bluuebunny/crossref_metadata_2025_split huggingface dataset:
Interactions between the toxin Kid of the bacterial parD system and the antitoxins Kis and MazE
Authors: Kamphuis Monique B. , Monti Maria Chiara , van den Heuvel Robert H. H. , Santos‐Sierra Sandra , Folkers Gert E. , Lemonnier Marc , Díaz‐Orejas Ramón , Heck Albert J. R. , Boelens Rolf 
Published: January 2007

AbstractThe proteins Kid and Kis are the toxin and antitoxin, respectively, encoded by the parD operon of Escherichia coli plasmid R1. Kis prevents the inhibition of E. coli cell growth caused by the RNA cleavage activity of Kid. Overproduction of MazE, the chromosome‐encoded homologue of Kis, has been demonstrated to neutralize Kid toxicity to a certain extent in the absence of native Kis. Here, we show that a high structural similarity exists between these antitoxins, using NMR spectroscopy. We report about the interactions between Kid and Kis that are responsible for neutralization of Kid toxicity and enhance autoregulation of parD transcription. Native macromolecular mass spectrometry data demonstrate that Kid and Kis form multiple complexes. At Kis:Kid ratios equal to or exceeding 1:1, as found in vivo in a plasmid‐containing cell, various complexes are present, ranging from Kid2–Kis2 tetramer up to Kis2–Kid2–Kis2–Kid2–Kis2 decamer. When Kid is in excess of Kis, corresponding to an in vivo situation immediately after loss of the plasmid, the Kid2–Kis2–Kid2 heterohexamer is the most abundant species. NMR chemical shift and intensity perturbations in the 1H 15N HSQC spectra of Kid and Kis, observed when titrating the partner protein, show that the interaction sites of Kid and Kis resemble those within the previously reported MazF2–MazE2–MazF2 complex. Furthermore, we demonstrate that Kid2–MazE2 tetramers can be formed via weak interactions involving a limited part of the Kis‐binding residues of Kid. The functional roles of the identified Kid–Kis and Kid–MazE interaction sites and complexes in toxin neutralization and repression of transcription are discussed. Proteins 2007; © 2007 Wiley‐Liss, Inc.
How lessons learned from using QFD led to the evolution of a process for creating quality requirements for complex systems
Authors: Hari Amihud , Kasser Joseph E. , Weiss Menachem P. 
Published: January 2007

AbstractWhile the requirements document is an important product, and the importance of good requirements has often been stated, little attention has been given in the systems engineering literature as to the application of published techniques for eliciting requirements for new products. It is likely that this lack will be remedied in the future, and many of those techniques will be adopted and published in the systems engineering literature. However, just reusing those tools for creating specifications for complex systems is as fraught as the reuse of software without investigating the context from where the proposed reusable module was taken from and its suitability for use in the new context. This paper addresses that issue, in the context of Quality Function Deployment (QFD), which has been used in the commercial arena to elucidate and negotiate requirements for new products for at least 20 years. QFD has a lot to offer with respect to new products, but when used to specify the requirements for complex systems, has been found to have a number of deficiencies. This paper summarizes the top six lessons learned from 15 years of experience in using QFD in the elicitation, elucidation, and negotiation of requirements for complex systems and documents a process for creating requirements by identifying the customer's needs and transforming them into well‐written requirements. The most important contributions made by this paper are the modifications to QFD in the form of the decision table and the evolution of QFD into a process for defining requirements for complex systems named Quality Requirements Definition (QRD). © 2007 Wiley Periodicals, Inc. Syst Eng 10: 45–63, 2007
Regulatory processes and population cyclicity in laboratory populations of Anagasta kühniella (Zeller) (lepidoptera: Phycitidae) V. Host finding and parasitization in a “small” universe by an entomophagous parasite, Venturia canescens (Gravenhorst) (Hymenoptera: Ichneumonidae)
Authors: Matsumoto B. M. , Huffaker C. B. 
Published: January 2007

