bluuebunny/crossref_metadata_2025_split huggingface dataset:
Closed-loop control of k-space sampling via physiologic feedback for cine MRI
Authors: Contijoch Francisco , Han Yuchi , Iyer Srikant Kamesh , Kellman Peter , Gualtieri Gene , Elliott Mark A. , Berisha Sebastian , Gorman Joseph H. , Gorman Robert C. , Pilla James J. , Witschey Walter R. 
Published: June 2020

AbstractBackgroundSegmented cine cardiac MRI combines data from multiple heartbeats to achieve high spatiotemporal resolution cardiac images, yet predefined k-space segmentation trajectories can lead to suboptimal k-space sampling. In this work, we developed and evaluated an autonomous and closed-loop control system for radial k-space sampling to increase sampling uniformity.MethodsThe closed-loop system autonomously selects radial k-space sampling trajectory during live segmented cine MRI and attempts to optimize angular sampling uniformity by selecting views in regions of k-space that were not previously well-sampled. Sampling uniformity and robustness to arrhythmias was assessed using ECG data acquired from 10 normal subjects in an MRI scanner. The approach was then implemented with a fast gradient echo sequence on a whole-body clinical MRI scanner and imaging was performed in 4 healthy volunteers. The closed-loop k-space trajectory was compared to random, uniformly distributed and golden angle view trajectories via measurement of k-space uniformity and the point spread function. Lastly, an arrhythmic dataset was used to evaluate a potential application of the approach.ResultsThe autonomous trajectory increased k-space sampling uniformity by 13±7%, main lobe point spread function (PSF) signal intensity by 14±6%, and reduced ringing relative to golden angle sampling. When implemented, the autonomous pulse sequence prescribed radial view angles faster than the scan TR (0.98 ± 0.02 ms, maximum = 1.38 ms) and increased k-space sampling mean uniformity by 5±12%, decreased uniformity variability by 45±14%, and increased PSF signal ratio by 5±5% relative to golden angle sampling.ConclusionThe closed-loop approach enables near-uniform radial sampling in a segmented acquisition approach which was higher than predetermined golden-angle radial sampling. This can be utilized to increase the sampling or decrease the temporal footprint of an acquisition and the closed-loop framework has the potential to be applied to patients with complex heart rhythms.
SARS-CoV-2 exposure, symptoms and seroprevalence in health care workers
Authors: Rudberg Ann-Sofie , Havervall Sebastian , Månberg Anna , Falk August Jernbom , Aguilera Katherina , Ng Henry , Gabrielsson Lena , Salomonsson Ann-Christine , Hanke Leo , Murrell Benjamin , McInerney Gerald , Olofsson Jennie , Andersson Eni , Hellström Cecilia , Bayati Shaghayegh , Bergström Sofia , Pin Elisa , Sjöberg Ronald , Tegel Hanna , Hedhammar My , Phillipson Mia , Nilsson Peter , Hober Sophia , Thålin Charlotte 
Published: June 2020

AbstractBackgroundSARS-CoV-2 may pose an occupational health risk to health care workers, but the prevalence of infections in this population is unknown. We examined the seroprevalence of SARS-CoV-2 antibodies among health care workers at a large acute care hospital in Stockholm, Sweden. We determined correlations between seroprevalence, self-reported symptoms and occupational exposure to SARS-CoV-2.Methods and findingsAll employees at Danderyd Hospital (n=4375) were invited to participate in a cross-sectional study. 2149 employees from all hospital departments were enrolled in the study between April 14th and May 8th 2020. Study participants completed a questionnaire consisting of symptoms compatible with SARS-CoV-2 infection since January 2020 and occupational exposure to patients infected with SARS-CoV-2. IgG antibodies against SARS-CoV-2 were analyzed using a multiplex assay evaluated to have 99.4% sensitivity and 99.1% specificity. The over-all seroprevalence among 2149 participants was 19.1% (n=410). There was no difference in age or sex between seropositive and seronegative participants. The symptoms with the strongest correlation to seroprevalence were anosmia and ageusia, with odds ratios of 28.4 (p=2.02*10^-120) and 19.2 (p=1.67*10^-99) respectively. Seroprevalence was strongly associated with patient-related work (OR 2.9, p=4.24*10^-8), covid-19 patient contact (OR 1.43, p=0.003), and occupation as assisting nurse (OR 3.67, p=2.16*10^-9).ConclusionThese results demonstrate that anosmia and ageusia should be included in screening guidance and in the recommendations of self-isolation to reduce further spread of SARS-CoV-2. The results furthermore imply an occupational health risk for SARS-CoV-2 infection among hospital workers. Continued measures are warranted to assure healthcare worker safety and reduce transmission from health care settings to the community during the covid-19 outbreak.
Age-structured non-pharmaceutical interventions for optimal control of COVID-19 epidemic
Authors: Richard Quentin , Alizon Samuel , Choisy Marc , Sofonea Mircea T. , Djidjou-Demasse Ramsès 
Published: June 2020

