bluuebunny/crossref_metadata_2025 huggingface dataset:
EGF‐like peptides mediate FSH‐induced maturation of cumulus cell‐enclosed mouse oocytes
Authors: Downs Stephen M. , Chen Jing
Published: June 2007

This study was carried out to examine the participation of epidermal growth factor (EGF)‐like peptides in the induction of germinal vesicle breakdown (GVB) in mouse cumulus cell‐enclosed oocytes (CEO). The EGF‐like peptide, amphiregulin (AR), dose‐dependently stimulated meiotic resumption in CEO, but not denuded oocytes (DO) maintained in meiotic arrest with 300 µM dbcAMP. The EGF receptor (EGFR) kinase inhibitor, AG1478, blocked meiotic resumption induced by FSH and AR in CEO, but had no effect in DO. FSH‐induced maturation was also suppressed by antisera to both EGFR and EGF. Maturation occurred with slightly faster kinetics in AR‐stimulated CEO when compared to FSH‐stimulated CEO. When CEO were maintained in meiotic arrest with a low level of dbcAMP, FSH was initially inhibitory to maturation and later stimulatory; the stimulatory phase was prevented by AG1478, indicating mediation by EGF‐like peptides. Pulsing CEO with high levels of dbcAMP also stimulated GVB and could be blocked by AG1478. Treatment of arrested CEO with PKC agonists stimulated maturation and this was prevented with AG1478 as well as antibodies to EGFR. FSH‐induced maturation of dbcAMP‐arrested CEO was blocked by bisindolylmaleimide I (BIM‐I), an inhibitor of PKC, implicating PKC in FSH action. EGF‐stimulated CEO failed to resume maturation in the presence of glycerrhetinic acid, a gap junction inhibitor, suggesting transfer of positive signal through the cell–cell coupling pathway. These data support the idea that EGF‐like peptides provide a common pathway mediating the meiosis‐inducing influence of FSH, cAMP pulsing, and PKC activation in mouse CEO by a gap junction‐dependent process. Mol. Reprod. Dev. 75: 105–114, 2008. © 2007 Wiley‐Liss, Inc.
Integrated production scheduling and preventive maintenance planning for a single machine under a cumulative damage failure process
Authors: Kuo Yarlin , Chang Zi‐Ann
Published: June 2007

This paper finds the optimal integrated production schedule and preventive maintenance plan for a single machine exposed under a cumulative damage process, and investigates how the optimal preventive maintenance plan interacts with the optimal production schedule. The goal is to minimize the total tardiness. The optimal policy possesses the following properties: Under arbitrary maintenance plan when jobs have common processing time, and different due dates, the optimal production schedule is to order the jobs by earliest due date first rule; and when jobs have common due date and different processing times, the optimal production schedule is shortest processing time first. The optimal maintenance plan is of control limit type under any arbitrary production schedule when machine is exposed under a cumulative damage failure process. Numerical studies on the optimal maintenance control limit of the maintenance plan indicate that as the number of jobs to be scheduled increases, the effect of jobs due dates on the optimal maintenance control limit diminishes. © 2007 Wiley Periodicals, Inc. Naval Research Logistics, 2007
Network disconnection problems in a centralized network
Authors: Myung Young‐Soo , Kim Hyun‐Joon
Published: June 2007

We consider three network disconnection problems in a centralized network where a source node provides service to the other nodes, called demand nodes. In network disconnection problems, each demand node gets a certain benefit when connected to a source node and a network attacker destroys edges to prevent demand nodes from achieving benefits. As destroying edges incurs expenses, an attacker considers the following three different strategies. The first is to maximize the sum of benefits of the disconnected nodes while keeping the total edge destruction cost no more than a given budget. The second is to minimize the total destruction cost needed to make a certain amount of benefits not accomplished. The last is to minimize the ratio of the total destruction cost to the benefits not accomplished. In this paper, we develop exact algorithms to solve the above three problems. © 2007 Wiley Periodicals, Inc. Naval Research Logistics, 2007
Examinations for terminal condition of Lagrange multiplier for heat transfer control problems
Authors: Kurahashi T. , Kawahara M.
Published: June 2007

This paper presents a method to express the terminal condition of Lagrange multiplier by the solution of the steady adjoint equation. In the control problem based on the adjoint equation method, the terminal condition of Lagrange multiplier has been set zero to satisfy the stationary condition of the extended performance function. Therefore, there is a possibility that the control value near the terminal time cannot be appropriately expressed. To solve this problem, a method to express the terminal condition of Lagrange multiplier by the solution of the steady adjoint equation is proposed and examined. Finally, to confirm the propriety of the proposed method, this method is applied to the sequential control problem, and some remarks are made. Copyright © 2007 John Wiley & Sons, Ltd.
Convergence of a difference scheme for the heat equation in a long strip by artificial boundary conditions
Authors: Han Houde , Sun Zhi‐zhong , Wu Xiao‐nan
Published: June 2007

The numerical solution of the heat equation on a strip in two dimensions is considered. An artificial boundary is introduced to make the computational domain finite. On the artificial boundary, an exact boundary condition is proposed to reduce the original problem to an initial‐boundary value problem in a finite computational domain. A difference scheme is constructed by the method of reduction of order to solve the problem in the finite computational domain. It is proved that the difference scheme is uniquely solvable, unconditionally stable and convergent with the convergence order 2 in space and order 3/2 in time in an energy norm. A numerical example demonstrates the theoretical results.© 2007 Wiley Periodicals, Inc. Numer Methods Partial Differential Eq 2007
Discontinuous Galerkin finite element methods for variational inequalities of first and second kinds
Authors: Djoko J.K.
Published: June 2007