SummaryHost finding by the entomophagous parasite, Venturia canescens (Grav.), parasitizing Anagasta kühniella (Zeller) was studied.Studies utilizing fixed densities and dispersion patterns of the hosts where no choice of density groupings was offered showed that within the experimental conditions used, host density relationships were more important than dispersion. Decreasing the time hosts were exposed to a parasite from 72 hours to 24 hours did not alter the overall parasitization. In both cases progressively less hosts were parasitized as host density increased, which exemplified aHolling‐type of response. However, when host densities were varied within the same universe, independent of dispersion patterns, and the parasites were given a “choice” of host densities to attack, an increasing percentage of hosts in the higher host density groups were parasitized; thus a density‐dependent behavioral response was exhibited.
Measuring the structural similarity of two communities composed of the same species
Authors: Poole Robert W. 
Published: January 2007

SummaryThe primary purpose of this paper is to propose empirical measures of the structural differences between two communities of plants or animals composed of the same species. Structure is defined to consist of; 1) the species in the community, 2) the pattern of interactions as represented by the covariance or correlation matrix of successive observations on each species, and 3) the mean abundances of each species in each of the two communities. Statistical tests are proposed for testing whether the covariance matrices and the vectors of mean densities for each community are equal and empirical measures of the differences between the covariance matrices and mean vectors are proposed. Given unequal covariance or correlation matrices the factor analysis model is used to derive empirical measures of the degree to which each variable of the ecosystem is responsible for the observed defferences in the pattern of interactions in each community. These tests and measures were applied to data gathered byHunter(1966) on the abundances of six species ofDrosophilacensused monthly over a period of approximately two and a half years in two adjacent, but different habitats near Bogota, colombia. The two covariance matrices were significantly different indicating different patterns of interactions in the twoDrosophilacommunities.
Use of some essential oils as natural preservatives for butter
Authors: Farag R. S. , Ali M. N. , Taha S. H. 
Published: January 2007

AbstractThyme and cumin essential oils were used in the present study in an attempt to prevent butter deterioration during storage at room temperature. Butter oxidation and lipolysis were followed by measuring the acid, peroxide and TBA values. Lipolytic activity and total microbial and lipolytic bacterial counts were also measured. During butter storage, very little change in the peroxide and TBA values were found while a gradual increase in the acid value was noticed. The addition of cumin and thyme oils at 200 ppm to butter caused very little increase in the acid value. The data for lipolytic bacterial counts were in general agreement with the acid values. Thyme and cumin essential oils showed a greater anti‐hydrolytic effect and act as superior preservatives compared to BHT.
A mathematical consideration on the adaptation strategy of marine fishes
Authors: Tanaka Syoiti 
Published: January 2007

Summary
Selections of life history is examined quantitatively for marine fishes based on mechanical models on survival, growth and maturation.
For survival model, usual exponential model is applied and for growth modelvon Bertalanffy growth curve is used.
Total assimilation, total egg production, mean duration of generation and equilibrium catch of one year class throughout its life are calculated. Effects on these quantities of manipulating parameters are examined particularly for K ofBertalanffy's growth curve, life span T and natural mortality coefficient M.
Three kinds of strategies are taken into consideration. They are to maximize (1) growth rate of population, (2) energy efficiency for egg production and (3) total egg production throughout the life.
Adaptation strategies are considered under the condition of no fishing. Strategists of first kind include anchovy and saury and have large K and M values and small T values. Strategiests of second kind include sardine and herring and have large values of all K, M and T. Strategists of third kind include tuna and flatfishes and have small K and M and large T values.
Referring to tuna, sardine and anchovy, three sets of parameter values are posturated and the effects of fishing are examined. Tuna type fish are most severely affected by fishing but sardine and anchovy type fish are affected moderately or slightly by fishing provided that only adult fish are exploited. Particularly anchovy type fish are considered to be quite tough against fishing.
Discussions are presented on such subjects as relation between environment and selection of life history, types of population fluctuation, and fisheries management problems.
Pea and lentil protein extraction and functionality
Authors: Swanson Barry G. 
Published: January 2007

