bluuebunny/crossref_metadata_2025 huggingface dataset:
Antioxidative effects of polyamines
Authors: Løvaas Erik
Published: July 2007

The antioxidative effects of spermine, spermidine and putrescine were determined by measurement of primary and secondary oxidation products of polyunsaturated fatty acids, using gas and liquid chromatography as well as spectrophotometric recordings. It was demonstrated that polyamines inhibit the oxidation of polyunsaturated fatty acids,α‐tocopherol and carotenoid pigments. Both linear and nonlinear dose/response relationships have been observed. The efficiency of a given polyamine was correlated with the number of amine groups in the molecule. Spermine was, thus, more efficient than spermidine, which in turn had a higher efficiency than putrescine. The relative antioxidative effect was as follows: spermine (100.0), spermidine (61.0), putrescine (23.0), ethoxyquin (27.6), ascorbyl palmitate (18.3), octyl gallate (7.9), tert butylhydroquinone (6.3), butylated hydroxyanisole (3.6) andα‐tocopherol (3.4).
Mustard seed processing: essential oil composition
Authors: Kirk L. D. , Black L. T. , Mustakas G. C.
Published: July 2007

Recent investigations into the processing of oriental mustard seed for production of livestock feed and of lipid‐containing erucic acid have stimulated interest in the composition of the by‐product essential oil. The development of a method for analysis of this oil by gas‐liquid chromatography has led to the demonstration of an equilibrium reaction between the two main constituents. A similarity in composition and response to heat is shown between the natural essential oil and oils prepared synthetically. These observed similarities should lead to a better understanding of the enzymatic reaction responsible for release of this oil from the seed.
Phospholipids of the South African pilchard(Sardina ocellata Jenyns)
Authors: Silk M. H. , De Koning A. J.
Published: July 2007

Chromatographic resolution of phospholipids from the flesh of the South African pilchard(Sardina ocellata Jenyns) revealed the presence of cardiolipins, cephalins, inositol phosphatides, cerebrosides, sphingomyelins, lecithins, lysoleci‐thins and plasmalogens. Column and paper Chromatographic techniques were used to identify ethanolamine, serine, cho‐line, sphinogsine and inositol in pilchard phos‐pholipid hydrolysates. The fatty acids of pilchard phospholipids com‐prised large amt of C22 hexaenoic, C20 pentaenoic and C16 saturated acids, with smaller amt of C18 dienoic, C18 monoenoic and C18 saturated acids.
Dilatometric properties of some butyropalmitins, butyrostearins, and acetopalmitins
Authors: Feuge R. O. , Lovegren N. V.
Published: July 2007

Six aceto‐ and butyroglycerides, including di‐and triglycerides, were prepared and purified, and a number of their physical properties were determined.

Melting and transition points for each of the glycerides were determined by experiments with small portions of the samples in capillary tubes; the “thrust‐in” technique was employed to detect some polymorphic transitions occurring in intervals as short as one second.

Using the data on melting and transition points, dilatometric data were obtained, insofar as possible, for the various crystalline modifications of the compounds as well as for the liquid state. From the dilatometric data calculations were made for expansibilities in the liquid and various solid states, and melting dilations for several solid states. In one instance the volume change on phase transition, without melting, was calculated.

From X‐ray diffraction patterns the long and short crystal spacings for the highest melting forms of several of the glycerides were determined. On the basis of the short spacings, polymorphic designations commonly used for fats and oils were assigned. The long spacings obtained indicated a triple chain length structure for some of the compounds and as yet an undetermined structure for the other compounds.
Alteration of long chain fatty acids of herring oil during hydrogenation on nickel catalyst
Authors: Sebedio J. ‐L. , Langman M. F. , Eaton C. A. , Ackman R. G.
Published: July 2007

During hydrogenation of a refined herring(Clupea harengus) oil iodine value (IV) 119, on a commercial nickel catalyst, samples were collected at IV 108, 101, 88 and 79. In the early stages of the process, IV 119 to IV 101, the positional and geometrical isomerization of the long chain monoenoic fatty acids (20:1 and 22:1) was hindered by the stronger absorption on the catalyst surface of the polyenes with 4, 5 and 6 double bonds. Consequently at IV 101, 70% of these polyenes had been converted to dienoic and trienoic fatty acids, but only 3‐4%trans 20:1 and 22:1 accumulated. As the hydrogenation proceeded, IV 101 to IV 79, the originaleis 20:1 and 22:1 isomers (mainly Δ11 with some ΔA9 and Δ13) decreased and new positional and geometrical isomers (both cis andtrans in positions Δ6 to Δ15) were formed. The majortrans isomers were Δ11 accompanied by important proportions of Δ10 and Δ12. At IV 79, moretrans 20:1 (ca. 36%) thantrans 22:1 (ca. 29%) was detected. Monoethylenic fatty acids newly formed from polyethylenic fatty acids made only minor contributions to the total 20:1 and 22:1 at these levels of hydrogenation, but a “memory effect” which skews the proportions of minorcis andtrans isomers can be attributed to the proportions of minorcis 22:1 isomers (Δ9, Δ13 and Δ15) orginally present.
Catalytic hydrogenation of soybean oil with Rh(l) dihydride complexes as catalysts
Authors: Andersson C. , Larsson R.
Published: July 2007

