bluuebunny/crossref_metadata_2025 huggingface dataset:
Development and Predictive Validity of a Teacher Screener for Child Behavioral and Emotional Problems at School
Authors: Kamphaus Randy W. , Thorpe Jennifer S. , Winsor Anne Pierce , Kroncke Anna P. , Dowdy Erin T. , VanDeventer Meghan C.
Published: April 2007

A principal components analysis of the Teacher Rating Scale—Child (TRS-C) of the Behavior Assessment System for Children was conducted with a cross-sectional cohort of 659 children in Grades 1 to 5. A predictive validity study was then conducted with a 2-year longitudinal sample of 206 children. The results suggested that scores from the resulting 23-item screener had strong initial reliability and validity evidence. Predictive validity coefficients for the screener scores were acceptable for both behavioral and academic outcomes and equal to or better than those for the full TRS-C, comprised of 148 items. The practicality of the screener was documented by teachers' experiences. Administration time was less than 5 minutes per child, and no specialized teacher training was necessary. These results provide preliminary evidence that routine school screening via a brief teacher rating scale can increase the probability that children with behavioral and emotional problems may be validly identified for diagnostic and treatment services.
Trust in News Media
Authors: Kohring Matthias , Matthes Jörg
Published: April 2007

The dimensions that individuals apply in evaluating the trustworthiness or credibility of news media bear great theoretical and practical relevance. In previous research, however, there is no standardized scale for the measurement of trust in news media. Thus, the purpose of this article is to present the development and validation of a multidimensional scale of trust in news media. A theoretically derived model is tested on a representative sample via confirmatory factor analysis. After some modifications, the model is then validated on another independent sample. These results confirm the hypothesis that trust in news media can be considered a hierarchical factor (of second order) that consists of four lower order factors, including trust in the selectivity of topics, trust in the selectivity of facts, trust in the accuracy of depictions, and trust in journalistic assessment. This model is the first validated scale of trust in news media in communication research.
Identifying Subgroups at High Risk of Dropping Out of Domestic Batterer Treatment
Authors: Stalans Loretta J. , Seng Magnus
Published: April 2007

This study identifies the subgroups of domestic batterers who are at a low or high risk of failing to complete domestic batterer cognitive behavioral treatment. The sample is composed of 355 domestic batterers ordered to complete treatment, with 31.8% not completing treatment. Three subgroups of batterers were identified as having at least a 60% chance of treatment failure: (a) unemployed generalized aggressors, (b) high school dropouts ordered into substance abuse treatment, and (c) unemployed offenders ordered into substance abuse treatment. Furthermore, a high school education, even when offenders are unemployed or living in poverty, buffers the negative effects of a substance abuse problem among court-mandated batterers required to participate in both domestic violence treatment and substance abuse treatment. Two thirds of substance-abusing high school graduates completed both domestic violence and substance abuse treatment, compared to only one third of the substance-abusing high school dropouts. Implications are discussed.
Definitions of and Beliefs About Wife Abuse Among Undergraduate Students of Social Work
Authors: Haj-Yahia Muhammad M. , Schiff Miriam
Published: April 2007

The article focuses on definitions of and beliefs about wife abuse among undergraduate social work students in Israel. Data were collected through self-administered questionnaires. The vast majority of students in Study 1 acknowledged acts thought to constitute wife assault and disapproved of a husband's use of force against his wife. The majority of students in Study 2 did not justify wife abuse nor tend to believe that battered women benefit from beating, although they tended to blame the violent husband for his behavior. Significant amounts of the variance in dependent variables were explained by the students' marital role expectations (Study 1) and their attitudes toward women and sex role stereotypes (Study 2). The students' year of study and participation in family violence or wife abuse courses did not contribute toward explaining the variance in their beliefs. Results are discussed in light of the students' patriarchal ideology, and implications for future research are presented.
Cognitive Impairment, Psychiatric Disorders, and Problematic Behaviors in a Tribal Nursing Home
Authors: Jervis Lori L. , Manson Spero M.
Published: April 2007

Objective: Residents' cognitive, psychiatric, and behavioral statuses were examined as part of a larger study of care in a nursing home (NH) owned and operated by a Northern Plains American Indian tribe. Method: Reviews of 45 medical records and semistructured interviews with 36 staff were completed. Results: Creekside residents had considerable psychiatric and behavioral morbidity. High prevalences of non-Alzheimer's disease dementia, cognitive impairment, anxious symptomatology, and resistance to care were met with psychopharmacotherapy, reorientation, and informal techniques for behavior management. Significant depressive, anxious, psychotic, and behavioral symptoms remained. Staff interpretations of resident problems consisted of an ethnopsychological schema emphasizing resident loneliness, grumpiness, and propensity to “fight” rather than formal psychiatric nosology. Discussion: Tribal NH residents were likely underdiagnosed for dementia and anxiety. Residual behavioral and psychiatric symptomatology suggest room for improvement in the NH's behavioral management regimen. Need for greater attention to conceptual, diagnostic, clinical, and documentation processes in the NH setting is noted.
Relative Body Weight and Psychological Distress in Late Life
Authors: Schieman Scott , McMullen Taralyn , Swan Meagan
Published: April 2007

