bluuebunny/crossref_metadata_2025 huggingface dataset:
Assessment of estrogenic potential of di-n-butyl phthalate and butyl benzyl phthalate in vivo
Authors: Ahmad Rahish , Verma Yogendra , Gautam Anil K , Kumar Sunil
Published: July 2013

Phthalate compounds are widely used industrial chemicals; when incorporated into polyvinyl chloride, they are not covalently bound and released into the surrounding media. Some of them have estrogenic potential in vitro but data on in vivo studies are scanty. For the 3-day uterotrophic assay, di- n-butyl phthalate (DBP;10 and 100 mg/kg), butyl benzyl phthalate (BBP; 20 and 200 mg/kg), and diethylstilbestrol (DES, 40 µg/kg, positive control) were administered orally to immature female rats for three consecutive days from postnatal day (PND) 21. For the 20-day pubertal onset assay, DBP (10 and 20 mg/kg), BBP (20 and 200 mg/kg), and DES (6 µg/kg) were administered orally from PND 21 daily for 20 days. In the uterotrophic assay, in groups treated with higher dose of DBP and BBP, the uterine wet weight significantly decreased in the higher dose, and there were minor variations in the ovary wet weight, while the wet weight of these organs increased significantly in DES-treated group. In the 20-day pubertal assay, the weight of uterus and ovary declined significantly and changes in vaginal weight were nonsignificant in DBP- and BBP-treated groups. However, in DES-treated group nonsignificant elevation in vagina weight was observed. All the DES-treated animals showed the vaginal opening (VO) on day 26.17 ± 0.16. However, VO was not observed in any of the animals in control, vehicle control, BBP-, and DBP-treated groups up to PND 42, except in one animal each in vehicle control and DBP (100 mg/kg)-treated groups. The data indicated that both DBP and BBP were unable to induce elevation in the uterine and ovarian weight. While DES treatment can accelerate the growth of uterus and ovary and alter the onset of puberty and estrous cyclicity in prepubertal rats. These suggest that these compounds may not have estrogenic potential in vivo.
Accumulation of Sensory Difficulties Predicts Fear of Falling in Older Women
Authors: Viljanen Anne , Kulmala Jenni , Rantakokko Merja , Koskenvuo Markku , Kaprio Jaakko , Rantanen Taina
Published: July 2013

Objectives: To explore whether the accumulation of sensory difficulties predicts fear of falling (FOF), and whether the traits correlate with each other regardless of familial factors. Methods: Self-reported hearing, vision and balance difficulties, and FOF were assessed using structured questionnaires at the baseline and after a 3-year follow-up in 63- to 76-year-old women ( n = 434). Results: Among the women without FOF at baseline ( n = 245), 41% reported FOF at follow-up. Increasing numbers of sensory difficulties at baseline predicted higher incidence of FOF. The relationship between accumulated sensory difficulties and FOF was not mediated by familial factors. Discussion: The accumulation of multiple sensory difficulties may hinder older people from receiving compensatory information about body position and environment, thus jeopardizing a person’s confidence in maintaining a balanced position. Regular screening of sensory functions followed by appropriate actions may prevent the development of FOF, and thus contribute to prevention of falls and promotion of healthy aging.
Liberalization, flexibility and industrial relations institutions: evidence from Italian and Greek banking
Authors: Kornelakis Andreas
Published: July 2013

The article seeks to explain how institutions change within varieties of capitalism, focusing on an important institution for the world of work: wage bargaining. Although there is a widespread expectation that liberalization and firms’ needs for flexibility brings convergence to the liberal market model of decentralized industrial relations, recent literature suggests that diversity persists and that there are a range of different responses. This article contributes to the debate by applying a coalitional perspective to highlight the factors that influence divergent trajectories of change in wage bargaining. The case studies of Italian and Greek banking suggest that the existence of ‘employer associability’ may moderate decentralizing tendencies and facilitate the reform of industrial relations institutions, while ‘labour–state coalitions’ are critical for the survival of institutions. Finally, the article discusses the findings in relation to wider debates in the comparative political economy of work.
Polymethyl methacrylate nanofiber-reinforced epoxy composite for shape-memory applications
Authors: Iyengar Prasanna Kumar , Bhat Kalambettu Aravind , Sangeetha Dharmalingam , Moorthy Tindivanam Vallam
Published: July 2013

Polymethyl methacrylate (PMMA) nanofiber-reinforced diglycidyl ether of bisphenol A shape memory epoxy composites were fabricated and their shape-memory properties were investigated. The PMMA nanofibers were found to be randomly distributed, while the tensile strength and Young’s modulus increased with increase in the percentage of PMMA. The glass transition temperature of the composites was found to decrease marginally with the addition of PMMA nanofibers. The shape recovery experiments showed that at low strain percentages, the composites exhibited excellent strain recovery. However, at higher strain percentages, the percentage of recovery was found to decrease gradually with increase in filler concentration.
Studies on thermal, mechanical, electrical, and morphological behavior of organoclay-reinforced polybenzoxazine–epoxy nanocomposites
Authors: Chozhan C. Karikal , Chandramohan Ayyavu , Alagar Muthukaruppan
Published: July 2013

