bluuebunny/crossref_metadata_2025 huggingface dataset:
Male genes with nowhere to hide; sexual conflict in haplodiploids
Authors: Kraaijeveld Ken
Published: November 2009

Conflicts of interest between male and females over reproduction and gene expression are thought to be widespread among animals. However, most research on sexual conflict focuses on diploid, bisexual organisms. It is not obvious that the role of sexual conflict is the same in diploids as in organisms with different reprodutive systems. Here, I consider the potential for evolutionary change through sexual conflict in haplodiploids. As very little sexual conflict theory has been developed specifically for haplodiploids, I rely on the analogy between haplodiploid reproduction and X-chromosomal inheritance. The main conclusions are that the opportunity for between-locus sexual conflict should be the same for haplodiploids as for diploids, provided that the sexually antagonistic alleles involved are sex-limited from when they first appear. Empirical data testing this hypothesis are almost non-existent. The dynamics of within-locus sexual conflict are likely to differ strongly between haplodiploid and autosomal diploid genes depending on the dominance interactions between male and female alleles. In general, it is expected that this type of conflict will often be resolved in favour of females in haplodiploids. A number of factors, such as genomic imprinting and lack of recombination between male and female genomes may prevent this outcome.
Reduced egg laying caused by a male accessory gland product opens the possibility for sexual conflict in a simultaneous hermaphrodite
Authors: Koene Joris , Brouwer Annelies , Hoffer Jeroen
Published: November 2009

Promiscuity, sperm storage and internal fertilization enhance sperm competition, which leads to sexual conflict whenever an advantageous trait for sperm donors is harmful to recipients. In separate-sex species, such conflicts can severely impact the evolution of reproductive characteristics, physiology and behaviours. For simultaneous hermaphrodites, the generality of this impact remains unclear and underlying mechanisms remain largely unexplored. In the hermaphrodite Lymnaea stagnalis several previous studies showed that investment in eggs differs depending on semen receipt, but these were inconsistent about the direction of change. We investigated whether the change in egg laying is caused by a seminal fluid component. By intravaginally injecting animals, we here reveal that a component of the seminal fluid inhibits egg laying, thus providing the first direct evidence for involvement of such components in competition for fertilization in hermaphrodites. We discuss the broad implications that this finding has on a number of previous studies performed in the same species.
Sexual conflict in humans: evolutionary consequences of asymmetric parental investment and paternity uncertainty
Authors: Goetz Aaron , Shackelford Todd
Published: November 2009

We argue that sexual conflict was a recurrent feature of human evolutionary history, just as it has been in every sexually reproducing species that does not practice life-long genetic monogamy. We suggest that the source of much of the conflict between men and women can be reduced to an asymmetry in reproductive biology. This asymmetry—fertilization and gestation occurring within women—produces (a) sex differences in minimum obligatory parental investment and (b) paternity uncertainty. We argue that these consequences of internal fertilization and gestation are responsible for many phenomena in humans, such as sexual coercion, commitment skepticism, sexual overperception, and a host of adaptations associated with sperm competition.
Political Scale and Electoral Turnout: Evidence From the Less Industrialized World
Authors: Remmer Karen L.
Published: November 2009

This article attempts to bring the politics of scale back into the study of comparative politics. Explicitly focusing on the question of electoral turnout in the less industrialized world, it explores the impact of variations in community size relative to other influences on citizen participation. The findings, which draw on both aggregate and individual-level data at the subnational level of analysis, offer considerable evidence that electoral participation declines with community size, but for reasons largely neglected by most prior literature on electoral turnout. The central theoretical conclusion is that future comparative research needs to address the role of political scale more directly and systematically.
PDK1 Regulates Chemotaxis in Human Neutrophils
Authors: Yagi M. , Kantarci A. , Iwata T. , Omori K. , Ayilavarapu S. , Ito K. , Hasturk H. , Van Dyke T.E.
Published: November 2009

Phosphoinositide-dependent kinase (PDK1) plays a central role in signal transduction mediated by phosphatidylinositol 3-kinases (PI3K) and regulates cellular functions in neutrophils. Neutrophils from individuals diagnosed with localized aggressive periodontitis (LAP) present an in vivo phenotype with depressed chemotaxis. The aim of this study was to test the hypothesis that PDK1 regulates chemotaxis in neutrophils and is responsible for the abnormal neutrophil chemotaxis LAP. Neutrophil chemotaxis was significantly suppressed by the PDK1 inhibitor staurosporine. When cells were transfected with PDK1 siRNA, there was a significant reduction in chemotaxis, while superoxide generation was not significantly affected. In primary neutrophils from persons with LAP, PDK1 expression and activation levels were significantly reduced, and this reduction was associated with the reduced phosphorylation of Akt (Thr308) and chemotaxis. Analysis of these data demonstrates that PDK1 is essential for the chemotactic migration of neutrophils, and in the absence of PDK1, neutrophil chemotaxis is impaired.
Genetic Risk Factors for Periodontitis in a Japanese Population
Authors: Kobayashi T. , Nagata T. , Murakami S. , Takashiba S. , Kurihara H. , Izumi Y. , Numabe Y. , Watanabe H. , Kataoka M. , Nagai A. , Hayashi J. , Ohyama H. , Okamatsu Y. , Inagaki Y. , Tai H. , Yoshie H.
Published: November 2009