We develop the error analysis for the h‐version of the discontinuous Galerkin finite element discretization for variational inequalities of first and second kinds. We establish an a priori error estimate for the method which is of optimal order in a mesh dependant as well as L2‐norm.© 2007 Wiley Periodicals, Inc. Numer Methods Partial Differential Eq 2007
Numerical solution to a linearized KdV equation on unbounded domain
Authors: Zheng Chunxiong , Wen Xin , Han Houde
Published: June 2007

Exact absorbing boundary conditions for a linearized KdV equation are derived in this paper. Applying these boundary conditions at artificial boundary points yields an initial‐boundary value problem defined only on a finite interval. A dual‐Petrov‐Galerkin scheme is proposed for numerical approximation. Fast evaluation method is developed to deal with convolutions involved in the exact absorbing boundary conditions. In the end, some numerical tests are presented to demonstrate the effectiveness and efficiency of the proposed method.© 2007 Wiley Periodicals, Inc. Numer Methods Partial Differential Eq 2008
EI/MS fragmentation of abieta‐8,11,13‐triene diterpenoid derivatives as a tool to identify swartziarboreols in Swartzia extracts
Authors: Santos Celira Caparica , Magalhães Eva Gonçalves , Magalhães Aderbal Farias
Published: June 2007

A systematic molecular fragmentation pathway (SMFP) was designed as an identifier to detect swartziarboreols (abieta‐8,11,13‐triene diterpenoid derivatives) in Swartzia extracts. The SMFP was rationalised through the interpretation of the EI/MS of swartziarboreols isolated from S. arborescens and S. langasdorffii and by analogy with the fragmentations observed for previously isolated compounds. Two pairs of swartziarboreol epimers were identified by GC‐MS in an extract of S. langsdorffii using SMFP. Acetylation and methylation of the dichloromethane extract furnished, respectively, 3 and 4, which suggested the occurrence of a new natural orthodiphenolic swartziarboreol. Copyright © 2007 John Wiley & Sons, Ltd.
Identification and quantification of C21 steroidal saponins from radix cynanchi atrati by high‐performance liquid chromatography with evaporative light scattering detection and electrospray mass spectrometric detection
Authors: Liang Mingjin , Zheng Zhaoguang , Yuan Ying , Kong Lingyi , Shen Yunheng , Liu Runhui , Zhang Chuan , Zhang Weidong
Published: June 2007

High‐performance liquid chromatography coupled with electrospray tandem mass spectrometry (HPLC‐ESI/MS) and evaporative light scattering detection (HPLC‐ELSD), respectively, has been performed for the simultaneous identification and quantification of six C21 steroid saponins, including cynanversicoside A, B, D, G, glaucoside C and glaucogenin C‐3‐O‐β‐d‐thevetopyranoside in Radix Cynanchi Atrati. The extraction of the C21 steroidal saponins was performed using a B‐811 Buchi Universal Extraction System in Warm Solvent Mode, and the analyte was concentrated by column chromatography before HPLC analysis. The chromatographic separation was performed on an Agilent Zorbax Extend C18 analytical column efficiently using gradient elution with acetonitrile and water. The method was validated with acceptable linearities (r > 0.9991) and recoveries (98.2–101.3%). The limits of detection of the C21 steroid saponins were from 0.2 µg for glaucogenin C‐3‐O‐β‐d‐thevetopyranoside to 0.5 µg for cynanversicoside B. The intra‐ and inter‐day precisions of the method were evaluated and were less than 5.0%. The method was successfully used to analyse 20 batches of Radix Cynanchi Atrati. The content of C21 steroid saponins in the plant material varied significantly from habitat to habitat, confirming the necessity to control the quality of Radix Cynanchi Atrati during its preparation and application in the clinic. Copyright © 2007 John Wiley & Sons, Ltd.
Does offering and performing prenatal screening influence women's attachment to their unborn child? A longitudinal randomized controlled trial
Authors: Kleinveld Johanna H. , Timmermans Daniëlle R. M. , van den Berg Matthijs , van Eijk Jacques Th. M. , Ten Kate Leo P.
Published: June 2007

Objective

The question addressed was: Does offering prenatal screening and receiving a negative screening outcome influence women's attachment to their unborn child?

Methods

Women were offered a nuchal translucency measurement, maternal serum screening, or no screening at all in a randomized controlled trial. Attachment was measured by a self‐developed questionnaire at four points in time: before screening was offered, after the offer, after receiving the negative screening result (or at comparable points in time) and in the last trimester of pregnancy. In the last trimester, the Prenatal Attachment Inventory was also filled in.

Results

Women who had been offered screening (n = 1031) showed more attachment (F(1,1415) = 19.42, p < .001) compared to women who had not been offered screening (n = 387). This difference disappeared later in pregnancy. At all points in time, negatively screened women (n = 466) had equal levels of attachment compared to screening decliners (n = 565). No difference was observed between women who received a negative result of the ultrasound screening (n = 285) as compared to the blood screening (n = 162).

