bluuebunny/crossref_metadata_2025 huggingface dataset:
Adaptive backward difference formula–Discontinuous Galerkin finite element method for the solution of conservation laws
Authors: Dolejší V. , Kůs P.
Published: August 2007

We deal with the numerical solution of the system of conservation laws. Although this approach has been proposed for a simulation of inviscid compressible flow, it can be straightforwardly applied to more general problems. We carried out the space semi‐discretization by the discontinuous Galerkin finite element (DGFE) method, which is based on a piecewise polynomial discontinuous approximation. The resulting system of ordinary differential equations is discretized by the backward difference formula (BDF). A suitable linearization of the physical fluxes leads to a scheme that is practically unconditionally stable and has a higher order of accuracy with respect to the space and time coordinates and we solve a linear algebraic system at each time level. Moreover, we develop an adaptive technique for a choice of the length of the time step that is based on the use of two BDFs of the same order of accuracy. We call the resulting scheme the ABDF–DGFE (adaptive BDF–DGFE)
method. Finally, the efficiency of the presented adaptive strategy is documented by a set of numerical examples. Copyright © 2007 John Wiley & Sons, Ltd.
Application of essential work of fracture concept to toughness characterization of high‐density polyethylene
Authors: Kwon H.J. , Jar P.‐Y.B.
Published: August 2007

Deformation and fracture toughness of high‐density polyethylene (HDPE) in plane‐stress tension was studied using the concept of essential work of fracture (EWF). Strain range for necking was determined from uniaxial tensile test, and was used to explain the deformation transition for 2‐staged crack growth in double‐edge‐notched tensile test. Through work‐partitioning, EWF values for HDPE were determined for each stage of the crack growth. Appropriateness of these EWF values to represent the material toughness is discussed. The study concludes that the EWF values for ductile polymers like HDPE may not be constant, but vary with the deformation behaviour involved in the crack growth process. POLYM. ENG. SCI., 47:1327–1337, 2007. © 2007 Society of Plastics Engineers
Evaluation of the fracture behavior of multilayered polypropylene sheets obtained by coextrusion
Authors: Gámez‐Pérez Jose , Santana Orlando O. , Gordillo Antonio , Maspoch Maria L.
Published: August 2007

The mechanical and fracture behavior of multilayered sheets (up to three layers) is presented. The sheets were processed by plane coextrusion‐calendering using two polypropylene‐based materials, isotactic polypropylene homopolymer (H0), and an ethylene–propylene block copolymer (C1) with 5.5% ethylene content in weight. Combining these materials five different sheets were produced, (H0, C1, H0–C1, H0–C1–H0, and C1–H0–C1), with an overall thickness of 0.5 mm. The processing variables (temperature, extrusion rate, calendering speed, etc.) were set constant among the different structures to facilitate the evaluation of the results. The structure of the sheets was characterized with wide angle X‐ray scattering (WAXS). The mechanical behavior was determined from dumbbell tensile specimens in the melt flow (MD) and transverse to the melt flow (TD) directions. The fracture parameters were determined by the essential work of fracture (EWF) technique in mode I in both MD and TD directions. The results show variations on the induced orientation of the sheets, with remarkable differences on the fracture properties. The poor fracture resistance of the homopolymer (H0) film in TD is improved through coextrusion with C1, obtaining the best results for toughness in the case of the three‐layered sheets. POLYM. ENG. SCI., 47:1365–1372, 2007. © 2007 Society of Plastics Engineers
Rotational molding cycle time reduction through surface enhanced molds: Part A—Theoretical study
Authors: Abdullah M.Z. , Bickerton S. , Bhattacharyya D.
Published: August 2007

Rotational molding has been regarded as a plastic molding method with great potential. The process offers virtually stress‐free products having no weld lines or material wastage, and utilizes relatively inexpensive molds. Yet its widespread growth is hindered due to long production cycle times, which are limited by the time required to heat up and cool down the mold and the product. To address this issue, efforts have been made to enhance heat transfer to and from molds, ultimately reducing cycle times. The application of extended and rough surfaces to molds is investigated here. The aim of this study is to predict reductions in cycle time due to the enhancement of mold surfaces (i.e. roughness‐enhanced and pin‐enhanced molds). By utilizing a combination of heat transfer correlations, numerical analysis, and an existing rotational molding process simulation, cycle time predictions were made. The average predicted cycle time reductions were ∼21 and 32% for the roughness‐enhanced and pin‐enhanced molds considered, under a variety of conditions. POLYM. ENG. SCI., 47:1406–1419, 2007. © 2007 Society of Plastics Engineers
Structure and properties of injection‐molded polypropylene with sorbitol‐based clarifier
Authors: Tenma Miwa , Yamaguchi Masayuki
Published: August 2007

The relationship between the structure and the optical properties of isotactic polypropylene (PP) containing 1,3:2,4‐di‐p‐methylbenzylidene sorbitol (MDBS) has been studied. It is found that thinner injection‐molded plaques of PP/MDBS show higher levels of transparency than compression‐molded plaques. The enhanced molecular orientation in the skin layer is responsible for the depression of light scattering because of polarizability fluctuation, i.e., orientation fluctuation in the crystalline phase, because the size of the fluctuation becomes larger than the wavelength of visible light. Further, the crowded network structure of the MDBS fibers generated in molten PP prohibits spherulite formation and, as a result, depresses the spatial size of polarizability fluctuation in the core, which is smaller than the wavelength of visible light. Consequently, light scattering from the core layer is also reduced. POLYM. ENG. SCI., 47:1441–1446, 2007. © 2007 Society of Plastics Engineers
Influence of UV absorber on photodegradation processes of poly(vinyl chloride) with different average degrees of polymerization
Authors: Shi Wei , Zhang Jun , Shi Xu‐Ming , Jiang Guo‐Dong
Published: August 2007

