bluuebunny/crossref_metadata_2025 huggingface dataset:
Cold‐spray ionization mass spectrometry: principle and applications
Authors: Yamaguchi Kentaro
Published: June 2003

A direct solution analysis method, cold‐spray ionization (CSI) mass spectrometry (MS), a variant of electrospray (ESI) MS operating at low temperature (ca −80 to 10 °C), allows the facile and precise characterization of labile organic species, especially those in which non‐covalent bonding interactions are prominent. We applied this method to investigations of the solution structures of many labile organic species, including unstable reagents and reaction intermediates, asymmetric catalysts, supramolecules and even primary biomolecules. Remarkable analytical results were obtained for highly ordered supramolecules using the CSI method. Whereas conventional ESI is not applicable to these compounds because of their instability to heat and/or air, CSI affords multiply charged molecular ions with many solvent molecules attached. Investigation of the constitution of Grignard reagents in solution is extremely challenging, but CSI‐MS allowed us to identify one of the key structures in THF solution. Recently, this method was adopted for investigations of the solution structures of primary biomolecules such as nucleosides, amino acids, sugars and lipids, revealing singly charged Na+ adducts of large clusters (chain structures), presumably linked by non‐covalent interactions, including hydrogen bonding and/or hydrophobic interactions. The principle of the CSI method and applications of the method to a wide variety of labile organic species and primary biomolecules in solution are described. Copyright © 2003 John Wiley & Sons, Ltd.
Genetic diversity of organoleptic properties in water yam (Dioscorea alata L)
Authors: Egesi Chiedozie N , Asiedu Robert , Egunjobi James K , Bokanga Mpoko
Published: May 2003

Improving the food quality of yams (Dioscorea spp) is an ongoing challenge to yam breeders and researchers. Forty accessions of D alata were evaluated for the suitability of their tubers for the preparation of two dominant food forms (boiled and pounded) as part of an effort to identify potential parents for use in genetic improvement. Trained panellists were presented with randomised, replicated and coded samples of boiled yam tuber pieces and asked to rate them for mealiness, colour, wetness, softness and taste. The sensory attributes considered for pounded yam (dough from boiled and pounded tubers) were consistency, colour, sheen, smoothness, stickiness, elasticity and hardness. Ratings were based on hedonic scales. Cluster analysis revealed groupings of accessions into eight and nine similarity clusters for boiled yam and pounded yam respectively. The mean scores for general preference were regressed on individual attribute scores. Mealiness, colour and taste were important in the general preference for boiled yam. Consistency, colour and stickiness determined the general preference for pounded yam. Of the accessions, 67% were identified as being suitable for preparation as a boiled vegetable, while 55% were assessed to be good for pounded yam, based on the respective quality attributes evaluated.

© 2003 Society of Chemical Industry
Sedimentation behaviour and turbidity of carrot juices in relation to the characteristics of their cloud particles
Authors: Reiter Martin , Neidhart Sybille , Carle Reinhold
Published: May 2003

The cloud stability of carrot juices was investigated using physical methods. In contrast to cloudy juices from fruits or other vegetables described so far, complete clarification of juice samples could not be achieved even after ultracentrifugation. Since the density of one particle fraction was almost equal to that of the continuous phase, this fraction was resistant to sedimentation by centrifugal forces up to 60 600 × g in an 8° Brix carrot juice. Cloud stability problems of carrot juices, therefore, are usually associated with bottom sediment formation, but not with visible loss of turbidity. Particle size and density were shown to be decisive for suspension stability, whilst both particle charge and serum viscosity did not show any effect on cloud stability. The reasons for the exceptional stability of the suspended particles are discussed. Based on three particle fractions, a new physical concept could be deduced according to particle size and density explaining the extraordinary suspension stability of carrot juices. Copyright © 2003 Society of Chemical Industry
Molecular identification of five commercial flatfish species by PCR–RFLP analysis of a 12S rRNA gene fragment
Authors: Comesaña Angel S , Abella Paz , Sanjuan Andrés
Published: May 2003

Refrigerated or frozen fillets of commercial flatfish species are sometimes mislabelled, and identification of those products is needed to avoid fraudulent substitution. Molecular identification of five commercial flatfish species (order Pleuronectiformes), ie Lepidorhombus whiffiagonis (megrim), Platichthys flesus (flounder), Reinhardtius hippoglossoides (Greenland halibut), Scophthalmus maximus (turbot) and Solea vulgaris (= S solea) (sole), has been carried out on the basis of the amplification of an approximately 433 bp segment from the mitochondrial 12S rRNA gene using the polymerase chain reaction (PCR) and universal primers. Direct DNA sequencing from two PCR products for each flatfish species was carried out, and sequences were used to select six restriction enzymes. PCR products of 15 individuals of each species were cut with each enzyme, resulting in species‐specific restriction fragment length polymorphism (RFLP). The five flatfish species could be identified by application of the restriction enzyme AluI as well as by using different combinations of a pair of enzymes, ie DdeI and either AciI or MwoI. No intraspecific genetic polymorphism was found for any of the six enzymes. Results confirmed the usefulness of this technique to distinguish and genetically characterise refrigerated or frozen pieces of these five flatfish species. Copyright © 2003 Society of Chemical Industry
Preparation and structural properties of small‐particle cassava starch
Authors: Sanguanpong Varangkana , Chotineeranat Sunee , Piyachomkwan Kuakoon , Oates Christopher G , Chinachoti Pavinee , Sriroth Klanarong
Published: May 2003

