bluuebunny/crossref_metadata_2025 huggingface dataset:
The Development and Adjustment of 7‐year‐old Children Adopted in Infancy
Authors: Stams Geert‐Jan J. M. , Juffer Femmie , Rispens Jan , Hoksbergen René A. C.
Published: September 2003

The present study (NO= 159) provides evidence of an increased risk for behavior problems of infant‐placed 7‐year‐old internationally, transracially adopted children in the Netherlands. However, parents reported more behavior problems for adopted boys than for adopted girls. Notably, about 30% of the adopted children were classified as clinical on the CBCL scale for total problems, which is a much larger percentage than the 10% found in the normative population. It was suggested that these results could be explained by the operation of multiple risk factors before and after adoption placement, e.g. the child's genetic disposition, pre‐natal and pre‐adoption care, or the child's cognitive understanding of adoption in middle childhood. Also, results suggest that maternal sensitive responsiveness in adoptive families declines in the transition from early to middle childhood. In contrast to the home setting, the adopted children showed favorable behavioral and socioemotional adjustment at school, while their academic achievement and intelligence were in the normal range or above average. In particular Korean children had high IQs: 31% of these children obtained an intelligence score above 120. It was suggested that adoptive parents seem to offer their children sufficient or even more than average cognitive stimulation. Furthermore, adopted girls scored higher in optimal ego‐control, social competence, and peer group popularity than nonadopted girls from the general population: 30% of the adopted girls were rated as popular by their classmates, which compares favorably to the 13% found in the general school population.
Psychiatric Comorbidity in Children and Adolescents with Reading Disability
Authors: Willcutt Erik G. , Pennington Bruce F.
Published: September 2003

This study investigated the association between reading disability (RD) and internalizing and externalizing psychopathology in a large community sample of twins with (NO= 209) and without RD (NO= 192). The primary goals were to clarify the relation between RD and comorbid psychopathology, to test for gender differences in the behavioral correlates of RD, and to test if common familial influences contributed to the association between RD and other disorders. Results indicated that individuals with RD exhibited significantly higher rates of all internalizing and externalizing disorders than individuals without RD. However, logistic regression analyses indicated that RD was not significantly associated with symptoms of aggression, delinquency, oppositional defiant disorder, or conduct disorder after controlling for the significant relation between RD and ADHD. In contrast, relations between RD and symptoms of anxiety and depression remained significant even after controlling for comorbid ADHD, suggesting that internalizing difficulties may be specifically associated with RD. Analyses of gender differences indicated that the significant relation between RD and internalizing symptoms was largely restricted to girls, whereas the association between RD and externalizing psychopathology was stronger for boys. Finally, preliminary etiological analyses suggested that common familial factors predispose both probands with RD and their non‐RD siblings to exhibit externalizing behaviors, whereas elevations of internalizing symptomatology are restricted to individuals with RD.
Assessing Exposure to Violence Using Multiple Informants: Application of Hierarchical Linear Model
Authors: Kuo Meichun , Mohler Beat , Raudenbush Stephen L. , Earls Felton J.
Published: September 2003

The present study assesses the effects of demographic risk factors on children's exposure to violence (ETV) and how these effects vary by informants. Data on exposure to violence of 9‐, 12‐, and 15‐year‐olds were collected from both child participants (NO= 1880) and parents (NO= 1776), as part of the assessment of the Project on Human Development in Chicago Neighborhoods (PHDCN). A two‐level hierarchical linear model (HLM) with multivariate outcomes was employed to analyze information obtained from these two different groups of informants. The findings indicate that parents generally report less ETV than do their children and that associations of age, gender, and parent education with ETV are stronger in the self‐reports than in the parent reports. The findings support a multivariate approach when information obtained from different sources is being integrated. The application of HLM allows an assessment of interactions between risk factors and informants and uses all available data, including data from one informant when data from the other informant is missing.
Understanding Theory of Mind in Children Who Are Deaf
Authors: Marschark Marc , Green Vanessa , Hindmarsh Gabrielle , Walker Sue
Published: September 2003

Research on theory of mind began in the context of determining whether chimpanzees are aware that individuals experience cognitive and emotional states. More recently, this research has involved various groups of children and various tasks, including the false belief task. Based almost exclusively on that paradigm, investigators have concluded that although “normal” hearing children develop theory of mind by age 5, children who are autistic or deaf do not do so until much later, perhaps not until their teenage years. The present study explored theory of mind by examining stories told by children who are deaf and hearing (age 9–15 years) for statements ascribing behaviour‐relevant states of mind to themselves and others. Both groups produced such attributions, although there were reliable differences between them. Results are discussed in terms of the cognitive abilities assumed to underlie false belief and narrative paradigms and the implications of attributing theory of mind solely on the basis of performance on the false belief task.
Network, exposure and rhetoric: Italian occupational fields and heterogeneity in constructing the globalized self
Authors: Monaci Massimiliano , Magatti Mauro , Caselli Marco
Published: September 2003

