bluuebunny/crossref_metadata_2025 huggingface dataset:
Large‐Amplitude Long‐Wave Instability of a Supersonic Shear Layer
Authors: Messiter A. F.
Published: September 2015

For sufficiently high Mach numbers, small disturbances on a supersonic vortex sheet are known to grow in amplitude because of slow nonlinear wave steepening. Under the same external conditions, linear theory predicts slow growth of long‐wave disturbances to a thin supersonic shear layer. An asymptotic formulation that adds nonzero shear‐layer thickness to the weakly nonlinear formulation for a vortex sheet is given here. Spatial evolution is considered for a spatially periodic disturbance having amplitude of the same order, in Reynolds number, as the shear‐layer thickness. A quasi‐equilibrium inviscid nonlinear critical layer is found, with effects of diffusion and slow growth appearing through a nonsecularity condition. Other limiting cases are also considered, in an attempt to determine a relationship between the vortex‐sheet limit and the long‐wave limit for a thin shear layer; there appear to be three special limits, corresponding to disturbances of different amplitudes at different locations along the shear layer.
Inaccessible States in Time‐Dependent Reaction Diffusion
Authors: Cohen Donald S. , Witelski Thomas P.
Published: September 2015

Using asymptotic methods we show that the long‐time dynamic behavior in certain systems of nonlinear parabolic differential equations is described by a time‐dependent, spatially inhomogeneous nonlinear evolution equation. For problems with multiple stable states, the solution develops sharp fronts separating slowly varying regions. By studying the basins of attraction of Abel's nonlinear differential equation, we demonstrate that the presence of explicit time dependence in the asymptotic evolution equation creates “forbidden regions” where the existence of interfaces is excluded. Consequently, certain configurations of stable states in the nonlinear system become inaccessible and cannot be achieved from any set of real initial conditions.
Solutions to the Navier‐Stokes Equations Describing Local Flows of Stratified and Compressible Fluids
Authors: Varley E. , Seymour B. R.
Published: September 2015

A family of exact solutions of the Navier‐Stokes equations is used to describe local flows of incompressible stratified and compressible fluids. For some of the flows, the coefficient of viscosity can depend on the temperature. An example of an incompressible stratified flow for which the analysis is applicable is the sheared swirling flow that is produced between two parallel plates that translate with different velocities and rotate with different angular velocities about different, but parallel, axes. The fluid may be stratified in the direction normal to the plates. These generalized von Karman flows are relevant to the study of strong local atmospheric disturbances, such as might be produced by the passage of a tornado. Also, when the coefficient of viscosity depends on the temperature, they can be used to analyze the flow of molten metals between surfaces that are in relative motion. An example of a compressible flow for which the analysis is applicable is that produced by a plane shock wave as it traverses a layer where the fluid is sheared in a direction normal to the shock.
Application of multisine nanoscale impedance microscopy to heterogeneous alloy surface investigations
Authors: Zieliński A. , Darowicki K.
Published: September 2015

In the recent years atomic force microscopy is recognized as valuable tool for investigation of surficial features of construction materials. It concerns, among other things, studies of changes caused by such phenomena as galvanic corrosion, passivation associated with the growth of oxide layers, or sensitization of austenitic steels with the formation of carbide phases. In addition, atomic force microscopy allows easy coupling with impedance technique which is especially promising because of its versatility in investigations of both conductive and dielectric materials. The authors discuss the possibility of application of such type of measurement, known as impedance microscopy. Copyright © 2015 John Wiley & Sons, Ltd.
A point‐process response model for spike trains from single neurons in neural circuits under optogenetic stimulation
Authors: Luo X. , Gee S. , Sohal V. , Small D.
Published: September 2015

Optogenetics is a new tool to study neuronal circuits that have been genetically modified to allow stimulation by flashes of light. We study recordings from single neurons within neural circuits under optogenetic stimulation. The data from these experiments present a statistical challenge of modeling a high‐frequency point process (neuronal spikes) while the input is another high‐frequency point process (light flashes). We further develop a generalized linear model approach to model the relationships between two point processes, employing additive point‐process response functions. The resulting model, point‐process responses for optogenetics (PRO), provides explicit nonlinear transformations to link the input point process with the output one. Such response functions may provide important and interpretable scientific insights into the properties of the biophysical process that governs neural spiking in response to optogenetic stimulation. We validate and compare the PRO model using a real dataset and simulations, and our model yields a superior area‐under‐the‐curve value as high as 93% for predicting every future spike. For our experiment on the recurrent layer V circuit in the prefrontal cortex, the PRO model provides evidence that neurons integrate their inputs in a sophisticated manner. Another use of the model is that it enables understanding how neural circuits are altered under various disease conditions and/or experimental conditions by comparing the PRO parameters. Copyright © 2015 John Wiley & Sons, Ltd.
Design of sequentially randomized trials for testing adaptive treatment strategies
Authors: Ogbagaber Semhar B. , Karp Jordan , Wahed Abdus S.
Published: September 2015