Conclusion

Offering prenatal screening seems to temporarily increase attachment. However, this difference is very small. Attachment is not influenced by whether a blood screening or an ultrasound screening is performed. Copyright © 2007 John Wiley & Sons, Ltd.
A further case with a small supernumerary marker chromosome (sSMC) derived from chromosome 1—evidence for high variability in mosaicism in different tissues of sSMC carriers
Authors: Fickelscher Ina , Starke Heike , Schulze Eberhard , Ernst Günther , Kosyakova Nadezda , Mkrtchyan Hasmik , MacDermont Kay , Sebire Neil , Liehr Thomas
Published: June 2007

A prenatally ascertained case with a de novo small supernumerary marker chromosome (sSMC) derived from chromosome 1 is reported. Due to a fetal heart defect the parents decided in favour of an induced abortion. Postmortem, a molecular cytogenetic study on eleven formalin fixed, paraffin‐embedded tissues of the fetus was performed, to further characterize the levels of mosaicism of the sSMC(1). sSMC presence varied between 13 and 62% within different tissues of sSMC carriers. This finding is something common in sSMC carriers and could explain why up to the present no clinical correlations for sSMC mosaicism and clinical outcome in the corresponding carriers could be established. Copyright © 2007 John Wiley & Sons, Ltd.
The disposition‐situation debate and research on aggression
Authors: Caprara Gian Vittorio
Published: June 2007

Person‐situation interaction is considered in the light of a redefinition of the notions of consistency, stability, coherence, and specificity. A research program able to combine the study of individual differences with experimental research in a developmental perspective is recommended. Findings from research on aggression are presented to support this approach.
Transactional theory and research on emotions and coping
Authors: Lazarus Richard S. , Folkman Susan
Published: June 2007

In this article we examine the fundamental premises of our cognitive‐relational theory of emotion and coping and assess our progress in examining them through 10 years of programmatic empirical research. Our discussion involves the metatheoretical topics of transaction and relationship, process, and emotion as a system. The person‐environment relationship is mediated by two key processess: cognitive appraisal and coping. We evaluate the findings of our research on these processes, their dynamic interplay, their antecedents, and their short‐term and long‐term outcomes. In the final section we highlight major substantive and methodological issues that need to be addressed. These include issues surrounding the theory and measurement of appraisal, functional and dysfunctional coping, causal inference, microanalytic vs macroanalytic research strategies, objective vs subjective approaches and confounding, and the problem of method variance.
Person‐centred coping research
Authors: Laux Lothar , Weber Hannelore
Published: June 2007

In this concluding article we discuss the three approaches to biographical stress and coping research presented in this issue, under four main headings. The first topic comprises the comparison of the three approaches with regard to their biographical features. In a second part we turn to the issue of coping and examine differences as well as similarities between the coping concept of Hans Thomae, on the one hand and that of Lazarus and Folkman on the other hand. The third and fourth of our discussion points deal with two central topics, that are accentuated in present personality psychology: the person‐situation issue and the idiographic‐nomothetic debate. With regard to both topics, we discuss the ideas and research findings which Lazarus and Folkman, as well as Thomae are contributing to these issues. We conclude our discussion of biographical approaches to stress and coping by proposing a person‐centred approach, that can be regarded as a further development of theoretical conceptualizations contained in the approaches of Lazarus and Thomae.
Zero‐variable theories in the analysis of social phenomena
Authors: Wicklund Robert A.
Published: June 2007

Are the background and context of complex social behaviour neglected in theory‐building? This sweeping question is handled here in a highly specific way. First, the character of the everyday ‘explainer's’ theories is examined, and it is found that the explainer's accounts of social behaviour can go in different directions. These directions, which are regarded here as opposite ends of a continuum, are: (1) the explainer takes into account the manifold personal and contextual factors that bear on psychological accompaniments of behaviour; (2) the person whose behaviour is to be explained is first categorized (e.g. ‘aggressive type’), whereby reference to the category then serves as the explanation. While an optimistic view of progress in psychological theorizing (cf. Lewin, 1931; Wegner and Vallacher, 1977) would lead one to think that the scientific psychologist would steer away from such simplified, ‘aggressive type’ explanations, a glance at widespread, current accounts of complex social behaviour reveals that these modes of explaining are indeed a dominant mode. The primary aspects of this paper are then devoted to several observations on this direction of theorizing, and it is proposed that such theorizing (a) reduces one's theory to a list of behaviours; (b) results in no antecedent, psychological variables; (c) depends on a trivial, circular form of research for support; (d) develops in the direction of trying to claim all of the variation within the behaviour realm being studied; and (e) precludes theoretical integration, in that the criterion of success within such endeavours is the uniqueness of the theorist's own classification system.
Childhood behaviour and adult personality in male and female subjects
Authors: Klinteberg Britt Af , Schalling Daisy , Magnusson David
Published: June 2007

In a follow‐up study, teacher ratings of behaviour at 13 years of age were analysed in relation to personality factors in adults (mean age 27 years) for a group of 77 male and 84 female subjects. In the male group, ratings of Aggressiveness, Motor Restlessness, and Concentration Dificulties correlated positively with a broad psychopathy‐related factor. Furthermore, ratings of Timidity correlated positively with two anxiety factors. In the female group, ratings of Motor Restlessness correlated positively with an extraversion factor. The rated childhood behaviours and the adult personality factors were assumed to be a differential reflection of vulnerability to externalizing and internalizing psychosocial disturbances.
The Health Orientation Scale: A measure of psychological tendencies associated with health
Authors: Snell William E. , Johnson Georgette , Lloyd Paul J. , Hoover M. Wayne
Published: June 2007