Objective: This study examines the association between relative body weight (measured with body mass index; BMI) and multiple forms of psychological distress and whether those associations are contingent on gender and race. Method: Interviews were conducted in 2001-2002 with persons 65 years and older in the District of Columbia and adjoining Maryland counties ( N = 1,152). BMI is associated (a) positively with depression, anger, and physical symptoms among White women; (b) positively with physical symptoms among Black women and men; and (c) negatively with anxiety among White men. Results: Tests for gender by race interactions find significant contrasts between White women and men when depression, anxiety, and physical symptoms are considered as outcomes; contrasts between White and Black women are significant for anger. Discussion: Results underscore the importance of gender by race interactions, multiple forms of distress in analyses of effects of BMI, and the role of negative self-evaluations and health difficulties as explanations.
Stride Width Discriminates Gait of Side-Fallers Compared to Other-Directed Fallers During Overground Walking
Authors: Ko Seung-Uk , Gunter Katherine B. , Costello Mark , Aum Ho , MacDonald Scott , White Karen N. , Snow Christine M. , Hayes Wilson C.
Published: April 2007

Purpose: The purpose was to identify differences in gait characteristics between older fallers with a tendency to fall sideways compared to those who do not fall to the side. Method: The authors conducted a prospective, case control study of ambulatory adults older than 70 residing in retirement communities. Measurements included spatial and temporal gait parameters and prospective fall surveillance. Results: In all, 29 participants fell to the side, and 64 fell in other directions (forward, backward, straight down); 46 participants experienced no falls. Side-fallers exhibited narrower stride widths compared to other-directed fallers, and stepwise and discriminant analysis correctly classified 67% of side-fallers and other-directed fallers using only stride width. Discussion: This study suggests that side-fallers, who have narrower stride widths compared to those who fall in other directions, may not be adapting their gait to compensate for lateral instability. More research is needed to determine whether narrow gait contributes to unstable walking patterns.
Risk Factors for Nursing Home Placement in Older Adults With and Without Dementia
Authors: Andel Ross , Hyer Kathryn , Slack April
Published: April 2007

Objective: The authors explored the effect of predisposing, enabling, and need characteristics on risk of nursing home placement (NHP) in participants with and without dementia. Method: Participants were 1,943 newly enrolled Medicare/Medicaid beneficiaries in Florida who were evaluated for health services by the Department of Elder Affairs. They were at least 65 years of age during fiscal year 1998-1999 and were followed for up to 4 years. Results: Cox proportional hazard regressions indicated that baseline characteristics including older age, White race, diabetes, incontinence, stroke, and difficulties with instrumental activities increased risk of NHP in those without dementia. Caregiver, widowed status, arthritis, and heart disease reduced the risk. Only age, race, and marital status were predictive among participants with dementia. Discussion: Dementia plays a central role in risk of NHP. Understanding risk factors for NHP in this relatively vulnerable population has important policy implications.
Handing IRB an Unloaded Gun
Authors: Rambo Carol
Published: April 2007

The author's autoethnographic article was accepted for publication and then blocked by her Institutional Review Board (IRB). The overt reasons for the “denial of approval” differ from accounts given behind closed doors. By weaving experience, excerpts from her article, and the responses of others into a narrative, the author creates an ongoing performance ethnography that resists the “tacit norm of silence” regarding discussions of incest and student/teacher attraction. Framing autoethnography as a “breach” of the academic norms regarding scientific inquiry helps her make sense of how IRB as a committee used the resources at hand—the existing religious/political context, their identities, their formal roles, and the written rules they had before them—to coconstruct a narrative that rendered her manuscript unpublishable. It is the author's hope that this performance of resistance will help facilitate the creation of a safe, defined space (similar to that of oral history) for autoethnography to occur.
The Dark Side of Truth(s)
Authors: Clark M. Carolyn , Sharf Barbara F.
Published: April 2007

This article explores the sometimes problematic issue of truth when conducting qualitative research on people's lives. Four ethical dilemmas are presented relating to the potentially harmful consequences of truth encountered by the authors in their own research: a promise to share the analysis of a patient's medical record containing unflattering comments by her physicians; the unintended sharing of a traumatic event, held secret since its occurrence, by a woman inmate; a disagreement with the Institutional Review Board over what constitutes ethical practice in online research; and an interview with a recently released political dissident in a totalitarian country. The authors advocate for multiple venues in which qualitative researchers can discuss ethical dilemmas such as these to learn from one another's experience and together develop a more reflexive practice.
Characterisation and formation of boundary in laser cladding AZ91D with Al + Al2O3
Authors: Yao J. , Sun G. P. , Lin W. G. , Liu C. , Mao G. L.
Published: April 2007