The influence of UV absorber (Chimassorb81) on the photodegradation mechanism of different average degrees of polymerization (DP) of poly (vinyl chloride) (PVC) with UV‐irradiation time was investigated by viscosity‐average molecular weight determination, UV‐vis spectroscopy, FTIR, contact angle measurement, and scanning electron microscopy (SEM). The PVC films with different DP (1000 and 3000), which contained 0.3 or 0.5 phr Chimassorb81, were prepared by solution casting. It was carried out by exposing specimens to xenon‐arc light source with a spectral irradiance of 0.68 W/(m2 nm) at 63°C. It is found that the Chimassorb81 is efficient photostabilizer for PVC with different DP. Although the Chimassorb81 delays the photodegradation of PVC, it does not influence the photodegradation mechanisms of PVC with different DP. The main photodegradation reaction for the lower DP of PVC is dehydrochlorination in the initial stage of UV‐irradiation, and then the crosslinking and chain scission reactions occurred after long irradiation. However, the main reaction of the higher DP of PVC is not dehydrochlorination but crosslinking and chain scission in the initial stage of UV‐irradiation. The results of carbonyl index, CCl index, contact angle measurement, and SEM also show that the photostability of Chimassorb81 is more effective for the higher DP of PVC, especially in the presence of higher concentration of Chimassorb81. POLYM. ENG. SCI., 47:1480–1490, 2007. © 2007 Society of Plastics Engineers
Intramolecular general base catalysis exerted by the carboxilate group in the spontaneous dehydration of the carbinolamine formed from benzoylformic anion and hydroxylamine at early values of pH
Authors: Calzadilla M. , Malpica A. , Mejias I.
Published: August 2007

Data obtained from the reaction of oxime formation from benzoylformic anion lead to the suggestion that the spontaneous dehydration observed after pH ∼ 5.0, proceeds through a transition state in which an intramolecular general base catalysis is exerted by the carboxylate group. Copyright © 2007 John Wiley & Sons, Ltd.
On the residual stress developed in the nanostructure of computer simulated thin films
Authors: Jalali‐Jafari Behdad , Savaloni Hadi , Gholipour‐Shahraki Mehran
Published: August 2007

A 1 + 1 dimensional computer simulation model based on aggregation of hard disks is used to investigate the relationship between the nanostructure of simulated thin metallic (e.g., Ni) films on the (111) face of fcc or the (100) face of hcp substrates under different deposition conditions and the stress developed in these films. The intrinsic mechanical stress in these films, while remaining almost constant up to a certain substrate temperature, passes a tensile stress maximum, which depends on the deposition rate, and decreases towards zero with increasing substrate temperature, owing to an increased diffusion process. By increasing the deposition angle, the microstructure of film changes from a dense film with few voids, to a microstructure with (somewhat densely packed) columns/bundles inclined towards the incidence atoms with elongated voids. The latter decreases the tensile stress, while the former increases the compressive stress, resulting in total compressive stress, particularly at deposition angles above 60°. The results are compared with the experiments performed on Ni/glass films that were produced under UHV condition and with different deposition parameters. The nanostrain in the latter films were obtained using the Warren–Averbach method for X‐ray diffraction line‐broadening analysis. A qualitatively good agreement between simulation and experimental results is obtained. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Kinetic Monte Carlo simulations of amorphous thin‐film growth
Authors: Elsholz F. , Schöll E. , Rosenfeld A.
Published: August 2007

Amorphous SiO2 and Nb2O5 thin‐film growth simulations are performed on the basis of a solid‐on‐solid model considering fluctuating effective atom binding energies. We show that by assuming laterally correlated random energy fluctuations, one can obtain effective growth exponents and overall film roughness in agreement with experimental results. The solid‐on‐solid model is solved by event‐based kinetic Monte Carlo simulations and the obtained results are compared to atomic force microscopy data. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Geometry optimization method based on approximate spin projection and its application to F2, CH2, CH2OO, and active site of urease
Authors: Kitagawa Yasutaka , Saito Toru , Ito Masahide , Nakanishi Yasuyuki , Shoji Mitsuo , Koizumi Kenichi , Yamanaka Shusuke , Kawakami Takashi , Okumura Mitsutaka , Yamaguchi Kizashi
Published: August 2007

A new geometry optimization method based on an approximate spin projection (AP) procedure is proposed to eliminate a spin contamination effect in an optimized structure on a low spin (LS) state of a broken symmetry (BS) method. First, an energy gradient with the AP (AP gradient) is derived and it is applied to the geometry optimization of F2, CH2, and CH2OO in order to obtain their structures without the spin contamination. The optimization method corrects HCH angle of the CH2 about 10° in comparison with the BS method, and indicates that the spin contamination in optimized geometry of the BS LS states is considerably large. Next, an active site of Urease that consists of two Ni(II) ions is optimized by the AP method. The result indicates that structure of the active site is sensitive to a water molecule called W3. © 2007 Wiley Periodicals, Inc. Int J Quantum Chem, 2007
Hybrid density functional study of ligand coordination effects on the magnetic couplings and the dioxygen binding of the models of hemocyanin
Authors: Takano Yu , Yamaguchi Kizashi
Published: August 2007