Acid and enzyme hydrolyses followed by ball milling were applied to fracture cassava starch granules. Microscopic and chromatographic evidence suggested different mechanisms of the two hydrolyses. Using the enzyme process, granules with a sponge‐like structure and shells with the interior hydrolysed were produced. Amylose and amylopectin were subjected equally to multiple attacks by enzymes, with no significant change in granule crystallinity. The hydrolysed residues could not be effectively broken down by ball milling, although the crystallinity was destroyed. In contrast, the acid treatment caused superficial external corrosion, mainly at the amorphous lamellae, ie the branch points of amylopectin. Acid‐lintnerised starch granules were mostly of Degree of polymerization, DP 10–15 and exhibited increased crystallinity and brittleness, making them more susceptible to breakdown upon milling. Ball milling, although destroying some degree of crystallinity, could effectively reduce the size of acid‐hydrolysed starch, with no further degradation of amylodextrin molecules. By a combination of lintnerisation and ball milling, smaller particle starch (3–8 µm compared with 3–30 µm for native starch) could be produced. It is clear that removal of the amorphous phase prior to milling is critical for effective rupture of the granules. Copyright © 2003 Society of Chemical Industry
Production of fungal biomass from cormel process waste‐water of cocoyam (Xanthosoma sagittifolium (L) Schott) using Aspergillus oryzae obtained from cormel flour
Authors: Duru C Chidi , Uma Ngwanma U
Published: May 2003

Aspergillus oryzae obtained from spoilt cormel flour was subjected to mutation treatments using X‐rays, solar radiation and bleach. Exposure of A oryzae spores to X‐radiation of 50 kV at 20 mA s and other treatments induced both mutation and lethality in the organism. Following selection and screening of viable colonies on a medium containing cormel process waste‐water as the only carbon source, two strains, A oryzae No 15 and A oryzae No 8, which significantly (P ≤ 0.05) produced more biomass at a higher growth rate than the wild parent, were chosen for single‐cell protein production. Nutrient content of the single‐cell protein produced by the mutants was comparable to that of the wild type. Addition of 3.0 g each of (NH4)2SO4, NH4NO3, NH4Cl, and urea in 1 l of Xanthosoma process waste‐water increased the growth rate of mutants, with the highest increase observed with urea. Medium amended with urea also produced fungal biomass with the highest protein level of 7.97 g l−1 for A oryzae No 8 strain compared with a protein yield of 3.97 g l−1 obtained in the control. Total biomass produced after 54 h was 22.47 g l−1 for A oryzae No 15 strain when urea was added, whereas only 15.20 g l−1 was produced when no nitrogen source was added. The optimal temperature for single‐cell protein production was found to be 35 °C and the optimal pH was 3.50. A speed of 100 rpm gave the largest quantity of fungal biomass for the mutants tested. Copyright © 2003 Society of Chemical Industry
Effect on protein digestibility of different processing conditions in the production of fish meal and fish feed
Authors: Opstvedt Johannes , Nygård Einar , Samuelsen Tor A. , Venturini Giorgio , Luzzana Umberto , Mundheim Harald
Published: May 2003

The effect of processing conditions on protein digestibility and fluorodinitrobenzene (FDNB)‐reactive (available) lysine in the production of fish meal and extruded fish feed has been studied under pilot and commercial conditions using mink as model animals. Fish meal produced under pilot‐plant conditions at processing temperatures below 70–80 °C (FM1) had protein digestibility of 929 (grams of protein digested per 1000 g protein consumed) compared with 905 when processed at temperatures above 100 °C (FM2). A low‐temperature‐processed commercial fish meal (CFM1) had protein digestibility of 940 compared with 888 for a standard commercial fish meal (CFM2). Pilot‐produced extruded fish feed had protein digestibility of 913 when based on FM1 as the main protein source (95% of total protein) compared with 892 when based on FM2. Commercial extruded fish feed had protein digestibility of 912 when based on CFM1 compared with 871 when based on CFM2. Varying extrusion conditions at the pilot scale, ie temperatures from 100 to 126 °C and moisture contents from 21 to 12%, did not affect protein digestibility. Similarly, under commercial conditions, variation in temperature from 89 to 110 °C and moisture from 24.5 to 19.5% did not affect FDNB‐reactive lysine and protein digestibility. The FDNB‐reactive lysine content and protein digestibility of the extruded feed were less than the values calculated from the ingredient mixture before extrusion. Thus, despite different extrusion conditions not giving different FDNB‐reactive lysine and protein digestibility, the total process, ie extrusion, drying and oil coating, caused a reduction. Copyright © 2003 Society of Chemical Industry
Supercritical carbon dioxide extraction for identification of adulteration of black pepper with papaya seeds
Authors: Bhattacharjee Paramita , Singhal Rekha S , Gholap Achyut S
Published: May 2003

Supercritical fluid extraction (SFE) using carbon dioxide was used to detect the adulteration of black pepper powder with ground papaya seed. Thin‐layer chromatography analysis of the SFE extracts showed a fluorescent band at 366 nm at Rf 0.172 that proved to be a promising marker for the presence of papaya seed powder in black pepper powder even at a level of 20 g kg−1. The straight‐chain aldehydes n‐nonanal, n‐decanal and n‐dodecanal were tentatively identified by gas chromatography–mass spectrometry analysis as components of this fluorescent marker and were not present in black pepper extracts. Copyright © 2003 Society of Chemical Industry
Improving the application of gibberellic acid to prolong dormancy of yam tubers (Dioscorea spp)
Authors: Tschannen Andreas B , Girardin Olivier , Nindjin Charlemagne , Daouda Dao , Farah Zakaria , Stamp Peter , Escher Felix
Published: May 2003

With the aim of reducing the cost and time needed to treat yam tubers with gibberellic acid (GA3), this study compared several new methods of application with the established dipping procedure (150 mg kg−1 for 1 h). Both GA3‐containing soil paste (25 mg kg−1) and gelatinized starch (860 mg kg−1) were applied to tuber heads of Dioscorea alata and D cayenensis‐rotundata in the Ivory Coast. Soil paste, gelatinized starch and dipping consistently prolonged dormancy and reduced fresh matter losses by 23–39% in D cayenensis‐rotundata 3‐year means. Although dipping reduced the storage losses most efficiently, soil paste and gelatinized starch used considerably less GA3. Both new treatments were easily prepared and quickly applied. Soil paste was most effective when the treatment was repeated before the end of dormancy. The third new method, spraying the tubers with a GA3 solution (150 mg kg−1), was not effective.

