By the end of oocyte development, the ovaries of Penaeus semisulcatus have accumulated almost equal amounts (approximately 16 mg lipid g-1 protein) of phospholipids and triacylglycerols. The phospholipids consist mainly of phosphatidylcholine (75-80 %) and phosphatidylethanolamine (20-25 %). Approximately 30 % of the total fatty acid content of both phospholipids and triacylglycerols is made up of polyunsaturated fatty acids. In fractions obtained by centrifugation of ovarian homogenates, most of the increase in levels of ovarian lipids during ovarian maturation was associated with an increase in triacylglycerol levels in the floating fat fraction and of phospholipids in the infranatant fraction. The presence of polyunsaturated fatty acids in the ovaries indicates the occurrence of lipid transport to the ovary during oocyte maturation. The gradual decrease in the relative abundance of polyunsaturated fatty acids as the ovaries matured supports previously published results suggesting intra-ovarian synthesis of saturated and mono-unsaturated fatty acids. Most of the lipids found in the female haemolymph (64.8 %) were recovered in the high-density lipoprotein fraction after density ultracentrifugation. The haemocyanin fraction recovered from this stage of fractionation contained substantial amounts of lipid (16.8 %) that could be removed by further sequential centrifugation at a higher NaBr density, leaving less than 0.9 % of the total haemolymph lipids associated with this fraction. While 16.2 % of the lipids were recovered from the very high-density lipoprotein fractions, these lipoproteins carried only 64-89 microg lipid mg-1 protein compared with 538.9 microg lipid mg-1 protein in the high-density lipoprotein fraction, indicating that the high-density lipoproteins are more likely to be the main transporters of lipids to the ovary. However, the contribution of very high-density lipoproteins to lipid transport cannot be ruled out at this stage. In this study, we present two models for lipid transport to the ovary based on the abundance of phospholipids and triacylglycerols in the haemolymph and on the amounts of polyunsaturated fatty acids accumulated within the ovary during vitellogenesis.
This article presents a relatively simple and transparent accounting-type approach to measuring employment impacts that can be applied by practitioners and policy analysts. This method uses program-generated employment impacts as a starting point and then adjusts these figures to account for the issues outlined in the text. These adjustments are performed using a variety of readily available indices and coefficients that are generated by some of the stock tools of regional analysis. The workings of this approach are then illustrated using data on a regional small business assistance program operating in Israel. The results emphasize the discrepancy between program-declared employment outcomes (gross employment impacts) and those "distilled" from the data on the basis of the procedure outlined below (net employment impacts). The conclusions relate to the need for methods and tools that will give analysts and practitioners the capability for performing rigorous yet straightforward evaluations of public policy.
Yelena Vinetsky and Shlomo. Magdassi. 1999. “Microcapsules in cosmetics..” In Cosmetic Science and Technology Series, 19: Pp. 295 - 313. Marcel Dekker, Inc. Abstract
A review with 54 refs. Microcapsules in topical formulations, methods of microencapsulation of cosmetic ingredients and their uses in cosmetic formulations are discussed. [on SciFinder(R)]
We present a molecular-level theory for lipid-protein interaction and apply it to the study of lipid-mediated interactions between proteins and the protein-induced transition from the planar bilayer (L-alpha to the inverse-hexagonal (H-II phase. The proteins are treated as rigid, membrane-spanning, hydrophobic inclusions of different size and shape, e.g., ``cylinder-like,'' ``barrel-like,'' or ``vase-like.'' We assume strong hydrophobic coupling between the protein and its neighbor lipids. This means that, if necessary, the flexible lipid chains surrounding the protein will stretch, compress, and/or tilt to bridge the hydrophobic thickness mismatch between the protein and the unperturbed bilayer. The system free energy is expressed as an integral over local molecular contributions. the latter accounting for interheadgroup repulsion, hydrocarbon-water surface energy, and chain stretching-tilting effects. We show that the molecular interaction constants are intimately related to familiar elastic (continuum) characteristics of the membrane, such as the bending rigidity and spontaneous curvature, as well as to the less familiar tilt modulus. The equilibrium configuration of the membrane is determined by minimizing the free energy functional, subject to boundary conditions dictated by the size, shape. and spatial distribution of inclusions. A similar procedure is used to calculate the free energy and structure of peptide-free and peptide-rich hexagonal phases. Two degrees of freedom are involved in the variational minimization procedure: the local length and local tilt angle of the lipid chains. The inclusion of chain tilt is particularly important for studying noncylindrical (for instance, barrel-like) inclusions and analyzing the structure of the H-II lipid phase; e.g., we find that chain tilt relaxation implies strong faceting of the lipid monolayers in the hexagonal phase. Consistent with experiment, we find that only short peptides (large negative mismatch) can induce the L-alpha –> H-II transition. At the transition, a peptide-poor L-alpha phase coexists with a peptide-rich H-II phase.
