bluuebunny/crossref_metadata_2025 huggingface dataset:
Field-programmable gate array controller design for air-powered motorcycle
Authors: Huang S-Y , Hwang Y-R
Published: May 2011

This article presents a field-programmable gate array (FPGA) speed controller design and applied in an air-powered motorcycle which utilizes an air motor and a high-pressure gas cylinder to replace the internal combustion engine and oil tank, respectively. One of the main purposes of this research is to find the relationship between velocity and efficiency of an air-powered motorcycle. In addition, a speed control system is developed based on FPGA in order to control the velocity of an air-powered motorcycle. The control theories are actualized by the hardware description language and modular conception is used to divide a complex system into many parts. This design methodology shortens the development time and is easy to modify for each module. Besides, the system dynamics of air-powered motorcycle was derived through the tractive effort and the dynamic response was simulated by the Matlab software. From the experimental results, the air-powered motorcycle can drive with the best efficiency, at the velocity expected by the proportional–integral (PI) and Lyapunov speed controllers. Also, the experimental data show that the chattering ranges are 2.7 per cent and 6.9 per cent of Lyapunov controller and PI controller, respectively, under the same velocity.
Numerical modelling of unsteady turbulent flow in smooth-walled pipes
Authors: Johnston D N
Published: May 2011

An efficient numerical model for turbulent friction has been developed for smooth-walled pipe flow. The aim was to develop a new approach to the numerical modelling, eliminating some important approximations and sources of error, such that the method can be applied reliably under a wide range of conditions. A simple two-region model of effective viscosity is used. For short timescales, the turbulence level and effective viscosity distribution are ‘frozen’ in time. The velocity profile is determined numerically for a range of frequencies and viscosity distributions, and this is used to determine the frequency-dependent friction. This is then approximated using simple weighing functions. This turbulence model can be implemented readily in several types of numerical model for pipe flow, including simple lumped parameter models, finite difference/finite element methods, and the method of characteristics.
Actuation Requirements of a Warp-Induced Variable Twist Rotor Blade
Authors: Mistry Mihir , Gandhi Farhan , Nagelsmit Martin , Gurdal Zafer
Published: May 2011

This article examines a warp-induced twist concept to obtain quasi-static large amplitude twist changes of helicopter or tiltrotor blades for performance benefits over diverse operating conditions. The presented concept has a cylindrical spar with rotating ribs which are attached to the blade skin that is slit along the trailing edge. Warping the skin then produces twisting of the blade section. Warp actuation is implemented by rotating a threaded rod assembly attached to the interior of the upper and lower skin near the trailing edge. Due to the slit at the trailing edge, the blade is soft in torsion during actuation, but is effectively a closed section due to the threaded rod assembly when in power off state. A prototype (NACA 0012, 10.75 in chord, 42 in span) based on this concept was built and tested for both the warp-twist relationship and the actuation torque requirements for producing the twist of the blade (up to ±18°). The finite element model developed in this article correlated very well with the experimental measurements made on the prototype. The validated finite element model is further used to conduct a study to understand the effect of various structural parameters on the system behavior.
Fiendishly Difficult Questions: Possible Limits and Aesthetic Pleasures of Simulation
Authors: Thorngate Warren
Published: May 2011

Simulations facilitate the construction of increasingly complex theories, which, in turn, suffer three attendant curses. By definition, complex theories have many variables, decreasing the chances that all of them will be clear and measurable. This makes complex theories difficult to test, decreasing the chances they will be adequately tested, and difficult to understand, and decreasing the chances of attracting or sustaining an audience. However, constructing simulations that embody complex theories provides an opportunity for new perspectives and insights, and an occasion to renew respect for the complexities of the phenomena that they simulate. These are aesthetic benefits concordant with the definition of science as art with numbers.
Adaptative Progressive Damage Modeling for Large-scale Composite Structures
Authors: Labeas G. N. , Belesis S. D. , Diamantakos I. , Tserpes K. I.
Published: May 2011

Progressive damage modeling (PDM) is a well-established methodology for the prediction of damage initiation and evolution in composite structures. However, as conventional PDM methodology involves a large post-processing procedure, it is impractical for application in large-scale structures due to the high computational cost it requires. In this study, the local character of nonlinearity, due to the scale of the damage topology compared to the size of the entire structure, is exploited to propose proper modifications in the ‘classical’ PDM methodology. Specifically, the sub-modeling technique principles are combined and integrated in the PDM methodology and the appropriate modifications required are discussed. Furthermore, two damage prediction indices, which are related to the criticality of damage state at specific sub-areas (material layers) of the structure are introduced, in order to achieve significant reductions of the required computational time. Both the improvements make the application of PDM in large-scale composite structures practically feasible; this is demonstrated in the case of a generic composite shear joint whose numerical model comprises over a million degrees of freedom.
Psychological Ownership in Small Family-Owned Businesses: Leadership Style and Nonfamily-Employees’ Work Attitudes and Behaviors
Authors: Bernhard Fabian , O'Driscoll Michael P.
Published: May 2011