In general, the optimal time of application was immediately post‐harvest. For D alata, treatment only 1 month after harvest was particularly ineffective, whereas D cayenensis‐rotundata tubers could be treated with some effect up to the end of dormancy. To achieve extended storage periods of healthy tubers of D cayenensis‐rotundata, GA3 application may be recommended as post‐harvest practice. Copyright © 2003 Society of Chemical Industry
Effectiveness of different processing methods in reducing hydrogen cyanide content of flaxseed
Authors: Feng Dingyuan , Shen Yingran , Chavez Eduardo R
Published: May 2003

A study was conducted to determine the effectiveness of reducing the hydrogen cyanide (HCN) content of flaxseed (FS) by processing. FS was processed by oven heating, single or repeated pelleting alone or in a mix with corn or other ingredients, autoclaving, and microwave roasting. The comparative effectiveness in reducing HCN in FS by these processes was monitored through HCN measurements by alkaline titration. The HCN content was 377 mg kg−1 in raw feed‐grade FS and 139 mg kg−1 in a human food‐grade FS. All processing methods tested significantly (p < 0.05) reduced the HCN content of FS. Autoclaving FS reduced its HCN content by 29.7%. Microwave roasting of FS reduced the HCN content by 83.3%. Because of the 5.7% water loss recorded after 4 min of FS roasting, this reduction could be related to more evaporation of the newly formed HCN. Pelleting FS once reduced HCN content by 13.3%, and three and six repeated pelleting processes reduced HCN content by 29.0% and 54.9% respectively. When FS was pelleted in a mix with 50% corn, the HCN reduction was even greater. After pelleting six times, HCN reduction reached 63.8%. However, the greatest reduction in HCN content was 73.8%, and was obtained when FS was mixed with several ingredients and pelleted twice. The HCN reduction could be the result of deactivation of the glycosidase, or the evaporation of HCN formed from cyanogenic glycosides. The HCN reduction increased as the number of pelletings and the temperature of the pelleted product increased. The greater and prolonged exposure to a higher temperature by several pelletings seems to promote a greater HCN reduction. The appropriate processing of FS is essential for the use of this oilseed in animal feeding. Copyright © 2003 Society of Chemical Industry
Sensory flavour discrimination of Greek dry red wines
Authors: Koussissi Elisabeth , Paterson Alistair , Piggott John R
Published: May 2003

Aroma (16) and oral (17)—flavour by mouth, after‐taste and mouthfeel—attributes were separately profiled in 27 Greek red wines, products of single Greek indigenous grapes (Aghiorghitiko and Xinomavro) and international (Syrah and Cabernet Sauvignon) varieties and blends. From univariate analysis (ANOVA) of assessor data, 6 of 16 aroma and 16 of 17 oral attributes were significant (P < 0.05) in discriminations. Principal component analysis (PCA) product spaces of aroma and oral attributes explained 40% and 71% variance respectively. Discriminant partial least‐squares regression (DPLS), ANOVA and PCA discerned similar influences of variety and region of origin. Coding DPLS2 for variety, 76% and 38% of oral and aroma attribute variance respectively, and 39% and 18% category respectively were explained. Aghiorghitiko usage conferred fruity and sweet tastes and after‐tastes and smooth mouthfeel, typical of Peleponnese wines where this cultivar dominates. In contrast, Xinomavro products were bitter and sour in taste and bitter in after‐taste, with astringent and dry/dehydrating mouthfeel, but this was not characteristic of all wines from Macedonia. Copyright © 2003 Society of Chemical Industry
Concentration of amino acids in wine after the end of fermentation by Saccharomyces cerevisiae strains
Authors: Valero Eva , Millán Carmen , Ortega José M , Mauricio Juan C
Published: May 2003

Both quantitative and qualitative differences in the utilization and release of assimilable nitrogen by two wine strains of Saccharomyces cerevisiae (cerevisiae and capensis) under different conditions of oxygen were observed. These differences were influenced by the presence of oxygen at the beginning of the fermentation, and by the strain of S cerevisiae. The release of some amino acids post‐fermentation may be the result of reoxidation of NAD(P)H in order to maintain a normal redox balance. Copyright © 2003 Society of Chemical Industry
Ellagic acid content in strawberries of different cultivars and ripening stages
Authors: Williner María R , Pirovani María E , Güemes Daniel R
Published: May 2003

