1,721,084 research outputs found
EFFETTO DELLA TECNICA DI ALLEVAMENTO SULLA REATTIVITÀ "FEAR" DELLE STARNE (PERDIX PERDIX L.)
No full textThe purpose of this study was to investigate if the tecnology of rearing system can influence the fear of Grey Prtridge chicks. Fear was measured in artificially reared chicks, laid-incubated then reared by parents chiks, and forcedly adopted by broody hens chiks. Results showed that, tonic immobility test, novel object test and metronome test can differentiate the rearing technologies while box plus experiment test, and box emergence test did not reach the m.d.s. between rearing systems
Sample treatment for the determination of steroid hormone contaminants in water samples: Analytical greenness assessment
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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
Electrochemical analysis and characterization of psychoactive substances glaucine and tetrahydropalmatine
No full textThe electrochemical behaviour of two alkaloids of forensic interest, namely glaucine and tetrahydropalmatine, has been investigated by Cyclic Voltammetry (CV) and Controlled Potential Electrolysis (CPE) and the results compared with those obtained with model compounds such as tetrahydroisoquinolines and methoxybenzenes. On the basis of these results, we developed an analytical procedure based on differential pulsed voltammetry (DPV), associated with a clean-up/preconcentration process by solid phase extraction (SPE) using Florisil, that can be applied for the detection and quantification of the analytes both in pharmaceutical preparations and in biological matrices such as urines. LOD values around 0.15 μg∙mL−1 and linearity up to 250 μg∙mL−1 were measured
Green and Efficient Determination of Fluoroquinolone Residues in Edible Green Fruits and Leafy Vegetables by Ultrasound-Assisted Extraction Followed by HPLC-MS/MS
No full textIn this work, a simple, quick and efficient analytical method for determination of human and veterinary fluoroquinolone antimicrobial residues in lettuce, cucumber and spinach is developed. The procedure entails a 6 min ultrasound-assisted extraction (UAE, 3 x 2 min) in an alkaline (2% v/v NH3) aqueous solution containing Mg2+ ions (3 x 6 mL), with no need for organic solvents. The extract is submitted to cleanup on the HLB (TM) cartridge and the fluoroquinolones are separated and quantified by HPLC-MS/MS in a 10 min chromatographic run, using a small amount of acetonitrile in the mobile phase. The method, entirely developed in real matrices, is validated according to the updated analytical guidelines and provided suitable recoveries in the range of 67-116% and precision (RSD <= 20%, n = 3) at different concentrations (15, 70 and 150 ng g(-1)), with method quantification limits of 2-10 ng g(-1). Fluoroquinolones were detected and quantified at concentrations from few to hundreds of nanograms per gram in vegetables from supermarkets, demonstrating the applicability of the method for monitoring residues of these pharmaceuticals
HPLC-MS/MS multiclass determination of steroid hormones in environmental waters after preconcentration on the carbonaceous sorbent HA-C@silica
No full textIn this study, a sensitive and multiclass method has been developed for analysis of three families of steroid hormones, i.e. progestins, oestrogens, androgens, by SPE-HPLC-ESI-MS/MS. The extraction efficiency of thermally condensed humic acids onto silica sorbent (HA-C@silica), here for the first time studied for multiclass enrichment of these sex hormones, was tested in different environmental waters (tap and river water, urban wastewater treatment plant effluent) spiked at the nanograms per litre levels (5–1000 ng L−1). Quantitative adsorption was achieved using 200 mg sorbent for preconcentration of 250–1000 mL sample, at the native pH (pH = 6.5–7.7). Elution was performed by two sequential fractions (methanol followed by acetonitrile), obtaining in all the matrices investigated satisfactory recoveries (71% to 124% for river waters and 71–113% for urban wastewater treatment plant effluent) and RSDs below 15% (n = 3). The high enrichment factors (up to 4000) coupled with high-performance liquid chromatography tandem mass spectrometry quantification (MRM mode) provided low limits of detection and quantification (a few ng L−1), that are suitable for environmental monitoring. Most of the analytes were detected in river water and in wastewater effluent samples (in the ng L−1 concentration range), attesting their environmental diffusion. The proposed method was extended to a fourth class, Glucocorticoids, achieving good results in river samples, by the same SPE cartridge and chromatographic run
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
Agri-food waste biochar-based green vial wall sorptive extraction: Downscaled portable device for steroids in fresh and brackish water samples
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