bluuebunny/crossref_metadata_2025_split huggingface dataset:
An approximate nyquist transmission scheme for QPSK digital mobile communications
Authors: Takami Tadao , Saito Shigeki , Tomisato Shigeru , Yamao Yasushi 
Published: July 2007

AbstractThis paper presents the design and implementation of an approximate Nyquist transmission scheme that employs a rational‐function receiving filter. A transitional Butterworth‐Thomson (TBT) filter is examined as a rational‐function receiving filter. This filter can easily be realized as a ceramic filter. It can also function as a channel filter to realize selectivity. Therefore, the newly proposed transmission scheme provides not only a simple and economical receiver circuit but also low power consumption. These features are suitable for mobile radios which must be as small as possible and operate with limited power sources.The effects of filter approximation error on waveform transmission characteristics and adjacent channel interference selectivity are evaluated by computer simulation, and the filter characteristics are optimized in terms of both characteristics. A ceramic receiving filter is developed with the optimum TBT characteristic. A π/4‐shifted QPSK transmission experiment performed with this filter confirms that it has such superior transmission characteristics as receiving sensitivity, robustness against co‐channel interference, and robustness against frequency selective fading. Such characteristics are superior to those of the conventional transmission scheme using a maximally flat receiving filter. It is verified that approximate Nyquist transmission provides improved transmission quality and spectrum utilization for digital mobile communication systems.
Linear non‐conservative systems with fractional damping and the derivatives of critical load parameter
Authors: Kobelev Vladimir V. 
Published: July 2007

AbstractIn this paper, the influence of small perturbation on a linear, non‐conservative dynamical system exhibiting a flutter type bifurcation has been investigated. An important role in considering design problems for non‐conservative structures plays the sensitivity analysis of the integral structural characteristics as fundamental frequencies, damping behavior and critical loads for instability. The hereditary damping is described accurately usually only by means of fractional derivatives. The stability conditions of the perturbed hereditary system were derived. A new analytical framework for the optimization of aero‐structural systems, exhibiting the non‐classical damping is presented. The approach is based on an adjoint system of pseudo‐differential equations to obtain aerodynamic sensitivities. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Procedures for finding optimal layouts of vehicle components with respect to durability
Authors: Eschenauer Hans A. , Idelberger Horst , Bieker Guido , Rottler Andreas , Weinert Matthias 
Published: July 2007

AbstractWhen designing complete systems or system components, it is of vital importance for the manufacturers to optimally fulfill the continuously increasing demands pertaining to safety, durability, reduction of energy consumption, noise reduction, improvement of comfort, accuracy, etc. This applies to all types of traffic and transportation systems like rail vehicles, automobiles, airplanes and ships. By combining structural analysis and simulation methods with optimization algorithms, required specifications can be met faster and more reliably, and hence the production development cycles can be substantially reduced. This paper shall give an overview on results of a method with the features of a damage approximation as precisely as possible on the one hand and, on the other hand, a load‐time history with few different load cycles so that a nonlinear calculation can be performed in the shortest possible time. Simulations with rigidly and elastically modeled components like bogie frames or carbodies show that depending on the type of modeling substantial differences may occur with respect to dynamic behavior and the interaction quantity between the bodies. This aspect has to be taken into consideration for quantitatively sufficient fatigue strength and durability calculation. Mathematical optimization procedures are in general an efficient tool to guarantee the optimal fulfillment of all required design objectives and constraints in all stages of the design process. Some of the procedures are illustrated at two examples (bogie frame, carbody). (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Heterogeneous expression of Wnt/β‐catenin target genes within colorectal cancer
Authors: Hlubek Falk , Brabletz Thomas , Budczies Jan , Pfeiffer Sabine , Jung Andreas , Kirchner Thomas 
Published: July 2007

AbstractInvasion of common colorectal adenocarcinomas is coupled with a transient loss of epithelial differentiation of tumor cells. Previously, we have shown that dedifferentiated tumor cells at the invasive front (IF) accumulate the transcriptional activator β‐catenin in the nucleus, in contrast to cells of the tumor center. To characterize the cells of these two morphogenic tumor areas, gene expression profiling was performed. Our study demonstrates that intratumorous heterogeneity in colorectal cancer correlates with differential expression of 510 genes between the central tumor region (TC) and the IF. Many genes differentially expressed at the IF are involved in cellular invasion processes like cell motility, cell adhesion and extracellular matrix interaction. This in vivo analysis shows overexpression of known Wnt/β‐catenin target genes either in the entire tumor tissue (compared to normal mucosa) or specifically at the IF. Thus, even though all tumor cells overexpress β‐catenin, the existence of at least 2 groups of Wnt/β‐catenin target genes selectively activated in different tumor regions is suggested. The concomitant high expression of inflammation‐ and tissue repair‐related genes at the IF supports the hypothesis that an inflammation‐activated microenvironment may trigger selective Wnt/β‐catenin target gene expression and contribute to the malignant progression of colorectal cancer. © 2007 Wiley‐Liss, Inc.
A comparative study of semiempirical, ab initio, and DFT methods in evaluating metal–ligand bond strength, proton affinity, and interactions between first and second shell ligands in Zn‐biomimetic complexes
Authors: Frison Gilles , Ohanessian Gilles 
Published: July 2007