An adaptive treatment strategy (ATS) is an outcome‐guided algorithm that allows personalized treatment of complex diseases based on patients' disease status and treatment history. Conditions such as AIDS, depression, and cancer usually require several stages of treatment because of the chronic, multifactorial nature of illness progression and management. Sequential multiple assignment randomized (SMAR) designs permit simultaneous inference about multiple ATSs, where patients are sequentially randomized to treatments at different stages depending upon response status. The purpose of the article is to develop a sample size formula to ensure adequate power for comparing two or more ATSs. Based on a Wald‐type statistic for comparing multiple ATSs with a continuous endpoint, we develop a sample size formula and test it through simulation studies. We show via simulation that the proposed sample size formula maintains the nominal power. The proposed sample size formula is not applicable to designs with time‐to‐event endpoints but the formula will be useful for practitioners while designing SMAR trials to compare adaptive treatment strategies. Copyright © 2015 John Wiley & Sons, Ltd.
Playing dirty or building capability? Corruption and HR training as competitive actions to threats from informal and foreign firm rivals
Authors: Iriyama Akie , Kishore Rajiv , Talukdar Debabrata
Published: September 2015

Research summary: We examine why a firm takes specific competitive action in nonmarket and resource‐market spaces, particularly when it perceives threats from informal and foreign competitor groups, respectively. We address this question by combining insights from competitive rivalry, strategic groups, and nonmarket strategy literatures in an emerging economy context. Specifically, we theorize how threats from informal and foreign rival firms in an emerging market influence a firm's engagement in corruption activities and its investments in HR training, respectively. We also argue that the likelihoods of such focal firm actions against competitor group threats differ, contingent on the focal firm's market and resource profiles. Results from the empirical analyses, with survey data from the Indian IT industry, provide broad support to our hypotheses.

Managerial summary: Based on a World Bank dataset on the Indian IT industry, this study finds that corruption and HR training are pursued by firms in emerging economies as mindful strategies against specific types of rivals—informal and foreign firm rivals, respectively, and are not pursued simply as culturally‐based practices. Multinational companies may need to understand that domestic firms in emerging countries will engage in corruption strategically to reduce their costs and time to market of their products/services. Therefore, multinational firms may need to devise suitable strategies other than corruption to reduce their costs and time to market if they wish to compete with firms in emerging economies for customers who don't care about ethical issues and will buy a cheaper product/service that is delivered quickly. Copyright © 2015 John Wiley & Sons, Ltd.
Probing Bio–Nano Interactions between Blood Proteins and Monolayer‐Stabilized Graphene Sheets
Authors: Gan Shiyu , Zhong Lijie , Han Dongxue , Niu Li , Chi Qijin
Published: September 2015

Meeting proteins is regarded as the starting event for nanostructures to enter biological systems. Understanding their interactions is thus essential for a newly emerging field, nanomedicine. Chemically converted graphene (CCG) is a wonderful two‐dimesional (2D) material for nanomedecine, but its stability in biological environments is limited. Systematic probing on the binding of proteins to CCG is currently lacking. Herein, we report a comprehensive study on the interactions between blood proteins and stabilized CCG (sCCG). CCG nanosheets are functionalized by monolayers of perylene leading to significant improvement in their resistance to electrolyte salts and long‐term stability, but retain their core structural characteristics. Five types of model human blood proteins including human fibrinogen, γ‐globulin, bovine serum albumin (BSA), insulin, and histone are tested. The main drving forces for blood protein binding involve the π–π interacations between the π‐plane of sCCG and surface aromatic amonic acid (sAA) residues of proteins. Several key binding parameters including the binding amount, Hill coefficient, and binding constant are determined. Through a detailed analysis of key controlling factors, we conclude that the protein binding to sCCG is determined mainly by the protein size, the number, and the density of the sAA.
Systemic Management to Address the Challenges Facing the Performance of Agriculture in Africa: Case Study in Ghana
Authors: Banson Kwamina E. , Nguyen Nam C. , Bosch Ockie J. H.
Published: September 2015

Constraints and challenges in the agricultural industry of Ghana limit its productivity. Policy constraints could be a major issue when it comes to agricultural sustainability. Whether policymaking is based on sound principles that take into account the intended and unintended consequences led to exploring the use of a fresh approach towards determining effective interventions (policies) through a systems approach. Capacity building using a systems thinking approach that focuses on the four levels of thinking and using the concepts of an Evolutionary Learning Laboratory during a series of stakeholder workshops in Ghana has shown a remarkable impact on the ability of the agricultural industry to evolve, improve and raise its efficacy. Results from Bayesian belief network (BBN) models indicated that the implementation of systemically determined interventions, policies and strategies could result in chances of ‘agricultural productivity’ being ‘good’ as high as 92.2% from 57.5%, while the chances of reducing poverty levels from 44.9% to 10.0% are plausible. These would also lead to a significant increase in the yield and profit of the farmers. These BBNs are used for scenario testing to determine the potential outcomes of different systemic interventions by observing what would happen to the system as a whole when a particular intervention/strategy or combination of interventions/strategies are implemented: that is, before any time or money is invested in actual implementation. This approach provides more clarity on dealing with complex sustainability challenges and should gradually replace the reductionist approach (e.g. short‐term quick fixes and treating the symptoms) in dealing with challenges and developing policies. Copyright © 2015 John Wiley & Sons, Ltd.
Reduction Behavior and Structural Evolution of Iron Ores in Fluidized Bed Technologies. Part 1: Method for the Determination
Authors: Skorianz Michael , Mali Heinrich , Pichler Anton , Plaul Friedemann , Schenk Johannes , Weiss Bernd
Published: September 2015