The laser surface cladding of AZ91D magnesium alloy with Al + Al2O3 powders was investigated. The growth morphology of the boundary zone between the laser surface cladding layer and AZ91D substrate, and the distribution of Al2O3 particles in the laser surface cladding layer, were observed by optical microscope and scanning electron microscope. Furthermore, the element line and mapping scans analyses on the boundary zone were carried out with energy dispersive spectrum. The phases in the laser cladding layer and the substrate of AZ91D magnesium alloy were identified by X-ray diffraction. The results showed that the distribution of the Al2O3 particles was homogeneous in the laser surface cladding layer and the growth morphology of the boundary zone was in a unique parallel branching feature. The formation of the parallel branching dendrite is mainly related to the temperature gradient, the ultimate rate of dendrite growth and the rate of pool solidification on the growing fronts.
Effect of high temperature storage test on reliability of eutectic Sn–Cu/ENIG solder joint
Authors: Yoon J.-W. , Kim S.-W. , Jung S.-B.
Published: April 2007

The interfacial reactions between Sn–0·7 wt-%Cu solder and electroless nickel immersion gold (ENIG) substrate were investigated during multiple reflows and isothermal aging at temperatures between 70 and 150°C for aging times of up to 60 days. After reflowing and aging, the intermetallic compound (IMC) formed at the interface was only (Cu,Ni)6Sn5. In addition, a P rich Ni (Ni3P) layer formed at the interface between the (Cu,Ni)6Sn5 and the Ni–P layer. The thickness of the interfacial (Cu,Ni)6Sn5 IMC layer slightly increased with the multiple reflows and isothermal aging. In contrast, the thickness of the Ni3P layer did not significantly increase. The formation of the (Cu,Ni)6Sn5 IMC layer retarded the consumption of the Ni from the electroless Ni–P substrate. As a result, a very thin Ni3P layer formed at the interface. In the ball shear test performed after aging treatment, the shear strength decreased for all temperatures tested until the samples had been aged for three days, and then remained at a constant value with prolonged aging. In addition, the shear strength could not be significantly related to the aging temperatures used in the present study. All fractures occurred in the bulk solder. The present study shows that the Sn–0·7Cu/ENIG solder joint has superior joint reliability with respect to shear tests.
Damping properties of porous AZ91 magnesium alloy reinforced with copper particles
Authors: Hao G. L. , Han F. S. , Wu J. , Wang X. F.
Published: April 2007

The well distributed open porous AZ91 magnesium alloy reinforced with copper particles was successfully prepared through powder metallurgy route based on space holder method. Its damping properties were characterised by internal friction and the internal friction measurement in a temperature range from room temperature to 100°C was performed by a multifunction internal friction apparatus. Experimental results revealed that the damping capacity of the porous AZ91 magnesium alloy was increased as a result of the addition of copper particle and the increase was further enhanced with increasing volume fraction of copper particle. Attempt is performed to correlate the increase in damping with the microstructural change arising due to the addition of copper particles. It was suggested that the increase should be related to the appearance of plastic zone and thus an increase in dislocation density at the matrix particles interfaces.
Basophils are essential initiators of a novel type of chronic allergic inflammation
Authors: Obata Kazushige , Mukai Kaori , Tsujimura Yusuke , Ishiwata Kenji , Kawano Yohei , Minegishi Yoshiyuki , Watanabe Naohiro , Karasuyama Hajime
Published: April 2007

Basophils represent less than 1% of peripheral blood leukocytes and have often been considered as minor and possibly redundant circulating mast cells. The recent finding that basophils readily generate large quantities of T helper 2 (Th2) cytokines such as IL-4 provided new insights into the possible role of basophils in allergic disorders and immunity to pathogens. However, in-depth studies on basophils, particularly their functions in vivo, have been hampered by the lack of appropriate animal models, such as mutant animals deficient only in basophils. Here, we established a mAb that reacted with mouse basophils and depleted them when administered in vivo. The mAb treatment of mice did not show any significant effect on classical allergic reactions such as passive cutaneous anaphylaxis and contact hypersensitivity. In contrast, it completely abolished the development of IgE-mediated chronic allergic dermatitis that is characterized by massive eosinophil infiltration, even though basophils accounted for only approximately 2% of the infiltrates. The treatment during the progression of the dermatitis resulted in drastic reduction in numbers of infiltrating eosinophils and neutrophils, concomitantly with elimination of basophils from the skin lesions. Thus, basophils play a pivotal role in the development of IgE-mediated chronic allergic inflammation, as an initiator rather than as an effector.
Imaging‐Guided Microarray
Authors: PEREIRA ANA CAROLINA , WU WILLIAM , SMALL SCOTT A.
Published: April 2007

