The coacervation of a dialkyldimethylammonium salt was induced by various electrolytes. The electrolyte concn. in which coacervation was obsd. was in the range of 0.01-0.2M, depending on the electrolyte type. The effectiveness order for coacervation is NaSCN > NaI > NaBr > NaCl > NaF. A correlation between the ionic radii of the anion and the concn. in which coacervation is induced, is suggested. This correlation indicates that the coacervation process depends on the degree of counter ion binding to the cationic surfactant. [on SciFinder(R)]
Activity of the cat gene driven by the cauliflower mosaic virus 35S promoter has been assayed by transfecting petunia protoplasts with the pUC8CaMVCAT plasmid. In vitro methylation of this plasmid with M.HpaII (methylates C in CCGG sites) and M.HhaI (methylates GCGC sites) did not affect bacterial chloramphenicol acetyltransferase (CAT) activity. It should be noted, however, that no HpaII or HhaI sites are present in the promoter sequence. In contrast, in vitro methylation of the plasmid with the spiroplasma methylase M.SssI, which methylates all CpG sites, resulted in complete inhibition of CAT activity. The promoter sequence contains 16 CpG sites and 13 CpNpG sites that are known to be methylation sites in plant DNA. In the light of this fact, and considering the results of the experiments presented here, we conclude that methylation at all CpG sites leaving CpNpG sites unmethylated is sufficient to block gene activity in a plant cell. Methylation of CpNpG sites in plant cells may, therefore, play a role other than gene silencing.
We have studied the effect of acute short-term starvation (in 9 patients) and of prolonged caloric deprivation (in 10 patients with anorexia nervosa), on cell-mediated cytoxicity (CMC). CMC became severely depressed after six days on a very low caloric diet (1.2±1.4 vs. 7.0±2.9 lytic units/106 cells; P<0.01). CMC was also low in our patients with anorexia nervosa compared to a matched control group (3.3±1.7 vs 10.0±3.0 lytic units/106 cells; P<0.01) and increased in most of the patients studied (five cases) after the first 3–4 weeks of refeeding in correlation with weight gain. Dietary deprivations may lead to a significant impairment in cell-mediated cytotoxicity, which appears to be reversible after refeeding.
The role of the local entrepreneur in the development of rural industrialization is often overlooked. Based on an empirical survey of entrepreneurs in both urban and rural areas in Israel, this paper shows that the rural setting scores less favorably than the urban for nearly all those locational attributes that would attract industrial development. Consequently, the chances of attracting external initiatives to rural areas would seem slim. Instead, it is argued that a strategy for rural industrial development needs to be based on the mobilization of indigenous entrepreneurial potential for which the rural setting provides a subjective relative advantage.
Michael Beenstock. 1990. “Exchange Rate Dynamics..” In Current issues in international monetary economics, Pp. 44 - 62. Hebrew U Jerusalem: Current Issues in Economics series, vol. 4. Publisher's Version
A chick genomic clone that reveals a high degree of homology to the mammalian and Xenopus bFGF gene has been isolated. The pattern of expression of bFGF has been examined during early chick embryogenesis. RNA blot analysis revealed that chick bFGF is already transcribed at pregastrula stages. Immunolabeling analysis indicated that bFGF protein is present at these early developmental stages and is distributed evenly in the epiblast, hypoblast and marginal zone of the chick blastula. Substances that can inhibit FGF action were applied to early chick blastoderms grown in vitro under defined culture conditions (DCM). Both heparin and suramin were capable of blocking the formation of mesodermal structures in a dose-dependent manner. Our results indicate that FGF-like substances may need to be present for axial structures to develop although they may be acting earlier during the induction of non-axial mesoderm.
Flocculation of bentonite suspensions by a bioflocculant, produced by the cyanobacterium Phormidium species strain J1, was correlated with the adsorption mechanism of the flocculant on the bentonite particles in the presence of various CaCl2 concns. The optimum flocculant concn. decreased with an increase in CaCl2 concn., and the adsorption increased with an increase in CaCl2 concn. Langmuir-type isotherms are obtained and yield ΔG°ads. = - 12 kcal mol-1 at any CaCl2 concn., while max. adsorption increases with increasing CaCl2 concn. Measurements of electrophoretic mobility and Ca2+ uptake by the particles and the flocculant indicate that the role of CaCl2 is to increase the amt. of adsorbed flocculant at any given flocculant concn., thus shifting the optimal flocculant concn. toward lower values. [on SciFinder(R)]
Reviews two books about rabbi Menasseh ben Israel. "Menasseh ben Israel and His World," edited by Yosef Kaplan, Henry Méchoulan and Richard H. Popkin; "Sceptics, Millenarians and Jews," edited by David S. Katz and Jonathan I. Israel.
The formation and stabilization of perfluorocarbon emulsions with pluronic F-68 and soya lecithin were investigated. Greater ease of formation and stability were achieved with the soya lecithin. In general, smaller droplet size was obtained with the emulsions prepd. with lecithin, at all dispersed phase fractions. Zeta potential measurements indicated that the emulsions are stabilized via an electrostatic mechanism; the zeta potential increased with increasing lecithin concn., up to a const. high value, and decreased with increasing dispersed phase fraction. [on SciFinder(R)]
Oil-in-glycerol/water emulsions at various ratios of water to glycerol in the external phase were prepd. with polyoxyethylated octylphenols and light mineral oil. As the water concn. in the external phase decreased, oil droplet size decreased down to a min. size beyond which oil sepn. occurred. Also, the cloud points of various surfactants were depressed toward room temp. as the water content of the glycerol/water mixt. decreased. The concn. of water needed for formation of the smallest droplets was correlated to the concn. of water needed for depression of the cloud point of each surfactant to room temp. [on SciFinder(R)]
