bluuebunny/crossref_metadata_2025 huggingface dataset:
Droplet Generation by Disintegration of Oil Films at the Rim of a Rotating Disk
Authors: Glahn A. , Busam S. , Blair M. F. , Allard K. L. , Wittig S.
Published: August 2014

A fundamental study has been performed to examine oil film disintegration mechanisms at the rim of a rotating disk. The configuration investigated is an abstraction of one of the droplet generation sources in an aero-engine bearing compartment. The paper aims to contribute to both the determination of directly applicable droplet characteristics and the establishment of a data-base that can be used for the development of droplet generation models. The near-term objectives of the study are (i) to identify disintegration modes relevant with respect to aero-engine bearing compartment operating conditions, (ii) to determine droplet sizes under those operating conditions, and (iii) to measure individual droplet diameter/velocity relationships. The long-term objective is to incorporate this information into advanced CFD-based design tools.

The disintegration modes identified here were similar to previously reported flow regimes generated by rotary atomizers (Lefebvre, 1989). However, slightly different transition characteristics are documented for the turbine oil considered here, indicating a transition occurring at either higher speeds or higher flow rates. Droplet diameters and velocities are presented for relevant bearing compartment conditions. In this mode, droplet diameters appear to be insensitive to the volume flow rate, but show a finer atomization for increasing rotational speeds. Eventually a speed is reached beyond which no further droplet diameter reduction is obtained. For the first time, size class resolved droplet velocities are presented. A variation of operating parameters at a constant radial location does not have a significant impact on either the normalized droplet velocity or the flow angle. Radial traverses show a decrease of the droplet velocity with increasing distance from the rim of the disk and a transition from a more tangentially orientated droplet trajectory to a more radial motion.
Computed Effect of Rub-Groove Size on Stepped Labyrinth Seal Performance
Authors: Rhode David L. , Adams Richard G.
Published: August 2014

A numerical study was undertaken to explore the effects of the size of wear-in rub grooves that are typically cut into the abradable land of stepped labyrinth seals. The elliptic form of the 2-D axisymmetric Navier-Stokes equations for compressible turbulent flow were solved. The relationships among the friction coefficient, the leakage Reynolds number, the groove depth and width and the pre-rub radial clearance were examined.

It was found that the standard k-ε turbulence model and wall functions are effective for computing the friction coefficient and leakage for labyrinth seals with honeycomb land surfaces, both with and without the presence of rub grooves. The so-called rub grooves are the result of labyrinth teeth cutting wear grooves into the abradable surface of the land (stationary housing of the seal). Furthermore, it was found that the case of a small pre-rub tooth radial clearance, a wide rub groove and an intermediate step height is the most sensitive to the presence of a rub groove, with a leakage increase over the no-groove case of about 100 percent and 194 percent for the shallow and deep grooves, respectively. It was also found, for example, that the leakage varied with pre-rub clearance and groove width, in order from lowest to highest leakage, as: (a) small clearance and narrow groove, (b) small clearance and wide groove, (c) large clearance and narrow groove and (d) large clearance and wide groove.
Active Controlled Hydrostatic Bearings for a New Generation of Machines
Authors: Bently Donald E. , Grant John W. , Hanifan Phillip C.
Published: August 2014

This paper presents a revolutionary approach of using a fluid-lubricated bearing for both traditional functions (load support, damping, and heat removal) and to actively control the rotor dynamics of rotating machinery. We will discuss how its use in the design of next generation turbomachinery can yield dramatic benefits. This includes an increase in efficiency, operational life, fault diagnostic, and reductions in machine size, weight, and cost. With the use of hydrostatic instead of hydrodynamic lubrication, traditional lubricants can be replaced by fluids more friendly to the process and environment. In this paper a comparison between the new hydrostatic bearing (Bently ServoFluid™ Control Bearing) and active magnetic bearings (AMB) will be presented.

The Bently ServoFluid™ Control Bearing is an active controlled externally pressurized (a hybrid hydrostatic) bearing using fluid restoring force to compensate for rotor-related forces. It has the positive features of rolling element, fluid film and magnetic bearings with fewer negative attributes. The fluid restoring forces provide static and dynamic motion control similar to magnetic bearings, but with significantly larger compensation forces and with higher stiffness control.

This revolutionary approach enables machinery owners to identify, understand and compensate for rotor system forces, an improvement over simply using vibration (motion) information for machinery diagnostics. This allows more complete diagnostics and prognostics of machine health. The bearing can be used to apply known perturbation forces to the rotor. Perturbation forces enable the determination of rotor system stiffness, and subsequent changes, thus improving machinery diagnostics. It can also provide information, such as the mechanical parameters governing the motion, system linearity, and stability margins for more accurate modeling of machines.

