1,721,033 research outputs found
La filiere laitiere en Afrique sahelienne: valorisation du produit local
No full textUne étude bibliographique et de synthèse sur la filière laitière en Afrique sahélienne a été réalisée. Après une description générale sur le Sahel et le rôle des produits laitiers au sein des économies locales, ce travail fait le point sur la dépendance des importations du lait en poudre par plusieurs de ces pays. Bien que le lait représente un élément important dans les civilisations pastorales au Sahel, les filières laitières locales tardent à s’affranchir des marchés internationaux. L’étude analyse la filière locale dans ses différents aspects et en particulier son récent développement dans un contexte urbain et celui plus traditionnel au niveau pastoral. La chaine urbaine, étant plus développée et complexe fait l’objet d’une analyse plus approfondie. Les étapes de production, transformation, commercialisation et consommation sont passées en revue selon les deux contextes, en faisant ressortir les possibilités d’amélioration et les freins qui empêchent la croissance de la filière locale. Une description des produits laitiers locaux est suivie par l’analyse des potentialités qu’ils pourraient jouer dans le processus de lutte à l’insécurité alimentaire. Cette zone d’Afrique souffre encore de ce problème et le lait produit localement pourrait intervenir comme un important maillon de la chaine alimentaire. Pour émanciper les pays sahéliennes de la dépendance des importations et promouvoir la production locale, il est important que la recherche et l’aide au développement s’orientent davantage vers la filière laitière, au profit d’un échange économique plus équilibré et de la valorisation des produits locaux. Une connaissance plus approfondie de cette filière au Sahel vise à faire connaître et à mieux développer les programmes orientés à la promotion et valorisation du lait local et de ses produits dérivés
Biodiversità e allevamento in Niger : il Parco W
No full textIl video racconta del progetto “Difesa e valorizzazione della biodiversità in Niger attraverso programmi di educazione ambientale e strategie operative” finanziato dal Comune di Milano e svolto sotto la supervisione scientifica del Dipartimento di Scienze Veterinarie e Sanità Pubblica in partenariato con l'ONG Terre Solidali.Lo scopo del progetto è stato la valorizzazione della biodiversità nella zona di transizione della Riserva della Biosfera del Parco W, al confine tra Niger, Benin e Burkina Faso, attraverso il rafforzamento delle capacità degli attori locali (guardie del Parco, allevatori, giovani in età scolare), che possono essere a vario titolo coinvolti nella salvaguardia della biodiversità, e la messa a punto di strategie operative di gestione delle risorse naturali.
ATTIVITÀ REALIZZATE:
- Formazione delle guardie del Parco W a una corretta gestione della biodiversità.
- Allestimento di un Centro Visitatori all’interno del Parco per la divulgazione e la sensibilizzazione del pubblico sui temi legati alla biodiversità.
- Monitoraggio delle interazioni spaziali e sanitarie tra animali domestici e selvatici nelle aree alla periferia del Parco W.
- Messa a punto di uno specifico database in grado di catalogare e rappresentare graficamente le informazioni raccolte.
- Attività formative sulla corretta gestione degli animali domestici rivolte agli allevatori situati alla periferia del Parco W.
