bluuebunny/crossref_metadata_2025 huggingface dataset:
Unravelling diet composition and niche segregation of colonial waterbirds in a Mediterranean wetland using stable isotopes
Authors: Antón‐Tello María , Britto Vanessa Oliveira , Gil‐Delgado José Antonio , Rico Eugenio , Dies José Ignacio , Monrós Juan Salvador , Vera Pablo
Published: January 2021

Rice fields and waterbirds are an example of a synergy that can occur between agriculture and conservation. This connection is especially relevant during the farming period, when nesting waterbirds need to obtain resources to cover their energy requirements and those of their chicks in rice fields. However, new farming techniques may potentially put fulfilling this role at risk. Studies on how species use rice fields to feed during this critical period are essential to understand waterbird population dynamics and to optimize conservation measures. At present, several species of colonial birds in l’Albufera de València (Spain) that depend on trophic resources available in rice fields have decling populations and decreases in productivity. We therefore assessed trophic niche segregation in the diet of chicks of a waterbird community composed of seven species through stable isotope analyses of carbon (δ13C) and nitrogen (δ15N) obtained from chick blood and tissue samples of potential prey. According to trophic niche widths, chicks of Black‐headed GullChroicocephalus ridibundusand Gull‐billed TernGelochelidon niloticashowed a similar diet, although Gull‐billed Tern had a major trophic specialization. The Western Cattle EgretBubulcus ibisfed its chicks in a wider range of different habitats, with organisms located at the base of the food chain and with a greater importance of terrestrial prey than other species. Conversely, the Glossy IbisPlegadis falcinellushad a more differentiated diet, mostly in freshwater habitats and mainly consuming odonates. Grey HeronArdea cinerea, Little EgretEgretta garzettaand Squacco HeronArdeola ralloidesshowed overlap between their niches, largely explained by the presence and abundance of cyprinid fish and odonates in their diets. Our results suggest a less important role than expected of Red‐swamp CrayfishProcambarus clarkii, and a more important role of odonates despite being a less energy‐rich prey. In conclusion, the diet of generalistic species of waterbirds in this study suggests that their trophic niches can overlap when relative prey abundance is high.
Can an online mental health training programme improve physician supervisors' behaviour towards trainees?
Authors: Gayed Aimee , Kugenthiran Nathasha , LaMontagne Anthony D. , Christensen Helen , Glozier Nick , Harvey Samuel B.
Published: January 2021

Background

Physician trainees have elevated rates of psychological distress, mental disorders and suicide. Physician supervisors can support the mental health needs of trainees.

Aims

To test the feasibility and acceptability of a tailored online mental health training programme and to ascertain the potential effectiveness of the programme to alter the confidence and behaviours of physician supervisors.

Methods

Thirty Australian hospital‐based physicians who were supervising physician trainees participated in this quasi‐experimental pre–post pilot study. All received the intervention that comprised 12 5‐min modules to complete over a 3‐week period. Baseline and post‐intervention data were collected. The primary outcome evaluated participants' confidence to respond to trainees experiencing mental ill‐health and promote a mentally healthy workplace. Secondary outcomes evaluated change in self‐reported behaviour, mental health knowledge and stigmatising attitudes. Differences in mean scale scores for each outcome measure from baseline and post‐intervention were compared using paired sample t‐tests.

Results

Thirty physicians completed the baseline assessment and 23 (76.7%) completed all programme modules. Most participants found the programme engaging, interesting and useful. Post‐intervention data, available for 25 (83.3%) participants, showed a significant increase in participants' knowledge of their role in supporting trainees under their supervision (P = 0.002), confidence to initiate conversations about mental health with staff (P < 0.001), and application of preventive and responsive supervisory behaviours to support the mental health needs of those they supervise (P < 0.001).

Conclusions

This online mental health training programme for physician supervisors was feasible and associated with improved confidence and behaviour to support the mental health needs of trainees they supervised.
Impacts of multidisciplinary meeting case discussion on palliative care referral and end‐of‐life care in lung cancer: a retrospective observational study
Authors: Sridharan Krita , Paul Eldho , Stirling Robert G. , Li Chi
Published: January 2021

Background

Multidisciplinary meeting (MDM) discussion and early palliative care are recommended in lung cancer management. The literature is unclear whether MDM discussion leads to early palliative care and improved end‐of‐life care.

Aims

To evaluate impacts of discussion at an Australian lung MDM on palliative care referral, and MDM and early palliative care on aggressive end‐of‐life care.

Methods

A retrospective, cross‐sectional study was conducted of 352 patients diagnosed with primary lung cancer from 2017 to 2019 at the Alfred Hospital, Melbourne. The primary question was whether MDM discussion influenced palliative care referrals. Secondary questions were whether MDM discussion and early palliative care reduced aggressive treatment (chemotherapy, hospitalisation, emergency department visits, intensive care admission and in‐hospital death) during the last 30 days of life. Multivariable logistic regression was used to determine independent association between MDM discussion and palliative care referral.