Cationic rhodium(I) complexes of the type [NBD Rh L2]+[C1O4]− (NBD = norbornadiene and L = diphenylphosphinoethane or triphenylphosphine) have been studied as catalysts for the hydrogenation of soybean oil. These catalysts give a good yield of products with cis‐configuration. Indeed, hydrogenation could be performed under mild conditions (30 C, 1 atm hydrogen pressure) to an iodine value of 80 with not more than 12% oftrans monoenes and only 5% conjugated isomers formed. The results obtained are interpreted on the basis of the equilibrium H2RhLn+⇌HRhLn+H+. By the addition of acid (HClO4) the bishydrido form of the catalyst could be studied. With this system only small amounts of trans monoenes were formed and no othertrans isomers could be detected. By the addition of a base such as triethylamine, the monohydridic form of the catalyst could be studied. In contrast to the bishydrido complex, this system gave large amounts oftrans monoenes, together withcis‐trans andtrans‐trans forms of the 18:2 acid. With both forms of the catalyst system, conjugated isomers were formed.
Major Factors That Influence Bleaching Performance
Authors: Rich A. D.
Published: July 2007

The three major factors which affect bleaching performance are type of clay, bleaching method, and oil quality. These are discussed in order. Under the first are such topics as purpose of clay in industry, source of raw material, clay types, physical structure, effect of activation on structure, variation in effectiveness of clays produced from different raw materials, and mechanism of the clay's action. Also covered is the effect of the clay's properties‐moisture, apparent bulk density, specific gravity, acidity, pH, hydrated silica, particle‐size distribution, and the theory of variability. Under the second are effect of bleaching conditions, such as temperature, time, agitation, temperature of clay addition, vacuum versus atmospheric bleaching; commercial methods including atmospheric batch, vacuum batch, vacuum continuous; and effect of oil quality. Under the third are response of different color pigments to bleaching, effect of moisture, oxidation, and organic impurities in the oil. Of the three factors, oil quality has the greatest influence upon bleaching performance.
Determination of the glyceride structure of fats. glyceride structure of fats with unusual fatty acid compositions
Authors: Subbaram M. R. , Youngs C. G.
Published: July 2007

Five fats containing less common fatty acids, nutmeg butter (myristic), rapeseed oil (erucic, eicosenoic), peanut oil (arachidic, behenic, lignoceric), tung oil (eleostearic), and coriander seed oil (petroselinic) were oxidized, and the oxidized esterified glycerides were analyzed by gas‐liquid chromatography (GLC). The values obtained are compared with those calculated from lipase hydrolysis data. Although there was a general over‐all agreement between the compositions calculated from lipase hydrolysis data and that obtained by GLC analysis of the oxidized glycerides, there were some discrepancies that exceeded the range of experimental error.
The flavor potential of milk fat. A review of its chemical nature and biochemical origin
Authors: Kinsella J. E. , Patton S. , Dimick P. S.
Published: July 2007

Actual and potential flavors are among the most important attributes of milk fat. In some dairy products (milk, cream, ice cream, uncul‐tured butter) the aim is to retain the faint pleasant flavor associated with the fat of fresh milk. However in cooking, baking, and many processed food applications the object is to gen‐erate buttery, creamy, cheesy, and caramel‐like flavor qualities from milk fat. Although the ulti‐mate chemical characterization of all these fla‐vors has not been achieved, the existing infor‐mation is reviewed in this paper. Some recent findings concerning the biological variability and significance of the lactone and ketone flavor po‐tential of milk fat are also presented. A scheme which outlines means for more effectively utiliz‐ing the flavor capabilities of milk fat is included.
Polymorphism of POP and SOS. II. kinetics of melt crystallization
Authors: Koyano T. , Hachiya I. , Arishimo T. , Sato K. , Sagi N.
Published: July 2007

Melt crystallization of the polymorphs of SOS, α,γ, pseudo‐β′, β2 and β1. and of POP, α,γ, pseudo‐β′2 pseudo‐β1, β2andβ1was examined using pure samples (99.9%). Induction time τ for newly occurring crystals in the melt phase was measured with a polarizing microscope equipped with a temperature‐controlled growth cell. Rate of crystallization, 1/τ, was obtained for each polymorph of POP and SOS whose identification was done with X‐ray diffraction and differential scanning calorimetry (DSC). Two modes of crystallization, melt‐cooling and melt‐mediation, yielded approximately the same results for POP and SOS: (a) The rates of crystallization were always higher in less stable than in more stable forms,β2only crystallized via a γ‐melt mediation, butβ1did not occur by the melt crystallization; (b) the rate of meltmediated crystallization was always higher than the simple melt‐cooling as examined at the same crystallization temperature; (c) the occurrence behavior of the polymorphs differed between the simple‐cooling and meltmediation. The results were related to the solidification behavior of the polymorphs of cocoa butter.
Polymorphism and transformation energetics of saturated monoacid triglycerides from differential scanning calorimetry and theoretical modeling
Authors: Hagemann J. W. , Rothfus J. A.
Published: July 2007

