bluuebunny/crossref_metadata_2025_split huggingface dataset:
Feedback Control of Truss Structures With Distributed Flexibility
Authors: Kevorkian Sandrine , Pascal Madeleine 
Published: November 2020

Abstract
Among other applications, truss structures are used for space applications and several strategies of active control are studied, including recently the use of piezoelectric actuators. However, the standard method for designing active control of structures is to use modal approximation for distributed flexibility. The actual system is infinite-dimensional and the modes describing its flexible behavior depend on the feedback control. Very few attempts to use the continuous elements method for purposes of control were proposed in the past and concern only manipulators composed of one or two flexible arms. In this work, a strategy of active control using the exact transfer matrix of a two-cells planar truss is defined. Both collocated and non collocated control are considered. For both cases, the closed-loop pole locations are compared as a function of feedback controller parameters.
On the Vibrations of a Linear, and a Weakly Nonlinear Damped System
Authors: Yò Darmawijo , van Horssen W. T. 
Published: November 2020

Abstract
In this paper initial-boundary value problems for a linear, and a weakly nonlinear string (or wave) equation are considered. One end of the string is assumed to be fixed and the other end of the string is attached to a spring-mass-dashpot system, where the damping generated by the dashpot is assumed to be small. This problem can be regarded as a simple model describing oscillations of flexible structures such as overhead power transmission lines. For a linear problem a semigroup approach will be used to show the well-posedness of the problem as well as the asymptotic validity of formal approximations of the solution on long time-scales. It is also shown hov a multiple time-scales perturbation method as described in Kevorkian and Cole (Kevorkian and Cole, 1981) can be used effectively to construct asymptotic approximations of the solution on long timescales.
Stochastically Perturbed Rotating Shafts
Authors: Vedula Lalit , Namachchivaya N. Sri 
Published: November 2020

Abstract
The objective of this work is to study the long term effects of small symmetry-breaking, dissipative and noisy perturbations on the dynamics of a rotating shaft. Hamilton’s principle is used to derive the equations of motion and a one mode Galerkin approximation is applied to obtain a two-degree-of-freedom (four dimensional) model. A stochastic averaging method is developed to reduce the dimension of this four dimensional system. Making use of the interaction between the gyroscopic and dissipative forces and the separation of time scales, the original system is reduced to a one dimensional Markov process. Depending on the system parameters, the reduced Markov process takes its values on a line or a graph. For the latter case, the glueing conditions required to complete the description of the problem in the reduced space are derived. This provides a qualitatively accurate and computationally feasible description of the system. Analytical results are obtained for the mean first passage time problem. The stationary probability density is obtained by solving the Fokker Planck Equation (FPE). Finally, the qualitative changes in the stationary density as a result of varying the system parameters are described.
Digital Signal Processor Based Active Vibration Control System Using Adaptive Control Algorithm and Smart Actuators/Sensors
Authors: Shashikala P. , Shankar V. , Nagaraja B. V. , Balasubramaniam R. , Harikrishnan J. 
Published: November 2020

Abstract
Adaptive feed forward control of structure based on ‘filtered -x’ LMS algorithm has been brought out for the active control of vibration in a typical CFRP beam structure. Initially the conventional filtered-x LMS control configuration and offline system identification method using DSP is discussed. Also the on-line system identification and control by additive random noise technique has been brought out. FIR filters are used for both system identification and control.
Recent advances in electronics, high-speed digital signal processors have made active systems realizable, effective and inexpensive. Hence the active control method has been used to investigate a typical composite CFRP beam structure bonded externally with PZT actuators/sensors. At present vibration reduction of the order of 3db has been achieved.
Analysis of Axial Vibration of Compound Bars by Several Different Methods
Authors: Bert Charles W. , Zeng Huan 
Published: November 2020