Results

MDM discussion did not independently impact palliative care referral. There was reduced likelihood of MDM presentation in patients with metastatic disease (P< 0.0001) and poorer performance status (P= 0.025), and higher likelihood of palliative care referral in these patients (bothP< 0.001). MDM discussion reduced end‐of‐life intensive care unit (ICU) admission in patients with metastatic disease (P= 0.04). A palliative care referral‐to‐death interval of ≥30 days was associated with reduced hospitalisation at the end of life (P< 0.0001) and hospital deaths (P= 0.001).

Conclusion

Discussion at lung MDM did not increase palliative care referral, but did reduce ICU admission among metastatic patients at the end of life. Longer palliative care referral‐to‐death interval was associated with reduced aggressive end‐of‐life care. Further research is needed in these areas.
Enhancement of cyclodextrin production through use of debranching enzymes
Authors: Rendleman Jacob A.
Published: January 2021

In the presence of a complexant and a debranching enzyme capable of cleaving a‐(1 6) linkages in a‐D‐glucans, Bacillus mascerans cyclodextrin glucanotransferase (CGTase; EC 2.4.1.19) converted starch, maltodextrin and glycogen into cyclodextrin (CD) in yields higher than those obtainable in the absence of debranching enzyme. The extent of yield enhancement by pullulanase (EC 3.2.1.41; from Enterobacter aerogenes) was dependent upon temperature, type of substrate (including source of starch) and kind of complexant. Highest yields with pullulanase were attained generally by use of low temperature (15Ő25 ° C) and starches of low amylose content. At 25 ° C and pH 7, with cyclodecanone as complexant, 91Ő93% yields of b‐CD were obtainable from amylopectin, waxy‐maize starch, and tapioca starch. With decan‐1‐ol as complexant, amylopectin was converted at 15 ° C into a‐CD in 84% yield. With cyclotridecanone as complexant, amylopectin was converted at 40 ° C into ‐CD in 72% yield. The debranching enzyme isoamylase (EC 3.2.1.68; from Pseudomonas amyloderamosa) was also employed successfully to achieve high b‐CD yields. A 90% yield of b‐CD from amylopectin was obtained by applying isoamylase, CGTase and cyclodecanone at pH 6 and 25 ° C.
Photoelastic confirmation of surface stress relaxation in silica glasses: Fiber bending and rod torsion
Authors: Hausmann Bronson D. , Aaldenberg Emily M. , Tomozawa Minoru
Published: January 2021

Silica glass samples were given various heat treatments under stress at low temperatures and subsequently their residual stress distributions in terms of retardance were observed using a polarized light microscope, confirming previously reported fast surface stress relaxation while providing more detailed characterization. Retardance profiles of silica glass fibers heat‐treated under a constant bending strain in the presence of atmospheric water vapor were measured and fit to a previously developed diffusion‐based relaxation model. The retardance of a cross‐section of a silica glass rod heat‐treated at 650°C in lab air under applied torsional shear strain was also measured to confirm the presence of residual surface shear stress which was predicted by the decrease of torque with time for the rod. Together, these results confirm the low‐temperature fast surface stress relaxation which occurs when water vapor is present for both bending and shear stresses.
Attendance at the Interparliamentary Conference on the CFSP/CSDP: Fostering the Emergence of a Parliamentary Epistemic Community in the EU?
Authors: Schade Daniel , Stavridis Stelios
Published: January 2021

There has been a gradual consolidation of interparliamentary cooperation over EU foreign and security policies (CFSP/CSDP). This has culminated in the setting up of a dedicated interparliamentary conference (IPC) on the CFSP/CSDP. This paper considers whether IPC gatherings in their current form help foster the creation of a transnational epistemic community of parliamentarians in foreign and security affairs and thereby aid the empowerment of parliamentary actors in the EU. To this end, IPC attendance patterns are analysed. The article finds that attendance at IPCs' diverges between EU parliaments. This and the fact that few parliamentarians choose to participate again reduces the IPC's utility to facilitate regular interparliamentary contacts. The article then explores structural and individual determinants of these patterns. The findings are relevant for the larger literature on parliamentary participation, as well as on interparliamentary cooperation in general.
Prevalence, Related Factors, and Levels of Burnout Among Midwives: A Systematic Review
Authors: Albendín‐García Luis , Suleiman‐Martos Nora , Cañadas‐De la Fuente Guillermo A. , Ramírez‐Baena Lucía , Gómez‐Urquiza José L. , De la Fuente‐Solana Emilia I.
Published: January 2021

Introduction

Burnout refers to a constellation of feelings of exhaustion, depersonalization, and low sense of personal accomplishment that develops secondary to long‐term occupational stress. Several studies have identified that health care professionals are a high‐risk occupational group for burnout, but knowledge about this syndrome among midwives has not been fully explored. The purpose of this study was to perform a systematic review of the prevalence and levels of burnout among midwives and analyze the related factors.

Methods

The following databases were searched: CINAHL, LILACS, MEDLINE, ProQuest, PsycINFO, SciELO, and Scopus. Any date of publication was acceptable. Literature from different countries was included. Studies were appraised for quality following the recommendations of the Oxford Centre for Evidence‐Based Medicine.