Due to environmental and economic constraints, alternative iron‐making processes to the traditional blast furnace technology have been developed in recent decades. These are direct reduction and smelting reduction technologies, some using iron ore fines directly without prior agglomeration processes. This work deals with the development of a new method for the investigation of reduction behavior and structural evolution of iron ore fines under fluidized bed conditions – in order to optimize fluidized bed‐based technologies for iron‐ and steelmaking. Regarding iron ore fines reduction under fluidized bed conditions, several investigations have been performed in recent years. With previous methods, the reduction behavior during the process is evaluated by the extraction of samples and their chemical analysis. The advantage of the new method is the continuous measurement of the main relevant process parameters, especially the weight loss of the fluidized sample caused by reduction. Based on the gathered data, the process behavior and the reduction progress can be determined and compared with chemical analyses, morphology, and mass balances. A benefit of the applied method is that test conditions are closer to real industrial processes in comparison to prior research work.
Clinical utility of postmortem microcomputed tomography of the fetal heart: diagnostic imaging vs macroscopic dissection
Authors: Hutchinson J. C. , Arthurs O. J. , Ashworth M. T. , Ramsey A. T. , Mifsud W. , Lombardi C. M. , Sebire N. J.
Published: September 2015

Objectives

Congenital cardiac malformations are commonly identified at perinatal autopsy, which can be challenging in fetuses of early gestation and in macerated fetuses. Our objective was to examine fetal complex congenital heart disease by microcomputed tomography (micro‐CT), using standard autopsy as the gold standard.

Methods

In this ethically approved study, ex‐vivo isolated fetal heart and fetal heart‐lung blocks underwent iodine preparation prior to micro‐CT, and were fixed in formalin after the micro‐CT examination. Images were acquired using a microfocus‐CT scanner with individual specimen image optimization. Twenty‐one indices assessed normally at autopsy were evaluated for each dataset. Cardiac dissection was performed using a dissecting microscope within 24 h of the micro‐CT examination.

Results

We examined six fetal hearts, comprising five with complex congenital cardiac malformations at a gestational age of 17–23 weeks and an anatomically normal heart of 23 weeks' gestation for reference. All specimens demonstrated excellent internal contrast at micro‐CT examination, and the correct overall diagnosis was made in all cases. There was agreement for 114/126 indices assessed on micro‐CT and at autopsy dissection (overall concordance of 95.8% (95% CI, 90.5–98.2%)). Micro‐CT was particularly useful in the assessment of ventricular morphology in macerated fetuses.

Conclusions

Micro‐CT of small ex‐vivo fetal specimens can provide highly accurate three‐dimensional rendering of complex congenital fetal heart disease. This approach represents a significant advance in postmortem imaging and confirms the potential of this technology for non‐invasive examination of small fetuses and organs. Copyright © 2015 ISUOG. Published by John Wiley & Sons Ltd.
The complementarity and comparability of climate change adaptation and mitigation
Authors: Watkiss Paul , Benzie Magnus , Klein Richard J.T.
Published: September 2015

Both mitigation and adaptation can reduce the risks of climate change. This study reviews the complementarity and comparability between the two, looking first at the global level and then at the national‐to‐local domain. At the global level, the review finds differing definitions and viewpoints exist in the literature. Much of the economic literature reports that global mitigation and adaptation are substitutes (in economic terms). In contrast, the scientific literature considers them to be complementary (in policy terms), as they address different risks that vary temporally and spatially. The degree of complementarity and comparability therefore depends on the perspective taken, although there is a policy space where the two can overlap. However, the governance, institutional, and policy‐based literature identifies that even if a global mitigation and adaptation mix could be defined, it would be highly contentious and extremely difficult to deliver in practice. The review then considers the complementarity and comparability of mitigation and adaptation at the national‐to‐local domain, in national policy and at sector level. The review finds there is greater potential for complementarity at this scale, although possible conflicts can also exist. However, the institutional, governance, and policy literature identifies a number of barriers to practical implementation, and as a result, complementary mitigation and adaptation action is unlikely to happen autonomously. Finally, the lessons from the review are drawn together to highlight policy relevant issues and identify research gaps. WIREs Clim Change 2015, 6:541–557. doi: 10.1002/wcc.368

