bluuebunny/crossref_metadata_2025_split huggingface dataset:
Dynamical Renormalization Group for Mode-Coupling Field Theories with Solenoidal Constraint
Authors: Cavagna Andrea , Di Carlo Luca , Giardina Irene , Grigera Tomas , Pisegna Giulia , Scandolo Mattia 
Published: August 2021

AbstractThe recent inflow of empirical data about the collective behaviour of strongly correlated biological systems has brought field theory and the renormalization group into the biophysical arena. Experiments on bird flocks and insect swarms show that social forces act on the particles’ velocity through the generator of its rotations, namely the spin, indicating that mode-coupling field theories are necessary to reproduce the correct dynamical behaviour. Unfortunately, a theory for three coupled fields—density, velocity and spin—has a prohibitive degree of intricacy. A simplifying path consists in getting rid of density fluctuations by studying incompressible systems. This requires imposing a solenoidal constraint on the primary field, an unsolved problem even for equilibrium mode-coupling theories. Here, we perform an equilibrium dynamic renormalization group analysis of a mode-coupling field theory subject to a solenoidal constraint; using the classification of Halperin and Hohenberg, we can dub this case as a solenoidal Model G. We demonstrate that the constraint produces a new vertex that mixes static and dynamical coupling constants, and that this vertex is essential to grant the closure of the renormalization group structure and the consistency of dynamics with statics. Interestingly, although the solenoidal constraint leads to a modification of the static universality class, we find that it does not change the dynamical universality class, a result that seems to represent an exception to the general rule that dynamical universality classes are narrower than static ones. Our results constitute a solid stepping stone in the admittedly large chasm towards developing an off-equilibrium mode-coupling theory of biological groups.
Pixel-wise parallel calculation for depth from focus with adaptive focus measure
Authors: Matsubara Yoichi , Shirai Keiichiro , Ito Yuya , Tanaka Kiyoshi 
Published: August 2021

AbstractDepth-from-focus methods can estimate the depth from a set of images taken with different focus settings. We recently proposed a method that uses the relationship of the ratio between the luminance value of a target pixel and the mean value of the neighboring pixels. This relationship has a Poisson distribution. Despite its good performance, the method requires a large amount of memory and computation time because it needs to store focus measurement values for each depth and each window radius on a pixel-wise basis, and filtering to compute the mean value, which is performed twice, makes the relationship among neighboring pixels too strong to parallelize the pixel-wise processing. In this paper, we propose an approximate calculation method that can give almost the same results with a single time filtering operation and enables pixel-wise parallelization. This pixel-wise processing does not require the aforementioned focus measure values to be stored, which reduces the amount of memory. Additionally, utilizing the pixel-wise processing, we propose a method of determining the process window size that can improve noise tolerance and in depth estimation in texture-less regions. Through experiments, we show that our new method can better estimate depth values in a much shorter time.
Delay-induced bifurcations in collocated position control of an elastic arm
Authors: Szaksz Bence , Stepan Gabor 
Published: August 2021

AbstractThe interference of the elasticity of a single robotic arm and the unavoidable time delay of its position control is analysed from nonlinear vibrations viewpoint. The simplified mechanical model of two blocks and a connecting spring considers the first vibration mode of the arm, while the collocated proportional-derivative (PD) control uses the state of the first block only and actuates also there. It is assumed that the relevant nonlinearity is the saturation of the delayed control force. The linear stability analysis proves that stabilizable and non-stabilizable parameter regions follow each other periodically even for large spring stiffnesses and for tiny time delays. Hopf bifurcation calculation is carried out after an infinite-dimensional centre manifold reduction, and closed-form algebraic expressions are given for the amplitudes of the emerging oscillations. These results support the experimental tuning of the control gains since the parameters of the arising and often unexpected self-excited vibrations can serve as a guide for this practical procedure.
Alkaloid diversification in the genus Palicourea (Rubiaceae: Palicoureeae) viewed from a (retro-)biogenetic perspective
Authors: Berger Andreas , Valant-Vetschera Karin , Schinnerl Johann , Brecker Lothar 
Published: August 2021

AbstractThe species-rich genus Palicourea (Rubiaceae: Palicoureeae) is source of an intriguing diversity of alkaloids derived from tryptamine and its precursor tryptophan. So far simple tryptamine analogues, polypyrroloindoline, β-carboline, and, most importantly, monoterpene-indole, i.e., tryptamine-iridoid alkaloids of various structural types including javaniside, alstrostine and strictosidine derivatives have been identified. Here the diverse alkaloids that numerous studies have found in the genus are examined and organized according to their structures and biosynthetic groups. Using a parsimony-based approach that follows the concept of retro-biogenesis usually applied in synthetic chemistry, possible biosynthetic pathways are proposed and important steps and relationships between these alkaloids are highlighted. Understanding alkaloid diversification is of importance in studying the ecological significance and evolution of biosynthetic capabilities of the genus Palicourea, and should stimulate future investigations on the biochemical and genetic background.
Evaluation and GWAS of radicle gravitropic response in a core rice germplasm population
Authors: Lou Qiaojun , Li Qingsong , Feng Fangjun , Joynson Ryan , Yang Yunan , Luo Lijun , Chen Liang 
Published: August 2021

Abstract
Aims
Since gravitropism is one of the primary determinants of root development, facilitating root penetration into soil and subsequent absorption of water and nutrients, we studied this response in rice.

