707 research outputs found
Curculionidae (Coleoptera) associated with paricá, Schizolobium parahyba (Vell.) S.F. Blake var. amazonicum (Huber ex ducke) Barneby, in Pará, Brazil.
Rooting Pattern Distribution and Spatial Variability of Italian Ryegrass (Lolium Multiflorum Lam) in a Mediterranean Region
It is estimated that less than 10% of the studies on pastures and forages have evaluated the subterranean biomass production. The objective of this study was to evaluate for a Mediterranean region the rooting characteristics and spatial variability of Italian ryegrass (Lolium multiflorum Lam) under two different soil water status conditions
Primeiro relato do pulgão cerataphis brasiliensis (Hempel) (Hemiptera: Aphididae) atacando mudas de duas espécies de tucumanzeiro (Astrocaryum spp.): descrição e controle.
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Molecular modeling and inhibitory activity of cowpea cystatin against bean bruchid pests.
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On the non-planar beta-deformed N=4 super-Yang-Mills theory
The beta-deformation is one of the two superconformal deformations of the N=4
super-Yang-Mills theory. At the planar level it shares all of its properties
except for supersymmetry, which is broken to the minimal amount. The tree-level
amplitudes of this theory exhibit new features which depart from the commonly
assumed properties of gauge theories with fields in the adjoint representation.
We analyze in detail complete one-loop amplitudes and a nonplanar two-loop
amplitude of this theory and show that, despite having only N=1 supersymmetry,
two-loop amplitudes have a further-improved ultraviolet behavior. This
phenomenon is a counterpart of a similar improvement previously observed in the
double-trace amplitude of the N=4 super-Yang-Mills theory at three and four
loop order and points to the existence of additional structure in both the
deformed and undeformed theories.Comment: 39 pages, 8 figure
A recombinant form of chagasin from Trypanosoma cruzi: inhibitory activity on insect cysteine proteinases.
Relationship Between Biogenic Amines and Free Amino Acid Contents of Winesand Musts from Alentejo (Portugal)
The concentration of biogenic amines and free amino acids was studied in 102
Portuguese wines and 18 musts from Alentejo demarcated (D.O.C.) regions. Most wines
were commercial, except for 38 monovarietals obtained by micro vinification. Musts
from the varieties used to produce the latter wines were also studied. Both biogenic
amines and free amino acids were analyzed by HPLC using fluorescence detection for
their o-phthalaldehyde/fluorenylmethyl chloroformate (OPA/FMOC) derivatives. The
most significant amines (average 10.8 mg/L for histamine+tyramine in red, and 7.4
mg/L for white wines) were found to be present at low levels and, although no important
relationship between each individual biogenic amine could be obtained, the total amine
content depends significantly on the assimilable amino acid content in wine
Transport of small anionic and neutral solutes through chitosan membranes: Dependence on cross-linking and chelation of divalent cations
Chitosan membranes were prepared by solvent casting and cross-linked with glutaraldehyde at several ratios
under homogeneous conditions. The cross-linking degree, varying from 0 to 20%, is defined as the ratio between
the total aldehyde groups and the amine groups of chitosan. Permeability experiments were conducted using a
side-by-side diffusion cell to determine the flux of small molecules of similar size but with different chemical
moieties, either ionized (benzoic acid, salicylic acid, and phthalic acid) or neutral (2-phenylethanol) at physiological
pH. The permeability of the different model molecules revealed to be dependent on the affinity of those structurally
similar molecules to chitosan. The permeability of the salicylate anion was significantly enhanced by the presence
of metal cations commonly present in biological fluids, such as calcium and magnesium, but remained unchanged
for the neutral 2-phenylethanol. This effect could be explained by the chelation of metal cations on the amine
groups of chitosan, which increased the partition coefficient. The cross-linking degree was also correlated with
the permeability and partition coefficient. The change in the permeation properties of chitosan to anionic solutes
in the presence of these metallic cations is an important result and should be taken into consideration when trying
to make in vitro predictions of the drug release from chitosan-based controlled release systems
Serum leptin and insulin levels in lactating protein-restricted rats: implications for energy balance
Measurement of inclusive D*+- and associated dijet cross sections in photoproduction at HERA
Inclusive photoproduction of D*+- mesons has been measured for photon-proton
centre-of-mass energies in the range 130 < W < 280 GeV and a photon virtuality
Q^2 < 1 GeV^2. The data sample used corresponds to an integrated luminosity of
37 pb^-1. Total and differential cross sections as functions of the D*
transverse momentum and pseudorapidity are presented in restricted kinematical
regions and the data are compared with next-to-leading order (NLO) perturbative
QCD calculations using the "massive charm" and "massless charm" schemes. The
measured cross sections are generally above the NLO calculations, in particular
in the forward (proton) direction. The large data sample also allows the study
of dijet production associated with charm. A significant resolved as well as a
direct photon component contribute to the cross section. Leading order QCD
Monte Carlo calculations indicate that the resolved contribution arises from a
significant charm component in the photon. A massive charm NLO parton level
calculation yields lower cross sections compared to the measured results in a
kinematic region where the resolved photon contribution is significant.Comment: 32 pages including 6 figure
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