Ellagic acid is a phenolic compound which occurs naturally in strawberries. Interest in ellagic acid has increased during the past few years owing to its properties as a micronutrient. The objective of this study was to determine the ellagic acid content in strawberries compared with that in other common fruits and to evaluate its variability, the effects of ripening stage, and the tissue and seasonal variability in selected cultivars widely grown in Argentina. Strawberries showed significantly higher levels of ellagic acid than many other fruits of economic importance, ranging from 0.16 to 2.07 mg g−1 dry weight. The ellagic acid content was highest in green fruit, intermediate in mid‐ripe fruit and lowest in full‐ripe fruit. Cultivars ‘Chandler’ and ‘Camarosa’ contained the highest amounts of ellagic acid in strawberries with edible value (0.78 and 0.70 mg g−1 dry weight respectively), while ‘Oso Grande’ and ‘Milsei’ exhibited the lowest (0.35 and 0.31 mg g−1 dry weight respectively). Moreover, the level of this phytochemical was found to be higher when considering pulp with achenes compared with pulp without achenes. Copyright © 2003 Society of Chemical Industry
Solvent and salt effects on the kinetics of the reaction between [Ru(NH3)5pz]2+ and [Fe(CN)5H2O]3–
Authors: Prado‐Gotor R. , Ayala A. , Tejeda A. B. , Suárez M. B. , Mariscal C. , Sánchez M. D. , Hierro G. , Lama A. , Aldea A. , Jiménez R.
Published: May 2003

The kinetics of replacement of H2O by [Ru(NH3)pz]2+ (pz = pyrazine) in [Fe(CN)5H2O]3− have been studied in various concentrated electrolyte solutions and in various water–cosolvent mixtures, at 298 K. Salt and cosolvent effects can be rationalized taking into account specific medium effects on both the encounter complex formation process and the ligand‐substitution process, once the encounter complex is formed. These effects in water–cosolvent mixtures depend on the solvation of the reactants by the components of the mixture, as well as on the solvent–solvent interactions in these mixtures. Salt effects seem to be related to a primary salt effect as well as to the effect of the cations on the electronic density on the iron complex. © 2003 Wiley Periodicals, Inc. Int J Chem Kinet 35: 367–373, 2003
Kinetics and mechanism of the reactions of platinum(II)‐dipicolinate and platinum(II)‐glycylglycine with oxalate ion
Authors: Dey Sukalpa , Banerjee Pradyot
Published: May 2003

The kinetics of the reactions of [Pt(dipic)(H2O)] and [Pt(digly)(H2O)] (where H2dipic = pyridine‐2,6‐dicarboxylic acid and H2digly = glycylglycine) with oxalate ion were studied at 25°C in aqueous medium by UV–vis spectroscopy at I = 0.1 mol dm−3 over an wide range of pH. A probable associative pathway may involve a five‐coordinate intermediate leading to the formation of an unidentate oxalate species, which converts to bidentate chelate in subsequent fast steps. The products are isolated and characterized by CHN analysis, IR, and 1H NMR spectra. The kinetic data from pH variation experiments are fitted by a computer program to a sequence of reactions and the different rate constants are evaluated. © 2003 Wiley Periodicals, Inc. Int J Chem Kinet 35: 327–333, 2003
Rate coefficients and mechanisms of the reaction of cl‐atoms with a series of unsaturated hydrocarbons under atmospheric conditions
Authors: Orlando John J. , Tyndall Geoffrey S. , Apel Eric C. , Riemer Daniel D. , Paulson Suzanne E.
Published: May 2003

Rate coefficients and/or mechanistic information are provided for the reaction of Cl‐atoms with a number of unsaturated species, including isoprene, methacrolein (MACR), methyl vinyl ketone (MVK), 1,3‐butadiene, trans‐2‐butene, and 1‐butene. The following Cl‐atom rate coefficients were obtained at 298 K near 1 atm total pressure: k(isoprene) = (4.3 ± 0.6) × 10−10cm3 molecule−1 s−1 (independent of pressure from 6.2 to 760 Torr); k(MVK) = (2.2 ± 0.3) × 10−10 cm3 molecule−1 s−1; k(MACR) = (2.4 ± 0.3) × 10−10 cm3 molecule−1 s−1; k(trans‐2‐butene) = (4.0 ± 0.5) × 10−10 cm3 molecule−1 s−1; k(1‐butene) = (3.0 ± 0.4) × 10−10 cm3 molecule−1 s−1. Products observed in the Cl‐atom‐initiated oxidation of the unsaturated species at 298 K in 1 atm air are as follows (with % molar yields in parentheses): CH2O (9.5 ± 1.0%), HCOCl (5.1 ± 0.7%), and 1‐chloro‐3‐methyl‐3‐buten‐2‐one (CMBO, not quantified) from isoprene; chloroacetaldehyde (75 ± 8%), CO2 (58 ± 5%), CH2O (47 ± 7%), CH3OH (8%), HCOCl (7 ± 1%), and peracetic acid (6%) from MVK; CO (52 ± 4%), chloroacetone (42 ± 5%), CO2 (23 ± 2%), CH2O (18 ± 2%), and HCOCl (5%) from MACR; CH2O (7 ± 1%), HCOCl (3%), acrolein (≈3%), and 4‐chlorocrotonaldehyde (CCA, not quantified) from 1,3‐butadiene; CH3CHO (22 ± 3%), CO2 (13 ± 2%), 3‐chloro‐2‐butanone (13 ± 4%), CH2O (7.6 ± 1.1%), and CH3OH (1.8 ± 0.6%) from trans‐2‐butene; and chloroacetaldehyde (20 ± 3%), CH2O (7 ± 1%), CO2 (4 ± 1%), and HCOCl (4 ± 1%) from 1‐butene. Product yields from both trans‐2‐butene and 1‐butene were found to be O2‐dependent. In the case of trans‐2‐butene, the observed O2‐dependence is the result of a competition between unimolecular decomposition of the CH3CH(Cl)CH(O•)CH3 radical and its reaction with O2, with kdecomp/kO2 = (1.6 ± 0.4) × 1019 molecule cm−3. The activation energy for decomposition is estimated at 11.5 ± 1.5 kcal mol−1. The variation of the product yields with O2 in the case of 1‐butene results from similar competitive reaction pathways for the two β‐chlorobutoxy radicals involved in the oxidation, ClCH2CH(O•)CH2CH3 and •OCH2CHClCH2CH3. © 2003 Wiley Periodicals, Inc. Int J Chem Kinet 35: 334–353, 2003
Isomeric hexyl‐ketohydroperoxides formed by reactions of hexoxy and hexylperoxy radicals in oxygen
Authors: Jorand François , Heiss Adolphe , Perrin Olivier , Sahetchian Krikor , Kerhoas Lucien , Einhorn Jacques
Published: May 2003

