257 resultados para Shea
Resumo:
Référence bibliographique : Rol, 60650
Resumo:
Proanthocyanidins (PA) from shea (Vitellaria paradoxa) meal were investigated by thiolytic degradation with benzyl mercaptan and the reaction products were analysed by high performance liquid chromatography–mass spectrometry. These PA were galloylated (≈40%), contained only B-type linkages and had a high proportion of prodelphinidins (>70%). The mean degree of polymerisation was 8 (i.e. average molecular size was 2384 Da) and epigallocatechin gallate (EGCg) was the major flavan-3-ol subunit in PA. Shea meal also proved to be a potentially valuable source for extracting free flavan-3-ol-O-gallates, especially EGCg (575 mg/kg meal), which is known for its health and anti-parasitic benefits. Proanthocyanidins were isolated and tested for bioactivity against Ascaris suum, which is an important parasite of pigs. Migration and motility tests revealed that these PA have potent activity against this parasitic nematode.
Resumo:
Proanthocyanindins (PAs) from shea meal (SM), a by-product obtained after lipid extraction of the nuts, contained B-type linkages, had a high ratio of prodelphinidins (73%) and were galloylated (42%). The average polymer size was 8 flavan-3-ol subunits (≈2384 Daltons) and epigallocatechin gallate was the major subunit. Purified PA fractions from SM were tested in vitro for anthelmintic properties against gastrointestinal nematodes from ruminants (H. contortus and T. colubriformis) [1] by the larval exsheathment inhibition assay and from pigs (A. suum) by the larval migration inhibition assay. Results showed that PAs from SM have a potent anthelmintic activity against those parasites similar to white clover (Trifolium repens) flowers (WCF) [1, 2] (EC50 µg/mL; SM: 55.1, 16.5, 75.9; WCF: 37.4, 14.5, 110.1 for A. suum, H. contortus and T. colubriformis respectively). WCF PAs are constituted almost exclusively of prodelphinidin (PD) compared to SM (98% vs. 73%) but do not contained galloylated PAs. Studies [1, 2] have shown that anthelmintic activity of PAs was mainly associated with their PD ratio but our current results suggest that galloylation can be a major factor to anthelmintic activity and SM as a potential nutraceutical anthelmintic feed for controlling parasitic nematodes.
Resumo:
Agroforestry parklands represent a vast majority of the agricultural landscape under subsistent-oriented farming in semi-arid West Africa. Parklands are characterized by the growth of well- maintained trees (e.g., shea) on cultivated fields as a result of both environmental and human influences. Shea (Vitellaria paradoxa) provides a cultural and economic benefit to the local people of Ghana, especially women. Periods between traditional fallow rotation systems have reduced recently due to agricultural development and a demand for higher production. As a result, shea trees, which regenerate during fallow periods, has decreased over the landscape. The aim of this study was to determine beneficial spatial distributions of V. paradoxa to maintain high yields of staple crops, and how management of V. paradoxa will differ between male and female farmers as a result of farmer based needs and use of shea. Vegetation growth and grain yield of maize (Zea mays) associated with individual trees, clumped trees, and open fields were measured. Soil moisture and light availability were also measured to determine how V. paradoxa affected resource availability of maize in either clumped or scattered distributions of V. paradoxa. As expected, light availability increased as measurement locations moved farther away from all trees. However, soil moisture was actually greater under trees in clumps than under individual trees. Maize stalk height and cob length showed no difference between clumped and single trees at each measurement location. Grain yield per plot and per cob increased as measurement locations moved farther from single trees, but was actually greater near clumped trees that in the open field subplots. Cob length and maize stalk height increased with greater light availability, but grain yield per cob or per plot showed no relationship with light, but were not affected by soil moisture. Conversely, grain yield increased with increasing soil moisture, but had no relationship with light availability. Initial farming capital is the largest constraint to female farmers; therefore the collection of shea can help provide women with added income that could meet their specific farming needs. Our data indicate that overall effects of maintaining clumped distributions of V. paradoxa provided beneficial microclimates for staple crops when compared to single trees. It is recommended that male and female farmers allow shea to grow in clumped spatial distributions rather than maintaining scattered, individual trees.
Resumo:
Memoria de prácticas-Viaje a Puertollano-Visita a las minas y fábricas de Asturias-Mina de carbón de Arnao-Fábrica de La Felguera
Resumo:
Advertising matter at end: 20 p.
Resumo:
3e éd.
Resumo:
The PHENIX experiment at the Relativistic Heavy Ion Collider has performed systematic measurements of phi meson production in the K(+)K(-) decay channel at midrapidity in p + p, d + Au, Cu + Cu, and Au + Au collisions at root s(NN) = 200 GeV. Results are presented on the phi invariant yield and the nuclear modification factor R(AA) for Au + Au and Cu + Cu, and R(dA) for d + Au collisions, studied as a function of transverse momentum (1 < p(T) < 7 GeV/c) and centrality. In central and midcentral Au + Au collisions, the R(AA) of phi exhibits a suppression relative to expectations from binary scaled p + p results. The amount of suppression is smaller than that of the pi(0) and the. in the intermediate p(T) range (2-5 GeV/c), whereas, at higher p(T), the phi, pi(0), and. show similar suppression. The baryon (proton and antiproton) excess observed in central Au + Au collisions at intermediate p(T) is not observed for the phi meson despite the similar masses of the proton and the phi. This suggests that the excess is linked to the number of valence quarks in the hadron rather than its mass. The difference gradually disappears with decreasing centrality, and, for peripheral collisions, the R(AA) values for both particle species are consistent with binary scaling. Cu + Cu collisions show the same yield and suppression as Au + Au collisions for the same number of N(part). The R(dA) of phi shows no evidence for cold nuclear effects within uncertainties.
Resumo:
The production of e(+)e(-) pairs for m(e+e-) < 0.3 GeV/c(2) and 1< p(T) < 5 GeV/c is measured in p + p and Au + Au collisions at root s(NN) = 200 GeV. An enhanced yield above hadronic sources is observed. Treating the excess as photon internal conversions, the invariant yield of direct photons is deduced. In central Au + Au collisions, the excess of the direct photon yield over p + p is exponential in transverse momentum, with an inverse slope T = 221 +/- 19(stat) +/- 19(syst) MeV. Hydrodynamical models with initial temperatures ranging from T(init) similar to 300-600 MeV at times of similar to 0.6-0.15 fm/c after the collision are in qualitative agreement with the data. Lattice QCD predicts a phase transition to quark gluon plasma at similar to 170 MeV.