Using a sample of 229 nonfamily employees working in 52 small family-owned businesses, we examined the relationships between owner-managers’ leadership style and employees’ psychological ownership of the family business and their job. We also examined whether psychological ownership mediated the link between leadership style and employees’ organizational attitudes and behaviors. Hierarchical linear modeling (HLM) analysis confirmed transformational and transactional leadership as contextual facilitators of psychological ownership for the family business and for the job. Passive (laissez-faire) leadership was negatively related to employees’ ownership feelings for the family business. Psychological ownership of the organization and the job mediated the relationship between leadership style and affective organizational commitment, job satisfaction, and turnover intentions. In addition, feelings of psychological ownership for the family business mediated the relationship between transformational leadership and organizational citizenship behavior (OCB). Implications for research and practice are discussed.
The Integration of Counseling and Nursing Services into Schools
Authors: Maughan Erin , Troup K. D.
Published: May 2011

The purpose of this comparative review was to examine the legislative evolution of school guidance and school nursing over the past century, in hopes of identifying reasons why guidance counselors have been more successful in compliance to recommended ratios than school nurses. A literature review was conducted including CINAHL, MEDLINE, ERIC and other EBSCO databases. The results from this review indicate school guidance programs have been included in more federal legislation, mandating funding, education and certification requirements, which gives counselors a uniformly recognizable credential understood by educators. An extensive effort to develop a national model of school guidance has assisted counselors to uniformly show how they impact student academic success. School nurses can learn how to further integrate the school nursing role into education from the example of guidance counselors.
Which Comes First in Fragile X Syndrome, Dendritic Spine Dysgenesis or Defects in Circuit Plasticity?
Authors: Portera-Cailliau Carlos
Published: May 2011

The salient neuropathological defect in fragile X syndrome is the overabundance of immature dendritic spines in cortical pyramidal neurons. This review examines this anatomical synaptic defect in the context of other alterations in synaptic and circuit plasticity in fragile X mice. In theory, abnormal spines could lead to dysfunctional circuits and vice versa, so it is still not clear which problem comes first. Because of the tight structure-function relationships at the synapse, and given the significant overlap between signaling pathways that regulate spine shape/dynamics and long-term synaptic plasticity (both of which involve proteins regulated by fragile X mental retardation protein [FMRP]), it is argued that the two defects cannot be separated. It will be critical to determine whether neurons that lack FMRP and demonstrate alterations in long-term potentiation/depression also fail to undergo the expected enlargement/shrinkage of dendritic spines associated with those forms of synaptic plasticity or to establish clear links from FMRP signaling to either spine instability or defective synaptic plasticity, especially during critical periods of brain development. The resulting data will be vital in guiding translational research that can identify novel molecular targets for therapy in this devastating disorder.
In Utero Electroporation as a Tool For Genetic Manipulation In Vivo to Study Psychiatric Disorders
Authors: Taniguchi Yu , Young-Pearse Tracy , Sawa Akira , Kamiya Atsushi
Published: May 2011

Many genetic risk factors for major mental disorders have key roles in brain development. Thus, exploring the roles for these genetic factors for brain development at the molecular, cellular, and neuronal circuit level is crucial for discovering how genetic disturbances affect high brain functions, which ultimately lead to disease pathologies. However, it is a tremendously difficult task, given that most mental disorders have genetic complexities in which many genetic risk factors have multiple roles in different cell types and brain regions over a time-course dependent manner. Furthermore, some genetic risk factors are likely to act epistatically in common molecular pathways. For this reason, a technique for spatial and temporal manipulation of multiple genes is necessary for understanding how genetic disturbances contribute to disease etiology. Here, the authors will review the said technique, in utero electroporation, which investigates the molecular disease pathways in rodent models for major mental disorders. This technique is also useful to examine the effect of genetic risks at the behavioral level. Furthermore, the authors will discuss the recent progress of this technology, such as inducible and cell type-specific targeting, as well as nonepisomal genetic manipulation, which provide further availability of this technique for research on major mental disorders.
Dynamic Risk Groups Among Adult Male Sexual Offenders
Authors: Seto Michael C. , Fernandez Yolanda M.
Published: May 2011