Results

The literature review identified 27 studies with a total of N = 5612 midwives. The main factors related to burnout were working conditions such as work overload, lack of autonomy, and professional recognition. Midwives who had less than 10 years of experience were more vulnerable to burnout than those who had more than 10 years’ experience. With regard to the subcategories of burnout (emotional exhaustion, depersonalization and perceived personal achievement), midwives who did not live with a partner were more vulnerable low levels of personal accomplishment when compared with midwives who were living with a partner. The most significant protective factors against burnout were good leadership and the use of continuity models of care.

Discussion

Midwives had moderate levels of emotional exhaustion and low levels of personal accomplishment. Working conditions were identified as the main modifiable factors related to burnout syndrome. Intervention programs for midwives should be aimed at reducing emotional exhaustion and enhancing personal accomplishment.
Beyond illegality: Primary healthcare providers' perspectives on elimination of female genital mutilation/cutting.
Authors: Ogunsiji Olayide , Ussher Jane
Published: January 2021

Aims and objectives

To report primary healthcare providers' perspectives on elimination of female genital mutilation/cutting (FGM/C).

Background

Eradication of FGM/C by 2030 is one of the United Nations Sustainable Development goals. World Health Organization recognises the unique role of nurses and other primary healthcare providers. However, their voices on the current legislative approach are underreported. These voices are important in informing directions that can expedite achievement of the global goal.

Design

Qualitative interpretivist phenomenology.

Methods

This qualitative study used purposive sampling approach and involved 19 individual interviews conducted face to face or by telephone with Australian primary healthcare providers. Data collected between October and December 2019 were transcribed verbatim and thematically analysed. Three themes exploring Australian healthcare providers' perspectives on elimination of FGM/C were identified, namely understanding Australian laws against FGM/C; perspectives on culturally sensitive education; and exploring public awareness raising activities in Australia. This study was guided by Consolidated Criteria for Reporting Qualitative Research, the checklist for qualitative studies.

Results

“Understanding Australian laws against FGM/C” identified participants' knowledge that FGM/C is illegal in Australia and that mandatory reporting applies if a child is or at risk of being taken oversees for the procedure. Through “Perspectives on culturally sensitive education,” the participants argued that education is the key to questioning the practice of FGM/C. “Exploring public awareness‐raising activities in Australia” described the need for collective action germane to FGM/C eradication.

Conclusions

This study emphasised that laws and legislation prohibiting FGM/C need to be complemented with culturally sensitive education and public awareness‐raising activities, to produce optimal outcome for the elimination of FGM/C in Australia.

Relevance to clinical practice

Voices of these healthcare providers are crucial for FGM/C to be eradicated. Listening and acting on these voices are important in achieving the global sustainable development goal of eradicating FGM/C.
Identifying the risk factors and incidence of Asherman Syndrome in women with post‐abortion uterine curettage
Authors: Sevinç Fahrünnisa , Oskovi‐Kaplan Z. Asli , Çelen Şevki , Ozturk Atan Deniz , Topçu Hasan Onur
Published: January 2021

Aim

To evaluate the risk factors and incidence of Asherman Syndrome in women with post‐abortion uterine evacuation and curettage.

Methods

A total of 2546 patients who had surgical abortion (uterine evacuation and curettage) before the 20th gestational week with indications of missed abortion, anembryonic pregnancy, incomplete abortion, and elective curettage in a tertiary antenatal care center were recruited. The patients were called and surveyed for their symptoms; including infertility, oligo‐amenorrhea and recurrent pregnancy loss, preterm birth and intrauterine growth retardation and abnormal placentation as criteria of Asherman Syndrome. Diagnostic (office) hysteroscopy was performed for 177 who had one of those complaints.

Results

The incidence of Asherman Syndrome was 1.6% (n = 43/2546). History of ≥3 abortions was the main factor that increased the risk of Asherman Syndrome for by 4.6 times. Use of vacuum aspiration or sharp curettage, premedication for cervical priming, and having a pregnancy >10th gestational weeks were not risk factors for Asherman Syndrome.

Conclusion

When the diagnosis was based on presence of symptoms who underwent uterine instrumentation, the incidence of Asherman Syndrome was found to be 1.6%. Repeated abortions were the main risk factor for Asherman Syndrome and avoiding from repeated uterine instrumentations may have a role in prevention.
Long‐term recovery from COVID‐19 anosmia: Promising findings and unanswered questions
Authors: Locatello Luca Giovanni , Gallo Oreste
Published: January 2021

Click here to view the Brief Report by Lechien et al.
Social disparities in obesity treatment for children age 3–10 years: A systematic review
Authors: Lobstein Tim , Neveux Margot , Brown Tamara , Chai Li Kheng , Collins Clare E. , Ells Louisa J. , Nowicka Paulina ,   for the STOP project consortium
Published: January 2021