Organoclay-reinforced polybenzoxazine–epoxy nanocomposites were prepared via in situ polymerization and thermal, thermomechanical, mechanical, electrical, and morphological properties were characterized by standard methods. Two types of skeletal-modified benzoxazines namely 1,1-bis(3-methyl-4-hydroxyphenyl)cyclohexane benzoxazine and bis(4-maleimidophenyl) benzoxazine were synthesized by reacting paraformaldehyde and 4,4′-diaminodiphenylmethane with 1,1-bis(3-methyl-4-hydroxyphenyl)cyclohexane and N-(4-hydroxyphenyl)maleimide, respectively. Diglycidyl ether bisphenol A epoxy resin was modified with 5, 10, and 15 wt% of benzoxazines and were cured using 4,4′-diaminodiphenylmethane at appropriate conditions. The occurrence of chemical reaction between benzoxazines and epoxy resin was ascertained by Fourier transform infrared spectra. Epoxy and benzoxazines-modified epoxy systems were further reinforced with 1, 3 and 5 wt% of organically modified montmorillonite (OMMT). Thermal behavior of matrices was characterized by differential scanning calorimetry, thermogravimetric analysis, and dynamic mechanical analysis. Mechanical properties were studied as per ASTM standards. The organoclay (OMMT)-reinforced polybenzoxazine–epoxy nanocomposites exhibited lower values of glass transition temperature and dielectric constant/dielectric loss with enhanced values of thermal stability, char yield, impact strength, and storage modulus than those of neat matrix. The morphology of organoclay-reinforced benzoxazine-modified epoxy matrix was studied by scanning electron microscopy, x-ray diffraction, and transmission electron microscopy analyses.
Effects of the ignition timing retard and the compression ratio on the full-load performance and the emissions characteristics of a heavy-duty engine fuelled by hydrogen–natural-gas blends
Authors: Park Cheolwoong , Lim Gihun , Lee Sungwon , Kim Changgi , Choi Young
Published: July 2013

Heavy-duty natural-gas vehicles contribute towards environmental improvement in the air quality of downtown areas because the particulate matter emissions are quite low and lean combustion facilitates improvement in the efficiency and reduction in the harmful emissions. However, because stronger emission regulations such as Euro VI cannot be satisfied using the current technology, new technology is required. Hydrogen–natural-gas blend engines have been investigated as an alternative in preparation for the hydrogen era. Such engines make further emission reductions and efficiency improvements possible by extending the lean-combustion limit. However, they do have some disadvantages such as the degradation in the full-load performance, which can limit the reduction in the nitrogen oxide emissions or the operation range because the extension of the lean-burn limit requires a larger amount of intake air even under a wide-open throttle operating condition. In the present study, the full-load performance and emissions characteristics of a hydrogen–compressed-natural-gas engine were evaluated using hydrogen–compressed-natural-gas fuel with a hydrogen content of 30 vol %. In order to achieve performance improvement, a spark timing retard strategy was employed, together with a change in the compression ratio. After examining the full-load performance for each parameter change, the emission characteristics were assessed to analyse the commercialization potential and feasibility of this hydrogen–compressed-natural-gas engine. For a higher compression ratio, the specified torque value could be achieved with spark timing retard; an excess air ratio of 1.8 was found to be preferable, and the nitrogen oxide emissions standard of Euro VI was satisfied.
Three-dimensional design method for mixed-flow pump blades with controllable blade wrap angle
Authors: Bing Hao , Cao Shuliang
Published: July 2013

In this article, a direct and inverse iteration design method for mixed-flow pumps was introduced, and a three-dimensional design platform for mixed-flow pumps was established. Through iteration calculation of two kinds of stream surfaces to solve both the continuity equation and motion equation of the fluid at the same time, and therefore obtaining the quasi-three-dimensional flow field inside the mixed-flow pump, the accuracy of the flow field calculation was improved. By repeating iteration of the direct calculation and inverse design, influence of blade shape on flow field calculation was fully considered, thus assuring that the final design of blade camber line complies with actual flow pattern. After comparing and analyzing the meridional velocity distribution, as well as the relative circulation distribution and expelling coefficient in the blade zone, it was proved that compared with others designed by conventional methods, the impeller designed with three-dimensional design platform has a better hydraulic performance, especially the blade energy conversion capacity that witnessed a significant improvement. With this three-dimensional design platform, a parametrization was applied to velocity moment distribution and blade leading and trailing edges positions. The influence of velocity moment distribution parameters P and a0, and the blade leading and trailing edges positions parameters θh and θt on blade wrap angle and the internal flow of the impeller were analyzed. By curve fitting, the functional relationship between blade wrap angle ϕ and parameters θt, P and a0 was obtained. The blade wrap angle control strategy during the process of mixed-flow pump impeller design was then put forward, thus realizing three-dimensional design of mixed-flow pump blades with controllable blade wrap angle. The performance test for the mixed-flow pump model suggested that the three-dimensional design method with controllable blade wrap angle, by controlling blade wrap angle size and adopting direct and inverse iteration design method, ensures a better hydraulic and cavitation performance for the mixed-flow pump impeller designed with three-dimensional design platform.
Modal tests on buildings: correlating large amounts of acquisitions with different space–time collocations
Authors: Garziera Rinaldo , Collini Luca , Manconi Elisabetta
Published: July 2013

