bluuebunny/crossref_metadata_2025 huggingface dataset:
Discrete singular convolution–polynomial chaos expansion method for free vibration analysis of non-uniform uncertain beams
Authors: Seçgin Abdullah , Kara Murat , Ferguson Neil
Published: February 2021

This article enhances the discrete singular convolution method for free vibration analysis of non-uniform thin beams with variability in their geometrical and material properties such as thickness, specific volume (inverse of density) and Young’s modulus. The discrete singular convolution method solves the differential equation of motion of a structure with a high accuracy using a small number of discretisation points. The method uses polynomial chaos expansion to express these variabilities simulating uncertainty in a closed form. Non-uniformity is locally provided by changing the cross section and Young’s modulus of the beam along its length. In this context, firstly natural frequencies of deterministic uniform and non-uniform beams are predicted via the discrete singular convolution. These results are compared with finite element calculations and analytical solutions (if available) for the purpose of verification. Next, the uncertainty of the beam because of geometrical and material variabilities is modelled in a global manner by polynomial chaos expansion to predict probability distribution functions of the natural frequencies. Monte Carlo simulations are then performed for validation purpose. Results show that the proposed algorithm of the discrete singular convolution with polynomial chaos expansion is very accurate and also efficient, regarding computation cost, in handling non-uniform beams having material and geometrical variabilities. Therefore, it promises that it can be reliably applied to more complex structures having uncertain parameters.
Covariance regression for operational modal analysis
Authors: Lu Zhong-Rong , Yang Dahao , Huang Linchong , Wang Li
Published: February 2021

This article proposes a covariance regression procedure for operational modal analysis. The whole work is mainly twofold. On the one hand, two identities on the covariance are presented and they reveal that the covariance at different times is linearly dependent through both scalar and matrix coefficients. On the other hand, based on the two identities, the scalar covariance regression approach and the matrix covariance regression approach are naturally invoked. In proceeding so, the scalar or matrix coefficients are first acquired through covariance regression, and then, the modal parameters are simply extracted from the coefficients. Numerical examples and a field test case are studied to see the effectiveness of the proposed covariance regression procedure, and the ability to deal with harmonic load, large damping, and closely spaced modes is clearly verified.
Safely Increasing Connection to Community-Based Services: A Study of Multidisciplinary Team Decision Making for Child Welfare Referrals
Authors: Chambers Jaclyn E. , Roscoe Joseph N. , Berrick Jill Duerr , Lery Bridgette , Thompson Doug
Published: February 2021

Initial child welfare screening decisions, traditionally made by an individual worker, determine if a family will receive further intervention by child protective services. A multi-disciplinary team (MDT) decision-making approach for child welfare referrals aims to provide a more thorough assessment of needs and strengths and to connect families to appropriate community-based providers. This study examined 159 child welfare referrals handled by MDTs compared to 331 referrals handled via the traditional screening approach. The study used a pseudo randomization procedure to assign referrals to the study conditions: Referrals logged on 2.5 days of the week were assigned to the treatment group; all others were assigned to the comparison group. Referrals handled by an MDT were more than four times as likely as those not handled by an MDT to be referred to community-based organizations ( OR = 4.32, p < .001). There were no statistically significant differences in families’ engagement with community-based organizations or child welfare outcomes. MDTs are a promising step in the initial process of connecting families to services, although they did not affect this study’s longer-term outcomes.
Attachment Characteristics Among Women Victimized in No, One, and Multiple IPV Relationships: A Case–Control Study
Authors: Ørke Elisabeth Christie , Bjørkly Stål , Dufort Mariana , Vatnar Solveig Karin Bø
Published: February 2021

This cross-sectional study compared attachment characteristics among women victimized by intimate partner violence (IPV) in no, one, and multiple relationships ( N = 154). Results indicated that compared with the nonvictimized, victimized women had increased likelihood of higher attachment avoidance. Compared with women victimized in one relationship, women victimized in multiple relationships had higher likelihood of higher attachment anxiety scores. Adjusting for childhood adversities, childhood sexual abuse was an independent risk factor for IPV. Childhood emotional abuse mediated the association between attachment anxiety and IPV victimization in multiple relationships in particular. Attachment theory appeared useful for better understanding women’s vulnerability for multiple violent relationships.
Understanding relevant immune mechanisms in gastrointestinal oncology
Authors: Cetin Bulent , Gumusay Ozge
Published: February 2021

Rapid and successful drug development has resulted in multiple treatment options for gastrointestinal cancer, requiring careful decision making for individual patients. The general theme in modern immunology is that the field is moving beyond establishing the fundamental principles of immune response mechanisms to applying these propositions to understand human diseases and develop new therapies. Immunotherapy has contributed enormously to cancer treatments with a virtual explosion in novel therapeutics including checkpoint inhibitors and other recently developed immunomodulators and the development of novel therapeutic approaches. Although the majority of gastrointestinal (GI) cancers are generally considered poorly immunogenic, clinical trials have revealed that some of the patients with various gastrointestinal cancers are highly responsive to immune checkpoint inhibition-based therapies. We paid special attention to the clinical relevance of immunology and emphasized how newly developed therapies work, including what their strengths and pitfalls are. This review aims to enhance the interest of practitioners in the many specialties and subspecialties that the discipline influences and to assist them in understanding this increasing complexity.
Reformists, Decouplists, and Activists: A Typology of Ecocentric Management
Authors: Hernández Mauricio , Muñoz Pablo
Published: February 2021