AbstractIn an epidemic, individuals can widely differ in the way they spread the infection, for instance depending on their age or on the number of days they have been infected for. The latter allows to take into account the variation of infectiousness as a function of time since infection. In the absence of pharmaceutical interventions such as a vaccine or treatment, non-pharmaceutical interventions (e.g. social distancing) are of great importance to mitigate the pandemic. We propose a model with a double continuous structure by host age and time since infection. By applying optimal control theory to our age-structured model, we identify a solution minimizing deaths and costs associated with the implementation of the control strategy itself. This strategy depends on the age heterogeneity between individuals and consists in a relatively high isolation intensity over the older populations during a hundred days, followed by a steady decrease in a way that depends on the cost associated to a such control. The isolation of the younger population is weaker and occurs only if the cost associated with the control is relatively low. We show that the optimal control strategy strongly outperforms other strategies such as uniform constant control over the whole populations or over its younger fraction. These results bring new facts the debate about age-based control interventions and open promising avenues of research, for instance of age-based contact tracing.
National Health Insurance Scheme: A pathway to a sustained access to medicine in Nigeria
Authors: Uguru Nkoli P. , Ogu Udochukwu U. , Uguru Chibuzo C. , Ibe Ogochukwu 
Published: June 2020

AbstractObjectiveThe National Health Insurance Scheme (NHIS) has at its aim the need to ensure that every Nigerian has equal access to good quality health care services. So far, only the Formal Sector Social Health Insurance Program (FSSHIP) aspect of the scheme has been fully activated. The question remains, why the delay towards universal coverage?DesignThe study was a cross-sectional and mixed method design. Both qualitative and quantitative methods were utilized for the study.SettingThis study was conducted in NHIS accredited facilities in Enugu State.ParticipantsA sample of 300 enrolees were selected randomly. For the qualitative study, 6 in-depth interviews (IDIs) were conducted face to face with NHIS desk officers across the three tiers of health care represented.ResultsThe qualitative findings shows that 94.9% of respondents sought medical help. 78.4% of the respondents indicated that the scheme improved their access to care. The qualitative finding found that there was no discrepancy in access among socio-economic groups. NHIS was reported to have improved access to medicine over the years. In the qualitative, majority of the IDI respondents stated that many of the staff in NHIS accredited facilities are not trained on what is expected or required of them with regards to the scheme.ConclusionA focus on accessibility, affordability and availability for the scheme means that on account of either of the three, all facility categories and their interests must be considered in further planning of the scheme to ensure that things hold up fine.Article SummaryStrengths and LimitationsThe study participants were only from one state.The study only focused on NHIS and NHIS accredited facilities.NHIS desk officers, hospital directors and admin officers were the focus for IDIs.
The Tomato DELLA Protein PROCERA Promotes Abscisic Acid Responses in Guard Cells by Upregulating an Abscisic Acid Transporter
Authors: Shohat Hagai , Illouz-Eliaz Natanella , Kanno Yuri , Seo Mitsunori , Weiss David 
Published: June 2020