Genetic variants at multiple loci have been shown to be associated with susceptibility to periodontitis. To better assess the genetic risk factors for periodontitis, we performed a case-control study in 319 Japanese individuals with periodontitis (172 aggressive and 147 chronic disease) and 303 race-matched healthy control individuals. Thirty-five functional gene polymorphisms that had been previously associated with immune responses were genotyped. For all gene polymorphisms tested, no significant differences were observed in the allele frequencies of persons with aggressive, chronic, and combined (aggressive and chronic) periodontitis, compared with control individuals. Multiple logistic regression analysis revealed a significant association of the vitamin D receptor +1056 T/C polymorphism with susceptibility to chronic periodontitis, after adjustment for age, gender, and smoking status (P = 0.002). These results suggest that none of the polymorphisms tested was strongly associated with periodontitis in a Japanese population. However, the vitamin D receptor +1056 polymorphism may be related to chronic periodontitis.
Effects of Chemical Cross-linkers on Caries-affected Dentin Bonding
Authors: Macedo G.V. , Yamauchi M. , Bedran-Russo A.K.
Published: November 2009

The achievement of a strong and stable bond between composite resin and dentin remains a challenge in restorative dentistry. Over the past two decades, dental materials have been substantially improved, with better handling and bonding characteristics. However, little attention has been paid to the contribution of collagen structure/stability to bond strength. We hypothesized that the induction of cross-linking in dentin collagen improves dentin collagen stability and bond strength. This study investigated the effects of glutaraldehyde-and grape seed extract-induced cross-linking on the dentin bond strengths of sound and caries-affected dentin, and on the stability of dentin collagen. Our results demonstrated that the application of chemical cross-linking agents to etched dentin prior to bonding procedures significantly enhanced the dentin bond strengths of caries-affected and sound dentin. Glutaraldehyde and grape seed extract significantly increased dentin collagen stability in sound and caries-affected dentin, likely via distinct mechanisms.
An Application of a Stated Preference Method to Value Urban Amenities
Authors: Howie Peter , Murphy Sean M. , Wicks John
Published: November 2009

This is a case study analysis of how residents value the amenities of a small US city—Missoula, Montana. A measure of a community’s amenity values is needed in city planning so as to protect those elements of urban communities that are highly valued. Missoulians favoured their local amenities against an average of 30 comparison cities. Results from this study’s stated preference model indicate that Missoulians highly value amenities such as outdoor recreation, low population density and scenery; whereas, they are generally willing to tolerate less than average levels of job opportunities. The study’s results raise questions about the appropriate methods for local governments to pursue when attempting to raise wage rates by ‘growing the economy’ of a city like Missoula.
The Occupation—Industry Mismatch: New Trajectories for Regional Cluster Analysis and Economic Development
Authors: Currid Elizabeth , Stolarick Kevin
Published: November 2009

This article is a natural extension of the current discussion on occupational clustering and economic growth. It is argued that, while there has been increased interest in the role of occupations, little has been done from a methodological and empirical approach to discover how the study of occupations can illuminate the study of industry. Prior work in cluster analysis has generally taken an ‘either/or’ approach towards occupational and industrial analysis. Porter’s clustering model has illuminated the cross-fertilising linkages across industries, but this is only half the story. It is argued that what drives these clusters is not only the industry, but also the people and their occupational skills and, therefore, such analysis must be expanded. Using the case of the IT sector in Los Angeles, the industry approach is combined with an ‘occupational cluster analysis’. It is concluded that this approach leads to a better understanding of regional competitiveness and growth.
An Industry Perspective on the Utility of Short-Term Carcinogenicity Testing in Transgenic Mice in Pharmaceutical Development
Authors: Storer Richard D. , Sistare Frank D. , Vijayaraj Reddy M. , Degeorge Joseph J.
Published: November 2009

