bluuebunny/crossref_metadata_2025 huggingface dataset:
Utility‐based designs for randomized comparative trials with categorical outcomes
Authors: Murray Thomas A. , Thall Peter F. , Yuan Ying
Published: May 2016

A general utility‐based testing methodology for design and conduct of randomized comparative clinical trials with categorical outcomes is presented. Numerical utilities of all elementary events are elicited to quantify their desirabilities. These numerical values are used to map the categorical outcome probability vector of each treatment to a mean utility, which is used as a one‐dimensional criterion for constructing comparative tests. Bayesian tests are presented, including fixed sample and group sequential procedures, assuming Dirichlet‐multinomial models for the priors and likelihoods. Guidelines are provided for establishing priors, eliciting utilities, and specifying hypotheses. Efficient posterior computation is discussed, and algorithms are provided for jointly calibrating test cutoffs and sample size to control overall type I error and achieve specified power. Asymptotic approximations for the power curve are used to initialize the algorithms. The methodology is applied to re‐design a completed trial that compared two chemotherapy regimens for chronic lymphocytic leukemia, in which an ordinal efficacy outcome was dichotomized, and toxicity was ignored to construct the trial's design. The Bayesian tests also are illustrated by several types of categorical outcomes arising in common clinical settings. Freely available computer software for implementation is provided. Copyright © 2016 John Wiley & Sons, Ltd.
Response of cracked simply supported concrete beam with moving vehicle load
Authors: Zhou Linyun , Liu Huangin
Published: May 2016

The dynamic response of a cracked beam subjected to moving loads has been studied extensively in the past decades. However, very little is known about the dynamic impact factors and crack propagation when vehicles move along the cracked beam. It can be reasonably postulated that a crack extension may occur when the vehicle loads cross the cracked bridge at a high speed. As a result, the dynamic response will be enlarged significantly due to the flexural rigidity reduction induced by cracks, which may result in a dangerous effect on structures. To address this problem, a three‐dimensional vehicle‐bridge model was developed to investigate the dynamic response of cracked bridges with crack breathing. Crack breathing is simulated at the crack surface using contact elements. The modified crack closure method is adopted to calculate the stress intensity factors. The results showed that the impact factors for the damaged bridge under a moving load could be notably larger than those for the intact bridge, and could exceed the value specified in the AASHTO bridge design code. Meanwhile, crack propagation may occur when the vehicles move along the cracked bridge at a high speed. So, it is very necessary to limit the velocity and transverse position of the vehicles to avoid further damage to the cracked bridge.
Mechanical properties of lightweight concrete after fire exposure
Authors: Torić Neno , Boko Ivica , Juradin Sandra , Baloević Goran
Published: May 2016

The paper presents an experimental research project that focused on analysing the short‐term residual mechanical properties of lightweight concrete after exposure to temperatures of up to 600 °C and the effects of the short‐term residual mechanical properties on the post‐fire loadbearing capacity of different concrete sections. The experimental programme was conducted on four different concrete mixes by determining the mechanical properties immediately after cooling and up to 96 h after cooling. The following properties were investigated: compressive strength, ultrasonic pulse velocity and stress‐strain curves. The results show that the compressive strength undergoes an additional reduction in comparison to the initial residual strength (0 h property) of up to 20 % in the reference time period. A numerical study is presented at the end of the paper in order to quantify the effects of the short‐term strength reduction on the axial loadbearing capacity of slender and stocky concrete columns.
Long‐term aging effects on tensile characterization of steel fibre reinforced concrete
Authors: Teixeira Buttignol Thomaz Eduardo , Colombo Matteo , di Prisco Marco
Published: May 2016

The paper discusses the effect of aging on steel fibre reinforced concrete (SFRC) after 10 years. The aim is to observe the change in mechanical properties, especially of the residual post‐cracking tensile strength, due to long‐term aging. For this purpose, a comparison between the results of four‐point bending tests (4PB) at the age of 1 year and 10 years was carried out and it indicates that aging affects the serviceability post‐cracking residual strength, increasing fibre interfacial bond strength. Material classification is performed according to fib Model Code 2010 for 1‐year old and 10‐year old specimens. The objective is to estimate possible changes in the material class through the years. Three‐ and four‐point bending test results on 10‐year old specimens are described, together with a comparison between those tests. Both tests showed very similar results; slightly higher values were obtained with the three‐point bending (3PB) test. The tensile constitutive law is obtained according to fib Model Code 2010 and is compared with results of direct tensile tests on cylindrical specimens and Double Edge Wedge Splitting tests on prismatic specimens. A plane section (PS) approach adopting the tensile constitutive law is applied to predict the bending behaviour in terms of nominal stress against crack mouth opening displacement and it is compared with the bending test results.
Enhanced Recovery Pathway for Right and Left Colectomy: Comparison of Functional Recovery
Authors: Kummer Anne , Slieker Juliette , Grass Fabian , Hahnloser Dieter , Demartines Nicolas , Hübner Martin
Published: May 2016

Background

Enhanced recovery (ERAS) guidelines do not differentiate between left‐ and right‐sided colectomies, but differences in recovery have been reported for the two procedure types. We aimed to compare compliance with the ERAS protocol and outcomes after right versus left colectomy.

