bluuebunny/crossref_metadata_2025 huggingface dataset:
Photocurrent induced by intersubband transition in a type II and broken‐gap quantum well system
Authors: Wei X. F. , Xu W. , Zeng Z. , Zhang C.
Published: February 2007

We demonstrate theoretically that when an InAs/GaSb based type II and broken‐gap quantum well is subjected to a light field, conductance can be observed along the growth direction due to charge transfer between electron and hole layers. A sharp peak can be observed in conductance within sub‐THz bandwidth. The peak shifts to the lower frequency (red‐shift) with increasing temperature. Our results indicate that InAs/GaSb based quantum well systems are of potential to be applied as sub‐THz photovoltaic devices. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
The electronic structure of a Bi/Sb superlattice nanowire
Authors: Zhang G. R. , Zeng Z.
Published: February 2007

The electronic structure of a Bi/Sb superlattice nanowire have been investigated using a theoretical model, in which the nanowire is assumed to possess a circular cross section with a uniform diameter. The variation of the electronic structure as a function of segment length and the total density of states for a Bi/Sb superlattice nanowire with a certain diameter of 5 nm are presented. The minigaps in the total density of states may lead to change in sign of the thermopower for certain energy ranges as the Fermi energy varies, which indicates that the superlattice nanowire can demonstrate n ‐ or p ‐type behavior by using the same dopants. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Neubau der nördlichen Monbijoubrücke über die Spree in Berlin‐Mitte
Authors: Krone Martin , Reinke Klaus‐Dieter
Published: February 2007

Im Oktober 2006 wurde nach sechs Jahren Bauzeit das Bodemuseum als nordwestlicher Abschluß der Museumsinsel in Berlin‐Mitte wieder eröffnet. Die Verbindung der Spandauer Vorstadt mit der Museumsinsel über die Spree erfolgt über die nördliche Monbijoubrücke. Für die im Krieg zerstörte zweifeldrige Bogenbrücke war ein Ersatzbauwerk zu errichten, welches in Anlehnung an die historische Brücke als einfeldrige natursteinverkleidete Bogenbrücke ausgeschrieben wurde. Im Zuge der Ausführungsplanung erforderten der gering tragfähige Baugrund am nördlichen Ufer und die Natursteinverblendung des Überbaus eine besonders sorgfältige Planung und Ausführung. Nach 14 Monaten Bauzeit wurde der Neubau am 12. Oktober 2006 rechtzeitig zur Eröffnung des Bodemuseums fertiggestellt.
Fatty acid selectivity of lipases: Erucic acid from rapeseed oil
Authors: Sonnet Philip E. , Foglia Thomas A. , Feairheller Stephen H.
Published: February 2007

The fatty acid selectivity of several commercial lipases was evaluated in the hydrolysis of high‐erucic acid rapeseed oil (HEARO). The lipase ofPseudomonas cepacia catalyzed virtually complete hydrolysis of the oil (94–97%), while that ofGeotrichum candidum discriminated strongly against erucic acid, especially in esterification. A two‐step process is suggested for obtaining a highly enriched erucic acid in which theG. candidum lipase is employed to selectively esterify the fatty acid residues of unsaturated C‐18, and shorter chain acids, from a mixture of HEARO fatty acids obtained from total hydrolysis of the oil withP. cepacia lipase.
Hydrogenation of heptaldehyde to heptyl alcohol with nickel catalysts
Authors: Vijayalakshmi P. , Subbarao R.
Published: February 2007

Hydrogenation of heptaldehyde to heptyl alcohol was studied with W2 Raney nickel catalyst, prepared in the laboratory, commercial Raney nickel catalyst and Rufert nickel catalyst by varying temperature, catalyst concentration, hydrogen pressure and reaction time. The products were analyzed by gas‐liquid chromatography on SE‐30 column. The optimum conditions found for quantitative conversion (99.6%) of heptaldehyde to heptyl alcohol were: temperature, 100°C, W2 Raney nickel catalyst concentration, 2% based on heptaldehyde (w/w), hydrogen pressure, 145 psig and reaction time, 1 h.
Characteristics of guindilla (Valenzuela trinervis Bert.) oil
Authors: Aguilera J. M. , Fretes A. , Martin R. San
Published: February 2007

Seed of Guindilla (Valenzuela trinervis Bert.) and its oil were characterized. On a dry weight basis, the seed consists of 56% hull and seed coat and 44% cotyledon, containing about 67.0% lipids. The main fatty acids are: 62.3% oleic, 12.9% gadoleic, 10.1% linoleic and 9.6% palmitic. Physical properties of oil, expressed by hand press, include: melting point, −6 to −2 C; iodine value, 75.1; saponification value, 192; and unsaponifiable matter, 0.8%.
Comparative evaluation of polymers of heat‐bodied conjugated and non‐conjugated linseed and soybean oils
Authors: Radlove S. B. , Falkenburg L. B.
Published: February 2007

Films from polymers of heat‐bodied, catalytically conjugated linseed and soybean oils have been shown to be superior, in their resistance to water and dilute alkali solution, to films from polymers of non‐conjugated oils that were heat‐bodies alone and with 0.5% diphenyl disulfide as a polymerization catalyst. These results are not accounted for on the basis of the Scheiber theory of polymerization.
The nondistillation alcohol extraction process for soybean oil
Authors: Beckel A. C. , Belter P. A. , Smith A. K.
Published: February 2007

