On the feasibility of utilising gearing to extend the rotational workspace of a class of parallel robots

Parallel manipulators provide several benefits compared to serial manipulators of similar size. These advantages typically include higher speed and acceleration, improved position accuracy and increased stiffness. However, parallel manipulators also suffer from several disadvantages. These drawbacks commonly include a small ratio of the positional workspace relative to the manipulator footprint and a limited rotational capability of the manipulated platform. A few parallel manipulators featuring a large ratio of the positional workspace relative to the footprint have been proposed. This paper investigates the feasibility of employing gearing to extend the range of the end-effector rotation of such mechanisms. The objective is to achieve parallel manipulators where both the positional and rotational workspace are comparable to that of serial manipulators.

Redox sulfur chemistry of the copper chaperone Atox1 is regulated by the enzyme glutaredoxin 1, the reduction potential of the glutathione couple GSSG/2GSH and the availability of Cu(I)

Glutaredoxins have been characterised as enzymes regulating the redox status of protein thiols via cofactors GSSG/GSH. However, such a function has not been demonstrated with physiologically relevant protein substrates in in vitro experiments. Their active sites frequently feature a Cys-xx-Cys motif that is predicted not to bind metal ions. Such motifs are also present in copper-transporting proteins such as Atox1, a human cytosolic copper metallo-chaperone. In this work, we present the first demonstration that: (i) human glutaredoxin 1 (hGrx1) efficiently catalyses interchange of the dithiol and disulfide forms of the Cys(12)-xx-Cys(15) fragment in Atox1 but does not act upon the isolated single residue Cys(41); (ii) the direction of catalysis is regulated by the GSSG/2GSH ratio and the availability of Cu(I); (iii) the active site Cys(23)-xx-Cys(26) in hGrx1 can bind Cu(I) tightly with femtomolar affinity (K(D) = 10(-15.5) M) and possesses a reduction potential of E(o)' = -118 mV at pH 7.0. In contrast, the Cys(12)-xx-Cys(15) motif in Atox1 has a higher affinity for Cu(I) (K(D) = 10(-17.4) M) and a more negative potential (E(o)' = -188 mV). These differences may be attributed primarily to the very low pKa of Cys23 in hGrx1 and allow rationalisation of conclusion (ii) above: hGrx1 may catalyse the oxidation of Atox1(dithiol) by GSSG, but not the complementary reduction of the oxidised Atox1(disulfide) by GSH unless Cu(aq)(+) is present at a concentration that allows binding of Cu(I) to reduced Atox1 but not to hGrx1. In fact, in the latter case, the catalytic preferences are reversed. Both Cys residues in the active site of hGrx1 are essential for the high affinity Cu(I) binding but the single Cys(23) residue only is required for the redox catalytic function. The molecular properties of both Atox1 and hGrx1 are consistent with a correlation between copper homeostasis and redox sulfur chemistry, as suggested by recent cell experiments. These proteins appear to have evolved the features necessary to fill multiple roles in redox regulation, Cu(I) buffering and Cu(I) transport.

Perspectives of engineered marine derived polymers for biomedical nanoparticles

Marine environment exhibits an enormous diversity of organisms which contains an abundant source of polysaccharides. As polymer matrix carriers, marine-based polymers possess several valuable properties including high stability, non-toxicity, hydrophilicity, biodegradability, with low production cost. Despite notable biological activities of these natural polymers, there are certain limitations in exploring their functions in applications of nano-sized drug delivery systems. The review aims to demonstrate exceptional characteristics of marine-based polymers including fucoidan, alginate, carrageenan, hyaluronic acid, chondroitin sulfate, and chitosan as well as provide perspectives of current publications on their nanoparticle formulations for biomedical applications.

Promoting physical activity participation among children and adolescents

With global increases in the prevalence of overweight and obesity among children and adolescents, there has never been a more urgent need for effective physical activity programs. The aim of this narrative review is to summarize the evidence of the effectiveness of interventions that report physical activity outcomes in children aged 4–12 years and adolescents aged 13–19 years. A systematic search of electronic databases identified 76 interventions. Most interventions were delivered via the school setting (57 interventions), nine through the family setting, six via primary care, and four in community- or Internet-based settings. Children's physical activity interventions that were most effective in the school setting included some focus on physical education, activity breaks, and family strategies. Interventions delivered in the family setting were not highly effective, but many were pilot studies. The use of motivationally tailored strategies and program delivery in the primary care setting showed promise among adolescents. Many studies had methodological and reporting flaws (e.g., no baseline data, poor study design, physical activity measures of unknown reliability and validity, and poor reporting of sample size, response rates, attrition/retention, compliance, year of intervention, and duration of intervention). Publications reporting the results of evaluations of intervention studies should follow the Consolidated Standards of Reporting Trials guidelines or, for nonrandomized studies, should follow the Transparent Reporting of Evaluations with Nonrandomized Designs guidelines. Further evidence of the effectiveness of interventions promoting young people's physical activity in family and community settings is needed.