Ecocentric management has grown in interest in business sustainability research, driven by recent debates on sustainability-as-flourishing and novel nature-based business approaches. While relevant and promising, examination and explanations remain anchored in conventional dualistic thinking and piecemeal logics. In this article, we seek to understand what conditions or combination of conditions enable the formation of ecocentrism in business management. Drawing on deep ecology and ecocentric philosophy, we develop a conceptual framework for ecocentric management, comprising ecological sensing, envisioning, and enacting. Leveraging this framework and fuzzy-set qualitative comparative analysis, we map the responses of 160 small business owners and managers in Chile. Our analyses reveal three configurations of conditions, forming a typology of ecocentric management: Market Reformist, Legitimated Decouplist, and Self-Centered Activist. The article offers a new conceptual apparatus and systemic characterization of ecocentrism in business sustainability. It shows what matters and when for the formation of ecocentric thinking and decision-making in management.
Causes of Problems in Post-Disaster Emergency Re-Construction Projects—Iraq as a Case Study
Authors: Waheeb Rasha A. , Andersen Bjørn S.
Published: February 2021

This study examines the causes of time delays and cost overruns in a selection of thirty post-disaster reconstruction projects in Iraq. Although delay factors have been studied in many countries and contexts, little data exists from countries under the conditions characterizing Iraq during the last 10-15 years. A case study approach was used, with thirty construction projects of different types and sizes selected from the Baghdad region. Project data was gathered from a survey which was used to build statistical relationships between time and cost delay ratios and delay factors in post disaster projects. The most important delay factors identified were contractor failure, redesigning of designs/plans and change orders, security issues, selection of low-price bids, weather factors, and owner failures. Some of these are in line with findings from similar studies in other countries and regions, but some are unique to the Iraqi project sample, such as security issues and low-price bid selection. While many studies have examined factors causing delays and cost overruns, this study offers unique insights into factors that need to be considered when implementing projects for post disaster emergency reconstruction in areas impacted by wars and terrorism.
The Effect of Absolute and Relative Deprivation on Homicides in Brazil
Authors: Aransiola Temidayo James , Ceccato Vania , Justus Marcelo
Published: February 2021

This paper investigates the effect of absolute deprivation (proxy unemployment) and relative deprivation (proxy income inequality) on homicide levels in Brazil. A database from the Brazilian Information System about Mortality and Census of the year 2000 and 2010 was used to estimate negative binomial models of homicide levels controlling for socioeconomic, demographic, and geographic factors. Findings show that unemployment and income inequality affect homicides levels and that the effect of the former is more pronounced compared to the latter. Moreover, the combination of income inequality and unemployment exacerbates the overall effect of deprivation on homicide levels.
Gender Differences in the Relationship Between Exercise, Sleep, and Mood in Young Adults
Authors: Glavin Emily E. , Matthew Juliet , Spaeth Andrea M.
Published: February 2021

Insufficient sleep is a serious public health problem in college students. Exercise is a widely prescribed behavioral treatment for sleep and mood issues; however, more focused and gender-specific prescriptions are needed. The present study examined relationships between exercise, sleep, and mood in undergraduate men and women. Students ( N = 866, 19.6 ± 1.4 years, 38.7% women) were recruited from campus recreation facilities and completed demographic, the Pittsburgh Sleep Quality Index, mood (Patient-Reported Outcomes Measurement Information System), and exercise questionnaires. The Department of Health and Human Services Physical Activity Guidelines were used to dichotomize those who did and did not meet weekly aerobic and strength training exercise recommendations. In men, greater exercise frequency associated with less daytime dysfunction (β = 0.147) and less depressive mood (β = −0.64, ps < .05). In women, greater exercise frequency associated with earlier bedtime (β = −12.6), improved sleep quality (β = 0.17), increased positive affect (β = 0.91), less depressive mood (β = −0.71), and less anger (β = −1.24, ps < .05). Compared to men, women reported earlier bedtime, poorer sleep efficiency, and more anxiety and depressive mood ( ps < .05, [Formula: see text] range: 0.01–0.04 ). Compared to individuals who met physical activity guidelines, those who did not meet the guidelines reported later bedtimes, less positive affect, more anxiety, and more anger ( ps < .05 [Formula: see text]s = 0.01). Among men, those who met physical activity guidelines reported falling asleep more quickly than those who did not meet guidelines ([Formula: see text] = 0.01, p = .007); however, no relationship between guideline adherence and sleep latency was observed in women. Adhering to physical activity guidelines may be important for optimal sleep and emotional health. Clinicians should consider gender when creating exercise prescriptions for sleep issues.
Resilience and fault tolerance in high-performance computing for numerical weather and climate prediction
Authors: Benacchio Tommaso , Bonaventura Luca , Altenbernd Mirco , Cantwell Chris D , Düben Peter D , Gillard Mike , Giraud Luc , Göddeke Dominik , Raffin Erwan , Teranishi Keita , Wedi Nils
Published: February 2021