AbstractPlants reduce transpiration through stomatal closure to avoid drought stress. While abscisic acid (ABA) has a central role in the regulation of stomatal closure under water-deficit conditions, we demonstrated in tomato (Solanum lycopersicum) that a gibberellin response inhibitor, the DELLA protein PROCERA (PRO), promotes ABA-induced stomatal closure and gene transcription in guard cells. To study how PRO affects stomatal closure, we performed RNA-sequencing analysis of isolated guard cells and identified the ABA transporters ABA-IMPORTING TRANSPORTER1.1 (AIT1.1) and AIT1.2, also called NITRATE TRANSPORTER1/PTR TRANSPORTER FAMILY4.6 in Arabidopsis (Arabidopsis thaliana), as being upregulated by PRO. Tomato has four AIT1 genes, but only AIT1.1 and AIT1.2 were upregulated by PRO, and only AIT1.1 exhibited high expression in guard cells. Functional analysis of AIT1.1 in yeast (Saccharomyces cerevisiae) confirmed its activity as an ABA transporter, possibly an importer. A clustered regularly interspaced short palindromic repeats-Cas9–derived ait1.1 mutant exhibited an increased transpiration, a larger stomatal aperture, and a reduced stomatal response to ABA. Moreover, ait1.1 suppressed the promoting effects of PRO on ABA-induced stomatal closure and gene expression in guard cells, suggesting that the effects of PRO on stomatal aperture and transpiration are AIT1.1-dependent. Previous studies suggest a negative crosstalk between gibberellin and ABA that is mediated by changes in hormone biosynthesis and signaling. The results of this study suggest this crosstalk is also mediated by changes in hormone transport.
Repatriation of self-initiated expatriates: expectations vs. experiences
Authors: Ellis David R. , Thorn Kaye , Yao Christian 
Published: June 2020

PurposeWhile there is a burgeoning literature on self-initiated expatriates (SIEs), the emphasis has been on expatriation not repatriation. The purpose of this paper therefore is to explore how repatriating SIEs perceive the experience of repatriation compared with their pre-repatriation expectations. Further, we examine the seminal work of Black et al. (1992) in the light of current day realities.Design/methodology/approachThis qualitative research draws on interviews with SIE New Zealanders returning home. It is an exploratory longitudinal study, based on interview data collected prior to (n = 32), and after (n = 27) repatriation, comparing expectations and experiences of repatriation.FindingsFindings show that there is a strong level of congruence between the expectations of the return and their experience of repatriation. This congruence eases the transition and mitigates the impact of reverse culture shock. We revise Black et al.'s framework of repatriation adjustment to more accurately reflect the expectations and experiences of repatriating SIEs, recognising the importance of individual agency and the impact of today's technological advances on repatriation.Research limitations/implicationsThe contributions of this paper include clarification of repatriating SIEs. Further, through the revision of the framework, we identify new areas of research that would aid our understanding of repatriating SIEs and lead to the development of a more detailed model. We highlight the interplay between variables showing how these might mitigate the shock of repatriation.Originality/valueRepatriation is an under-researched phase of the SIE, and this study provides empirical data that contributes to our understanding of the construct. Black et al.'s framework of repatriation adjustment is revised in the context of contemporary SIE, highlighting the holistic nature of self-initiated expatriation and repatriation, viewing the events not as discrete, but as a continuum of time.
Analytical solution of the Duffing equation
Authors: Georgiev Zhivko , Trushev Ivan , Todorov Todor , Uzunov Ivan 
Published: June 2020

Purpose
The purpose of this paper is to find an exact analytical expression for the periodic solutions of the double-hump Duffing equation and an expression for the period of these solutions.

Design/methodology/approach
The double-hump Duffing equation is presented as a Hamiltonian system and a phase portrait of this system has been found. On the ground of analytical calculations performed using Hamiltonian-based technique, the periodic solutions of this system are represented by Jacobi elliptic functions sn, cn and dn.

Findings
Expressions for the periodic solutions and their periods of the double-hump Duffing equation have been found. An expression for the solution, in the time domain, corresponding to the heteroclinic trajectory has also been found. An important element in various applications is the relationship obtained between constant Hamiltonian levels and the elliptic modulus of the elliptic functions.