Drawing on the findings of a broad inter‐university research programme conducted in Italy, in this article we explore how individuals' transnational networks combine with other dimensions of their social experience in the production of a self‐perception of their own ‘global identity’. In particular, attention is focused on the structures and social spaces of everyday life in five crucial occupations (corporate managers, financial services workers, artists, media professionals and schoolteachers) where people's professional action is performed simultaneously along local and global axes. Within these groups the globalized self does not merely reflect individuals' engagement in transnational networks, but is also the outcome of a complex process including two added dimensions of social life in the job setting: (1) the degree and type of non‐filtered exposure to pressures stemming from the global environment, which both constrain and enable subjective practices of coping with change and ambiguity; and (2) the degree and type of competence in the rhetorics of globalization, namely the level of access to well‐known repertoires of interpretive resources for making sense of global trends. This analysis is consistent with social science conceptualizations arguing for a more nuanced understanding of globalization. In this light, not only is globalization a multidimensional process but it also produces a variety of responses and meanings by differently positioned actors.
What Focus Groups Can and Cannot Do: A Reply to Seymour
Authors: McQuarrie Edward F. , McIntyre Shelby H.
Published: September 2003

In their reply to Seymour, Edward McQuarrie and Shelby Mclntyre address the question of the advantages and disadvantages of focus groups as a research technique. They argue that the biases incurred with focus groups are no greater than those that result from any other market research technique, but caution that polls of focus group members cannot be extrapolated to estimate the incidence of some response in the population. What is unique to group discussions is the social interaction among respondents. This interaction can help to resolve some of the questions that occupy the attention of new products managers. The authors conclude with suggestions for empirical research which could advance our understanding of the use of focus groups.
Managing Relations Between R&D and Marketing in New Product Development Projects
Authors: Souder William E.
Published: September 2003

This article examines the R&D/marketing interface conditions found within an extensive data base of new product development innovation projects. The incidence of different types of problems between these two important functions are analyzed and the effects of these observations on project outcomes are discussed. The article contains a number of recommendations for increasing the success rates of innovation projects by using a model that improves conditions at the R&D/marketing interface.
The Credibility–Cooperation Connection at the R&D‐Marketing Interface
Authors: Gupta Ashok K. , Wilemon David
Published: September 2003

Research and development (R&D) managers' perceptions of both marketing information and marketing managers are analyzed using an information and source credibility framework. The findings are based on a study of R&D directors in 80 technology‐intensive companies and focus on activities and interactions during the new product development process. The authors found that the R&D managers' perceptions differed significantly in high and low integration companies. These perceptions also were influenced by various organizational practices. The R&D‐marketing cooperation was highest where organizational practices were conducive to cooperation and R&D perceived marketing input as credible. Several implications for creating a corporate climate conducive to interfunctional cooperation are developed.
Licensing as an Alternative to Foreign Direct Investment
Authors: Adam Y. , Ong C. H. , Pearson A. W.
Published: September 2003

This article addresses issues linked to the sales of manufacturing technology and know‐how through licensing by British companies to unaffilated firms located overseas. It identifies a number of characteristics that make these companies more likely to license abroad. The authors test a model of foreign licensing on data gathered from 145 firms based in the United Kingdom. Many companies do evaluate licensing to unaffilated firms as an alternative to foreign direct investment when they consider manufacturing in foreign markets. These firms tend to be relatively large in their industry, highly diversified, spend a relatively higher proportion of their value‐added on research and development, and have less foreign experience.
Determinants of Innovative Durables Adoption
Authors: Holak Susan L.
Published: September 2003

This research uses innovation characteristics to assess product potential at two points in time. The two phases of the study consist of: (1) proposing and estimating purchase intention models and (2) reconciling predicted success with actual product performance. The investigation focuses on the impact of perceived product attributes, environmental variables, and consumer traits on the purchase intention of actual innovations within several technologically intensive product categories. Differences in model specification and parameter values are noted across product types. Results indicate consistency in the impact of product attributes across categories on an innovation's acceptability, but suggest differences in model specification with respect to environmental variables and consumer traits. The existence of a generic‐to‐specialized innovation continuum is a possible cause of the heterogeneity in results across products. An ex post analysis of the innovations indicates that, while success can be predicted quite accurately using perceived product attribute ratings, consumer and environmental variables should not be ignored for particular categories. The study has implications for the early screening of innovative durables, specifically with respect to forecasting model potential, determining product design and positioning, and developing promotional messages.
Product Development
Authors: Apple L. Eugene , Vanier Dinoo J.
Published: September 2003

This study investigates the prevalence of product‐development courses at accredited educational institutions. The authors assess pedagogical approaches and instructional materials used in these courses. The analysis is based on a survey of 320 accredited business schools, supplemented by an archival review of other business schools' catalogs. The results suggest considerable growth in the number of product development/management courses compared to a decade ago. Four textbooks dominate the market, but other contenders for adoption are available. Cases are commonly used to facilitate understanding of presented issues. Geographic differences show that schools located in the Northeast, Midwest, and West are more likely to address product‐related issues in their business curricula.
The Marketing–R&D Interface: Do Personality Factors Have an Impact?
Authors: Lucas George H. , Bush Alan J.
Published: September 2003

