Major Ones (major + ones)

Distribution by Scientific Domains

Selected Abstracts

Flavour volatiles of flowers and stalks of Murraya koenigii L.

S. G. Walde
Abstract The volatiles of fresh leaf stalks and flowers of Murraya koenigii (curry leaf plant), grown in Hyderabad, India, were isolated by simultaneous distillation and extraction method and analysed by GC,MS. Thirty-one components were identified in the leaf stalk oil, constituting 88.1% of the volatile oil. The major components were the mono- and sesquiterpene hydrocarbons (66.7%), of which the major ones were , -pinene (24.2%), , -pinene (6.9%), , -phellandrene (7.3%) and , -copaene (8.9%). In addition, the oil had nine oxygenated monoterpenes (14.2%) and four sesquiterpene alcohols (8.1%). In the flower oil, 24 components were identified, constituting 91.8% of the volatile oil. Here, too, the major constituents were mono- and sesquiterpenes (87%), of which cis -ocimene (34.1%), , -pinene (19.1%), , -terpinene (6.7%) and , -caryophyllene (9.5%) were predominant. It also contained seven oxygenated monoterpenes and three oxygenated sesquiterpenes, constituting 4.7% of the oil. The larger number of oxygenated mono- and sesquiterpenes present appear to be responsible for the intense odour associated with the stalk and flower parts of Murraya koenigii as compared to the leaf. Copyright 2006 John Wiley & Sons, Ltd. [source]

Molecular mechanics (MM4) calculations on carbonyl compounds part I: aldehydes

Charles H. Langley
Abstract Aliphatic aldehydes have been studied with the aid of the MM4 force field. The structures, moments of inertia, vibrational spectra, conformational energies, barriers to internal rotation, and dipole moments have been examined for six compounds (nine conformations). MM4 parameters have been developed to fit the indicated quantities to the wide variety of experimental data. Ab initio (MP2) and density functional theory (B3LYP) calculations have been used to augment and/or replace experimental data, as appropriate. Because more, and to some extent, better, data have become available since MM3 was developed, it was anticipated that the overall accuracy of the information calculated with MM4 would be better than with MM3. The best single measure of the overall accuracy of a force field is the accuracy to which the moments of inertia of a set of compounds (from microwave spectroscopy) can be reproduced. For all of the 20 moments (seven conformations) experimentally known for the aldehyde compounds, the MM4 rms error is 0.30%, while with MM3, the most accurate force field presently available, the rms error over the same set is 1.01%. The calculation of the vibrational spectra was also improved overall. For the four aldehydes that were fully analyzed (over a total of 78 frequencies), the rms errors with MM4 and MM3 are 18 and 38 cm,1, respectively. These improvements came from several sources, but the major ones were separate parameters involving the carbonyl carbon for formaldehyde, the alkyl aldehydes and the ketones, and new crossterms featured in the MM4 force field that are not present in the MM3 version. 2001 John Wiley & Sons, Inc. J Comput Chem 22: 1396,1425, 2001 [source]

Optimising the policy cost of market stabilisation: Which commodity matters most in Ethiopia?

Kindie Getnet
Abstract Unprecedented food crop price spikes in recent years prompted the Ethiopian government to impose grain export ban and to distribute grain stocks as price stabilization strategies. Successful price stabilization and size of public spending for such programs depend, to a large extent, on the choice and targeting of stabilization strategies. In a situation where a single commodity plays a leadership role in the price dynamics of other crops, targeting intervention at such a commodity would provide a useful mechanism to reduce policy cost of price stabilization while achieving commodity-wide stabilization objectives. Using multiple cointegration analysis techniques to generate knowledge useful in targeting price stabilization intervention, this study investigates whether there is a single food crop in Ethiopia, among the three major ones (teff, wheat, and maize), with an exclusive price leadership role in the price formation process of the rest. The results show that maize price plays a leadership role in the dynamics of teff and wheat prices at all markets studied, except that of Addis Ababa teff market. Given the major evidence of a price leadership role of maize, it might be possible to achieve commodity-wide price stabilization objectives through targeting intervention on maize. Such targeted intervention may also prove efficiency in terms of reducing policy cost and public spending. Copyright 2008 John Wiley & Sons, Ltd. [source]

Molecular Bases of Congenital Hypopigmentary Disorders in Humans and Oculocutaneous Albinism 1 in Japan

The molecular bases of various types of congenital hypopigmentary disorders have been clarified in the past 10 years. Homozygous gene mutations of enzymes functional in melanogenesis such as tyrosinase, P protein and DHICA oxidase, result in oculocutaneous albinism (OCA) 1, OCA 2, and OCA 3, respectively. The genes responsible for Hermansky-Pudlak syndrome (HPS) and Chediak-Higashi syndrome (CHS) have also recently been isolated and cloned. The transcription factor paired box 3 (PAX3) works at the promoter region of the microphthalmia-associated transcription factor (MITF) gene, and the MITF transcription factor orders the expression of c-kit, which encodes the receptor for stem-cell factor, which in turn stimulates melanoblast migration from the neural tube to the skin in the embryo. Heterozygous mutations of PAX3, MITF, or c-kit genes induce Waardenburg syndrome (WS) 1/3, WS 2 or Piebaldism, respectively. A defect of endothelin-3 or the endothelin-B receptor produces WS 4. In our examination of 26 OCA 1 patients in Japan, all were found to have homozygous or heterozygous tyrosinase gene mutations at codons 77 or 310. Therefore, mutations at codons 77 and 310 are the major ones in Japanese patients with OCA 1. An autosomal dominant pigmentary disease of dyschromatosis symmetrica hereditaria (DSH) is well known in Japan, and is characterized by a mixture of hypo- and hyper-pigmented macules of various sizes on the backs of the hands and feet. The disease gene and its chromosomal localization have not been identified yet. Our trial of linkage analysis and positional cloning to determine the disease gene is presented. [source]