This article is categorized under:

Integrated Assessment of Climate Change > Methods of Integrated Assessment of Climate Change

The Carbon Economy and Climate Mitigation > Benefits of Mitigation

Climate and Development > Sustainability and Human Well‐Being
Experimental and numerical investigation of tip vortex generation and evolution on horizontal axis wind turbines
Authors: Micallef Daniel , Ferreira Carlos Simão , Sant Tonio , Bussel Gerard van
Published: September 2015

The tip vortex of a wind turbine rotor blade is the result of a distribution of aerodynamic loads and circulation over the blade tip. The current knowledge on the generation of the tip vorticity in a 3D rotating environment still lacks detailed experimental evidence, particularly for yawed flow. The aim of this paper is to investigate how circulation at the blade tip behaves and how vorticity is eventually released in the wake, for both axial and 30° yawed flow conditions through the combination of experimental and numerical simulations. Stereo particle image velocimetry is used to measure the flow field at the tip of a 2m diameter, two‐bladed rotor at the TU Delft Open Jet Facility, for both axial and yawed flow; numerical simulations of the experiments are performed using a 3D, unsteady potential flow free‐wake vortex model. The generation mechanisms of the tip vorticity are established. The spanwise circulation along the blade exhibits a similar variation in both axial and yaw cases. A comparison of the chordwise directed circulation variation along the chord between axial and yawed flow is also presented and shown to be different. The analysis is based on contour integration of the velocity field. The tip vortex trajectory for axial flow confirms previous observations on the MEXICO rotor. The experimental results for yawed conditions have clearly shown how vorticity is swept radially away from the blade under the influence of the in‐plane radial component of flow. Such phenomena were only partially captured by the numerical model. The results of this work have important implications on the modelling of blade tip corrections. Copyright © 2015 John Wiley & Sons, Ltd.
A prospective analysis of GERD after POEM on anterior myotomy
Authors: Shiwaku Hironari , Inoue Haruhiro , Sasaki Takamitsu , Yamashita Kanefumi , Ohmiya Toshihiro , Takeno Shinsuke , Nimura Satoshi , Yamashita Yuichi
Published: September 2015

Background

Peroral endoscopic myotomy (POEM) is an emerging, minimally invasive procedure capable of overcoming limitations of achalasia treatments, but gastroesophageal reflux disease (GERD) after POEM is of concern and its risk factors have not been evaluated. This prospective study examined GERD and the association of POEM with reflux esophagitis.

Methods

Achalasia patients were recruited from a single center. The pre- and postoperative assessments included Eckardt scores, manometry, endoscopy, and pH monitoring.

Results

Between September 2011 and November 2014, 105 patients underwent POEM; 70 patients were followed up 3 months after POEM. Postoperatively, significant reductions were observed in lower esophageal sphincter (LES) pressure [from 40.0 ± 22.8 to 20.7 ± 14.0 mmHg (P < 0.05)], LES residual pressure [from 22.1 ± 13.3 to 11.4 ± 6.6 mmHg (P < 0.05)], and Eckardt scores [from 5.7 ± 2.5 to 0.7 ± 0.8 (P < 0.05)]. Symptomatic GERD and moderate reflux esophagitis developed in 5 and 11 patients (grade B,n = 8; grade C,n = 3), respectively, and were well controlled with proton pump inhibitors. Univariate logistic regression analysis revealed integrated relaxation pressure was a predictor of ≥grade B reflux esophagitis. No POEM factors were found to be associated with reflux esophagitis.

Conclusion

POEM is effective and safe in treating achalasia, with no occurrence of clinically significant refractory GERD. Myotomy during POEM, especially of the gastric side, was not associated with ≥grade B (requiring medical intervention) reflux esophagitis. Extended gastric myotomy (2–3 cm) during POEM is recommended to improve outcomes.
Aggression Norms in the Classroom Social Network: Contexts of Aggressive Behavior and Social Preference in Middle Childhood
Authors: Jackson Daisy R. , Cappella Elise , Neal Jennifer Watling
Published: September 2015

In a cross‐sectional sample of African‐American 2nd–4th grade students (N = 681), we examine the moderating effects of classroom overt and relational aggression norms on peers’ social acceptance of classmates who exhibit overt and relational aggression in urban schools. Extending theory and research on classroom norms, we integrate social network data to adjust aggression norms based on children’s direct and indirect connections in the classroom. Results of multilevel models indicate that network‐based classroom aggression norms moderated relations between children’s aggressive behavior and their social preference. Specifically, children benefited socially when their form of aggressive behavior fit with what was normative in the classroom social context. The moderating effect of classroom aggression norms was stronger for the association between overt aggression and social preference than relational aggression and social preference. Relationally aggressive youth were socially preferred by peers regardless of the classroom norm, although this positive association was magnified in classrooms with higher levels of relational aggression. Future research focused on aggression norms within classroom social networks are discussed and implications for school prevention efforts are considered.
Transition von der Kindheit in das Erwachsenenalter bei chronischen Krankheiten
Authors: Plöckinger Ursula
Published: September 2015