Socio‐economic status and ethnic background are recognized as predictors of risk for the development of obesity in childhood. The present review assesses the effectiveness of treatment for children according to their socio‐economic and ethnic background. Sixty‐four systematic reviews were included, from which there was difficulty reaching general conclusions on the approaches to treatment suitable for different social subgroups. Eighty‐one primary studies cited in the systematic reviews met the inclusion criteria, of which five directly addressed differential effectiveness of treatment in relation to social disparities, with inconsistent conclusions. From a weak evidence base, it appears that treatment effectiveness may be affected by family‐level factors including attitudes to overweight, understanding of the causes of weight gain and motivation to make and maintain family‐level changes in health behaviours. Interventions should be culturally and socially sensitive, avoid stigma, encourage motivation, recognize barriers and reinforce opportunities and be achievable within the family's time and financial resources. However, the evidence base is remarkably limited, given the significance of social and economic disparities as risk factors. Research funding agencies need to ensure that a focus on social disparities in paediatric obesity treatment is a high priority for future research.
Comparative effectiveness of school‐based interventions targeting physical activity, physical fitness or sedentary behaviour on obesity prevention in 6‐ to 12‐year‐old children: A systematic review and meta‐analysis
Authors: Podnar Hrvoje , Jurić Petra , Karuc Josip , Saez Marc , Barceló Maria A. , Radman Ivan , Starc Gregor , Jurak Gregor , Đurić Saša , Potočnik Žan Luca , Sorić Maroje
Published: January 2021

A systematic search of the literature was performed to compare the effects of interventions that targeted sedentary behaviours or physical activity (PA) or physical fitness on primary prevention of obesity in 6‐ to 12‐year‐old children. The search identified 146 reports that provided relevant data for meta‐analysis. Point estimates in % body fat were higher for fitness interventions compared with PA interventions (standardized mean difference = −0.11%; 95% CI = −0.26 to 0.04, and −0.04%; 95% CI = −0.15 to 0.06, respectively). Including sedentary behaviour to a PA‐ or fitness‐oriented intervention was not accompanied by an increase in intervention effectiveness, as the point estimates were slightly smaller compared with those for PA‐ or fitness‐only interventions. Overall, the effects tended to be larger in girls than in boys, especially for PA + sedentary behaviour interventions. There was some evidence for inequality, as the effects on body mass index were seen when interventions were delivered in the general population (standardized mean difference = −0.05, 95% CI = −0.07 to −0.02), but not in groups of disadvantaged children (standardized mean difference = −0.01, 95% CI = −0.29 to 0.19). In conclusion, school‐based PA interventions appear to be an effective strategy in the primary prevention of childhood obesity among 6‐ to 12‐year‐old children, but targeting sedentary behaviour in addition to PA or fitness does not increase the effectiveness of the intervention.
Collaborative gaming: When principals and agents agree to game the system
Authors: Pierre Jon , de Fine Licht Jenny
Published: January 2021

This paper presents a previously unexplored type of gaming of performance data, collaborative gaming, where the performance measurement system incentivizes the executive and an agency to game collaboratively. The paper shows how overlapping incentives between government departments and agencies to present successful implementation of programs can drive collaboration to modify performance targets and/or performance measurements. The argument is illustrated by two brief case studies of collaboration between the Swedish Department of Employment and the Swedish Public Employment Service in the implementation of labor‐market programs.
Copy number alteration analysis for neuroblastoma using droplet digital polymerase chain reaction
Authors: Ishii Yuko , Sato‐Otsubo Aiko , Takita Junko , Morio Tomohiro , Takagi Masatoshi
Published: January 2021

Background

Neuroblastoma (NB) is a malignant tumor derived from the neural crest. MYCN amplification is a well‐known adverse molecular prognostic factor for NB. Genome copy number alterations (CNAs) such as chromosome (Chr) 11q deletion, 1p deletion, and 17q gain are associated with a poor prognosis. Fluorescence in situ hybridization (FISH) and Southern blotting analysis are frequently used to detect MYCN amplification. Although comparative genomic hybridization (CGH) and single‐nucleotide polymorphism (SNP) chip arrays can easily detect CNAs, these methods are impractical for clinical use due to their cost and run time. Consequently, genome copy number analysis using digital droplet PCR has become widely used to monitor CNAs.

Methods

In this study, we used digital droplet polymerase chain reaction to detect MYCN amplification and Chr 11q CNA, which was used for risk stratification according to the International Neuroblastoma Risk Group classification system. We compared the results with data from SNP chip arrays in seven NB cell lines and eight primary NB samples.

Results

Digital droplet PCR assays successfully detected MYCN amplification and 11q CNA. The results were very consistent with those obtained by SNP chip assay.

Conclusions

Digital droplet PCR can be conducted more rapidly than FISH or Southern blotting. Accordingly, it should be useful for on‐site clinical applications aimed at detecting CNAs in NB and performing risk stratification promptly after diagnosis.
An experimental animal model of bronchopulmonary dysplasia: Secondary publication
Authors: Namba Fumihiko
Published: January 2021