International guidelines allow for use of a short-term cancer bioassay (twenty-six weeks) in transgenic mice as a substitute for one of the two required long-term rodent bioassays in the preclinical safety evaluation of pharmaceuticals. The two models that have gained the widest acceptance by sponsors and regulatory authorities are the CB6F1-RasH2 mouse hemizygous for a human H-ras transgene and the B6.129N5-Trp53 mouse heterozygous for a p53 null allele. The p53+/- model is of particular value for compounds with residual concern that genotoxic activity may contribute to tumorigenesis. The rasH2 model is an appropriate alternative without regard to evidence of genotoxic potential. Since results from a short-term bioassay can be obtained relatively early in drug development, there is the potential for more timely assessment of cancer risk for individuals in long-term clinical trials. Use of these models in preclinical safety evaluation also significantly reduces animal use, time, and manpower. Preliminary findings indicate that prediction of two-year rat bioassay outcomes based on data from chronic rat toxicity studies, together with early assessment of carcinogenic potential in short-term transgenic models, may have the potential to increase the timeliness and efficiency of strategies for the identification of human carcinogenic hazards.
The Changing Urban Landscapes of Media Consumption and Production
Authors: Hartmann Maren
Published: November 2009

■ Questions of change have always been at the forefront of the social sciences. The article addresses the question of the adequacy of media and communication studies theories through looking at change in both a concrete environment and more generally in terms of linking this example with wider debates concerning social changes in the world of work. The example stems from a study on Wi-Fi cafe environments, in which work does play an important role. To introduce this topic, the article begins by discussing cafe environments overall and Wi-Fi cafes in particular, as well as the seemingly old-fashioned concept of telework. It then briefly presents the study as such, before discussing possible frameworks: the question of the public sphere on the one hand and of concpets such as ‘digital bohème’ to describe emerging work forms on the other hand. The latter is taken to be the more appropriate framework. This is also the answer to the question of which media and communication studies theories appear to be adequate for analysing such changes. ■
Media Industries, Work and Life
Authors: Deuze Mark
Published: November 2009

■ Convergence culture, as a concept, articulates a shift in the way global media industries operate, and how people as audiences interact with them. It recognizes contemporary media culture as a primarily participatory culture. In turn, this assumption renders notions of production and consumption of (mass, mediated) culture not just theoretically problematic — as has been established earlier in disciplines as varied as communication studies, cultural geography and media anthropology — but also less than useful on a practical level when making sense of the role media play in people’s everyday lives. This paper explores the practical applications of convergence culture from the perspectives of media workers, suggesting not so much the use of ‘new’ categories, but rather an alignment of production, mediation and consumption as constituent practices in all experience of (in) media life. ■
Participation Is Not Enough
Authors: Carpentier Nico
Published: November 2009

■ The popularization of ‘new’ Internet-based media has generated much optimism about the social and participatory-democratic potentialities of these media, leading to predictions about the demise of the mass communication paradigm, and its replacement by a many-to-many communicative paradigm. But as happened before, the reappraisal of participation also produced a number of theoretical, conceptual and empirical problems. Participation became (at least partially) an object of celebration, trapped in a reductionist discourse of novelty, detached from the reception of its audiences and decontextualized from its political-ideological, communicative-cultural and communicative-structural contexts. These celebratory perspectives on participation cover how some of the basic concepts of the mass communication paradigm are still very much alive, providing the discursive frameworks for the reception of old and new media products. This article aims to show the persistence of (a number of components of) the mass communication paradigm through an analysis of the reception of two north Belgian participatory media products. One of these case studies is based on the ‘new’ world of a YouTube-like online platform called 16plus; the second case study is based on the ‘old’ concept of access television in a 2002 TV programme called Barometer. Through an analysis of these multilayered audience receptions, this article shows that participatory practices are not unconditionally appreciated by audience members, but are subject to specific conditions of possibility that are still embedded within the mass communication paradigm. Albeit in different degrees, these case studies show the importance of two ‘old’ key concepts — professional quality and social relevance — for these audiences’ evaluation of participatory practices. ■
Using Desktop Videoconferencing to Deliver Interventions to a Preschool Student With Autism
Authors: Gibson Jason L. , Pennington Robert C. , Stenhoff Donald M. , Hopper Jessica S.
Published: November 2009

The purpose of this study is to evaluate the impact of functional communication training on elopement when consultation support is delivered via desktop videoconferencing. An ABAB design was used to evaluate the effectiveness of functional communication training to reduce the elopement of a preschool student with autism. Intervention development, teacher training, and data collection were conducted at a distance using technology. Results show that the teaching staff was able to implement the intervention with a high degree of fidelity and that elopement was significantly reduced during intervention phases. The authors discuss the implications of using desktop videoconferencing to deliver consultation support, along with future applications in early childhood settings.
Scale Economies in American Retailing: A Cross-Industry Comparison
Authors: Ingene Charles A.
Published: November 2009

