bluuebunny/crossref_metadata_2025_split huggingface dataset:
Estimation of Rayleigh flat channel coefficients using deep learning
Authors: Melkote NanjundaShetty Drakshayini , Kounte Manjunath R. 
Published: September 2022

AbstractChannel estimation is a significant prerequisite in wireless communication, especially where the multipath radio propagation incurs significant fading in a noisy environment. In such a scenario, Rayleigh fading model is traditionally adopted to represent the communication channel. In this article, a new method of getting the Rayleigh flat channel coefficients using deep learning is presented. Here, we presume that the channel state and the corresponding channel coefficients remain constant in a given communication context which depends on the locations of transmitter/receiver, time of the day and the communication environment. When the context changes, the channel state also changes and the corresponding coefficients switch to the respective matching values. Thus the channel coefficients can have several possible realizations or classes. In our scheme, the deep learning network, after training, acts as a classifier to detect the class or the context of the channel state and based on that determines the corresponding channel coefficients. In our proposed method, the percentage reduction in the percentage error is about 26% of that of its nearest competitor when the channel SNR is 10 dB.
Definitions of health and social care standards used internationally: A narrative review
Authors: Kelly Yvonne , O’Rourke Niamh , Flynn Rachel , Hegarty Josephine , O’Connor Laura 
Published: September 2022

AbstractSetting standards is a quality improvement mechanism and an important means for shaping the provision of health and social care services. Standards comprise statements describing a process or outcome of care. Setting standards is a global practice. It would be useful to have an understanding of the underpinning definitions of standards used internationally. Therefore, the aim of this review was to examine definitions of health and social care standards used internationally and identify similarities and differences. A targeted grey literature search of standard‐setting bodies' websites and related health legislation was conducted to retrieve explicit definitions of standards. Of 15 standard‐setting bodies that were searched, 12 definitions of standards were narratively synthesised. Terms that appeared in two or more of the definitions were extracted. Counts and percentages were calculated for these terms to determine magnitude of use. The commonalities among definitions included ‘quality’ (n = 6, 50%), ‘statements’ (n = 5, 42%), ‘performance’ (n = 5, 42%), and ‘measureable’ (n = 4, 33%). The less commonly used terms were ‘processes’ (n = 3, 25%), ‘set’ (n = 3, 25%), ‘evidence based’ (n = 2, 17%), ‘outcome’ (n = 2, 17%), ‘safe’ (n = 2, 17%), and ‘guidance’ (n = 2, 17%). Explicit definitions of standards were not retrieved from health legislation documents. Standard‐setting bodies develop standards in the context of the health systems in which they are implemented; some are aspirational levels of quality, while others are minimum levels of quality. Researchers, standards developers and policy makers should be cognisant of this when comparing standards between countries.
The magnitude of out‐of‐pocket expenditure for antenatal care in low and middle‐income countries: A systematic review and meta‐analysis
Authors: Gunarathne Sajaan Praveena , Wickramasinghe Nuwan Darshana , Agampodi Thilini Chanchala , Prasanna Indika Ruwan , Agampodi Suneth Buddhika 
Published: September 2022

AbstractBackgroundOwing to the lack of compiled global evidence on out‐of‐pocket expenditure (OOPE) for antenatal care (ANC), this systematic review and meta‐analysis estimated the magnitude of OOPE for ANC in low and middle‐income countries (LMICs).MethodsAn electronic search was conducted using 10 databases and a hand search of the eligible studies' reference lists. Studies on OOPE for ANC in LMICs, published in English without time restriction, were included. The comparability of OOPE values was improved using inflation and exchange rate adjustment to the year 2019. Random‐effects meta‐analysis was performed to generate pooled estimates.ResultsAmong the 9766 articles retrieved, 32 were selected. Only 13/137 (9.5%) countries reported evidence of OOPE during pregnancy in LMICs. The majority of the studies (n = 2779.4%) were from lower‐middle‐income settings. Ten (31.3%) studies from African region, 21 (65.6%) studies from South‐East‐Asian region, 1 (3.1%) study from region of Americas and none from the other regions were included. The average OOPE for ANC and single ANC visit ranged from United States Dollar (USD) 2.41 to USD 654.32 in LMICs, the lowest in Tanzania and the highest in India. The pooled OOPEs were USD 63.29 (95% confidence interval [CI] = 51.93–74.65) and USD 12.93 (95%CI = 4.54–21.31) for ANC and single ANC visit in LMICs, respectively.ConclusionThe study revealed that the pooled estimates of OOPE for ANC throughout pregnancy and per visit were high in some countries, with a wide variability observed across countries. There was a lack of evidence on OOPE for ANC from many LMICs, and filling the evidence gap in LMICs is highlighted.
Thermal characteristics of arrays of swirling impinging jets: Effect of Reynolds number, impingement distance, and jet‐to‐jet separation
Authors: Debnath Sudipta , Ahmed Zahir U. , Ikhlaq Muhammad , Khan Tanvir 
Published: September 2022