A new vegetable oil extraction process has been developed, with alcohol as the oil solvent. The process requiresno distillation to recover the oil or the solvent characteristics of the alcohol. This has been demonstrated by reuse of the solvent more than 85 times. The theoretical energy requirement of the process is about three‐fourths that of the hexane process.
Destruction of aflatoxins in peanut protein isolates by sodium hypochlorite
Authors: Natarajan K. R. , Rhee K. C. , Cater C. M. , Mattil K. F.
Published: February 2007

Sodium hypochlorite has been tested for destruction of aflatoxins during the preparation of peanut protein isolates from raw peanuts and defatted peanut meal. The treatments were evaluated by determination of the aflatoxins in the products by thin layer chromatography. Effects of sodium hypochlorite concentration, reaction pH, temperature, and time were studied. Results show that both the sodium hypochlorite concentration and pH are important factors in reducing the concentration of aflatoxins in the protein isolates to nondetectable levels. The treatment with 0.4% sodium hypochlorite at pH 8 produced protein isolates with trace amounts of aflatoxins B1 and B2 from ground raw peanuts containing 725 ppb aflatoxin B1 and 148 ppb aflatoxin B2, whereas untreated protein isolates contained 384 ppb aflatoxin B1 and 76 ppb aflatoxin B2. At pH 9, 0.3% sodium hypochlorite reduced the aflatoxin B1 content in the protein isolates from 300 ppb to below detectable quantities and the aflatoxin B2 content from 52 ppb to 2 ppb. Similar results were obtained at pH 10 for 0.3% sodium hypochlorite concentration. In the case of defatted peanut meal which contained 136 ppb aflatoxin B1 and 36 ppb aflatoxin B2, 0.25% sodium hypochlorite concentration at pH 8 (0.20% at pH 9; 0.15% at pH 10) reduced both the aflatoxin B1 and B2 contents to below detectable quantities in protein isolates as compared to aflatoxin levels of ca. 75 ppb B1 and 17 ppb B2 in the untreated protein isolates. Reaction temperature and time did not affect the destruction of aflatoxins significantly.
Micro vapor‐phase hydrogenation monitored with tandem chromatography‐radioactivity. II. Evaluation of catalyst selectivity for linolenate
Authors: Mounts T. L. , Dutton H. J.
Published: February 2007

Micro vapor‐phase hydrogenation is a rapid and effective method of studying the kinetic characteristics of hydrogenation catalysts. Eight catalysts were investigated, and reaction rates and selectivity ratios determined by an analog computer. Fatty esters labeled with C14 were utilized to clarify reactions and to assist in achieving a unique simulation of the data for a particular catalyst.
Automated gradient‐elution column chromatography of lipids
Authors: Nelson Gary J.
Published: February 2007

An automated gradient‐elution chromatography system was developed specifically for the separation of complex mixtures of naturally occuring lipids obtained from various tissues. It uses silica gel columns with concave gradients of increasing polarity. These gradients offer advantages over the convex type because of the absorptive properties of most lipid classes on silica gel.

The entire system is operated automatically once the charge is placed on the column. The flow rate is constant throughout the run and the shape of the gradient is predetermined by selecting known values for three parameters. The selection of the gradient is arbitrary but previous knowledge of the chromatographic behavior of the substances to be separated is useful in determining the shape of the gradient. The entire system is controlled by timers, pumps, and solenoid valves. Details of the construction of the apparatus are described and criteria for the selection of acceptable pumps for organic solvents are discussed.

Several examples of the separations obtained with the system are described. While silica gel was used as the adsorbent, there is no reason to believe that other adsorbers cannot be substituted for other application. In addition, column size and elution times can be changed to provide better resolution for the specific problems, greatly broadening the application of liquid column chromatography, particularly in the area of routine quantitative analysis of nonvolatile substances. Nongradient elution can also be performed by this apparatus.
The fatty acids of degras
Authors: Pelick Nicholas , Shigley J. W.
Published: February 2007

Degras contains a complex mixture of lipids comprised of branched and normal chain fatty acids, hydroxy acids, sterols, sterol esters and long chain wax esters. There are no glycerides in degras. This paper is a report on the composition of the branched and normal chain fatty acids. Preparative techniques of thin‐layer chromatography were used to isolate the fatty acids from the other lipid classes. Gas chromatography was used on three different stationary phase separations of the fatty acid methyl esters. Identifications of the composition were based on a combination of techniques and known standards.
Volatile compounds produced by copper‐catalyzed oxidation of butterfat
Authors: Forss D. A. , Angelini Pio , Bazinet M. L. , Merritt Charles
Published: February 2007

Anhydrous butterfat treated with copper and stored under vacuum at 38C in the dark for 9 weeks yielded the C5‐8n‐alkanes, acetic acid and the C4,5,7,9 alkan‐2‐ones. The same butterfat stored under oxygen for 1 week yielded the C1,2,3,5–7n‐alkanes, the C2,4‐6,8 alk‐l‐enes, the C7,8 alk‐l‐ynes, the C2‐6n‐alkanoic acids, ethanol, the C2‐7n‐alkanals, 3‐methylbutanal and 4‐methylpentanal, the C1‐4n‐alkyl formates, ethyl acetate and propionate,n‐propyl acetate and propionate, and butanone. Both treatments yielded carbon dioxide. All samples including those not treated with copper yielded butane‐2,3‐dione.
Seed and seed oil ofPistacia Terebinthus andP. Lentiscus
Authors: Marcopoulos C. A.
Published: February 2007

Seeds ofPistacia Terebinthus L. andP. Lentiscus L. were collected from Greek Islands and their composition was determined.