Abstract
Although solutions for the free vibration of dynamically slender prismatic or tapered bars in axial vibration are well known, apparently there have been only a few published analyses for the case of compound bars, i.e., bars of different cross section connected in mechanical series. The primary objective here is to analyze this problem by several exact methods: (1) classical solution of the set of governing differential equations, and (2) application of a relatively new technique originated in 1986 and known as the differential transformation (DT) method. The secondary objective is to present some simple approximate algebraic formulas for the fundamental frequency of an n-segment, axially vibrating bar for preliminary design use.
Magneto-Elastic Compliant Mechanisms
Authors: Venkataraghavan Janarthanan , Srinivasa Arun R. 
Published: November 2020

Abstract
The motivation for this work has been a variety of motions like navigation of pipelines, insertion operations in assembly, and gripping actions, which require the adaptation of the mechanism to the external constraints, rather than avoid them. To this effect, efforts have been made towards building mechanisms that obtain the required degrees of freedom through deformations rather than explicit joints in them. Although the use of many joints provides the required number of degrees of freedom, it does so at the cost of making the system very bulky and complex. With the advent of new polymers, the possibility of building such mechanisms without joints, that fulfil the requirements of adaptation, have increased. Based on this approach, a Magneto Active Polymer (MAP) material has been developed in-house at the Texas A&M University, in which the actuation is performed by the conversion of electromagnetic energy into mechanical energy. The initial experimentation has proved the vast potential of the use of such a material, and a few mechanisms, like a magneto active peristaltic pump, have already been developed and tested, using this material. In this mechanism the pumping action is obtained when a moving magnetic field produces peristaltic waves in the magneto active material shaped as a tube. These waves help in pushing the fluid forward, in the tube. The advantage of this mechanism is that there is not physical contact of the actuating mechanism an the MAP tube, thereby reducing the wear. In developing the design for the peristaltic pump and other conceptual models described in this paper, ideas have been drawn from the different modes of locomotion and actuators used, in lower organisms and these have been good sources of inspiration for the work detailed in this paper.
The Anthropometric, Physiological, and Strength-Related Determinants of Handcycling 15-km Time-Trial Performance
Authors: Nevin Jonpaul , Smith Paul M. 
Published: November 2020

Purpose: The aim of this study was to investigate the relationship between selected anthropometric, physiological, and upper-body strength measures and 15-km handcycling time-trial (TT) performance. Methods: Thirteen trained H3/H4 male handcyclists performed a 15-km TT, graded exercise test, 15-second all-out sprint, and 1-repetition-maximum assessment of bench press and prone bench pull strength. Relationship between all variables was assessed using a Pearson correlation coefficient matrix with mean TT velocity representing the principal performance outcome. Results: Power at a fixed blood lactate concentration of 4 mmol·L−1 (r = .927; P < .01) showed an extremely large correlation with TT performance, whereas relative (peak oxygen uptake) (r = .879; P < .01), power-to-mass ratio (r = .879; P < .01), peak aerobic power (r = .851; P < .01), gross mechanical efficiency (r = 733; P < .01), relative prone bench pull strength (r = .770; P = .03) relative bench press strength (r = .703; P = .11), and maximum anaerobic power (r = .678; P = .15) all demonstrated a very large correlation with performance outcomes. Conclusion: Findings of this study indicate that power at a fixed blood lactate concentration of 4 mmol·L−1, relative , power-to-mass ratio, peak aerobic power, gross mechanical efficiency, relative upper-body strength, and maximum anaerobic power are all significant determinants of 15-km TT performance in H3/H4 handcyclists.
Blinding practices during acute point-of-care ultrasound research: the BLIND-US meta-research study
Authors: Prager Ross , Wu Kay , Bachar Roudi , Unni Rudy R , Bowdridge Joshua , McGrath Trevor A , Thavanathan Rajiv , Woo Michael Y , McInnes Matthew D F 
Published: November 2020