Differential scanning calorimetry studies on saturated monoacid triglycerides were extended to include most odd and even chain lengths from tricaprylin (C8) through tritriacontanoin (C30). Two β’‐forms were common with triglycerides C15 through C24: shorter odd chain length triglycerides (C9‐C13) exhibited only one β’‐form; short even chain length triglycerides (C8‐C14) exhibited three. Odd chain length C21 and C23 triglycerides showed two β‐forms. Triglycerides of even chain lengths greater than C21 produced two α‐forms. Apparent energies of phase excitation for α‐form transformations (determined from scans at different heating rates) showed odd‐even alternation for short chain lengths, but increased linearly with chain length above C14, evidencing the importance of extended chain conformation and interactions as determinants of polymorph properties. Changes in melting point patterns, particularly for β’ and β‐forms, at C14 correlated with the change in apparent phase excitation energy. Comparisons of X‐ray data with dimensions from space‐filling models and agreement between observed entropies of fusion and values calculated for probabilistic models also emphasize the importance of extended chain conformation and suggest configurational differences, and possibly different polymorph conversion pathways for odd versus even chain length triglycerides.
Selection of bleaching agents for dry bleaches
Authors: Parker John
Published: July 2007

Dry bleaches or all‐fabric dry bleaches are increasing in usage (7% +, annually, is quoted) because the consumer is seeking fabric and dye safety coupled with good stain removal. Additionally, the consumer wants a product which requires less sorting of fabrics or colors and aids in the cleansing and stain‐removal action without color, fabric, or finish damage. The leading bleach ingredients for dry all‐fabric bleaches are peroxygen salts. One of the newest of these peroxygens with a good combination of performance characteristics — for bleaching, good stain removal, positive building action, and cumulative whitening — is the advanced FB™ Sodium Percarbonate. This presentation looks at the formulation of dry bleaches, their constituents, and how market needs are met, and examines the properties of the two persalt alternatives.
The fatty acid composition of various cruciferous seeds
Authors: Jart A.
Published: July 2007

Seeds from 26 Cruciferae species in 7 genera have been investigated for fat content and fatty acid composition of the oil. The GLC retention data have been verified by mass spectrometry. The oil from Cardamine graeca contained 54% of cis‐15‐tetracosenoic acid; it is the highest content of this acid so far reported in any seed fat.
Hydrocarbons and other weakly polar unsaponifiables in some vegetable oils
Authors: Basti′c M. , Bastl′c L. , Jovanovi′c J. J. , Spiteller G.
Published: July 2007

The hydrocarbon fractions obtained from sunflower, olive, soybean, rapeseed and pumpkin seed oils by fractionation of unsaponifiable matter were composed of n‐paraffins, isoprenoidal polyolefins, squalene, diterpene and triterpene hydrocarbons and compounds with oxygen. Iso‐, anteiso‐ and other branched hydrocarbons were not identified in any of investigated oils. Possible compounds with oxygen are aliphatic and alicyclic ketones, conjugated steroid ketones, esters and lactones. The differences in the hydrocarbon fractions of investigated oils suggest they may be used for characterization.
Chemical reactions involved in the deep‐fat frying of foods. VII. Identification of volatile decomposition products of trilinolein1
Authors: Thompson J. A. , May W. A. , Paulose M. M. , Peterson R. J. , Chang Stephen S.
Published: July 2007

The acidic and nonacidic volatile decomposition products (VDP) produced by pure trilinolein maintained at 185 C with periodic injection of steam were collected, fractionated, and identified. One hundred thirty‐three volatile compounds were positively or tentatively identified. The compounds identified included a number of new and interesting compounds, some with valuable organoleptic properties, such as the unsaturated lactones.
Indian stillingia oil and tallow
Authors: Narang S. A. , Sadgopal
Published: July 2007

The stillingia oil and tallow from the seeds ofSapium sebiferum Roxb., have been studied for their component fatty acids and component glycerides. The fatty acids composition was determined by Twitchell's lead‐salt‐alcohol method followed by systematic fractionation of the methyl esters under high vacuum. The glyceridic composition of the stillingia oil has been examined by permanganate‐oxidation and bromination methods whereas the composition of the glycerides of the stillingia tallow was arrived at by using the low‐temperature crystallization technique.

The component fatty acids of the stillingia oil have been found to consist of caprylic (1.5%), capric (1.0%), myristic (0.97%), palmitic (2.8%), stearic (1.0%), oleic (9.4%), linoleic (53.4%), and linolenic (30.0%); the latter two are the major constituents.

The glycerides of the oil were found to consist of disaturated‐mono‐linolein (7.9%), mono‐saturated‐dilinolein (7.9%), mono‐oleo‐di‐linolein (6.1%), monolinoleno‐di‐linolein (45.7%), mono‐linoleo‐di‐linolenin (10.7%), mono‐oleo‐di‐linolenin (3.3%), and oleo‐linoleo‐linolenin (18.4%).