Seed oil was taken through various processes and the determination of its physical constants and chemical characteristics was carried out. The maximum and minimum of all the values obtained as well as mean values are given. From iodine and thiocyanogen values the glyceride composition of Pistacia oil was also calculated. Average values are also tabulated.
Reaction of dichlorocarbene with fats and oils
Authors: Kenney H. E. , Komanowsky Daria , Wrigley A. N.
Published: February 2007

Dichlorocarbene was generated in the presence of lard, olive, safflower, tung and menhaden oil. When solutions of fats or oils in ethyl trichloroacetate were mixed with sodium methoxide inn‐heptane at 2C, unsaturated components were transformed in high conversion to dichlorocyclopropane derivatives; fats were converted to methyl‐and‐ethyl esters (90%) or appeared as glycerides (10%). The proportion of dichlorocyclopropane rings was the same in the glycerides as in the ester products. The reactivity of safflower oil required metered addition of reactants at 25舑55C.

Properties were measured on dichlorocyclo‐propanoid fatty esters freed from glycerides but containing saturated esters. Chlorine content ranged from 12舑33%. Compatibility with silicone oils was substantially improved. Viscosities and densities increased with chlorine content. Viscosity indices were 135,150,49,67 and 79 for products from lard, olive, safflower, tung and menhaden oil.

Dichlorocarbene could be generated without alcoholysis of glycerides by decomposition of sodium trichloroacetate. This gave dichlorocyclopropanes from safflower oil unsaturates in 50% conversion, but failed with lard.

Analyses were performed by TLC, argentation and GLC.
Mustard seed processing: Improved methods for isolating the pungent factor and controlling protein quality
Authors: Mustakas G. C. , Kirk L. D. , Sohns V. E. , Griffin E. L.
Published: February 2007

A modified cooking and extraction process for mustard seed is reported in which the pungent factor, allyl isothiocyanate, is separated from the seed to yield triglyceride oil and protein meal. Although removal of the pungent factor from the oil and meal products was previously reported, investigations were continued to develop critical improvements in the process. A reduction in conversion time, combined with steam stripping and shorter heating preiods, resulted in quantitative recovery of the essential oil and in improved protein quality, as measured by the basic amino acids. Biological testing with rats showed the processed meals to be free of toxic and goitrogenic factors and to be well utilized nutritionally. Preliminary estimates indicate that process costs are nearly the same as for a comparable soybean plant.
Cod liver oil fatty acids as secondary reference standards in the GLC of polyunsaturated fatty acids of animal origin: analysis of a dermal oil of the atlantic leatherback turtle
Authors: Ackman R. G. , Burgher R. D.
Published: February 2007

The use of the esters of whole cod liver oil fatty acids as secondary standards in the GLC identification of animal polyunsaturated fatty acids is feasible. This technique is exemplified by an analysis on several polyester substrates of the component fatty acids of a somewhat unusual marine‐type oil from the Atlantic Leatherback turtleDermochelys coriacea coriacea (Linnȳ), with provisional identifications of minor components through the linear log plot and separation factor procedures.
Chromatographically homogeneous lecithin from egg phospholipids
Authors: Singleton W. S. , Gray M. S. , Brown M. L. , White J. L.
Published: February 2007

Chromatographically homogeneous egg lecithin, as determined by TLC on Silica Gel G, has been isolated from crude egg phosphatides by column chromatography on alumina through modification of existing, lengthy methods. The modified method involved application of crude egg phosphatides to a column of alumina in the proportion of 1 g phosphatide/25 g alumina, and elution of the lecithin fraction with the 2‐component solvent system chloroform:methanol, 9:1 by vol. This method of purification separated lecithin from other choline and non‐choline components of crude phosphatides, avoided overloading of the alumina column, and made unnecessary the need for a second chromatographic fractionation of partially purified lecithin on silicic acid, which is needed in existing methods of purification of lecithin.

The use of fresh yolks permitted easier removal of pigment from the final product than was possible with commercially dried yolks.

Phosphatides extracted from dried yolks were much more highly colored than were the phosphatides extracted from fresh yolks and the color presisted through chromatography on alumina.

The fatty acid/phosphorus molar ratio of the purified lecithin was 2.00, which is the theoretical FA/P molar ratio of phosphatidylcholine; other materials with this ratio were not present.
Positional distribution of fatty acids in the triacylglycerols of developing oil palm fruit
Authors: George S. , Arumughan C.
Published: February 2007

The pattern of accumulation of triacylglycerols, their fatty acid compositions and the positional distribution of the fatty acids at thesn‐2‐ andsn‐1,3‐positions of the triacylglycerol molecules at progressive stages of oil palm fruit development were determined. There was an exponential rate of increase of triacylglycerols and their fatty acids toward the end of fruit development. The fatty acid composition of the triacylglycerols in the early stages of development, prior to active accumulation, was more or less similar, but differed appreciably from the later stages, and the transition of fatty acid composition toward that of normal palm oil occurred at around 16 wk after anthesis (WAA) and stabilized at 20 WAA. All fatty acids increased in terms of absolute quantity. There was an overall consistency in fatty acid positional distribution, irrespective of development stage. More saturated fatty acids were found to be esterified at thesn‐1,3‐positions and more unsaturated fatty acids at thesn‐2‐position of triacylglycerol. Higher rate of incorporation of 16:0 at the 1,3‐positions during the active phase of triacylglycerol synthesis was observed, while 18:1 acid exhibited a reverse trend.
Thermal densturation of glycinin as a function of hydration
Authors: Sessa David J.
Published: February 2007