Progress in numerical weather and climate prediction accuracy greatly depends on the growth of the available computing power. As the number of cores in top computing facilities pushes into the millions, increased average frequency of hardware and software failures forces users to review their algorithms and systems in order to protect simulations from breakdown. This report surveys hardware, application-level and algorithm-level resilience approaches of particular relevance to time-critical numerical weather and climate prediction systems. A selection of applicable existing strategies is analysed, featuring interpolation-restart and compressed checkpointing for the numerical schemes, in-memory checkpointing, user-level failure mitigation and backup-based methods for the systems. Numerical examples showcase the performance of the techniques in addressing faults, with particular emphasis on iterative solvers for linear systems, a staple of atmospheric fluid flow solvers. The potential impact of these strategies is discussed in relation to current development of numerical weather prediction algorithms and systems towards the exascale. Trade-offs between performance, efficiency and effectiveness of resiliency strategies are analysed and some recommendations outlined for future developments.
Testing for Collinearity using Bayesian Analysis
Authors: Assaf A. George , Tsionas Mike
Published: February 2021

Testing for collinearity continues to be a controversial issue in the literature. Multicollinearity detection criteria, such as the variance inflation factor, often fail to detect the true extent of multicollinearity. In this article, we propose utilizing the Bayesian approach as an attractive alternative. Under the Bayesian approach, we recommend comparing the marginal posterior of regression parameters under two different priors. If the difference in the posterior under these two priors is pronounced, one can surmise that collinearity is harmful. The Kolmogorov–Smirnov test can also be used as further evidence to confirm whether the posterior difference is significant.
Ophthalmology-focused publications and findings on COVID-19: A systematic review
Authors: Jin Ya-Ping , Trope Graham E , El-Defrawy Sherif , Liu Elin Y , Buys Yvonne M
Published: February 2021

Purpose:

To summarize COVID-19 research endeavors by ophthalmologists/researchers in terms of publication numbers, journals and author countries, and to detail key findings.

Methods:

The LitCovid database was systematically reviewed for ophthalmology-focused COVID-19 articles. The quality of the evidence was assessed for articles investigating conjunctivitis in COVID-19 patients.

Results:

There were 21,364 articles in LitCovid on June 12, 2020, of which 215 (1%) were ophthalmology-focused. Of articles on COVID-19 transmission, 3.3% were ophthalmology-focused. Ophthalmology-focused articles were published in 68 journals and originated from 25 countries. The top five countries publishing ophthalmology-focused articles (China, India, United States of America, Italy, and United Kingdom) produced 145/215 (67%) articles. A total of 16 case reports/series from eight countries reported that conjunctivitis can be the initial or the only symptom of COVID-19 infection. Conjunctivitis may occur in the middle phase of COVID-19 illness. A total of 10 hospital-based cross-sectional studies reported that between 0% and 31.6% of COVID-19 patients have conjunctivitis or other ocular conditions, with a pooled prevalence of 5.5% reported in a meta-analysis. Viral RNA was detected in conjunctival swabs of patients with and without ocular manifestations, after resolution of conjunctivitis, after nasopharyngeal swabs turned negative and in retina of deceased COVID-19 patients.

Conclusion:

Within 3 months of declaring the COVID-19 pandemic, 215 ophthalmology-focused articles were published in PubMed, concentrating on disease manifestations and transmission. The reported presence of conjunctivitis or other ocular conditions in COVID-19 patients is varied. Clinicians should be alert for ocular involvement in COVID-19 infections and possible ocular transmission even in patients without ocular symptoms.
Does Exercise Influence Kynurenine/Tryptophan Metabolism and Psychological Outcomes in Persons With Age-Related Diseases? A Systematic Review
Authors: Lim Anthony , Harijanto Christel , Vogrin Sara , Guillemin Gilles , Duque Gustavo
Published: February 2021

Background:

The kynurenine (KYN) pathway has been implicated in many diseases associated with inflammation and aging (“inflammaging”). Targeting the kynurenine pathway to modify disease outcomes has been trialled pharmacologically, but the evidence of non-pharmacological means (ie, exercise) remains unclear.

Objective:

We aim to assess the evidence of the effects of exercise on the kynurenine pathway and psychological outcomes.

Methods:

Under Preferred Reporting Items for Systematic Review and Meta-Analysis (PRISMA) guidelines, a systematic literature search was performed in MEDLINE, EMBASE, EMCARE, and the Cochrane Central Registry of Controlled Trials. The main outcomes were changes in kynurenine pathway metabolite levels and psychological outcomes.