The fatty acids composition of the stillingia tallow was found to be lauric (0.3%), myristic (4.2%), palmitic (62.3%), stearic (5.9%), and oleic (27.4%). The component glycerides were found to be trisaturated (31.2%), disaturated monounsaturated (64.0%) and monsaturated, diunsaturated (4.8%).
3‐amino‐1‐propanol as a complexing agent in the determination of total gossypol
Authors: Pons Walter A. , Pittman Robert A. , Hoffpauir Carroll L.
Published: July 2007

A method is proposed for the determination of total gossypol in cottonseed meals, crude oils, and soapstocks based on a rapid extraction of gossypol by neutralized 3‐amino‐1‐propanol in dimethylformamide to form a stable complex, followed by colorimetric analysis of an aliquot of the extract by means of an aniline reaction. A determination can be completed in about 2 hrs. and with minor modification in 1 hr. compared to about 7 hrs. for current methods. Results obtained by the proposed procedure on meals, oils, and soapstocks are in essential agreement with those found by use of other accepted methods. Desirable features, such as stability of reagents and extracts and a high degree of reproducibility, suggest that the procedure will satisfy the requirements for a rapid and simplified method for the analysis of all cottonseed products for total gossypol.
Changes in lipid components of seeds during growth and ripening of cacao fruit
Authors: Lehrian D. W. , Keeney P. G.
Published: July 2007

The biosynthesis of lipid in maturing cacao seeds was studied over two cropping seasons (1975\s‐1976) in Brazil using hybrids produced by cross pollination of Catongo with Amelonado cultivars. Seeds were collected at intervals between seed solidification (110\s‐120 days postpollination) and harvesting of ripe fruits at 175\s‐180 days. Lipid accumulated in seeds at a rapid, linear rate after the seeds solidified until near the beginning of ripening, when lipid build up proceeded at a greatly reduced rate. Triglyceride was the major lipid component at all stages of maturity, increasing from 69% to 96% of the total lipid over the period studied. The contributions of other lipid components to total lipids became less prominent as fat accumulated in seeds. However, on an individual seed basis their mass increased throughout development, except for phospholipids and diglycerides, which decreased on a mass/seed basis in the latter stages of fruit maturation. Since the rate of triglyceride production slowed at about the same time, the reduced amounts of phospholipids and diglycerides indicate the classical Kennedy pathway for triglyceride synthesis is operative in seeds of cacao. Fat present early in seed development was more unsaturated than typical cocoa butter of commerce. However, as lipid deposited during the period of active lipid synthesis, starting at about 130 days postpollination, a normal fatty acid composition was quickly established and did not change materially thereafter.
The fatty acid composition of seed oils from ten plant families with particular reference to cyclopropene and dihydrosterculic acids
Authors: Vickery J. R.
Published: July 2007

Oil contents and fatty acid compositions of 40 seed oils of the plant families Elaecarpaceae, Thymelaeceae, Malvaceae, Sterculiaceae (order Malvales); Anacardiaceae, Celestraceae, Sapindaceae (Sapindales); Ebenaceae, Sapotaceae (Ebenales) and Rhamnaceae (Rhamnales) are presented. Cyclopropene fatty acids (CPFA) occur in two families in the order malvales not hitherto assayed. CPFA contents of seed oils of 12 Australian and Pacific species of Malvaceae and Sterculiaceae are given. CPFA occur randomly in small amounts in at least six families not in the order Malvales. Dehydrosterculic acid (DHS) occurs in small amounts in many species of Anacardiaceae, Celestraceae, Elaeocarpaceae, Malvaceae, Sapindaceae, Sapotaceae and Sterculiaceae. Linoleic acid was predominant in 28 of 40 seed oils, being as high as 63.9% in two species. The sum of 18:1 and 18:2 esters exceeded 70% in 20 oils.
Growth and body composition in children with classical phenylketonuria: Results in 34 patients and review of the literature
Authors: Huemer M. , Huemer C. , Möslinger D. , Huter D. , Stöckler‐Ipsiroglu S.
Published: July 2007

Treatment of phenylketonuria (PKU, OMIM 261600) means a diet restricted in natural protein and supplemented with phenylalanine (Phe)‐free l‐amino acid mixtures. Growth impairment has been described even in patients with a total protein intake at or above the recommended dietary allowance (RDA). In the present study, growth and body composition (fat‐free mass (FFM) and fat) were recorded over 12 months in 34 treated PKU patients (mean age 8.7 years at baseline). Measurements were compared with those of healthy peers and with general population standard (Z‐) scores calculated using the LMS method. In 28 PKU patients, data on birth weight and birth length were available and related to measurements at baseline of the study. Mean total protein intake in PKU patients was 124% (range 77–193%) of the RDA (DACH 2000). No significant differences in growth and body composition were present between PKU patients and healthy populations either at birth or during the study period. The significant correlation of FFM (representing muscle mass) with intake of natural protein—rather than total protein—indicates that the enhancement of tolerance to natural protein may be of value in PKU patients.
Predicting the surface tension of biodiesel fuels from their fatty acid composition
Authors: Allen Cecil A. W. , Watts K. Chris , Ackman Robert G.
Published: July 2007

The emergence of biodiesel fuels as diesel fuel substitutes has led to several studies on their properties. Surface tension, which plays a role in atomization, has lacked attention compared to other properties. This paper presents a method to predict the surface tension of biodiesel fuels based on the fatty acid composition. Several binary, ternary, and quaternary mixtures of fatty acid ethyl ester gas chromatographic (GC) standards were prepared, and we found that a mass‐average equation predicted the surface tension of these mixtures within ±3.5% of their measured values. Six complex mixtures of fatty acid methyl ester GC standards that simulated typical oils used as biodiesel fuels were also prepared. For these complex mixtures the predicted surface tensions of the mixtures, calculated from a mass‐average equation, were 2–6% higher than the measured values. A mass‐average equation was developed in which we used a weighted surface tension for the individual components, and we found that this method predicted the surface tension of the simulated oils within ±4.5% of their measured values. Five natural vegetable oils were used to produce biodiesel fuels by the transesterification process. The predicted surface tensions of these fuels were all within ±3.5% of their measured values. The surface tensions of 15 biodiesel types were then predicted, based on their fatty acid composition as published in the literature. These results show that the differences in surface tension between biodiesel types are not the main cause of the reported differences in engine tests.
Tocopherols in breeding lines and effects of planting location, fatty acid composition, and temperature during development
Authors: Dolde David , Vlahakis Chris , Hazebroek Jan
Published: July 2007