Design-related bias in hospital fall risk screening tool predictive accuracy evaluations: systematic review and meta-analysis.

Introduction: Fall risk screening tools are frequently used as a part of falls prevention programs in hospitals. Design-related bias in evaluations of tool predictive accuracy could lead to overoptimistic results, which would then contribute to program failure in practice.

Methods: A systematic review was undertaken. Two blind reviewers assessed the methodology of relevant publications into a four-point classification system adapted from multiple sources. The association between study design classification and reported results was examined using linear regression with clustering based on screening tool and robust variance estimates with point estimates of Youden Index (= sensitivity + specificity - 1) as the dependent variable. Meta-analysis was then performed pooling data from prospective studies.

Results: Thirty-five publications met inclusion criteria, containing 51 evaluations of fall risk screening tools. Twenty evaluations were classified as retrospective validation evaluations, 11 as prospective (temporal) validation evaluations, and 20 as prospective (external) validation evaluations. Retrospective evaluations had significantly higher Youden Indices (point estimate [95% confidence interval]: 0.22 [0.11, 0.33]). Pooled Youden Indices from prospective evaluations demonstrated the STRATIFY, Morse Falls Scale, and nursing staff clinical judgment to have comparable accuracy.

Discussion: Practitioners should exercise caution in comparing validity of fall risk assessment tools where the evaluation has been limited to retrospective classifications of methodology. Heterogeneity between studies indicates that the Morse Falls Scale and STRATIFY may still be useful in particular settings, but that widespread adoption of either is unlikely to generate benefits significantly greater than that of nursing staff clinical judgment.

Journal impact factors: implications for the nursing profession

Background: The journal impact factor (IF) has become widely used as an absolute measure of the quality of professional journals. It is also increasingly used as a tool for measuring the academic performance of researchers and to inform decisions concerning the appointment and tenure of academic staff as well as the viability of their departments/schools. In keeping with these IF-related trends, nurse researchers and faculty the world over are being increasingly expected to publish only in journals that have a high IF and to abandon all other forms of publishing (including books and book chapters) that do not attract IF rankings.

Issues: The IF obsession is placing in jeopardy the sustainability and hence viability of nursing journals and academic nursing publication lists (academic texts). If nurse authors abandon their publishing agenda and publish only in 'elite' journals (many of which may be outside nursing), the capacity of the nursing profession to develop and control the cutting edge of its disciplinary knowledge could be placed at risk.

Actions: Other means for assessing the quality and impact of nursing journals need to be devised. In addition, other works (such as books and book chapters) need also to be included in quality metrics. Nurse authors and journal editors must work together and devise ways to ensure the sustainability and viability of nursing publications.

Fiscal stringency and fiscal sustainability : panel evidence from the American state and local governments

Most state (and local) governments in the U.S. operate under formal fiscal rules which limit their ability to run budget deficits and resort to debt financing. A priori, one would expect to find evidence in favor of an intertemporally balanced budget, or fiscal sustainability, for these states, especially those characterized by a relatively high degree of fiscal stringency. We test this hypothesis for a panel of 47 state–local government units (1961–2006) using four budget balance definitions and several subsamples defined based on regional classifications, or presence of certain balanced budget requirements (BBRs). Our results, obtained from panel estimation techniques that allow for general forms of serial and cross-sectional dependence, suggest that a sufficient condition for “strong” sustainability is consistently satisfied for the full sample and all subsamples in relation to balances that include special funds and/or federal grants. However, we find evidence consistent with the “weak” version of sustainability for the full sample and some regional subsamples (particularly Far West dominated by California) in at least one of the two balances that exclude these items. Finally, the BBRs seem to matter only in relation to the sustainability of the more narrowly defined balances. We discuss the implications of these findings for the role of fiscal rules and federal grant policies.

Estimator-based sliding mode control strategy design

This study addresses the design and properties of serial sliding mode control (SMC) systems for an induction servo motor drive to track periodic commands. It contains a SMC, an adaptive SMC (ASMC) and an estimator-based SMC (ESMC). The effectiveness of the proposed control systems is verifi ed by numerical simulations, and the superiority of the ESMC system is indicated in comparison with the SMC and ASMC systems.