Originality/value
The results obtained in this paper represent a generalization and improvement of the existing ones. They can find various applications, such as analysis of limit cycles in perturbed Duffing equation, analysis of damped and forced Duffing equation, analysis of nonlinear resonance and analysis of coupled Duffing equations.
Energy-efficient data retention in D flip-flops using STT-MTJ
Authors: Monga Kanika , Chaturvedi Nitin , Gurunarayanan S. 
Published: June 2020

Purpose
Emerging event-driven applications such as the internet-of-things requires an ultra-low power operation to prolong battery life. Shutting down non-functional block during standby mode is an efficient way to save power. However, it results in a loss of system state, and a considerable amount of energy is required to restore the system state. Conventional state retentive flip-flops have an “Always ON” circuitry, which results in large leakage power consumption, especially during long standby periods. Therefore, this paper aims to explore the emerging non-volatile memory element spin transfer torque-magnetic tunnel junction (STT-MTJ) as one the prospective candidate to obtain a low-power solution to state retention.

Design/methodology/approach
The conventional D flip-flop is modified by using STT-MTJ to incorporate non-volatility in slave latch. Two novel designs are proposed in this paper, which can store the data of a flip-flip into the MTJs before power off and restores after power on to resume the operation from pre-standby state.

Findings
A comparison of the proposed design with the conventional state retentive flip-flop shows 100 per cent reduction in leakage power during standby mode with 66-69 per cent active power and 55-64 per cent delay overhead. Also, a comparison with existing MTJ-based non-volatile flip-flop shows a reduction in energy consumption and area overhead. Furthermore, use of a fully depleted-silicon on insulator and fin field-effect transistor substituting a complementary metal oxide semiconductor results in 70-80 per cent reduction in the total power consumption.

Originality/value
Two novel state-retentive D flip-flops using STT-MTJ are proposed in this paper, which aims to obtain zero leakage power during standby mode.
Predictors of health behaviours among Indian college students: an exploratory study
Authors: Chawak Shweta , Chittem Mahati , S Aswini , Varghese Daigy , Epton Tracy 
Published: June 2020

PurposeThe purpose of this study is to understand the association between health behaviours of diet, physical activity, smoking cigarettes, alcohol consumption, safe sex and sleep quality with demographic (e.g. age, gender) and psychological (i.e. stress, self-esteem and sense of coherence) factors in Indian residential college students.Design/methodology/approachStudents studying for Bachelor of Technology at residential colleges in India were invited to complete an online questionnaire regarding their health behaviours, demographics and psychological variables. Each health behaviour was regressed onto demographic and psychological factors to determine which of them were associated with performing each behaviour.FindingsThere was no clear pattern of predictors for the health behaviours overall. Self-esteem was related to healthy diet, being single was related to adequate sleep, higher parental income was related to safer sex and being older was related to more alcohol use and safer sex.Research limitations/implicationsThis study revealed that health education efforts may need to be designed for specific behaviours and correlates among Indian college students. Interventions regarding (1) healthy eating should target students with lower self-esteem, (2) sleep should target students in a relationship and (3) safer sex should target younger students and those from less affluent backgrounds.Originality/valueThis research is one of the first attempts to study the predictors of health behaviours among Indian college students. The study highlighted that psychological factors (e.g. self-esteem) and demographic factors (e.g. relationship status, parental income, age) affect different health behaviours. These findings can help health educators to design tailored interventions and aid in health education and promotion among Indian college students.
Comparative analysis on the film cooling mechanisms of elliptical and cylindrical holes with 90° compound angle
Authors: Zhang Guohua , Xie Gongnan , Sunden Bengt Ake 
Published: June 2020

Purpose
In this study, numerical simulations are performed to compare the adiabatic film cooling effectiveness and reveal the difference of film cooling mechanisms of two models with the same geometries and cross-section areas of film holes’ exits at three typical blowing ratios (M = 0.5, 1 and 1.5). The two models are an elliptical model and a cylindrical model with 90° compound angle, respectively.

Design/methodology/approach
Three different cases are considered in this work and the baseline is the model with a cylindrical film hole. The same boundary conditions and a validated turbulence model (realizable k-ε) are adopted for all cases.