Hydration effects on the thermal stability of glycinin (soybean 11S protein) were examined by differential scanning calorimetry (DSC). In a model system with pure glycinin, the denaturation temperature (Td) decreased with increasing moisture. Between 22 and 44% moisture, two endotherms were observed, where the lower‐temperature endotherm became progressively reduced in magnitude with a concomitant increase in a higher‐temperature transition. At 45.5% moisture, only a single endotherm was observed. The regression curves over the entire moisture range from 2 to 66% were derived as asymptote functions, where M equals the percentage total moisture. Equations were developed from the curves, and the relationship between Td and moisture were: Td=92.4+196.5e−0.068M and, for the low‐temperature endotherm, 82.4+144.3e−0.068M. By interaction of 11S protein with either ethanol, a neutral detergent (Triton X‐100) or 40% sucrose, both one‐ and two‐endotherm curves were generated. Such calorimetric behavior is indicative of nonequilibrium denaturation and supports the notion that structure reorganization during DSC is water content‐dependent. Our findings suggest that either glycinin’s acidic/basic subunits or a change in secondary protein structure may give rise to two endotherms.
Apolipoprotein E polymorphism and changes in serum lipids during a family-based counselling intervention
Authors: Salminen Marika , Lehtimäki Terh , Fan Yue-Mei , Vahlberg Tero , Kivelä Sirkka-Liisa
Published: February 2007

Objective

To compare serum lipids and their changes during a family-based health education in children aged 6–17 years with or without the ɛ4 allele of the gene encoding apolipoprotein E (apoE).

Design

An intervention study.

Setting

A family-based prevention of risk factors of coronary heart disease in Eastern Finland. The programme consisted of two counselling meetings at children's schools and three at children's homes.

Subjects

Four hundred and thirty-nine children with a family history of cardiovascular diseases (CVD) participated in a family-based health education. The children were divided into two groups according toapoEgenotype. The risk group consisted of 143 children havingapoEɛ4 allele (genotype ɛ3/4 or ɛ4/4) and the non-risk group of 296 children withoutapoEɛ4 allele (ɛ2/3 or ɛ3/3). The final sample of the follow-up study included 354 (81%) children (114 and 240, respectively).

Results

Baseline differences were found in low-density lipoprotein cholesterol (LDL-C) (P= 0.007) and LDL-C/high-density lipoprotein cholesterol (HDL-C) ratio (P= 0.030) among boys and in total cholesterol (TC)/HDL-C (P= 0.008) and LDL-C/HDL-C ratios (P= 0.006) among girls. Differences between groups in changes during the follow-up were observed only for TC/HDL-C ratio (P-value adjusted for age = 0.049) among boys.

Conclusions

At baseline, children withapoEɛ4 allele had on average a more unfavourable lipid profile than those withoutapoEɛ4 allele. However, the effect of about 33 months' family-based health education on plasma lipids did not depend onapoEgenotype in children with a family history of CVD.
Between Decision and Deliberation: Political Paradox in Democratic Theory
Authors: HONIG BONNIE
Published: February 2007

Deliberative democratic theorists (in this essay, Seyla Benhabib and Jurgen Habermas) seek to resolve, manage, or transcend paradoxes of democratic legitimation or constitutional democracy. Other democratic theorists, such as Chantal Mouffe, embrace such paradoxes and affirm their irreducibility. Deliberativists call that position “decisionism.” This essay examines the promise and limits of these various efforts by way of a third paradox: Rousseau's paradox of politics, whose many workings are traced through Book II, Chapter 7 of theSocial Contract. This last paradox cannot be resolved, transcended, managed, or even affirmed as an irreducible binary conflict. The paradox of politics names not a clash between two logics or norms but a vicious circle of chicken-and-egg (which comes first—good people or good law?). It has the happy effect of reorienting democratic theory: toward the material conditions of political practice, the unavoidable will of the people who are also always a multitude, and the not only regulative but also productive powers of law.
Sensitivity of climate forcing and response to dust optical properties in an idealized model
Authors: Shell Karen M. , Somerville Richard C. J.
Published: February 2007

An idealized global climate model is used to explore the response of the climate to a wide range of dust radiative properties and dust layer heights. The top‐of‐the‐atmosphere (TOA) shortwave forcing becomes more negative as the broadband shortwave single scattering albedo increases and the broadband shortwave asymmetry parameter decreases, but the sensitivity is highly dependent on the location of the dust layer with respect to clouds. The longwave TOA forcing is most affected by the height of the dust layer. The net TOA forcing is most sensitive to the shortwave single scattering albedo and shortwave asymmetry parameter. The surface and atmospheric temperature responses are approximately linear with respect to the TOA forcing, as opposed to the surface or atmospheric forcings. Thus the TOA forcing can be used to estimate both the surface and atmospheric temperature responses to dust. The corresponding changes in latent and sensible heat fluxes are essential for the close relationship of the surface temperature response to the TOA forcing. Estimating the hydrological cycle response requires knowledge of the vertical distribution of dust with respect to clouds or other reflective particles. The sensitivity of the latent heat flux to variations in the shortwave single scattering albedo changes sign with dust height. The latent heat flux change becomes less negative as the shortwave single scattering albedo increases if the dust layer is below clouds. However, when the dust is above clouds, the latent heat response becomes more negative as the single scattering albedo increases.
Anatomy-performance correlation in Ti-based contact metallizations on AlGaN∕GaN heterostructures
Authors: Mohammed Fitih M. , Wang Liang , Koo Hyung Joon , Adesida Ilesanmi
Published: February 2007