Abstract:  Although both Alzheimer's disease (AD) and normal aging contribute to age‐related hippocampal dysfunction, they are likely governed by separate molecular mechanisms. In principle, gene expression profiling can offer molecular clues about underlying mechanisms, but in practice techniques like microarray present unique analytic challenges when applied to disorders of the brain. Imaging‐guided microarray is an approach designed to address these analytic challenges. Here, we will first review findings applying variants of functional magnetic resonance imaging (fMRI) to AD and normal aging, establishing the spatiotemporal profiles that dissociate one from the other. Then, we will review preliminary findings applying imaging‐guided microarray to AD and normal aging, in an attempt to isolate molecular profiles that dissociate the two main causes of age‐related hippocampal dysfunction.
Quantitative EEG and Electromagnetic Brain Imaging in Aging and in the Evolution of Dementia
Authors: PRICHEP LESLIE S.
Published: April 2007

Abstract:  Electroencephalographic (EEG) changes with normal aging have long been reported. Departures from age‐expected changes have been observed in mild cognitive impairment and dementia, the magnitude of which correlates with the degree of cognitive impairment. Such abnormalities include increased delta and theta activity, decreased mean frequency, and changes in coherence. Similar findings have been reported using magnetoencephalography (MEG) at rest and during performance of mental tasks. Electrophysiological features have also been shown to be predictive of future decline in mild cognitive impairment (MCI) and Alzheimer's disease (AD). We have recently reported results from initial quantitative electroencephalography (QEEG) evaluations of normal elderly subjects (with only subjective reports of memory loss), predicting future cognitive decline or conversion to dementia, with high prediction accuracy (approximately 95%). In this report, source localization algorithms were used to identify the mathematically most probable underlying generators of abnormal features of the scalp‐recorded EEG from these patients with differential outcomes. Using this QEEG method, abnormalities in brain regions identified in studies of AD using MEG, MRI, and positron emission tomography (PET) imaging were found in the premorbid recordings of those subjects who go on to decline or convert to dementia.
Linking Brain Imaging and Genomics in the Study of Alzheimer's Disease and Aging
Authors: REIMAN ERIC M.
Published: April 2007

Abstract:  My colleagues and I have been using positron emission tomography (PET) and magnetic resonance imaging (MRI) to detect and track the brain changes associated with Alzheimer's disease (AD) and normal brain aging in cognitively normal persons with two copies, one copy, and no copies of the apolipoprotein E (APOE) ɛ4 allele, a common AD susceptibility gene. In this review article, I consider how brain imaging techniques could be used to evaluate putative AD prevention therapies in cognitively normal APOE ɛ4 carriers and putative age‐modifying therapies in cognitively normal APOE ɛ4 noncarriers, how they could help investigate the individual and aggregate effects of putative AD risk modifiers, and how they could help guide the investigation of a molecular mechanism associated with AD vulnerability and normal neurological aging. I suggest how high‐resolution genome‐wide genetic and transcriptomic studies could further help in the scientific understanding of AD, aging, and other common and genetically complex phenotypes, such as variation in normal human memory performance, and in the discovery and evaluation of promising treatments for these phenotypes. Finally, I illustrate the push–pull relationship between brain imaging, genomics research, and other neuroscientific research in the study of AD and aging.
Shifting Paradigms in Dementia
Authors: Van Der FLIER WIESJE M. , BARKHOF FREDERIK , SCHELTENS PHILIP
Published: April 2007

Abstract:  Atrophy and cerebrovascular disease are the two most important magnetic resonance imaging (MRI) characteristics in the evaluation of dementia. On MRI, atrophy is the primary hallmark of neurodegenerative dementias including Alzheimer's disease (AD), while vascular dementia is characterized by the presence of ischemic vascular damage, such as territorial infarcts, lacunes, and white matter hyperintensities. Evidence is accumulating that vascular factors play an important role in the development of cognitive decline at old age and clinical AD. In the present article we present results of four recent MRI studies suggesting the additional involvement of small vessel disease in neurodegenerative disorders. Atrophy in the medial temporal lobe, as typically observed in AD, and small vessel disease often coincide. In terms of clinical significance, their effects may even be synergistic. The strict distinction between AD and vascular dementia is often artificial, as most patients suffer from both disorders to some extent. For the future, we see an important role for MRI in identifying those different compartments, regardless of clinical classification. Treatment could be directed by (and evaluated through) MRI patterns, rather than a diagnostic label.
Brain Aging and Its Modifiers
Authors: RAZ NAFTALI , RODRIGUE KAREN M. , HAACKE E. MARK
Published: April 2007