AbstractAlthough theoretical methods are now available which give very accurate results, often comparable to the experimental ones, modeling chemical or biological interesting systems often requires less demanding and less accurate theoretical methods, mainly due to computer limitations. Therefore, it is crucial to know the precision of such less reliable methods for relevant models and data. This has been done in this work for small zinc‐active site models including O‐ (H2O and OH−) and N‐donor (NH3 and imidazole) ligands. Calculations using a number of quantum mechanical methods were carried out to determine their precision for geometries, coordination number relative stability, metal–ligand bond strengths, proton affinities, and interaction energies between first and second shell ligands. We have found that obtaining chemical accuracy can be as straightforward as HF geometry optimization with a double‐ζ plus polarization basis followed by a B3LYP energy calculation with a triple‐ζ quality basis set including diffuse and polarization functions. The use of levels as low as PM3 geometry optimization followed by a B3LYP single‐point energy calculation with a double‐ζ quality basis including polarization functions already yields useful trends in bond length, proton affinities or bond dissociation energies, provided that appropriate caution is taken with the optimized structures. The reliability of these levels of calculation has been successfully demonstrated for real biomimetic cases. © 2007 Wiley Periodicals, Inc. J Comput Chem, 2008
Lentiviral vectors that carry anti‐HIV shRNAs: problems and solutions
Authors: ter Brake Olivier , Berkhout Ben 
Published: July 2007

AbstractBackgroundHIV‐1 replication can be inhibited with RNA interference (RNAi) by expression of short hairpin RNA (shRNA) from a lentiviral vector. Because lentiviral vectors are based on HIV‐1, viral sequences in the vector system are potential targets for the antiviral shRNAs. Here, we investigated all possible routes by which shRNAs can target the lentiviral vector system.MethodsExpression cassettes for validated shRNAs with targets within HIV‐1 Leader, Gag‐Pol, Tat/Rev and Nef sequences were inserted in the lentiviral vector genome. Third‐generation self‐inactivating HIV‐1‐based lentiviral vectors were produced and lentiviral vector capsid production and transduction titer determined.ResultsRNAi against HIV‐1 sequences within the vector backbone results in a reduced transduction titer while capsid production was unaffected. The notable exception is self‐targeting of the shRNA encoding sequence, which does not affect transduction titer. This is due to folding of the stable shRNA hairpin structure, which masks the target for the RNAi machinery. Targeting of Gag‐Pol mRNA reduces both capsid production and transduction titer, which was improved with a human codon‐optimized Gag‐Pol construct. When Rev mRNA was targeted, no reduction in capsid production and transduction titer was observed.ConclusionsLentiviral vector titers can be negatively affected when shRNAs against the vector backbone and the Gag‐Pol mRNA are expressed during lentiviral vector production. Titer reductions due to targeting of the Gag‐Pol mRNA can be avoided with a human codon‐optimized Gag‐Pol packaging plasmid. The remaining targets in the vector backbone may be modified by point mutations to resist RNAi‐mediated degradation during vector production. Copyright © 2007 John Wiley & Sons, Ltd.
Coping by police officers: A study of role stress and Type A and Type B Behavior Patterns
Authors: Kirmeyer Sandra L. , Diamond Alice 
Published: July 2007

AbstractThis research examined the ways police officers appraise and cope with naturally occurring stressful events. We utilized interview and questionnaire instruments to obtain descriptions of the stressful events, how the events were appraised, and the ways in which officers coped. Analyses tested the situational specificity of the Type A behaviour pattern. As hypothesized, Type A officers selected strategies that were more active and narrowly focused on the problem than did Type B officers. For the Type A officer coping was relatively independent of appraisal, whereas for the Type B officer coping and appraisal were interdependent processes.
Social support by four categories of work colleagues: Relationships between activities, stress and satisfaction
Authors: Henderson Monika , Argyle Michael 
Published: July 2007