ObjectivesPoint-of-care ultrasound (POCUS) diagnostic accuracy research has significant variation in blinding practices. This study characterises the blinding practices during acute POCUS research to determine whether research methodology adequately reflects POCUS use in routine clinical practice.Design, settings and participantsA search for POCUS diagnostic accuracy studies published inEmergency Medicine,AnaesthesiaandCritical Carejournals from January 2016 to January 2020 was performed. Studies were included if they were primary diagnostic accuracy studies. The study year, journal impact factor, population, hospital area, body region, study design, blinding of the POCUS interpreter to clinical information, whether the person performing the POCUS scan was the same person interpreting the scan, and whether the study reported incremental diagnostic yield were extracted in duplicate by two authors. Descriptive statistics were provided and prespecified subgroup analysis was performed.Main outcome measuresThe primary outcome was the number of studies that blinded the POCUS interpreter to at least some part of the clinical information. Secondary outcomes included whether the person performing the POCUS scan was the same person interpreting it and whether the study reported incremental diagnostic yield.Results520 abstracts were screened with 97 studies included. The POCUS interpreter was blinded to clinical information in 37 studies (38.1%), not blinded in 34 studies (35.1%) and not reported in 26 studies (26.8%). The POCUS interpreter was the same person obtaining the images in 72 studies (74.2%), different in 14 studies (14.4%) and not reported in 11 studies (11.3%). Only four studies (4.1%) reported incremental diagnostic yield for POCUS. Inter-rater reliability was moderate (k=0.64). Subgroup analysis based on impact factor, body region, hospital area, patient population and study design did not show significant differences after completing pairwise comparisons.ConclusionsAlthough blinding the POCUS interpreter to clinical information may be done in a perceived attempt to limit bias, this may result in accuracy estimates that do not reflect routine clinical practice. Similarly, having a different clinician perform and interpret the POCUS scan significantly limits generalisability to practice as it does not truly reflect ‘point-of-care’ ultrasound at all. Reporting incremental diagnostic yield from implementing POCUS into a diagnostic pathway better reflects the value of POCUS; however, this methodology was infrequently used.Trial registration numberThe study protocol was registered on Open Science Framework (https://osf.io/h5fe7/).
High incidence of glucocorticoid-induced hyperglycaemia in inflammatory bowel disease: metabolic and clinical predictors identified by machine learning
Authors: McDonnell Martin , Harris Richard J , Borca Florina , Mills Tilly , Downey Louise , Dharmasiri Suranga , Patel Mayank , Zare Benjamin , Stammers Matt , Smith Trevor R , Felwick Richard , Cummings J R Fraser , Phan Hang T T , Gwiggner Markus 
Published: November 2020

BackgroundGlucocorticosteroids (GC) are long-established, widely used agents for induction of remission in inflammatory bowel disease (IBD). Hyperglycaemia is a known complication of GC treatment with implications for morbidity and mortality. Published data on prevalence and risk factors for GC-induced hyperglycaemia in the IBD population are limited. We prospectively characterise this complication in our cohort, employing machine-learning methods to identify key predictors of risk.MethodsWe conducted a prospective observational study of IBD patients receiving intravenous hydrocortisone (IVH). Electronically triggered three times daily capillary blood glucose (CBG) monitoring was recorded alongside diabetes mellitus (DM) history, IBD biomarkers, nutritional and IBD clinical activity scores. Hyperglycaemia was defined as CBG ≥11.1 mmol/L and undiagnosed DM as glycated haemoglobin ≥48 mmol/mol. Random forest (RF) regression models were used to extract predictor-patterns present within the dataset.Results94 consecutive IBD patients treated with IVH were included. 60% (56/94) of the cohort recorded an episode of hyperglycaemia, including 57% (50/88) of those with no history of DM, of which 19% (17/88) and 5% (4/88) recorded a CBG ≥14 mmol/L and ≥20 mmol/L, respectively. The RF models identified increased C-reactive protein (CRP) followed by a longer IBD duration as leading risk predictors for significant hyperglycaemia.ConclusionHyperglycaemia is common in IBD patients treated with intravenous GC. Therefore, CBG monitoring should be included in routine clinical practice. Machine learning methods can identify key risk factors for clinical complications. Steroid-sparing treatment strategies may be considered for those IBD patients with higher admission CRP and greater disease duration, who appear to be at the greatest risk of hyperglycaemia.
Cohort profile: The Forzani & MacPhail Colon Cancer Screening Centre biorepository, Calgary, Alberta
Authors: Hilsden Robert J , Heitman Steven J , Lamidi Mubasiru , Diallo Mamadou Dian , English Janine , Town Susanna , Cartwright Shane , Maxwell Courtney , McGillivray Mary-Elizabeth , McGregor Elizabeth , Barberio Amanda , Pader Joy , Brenner Darren , Rabeneck Linda 
Published: November 2020