Dank des medizinischen Fortschritts erleben zunehmend mehr Kinder mit chronischen Erkrankungen das Erwachsenenalter. Patienten mit angeborenen Stoffwechselkrankheiten stellen nur eine, jedoch in ihrer Größe und Problematik besondere Gruppe heranwachsender Patienten dar. Allerdings fehlen vielfach begleitende Strukturen im Gesundheitssystem, um eine erfolgreiche Transition zu ermöglichen. Dies kann zu erheblicher Beeinträchtigung der Gesundheit der Betroffenen führen. Der Artikel beschreibt den Transitionsprozess des gesunden Adoleszenten zum jungen Erwachsenen sowie die Schwierigkeiten dieses Prozesses für chronisch kranke junge Menschen mit erhöhtem Bedarf an Gesundheitsbetreuung, die zusätzlich den Übergang aus der pädiatrischen Medizin in die Erwachsenenmedizin zu bewältigen haben.
Brief report: Assessing youth well‐being in global emergency settings: Early results from the Emergency Developmental Assets Profile
Authors: Scales Peter C. , Roehlkepartain Eugene C. , Wallace Teresa , Inselman Ashley , Stephenson Paul , Rodriguez Michael
Published: September 2015

The 13‐item Emergency Developmental Assets Profile measures the well‐being of children and youth in emergency settings such as refugee camps and armed conflict zones, assessing whether young people are experiencing adequate positive relationships and opportunities, and developing positive values, skills, and self‐perceptions, despite being in crisis circumstances. The instrument was found to have acceptable and nearly identical internal consistency reliability in 22 administrations in non‐emergency samples in 15 countries (.75), and in 4 samples of youth ages 10–18 (n = 1550) in the emergency settings (war refugees and typhoon victims, .74) that are the measure's focus, and evidence of convergent validity. Confirmatory Factor Analysis showed acceptable model fit among those youth in emergency settings. Measures of model fit showed that the Em‐DAP has configural and metric invariance across all emergency contexts and scalar invariance across some. The Em‐DAP is a promising brief cross‐cultural tool for assessing the developmental quality of life as reported by samples of youth in a current humanitarian crisis situation. The results can help to inform international relief program decisions about services and activities to be provided for children, youth, and families in emergency settings.
The influence of inertia on the rheology of a periodic suspension of neutrally buoyant rigid ellipsoids
Authors: Daghooghi Mohsen , Borazjani Iman
Published: September 2015

We investigate the rheological properties of a suspension of neutrally buoyant rigid ellipsoids by fluid–structure interaction simulations of a particle in a periodic domain under simple shear using the curvilinear immersed-boundary (CURVIB) method along with a quaternion–angular velocity technique to calculate the dynamics of the particle’s motion. We calculate all the different terms of particle stress for the first time for non-spherical particles, i.e. in addition to the stresslet, we calculate the acceleration and Reynolds stress, which are typically ignored in previous similar works. Furthermore, we derive analytical expressions for all these terms to verify the numerical results and deduce the effect of inertia by comparing our numerical results with the analytical solution. The effect of particle Reynolds number ($\mathit{Re}$), volume fraction (${\it\phi}$), and the shape of particles has been studied on all mechanisms of stress generation, the intrinsic viscosity, and normal stress differences of the suspension for the range$0.008\leqslant {\it\phi}\leqslant 0.112$and$0.01\leqslant \mathit{Re}\leqslant 10.0$. We found that inertia increases the shear and the second normal difference of the stresslet (dominant term of the particle stress), and decreases the first normal difference that is generated due to the strain field. The contribution of acceleration stress to the total stress is found to be important in the second normal stress difference, with a cycle-average comparable to the stresslet component. We also discovered that the contribution of Reynolds stress in the first normal stress difference becomes important even when inertia is as low as$\mathit{Re}\sim O(0.1)$, and its value can be even greater than the stresslet when inertia increases, i.e. Reynolds stresses cannot be ignored for non-spherical particles. For concentrations in the range from dilute to semi-dilute, the effect of inertia on the intrinsic viscosity of a suspension is found to be comparable to the volume fraction. Furthermore, our calculations show that for a dilute concentration and the low-inertia regime ($\mathit{Re}<1.0$), the intrinsic viscosity of a suspension consisting of ellipsoids with an aspect ratio of five can be 20 % higher than its Stokesian analytical value.
Using functional gains for effective sensor location in flow control: a reduced-order modelling approach
Authors: Akhtar Imran , Borggaard Jeff , Burns John A. , Imtiaz Haroon , Zietsman Lizette
Published: September 2015