Results:

Six studies were analyzed (total n = 379) with exercise demonstrating significant concomitant effects on kynurenine pathway metabolite levels and associated psychological outcomes in domains of somatization, anxiety, and depression.

Conclusion:

Exercise has significant concomitant effect on kynurenine pathway metabolite levels and psychological outcomes. However, clear limitations exist in determining if the changes in the kynurenine pathway can fully explain the changes in psychological outcomes, or whether different diseases and exercise interventions act as confounding factors.
Working with the potential of arts-based learning: Making sense and leaving ‘business as usual’ behind in an art seminar
Authors: Flamand Guillaume , Perret Véronique , Picq Thierry
Published: February 2021

The purpose of this study is to contribute to the interest in arts-based learning as part of the growing literature on artistic initiatives in business contexts, by advancing the understanding of the potential of arts-based business learning that people can yet fail to benefit from. We draw on Weick’s framework for how people construct meaning in organized situations and on a qualitative study of an art seminar in business education to consider arts-based learning in the face of pitfalls that can prevent people from engaging in approaches that differ from their usual ones and from which they can learn. We show that people can benefit from the potential of arts-based business learning when collective meaning-construction processes such as sensemaking or sensegiving can unfold and work in an iterative, active and intense way, to take people towards new experiences. Our study also highlights the usefulness of taking a perspective centred on ongoing collective meaning-construction processes and of focusing on both learning activities and learning situations when studying business learning.
Why democrats abandon democracy: Evidence from four survey experiments
Authors: Fossati Diego , Muhtadi Burhanuddin , Warburton Eve
Published: February 2021

In several world regions, democracy is in retreat. This retreat is taking place amid growing polarization in many countries, and analysts are increasingly concerned with the role that deepening political divisions play in processes of democratic decline. This article investigates the relationship between partisan polarization and deteriorating public support for democratic institutions. It leverages the case of Indonesia, a major third-wave democracy now in the midst of a democratic regression. Indonesia’s political landscape has become more ideologically polarized in recent years, despite the strength of clientelist networks and low levels of party identification. Using four survey experiments, we find that Indonesians embrace illiberal interventions and abandon democratic institutions when exposed to party and leadership cues. These results suggest that political polarization may prompt citizens to abandon democratic norms even in democracies without strong partisan identities.
The role of mashup music in creating Web 2.0’s democratic promise
Authors: Jones Ellis
Published: February 2021

This article employs Stuart Hall’s concept of ‘articulation’ to show how, in the mid-2000s, a loose coalition of tech activists and commentators worked to position mashup music as ‘the sound of the Internet’. Key aesthetic characteristics of mashups were utilized to present Web 2.0 as a specific kind of democratic, participatory media environment – one that had the power to dethrone old social institutions, and to render various kinds of borders and boundaries redundant. This short-lived articulation between mashup and the Internet has had significant benefits for contemporary platforms that have made their fortune on user participation; it has been less beneficial for the longevity of mashup as a genre. Thus, this article inverts the standard presentation of mashup music and network technologies. Generally presented as a musical culture that needed the Internet, mashup can be more fruitfully understood as a music culture that the Internet needed. This reformulation provides cause to question our contemporary relationship to ‘digital optimism’ more generally.
Impact of a telemonitoring intervention in patients with chronic heart failure in Germany: A difference-in-difference matching approach using real-world data
Authors: Rabbe Stefan , Blankart Carl R , Franz Wolfgang-Michael , Hager Lutz , Schreyögg Jonas
Published: February 2021

Introduction

The aim of this study was to evaluate the effects of a non-invasive telemonitoring intervention on mortality, healthcare costs, and hospital and pharmaceutical utilisation in patients with chronic heart failure (CHF) of a large statutory health insurer in Germany.

Methods

In a retrospective observational cohort study using real-world data, we assessed differences between 635 patients who received a telemonitoring intervention versus 635 receiving usual care covering 36 months after intervention. We used propensity score matching on a set of 102 parameters collected in the 24-month pre-intervention period to correct for observed differences, as well as difference-in-difference (DiD) estimators to account for unobserved differences. We analysed the effect of the intervention for up to three years on (i) all-cause mortality; (ii) costs (i.e. inpatient stays, ambulatory care, pharmaceuticals, and medical aids and appliances); and (iii) healthcare utilisation (i.e. length and number of hospital stays, number of prescriptions).

Results

DiD estimates suggest lower inpatient costs of the telemonitoring group of up to €1160 (95% confidence interval (CI): –2253 to –69) in year three. Ambulatory care costs increased significantly in all three years up to €316 (95% CI: 1267 to 505) per year. Telemonitoring had a positive effect on survival (hazard ratio = 0.71; 95% CI: 0.51 to 0.99) and increased the number of prescriptions for diuretics. Effects were more prominent for patients with severe CHF.