Health professionals have recently begun to examine the impact of psychological tendencies on people's physical health. The present investigation sought to facilitate this research endeavour through the development and validation of a self‐report instrument designed to measure multiple health‐related psychological tendencies. Reliability analyses provided evidence of internal consistency for the subscales of the Health Orientation Scale. Other results indicated that both gender and age jointly influenced people's responses to the Health Orientation Scale. A final set of results revealed that the psychological variables measured by the Health Orientation Scale were predictive of women's and men's self‐reported compliance with health‐promoting behaviours. The discussion focuses on the potential uses of the Health Orientation Scale in both research and applied settings.
Breadth, bandwidth, and fidelity of personality‐descriptive categories
Authors: Borkenau Peter , Müller Burkhard
Published: June 2007

The hypothesis of a bandwidth/fidelity trade‐off among personality‐descriptive categories that differ in level was investigated for 25 personality‐descriptive categories. Two measures of inclusiveness, a rating of category breadth and the grammatical form of the category descriptor (verb or adjective), correlated substantially. Bandwidth and fidelity of the categories were measured by analysing the distributions of prototypicality ratings in a sample of naturally occurring activities. It was found that broad categories refer to more exemplars than narrow categories, whereas the exemplars of narrow categories are more prototypical. Such a bandwidth/fidelity trade‐off however, is not found for adjectives and verbs. Rather, adjectives have a lower fidelity but not a broader bandwidth than verbs, and they are therefore the less informative behaviour descriptors.
A geometric taxonomy of personality scales
Authors: Wiggins Jerry S. , Broughton Ross
Published: June 2007

Previous taxonomies of personality traits have been lexical in nature and have been concerned primarily with the meaning of adjectives in personality description. The taxonomy presented in this article employed personality scales as the units to be classified and was guided by theoretical, rather than lexical, considerations. A priori distinctions among different domains of trait‐descriptive terms identified a distinctive domain of interpersonal traits within which a preliminary conceptually‐based taxonomy was developed. The Interpersonal Adjective Scales (IAS) were constructed to provide geometrically precise semantic markers of that domain in the form of a circumplex model organized around the orthogonal coordinates of dominance and nurturance. In the course of a decade of research, some 172 personality scales were classified with reference to the IAS by computational procedures described in detail. Advantages and limitations of the current geometric taxonomy of personality scales are discussed, and future research directions are indicated.
Multiple uses for longitudinal personality data
Authors: Costa Paul T. , McCrae Robert R.
Published: June 2007

Most longitudinal studies are designed to serve fairly narrow purposes, such as the prediction of life outcomes from theoretically relevant antecedent variables, or the documentation of age‐related changes in the level of personality or cognitive variables. However, the accumulation of data on a single group of people observed over a period of many years permits a variety of other types of analyses. Creative use of a longitudinal archive can amply justify the costs of maintaining the sample and should encourage investigators to initiate more longitudinal projects. Findings from the Baltimore Longitudinal Study of Aging are used to illustrate both traditional and alternative uses of personality data, including (a) development of nomological nets for the interpretation of personality measures, (b) evaluation of state effects in personality measurement, (c) validation of retrospective reports, and (d) heuristic exploratory analyses. Current knowledge on the stability of personality in adulthood, the correspondence of observer ratings and self‐reports, and the comprehensiveness of the five‐factor model can enhance the design of future longitudinal studies.
Interactionism revisited: Reflections on the continuing crisis in the personality area
Authors: Endler Norman S. , Parker James D. A.
Published: June 2007

The current status of the personality area is critically examined with the view that problems in the discipline voiced two decades ago are still prevalent. Recurring problems in the personality area have important ramifications for much of contemporary theoretical and applied psychology. The interactional approach to personality came to the fore in the 1970s and early 1980s as an explicit attempt to resolve a number of perceived weaknesses in the personality area. While it has become common for researchers to publicly advocate an interactional position, in practice little interactional research has been conducted recently. The historical developments of the trait and situationism models of personality research and relevant assessment issues are outlined. This history is of interest because it helps to illuminate why and how many current personality researchers continue to perpetuate problems in the personality area. The interactional model of personality is also examined. Finally, the development of an interactional model for the study of anxiety is examined as a specific example of the theoretical, research, and practical benefits of this approach.
Procrastinators and fear of failure: an exploration of reasons for procrastination
Authors: Schouwenburg Henri C.
Published: June 2007

Procrastination, the act or tendency of putting things off that should be done today until tomorrow, has recently become a field of interest in the study of academic underachievement. In constructing tests for the measurement of procrastination, and in comparing test scores with self‐attributions of reasons for procrastination, an unexpected discrepancy has been observed between fear of failure as a prominent reason for procrastination and test fear of failure being unrelated to procrastination. This study was meant to clarify this discrepancy. Students who procrastinate generally endorse many reasons for procrastination simultaneously. For some relatively homogeneous groups of students fear of failure is one of these reasons. Other groups of students do not attribute procrastination to fear of failure at all. For the sample as a whole, procrastination and fear of failure appear unrelated. However, trait procrastination and fear of failure may interact and result in increased levels of actualprocrastinatory behaviour.
Hardiness and sense of coherence and their relation to negative affect
Authors: Kravetz Shlomo , Drory Yaacov , Florian Victor
Published: June 2007