The problem of active feedback control of fluid flows falls into a class of problems in the area of distributed parameter control. Distributed parameter systems are typically defined by partial differential equations that model the time and spatial evolution of the process. We consider the problem of locating sensors for effective feedback control of a fluid flow problem described by the Navier–Stokes equations. In this setting, the state of the system is the velocity field$\boldsymbol{v}(t,x)$, and hence all feedback laws are a function of this velocity field or, in most practical settings, a function of sensor outputs. In many designs, the feedback control law can be represented as a linear function of the state defined by an integral operator with a kernel function called the functional gain. In this paper we show that these functional gains can be used to determine effective sensor placement in complex flow control applications. The approach is to choose measurements of the state that would provide good quadrature points for the integral operator. We provide a computational validation of this approach by controlling the vortex shedding in a two-dimensional cylinder flow using a pair of fluid actuators on the cylinder surface. This model is linearized about the mean flow and a feedback control is designed by pole placement. Distributed parameter control theory yields the existence and form of the functional gains which are used to locate sensors. In particular, we use the location of the supports of the functional gains to determine two sets of four sensor locations in the wake. One of these measurement sets coincides with large magnitudes of the gain and the other set coincides with small magnitudes. Numerical experiments with a reduced-order model confirm superior performance of the closed-loop (CL) system using the former sensor set. We also show that choosing sensor locations associated with small magnitudes of the functional gains actually destabilizes the CL system.
Self-induced flapping dynamics of a flexible inverted foil in a uniform flow
Authors: Gurugubelli P. S. , Jaiman R. K.
Published: September 2015

We present a numerical study on the self-induced flapping dynamics of an inverted flexible foil in a uniform flow. A high-order coupled fluid–structure solver based on fully coupled Navier–Stokes and nonlinear structural dynamic equations has been employed. Unlike a conventional flexible foil flapping where the leading edge is clamped, the inverted elastic foil is fixed at the trailing edge and the leading edge is allowed to oscillate freely. We investigate the evolution of flapping instability of an inverted foil as a function of the non-dimensional bending rigidity, $K_{B}$, Reynolds number, $\mathit{Re}$, and structure-to-fluid mass ratio, $m^{\ast }$, and identify three distinct stability regimes, namely (i) fixed-point stable, (ii) deformed steady and (iii) unsteady flapping state. With the aid of a simplified analytical model, we show that the fixed-point stable regime loses its stability by static-divergence instability. The transition from the deformed steady state to the unsteady flapping regime is marked by a flow separation at the leading edge. We also show that an inverted foil is more vulnerable to static divergence than a conventional foil. Three distinct unsteady flapping modes have been observed as a function of decreasing $K_{B}$: (i) inverted limit-cycle oscillations, (ii) deformed flapping and (iii) flipped flapping. We characterize the transition to the deformed-flapping regime through a quasistatic equilibrium analysis between the structural restoring and the fluid forces. We further examine the effects of $m^{\ast }$ on the post-critical flapping dynamics at a fixed $\mathit{Re}=1000$. Finally, we present the net work done by the fluid and the bending strain energy developed in a flexible foil due to the flapping motion. For small $m^{\ast }$, we demonstrate that the flapping of an inverted flexible foil can generate $O(10^{3})$ times more strain energy in comparison to a conventional flexible foil flapping, which has a profound impact on energy harvesting devices.
Water–substrate physico-chemistry in wetting dynamics
Authors: Johansson Petter , Carlson Andreas , Hess Berk
Published: September 2015

We consider the wetting of water droplets on substrates with different chemical composition and molecular spacing, but with an identical equilibrium contact angle. A combined approach of large-scale molecular dynamics simulations and a continuum phase field model allows us to identify and quantify the influence of the microscopic physics at the contact line on the macroscopic droplet dynamics. We show that the substrate physico-chemistry, in particular hydrogen bonding, can significantly alter the flow. Since the material parameters are systematically derived from the atomistic simulations, our continuum model has only one adjustable parameter, which appears as a friction factor at the contact line. The continuum model approaches the atomistic wetting rate only when we adjust this contact line friction factor. However, the flow appears to be qualitatively different when comparing the atomistic and continuum models, highlighting that non-trivial continuum effects can come into play near the interface of the wetting front.
Enabling Voice: Aboriginal Parents, Experiences and Perceptions of Sending a Child to Boarding School in Western Australia
Authors: Mander David J.
Published: September 2015

This study explored the experience of having a child educated away from home at boarding school for Aboriginal parents living in regional and remote communities in Western Australia (WA). In-depth interviews were conducted with 11 participants and thematic analysis found the following major themes emerged from the data: (1) Access, Standards and Quality, and the subthemes of Declining Local Schools, Opportunity, and Worldliness; (2) Parental Agency and the subthemes of Parent-School Connection, Parenting Style, Communication, and Milestones and Siblings and; (3) Cultural Heritage and the subtheme of Maintenance and Transmission. The findings are described and then discussed in terms of practice implications relevant to boarding schools in WA. Limitations of the current study are acknowledged and directions for future research are proposed.
Learning in Place, Cultural Mapping and Sustainable Values on the Millawa Billa (Murray River)
Authors: Heckenberg Robyn
Published: September 2015

