bluuebunny/crossref_metadata_2025_split huggingface dataset:
Bifurcations and Chaos in Forced, Coupled Pendula
Authors: Yagasaki Kazuyuki 
Published: November 2020

Abstract
We consider forced, coupled pendula and show that they exhibit very complicated dynamics using the averaging method and Melnikov-type techniques. First, the averaged system for small oscillations of the pendula near the hanging state is analyzed. Codimension-one and -two local bifurcations at which several non-synchronized periodic orbits and quasiperiodic orbits are born in the original system are detected. The validity of the theoretical results is demonstrated by comparison with direct numerical integration results. Moreover, chaotic motions, which result from the Shilnikov type phenomena in the averaged systems, are observed in numerical simulations. Second, the second-order averaging method is applied to small perturbations of rotary orbits with no damping and external forcing. Analyzing the averaged system, we can describe nonlinear behavior in the original system. Finally, using a generalization of Melnikov method, we prove the occurrence of many other homo-clinic phenomena, which also yield chaotic dynamics.
Nonlinear Design-for-Control: Deploying Nonlinearity for Useful Purposes
Authors: Adams Douglas E. 
Published: November 2020

Abstract
Nonlinearity can be beneficial. It can enhance/degrade system performance, strengthen/weaken linear systems, and give rise to extraordinarily constructive/destructive behaviors. In spite of these potential benefits, engineers have historically neglected and/or removed nonlinearity when designing, analyzing, and controlling mechanical systems for good reason. This paper examines the notion of nonlinear mechanical design-for-control in the context of common applications where nonlinearity enhances performance in some way. Examples of how general nonlinear characteristics and specific nonlinear behaviors have been used in engineering applications are given. A framework for carrying out design optimization with reconfigurable nonlinear mechanical feedback loops is also discussed.
An Experimental Study for Collision Stimulus Device Using a Magneto-Spring
Authors: Fujita Etsunori , Nakagawa Noritoshi , Soga Norio , Ogura Yumi , Sugimoto Eiji , Kojima Shigeyuki 
Published: November 2020

Abstract
An experimental device that utilizes a magneto-spring and collision forces for a single-degree-of-freedom stimulus is proposed. By way of an actuator, the experimental device that was created in order to test the response created by a magneto-spring stimulus force arising from an impact force, applies a displacement stimulus to the magnet on one side, changing the distance between the magnets as well as the faced surface area of the magnets. The moving mass that, which supports the loaded mass and the magnet on other side, provides kinetic energy via the actuator and the magneto-spring. When the moving mass impact on impact plate, the impact plate turn over the motion of direction. This collision stimulus device is composed of a mechanisms having low damping, and being vibration device using a magneto-spring, it was verified through analysis and experimental studies to be a highly efficient shaker mechanism. In addition, when the stimulus energy from the shock vibration experiment is low, due to loaded mass move a quasi-zero spring constant or a low magnetic field gradient, it is thought that by generating anti-phase and a large relative displacement from a low frequency, a highly efficient shock stimulus mechanism can be achieved, even by applying the momentary impulse input as a disturbance, the magneto-spring, constant of non-linear characteristics and strong spring constant, elastic energy is used to create a symmetrical triangular shock wave.
On one hand, the relation between the inputs and outputs that use variations in the magnetostatic energy created by changes in the distance between the repulsed magnets and the faced surface area was verified by studying the amount of work created by the magneto-spring stimulus energy of a repulsed magnet system during one vibration cycle of the moving mass attached to a moving magnet and a fixed magnet. It is seen that the input/output energy characteristics of the magneto-spring stimulus force are a highly efficient mechanism due to mageto-spring move in a strong magnetic field gradient. However, it is seen that mechanical amplification mechanism that utilizes a magneto-spring and collision forces are a highly efficient mechanism due to mageto-spring move in a low magnetic field gradient. The collision stimulus device using a quasi-zero spring constant and a elastic energy of magneto-spring changes sinusoidal wave, that vibration device applies, into a symmetrical triangular shock wave found in a large collision force and amplified amplitude, due to external disturbance which acts as a trigger, a elastic energy of magneto-spring and distance between impact plates optimized. However, it was realized that when a force greater than the prescribed amount is applied as resistance. As a results, the vibration energy is diminished, a shock wave change a symmetrical sinusoidal wave due to loaded mass move in a low magnetic field gradient or a quasi-zero spring constant.
A Study on the Characteristics of Rubber Flexible Pipes
Authors: Zhao Yin-Long , He Lin , Qian Wei-Jian , Zhu Shi-Jian 
Published: November 2020