Abstract:  Aging is marked by individual differences and differential vulnerability of cognitive operations and their neural substrates. Cross‐sectional studies of brain volume reveal greater age‐related shrinkage of the prefrontal cortex (PFC) and the hippocampus than in the entorhinal and primary visual cortex. Longitudinal studies of regional brain shrinkage indicate that when individual differences are controlled, larger and broader shrinkage estimates are evident, with most polymodal cortices affected to the same extent. The mechanisms of age‐related shrinkage are unclear. Vascular risk factors may exacerbate brain aging and account for some of the observed declines as both the PFC and the hippocampus show elevated vulnerability to hypertension. MRI techniques that are sensitive to small vessels function, tissue oxygenation, and perfusion may be especially well suited to study brain aging and its vascular modifiers. We present an example of one such technique, susceptibility weighted imaging (SWI), that allows direct measurement of T2* values that reflect deoxy‐ to oxyhemoglobin fraction in blood vessels and iron deposits in cerebral tissue. The T2* shortening is associated with advanced age, but the effect is significantly stronger in the PFC and the hippocampus than the entorhinal and visual cortices. Moreover, T2* is shorter in hypertensive participants than in their matched normotensive counterparts, and the difference is especially prominent in the hippocampus, thus mirroring the findings of the neuromorphometric studies. Future research on brain aging would benefit from combining structural and metabolic techniques in a longitudinal design, as such studies will allow examination of leading–trailing effects of those factors.
Role of Aerobic Fitness and Aging on Cerebral White Matter Integrity
Authors: MARKS BONITA L. , MADDEN DAVID J. , BUCUR BARBARA , PROVENZALE JAMES M. , WHITE LEONARD E. , CABEZA ROBERTO , HUETTEL SCOTT A.
Published: April 2007

Abstract:  Neuroimaging research suggests that cerebral white matter (WM) integrity, as reflected in fractional anisotropy (FA) via diffusion tensor imaging (DTI), is decreased in older adults, especially in the prefrontal regions of the brain. Behavioral investigations of cognitive functioning suggest that some aspects of cognition may be better preserved in older adults who possess higher levels of aerobic fitness. There are only a few studies, however, investigating potential mechanisms for the improvements in aerobic fitness. Our study suggests that greater aerobic fitness may be related to greater WM integrity in select brain regions.
Impaired Recognition Memory and Decreased Prefrontal Cortex Spine Density in Aged Female Rats
Authors: WALLACE MAUREEN , FRANKFURT MAYA , ARELLANOS ADOLFO , INAGAKI TOMOKO , LUINE VICTORIA
Published: April 2007

Abstract:  Aged F344 female rats (21 months) showed decreased performance, as compared to young rats (4 months), on an object recognition memory task. Golgi impregnation measured dendritic spine density of pyramidal neurons in the prefrontal cortex (layer II–III), a brain area important for recognition memory. Densities of spines in aged rats were 16% lower in tertiary, apical dendrites, but not significantly different in secondary basal dendrites. Concurrent measures of memory and spine density in the young and aged subjects show that age‐related declines in recognition memory are associated with decreased cortical spine density.
Prospects for Prediction
Authors: ILLES J. , ROSEN A. , GREICIUS M. , RACINE E.
Published: April 2007

Abstract: This article focuses on the prospects and ethics of using neuroimaging to predict Alzheimer's disease (AD). It is motivated by consideration of the historical roles of science in medicine and society, and considerations specifically contemporary of capabilities in imaging and aging, and the benefits and hope they bring. A general consensus is that combinations of imaging methods will ultimately be most fruitful in predicting disease. Their roll‐out into translational practice will not be free of complexity, however, as culture and values differ in terms of what defines benefit and risk, who will benefit and who is at risk, what methods must be in place to assure the maximum safety, comfort, and protection of subjects and patients, and educational and policy needs. Proactive planning for the ethical and societal implications of predicting diseases of the aging brain is critical and will benefit all stakeholders—researchers, patients and families, health care providers, and policy makers.
The F-actin-microtubule crosslinker Shot is a platform for Krasavietz-mediated translational regulation of midline axon repulsion
Authors: Lee Seongsoo , Nahm Minyeop , Lee Mihye , Kwon Minjae , Kim Euijae , Zadeh Alireza Dehghani , Cao Hanwei , Kim Hyung-Jun , Lee Zang Hee , Oh Seog Bae , Yim Jeongbin , Kolodziej Peter A. , Lee Seungbok
Published: April 2007

Axon extension and guidance require a coordinated assembly of F-actin and microtubules as well as regulated translation. The molecular basis of how the translation of mRNAs encoding guidance proteins could be closely tied to the pace of cytoskeletal assembly is poorly understood. Previous studies have shown that the F-actin-microtubule crosslinker Short stop (Shot) is required for motor and sensory axon extension in the Drosophila embryo. Here,we provide biochemical and genetic evidence that Shot functions with a novel translation inhibitor, Krasavietz (Kra, Exba), to steer longitudinally directed CNS axons away from the midline. Kra binds directly to the C-terminus of Shot, and this interaction is required for the activity of Shot to support midline axon repulsion. shot and kra mutations lead to weak robo-like phenotypes, and synergistically affect midline avoidance of CNS axons. We also show that shot and kra dominantly enhance the frequency of midline crossovers in embryos heterozygous for slitor robo, and that in kra mutant embryos, some Robo-positive axons ectopically cross the midline that normally expresses the repellent Slit. Finally, we demonstrate that Kra also interacts with the translation initiation factor eIF2β and inhibits translation in vitro. Together,these data suggest that Kra-mediated translational regulation plays important roles in midline axon repulsion and that Shot functions as a direct physical link between translational regulation and cytoskeleton reorganization.
The Mrj co-chaperone mediates keratin turnover and prevents the formation of toxic inclusion bodies in trophoblast cells of the placenta
Authors: Watson Erica D. , Geary-Joo Colleen , Hughes Martha , Cross James C.
Published: April 2007