Test results will be included to show experimentally determined transfer functions of each of the control loop elements, and predicted rotor forces. A typical root locus plot will be shown demonstrating how the characteristics change with bearing stiffness. Prototype machines, with both low viscosity fluid (water) and typical viscous fluid (T-10 turbine oil), have been built, tested, and successfully operated.
Aerodynamic and Performance Studies of a Three-Stage High Pressure Research Turbine With 3-D - Blades, Design Point and Off-Design Experimental Investigations
Authors: Schobeiri M. T. , Gilarranz J. L. , Johansen E. S.
Published: August 2014

This paper deals with the aerodynamic and performance behavior of a three-stage high pressure research turbine with 3-D curved blades at its design and off-design operating points. The research turbine configuration incorporates six rows beginning with a stator row. Interstage aerodynamic measurements were performed at three stations, namely downstream of the first rotor row, the second stator row, and the second rotor row. Interstage radial and circumferential traversing presented a detailed flow picture of the middle stage. Performance measurements were carried out within a rotational speed range of 75% to 116% of the design speed. The experimental investigations have been carried out on the recently established multi-stage turbine research facility at the Turbomachinery Performance and Flow Research Laboratory, TPFL, of the Texas A&M University.
Analysis of the Inter-Row Flow Field Within a Transonic Axial Compressor: Part 2 — Unsteady Flow Analysis
Authors: Ottavy Xavier , Trébinjac Isabelle , Vouillarmet André
Published: August 2014

An analysis of the experimental data, obtained by laser two-focus anemometry in the IGV-rotor inter-row region of a transonic axial compressor, is presented with the aim of improving the understanding of the unsteady flow phenomena. A study of the IGV wakes and of the shock waves emanating from the leading edge of the rotor blades is proposed. Their interaction reveals the increase in magnitude of the wake passing through the moving shock. This result is highlighted by the streamwise evolution of the wake vorticity. Moreover, the results are analyzed in terms of a time averaging procedure and the purely time-dependent velocity fluctuations which occur are quantified. It may be concluded that they are of the same order of magnitude as the spatial terms for the inlet rotor flow field. That shows that the temporal fluctuations should be considered for the 3D rotor time-averaged simulations.
Compressor and Turbine Volute Design System
Authors: Maguire J. M. , Bruce G. J. , Engeda A. , Gu F.
Published: August 2014

This paper describes a computer based volute design system that integrates geometry generation with aerodynamic analysis. The system is capable of generating and analysing turbine and compressor volutes. The program, VoluteCad, allows for graphical geometry manipulation of the volute cross-section shapes, area distributions, and outline connections. Aerodynamic analysis is performed using computational fluid dynamics, CFD. The CFD mesh node spacing and boundary conditions are automatically generated from within the program, thus eliminating the need to manually set up third party mesh generators. Program output includes information for CAD and 3D viewing of the volute core.
Analysis Strategies for Tubular SOFC Based Hybrid Systems
Authors: Rao A. D. , Samuelsen G. S.
Published: August 2014

The emergence of fuel cell systems and hybrid fuel cell systems requires the evolution of analysis strategies for evaluating thermodynamic performance and directing design and development. A description and application of the recently developed tool for analyzing tubular SOFC based systems is presented. The capabilities of this tool include an analytical model for the tubular SOFC as well as the secondary equipment required to analyze hybrid power plants. Examples of such secondary equipment are gas turbine, reformer, partial oxidation reactor, shift reactor, humidifier, steam turbine, compressor, gas expander, heat exchanger and pump. In addition to these equipment models, modules required for performing functions such as separating a component from a stream, splitting a stream or combining streams are also included. A “Solver” is included which is essential for modeling systems to automatically iterate in order to meet the desired process or system design criteria such as maintaining a specified steam to carbon ratio in the reformer feed stream or a specified temperature difference between two streams in the system. Another important capability that is included is to be able to arrange the various components or modules as defined by the user in order to configure different hybrid systems.
The Aerodynamic Interaction of Stator Shroud Leakage and Mainstream Flows in Compressors
Authors: Demargne A. A. J. , Longley J. P.
Published: August 2014

The aerodynamics of stator shroud leakage and mainstream flow interactions have been investigated using a linear cascade in which leakage mass flow and tangential velocity could be varied independently. Experimental measurements confirm the detrimental effect of increasing leakage mass flow rate, but also show clearly that increasing cavity tangential velocity improves the performance of the blade row. Shroud leakage is also found to modify significantly the spanwise distribution of blockage, flow turning and loss at exit of the stator passage. The mechanisms behind these large-scale effects are identified and a description of the interaction process based on momentum thickness arguments is proposed.