Ligand coordination effects on the magnetic interaction and the reversible dioxygen binding process for the models of hemocyanin have been investigated with hybrid density functional theory. Hemocyanin is an oxygen transport protein found in mollusks and arthropods. The active site of hemocyanin contains a pair of copper atoms, each of which is coordinated by three histidine residues. We utilized NH3 (a), methylimidazole (b), and histidine (c) as the ligands of the models of hemocyanin, which coordinate to the binuclear copper core in the active site of oxygenated (1z) (z = a–c) and deoxygenated hemocyanin (2z). The difference of the ligand coordination in the magnetic couplings for the model of hemocyanin 1z complexed with peroxide (1z‐O) shows that the substitution from histidine to methylimidazole group is not serious, but that the substitution from imidazole to NH3 is influential. In the dioxygen binding process, the ligands influence the binding energy and the shapes of potential energy surfaces of the models of hemocyanin 1z and 2z with dioxygen due to the strength of the mixing between the ground state and the charge transfer one. The active dxy ± dxy orbitals of the copper core of 1b and 1c strongly interact with π and π orbitals of the dioxygen than those of 1a, leading to the larger binding energy of the model 1b (1c) with dioxygen. The orbital energies of the active orbitals for the synthetic model, [Cu(HB(3,5‐iPr2‐Pz)3)]2 (HB(3,5‐iPr2‐Pz)3 = hydrotris{3,5‐diisopropyl‐pyrazolyl}borate), imply that it irreversibly binds dioxygen because HB(3,5‐iPr2‐Pz)3 groups show stronger electron‐release character and raise the orbital energies nearer that to π* orbitals of O2. The effective bond‐order, localized electron density, and information entropy for 1z with dioxygen were calculated in terms of occupation numbers of the natural orbitals of the broken‐symmetry UB2LYP solution in order to elucidate the nature of the Cu2O2 bonding. These chemical indices indicate that the copper–oxygen bonds in Hc exhibit an intermediate covalent‐bonding character (half bonding), which is the origin of an active control of oxygen transport: addition and dissociation of O2 in hemocyanin by the conformational changes. © 2007 Wiley Periodicals, Inc. Int J Quantum Chem, 2007
Computation of profile likelihood‐based confidence intervals for reference limits with covariates
Authors: Virtanen A. , Uusipaikka E.
Published: August 2007

Many biochemical quantities depend on age or some other covariate. Reference limits that allow for these dependencies help physicians to interpret the results of biochemical tests. Because reference limits must be estimated, it is important to assess their precision with, for example, confidence intervals. This paper relies on the assumption that data can be modeled by a generalized linear model and presents a method for calculating approximate profile likelihood‐based confidence intervals for reference limits. The calculation of confidence intervals is based on a new method that draws on profile likelihood‐based confidence intervals in general statistical models. The asset of this new method is that only two constrained optimization problems have to be solved instead of several in the standard method. We motivate our confidence interval calculation method with two applications. The first is for data on immunoglobulin concentration in the context of a generalized linear model with gamma distribution. This model is compared with the often used lognormal model. The second application handles data on serum alpha‐fetoprotein and is presented in a linear regression situation. In the latter application the widths of the calculated profile confidence intervals are compared with exact and approximate regression‐based intervals and the actual confidence levels are determined by simulation. Copyright © 2007 John Wiley & Sons, Ltd.
Tests of non‐null hypothesis on proportions for stratified data
Authors: Zhao G.
Published: August 2007

It is more reasonable to interpret the efficacy of therapies under non‐null hypothesis, hence tests of non‐null hypothesis have been carried out. Most clinical trials adopt multi‐center campaign and yield stratified data. However, the existing non‐null hypothesis tests are not suitable for stratified data. This paper proposes the tests of non‐null hypothesis on proportions for stratified data. Averaging the treatment‐control difference in each stratum yields the mean treatment‐control difference. Comparing its expectation with the minimal detectable difference leads to set up a non‐null hypothesis. Its variance is used to construct the equation of the basic relationship for stratified designs under the non‐null hypothesis. Then follow the derivations for the one‐ and two‐sample tests. Their performance is demonstrated by the Monte Carlo method. As far as the two‐sample tests are concerned, they reduce to the Cochran test and the Mantel–Haenszel test, on setting the minimal detectable difference equal to zero, and to the Dunnett–Gent test when there is only one stratum. As for the one‐sample test, it also reduces to its classical counterparts in these situations. The observed power coincides with the prescribed power and the relevant operating characteristic curves. The tests can be applied to the active control clinical trials with multi‐center or stratified designs for establishing the clinical superiority or non‐inferiority of a tested drug versus control. Worked examples illustrate the methodology. Copyright © 2007 John Wiley & Sons, Ltd.
Tragverhalten von bewitterten Verbund‐Sicherheitsglas‐Scheiben
Authors: Ensslen Frank
Published: August 2007