The marketing–R&D interface is generally regarded as the most critical functional interface in the new product development process. A great deal of discussion has recently taken place over which of these two areas should dominate product development. Only recently has the issue of how to foster a successful marketing—R&D interface been the topic of empirical investigation. George Lucas and Alan Bush present results of a study which addresses individual differences, in particular, personality differences, between the two areas as an influence on their integration and resultant new product success level. The results are largely consistent with findings from the occupational choice literature. These findings provide some preliminary suggestions for top management in its attempt to maximize positive outcomes from this critical business process.
Adaptive Responses by Conservative and Entrepreneurial Firms
Authors: Karagozoglu Necmi , Brown Warren B.
Published: September 2003

Over time, most corporate managements face the necessity of adapting their organizations to new environments. The style of such adaptation depends both on the original strategy of the company and its new objectives and environment. Necmi Karagozoglu and Warren Brown report the results of research which explores the changes in the organization's rate of innovation in response to environmental shifts. The changes in the innovative behavior of conservative firms (which emphasize stability, standardized products and cost‐minimization strategies) are contrasted with that of entrepreneurial firms (which emphasize flexibility, rapid product change and state‐of‐the‐art product features). Organizational competence and management's willingness to change are some of the key independent variables used in the project. The data are from a study of 56 manufacturing companies representing 26 industries.
A Model for the Development of Small High‐Technology Businesses Based on Case Studies from an Incubator
Authors: Scherer Alf , McDonald David W.
Published: September 2003

Alf Scherer and D. W. McDonald examine several emerging companies that are currently being assisted by an incubator for small, technology‐based businesses. The case studies illustrate how the short‐ and long‐term responses to new technical and market opportunities need to be clearly separated and prioritized. A common failing observed is the underestimation of the time and resources required to successfully commercialize the first product before moving on to the development of second‐generation products. A multistep process model of business and product development was found to be a useful tool in diagnosing the status of the start‐up companies, as well as identifying future decision points and alternative courses of action.
Global Design
Authors: Blaich Robert
Published: September 2003

Robert Blaich, Philips' Managing Director of Corporate Industrial Design, shares his insights on ways to integrate product design with other new products development activities. During an eight‐year period, these initiatives have attracted increasing international attention among design professionals. Blaich describes the creation of a design policy, provides criteria for evaluating the quality of design and discusses the creation of a design management process at both corporate and divisional levels. He argues that design can become a major competitive factor in new product strategies.
New Product Development Process: A Perspective for Reexamination
Authors: Wind Yoram , Mahajan Vijay
Published: September 2003

In spite of the increased sophistication of new product development processes, the percentage of successful new product introductions has not improved significantly in the last two decades. This calls for a reexamination of the new products development process. Yoram Wind and Vijay Mahajan suggest 13 strategic guidelines for the development of new or modified products. These guidelines, if followed, could improve a firm's chances of developing and introducing successful new products.
Packaging of Optical MEMS Devices
Authors: Low Yee L. , Scotti Ronald E. , Ramsey David A. , Bolle Cristian A. , O’Neill Steven P. , Nguyen Khanh C.
Published: September 2003

Recently, optical MEMS devices have gained considerable attention in the telecommunications industry—particularly in the optical networking and switching arenas. Since optical MEMS are micro-systems which rely on high precision optics, electronics and mechanics working in close concert, these emerging devices pose some unique packaging challenges yet to be addressed by the general packaging industry. Optical MEMS packages often are required to provide both optical and electrical access, hermeticity, mechanical strength, dimensional stability, and long-term reliability. Hermetic optical access necessitates the use of metallized and anti-reflection coated windows, and ever-increasing electrical I/O count has prompted the use of higher density substrate/package technologies. Taking these requirements into consideration, we explore three ceramic packaging technologies, namely high-temperature co-fired ceramic (HTCC), low-temperature co-fired ceramic (LTCC), and thin-film ceramic technologies. In this paper, we describe some optical MEMS packages designed using these three technologies and discuss their substrate designs, package materials, ease of integration and assembly.
Robustness of Rotating Stall Control for Axial-Flow Compressors*
Authors: Tahmasebi Ali , Chen Xiang
Published: September 2003

Feedback control has been pursued to address the rotating stall problem in axial flow compressors in order to extend the stable operating range and to improve engine performance. These controllers guarantee the stability of the bifurcated operating solution near the stall point. In this paper, an analytic approach is developed to characterize the robustness of some stabilizing controllers for rotating stall in axial-flow compressors. The numerical examples show that the size of the admissible uncertainty set changes for stabilizing controllers with different feedback gains. It is also proved that a nonlinear stabilizing control is not necessarily superior to a linear one.
Hydraulic Flow Compensator for Fast Switching Devices
Authors: de Ojeda William , Ruiz Francisco
Published: September 2003