Methods

Between June 2011 and September 2014, all patients undergoing elective colonic resection were treated according to a standardized ERAS protocol and entered a prospective database. This retrospective analysis compared right and left colectomy regarding application of the ERAS pathway, bowel recovery, complications, and hospital stay.

Results

Eighty‐five patients with right colectomy matched well with 138 left‐sided resections for baseline demographics. Overall compliance with the ERAS protocol was 76 % for right versus 77 % for left colectomy patients (p = 0.492). First flatus occurred at postoperative day 2 in both groups (p = 0.057); first stool was observed after a median of 3 (right) and 2 days (left), respectively (p = 0.189). Twenty patients (24 %) needed postoperative nasogastric tube after right colectomy compared to 11 patients (8 %) after left colectomy (p = 0.002). Overall complication rates were 49 and 37 % for right and left colectomy, respectively (p = 0.071). Median postoperative length of stay was 6 days (IQR 4–9) after right and 5 days (IQR 4–7.5) after left colectomy (p = 0.020).

Conclusion

Overall compliance with the protocol was equally high in both groups showing that ERAS protocol was applicable for right and left colectomy. Functional recovery however, tended to be slower after right colectomy, and postoperative ileus rate was significantly higher. More cautious early feeding after right colectomy should be considered.
Deer herbivory affects the functional diversity of forest floor plants via changes in competition‐mediated assembly rules
Authors: Nishizawa Keita , Tatsumi Shinichi , Kitagawa Ryo , Mori Akira S.
Published: May 2016

Distorted plant diversity patterns due to ungulate herbivory could be explained by changes in community assembly processes, but the effects of ungulate herbivory on plant community assembly remain unclear. Here, we examined the role of deer herbivory in the regulation of the assembly processes of a forest floor plant community by assessing species and functional diversity in over‐ and no‐grazing plots (control and exclosure plots, respectively) in Shiretoko National Park in Japan. Compared with the exclosure plot, vegetation coverage was considerably lower, and species richness and diversity were higher in the control plot. Functional traits associated with competitive ability (leaf area and chlorophyll content) were significantly higher in the exclosure plot. The pattern of functional diversity changed from overdispersion to clustering with an increase in local crowdedness. This trait clustering indicates that the local communities that were free from ungulate disturbance gradually became dominated by some competitively superior plant species, which led to low species diversity and biotic homogenization. In contrast, the reduction in vegetation due to overgrazing by deer resulted in an increase in the relative importance of stochastic assembly processes, which enabled the coexistence of various species, including less competitive ones. Our results emphasize that although deer overabundance is of concern, their complete exclusion has a negative consequence from an ecological perspective. Because deer herbivory is an inherent process that affects the biodiversity of plants on the forest floor, the establishment of fences requires careful consideration to ensure the conservation of ecological processes and their associated biodiversity.
Comparison of Cox Model Methods in a Low-Dimensional Setting with Few Events
Authors: Ojeda Francisco M. , Müller Christian , Börnigen Daniela , Trégouët David-Alexandre , Schillert Arne , Heinig Matthias , Zeller Tanja , Schnabel Renate B.
Published: May 2016

Prognostic models based on survival data frequently make use of the Cox proportional hazards model. Developing reliable Cox models with few events relative to the number of predictors can be challenging, even in low-dimensional datasets, with a much larger number of observations than variables. In such a setting we examined the performance of methods used to estimate a Cox model, including (i) full model using all available predictors and estimated by standard techniques, (ii) backward elimination (BE), (iii) ridge regression, (iv) least absolute shrinkage and selection operator (lasso), and (v) elastic net. Based on a prospective cohort of patients with manifest coronary artery disease (CAD), we performed a simulation study to compare the predictive accuracy, calibration, and discrimination of these approaches. Candidate predictors for incident cardiovascular events we used included clinical variables, biomarkers, and a selection of genetic variants associated with CAD. The penalized methods, i.e., ridge, lasso, and elastic net, showed a comparable performance, in terms of predictive accuracy, calibration, and discrimination, and outperformed BE and the full model. Excessive shrinkage was observed in some cases for the penalized methods, mostly on the simulation scenarios having the lowest ratio of a number of events to the number of variables. We conclude that in similar settings, these three penalized methods can be used interchangeably. The full model and backward elimination are not recommended in rare event scenarios.
Combinatorial particle swarm optimization for solving blocking flowshop scheduling problem
Authors: Eddaly Mansour , Jarboui Bassem , Siarry Patrick
Published: May 2016

This paper addresses to the flowshop scheduling problem with blocking constraints. The objective is to minimize the makespan criterion. We propose a hybrid combinatorial particle swarm optimization algorithm (HCPSO) as a resolution technique for solving this problem. At the initialization, different priority rules are exploited. Experimental study and statistical analysis were performed to select the most adapted one for this problem. Then, the swarm behavior is tested for solving a combinatorial optimization problem such as a sequencing problem under constraints. Finally, an iterated local search algorithm based on probabilistic perturbation is sequentially introduced to the particle swarm optimization algorithm for improving the quality of solution. The computational results show that our approach is able to improve several best known solutions of the literature. In fact, 76 solutions among 120 were improved. Moreover, HCPSO outperforms the compared methods in terms of quality of solutions in short time requirements. Also, the performance of the proposed approach is evaluated according to a real-world industrial problem.