Isomerization reactions of peroxy radicals during oxidation of long‐chain hydrocarbons yield hydroperoxides, and therefore play an important role in combustion and atmospheric chemistry, because of their action as branching agents in these chain reaction processes. Different formation mechanisms and structures are involved. Three isomeric hexyl‐ketohydroperoxides are formed via isomerization reactions in oxygen of either hexoxy RO or hexylperoxy RO2 radicals. In the temperature range 373–473 K, 2‐hexoxy (C6H13O) radical in O2/N2 mixtures gives 2‐hexanone‐5‐hydroperoxide via two consecutive isomerizations. The second one is a H transfer from a HC(OH) group occurring via a seven‐membered ring intermediate:

equation image

Its rate constant has been determined at 453 and 483 K, and the general expression can be written as

equation image

Hexylperoxy C6H13O2 radical, present in n‐hexane oxidation by oxygen/nitrogen mixtures in the temperature range 543–573 K, gives 2‐hexanone‐4‐hydroperoxide, 3‐hexanone‐5‐hydroperoxide, and 2‐hexanone‐5‐hydroperoxide. The first two are formed through an isomerization reaction via a six‐membered ring intermediate, and the last through an isomerization reaction via a seven‐membered ring intermediate. The ratio of the rate constant of the isomerization reactions of RO2 radicals via a seven‐membered ring intermediate to that via a six‐membered ring is found to be 0.795, and the rate constant expression via a seven‐membered ring intermediate is proposed:

equation image

The role of these reactions in the formation of radicals in the troposphere is discussed.

Other products arising in the reactional path, such as ketones, furans, and diketones, are identified.

Identification of these ketohydroperoxides was made using gas chromatography/mass spectrometry with electron impact, and with NH3 (or ND3) chemical ionization. © 2003 Wiley Periodicals, Inc. Int J Chem Kinet 35: 354–366, 2003
The H+NO recombination reaction over a wide temperature range
Authors: Riley Patrick S. , Cosic Biljana , Fontijn Arthurxy
Published: May 2003

Rate coefficients of the title reaction have been measured in a high‐temperature photochemistry (HTP) reactor using Ar as the bath gas. H atoms were generated by flash photolysis of NH3 and their relative concentrations were monitored by resonance fluorescence. The data are best fitted by k(295–905 K) = 6.5 × 10−34 (T/K)0.206 exp(780K T) cm6 molecule−2 s−1, with ±2σ precision values varying from 16 to 36% and corresponding suggested accuracy levels of 29–42%. Using a literature value for the relative collision efficiencies of N2 and Ar indicates that for N2 as the third body the above rate coefficient expression should be multiplied by 1.6. This leads to good agreement with two recent near 1000 K measurements. © 2003 Wiley Periodicals, Inc. Int J Chem Kinet 35: 374–380, 2003
A shock tube, laser‐schlieren study of the pyrolysis of isobutene: Relaxation, incubation, and dissociation rates
Authors: Santhanam S. , Kiefer J. H. , Tranter R. S. , Srinivasan N. K.
Published: May 2003

Dissociation, vibrational relaxation, and unimolecular incubation have all been observed in shock waves in isobutene with the laser‐schlieren technique. Experiments covered a wide range of high‐temperature conditions: 900–2300 K, and post‐incident shock pressures from 7 to 400 torr in 2, 5, and 10% mixtures with krypton. The surprising observation is that of vibrational relaxation, well resolved over the full temperature range. The resolved process is completely exponential, with relaxation times in the range 20–120 ns atm. Relaxation and dissociation are clearly separated for T > 1850 K, with estimated incubation times near 200 ns atm. Incubation is essential for modeling of the very low‐pressure decomposition. Modeling of gradients with a chain mechanism initiated by CH fission produces an excellent fit and accurate dissociation rates that show severe falloff. A restricted‐rotor, Gorin‐model RRKM analysis fits these rates quite well with the known bond‐energy as barrier and 〈ΔE〉down = 680 cm−1. The extrapolated k∞ is log k∞(s−1) = 19.187–0.865 log T −87.337 (kcal/mol)/RT, in good agreement with previous work. © 2003 Wiley Periodicals, Inc. Int J Chem Kinet 35: 381–390, 2003
Estimates of hyperbolic equations in Hardy spaces
Authors: Chang Der–Chen , Lee Yong–Seok
Published: June 2003

The aim of this paper is to study estimates of hyperbolic equations in Hardy classes. Consider the Cauchy problem P(Dt,Dx)u(t, x) = 0 for x ∈ ℝd and t > 0 with the initial conditions Djtu(0, x) = gj (x), j = 0, 1, …, m – 1. We assume that the symbol 𝒫(τ, ξ) of P(Dt,Dx) can be factorized as 𝒫(τ, ξ) = $ \prod ^{m}_{j=1} $(τ–ϕj(ξ)) where ϕj (ξ) = $ \left( \xi ^{2n_{j}}_{1} + \ldots + \xi ^{2n_{j}}_{d} \right)^{{1\over {2n_{j}}}} $, j = 1, …, m. We assume further that gj ∈ Hpk (ℝd) for j = 1, …, m – 1. Then the solution u of the problem (3.13) is in Hp(ℝd) provided k ≥ (d– 1) $ \left\vert {1 \over p} - {1 \over 2}\right\vert $ and $ {{2n-2} \over {2n-1}} $ < p < ∞. Here n = max{n1, …, nm}. In particular, P(Dt, Dx)u = $ {{\partial ^2 u} \over {\partial t^2}} $ – Δu = 0 with u(0, x) = f(x) and $ {{\partial u} \over {\partial t}} $ (0, x) = g(x), then the solution u of the wave equation is in Hp(ℝd) provided k ≥ (d – 1) $ \left\vert {1 \over p} - {1 \over 2}\right\vert $ and 0 < p < ∞.
Geodesic graphs on the 13–dimensional group of Heisenberg type
Authors: Dušek Z. , Kowalski O.
Published: June 2003