This study attempted to determine the degree to which measures of health proneness and measures of negative affect represent two distinct, although related, constructs. In addition, it examined the relation between Antonovsky's salutogenic construct of sense of coherence (SOC) and Kobasa's health proneness construct of hardiness. Five health proneness and three negative affect measures were filled out by 164 male patients with coronary heart disease. The pattern of correlations between these measures and confirmatory factor analysis indicated that although the measures of health proneness are negatively related to measures of negative affect, these two sets of measures and the constructs to which they are related can be differentiated from each other. However, SOC was found to be less independent of negative affect than was hardiness.
Optimism, perceived control over stress, and coping
Authors: Fontaine Kevin R. , Manstead Antony S. R. , Wagner Hugh
Published: June 2007

To examine the ability of the expectancy‐based personality dimensions dispositional optimism and perceived control over stress to predict the ways in which people characteristically attempt to cope with stress, 420 undergraduate students completed the Life Orientation Test (LOT; Scheier and Carver, 1985), a measure of perceived control over stress, and the dispositional version of the COPE Inventory (Carver, Scheier and Weintraub, 1989). The results revealed a modest but reliable positive correlation between optimism and the perceived control measure. Principal‐components analysis of the COPE revealed a factor structure which was generally in accord with prior research. Optimism was positively correlated with active coping and positive reinterpretation, and negatively correlated with focusing on and venting of emotion. Perceived control over stress was negatively correlated with behavioural disengagement. Implications and directions for future research are discussed.
Seeking person‐related predictors of coping: Exploratory analyses
Authors: Amirkhan James H.
Published: June 2007

Studies using person‐related variables to predict the nature of coping responses have had only limited success. However, besides often using measures of unknown reliability, such studies have not recognized that consistency or variability of response may itself be dispositional. Current analyses of archival, community‐based data selected only psychometrically sound indices and segregated consistent from flexible copers. Demographic predictors were found to have considerably greater explanatory power within the consistent groups, those variables tapping informational or material resources proving particularly germane to the choice between instrumental and avoidant strategies. These results suggest that person‐related influences on coping may currently be underestimated; implications for the future study of such influences are discussed.
Who should own the definition of personality?
Authors: Hofstee Willem K. B.
Published: June 2007

The averaged judgment of knowledgeable others provides the best available point of reference both for the definition of personality structure in general and for assessing someone's personality in particular. Self‐judgments, as in personality questionnaires, are intrinsically deficient because judgment errors cannot be averaged out. The recommended procedure for assessing someone's personality is to give a personality questionnaire, phrased in the third person singular, to those who know the target best. This set may or may not include the target person as a judge.
Doping phosphoric acid in polybenzimidazole membranes for high temperature proton exchange membrane fuel cells
Authors: He Ronghuan , Li Qingfeng , Jensen Jens Oluf , Bjerrum Niels J.
Published: June 2007

Polybenzimidazole (PBI) membranes were doped in phosphoric acid solutions of different concentrations at room temperature. The doping chemistry was studied using the Scatchard method. The energy distribution of the acid complexation in polymer membranes is heterogeneous, that is, there are two different types of sites in PBI for the acid doping. The protonation constants of PBI by phosphoric acid are found to be 12.7 L mol−1 (K1) for acid complexing sites with higher affinity, and 0.19 L mol−1 (K2) for the sites with lower affinity. The dissociation constants for the complexing acid onto these two types of PBI sites are found to be 5.4 × 10−4 and 3.6 × 10−2, respectively, that is, about 10 times smaller than that of aqueous phosphoric acid in the first case but 5 times higher in the second. The proton conducting mechanism is also discussed. © 2007 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 45: 2989–2997, 2007
Preparation and properties of novel thermotropic liquid crystalline hyperbranched polyesters composed of five‐membered heterocyclic mesogen by A2 + B3 approach
Authors: Sato Moriyuki , Matsuoka Yoichi , Yamaguchi Isao
Published: June 2007

New thermotropic liquid crystalline (LC) hyperbranched (HB) polyesters containing 2,5‐diphenyl‐1,3,4‐thiadiazole (DTD) unit as mesogen in the interiors were prepared at various mole ratios (A2/B3) by melt and solution polycondensations of a dioxydiundecanol of DTD (A2) and 1,2,3‐propanetricarboxylic acid (B3) via the A2 + B3 approach and their LC and optical properties were investigated. FTIR and 1H‐NMR spectroscopies indicated that all the expected HB polyesters, which show good solubilities in organic solvents, are produced without gelation during the polymerization. Among them, the HB polymer prepared in the mole ratio of A2/B3 = 3/2 by the solution polycondensation had the highest inherent viscositiy. DSC measurents, polarizing microscope observations of optical textures, and X‐ray analyses suggested that the LC properties of HB polymers depend on the polymerization methods and the feed mole ratios. In the HB polymers prepared using the melt polycondensation, only the polymer prepared in the mole ratio of A2/B3 = 3/1 formed a highly‐ordered, tilted, crystal‐like smectic phase, but all the polymers prepared by the solution polycondensation formed highly‐ordered, tilted, smectic phases. Solution and solid‐state UV‐vis and photoluminescent (PL) spectra indicated that the HB polymers show maximum absorbances and blue‐light emission on the basis of the DTD unit, where the Stokes‐shifts were observed, probably because of intermolecular aggregation effects © 2007 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 45: 2998–3008, 2007
Optical characterization of ZnSe/ZnMgSSe microdisks with embedded CdSe quantum dots
Authors: Renner Johannes , Worschech Lukas , Mahapatra Suddhasatta , Brunner Karl , Forchel Alfred
Published: June 2007