Findings
The results show that both the elliptical and cylindrical models with 90° compound angle can enhance the film cooling effectiveness compared with the baseline. However, the elliptical model performs well at lower blowing ratios and in the near region at each blowing ratio because of the wider width of the film hole’s exit. The cylindrical model with 90° compound angle provides better film cooling effectiveness in the further downstream area of the film hole at higher blowing ratio because of the less lift-off and better coolant coverage in the larger x/D region along the mainstream direction.

Originality/value
Overall, it can be concluded that although the elliptical and cylindrical models with 90° compound angle have identical hole exits, the different inlet direction and cross-sectional geometry affect the flow structures when the coolant enters, moves through and exits the hole and finally different film cooling results appear.
Correlation of tribo-mechanical properties of internal geometry structures of fused filament fabrication 3D-printed acrylonitrile butadiene styrene
Authors: Norani Mohamad Nordin Mohamad , Abdollah Mohd Fadzli Bin , Abdullah Muhammad Ilman Hakimi Chua , Amiruddin Hilmi , Ramli Faiz Redza , Tamaldin Noreffendy 
Published: June 2020

Purpose
This study aims is to investigate the correlation between tribological and mechanical properties of the fused filament fabrication 3D-printed acrylonitrile butadiene styrene (ABS) pin with different internal geometries.

Design/methodology/approach
The tribological properties were determined by a dry sliding test with constant test parameters, while the hardness and modulus of elasticity were determined by microhardness and compression tests.

Findings
Although the internal geometry of the pin sample slightly affects the coefficient of friction (COF) and the wear rate of the 3D-printed ABS, it was important to design a lightweight tribo-component by reducing the material used to save energy without compromising the strength of the component. The COF and wear rate values are relatively dependent on the elastic modulus. A 3D-printed ABS pin with an internal triangular flip structure was found to have the shortest run-in period and the lowest COF with high wear resistance. Abrasive wear and delamination are the predominant wear mechanisms involved.

Research limitations/implications
The findings are the subject of future research under various sliding conditions by investigating the synergistic effect of sliding speeds and applied loads to validate the results of this study.

Originality/value
The internal structure affects the mechanical properties and release stress concentration at the contact point, resulting in hypothetically low friction and wear. This approach may also reduce the weight of the parts without scarifying or at least preserving their preceding tribological performance. Therefore, based on our knowledge, limited studies have been conducted for the application of 3D printing in tribology, and most studies focused on improving their mechanical properties rather than correlating them with tribological properties that would benefit longer product lifespans.

Peer review
The peer review history for this article is available at: https://publons.com/publon/10.1108/ILT-04-2020-0143/
Islamic bank contribution to Indonesian economic growth
Authors: M. Anwar Suhardi , Junaidi Junaidi , Salju Salju , Wicaksono Ready , Mispiyanti Mispiyanti 
Published: June 2020

Purpose
This paper aims to examine the short run and long run of Indonesia Islamic bank (IIB) contribution to economic growth over the periods 2009: Q1 – 2019: Q4. IIB is considered which supported by the largest Muslim population in the world. Deposits, financing and offices are proxy to highlight the relationship between Islamic banks and Indonesia's economic growth.

Design/methodology/approach
Through cointegration analysis, autoregressive distributed lag (ARDL), vector error correction model (VECM), variance decompositions (VDCs) and impulse response functions (IRFs), this study investigates the Islamic bank and economic growth nexus.

Findings
A significant relationship in the short-run and long-run between IIB deposits and offices and economic growth. There is evidence of a bidirectional relationship between the Islamic bank and economic growth.

Social implications
In spite of their market share less than a conventional bank. The result proved than IB a prosperous sector and has a contribution to economic growth. This address regulator must have a dedicated unit to handle IIB legal cases should it go to the court for adjudication.

Originality/value
The study role of Islamic banking contribution to economic growth in the context of Indonesia is limited. This paper is the first study that examines empirically the effect of Indonesian Islamic banks on economic growth measured by the amount of gross domestic product (GDP), financing, offices and deposits.