Highlights The blocking flowshop scheduling problem is very attractive problem in engineering. A particle swarm optimization approach is proposed. Extensive experiments are conducted to choose the initialization way. Improvement procedure is introduced based on iterated local search algorithm. A real-world case is solved by the proposed algorithm.
A Qualitative Study on Experiences After Vulvar Surgery in Women with Lichen Sclerosus and Sexual Pain
Authors: Brauer Marieke , van Lunsen Rik H.W. , Laan Ellen T.M. , Burger Matthé P.M.
Published: May 2016

Introduction

Lichen sclerosus (LS) of the vulva can profoundly affect sexual interaction because of painful fissures and narrowing of the vaginal introitus. Successful surgical treatment is usually defined as restoration of (pain-free) penetrative sexual activity.

Aims

To evaluate the impact of surgery on (dyadic) sexual functioning and pleasure and psychological well-being.

Methods

Nineteen women with anogenital LS participated in audiotaped, qualitative, individual interviews after surgery to re-enable sexual intercourse.

Main Outcome Measures

Physical, sexual, and psychological experiences were analyzed using the constant comparative method.

Results

Vulvar surgery resulted in a decrease of sexual pain in 13 of 19 patients (68%). Of these 13 patients, 4 were completely free of pain and the other 9 patients expressed a shift from preoperative sexual pain to postoperative sexual discomfort. These women reported improved sexual functioning, increased sexual activity and intimacy with the partner, and reinstated feelings of being an adequate woman and sexual partner. In 1 of the 19 patients (5%), surgery did not result in decreased sexual pain, yet she continued to have intercourse. Five of the 19 patients (26%) stopped having intercourse because of pain; one woman had secondary vaginismus and another woman, in retrospect, had premorbid generalized unprovoked vulvodynia. Four of these women were unable to communicate with their partner about sexual matters and to change their sexual repertoire (satisfactorily) once they had ceased intercourse (attempts). Eighteen women (95%) reported a decrease of LS symptoms in daily life.

Conclusion

Vulvar surgery seems an effective treatment for most women with LS who experience sexual pain owing to anatomic or epithelial changes and who wish to resume intercourse. To assess whether women might benefit from such surgery and/or whether (additional) sexual counseling is indicated, preoperative sexological couple-based consultation is needed. This consultation should exclude comorbid vaginismus and generalized unprovoked vulvodynia and index the couple's pre-existing sex life, including sexual communication skills, and the ability to incorporate non-coital pain-free sexual activities.
Hyperuricemia Is an Independent Risk Factor for Erectile Dysfunction
Authors: Long Hao , Jiang Jun , Xia Jiyi , Jiang Rui , He Yanzheng , Lin Haocheng , Fan Zhongcai , Zeng Tiebing
Published: May 2016

Introduction

Hyperuricemia may be related to the development of endothelial dysfunction and cardiovascular diseases. However, the association between hyperuricemia and erectile dysfunction (ED) is not currently clear.

Aim

The goal of this study is to investigate the effect of hyperuricemia on erectile function and possible mechanisms.

Methods

Twenty-four 8-week-old male SD rats were randomly divided into 4 groups. Group A (control): Rats received normal saline and served as controls. Group B (hyperuricemia): rats were given oxonic acid 250 mg/kg bw/day through gastric gavage for 4 weeks. Group C (febuxostat): normal rats were treated with 5 mg/kg febuxostat through gastric gavage for 4 weeks. Group D (hyperuricemia + Febuxostat): normal rats were treated with 250 mg/kg bw/day oxonic acid and 5 mg/kg bw/day febuxostat with 1 hour interval for 4 weeks.

Measurements

The level of serum uric acid, the maximum intracavernosal pressure (ICPmax), mean arterial pressure (MAP), and the expression of endothelial nitric oxide synthase (eNOS), phospho-eNOS, neuronal NOS, Rho-associated protein kinaise (ROCK)1 and ROCK2 and the level of nitric oxide (NO) and reactive oxygen species (ROS) in cavernous tissue were determined.

Results

The level of serum uric acid and ROS in hyperuricemic rats was significantly higher than that in the other 3 groups (P < .05). After electrostimulation with 3 and 5 voltage, the ratio of ICPmax/MAP in hyperuricemic rats was significantly less than that in other 3 groups (P < .05), respectively. eNOS, p-eNOS, and nNOS expression in hyperuricemic rats were significantly decreased compared to the other 3 groups (P < .05), respectively.

Conclusion

Erectile function is impaired by hyperuricemia. The decrease of eNOS, p-eNOS, and nNOS protein expression and increase of ROS in cavernous tissue may be one of the key mechanisms of ED caused by hyperuricemia.
Female Partners of Men with Peyronie's Disease Have Impaired Sexual Function, Satisfaction, and Mood, While Degree of Sexual Interference Is Associated with Worse Outcomes
Authors: Davis Seth N.P. , Ferrar Saskia , Sadikaj Gentiana , Gerard Marina , Binik Yitzchak M. , Carrier Serge
Published: May 2016

Introduction

Peyronie's disease (PD) causes penile deformity and can result in sexual dysfunction and psychological distress. Currently, nothing is known about the psychosexual impact on the partners of men with PD. Research carried out on the partners of men with other chronic illnesses suggests that the partners of men with PD might have increased rates of sexual dysfunction and decreased sexual satisfaction.