AbstractAn approach to the study of social support at work is presented emphasizing nature and type of social support. One hundred employees in a range of occupations rated the frequency of engaging in 12 types of social and work‐related activity with each of four work colleagues varying in degree of intimacy. They also rated levels of job satisfaction and work stress. The results confirm the usefulness of this approach and also suggest that type of work relationship is associated with different sorts of socially supportive activities, and that these affect stress but not satisfaction. These findings were discussed in terms of the interaction between type of support given, source of support, and outcome.
Organizational test of goal linkage theory
Authors: Tjosvold Dean 
Published: July 2007

AbstractDeutsch's theory of cooperation and competition or goal linkage has been developed by considerable experimental research, but is little used to study interdependence in organizations. Organizational members were interviewed in depth on a specific interaction and completed a questionnaire to describe their relationships with their co‐workers and supervisors. Positive linkage, in contrast to negative linkage, was related to effective negotiations and the development of feelings of success and satisfaction. Positive linkage compared to negative linkage was also found to stengthen work relationshps and facilitate productivity. Independent linkage had dynamics similar to negative linkage, but was positively related to productivity. Questionnaire results also support the theory of goal linkage. Goal linkage, dynamics, and outcomes appear to be self‐sealing and mutually causal. Results suggest that goal linkage theory has considerable potential to describe and influence actual organizational work relationships.
Work role centrality of industrial workers as related to organizational conditions, task autonomy, managerial orientations and personal characteristics
Authors: Mannheim Bilha , Dubin Robert 
Published: July 2007

AbstractThe study shows that, for a sample of 818 industrial workers, work role centrality (WRC) is positively related to task autonomy and to organizational conditions of sector of ownership, unit‐type of production system, and production stability; it is also weakly related to the orientations of production managers concerning the sharing of information, general supervision and granting autonomy. The task autonomy ‐ work role centrality relationship is maintained beyond other organizational conditions, but the effects of managerial orientations are attenuated by task autonomy and by organizational conditions. Situational conditions such as production system and stability, managerial orientations and task autonomy add to the variance of WRC explained by personal attributes of gender, education and job training, and by the outcome of job satisfaction, and a combined model of both types of variables is the most efficient. Generally, work role centrality is found to be a fairly sensitive response to the work situation, but it is suggested that perceptual and attitudinal data be added to the explanatory model.
R&D professionals' views of criteria for intrafirm job mobility: Individual and aggregate analyses of transfer climate perceptions in West German and British Industrial R&D Organizations
Authors: Gerpott Torsten J. , Domsch Michel , Pearson Alan W. 
Published: July 2007

AbstractPrior research on employees' views of various criteria for obtaining a desirable intrafirm transfer has conceptualized these perceptions on an individual level of analysis (i.e. has examined psychological transfer climates). It is argued that the identification of aggregate transfer climate dimensions on an organizational (subsystem) level of analysis is important for improving the effectiveness of R&D via better transfer policies. Factor analyses of questionnaire data obtained from 729 R&D professionals in 11 FRG industrial firms and 141 R&D professionals in three U.K. industrial firms revealed that both FRG and U.K. subjects perceived three broad means (overall task performance, publication and patent productivity, favouritism) for obtaining a desirable job transfer. Empirically the idea was supported that, for certain transfer criteria (overall task performance, manifest professional output, educational level, luck), individuals' scores can be meaningfully aggregated to obtain organizational transfer climate measures. Remarkable differences in the importance of company tenure and educational level as criteria for transfers in R&D were found between FRG and U.K. organizations. Using the FRG data set differences in the performance responsiveness of organizational transfer climates were shown to be significantly related to work‐related outcome variables. Implications are sketched for R&D transfer policies and for explaining U.K./FRG differences in the corporate treatment of R&D activities.
The measurement of job characteristics: A content and contextual analytic look at scale validity
Authors: Pierce Jon L. , McTavish Donald G. , Knudsen Kjell R. 
Published: July 2007

AbstractThis investigation provides an examination of the validity of the Job Diagnostic Survey (JDS) and the Job Characteristics Inventory (JCI). The verbal content of the two measure is examined, as are the contrasts between the verbal content of these scales and the verbal content of three popular measures of job satisfaction. The Minnesota Contextual Content Analysis program is used to examine the ideas emphasized by these research scales. Both measures of job characteristics were found to discriminate from certain measures of job satisfaction, to emphasize an instrumental and not an affective context, and to possess some internal dimensionality problems.
Work environment and the well‐being of clerical and VDT workers
Authors: Stellman Jeanne M. , Klitzman Susan , Gordon Gloria C. , Snow Barry R. 
Published: July 2007