Defects in protein-folding and -degradation machinery have been identified as a major cause of intracellular protein aggregation and of aggregation-associated diseases. In general, it remains unclear how these aggregates are harmful to normal cellular function. We demonstrate here that,in the developing placenta of the mouse, the absence of the Mrj (Dnajb6)co-chaperone prevents proteasome degradation of keratin 18 (K18; Krt18)intermediate filaments, resulting in the formation of keratin inclusion bodies. These inclusions in chorionic trophoblast cells prevent chorioallantoic attachment during placental development. We show further that keratin-deficient embryos undergo chorioallantoic attachment and that, by genetically reducing keratin expression in Mrj-/-conceptuses, chorioallantoic attachment was rescued. Therefore, the chorioallantoic attachment phenotype in Mrj mutants is not due to a deficiency of the normal keratin cytoskeleton, but rather is cytotoxicity caused by keratin aggregates that disrupt chorion trophoblast cell organization and function.
The proneural determinant MASH1 regulates forebrainDlx1/2expression through the I12b intergenic enhancer
Authors: Poitras Luc , Ghanem Noël , Hatch Gary , Ekker Marc
Published: April 2007

Establishment of neuronal networks is an extremely complex process involving the interaction of a diversity of neuronal cells. During mammalian development, these highly organized networks are formed through the differentiation of multipotent neuronal progenitors into multiple neuronal cell lineages. In the developing forebrain of mammals, the combined function of the Dlx1, Dlx2, Dlx5 and Dlx6 homeobox genes is necessary for the differentiation of the GABAergic interneurons born in the ventricular and subventricular zones of the ventral telencephalon, as well as for the migration of these neurons to the hippocampus, cerebral cortex and olfactory bulbs. The 437 bp I12b enhancer sequence in the intergenic region of the Dlx1/2 bigene cluster is involved in the forebrain regulation of Dlx1/2. Using DNase I footprinting, we identified six regions of I12b potentially bound by transcription factors. Mutagenesis of each binding site affected the expression of reporter constructs in transgenic mice. However,the effects of impairing protein-DNA interactions were not uniform across the forebrain Dlx1/2 expression domains, suggesting that distinct regulatory interactions are taking place in the different populations of neuronal precursors. Analyses of protein-DNA interactions provide evidence of a direct role for MASH1 in Dlx1/2 regulation in the forebrain. DLX proteins play a crucial role in the maintenance of their own expression, as shown by transgenic and co-transfection experiments. These studies suggest that the seemingly continuous domains of Dlx gene expression in the telencephalon and diencephalon are in fact the combination of distinct cell populations within which different genetic regulatory interactions take place.
A knowledge-based parameter consistency management system for concurrent and collaborative design
Authors: Wang Wei-ming , Hu Jie , Yin Ji-long , Peng Ying-hong
Published: April 2007

This paper discusses rule-based reasoning parameter consistency management system based on knowledge in concurrent and corroborative product design using a combination of both mathematical methods and knowledge-based Engineering (KBE) techniques. First, the framework of the parameter consistency management system is developed. Second, a data-mining algorithm known as the fuzzy-rough algorithm is presented for modelling of knowledge-level constraints from numerical simulation. Then, the method of integrated case-based reasoning (CBR) and rule-based reasoning (RBR) with an interval consistency algorithm is adopted to predict the potential conflicts and specify the interval of design parameters. Finally, ontology is used as a communication language between cooperating engineering design teams. The system is demonstrated by the design of a crank connecting link in a V6 engine.
An integrated process for designing around existing patents through the theory of inventive problem-solving
Authors: Hung Yung-Chieh , Hsu Yeh-Liang
Published: April 2007

Patent infringements have become an important issue for industries when developing products. Designing around existing patents of competitors is a task constantly faced by designers. New design problems, which are often a ‘local innovation’ of an existing patent, are generated during the design-around process. Innovative design methodologies are needed to solve these new design problems, while the rules of patent infringement judgement present the major constraints to such design problems. This paper proposes an integrated process for designing around existing patents through the theory of inventive problem-solving (TRIZ). This process integrates patent design-around strategies, innovative design methods in TRIZ, and rules of patent infringement judgement systematically to design around existing patents and increase the patentability of results of innovation. Redesign of a portable magnetic impact tool to design around an existing patent is used to illustrate the integrated process.
Accuracy issues in rapid manufacturing CastForm™ patterns
Authors: Dotchev K D , Dimov S S , Pham D T , Ivanov A I
Published: April 2007