A hydraulic circuit design composed of a pressure-regulating device in conjunction with a spring-loaded flow compensator is shown to be an effective mechanism to improve the pressure control functionality, specifically by minimizing the excursions of pressures experimented in the system and by minimizing the time required by the supply pump to restore pressure. The design stores fluid energy and restores it to a system where fast switching devices control fluid consumption. The effectiveness of the mechanism resides in controlling the back pressure on the pressure regulator and compensator to just below the system pressure. The flow compensator can reduce pressure recovery times by over 60% and minimize pressure drops by 20%. The compensator effectively allows for better pump size optimization and smaller required volumes for added power savings and better packaging.
A Parallel Observer System for Non-Deterministic Multirate Systems
Authors: Thein May-Win L. , Misawa Eduardo A.
Published: September 2003

This paper proposes the parallel observer system (POS), a multirate estimation technique for discrete time systems, to compensate for systems whose output measurements are only periodically available and under the presence of matched and unmatched uncertainties/disturbances. A stability proof and error bounds are provided, given maximum bounds of the uncertainties/disturbances. A simulation of the POS is provided to show proof of concept.
Accuracy/Robustness Dilemma in Impedance Control
Authors: Valency Tomer , Zacksenhouse Miriam
Published: September 2003

Impedance control facilitates the execution of tasks that involve contact with the environment. However, task performance depends on the accuracy at which the desired impedance is attained. This paper focuses on feedback methods for implementing impedance control and reveals the underlying conflict between impedance accuracy and robustness to uncertainties. Furthermore, we propose a novel yet practical method that facilitates robustness while maintaining accurate impedance tracking. Eigenvalue analysis and simulation results are presented to demonstrate the accuracy/robustness dilemma and the relative merits of the different methods.
Control Design for Relative Stability in a PWM-Controlled Pneumatic System
Authors: Barth, Eric J. , Zhang, and Jianlong , Goldfarb Michael
Published: September 2003

This paper presents a control design methodology that provides a prescribed degree of stability robustness for plants characterized by discontinuous (i.e., switching) dynamics. The proposed control methodology transforms a discontinuous switching model into a linear continuous equivalent model, so that loop-shaping methods may be utilized to provide a prescribed degree of stability robustness. The approach is specifically targeted at pneumatically actuated servo systems that are controlled by solenoid valves and do not incorporate pressure sensors. Experimental demonstration of the approach validates model equivalence and demonstrates good tracking performance.
A Variable-Speed Method for Reducing Residual Vibrations in Elastic Cam-Follower Systems
Authors: Yao Yan-An , Yan Hong-Sen , Zhang Ce
Published: September 2003

This paper applies the concept of variable speeds to vibration control of elastic cam-follower systems. A multi-design-point approach, based on optimal control theory, is developed for selecting suitable input speed functions of the cam that can reduce both primary and residual vibrations of the output in elastic cam-follower systems despite parameter variations. A design example is given to verify the feasibility of the approach.
The Theoretical Flow Ripple of an External Gear Pump
Authors: Manring Noah D. , Kasaragadda Suresh B.
Published: September 2003

In this paper, the theoretical flow ripple of an external gear pump is studied for pumps of similar size using different numbers of teeth on the driving and driven gears. In this work, the flow ripple equation is derived based upon the flow of incompressible fluid across the changing boundaries of a control volume. From this method, it is shown that the instantaneous length of action within the gear mesh determines the instantaneous flow ripple. A numerical and a closed-form approximation are presented for the instantaneous length of action and it is shown that the difference between these two solutions is negligible. Fast Fourier transform analysis is employed for identifying the harmonic frequencies and amplitudes of the flow pulse and these results are compared for 16 different pump designs. In summary, the results of this study show that the driving gear dictates the flow ripple characteristics of the pump while the driven gear dictates the pump size. As a result, it may be advantageous to design an external gear pump with a large number of teeth on the driving gear and a fewer number of teeth on the driven gear. This design configuration will tend to reduce both the physical pump size (without reducing the volumetric displacement of the pump) and the amplitude of the flow pulsation, while increasing the natural harmonic frequencies of the machine.
Die Cracking at Solder (In60-Pb40) Joints on Brittle (GaAs) Chips: Fracture Correlation Using Critical Bimaterial Interface Corner Stress Intensities
Authors: Su Bingzhi , Lee Y. C. , Dunn Martin L.
Published: September 2003