Neben bekannten Einflüssen auf das Schubtragverhalten von Verbund‐Sicherheitsglas (VSG) wie Folientemperatur, Belastungshöhe und ‐dauer existieren weitere Faktoren aus klimatischer Belastung: z. B. langzeitliche UV‐Strahlung, Feuchte und Lufttemperatur. Diese sind besonders bei Außenanwendungen von Bedeutung. Experimentelle Untersuchungen zeigten, dass eine Durchfeuchtung der Polyvinylbutyral‐Folie (PVB‐Folie) an den Glaskanten einen negativen Einfluss für die Beständigkeit von VSG darstellt. Hierdurch ergibt sich eine Beeinträchtigung der Schubsteifigkeit wie auch des Haftverbundes. Bei großformatigem Architektur‐VSG, welches durch Wind, Schnee und Eigengewicht belastet wird, sind keine bedeutsamen Konsequenzen für die Tragsicherheit zu erwarten, wenn sich die Veränderungen auf den Randbereich beschränken. Um optische Beeinträchtigungen bei der Exposition von VSG in extrem feuchter Umgebung (z. B. Regen) zu vermeiden, wird empfohlen, die Kanten sorgfältig und nachhaltig zu versiegeln. Eine Alterung der Folie durch UV‐Strahlung und hohe Lufttemperaturen hängt von ihrer Dauer und Intensität ab, führt hingegen zu einer Versteifung (Versprödung) der Materialeigenschaften, nicht aber zu einer Beeinträchtigung der Tragsicherheit.
Optimum strength distribution for seismic design of tall buildings
Authors: Moghaddam H. , Hajirasouliha I.
Published: August 2007

This paper examines the effects of strength distribution pattern on seismic response of tall buildings. It is shown that in general for an MDOF structure there exists a specific pattern for height‐wise distribution of strength and stiffness that results in a better seismic performance in comparison with all other feasible patterns. This paper presents a new optimization technique for optimum seismic design of structures. In this approach, the structural properties are modified so that inefficient material is gradually shifted from strong to weak areas of a structure. This process is continued until a state of uniform deformation is achieved. It is shown that the seismic performance of such a structure is optimal, and behaves generally better than those designed by conventional methods. The optimization algorithm is then conducted on shear building models with various dynamic characteristics subjected to a group of severe earthquakes. Based on the results, a new load pattern is proposed for seismic design of tall buildings that is a function of fundamental period of the structure and the target ductility demand. The optimization method presented in this paper could be useful in the conceptual design phase and in improving basic understanding of seismic behavior of tall buildings. Copyright © 2007 John Wiley & Sons, Ltd.
Unifying theories in ProofPower-Z
Authors: Oliveira Marcel , Cavalcanti Ana , Woodcock Jim
Published: August 2007

The increasing interest in the combination of different computational paradigms is well represented by Hoare and He in the
Unifying Theories of Programming
(UTP). In this paper, we present a mechanisation of part of that work in a theorem prover, ProofPower-Z; the theories of alphabetised relations, designs, reactive and CSP processes are in the scope of this paper. Furthermore, the mechanisation of
Circus
, a language that combines Z, CSP, specification statements and Dijkstra’s guarded command language, is also presented here. We also present an account of how this mechanisation is achieved, and more interestingly, of what issues were raised, and of our decisions. We aim at providing tool support not only for CSP and
Circus
, but also for further explorations of Hoare and He’s unification, and for the mechanisation of languages whose semantics is based on the UTP.
Career Research Interests and Training of Genetic Counseling Students
Authors: Bedard Angela C. , Huether Carl A. , Shooner Kerry , Buncher C. Ralph , Warren Nancy Steinberg
Published: August 2007

Research is important to validate clinical services, provide information on the effectiveness of practice techniques, and develop the knowledge base of a clinical profession. Genetic counseling students from American Board of Genetic Counseling (ABGC) accredited training programs were surveyed to determine their career research interests and interest in pursuing a hypothetical doctoral degree in genetic counseling. Genetic counseling program directors were surveyed to assess the emphasis on research training within their programs. A substantial number (46%, n = 92) of genetic counseling students are interested in performing research in their careers and many (40%, n = 80) would pursue a doctoral degree in genetic counseling if it was available. Students and directors from programs with a thesis requirement reported a significantly higher emphasis on career research preparation than those from programs without a thesis requirement. The results of this study indicate that future genetic counselors are interested in contributing to the research base that will advance the field. This study suggests a need to strengthen research training within ABGC accredited graduate programs and explore the development of a doctoral degree option in genetic counseling.
Relation between diacylglycerol acyltransferase activity and oil concentration in soybean
Authors: Settlage Sharon B. , Kwanyuen Prachuab , Wilson Richard F.
Published: August 2007

Diacylglycerol acyltransferase (EC 2.3.1.20; DGAT) catalyzes synthesis of triacylglycerol from acyl‐CoA and diacylglycerol. Activity of this enzyme and developmental changes in oil accumulation were estimated at various stages of seed growth in soybean germplasm with phenotypic differences in oil content. Oil deposition in seed of these genotypes followed a sigmoid pattern that was modeled to predict incremental rates of oil accumulation during seed development. A strong positive correlation was found between the estimated peak rate of oil deposition (near the mid‐term of seed development) and oil concentration in mature seed. At saturating substrate levels, DGAT activity measured near the peak rate of oil deposition also was correlated positively with oil phenotype. In the latter stages of seed development, a positive correlation between estimates of enzyme activity at or below the apparent Km for diolein and comparable oil accumulation rates was attributed to reduced synthesis of substrates and/or potential change in affinity for substrate as suggested by an increase in apparent Km for diolein in older seed. These data indicated that DGAT activity may be a rate‐limiting step in triacylglycerol synthesis. However, it is difficult to accept the idea of a single rate‐limiting step at the end of a complex metabolic pathway. Because oil is a quantitatively inherited trait, several genes determine genotypic differences in oil content among soybeans. Hence, DGAT activity may be an indicator of coordinated genetic expression of gene‐products in the entire glycerolipid synthetic pathway for a given genotype. In any case, results of this investigation demonstrated that genotypic differences in DGAT activity contributed to expression of genetic variation in oil content among soybean gemplasm.
Quantitative structure‐liquid chromatographic retention time relationships on natural phenols found in olive oil
Authors: Hueso‐Ureña Francisco , Jiménez‐Pulido Sonia B. , Moreno‐Carretero Miguel N. , Rodríguez‐Avi José
Published: August 2007