Selective laser sintering (SLS) or laser sintering (LS) is a very popular layer manufacturing technique extensively used to produce concept models, functional parts, cores, and cavities for different types of moulding tool, and also patterns for investment casting. CastForm™ polystyrene (CF) is a material used for fabrication of investment casting patterns employing the SLS process. The use of the CF material is one of the fastest and most cost-effective manufacturing routes to produce small-quantity wax-like patterns for shell or flask investment casting. Unlike other materials suitable for LS, the manufacture of CF casting patterns is done in two stages. The first is the building of a ‘green’ part and the second is its infiltration with wax. The accuracy of the patterns, and ultimately the final accuracy of the metal castings, is determined by the CF properties and the applied process parameters. The factors affecting the accuracy of the CF patterns are investigated in this paper. In addition, different ways to improve the process accuracy are discussed. An analysis of advantages and limitations of this manufacturing route for producing patterns for investment casting is provided.
Interchange of the holding/shortage costs in multiproduct manufacture
Authors: Sharma S
Published: April 2007

In the context of cyclic manufacturing, multiple items are produced in a common cycle time. Relevant total cost is formulated, including various parameters such as inventory holding cost and manufacturing facility set-up cost. This total cost is optimized and cycle time is computed. For internal benchmarking or continuous improvement, the production rates of two items have been interchanged in previous researches. The present work focuses on interchange of the inventory holding costs of two items in multiproduct engineering manufacture. The work is also extended to swapping the shortage costs. Effects on the costs are analysed, and conditions are developed for guaranteed cost improvement. A conscious effort in industries to implement the proposed method is expected to be useful in productivity improvement.
A comparison of railway track foundation design methods
Authors: Burrow M P N , Bowness D , Ghataora G S
Published: April 2007

One of the primary functions of the layers that make up the trackbed in a conventional railway track system is to distribute wheel/rail contact forces so that the stresses in the subgrade are of an acceptable level. To ensure that the trackbed layers perform this task adequately, there are a number of design procedures that may be used to calculate an appropriate thickness of the layers. This paper describes and compares five such design procedures from the USA, UK, Europe, and Japan. The comparisons show that the design procedures give large differences in the calculated layer thicknesses which are due to the design methodologies used in each procedure. Consequently, to enable an appropriate design procedure to be adopted for a given set of conditions, it is necessary to have a thorough knowledge of the methodologies employed together with their inherent assumptions.
Energy storage devices in hybrid railway vehicles: A kinematic analysis
Authors: Hillmansen S , Roberts C
Published: April 2007

Concerns over future energy security, energy costs, and competitiveness with other modes have prompted the railway industry to search for cost-effective energy efficient traction solutions which will ensure continuing business feasibility. For non-electrified routes, where the business case for electrification is unfavourable, traction is usually provided by diesel fuel combustion. Hybridization offers the potential to achieve a step change in energy efficiency. This article presents an analysis of the potential benefits of hybridization for rail vehicles. The performance requirements of the energy storage device in a hybrid rail vehicle which is storage device dominant are derived. A rail vehicle simulator has been developed in order to compute the drive train duty cycle in typical high-speed and commuter passenger services. The outputs from the simulator have been inputted into a series hybrid model, which has been optimized to preserve the state of charge of the energy storage device over a single typical rail journey. The analysis suggests the energy savings of up to 28 per cent for high-speed intercity vehicles and 35 per cent for commuter vehicles are achievable with practical system components. A sensitivity analysis exploring the effect of the inherent efficiency of the regenerative braking capability and the energy storage device revealed that primary energy savings are only realized with in/out storage efficiencies of greater than ∼40 per cent.
Modelling wear and crack initiation in rails
Authors: Franklin F J , Kapoor A
Published: April 2007

Wear and crack initiation of steel rails is a problem of great significance to the railway industry. A high wear rate shortens the life of rails and the frequent rail replacement is expensive in terms not only of resources but also of track access time and delays affecting timetables. In addition, railhead profiles change gradually as the rails are worn and the greater the wear rate, the more often the rails need to be reground to maintain good train running performance. In contrast, a low wear rate means that cracks have time to develop in the plastically deformed rail steel and these may propagate deeper into the rails with potentially disastrous consequences. Finding the optimum combination of wear and grinding to maintain railhead profile and prevent cracks from growing is key to running a safe and cost-efficient railway.

The large number of variables arising from track geometry, train dynamics, and wheel and rail profiles leads to wide variation in contact patch size and location. The two-dimensional model of ratcheting wear developed by Kapoor et al. has been developed to model the damage accumulation near the surface of the rail on the basis of a full three-dimensional contact stress distribution. Different rail steel microstructures can also be modelled and the effects of microstructure on wear and crack initiation are explored.
Monitoring lateral track irregularity from in-service railway vehicles
Authors: Weston P F , Ling C S , Goodman C J , Roberts C , Li P , Goodall R M
Published: April 2007