In the present study, the 16-item Stable-2000 was used to identify different dynamic risk groups among 419 adult male sexual offenders who were referred for assessments between 2000 and 2007. Using a two-stage cluster analysis, four dynamic risk groups were identified: (a) a low needs group who scored below the overall sample mean on all of the Stable-2000 items; (b) a typical group who had intermediate scores on many items; (c) a sexually deviant group who scored relatively high on deviant sexual interests, sexual preoccupation, emotional identification with children, and child molester attitudes; and (d) a pervasive high-needs group who scored relatively high on many Stable-2000 items, reflecting a variety of problems in both general and sexual self-regulation. These dynamic risk groups were not redundant with offender type based on victim age, relatedness, or gender, and did not differ in terms of age at time of assessment, marital status, number of sexual victims, or long-term risk, estimated using the Static-99. The implications for treating and supervising sexual offenders with different dynamic risk profiles are discussed.
Preliminary Investigation of the Sources of Self-Efficacy Among Teachers of Students with Autism
Authors: Ruble Lisa A. , Usher Ellen L. , McGrew John H.
Published: May 2011

Teacher self-efficacy refers to the beliefs teachers hold regarding their capability to bring about desired instructional outcomes and may be helpful for understanding and addressing critical issues such as teacher attrition and teacher use of research-supported practices. Educating students with autism likely presents teachers with some of the most significant instructional challenges. The self-efficacy of 35 special education teachers of students with autism between the ages of 3 to 9 years was evaluated. Teachers completed rating scales that represented self-efficacy and aspects of the following 3 of Bandura’s 4 sources of self-efficacy: (1) sense of mastery, (2) social persuasions, and (3) physiological/affective states. Significant associations were observed between physiological/affective states and self-efficacy, but no associations were observed for the other sources.
A Review of Parent Education Programs for Parents of Children With Autism Spectrum Disorders
Authors: Schultz Tia R. , Schmidt Carla T. , Stichter Janine P.
Published: May 2011

Benefits of parent education have been demonstrated for decades. However, there exists a lack of formative evaluation of parent education for parents of children with autism spectrum disorders (ASD), limiting the interpretation of ongoing and future research. To understand the current status, key characteristics, and evaluation methods of parent education specific to ASD, relevant research was reviewed with an emphasis on presentation format, evaluation methods, and participant demographics. Of the 30 articles that met inclusion criteria, more than half included descriptions of programs for parents of children with ASD ages 3—5 years, 76% involved a one-on-one training approach, 40% relied on a manual or curriculum, 86% included data on parent and child outcomes, and 70% used single-case designs to evaluate program effectiveness. None of the researchers reported data on fidelity of implementation. Suggestions for further evaluation and next-generation research are provided.
Schema-Based Strategy Instruction in Mathematics and the Word Problem-Solving Performance of a Student With Autism
Authors: Rockwell Sarah B. , Griffin Cynthia C. , Jones Hazel A.
Published: May 2011

The purpose of this study was to provide preliminary results on the use of schema-based strategy instruction to teach addition and subtraction word problem solving to a fourth grade student with autism. The student was taught to use schematic diagrams to solve three types of addition and subtraction word problems. A multiple probes across behaviors single-case design was used, with solving each of the three problem types treated as a separate behavior. Interpretation of results indicated that the participant’s ability to solve all types of one-step addition and subtraction word problems improved following instruction. Improvement also generalized to problems with unknowns in the initial and medial position and was maintained over time.
Teaching Paraprofessionals of Students With Autism to Implement Pivotal Response Treatment in Inclusive School Settings Using a Brief Video Feedback Training Package
Authors: Robinson Suzanne Elaine
Published: May 2011

Given that students with autism spend the majority of their days in school settings, largely supported by paraprofessionals, it is important that these paraprofessionals receive adequate training. The author investigated a training package consisting of modeling and video-based feedback as a means of enabling paraprofessionals to implement Pivotal Response Treatment (PRT) in the inclusive school setting. A multiple baseline design across four paraprofessional -focal student pairs was employed. The findings suggest that the training package was effective and efficient in improving paraprofessional PRT implementation and levels of involvement as well as social communication target behaviors of the students with autism. Generalization across activities and students, maintenance, and social validity were also assessed.
Mexican American Mothers’ Perceptions of Childhood Obesity
Authors: Sosa Erica T.
Published: May 2011

Childhood obesity continues to increase, disproportionately affecting Mexican American children. The aims of this review are to (a) assess the literature regarding Mexican American mothers’ knowledge and perceptions of childhood obesity, prevention, and their role in prevention; (b) critically evaluate the methodological quality of the research conducted on mothers’ perceptions of childhood obesity; and (c) make recommendations for future research on parental perceptions of childhood obesity. Four databases were searched for relevant articles and 22 studies met inclusion criteria and were included in the review. Social cognitive theory was used to sort findings across studies. Major findings included the following: (a) barriers to childhood obesity prevention included lack of education regarding prevention and role modeling, (b) only 23% of studies explicitly used a theoretical framework to guide their study, and (c) most studies used heterogeneous groups to examine perceptions. Implications for future research and practice are presented.
The evaluation of knowledge claims in an innovation project: A case study
Authors: Peters Kristian , Maruster Laura , Jorna René J
Published: May 2011