Determination of the nature and scope of competition in the channel of distribution is of increasing interest to macromarketers because of the growing importance of marketing in the American economy. This competition is influenced by many factors, among which is the extent of scale economies. This article investigates economies of scale in retailing from both a conceptual and an empirical perspective. This represents the first stage in an analysis of competition in retailing and, ultimately, throughout the channel of distribution.
Human Resources Management in a Changing World: Reassessing Public Human Resources Management Education
Authors: Llorens Jared J. , Battaglio R. Paul
Published: November 2009

Public administration scholars have gone to great lengths to assess both the extent of personnel reform efforts across the public sector and their impact on employee attitudes toward public sector employment. However, to the degree that these reforms represent the future of public sector human resources management (HRM), the field has yet to fully address how the education of future public servants and human resources professionals should be adjusted to reflect this transformation. This article seeks to address this issue by reevaluating those subject areas and competencies that have long been considered the core of public sector HRM education, proposing what new competencies should be introduced into the core in light of the contemporary reform environment and providing a preliminary assessment of the extent to which contemporary academic and practitioner-based educational programs reflect the current landscape of public sector HRM.
The Health Impact of a Hearing Disability on Older People in Australia
Authors: Hogan Anthony , O'Loughlin Kate , Miller Peta , Kendig Hal
Published: November 2009

Objectives: A series of studies has proposed that hearing loss has adverse effects for other aspects of health. This article examines the health effects associated with self-reported hearing disability on older people. Methods: The study utilized the 2003 Australian Survey of Disability, Ageing, and Carers ( n = 43,233), a weighted population-based survey providing data on self-reported disability and quality of life, to examine hearing disability among older Australians (55 years plus). Results: Of the estimated 654,113 people reporting hearing disability, 71% experienced limited communication and 60% used hearing aids. Compared with population norms, hearing disability at all levels was associated with poorer physical and mental health scores on the SF-12 measure, especially for people with severe or profound hearing loss, thus suggesting a threshold effect at advanced levels of disability. Discussion: Data support emerging literature suggesting a causal relationship between hearing disability and quality of life. Prospective studies to further examine this relationship are indicated.
The Adult Body: How Age, Gender, and Body Mass Index Are Related to Body Image
Authors: Ålgars Monica , Santtila Pekka , Varjonen Markus , Witting Katarina , Johansson Ada , Jern Patrick , Sandnabba N. Kenneth
Published: November 2009

Objectives: Body image and perceived attractiveness were examined, and the impact of age, gender, and body mass index (BMI) was analyzed and discussed from an evolutionary and a sociocultural perspective. Method: The population-based sample consisted of 11,468 Finnish men and women aged 18 to 49 years. Results: Both age-related decrease and increase in body satisfaction was detected as well as interactions between age and gender. Some effects were nonlinear. Women were generally less satisfied with their bodies than men. BMI had a stronger influence on women’s body image than men’s. Discussion: It was proposed that it is insufficient to merely study how age affects general body image because adults might become more satisfied with some aspects of their bodies as a function of age and less satisfied with other aspects. Body satisfaction might also fluctuate during different phases of the adult life, and the patterns possibly differ between men and women.
The Relationship Between Obesity, Physical Activity, and Physical Function in Older Adults
Authors: Riebe Deborah , Blissmer Bryan J. , Greaney Mary L. , Ewing Garber Carol , Lees Faith D. , Clark Philip G.
Published: November 2009

Objective: This study investigated the relationship between overweight and obesity, age, and gender with physical activity and physical function in community-dwelling older men and women. Method: Multivariate analysis of covariance was used to analyze differences between normal weight, overweight, and obese adults ( n = 821) above the age of 60 years. Results: Obesity but not overweight was associated with lower levels of physical activity and physical function. Within BMI groups, individuals who were physically active were less likely to have abnormal physical function scores compared to those who were sedentary. Compared to men, obese women had lower physical function scores, placing them at higher risk for future disability. Aging was associated with lower levels of physical activity and physical function. Discussion: The study illustrates the importance of avoiding obesity and participating in regular physical activity to prevent or slow down the loss of functioning in older age.
The Effects of Developing a Dual Sensory Loss on Depression in Older Adults: A Longitudinal Study
Authors: Capella McDonnall Michele
Published: November 2009

Objectives: To determine the effect of developing a dual sensory loss (DSL) on depression over time and evaluate the impact of preexisting single sensory loss on this effect. Method: Multilevel modeling was used to analyze data ( N = 2,689) from the Health and Retirement Study. Results: A significant increase in depression at the first report of DSL occurred, and depression increased at a significantly faster rate following DSL, in a curvilinear pattern. In addition, persons who eventually developed DSL began the study with a depression score significantly higher than persons who did not experience sensory loss. A preexisting single sensory loss did not alter the effect of DSL on depression. Discussion: Two sources of disparity in depression between persons with and without DSL were identified: preexisting differences and differences that occurred due to the DSL. The relationship exhibited between depression and developing a DSL indicated an adjustment process.
Blaming Europe? Exploring the variable impact of national public service dissatisfaction on EU trust
Authors: Kumlin Staffan
Published: November 2009