Aims

To examine (i) sexual functioning, sexual satisfaction, negative affect, and relationship satisfaction of men with PD and their female partners and (ii) the effect of male-perceived sexual interference on partners' outcomes.

Methods

Forty-four men diagnosed with PD and their female partners completed a questionnaire package.

Main Outcome Measures

Each partner filled out the Revised Dyadic Adjustment Scale, the Positive and Negative Affect Scale, the Global Measure of Sexual Satisfaction, and the Female Sexual Function Index (women) or the International Index of Erectile Function (men).

Results

Overall, partners of men with PD were found to have decreased sexual function, sexual satisfaction, and mood compared with population-based norms. Men and their partners showed non-distressed levels of relationship satisfaction. The degree to which PD interfered with sexual activity was an important correlate of outcomes. Increased sexual interference was associated with lower sexual function and satisfaction for the person experiencing interference. Sexual interference also was associated with negative affect and relationship satisfaction in partners and the person experiencing interference.

Conclusion

PD is associated with negative psychosexual and psychosocial effects on those with the disease and their partners. As a result, assessment and intervention should include the two members of the couple.
Corticospinal Excitability and Inhibition of the Soleus in Individuals With Chronic Ankle Instability
Authors: Terada Masafumi , Bowker Samantha , Thomas Abbey C. , Pietrosimone Brian , Hiller Claire E. , Gribble Phillip A.
Published: May 2016

Background

Understanding the mechanisms of neurophysiological alterations with chronic ankle instability (CAI) may be essential in the development of the most‐effective intervention programs to treat neuromuscular dysfunction in patients with CAI. Specifically, the presence of CAI may be associated with an altered supraspinal mechanism within the central nervous system to inhibit neural drive to the undamaged soleus surrounding the injured ankle joint.

Objective

To investigate the influence of CAI on corticospinal excitability and inhibition of the soleus.

Design

A single‐blinded, case‐control study.

Setting

Research laboratory.

Participants

Sixteen participants with self‐reported CAI and 17 healthy control participants volunteered.

Methods

Transcranial magnetic stimulation was used to assess corticospinal excitability and inhibition of the soleus muscle. Active motor threshold (AMT), defined as the lowest stimulator intensity required to elicit a peak‐to‐peak motor‐evoked potential (MEP) amplitude ≥100 μV in at least four of 8 trials, was found to assess corticospinal excitability of the soleus. Eight stimuli were delivered at 120% of AMT, and peak‐to‐peak MEP amplitudes were recorded for each trial. The amplitude of 8 MEPs at 120% of AMP were averaged and normalized to the maximum M‐response. Cortical silent period (CSP) was measured as the distance from the end of the MEP to a return of the mean electromyographic signal plus 2 times the standard deviation of the baseline (prestimulus) electromyographic signal. The ratio of the CSP to the MEP at 120% AMT (CSP:MEP120) were calculated to assess corticospinal inhibition.

Results

The CAI group had a greater CSP:MEP120 ratio compared with the control group (P = .02). No significant differences between groups were observed for AMT (P = .67) and normalized MEP at 120% of AMT (P = .42).

Conclusions

The greater CSP:MEP120 ratio in participants with CAI suggests an altered balance in corticospinal inhibition and excitability to the soleus of the CAI cohort. Future research is needed to determine the role of corticospinal inhibition in physical and self‐reported function in patients with CAI.

Level of Evidence

IV
Fuzzy-PID side-stick force control for flight simulation
Authors: Fellah K. , Guiatni M. , Ournid A.K. , Boulahlib M.A.
Published: May 2016

In this paper, we present a new force-feedback side-stick which has been developed and integrated into a research flight simulator. The developed 2 Degrees of Freedom (DOF) force-feedback joystick, as a kind of haptic device, provides two-way communication in both position and force, and allows users to interact with the simulation system. It has been designed by considering the main factors in designing a general use force-feedback device. Thus, the design must allow the restitution of aerodynamic forces onto the hand of the pilot. This is an important feature, which gives the pilot the ‘natural feel’ of traditional mechanical aircraft control. In order to provide the force feedback to enhance the realism of the simulation, we added the necessary software using Commercial-Off-the-Shelf (COTS) solutions (Microsoft Flight Simulator Software (MSFS)) and built-in data structure and methods. Thus, the main contribution of this paper concerns the design and implementation of an automatic controller based on fuzzy logic systems. It is not simply designing a force-feedback stick for flight simulation: we proposed a novel control principles and more importantly completely new approach to compute in real-time force feedback on the stick based on pilot knowledge that avoids the use of complex aerodynamics equations with unknown parameters. To our best knowledge, this work is the first to propose the integration of fuzzy logic force controller in flight simulation for creating force feedback. Results using the overall simulation are presented and evaluated and interesting sensations have been recorded.
Design and evaluation of the objective motion cueing test and criterion
Authors: Hosman R. , Advani S.
Published: May 2016