This paper presents an Indigenous perspective on the significance of land, culture and Indigenous rights. The United Nations (UN) Declaration on the Rights of Indigenous Peoples promote the importance of traditional Indigenous societies, such as Aboriginal Australians. Participating in caring for country methods and having a close on-going relationship to the land is also supported in this Declaration. As well as this, these principles support the notion of Indigenous education for community, and youth in particular, in places of cultural significance and places of longstanding occupation. All of this lends itself to an Aboriginal way of being in terms of cultural teaching and learning. These principles are incorporated into a performative perspective of traditional pedagogy and the incorporation of cultural practices in a best practice model that can incorporate cultural mapping as an exercise that expounds environmental and ecological perspectives within learning places on the land. Through connection to land and community relationships to cultural knowledge and cultural values, this paper will provide an Indigenous standpoint on Indigenous experiences and senses of place and the importance of the UN Declaration on the Rights of Indigenous Peoples in advancing significant principles and initiatives that value Indigenous ways of being and doing.
Effects of work stressors on desire for organizational construction: The moderating role of leader–member exchange
Authors: Zhang Li , Chen Long , Zhao Ning
Published: September 2015

This study constructs the relationship between work stressors and the desire for organizational construction and the moderating role of leader–member exchange. The study is conducted by integrating social exchange and uncertainty management theory. Through investigating 204 employees and performing a scenario study in China, this research confirms that challenge stressors are positively related to desire for organizational construction. The relationship between hindrance stressors and desire for organizational construction tends to be U-shaped in the condition of high leader–member exchange, and the relationship tends to have an inverted U-shape in the condition of low leader–member exchange. This study has important implications for discerning the scope of application for both social exchange and uncertainty management theory, as managers seek to explain the relationship between negative treatment of employees and their desire for organizational construction.
The effect of macronutrients on glycaemic control: a systematic review of dietary randomised controlled trials in overweight and obese adults with type 2 diabetes in which there was no difference in weight loss between treatment groups
Authors: Emadian Amir , Andrews Rob C. , England Clare Y. , Wallace Victoria , Thompson Janice L.
Published: September 2015

Weight loss is crucial for treating type 2 diabetes mellitus (T2DM). It remains unclear which dietary intervention is best for optimising glycaemic control, or whether weight loss itself is the main reason behind observed improvements. The objective of this study was to assess the effects of various dietary interventions on glycaemic control in overweight and obese adults with T2DM when controlling for weight loss between dietary interventions. A systematic review of randomised controlled trials (RCT) was conducted. Electronic searches of Medline, Embase, Cinahl and Web of Science databases were conducted. Inclusion criteria included RCT with minimum 6 months duration, with participants having BMI≥25·0 kg/m2, a diagnosis of T2DM using HbA1c, and no statistically significant difference in mean weight loss at the end point of intervention between dietary arms. Results showed that eleven studies met the inclusion criteria. Only four RCT indicated the benefit of a particular dietary intervention over another in improving HbA1c levels, including the Mediterranean, vegan and low glycaemic index (GI) diets. However the findings from one of the four studies showing a significant benefit are questionable because of failure to control for diabetes medications and poor adherence to the prescribed diets. In conclusion there is currently insufficient evidence to suggest that any particular diet is superior in treating overweight and obese patients with T2DM. Although the Mediterranean, vegan and low-GI diets appear to be promising, further research that controls for weight loss and the effects of diabetes medications in larger samples is needed.
Rapid effects of essential fatty acid deficiency on growth and development parameters and transcription of key fatty acid metabolism genes in juvenile barramundi (Lates calcarifer)
Authors: Salini Michael J. , Turchini Giovanni M. , Wade Nicholas M. , Glencross Brett D.
Published: September 2015

Barramundi (Lates calcarifer), a catadromous teleost of significant and growing commercial importance, are reported to have limited fatty acid bioconversion capability and therefore require preformed long-chain PUFA (LC-PUFA) as dietary essential fatty acid (EFA). In this study, the response of juvenile barramundi (47·0 g/fish initial weight) fed isolipidic and isoenergetic diets with 8·2 % added oil was tested. The experimental test diets were either devoid of fish oil (FO), and thus with non-3 LC-PUFA (FO FREE diet), or with a low inclusion of FO (FO LOW diet). These were compared against a control diet containing only FO (FO CTRL diet) as the added lipid source, over an 8-week period. Interim samples and measurements were taken fortnightly during the trial in order to define the aetiology of the onset and progression of EFA deficiency. After 2 weeks, the fish fed the FO FREE and FO LOW diets had significantly lower live-weights, and after 8 weeks significant differences were detected for all performance parameters. The fish fed the FO FREE diet also had a significantly higher incidence of external abnormalities. The transcription of several genes involved in fatty acid metabolism was affected after 2 weeks of feeding, showing a rapid nutritional regulation. This experiment documents the aetiology of the onset and the progression of EFA deficiency in juvenile barramundi and demonstrates that such deficiencies can be detected within 2 weeks in juvenile fish.
The History of Multinationals: A 2015 View
Authors: Wilkins Mira
Published: September 2015