Experimental and numerical results show that the amount of leakage is a linear function of the difference between cavity pressure and average pressure on the hub upstream of the stator. This result is shown to be an axisymmetric result, and thus largely independent of the pitchwise variation in blade loading. Departures from linearity at low leakage fractions are associated to the blade loading inducing pitchwise non-uniformities in the structure of the flow at the interface between the shroud cavity and the mainstream. These non-uniformities involve vortical structures, which participate in the exchange of fluid and momentum between the cavity and the mainstream, even at zero net leakage. Experiments also show that these non-uniformities in flow structure contribute to the generation of loss.
Analysis of the Mixing Process in a 1.5 Stage Turbine With Coolant Ejection
Authors: Gehring Stefan , Riess Walter
Published: August 2014

The addition of cooling fluid into the main flow affects the aerodynamic performance of the blading and causes changes of the overall flow capacity and efficiency of a turbine. Computing systems which consider all those effects are necessary for the performance prediction of cooled multistage turbines. The throughflow method presented here is based on the finite element method and includes models for the radial distribution of losses, for the spanwise mixing and for different cooling configurations, e.g. convection cooling with trailing edge outlet and film cooling. The reliability of the method is verified by comparisons with experimental data of a 1.5 stage cold air turbine with nitrogen ejection in front of the first stator. Because the coolant is ejected at different radii in order to observe the flow path, the radial mixing process is of special importance for this test case. Due to the reliable models used in the throughflow method the mixing between main flow and coolant at the ejection locus and the radial mixing process downstream is well predicted.
Intrarater Test-Retest Reliability of Static and Dynamic Stability Indexes Measurement Using the Biodex Stability System During Unilateral Stance
Authors: Arifin Nooranida , Osman Noor Azuan Abu , Abas Wan Abu Bakar Wan
Published: August 2014

The measurements of postural balance often involve measurement error, which affects the analysis and interpretation of the outcomes. In most of the existing clinical rehabilitation research, the ability to produce reliable measures is a prerequisite for an accurate assessment of an intervention after a period of time. Although clinical balance assessment has been performed in previous study, none has determined the intrarater test-retest reliability of static and dynamic stability indexes during dominant single stance. In this study, one rater examined 20 healthy university students (female = 12, male = 8) in two sessions separated by 7 day intervals. Three stability indexes—the overall stability index (OSI), anterior/posterior stability index (APSI), and medial/lateral stability index (MLSI) in static and dynamic conditions—were measured during single dominant stance. Intraclass correlation coefficient (ICC), standard error measurement (SEM) and 95% confidence interval (95% CI) were calculated. Test-retest ICCs for OSI, APSI, and MLSI were 0.85, 0.78, and 0.84 during static condition and were 0.77, 0.77, and 0.65 during dynamic condition, respectively. We concluded that the postural stability assessment using Biodex stability system demonstrates good-to-excellent test-retest reliability over a 1 week time interval.
Nematic spin correlations in the tetragonal state of uniaxial-strained BaFe
2−

x

Ni

x

As
2
Authors: Lu Xingye , Park J. T. , Zhang Rui , Luo Huiqian , Nevidomskyy Andriy H. , Si Qimiao , Dai Pengcheng
Published: August 2014

Scattering neutrons asymmetrically

The crystal structure of solid materials often influences their properties. The more symmetric the structure, the less dependent these properties are on the spatial direction. The superconductors that derive from the compound BaFe
2
As
2
are an exception: Their electronic transport properties can be anisotropic even in the phase where the crystal is symmetric. By scattering neutrons off their samples, Lu
et al.
found that the magnetic properties of these materials can also be anisotropic. The similar temperature and doping dependence of the anisotropies of both transport and magnetic properties suggests that they may have a common cause.

Science
, this issue p.
657
Poly-dipeptides encoded by the
C9orf72
repeats bind nucleoli, impede RNA biogenesis, and kill cells
Authors: Kwon Ilmin , Xiang Siheng , Kato Masato , Wu Leeju , Theodoropoulos Pano , Wang Tao , Kim Jiwoong , Yun Jonghyun , Xie Yang , McKnight Steven L.
Published: August 2014

Dipeptide repeat peptides on the attack

Certain neurodegenerative diseases, including amyotrophic lateral sclerosis (ALS), are associated with expanded dipeptides translated from RNA transcripts of disease-associated genes (see the Perspective by West and Gitler). Kwon
et al.
show that the peptides encoded by the expanded repeats in the C9orf72 gene interfere with the way cells make RNA and kill cells. These effects may account for how this genetic form of ALS causes disease. Working in
Drosophila
, Mizielinska
et al.
aimed to distinguish between the effects of repeat-containing RNAs and the dipeptide repeat peptides that they encode. The findings provide evidence that dipeptide repeat proteins can cause toxicity directly.