These studies have demonstrated that peas and lentils can be used as protein sources for flours, concentrates and isolates. Less research attention has been devoted to lentil protein extraction, probably because of the greater cost of lentils as compared to peas. Pin‐milling and air classification is well adapted to extracting pea flours to produce pea protein concentrates. Apparently, air‐classification can be applied successfully to starch rich legumes, but will not give satisfactory results with lipid rich legumes.Wet processes, including alkaline and salt and acid solubilization, together with isoelectric precipitation or ultrafiltration, have been developed. The pea and lentil protein extracts of these processes exhibit comparable and complementary functionality to homologous soybean products. Air‐classified pea protein concentrates are different from soy protein concentrates because of residual starch which can be useful for particular functional applications. Pea isolates appear to exhibit better foaming properties and more solubility than soy isolates, but pea isolates have to be more concentrated than soy isolates to produce viscous dispersions. The economic feasibility of pea and lentil protein extracts is related directly to protein content of the flour, unique functionality of the extracts, marketability of the by‐products of extraction and the cost of peas or lentils.
Monomeric dihydroperoxide concentrates from autoxidized methyl docosahexaenoate
Authors: Fukuzumi Kazuo , Miyakawa Takero , Morohira Hidenori 
Published: January 2007

AbstractAn amount of 97% methyl docosahexaenoate (obtained from mackerel pike oil) was prepared, and then its autoxidized products were concd by a countercurrent extraction procedure. By partition chromatography, the autoxidized concs were separated into three fractions. From the first fraction, methyl docosahexaenoate monomeric dihydroperoxide concs were obtained for the first time, though the presence of the dihydroperoxide had been ascertained by the authors before. The dihydroperoxide concs were identified by determining the peroxide value, the mol wt, and UV and IR spectra. From IR data it was confirmed that weak absorptions due toa‐methylene groups and C=C stretching vibrations, respectively, were present in the concs. Thetrans‐trans conjugated diene andcis nonconjugated double bond absorptions appear as relatively strong bands, but thecis‐trans conjugated one is weak. Therefore, the molecules of the concs may have relatively symmetrical structures. The second fraction eluted after the first one contains the products to which the dihydroperoxides have changed on the chromatographic column.
Composition and structure of phospholipids in chicken muscle tissues
Authors: Peng C. Y. , Dugan L. R. 
Published: January 2007

AbstractLipids extracted from breast muscle and thigh muscle of one‐year old chickens on a standard MSU‐Z‐4 diet have been fractionated by silicic acid column chromatography into nonphospholipids, phosphatidyl ethanolamine, phosphatidyl serine, phosphatidyl choline (lecithin), and sphingomyelins. Phospholipid fractions were identified by thin‐layer chromatography and the quantity of each determined by gravimetric analysis, analysis of the phosphorus content, and infrared spectra.The phospholipid content of thigh muscle (dark meat) lipids was higher than that in the breast muscle (white meat). Phosphatidyl choline and phosphatidyl ethanolamine were found in relatively greater amts than phosphatidyl serine and sphingomyelins. Enzymatic hydrolysis followed by gas‐liquid chromatographic analysis of the fatty acids liberated and those in the lysocompounds was used to establish the positional specificity of the fatty acids in the phosphoglycerides. The polyunsaturated fatty acids are located primarily at the ॆ‐position and the saturated fatty acids at the ॅ艂‐position. The qualitative and quantiative determination of the plasmalogens was also accomplished.
Gas‐liquid chromatography of glycerides
Authors: Kuksis Arnis 
Published: January 2007

AbstractAvailable techniques are reviewed for gas‐liquid chromatography of mono‐, di‐ and triglycerides and their chemical modification products. Major emphasis is placed upon optimum separation and quantitative estimation of the recorded peaks. Nonlinear rates of temp programming are shown to be superior to linear rates for maximum resolution of complex glyceride mixtures. The use of short columns improves the recoveries of the components but may not provide a sufficient number of theoretical plates for all types of separations. The quantitative interpretation of the results is facilitated by the utilization of a flame ionization detector which gives correct weight response for the combustible carbon content of these materials.
A rapid low temperature method for preparation of methyl esters of fatty acids
Authors: McGinnis Gertrude W. , Dugan L. R. 
Published: January 2007