A study of the relationship between the liquid chromatographic retention times for a group of 16 natural phenols on olive oil and an initial set of 62 molecular descriptors has been made. The descriptors used may be arranged into three well‐defined kinds: conventional, topological, and quantum‐chemical parameters. By using multivariate regression, three empirical functions were obtained, which were selected on the basis of their respective statistical parameters. The first model relates the retention index with the quantum‐chemical descriptors; the second, with both topological and conventional descriptors; and finally, the third model has been established by considering the relation of the experimental magnitude with the two above‐mentioned sets of parameters together. The correlation coefficients of the empirical functions were 0.9825, 0.9911, and 0.9974, with mean relative errors of 6.8, 4.6, and 2.6%, respectively.
Triacylglycerols and regiospecific fatty acid analyses of philippine seed oils
Authors: Pham Laura J. , Casa Edmar P. , Gregorio Myla A. , Kwon Dae Young
Published: August 2007

Three Philippine seed oils, namely coconut (Cocos nucifera Linn.), pilinut (Canarium ovatum Engl.), and cashew (Anacardium occidentale Linn.), which were selected for their local abundance and availability, were examined for their triacylglycerol profiles and fatty acid compositions. Triacylglycerol molecular species in terms of carbon number and partition number were determined by gas chromatography and liquid chromatography, respectively. The distribution of fatty acids in the primary and secondary positions of the glycerol backbones for the three oils were examined by regiospecific analysis by using pancreatic lipase. Coconut oil had high concentrations of lauric and myristic acids, while the other two oils did not have such fatty acids. Lauric acid in coconut oil and linoleic acid in pilinut oil were distributed mainly in the primary positions (sn‐1,3) of the glycerol backbone. Trilaurin and dioleylpalmitoylglycerol were the major triglycerides in coconut and pilinut oils, respectively.
Triacylglycerol composition of Pinus koraiensis seed oil
Authors: Imbs A. B. , Nevshupova N. V. , Pham L. Q.
Published: August 2007

The triacylglycerol (TG) composition of Pinus koraiensis seed oil, which contains Δ5 nonmethylene‐interrupted (NMI) fatty acids (FA) (the main acid is pinolenic, 18:3 Δ5, 9, 12), was determined. TG were preliminarily separated by argentation thin‐layer chromatography (TLC), and the obtained fractions were analyzed by high‐temperature gas chromatography (GC) on a capillary column with methyl phenyl silicone phase. Additionally, high‐performance liquid chromatography (HPLC) of TG was applied. The FA composition of all TG fractions was identified. The identification of TG was carried out by combining TLC, GC, HPLC, and calculated equivalent carbon numbers of TG standards. The TG species identification was confirmed by comparison of the theoretical recalculated and directly analyzed FA compositions of all TLC fractions of TG. Species of TG with unsaturation degrees of 1 to 7 and trace amounts of saturated and octaenoic TG species were found. Except for minor compounds, 26 TG molecular species of 32 main components were quantitatively determined. The main species were oleoyl dilinoleoylglycerol (14.7%), dilinoleoyl pinolenoylglycerol (10.7%), palmitoyl oleoyl linoleoylglycerol (8.3%), triolein (7.6%), and dioleoyl, linoleoylglycerol (7.4%). Seven TG species contained Δ5 NMI acyl groups. Of these, the major were dilinoleoyl pinolenoyglycerol (10.7%), stearoyl linoleoyl pinolenoylglycerol (6.5%) dioleoyl, pinolenoylglycerol (5.4%), and palmitoyl linoleoyl pinolenoyl‐glycerol (5.5%). TG species with two or three NMI acyl groups were not detected.
Rheology of lecithin dispersions
Authors: Bhattacharya Suvendu , Shylaja M. H. , Manjunath M. S. , Sankar Udaya
Published: August 2007

Dispersions of lecithin (1–25% solids, dry basis) in soybean oil or water were subjected to rheological measurement in a coaxial‐cylinder viscometer. The different rheological characteristics determined included yield stress, flow behavior index, consistency index, and apparent viscosity. Pseudoplastic behavior was observed for all lecithin emulsions in oil and for dispersions in water. The flow behavior indices for lecithin‐oil emulsions (0.855–0.875) were higher than for lecithin‐water dispersions (0.472–0.584). Yield stresses were observed only for lecithin‐water dispersions. An increase in the concentration of lecithin in oil or water increased yield stress, consistency index, and apparent viscosity. The apparent viscosities of the lecithin‐oil emulsions were higher than those for corresponding lecithin‐water dispersions. The power law model can adequately fit (r≥0.988, p≤0.01) the shear‐rate vs. shear‐stress data for lecithin‐oil emulsions, whereas the Herschel‐Bulkley model was suitable (r≥0.988, p≤0.01) for lecithin‐water dispersions.
Genetik des Schlaganfalls
Authors: Gschwendtner A. , Dichgans M.
Published: August 2007