Since the introduction of hexapod-type motion systems for flight simulation in the 1970s, Motion Drive Algorithm tuning has been primarily based on the subjective judgement of experienced pilots. This subjective method is often not transparent and often leads to ambiguous process of adjustment of the tuning parameters. Consequently, there are large variations in the motion cueing characteristics of flight training devices, a variability that subsequently raises questions regarding the value of motion cueing for pilot training itself. The third revision of ICAO 9625 Manual of Criteria for the Qualification of Flight Simulation Training Devices offered the opportunity to take a closer look at simulator motion cueing requirements in general. This led to the concept of the objective motion cueing test (OMCT), which was reported in 2006. After the method was evaluated on three research flight simulators, the results were published in 2007, demonstrating a larger spread in dynamic behaviour of cueing algorithms than expected. After discussions with the simulator industry regarding the form and methodology of the OMCT, an evaluation of the test in cooperation with the industry started in 2011. This led to the final form of the OMCT and cueing parameter criterion for the in-flight mode of transport aircraft. This paper describes the OMCT, the evaluation results and the criterion.
Medical Rescue of China International Search & Rescue Team (CISAR) in Nepal Earthquake
Authors: Yang Jiong , Yang Zhen , Lv Qi , Liu Hai-feng , Ding Hui , Yu Meng-yang , Zeng Xi-huan , Wang Xin , Fan Hao-jun
Published: May 2016

On April 25, 2015, a massive 8.1-magnitude earthquake struck Nepal at 2:11 pm (Beijing time). The 68-member-strong China International Search & Rescue Team (CISAR) left for Nepal at 6 am, April 26, to help with relief work. The CISAR was the first foreign team to rescue a survivor who was trapped beneath the rubble in the Gongabu area after the earthquake. On May 8, the team fulfilled the search-and-rescue mission and returned to Beijing. During the 2 weeks of rescue work, the team treated more than 3700 victims and cleared approximately 430 buildings. In this rescue mission, 10 experienced medical officers (including nine doctors and a nurse) from the General Hospital of Chinese People’s Armed Police Force (PAP) comprised the medical team of CISAR. In this report, we focus on the medical rescues by CISAR and discuss the characteristics of the medical rescue in Nepal. (Disaster Med Public Health Preparedness. 2018;12:536–538)
How Prepared Are Hospitals’ Emergency Management Capacity? Factors Influencing Efficiency of Disaster Rescue
Authors: Gao Lijun , Wu Qunhong , Li Ye , Ding Ding , Hao Yanhua , Cui Yu , Kang Zheng , Jiao Mingli , Liang Libo , Ferrier Adamm , Ning Ning , Sun Hong
Published: May 2016

Objectives

In light of government investment over the past decade, we explored the capacity for disaster response in Heilongjiang Province, identifying the factors that affect response capacity.

Methods

We surveyed 1257 medical staff in 65 secondary and tertiary hospitals in Heilongjiang province to explore their perceptions of disaster management capacity using a cross-sectional multistage, stratified cluster sampling method.

Results

All tertiary hospitals (100%) and most secondary hospitals (93%) have documented disaster management plans that are regularly reviewed. In secondary hospitals, drills were less prevalent (76.7%) but the occurrence of simulated training exercises was closer to tertiary hospitals (86.0%). We noted that 95.4% of all hospitals have leadership groups responsible for disaster preparedness capacity building, but only 10.8% have a stockpiled network of reserve supplies.

Conclusions

Although response capacity has improved in Heilongjiang Province, vulnerabilities remain. We recommend that priorities should be targeted at preparedness capacity building, in terms of reliable and relevant operational response plans, the expansion of existing response mechanisms to oversee local education and scenario training, and to ensure there is sufficient access to protective equipment and materials, either held in reserve, or alternatively by activating resilient supply chain mechanisms. (Disaster Med Public Health Preparedness. 2018;12:176–183)
On the three-dimensional stability of a solid-body rotation flow in a finite-length rotating pipe
Authors: Wang Shixiao , Rusak Zvi , Gong Rui , Liu Feng
Published: May 2016

The three-dimensional, inviscid and viscous flow instability modes that appear on a solid-body rotation flow in a finite-length straight, circular pipe are analysed. This study is a direct extension of the Wang & Rusak (Phys. Fluids, vol. 8 (4), 1996a, pp. 1007–1016) analysis of axisymmetric instabilities on inviscid swirling flows in a pipe. The linear stability equations are the same as those derived by Kelvin (Phil. Mag., vol. 10, 1880, pp. 155–168). However, we study a general mode of perturbation that satisfies the inlet, outlet and wall conditions of a flow in a finite-length pipe with a fixed in time and in space vortex generator ahead of it. This mode is different from the classical normal mode of perturbations. The eigenvalue problem for the growth rate and the shape of the perturbations for any azimuthal wavenumber $m$ consists of a linear system of partial differential equations in terms of the axial and radial coordinates ($x,r$). The stability problem is solved numerically for all azimuthal wavenumbers $m$. The computed growth rates and the related shapes of the various perturbation modes that appear in sequence as a function of the base flow swirl ratio (${\it\omega}$) and pipe length ($L$) are presented. In the inviscid flow case, the $m=1$ modes are the first to become unstable as the swirl ratio is increased and dominate the perturbation’s growth in a certain range of swirl levels. The $m=1$ instability modes compete with the axisymmetric ($m=0$) instability modes as the swirl ratio is further increased. In the viscous flow case, the viscous damping effects reduce the modes’ growth rates. The neutral stability line is presented in a Reynolds number ($Re$) versus swirl ratio (${\it\omega}$) diagram and can be used to predict the first appearance of axisymmetric or spiral instabilities as a function of $Re$ and $L$. We use the Reynolds–Orr equation to analyse the various production terms of the perturbation’s kinetic energy and establish the elimination of the flow axial homogeneity at high swirl levels as the underlying physical mechanism that leads to flow exchange of stability and to the appearance of both spiral and axisymmetric instabilities. The viscous effects in the bulk have only a passive influence on the modes’ shapes and growth rates. These effects decrease with the increase of $Re$. We show that the inviscid flow stability results are the inviscid-limit stability results of high-$Re$ rotating flows.
Midlife moderation-quantified healthy diet and 40-year mortality risk from CHD: the prospective National Heart, Lung, and Blood Institute Twin Study
Authors: Dai Jun , Krasnow Ruth E. , Reed Terry
Published: May 2016