A g.o. space is a homogeneous Riemannian manifold M = (G/H, g) on which every geodesic is an orbit of a one–parameter subgroup of the group G. (G acts transitively on M as a group of isometries.) Each g.o. space gives rise to certain rational maps called “geodesic graphs”. We are particularly interested in the case when the geodesic graphs are of nonlinear character.

Up to recently only linear geodesic graphs and nonlinear geodesic graphs of degree two were observed. Here we study the generalized Heisenberg group (in the sense of A. Kaplan) of dimension 13 and with 5–dimensional center. We show that this is a g.o. space for which the lowest degree of a geodesic graph is equal to six or three, depending on the choice of the isometry group G.
Log–canonical forms and log canonical singularities
Authors: Flenner Hubert , Zaidenberg Mikhail
Published: June 2003

For a normal subvarietyVof ℂnwith a good ℂ*–action we give a simple characterization for when it has only log canonical, log terminal or rational singularities. Moreover we are able to give formulas for the plurigenera of isolated singular points of such varieties and of the logarithmic Kodaira dimension ofV\{0}. For this purpose we introduce sheaves ofm–canonical andL2,m–canonical forms on normal complex spaces. For the case of affine varieties with good C*–action we give an explicit formula for these sheaves in terms of the grading of the dualizing sheaf and its tensor powers.
A geometric description of the neutral component of the Jacobian of a real plane curve having many pseudo–lines
Authors: Fichou G. , Huisman J.
Published: June 2003

A pseudo–line of a real plane curve is a real branch that is not homologically trivial in ℙ2(ℝ). A real plane curve C of degree d is said to have many pseudo–lines if it has exactly d – 2 pseudo–lines and if the genus of its normalization C̃ is equal to d – 2. Let C be such a curve. We give a planar description of the neutral component of the set of real points of the Jacobian of the normalization C̃ of C.
Non nuclear integral operators with continuous kernels
Authors: Frerick Leonhard
Published: June 2003

In this note we give a positive answer to the following question posed by A. Pietsch:

Is there for all p, q ∈ (1, ∞) a continuous kernel K such that the associated integral operator TK : Lq([0, 1]) → Lp([0, 1]) fails to be nuclear?
The counting function for a λ–rational Sturm–Liouville problem
Authors: Greenberg Leon , Marletta Marco
Published: June 2003

We develop an oscillation theory for an equation of Hain–Lüst type, valid both outside and inside the essential spectrum. The results proved allow us to locate eigenvalues in the essential spectrum or resonances close to the essential spectrum. The numerical implementation of the oscillation theory requires a regularizing transformation of Niessen and Zettl.
Simple criterions for strongly starlikeness and starlikeness of certain order
Authors: Hamada Hidetaka , Kohr Gabriela
Published: June 2003

In this paper, we will give a sufficient condition for locally univalent holomorphic functions on the unit disc . in C to be strongly starlike. Also, we will give sufficient conditions for locally biholomorphic mappings on the unit ball B in a complex Banach space X to be starlike of certain order or strongly starlike.
Profinite quantum groups
Authors: Ng Chi–Keung
Published: June 2003

In this paper, we study a special class of compact quantum groups, namely, the profinite quantum groups.
Role of the somatosensory system in primary dystonia
Authors: Tinazzi Michele , Rosso Tiziana , Fiaschi Antonio
Published: May 2003

The pathophysiology of dystonia is still not fully understood, but it is widely held that a dysfunction of the corticostriatal–thalamocortical motor circuits plays a major role in the pathophysiology of this syndrome. Although the most dramatic symptoms in dystonia seem to be motor in nature, marked somatosensory perceptual deficits are also present in this disease. In addition, several lines of evidence, including neurophysiological, neuroimaging and experimental findings, suggest that both motor and somatosensory functions may be defective in dystonia. Consequently, abnormal processing of the somatosensory input in the central nervous system may lead to inefficient sensorimotor integration, thus contributing substantially to the generation of dystonic movements. Whether somatosensory abnormalities are capable of triggering dystonia is an issue warranting further study. Although it seems unlikely that abnormal somatosensory input is the only drive to dystonia, it might be more correlated to the development of focal hand than generalized dystonia because local somesthetic factors are more selectively involved in the former than in the latter where, instead it seems to be a widespread deficit in processing sensory stimuli of different modality. Because basal ganglia and motor areas are heavily connected not only with somatosensory areas, but also with visual and acoustic areas, it is possible that abnormalities of other sensory modalities, such as visual and acoustic, may also be implicated in the pathophysiology of more severe forms of primary dystonia. Further studies have to be addressed to the assessment of the role of sensory modalities and their interaction on the pathophysiology of different forms of primary dystonia. © 2003 Movement Disorder Society
Unilateral subthalamic deep brain stimulation in advanced Parkinson's disease
Authors: Linazasoro Gurutz , Van Blercom Nadège , Lasa Asier
Published: May 2003