Schlaganfälle umfassen ischämische Hirninfarkte, intrazerebrale Blutungen und Subarachnoidalblutungen. Monogene Erkrankungen sind zwar nur für einen geringen Teil der Schlaganfälle verantwortlich, bei jüngeren Patienten sind sie allerdings eine wichtige Differenzialdiagnose. Bei den sporadischen Fällen spielen genetische Einflüsse neben konventionellen Risikofaktoren eine in zunehmendem Maß als bedeutsam erkannte Rolle. Der Beitrag liefert eine Übersicht über die wichtigsten monogenen Schlaganfallursachen und neuere Entwicklungen bei der Identifizierung von Risikogenen für den sporadischen Schlaganfall.
Iraqi adolescents: Self‐regard, self‐derogation, and perceived threat in war
Authors: Carlton‐Ford Steve , Ender Morten G. , Tabatabai Ahoo
Published: August 2007

A year into the 2003 US–Iraq war, how were adolescents in Baghdad faring? Conflict‐related events typically lower psychological well‐being; in contrast, investment in and protection of threatened identities should lead to self‐esteem striving and, presumably, better well‐being. How threatened do Iraqi adolescents feel? Is their self‐esteem related to their sense of threat? Do age, religion, ethnicity, and gender alter the link between perceived threat and self‐esteem?

We use data from 1000 randomly selected adolescents living in Baghdad during July 2004. Iraqi adolescents reported high levels of threat; those feeling more threatened reported higher levels of self‐esteem. Social background correlates with both self‐esteem and perceived threat, but controlling for social background does not eliminate the relationship between self‐esteem and perceived threat. We interpret our results in light of theory and research concerning social identity, mortality threats, and war trauma.
Age‐related changes in BDNF protein levels in human serum: differences between autism cases and normal controls
Authors: Katoh‐Semba Ritsuko , Wakako Rie , Komori Taku , Shigemi Hiroko , Miyazaki Noriko , Ito Hironori , Kumagai Toshiyuki , Tsuzuki Masako , Shigemi Kenji , Yoshida Futoshi , Nakayama Atsuo
Published: August 2007

Accumulating evidence suggests the possible association between the concentrations of serum brain‐derived neurotrophic factor (BDNF) and psychiatric disease with impaired brain development. Yet the reasons remain unclear. We therefore investigated the characteristics of serum BDNF as well as its age‐related changes in healthy controls in comparison to autism cases. BDNF was gradually released from platelets at 4 °C, reached a maximal concentration after around 24 h, and remained stable until 42 h. At room temperature, BDNF was found to be immediately degraded. Circadian changes, but not seasonal changes, were found in serum levels of BDNF existing as the mature form with a molecular mass of 14 kDa. In healthy controls, the serum BDNF concentration increased over the first several years, then slightly decreased after reaching the adult level. There were no sex differences between males and females. In the autism cases, mean levels were significantly lower in children 0–9 years old compared to teenagers or adults, or to age‐matched healthy controls, indicating a delayed BDNF increase with development. In a separate study of adult rats, a circadian change in serum BDNF was found to be similar to that in the cortex, indicating a possible association with cortical functions.
Linked and pleiotropic QTLs influencing carcass composition traits detected on porcine chromosome 7
Authors: GILBERT HÉLÈNE , LE ROY PASCALE , MILAN DENIS , BIDANEL JEAN-PIERRE
Published: August 2007

A multivariate QTL detection was carried out on fatness and carcass composition traits on porcine chromosome 7 (SSC7). Single-trait QTLs have already been detected in the SLA region, and multivariate approaches have been used to exploit the correlations between the traits to obtain more information on their pattern: almost 500 measurements were recorded for backfat thickness (BFT1, BFT2), backfat weight (BFW) and leaf fat weight (LFW) but only about half that number for intramuscular fat content (IMF), affecting the detection. First, groups of traits were selected using a backward selection procedure: traits were selected based on their contribution to the linear combination of traits discriminating the putative QTL haplotypes. Three groups of traits could be distinguished based on successive discriminant analyses: external fat (BFT1, BFT2), internal fat (LFW, IMF) and BFW. At least four regions were distinguished, preferentially affecting one or the other group, with the SLA region always influencing all the traits. Meishan alleles decreased all trait values except IMF, confirming an opportunity for marker-assisted selection to improve meat quality with maintenance of carcass composition based on Meishan alleles.
Phenotypic effects induced by knock-down of theperiodclock gene inBombyx mori
Authors: SANDRELLI FEDERICA , CAPPELLOZZA SILVIA , BENNA CLARA , SAVIANE ALESSIO , MASTELLA ANTONIO , MAZZOTTA GABRIELLA M. , MOREAU STEPHANE , PEGORARO MIRKO , PICCIN ALBERTO , ZORDAN MAURO A. , CAPPELLOZZA LUCIANO , KYRIACOU CHARALAMBOS P. , COSTA RODOLFO
Published: August 2007