A comprehensive study of the electrical and surface microstructural characteristics of Ti∕Au, Ti∕Al∕Au, Ti∕Mo∕Au, and Ti∕Al∕metal∕Au schemes, where metal is Ir, Mo, Nb, Pt, Ni, Ta, and Ti, has been carried out to determine the role of constituent components of multilayer contact metallizations on Ohmic contact formation on AlGaN∕GaN heterostructures. Attempts have been made to elucidate the anatomy (composition–structure) performance correlation in these schemes. Evidences have been obtained for the necessity of the Al and metal barrier layer as well as an optimal amount of Ti for achieving low-resistance Ohmic contact formation. A strong dependence of electrical properties and intermetallic interactions on the type of metal barrier layer used was found. Scanning electron microscopy characterization, coupled with energy dispersive x-ray spectroscopy, has shown evidence for alloy aggregation, metal layer fragmentation, Al–Au solid solution formation, and possible Au and/or Al reaction with metal layer. Results from the present study provide insights on the active and the necessary role various components of a multilayer contact metallization play for obtaining excellent Ohmic contact formation in the fabrication of AlGaN∕GaN high electron mobility transistors.
Highly efficient photoluminescent films made by mixing aminopropyltriethoxysilane, Eu3+ ions, and thenoyltrifluoroacetone
Authors: Stathatos Elias , Lianos Panagiotis
Published: February 2007

A very efficient phosphor based on a nanocomposite organic-inorganic aminopropyltriethoxysilane gel, incorporating Eu3+ ions, and thenoyltrifluoroacetone has been synthesized. Gels have been deposited as thin films on solid substrates using a sol-gel procedure based on acetic acid solvolysis. The luminescence intensity of this material by near-UV excitation and ligand-to-metal energy transfer was very high. It was equivalent to that of laser dyes and the luminescence quantum yield approached 100%.
Insight into clogging of micromachined cryogenic coolers
Authors: Lerou P. P. P. M. , ter Brake H. J. M. , Holland H. J. , Burger J. F. , Rogalla H.
Published: February 2007

Cryogenic microcoolers can be used to cool small electronic devices to improve their performance. The authors present a micro-cold-stage of only 0.05cm3 that cools to 96K, applying Joule-Thomson expansion in a 300nm high flow restriction. Critical in such a microcooler is the deposition of water molecules that migrate to the restriction and block the flow. Because the microcooler is made of glass the authors had the unique opportunity to monitor this phenomenon and combine this visualization with experimental data. This provides significant insight in the way this clogging develops and opens possibilities to realize stable operation.
Identification and functional expression of the
Arabidopsis thaliana
vacuolar glucose transporter 1 and its role in seed germination and flowering
Authors: Aluri Sirisha , Büttner Michael
Published: February 2007

Sugar compartmentation into vacuoles of higher plants is a very important physiological process, providing extra space for transient and long-term sugar storage and contributing to the osmoregulation of cell turgor and shape. Despite the long-standing knowledge of this subcellular sugar partitioning, the proteins responsible for these transport steps have remained unknown. We have identified a gene family in
Arabidopsis
consisting of three members homologous to known sugar transporters. One member of this family,
Arabidopsis thaliana
vacuolar glucose transporter 1 (
AtVGT1
), was localized to the vacuolar membrane. Moreover, we provide evidence for transport activity of a tonoplast sugar transporter based on its functional expression in bakers' yeast and uptake studies in isolated yeast vacuoles. Analyses of
Atvgt1
mutant lines indicate an important function of this vacuolar glucose transporter during developmental processes like seed germination and flowering.
An antibiotic produced by an insect-pathogenic bacterium suppresses host defenses through phenoloxidase inhibition
Authors: Eleftherianos Ioannis , Boundy Sam , Joyce Susan A. , Aslam Shazia , Marshall James W. , Cox Russell J. , Simpson Thomas J. , Clarke David J. , ffrench-Constant Richard H. , Reynolds Stuart E.
Published: February 2007

Photorhabdus
is a virulent pathogen that kills its insect host by overcoming immune responses. The bacterium also secretes a range of antibiotics to suppress the growth of other invading microorganisms. Here we show that
Photorhabdus
produces a small-molecule antibiotic (
E
)-1,3-dihydroxy-2-(isopropyl)-5-(2-phenylethenyl)benzene (ST) that also acts as an inhibitor of phenoloxidase (PO) in the insect host
Manduca sexta
. The
Photorhabdus
gene
stlA
encodes an enzyme that produces cinnamic acid, a key precursor for production of ST, and a mutation in
stlA
results in loss of ST production and PO inhibitory activity, which are both restored by genetic complementation of the mutant and also by supplying cinnamic acid. ST is produced both
in vitro
and
in vivo
in sufficient quantities to account for PO inhibition and is the only detectable solvent-extractable inhibitor. A
Photorhabdus stlA
−
mutant is significantly less virulent, proliferates slower within the host, and provokes the formation of significantly more melanotic nodules than wild-type bacteria. Virulence of the
stlA
−
mutant is also rescued by supplying cinnamic acid. The proximate cause of the virulence effect, however, is the inhibition of PO, because the effect of the
stlA
−
mutation on virulence is abolished in insects in which PO has been knocked down by RNA interference (RNAi). Thus, ST has a dual function both as a PO inhibitor to counter host immune reactions and also as an antibiotic to exclude microbial competitors from the insect cadaver.
Visual Representations and Confirmation
Authors: Perini Laura
Published: February 2007