Eight patients with advanced PD received a unilateral STN DBS. The UPDRS III off drug–on DBS was improved by a mean 44%. Dyskinesias were ameliorated. Levodopa daily dose was reduced. Three patients required the implantation of the second electrode. Unilateral DBS may be efficacious in some patients with advanced PD. © 2003 Movement Disorder Society
Unusual phenotypes in DYT1 dystonia: A report of five cases and a review of the literature
Authors: Edwards Mark , Wood Nicholas , Bhatia Kailash
Published: May 2003

Since the advent of widespread testing for the presence of the DYT1 gene mutation, the range of phenotypes that have been associated with this genetic abnormality has expanded. We report on 5 DYT1 gene‐positive patients with unusual phenotypes. Two of them had late presentation, one of these after peripheral injury. Three additional patients had late progression of symptoms, onset after exposure to haloperidol, and severe bulbar involvement, respectively. The clinical heterogeneity of this condition raises problems for clinicians in selecting appropriate patients for diagnostic testing. Also, because of the low phenotypic penetrance of DYT1 dystonia, the discovery of the DYT1 mutation in a patient with an atypical clinical syndrome may not necessarily suggest a causal relationship. We have, therefore, analysed all published clinical studies of DYT1 dystonia to guide clinical decision making concerning DYT1 gene testing based on current information. © 2003 Movement Disorder Society
Neuropsychiatric interpretations of postencephalitic movement disorders
Authors: Ward Christopher D.
Published: May 2003

This study reviews the impact of encephalitis lethargica (EL) on concepts of behaviour and movement during the 1920s and 1930s. Clinicopathological correlations were imprecise but supported the role of subcortical structures in complex patterns of motor behaviour. This possibility challenged the widely assumed hegemony of the cerebral cortex. There was a perceived link between involuntary movements and reduced impulse control and also between parkinsonism and a defect in volition. Contemporary observers interpreted postencephalitic phenomena such as oculogyria in psychodynamic as well as in neurophysiological terms. EL also gave some support to the idea that neuroses such as obsessional neurosis and hysteria might have an organic basis. These speculations recently have acquired more credibility. The large amount of literature on EL and its sequelae could perhaps make further contributions to understanding the pathology of voluntary movement and action. © 2003 Movement Disorder Society
Does ageing have an effect on midbrain premotor nuclei for vertical eye movements?
Authors: Henson Craig , Staunton Hugh , Brett Francesca M.
Published: May 2003

Currently, there is debate in the clinical literature as to whether defects in vertical gaze are a consequence of normal ageing or a component of an underlying neurodegenerative disorder. Although pathological changes have been demonstrated in diseased subjects, no study to date has addressed the question of normal ageing effects. In this retrospective study, we examined 23 neurologically and pathologically normal subjects (age 18–91). Using an unbiased, frame‐based sampling method, we quantified neuronal and glial cell densities in 10 young (<50) and 13 aged (>65) subjects in the rostral interstitial nucleus of the medial longitudinal fasciculus (riMLF), the key premotor substrate in the vertical gaze pathway. We found no statistically significant difference in neuronal density, glial cell density, or neuron‐to‐glial cell ratios between the young and the aged. We conclude, therefore, that neuronal loss, neuronal atrophy, or gliosis in the riMLF are not consequences of normal ageing. © 2003 Movement Disorder Society
Brain perfusion SPECT in patients with corticobasal degeneration: Analysis using statistical parametric mapping
Authors: Hossain A.K.M. Moinul , Murata Yuji , Zhang Lin , Taura Shin‐ichi , Saitoh Yukinobu , Mizusawa Hidehiro , Oda Kenji , Matsushima Eisuke , Okubo Yoshiro , Shibuya Hitoshi
Published: May 2003

We sought to determine the characteristics of brain perfusion in patients with corticobasal degeneration (CBD) using single photon emission computed tomography (SPECT) and statistical parametric mapping (SPM). Thirteen patients with CBD and 10 age‐matched healthy volunteers were examined using brain perfusion SPECT and 99mTc‐ethyl cysteinate dimer (ECD). Regional cerebral blood flow (rCBF) measurements were performed noninvasively using a graphic analysis method. Both the absolute rCBF data (raw data) and the adjusted rCBF data (global CBF normalized to 50 ml/100 g/min) were used in the SPM analysis. A significant decrease in the absolute rCBF was observed in extended areas of the brain in CBD patients compared to the control group. These areas included the frontal, parietal, and temporal cortices; basal ganglia; thalamus; and pontocerebellar regions. Our results suggest that the extent of the reduced rCBF region in CBD patients is more widespread than previously reported. © 2003 Movement Disorder Society
Abnormal cortical sensory activation in dystonia: An fMRI study
Authors: Butterworth Stephen , Francis Sue , Kelly Edward , McGlone Francis , Bowtell Richard , Sawle Guy V.
Published: May 2003

Despite the obvious motor manifestations of focal dystonia, it is recognised that the sensory system plays an important role in this condition. This functional magnetic resonance imaging study examines the sensory representations of individual digits both within the subregions of the primary sensory cortex (SI) and in other nonprimary sensory areas. Patients with focal dystonia and controls were scanned during vibrotactile stimulation of both the index (digit 2) and little (digit 5) fingers of their dominant hand (which was the affected hand in all the dystonic subjects). The activation maps obtained were analysed for location, size, and magnitude of activation and three‐dimensional (3‐D) orientation of digit representations. Data from both groups were compared. There were significant differences in the average 3‐D separation between the two digit representations in area 1 of SI between subject groups (9.6 ± 1.2 mm for controls and 4.1 ± 0.2 mm for dystonic subjects). There were also strong trends for reversed ordering of the representation of the two digits in both the secondary sensory cortex and posterior parietal area between the two groups. In addition, in dystonic subjects, there was significant under activation in the secondary somatosensory cortex (SII/area 40) for both digits and in the posterior parietal area for digit 5. These results indicate the presence of widespread activation abnormalities in the cortical sensory system in dystonia. © 2003 Movement Disorder Society
Sleep attacks, daytime sleepiness, and dopamine agonists in Parkinson's disease
Authors: Paus Sebastian , Brecht Hans Michael , Köster Jürgen , Seeger Gert , Klockgether Thomas , Wüllner Ullrich
Published: May 2003