The lepidopteranBombyx moriis an insect of considerable scientific and economic importance. Recently, theB. moricircadian clock geneperiodhas been molecularly characterized. We have transformed aB. moristrain with a construct encoding aperioddouble-strand RNA in order to knock-downperiodgene expression. We observe that this post-transcriptional silencing produces a small but detectable disruption in the egg-hatching rhythm, as well as a reduction in egg-to-adult developmental time, without altering silk production parameters. Thus we show that both circadian and non-circadian phenotypes can be altered by changingperexpression, and, at a practical level, these results suggest thatperknock-down may provide a suitable strategy for improving the efficiency of rearing, without affecting silk productivity.
Quantitative and molecular genetic variation in sympatric populations ofMedicago laciniataandM. truncatula(Fabaceae): relationships with eco-geographical factors
Authors: BADRI MOUNAWER , ILAHI HOUCINE , HUGUET THIERRY , AOUANI MOHAMED ELARBI
Published: August 2007

Medicago laciniatais restricted to south of the Mediterranean basin and it extends in Tunisia from the inferior semi-arid to Saharan stages, whereasM. truncatulais a widespread species in such areas. The genetic variability in four Tunisian sympatric populations ofM. laciniataandM. truncatulawas analysed using 19 quantitative traits and 20 microsatellites. We investigated the amplification transferability of 52 microsatellites developed inM. truncatulatoM. laciniata. Results indicate that about 78·85% of used markers are valuable genetic markers forM. laciniata.M. laciniatadisplayed significantly lower quantitative differentiation among populations (QST=0·12) than didM. truncatula(QST=0·45). However, high molecular differentiations, with no significant difference, were observed inM. laciniata(FST=0·48) andM. truncatula(FST=0·47). Several quantitative traits exhibited significantly smallerQSTthanFSTforM. laciniata, consistent with constraining selection. ForM. truncatula, the majority of traits displayed no statistical difference in the level ofQSTandFST. Furthermore, these traits are significantly associated with eco-geographical factors, consistent with selection for local adaptation rather than genetic drift. In both species, there was no significant correlation between genetic variation at quantitative traits and molecular markers. The site-of-origin explains about 5·85% and 11·27% of total quantitative genetic variability among populations ofM. laciniataandM. truncatula, respectively. Established correlations between quantitative traits and eco-geographical factors were generally more moderate forM. laciniatathan forM. truncatula, suggesting that the two species exhibit different genetic bases of local adaptation to varying environmental conditions. Nevertheless, no consistent patterns of associations were found between gene diversity (He) and environmental factors in either species.
The Many Questions of Islamic Art
Authors: BLAIR SHEILA
Published: August 2007

This luster bowl, made by the Persian potter Abu Zayd in February–March 1204 (Jumada II 600), exemplifies the broad range of questions that can be raised by Islamic art. The first question is that of provenance. The bowl appeared on the art market in 2001, unknown and undocumented but in virtually perfect condition. A battery of tests supports its authenticity. Jonathan Bloom and I included it in the exhibition Cosmophilia: Islamic Art from the David Collection, Copenhagen, which we organized for the McMullen Museum, Boston College, and which was on view until 20 May 2007 at the Smart Museum, University of Chicago. However, we are in the dark about where the bowl has been in the eight centuries since it was made.
ABU BAKR IBN AL-MUNDHIR, AMPUTATION, AND THE ART OF IJTIHĀD
Authors: Lucas Scott C.
Published: August 2007

Few Islamic concepts have undergone as radical a semantic shift over the past couple of centuries as ijtihād. This Arabic term, confined for centuries to sophisticated works of legal theory (uṣūl al-fiqh), has been liberated and transformed into the handmaiden of modern Muslim reformists throughout the world. Numerous Western scholars have investigated either the classical legal ijtihād of the first definition above or the modern employment of ijtihād among reformists encapsulated in the second, succinct gloss of this word. Valuable studies have been published on topics ranging from the relationship between ijtihād and writing fatwas (iftāء) to the so-called “closure of the gate of ijtihād” to the role of ijtihād in 19th- and 20th-century reform movements. In short, ijtihād is ubiquitous in modern studies and formulations of Islam.
PRISON TALK: THE MUSLIM BROTHERHOOD'S INTERNAL STRUGGLE DURING GAMAL ABDEL NASSER'S PERSECUTION, 1954 TO 1971
Authors: Zollner Barbara
Published: August 2007

These words, which were written by the unnamed editor of the book Duʿat la Qudat (Preachers Not Judges), summarize the Society of the Muslim Brothers' (Jamʿiyya al-Ikhwan al-Muslimin) prison discourse in the late 1960s. The writer claims that once the organization became aware that radical ideas had surfaced in its midst, it objected to these ideas, even as it lived through the very context of their germination, namely Gamal Abdel Nasser's prisons.
Divine Right: Mark Twain's Joan of Arc
Authors: McWilliams Wilson Carey
Published: August 2007

Most readers have not agreed with Mark Twain in liking Joan of Arc best of all his novels, particularly because his hand is almost invisible in it. He presents the story as a translation by “Jean Francois Alden” of the remembrances of “Sieur Louis de Conte.” He did not think readers would take a work by “Mark Twain” seriously. Only the initials S. L. C. indicate the connection between the actual and the presumed author. Twain considered Joan to be “the most extraordinary person the human race has ever produced.” She was a woman—and a general. She genuinely believed that she was acting on the basis of commands from God. In relating her story, Twain nevertheless shows that nothing human, and certainly no government and no ruler, is entitled to divine honors or right.
The Original Position in José Saramago's Blindness
Authors: Keren Michael
Published: August 2007