As the use of tocopherols as natural antioxidants increases, it is economically and agronomically important to determine the range, composition, and factors that affect their levels in oilseed crops, a major commercial source. In this study, tocopherols were quantified from seeds of wheat, sunflower, canola, and soybean. The breeding lines analyzed possessed a broad range of economically important phenotypic traits such as disease or herbicide resistance, improved yield and agronomic characteristics, and altered storage oil fatty acid composition. Complete separation of all four native tocopherols was achieved using normal‐phase high‐performance liquid chromatography with ultraviolet detection. Total tocopherol concentration among wheat germ oil samples ranged from 1947 to 4082 µg g−1. Total tocopherol concentration ranges varied from 534 to 1858 µg g−1 in sunflower, 504 to 687 µg g−1 in canola, and 1205 to 2195 µg g−1 among the soybean oils surveyed. Although the composition of tocopherols varied substantially among crops, composition was stable within each crop. Total tocopherol concentration and the percentage linolenic acid were correlated positively in soybean oils with modified and unmodified fatty acid compositions. Tocopherol concentration and degree of unsaturation were not correlated in sunflower or canola seeds with genetically altered fatty acid composition. These findings suggest that breeding for altered storage oil fatty acid composition did not negatively impact tocopherol concentrations in sunflower and canola as they apparently did in soybeans. When 12 soybean breeding lines were grown at each of five locations, significant correlations were observed among planting location, breeding line, tocopherol concentration, and fatty acid composition. Analysis of seeds that matured under three different controlled temperature regimes suggests that the relationship between tocopherol concentration level and unsaturated fatty acids in commodity (not genetically modified for fatty acid composition) oil types is due to temperature effects on the biosynthesis of both compounds.
Clientelism and Ethiopia's post-1991 decentralisation
Authors: Chanie Paulos
Published: July 2007

This article addresses the question of why Ethiopia's post-1991 decentralisation reform is not taking the desired direction of matching diverse needs with available resources and creating accountable, responsive and autonomous regional governments. Given regional governments' relatively diverse socio-economic positions, the intention of the reform to create autonomous regions with devolved administrative, fiscal and political power is appropriate. Nonetheless, the implementation of the elements of the reform – expenditure assignment, revenue assignment, intergovernmental fiscal transfer and sub-national borrowing – is flawed. Existing studies that question the effectiveness of Ethiopia's devolution focus on political or fiscal aspects, and fail to link the de facto centre-region political power relationship with intergovernmental fiscal relations. This article, based on detailed field research in three regional governments, argues that the flawed intergovernmental fiscal relations reform is best explained by the clientelistic relationship between central and regional political parties.
Religion and politics: taking African epistemologies seriously
Authors: Ellis Stephen , Haar Gerrie ter
Published: July 2007

Religious modes of thinking about the world are widespread in Africa, and have a pervasive influence on politics in the broadest sense. We have published elsewhere a theoretical model as to how the relationship between politics and religion may be understood, with potential benefits for observers not just of Africa, but also of other parts of the world where new combinations of religion and politics are emerging. Application of this theoretical model requires researchers to rethink some familiar categories of social science.
Police commissioners, presidents and the governance of security
Authors: Hills Alice
Published: July 2007

Africa's police are usually assessed in terms of their adherence to democratic criteria. This results in inaccurate analysis because the police are actually governed according to presidential preference. This article uses the role of Africa's chief police officers to explore the relationship between presidents and their police, and the location of influence within the police. It identifies the significant variables shaping police governance in four countries with comparable institutional structures – Ghana, Kenya, Uganda and Zimbabwe – and confirms the negligible role played by public accountability.
Controversies in the determination of energy requirements
Authors: Elizabeth Weekes C.
Published: July 2007

To avoid any negative outcomes associated with under- or overfeeding it is essential to estimate nutrient requirements before commencing nutrition support. The energy requirements of an individual vary with current and past nutritional status, clinical condition, physical activity and the goals and likely duration of treatment. The evidence-base for prediction methods in current use, however, is poor and the equations are thus open to misinterpretation. In addition, most methods require an accurate measurement of current weight, which is problematic in some clinical situations. The estimation of energy requirements is so challenging in some conditions, e.g. critical illness, obesity and liver disease, that it is recommended that expenditure be measured on an individual basis by indirect calorimetry. Not only is this technique relatively expensive, but in the clinical setting there are several obstacles that may complicate, and thus affect the accuracy of, any such measurements. A review of relevant disease-specific literature may assist in the determination of energy requirements for some patient groups, but the energy requirements for a number of clinical conditions have yet to be established. Regardless of the method used, estimated energy requirements should be interpreted with care and only used as a starting point. Practitioners should regularly review the patient and reassess requirements to take account of any major changes in clinical condition, nutritional status, activity level and goals of treatment. There is a need for large randomised controlled trials that compare the effects of different levels of feeding on clinical outcomes in different disease states and care settings.
Session 6: Infant nutrition: future research developments in Europe EARNEST, the early nutrition programming project: EARly Nutrition programming – long-term Efficacy and Safety Trials and integrated epidemiological, genetic, animal, consumer and economic research
Authors: Fewtrell M. S. ,   on behalf of the EARNEST consortium
Published: July 2007