- Realizzazione di interventi formativi di educazione ambientale per la popolazione locale in età scolare nei villaggi limitrofi al Parco
IMPROVEMENT OF ESTRADIOL 17-BETA-D-GLUCURONIDE CHOLESTASIS BY INTRAVENOUS ADMINISTRATION OF DIMETHYLETHANOLAMINE IN THE RAT
No full textThe intravenous administration of dimethylethanolamine in the rat promotes a selective enrichment of liver membranes with polyunsaturated phosphatidylcholines. The effect of dimethylethanolamine pretreatment on cholestasis induced by estradiol 17-beta-D-glucuronide, a potent cholestatic agent, was assessed in this study. Dimethylethanolamine, dissolved in sodium-taurocholate was infused intravenously (0.3 mg/kg/min) for 15 hr. One group of control rats (estradiol 17-beta-D-glucuronide controls) received the bile salt only. An estradiol 17-beta-D-glucuronide bolus was then injected intravenously (10.4 mg/kg) into dimethylethanolamine-pretreated and estradiol 17-beta-D-control rats, and its effect on bile flow and biliary lipid secretion was compared for 3 hr. The estradiol 17-beta-D-glucuronide inhibitory effect on bile flow and biliary lipid secretion was significantly antagonized by dimethylethanolamine pretreatment. The maximum inhibition of bile flow was found 30 min after estradiol 17-beta-D-glucuronide administration, when it decreased from 3.5 +/- 0.4-mu-l/min/100 gm (basal) to 0.9 +/- 0.3-mu-l/min/100 gm in estradiol 17-beta-D-glucuronide controls, whereas in dimethylethanolamine-pretreated rats this decreased only from 3.2 +/- 0.4 (basal) to 2.3 +/- 0.4-mu-l/min/100 gm. Bile flow and the biliary secretion of cholesterol, phosphatidylcholine and bile salts were significantly higher in the dimethylethanolamine-pretreated rats than in estradiol 17-beta-D-glucuronide controls (p < 0.02) during the cholestatic phase. The inhibitory effect of estradiol 17-beta-D-glucuronide on bile flow was associated with a marked decrease of membrane fluidity (p < 0.001) assessed by 1,6-diphenyl-1,3,5-hexatriene fluorescence anisotropy and with a cholesterol enrichment of microsomes, sinusoidal and canalicular liver plasma membranes and inhibition of sinusoidal Na+, K+-ATPase activity (p < 0.05). These membrane alterations persisted 180 min after estradiol 17-beta-D-glucuronide administration despite complete normalization of bile flow. Dimethylethanolamine pretreatment significantly counteracted the reduction of membrane fludity (p < 0.001), the cholesterol enrichment and the inhibition of Na+, K+-ATPase (p < 0.05) promoted by estradiol 17-beta-D-glucuronide administration in all membrane subfractions 30 and 180 min after administration. In addition, dimethlethanolamine-pretreated rats had more poly-unsaturated fatty acids in membrane phosphatidylcholine with respect to the control groups. Dilatation of canaliculi and loss of microvilli were evident in estradiol 17-beta-D-glucuronide controls 180 min after estradiol 17-beta-D-glucuronide administration. Dimethylethanolamine pretreatment antagonized the toxic effect of estradiol 17-beta-D-glucuronide cholestasis, particularly in the canalicular zone, which had a normal structure both 30 and 180 min after estradiol 17-beta-D-glucuronide administration. In conclusion, the intravenous administration of dimethylethanolamine improves the biochemical, biophysical and ultra-structural features of estradiol 17-beta-D-glucuronide cholestasis in the rat
Influence of age on the lipoprotein profile of male Wistar rats.
No full textThis study shows that the age-dependent increase in plasma cholesterol levels of the rat is correlated with changes in the distribution of the high-density lipoprotein (HDL) fractions. In particular, it has been shown that when the that of older animals (up to 18 months of age) the level of HDL1 fraction displays a relevant increase which derives from a proportional decrease in the levels of both HDL2 and HDL3 fractions. No relevant change is observed in the distribution of very-low density and low-density lipoprotein fractions. The distribution of the major components present in each lipoprotein fraction isolated evidences that cholesteryl ester proportion has an age-related increase in all the fractions except the HDL2. Furthermore, also the total plasma concentration of lipoproteins shows an age-related increase. The results obtained in this study with male Wistar rats suggest that animals older than 10 months can be used as an experimental model for dietary and pharmacological studies on age-related cholesterol alterations
An improved gas liquid chromatographic method for the determination of fecal neutral sterols
No full textThe analysis of fecal neutral sterols has been improved by use of a highly selective gas-liquid chromatography column packed with SP-2401. This chromatographic column allows separation of cholesterol and cholestanol and Δ5-5α plant sterol homologs without employing silver nitrate thinlayer chromatography. Furthermore, there is no need to derivatize neutral sterols before injection. The main fecal neutral sterols are well resolved; retention times are reproducible; detector response is reproducible, linear, and sensitive to 0.2 μg. This method, successfully used for fecal samples, may be suggested as a routine method for the clinical study of cholesterol metabolism
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
Matrix-assisted laser desorption mass spectrometry for the detection of recombinant bovine growth hormone in sustained-release form
No full textWe employed matrix-assisted laser desorption mass spectrometry (LD-MS) to detect recombinant bovine growth hormone (r-bGH) in sustained-release preparations. After preliminary extraction in phosphate buffer, LD-MS provided a precise determination of the molecular mass (Mr) of the r-bGH contained in 38 sustained-release preparations. The hormone was characterised using enzyme immunoassay, immunoblotting and amino acid sequencing. Rapid detection is essential for analysing large numbers of samples, and for monitoring the use of r-bGH in zootechnical productions and its administration as a "high-tech" drug for therapeutic purposes
- …