It is unknown whether influences of midlife whole diet on the long-term CHD mortality risk are independent of genetic and common environmental factors or familial predisposition. We addressed this question prospectively using data from the National Heart, Lung, and Blood Institute Twin Study. We included 910 male twins who were middle-aged and had usual diet assessed with nutritionist-administered, cross-checked dietary history interview at baseline (1969–1973). Moderation-quantified healthy diet (MQHD), a dietary pattern, was created to evaluate a whole diet. Primary outcome was time-to-CHD death. Hazard ratios (HR) were estimated using frailty survival model. Known CHD risk factors were controlled. During the follow-up of 40 years through 31 December 2009, 113 CHD deaths, 198 total cardiovascular deaths and 610 all-cause deaths occurred. In the entire cohort, the multivariable-adjusted HR for the overall association (equivalent to a general population association) was 0·76 (95 % CI 0·66, 0·88) per 10-unit increment in the MQHD score for CHD, and the multivariable-adjusted HR for a twin with a MQHD score ten units higher than his co-twin brother was 0·79 (95 % CI 0·64, 0·96,P=0·02) for CHD independent of familial predisposition. Similar results were found for a slightly more food-specified alternative moderation-quantified healthy diet (aMQHD). The between-pair association (reflecting familial influence) was significant for CHD for both MQHD and aMQHD. It is concluded that associations of MQHD and aMQHD with a lower long-term CHD mortality risk are both nutritionally and familially affected, supporting their use for dietary planning to prevent CHD mortality.
“This Cockeyed City Is THEIRS”: Youth at Play in the Dances of West Side Story
Authors: ZHU YING , BELGRAD DANIEL
Published: May 2016

While ethnic rivalry between the Jets and the Sharks in the film West Side Story has long figured as a point of scholarly concern, we argue the musical's main conflict is not between the two gangs, but rather that of youth versus adult authority. Engaging in a close analysis of the dances choreographed by Jerome Robbins, we contend that the gangs' enmity against each other is subsumed by their collective struggle to reject the socially prescribed roles of adults and children in Cold War America, which fetishized childhood innocence. Robbins's complex representations of youthful play participated in defining a “youth counterculture.”
Gender Discrimination in Property Rights: Six Centuries of Commons Governance in the Alps
Authors: Casari Marco , Lisciandra Maurizio
Published: May 2016

Starting from the Medieval period, women in the Italian Alps experienced a progressive erosion in property rights over the commons. We collected documents about the evolution of inheritance regulations on collective land issued by hundreds of villages over a period of six centuries (thirteenth-nineteenth). Based on this original dataset, we provide a long-term perspective of decentralized institutional change in which gender-biased inheritance systems emerged as a defensive measure to preserve the wealth of village insiders. This institutional change also had implications for the population growth, marriage strategies, and the protection from economic shocks.
What Was Bad for General Motors Was Bad for America: The Automobile Industry and the 1937/38 Recession
Authors: Hausman Joshua K.
Published: May 2016

This article shows that there were timing, geographic, and sectoral anomalies in the 1937/38 recession, none of which are easily explained by aggregate shocks. I argue that an auto industry supply shock contributed both to the recession's anomalies and to its severity. Labor-strife-induced wage increases and an increase in raw material costs led auto manufacturers to raise prices in fall 1937. Expectations of these price increases brought auto sales forward. When auto prices finally rose, sales plummeted. This shock likely reduced 1938 auto sales by roughly 600,000 units and 1938 GDP growth by 0.5–1 percentage point.
PumaPuma concolordensity estimation in the Mediterranean Andes of Chile
Authors: Guarda Nicolás , Gálvez Nicolás , Leichtle Jorge , Osorio Christian , Bonacic Cristian
Published: May 2016