We study cracking from the interface of an In60-Pb40 solder joint on a brittle GaAs die when the joint is subjected to a uniform temperature change. Our primary objective is to apply and validate a fracture initiation criterion based on critical values of the stress intensities that arise from an analysis of the asymptotic elastic stress fields at the interface corner. In some regards the approach is similar to interface fracture mechanics; however, it differs in that it is based on a singular field other than that for a crack. We begin by determining the shape that the solder bump will assume after reflow when constrained by a fixed diameter wetting pad on the GaAs. To simplify the interpretation of the results, we focus on a class of solder bumps of various sizes, but with a self-similar shape. The approach, though, can be applied to different size and shape solder bumps. We then compute the asymptotic interface corner fields when the system is subjected to a uniform temperature change. The asymptotic structure (radial and angular dependence) of the elastic fields is computed analytically, and the corresponding stress intensities that describe the scaling of the elastic fields with geometry and loading are computed by axisymmetric finite element analysis. In order to assess the validity of fracture correlation using critical stress intensities, we designed and fabricated a series of test structures consisting of In60-Pb40 solder bumps on a GaAs chip. The test structures were subjected to uniform temperature drops from room temperature to induce cracking at the interface corner. From the tests we determined the relationship between the solder bump size and the temperature change at which cracking occurred. Not unexpectedly, smaller bumps required larger temperature changes to induce cracking. The observed scaling between solder bump size and temperature change is well described by the critical stress intensity failure criterion based on only a single parameter, the critical value of the mode 1 stress intensity, K1crn. Interestingly, this is because over a significant region, the mode 2 and constant terms in the asymptotic expansion cancel each other. This failure criterion provides the necessary machinery to construct failure maps in terms of geometry and thermomechanical loading. We conclude by describing how to apply the approach in more general and more practical settings that are possibly applicable to a wide range of problems in microelectronics, optoelectronics, and microelectromechanical systems packaging.
Thermo-Viscoelastic Analysis of Deflection in CSP Electronic Device Packages
Authors: Koguchi Hideo , Sasaki Chie , Nishida Kazuto
Published: September 2003

In the present paper, a deformation induced in a new bonding technology of chip-scale package (CSP) using resin encapsulation sheets is examined numerically and experimentally. Deflections after cooling from a bonding temperature are measured experimentally for various kinds of substrate and the thickness of an integrated circuit using a laser beam. In particular, a simple theory on the basis of a multilayered plate theory considering a viscoelastic property in the substrate is presented, and the thermo-viscoelastic analysis for the deflection of CSP is performed. Furthermore, the thermo-elastoplastic finite element method analysis is performed under the same temperature history. We could show that the simple formula for multilayered plates based on the thermo-viscoelatic theory can estimate fairly well the deflection of CSP in experiment.
Prediction of Thermal Performance of Wire-Bonded Plastic Ball Grid Array Package for Underhood Automotive Applications
Authors: Ramakrishna K. , Trent J. R.
Published: September 2003

Thermal performance of a three chip, overmolded wire-bonded plastic ball grid array (WB-PBGA) package with four layer substrate attached to a 1.52-mm-thick, four-layer (2s2p), FR4 printed wiring board (PWB) has been evaluated under horizontal natural convection conditions for underhood automotive applications as a function of ambient temperature, package design parameters, and thermophysical properties of the package and PWB materials. A two-tier modeling approach, which accurately accounts for multidimensional heat transfer effects caused by substrate features such as vias and C5 solder joints, has been developed and implemented. In this methodology, the effect of small features is first characterized using a detailed micromodel from which an effective thermal conductivity is computed. The effective thermal conductivity is implemented in the global model thereby excluding the small features in the global model. The actual stackups of the package and PWB have been used in the computations to accurately determine the in-plane heat spreading. Using this methodology for automotive underhood applications, a parametric study of thermal performance of the WB-PBGA package has been carried out. This study shows that: 1. The maximum junction temperature rise above ambient, ΔT, decreases with increase in ambient temperature by 30% as the ambient temperature increases from 23 to 125°C. 2. ΔT decreases by 20% as the emissivity of the molding compound and the PWB surfaces increases from 0 (no radiative loss) to 0.8 under natural convection conditions. 3. The decrease in ΔT is small (∼7%) as the thermal conductivity of the die attach material varies over a wide range. 4. ΔT decreases by 30% as the thermal conductivity of the molding compound is varied over a wide range. 5. ΔT decreases by 45% as the thermal conductivity of the substrate increases (i.e., as the number of vias in the substrate increase) from no vias case to densely populated vias.
Feature Simplification Techniques for Freeform Surface Models
Authors: Joshi Nikhil , Dutta Debasish
Published: September 2003

Freeform surface models are conventionally used to model sheet metal components, such as automobile body parts. Finite element meshes generated automatically for such models have poor quality around small detailed features. Manual correction of the mesh is extremely tedious. An approach presently receiving attention in industry aims to alleviate this problem by automatically simplifying these features in the surface model such that an acceptable mesh is automatically generated. Simplification involves recognition of the feature and modification of its geometry or complete suppression of the feature. Since features such as holes, notches, etc. are punched after the basic shape has been formed, such a simplification will also help in the modelling of forming dies and molds. The ability to detect features will also allow part comparison and classification in surface models. This paper proposes techniques to directly query the CAD data structure to recognize and suppress two basic features, viz. holes and fillets in freeform surface models. It further demonstrates how these techniques can be extended to suppress compound features that are composed of a combination of basic features. Results of a software implementation for the same are discussed with suitable examples and the improvement in mesh quality is demonstrated.
Handling Solids of Revolution in Volume-Based Construction of Solid Models From Orthographic Views
Authors: Soni Sourabh , Gurumoorthy B.
Published: September 2003