AbstractA rapid method for preparation of methyl esters of fatty acids in lipids has been accomplished by forming the sulfuric acid complex of the lipid in ethyl ether at the temp of a dry ice‐acetone bath. Decomposition of the complex with methanol results in direct formation of methyl esters of the fatty acids. A comparison was made of gas liquid chromatography (GLC) analysis of fatty acid composition of several fats using methyl esters prepared by this and by two other methods. Results of this comparison reveal that the method is not only rapid but provides complete reaction with no apparent changes in the fatty acids.
Combination of thin layer chromatography and gas chromatography in the analysis on a microgram scale of lipids from wheat flour and wheat flour doughs
Authors: Graveland A. 
Published: January 2007

AbstractLipids were extacted on a microgram scale from 3 to 6 mg flour or from freeze‐dried dough by percolation. The impure extract was separated into 12 nonpolar and 14 polar lipids by TLC. Then the fatty acid composition of most of these lipids was determined by gas chromatography. The microscale method renders possible qualitative and quantitative determination of the composition of the lipids in minute quantities of flour and dough. The selectivity of different extraction solvents was studied. In both flour and dough the fatty acid composition of a given component is identical in the free and bound lipid fractions. In dough, the quantity of free lipids is less than in flour; the extent of the decrease depends on the atmosphere in which it is mixed. During mixing, the carotenoid pigments, α‐monoglycerides and the free linoleic acid and linolenic acid are oxidized. Oxidation is apparently a function of the concentration of oxygen and of lipoxidase.
Compositional data on sunflower seed
Authors: Earle F. R. , Vanetten C. H. , Clark T. F. , Wolff I. A. 
Published: January 2007

AbstractComparative data are provided on the composition of achenes from sunflower varieties Armavirec, Peredovik, VNIIMK 8931, Smena, Krasnodarets, Arrowhead and Mingren. Handseparated achene components were analyzed. Kernel oil from seed raised in northern United States or southern Canada typically contains about 70% of linoleic acid. In addition to other common acids, traces of C17, C20, C22, C24 acids and linolenic acid are present. The amino acid composition of sunflower kernel protein suggests that the meal may be a valuable ingredient of high‐quality feed or food materials. The hull is primarily cellulose, lignin and pentosans; hull lipid and protein differ in composition from the corresponding kernel constituents.
Melting and solidification characteristics of confectionery fats: Anhydrous milk fat, cocoa butter and palm kernel stearin blends
Authors: Ali A. R. Md. , Dimick P. S. 
Published: January 2007

AbstractDifferential scanning calorimetry measurements of crystallization and melting characteristics of commercial samples of anhydrous milk fat (AMF), cocoa butter (CB) and hydrogenated palm kernel stearin (PKS) in ternary blends were studied. Results showed that stabilization at 26°C (either for 40 h or 7 d) did not greatly affect the melting thermogram trace of PKS. However, the effect of stabilization became prominent as CB was added into the system. Deviation of measured enthalpy from the corresponding values, calculated for thermodynamically ideal blends, showed clear interaction between all three fats. At 20°C, the strongest deviation occurred at about the AMF/CB/PKS (1∶1∶1) blend, whereas at 30°C the deviation moved toward the CB/MF (1∶1) blend. The presence of 25% AMF in PKS had little effect on its solidification capability, but solidification was adversely affected with inclusion of CB.
Effect of moisture, microwave heating, and live steam treatment on phospholipase D activity in soybeans and soy flakes
Authors: List G. R. , Mounts T. L. , Lanser A. C. , Holloway R. K. 
Published: January 2007