This article deals with a method for the time and space superposition of data acquired in the dynamical testing of large structures. The method permits two procedures comprising the integration of sets of measurements taken at different times and the integration of sets of measurements taken at different places. The latter is a very useful feature when dealing with huge structures, such as big buildings comprising a number of different architectural details. The validation of this method is a case study consisting of many dynamical tests performed on an ancient castle.
Religious beliefs, knowledge about science and attitudes towards medical genetics
Authors: Allum Nick , Sibley Elissa , Sturgis Patrick , Stoneman Paul
Published: July 2013

The use of genetics in medical research is one of the most important avenues currently being explored to enhance human health. For some, the idea that we can intervene in the mechanisms of human existence at such a fundamental level can be at minimum worrying and at most repugnant. In particular, religious doctrines are likely to collide with the rapidly advancing capability for science to make such interventions. The key ingredient for acceptance of genetics, on the other hand, is prototypically assumed to be scientific literacy – familiarity and understanding of the critical facts and methods of science. However, this binary opposition between science and religion runs counter to what is often found in practice. In this paper, we examine the association between religiosity, science knowledge and attitudes to medical genetics amongst the British public. In particular, we test the hypothesis that religion acts as a ‘perceptual filter’ through which citizens acquire and use scientific knowledge in the formation of attitudes towards medical genetics in various ways.
Employee Reactions to Job Insecurity in a Declining Economy
Authors: Murphy Wendy Marcinkus , Burton James P. , Henagan Stephanie C. , Briscoe Jon P.
Published: July 2013

In the context of the Great Recession, we examined the relationships among perceptions of job insecurity, job embeddedness, and important individual work outcomes. Specifically, we tested the role of job embeddedness as a mediator between job insecurity and the withdrawal outcomes of intention to remain and job search behavior. Results of a longitudinal study of 115 working adults indicated that perceptions of job embeddedness fully mediated the relationship between perceptions of job insecurity and intention to remain and partially mediated job insecurity’s relationship with job search behavior.
Introducing specialization in e-commerce recommender systems
Authors: Palopoli Luigi , Rosaci Domenico , Sarnè Giuseppe ML
Published: July 2013

Currently, customers’ trading activities are supported by recommender tools that are able to generate personalized suggestions. Many of these recommenders are centralized, lacking in efficiency and scalability, while others are distributed and, conversely, imply a computational overhead on the client side being often excessive or even unacceptable for many devices. In this article, we propose a distributed recommender, based on a multi-tiered agent system, where the agents of each tier are specialized in a different e-commerce activity. The proposed system is capable of generating effective suggestions without a too onerous computational burden. In particular, we show that our system introduces significant advantages in terms of openness, privacy, and security.
Radiographic Correction of Stage III Posterior Tibial Tendon Dysfunction With a Modified Triple Arthrodesis
Authors: Mehta Siddhant K. , Kellum R. Bradley , Robertson George H. , Moore Allen Ryves , Wingerter Scott A. , Tarquinio Thom A.
Published: July 2013

Background:

The literature supports fusion as the surgical treatment of choice for stage III posterior tibial tendon dysfunction (PTTD). The present study reports the radiographic correction following a modified triple arthrodesis (fusions of the subtalar, talonavicular, and first tarsometatarsal joints) in patients with stage III PTTD.

Methods:

An institutional review board–approved retrospective study was performed to assess the radiographic outcome of a modified triple arthrodesis in 21 patients (22 feet). Pre- and postoperative weight-bearing radiographs were reviewed in a blinded fashion by clinicians of varying levels of training. The talo–first metatarsal, talocalcaneal, and talonavicular coverage angles were measured on anteroposterior views. On lateral views, the talo–first metatarsal (Meary’s), talocalcaneal, calcaneal pitch, and talar declination angles and the medial cuneiform to floor distance were measured. Statistical analysis was performed to compare pre- and postoperative measurements, assess the degree of correction, and determine interobserver reliability of the radiographic measurements.

