Some Chemical Properties of Vitamin E

In continuation of work toward the isolation and identification of vitamin E,1 the following observations have been made. The inactive product obtained by mild bromination of vitamin E concentrates can be reactivated by boiling with Zn dust and HCl in methanol solution. Vitamin E was not destroyed by the catalytic hydrogenation of concentrates at 200° and 200 atmospheres pressure, but the concentrates, after such treatment, were still unsaturated, as indicated by iodine number determinations. An active concentrate of vitamin E has been prepared from crude cottonseed oil

Hydroquinone Monoacetate

Alkyl monoesters of hydroquinone and pyrocatechol have not hitherto been prepared. Hydroquinone monoacetate has been obtained by the following series of reactions. Hydroquinone plus one molar equivalent of carbobenzoxy chloride gives hydroquinone monobenzyl carbonate. This compound is acetylated, and then hydrogenated in alcohol with Pd or Ni catalyst. Hydroquinone monoacetate, plates or needles from petroleum ether, M. P. 57- 59oC., is obtained from the residue

Some Properties of Vitamin E Concentrates

Preparations of vitamin E were obtained from lettuce and from wheat germ oil by fractional crystallizations of the unsaponifiable lipids. Still further concentrated fractions were obtained from the lettuce unsaponifiable lipids by fractional distillation in vacuo. The fraction collected from 190-220° (0.1 mm.) was the most active. After the removal of traces of sterols and other solid alcohols by crystallization from acetone, 10 mg. were sufficient, when fed to a female rat deficient in vitamin E, to allow the birth of a normal litter. Concentrates so obtained were resin-like material which would not crystallize. Some of the physical and chemical properties were determined. The vitamin is not destroyed by acetylation, benzoylation, or mild hydrogenation but is destroyed by bromination

Antioxidants and the Autoxidation of Fats v. Mode of Action of Anti- and Pro-Oxidants

Experiments on the oxidation of purified methyl oleate support the view that its induction period, and probably that of natural oils, is due to the presence of inhibitors and that purified unsaturated compounds have no induction period, other than the time required for gaseous oxygen to diffuse into the liquid

Deuda pública "cierta" y "contingente": el caso de Colombia

Este documento examina la dinámica de la deuda pública colombiano, distinguiendo entre la deuda cierta y la deuda contingente. Los ejercicios tradicionales sobre sostenibilidad de la deuda rara vez incluyen los efectos de la deuda contingente. Nuestros resulttulos indican que se requiere generar un ahorro primario equivalente al 3% del PIB para estabilizar la relación deuda pública/PIB alrededor del 50%

Why dictators veto: legislation, legitimation and control in Kazakhstan and Russia

Why do authoritarian presidents still use their legislative power? Although recent studies have argued that authoritarian legislatures are more than “rubberstamps” and can serve as arenas for elite bargaining over policy, there is no evidence that legislators would pass bills that go against presidential preferences. This article investigates this apparent paradox and proposes a theoretical framework to explain presidential activism in authoritarian regimes. It argues that any bills that contravene constraints on policy-making set by the president should generally be stopped or amended by other actors loyal to the regime. Thus, presidents will rather use their veto (1) to protect the regime’s output legitimacy and stability, and/or (2) to reinforce their power vis-à-vis other actors. The argument is tested using two case studies of veto use in Kazakhstan and Russia over the last 10 years. The analysis supports the propositions of the theoretical framework and furthermore highlights the potential use of vetoes as a means of distraction, particularly in relation to international audiences. The article extends research on presidential veto power to authoritarian regimes and its findings contribute to the growing literature on the activities of authoritarian legislatures

Distribution of lipids in the grain of wheat (cv Hereward) determined by lipidomic analysis of milling and pearling fractions

Lipidomic analyses of milling and pearling fractions from wheat grain were carried out to determine differences in composition which could relate to the spatial distribution of lipids in the grain. Free fatty acids and triacylglycerols were major components in all fractions, but the relative contents of polar lipids varied, particularly lysophosphatidyl choline and digalactosyldiglyceride, which were enriched in flour fractions. By contrast, minor phospholipids were enriched in bran and offal fractions. The most abundant fatty acids in the analysed acyl lipids were C16:0 and C18:2 and their combinations, including C36:4 and C34:2. Phospholipids and galactolipids have been reported to have beneficial properties for bread making, while free fatty acids and triacylglycerols are considered detrimental. The subtle differences in the compositions of fractions determined in the present study could therefore underpin the production of flour fractions with optimised compositions for different end uses

The effects of stochastic resonance electrical stimulation and neoprene sleeve on knee proprioception