Science
, this issue p.
1139
and p.
1192
; see also p.
1118
Deep burial dissolution of K-feldspars in a fluvial sandstone, Pentland Formation, UK Central North Sea
Authors: Wilkinson Mark , Haszeldine R. Stuart , Morton Andrew , Fallick Anthony E.
Published: August 2014

The Pentland Formation of the UK Central North Sea is a quartzite in a sequence of more arkosic sandstones. Provenance-sensitive heavy mineral indices are interpreted to indicate that it was probably derived by erosion of arkosic sediments, which also supplied the arkosic marine sandstones of the contemporaneous Fulmar Formation. A lack of apatite within the Pentland Formation suggests that the feldspars could have dissolved during exposure to groundwaters during very shallow burial. However, petrographic and geochemical evidence supports survival of at least some of the feldspar to burial depths in excess of at least 2 km, when the sandstones had been stabilized against compaction by quartz cements or overpressure. Abundant kaolin, which has not reacted to form illite, is preserved at burial depths in excess of 4000 m, suggesting an unusual lack of available potassium. There is a strong contrast in diagenetic pathways with the overlying marine Fulmar Formation, which most probably had the same initial composition but in which kaolin is absent and fibrous illite is present. It is suggested that a lower concentration of potassium (and aluminium) within the Pentland Formation compared with the probable source and the comparably sourced Fulmar Formation represents export of K from the sands on a metre scale.
#swineflu
Authors: Kostkova Patty , Szomszor Martin , St. Louis Connie
Published: August 2014

The need to improve population monitoring and enhance surveillance of infectious diseases has never been more pressing. Factors such as air travel act as a catalyst in the spread of new and existing viruses. The unprecedented user-generated activity on social networks over the last few years has created real-time streams of personal data that provide an invaluable tool for monitoring and sampling large populations. Epidemic intelligence relies on constant monitoring of online media sources for early warning, detection, and rapid response; however, the real-time information available in social networks provides a new paradigm for the early warning function.

The communication of risk in any public health emergency is a complex task for governments and healthcare agencies. This task is made more challenging in the current situation when the public has access to a wide range of online resources, ranging from traditional news channels to information posted on blogs and social networks. Twitter’s strength is its two-way communication nature --- both as an information source but also as a central hub for publishing, disseminating and discovering online media.

This study addresses these two challenges by investigating the role of Twitter during the 2009 swine flu pandemic by analysing data collected from the SN, and by Twitter using the opposite way for dissemination information through the network. First, we demonstrate the role of the social network for early warning by detecting an upcoming spike in an epidemic before the official surveillance systems by up to two weeks in the U.K. and up to two to three weeks in the U.S. Second, we illustrate how online resources are propagated through Twitter at the time of the WHO’s declaration of the swine flu “pandemic”. Our findings indicate that Twitter does favour reputable t bogus information can still leak into the network.
A New Hypothesis on Facial Beauty Perception
Authors: Chen Fangmei , Xu Yong , Zhang David
Published: August 2014

In this article, a new hypothesis on facial beauty perception is proposed: the weighted average of two facial geometric features is more attractive than the inferior one between them. Extensive evidences support the new hypothesis. We collected 390 well-known beautiful face images (e.g., Miss Universe, movie stars, and super models) as well as 409 common face images from multiple sources. Dozens of volunteers rated the face images according to their attractiveness. Statistical regression models are trained on this database. Under the empirical risk principle, the hypothesis is tested on 318,801 pairs of images and receives consistently supportive results. A corollary of the hypothesis is attractive facial geometric features construct a convex set. This corollary derives a convex hull based face beautification method, which guarantees attractiveness and minimizes the before--after difference. Experimental results show its superiority to state-of-the-art geometric based face beautification methods. Moreover, the mainstream hypotheses on facial beauty perception (e.g., the averageness, symmetry, and golden ratio hypotheses) are proved to be compatible with the proposed hypothesis.
ECPC
Authors: Song Wen-Zhan , Xu Mingsen , De Debraj , Heo Deukhyoun , Kim Jong-Hoon , Kim Byeong-Sam
Published: August 2014

Sensor networks have particularly important applications in challenging environments. However, those challenging environments also pose significant challenges to network sustainability and reliability. In such environments, the network often becomes disruptive and even unavailable during downtime. This results in undesired loss of valuable spatial-temporal sensor data. Data persistence can be achieved by using in-situ encoding and caching of data through distributed mechanisms. However, the existing methods in the literature are mainly based on network random walks, which not only incur significant communication overhead, but also are prone to network or node failures. In this article, we presentECPC, a distributedErasureCoding with randomizedPowerControl protocol for preserving data in disruptive sensor networks.ECPConly requires each sensor node to perform several rounds of broadcast in its neighborhood at some randomly chosen radio transmission power levels, and thus it incurs low communication overhead. We proved thatECPCachieves the expected code degree distribution and pseudo-global randomness of erasure coding principles. We have also evaluated the performance ofECPCby comparing it with several key related approaches in the literature (such as EDFC and RCDS). The performance comparisons validate that our proposedECPCprotocol can reach higher data reliability under varying node failure probabilities. In addition,ECPCprotocol is also shown to be scalable with different network sizes.
Named data networking
Authors: Zhang Lixia , Afanasyev Alexander , Burke Jeffrey , Jacobson Van , claffy kc , Crowley Patrick , Papadopoulos Christos , Wang Lan , Zhang Beichuan
Published: August 2014