The impact of enzyme activity on the nonhydratable phospholipid content of crude soybean oil has been evaluated. A radiochemical method was used to assay phospholipase D activity in whole and flaked soybeans stored under a variety of storage and enzyme inactivating conditions. The crude enzyme was isolated and incubated with a mixture of14C‐labeled and unlabeled phosphatidylcholine. The amount of liberated radioactive choline was used as a measure of enzyme activity. whole soybeans with moisture contents of 8–18% were stored at 40°C and sampled weekly for up to four weeks. Although the enzyme was active in all samples, the optimum moisture content for enzyme activity was about 14%. Flaking and flake thickness were shown to increase phospholipas D activity. At moisture levels above 10%, flakes at .012″ showed about twice the activity of whole beans. As flake thickness was increased, enzyme activity decreased.Whole soybeans with moisture contents of 12–18% were treated by microwave heating under controlled conditions. During the early stages of heating, the enzyme was activated, and then was gradually destroyed by the time the temperature of the beans reached 115–120°C. Approximately 8–10 min of microwave heating was required to completely destroy enzymatic activity. The inactivation of phospholipase D in soyflakes treated with live steam was also evaluated. The enzyme is rapidly destroyed at temperatures of about 110°C. Evaluations of flakes subjected to live steam and whole beans treated by microwave heating to inactivate phospholipase D suggest that heat, moisture and enzyme activity are important factors contributing to the formation of nonhydratable phospholipid in extracted crude oils.
Low temperature deodorizations of fish oils with volatile acidic and basic steam sources
Authors: Karahadian C. , Lindsay R. C. 
Published: January 2007

AbstractMenhaden, cod liver and siscowet lake trout oils were vacuum steam deodorized at 100°C to 210°C using volatile acid (acetic and hydrochloric) and base (ammonium hydroxide) solutions (0.005N–0.25N) as steam sources. Volatiles in oils were analyzed by Tenax GC headspace analysis, and flavor and odor quality was evaluated. Deodorization of oils at 100°C with acidic solutions yielded oils that lacked the burnt/fishy flavors compared to similar oils that were deodorized with either water or alkaline solutions. Acid catalyzed hydrations of fishy aldehydes by deodorizing acids and flavor masking byt,c‐2,6‐nonadienal appeared to cause the suppression of fishy flavors in fish oils deodorized by acid solutions. Oils deodorized at 210°C exhibited less intense fishy flavors, and lower concentrations of fishy aldehydes,t,t,c‐2,4,7‐decatrienal,t,c,c,‐2,4,7‐decatrienal, andc‐4‐heptenal.
Cyclopropanation of unsaturated fatty acid methyl esters using diazomethane and palladium (II) acetate
Authors: Gangadhar A. , Subbarao R. , Lakshminarayana G. 
Published: January 2007

AbstractCyclopropanation of methyl esters of 10‐undecenoic, oleic, elaidic, erucic,trans‐2‐docosenoic and a mixture of hydnocarpic and chaulmoogric acids was effected using diazomethane in the presence of palladium (II) acetate as catalyst. The products were isolated by silver ion thin‐layer chromatography and characterized by infrared, proton nuclear magnetic resonance and mass spectrometric techniques. Terminally unsaturated, α, β‐unsaturated and cyclopentene fatty acid esters were found to be more reactive than elaidate which in turn was more reactive than oleate. The reaction proceeds stereospecifically under milder conditions in a shorter time than with diiodomethane and zinc‐copper couple.
Synergism in binary mixtures of surfactants. 7. Synergism in foaming and its relation to other types of synergism
Authors: Rosen Milton J. , Zhu Zhen Huo 
Published: January 2007

AbstractThe relationship between synergism in Ross‐Miles foaming and the existence of other types of synergism in binary mixtures of surfactants has been investigated. All studies were conducted in solutions of constant ionic strength (0.1 M NaCl) at 25 and/or 60 C. Six anionic‐zwitterionic or anionic‐nonionic mixtures and a sodium dodecylbenzenesulfonate (LAS)‐soap mixture, all consisting of commercial surfactants, were studied. Synergism in foaming effectiveness, measured by initial foam heights, appears to be related to synergism in surface tension (γ) reduction effectiveness, but not to synergism in γ reduction efficiency or in mixed micelle formation. The LAS‐soap system showed negative synergism in foaming effectiveness, correlated with negative synergism in γ reduction effectiveness, the conditions for which are defined. There appears to be no correlation between synergism in foaming efficiency and synergism in either γ reduction efficiency or mixed micelle formation. There also appears to be no unambiguous relationship between foam stability, measured by the ratio of the 5‐minute to the initial foam height, and the average area per surfactant molecule at the aqueous solution/air interface.