Volume-based approaches to construct solid models from orthographic views have several advantages over the traditional bottom up approach that has been popular thus far. The main advantages are—there is a valid solid model that is consistent with the input views always available at any point in the solution and there is no need for the intermediate wireframe. The first enables user intervention in complex drawings and the second eliminates the ambiguities due to the wireframe that have to be resolved to obtain a valid solid model. A major limitation of volume-based approaches that have been proposed thus far has been the limited domain of objects that they can handle. This is because these approaches typically use either pre-defined primitives or identify only entities (loops of edges) that can be extruded. This paper aims at extending the capabilities of the volume-based construction approaches by proposing a procedure to identify entities in the views that correspond to axis-aligned volumes of revolution and using these to construct the corresponding primitive volumes. Results of implementation are presented and further work has been identified.
Shedding Light on the Candela
Authors: Greene Nathaniel R.
Published: September 2003

Though the candela is one of the seven SI base units, it receives little attention from physics teachers. This paper will discuss the history of the candela, its measurement techniques (photometry), and its relation to the lumen. The luminous properties of incandescent and fluorescent lamps are compared. Of the SI base units, only the candela is linked to the peculiarities of human perception.
Second Chance
Authors: Beckman Mary
Published: September 2003

It's never too late to change bad habits, at least for some insects. Fruit flies can lengthen their life by slurping less food, even if they don't start dieting until old age, according to new research.
No Evidence for a Major Effect of Tumor Necrosis Factor Alpha Gene Polymorphisms in Periportal Fibrosis Caused bySchistosoma mansoniInfection
Authors: Eboumbou Moukoko Carole , El Wali Nasureldin , Saeed O. K. , Mohamed-Ali Qurashi , Gaudart Jean , Dessein Alain J. , Chevillard Christophe
Published: September 2003

Hepatic periportal fibrosis (PPF), associated with portal hypertension, is a major pathological consequence of infections withSchistosoma mansoniandSchistosoma japonicum. Indeed, affected subjects may die from portal hypertension. Previous studies have indicated that tumor necrosis factor alpha (TNF-α) may aggravate fibrosis. We therefore investigated whether PPF was associated with certain polymorphisms of the TNF-α gene. Four polymorphisms (TNF-α −376 G/A, −308 G/A, −238 G/A, and +488 G/A) were investigated in two Sudanese populations living in an area in whichS. mansoniis endemic. These polymorphisms were analyzed for 105 Sudanese subjects with various grades of PPF, from mild to advanced; all subjects were from two neighboring villages (Taweela and Umzukra). They were then analyzed for 70 subjects with advanced liver disease and for 345 matched controls from the Gezira region. We found no evidence of associations between these four polymorphisms and PPF in both of these studies. Thus, these four polymorphisms, two of which (TNF-α −376 and −308) were found to increase TNF-α gene transcription, are unlikely to have a major effect on PPF progression in these populations. However, this result does not exclude the possibility that these polymorphisms have a minor effect on PPF development.
Characterization and Pathogenic Significance of
Vibrio vulnificus
Antigens Preferentially Expressed in Septicemic Patients
Authors: Kim Young Ran , Lee Shee Eun , Kim Choon Mee , Kim Soo Young , Shin Eun Kyoung , Shin Dong Hyeon , Chung Sun Sik , Choy Hyon E. , Progulske-Fox Ann , Hillman Jeffrey D. , Handfield Martin , Rhee Joon Haeng
Published: September 2003

Many important virulence genes of pathogenic bacteria are preferentially expressed in vivo. We used the recently developed in vivo-induced antigen technology (IVIAT) to identify
Vibrio vulnificus
genes induced in vivo. An expression library of
V. vulnificus
was screened by colony blot analysis by using pooled convalescent-phase serum that had been thoroughly adsorbed with in vitro-expressed
V. vulnificus
whole cells and lysates. Twelve clones were selected, and the sequences of the insert DNAs were analyzed. The DNA sequences showed homologies with genes encoding proteins of diverse functions: these functions included chemotaxis (a methyl-accepting chemotaxis protein), signaling (a GGDEF-containing protein and a putative serine/threonine kinase), biosynthesis and metabolism (PyrH, PurH, and IlvC), secretion (TatB and plasmid
Achromobacter
secretion [PAS] factor), transcriptional activation (IlvY and HlyU), and the activity of a putative lipoprotein (YaeC). In addition, one identified open reading frame encoded a hypothetical protein. Isogenic mutants of the 12 in vivo-expressed (
ive
) genes were constructed and tested for cytotoxicity. Cytotoxic activity of the mutant strains, as measured by lactate dehydrogenase release from HeLa cells, was nearly abolished in
pyrH
,
purH
, and
hlyU
mutants. The intraperitoneal 50% lethal dose in mice increased by ca. 10- to 50-fold in these three mutants. PyrH and PurH seem to be essential for in vivo growth. HlyU appears to be one of the master regulators of in vivo virulence expression. The successful identification of
ive
genes responsible for the in vivo bacterial virulence, as done in the present study, demonstrates the usefulness of IVIAT for the detection of new virulence genes.
CadC Is the Preferential Target of a Convergent Evolution Driving Enteroinvasive
Escherichia coli
toward a Lysine Decarboxylase-Defective Phenotype
Authors: Casalino Mariassunta , Latella Maria Carmela , Prosseda Gianni , Colonna Bianca
Published: September 2003