AbstractThis paper numerically investigates both the inline and staggered arrays of circular multiple swirling air jets that impinge perpendicularly onto a smooth flat surface. The simulations were conducted for various flow and geometric parameters, such as Reynolds number (Re = 11,600, 24,600, and 35,000), jet‐to‐surface distance (H/D = 1, 2, 3, and 4), jet‐to‐jet separation distance (Z/D = 1.5, 3.0, and 4.5) and swirl numbers (S = 0, 0.3, and 0.75), where D is the nozzle diameter. For S = 0.75, a strong recirculation develops due to the vortex breakdown, depends on Z/D, around the axis and near the wall. The extent of the recirculation is larger for the staggered array. Intense heat transfer is anticipated at strong swirl and close impingement cases with the expense of uniformity; whereas a relatively even heat transfer is observed for larger impingements. The increase in jet‐to‐jet separation enhances the overall cooling effect and the staggered configuration of nozzles gives better performance. It appears that both the crossflow and turbulence around the periphery of each jet predominantly govern the heat transfer characteristics. The enhancement of heat transfer occurs for increasing Re, and the overall Nusselt number (Nu) prediction is scaled by Ren, with n dependent on S. Finally a correlation is developed for the average Nusselt number to relate different control parameters.
On the origin of photodynamic activity of hypericin and its iodine‐containing derivatives
Authors: De Simone Bruna Clara , Mazzone Gloria , Toscano Marirosa , Russo Nino 
Published: September 2022

AbstractThe main photophysical properties, useful for establishing whether hypericin in anionic form and some of its derivatives containing heavy atoms such as iodine, can be proposed for their use in photodynamic therapy, were determined using density functional based computations. The results showed that in the anionic form and in the iodinated derivatives, the absorption wavelength undergoes a bathochromic shift, the singlet‐triplet energy gap assumes values ​that allow to excite the oxygen molecule from its ground to the excited singlet state, and that the spin–orbit couplings between singlet and triplet states significantly increase.
Environmental temperature predicts resting metabolic rates in tropidurinae lizards
Authors: Giacometti Danilo , Bars‐Closel Melissa , Kohlsdorf Tiana , de Carvalho José Eduardo , Cury de Barros Fábio 
Published: September 2022

AbstractInterspecific variation in metabolic rates may be associated with climate, habitat structure, and resource availability. Despite a strong link between ecology and physiology, there is a dearth in the understanding of how the costs of body maintenance change during ecological transitions. We focused on an ecologically diverse group of neotropical lizards (Tropidurinae) to investigate whether and how resting metabolic rate (RMR) evolved under divergent micro‐ and macrohabitat conditions. Using a phylogenetic framework, we tested whether species from hot and dry habitats had lower RMRs in relation to those from cooler and mesic habitats, and investigated whether microhabitat usage had an effect over body mass‐adjusted RMRs. Our results suggest that RMRs are not phylogenetically structured in Tropidurinae. We found no correlation between metabolism, precipitation, and microhabitat usage. Species from warmer habitats had lower RMR compared to those from cooler habitats, supporting a mechanism of negative compensation in metabolic responses to temperature. Ectotherms from warmer habitats can limit energetic demand and expenditure through reduced RMR, whereas those from cooler habitats may sustain activity despite thermal constraints via increased RMR. Our work highlights the role of temperature in shaping metabolic responses in lizards, giving additional support to the notion that physiology and ecological contexts are intertwined.
The distinct problems of physical inconsistency and of multivariate bias involved in the statistical adjustment of climate simulations
Authors: Alavoine Mégane , Grenier Patrick 
Published: September 2022

