4,245 research outputs found
Fourier Transforms of Lorentz Invariant Functions
Fourier transforms of Lorentz invariant functions in Minkowski space, with
support on both the timelike and the spacelike domains are performed by means
of direct integration. The cases of 1+1 and 1+2 dimensions are worked out in
detail, and the results for 1+n dimensions are given.Comment: 15 pages, 1 figur
A Simple Vegetation Criterion (NDF Content) May Account for Diet Choices of Cattle Between Forages Varying in Maturity Stage and Physical Accessibility
The management of extensively grazed pastures requires an understanding and prediction of the diet choices of herbivores grazing on vegetation that is qualitatively (maturity stage) and quantitatively (biomass, sward height) heterogeneous. The Optimal Foraging Theory (OFT, Stephens & Krebs, 1986), bases its predictions on the relative energy intake rate (EIR) of forages. However, as EIRs are difficult to assess at pasture and are subject to wide intra- and inter-individual variations, another vegetation criterion was sought (accessibility, quality), by-passing the animal\u27s influence, to predict cattle diet choices quantitatively
A Simple Vegetation Criterion (NDF Content) May Account for Diet Choices of Cattle Between Forages Varying in Maturity Stage and Physical Accessibility
The management of extensively grazed pastures requires an understanding and prediction of the diet choices of herbivores grazing on vegetation that is qualitatively (maturity stage) and quantitatively (biomass, sward height) heterogeneous. The Optimal Foraging Theory (OFT, Stephens & Krebs, 1986), bases its predictions on the relative energy intake rate (EIR) of forages. However, as EIRs are difficult to assess at pasture and are subject to wide intra- and inter-individual variations, another vegetation criterion was sought (accessibility, quality), by-passing the animal\u27s influence, to predict cattle diet choices quantitatively
Ion specificity and anomalous electrokinetic effects in hydrophobic nanochannels
We demonstrate with computer simulations that anomalous electrokinetic
effects, such as ion specificity and non-zero zeta potentials for uncharged
surfaces, are generic features of electro-osmotic flow in hydrophobic channels.
This behavior is due to the stronger attraction of larger ions to the
``vapour--liquid-like'' interface induced by a hydrophobic surface. An
analytical model involving a modified Poisson--Boltzmann description for the
ion density distributions is proposed, which allows the anomalous flow profiles
to be predicted quantitatively. This description incorporates as a crucial
component an ion-size-dependent hydrophobic solvation energy. These results
provide an effective framework for predicting specific ion effects, with
important implications for the modeling of biological problems
New marine cytotoxic bispyrones : absolute sterochemistry of onchitriols I and II
The complete absolute stereochemistry of two new cytotoxic marine polyproniates isolated from the saponified extract of the pulmonate mollusc #Onchidium sp.$, onchitriol 1 and 2 (4,5), was established using Mosher-Trost's methodollogy. (Résumé d'auteur
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