Enteroinvasive
E. coli
(EIEC), like
Shigella
, is the etiological agent of bacillary dysentery, a particularly severe syndrome in children in developing countries. All EIEC strains share with
Shigella
the inability to synthesize lysine decarboxylase (the LDC phenotype). The lack of this function is considered a pathoadaptive mutation whose emergence was necessary to obtain the full expression of invasiveness. Cadaverine, the product of lysine decarboxylation, is a small polyamine which interferes mainly with the inflammatory process induced by dysenteric bacteria. Genes coding for lysine decarboxylase and its transporter constitute a single operon (
cadBA
) and are expressed at low pH under the positive control of CadC. This regulator is an inner membrane protein that is able to sense pH variation and to respond by transcriptionally activating the
cadBA
genes. In this study we show that, unlike in
Shigella
, mutations affecting the
cad
locus in the EIEC strains we have analyzed are not followed by a novel gene arrangement and that the LCD
−
phenotype is dependent mainly on inactivation of the
cadC
gene. Introduction of a functional CadC restores cadaverine expression in all EIEC strains harboring either an IS
2
element or a defective
cadC
promoter. Comparative analysis between the
cad
regions of
S. flexneri
and EIEC suggests that the LDC
−
phenotype has been attained by different strategies within the
E. coli
species.
Interleukin-8 Is Differentially Expressed by Human-Derived Monocytic Cell Line U937 Infected withMycobacterium tuberculosisH37Rv andMycobacterium marinum
Authors: Song Chang-Hwa , Lee Ji-Sook , Kim Hwa-Jung , Park Jeong-Kyu , Paik Tae-Hyun , Jo Eun-Kyeong
Published: September 2003

AlthoughMycobacterium marinumis closely related toMycobacterium tuberculosisH37Rv genomically, the clinical outcome in humans is quite different forM. marinumandM. tuberculosisinfections. We investigated possible factors in the host macrophages for determining differential pathological responses toM. tuberculosisandM. marinumusing an in vitro model of mycobacterial infection. Using suppression-subtractive hybridization, we identified 12 differentially expressed genes in the human monocytic cell line U937 infected withM. tuberculosisandM. marinum. Of those genes, the most frequently recovered transcript encoded interleukin-8 (IL-8). Northern hybridization revealed that IL-8 mRNA was highly upregulated inM. tuberculosis-infected U937 cells compared withM. marinum-infected cells. In addition, enzyme-linked immunosorbent assay showed that IL-8 protein secretion was significantly elevated inM. tuberculosis-infected U937 cells, human primary monocytes, and monocyte-derived macrophages compared with that inM. marinum-infected cells. The depressed IL-8 expression was unique inM. marinum-infected cells compared with cells infected with other strains of mycobacteria, includingM. tuberculosisH37Ra,Mycobacterium bovisBCG, orMycobacterium smegmatis. When the expression of NF-κB was assessed in mycobacterium-infected U937 cells, IκBα proteins were significantly degraded inM. tuberculosis-infected cells compared withM. marinum-infected cells. Collectively, these results suggest that differential IL-8 expression in human macrophages infected withM. tuberculosisandM. marinummay be critically associated with distinct host responses in tuberculosis. Additionally, our data indicate that differential signal transduction pathways may underlie the distinct patterns of IL-8 secretion in cells infected by the two mycobacteria.
Interleukin-18 Facilitates the Early Antimicrobial Host Response toEscherichia coliPeritonitis
Authors: Weijer Sebastiaan , Sewnath Miguel E. , de Vos Alex F. , Florquin Sandrine , van der Sluis Koen , Gouma Dirk J. , Takeda Kiyoshi , Akira Shizuo , van der Poll Tom
Published: September 2003