Abstract
This paper studies the static and dynamic properties of the rubber flexible pipes. The theoretical formula for calculating the strength of the rubber flexible pipes is given. A mathematical model for predicting the dynamic characteristics of the viscoelastic pipe wall pipeline is setup. Finally, the model is solved analytically.
Active Stabilization of Centrifugal Compressor Using Adjustable Geometry Impeller
Authors: Eldin K. M. Saad 
Published: November 2020

Abstract
Recent work has shown that variable impeller geometry of the centrifugal compression system can be actively stabilized against the instability known as surge, thereby realizing a significant gain in system mass flow rate. In this context, the paper presents an experimental study about the influence of the impeller blade configuration on the extension of the stabilized characteristic margin beyond the natural surge line and enlarge the usable compressor operating region. This method is estimated from the two major control methods which: surge avoidance control and surge suppression control. The impeller of tandem type with zero overlap is found to be a good sample to satisfy the above concept. The impeller is working as full bladed at stable regime, but it could be transferred into tandem bladed when the mass flow rate decreases below a certain minimum value, just before rotating stall occurs. The operating point moves downwards to another characteristic curve belonging to the new configuration, which has a surge margin less than the original one by 56 percent, at high speed.
Herein the effect of tandem shift angle on extending the stabilized range is studied experimentally and a control criterion is suggested. The pressure ratio at the new characteristic curve is decreased by about 3 percent and maximum efficiency is decreased also by about 28 percent.
Wavelet Based Demodulation of Vibration Signals Generated by Defects in Rolling Element Bearings
Authors: Yiakopoulos Christos T. , Antoniadis Ioannis A. 
Published: November 2020

Abstract
Envelope detection or demodulation methods for bearing vibration response signals have been established as a dominant analysis method for bearing fault diagnosis, since they can separate the useful part of the signal from its redundant contents. A new effective demodulation method is proposed, based on the Discrete Wavelet Transform (DWT). The method fully exploits the underlying physical concepts of the modulation mechanism, present in the vibration response of faulty bearings, using the excellent time-frequency localization properties of the wavelet analysis. Two key elements, resulting to the successful implementation of the method, are its practical independence from the choice of the specific wavelet family to be used and the limited number of the wavelet levels, that are required for its practical application. Experimental results and industrial measurements for three different types of bearing faults, confirm the validity of the overall approach.
Active Control for a 2DOF of Building Including Elastoplastic Soil-Structure Coupling Terms
Authors: Lamarque C.-H. , Kacprzak Grzegorz , Awrejcewicz Jan 
Published: November 2020

Abstract
An active control procedure has been applied to a two degrees-of-freedom mechanical system including the elastoplastic terms. The theoretical consideration resulted in a solution to the classical Riccati equations which holds for both stationary and non-stationary cases. The included numerical example demonstrates an efficiency of the introduced theory and the numerical scheme in order to an active control of building-soil-foundation model.
How Do Profiles of Need-Supportive and Controlling Coaching Relate to Team Athletes’ Motivational Outcomes? A Person-Centered Approach
Authors: Reynders Bart , Van Puyenbroeck Stef , Ceulemans Eva , Vansteenkiste Maarten , Vande Broek Gert 
Published: November 2020