Understanding how an organization determines what knowledge is valid leads to new insights about how firms cope with innovation. Although the evaluation of knowledge is a relevant topic in the field of knowledge management, the existing literature does not provide substantial contributions. Nonaka and Takeuchi’s (1995) theory of justification is the only established approach. This study adopts an empirical approach for improving the understanding of knowledge claim evaluation by presenting a conceptual framework based on Toulmin’s (1958) argumentation theory. We apply the framework in a small-scale study at the headquarters of a large building technology multinational. Based on the results, we reflect upon Nonaka and Takeuchi’s (1995) justification theory. Our findings indicate that the justification theory explains actual knowledge claim evaluation only partially. The unexplained parts, for which we explore alternative meanings, enlighten why innovations fail or succeed from the viewpoint of knowledge claim evaluation.
Selective layer chemical mechanical planarization process mimicked with atomic force microscope
Authors: Ilie F , Tita C
Published: May 2011

To understand the mechanisms of chemical mechanical planarization (CMP), an atomic force microscope (AFM) was used to characterize polished layer surfaces formed by selective transfer after a series of polishing experiments. The AFM allows one to examine the effects of applying highly localized stress to a surface. In the presence of solutions, tribochemical friction and wear can be investigated. We present the results of fundamental studies of the simultaneous application of chemical agents and mechanical stress using a single asperity model and a solid surface. At the same time, we show the consequences of combining highly localized mechanical stress (due to contact with AFM tip) and exposure to aqueous solutions of known pH. The experiment simulates several features of a single particle–substrate–slurry interaction in CMP.

To optimize the CMP process, one needs to obtain information on the interaction between the slurry abrasive particles and the polished surface. To study such interactions, we used AFM. An AFM tip of radius of about 50 nm was used to mimic a single abrasive particle, typical of those found in CMP slurry. Surface analysis of selective layer using the AFM revealed detailed surface characteristics obtained by CMP.

Studying the selective layer CMP, of which the predominant one is copper (in proportion of over 85 per cent), we found that the AFM scanning removes the surface oxide layer in different rates depending on the depth of removal and the pH of the solution. It was found that removal mechanisms depend also on the slurry chemistry, potential, percentage of oxidizer, and the applied load. We show that linear scans and raster scans display significantly different material removal rates.

Oxide removal happens considerably faster than the copper CMP removal from the selective layer. This is in agreement with generally accepted models of copper CMP.

Both long-range and the friction forces acting between the AFM tip and surface during the polishing process were measured. The correlation between those forces and removal rate is discussed. At the same time, this article complements recent observations of tip-induced friction and wear and growth in a number of inorganic surfaces in aqueous solutions.
Making sense of the ‘Big Society’: Social work and the moral order
Authors: Jordan Bill
Published: May 2011

• Summary: This article analyses the ‘Big Society’ agenda of the UK coalition government as a response to New Labour’s regulation of society through incentives, contracts, targets and micro-management.

• Findings: It argues that two sides of the programme are relevant for social work. Initially, most attention has understandably focused on the public spending cuts – rolling back the state and transferring responsibilities to voluntary organizations. But in the longer term, of equal significance will be its emphasis on increased citizen participation, empowered communities and collective action.

• Applications: This agenda poses challenges and opportunities for a practice which is less individualistic, formal and desk-bound; but it also raises issues about the wider solidarities upon which equality and social justice depend.
Investigating the use of an adjustment task to set the preferred illuminance in a workplace environment
Authors: Logadóttir Á , Christoffersen J , Fotios SA
Published: May 2011

An experiment was carried out to examine user preferences for light level using the method of adjustment. The study sought preferred illuminances under lighting from fluorescent lamps of different correlated colour temperature. It was hypothesised that the preferred illuminance would be influenced by variables inherent in the experimental design including the available stimulus range, the anchor (initial setting before adjustment) and adaptation time before onset of adjustment action. The experiment included three different stimulus ranges (21–482 lux, 38–906 lux and 72–1307 lux) and these lead to significantly different preferred illuminances (337 lux, 523 lux and 645 lux, respectively). The experimental results confirmed that stimulus range and anchor have significant effects on the outcome of the adjustment task, confirming the importance of considering and reporting these variables when determining user preference with this method.
Participating in cardiac rehabilitation: a systematic review and meta-synthesis of qualitative data
Authors: Neubeck Lis , Freedman S Ben , Clark Alexander M , Briffa Tom , Bauman Adrian , Redfern Julie
Published: May 2011

Background: Participation in cardiac rehabilitation (CR) benefits patients with coronary heart disease (CHD), yet worldwide only some 15–30% of those eligible attend. To improve understanding of the reasons for poor participation we undertook a systematic review and meta-synthesis of the qualitative literature.

Methods: Qualitative studies identifying patient barriers and enablers to attendance at CR were identified by searching multiple electronic databases, reference lists, relevant conference lists, grey literature, and keyword searching of the internet (1990–2010). Studies were selected if they included patients with CHD and reviewed experience or understanding about CR. Meta-synthesis was used to review the papers and to synthesize the data.

