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Persistance of illegal drugs in bovine manure
No full textOral or parenteral livestock drugs can be detected unmodified or as metabolites in animal dejections (urines and/or faeces). During manure maturation and before its disposal on cultivated lands, drugs present in cattle dejections can undergo a degradation, most of all due to the presence of faecal bacteria. The degradation level depends on the chemical structure of the different compounds. The general purpose of this work is to evaluate if manure can be a useful matrix to detect the presence of forbidden drugs in animal production, so to become a cheap and quick method of analysis.
Considering the compounds banned in European Directive 96/23/EC group A and in attachment IV of Reg. CEE 2377/90, some of them have been chosen, based on positive cases frequency in later years, to select those of most interest for cattle husbandry. A bibliographic research has been performed on these compounds, to analyze their metabolic characteristics and to find out the best analytical methods to check these substances during screening and confirmatory analysis.
Methods have been improved for screening analysis, using immunoassay techniques with sensitivity more or less up to ng/g. Generally we have adapted kits ELISA, already used in urine or in other tissues, to detect these compounds in manure. We optimized in manure matrix HPLC MS-MS methods for compounds where kit ELISA could not be used and to confirmatory analysis.
Afterwards, the degradation kinetics of substances in manure has been evaluated in a 4 months period, using in vitro models and both ELISA and HPLC MS-MS techniques. The studied substances and preliminary results are reported below.
STANOZOLOL
• ELISA technique: a kit for urine, serum and plasma has been adapted. We have found the limit of quantification about at 0.1ng/ml and the curve saturation was at 2ng/ml. Matrix effect was high.
• HPLC MS-MS: the method has been optimized for 16 β OH stanozolol with CCα of 0.42ng/ml, CCβ of 0.58ng/ml.
ZERANOL α and β
• ELISA technique: a kit for urine, serum and bovine tissue has been adapted. Matrix effect was high so the maximum level for quantification was 0.67ng/ml.
• HPLC MS-MS: the method has been optimized to show both of the compounds, CCα was 0.25ng/ml and 0.45 ng/ml for α and β-zeranol respectively; CCβ was 0.45ng/ml and 0.90ng/ml for α and β zeranol respectively.
NITROFURAN (AOZ and AMOZ)
• ELISA technique: a kit for different tissues in different animal species has been adapted. Matrix effect was scarce for AOZ but not so waek for AMOZ. Both metabolites showed sensibility close to 0.2ng/ml.
• HPLC MS-MS: samples have been derivatized before extraction. CCα was 0.20ng/ml and CCβ 0.30ng/ml for AMOZ and 0.45ng/ml and 1.30ng/ml for AOZ.
Β2 AGONISTS (CLENBUTEROL and TERBUTALINE)
• ELISA technique: a kit for analyzing clenbuterol and another one for analyzing together clenbuterol and terbutaline have been adapted. The limit of quantification was between 0.1 and 0.2ng/ml and saturation level about at 10ng/ml for clenbuterol on its own; together with terbutaline the limit of quantification was 0.5ng/ml and saturation level between 10 and 20ng/ml without matrix effect.
• HPLC MS-MS: CCα was 0.14ng/ml and CCβ was 0.22ng/ml.
DIETHYLSTILBESTROL
• ELISA technique: a kit for urine, bile, muscle and faeces has been adapted. The limit of quantification was between 12.5 and 25ppt, the saturation level about on 10ng/ml without matrix effect.
• HPLC MS-MS: CCα was 0.41ng/ml and CCβ was 0.86ng/ml.
TRENBOLONE
• ELISA technique: a kit for urine, bile, muscle, liver and faeces has been adapted. The limit of quantification was 2ng/ml and saturation level of 10ng/ml
• HPLC MS-MS: CCα was 0.80ng/ml and CCβ was 1.10ng/ml.
CHLORANPHENICOL
• ELISA technique: a kit for honey, eggs, urine, milk, plasma, meat and fish has been adapted. The limit of quantification was between 0.2 and 0.5ng/ml
• HPLC MS-MS: CCα was 0.32ng/ml and CCβ was 1.07ng/ml.
ISOXSUPRINE
• HPLC MS-MS: we searched this compound only with mass spectrometry and CCα and CCβ values were 0.24ng/ml and 0.36ng/ml respectively.
TIOURACIL
• HPLC MS-MS: it has been derivatized before extraction; we found 0.34ng/ml for CCα and 0.49ng/ml for CCβ.
CORTICOSTEROIDS
• HPLC MS-MS :we searched some drugs: prednisolone, prednisone, cortisol, cortisone, dexamethasone, betamethasone and methylprednisone and we found CCα from 0.10ng/ml to 0.60ng/ml and CCβ from 0.15ng/ml to 0.75ng/ml for all compounds.
ANABOLIC-ANDROGENIC STEROIDS
• HPLC MS-MS: we searched androstadienedione, α-boldenone, β-boldenone, androstenedione, testosterone and epitestosterone only with mass spectrometry. If we exclude ET CCα value range from 0.20ng/ml to 0.80ng/ml and CCβ from 0.40ng/ml to 2.50ng/ml
Studi preliminari di stabilità in vitro di boldenone (ALFA e BETA), testosterone ed epitestosterone glucuronati in feci bovine
No full textThe stability of and Boldenone glucuronides (BOLg), Testosterone glucuronide (Tg) and Epitestosterone glucuronide (ETg) in bovine faeces was studied in vitro. The detection of the glucuronide steroids, added to saline sospensions of faeces, and of the respective free forms, was performed by HPLC-MS/MS in positive APCI mode. The results show that Tg and BOLg, as previously observed for the free forms, resulted poorly stable; α Bolg and ETg transformed mainly into α Boldenone (α Bol) and Epitestosterone (ET). Neo formations of α Bol and ET were also confirmed
In vitro transformation of boldenone and related steroids in veal faeces : preliminary results
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Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe 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
Full text link“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
Full text linkWe 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
Evaluation of boldenone formation and related steroids transformations in veal faeces by liquid chromatography/tandem mass spectrometry
No full textIt is established that bovine urine can result positive for boldenone and androstadienedione in consequence of faecal contamination. The simple transfer of steroids to urine is one minor aspect of faecal contamination. A high de novo production of steroids in faeces after deposition and in faeces-contaminated urine is almost certainly due to microbial activity, although the precursor compounds and transformations leading to the presence of these illegal steroids are unclear. We developed a simple in vitro method - incubation of faecal matter suspended in 0.9% saline - to induce steroid transformations in faeces, and analyzed the products by liquid chromatography/tandem mass spectrometry, without the need for prior extraction. Norethandrolone was the internal standard. The linearity (R2: 0.987-0.999), sensitivity (LODs: 0.3 to 1.0 ng/mL; LOQs: 1.0 to 3.0 ng/mL), precision (intra-day CVs: 2.6-8.2; inter-day CVs: 4.5-11.5) and accuracy (percentage recovery: 89-120%) were calculated for the studied steroids. Androstenedione, androstadienedione, α- and β-boldenone, testosterone and epitestosterone transformations were investigated. Mutual interconversion of steroids was observed, although 17β-hydroxy steroids had low stability compared with 17α-hydroxy and 17-keto steroids. The results suggest that this simple in vitro system may be an effective way of studying hormone transformations in faeces and, after analogue studies, in faeces-contaminated urine. Copyrigh
Dispelling the Myths Behind First-author Citation Counts
Full text linkWe 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
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