Discussion

The study suggests that the telemonitoring intervention led to a significant decrease in mortality and a shift in costs from the inpatient to the ambulatory care sector 36 months after intervention.
Beliefs about medicines and adherence in women with breast cancer on adjuvant endocrine therapy
Authors: Tan Eng Hooi , Wong Andrea Li Ann , Tan Chuan Chien , Wong Patrick , Tan Sing Huang , Ang Li En Yvonne , Lim Siew Eng , Chong Wan Qin , Ho Jingshan , Lee Soo Chin , Tai Bee Choo
Published: February 2021

The Beliefs about Medicines Questionnaire (BMQ) and Adherence Starts with Knowledge (ASK-12) questionnaire were originally developed and validated in Western populations to assess beliefs and barriers to medication adherence. The study aim is to validate the BMQ and ASK-12 questionnaire for use in a Singapore population with early stage breast cancer. English-speaking women on adjuvant endocrine therapy ( n = 157) were recruited. The BMQ-Specific showed good internal consistency with structural validity. The internal consistency of BMQ-General and ASK-12 Behaviour scale improved with the new factor structure obtained from exploratory factor analysis. Further studies are needed to confirm these factor structures.
Monolingual versus multilingual foreign language teaching: French and Arabic at beginning levels
Authors: Brown Amanda
Published: February 2021

Macaro has stated that the choice between a monolingual, immersive, target language-only pedagogy versus a non-immersive, multilingual pedagogy is ‘probably the most fundamental question facing second language acquisition (SLA) researchers, language teachers, and policymakers’. Recognizing that prior empirical work on monolingual versus multilingual approaches has primarily been (1) descriptive, (2) in the context of English as a second or foreign language, and (3) very short term, often with one brief treatment, this intervention study examines the effectiveness of use of the L1/non-target language in the L2 classroom in a quasi-experimental, 10-week study examining French, a commonly learned foreign language, and Arabic, a less commonly learned foreign language, at beginning levels of proficiency in a community-based setting with 25 hours of instruction. Groups experiencing multilingual instruction outperformed those experiencing monolingual instruction in both languages with different instructors at almost all time periods and in almost all skill areas. Moderate to large effect sizes were found in inferential analyses of aggregated weekly progress quiz scores and scores in writing and vocabulary, and statistically significant differences between groups in Arabic were obtained in analyses of aggregated quiz scores overall and scores for vocabulary. These findings support theoretical position statements and a growing body of empirical research arguing for the potential benefits of inclusion of non-target languages in second language teaching and learning.
Seismic response characteristics of multi-story subway station through shaking table test
Authors: Chen Zhiyi , Huang Pengfei , Chen Wei
Published: February 2021

A series of shaking table tests were carried out to investigate the seismic response characteristics of a multi-story subway station. Dynamic responses, including accelerations of the soils and the underground structure, layer drift, dynamic earth pressure, and lateral deformation of soils were recorded and analyzed. Several seismic characteristics of multi-story subway station structures are figured out. It is found that in addition to the racking deformation, the rotation vibration is observed for the multi-story subway station subjected to acceleration waves. From the viewpoint of frequency, the low-frequency component and high-frequency component of the acceleration response of the subway station represent the translation and rotation component of the multi-story subway structure, respectively. In addition, the rotation vibration of the deep-depth structure leads to the local squeezing and detachment from the surrounding soils alternately at both top and bottom ends of the sidewalls. This results in the hump-shaped distribution of dynamic earth pressure. The racking deformation of the multi-story subway station has a linear relationship with the dynamic earth pressure at a certain area along the sidewall, where the top of hump-shaped distribution of dynamic earth pressure is.
Business managers in children’s playground : Exploring a problematic (or not!) identity construction of early childhood teachers in New Zealand
Authors: Kamenarac Olivera
Published: February 2021

The impacts of neo-liberal education reforms on the early childhood education sector have been a focal point of scholarly critiques in New Zealand. Interestingly, only a few studies have addressed how teacher professional identities and professionalism have changed in response to the neo-liberal context of New Zealand early childhood education. It has been, however, recognised that understanding the complexity of teacher professional identities within the rapidly transforming landscape of early childhood education is a key consideration in implementing and sustaining a change agenda in education policies and practices. In this article, the author draws on data from her research study about how teachers’ professional identities have been reconstructed in response to the shifting discourses in New Zealand early childhood education policies and practices. Specifically, the author explores the construction of teachers as business managers, which has emerged through an interplay of discourses of marketisation and privatisation driving some of the country’s early childhood education policies and practices. It is argued that the construction of teachers as business managers has altered core professional ethical values underpinning the teaching profession, professionalism and the purpose of early childhood education in New Zealand, which were traditionally embedded in discourses of collective democracy, equity and social justice.
Discourses in power: Policy and curriculum demands in the first year of compulsory school
Authors: Ruscoe Amelia , Barblett Lennie , Barratt-Pugh Caroline
Published: February 2021