Results: From 1165 papers, 34 unique studies were included after screening. These included 1213 patients from eight countries. Study methodology included interviews ( n = 25), focus groups ( n = 5), and mixed-methods ( n = 4). Key reasons for not attending CR were physical barriers, such as lack of transport, or financial cost, and personal barriers, such as embarrassment about participation, or misunderstanding the reasons for onset of CHD or the purpose of CR.

Conclusions: There is a vast amount of qualitative research which investigates patients’ reasons for non-attendance at CR. Key issues include system-level and patient-level barriers, which are potentially modifiable. Future research would best be directed at investigating strategies to overcome these barriers.
Glucose levels are associated with cardiovascular disease and death in an international cohort of normal glycaemic and dysglycaemic men and women: the EpiDREAM cohort study
Authors: Anand SS , Dagenais GR , Mohan V , Diaz R , Probstfield J , Freeman R , Shaw J , Lanas F , Avezum A , Budaj A , Jung H , Desai D , Bosch J , Yusuf S , Gerstein HC
Published: May 2011

Aims: In an international prospective cohort study we assessed the relationship between glucose levels and incident cardiovascular events and death.

Methods and results: 18,990 men and women were screened for entry into the DREAM clinical trial from 21 different countries. All had clinical and biochemical information collected at baseline, including an oral glucose tolerance test (OGTT), and were prospectively followed over a median (IQR) of 3.5 (3.0–4.0) years for incident cardiovascular (CV) events including coronary artery disease (CAD), stroke, congestive heart failure (CHF) requiring hospitalization, and death. After OGTT screening, 8000 subjects were classified as normoglycaemic, 8427 had impaired fasting glucose (IFG) or impaired glucose tolerance (IGT), and 2563 subjects had newly diagnosed type 2 diabetes mellitus (DM). There were incident events in 491 individuals: 282 CAD, 54 strokes, 19 CHF, and 164 died. The annualized CV or death event rate was 0.79/100 person-years in the overall cohort, 0.51/100 person-years in normoglycaemics, 0.92/100 person-years among subjects with IFG and/or IGT at baseline, and 1.27/100 person-years among those with DM ( p for trend <0.0001). Among all subjects, a 1 mmol/l increase in fasting plasma glucose (FPG) or a 2.52 mmol/l increase in the 2-h post-OGTT glucose was associated with a hazard ratio increase in the risk of CV events or death of 1.17 (95% CI 1.13–1.22).

Conclusions: In this large multiethnic cohort, the risk of CV events or death increased progressively among individuals who were normoglycaemic, IFG or IGT, and newly diagnosed diabetics. A 1 mmol/l increase in FPG was associated with a 17% increase in the risk of future CV events or death. Therapeutic or behavioural interventions designed to either prevent glucose levels from rising, or lower glucose among individuals with dysglycaemia should be evaluated.
Displaced unstable transverse fractures of the shaft of the proximal phalanx of the fingers in industrial workers: reduction and K-wire fixation leaving the metacarpophalangeal and proximal interphalangeal joints free
Authors: Al-Qattan Mohammad M.
Published: May 2011

A series of 35 adult male industrial workers with displaced unstable transverse fractures of the shaft of the proximal phalanx of the fingers were treated with reduction and K-wire fixation leaving the metacarpophalangeal and interphalangeal joints free to move immediately after surgery. At final follow-up, the total active motion score of the injured finger was graded as excellent, good, fair, or poor if it was greater than 240°, 220–240°, 180–219°, or less than 180°, respectively. Complications were also documented. The results were compared with our previously published series of these fractures treated with two other techniques: percutaneous K-wires immobilizing the metacarpophalangeal joint and open reduction and interosseous loop wire fixation. The final TAM scores in the current study were excellent in 43%, good in 29%, fair in 14% and poor in 14%. Four out of the 35 patients (11%) had minor pin tract infection. These results were significantly better than the results following percutaneous K-wire fixation immobilizing the metacarpophalangeal joint indicating that immediate mobilization of all joints has a significant effect on the outcome.
Estimating Cost Efficiency and the Technology Gap Ratio Using the Metafrontier Approach for Taiwanese International Tourist Hotels
Authors: Lin Yi-Hsing
Published: May 2011