European Social Survey data suggest that dissatisfaction with national public services has direct negative effects on EU trust in most EU15 countries, but also that there is significant country variation in their actual magnitude. Two-thirds of this variation can be explained jointly by two macro factors: the effect is stronger in larger welfare states where elites and citizens may perceive EU-induced obstacles for welfare state expansion. Likewise, it is stronger in political systems where the most Eurosceptic parties have tended to be the most welfare state-supporting ones. Under such conditions, it is more probable that citizens receive political cues conducive to a negative effect of dissatisfaction on EU trust.
Exploring the pathways of inequality in health, health care access and financing in decentralized Spain
Authors: Costa-Font Joan , Gil Joan
Published: November 2009

The regional organization of the Spanish national health system offers a ‘unique field’ for exploring the sources of health inequalities as well as for testing the effects of political decentralization on health and healthcare inequalities. Drawing from the results of an empirical analysis where inequalities in three dimensions of health (outcome), healthcare (access) and healthcare payments (financing) are estimated, this article first explores the association between three such inequality dimensions alongside other system and socio-economic controls. Second, we examine whether the first wave of asymmetric healthcare devolution which took place in Spain between (1980—2001) — whereby health policy responsibilities were transferred to a few region states (autonomous communities [ACs]) — correlates with higher inequalities in health, healthcare and health financing. Our findings suggest that inequalities in health and healthcare appear to be driven by income inequalities and inequalities in use but not by inequalities in financing and health expenditure. Region states politically responsible for the organization of healthcare did not exhibit significant differences in health and healthcare inequalities and tend to exhibit a better equity performance.
Transgender People in Australia and New Zealand: Health, Well-being and Access to Health Services
Authors: Pitts Marian K. , Couch Murray , Mulcare Hunter , Croy Samantha , Mitchell Anne
Published: November 2009

This research had its beginnings in an act of trans activism, including a campaign by a number of trans organizations advocating the need for research dealing with health, well-being and access to health services in relation to this population. This study set out to recruit the broadest possible community sample by using a range of recruitment techniques and an online survey. In total, 253 respondents completed the survey. Of these, 229 were from Australia (90.5%) and 24 (9.5%) were from New Zealand. Respondents rated their health on a five-point scale; the majority of the sample rated their health as ‘good’ or ‘very good’. On the SF36 scale, respondents had poorer health ratings than the general population in Australia and New Zealand. Respondents reported rates of depression much higher than those found in the general Australian population, with assigned males being twice as likely to experience depression as assigned females. Respondents who had experienced greater discrimination were more likely to report being currently depressed. Respondents were asked about their best and worst experiences with a health practitioner or health service in relation to being trans. They contrasted encounters where they felt accepted and supported by their practitioners with others where they were met with hostility.
Understandings of Cervical Screening in Sexual Minority Women: A Q-Methodological Study
Authors: Darwin Zoë , Campbell Carol
Published: November 2009

Discursive perspectives argue that cervical screening carries social and moral meaning. Overlooked by research into the health needs of sexual minority women, previous literature that has examined uptake of cervical screening has instead targeted increasing attendance via information and service provision. In order to explore the diversity of meanings that British sexual minority women have about cervical screening, the Q-sorts of 34 sexual minority women were factor analysed by-person and rotated to simple structure using Varimax. The five factors are interpreted and discussed relative to competing discourses on information provision within cervical screening. The five accounts are labelled ‘cervical screening is’: an essential health check that women have the right to refuse; a woman’s health entitlement; a vital test but degrading experience; a sensible thing to do; and an unnecessary imposition for some women. Critical approaches to informed choice are explored with attention to recent developments in cervical cancer prevention. Findings highlighting the need for affirmation of diversity within healthcare are considered in relation to existing criteria for UK national screening programmes.
Some statistical issues in the design of HIV-1 vaccine and treatment trials
Authors: Gilbert Peter B
Published: November 2009