Bronchopulmonary dysplasia (BPD) is a serious complication of preterm delivery and low birthweight infants. The incidence of BPD has not decreased, and there is no effective treatment for the disease. Since the survival rate of premature infants has increased, it has become difficult to obtain pathological tissue samples from BPD death cases. There is also no in vitro experimental system for complex three‐dimensional structures, such as alveolarization and pulmonary angiogenesis; thus, the use of animal models is necessary to elucidate the pathology of BPD and develop new treatments. To date, BPD animal models were being developed by exposing immature animal lungs to various stimuli. In the present review, I summarize BPD animal models that use (i) highly concentrated oxygen, (ii) mechanical ventilation, and (iii) infection/inflammation. In addition, with mesenchymal stromal cell (MSC) therapy for BPD as an example, I will discuss the expectations for new treatments that would be applied from animal models to humans.
Post‐transplant complications, patient, and graft survival in pediatric and adolescent kidney transplant recipients at a tropical tertiary care center across two immunosuppression eras
Authors: Mohapatra Anjali , Valson Anna T. , Annapandian Vellaichamy M. , David Vinoi George , Alexander Suceena , Jacob Shibu , Kakde Shailesh , Kumar Santosh , Devasia Antony , Vijayakumar Theophilus S. , Tamilarasi Veerasamy , Jacob Chakko Korula , Basu Gopal , John George Tharayil , Varughese Santosh
Published: January 2021

Background

We report pediatric PAKT patient and graft outcomes at a large tropical tertiary center spanning two transplant eras.

Methods

In this retrospective cohort study, all children ≤18 years who underwent kidney transplantation at our center between 1991 and 2016 were included. Data pertaining to their baseline characteristics, post‐transplant events, and outcome were retrieved from transplant records and compared between transplant eras (1991‐2005 and 2006‐2016).

Results

A total of 139 children (mean age 15.2 ± 2.9 years) underwent PAKT during this period. The incidence of UTIs, CMV disease, BKVN, invasive fungal infections, new‐onset diabetes after transplant, leucopenia, and recurrent NKD was higher in the 2006‐2016 era (P < .001 for all), while 1‐year cumulative BPAR was comparable (P = .100). Five‐year graft and patient survival in the two eras were 89.9% and 94.2% (P = .365) and 92.1% and 95.3% (P = .739), respectively. Incidence of CMV disease, BKVN, graft loss, and death was lower in the calcineurin withdrawal group. Non‐adherence accounted for 36% of graft loss; infections caused 43.7% of deaths. On multivariate Cox proportional hazards analysis, independent predictors for graft loss were UTIs and blood transfusion naïve status and for death were serious infections and glomerular NKD.

Conclusions

PAKT in India has excellent long‐term graft outcomes, though patient outcomes remain suboptimal owing to a high burden of infections. Current immunosuppression protocols need to be re‐examined to balance infection risk, graft, and patient survival.
Navigating Complexity in a Global Pandemic: The Effects of COVID‐19 on Children and Young People with Disability and Their Families in Australia
Authors: Yates Sophie , Dickinson Helen
Published: January 2021

While Coronavirus Disease 2019 (COVID‐19) does not discriminate against particular groups, our social structures and systems mean some people are more at risk in a pandemic context—from both the disease and the social and policy responses to the pandemic. This is particularly so for people with disability, in part because they often have poorer health outcomes from underlying conditions but also due to discrimination and social exclusion. Here, we draw from a survey about the impacts of the COVID‐19 pandemic on Australian children and young people with disability and their families. Respondents faced a range of inequities prior to the pandemic, and COVID‐19 has further exposed and often exacerbated them. We conclude that recent developments in the Australian disability context to personalize services have arguably made people with disability and their families less safe within a pandemic context, and we outline some ways in which these issues might be addressed.
How important is GVC participation to export upgrading?*
Authors: Ndubuisi Gideon , Owusu Solomon
Published: January 2021

Exporting higher quality and complex products is deemed pathway to economic growth and development. However, producing such products is knowledge‐intensive and requires quality intermediate inputs and advanced technologies. Integration into global trade networks is increasingly argued to be among the pathways to obtain such inputs and technologies, although not all countries may benefit equally from such integration. This paper builds on these arguments and investigates how participation in the global value chain (GVC) affects the quality of exported products. Using a highly disaggregated product‐level export data from 122 countries, we find that participation in (backward and forward) GVC impacts positively on the quality of exported products and brings the quality level closer to the quality frontier. While this result persists in the sub‐sample comprising developed countries, developing countries only benefit from backward GVC participation. Overall, the results indicate that GVC participation matters to export upgrading but points to a potential heterogeneity on the channel of impact across countries at different levels of development.
Identification of Dynamic Coefficients of a Five-Pad Tilting Pad Journal Bearing Up to Highest Surface Speeds
Authors: Zemella Philipp , Hagemann Thomas , Pfau Bastian , Schwarze Hubert
Published: January 2021