Knowledge about the pumaPuma concolorin the Mediterranean Andes of South America is scarce, with little information available about its distribution and ecology. The species has been hunted in the region for centuries and seems to be relegated to remote areas, where it still comes into conflict with rural communities. Camera-trap surveys have been used to estimate puma density across the species’ distribution, and this is a relatively cost-effective approach to generate information about species abundance. We tested the performance of this method in the Andes of central Chile, where the rugged topography, unknown detection probability, and an expected low density make abundance estimation by other methods unreliable or expensive. Using a rotation of 17 camera-trap stations, for a total of 680 camera-days, we obtained 16 records of pumas and were able to identify four individuals in an effective sampling area of 628 km2(1/2 mean maximum distance moved) or 1,518 km2(mean maximum distance moved). Capture–recapture models estimated a minimum density of 0.3 ± SE 0.07 to 0.75 ± SE 0.17 adult pumas per 100 km2. This is the first estimate of the density of the puma in the Mediterranean Andes, and one of the lowest reported for the Neotropics. Although this low abundance does not necessarily imply a threat to the species, it suggests that the population is potentially vulnerable to threats such as illegal hunting. Our findings demonstrate that camera trapping is an effective technique in difficult field conditions and may be the most appropriate method to assess puma densities in this region.
Re-examining British Welfare-to-Work Contracting using a Transaction Cost Perspective
Authors: BENNETT HAYLEY
Published: May 2016

This article critically reflects on the administration of activation services in the UK. It describes the welfare-to-work quasi-market and focuses on the impact of 2008 commissioning reforms that advocated amalgamating small contracts into larger ‘lots’, creating a top tier of prime providers to manage subcontractors, and increasing outcome-based funding. Drawing on transaction cost theory and empirical case study research, it is demonstrated that these changes led to an increase in a range of activities and costs for competing service providers that undermine government rhetoric of choice and efficiency. This article adds to the existing literature on welfare-to-work contracting by demonstrating the difficulties some organisations face in the context of welfare markets and questioning public service out-sourcing processes. It concludes by reflecting on the implications for future market-based social policy reforms.
A MARKOVIAN ANALYSIS OF IEEE 802.11 BROADCAST TRANSMISSION NETWORKS WITH BUFFERING
Authors: Fayolle Guy , Muhlethaler Paul
Published: May 2016

The purpose of this paper is to analyze the so-called back-off technique of the IEEE 802.11 protocol in broadcast mode with waiting queues. In contrast to existing models, packets arriving when a station (or node) is in back-off state are not discarded, but are stored in a buffer of infinite capacity. As in previous studies, the key point of our analysis hinges on the assumption that the time on the channel is viewed as a random succession of transmission slots (whose duration corresponds to the length of a packet) and mini-slots during which the back-off of the station is decremented. These events occur independently, with given probabilities. The state of a node is represented by a two-dimensional Markov chain in discrete-time, formed by the back-off counter and the number of packets at the station. Two models are proposed both of which are shown to cope reasonably well with the physical principles of the protocol. The stability (ergodicity) conditions are obtained and interpreted in terms of maximum throughput. Several approximations related to these models are also discussed.
ENERGY-AWARE NAVIGATION IN LARGE-SCALE EVACUATION USING G-NETWORKS
Authors: Bi Huibo , Abdelrahman Omer H.
Published: May 2016

Previous studies on emergency management of large-scale urban networks have commonly concentrated on system development to off-load intensive computations to remote cloud servers or improving communication quality during a disaster and ignored the effect of energy consumption of vehicles, which can play a vital role in large-scale evacuation owing to the disruptions in energy supply. Hence, in this paper we propose a cloud-enabled navigation system to direct vehicles to safe areas in the aftermath of a disaster in an energy and time efficient fashion. A G-network model is employed to mimic the behaviors and interactions between individual vehicles and the navigation system, and analyze the effect of re-routing decisions toward the vehicles. A gradient descent optimization algorithm is used to gradually reduce the evacuation time and fuel consumption of vehicles by optimizing the probabilistic choices of linked road segments at each intersection. The re-routing decisions arrive at the intersections periodically and will expire after a short period. When a vehicle reaches an intersection, if the latest re-routing decision has not expired, the vehicle will follow this advice, otherwise, the vehicle will stick to the shortest path to its destination. The experimental results indicate that the proposed algorithm can reduce the evacuation time and the overall fuel utilization especially when the number of evacuated vehicles is large.
FINITE TWO LAYERED QUEUEING SYSTEMS
Authors: Perel Efrat , Yechiali Uri
Published: May 2016

We study layered queueing systems comprised two interlacing finite M/M/• type queues, where users of each layer are the servers of the other layer. Examples can be found in file sharing programs, SETI@home project, etc. Let Li denote the number of users in layer i, i=1, 2. We consider the following operating modes: (i) All users present in layer i join forces together to form a single server for the users in layer j (j≠i), with overall service rate μjLi (that changes dynamically as a function of the state of layer i). (ii) Each of the users present in layer i individually acts as a server for the users in layer j, with service rate μj.