The Mongol empire was founded early in the 13th century by Chinggis Khan and within the span of two generations embraced most of Asia, becoming the largest land-based state in history. The united empire lasted only until around 1260, but the major successor states continued on in the Middle East, present day Russia, Central Asia and China for generations, leaving a lasting impact - much of which was far from negative - on these areas and their peoples. The papers in this volume present new perspectives on the establishment of the Mongol empire, Mongol rule in the eastern Islamic world, Central Asia and China, and the legacy of this rule. The various authors approach these subjects from the view of political, military, social, cultural and intellectual history.
We report the first observation of self-modified optical diffraction, beam ellipticity recovery and conservation, and intensity independent self-focusing in an anisotropic diffusion-type nonlinearity realized in ferroelectrics heated above the centrosymmetric transition. The interaction, a photorefractive diffusion-driven quadratic nonlinearity, constitutes the first known natural realization of a higher-order logarithmic nonlinearity and allows an analytical description of the observed phenomena and the prediction of a class of noncircular solitons with no characteristic length scale.
In accordance with the present invention, there are provided compns. and methods useful for the in vivo delivery of substantially water-insol. pharmacol. active agents (such as the anticancer drug paclitaxel) in which the pharmacol. active agent is delivered in the form of suspended particles coated with protein (which acts as a stabilizing agent). In particular, protein and pharmacol. active agent in a biocompatible dispersing medium are subjected to high shear, in the absence of any conventional surfactants, and also in the absence of any polymeric core material for the particles. The procedure yields particles with a diam. of <1 μm. The use of specific compn. and prepn. conditions (e.g., addn. of a polar solvent to the org. phase), and careful selection of the proper org. phase and phase fraction, enables the reproducible prodn. of unusually small nanoparticles of <200 nm diam., which can be sterile-filtered. The particulate system produced can be converted into a redispersible dry powder comprising nanoparticles of water-insol. drug coated with a protein, and free protein to which mols. of the pharmacol. agent are bound. This results in a unique delivery system, in which part of the pharmacol. active agent is readily bioavailable (in the form of mols. bound to the protein), and part of the agent is present within particles without any polymeric matrix therein. [on SciFinder(R)]
New approaches for creation of novel protein-based colloidal and micellar systems are presented. These systems consist of colloidal clusters of chem. modified (hydrophobized) proteins or surfactant aggregates (micelles) contg. incorporated biol. catalysts - enzymes, or mols. capable of specific recognition - antibodies. The principles of formation, functional properties as well as practical applications of the protein-based colloidal and micellar systems in the fields of chem. synthesis, chem. anal., immunodiagnostics, drug targeting and biosensors are discussed. [on SciFinder(R)]
The nuclear lamina is located between the inner nuclear membrane and the peripheral chromatin. It is composed mainly of nuclear lamins and lamina-associated proteins. The nuclear lamina is involved in nuclear organization, cell cycle regulation, and differentiation. As such, impairment in its architecture and/or function leads to genetic diseases and apoptosis. This article describes the molecular organization of the nuclear lamins, their assembly into filaments, their distribution within the nucleus, and the complex network of interactions between them and other proteins of the inner nuclear membrane. Recent findings unraveled evidence for specific interactions between proteins of the nuclear lamina and the chromatin. These include interactions between nuclear lamins and core histones, Lamina Associated Polypeptide 2 (LAP2), and the Barrier to Autointegration Factor (BAF) and interactions between lamin B receptor (LBR) and the chromodomain protein HP1. Taken together, these studies attribute a role for both the nuclear lamins and the lamina-associated proteins, LAP2 and LBR, in nuclear organization and nuclear assembly.
