difficulty in completing this for the hut study, as many of the questions do not relate to how the cows were used
Author-wise bibliometric analysis based on entropy.
No full textAuthor-wise bibliometric analysis based on entropy.</p
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