Building on recent self-determination theory research differentiating controlling coaching into a demanding and domineering approach, this study examined the role of both approaches in athletes’ motivational outcomes when accompanied by autonomy support or structure. Within team-sport athletes (N = 317; mean age = 17.67), four sets of k-means cluster analyses systematically pointed toward a four-cluster solution (e.g., high–high, high–low, low–high, and low–low), regardless of the pair of coaching dimensions used. One of the identified coaching profiles involved coaches who are perceived to combine need-supportive and controlling behaviors (i.e., high–high). Whereas combining need-supportive and domineering behaviors (i.e., high–high) yields lower autonomous motivation and engagement compared with a high need-support profile (i.e., high–low), this is less the case for the combination of need-supportive and demanding behaviors (i.e., high–high). This person-centered approach provides deeper insights into how coaches combine different styles and how some forms of controlling coaching yield a greater cost than others.
Accuracy of the Edinburgh Postnatal Depression Scale (EPDS) for screening to detect major depression among pregnant and postpartum women: systematic review and meta-analysis of individual participant data
Authors: Levis Brooke , Negeri Zelalem , Sun Ying , Benedetti Andrea , Thombs Brett D 
Published: November 2020

Abstract

Objective
To evaluate the Edinburgh Postnatal Depression Scale (EPDS) for screening to detect major depression in pregnant and postpartum women.

Design
Individual participant data meta-analysis.

Data sources
Medline, Medline In-Process and Other Non-Indexed Citations, PsycINFO, and Web of Science (from inception to 3 October 2018).

Eligibility criteria for selecting studies
Eligible datasets included EPDS scores and major depression classification based on validated diagnostic interviews. Bivariate random effects meta-analysis was used to estimate EPDS sensitivity and specificity compared with semi-structured, fully structured (Mini International Neuropsychiatric Interview (MINI) excluded), and MINI diagnostic interviews separately using individual participant data. One stage meta-regression was used to examine accuracy by reference standard categories and participant characteristics.

Results
Individual participant data were obtained from 58 of 83 eligible studies (70%; 15 557 of 22 788 eligible participants (68%), 2069 with major depression). Combined sensitivity and specificity was maximised at a cut-off value of 11 or higher across reference standards. Among studies with a semi-structured interview (36 studies, 9066 participants, 1330 with major depression), sensitivity and specificity were 0.85 (95% confidence interval 0.79 to 0.90) and 0.84 (0.79 to 0.88) for a cut-off value of 10 or higher, 0.81 (0.75 to 0.87) and 0.88 (0.85 to 0.91) for a cut-off value of 11 or higher, and 0.66 (0.58 to 0.74) and 0.95 (0.92 to 0.96) for a cut-off value of 13 or higher, respectively. Accuracy was similar across reference standards and subgroups, including for pregnant and postpartum women.

Conclusions
An EPDS cut-off value of 11 or higher maximised combined sensitivity and specificity; a cut-off value of 13 or higher was less sensitive but more specific. To identify pregnant and postpartum women with higher symptom levels, a cut-off of 13 or higher could be used. Lower cut-off values could be used if the intention is to avoid false negatives and identify most patients who meet diagnostic criteria.

Registration
PROSPERO (CRD42015024785).
Socioeconomic deprivation and development of diabetic retinopathy in patients with type 1 diabetes mellitus
Authors: Alvarez-Ramos Pablo , Jimenez-Carmona Soledad , Alemany-Marquez Pedro , Cordoba-Doña Juan Antonio , Aguilar-Diosdado Manuel 
Published: November 2020

IntroductionVery little is known about the influence of socioeconomic status on type 1 diabetes mellitus (T1DM) complications. Our aim was to determine whether socioeconomic level is a risk factor for the development of diabetic retinopathy (DR) in patients with T1DM.Research design and methodsA cohort of 150 patients with T1DM were studied prospectively over 9 years. Socioeconomic status was assessed using a neighborhood-level measure based on an index of deprivation. The contribution of other variables such as hypertension, dyslipidemia, diabetic nephropathy and smoking habit was evaluated. Cox proportional hazards models were used to quantify the associations.ResultsThe incidence of DR was 21.6 cases per 1000 patient-years. Multivariable analyses showed that for each percentage point increase in glycated hemoglobin (HbA1c), the risk of developing DR increased by 58% (HR 1.58, 95% CI 1.19 to 2.10).Patients with T1DM onset >18 years of age and resident in areas of lower socioeconomic levels presented with almost triple the risk of developing DR (HR 2.95, 95% CI 1.08 to 8.00) compared with those with onset <18 years of age and resident in less deprived areas. We did not find significant relationships with other variables studied such as hypertension, dyslipidemia, diabetic nephropathy and smoking habit.ConclusionsLow socioeconomic level is a risk factor, independent of glycemic control, in the development of DR in patients with T1DM when the onset of diabetes is in adulthood. This finding indicates that socioeconomic status and age of onset need to be considered in population screening for DR in patients with T1DM.
UK healthcare staff experiences and perceptions of a mass casualty terrorist incident response: a mixed-methods study
Authors: Skryabina Elena , Betts Naomi , Reedy Gabriel , Riley Paul , Amlôt Richard 
Published: November 2020