AbstractBias adjustment of numerical climate model simulations involves several arguments wherein the notion of physical inconsistency is referred to, either for rejecting the legitimacy of bias adjustment in general or for justifying the necessity of sophisticated multivariate techniques. However, this notion is often mishandled, in part because the literature generally proceeds without defining it. In this context, the central objective of this study is to clarify and illustrate the distinction between physical inconsistency and multivariate bias, by investigating the effect of bias adjustment on two different kinds of intervariable relationships, namely a physical constraint expected to hold at every step of a time series and statistical properties that emerge with potential bias over a climatic timescale. To this end, 18 alternative bias adjustment techniques are applied on 10 climate simulations at 12 sites over North America. Adjusted variables are temperature, pressure, relative humidity and specific humidity, linked by a thermodynamic constraint. The analysis suggests on the one hand that a clear instance of potential physical inconsistency can be avoided with either a univariate or a multivariate technique, if and only if the bias adjustment strategy explicitly considers the physical constraint to be preserved. On the other hand, it also suggests that sophisticated multivariate techniques alone are not complete adjustment strategies in presence of a physical constraint, as they cannot replace its explicit consideration. By involving common bias adjustment procedures with likely effects on diverse basic statistical properties, this study may also help guide climate information users in the determination of adequate bias adjustment strategies for their research purposes.
A perpetual motion machine: The preserved digital scholarly record
Authors: Cramer Tom , German Chip , Jefferies Neil , Wise Alicia 
Published: September 2022

Key points
Digital preservation will never be a solved problem: it needs constant reinvention, and is going to become harder over time.
Scholarship is changing and this is affecting what needs to be preserved and what preservation means to the future of knowledge discovery.
The diversification of outputs means that knowledge exists in a network of contextual metadata, data, software, standards and publications—requiring multilateral management of this complex knowledge graph.
Preservation demands new skills, technologies and resources from librarians, publishers, funders and institutions—and more joined‐up thinking about archiving.
Progression of Clinical and Eye Movement Markers in Preataxic Carriers of Machado‐Joseph Disease
Authors: de Oliveira Camila Maria , Leotti Vanessa Bielefeldt , Cappelli Amanda Henz , Rocha Anastacia Guimarães , Ecco Gabriela , Bolzan Gabriela , Kersting Nathalia , Saraiva‐Pereira Maria‐Luiza , Jardim Laura Bannach 
Published: September 2022

ABSTRACTBackgroundLittle is known about preclinical stages of Machado‐Joseph disease, a polyglutamine disorder characterized by progressive adult‐onset ataxia.ObjectiveWe aimed to describe the longitudinal progression of clinical and oculomotor variables in the preataxic phase of disease.MethodsCarriers and noncarriers were assessed at three visits. Preataxic carriers (Scale for Assessment and Rating of Ataxia score < 3) expected to start ataxia in ≤4 years were considered near onset (PAN). Progressions of ataxic and preataxic carriers, considering status at the end of the study, were described according to the start (or its prediction) of gait ataxia (TimeToAfterOnset) and according to the study time.ResultsA total of 35 ataxics, 38 preataxics, and 22 noncarriers were included. The “TimeToAfterOnset” timeline showed that Neurological Examination Scale for Spinocerebellar Ataxias (NESSCA; effect size, 0.09), Inventory of Non‐Ataxia Symptoms (INAS0.07), and the vestibulo‐ocular reflex gain (0.12) progressed in preataxic carriers, and that most slopes accelerate in PAN, turning similar to those of ataxics. In the study time, NESSCA (1.36) and vertical pursuit gain (1.17) significantly worsened in PAN, and 6 of 11 PANs converted to ataxia. For a clinical trial with 80% power and 2‐year duration, 57 PANs are needed in each study arm to detect a 50% reduction in the conversion rate.ConclusionsNESSCA, INAS, vestibulo‐ocular reflex, and vertical pursuit gains significantly worsened in the preataxic phase. The “TimeToAfterOnset” timeline unveiled that slopes of most variables are small in preataxics but increase and reach the ataxic slopes from 4 years before the onset of ataxia. For future trials in preataxic carriers, we recommend recruiting PANs and using the conversion rate as the primary outcome. © 2022 International Parkinson and Movement Disorder Society.
SuperMAP: Deep ultrafast MR relaxometry with joint spatiotemporal undersampling
Authors: Li Hongyu , Yang Mingrui , Kim Jee Hun , Zhang Chaoyi , Liu Ruiying , Huang Peizhou , Liang Dong , Zhang Xiaoliang , Li Xiaojuan , Ying Leslie 
Published: September 2022