Maintaining the alignment of railway track is vitally important for the smooth and safe passage of railway vehicles. Poor track alignment can result in poor ride quality, flange contact, or even flange climb. Accurate horizontal track geometry can be measured using a dedicated track recording vehicle or from a full track geometry recording system mounted on an in-service vehicle. This paper describes the use of sensors mounted on the bogie of an in-service vehicle to estimate the mean track alignment without the use of optical or contact sensors. In principle, either bogie lateral acceleration or yaw rate can be processed to give an estimate of mean lateral track irregularity, but a yaw rate gyro provides consistent estimates down to lower vehicle speeds than does an accelerometer and does not require compensation for the effects of bogie roll. An improved estimate can be obtained by inverting the dynamic relationship between the mean track alignment and the bogie yaw motion. This is demonstrated with results from a Class 175 vehicle. Continually monitoring the lateral response of a bogie on an in-service vehicle, using only a yaw rate gyro, can provide data enabling the prioritization of maintenance operations.
Monitoring vertical track irregularity from in-service railway vehicles
Authors: Westeon P F , Ling C S , Roberts C , Goodman C J , Li P , Goodall R M
Published: April 2007

Condition monitoring of track geometry from sensors mounted on an in-service vehicle offers continual monitoring of track geometry that can aid track maintenance strategies. Mounting and maintaining a full track geometry recording system on an in-service vehicle is an expensive proposition as the commonly used optical sensors are difficult to keep working in the dirty railway environment. A simpler and more cost-effective alternative is to estimate track geometry using a small number of robust sensors such as accelerometers and rate gyroscopes, from which a worthwhile proportion of geometric quality measures and specific irregularities can be identified. This paper describes the theory and practical results of using a bogie-mounted pitchrate gyro to obtain mean vertical alignment, conditional on the secondary vertical damper geometry. Left and right axlebox-mounted accelerometers can be added to provide short wavelength irregularity, if required. Results from trials on Tyne and Wear Metro vehicles and on a Class 175 mainline vehicle demonstrate effective vertical irregularity monitoring, in particular the ability to monitor vertical irregularity over a wide range of vehicle speeds down to about 1 ms-1, where vertically sensing accelerometers combined with displacement transducers are unable to function correctly.
Experimental and theoretical investigation of railway wheel squeal
Authors: Hsu S S , Huang Z , Iwnicki S D , Thompson D J , Jones C J C , Xie G , Allen P D
Published: April 2007

The tangential contact forces that arise at the interface between the wheel of a railway vehicle and the rail provide all the traction, braking, and guidance required by the vehicle. These forces are the result of microslip or creepage and can become unstable exciting vibration of the wheel, particularly at frequencies corresponding to the wheel's axial (and radial) modes.

Although theories exist for predicting these creep forces and their relationship to creepages, most lack experimental verification in the characterization of the falling friction coefficient during unsteady squealing. This paper presents some new results from a project which aims to develop a complete, validated model of curve squeal noise generation accounting for friction characteristics, excitation due to unstable forces between the wheel and rail and vehicle dynamic behaviour. The model includes wheel and track dynamic response and acoustic radiation. As part of the project, a twin disc rig has been modified to provide experimental data for the validation of the model and measurements were made of the lateral force and dynamic response of the rollers due to varying amounts of lateral creepage during squealing. The main feature of the twin disc rig compared with previous research [1] is that the contact force measuring system measures the contact forces at the web of the rollers and therefore close to the contact patch and through a slipring arrangement enables the lateral vibration of both rollers in relation to squeal be measured with relative ease.

In this paper, detailed descriptions of the twin disc rig and the test method developed are given. An outline of the squeal model is also presented. Results from the tests have been compared with the prediction from the squeal model and with available theories and showed good agreement.
Comparison of numerical methods for elastohydrodynamic lubrication analysis of metal-on-metal hip implants: Multi-grid verses Newton-Raphson
Authors: Gao L. M. , Meng Q. E. , Wang F. C. , Yang P. R. , Jin Z. M.
Published: April 2007

Elastohydrodynamic lubrication (EHL) of a metal-on-metal hip implant was investigated under quasi-static operating conditions. Various numerical methods, such as Newton-Raphson (N-R), multi-grid (MG), multi-level multi-integration, and fast Fourier transform technique (FFT), were considered and compared in terms of the convergence and accuracy of the numerical solution. It was found that the numerical convergence for the MG method was much faster, and consequently the computational time required was significantly lower than the N-R method. This feature was particularly evident, when a tighter tolerance was specified on the pressure iteration and a high load or low viscosity was considered. Furthermore, the multi-integration method was found to be more effective, only when four-level grids were considered and compared with the FFT technique. It was concluded that the MG method has the potential to be applied efficiently and effectively for modelling realistic EHL problems of artificial hip joints such as under transient conditions of walking and when the surface topography is considered.
An integration of vehicle motion controls for full drive-by-wire vehicle
Authors: Abe M , Mokhiamar O
Published: April 2007

The optimum tyre force distribution is dealt with in this article, which rests on the premise of full drive-by-wire vehicle that follows a model vehicle response to driver's command. All the wheel-steer angles and wheel torques are controlled independently to distribute lateral and longitudinal forces to each tyre to optimize the tyre performance and to obtain the required vehicle response. It may be said to be one of the generic strategies of the integrated chassis controls. The effects of the integrated control are validated with computer simulations and the driving simulator under severe manoeuvring conditions.