Increasing evidence from lifetime experimental studies in animals and observational and experimental studies in human subjects suggests that pre- and postnatal nutrition programme long-term health. However, key unanswered questions remain on the extent of early-life programming in contemporary European populations, relevant nutritional exposures, critical time periods, mechanisms and the effectiveness of interventions to prevent or reverse programming effects. The EARly Nutrition programming – long-term Efficacy and Safety Trials and integrated epidemiological, genetic, animal, consumer and economic research (EARNEST) consortium brings together a multi-disciplinary team of scientists from European research institutions in an integrated programme of work that includes experimental studies in human subjects, modern prospective observational studies and mechanistic animal work including physiological studies, cell-culture models and molecular techniques. Theme 1 tests early nutritional programming of disease in human subjects, measuring disease markers in childhood and early adulthood in nineteen randomised controlled trials of nutritional interventions in pregnancy and infancy. Theme 2 examines associations between early nutrition and later outcomes in large modern European population-based prospective studies, with detailed measures of diet in pregnancy and early life. Theme 3 uses animal, cellular and molecular techniques to study lifetime effects of early nutrition. Biomedical studies are complemented by studies of the social and economic importance of programming (themes 4 and 5), and themes encouraging integration, communication, training and wealth creation. The project aims to: help formulate policies on the composition and testing of infant foods; improve the nutritional value of infant formulas; identify interventions to prevent and reverse adverse early nutritional programming. In addition, it has the potential to develop new products through industrial partnerships, generate information on the social and economic cost of programming in Europe and help maintain Europe's lead in this critical area of research.
On the existence and ‘blow-up’ of solutions to a two-dimensional nonlinear boundary-value problem arising in corrosion modelling
Authors: Kavian Otared , Vogelius Michael
Published: July 2007

Let Ω be a bounded C2,α domain in R2. We prove that the boundary-value problem Δυ = 0 in Ω, ∂υ/∂n = λsinh(υ) on ∂Ω, has infinitely many (classical) solutions for any given λ > 0. These solutions are constructed by means of a variational principle. We also investigate the limiting behaviour as λ → 0+; indeed, we prove that each of our solutions, as λ → 0+, after passing to a subsequence, develops a finite number of singularities located on ∂Ω.
Homogenized model for a laminar ferromagnetic medium
Authors: Haddar H. , Joly P.
Published: July 2007

We study the homogenization of ferromagnetic equations with periodic coefficients in space dimension 2. The obtained nonlinear homogenized law can only be written using a two-scale framework, which couples microscopic and macroscopic scales. It also involves corrector terms, at the microscopic scale, in the form of pseudo-differential operators. We prove the L2 two-scale strong convergence in the laminar case (one-dimensional periodicity).
Indefinite Sturm–Liouville problems
Authors: Kong Q. , Wu H. , Zettl A. , Möller M.
Published: July 2007

We study the spectrum of regular and singular Sturm–Liouville problems with real-valued coefficients and a weight function that changes sign. The self-adjoint boundary conditions may be regular or singular, separated or coupled. Sufficient conditions are found for (i) the spectrum to be real and unbounded below as well as above and (ii) the essential spectrum to be empty. Also found is an upper bound for the number of non-real eigenvalues. These results are achieved by studying the interplay between the indefinite problems (with weight function which changes sign) and the corresponding definite problems. Our approach relies heavily on operator theory of Krein space.
Relative normal modes for nonlinear Hamiltonian systems
Authors: Ortega Juan-Pablo
Published: July 2007

An estimate on the number of distinct relative periodic orbits around a stable relative equilibrium in a Hamiltonian system with continuous symmetry is given. This result constitutes a generalization to the Hamiltonian symmetric framework of a classical result by Weinstein and Moser on the existence of periodic orbits in the energy levels surrounding a stable equilibrium. The estimate obtained is very precise in the sense that it provides a lower bound for the number of relative periodic orbits at each prescribed energy and momentum values neighbouring the stable relative equilibrium in question and with any prefixed (spatio-temporal) isotropy subgroup. Moreover, it is easily computable in particular examples. It is interesting to see how, in our result, the existence of non-trivial relative periodic orbits requires (generic) conditions on the higher-order terms of the Taylor expansion of the Hamiltonian function, in contrast with the purely quadratic requirements of the Weinstein–Moser theorem, which emphasizes the highly nonlinear character of the relatively periodic dynamical objects.
Existence and stability of ground-state solutions of a Schrödinger—KdV system
Authors: Albert John , Pava Jaime Angulo
Published: July 2007