Publications in contemporary science journals often include figures like graphs, diagrams, photographs, and MRIs, which are presented as support for the hypothesis the author is defending. As a first step to explaining how figures contribute to confirmation, I present an account of visual representation and use examples to show how the visual format is involved in the support those figures provide the authors’ conclusions. I then show that attempts to explain what figures contribute to scientific arguments without analyzing them as visual representations (for example by translating them into linguistic representations) will not succeed.
Male coercion and the costs of promiscuous mating for female chimpanzees
Authors: Muller Martin N , Kahlenberg Sonya M , Emery Thompson Melissa , Wrangham Richard W
Published: February 2007

For reasons that are not yet clear, male aggression against females occurs frequently among primates with promiscuous mating systems. Here, we test the sexual coercion hypothesis that male aggression functions to constrain female mate choice. We use 10 years of behavioural and endocrine data from a community of wild chimpanzees (
Pan troglodytes schweinfurthii
) to show that sexual coercion is the probable primary function of male aggression against females. Specifically, we show that male aggression is targeted towards the most fecund females, is associated with high male mating success and is costly for the victims. Such aggression can be viewed as a counter-strategy to female attempts at paternity confusion, and a cost of multi-male mating.
Protein carbon content evolves in response to carbon availability and may influence the fate of duplicated genes
Authors: Bragg Jason G , Wagner Andreas
Published: February 2007

Natural selection can influence even the lowest level of biological organization, the atomic composition of biological macromolecules. In analysing genome-scale gene expression data, we find that ancestral yeast strains preferentially express proteins with low carbon content during carbon limitation, relative to strains selected in the laboratory under carbon limitation. The likely reason is that the artificially selected strains acquire adaptations that refine their response to the limitation or partly circumvent the limiting condition. This finding extends previous work which shows that natural selection can act on the atomic costs of proteins. We also show that genes with high carbon and nitrogen content are less likely to have duplicates, indicating that atomic composition also plays a role in evolution by gene duplication. Taken together, our results contribute to the emerging view that protein atomic composition influences genome and transcriptome evolution.
Stem cell myths
Authors: Magnus Tim , Liu Ying , Parker Graham C , Rao Mahendra S
Published: February 2007

Stem cells, although difficult to define, hold great promise as tools for understanding development and as therapeutic agents. However, as with any new field, uncritical enthusiasm can outstrip reality. In this review, we have listed nine common myths that we believe affect our approach to evaluating stem cells for therapy. We suggest that careful consideration needs to be given to each of these issues when evaluating a particular cell for its use in therapy. Data need to be collected and reported for failed as well as successful experiments and a rigorous scientific approach taken to evaluate the undeniable promise of stem cell biology.
mtDNA phylogeny and evolution of laboratory mouse strains
Authors: Goios Ana , Pereira Luísa , Bogue Molly , Macaulay Vincent , Amorim António
Published: February 2007

Inbred mouse strains have been maintained for more than 100 years, and they are thought to be a mixture of four different mouse subspecies. Although genealogies have been established, female inbred mouse phylogenies remain unexplored. By a phylogenetic analysis of newly generated complete mitochondrial DNA sequence data in 16 strains, we show here that all common inbred strains descend from the same Mus musculus domesticus female wild ancestor, and suggest that they present a different mitochondrial evolutionary process than their wild relatives with a faster accumulation of replacement substitutions. Our data complement forthcoming results on resequencing of a group of priority strains, and they follow recent efforts of the Mouse Phenome Project to collect and make publicly available information on various strains.
Early post‐operative morbidity after superficial parotidectomy: a prospective study concerning pain and resumption of normal activity
Authors: Foghsgaard S. , Foghsgaard J. , Homøe P.
Published: February 2007

Keypoints

• The degree of pain and time to return to work following superficial parotidectomy has not previously been reported.

• Pain is measured by use of visual analogue scale and the use of analgesics is registered 14 days after superficial parotidectomy.

• Results showed that pain is generally weak after superficial parotidectomy and can be treated with mild analgesics. Pain is considerably lower than, e.g. after tonsillectomy.

• Median number of days until total recovery was 12 days (range: 3–70), and median time to return to work was 16 days (range: 3–70).

• We recommend 2 weeks recreation period after superficial parotidectomy.
Cochlear implant electrode array insertion monitoring with intra‐operative 3D rotational X‐ray
Authors: Carelsen B. , Grolman W. , Tange R. , Streekstra G.J. , Van Kemenade P. , Jansen R.J. , Freling N.J.M. , White M. , Maat B. , Fokkens W.J.
Published: February 2007

Keypoints

• During cochlear implantation surgery, we use a mobile C‐arm with 3D functionality to acquire per‐operative 3D X‐ray images.

• Scanning the multielectrode array is performed once before removal of the stylet and once after full insertion.

• When dissatisfied with the position of the multielectrode a repositioning is considered which happened occasionally.

• The major advantage is the extra certainty of the multielectrode array position in the cochlea with low‐dose and little extra time.

• All cochlear implantations are now routinely scanned during surgery.
Is secondary haemorrhage after tonsillectomy in adults an infective condition? Objective measures of infection in a prospective cohort
Authors: Ahsan F. , Rashid H. , Eng C. , Bennett D.M. , Ah‐See K.W.
Published: February 2007

Objectives:  Traditionally secondary post‐tonsillectomy haemorrhage has been thought to be due to post‐operative infection and as such is treated with broad‐spectrum antibiotics. The aim of this study was to identify clinical evidence of infection in patients with secondary post‐tonsillectomy haemorrhage that might justify the use of antibiotics in these patients.