The influence of curriculum and policy documents on the decision-making of educators is of particular interest in the field of early childhood. Reports of competing pedagogical approaches with a ‘push-down’ of curriculum alongside advocacy for play-based pedagogies raise questions as to the potential of curriculum and policy documents to create tension through multiple discourses. This is significant in light of politically driven discourses in education and their potential to influence the decision-making of educators. This research draws on an interpretivist epistemology framed by a post-structural approach to induce and examine discourses that exist across curriculum and policy documents relevant to the first year of compulsory school in Western Australia. A discourse analysis revealed three powerful discourses: inclusivity, achievement and ‘PED’ – a discourse encapsulating the interrelationships between play, engagement and development. The power embedded within these discourses provided evidence of how persuasive and prescriptive language is used to engender distinct ethical responsibilities. The findings illuminate the potent influence of powerful discourses on the negotiation of priorities in pedagogical decision-making in the early years.
Analysis and evaluation of mechanical descriptors from micro compression tests on spherical samples
Authors: Sonnenberg H , Clausen B
Published: February 2021

Within the development of a novel high-throughput method for the discovery of new structural materials, a compression test on spherical micro samples is established as a short-term characterization process. In this study, the experimental investigations regarding the elastic–plastic deformation behavior of microspheres are carried out on the bearing steel X46Cr13 in 10 different heat treatment conditions. Characteristic values, so-called descriptors, can be derived directly from continuously measured force–displacement curves or are normalized by taking the sample geometry into account. In addition to micro compression tests with quasi-static loading, load increase tests are performed, in which a spherical sample is repeatedly loaded and unloaded with progressively increasing loads. Loading and unloading phases and the development of the displacement amplitude of the hysteresis are analyzed. New descriptors of load increase tests are extracted and discussed regarding their statistical significance and validity as descriptor showing a high potential for a fast characterization of the material behavior during cyclic loading. The descriptor-based micro compression test proves to be a robust method and is a promising approach for a fast evaluation of different material conditions.
Psychometric validation of a pre-existing questionnaire used to measure patient satisfaction following orthodontic treatment in a UK population
Authors: Tidbury Katy , Sayers Mark , Andiappan Manoharan , Newton Jonathon T
Published: February 2021

Objective:

To determine the psychometric properties of a pre-existing orthodontic satisfaction questionnaire and to assess patient satisfaction of their orthodontic treatment.

Design:

Psychometric assessment of a pre-existing orthodontic satisfaction questionnaire.

Setting:

Two sites at King’s College Hospital NHS Foundation Trust.

Participants:

Individuals aged 12–15 years who had completed fixed orthodontic treatment.

Methods:

An expert panel assessed a pre-existing orthodontic treatment satisfaction questionnaire for validity and readability. As a result, revisions were made to the questionnaire and it was distributed to 103 participants aged 12–15 years, on completion of their fixed orthodontic treatment (T1). Test–retest reliability of the questionnaire was assessed through completion of a second questionnaire by 17 participants, at a two-week interval (T2). The questionnaire was assessed for reliability using item-total correlations (I-TC) and Cronbach’s alpha. Factor analysis allowed exploration of the underlying factor structure of the questionnaire. Test–retest reliability was assessed using Cohen’s kappa coefficient. Multiple regression analysis was used to find out the significant demographic variables that predicts the satisfaction level of treatment.

Results:

Following validity and readability assessment by the expert panel, the questionnaire was revised. Eleven items were removed following item analysis (with I-TC ⩽ 0.3). Factor analysis was deemed uninterpretable. The overall scale demonstrated greater reliability than the underlying sub-scales. Therefore, the sub-scales were removed, resulting in one scale which assessed overall orthodontic satisfaction, comprising 37 items, with a Cronbach alpha of 0.92. The test–retest reliability of the revised 37-item scale was deemed to be poor (kappa coefficient = 0.39). Multiple regression analysis identified ethnicity as a significant predictor of orthodontic treatment satisfaction ( P = 0.01).

Conclusion:

This study provides a valid measure to assess orthodontic treatment satisfaction for use in a UK population aged 12–15 years on completion of fixed orthodontic treatment.
Microscopic spray characteristics of ethanol and methanol blended gasoline in a direct injection spark ignition engine
Authors: Sharma Nikhil , Agarwal Avinash Kumar
Published: February 2021

Renewable fuels are continuously being refined/ upgraded for automotive applications to reduce dependence on conventional fossil fuels. However, optimized use of these renewable fuels in existing and new engines/ vehicles requires comprehensive characterization and understanding of spray atomization and fuel-air mixture formation processes. Spray atomization and mixture formation depends on fuel injection pressure (FIP), fuel injection quantity and ambient conditions. This study is aimed at exploring microscopic spray characteristics of ethanol and methanol blended gasoline for automotive applications, particularly in direct injection Spark Ignition (DISI) engines. Phase Doppler interferometer (PDI) technique was used for comparative microscopic spray characterization in a constant volume spray chamber (CVSC) at ambient pressure condition, to evaluated spray droplet size-velocity distributions and joint probability density function (JPDF) of different test fuels. In this study, two gasohol mixtures [15% v/v ethanol and methanol blended with 85% v/v gasoline] and baseline gasoline were experimentally evaluated for comparing spray droplet size-velocity distributions at two different FIPs of 80 and 160 bars, at two different fuel injection quantities of 12 and 28 mg/injection, which are typical representative conditions for a DISI engines. The results from this experimental investigation are valuable for automotive and fuel industries, and spray community, which are continuously upgrading renewable and oxygenated fuels and engine technologies for efficiency improvement and emission reduction.
Prediction and optimization of dual-fuel marine engine emissions and performance using combined ANN with PSO algorithms
Authors: Ma Cheng , Yao Chong , Song En-Zhe , Ding Shun-Liang
Published: February 2021