We consider the coupled Schrödinger–Korteweg–de Vries system

which arises in various physical contexts as a model for the interaction of long and short nonlinear waves. Ground states of the system are, by definition, minimizers of the energy functional subject to constraints on conserved functionals associated with symmetries of the system. In particular, ground states have a simple time dependence because they propagate via those symmetries. For a range of values of the parameters α, β, γ, δi, ci, we prove the existence and stability of a two-parameter family of ground states associated with a two-parameter family of symmetries.
Non-stabilizing solutions of semilinear hyperbolic and elliptic equations with damping
Authors: Jendoubi M. A. , Poláčik P.
Published: July 2007

We consider two types of equations on a cylindrical domain Ω × (0, ∞), where Ω is a bounded domain in RN, N ≥ 2. The first type is a semilinear damped wave equation, in which the unbounded direction of Ω × (0, ∞) is reserved for time t. The second type is an elliptic equation with a singled-out unbounded variable t. In both cases, we consider solutions that are defined and bounded on Ω × (0, ∞) and satisfy a Dirichlet boundary condition on ∂Ω × (0, ∞). We show that, for some nonlinearities, the equations have bounded solutions that do not stabilize to any single function φ: Ω → R, as t → ∞; rather, they approach a continuum of such functions. This happens despite the presence of damping in the equation that forces the t derivative of bounded solutions to converge to 0 as t → ∞. Our results contrast with known stabilization properties of solutions of such equations in the case N = 1.
Large deviations in Axiom A endomorphisms
Authors: Liu Pei-Dong , Qian Min , Zhao Yang
Published: July 2007

By applying a general large-deviation theorem of Kifer and Ruelle's Smale space technique, some large-deviation estimates are proved for Axiom A endomorphisms.
A counterexample in Sturm–Liouville completeness theory
Authors: Binding Paul , Ćurgus Branko
Published: July 2007

We give an example of an indefinite weight Sturm-Liouville problem whose eigenfunctions form a Riesz basis under Dirichlet boundary conditions but not under anti-periodic boundary conditions.
Non-zero solutions for a Schrödinger equation with indefinite linear and nonlinear terms
Authors: Costa David G. , Tehrani Hossein , Ramos Miguel
Published: July 2007

We prove the existence of a non-trivial solution for the nonlinear elliptic problem −Δu + V(x)u = a(x)g(u) in RN, where g is superlinear near zero and near infinity, a(x) changes sign and V ∈ C(RN) is positive at infinity. For g odd, we prove the existence of an infinite number of solutions.
Boundedness of the Cesàro averaging operators on Dirichlet spaces
Authors: Andersen Kenneth F.
Published: July 2007

It is shown that the Cesàro averaging operators Cα, Re α > −1, introduced by Stempak, are bounded on the Dirichlet space Da if and only if a > 0, while the associated operators Aα are bounded on Da if and only if −1 < a < 2. This extends results of Galanopoulos, who considered the particular case α = 0 for 0 ≤ a ≤ 1.
Multiple solutions for semilinear elliptic equations in unbounded cylinder domains
Authors: Hsu Tsing-San
Published: July 2007

In this paper, we show that if b(x) ≥ b∞ > 0 in Ω̄ and there exist positive constants C, δ, R0 such that

where x = (y, z) ∈ RN with y ∈ Rm, z ∈ Rn, N = m + n ≥ 3, m ≥ 2, n ≥ 1, 1 < p < (N + 2)/(N − 2), ω ⊆ Rm a bounded C1,1 domain and Ω = ω × Rn, then the Dirichlet problem −Δu + u = b(x)|u|p−1u in Ω has a solution that changes sign in Ω, in addition to a positive solution.
On the transition to instability for compressible vortex sheets
Authors: Coulombel Jean-François , Secchi Paolo
Published: July 2007

We study the linear stability of a vortex sheet in a limit case that corresponds to a transition between a weakly stable regime and a violently unstable regime. We prove an energy estimate that reflects the high degeneracy of the uniform Kreiss–Lopatinskii condition.
Multiplicity of non-radial solutions of critical elliptic problems in an annulus
Authors: de Figueiredo Djairo Guedes , Miyagaki Olímpio Hiroshi
Published: July 2007

By looking for critical points of functionals defined in some subspaces of , invariant under some subgroups of O (N), we prove the existence of many positive non-radial solutions for the following semilinear elliptic problem involving critical Sobolev exponent on an annulus,

where 2* − 1 := (N + 2)/(N − 2) (N ≥ 4), the domain is an annulus

and f : R+ × R+ → R is a C1 function, which is a subcritical perturbation.
Uniqueness for an inverse problem originating from magnetohydrodynamics. A class of smooth domains
Authors: Beretta Elena , Vessella Sergio
Published: July 2007

We consider the homogeneous Dirichlet problem δu = −f(u) ≤ 0 in Ω with u = 0 on ∂Ω. We are interested in the inverse problem of determining the nonlinear source f from knowledge of the normal derivative of u, ∂u/δn, on an open arc Γ of ∂Ω. It is well known that this fails if Ω is a ball. On the other hand, Beretta and Vogelius proved that an analytic source f is uniquely determined from knowledge of (∂u/∂n)|Γ if Γ has at least a true corner. In this paper we try to bridge the gap finding a class of smooth domains for which the determination of analytic f is possible
Compact hypersurfaces in a unit sphere
Authors: Cheng Qing-Ming , Shu Shichang , Suh Young Jin
Published: July 2007