Named Data Networking (NDN) is one of five projects funded by the U.S. National Science Foundation under its Future Internet Architecture Program. NDN has its roots in an earlier project, Content-Centric Networking (CCN), which Van Jacobson first publicly presented in 2006. The NDN project investigates Jacobson's proposed evolution from today's host-centric network architecture (IP) to a
data-centric
network architecture (NDN). This conceptually simple shift has far-reaching implications for how we design, develop, deploy, and use networks and applications. We describe the motivation and vision of this new architecture, and its basic components and operations. We also provide a snapshot of its current design, development status, and research challenges. More information about the project, including prototype implementations, publications, and annual reports, is available on named-data.net.
MobilityFirst
Authors: Venkataramani Arun , Kurose James F. , Raychaudhuri Dipankar , Nagaraja Kiran , Mao Morley , Banerjee Suman
Published: August 2014

MobilityFirst is a future Internet architecture with mobility and trustworthiness as central design goals. Mobility means that all endpoints -- devices, services, content, and networks -- should be able to frequently change network attachment points in a seamless manner. Trustworthiness means that the network must be resilient to the presence of a small number of malicious endpoints or network routers. MobilityFirst enhances mobility by cleanly separating names or identifiers from addresses or network locations, and enhances security by representing both in an intrinsically verifiable manner, relying upon a massively scalable, distributed, global name service to bind names and addresses, and to facilitate services including device-to-service, multicast, anycast, and context-aware communication, content retrieval, and more. A key insight emerging from our experience is that a logically centralized global name service can significantly enhance mobility and security and transform network-layer functionality. Recognizing and validating this insight is the key contribution of the MobilityFirst architectural effort.
Why project size matters for contract choice in software development outsourcing
Authors: Fink Lior , Lichtenstein Yossi
Published: August 2014

The contractual mechanism of software development outsourcing, typically either fixed-price (FP) or time-and-materials (T&M), determines the nature of incentives, risk sharing, and coordination between client and vendor. While software engineering considers project size as crucial for project planning and success, neither economic nor organizational theory considers size per se among the determinants of contract choice. In this paper, we address the gap between the centrality of project size in the software engineering literature and the attention it receives in software contracting research by modeling and testing the association between project size and contract choice. Existing empirical evidence indicates that FP contracts are appropriate for small development efforts whereas T&M contracts are suitable for larger projects, based on the reasoning that cost and schedule are difficult to estimate in larger projects. This prediction that size is directly associated with contract choice is the basis upon which two models are developed. The first model draws on the contracting efficiency approach to hypothesize that the effect of project size on contract choice is mediated by project detail. The second model draws on the contingency approach to software development risk management to hypothesize that the effect of project size on contract choice is moderated by project detail and vendor familiarity. We test these models using a large portfolio of software development contracts entered into by a leading European bank, and the results confirm that both mediation and moderation are at play.
Rates of and Factors Associated With Infection in 200 909 Medicare Implantable Cardioverter-Defibrillator Implants
Authors: Prutkin Jordan M. , Reynolds Matthew R. , Bao Haikun , Curtis Jeptha P. , Al-Khatib Sana M. , Aggarwal Saurabh , Uslan Daniel Z.
Published: August 2014

Background—

The rate of implantable cardioverter-defibrillator (ICD) infections has been increasing faster than that of implantation. We sought to determine the rate and predictors of ICD infection in a large cohort of Medicare patients.

Methods and Results—

Cases submitted to the ICD Registry from 2006 to 2009 were matched to Medicare fee-for-service claims data using indirect patient identifiers. ICD infections occurring within 6 months of hospital discharge after implantation were identified by ICD-9 codes. Logistic regression was used to examine factors associated with risk of ICD infection. Of 200 909 implants, 3390 patients (1.7%) developed an ICD infection. The infection rate was 1.4%, 1.5%, and 2.0% for single, dual, and biventricular ICDs, respectively (
P
<0.001). Generator replacement had a higher rate compared with initial implant (1.9% versus 1.6%,
P
<0.001). The factors associated with infection were adverse event during implant requiring reintervention (odds ratio [OR], 2.692; 95% confidence interval [CI], 2.304–3.145), previous valvular surgery (OR, 1.525; 95% CI, 1.375–1.692), reimplantation for device upgrade, malfunction, or manufacturer advisory (OR, 1.354; 95% CI, 1.196–1.533), renal failure on dialysis (OR, 1.342; 95% CI, 1.123–1.604), chronic lung disease (OR, 1.215; 95% CI, 1.125–1.312), cerebrovascular disease (OR, 1.172; 95% CI, 1.076–1.276), and warfarin (OR, 1.155; 95% CI, 1.060–1.257).