PurposeTo develop an ultrafast and robust MR parameter mapping network using deep learning.Theory and MethodsWe design a deep learning framework called SuperMAP that directly converts a series of undersampled (both in k‐space and parameter‐space) parameter‐weighted images into several quantitative maps, bypassing the conventional exponential fitting procedure. We also present a novel technique to simultaneously reconstruct T1rho and T2 relaxation maps within a single scan. Full data were acquired and retrospectively undersampled for training and testing using traditional and state‐of‐the‐art techniques for comparison. Prospective data were also collected to evaluate the trained network. The performance of all methods is evaluated using the parameter qualification errors and other metrics in the segmented regions of interest.ResultsSuperMAP achieved accurate T1rho and T2 mapping with high acceleration factors (R = 24 and R = 32). It exploited both spatial and temporal information and yielded low error (normalized mean square error of 2.7% at R = 24 and 2.8% at R = 32) and high resemblance (structural similarity of 97% at R = 24 and 96% at R = 32) to the gold standard. The network trained with retrospectively undersampled data also works well for the prospective data (with a slightly lower acceleration factor). SuperMAP is also superior to conventional methods.ConclusionOur results demonstrate the feasibility of generating superfast MR parameter maps through very few undersampled parameter‐weighted images. SuperMAP can simultaneously generate T1rho and T2 relaxation maps in a short scan time.
Test–retest reproducibility of human brain multi‐slice1H FID‐MRSIdata at 9.4T after optimization of lipid regularization, macromolecular model, and spline baseline stiffness
Authors: Ziegs Theresia , Wright Andrew Martin , Henning Anke 
Published: September 2022

PurposeThis study analyzes the effects of retrospective lipid suppression, a simulated macromolecular prior knowledge and different spline baseline stiffness values on 9.4T multi‐slice proton FID‐MRSI data spanning the whole cerebrum of human brain and the reproducibility of respective metabolite ratio to total creatine (/tCr) maps for 10 brain metabolites.MethodsMeasurements were performed twice on 5 volunteers using a short TR and TE FID MRSI 2D sequence at 9.4T. The effects of retrospective lipid L2‐regularization, macromolecular spectrum and different LCModel baseline flexibilities on SNR, FWHM, fitting residual, Cramér‐Rao lower bound, and metabolite ratio maps were investigated. Intra‐subject, inter‐session coefficient of variation and the test–retest reproducibility of the mean metabolite ratios (/tCr) of each slice was calculated.ResultsTransversal, sagittal, and coronal slices of many metabolite ratio maps correspond to the anatomically expected concentration relations in gray and white matter for the majority of the cerebrum when using a flexible baseline in LCModel fit. Results from the second measurements of the same subjects show that slice positioning and data quality correlate significantly to the first measurement. L2‐regularization provided effective suppression of lipid‐artifacts, but should be avoided if no artifacts are detected.ConclusionReproducible concentration ratio maps (/tCr) for 4 metabolites (total choline, N‐acetylaspartate, glutamate, and myoinositol) spanning the majority of the cerebrum and 6 metabolites (N‐acetylaspartylglutamate, γ‐aminobutyric acid, glutathione, taurine, glutamine, and aspartate) covering 32 mm in the upper part of the brain were acquired at 9.4T using multi‐slice FID MRSI with retrospective lipid suppression, a macromolecular spectrum and a flexible LCModel baseline.
MR multitasking‐based dynamic imaging for cerebrovascular evaluation (MT‐DICE): Simultaneous quantification of permeability and leakage‐insensitive perfusion by dynamic T1/T2* mapping
Authors: Hu Zhehao , Christodoulou Anthony G. , Wang Nan , Xie Yibin , Shiroishi Mark S. , Yang Wensha , Zada Gabriel , Chow Frances E. , Margol Ashley S. , Tamrazi Benita , Chang Eric L. , Li Debiao , Fan Zhaoyang 
Published: September 2022