Results:

All measurements improved significantly after treatment with a modified triple arthrodesis ( P ≤ .001). The medial cuneiform to floor distance (0.910), talonavicular coverage angle (0.896), and lateral talo–first metatarsal angle (0.873) were the most reproducible between observers. Postoperatively, 100% of feet were corrected to normal medial cuneiform to floor distance and talonavicular coverage angle, and 90.9% were corrected to a normal lateral talo–first metatarsal angle.

Conclusion:

The modified triple arthrodesis resulted in a reliable and reproducible correction of the deformity seen in rigid stage III PTTD.

Level of Evidence:

Level IV, case series.
Online monitoring and self-tuning control using pole placement method for active vibration control of a flexible beam
Authors: Saad Mohd Sazli , Jamaluddin Hishamuddin , Mat Darus Intan Zaurah
Published: July 2013

This paper presents the experimental results of online self-tuning pole placement control for active vibration of a flexible beam. The vibration is controlled using a piezoelectric actuator bonded on a flexible beam. An online computer control that runs on a PC-based control and its graphical user interface have been developed in such a way that the user can perform online monitoring and manipulation of control parameters of the active vibration control algorithm for a flexible beam system. The parameters of the pole placement controller have been self-tuned based on autoregression with an exogenous terms model of a bonded piezoelectric actuator beam identified via a recursive least square algorithm. A PC-based control system was implemented using a peripheral component interconnect data acquisition card and LABVIEW software. Results show that the online self-tuning pole placement control offers better transient performance over the fixed controller when tested at different tip loads. The control parameters have converged to a new value as the physical parameter of a flexible beam is changed.
Sliding mode control of a class of fractional chaotic systems in the presence of parameter perturbations
Authors: Xu Yong , Wang Hua , Liu Di , Huang Hui
Published: July 2013

This paper deals with a sliding mode control for a class of fractional uncertain chaotic systems under perturbations of parameters. A fractional integral sliding surface is proposed for fractional-order systems and then the sliding mode control technique is carried out to realize the control of the given systems. Based on Lyapunov stability theory, we theoretically verify that the controller is effective, and the designed control scheme can go against the system’s uncertainty to guarantee the property of asymptotical stability in the presence of parameter fluctuations. Later, two typical examples are illustrated numerically to show that the control approach in this paper is capable for any form of fractional-order uncertain systems.
Building a Solid Foundation for Sexual Violence Research
Authors: Backes Bethany L.
Published: July 2013

The extant research on sexual violence has developed into a substantial body of knowledge, in large part supported by federal funds from agencies such as the Centers for Disease Control and Prevention (CDC), the National Institute of Justice (NIJ), and National Institutes of Health (NIH) components. Overall, NIJ has dedicated over US$20 million in research funds to study sexual violence resulting in more than 60 studies and multiple topic-specific research-to-practice meetings. From an initial study on the criminal justice response to rape in 1973 to present-day initiatives on multidisciplinary responses, forensic sciences, and methodological queries, NIJ has made a significant contribution to current knowledge in the field of sexual violence. A strength of the program is its use of an interdisciplinary approach, encompassing the perspectives of those within the field of research and practice to guide the development of its research program. This article details the history and development of NIJ’s program of research, highlighting key studies and their contribution to the field, and provides a framework for the continued study of sexual violence.
A modified slip model for gas lubrication at nanoscale head-disk interface
Authors: Zhou Weidong , Yu Shengkai , Hua Wei , Myo Kyaw Sett
Published: July 2013

In this work, we derive a modified slip model for gas lubrication based on the effective viscosity concept and a kinetic-theory-based slip-boundary condition. A more accurate expression for the effective mean-free path is proposed, which can overcome the deficiency of other slip models in predicting effective mean-free path. In comparison with the existing slip models, such as the first, second, and 1.5-order slip models, the current slip model agrees well with F-K model over the entire flow regimes and therefore is expected to be more accurate for ultra-thin gas film lubrication at head-disk interface.
Use of mobile phone text messaging to deliver an individualized smoking behaviour intervention in Chinese adolescents
Authors: Shi Hui-Jing , Jiang Xiao-Xiao , Yu Chun-Yan , Zhang Yue
Published: July 2013

We evaluated the effectiveness of a mobile phone text-messaging based smoking cessation intervention package among Chinese adolescent smokers. Students aged 16–19 years were recruited from six vocational high schools located in Shanghai. We assigned the six schools to an intervention group or a control group by cluster randomization. The 92 participants in the intervention group were given tailored information via mobile phone text-messaging for 12 weeks. The 87 participants in the control group were provided with a self-help pamphlet about smoking cessation instead. After the intervention, attitudes towards the disadvantages of smoking were significantly improved, and the level of nicotine dependence and cigarette dependence significantly decreased in the intervention group. The intervention group had a relatively higher self-reported 7-day abstinence compared to the control group and 30-day abstinence, but the differences were not significant. However, the intervention group had a significantly higher rate of smoking reduction (66% vs. 35%) and moving forward in quitting stages (52% vs. 18%) compared to the control group. The interactive and tailored assistance provided by the mobile phone text-messaging was effective in smoking behaviour intervention in Chinese adolescent smokers.
Metalanguage: The ‘teacher talk’ of explicit literacy teaching in practice
Authors: Geoghegan Deborah , O’Neill Shirley , Petersen Shauna
Published: July 2013