Rather than estimating cost efficiency based on an assumption of identical frontiers, this paper uses a metafrontier model, which is developed based on the idea that different groups of hotels apply different technologies. The analysis is applied to the meta-cost efficiencies of sixty-two international tourist hotels in Taiwan from 2002 through 2006. Because the hotels operate under different circumstances, they can be said to use various production technologies. The analysis specifically tests the efficiency effects of three hotel management factors, namely, the type of guests (i.e., international travelers in the Taipei metropolitan hotels or local travelers in non-Taipei metropolitan properties), the size of hotel, and the management framework (i.e., independent, domestic chain, or international chain). The results show that conventional cost efficiency analysis overestimates the hotels’ efficiency. In contrast to previous studies, this analysis finds no significant difference in the average cost efficiencies of the Taipei metropolitan hotels compared to the non-Taipei metropolitan properties. However, the average cost efficiency of small-scale hotels is significantly higher than that of large-scale hotels. The average cost efficiency of domestic chain hotels is clearly higher than that of independent hotels, which is in turn higher than the average cost efficiency of international chain hotels.
Simulation of the structural modifications of a disc brake system to reduce brake squeal
Authors: Nouby M , Srinivasan K
Published: May 2011

The noise and vibration generated by the braking system in passenger cars are important technical and economic problems in the automotive industry. In recent years, the finite element (FE) method has been found to be a useful tool in predicting the occurrence of noise in a particular brake system during the design stage. This paper presents a more refined FE model of the disc brake corner that includes the wheel hub and steering knuckle. The model is an extension of earlier FE disc brake models. Experimental modal analysis of the disc brake system is initially used to validate the FE model. The unstable frequencies were then predicted by applying a complex eigenvalue analysis to the FE model. Finally, a number of structural modifications are made and simulated to evaluate brake squeal at the design stage. From the predicted results, it is found that the most significant improvements in brake squeal performance could be achieved by using an aluminium metal matrix composite brake rotor, steel calliper, and steel bracket. It is also found that a stiffer friction material with a diagonal slot could reduce the propensity for brake squeal.
Evaluation of variable mass moment of inertia of the piston–crank mechanism of an internal combustion engine
Authors: Bulatović Ž M , Tomić M V , Knežević D M , Cvetić M R
Published: May 2011

The current paper presents an original method for evaluating the variable mass moment of inertia of the piston–crank mechanism of an internal combustion engine based on the principle of kinetic energy equality of the real mechanism and its reduced model. The method has been developed to evaluate the variable mass moment of inertia of a 12-cylinder V-engine having a piston–crank mechanism with main and auxiliary connecting rods. In order to study the influence of the piston–crank mechanism configuration on mass moment of inertia variability, the procedure has been also applied on virtual ‘shortened’ variants: 2-cylinder and 6-cylinder V-engines with main and auxiliary connecting rods, and a 6-cylinder in-line engine with simple piston–crank mechanism. The results are compared with values obtained using the usual simple method for determining the approximate constant mass moment of inertia based on Huygens–Steiner theorem. It is shown that there is negligible difference between the constant value obtained by the simple method and the mean value of variable mass moment of inertia evaluated using the proposed model. Variability of mass moment of inertia is relatively small for a large number of cylinders, but it rises with cylinder number reduction. The presented method with appropriate modifications may be applied to any piston–crank mechanism arrangement.
A Review of Diagnostic Process and Postdiagnostic Support for People With Dementia in Rural Areas
Authors: Szymczynska Paulina , Innes Anthea , Mason Anne , Stark Cameron
Published: May 2011

Purpose: Early diagnosis of dementia allows the affected individuals to make plans, and helps services to identify and act on need. Previous work has suggested that obtaining an early diagnosis in rural areas can be difficult. This paper discusses diagnosis and postdiagnostic support for people with dementia, with a focus on service delivery in rural areas. Methods: A review of published English language literature 1999 to 2011 identified in Medline, PsycINFO, PubMed, Cochrane Library, and ScienceDirect. Results: Primary care services play a key role in accessing services in many health care systems. The role of primary care staff, and in particular general practitioners, is greatest in rural communities where specialist service access is often reduced. Despite this, rural staff often report limited training on supporting people with dementia. Postdiagnostic services can be more difficult to access in rural areas, and informal caregivers in rural areas can be more reluctant to seek such services. Transport difficulties and distance from specialist services can act as a barrier to service use. Memory services have been offered in both rural and urban areas. Conclusions: Addressing stigma, supporting staff, and signposting access are important in all areas, but seem to be particularly important in rural areas. Training and support for general staff in rural areas can be improved. Memory services provide one way of delivering services in rural areas. Service planners should take negative perceptions of dementia, barriers to access, and training of generalist service providers into account when designing dementia services in rural areas.
Antiangiogenic antitumor activities of IGFBP-3 are mediated by IGF-independent suppression of Erk1/2 activation and Egr-1–mediated transcriptional events
Authors: Kim Jai-Hyun , Choi Dong Soon , Lee Ok-Hee , Oh Seung-Hyun , Lippman Scott M. , Lee Ho-Young
Published: May 2011