With the increasingly stringent environmental issues and regulations, there are higher requirements for improving engine performance and reducing pollution. Combining artificial neural network and particle swarm optimization algorithm to optimize the fuel consumption and emissions for micro-ignition dual-fuel engines. A model-based calibration scheme is maintained to reduce the number of experimental points by employing space-filling and V optimization design, to save the experimental cost and improve efficiency. The experimental data used to establish an RBF neural network prediction model that achieves a perfect mapping of engine input and output parameters. Controllable variables such as speed, torque, main injection timing, pilot injection timing, pilot injection quantity, rail pressure, excess air coefficient, and substitution rate limit parameters are input as neural networks. Subsequently, the combination of control parameters was optimized through PSO, thereby to achieve fuel consumption and emissions trade-off. Matching experiment results show actual emissions of NOx, THC, and CO decreased by 20.5%, 30.3%, and 43.1%, respectively, and the BSFC declined by an average of 2.1% contrasted with the original data. It achieves the optimum of emission and fuel consumption at the same time.
Reflections on Murray Aitkin's contributions to nonparametric mixture models and Bayes factors
Authors: Agresti Alan , Bartolucci Francesco , Mira Antonietta
Published: February 2021

We describe two interesting and innovative strands of Murray Aitkin's research publications, dealing with mixture models and with Bayesian inference. Of his considerable publications on mixture models, we focus on a nonparametric random effects approach in generalized linear mixed modelling, which has proven useful in a wide variety of applications. As an early proponent of ways of implementing the Bayesian paradigm, Aitkin proposed an alternative Bayes factor based on a posterior mean likelihood. We discuss these innovative approaches and some research lines motivated by them and also suggest future related methodological implementations.
Are spousal carers’ perceptions of continuity and discontinuity within the relationship influenced by the symptoms of dementia?
Authors: Lewis Meryl A , Riley Gerard A
Published: February 2021

Some spousal carers experience their current relationship with the person with dementia as a continuation of the loving relationship they shared prior to the onset of dementia. For others, the experience is one of discontinuity; the prior relationship is lost and replaced with a different kind of relationship. The aim of this study was to investigate whether these differences are associated with particular symptoms of dementia. Thirty-five spousal carers completed the Birmingham Relationship Continuity Measure, the Revised Memory and Behavior Checklist (providing scores relating to cognitive decline, depression and challenging interpersonal behaviour), the Communicative Effectiveness Index and the Bristol Activities of Daily Living Scale. Experiencing discontinuity in the relationship was significantly correlated with communication difficulties, challenging interpersonal behaviour and the need for assistance in activities of daily living, but not with cognitive decline or depression. In a multiple regression, only the measures of challenging interpersonal behaviour and activities of daily living made significant unique contributions to the variance in continuity/discontinuity scores. Discontinuity is associated with reduced psychological well-being for the spousal carer and the provision of less person-centred care. Understanding which symptoms are more likely to lead to discontinuity allows the identification of those at risk of these experiences. Those at risk may require support to enable them to make sense of, and adjust to, certain symptoms of dementia in a way that has a less negative impact on their relationship.
Two-dimensional simulations of vortex-induced vibration of a circular cylinder
Authors: Mutlu Asim Ozan , Bayraktar Meral , Bayraktar Seyfettin
Published: February 2021

In the present study, one of the cross-disciplinary problems known as vortex-induced vibration is numerically investigated. Effects of four different low mass-damping ratios; ζ = 0.013, 0.028, 0.074, and 0.124 of a smooth cylinder are taken into account for transition of shear layer 2 (TrSL2) type flow that falls between the Reynolds numbers from 2500 to 10,830 utilizing a two-dimensional cylinder that is free to move in normal-direction. Unsteady Reynolds-Averaged Navier–Stokes solutions indicate that the general trend is well captured with the adopted shear stress transport k-ω turbulence model, however, due to two-dimensional limitations some results are not consistent with experimental data. An inverse relation between the mass-damping ratio and the transition from the upper to the lower branch is detected. Change of drag and lift coefficients with the reduced velocities revealed that the maximum drag coefficient increases with reduced velocity until it reaches Ur = 5 and then decreases dramatically while the lift coefficients decrease consistently from the beginning.
Youthful victimization in post-war Bosnia and Herzegovina: A multi-level analysis of a national sample
Authors: Rees Carter , Winfree L Thomas
Published: February 2021