Tilting-pad journal bearings are widely used in turbomachinery industry due to their positive dynamic properties at high rotor speeds. However, the exact description of this dynamic behavior is still part of current research. This paper presents the measurement results for a five-pad tilting-pad journal bearing in load between pivot configurations. The bearing is characterized by a nominal diameter of 100 mm, a length of 90 mm, and a pivot offset of 0.6. Investigations include the results for surface speeds between 25 and 120 m/s and specific bearing loads ranging from 0.0 to 3.0 MPa. The results of theoretical predictions are commonly derived from perturbation of stationary operation under static load. Therefore, experimental results for stationary operation including pad deflection under static load are presented first to characterize the investigated bearing. Measured results indicate considerable nonlaminar flow in the upper region of the investigated range of rotor speeds. Second, dynamic excitation tests are performed with excitation frequencies up to 400 Hz to evaluate dynamic coefficients of a stiffness (K) and damping (C) KC model, and additionally, a KCM model using additional virtual mass (M) coefficients. KCM coefficients are obtained by fitting frequency dependent KC-characteristics to the KCM model structure using least square approach. The wide range of rotating and excitation frequencies leads to subsynchronous as well as supersynchronous vibrations. Excitation forces are applied with multisinus and single-sinus characteristics. The latter one allows evaluation of KC coefficients at the particular frequency ratio in the time domain. Here, frequency and time domain evaluation algorithms for dynamic coefficients are used in order to assess their special properties and quality. The impact of surface speed, bearing load, and oil flow rate on measured and predicted KCM coefficients is investigated. Measured and predicted results can be well fitted to a KCM model and show a significant influence of the ratio between fluid film and pivot support stiffness on the speed dependent characteristic of bearing stiffness coefficients. However, the impact of this ratio on damping coefficients is considerably lower. Further investigations on the impact of oil flow rates indicate that a significant decrease of direct damping coefficients exists below a certain level of starvation. Above this limit, direct damping coefficients are nearly independent of oil flow rate. Results are analyzed in detail and demands on improvements for predictions are derived.
Failure Modeling and Sensitivity Analysis of Ceramics Under Impact
Authors: Bhattacharjee Amartya , Bhaduri Anindya , Hurley Ryan C. , Graham-Brady Lori
Published: January 2021

A micromechanical multi-physics model for ceramics has been recalibrated and used to simulate impact experiments with boron carbide in abaqus. The dominant physical mechanisms in boron carbide have been identified and simulated in the framework of an integrated constitutive model that combines crack growth, amorphization, and granular flow. The integrative model is able to accurately reproduce some of the key cracking patterns of Sphere Indentation experiments and Edge On Impact experiments. Based on this integrative model, linear regression has been used to study the sensitivity of sphere indentation model predictions to the input parameters. The sensitivities are connected to physical mechanisms, and trends in model outputs have been intuitively explored. These results help suggest material modifications that might improve material performance, prioritize calibration experiments for materials-by-design iterations, and identify model parameters that require more in-depth understanding.
Hemodynamic Assessment of Hollow-Fiber Membrane Oxygenators Using Computational Fluid Dynamics in Heterogeneous Membrane Models
Authors: Dipresa Daniele , Kalozoumis Panagiotis , Pflaum Michael , Peredo Ariana , Wiegmann Bettina , Haverich Axel , Korossis Sotirios
Published: January 2021

Extracorporeal membrane oxygenation (ECMO) has been used clinically for more than 40 years as a bridge to transplantation, with hollow-fiber membrane (HFM) oxygenators gaining in popularity due to their high gas transfer and low flow resistance. In spite of the technological advances in ECMO devices, the inevitable contact of the perfused blood with the polymer hollow-fiber gas-exchange membrane, and the subsequent thrombus formation, limits their clinical usage to only 2–4 weeks. In addition, the inhomogeneous flow in the device can further enhance thrombus formation and limit gas-transport efficiency. Endothelialization of the blood contacting surfaces of ECMO devices offers a potential solution to their inherent thrombogenicity. However, abnormal shear stresses and inhomogeneous blood flow might affect the function and activation status of the seeded endothelial cells (ECs). In this study, the blood flow through two HFM oxygenators, including the commercially available iLA® MiniLung Petite Novalung (Xenios AG, Germany) and an experimental one for the rat animal model, was modeled using computational fluid dynamics (CFD), with a view to assessing the magnitude and distribution of the wall shear stress (WSS) on the hollow fibers and flow fields in the oxygenators. This work demonstrated significant inhomogeneity in the flow dynamics of both oxygenators, with regions of high hollow-fiber WSS and regions of stagnant flow, implying a variable flow-induced stimulation on seeded ECs and possible EC activation and damage in a biohybrid oxygenator setting.
Parametric Wave Spectrum Model for Typhoon-Generated Waves Based on Field Measurements in Nearshore Strait Water
Authors: Wei Kai , Imani Hasan , Qin Shunquan
Published: January 2021

The stochastic waves generated by storm landfalls usually determine the design and safety of coastal and offshore structures in typhoon regions. This study developed a parametric wave spectrum model for typhoon-generated stochastic waves that considers the variation in the wave spectrum due to the temporal variation in the typhoon. A field measurement campaign was conducted in nearshore strait water on the east coast of China to measure the wave data for two landfall typhoons: Soudelor and Dujuan. The measured wave data were filtered through a preprocessing framework. The parametric wave spectrum model was then developed based on the measured wave spectra for different stages of the typhoon. The main conclusions include the following: (1) 78% of the measured wave spectra at the example site under a typhoon are double-peaked, and approximately 15% are single-peaked; (2) the parametric model with either the Joint North Sea Wave Project (JONSWAP) or Ochi-Hubble (OH) kernel function is effective in defining the typhoon-generated wave spectra; and (3) the critical parameters of the developed model for typhoon-generated waves are site-specific and depend on the temporal variation of the typhoon.
Control Allocation Application to Automotive Suspension Actuators for Handling Objectives
Authors: Beckerman Alex K. , Abapo Gladys , Clemen Layne
Published: January 2021