Most antiangiogenic therapies currently being evaluated in clinical trials target the vascular endothelial growth factor pathway; however, the tumor vasculature can acquire resistance to vascular endothelial growth factor-targeted therapy by shifting to other angiogenesis mechanisms. Insulin-like growth factor binding protein-3 (IGFBP-3) has been reported to suppress tumor growth and angiogenesis by both IGF-dependent and IGF-independent mechanisms; however, understanding of its IGF-independent mechanisms is limited. We observed that IGFBP-3 blocked tumor angiogenesis and growth in non–small cell lung cancer and head and neck squamous cell carcinoma. Conditioned media from an IGFBP-3–treated non–small cell lung cancer cell line displayed a significantly decreased capacity to induce HUVEC proliferation and aortic sprouting. In cancer cells, IGFBP-3 directly interacted with Erk1/2, leading to inactivation of Erk1/2 and Elk-1, and suppressed transcription of early growth response protein 1 and its target genes, basic fibroblast growth factor and platelet-derived growth factor. These data suggest that IGF-independent Erk1/2 inactivation and decreased IGFBP-3–induced Egr-1 expression block the autocrine and paracrine loops of angiogenic factors in vascular endothelial and cancer cells. Together, these findings provide a molecular framework of IGFBP-3's IGF-independent antiangiogenic antitumor activities. Future studies are needed for development of IGFBP-3 as a new line of antiangiogengic cancer drug.
ArrayInitiative - a tool that simplifies creating custom Affymetrix CDFs
Authors: Overall Christopher C , Carr D Andrew , Tabari Ehsan S , Thompson Kevin J , Weller Jennifer W
Published: May 2011

Background

Probes on a microarray represent a frozen view of a genome and are quickly outdated when new sequencing studies extend our knowledge, resulting in significant measurement error when analyzing any microarray experiment. There are several bioinformatics approaches to improve probe assignments, but without in-house programming expertise, standardizing these custom array specifications as a usable file (e.g. as Affymetrix CDFs) is difficult, owing mostly to the complexity of the specification file format. However, without correctly standardized files there is a significant barrier for testing competing analysis approaches since this file is one of the required inputs for many commonly used algorithms. The need to test combinations of probe assignments and analysis algorithms led us to develop ArrayInitiative, a tool for creating and managing custom array specifications.

Results

ArrayInitiative is a standalone, cross-platform, rich client desktop application for creating correctly formatted, custom versions of manufacturer-provided (default) array specifications, requiring only minimal knowledge of the array specification rules and file formats. Users can import default array specifications, import probe sequences for a default array specification, design and import a custom array specification, export any array specification to multiple output formats, export the probe sequences for any array specification and browse high-level information about the microarray, such as version and number of probes. The initial release of ArrayInitiative supports the Affymetrix 3' IVT expression arrays we currently analyze, but as an open source application, we hope that others will contribute modules for other platforms.

Conclusions

ArrayInitiative allows researchers to create new array specifications, in a standard format, based upon their own requirements. This makes it easier to test competing design and analysis strategies that depend on probe definitions. Since the custom array specifications are easily exported to the manufacturer's standard format, researchers can analyze these customized microarray experiments using established software tools, such as those available in Bioconductor.
Origin of land plants: Do conjugating green algae hold the key?
Authors: Wodniok Sabina , Brinkmann Henner , Glöckner Gernot , Heidel Andrew J , Philippe Hervé , Melkonian Michael , Becker Burkhard
Published: May 2011

Background

The terrestrial habitat was colonized by the ancestors of modern land plants about 500 to 470 million years ago. Today it is widely accepted that land plants (embryophytes) evolved from streptophyte algae, also referred to as charophycean algae. The streptophyte algae are a paraphyletic group of green algae, ranging from unicellular flagellates to morphologically complex forms such as the stoneworts (Charales). For a better understanding of the evolution of land plants, it is of prime importance to identify the streptophyte algae that are the sister-group to the embryophytes. The Charales, the Coleochaetales or more recently the Zygnematales have been considered to be the sister group of the embryophytes However, despite many years of phylogenetic studies, this question has not been resolved and remains controversial.

Results

Here, we use a large data set of nuclear-encoded genes (129 proteins) from 40 green plant taxa (Viridiplantae) including 21 embryophytes and six streptophyte algae, representing all major streptophyte algal lineages, to investigate the phylogenetic relationships of streptophyte algae and embryophytes. Our phylogenetic analyses indicate that either the Zygnematales or a clade consisting of the Zygnematales and the Coleochaetales are the sister group to embryophytes.