More than forty years ago (in the autumn of 1974), Business History Review had a special issue on multinational enterprise (MNE). With two exceptions, the authors in this new special issue were not yet born or were toddlers when that issue was published. Whereas in 1974 relatively few individuals were writing on topics directly related to the history of multinational enterprise, in 2015 numerous authors are considering subjects that fall under this rubric. Still, by the mid-1970s the study of the history of multinationals was not virgin territory. Glenn Porter, then editor of Business History Review, wrote in a preface to the 1974 issue, “Most of the contributions here underscore the deep historical roots of multinational business and point to the importance of an awareness of the past in understanding the present.”
Multinationals and Gender: Singer Sewing Machine and Marketing in Mexico, 1890–1930
Authors: de la Cruz-Fernández Paula A.
Published: September 2015

Headquartered in the United States, the Singer Sewing Machine Co. did business all around the world in the early twentieth century. It regularly encountered wars, economic nationalism, and revolutions; in response, it normally created subsidiaries or gave in to expropriation. After the revolution in Mexico (1910–1920), Singer's marketing organization maintained normal operations and even prospered. The company succeeded, in part, by constantly associating the sewing machine with the idea of “modern” womanhood in Revolutionary Mexico. By revealing Singer's marketing strategies and focusing on gender, this article shows that multinational corporations and Latin American governments were not always at odds and could sometimes forge a profitable relationship.
You’re Fired! New Evidence on Portfolio Manager Turnover and Performance
Authors: Kostovetsky Leonard , Warner Jerold B.
Published: September 2015

We study managerial turnover for both internally managed mutual funds and those managed externally by subadvisors. We argue that turnover of subadvisors provides sharper tests and helps address several unresolved issues and puzzles from the previous literature. We find dramatically stronger inverse relations between subadvisor departures and lagged returns, and new evidence on how past flow predicts turnover. We find no evidence of improvements in return performance related to departures, but flow improvements are associated with departures of poor past performers. Our findings represent new evidence on how investors, sponsors, and boards learn about and evaluate mutual fund management performance.
Marine colonization and biodiversity at Ascension Island and remote islands
Authors: Barnes David K.A.
Published: September 2015

Little is known about colonization of remote island coasts by marine invertebrates, other than corals. The structure of hard substrata assemblages was investigated across Ascension Island's littoral zone in comparison with other sites. Arrays of acrylic panels were deployed at two sites for 2 years at Ascension Island to measure subtidal recruitment. Colonization of panels at Ascension I. was low, though space occupation, abundance and richness varied considerably. After ~1 and 2 years Ascension panels were <17 and <37% covered by fauna and each had <22 recruits and 54 recruits (per 100 cm2) respectively, amongst the lowest density of recruits reported. Recruitment rates of corals (25 m2 year−1) at Ascension I. were also similar to the lowest levels reported elsewhere (e.g. at Bermuda or Midway islands). Less dispersive animal types, e.g. cheilostome bryozoans, were poorly represented. Panels immersed in Tanzania and Scotland were >30% covered, with >76 recruits per 100 cm2 and with bryozoans well represented after 1 year. Across-littoral surveys of established macrofauna at five remote islands (Ascension I., Easter I., Azores, South Georgia and Signy I., Antarctica) revealed similar trends of a rich sublittoral and lower littoral reducing drastically up-shore; molluscs dominating abundance and species numbers, whilst polychaetes, crustaceans and echinoderms were well represented. Established sessile animals occurred patchily at a mean density of 8.26 m−2 but recruits had mortality levels >99%. Polar or remote temperate/tropical sites are typically less colonized than at non-remote, low latitudes but the lowest levels reported are at remote polar sites. Reduced colonization at Ascension island reflects remoteness.
The belated formation of the China Bible House (1937): Nationalism and the indigenization of Protestantism in Republican China
Authors: Mak George Kam Wah
Published: September 2015

This paper investigates the belated formation of the China Bible House, the first national Bible society in China, as a result of the interplay between the politics of foreign Bible societies and the indigenizing Chinese church in relation to rising nationalism during the Republican era. The challenge of Chinese nationalism to Christianity drove foreign Bible societies and Chinese Protestants to work towards the indigenization of Bible work. However, distrust and conflicts hindered foreign Bible societies' co-operation among themselves and also with Chinese Protestants. While Chinese church leaders saw the founding of a Chinese Bible society as a manifestation of the Chineseness of the Protestant church in China, they agreed with foreign Bible societies on the global identity of Bible work, which justified the latter's continuing presence in China. This understanding, together with the need for foreign financial support and expertise, explains why Sino-foreign co-operation existed in Bible work in China.