Conclusions—

Patients who developed an ICD infection were more likely to have had peri-ICD implant complications requiring early reintervention, previous valve surgery, device replacement for reasons other than battery depletion, and increased comorbidity burden. Efforts should be made to carefully consider when to reenter the pocket at any time other than battery replacement.
Defense Mechanisms and Implicit Emotion Regulation
Authors: Rice Timothy R. , Hoffman Leon
Published: August 2014

A growing interest in the neuroscience of emotion regulation, particularly the subfield of implicit emotion regulation, brings new opportunity for the psychodynamic treatment of neuropsychiatric disorders of childhood. At the same time, psychodynamic theorists have become more aware of the centrality of affects in mental life. This paper introduces a manualized psychodynamic approach called Regulation-Focused Dynamic Psychotherapy (RFP-C). Theoretically based on the domain construct of implicit emotion regulation (ER), this approach posits that contemporary affect-oriented conceptualizations of defense mechanisms are theoretically similar to the neuroscience construct of implicit emotion regulation. To illustrate this theoretical similarity, the literature connected with both concepts is reviewed. The implications of this idea, which could promote an interface between psychodynamics and contemporary academic psychiatry and psychology, are discussed.
Greater Inequalities in Dental Treatment than in Disease Experience
Authors: Mejia G. , Jamieson L.M. , Ha D. , Spencer A.J.
Published: August 2014

This study aimed to (1) describe social gradients in dental caries in a population-level survey and (2) examine whether inequalities are greater in disease experience or in its treatment. Using data from Australia’s National Survey of Adult Oral Health 2004-2006, we examined absolute and relative income inequalities for DMFT and its separate components (DT, MT, FT) using adjusted proportions, means, and health disparity indices [Slope Index of Inequality (SII) and Relative Index of Inequality (RII)]. Approximately 90% of Australian adults had experienced caries, with prevalence ranging from 89.7% in the highest to 96.6% in the lowest income group. Social gradients in caries were evident across all components of DMFT, but particularly notable in Missing (SII = −15.5, RII = −0.3) and untreated Decay (SII = −23.7, RII = −0.9). Analysis of age- and gender-adjusted data indicated less variation in levels of disease experienced (DMFT) than in the health outcomes of its management (missing teeth). The findings indicate that social gradients for dental caries have a greater effect on how the disease was treated than on lifetime disease experience.
Health and safety of homecare workers engaged by temporary employment agencies
Authors: Quinlan Michael , Bohle Philip , Rawlings-Way Olivia
Published: August 2014

Shifts in demographics, lifestyles and employment and business practices are generating increased demand for homecare services. While providing support to vulnerable members of the community, homecare workers are themselves vulnerable. Precarious work and isolated workplaces expose them to poorly controlled occupational health and safety (OHS) hazards. This study examined OHS issues encountered by homecare agency workers. Eighteen carers working in aged care, disability support and youth services were interviewed in Adelaide and the Barossa Valley, South Australia. Participants identified a range of OHS problems, including inadequate risk assessment, unsatisfactory OHS policies and procedures, poor training, lack of employment benefits, problematic working hours, lack of agency support and the demands of particular types of work. These findings provide preliminary evidence of significant OHS management deficiencies. The results require further investigation to guide the development of policies and practices intended to provide healthy, productive and sustainable work environments for homecare workers. Such policies and practices should address compliance with OHS and workers’ compensation legislation, the prevention of negative OHS outcomes, provision of effective mechanisms for workers to raise OHS concerns and implementation of support structures.
Mechanism of Disyllabic Tonal Reduction in Taiwan Mandarin
Authors: Cheng Chierh , Xu Yi
Published: August 2014

This study was designed to test the hypothesis that time pressure is a direct cause of tonal reduction in Taiwan Mandarin. Tonal reduction refers to the phenomenon of the tones of a disyllabic unit being contracted into a monosyllabic unit. An experiment was carried out in which six native Taiwan Mandarin male speakers produced sentences containing disyllabic compound words /ma/+/ma/ with varying tonal combinations at different speech rates. Analyses indicated that increasing time pressure led to severe tonal reductions. Articulatory effort, measured by the slope of F0 peak velocity of unidirectional movement over F0 movement amplitude, is insufficient to compensate for duration-dependent undershoot (in particular, when time pressure exceeds certain thresholds). Mechanisms of tonal reduction were further examined by comparing F0 velocity profiles against the Edge-in model, a rule-based phonological model. Results showed that the residual tonal variants in contracted syllables are gradient rather than categorical—as duration is shortened, the movement towards the desired targets is gradually curtailed.
SMART Recovery
Authors: O’Sullivan Deirdre , Blum Jillian B. , Watts Justin , Bates Julie K.
Published: August 2014

Peer support groups are the most utilized form of treatment for individuals recovering from substance abuse and substance dependence. This study examined an understudied peer support program (Self-Management and Recovery Training [SMART] Recovery), which is distinct from traditional 12-step models. Although treatment planning for substance use disorders is not the primary focus of vocational rehabilitation (VR), persons with disabilities are at increased risk for these disorders. Due to the bio-psycho-social nature of substance use disorders, VR counselors must consider ethical treatment recommendations for clients who demonstrate need for supplemental treatment. This descriptive-survey study investigated two samples of member and facilitator characteristics, motivations, and recovery goals among the SMART Recovery community. Implications for VR counselors making best practice recommendations for clients with substance use disorders are discussed.
A Critical Geographic Approach to Youth Civic Engagement
Authors: Burke Kevin J. , Greene Stuart , McKenna Maria K.
Published: August 2014