PurposeThe Colon Cancer Screening Centre (CCSC) biorepository (Calgary, Canada) supports a wide range of research topics related to colorectal cancer (CRC) by collecting, and storing biospecimens (blood, urine, normal colon tissue) from consenting patient participants. Housing unique biospecimens along with detailed participant lifestyle and health history questionnaire data, the CCSC biorepository can support a variety of research related to CRC risk factors, biomarkers, genetic causes and more.ParticipantsCurrently, 2292 average risk CRC patients have consented to participate in the CCSC cohort and have provided stored biospecimens. The collected samples and data provide important high-quality materials for research, discovery and evaluation related to CRC screening and carcinogenesis and is available for access by outside researchers. In addition to biological samples, the CCSC collects detailed patient information on their lifestyle, physical activity and dietary patterns through questionnaires at the time of their enrolment.Findings to dateThe majority of participants (75%) are between 50 and 64 years of age. Women make up 46% (1055) of the cohort. Additional characteristics of the cohort included 44% reporting a body mass index of 25–30 kg/m2 (overweight), 53% having never smoked tobacco and 13% having a family member with CRC.Future plansThe CCSC cohort plans to include the recruitment of high risk CRC cohorts. High-risk participants would comprise patients with a positive faecal immunochemical test and family history of CRC.
Development and validity testing of the Adolescent Health Literacy Questionnaire (AHLQ): Protocol for a mixed methods study within the Irish school setting
Authors: Spillane Ailbhe , Belton Sarahjane , McDermott Clare , Issartel Johann , Osborne Richard H , Elmer Shandell , Murrin Celine 
Published: November 2020

IntroductionHealth literacy research has focused predominantly on the adult population, and much less is understood about this concept from an adolescent perspective. The tools currently available to measure adolescent health literacy have been adapted from adult versions. This limits their applicability to young people because of the developmental characteristics that impact on adolescents’ behaviour, including impulse control and judgement skills. This protocol describes the intended development and validity testing of a questionnaire to measure health literacy in adolescents.Methods and analysisThis protocol describes this mixed methods study that has three phases: the first phase will involve grounded research with adolescents using qualitative group interviews, co-design and concept mapping workshops to understand what health and healthy behaviours mean to adolescents and to explore their health literacy needs and the potential domains for the questionnaire. The draft health literacy domains identified will be presented to the youth advisory panel, and the questionnaire will be altered based on their feedback. Cognitive pretesting of the questionnaire items will also be conducted. Phase 2 will involve piloting the questionnaire to a two-stage random sample of young people in five urban and rural schools in Ireland. Test–retest reliability will be conducted using Pearson correlation coefficient. Confirmatory factor analysis will also be conducted to analyse the psychometric properties of the questionnaire. Phase 3 will involve the questionnaire being rolled out to a nationally representative sample of adolescents (n=6052) in Ireland to assess their levels of health literacy.Ethics and disseminationEthical approval to conduct this study has been granted from the University College Dublin Human Research Ethics Committee – Sciences (LS-20–08). Informed assent from adolescents and informed consent from parents/guardians will be sought. The findings of this research will be disseminated at national and international conferences, as well as through publication in peer-reviewed journals.
Factors associated with attitudes towards HIV cure research among transgender women and travestis: a cross-sectional survey in São Paulo, Brazil
Authors: Wozniak Robert J , Cerqueira Natalia B , Dantas Maria Candida S , Mahafe Bianca , Barros Daniel A C , Alves de Medeiros Edmilson , Soares de Oliveira Ana Carolina , Sabino Thiago , Roggenbuck Albert , Avelino-Silva Vivian Iida , Johnston Carrie D , Marston Jez L , Bidegain Sebastian C , Magnus Manya , Kallas Esper G , Nixon Douglas F , Donini Camila S 
Published: November 2020