This article summarizes material on statistical issues in the design of HIV-1 preventive vaccine trials and antiretroviral HIV-1 treatment trials that was presented at the first school on Modern Statistical Methods in Medical Research, held at the International Centre for Theoretical Physics in Trieste, in September 1999. Design issues for the two trial types are discussed separately and are compared, which highlights the relative complexity of vaccine trials. Vaccine trial designs for assessing various vaccine effects are considered, including classical double-blind individual-randomized designs for evaluating biological vaccine effects on susceptibility to infection, and augmented partners, cluster-randomized, and infant designs for evaluating biological vaccine effects on infectiousness as well as on susceptibility. Within these designs, covered topics include surrogate endpoints for measuring vaccine effects on secondary transmission and on HIV-1 disease progression, and exploratory and confirmatory methods for assessing host immune and viral genotypic or phenotypic correlates of vaccine protection against infection or disease. For antiretroviral trials, covered topics include endpoint selection and structured designs such as fractional factorial and Latin square designs for rapidly screening combination drug regimens and for identifying patterns of HIV-1 genomic evolution that predict loss of drug efficacy.
Ticks and tick-borne diseases: a vector-host interaction model for the brown ear tick (Rhipicephalus appendiculatus)
Authors: Mwambi H G , Baumgärtner J , Hadeler K P
Published: November 2009

An analytical model is derived for the interaction of the brown ear tick ( Rhipicephalus appendiculatus) with its hosts. Such models are rare due to the complexity and lack of information on the entire stages of ticks life cycles. Most models are simulations rather than analytical. The vector is categorized into a discrete number of compartments according to its life cycle. The starting model in this article consists of a system of differential equations with constant coefficients. A general model on a stage structured population with unlimited host density is developed. From the characteristic polynomial of the system a sensitivity analysis for the population parameters is carried out in detail. The model is then improved by incorporating host abundance and availability. This is done on the basis of a demand-driven and ratio-dependent functional response model. The improved model adequately represents the dynamics of a stage-structured vector population under conditions of varying host density. The model allows the qualitative evaluation of several management strategies and is expected to guide future research work.
Development of 3-DOF Soft Manipulator with ER Fluid Clutches
Authors: Boku Kazuhiko , Nakamura Taro
Published: November 2009

With robots and users more commonly sharing space such as in the fields of medicine and home automation, the possibility of a physical collision has increased, even though many robots use actuators with high-ratio gear trains to minimize the effects of impact. We developed a 3-DOF manipulator having a smart flexible joint using an ER fluid and a sensor-equipped pneumatic cushion. Results of position control and collision experiments using the manipulator demonstrated its effectiveness.
Magnetorheological Fluid in Oscillatory Shear and Parameterization with Regard to MR Device Properties
Authors: Laun H.M. , Gabriel C. , Kieburg Ch.
Published: November 2009

Storage and loss moduli of an MRF submitted to a magnetic field, as measured by a plate—plate magnetorheometer versus shear amplitude in oscillatory shear, exhibit a complex non-linear response. Above a critical amplitude, the storage modulus decreases strongly, while the loss modulus passes through a distinct maximum. The periodic shear stress signal changes from sinusoidal to saw-tooth like. A mechanical analogue, consisting of a Bingham element (friction element and damper arranged in parallel) and elastic spring in series, is capable to capture the measured behaviour. Model predictions for the time-dependent shear stress and resulting moduli at agitation frequency (fundamental mode) for various amplitudes are discussed and the determination of model parameters from the experimental data is addressed. The linear radial shear strain profile in plate—plate geometry causes a smearing of the moduli and shift to higher amplitudes by about a factor of 4/3. The conversion from physical to engineering parameters for an MR device is demonstrated for disk clutches using cone—plate and plate—plate geometry. Complications due to a nonhomogeneous shear in the device are addressed. The elastic modulus of the MRF may be relevant for vibration damping and may cause some shift in the resonance frequency of the device.
Performance of Magnetorheological Fluids in a Novel Damper with Excellent Fail-safe Behavior
Authors: Boese Holger , Ehrlich Johannes
Published: November 2009

A novel magnetorheological (MR) damper, whose magnetic circuit contains two permanent magnets apart from an electromagnet, is described and tested. Without any consumption of electric energy, a medium damping force is achieved, which ensures an excellent fail-safe behavior in case of an electric power loss. This medium damping force can be increased or decreased, depending on the polarity of the current in the coil. The influence of the composition of the MR fluid in terms of the concentration of iron particles between 20 and 50 vol.% on the damping force and frequency dependency could be evaluated. Finally, the damping force after various storage times of the damper was studied and indicated a good redispersibility of the MR fluid.
Tailoring the Response Time of Shape Memory Alloy Wires through Active Cooling and Pre-stress
Authors: Tadesse Yonas , Thayer Nicholas , Priya Shashank
Published: November 2009