Design:  Prospective data collection.

Setting:  Tertiary University Teaching Hospital.

Participants:  Adult patients admitted with post‐tonsillectomy haemorrhage over a 2‐year period.

Main Outcome Measures:  Temperature, white cell count, Neutrophil count and C‐reactive protein.

Results:  47 patients were admitted with secondary post‐tonsillectomy haemorrhage. Fifteen out of 47 patients (32%) had an elevated white cell count but in them the other indicators of temperature and C‐reactive protein were extremely variable: none of these 15 patients was pyrexial (> 37.6 C). An elevated C‐reactive protein was found in 55% of patients but none had an elevated white cell count. The elevated C‐reactive protein may have been influenced by the recent surgery rather than infection. Overall there was no clear interrelation between the indicators of infection in the patients and none had the three main indicators of infection (pyrexia, increased white cell count and elevated C‐reactive protein).

Conclusions:  Our results suggest that clinical signs of infection are lacking in patients with secondary tonsillectomy bleeding. Correspondingly the routine use of antibiotics should be questioned for secondary tonsillectomy haemorrhage.
Use of a ranked scoring system to detect occlusal caries in primary molars
Authors: DUNKLEY SUZANNE , ASHLEY PAUL
Published: February 2007

Objective.  The available literature concerning systems for occlusal caries detection in primary teeth is limited. The aim of this study was to compare in vitro a ranked scoring system for occlusal caries detection in primary molar teeth with bitewing radiography and to investigate the most accurate cut‐off point for dentine caries detection when using this ranked scoring system.

Methods.  Sixty primary molar teeth were examined in vitro visually and by bitewing radiography (two examiners) using Ekstrand’ criteria.

Results.  Histological examination revealed that 13% were sound, 38% had enamel caries and the remainder had dentine caries. Similar accuracy was seen when comparing bitewing radiographs and visual examination for caries detection at the d3 threshold, while visual examination was more accurate at the d1 threshold. The most suitable cut‐off for diagnosing caries at the d1 threshold was V1 (no/slight change in enamel translucency after air drying). Either V2 (opacity/discoloration visible without air drying) or V3 (enamel breakdown in opaque/discoloured enamel and/or greyish discoloration) were suitable cut‐off points at the d3 threshold.

Conclusion.  Visual examination was more accurate than bitewing radiographs for detection at the d1 threshold (the cut‐off point of V1). Either V2 or V3 can be used for caries detection at the d3 threshold.
The clinical significance of food specific IgE/IgG4 in food specific atopic dermatitis
Authors: Noh Geunwoong , Ahn Hyun‐Sook , Cho Nam‐Yun , Lee Sangsun , Oh Jae‐Won
Published: February 2007

Food is closely associated with the pathogenesis of atopic dermatitis. Food allergy is usually mediated by IgE antibody to specific food proteins and determination of specific IgE antibody is the basis of the common diagnostic test for food allergy. IgG4 have been reported as blocking antibody and the protective effects of blocking antibody may be clear in inhalant allergy. However, the role of IgG4 in food allergy is still a matter of debate. In this study, the clinical significance of food allergen‐specific IgE/IgG4 in atopic dermatitis was investigated and compared with that of IgE. A total of 97 patients who fulfilled the diagnostic criteria for atopic dermatitis participated in this study. Skin prick test and allergy patch test were performed. Specific IgE and IgG4 concentration were measured using allergy protein chip, ‘AllergyChip’. Double blinded placebo controlled food challenge test (DBPCFC) was performed for the diagnosis of allergy to milk, egg white, wheat, and soybean. DBPCFCs for milk, egg white, soybean, and wheat were performed. The positive rates were 31.7% (19/60) in milk, 36.7% (18/49) in egg white, 30.4% (7/23) in soybean, and 34.8% (8/23) in wheat. Mean IgE/IgG4 levels in DBPCFC (+) subjects is higher than those in DBPCFC (−) subjects in all food items studied. Of them, there were significantly different between two groups in egg white and wheat (Egg white in DBPCFC (+) vs. (−): 0.4 ± 0.3 vs. 0.2 ± 0.2, wheat in DBPCFC (+) vs. (−): 1.2 ± 1.2 vs. 0.3 ± 0.3, p < 0.05). Allergen‐specific IgE/IgG4 may provide one of the clues to understand the mechanism of food allergy in atopic dermatitis. The present study suggests that protein microarray can be one of the useful methods to assess ongoing status of allergic diseases.
Casein‐specific immunoglobulins in cow's milk allergic patient subgroups reveal a shift to IgA dominance in tolerant patients
Authors: Sletten Gaynour B. G. , Halvorsen Ragnhild , Egaas Eliann , Halstensen Trond S.
Published: February 2007

