1,720,961 research outputs found
Does Ivermectin Pollute the Surroundings of Swine Farms?
No full text: Pharmaceuticals are emerging environmental pollutants, with macrocyclic lactones like ivermectin raising concerns due to their widespread use and persistence. This study investigated ivermectin residues in intensive swine farms in Emilia-Romagna, Italy, focusing on treated sows' faeces and environmental samples. Two farms using ivermectin and a control farm without antiparasitic drugs were studied. Faecal, slurry, soil, and wastewater samples were collected at three treatment points: before, and 1 and 10 days post-treatment. Ivermectin was administered either orally or by injection and analysed via liquid chromatography-tandem mass spectrometry. Faecal residues varied significantly with administration route: orally treated sows had higher concentrations in faeces shortly after treatment (median = 930.25 μg kg-1) than injected sows (median = 14.84 μg kg-1). However, 10 days post-treatment, injected sows exhibited higher residue levels in faeces, indicating different excretion patterns. Soil samples fertilised with farm slurry contained ivermectin residues, sometimes exceeding ecotoxicological thresholds for non-target species like dung beetles and earthworms, with the highest concentration reaching 39.23 μg kg-1. No residues above detection limits were found in slurry or wastewater, likely due to ivermectin's hydrophobicity and dilution. The findings underscore the environmental risks of ivermectin use in swine farming and emphasise the need for sustainable drug management. Broader studies are necessary to refine residue distribution patterns and improve environmental guidelines, particularly for other livestock systems and soil types, to ensure ecological sustainability
Evaluation of environmental residues of ivermectin produced by swine farms
No full textIn recent years, interest in ecotoxicology has increased, especially regarding pharmaceutical residues. The toxic effect of environmental residues of ivermectin is proven in several species. Those residues may represent a possible threat to non-target organisms, among which fish and some arthropods, who suffer serious effects when in contact with the lowest doses of the drug (33.3 PPB in dung beetle 1). In this study, our aim was to follow the route of ivermectin from the animal (feces) to the sewage, ending in the soil, and to understand if the concentrations reached in the soil were capable of causing the toxic effects reported in the literature. The same number of samples were collected from two swine farms in Emilia Romagna, Italy: an intensive and an extensive organic farm, which served as the negative control. We analyzed fecal samples from the rectal ampoule of sows one day after subcutaneous treatment (300 μg per kilogram of body weight), and samples of sewage from collection tanks and soil at the time of fertilization. An analytical method recently published was used for the extraction and purification of samples 2. The method was then adapted and validated for LC/MS/MS analysis to reach PPT concentrations. The limit of detection (LOD) was 150 PPT and the limit of quantification (LOQ) was 300 PPT in the extract. Doramectin, a macrocyclic lactone like ivermectin, was used as the process standard. The samples were concentrated to the fourth or eighth power to measure the analyte in feces, sewage, and soil. The results were interpreted using a calibration curve, with intercept values, indicating excellent linearity (R2>0.999). The measured levels in the intensive farm samples were 156-589 PPB in feces, 327-674 PPT in sewage, and 150-500 PPT in soil. Even if ivermectin in feces reaches concentrations measurable in PPB, the dilution provoked by sewage stocking and distribution on the fields for fertilization may considerably reduce the environmental risk. Ivermectin was not detected in samples from the organic farm, confirming that the antiparasitic drug was not in use at the farm. These preliminary results suggest that ivermectin residues could be irrelevant to cause toxic effects on non-target species. Moreover, further studies and analysis will be necessary to deepen the knowledge of the impact of ivermectin on the swine farm
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
Quantitative determination of tetracyclines in medicated feed for food-producing animals by HPLC–DAD
No full textTetracyclines are a group of antibiotic substances largely administered through medicated feed to control diseases in food-producing animals. Fine dosing of antibiotics contained in medicated feed is crucial for the success of the treatment as well as minimising potential threats such as the spread of antimicrobial resistance and the transfer of antibiotic residues in food. A rapid analytical method based on HPLC with diode array detection (HPLC–DAD) was developed to quantify oxytetracycline, chlortetracycline and doxycycline in medicated feed. The reported method underwent in-house validation and was found to be suitable for the quantification of three target tetracyclines within the concentration range of 40–1000 mg kg−1 in official routine analysis. The method was applied to 103 official samples in the framework of the Italian National Plan on animal feed during the years 2021–2023 and nine non-compliant concentrations were identified in swine and fish feed samples
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