We report on photoluminescence (PL) studies of ZnSe/ZnMgSSe microdisks with embedded CdSe quantum dots. The multilayer structure was grown by molecular beam epitaxy with a single layer of self‐assembled quantum dots. Microdisks were realized by electron beam lithography and etching techniques. To avoid absorption losses, the GaAs substrate was removed totally. Optical confinement is demonstrated by the appearance of whispering gallery modes. Lasing of quantum dots with low thresholds and β factors close to unity were observed, reflecting an excellent coupling of the microdisk modes with the quantum dots. At room temperature, optical modes with quality factors of several thousands dominate in the quantum dot spectrum in the green spectral range. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Magneto‐optics of modulation doped quantum wells based on II–VI semiconductor compounds
Authors: Astakhov G. V. , Ossau W.
Published: June 2007

We review on optical studies of exciton‐electron interaction in modulation doped quantum wells (QWs) based on ZnSe and CdTe semiconductor compounds. The optical properties of QWs containing diluted two‐dimensional electron gases (2DEGs) are well described in terms of charged excitons (trions). Their parameters such as oscillator strength, binding energy, and fine structure are considered in details. In case of moderate densities of 2DEGs, when the Fermi energy falls between the trion and exciton binding energies, the optical properties can be understood in terms of combined exciton‐electron excitations. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Optical studies of structural and magnetic anisotropies in epitaxial CdSe/ZnSe quantum dots
Authors: Kiessling T. , Astakhov G. V. , Platonov A. V. , Mahapatra S. , Slobodskyy T. , Ossau W. , Schmidt G. , Brunner K. , Molenkamp L. W.
Published: June 2007

We summarize experimental studies on the optical polarization properties of MBE‐grown shape‐asymmetric self‐assembled CdSe/ZnSe quantum dots (QDs). The zero magnetic field fine structure splitting of excitonic transitions in structurally anisotropic QDs gives rise to an effective linear‐to‐circular and circular‐to‐linear optical polarization conversion upon resonant excitation of the QD ensemble. The effect is qualitatively modelled in terms of a pseudospin formalism. Furthermore, we show how an in‐plane magnetic field leads to a complex rotation behavior of the axis of the optical polarization. Our analysis based on the exciton pseudospin Hamiltonian unambiguously displays that these effects are induced by isotropic and anisotropic contributions to the heavy hole Zeeman term. Likewise we show that the latter mechanism can be used to tune the optical respone of shape‐anisotropic QDs such that the optical polarization properties are equal to QDs of perfect D2d symmetry. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Hot filament effects on CVD of carbon nanotubes
Authors: Choi Seungho , Lee Soonil , Koh Ken Ha
Published: June 2007

We grew vertically aligned CNTs via HFCVD using mixtures of methane and hydrogen as feedstock, and investigated the dependence of CNT growth on feedstock composition, filament temperature, and filament types. At the filament temperature of 2050 °C tungsten filaments were more efficient for CNT growth than tantalum ones, and higher CNT growth rates were observed when tungsten filaments were operated at 1900 °C. Regardless of filament temperatures and types, monotonic increase in growth rate of vertically aligned CNTs was observed as we increased the methane concentration in the feedstock. In‐situ investigation of feedstock dissociation revealed the generation of various radical species, and, moreover, a strong correlation between CNT growth rates and relative mole fractions of single‐carbon radicals. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Comparison of Shuffling‐Adaptive Neuro Fuzzy Inference System (Shuffling‐ANFIS) with Conventional ANFIS as Feature Selection Methods for Nonlinear Systems
Authors: Jalali‐Heravi Mehdi , Kyani Anahita
Published: June 2007

This paper compares the Shuffling‐Adaptive Neuro Fuzzy Inference System (Shuffling‐ANFIS) with conventional ANFIS as the method for selecting the features of nonlinear systems. Shuffling‐ANFIS technique uses the advantage of data splitting with the ANFIS as a powerful feature selection method to select the most important factors affecting nonlinear phenomena. In this technique, the features with the largest percent of frequency can be found by running the conventional ANFIS sequential forward search on the large number of training and test sets using leave‐one‐out validation criteria. The superiority of Shuffling‐ANFIS over the conventional ANFIS was evaluated by using two synthetic and one biological dataset. For all three sets, Shuffling‐ANFIS method was superior in finding effective variables compared with five different conventional ANFIS and multiple linear regression technique. As a real dataset, a series of 80 1‐[(2‐Hydroxyethoxy)methyl]‐6‐(phenylthio)thymine (HEPT) derivatives acting as Non‐Nucleoside Reverse Transcriptase Inhibitors (NNRTIs) was studied. Five descriptors were selected by Shuffling‐ANFIS and were used to interpret the mechanism of HIV‐1 inhibition of HEPT derivatives. A 5‐5‐1 network was developed using the five descriptors as its inputs. The accuracy of this network was illustrated by validation techniques of Leave‐One‐Out (LOO) and Leave‐Multiple‐Out (LMO) Cross‐Validations (CV) and Y‐randomization test. Superiority of Shuffling‐ANFIS‐ANN method with generalized bell membership functions over the previous works and also the five conventional ANFIS‐ANN models indicates the power of this approach in selecting of the variables for nonlinear systems.
A probabilistic algorithm for robust interference suppression in bioelectromagnetic sensor data
Authors: Nagarajan Srikantan S. , Attias Hagai T. , Hild Kenneth E. , Sekihara Kensuke
Published: June 2007