Application of shape memory alloy (SMA) actuators is limited to low frequencies due to slow cooling time especially in the embedded conditions where heat transfer rate is the controlling factor. In this study, we investigate various active cooling techniques and effect of pre-stress to improve the response time of two commercially available SMAs: Flexinol from Dynalloy Inc. and Biometal fiber from Toki Corporation. Flexinol and Biometal fiber of equal length and diameter were found to exhibit different actuation behavior under pre-stress. Time domain force response of SMA actuators was found to be dependent upon the applied pre-stress, heating rate, and amplitude of applied electrical stimulus. Compared to Biometal fibers, time domain response of Flexinol was found to decrease significantly with increasing pre-stress indicating the difference in transformation behavior. Fluid flow and heat sinking were found to be suitable methods for improving the response time by reducing the cooling cycle from 1.6 s to 0.30—0.45 s. This is a significant improvement in the actuation capability of SMAs.
Design and Characterization of a Biomimetic Piezoelectric Pump Inspired on Group Fish Swimming Effect
Authors: Vatanabe Sandro L. , Choi Andres , de Lima Cícero R. , Nelli Silva Emílio Carlos
Published: November 2009

Flow pumps are important tools in several engineering areas, such as in the fields of bioengineering and thermal management solutions for electronic devices. Nowadays, many of the new flow pump principles are based on the use of piezoelectric actuators, which present some advantages such as miniaturization potential and lower noise generation. In previous work, authors presented a study of a novel pump configuration based on placing an oscillating bimorph piezoelectric actuator in water to generate flow. It was concluded that this oscillatory behavior (such as fish swimming) yields vortex interaction, generating flow rate due to the action and reaction principle. Thus, following this idea the objective of this work is to explore this oscillatory principle by studying the interaction among generated vortex from two bimorph piezoelectric actuators oscillating inside the same pump channel, which is similar to the interaction of vortex generated by frontal fish and posterior ones when they swim together in a group formation. It is shown that parallel−series configurations of bimorph piezoelectric actuators inside the same pump channel provide higher flow rates and pressure for liquid pumping than simple parallel−series arrangements of corresponding single piezoelectric pumps, respectively. The scope of this work includes structural simulations of bimorph piezoelectric actuators, fluid flow simulations, and prototype construction for result validation.
School Nurses and Teachers
Authors: Spear Hila J.
Published: November 2009

School nurses and middle and high school teachers ( N = 107) participated in a survey that explored their attitudes and behaviors related to the inclusion of breastfeeding content to highlight the scientific and exceptional health advantages of breastfeeding and to promote a breastfeeding culture. Although some participants believed that breastfeeding content should not be part of school curriculum, the vast majority (86.9%) agreed that the benefits of breastfeeding should be taught to high school students; and over half (57.9%) supported teaching about the value of breastfeeding to middle school children. School nurses are well positioned to promote healthy lifestyle behaviors among student populations and play a pivotal and important role in the promotion of a breastfeeding culture and related positive behaviors.
Crafting Urban Policy
Authors: Lawrence Eric , Stoker Robert , Wolman Harold
Published: November 2009

This article assesses how policy framing and targeting may influence public support for federal initiatives that address urban problems. Does directing federal aid to specific target groups, programmatic uses, or types of cities affect the level of public support? To explore these questions, the authors conducted two survey experiments asking whether respondents support aid to cities while randomly varying the framing and targeting conditions. The evidence suggests that some framing and targeting strategies (particularly, targeting specific programmatic uses) do affect public support for urban aid. The authors conclude by discussing the implications of the analysis for support for federal urban assistance.
Air Leakage of Curtain Walls - Diagnostics and Remediation
Authors: Becker R.
Published: November 2009

This article demonstrates how monitoring of construction during a laboratory mock-up test was used to diagnose proneness to air leakage and to devise improved details. The curtain wall was built on a moveable, rigid frame that simulates the load-bearing structure. Construction details and components were identical to those used in actual buildings. The frame brings the curtain wall into contact with the test box, ensuring that the wall’s structural supports are not affected. Construction activities were monitored while the measurements included air flow rate versus air pressure difference across the wall, and horizontal deflections of wall mullions and beams. Locations of leakage points were detected using white smoke. The wall showed a density of air flow rate of 1.5 m3m-2h -1 at a pressure difference of ∼300 Pa, barely meeting the requirements for EN 12152 classification level A2. Correlating leakage points with detected construction weaknesses led to remedial actions by the manufacturer. The tests were repeated, revealing an improved air-tightness (density of air flow rate less than 0.6 m3m- 2h-1 at 350 Pa, and 0.8 m3m -2h-1 when extrapolated to 600 Pa), which meets the requirements for classification level E.
A Numerical Procedure for Calculating Combined Conduction and Radiation Heat Flux Through Fibrous Insulation
Authors: Stephenson D.G.
Published: November 2009