To determine the role of endogenous interleukin-18 (IL-18) during peritonitis, IL-18 gene-deficient (IL-18 KO) mice and wild-type mice were intraperitoneally (i.p.) infected withEscherichia coli, the most common causative agent found in septic peritonitis. Peritonitis was associated with a bacterial dose-dependent increase in IL-18 concentrations in peritoneal fluid and plasma. After infection, IL-18 KO mice had significantly more bacteria in the peritoneal lavage fluid and were more susceptible for progression to systemic infection at 6 and 20 h postinoculation than wild-type mice. The relative inability of IL-18 KO mice to clearE. colifrom the abdominal cavity was not due to an intrinsic defect in the phagocytosing capacity of their peritoneal macrophages or neutrophils. IL-18 KO mice displayed an increased neutrophil influx into the peritoneal cavity, but these migratory neutrophils were less activate, as reflected by a reduced CD11b surface expression. These data suggest that endogenous IL-18 plays an important role in the early antibacterial host response duringE. coli-induced peritonitis.
Construction and Evaluation of a Safe, Live, Oral
Vibrio cholerae
Vaccine Candidate, IEM108
Authors: Liang Weili , Wang Shixia , Yu Fenggang , Zhang Lijuan , Qi Guoming , Liu Yanqing , Gao Shouyi , Kan Biao
Published: September 2003

IEM101, a
Vibrio cholerae
O1 El Tor Ogawa strain naturally deficient in CTXΦ, was previously selected as a live cholera vaccine candidate. To make a better and safer vaccine that can induce protective immunity against both the bacteria and cholera toxin (CT), a new vaccine candidate, IEM108, was constructed by introducing a
ctxB
gene and an El Tor-derived
rstR
gene into IEM101. The
ctxB
gene codes for the protective antigen CTB subunit, and the
rstR
gene mediates phage immunity. The stable expression of the two genes was managed by a chromosome-plasmid lethal balanced system based on the housekeeping gene
thyA
. Immunization studies indicate that IEM108 generates good immune responses against both the bacteria and CT. After a single-dose intraintestinal vaccination with 10
9
CFU of IEM108, both anti-CTB immunoglobulin G and vibriocidal antibodies were detected in the immunized-rabbit sera. However, only vibriocidal antibodies are detected in rabbits immunized with IEM101. In addition, IEM108 but not IEM101 conferred full protection against the challenges of four wild-type toxigenic strains of
V. cholerae
O1 and 4 μg of CT protein in a rabbit model. By introducing the
rstR
gene, the frequency of conjugative transfer of a recombinant El Tor-derived RS2 suicidal plasmid to IEM108 was decreased 100-fold compared to that for IEM101. This indicated that the El Tor-derived
rstR
cloned in IEM108 was fully functional and could effectively inhibit the El Tor-derived CTXΦ from infecting IEM108. Our results demonstrate that IEM108 is an efficient and safe live oral cholera vaccine candidate that induces antibacterial and antitoxic immunity and CTXΦ phage immunity.
Chimeric Dr Fimbriae with a Herpes Simplex Virus Type 1 Epitope as a Model for a Recombinant Vaccine
Authors: Zalewska Beata , Piątek Rafał , Konopa Graz˙yna , Nowicki Bogdan , Nowicki Stella , Kur Józef
Published: September 2003

The potential of the major structural protein DraE of
Escherichia coli
Dr fimbriae has been used to display an 11-amino-acid peptide of glycoprotein D derived from herpes simplex virus (HSV) type 1. The heterologous sequence mimicking an epitope from glycoprotein D was inserted in one copy into the
draE
gene in place of a predicted 11-amino-acid sequence in the N-terminal region of surface-exposed domain 2 within the conserved disulfide loop (from Cys21 to Cys53). The inserted epitope was displayed on the surface of the chimeric DraE protein as evidenced by immunofluorescence and was recognized by monoclonal antibodies to the target HSV glycoprotein D antigen. Conversely, immunization of rabbits with purified chimeric Dr-HSV fimbriae resulted in a serum that specifically recognized the 11-amino-acid epitope of HSV glycoprotein D, indicating the utility of the strategy employed.
Kinome Analysis of Host Response to Mycobacterial Infection: a Novel Technique in Proteomics
Authors: Hestvik Anne Lise K. , Hmama Zakaria , Av-Gay Yossef
Published: September 2003

An array of mammalian phospho-specific antibodies was used to screen for a host response upon mycobacterial infection, reflected as changes in host protein phosphorylation. Changes in the phosphorylation state of 31 known signaling molecules were tracked after infection with live or heat killedMycobacterium bovisBCG or after incubation with the mycobacterial cell wall component lipoarabinomannan (LAM). Mycobacterial infection triggers a signaling cascade leading to activation of stress-activated protein kinase and its subsequent downstream target, c-Jun. Mycobacteria were also shown to inhibit the activation of protein kinase C ε and to induce phosphorylation of proteins not yet known to be involved in mycobacterial infection, such as the cytoskeletal protein α-adducin, glycogen synthase kinase 3β, and a receptor subunit involved in regulation of intracellular Ca2+levels. The mycobacterial cell wall component LAM has been identified as a trigger for some of these modulation events.