Current research within the automotive community suggests an increasing trend in applying mechatronic actuators for improved ride and handling. In particular, there is an increasing trend towards semi-active and active suspension actuators. This research presents various novel suspension control strategies specific to handling by building upon a control allocation type framework. Such a framework is common in the aerospace and marine industries due its multi-objective control properties, suitability for over-actuated systems, the ease in which nonlinear or time-varying properties are included, in addition to many other benefits. Control allocation is becoming increasingly more appropriate for automotive applications due to the increasing trend in applying mechatronic actuators for improved ride and handling.

Specifically, this paper develops methods for improving yaw rate with active suspension actuators. It will be shown that this task is nontrivial within an allocation framework due to properties of the physical system. By using the methods developed in this paper, it becomes trivial to incorporate this and other handling related methods into a larger and more integrated framework with a higher number of control objectives and actuators. The methods in this paper take advantage of the complicated dynamics and inherent nonlinear relationship between suspension actuator forces and resultant tire lateral forces. It is demonstrated through simulation that a vehicle with the proposed allocation framework outperforms a vehicle with no suspension actuation. Different methods are evaluated and compared based on stability and robustness properties.
On the Nonlinear Vibration Analysis of a Hand-Held Impact Machine
Authors: Alabi Oreoluwa , Barry Oumar
Published: January 2021

Prolonged exposure of the human arm to vibrations from hand-held impact (HIM) tools can be hazardous as such, it is important that the level of vibration suppression in HIMs is improved. This paper sought to address this issue by studying a model of the hand-arm system (HAS) coupled to a HIM which is also coupled to a nonlinear tuned vibration absorber inerter (NVAI). The HAS is modelled as a 2-DOF system coupled to the HIM at a single point. The HIM is modelled as an oscillator with linear damping, and both linear and nonlinear stiffnesses. The nonlinear stiffness of the HIM is introduced to represent the nonlinearities introduced by the vibro-impact dynamics of the HIM. After obtaining the equations of motion for the system, an analytical solution is obtained using the harmonic balance method. The analytical solution is validated using direct numerical integration and the results show very good agreement. The performance of the NVAI is compared to those of the classical nonlinear and linear vibration absorbers. Parametric study is carried out to examine the role of key design parameters, such as the damping of the absorber, nonlinear stiffness of the HIM and inertance of the NVAI, on the performance of the NVAI.
Improving Passenger Comfort by Exploiting Hub Motors in Electric Vehicles: Suspension Modeling
Authors: Chen Di , Danielson Claus , Iezawa Masahiro
Published: January 2021

This paper examines using electric vehicles with independently actuated wheels and anti-squat/lift/dive suspensions to improve passenger comfort by reducing the lift, pitch, and roll motion of the vehicle chassis. Anti-squat/lift/dive suspensions use an angled suspension bar to transfer a portion of the longitudinal driving force into a vertical reaction force on the chassis. Using this effect, we derive a control-oriented model of the lift, pitch, and roll of the chassis where the steering angle and the four driving forces of the individual wheels are the control inputs and the road-height is a disturbance. The model is simplified under the assumption that the suspension deflections are small during normal, comfortable driving. Finally, we use steady-state analysis and open-loop simulations to provide intuition about the relationship between the driving forces and the chassis motions.
Galvanic Skin Response As a Measure of Engagement During Play in Virtual Reality
Authors: Ventura Roni Barak , Porfiri Maurizio
Published: January 2021

Competition is a common design strategy used to enhance user engagement and participation. However, it remains unclear how winning or losing might influence player’s engagement. In a recent study, we used behavioral metrics to quantify player engagement during competitive gameplay in virtual reality. To control for players’ status of winning or losing, we programmed a virtual opponent to either under-perform, over-perform, or tie with them. We conducted a series of experiments and found that players’ engagement was higher when they were losing, compared to when they played alone. Nevertheless, players’ engagement did not change during competition with an under-performing or equally-performing opponent. By applying the information-theoretic notion of transfer entropy, we unveiled a causal relationships between relative performance and engagement, whereby players monitored the scores and adapted their behavior accordingly. However, behavioral metrics are not detached from volition and may be influenced by confounding factors. This limitation is addressed by the use of physiological metrics, which offer largely unbiased measurements of cognitive and emotional processes. In the present study, we sought to strengthen our prior findings by measuring engagement with a physiological correlate. We conducted experiments in the same experimental setting and we measured players’ galvanic skin response during competition. We discovered that players’ skin conductance was higher when they were outperformed by their opponent, indicating that they were experiencing less flow. The results inform the design of technology-mediated applications toward sustaining user engagement and participation.
Combining Non-Parametric and Parametric Models for Stable and Computationally Efficient Battery Health Estimation
Authors: Aitio Antti , Howey David
Published: January 2021