Much has been written about what constitutes effective literacy teaching and learning, the power of effective ‘teacher talk’ and the impact on student learning outcomes. There is a growing body of research into pedagogical change to improve literacy outcomes and the implementation of schoolwide approaches to teaching and learning, particularly within the context of school improvement. This article ties together these two threads through the powerful stories of two primary schools that had undertaken a long-term school improvement project. The evidence of their explicit teaching of literacy is examined through investigation of the ‘teacher talk’ that occurs in classroom interactions and professional conversations. The way this talk reflects teachers’ shared pedagogical practices, their use of metalanguage for learning and students’ engagement is exemplified. It shows how, in each case, the pedagogical dialogue and literacy learning is mutually used by teachers and students in their literacy practices.
The feasibility of measuring social networks among older adults in assisted living and dementia special care units
Authors: Abbott Katherine M. , Bettger Janet Prvu , Hampton Keith N. , Kohler Hans-Peter
Published: July 2013

Background

Studies indicate that social integration has a significant influence on physical and mental health. Older adults experience an increased risk of social isolation as their social networks decline with fewer traditional opportunities to add new social relationships. Deaths of similar aged friends, cognitive and functional impairments, and relocating to a nursing home (NH) or assisted-living (AL) facility contribute to difficulties in maintaining one’s social network. Due to the paucity of research examining the social networks of people residing in AL and NH, this study was designed to develop and test the feasibility of using a combination of methodological approaches to capture social network data among older adults living in AL and a dementia special care unit NH.

Methods

Social network analysis of both egocentric and sociocentric networks was conducted to visualize the social networks of 15 residents of an AL neighborhood and 12 residents of a dementia special care unit NH and to calculate measures network size, centrality, and reciprocity.

Results

The combined egocentric and sociocentric method was feasible and provided a robust indicator of resident social networks highlighting individuals who were socially integrated as well as isolated.
Fluid management in diabetic ketoacidosis: are we adhering to recommended guidelines?
Authors: Freudenthal Robert , Tufton Nicola , Podesta Christine , Mulholland Rebecca , Rossi Michela
Published: July 2013

Introduction:

Diabetic ketoacidosis (DKA) is an acute complication of diabetes mellitus that requires prompt treatment. However delays in treatment are common and can have serious consequences. Local guidelines state all patients with DKA should receive intravenous fluids within 60 minutes. This audit series establishes if there is local adherence to this guideline.

Methods:

In total 111 cases were audited over four consecutive years. Case notes were identified retrospectively by clinical coding and notes were reviewed to establish the time between arrival to Accident and Emergency and administration of intravenous fluids.

Results:

In 2008, 17 of 29 patients who attended Accident and Emergency with DKA received intravenous fluids as per the guideline, 11 of 24 patients in 2009, 17 of 28 patients in 2010 whilst in 2011 20 of 27 patients received fluids as recommended.

Discussion:

Although this audit found that there have been improvements in administration of prompt intravenous fluids at Whittington hospital, there are still patients who do not receive this treatment as recommended. It remains to be seen if the introduction of bedside ketone testing will facilitate a speedier diagnosis and therefore more timely initiation of intravenous fluids.
Exploring Intimate Partner Violence Status Among Male Veterans and Associated Health Outcomes
Authors: Cerulli Catherine , Bossarte Robert M. , Dichter Melissa E.
Published: July 2013

The World Health Organization has identified intimate partner violence (IPV) as a public health issue affecting both men and women, though significantly more information is available regarding female victimization. This study examines IPV through the lens of male victimization, focusing on a comparison of physical and mental health consequences among men who are and are not military veterans. Results from a secondary analysis of data from the Behavior Risk Factor Survey taken by 13,765 males indicated that all males, regardless of veteran status, should be screened for IPV victimization given the prevalence reported in this sample (9.5% to 12.5%). Furthermore, it was found that veteran status did affect prevalence of particular health consequences, such as depression, smoking, and binge drinking. Based on the specific comparisons examined in this study, implications for Veteran’s Administration Health Services are discussed, as is the need for more research on IPV victimization rates for men and the particular health consequences that they suffer.
Quantitative Analysis of Qualitative Information From Interviews
Authors: Fakis Apostolos , Hilliam Rachel , Stoneley Helen , Townend Michael
Published: July 2013