This article presents a numerical procedure for calculating heat flux through fibrous insulation. It deals primarily with the radiation component, and the interaction between the radiation and conduction. The program determines the temperature profile by an iterative method, and uses it to evaluate the conductivity of the air and the extinction coefficient of the fibrous material at locations through the material. The temperature dependence of the extinction coefficient accounts for the nongray nature of fibrous materials. The algorithm allows for the edge effect. The article deals primarily with steady state heat flow, and includes an example of nonsteady heat flow. A method to estimate the contribution of the fiber structure is included. The thermal properties of insulation are derived from the results of R-value tests in vacuum and in air at different mean temperatures.
Nurses’ knowledge of intravenous connectors
Authors: Chernecky Cynthia , Casella Lindsey , Jarvis Erin , Macklin Denise , Rosenkoetter Marlene
Published: November 2009

No published studies assess the knowledge of staff nurses regarding intravenous connectors, yet connectors remain a primary cause of infection and mortality. Anonymous survey (N = 100) in acute hospitals revealed 78% of nurses were uninformed about different connector types and their different care and 43% could not name two complications of connectors. No significant relationship was found between education (r = 0.121, p < 0.05) or nursing specialty (r =-0.059, p < 0.05) and identifying types of connectors. Sixty-four per cent were involved in 5—6 hours of intravenous therapy and maintenance per 12-hour shift, hence connector care is significant. Education about connectors has implications for nursing associated with catheter-related bloodstream infections, occlusion and thrombosis. The Centers for Disease Control includes catheter-related bloodstream infections as a worldwide priority. This study identified a significant need for further nursing education and research regarding the types, maintenance and care of intravenous connectors.
Review: Advances in the diagnosis and treatment of small bowel lesions with Crohn’s disease using double-balloon endoscopy
Authors: Sunada Keijiro , Yamamoto Hironori , Yano Tomonori , Sugano Kentaro
Published: November 2009

With the recent development of double-balloon endoscopy (DBE) and capsule endoscopy (CE), it has become possible to observe the entire small bowel endoscopically. DBE enables us to make detailed observations and at the same time takes biopsy samples. Single-balloon endoscopy (SBE), which has a balloon only at the tip of the overtube, has also been introduced. Since DBE and SBE are similar in the concept of insertion method, a general term ‘balloon-assisted endoscopy’ (BAE) is used when referring to these methods. Characteristic small bowel lesions observed with BAE in Crohn’s disease are aphthoid ulcers, round ulcers, irregular ulcers and longitudinal ulcers. These ulcers tend to be located on the mesenteric side of the small bowel. Since BAE can determine the location (mesenteric or antimesenteric side) of the ulceration, it is useful in distinguishing Crohn’s disease from other diseases that have ulcers in the small bowel. Strictures are a major clinical problem in the course of Crohn’s disease. Traditionally, surgery was the main choice for small bowel strictures. In some cases, strictures located in distal ileum or proximal jejunum have been dilated using standard enteroscopes. DBE now enables balloon dilatation to be performed endoscopically even in the deep small bowel.
Review: Second-line rescue therapy of Helicobacter pylori infection
Authors: Gisbert Javier P.
Published: November 2009

Helicobacter pylori infection is the main known cause of gastritis, gastroduodenal ulcer disease and gastric cancer. After more than 20 years of experience in H. pylori treatment, however, the ideal regimen to treat this infection has still to be found. Nowadays, apart from having to know well first-line eradication regimens, we must also be prepared to face treatment failures. Therefore, in designing a treatment strategy we should not focus on the results of primary therapy alone, but also on the final (overall) eradication rate. The choice of a ‘rescue’ treatment depends on which treatment is used initially. If a first-line clarithromycin-based regimen was used, a second-line metronidazole-based treatment (quadruple therapy) may be used afterwards, and then a levofloxacin-based combination would be a third-line ‘rescue’ option. Alternatively, it has recently been suggested that levofloxacin-based ‘rescue’ therapy constitutes an encouraging second-line strategy, representing an alternative to quadruple therapy in patients with previous PPI-clarithromycin-amoxicillin failure, with the advantage of efficacy, simplicity and safety. In this case, quadruple regimen may be reserved as a third-line ‘rescue’ option. Finally, rifabutin-based ‘rescue’ therapy constitutes an encouraging empirical fourth-line strategy after multiple previous eradication failures with key antibiotics such as amoxicillin, clarithromycin, metronidazole, tetracycline, and levofloxacin. Even after two consecutive failures, several studies have demonstrated that H. pylori eradication can finally be achieved in almost all patients if several ‘rescue’ therapies are consecutively given. Therefore, the attitude in H. pylori eradication therapy failure, even after two or more unsuccessful attempts, should be to fight and not to surrender.