<p>Abstract</p> <p>Background</p> <p>A variety of knee injuries and pathologies may cause a deficit in knee proprioception which may increase the risk of reinjury or the progression of disease. Stochastic resonance stimulation is a new therapy which has potential benefits for improving proprioceptive function. The objective of this study was to determine if stochastic resonance (SR) stimulation applied with a neoprene sleeve could improve knee proprioception relative to a no-stimulation/no-sleeve condition (control) or a sleeve alone condition in the normal, healthy knee. We hypothesized that SR stimulation when applied with a sleeve would enhance proprioception relative to the control and sleeve alone conditions.</p> <p>Methods</p> <p>Using a cross-over within subject design, twenty-four healthy subjects were tested under four combinations of conditions: electrical stimulation/sleeve, no stimulation/sleeve, no stimulation/no sleeve, and stimulation/no sleeve. Joint position sense (proprioception) was measured as the absolute mean difference between a target knee joint angle and the knee angle reproduced by the subject. Testing was conducted during both partial-weight bearing (PWB) and non-weight bearing (NWB) tasks. Differences in joint position sense between the conditions were evaluated by repeated-measures analysis of variance testing.</p> <p>Results</p> <p>Joint position sense error during the stimulation/sleeve condition (2.48° ± 1.32°) was found to be more accurate (P < 0.05) relative to the control condition (3.35° ± 1.63°) in the PWB task. No difference in joint position sense error was found between stimulation/sleeve and sleeve alone conditions for the PWB task. Joint position sense error was not found to differ between any of the conditions for the NWB task.</p> <p>Conclusion</p> <p>These results suggest that SR electrical stimulation when combined with a neoprene sleeve is an effective modality for enhancement of joint proprioception in the PWB knee. We believe these results suggest the need for further study of the potential of SR stimulation to correct proprioceptive deficits in a clinical population with knee injury/pathology or in subjects at risk of injury because of a proprioceptive deficit.</p

Lethality and Developmental Delay in Drosophila melanogaster Larvae after Ingestion of Selected Pseudomonas fluorescens Strains

The fruit fly, Drosophila melanogaster, is a well-established model organism for probing the molecular and cellular basis of physiological and immune system responses of adults or late stage larvae to bacterial challenge. However, very little is known about the consequences of bacterial infections that occur in earlier stages of development. We have infected mid-second instar larvae with strains of Pseudomonas fluorescens to determine how infection alters the ability of larvae to survive and complete development.We mimicked natural routes of infection using a non-invasive feeding procedure to study the toxicity of the three sequenced P. fluorescens strains (Pf0-1, SBW25, and Pf-5) to Drosophila melanogaster. Larvae fed with the three strains of P. fluorescens showed distinct differences in developmental trajectory and survival. Treatment with SBW25 caused a subset of insects to die concomitant with a systemic melanization reaction at larval, pupal or adult stages. Larvae fed with Pf-5 died in a dose-dependent manner with adult survivors showing eye and wing morphological defects. In addition, larvae in the Pf-5 treatment groups showed a dose-dependent delay in the onset of metamorphosis relative to control-, Pf0-1-, and SBW25-treated larvae. A functional gacA gene is required for the toxic properties of wild-type Pf-5 bacteria.These experiments are the first to demonstrate that ingestion of P. fluorescens bacteria by D. melanogaster larvae causes both lethal and non-lethal phenotypes, including delay in the onset of metamorphosis and morphological defects in surviving adult flies, which can be decoupled

Genotype and Gene Expression Associations with Immune Function in Drosophila

It is now well established that natural populations of Drosophila melanogaster harbor substantial genetic variation associated with physiological measures of immune function. In no case, however, have intermediate measures of immune function, such as transcriptional activity of immune-related genes, been tested as mediators of phenotypic variation in immunity. In this study, we measured bacterial load sustained after infection of D. melanogaster with Serratia marcescens, Providencia rettgeri, Enterococcus faecalis, and Lactococcus lactis in a panel of 94 third-chromosome substitution lines. We also measured transcriptional levels of 329 immune-related genes eight hours after infection with E. faecalis and S. marcescens in lines from the phenotypic tails of the test panel. We genotyped the substitution lines at 137 polymorphic markers distributed across 25 genes in order to test for statistical associations among genotype, bacterial load, and transcriptional dynamics. We find that genetic polymorphisms in the pathogen recognition genes (and particularly in PGRP-LC, GNBP1, and GNBP2) are most significantly associated with variation in bacterial load. We also find that overall transcriptional induction of effector proteins is a significant predictor of bacterial load after infection with E. faecalis, and that a marker upstream of the recognition gene PGRP-SD is statistically associated with variation in both bacterial load and transcriptional induction of effector proteins. These results show that polymorphism in genes near the top of the immune system signaling cascade can have a disproportionate effect on organismal phenotype due to the amplification of minor effects through the cascade