1,720,959 research outputs found
Pesticide management practices among rural market gardening farmers near Harare, Zimbabwe
No full textIn 2014, we carried out a survey in Chinamhora and Chihota communal lands on the outskirts of Harare city, with the aim of understanding pesticide management practices among market gardening farmers. The farmers grew vegetables that mostly included tomatoes, cabbages, rape, cucumbers, onions and carrots, and they used mainly organophosphates and pyrethroids to control pests. A questionnaire was administered to 119 male heads of households across both study areas. The questionnaire contained 13 closed-ended questions in three sections: source and quality of pesticides, handling and use, and storage and disposal of pesticides used to protect crops. The study identified numerous gaps related to the handling of pesticides. Although the quality of labelling and packaging can largely identify the quality of pesticide, most of the farmers (77.3%) could not distinguish between genuine and counterfeit pesticides; approximately half (47.9%) of the farmers were not concerned about expiry dates; 27% did not observe post-spray periods; and 63% did not take precautions according to colour-coding of the pesticides. Also of concern were the large numbers of farmers who were not using protective coveralls (54.3%); a substantial number who were not using knapsacks for spraying (21.8%); poor storage of the pesticides, as shown by the variation in storage facilities; the use of empty pesticide containers for domestic purposes (20.2%); and lack of strict adherence to recommended dose levels, with some farmers (28.6%) merely estimating the dilution of pesticides. Training through outreach programmes is recommended. Significance:
• Identifies gaps in the way pesticides are used and stored by rural market gardening farmers.
• Highlights the need for government agricultural extension workers to hold regular workshops for farmers.
• Indicates the need for government ministries to monitor counterfeit pesticides
African potato ( Hypoxis Spp): Diversity and comparison of the phytochemical profiles and cytotoxicity evaluation of four Zimbabwean species
No full textThe Hypoxis corm has a catalogue of medicinal uses and also serves as a source of food. Most scientific research on Hypoxis has centred on Hypoxis hemerocallidea
although many other species are exploited medicinally. Hypoxis corms look similar and this has resulted in different species being prescribed and sold as the same
species raising important public health issues of the efficacy and quality of the medicines sold. The aim of this study was to investigate and compare the phytochemical profiles and cytotoxicity of Hypoxis hemerocallidea, Hypoxis rigidula, Hypoxis galpinii and Hypoxis obtusa. Corm methanolic extracts of the four species were qualitatively screened for different phytochemicals following standard methods.
Tests indicated presence of terpenoids, saponins, cardiac glycosides, tannins and reducing sugars and negative for alkaloids, flavonoids and anthraquinones in the four
Hypoxis species. Cytotoxic effects of the plants were assessed through Brine shrimp lethality (BSL) bioassay. LC50 values ranged from 6.3 -409 mg/ml showing that the plants are non toxic
Phytochemical and analgesic activity of root crude extracts of Dicoma niccolifera wild (Asteraceae)
No full textThe study aimed at evaluating the phytochemical profile and anti-nociception activity of root crude extracts of D. niccolifera, a plant commonly used to alleviate painful conditions by local communities. Standard phytochemical screening tests revealed presence of tannins, alkaloids, flavonoids, terpenoids, reducing sugars, cardiac glycosides and anthraquinones. Anti-nociception was assessed using the hot plate model on Swiss Albino mice. Mice intraperitoneally injected with root crude extract showed that the D. niccolifera root extract had analgesic activity by taking longer to react to the thermal stimulus than the control group. The extract higher doses of 500 and 1000mg/kg showed peak mean latency times of 2.39 and 2.12 seconds respectively. These latency times were found to be significantly different (p<0.05) from the control. The anti-nociception activity may be attributed to the phenolic compounds in the extract. The study validates the use of D. niccolifera in managing painful conditions
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
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