Background: A systematic literature review was conducted on mixed methods area. Objectives: The overall aim was to explore how qualitative information from interviews has been analyzed using quantitative methods. Methods: A contemporary review was undertaken and based on a predefined protocol. The references were identified using inclusion and exclusion criteria and specific key terms in 11 search databases. Results: Evidence was synthesized from 14 references that included the methods used for quantifying qualitative information, analyzing it statistically and the rationale behind this. Gaps in the existing literature and recommendations for future research were identified. Conclusions: This review highlights the need for a new mixed method based on advanced statistical modeling method that will explore complex relationships arising from qualitative information.
Inference following designs which adjust for imbalances in prognostic factors
Authors: Barbáchano Yolanda , Coad D Stephen
Published: July 2013

Background

When the minimisation method due to Taves is used to balance treatment groups across prognostic factors, a problem arises at the time of analysing the results. Since minimisation is essentially a deterministic method, any statistical test based on the assumption of complete randomisation should not be used in the analysis. Previous articles have shown that analysis of covariance (ANOCOVA) produces valid tests.

Methods

In this article, these results are extended to trials with more than one prognostic factor and more than two treatments. An alternative design to minimisation which makes use of optimum design theory is also considered, with two choices of biased coin. Simulation is used to study the effect on the power and the coverage probabilities of the usual tests and confidence intervals when these different allocation methods are applied. The results are then illustrated using data from an actual clinical trial.

Results

Simulation shows that when ANOCOVA is used, it is sometimes more powerful with these designs than with minimisation and produces slightly conservative confidence intervals for the treatment mean differences. The increase in power and conservativeness is more pronounced when there are more prognostic factors. The possibility of treatment–covariate interactions is also addressed.

Limitations

Results are only given when treatment responses are normally distributed.

Conclusions

Under the simulated situations considered, when a covariate-adaptive design is used, the use of ANOCOVA yields a test which preserves the nominal significance level as compared to the conservativeness of analysis of variance.
On designing step-stress partially accelerated life tests under failure-censoring scheme
Authors: Ismail Ali A
Published: July 2013

In this article the maximum likelihood estimates of the model parameters under step-stress partially accelerated life tests (SSPALT) are obtained assuming the Weibull distribution with Type-II censored data. Also, the confidence bounds of the parameters are obtained. In addition, optimum step stress test plans are developed. The optimum test plan determines the optimal stress change point that minimizes the generalized asymptotic variance of the maximum likelihood estimators for the model parameters. That is, improving the quality of the statistical inference.
Age and the distance to crime
Authors: Andresen Martin A , Frank Richard , Felson Marcus
Published: July 2013

The journey-to-crime literature consistently shows that the distance to crime is short, particularly for violent crimes. Recent research has revealed methodological concerns regarding various (improper) groupings of data (nesting effects). In this article we investigate one such nesting effect: the relationship between age and the distance to crime. Contrary to much of the research that investigates this phenomenon, using a large incident-based data set of more than 100,000 crime trips, we find that the relationship between age and the distance to crime is best described as quadratic but this quadratic relationship is not universal across all crime classifications.
Combating Concentrated Poverty in Urban Neighborhoods
Authors: Wilson William Julius
Published: July 2013

Appearing a few months after the 25th anniversary of the publication of The Truly Disadvantaged, this article critically reflects on some of the more important research on the nature of concentrated poverty that specifically relates to the problem of neighborhood effects. The article then considers whether the response of the policy community has sufficiently addressed the challenges posed.
State-Mandated Principal Preparation Program Redesign
Authors: Phillips Joy C.
Published: July 2013

Increasing criticism of practicing educational leaders has led to additional critiques of the university programs in which they are prepared. In response, many states have mandated statewide university preparation program redesign. The articles in this special issue describe five unique cases of principal preparation program redesign—including both process and product—presented through the chronology of state-level policy development and local implementation. These five case studies establish a literature base that examines the following research questions: (a) Whether and to what degree did externally imposed redesign mandates influence substantive program changes, (b) How did university program faculty respond to the state mandates, and (c) To what degree did program redesign efforts reflect emerging empirical research guidelines on the characteristics of quality educational leadership programs?
Seeking Clarity in New Jersey for Leadership Preparation Program Design
Authors: Doolittle Gini
Published: July 2013

In 2004, the New Jersey Department of Education issued a mandate to the 17 leadership preparation program providers to revise their leadership preparation programs after completing a critical friends review. This case study explores the challenges, programmatic, and political experiences of one preparation program as state support dwindled. Presenting the pre- and postprogram designs, the case study provides an account of the program’s transition to an 8-week module, recently offered in face-to-face, hybrid online, and fully online formats. The case study concludes with a discussion of how diminishing state support exposes leadership preparation programs to external political forces.
The Roles of Mechanical Stresses in the Pathogenesis of Osteoarthritis
Authors: Buckwalter Joseph A. , Anderson Donald D. , Brown Thomas D. , Tochigi Yuki , Martin James A.
Published: July 2013