Differences in casein‐specific immunoglobulin (Ig) G‐subclass and IgA serum levels between reactive and tolerant patients may hint at the immunopathogenesis during tolerance development in cow's milk allergy (CMA). α‐, β‐ and κ‐casein‐specific IgG1, IgG4, IgE and IgA serum levels were compared in clinically reactive and tolerized IgE‐mediated (n = 15) and non‐IgE‐mediated (n = 14) CMA with delayed gastrointestinal symptoms, using enzyme‐linked immunosorbent assay (ELISA) and immunoblot techniques. The median anti‐casein IgE levels in clinically reactive IgE‐mediated CMA patients (n = 9) were 140‐ to 180‐fold higher than in tolerized patients (n = 6) and 160‐ to 200‐fold higher than in controls (n = 10). Median α‐, β‐ and κ‐casein‐specific IgG1 and IgG4 levels were nine‐ to 60‐fold higher in reactive patients and five‐ to 60‐fold in tolerized patients. Clinical tolerance in IgE‐mediated CMA was thus associated with decreased casein‐specific IgE, IgG4 and IgG1, whereas serum IgA anti‐α ‐, β‐ and κ‐casein remained practically unaltered. Tolerized cow's milk protein (CMP)‐sensitive atopic dermatitis had, in particular, decreased κ‐casein‐specific IgG1 levels, compared with clinically reactive patients. The ELISA levels to immunoblot correlation profile for the α‐, β‐ and κ‐casein‐specific IgE suggested that the IgE‐mediated CMA patients predominantly reacted to tertiary α‐ and β‐casein epitopes whereas the IgE in non‐IgE‐mediated patients reacted to linearized α‐, β‐ and κ‐casein epitopes. Clinical tolerance in non‐IgE‐mediated CMA patients (n = 9) was associated with a four‐ to 10‐fold decrease in casein‐specific IgE levels, accompanied by a five‐ to eightfold decrease in IgG1 and five‐ to 60‐fold decrease in IgG4 levels, whereas casein‐specific IgA levels remained unaltered. Thus, tolerance in both patient groups was characterized by a generalized decreased humoral immune response to caseins, which induced a functional shift to IgA dominance.
Alkylator‐free conditioning regimen for patients with acquired aplastic anemia, transplanted from genetically identical twins
Authors: Trakhtman P. , Balashov D. , Shipicina I. , Skvortsova Y. , Shelikhova L. , Filimonov A. , Novichkova G. , Skorobogatova E. , Maschan M. , Maschan A.
Published: February 2007

Abstract:  Allogeneic stem cell transplantation remains the best option for young patients with SAA. With genetically identical twin as an ideal donor, the majority of SAA patients require appropriate immunosuppression before and after stem cell transplantation to obtain long‐term hematopoietic reconstitution. Alkylating agents, used during conditioning, are associated with short‐ and long‐term toxic effects that lead to poor compliance of treatment and could compromise the quality of future life. Three SAA patients, transplanted from genetically identical twins without using alkylating agents during conditioning, showed rapid and sustained hematological reconstitution without any evidence of conditioning‐related toxicity.
General Comment No. 17 on “Authors' Rights”
Authors: Haugen Hans Morten
Published: February 2007

General Comment No. 17 on authors' rights is a comprehensive assessment of the normative content of article 15, paragraph 1(c) of the International Covenant on Economic, Social and Cultural Rights (the Covenant). Also, the obligations and violations are spelled out in great detail. It is found that the General Comment makes a clear distinction in principle between standard intellectual property rights and the protection given in accordance with article 15, paragraph 1(c). At the same time, the General Comment does not outline any specific tools for determining when an intellectual effort would result in human rights protection and when it would fall outside of the scope of this protection. Two clarifications have resulted in a positive reception of the General Comment among those who expressed criticism during the drafting. First, General Comment No. 17 acknowledges the need for human rights protection for local and indigenous communities. Second, General Comment No. 17 emphasizes the balance between the private interests of the authors and the other human rights recognized in the Covenant.
Australian haemodialysis patients on intravenous epoetin alfa or intravenous darbepoetin alfa: How do they compare?
Authors: PUSSELL BRUCE A , WALKER ROWAN ,   THE AUSTRALIAN RENAL ANAEMIA GROUP
Published: February 2007

Aim:  The purpose of the present study was to determine whether Australian haemodialysis patients receiving intravenous epoetin alfa are comparable to those receiving darbepoetin alfa with respect to a range of demographic and clinical characteristics.

Methods:  Data on haemodialysis patients were extracted from the Renal Anaemia Management database for the period from July 2003 to March 2004.

Results:  Patients on haemodialysis were more likely to receive epoetin alfa than to receive darbepoetin alfa (n = 1898 vs n = 603, respectively). Patients receiving epoetin alfa were marginally older than patients receiving darbepoetin alfa (61 ± 15 vs 59 ± 15, mean ± SD; P < 0.05). Patients were similar in terms of proportion of males, incidence of diabetes, and angiotensin‐converting enzyme inhibitor and antihypertensive use. However, patients receiving epoetin alfa had higher haemoglobin (116 ± 13 g/L vs 113 ± 15 g/L), serum ferritin (582 ± 414 μg/L vs 461 ± 350 μg/L) and transferrin saturation levels (29 ± 13% vs 26 ± 14%), and better dialysis adequacy test results, as measured by urea reduction ratio (URR) or Kt/V, than patients on darbepoetin alfa (P < 0.001 in all cases). The frequency of dosing was higher in the epoetin alfa group (1.7 ± 0.7 doses/week vs 1.0 ± 0.4 doses/week, P < 0.001). Using the 240:1 dose ratio recommended in the Australian prescribing information for darbepoetin alfa, epoetin alfa was administered at a lower dose compared with darbepoetin alfa (164 ± 116 IU/kg per week vs 192 ± 152 IU/kg per week, P < 0.001).

Conclusion:  This cross‐sectional sample of Australian clinical practice suggests that there are differences in the haematological parameters of patients receiving epoetin alfa compared with patients receiving darbepoetin alfa.