ObjectiveCharacterising the perceptions of groups most affected by HIV is fundamental in establishing guidelines for biomedical advancement. Although Brazil has successfully fought HIV/AIDS through several measures, transgender women still have a likelihood of HIV infection 55 times higher than the general population. This study aimed to better understand the perception and awareness of HIV cure research among the trans-identifying population in São Paulo, Brazil, and to determine factors that motivate or discourage participation in HIV cure studies.SettingThis cross-sectional study analysed data collected from a questionnaire administered to 118 transgender women and travestis at 5 sites within the city of São Paulo. It uses quantitative methodology to describe the perspectives of transgender and travesti people in relation to HIV cure research and the context in which such perspectives are produced.ResultsOf 118 participants, most participants (73%) had some knowledge of HIV cure research and were most willing to participate in online surveys (52%), interviews (52%), focus groups (52%) and studies involving blood draws (57%). Those with a higher education or employment status were more likely to agree that someone had been cured of HIV, people living with HIV are discriminated against, and more information about HIV cure research is needed before the community embraces it. Only 55% of participants completely trusted their physician. The biggest motivational factors included gaining additional knowledge about HIV infection (77%) and the potential for a longer, healthier life for all (73%).ConclusionsAs a primary analysis of HIV cure attitudes among the transgender and travesti population as well as the social context in which they are formed, this study identifies opportunities to strengthen the dialogue and develop more educational collaborations between scientific investigators, community educators and the trans-identifying population to ensure that HIV cure research is inclusive of diverse perspectives.
Fidelity of human ovarian cancer patient-derived xenografts in a partially humanized mouse model for preclinical testing of immunotherapies
Authors: Odunsi Adekunle , McGray A J Robert , Miliotto Anthony , Zhang Yali , Wang Jianming , Abiola Adebukola , Eppolito Cheryl , Huang Ruea-Yea 
Published: November 2020

BackgroundImmune checkpoint blockers (ICBs) have been approved by the Food and Drug Administration to be used alone in front-line therapies or in combination with other regimens for certain advanced cancers. Since ICB only works in a subset of patients and has limited efficacy in treating ovarian cancer (OVC), developing preclinical models that help to understand which patients may derive benefit from ICB would be of tremendous benefit in OVC.MethodsHere, we generated preclinical human OVC models from freshly resected tumors, which include six patient-derived xenografts (PDXs) from six different patient tumors, three transplantable OVC PD spheroid lines (PD-sphs), and 3 cell lines (PD-CLs). We tested the therapeutic combination of anti-PD1/CTLA4 antibodies with (1) autologous tumor-associated leukocytes (TALs) on the growth of PD-sphs in a coculture system in vitro, (2) with adoptively transferred autologous peripheral blood mononuclear cells or TALs in patient-derived OVC models using partially humanized mice, NSG-HHDxSGM3 (N-HSGM3).ResultsWe show that PD-1 and CTLA-4 dual blockade when combined with autologous TALs effectively reduced PD-sph number in a co-culture system and led to regression of established PD-CLs and PDXs in the N-HSGM3 mice. Combinatorial PD-1 and CTLA-4 blockade increased the frequency and function of tumor-specific CD8 T cells. These CD8 T cells persisted in the tumor microenvironment, exhibited memory phenotype and protected animals from tumor growth on tumor rechallenge. Gene expression analysis of tumors resistant to dual PD1/CTLA4 blockade treatment identified upregulation of antigen processing and presentation pathways and downregulation of extracellular matrix organization genes.ConclusionsThese findings describe a novel platform for developing patient-derived preclinical tumor models suitable for rationally testing combinatorial ICB in the context of autologous tumor-reactive T cells. This platform can be further developed for testing additional targeted therapies relevant to OVC.