Conclusions

Our analyses support the notion that the Charales are not the closest living relatives of embryophytes. Instead, the Zygnematales or a clade consisting of Zygnematales and Coleochaetales are most likely the sister group of embryophytes. Although this result is in agreement with a previously published phylogenetic study of chloroplast genomes, additional data are needed to confirm this conclusion. A Zygnematales/embryophyte sister group relationship has important implications for early land plant evolution. If substantiated, it should allow us to address important questions regarding the primary adaptations of viridiplants during the conquest of land. Clearly, the biology of the Zygnematales will receive renewed interest in the future.
Identification of novel target genes of nerve growth factor (NGF) in human mastocytoma cell line (HMC-1 (V560G c-Kit)) by transcriptome analysis
Authors: Dutta Priyanka , Koch Alexandra , Breyer Bjoern , Schneider Heike , Dittrich-Breiholz Oliver , Kracht Michael , Tamura Teruko
Published: May 2011

Background

Nerve growth factor (NGF) is a potent growth factor that plays a key role in neuronal cell differentiation and may also play a role in hematopoietic differentiation. It has been shown that NGF induced synergistic action for the colony formation of CD34 positive hematopoietic progenitor cells treated withmacrophage-colonystimulatingfactor (M-CSF or CSF-1), orstemcellfactor (SCF). However, the exact role of NGF in hematopoietic system is unclear. It is also not clear whether NGF mediated signals in hematopoietic cells are identical to those in neuronal cells.

Results

To study the signal transduction pathways induced by NGF treatment in hematopoietic cells, we utilized the mastocytoma cell line HMC-1(V560G c-Kit) which expresses the NGF receptor,tropomyosin-receptor-kinase (Trk)A, as well as the constitutively activated SCF receptor, V560G c-Kit, which can be inhibited completely by treatment with the potent tyrosine kinase inhibitor imatinib mesylate (imatinib). NGF rescues HMC-1(V560G c-Kit) cells from imatinib mediated cell death and promotes proliferation. To examine the NGF mediated proliferation and survival in these cells, we compared the NGF mediated upregulated genes (30 and 120 min after stimulation) to the downregulated genes by imatinib treatment (downregulation of c-Kit activity for 4 h) by transcriptome analysis. The following conclusions can be drawn from the microarray data: Firstly, gene expression profiling reveals 50% overlap of genes induced by NGF-TrkA with genes expressed downstream of V560G c-Kit. Secondly, NGF treatment does not enhance expression of genes involved in immune related functions that were down regulated by imatinib treatment. Thirdly, more than 55% of common upregulated genes are involved in cell proliferation and survival. Fourthly, we found Kruppel-like factor (KLF) 2 and Smad family member 7 (SMAD7) as the NGF mediated novel downstream genes in hematopoietic cells. Finally, the downregulation of KLF2 gene enhanced imatinib induced apoptosis.

Conclusion

NGF does not induce genes which are involved in immune related functions, but induces proliferation and survival signals in HMC-1(V560G c-Kit) cells. Furthermore, the current data provide novel candidate genes, KLF2 and SMAD7 which are induced by NGF/TrkA activation in hematopoietic cells. Since the depletion of KLF2 causes enhanced apoptosis of HMC-1(V560G c-Kit), KLF2 may play a role in the NGF mediated survival signal.
A comprehensive platform for highly multiplexed mammalian functional genetic screens
Authors: Ketela Troy , Heisler Lawrence E , Brown Kevin R , Ammar Ron , Kasimer Dahlia , Surendra Anuradha , Ericson Elke , Blakely Kim , Karamboulas Dina , Smith Andrew M , Durbic Tanja , Arnoldo Anthony , Cheung-Ong Kahlin , Koh Judice LY , Gopal Shuba , Cowley Glenn S , Yang Xiaoping , Grenier Jennifer K , Giaever Guri , Root David E , Moffat Jason , Nislow Corey
Published: May 2011

Background

Genome-wide screening in human and mouse cells using RNA interference and open reading frame over-expression libraries is rapidly becoming a viable experimental approach for many research labs. There are a variety of gene expression modulation libraries commercially available, however, detailed and validated protocols as well as the reagents necessary for deconvolving genome-scale gene screens using these libraries are lacking. As a solution, we designed a comprehensive platform for highly multiplexed functional genetic screens in human, mouse and yeast cells using popular, commercially available gene modulation libraries. The Gene Modulation Array Platform (GMAP) is a single microarray-based detection solution for deconvolution of loss and gain-of-function pooled screens.

Results

Experiments with specially constructed lentiviral-based plasmid pools containing ~78,000 shRNAs demonstrated that the GMAP is capable of deconvolving genome-wide shRNA "dropout" screens. Further experiments with a larger, ~90,000 shRNA pool demonstrate that equivalent results are obtained from plasmid pools and from genomic DNA derived from lentivirus infected cells. Parallel testing of large shRNA pools using GMAP and next-generation sequencing methods revealed that the two methods provide valid and complementary approaches to deconvolution of genome-wide shRNA screens. Additional experiments demonstrated that GMAP is equivalent to similar microarray-based products when used for deconvolution of open reading frame over-expression screens.

Conclusion

Herein, we demonstrate four major applications for the GMAP resource, including deconvolution of pooled RNAi screens in cells with at least 90,000 distinct shRNAs. We also provide detailed methodologies for pooled shRNA screen readout using GMAP and compare next-generation sequencing to GMAP (i.e. microarray) based deconvolution methods.