AbstractThis paper explores the relationships between extent of video display terminal usage, perceptions of the physical work environment, task characteristics, and workers' health and well‐being among a group of 1032 female office clerical workers. Data are drawn from responses to a 30‐minute questionnaire administered at four employment sites during 1981 and 1982. All‐day terminal users reported significantly higher levels of job and physical environment stressors than part‐day VDT users, typists and non machine‐interactive clerical workers. Reports of musculo‐skeletal strain and dissatisfaction were also highest among all day terminal users. Part‐day VDT users, typists and clerks all reported relatively similar levels of job and physical working conditions, health symptoms and job satisfaction. No significant differences between any of the groups were observed for gastrointestinal, respiratory, psychological and other non‐specific health complaints. Typists and clerical workers who also held supervisory positions reported fewer stressors and greater job satisfaction than workers with no supervisory tasks; however there were no such differences between supervisors and non‐supervisors engaged in all‐day VDT work.Implications of these findings for further research and for job redesign strategies to alleviate the potentially stressful aspects of office automation are discussed.
Some psychological consequences of striking: A six month, longitudinal study
Authors: Barling Julian , Milligan Jill 
Published: July 2007

AbstractThe literature available on organizational psychology has largely neglected the issue of industrial conflict, and little is known about individual psychological effects of industrial conflict such as labour disputes and strikes. Psychological consequences of involvement in a strike were assessed in this research. Data were collected from 117 full‐time, white collar union members immediately following a 22 day strike, and again two and six months later. Negatively perceived industrial relations events (e.g. 'strike or lockout', 'being involved in negotiations') were associated with marital adjustment, psychosomatic symptoms and a lack of psychological well‐being on completion of the strike, and predicted unfavourable changes in psychological well‐being over the next two and six months. A framework for understanding the negative effects of labour disputes and strikes is proposed, and the role of the organizational psychologist when such conflicts occur is considered.
Individual demographic differences and job satisfaction
Authors: Brush Donald H. , Moch Michael K. , Pooyan Abdullah 
Published: July 2007

AbstractEmpirical research and theoretical literature support the notion that demographic differences among employees are associated with job satisfaction. However, the evidence is inconsistent, and little is known about the stability of many of the reported relationships. A meta‐analysis was conducted involving 21 independent studies and over 10,000 employees to discern selected population relationships. Results indicated that, with the exception of age and organizational tenure, associations do not differ significantly from zero. Large amounts of variance around each mean correlation, however, warranted a moderator analysis. Results indicated that the strength and pattern of associations differ by organizational type. Theoretical propositions and implications for future research in the area of demographic moderators are discussed.
A decade's experience with the Scanlon Plan: A case study
Authors: Millers Christopher S. , Schuster Michael 
Published: July 2007

AbstractThis field study examined the operation and impact of the Scanlon Plan at a large manufacturing facility. An interrupted time‐series research design, augmented by extensive qualitative data analysis was used to analyse the productivity and employment experience over a nine‐year period. The plan resulted in modest increases in productivity and stable employment, while improving the overall union‐management relationship. Through the Scanlon structure for employee involvement, over 5000 suggestions have been made. Moderate and consistent productivity sharing bonuses were paid.
Organizational socialization: A stress perspective
Authors: Nelson Debra L. 
Published: July 2007

AbstractThis paper examines socialization and adjustment processes of newcomers to organizations. While scholars in this area agree that the socialization process is a stressful event, few have empirically approached the process from this perspective. In addressing this problem, a theoretical synthesis of the literatures of organizational socialization and organizational stress is proposed. From this integration, a model is developed which facilitates an examination of the task, role, and interpersonal demands which individuals face in the stages of socialization and an analysis of the interrelationships of these demands and their effects upon individual and organizational outcomes of the socialization process. Finally, directions for future research are proposed for extending understanding of this crucial part of organizational entry.
Sex segregation of work in Finland and the quality of women's work
Authors: Kauppinen‐Toropainen Kaisa , Kandolin Irja , Haavio‐Mannila Elina 
Published: July 2007

AbstractThe Finnish labor market is sharply segregated by sex. This is a statistically well‐documented fact and holds true for all Western European market economies. The aim of this article was to find out whether women profit (regarding the quality of their work) from performing the same sort of work as men. The qualitative aspects of work were the following: autonomy at work; lack of routinization of work; the compulsory rhythm of work; and the demands for social skills. We also analyzed monthly pay and its variation according to functional segregation of work. The empirical data came from the Finnish Study on Working Conditions (1984) which is a representative sample of the Finnish wage‐earning population with 4502 persons of whom 48 per cent were women and 52 per cent men. Our results indicate that women often profit from the fact that they perform the same sort of work as men. This profit was more apparent for white‐collar than for blue‐collar women. For men the effects of segregation on job characteristics were the opposite. They often profit from sex segregated work. Social status played a major role regarding the qualitative aspects of work.