Equivalent circuit models for batteries are commonly used in electric vehicle battery management systems to estimate state of charge and other important latent variables. They are computationally inexpensive, but suffer from a loss of accuracy over the full range of conditions that may be experienced in real-life. One reason for this is that the model parameters, such as internal resistance, change over the lifetime of the battery due to degradation. However, estimating long term changes is challenging, because parameters also change with state of charge and other variables. To address this, we modelled the internal resistance parameter as a function of state of charge and degradation using a Gaussian process (GP). This was performed computationally efficiently using an algorithm [1] that interprets a GP to be the solution of a linear time-invariant stochastic differential equation. As a result, inference of the posterior distribution of the GP scales as 𝒪(n) and can be implemented recursively using a Kalman filter.
Autonomous Light Assessment Drone for Dark Skies Studies
Authors: Goodell Matthew N. , Truong Takara E. , Marston Stephanie R. , Smiley Brett J. , Befus Elliot R. , Bingham Alex , Allen Kent , Bourne Joseph R. , Wei Yi , Magargal Kate E. , Ganesan Vellachi , Mendoza Daniel L. , Seth Anil C. , Harwood Stacy A. , Bodson Marc , Hermans Tucker , Leang Kam K.
Published: January 2021

The improper use of artificial light causing skyglow is detrimental to many types of wildlife and can potentially cause irregular human sleeping patterns. Studies have been performed to analyze light pollution on a global scale. However, light pollution data on a local scale is not of ten available and the effects at local scale have rarely been studied. Herein, a new custom-designed autonomous light assessment drone (ALAD) is described for evaluating light pollution at local scale. The ALAD is designed and equipped with a sky quality meter (SQM) to measure skyglow and a low-cost illuminance sensor to measure light from artificial sources. Outdoor field tests are performed at a remote site in central Utah and the measured results are validated against data from lightpollution-map.info. The SQM measurements are in agreement with the estimates from the light pollution map, and the initial results demonstrate feasibility of the ALAD for local-scale skyglow assessment.
Sensor and Actuator Intrusion Detection for Cyber-Physical Systems via Adaptive Estimation Algorithm
Authors: Su Jiayi , Weng Yuqin , Schneider Susan C. , Yaz Edwin E.
Published: January 2021

In this work, a new approach to detect sensor and actuator intrusion for Cyber-Physical Systems using a bank of Kalman filters is presented. The case where the unknown type of the intrusion signal is considered first, using two Kalman filters in a bank to provide the conditional state estimates, then the unknown type of intrusion signal can be detected properly via the adaptive estimation algorithm. The case where the target (either sensor or actuator) of the intrusion signal is unknown is also considered, using four Kalman filters in a bank designed to detect if the intrusion signal is about to affect healthy sensor or actuator signal. To test these methods, a DC motor speed control system subject to attack by different types of sensor and actuator signals is simulated. Simulations show that different types of sensor and actuator intrusion signals can be detected properly without the knowledge of the nature and the type of these signals.
Maximum Correntropy Kalman Filter for Orientation Estimation With Application to LiDAR Inertial Odometry
Authors: Fakoorian Seyed , Palieri Matteo , Santamaria-Navarro Angel , Guaragnella Cataldo , Simon Dan , Agha-mohammadi Ali-akbar
Published: January 2021

Accurate attitude estimation using low-cost sensors is an important capability to enable many robotic applications. In this paper, we present a method based on the concept of correntropy in Kalman filtering to estimate the 3D orientation of a rigid body using a low-cost inertial measurement unit (IMU). We then leverage the proposed attitude estimation framework to develop a LiDAR-Intertial Odometry (LIO) demonstrating improved localization accuracy with respect to traditional methods. This is of particular importance when the robot undergoes high-rate motions that typically exacerbate the issues associated with low-cost sensors. The proposed orientation estimation approach is first validated using the data coming from a low-cost IMU sensor. We further demonstrate the performance of the proposed LIO solution in a simulated robotic cave exploration scenario.
Application of Fuzzy Logic for Developing Sense and Avoid Techniques for UAV Flight Operations in National Airspace
Authors: Lee Zoe , Kumar Rumit , Radmanesh Reza , Kumar Manish , Cohen Kelly
Published: January 2021

In this work, a Fuzzy Inference System (FIS) is proposed to develop a sense and avoid technique for conflict-free Unmanned Aerial Vehicle (UAV) flight operations in the national airspace. The proposed method is implemented alongside the flight control software guiding the UAV towards a predefined goal. The fuzzy system makes decisions for sense and avoid with respect to the state of other intruder aircraft in the airspace. The fuzzy rules are selected under consideration of the heading and position data of the intruder aircraft obtained using ADS-B sensor relative to the controlled UAV. The avoidance controller is implemented alongside a traditional PID-based flight controller to test the effectiveness of the sense-and-avoid technique. The PID controller drives the controlled UAV towards the goal and the fuzzy controller is for conflict avoidance based on an event trigger logic if the controlled UAV is in the intrusion zone of another aircraft. The integration of the dynamic model of the controlled UAV and fuzzy inference system is described. The numerical simulations are shown to evaluate the performance of the proposed method in the presence of moving as well as stationary intruder aircraft.