IntroductionSystem learning from major incidents is a crucial element of improving preparedness for response to any future incidents. Sharing good practice and limitations stimulates further actions to improve preparedness and prevents duplicating mistakes.MethodsThis convergent parallel mixed methods study comprises data from responses to an online survey and individual interviews with healthcare staff who took part in the responses to three terrorist incidents in the UK in 2017 (Westminster Bridge attack, Manchester Arena Bombing and London Bridge attack) to understand limitations in the response and share good practices.ResultsThe dedication of NHS staff, staff availability and effective team work were the most frequently mentioned enabling factors in the response. Effective coordination between teams and a functional major incident plan facilitated an effective response. Rapid access to blood products, by positioning the blood bank in the ED, treating children and parents together and sharing resources between trauma centres were recognised as very effective innovative practices. Recent health emergency preparedness exercises (HEPEs) were valued for preparing both Trusts and individual staff for the response. Challenges included communication between ambulance services and hospitals, difficulties with patient identification and tracking and managing the return to ‘normal’ work patterns post event. Lack of immediately available clinical protocols to deal with blast injuries was the most commonly mentioned clinical issue. The need for psychosocial support for responding and supporting staff was identified.DiscussionBetween-agencies communication and information sharing appear as the most common recurring problems in mass casualty incidents (MCIs). Recent HEPEs, which allowed teams, interdisciplinary groups, and different agencies to practice responding to similar simulated incidents, were important and informed actions during the real response. Immediate and delayed psychosocial support should be in place for healthcare staff responding to MCIs.
Endocrine therapy use and cardiovascular risk in postmenopausal breast cancer survivors
Authors: Matthews Anthony A , Peacock Hinton Sharon , Stanway Susannah , Lyon Alexander Richard , Smeeth Liam , Lund Jennifer L , Bhaskaran Krishnan 
Published: November 2020

ObjectiveExamine the effect of tamoxifen and aromatase inhibitors (AIs) on the risk of 12 clinically relevant cardiovascular outcomes in postmenopausal female breast cancer survivors.MethodsWe carried out two prospective cohort studies among postmenopausal women with breast cancer in UK primary care and hospital data (2002–2016) and US Surveillance, Epidemiology and End Results-Medicare data (2008–2013). Using Cox adjusted proportional hazards models, we compared cardiovascular risks between AI and tamoxifen users; and in the USA, between users of both drug classes and women receiving no endocrine therapy.Results10 005 (UK) and 22 027 (USA) women with postmenopausal breast cancer were included. In both countries, there were higher coronary artery disease risks in AI compared with tamoxifen users (UK age-standardised incidence rate: 10.17 vs 7.51 per 1000 person-years, HR: 1.29, 95% CI 0.94 to 1.76; US age-standardised incidence rate: 36.82 vs 26.02 per 1000 person-years, HR: 1.29, 95% C I1.06 to 1.55). However, comparisons with those receiving no endocrine therapy (US data) showed no higher risk for either drug class and a lower risk in tamoxifen users (age-standardised incidence rate tamoxifen vs unexposed: 26.02 vs 35.19 per 1000 person-years, HR: 0.74, 95% 0.60 to 0.92; age-standardised incidence rate AI vs unexposed: 36.82 vs 35.19, HR: 0.96, 95% CI 0.83 to 1.10). Similar patterns were seen for other cardiovascular outcomes (arrhythmia, heart failure and valvular heart disease). As expected, there was more venous thromboembolism in tamoxifen compared with both AI users and those unexposed.ConclusionsHigher risks of several cardiovascular outcomes among AI compared with tamoxifen users appeared to be driven by protective effects of tamoxifen, rather than cardiotoxic effects of AIs.
Long-term survival of patients with stage III colon cancer treated with VRP-CEA(6D), an alphavirus vector that increases the CD8+ effector memory T cell to Treg ratio
Authors: Crosby Erika J , Hobeika Amy C , Niedzwiecki Donna , Rushing Christel , Hsu David , Berglund Peter , Smith Jonathan , Osada Takuya , Gwin III William R , Hartman Zachary C , Morse Michael A , Lyerly Herbert Kim 
Published: November 2020