To study the putative association of dopamine agonists with sleep attacks in patients with Parkinson's disease (PD) and their relation to daytime sleepiness, we performed a survey of 2,952 PD patients in two German counties. In 177 patients, sudden, unexpected, and irresistible sleep episodes while engaged in some activity were identified in a structured telephone interview. Ninety‐one of these patients denied the occurrence of appropriate warning signs. A total of 133 patients (75%) had an Epworth Sleepiness Scale (ESS) score >10; 65 (37%) >15. Thirty‐one patients (18%) had an ESS score ≤10 and yet experienced sleep attacks without warning signs. Thus, although a significant proportion of patients at risk for sleep attacks might be identified using the ESS, roughly 1% of the PD patient population seems to be at risk for sleep attacks without appropriate warning signs and without accompanying daytime sleepiness. Sleep attacks occurred with all dopamine agonists marketed in Germany (α‐dihydroergocryptine, bromocriptine, cabergoline, lisuride, pergolide, pramipexole, ropinirole), and no significant difference between ergot and nonergot drugs was evident. Levodopa (L‐dopa) monotherapy carried the lowest risk for sleep attacks (2.9%; 95% confidence interval [CI], 1.7–4.0%) followed by dopamine agonist monotherapy (5.3%; 95% CI, 1.5–9.2%) and combination of L‐dopa and a dopamine agonist (7.3%; 95% CI, 6.1–8.5%). Neither selegeline nor amantadine or entacapone appeared to influence the occurrence of sleep attacks. A high ESS score, intake of dopamine agonists, and duration of PD were the main influencing factors for the occurrence of sleep attacks. The odds ratio for dopamine agonist therapy was 2.9 compared to 1.9 with L‐dopa therapy and 1.05 for a 1‐year‐longer disease duration. © 2003 Movement Disorder Society
Effect of cognitive and motor tasks on postural stability in Parkinson's disease: A posturographic study
Authors: Marchese Roberta , Bove Marco , Abbruzzese Giovanni
Published: May 2003

To analyse the effect of concomitant cognitive or motor task performance on balance control in Parkinson's disease (PD), we performed a posturographic study in 24 PD patients and in 20 sex‐ and age‐matched control subjects. Postural sway was measured with eyes open (EO) and eyes closed (EC) during quiet stance and during performance of calculation or motor sequence of thumb opposition to the other fingers. No difference of centre of foot pressure (COP) parameters was observed during quiet standing (either EO or EC) between patients and controls, but visual deprivation induced in both groups a worsening of postural stability. COP area was significantly increased in PD patients during dual task performance, whereas no difference of COP path and x–y axes was observed. The effects induced by the performance of cognitive or motor task were significantly more evident in PD patients with clinical evidence of postural instability (presence of prior falls in the history). This study demonstrates that dual task interference on postural control can be observed in PD patients during performance of cognitive as well as motor tasks. The balance deterioration during dual task performance was significantly enhanced in patients with history of prior falls. These findings have some implications for the strategies to be used in reducing the risk of fall in PD. © 2003 Movement Disorder Society
Akathisia as a side effect of antipsychotic treatment with quetiapine in a patient with Parkinson's disease
Authors: Prueter Christian , Habermeyer Benedikt , Norra Christine , Kosinski Christoph M.
Published: May 2003

Due to its low profile for extrapyramidal side‐effects, quetiapine has become an alternative to clozapine in the treatment of dopamimetic psychosis in patients with Parkinson's disease (PD). We describe the case of a patient with PD who developed severe akathisia, a common complication with classical antipsychotics, with quetiapine. © 2003 Movement Disorder Society
Double‐blind, placebo‐controlled study to evaluate the efficacy and safety of botulinum toxin type A in the treatment of drooling in parkinsonism
Authors: Mancini Francesca , Zangaglia Roberta , Cristina Silvano , Sommaruga Maria Grazia , Martignoni Emilia , Nappi Giuseppe , Pacchetti Claudio
Published: May 2003

Drooling is a frequent symptom in Parkinson's disease (PD), occurring in almost 75% of all patients. Although it is now well known that drooling in PD is the result of swallowing difficulties rather than excessive saliva production, few treatments have been developed to reduce it. Clinical studies suggest that botulinum toxin A (BTX) injections into salivary glands are effective in decreasing drooling in PD patients. In this double‐blind, placebo‐controlled study, 20 patients with parkinsonism (idiopathic PD or multiple system atrophy), were randomly assigned to receive 450 U of BTX (Dysport; Ipsen, Berkshire, UK) or 2 ml of placebo, injected into the parotids and submandibular glands under ultrasonographic guidance. Treatment efficacy and safety were assessed at baseline, 1 week and 3 months after BTX injections using clinical scales (Drooling Severity and Drooling Frequency scales) and side effects surveillance. After treatment, the average secretion of saliva in the BTX group was significantly lower than in the placebo group, as appraised by clinical measurements. No side effects were observed in either group. BTX injection into parotids and submandibular glands, under ultrasonographic guidance, is an effective and safe treatment for drooling in parkinsonism. © 2003 Movement Disorder Society