Intra-national conflicts with racial or ethnic elements can complicate post-war reconciliation. From 1992 to 1995, much of the former Yugoslavia, a nation largely drawn from three distinct ethnic groups, was embroiled in such a conflict. After the signing of the Dayton Peace Accord, it was feared that schools would become a surrogate battlefield for school-aged children within the newly created nation of Bosnia and Herzegovina (BiH). Group threat theory and the imbalance of power thesis provide differing views on such conflicts. Group threat theory posits that as a population – in this case a school – approaches maximum ethnic diversity, the residents – in this case the students – will feel increasingly threatened, resulting in higher cross-group victimizations. The imbalance of power thesis suggests that a group’s decision to victimize another group depends on the relative lack of ethnic diversity: the extent to which one ethnic group dominates a school, the likelihood of victimization of any smaller groups increases. We explore which of these two theories best explains victimization levels within a sample of 2003 school-aged BiH adolescents born in areas dominated by Muslim Bosnians, Eastern Orthodox Serbians, or Roman Catholic Croatians. We find that there is an ethnic component to victimizations: students born in Serbia face higher levels of victimization than do their Bosnian-born counterparts under conditions that fit better with group threat theory than the imbalance of power thesis. We speculate about the significance of these findings for national ethnic harmony in BiH.
The ethics of interpreter use
Authors: Gray Ben , Hilder Jo
Published: February 2021

Consulting with a patient where there is a language barrier is unethical unless the barrier is overcome. Every patient with a language barrier should have this prominently documented on their file. Much of the literature relating to working with interpreters suggests that a professional interpreter should be used all the time, although in practice this is far from standard practice. In this paper we look at the issue using normative ethics, utilitarian ethics, an argument based on equality of health outcomes before making an argument for an approach based on clinical judgement in each consultation of what form of language assistance is acceptable.
The effect of providing usual care only for control subjects on the reliability of results obtained by controlled clinical trials assessing the benefits of diabetes self-management educational programs
Authors: Mikhael Ehab Mudher , Hassali Mohamed Azmi , Hussain Saad
Published: February 2021

Diabetes self-management (DSM) is a crucial part in the management of diabetic patients. Most randomized controlled clinical trials reported significant benefits by diabetes self-management education (DSME) on DSM behaviors and metabolic control. Although the randomized clinical trials are the gold standard method in assessing the effectiveness of any intervention, including DSME interventions, the outcomes of these studies may reflect exaggerated effects; because in most of these studies, subjects in control group receive usual (standard) care with no any DSME. The lack of such education in the control group had many drawbacks: ( 1 ) make blindness impossible; at which non blinded studies may result in false-positive findings; ( 2 ) it may be unethical to recruit patients for participation in DSME studies as control subjects, most of these studies with long periods of follow up, without any direct benefit to them during the study period; the lack of direct benefit to control subjects in any clinical trial may results in high attrition (drop-out) rate. The high attrition rate in clinical trials especially in the control group can lower the statistical power of the study results; thus, the DSME program would appear to have positive effects even if the program had no real benefit. This problem of the DSME exaggerated effects can be solved partially through providing control subjects with education about some DSM behaviors or comparing the effect of DSME through different educational approaches (for example DSME by didactic vs interactive approach).
Hyperglycemia compromises the ischemia-provoked dedifferentiation of cerebral pericytes through p21–SOX2 signaling in high-fat diet-induced murine model
Authors: Wang Hao-Kuang , Huang Chih-Yuan , Chen Yun-Wen , Sun Yuan-Ting
Published: February 2021

Aim:

Diabetes-related cerebral small vessel disease (CSVD) causes neurological deficits. Patients with diabetes showed pericyte loss as a hallmark of retinopathy. Cerebral pericytes, which densely localize around brain capillaries, are quiescent stem cells regulating regeneration of brain and may have a role in CSVD development. This study investigated whether diabetes impairs ischemia-provoked dedifferentiation of pericytes.

Methods:

A murine high-fat diet (HFD)-induced diabetes model was used. After cerebral ischemia induction in the mice, pericytes were isolated and grown for a sphere formation assay.

Results:

The sphere counts from the HFD group were lower than those in the chow group. As the spheres formed, pericyte marker levels decreased and SOX2 levels increased gradually in the chow group, but not in the HFD group. Before sphere formation, pericytes from the HFD group showed high p21 levels. The use of a p21 inhibitor rescued the reduction of sphere counts in the HFD group. At cellular level, hyperglycemia-induced ROS increased the level of p21 in cerebral pericytes. The p21-SOX2 signaling was then activated after oxygen-glucose deprivation.

Conclusion:

HFD-induced diabetes compromises the stemness of cerebral pericytes by altering p21–SOX2 signaling. These results provide evidence supporting the role of pericytes in diabetes-related CSVD and subsequent cerebral dysfunction.