The article draws on work in Critical Geography Studies and Photovoice methodology, to illustrate the ways in which youth in an inner city conceptualize neighborhoods and public spaces. We utilize youth’s photographs, narratives, and maps to tell a story of youth’s lived experiences and argue that these experiences are vital sources of knowledge about how an unequal distribution of resources affects them. It is important, we argue, to not only hear student voices but also prepare them to become critical, independent thinkers, who can use multiple literacies as affordances for creating changes that help nourish them. This means fundamentally rethinking how as educators we listen to and walk with youth as they reframe the ways in which we might use public parks, neighborhood schools, community centers, and sidewalks as pedagogical and political spaces.
Wonder of Life (kalanchoe pinnata) leaves to treat diabetic foot infections in Trinidad & Tobago: a case control study
Authors: Cawich Shamir O , Harnarayan Patrick , Budhooram Steve , Bobb Nahmorah J , Islam Shariful , Naraynsingh Vijay
Published: August 2014

Wonder of Life ( kalanchoe pinnata) leaves are commonly used to treat diabetic foot infections. These patients are usually non-compliant with conventional medical therapy. We surmised that these patients would have a higher incidence of treatment failures. Patients admitted with diabetic foot infections were separated into two groups: a Study Group comprised patients who used topical kalanchoe pinnata and a Medical Therapy Group contained patients who were compliant with conventional treatment. The patients were observed over the course of their hospitalisation.

Results

There were 382 patients in the Medical Therapy Group and 96 in the Study Group, who waited 9.21 ± 5.3 days (Mean ± SD) before seeking medical attention. There were similar rates of all amputations (34.8% vs. 37.5%; P = 0.643) and mortality (0.8% vs. 1.0%; P = 1.000) in the Study and Medical Therapy groups.

Conclusions

There may be value in the use of topical kalanchoe pinnata to treat diabetic foot infections.
Causality Between High-Performance Work Systems and Organizational Performance
Authors: Shin Duckjung , Konrad Alison M.
Published: August 2014

Previous researchers have questioned whether the association between high-performance work systems (HPWS) and organizational performance indicates causality. Strategic human resource management theories, including the resource-based view of the firm and the behavioral perspective, have provided explanations linking human resource management practices to organizational performance. We add arguments based upon general systems theory to suggest a more complex relationship where performance provides feedback on HPWS in the form of information and resources. This feedback generates both the data and the slack resources needed to support an adaptive process of HPWS implementation. We test the causal associations between HPWS and performance using a large longitudinal data set with three time points. Findings showed that past HPWS positively contributes to later productivity as well as the reverse. The reciprocal relationship supports the need to extend strategic human resource management theory by considering productivity as an antecedent as well as an outcome of human resource management practices.
Smoking, Physical Activity, and Eating Habits Among Adolescents
Authors: Lee Bokim , Yi Yunjeong
Published: August 2014

The purpose of this study was to compare physical activity and eating habits of adolescent smokers with those of adolescent non-smokers in South Korea. This was a secondary analysis of data collected from the 2012 Korean Youth Risk Behavior Web-Based Survey. The sample included 72,229 adolescents aged 12 to 18. A multiple logistic regression analysis was performed to examine the association between smoking status and physical activity and between smoking status and eating habits, while controlling for other factors. Boys and girls were analyzed separately for all analyses. The proportion of self-reporting smokers was 11%. Surprisingly, girl smokers exercised significantly more frequently than non-smokers. Adolescent smokers were significantly less likely to consume fruits, vegetables, and milk/dairy products, and they ate significantly more fast-food than non-smokers. Health care professionals who plan smoking cessation programs should pay attention to South Korean adolescents’ specific characteristics and cultural values in terms of health behavior.
Effect of Cardiac Arrhythmia Simulation on Nursing Students’ Knowledge Acquisition and Retention
Authors: Tubaishat Ahmad , Tawalbeh Loai I.
Published: August 2014

The realistic and practical environment that simulation provides is an extremely useful part of the teaching process. Simulation is widely used in health and nursing education today. This study aims to evaluate the effect of simulation-based teaching on the acquisition and retention of arrhythmia-related knowledge among nursing students. A randomized controlled design involving a pretest–posttest was used. Nursing students were allocated randomly either to the experimental group ( n = 47), who attended simulation scenarios on cardiac arrhythmia, or to the control group ( n = 44) who received a traditional lecture on the same topic. A paired t test showed that the mean knowledge score at the posttest was significantly higher than at the pretest for both groups. However, participants in the experimental group demonstrated significantly increased knowledge of cardiac arrhythmia in the first and the second posttest compared with those in the control group. Thus, simulation is superior and significantly improves students’ arrhythmia knowledge.
Chronic cerebrospinal venous insufficiency is not associated with chronic venous disorders: A case–control study
Authors: Leone Maurizio A , Raymkulova Olga , Lochner Piergiorgio , Bolamperti Laura , Rivadossi Gianandrea , Stecco Alessandro , Zaccala Giuseppe , Maggio Maurizio , Liboni William , Guido Marilena , Coppo Lorenzo , Imperiale Daniele
Published: August 2014

Objectives

To evaluate the relationship between chronic cerebrospinal venous insufficiency (CCSVI) and the presence of a Chronic Venous Disorder (CVD).