Magnetoencephalography (MEG) and electroencephalography (EEG) sensor measurements are often contaminated by several interferences such as background activity from outside the regions of interest, by biological and non‐biological artifacts, and by sensor noise. Here, we introduce a probabilistic graphical model and inference algorithm based on variational‐Bayes expectation‐maximization for estimation of activity of interest through interference suppression. The algorithm exploits the fact that electromagnetic recording data can often be partitioned into baseline
periods, when only interferences are present, and active time periods, when activity of interest is present in addition to interferences. This algorithm is found to be robust and efficient and significantly superior to many other existing approaches on real and simulated data. Copyright © 2007 John Wiley & Sons, Ltd.
Die Brücke Lockwitztal – eine Revision nach Entwurf und Ausführung
Authors: Reintjes Karl‐Heinz , Zichner Tilman , Tang Shengwei , Küchler Michael
Published: June 2007

Im Zuge der A 17 wird das langgestreckte Lockwitztal in einer Höhe von 64 m und mit einer Gesamtlänge von 723 m von einer Stahlverbund‐Brücke gequert. Im Talgrund liegen die Ausläufer des Dresdner Vorortes Lockwitz, und an den Talflanken befinden sich ungestört zu belassende Naturräume. Für die anspruchsvolle landschaftliche Situation wurde mit dem ausgeführten Entwurf eine adäquate Brückenkonstruktion geschaffen. Die Stützweiten in den beiden Hauptfeldern betragen jeweils 125 m, die durch je zwei in den Drittelspunkten endenden Bogenstreben zusätzlich gestützt werden. In dem jeweils beidseits anschließenden Feld wird dieses System mit einer weiteren Bogenstrebe fortgesetzt. Zusammen mit den auf den Bogenstreben angeordneten Stützen und dem mit externen Spanngliedern vorgespannten Verbundüberbau bilden sie ein ansprechendes und technisch interessantes Hybridsystem. Die Brücke zeigt einen neuen Weg, die visuelle Wirkung von Bogentragwerken auch bei Talüberquerungen einzusetzen, die von der Topographie und der Straßentrassierung bisher als nicht dafür geeignet erschienen. Mit der neuartigen Konstruktion wurde ein Bindeglied zwischen Bogentragwerken und abgestrebten Rahmentragwerken entwickelt.

Im Folgenden werden die wesentlichen Elemente von Konstruktion und Bauverfahren aus der Sicht der Ausführung diskutiert.
Bemessungskonzept für fußgängerinduzierte Brückenschwingungen
Authors: Butz Christiane , Sedlacek Gerhard
Published: June 2007

Unerwartete Brückenschwingungen, z. B. bei der Eröffnung der Millennium Bridge in London und der Passerelle Solferino in Paris haben das Augenmerk der Ingenieure auf genauere Prognosemöglichkeiten fußgängerinduzierter Schwingungen und besonders der Fußgänger‐Bauwerk‐Interaktion bei leichten und gering gedämpften Fußgängerbrücken gerichtet.

Ein Simulationsprogramm für Brückenschwingungen mit realistischen “numerischen Fußgängern” wird vorgestellt, das an Messergebnissen kalibriert ist und mit dem die beobachteten Schwingungen und Fußgänger‐Bauwerk‐Interaktionsvorgänge erklärt werden können. Anschließend wird ein Ingenieurmodell zur Bestimmung charakteristischer fußgängerinduzierter Tragwerksreaktionen auf Basis der Leistungsspektralmethode hergeleitet, mit dem Entscheidungen zur Konstruktion und Dämpfungsmaßnahmen in der Planungsphase gefällt werden können.

Abschließend wird ein Bemessungskonzept für den Schwingungsnachweis in Form eines Nachweises für den reversiblen Grenzzustand der Gebrauchstauglichkeit erläutert, das die Anforderungen der Eurocodes erfüllt. Dabei wird eine neuartige Betrachtung und Definition der Komfortkriterien vorgeschlagen.
Spatially‐aware systems engineering design modeling applied to natural hazard vulnerability assessment
Authors: Eveleigh Timothy J. , Mazzuchi Thomas A. , Sarkani Shahram
Published: June 2007