Excessive joint surface loadings, either single (acute impact event) or repetitive (cumulative contact stress), can cause the clinical syndrome of osteoarthritis (OA). Despite advances in treatment of injured joints, the risk of OA following joint injuries has not decreased in the past 50 years. Cumulative excessive articular surface contact stress that leads to OA results from posttraumatic joint incongruity and instability, and joint dysplasia, but may also cause OA in patients without known joint abnormalities. In vitro investigations show that excessive articular cartilage loading triggers release of reactive oxygen species (ROS) from mitochondria, and that these ROS cause chondrocyte death and matrix degradation. Preventing release of ROS or inhibiting their effects preserves chondrocytes and their matrix. Fibronectin fragments released from articular cartilage subjected to excessive loads also stimulate matrix degradation; inhibition of molecular pathways initiated by these fragments prevents this effect. Additionally, injured chondrocytes release alarmins that activate chondroprogentior cells in vitro that propogate and migrate to regions of damaged cartilage. These cells also release chemokines and cytokines that may contribute to inflammation that causes progressive cartilage loss. Distraction and motion of osteoarthritic human ankles can promote joint remodeling, decrease pain, and improve joint function in patients with end-stage posttraumatic OA. These advances in understanding of how altering mechanical stresses can lead to remodeling of osteoarthritic joints and how excessive stress causes loss of articular cartilage, including identification of mechanically induced mediators of cartilage loss, provide the basis for new biologic and mechanical approaches to the prevention and treatment of OA.
Acute endovascular repair of iatrogenic right internal carotid arterial laceration
Authors: Morken Marit Helene , Cappelen Johan , Kvistad Kjell Arne , Søvik Edmund , Stensæth Knut Haakon
Published: July 2013

Carotid arterial bleeding is a feared and possible life-threatening complication of transsphenoidal surgery. We present a case of a meningioma that during resection had a serious complication with laceration of the internal carotid artery (ICA). These patients rarely undergo endovascular treatment, with indications mainly due to the development of pseudoaneurysms or penetrating trauma. However, endovascular treatment with covered stents of carotid arterial bleedings is a feasible alternative due to technical advances and smaller sized stentgrafts that expand treatment options.
Housing Assistance
Authors: Baker Emma , Lester Laurence , Beer Andrew
Published: July 2013

In Australia, an increasing number of households face problems of access to suitable housing in the private market. In response, the Federal and State Governments share responsibility for providing housing assistance to these, mainly low-income, households. A broad range of policy instruments are used to provide and maintain housing assistance across all housing tenures, for example, assisting entry into homeownership, providing affordability assistance in the private rental market, and the provision of socially owned and managed housing options. Underlying each of these interventions is the premise that secure, affordable, and appropriate housing provides not only shelter but also a number of nonshelter benefits to individuals and their households. Although the nonshelter outcomes of housing are well acknowledged in Australia, the understanding of the nonshelter outcomes of housing assistance is less clear. This paper explores nonshelter outcomes of three of the major forms of housing assistance provided by Australian governments—low-income mortgage assistance, social housing, and private rent assistance. It is based upon analysis of a survey of 1,353 low-income recipients of housing assistance, and specifically measures the formulation of health and well-being, financial stress, and housing satisfaction outcomes across these three assistance types. We find clear evidence that health, finance, and housing satisfaction outcomes are associated with quite different factors for individuals in these three major housing assistance types.
Civic Engagement Scale
Authors: Doolittle Amy , Faul Anna C.
Published: July 2013

This study reports on the development and validation of the Civic Engagement Scale (CES). This scale is developed to be easily administered and useful to educators who are seeking to measure the attitudes and behaviors that have been affected by a service-learning experience. This instrument was administered as a validation study in a purposive sample of social work and education majors at three universities ( N = 513) with a return of 354 (69%). After the reliability and validity analysis was completed, the Attitude subscale was left with eight items and a Cronbach’s alpha level of .91. The Behavior subscale was left with six items and a Cronbach’s alpha level of .85. Principal component analysis indicated a two-dimensional scale with high loadings on both factors (mean factor loading for the attitude factor = .79, and mean factor loading for the behavior factor = .77). These results indicate that the CES is strong enough to recommend its use in educational settings. Preliminary use has demonstrated that this scale will be useful to researchers seeking to better understand the relationship of attitudes and behaviors with civic engagement in the service-learning setting. The primary limitations of this research are that the sample was limited to social work and education majors who were primarily White ( n = 312, 88.1%) and female ( n = 294, 83.1%). Therefore, further research would be needed to generalize this research to other populations.
A common 56-kilobase deletion in a primate-specific segmental duplication creates a novel butyrophilin-like protein
Authors: Aigner Johanna , Villatoro Sergi , Rabionet Raquel , Roquer Jaume , Jiménez-Conde Jordi , Martí Eulàlia , Estivill Xavier
Published: July 2013

Background

The Butyrophilin-like (BTNL) proteins are likely to play an important role in inflammation and immune response. Like the B7 protein family, many human and murine BTNL members have been shown to control T lymphocytes response, and polymorphisms in human BTNL2 have been linked to several inflammatory diseases, such as pulmonary sarcoidosis, inflammatory bowel disease and neonatal lupus.