Method

We included 55 subjects with CCSVI aged >18 years, and 186 controls without CCSVI. Each subject was evaluated with color Doppler sonography in accordance with Zamboni’s five criteria, examined by two neurologists and interviewed with an ad-hoc designed form. The neurologists and the sonographers were mutually blinded. CVD were classified according to CEAP.

Results

Mean age was 42 years (SD = 9) in cases and 43 years (10) in controls ( p = ns). The odds ratios in subjects CCSVI were 0.6 (0.2–2.2) for CEAP 1, 0.9 (0.2–4.5) for CEAP 2, and 1.0 (0.6–1.9) for family history of varicose veins. The prevalence of CVD and, family history of varicose veins, was similar between cases and controls for each Zamboni criterion.

Conclusions

We found no association of CCSVI with the presence of CVD or family history of varicose veins.
Training balance with opto-kinetic stimuli in the home: a randomized controlled feasibility study in people with pure cerebellar disease
Authors: Bunn Lisa M , Marsden Jonathan F , Giunti Paola , Day Brian L
Published: August 2014

Objective:

To investigate the feasibility of a randomized controlled trial of a home-based balance intervention for people with cerebellar ataxia.

Design:

A randomized controlled trial design.

Setting:

Intervention and assessment took place in the home environment.

Participants:

A total of 12 people with spinocerebellar ataxia type 6 were randomized into a therapy or control group. Both groups received identical assessments at baseline, four and eight weeks.

Interventions:

Therapy group participants undertook balance exercises in front of optokinetic stimuli during weeks 4–8, while control group participants received no intervention.

Main measures:

Test–retest reliability was analysed from outcome measures collected twice at baseline and four weeks later. Feasibility issues were evaluated using daily diaries and end trial exit interviews.

Results:

The home-based training intervention with opto-kinetic stimuli was feasible for people with pure ataxia, with one drop-out. Test–retest reliability is strong (intraclass correlation coefficient >0.7) for selected outcome measures evaluating balance at impairment and activity levels. Some measures reveal trends towards improvement for those in the therapy group. Sample size estimations indicate that Bal-SARA scores could detect a clinically significant change of 0.8 points in this functional balance score if 80 people per group were analysed in future trials.

Conclusions:

Home-based targeted training of functional balance for people with pure cerebellar ataxia is feasible and the outcome measures employed are reliable.
A randomized controlled trial studying efficacy and tolerance of a knee-ankle-foot orthosis used to prevent equinus in children with spastic cerebral palsy
Authors: Maas JC , Dallmeijer AJ , Huijing PA , Brunstrom-Hernandez JE , van Kampen PJ , Bolster EAM , Dunn C , Herndon K , Jaspers RT , Becher JG
Published: August 2014

Objective:

To examine whether using a knee-ankle-foot orthosis helps maintain ankle-foot dorsiflexion range of motion over time.

Design:

A multicentre randomized controlled trial.

Setting:

Two hospitals and one rehabilitation centre in the Netherlands and the USA.

Subjects:

Children (4-16 years old) with spastic cerebral palsy who were able to walk.

Intervention:

Use of a knee-ankle-foot orthosis, equipped with an Ultraflex® ankle power unit, for at least 6 hours every other night for one year.

Main measures:

Primary outcome measure: ankle-foot dorsiflexion range of motion. Secondary outcome measures: ankle-foot and knee angle in gait and gross motor function. Wearing time was also measured. Measurements were taken at baseline and at 3, 6, 9 and 12 months.

Results:

28 children (experimental group: n=15, control group: n=13) participated in the study. 11 participants (experimental: n=4, control: n=7) did not complete all five measurements, as they needed additional treatment. No significant difference was found in the decrease of ankle-foot dorsiflexion range of motion between the experimental and control groups (difference: −1.05°, 95% confidence interval: −4.71° – 2.61°). In addition, secondary outcome measures did not show differences between groups. Despite good motivation, knee-ankle-foot orthosis wearing time was limited to a mean±SD of 3.2±1.9 hours per prescribed night due to discomfort.

Conclusions:

Knee-ankle-foot orthosis with dynamic ankle and fixed knee are poorly tolerated and are not beneficial in preventing a reduction in ankle-foot dorsiflexion range of motion in children with spastic cerebral palsy, at least with limited use.