These operating modes lead to three different models which we analyze by formulating them as finite level-dependent quasi birth-and-death processes. We derive a procedure based on Matrix Analytic methods to derive the steady state probabilities of the two dimensional system state. Numerical examples, including mean queue sizes, mean waiting times, covariances, and loss probabilities, are presented. The models are compared and their differences are discussed.
OF MOVING TARGETS AND CHAMELEONS
Authors: DeKeyser Robert
Published: May 2016

In this short article I try to present a taxonomy of sources of difficulty, in particular complexity. I emphasize how these factors interact with each other and with individual differences and treatments, before illustrating some of these interactions and the methodological issues involved in studying them with examples from the empirical studies in this issue. Finally, I make some suggestions for future research.
On some Fricke families and application to the Lang–Schertz conjecture
Authors: Jung Ho Yun , Koo Ja Kyung , Shin Dong Hwa
Published: May 2016

We investigate two kinds of Fricke families, those consisting of Fricke functions and those consisting of Siegel functions. In terms of their special values we then generate ray class fields of imaginary quadratic fields over the Hilbert class fields, which are related to the Lang–Schertz conjecture.
PBR1 selectively controls biogenesis of photosynthetic complexes by modulating translation of the large chloroplast gene Ycf1 in Arabidopsis
Authors: Yang Xiao-Fei , Wang Yu-Ting , Chen Si-Ting , Li Ji-Kai , Shen Hong-Tao , Guo Fang-Qing
Published: May 2016

The biogenesis of photosystem I (PSI), cytochrome b6f (Cytb6f) and NADH dehydrogenase (NDH) complexes relies on the spatially and temporally coordinated expression and translation of both nuclear and chloroplast genes. Here we report the identification of photosystem biogenesis regulator 1 (PBR1), a nuclear-encoded chloroplast RNA-binding protein that regulates the concerted biogenesis of NDH, PSI and Cytb6f complexes. We identified Ycf1, one of the two largest chloroplast genome-encoded open reading frames as the direct downstream target protein of PBR1. Biochemical and molecular analyses reveal that PBR1 regulates Ycf1 translation by directly binding to its mRNA. Surprisingly, we further demonstrate that relocation of the chloroplast gene Ycf1 fused with a plastid-transit sequence to the nucleus bypasses the requirement of PBR1 for Ycf1 translation, which sufficiently complements the defects in biogenesis of NDH, PSI and Cytb6f complexes in PBR1-deficient plants. Remarkably, the nuclear-encoded PBR1 tightly controls the expression of the chloroplast gene Ycf1 at the translational level, which is sufficient to sustain the coordinated biogenesis of NDH, PSI and Cytb6f complexes as a whole. Our findings provide deep insights into better understanding of how a predominant nuclear-encoded factor can act as a migratory mediator and undergoes selective translational regulation of the target plastid gene in controlling biogenesis of photosynthetic complexes.
On the general constraints in single qubit quantum process tomography
Authors: Bhandari Ramesh , Peters Nicholas A.
Published: May 2016

We briefly review single-qubit quantum process tomography for trace-preserving and nontrace-preserving processes, and derive explicit forms of the general constraints for fitting experimental data. These forms provide additional insight into the structure of the process matrix. We illustrate this with several examples, including a discussion of qubit leakage error models and the intuition which can be gained from their process matrices.
Efficient artificial mineralization route to decontaminate Arsenic(III) polluted water - the Tooeleite Way
Authors: Malakar Arindam , Das Bidisa , Islam Samirul , Meneghini Carlo , De Giudici Giovanni , Merlini Marco , Kolen’ko Yury V. , Iadecola Antonella , Aquilanti Giuliana , Acharya Somobrata , Ray Sugata
Published: May 2016

Increasing exposure to arsenic (As) contaminated ground water is a great threat to humanity. Suitable technology for As immobilization and removal from water, especially for As(III) than As(V), is not available yet. However, it is known that As(III) is more toxic than As(V) and most groundwater aquifers, particularly the Gangetic basin in India, is alarmingly contaminated with it. In search of a viable solution here, we took a cue from the natural mineralization of Tooeleite, a mineral containing Fe(III) and As(III)ions, grown under acidic condition, in presence of SO42− ions. Complying to this natural process, we could grow and separate Tooeleite-like templates from Fe(III) and As(III) containing water at overall circumneutral pH and in absence of SO42− ions by using highly polar Zn-only ends of wurtzite ZnS nanorods as insoluble nano-acidic-surfaces. The central idea here is to exploit these insoluble nano-acidic-surfaces (called as INAS in the manuscript) as nucleation centres for Tooeleite growth while keeping the overall pH of the aqueous media neutral. Therefore, we propose a novel method of artificial mineralization of As(III) by mimicking a natural process at nanoscale.
Topological distortion and reorganized modular structure of gut microbial co-occurrence networks in inflammatory bowel disease
Authors: Baldassano Steven N. , Bassett Danielle S.
Published: May 2016

The gut microbiome plays a key role in human health and alterations of the normal gut flora are associated with a variety of distinct disease states. Yet, the natural dependencies between microbes in healthy and diseased individuals remain far from understood. Here we use a network-based approach to characterize microbial co-occurrence in individuals with inflammatory bowel disease (IBD) and healthy (non-IBD control) individuals. We find that microbial networks in patients with IBD differ in both global structure and local connectivity patterns. While a “core” microbiome is preserved, network topology of other densely interconnected microbe modules is distorted, with potent inflammation-mediating organisms assuming roles as integrative and highly connected inter-modular hubs. We show that while both networks display a rich-club organization, in which a small set of microbes commonly co-occur, the healthy network is more easily disrupted by elimination of a small number of key species. Further investigation of network alterations in disease might offer mechanistic insights into the specific pathogens responsible for microbiome-mediated inflammation in IBD.