Following the tradition of social contract theories of the early modern age, John Rawls, in A Theory of Justice, renewed the notion of the “original position,” that is, a set of behavioral assumptions from which general principles of justice are deduced. José Saramago's novel Blindness enriches Rawls's normative theory by adding behavioral assumptions that help clarify some of the problems raised by the theory's critics and enhance its application to social and political settings.
More developments in computational models: introduction
Authors: FERNÁNDEZ MARIBEL , MACKIE IAN
Published: August 2007

This second special issue devoted to ‘developments in computational models’ (the first was Volume 16 Issue 4) came out of an open call for papers following the First International Workshop on Developments in Computational Models (DCM). This took place in Lisbon, Portugal, on the 10th July 2005, and was a satellite event of ICALP 2005 focused on abstract models of computation and their associated programming paradigms.
Effect of oestradiol benzoate, progesterone and vaginal bolt on superovulation of Holstein heifers
Authors: Bao-Ning Duan , Jian-Hua Xue , Xin-Hui Zhang , Sheng-Quan Wu , Feng-Jun Sun , Run-Zi Sang
Published: August 2007

This trial was aimed at investigating the effect of different doses of progesterone (P4) and types of vaginal bolts on new follicular wave induction, oestrus synchronization and superovulation in Holstein heifers. Results showed that the interval after prostaglandin F2α (PGF2α) application and oestrus occurrence between the sponge blot (SP) group (48.3 h) and the progestin release device (PRD) group (39 h) was significantly different (P<0.05). The average number of embryos obtained in the SP group (13.2) was significantly higher than that (8.7) in the PRD group (P<0.05). The same trend was observed for the number of usable embryos (5.7 and 3.3 for SP and PRD groups, respectively). The injection of 50 and 100 mg of P4 efficiently induced a new follicular wave, whereas no significant difference (P>0.05) was recorded on oestrus synchronization and superovulation between the two groups.
A modified GLGI method for identification of novel porcine genes from long serial analysis of gene expression tags
Authors: Zhong-Lin Tang , Yong Li , Shu-Hong Zhao , Bang Liu , Bin Fan , Kui Li
Published: August 2007

Combining the long serial analysis of gene expression (LongSAGE) and the generation of longer cDNA fragments from serial analysis of gene expression tags for gene identification (GLGI) technique, a new strategy called modified GLGI (M-GLGI) was developed to isolate unknown 3′ expressed sequence tags (ESTs) and discover novel genes. A 17 bp LongSAGE tag was used as sense primer instead of a 10-base SAGE tag; PCR reaction was performed under an appropriate annealing temperature for each tag; universal DNA polymerase was used in PCR amplification instead of Pfu enzyme; a common cloning strategy using pMD-18T vector and Escherichia coli DH5α cells were used instead of a special vector and competent cells. Moreover, ESTs isolated by M-GLGI had 3′ ends with the polyadenylation signals and poly(dA) tails. This method is more sensitive for identifying genes expressed in low abundance than conventional EST sequencing.
Diversity of endophytic diazotrophs isolated fromBambusa blumeanain Guangdong province
Authors: Wei How , Gui-Xiang Peng , Zhi-Jun Xu , Shi-Xian Chen , Zhi-Yuan Tan
Published: August 2007

Endophytic bacteria isolated from Guangdong bamboo (Bambusa blumeana) plants were obtained under aerobic and anaerobic cultural conditions. Using the acetylene reduction assay (ARA), 40 strains were identified as diazotrophs. Diazotrophic isolates were grouped into five clusters (I, II, III, IV and V) by SDS-PAGE whole-cell protein patterns. The analysis of full-length 16S rDNA sequences of the representative strains of each group indicated that the endophytic diazotrophs showed great diversity and belonged to the generaAzospirillum(α-subclass of proteobacteria),EscherichiaandPseudomonas(γ-subclass of proteobacteria), andAquaspirillum(β-subclass of proteobacteria).
Tracking solitary waves below land‐fast ice
Authors: Marsden R. F.
Published: August 2007

Data from two acoustic Doppler current profilers, separated by 76 m and deployed through land‐fast ice in the Canadian Arctic Archipelago in May 2002, are examined. The three velocity components were sampled intermittently at 1‐minute intervals over a 3‐week period to 19 m below the ice‐water interface. The vertical structure was resolved using empirical orthogonal functions (EOF), while the shallow water Korteweg de Vries (KdV) and deep water Benjamin‐Ono (BO) theoretical solutions were used to guide a pseudo‐wavelet analysis of the horizontal structure. Numerous instances of near‐simultaneous spikes were detected in the empirical mode 1 time series. A 3.5‐hour period on 21 May 2002 containing two disturbances was examined in detail. Wavelet scalograms suggested that there was a 20‐minute lag in the first disturbance and 16 minutes in the second. The scalogram values indicated that KdV was more consistent with the waveshapewave shapes than BO theory. The character of the two events was very different. The first had a broader spatial distribution than the second, and the measured translational speed was reasonably consistent with that of a mode 1 KdV solitary wave. The second event had a much slower propagation speed and a near surface maximum in the vertical velocity eigenvector, suggesting a mode 2 wave. It is suggested that ice keels from a nearby pressure ridge could be the source.