BackgroundThere remains a significant need to eliminate the risk of recurrence of resected cancers. Cancer vaccines are well tolerated and activate tumor-specific immune effectors and lead to long-term survival in some patients. We hypothesized that vaccination with alphaviral replicon particles encoding tumor associated antigens would generate clinically significant antitumor immunity to enable prolonged overall survival (OS) in patients with both metastatic and resected cancer.MethodsOS was monitored for patients with stage IV cancer treated in a phase I study of virus-like replicon particle (VRP)-carcinoembryonic antigen (CEA), an alphaviral replicon particle encoding a modified CEA. An expansion cohort of patients (n=12) with resected stage III colorectal cancer who had completed their standard postoperative adjuvant chemotherapy was administered VRP-CEA every 3 weeks for a total of 4 immunizations. OS and relapse-free survival (RFS) were determined, as well as preimmunization and postimmunization cellular and humoral immunity.ResultsAmong the patients with stage IV cancer, median follow-up was 10.9 years and 5-year survival was 17%, (95% CI 6% to 33%). Among the patients with stage III cancer, the 5-year RFS was 75%, (95%CI 40% to 91%); no deaths were observed. At a median follow-up of 5.8 years (range: 3.9–7.0 years) all patients were still alive. All patients demonstrated CEA-specific humoral immunity. Patients with stage III cancer had an increase in CD8 +TEM(in 10/12) and decrease in FOXP3 +Tregs (in 10/12) following vaccination. Further, CEA-specific, IFNγ-producing CD8+granzyme B+TCMcells were increased.ConclusionsVRP-CEA induces antigen-specific effector T cells while decreasing Tregs, suggesting favorable immune modulation. Long-term survivors were identified in both cohorts, suggesting the OS may be prolonged.
Safety and efficacy of oral antiplatelet for patients who had acute ischaemic stroke undergoing endovascular therapy
Authors: Huo Xiaochuan , ­ Raynald , Jing Jing , Wang Anxin , Mo Dapeng , Gao Feng , Ma Ning , Wang Yilong , Wang Yongjun , Miao Zhongrong 
Published: November 2020

Background and purposeTo investigate the safety and efficacy of oral antiplatelet therapy (APT) for patients who had acute ischaemic stroke (AIS), receiving endovascular therapy (EVT).MethodsPatients were divided into non-APT group and APT (single APT or dual APT (DAPT)) group. The safety and efficacy endpoints at 3-month follow-up were symptomatic intracranial haemorrhage (sICH), recanalisation rate, clinical outcome and mortality.ResultsAmong 915 patients who had AIS, those in APT group (n=199) showed shorter puncture-to-recanalisation time, lower frequency of intravenous thrombolysis and more use of tirofiban compared with those in non-antiplatelet group (n=716) (p<0.05 for all). Oral APT was found to be associated with superior clinical outcome compared with non-APT (APT (44.2%) versus non-APT (41.1%)), adjusted OR=2.605, 95% CI 1.244 to 5.455, p=0.011). DAPT showed superior clinical outcome compared with non-APT (DAPT (56.5%) versus non-APT (41.1%), adjusted OR=5.405, 95% CI 1.614 to 18.102, p=0.006) and lower risk of mortality at 3-month follow-up (DAPT (4.8%) versus non-DAPT (17.7%), adjusted OR=0.008, 95% CI 0.000 to 0.441, p=0.019). There was no significant difference in sICH between the two groups.ConclusionsOral APT prior to undergoing EVT is safe and may accompany with superior clinical outcomes. DAPT may associate with superior clinical outcomes and lower risk of mortality.