Results

In this study we provide a comprehensive population, genomic and transcriptomic analysis of a 56-kb deletion copy number variant (CNV), located within two segmental duplications of two genes belonging to the BTNL family, namely BTNL8 and BTNL3. We confirm the presence of a novel BTNL8*3 fusion-protein product, and show an influence of the deletion variant on the expression level of several genes involved in immune function, including BTNL9, another member of the same family. Moreover, by genotyping HapMap and human diversity panel (HGDP) samples, we demonstrate a clear difference in the stratification of the BTNL8_BTNL3-del allele frequency between major continental human populations.

Conclusion

Despite tremendous progress in the field of structural variation, rather few CNVs have been functionally characterized so far. Here, we show clear functional consequences of a new deletion CNV (BTNL8_BTNL3-del) with potentially important implication in the human immune system and in inflammatory and proliferative disorders. In addition, the marked population differences found of BTNL8_BTNL3-del frequencies suggest that this deletion CNV might have evolved under positive selection due to environmental conditions in some populations, with potential phenotypic consequences.
Alpha tubulin genes from Leishmania braziliensis:genomic organization, gene structure and insights on their expression
Authors: Ramírez César A , Requena José M , Puerta Concepción J
Published: July 2013

Background

Alpha tubulin is a fundamental component of the cytoskeleton which is responsible for cell shape and is involved in cell division, ciliary and flagellar motility and intracellular transport. Alpha tubulin gene expression varies according to the morphological changes suffered by Leishmania in its life cycle. However, the objective of studying the mechanisms responsible for the differential expression has resulted to be a difficult task due to the complex genome organization of tubulin genes and to the non-conventional mechanisms of gene regulation operating in Leishmania.

Results

We started this work by analyzing the genomic organization of α-tubulin genes in the Leishmania braziliensis genome database. The genomic organization of L. braziliensis α-tubulin genes differs from that existing in the L. major and L. infantum genomes. Two loci containing α-tubulin genes were found in the chromosomes 13 and 29, even though the existence of sequence gaps does not allow knowing the exact number of genes at each locus. Southern blot assays showed that α-tubulin locus at chromosome 13 contains at least 8 gene copies, which are tandemly organized with a 2.08-kb repetition unit; the locus at chromosome 29 seems to contain a sole α-tubulin gene. In addition, it was found that L. braziliensis α-tubulin locus at chromosome 13 contains two types of α-tubulin genes differing in their 3′ UTR, each one presumably containing different regulatory motifs. It was also determined that the mRNA expression levels of these genes are controlled by post-transcriptional mechanisms tightly linked to the growth temperature. Moreover, the decrease in the α-tubulin mRNA abundance observed when promastigotes were cultured at 35°C was accompanied by parasite morphology alterations, similar to that occurring during the promastigote to amastigote differentiation.

Conclusions

Information found in the genome databases indicates that α-tubulin genes have been reorganized in a drastic manner along Leishmania speciation. In the L. braziliensis genome database, two loci containing α-tubulin sequences were found, but only the locus at chromosome 13 contains the prototypic α-tubulin genes, which are repeated in a head-to-tail manner. Also, we determined that the levels of α-tubulin mRNAs are down-regulated drastically in response to heat shock by a post-transcriptional mechanism which is dependent upon active protein synthesis.
The application of the Risdon approach for mandibular condyle fractures
Authors: Nam Seung Min , Lee Jang Hyun , Kim Jun Hyuk
Published: July 2013

Background

Many novel approaches to mandibular condyle fracture have been reported, but there is a relative lack of reports on the Risdon approach. In this study, the feasibility of the Risdon approach for condylar neck and subcondylar fractures of the mandible is demonstrated.

Methods

A review of patients with mandibular condylar neck and subcondylar fractures was performed from March 2008 to June 2012. A total of 25 patients, 19 males and 6 females, had 14 condylar neck fractures and 11 subcondylar fractures.

Results

All of the cases were reduced using the Risdon approach. For subcondylar fractures, reduction and fixation with plates was done under direct vision. For condylar neck fractures, reduction and fixation was done with the aid of a trochar in adults and a percutaneous threaded Kirschner wire in children. There were no malunions or nonunions revealed in follow-up care. Mild transient neuropraxia of the marginal mandibular nerve was seen in 4 patients, which was resolved within 1–2 months.

Conclusions

The Risdon approach is a technique for reducing the condylar neck and subcondylar fractures that is easy to perform and easy to learn. Its value in the reduction of mandibular condyle fractures should be emphasized.