We study curvature structures of compact hypersurfaces in the unit sphere Sn+1(1) with two distinct principal curvatures. First of all, we prove that the Riemannian product is the only compact hypersurface in Sn+1(1) with two distinct principal curvatures, one of which is simple and satisfies

where n(n − 1)r is the scalar curvature of hypersurfaces and c2 = (n − 2)/nr. This generalized the result of Cheng, where the scalar curvature is constant is assumed. Secondly, we prove that the Riemannian product is the only compact hypersurface with non-zero mean curvature in Sn+1(1) with two distinct principal curvatures, one of which is simple and satisfies

This gives a partial answer for the problem proposed by Cheng.
On a simple model of reacting compressible flows arising in astrophysics
Authors: Feireisl Eduard , Novotný Antonín
Published: July 2007

We establish the existence of global-in-time weak solutions to a system of equations describing the motion of a compressible, viscous and heat conducting fluid undergoing a simple chemical reaction. Similar systems of equations arise as simple models in astrophysics.
Landau–Ginzburg-type equations on the half-line in the critical case
Authors: Kaikina Elena I. , Ruiz-Paredes Hector F.
Published: July 2007

We study nonlinear Landau–Ginzburg-type equations on the half-line in the critical case

where β ∈ C, ρ > 2. The linear operator K is a pseudodifferential operator defined by the inverse Laplace transform with dissipative symbol K(p) = αpρ, M = [1/2ρ]. The aim of this paper is to prove the global existence of solutions to the initial–boundary-value problem and to find the main term of the asymptotic representation of solutions in the critical case, when the time decay of the nonlinearity has the same rate as that of the linear part of the equation.
Non-homogeneous elliptic equations in exterior domains
Authors: do Ó J. , Lorca S. , Sánchez J. , Ubilla P.
Published: July 2007

We study the existence and multiplicity of positive solutions of the non-homogeneous elliptic equation

where N ≥ 3, the nonlinearity f is superlinear at both zero and infinity, q is a non-trivial, non-negative function, and a and b are non-negative parameters. A typical model is given by f(u) = up, with p ≥ 1.
Homogeneous sharp Sobolev inequalities on product manifolds
Authors: Ceccon Jurandir , Montenegro Marcos
Published: July 2007

Let (M, g) and (N, h) be compact Riemannian manifolds of dimensions m and n, respectively. For p-homogeneous convex functions f(s, t) on [0,∞) × [0, ∞), we study the validity and non-validity of the first-order optimal Sobolev inequality on H1, p(M × N)

where

and Kf = Kf (m, n, p) is the best constant of the homogeneous Sobolev inequality on D1, p (Rm+n),

The proof of the non-validity relies on the knowledge of extremal functions associated with the Sobolev inequality above. In order to obtain such extremals we use mass transportation and convex analysis results. Since variational arguments do not work for general functions f, we investigate the validity in a uniform sense on f and argue with suitable approximations of f which are also essential in the non-validity. Homogeneous Sobolev inequalities on product manifolds are connected to elliptic problems involving a general class of operators.
Critical Fujita exponents of degenerate and singular parabolic equations
Authors: Wang Chunpeng , Zheng Sining
Published: July 2007

In this paper we investigate the critical Fujita exponent for the initial-value problem of the degenerate and singular nonlinear parabolic equation

with a non-negative initial value, where p > m ≥ 1 and 0 ≤ λ1 ≤ λ2 < p(λ1 + 1) − 1. We prove that, for m < p ≤ pc = m + (2 + λ2)/(n + λ1), every non-trivial solution blows up in finite time, while, for p > pc, there exist both global and non-global solutions to the pro
Heparin and dermatan sulphate induced capacitation of frozen-thawed bull spermatozoa measured by merocyanine-540
Authors: Bergqvist A.-S. , Ballester J. , Johannisson A. , Lundeheim N. , Rodríguez-Martínez H.
Published: July 2007

Glycosaminoglycans (GAGs) are present in the oviduct in which the major part of sperm capacitation occurs. In this study we have tested how capacitation of frozen-thawed bull spermatozoa is effected by exposure to different GAGs detectable or possibly present in oviductal fluid; i.e. heparin, hyaluronan, heparan sulphate, dermatan sulphate and chondroitin sulphate. Following exposure of different duration, the spermatozoa were stained with either Chlortetracycline (CTC) or merocyanine-540 and evaluated with epifluorescent light microscopy or flow cytometry, respectively. Heparin elicited a significant increase in the number of alive, capacitated spermatozoa, either expressed as higher merocyanine-540 fluorescence (p< 0.0001) or as B-pattern (p= 0.0021) in the CTC assay, during 4 h of incubation. When comparing the different GAG treatments one by one to the negative control in the flow cytometric study, only heparin and dermatan sulphate were significant (p< 0.0001) higher than the control at 0–30 min of incubation. Duration of incubation did not affect the proportion of capacitated spermatozoa when measured as merocyanine-540 fluorescence or CTC B-pattern, but the length of the incubation did affect the number of dead (Yo-PRO 1 positive) spermatozoa (p< 0.0001). Exposure to zona pellucida proteins significantly increased the proportion of acrosome reacted spermatozoa (p= 0.016). Both heparin and dermatan sulphate induce capacitation of frozen-thawed bull spermatozoain vitro.