Human socio‐technical systems are particularly vulnerable to natural and manmade disasters that project vast physical effects on interdependent functional infrastructure. Many disciplines are trying to understand the complex interactions between the physical world and the systems at risk within it. Systems engineering design is directly concerned with relationships between requirements, functions, and the physical architecture that implements functions. This paper explores the use and advantages of systems engineering design modeling that has been made sensitive to the spatial effects of the physical world by using a geographic information system (GIS) to represent elements of the physical architecture. The paper begins with a description of the spatial context and geographic information systems technology. We review how the spatial context is presently manifested in systems engineering and design modeling and then describe how we combined a geospatial model with a systems engineering design model and explored the unique views that the combined conceptual models introduce. We present a process approach developed for the natural hazard vulnerability domain and discuss our findings to date and the challenges that resulted from mixing models of greatly different fidelity. We conclude by suggesting future work that is needed to further investigate spatially‐aware systems engineering conceptual models. © 2007 Wiley Periodicals, Inc. Syst Eng 10: 187–202, 2007
Catalytic activation through metal enolization of nucleophile precursors and synthetic applications to enantioselective Michael additions
Authors: Kanemasa Shuji , Hasegawa Masayuki , Ono Fumiyasu
Published: June 2007

Catalytic activation methods of nucleophile precursors recently developed in our research group were reviewed in this paper. These include (i) the catalytic double activation method of nucleophile precursors through enol formation and of electrophiles through coordination in alcohols; (ii) the double catalytic activation method by use of both catalytic amounts of chiral Lewis acid and external achiral amine; (iii) the catalytic activation method of nucleophile precursors with a chiral cationic Lewis acid in the presence of molecular sieves; and (iv) the single catalytic activation of nucleophile precursors through metal enolization in alcohol media. © 2007 The Japan Chemical Journal Forum and Wiley Periodicals, Inc. Chem Rec 7: 137–149; 2007: Published online in Wiley InterScience (www.interscience.wiley.com) DOI 10.1002/tcr.20105
Development of efficient Lewis acid catalysts for intramolecular cycloaddition reactions of ester‐tethered substrates
Authors: Taguchi Takeo , Saito Akio , Yanai Hikaru
Published: June 2007

We have developed novel bidentate Lewis acids that efficiently promote the intramolecular cycloaddition reactions of ester‐tethered substrates. Bis‐aluminated triflic amide derivatives [TfN(AlR1R2)2], which are generated by simply mixing triflic amide and 2 equiv of methyl aluminum or aluminum hydride, catalyzed intramolecular Diels–Alder (DA) reactions of ester‐tethered 1,7,9‐trienes and intermolecular DA reactions of α,β‐unsaturated lactones. We also found that bimetallic Lewis acid derived from 1,1′‐biphenyl‐2,2′‐di(triflyl)amide and dimethylaluminum chloride promoted the intramolecular [3 + 2] cycloaddition reaction of acrylate derivatives having an allylsilane part. © 2007 The Japan Chemical Journal Forum and Wiley Periodicals, Inc. Chem Rec 7: 167–179; 2007: Published online in Wiley InterScience (www.interscience.wiley.com) DOI 10.1002/tcr.20112
Vergleich zwischen Diskretisierungsverfahren und parametrischen Methoden an einfachen Testbeispielen
Authors: Collatz L. , Günther H. , Sprekels J.
Published: June 2007

Als Beitrag zur wiederholten Diskussion auf Kongressen der letzten Jahre wird zwischen den beiden im Titel genannten zur Zeit viel verwendeten Näherungsverfahren zur Lösung partieller Differentialgleichungen an Testbeispielen ein Vergleich bezüglich Rechenaufwand und garantierbarer Genauigkeit vorgenommen. Hinweise auf die Durchführung der Rechnung und auf Verfahren, die bei verschiedenen einfacheren Klassen auch nichtlinearer Aufgaben und bei Auftreten von Singularitäten die Angabe exakter Fehlerschranken erlauben, werden gegeben.
Diffraction of Antiplane Shear Waves by a Finite Crack in the Presence of the Magnetic Field
Authors: Shjndo Y.
Published: June 2007

Under the assumption that the motion of the body cases only weak perturbations in the electromagnetic field, the scattering of horizontally polarized shear waves by a finite crack in a uniform magnetostatic field is considered for two cases of the magnetic field being parallel to the crack surfaces and perpendicular to the crack surfaces. It is assumed that the elastic medium under consideration is a homogeneous, isotropic and infinitely conducting one. Using an integral transform technique, the problem is reduced to that of solving a Fredholm integral equation of the second kind having the kernel of a finite integration which can be solved numerically by the use of Gaussian quadrature formulas. By obtaining the singular stress distributions near the crack tip and dynamic stress‐intensity factors, the effects on the stress‐intensity factors due to the presence of the magnetic field are shown graphically. For the low frequencies, the stress‐intensity factors are expressed in series of ascending powers of the normalized frequency. The approximate solutions are compared with exact solutions.
Approximate Methods for Transonic Flow Past Finite Wedge Profiles
Authors: Liu D. D. , Platzer M. F.
Published: June 2007

Solutions to the transonic small perturbation equation are obtained by approximating the velocity perturbation potential by suitably chosen decaying functions in the lateral direction. Two related methods are used to reduce the partial differential equation to non‐linear ordinary differential equations. Closed form solutions of these equations are then obtained showing that a different choice of the decaying function only affects the drag, but not the pressure behaviour. Comparisons with other theories are also given.
A Variational Principle for Granular Materials
Authors: Cowin S. C. , Goodman M. A.
Published: June 2007

A variational principle for the continuum theory of granular materials is presented. This principle is used to obtain the basic equations of the equilibrium theory and the boundary conditions for both the incompressible granule case, and the compressible granule case.