Dielectric percolative composites with high dielectric constant and low dielectric loss based on sulfonated poly(aryl ether ketone) and a-MWCNTs coated with polyaniline

Acidified multi-walled carbon nanotubes (a-MWCNTs) coated with polyaniline (PANI) (a-MWCNTs@PANI) nanofiller were prepared by in situ polymerization. Novel dielectric percolative composites, sulfonated poly(aryl ether ketone) (SPAEK)/a-MWCNTs@PANI, with high dielectric constant and low dielectric loss were fabricated using simple solution blending technique. A SPAEK/a-MWCNTs@PANI composite prepared in this fashion exhibited a high dielectric constant above 800, a dielectric loss tangent less than 1.1 at 10 kHz and room temperature. The morphological study of composites by SEM suggested that the in situ polymerization method of preparing a-MWCNTs@PANI nanofillers was useful to achieve good dispersion of fillers in SPAEK matrix.

Seriality and persona

 Persona is a public presentation of identity. One of the key values of a persona is its consistency in its presentation of the self. This article is designed to be the first exploratory steps and overview in charting the idea of seriality in relation to persona and its utility as a concept to describe the constancy and transformation of identity that is now elemental to understanding contemporary persona or the public presentation of the self and its online manifestations. Seriality in terms of persona is first investigated from its entertainment culture origins – with its use in the constitution of characters in fiction in novels, films, games and most prevalently in television. Several examples of serial persona will be analysed with an emphasis on how television has constructed often the most powerful personas: Kevin Spacey’s persona as Frank Underwood in House of Cards is discussed in greater detail in terms of the economic, cultural and affective value of serial persona and its associated formations of risk. It then explores the blending of the fictional and the real in seriality through how popular music performers – in particular Eminem - construct an authentic register of persona to allow for the exploration of the self through emotion and connection. The article concludes with thinking how seriality is connected to the constitutions of online identity and links the concept with aspects of virality and meme culture and their constructions of value, patterns and constancy as it relate to the presentation of the public self.

Decoupled ion conduction in poly(2-acrylamido-2-methyl-1-propane-sulfonic acid) homopolymers

As the focus on developing new polymer electrolytes continues to intensify in the area of alternative energy conversion and storage devices, the rational design of polyelectrolytes with high single ion transport rates has emerged as a primary strategy for enhancing device performance. Previously, we reported a series of sulfonate based copolymer ionomers based on using mixed bulky quaternary ammonium cations and sodium cations as the ionomer counterions. This led to improvements in the ionic conductivity and an apparent decoupling from the Tg of the ionomer. In this article, we have prepared a new series of ionomers based on the homopolymer of poly(2-acrylamido-2-methyl-1-propane-sulfonic acid) using differing sizes of the ammonium counter-cations. We observe a decreasing Tg with increasing the bulkiness of the quaternary ammonium cation, and an increasing degree of decoupling from Tg within these systems. Somewhat surprisingly, phase separation is observed in this homopolymer system, as evidenced from multiple impedance arcs, Raman mapping and SEM. The thermal properties, morphology and the effect of plasticizer on the transport properties in these ionomers are also presented. The addition of 10 wt% plasticizer increased the ionic conductivity between two and three orders of magnitudes leading to materials that may have applications in sodium based devices. This journal is

Sport-for-development: an integrated literature review

Despite the significant increase of published research in sport-for-development (SFD), to date there have been no attempts to rigorously review and synthesize scholarly contributions in this area. To address this issue, we conducted an integrative review of SFD literature to portray an overarching and holistic picture of the field. Through a comprehensive literature analysis following Whittemore and Knafl’s (2005) five-step process, we provide evidence of the status quo of current SFD research foci, authorship, geographical contexts, theoretical frameworks, sport activity, level of development, methodologies, methods, and key research findings. Our study shows an increasing trend of journal publications since 2000, with a strong focus on social and educational outcomes related to youth sport and with football (soccer) as the most common activity. A large majority of SFD research has been conducted at the community level, where qualitative approaches are dominant. The geographical contexts of authorship and study location present an interesting paradox: Although the majority of SFD projects are carried out in Africa, Asia, and Latin America, 90% of SFD authors are based in North America, Europe, and Australia. We conclude our study by providing new perspectives on key issues in SFD and by outlining current research and theoretical gaps that provide the basis for future scholarly inquiry.

Are the earliest field monuments of the pacific landscape serial sites?

Explanations of the origin and genesis of Pacific field monuments commonly assume they reflect local social change in islands or island groups which were increasingly isolated following colonization. A recent review of early West Polynesian archaeology suggests that the penecontemporaneous appearance of various kinds of field monuments from eastern Melanesia to Polynesia may be better explained as evidence of interaction and the movement of people and/or ideas, possibly associated with the colonization of East Polynesia.