PurposeTo develop an MR multitasking‐based dynamic imaging for cerebrovascular evaluation (MT‐DICE) technique for simultaneous quantification of permeability and leakage‐insensitive perfusion with a single‐dose contrast injection.MethodsMT‐DICE builds on a saturation‐recovery prepared multi‐echo fast low‐angle shot sequence. The k‐space is randomly sampled for 7.6 min, with single‐dose contrast agent injected 1.5 min into the scan. MR multitasking is used to model the data into six dimensions, including three spatial dimensions for whole‐brain coverage, a saturation‐recovery time dimension, and a TE dimension for dynamic and quantification, respectively, and a contrast dynamics dimension for capturing contrast kinetics. The derived pixel‐wise time series are converted into contrast concentration‐time curves for calculation of kinetic metrics. The technique was assessed for its agreement with reference methods in and measurements in eight healthy subjects and, in three of them, inter‐session repeatability of permeability and leakage‐insensitive perfusion parameters. Its feasibility was also demonstrated in four patients with brain tumors.ResultsMT‐DICE values of normal gray matter and white matter were in excellent agreement with reference values (intraclass correlation coefficients = 0.860/0.962 for gray matter and 0.925/0.975 for white matter ). Both permeability and perfusion parameters demonstrated good to excellent intersession agreement with the lowest intraclass correlation coefficients at 0.694. Contrast kinetic parameters in all healthy subjects and patients were within the literature range.ConclusionBased on dynamic mapping, MT‐DICE allows for simultaneous quantification of permeability and leakage‐insensitive perfusion metrics with a single‐dose contrast injection.
The future of MRI in radiation therapy: Challenges and opportunities for the MR community
Authors: Goodburn Rosie J. , Philippens Marielle E. P. , Lefebvre Thierry L. , Khalifa Aly , Bruijnen Tom , Freedman Joshua N. , Waddington David E. J. , Younus Eyesha , Aliotta Eric , Meliadò Gabriele , Stanescu Teo , Bano Wajiha , Fatemi‐Ardekani Ali , Wetscherek Andreas , Oelfke Uwe , van den Berg Nico , Mason Ralph P. , van Houdt Petra J. , Balter James M. , Gurney‐Champion Oliver J. 
Published: September 2022

AbstractRadiation therapy is a major component of cancer treatment pathways worldwide. The main aim of this treatment is to achieve tumor control through the delivery of ionizing radiation while preserving healthy tissues for minimal radiation toxicity. Because radiation therapy relies on accurate localization of the target and surrounding tissues, imaging plays a crucial role throughout the treatment chain. In the treatment planning phase, radiological images are essential for defining target volumes and organs‐at‐risk, as well as providing elemental composition (e.g., electron density) information for radiation dose calculations. At treatment, onboard imaging informs patient setup and could be used to guide radiation dose placement for sites affected by motion. Imaging is also an important tool for treatment response assessment and treatment plan adaptation. MRI, with its excellent soft tissue contrast and capacity to probe functional tissue properties, holds great untapped potential for transforming treatment paradigms in radiation therapy. The MR in Radiation Therapy ISMRM Study Group was established to provide a forum within the MR community to discuss the unmet needs and fuel opportunities for further advancement of MRI for radiation therapy applications. During the summer of 2021, the study group organized its first virtual workshop, attended by a diverse international group of clinicians, scientists, and clinical physicists, to explore our predictions for the future of MRI in radiation therapy for the next 25 years. This article reviews the main findings from the event and considers the opportunities and challenges of reaching our vision for the future in this expanding field.