Methods
The gravitropism of 226 Chinese rice micro-core accessions and drought-resistant core accessions were assessed through the modified gravity-bending experiment and genome-wide association analysis (GWAS) was used to map the associated QTLs.

Results
The average value of gravitropic response speed of seminal roots was 41.05°/h, ranging from 16.77°/h to 62.83°/h. The gravity response speed of Indica (42.49°/h) was significantly (P < 0.002) higher than Japonica (39.71°/h) subspecies. The gravitational response speed of seminal roots was significantly positively correlated with the number of deep roots (r = 0.16), the growth speed of seminal roots (r = 0.21) and the drought resistance coefficient (r = 0.14).

Conclusions
In total, 3 QTLs (quantitative traits) associated with gravitropic response speed were identified on chromosome 4, 11 and 12. There are some known QTLs relating to roots traits and drought resistance located nearby the QTLs identified here, which confirms the close relationship between radicle gravitropism and the drought resistance. From within these intervals, 5 candidate genes were screened and verified by qPCR in a few rice varieties with extreme phenotypic values, demonstrating that gene LOC_Os12g29350 may regulate gravitropism negatively. This may be a promising candidate to be confirmed in further studies.
The role of unpaid domestic work in explaining the gender gap in the (monetary) value of leisure
Authors: Jokubauskaitė Simona , Hössinger Reinhard , Jara-Díaz Sergio , Peer Stefanie , Schneebaum Alyssa , Schmid Basil , Aschauer Florian , Gerike Regine , Axhausen Kay W. , Leisch Friedrich 
Published: August 2021

AbstractThe value of travel time savings (VTTS) representing the willingness to pay to reduce travel time, consists of two components: the value of liberating time [equal to the value of leisure (VoL)] and the value of time assigned to travel (VTAT), representing the travel conditions of a trip. Their relative values indicate which dimension to emphasize when investing in transport: speed or comfort. In this paper, we formulate and estimate a framework aimed at the improvement in the estimation of the VoL. By introducing a novel treatment of time assigned to domestic work, we consider that unpaid labor should be assigned a wage rate as a measure of the expenses avoided when assigning time to those chores. We use state-of-the-art data on time use and expenses as well as online data on gig workers collected in Austria, and apply the time-use and expenditure model of Jara-Diaz et al. (Transp Res Part B 42(10):946–957, 2008). The wage rates for paid and unpaid work were combined to re-formulate the budget constraint, which affected women more than men due to the higher involvement of the former in domestic activities. Compared against the original estimation, the VoL changed from €10/h for men and €6/h for women to €9/h for both genders, which in turn yields a larger average VTAT, which becomes positive for public transport. As a conclusion, the novel treatment of domestic labor contributes to closing the gap in the VoL between genders and highlights the power of unveiling the components behind the VTTS. The empirical findings imply that investments in travel time reductions rather than in comfort should be prioritized, given the very good conditions of public transport in Austria.
Strategic reporting by nonprofit hospitals: an examination of bad debt and charity care
Authors: Beck Amanda , Gilstrap Collin , Rippy Jordan , Vansant Brian 
Published: August 2021

AbstractIn this paper, we examine bad debt and charity care reporting by nonprofit hospitals around bond issuance. Given the tax advantages afforded to nonprofit hospitals, including the ability to issue tax-exempt debt, hospital managers encounter stakeholder pressure to provide community benefits. When nonprofits issue debt, they also face economic pressure to meet creditors’ financial performance expectations. We document a reporting strategy that allows nonprofit hospitals to reduce the cost of bond debt while simultaneously alleviating regulators’ and community members’ concerns about inadequate provision of charity care. Using data from public bond issues for California nonprofit hospitals, we find that hospital managers shift costs from bad debt expense to charity care in periods prior to a public bond issuance and that the strategy is associated with a lower cost of debt. Our results inform those relying on accounting measurements to infer nonprofit hospitals’ social good provisions and financial health.
Rheology of Immiscible Two-phase Flow in Mixed Wet Porous Media: Dynamic Pore Network Model and Capillary Fiber Bundle Model Results
Authors: Fyhn Hursanay , Sinha Santanu , Roy Subhadeep , Hansen Alex 
Published: August 2021

AbstractImmiscible two-phase flow in porous media with mixed wet conditions was examined using a capillary fiber bundle model, which is analytically solvable, and a dynamic pore network model. The mixed wettability was implemented in the models by allowing each tube or link to have a different wetting angle chosen randomly from a given distribution. Both models showed that mixed wettability can have significant influence on the rheology in terms of the dependence of the global volumetric flow rate on the global pressure drop. In the capillary fiber bundle model, for small pressure drops when only a small fraction of the tubes were open, it was found that the volumetric flow rate depended on the excess pressure drop as a power law with an exponent equal to 3/2 or 2 depending on the minimum pressure drop necessary for flow. When all the tubes were open due to a high pressure drop, the volumetric flow rate depended linearly on the pressure drop, independent of the wettability. In the transition region in between where most of the tubes opened, the volumetric flow depended more sensitively on the wetting angle distribution function and was in general not a simple power law. The dynamic pore network model results also showed a linear dependence of the flow rate on the pressure drop when the pressure drop is large. However, out of this limit the dynamic pore network model demonstrated a more complicated behavior that depended on the mixed wettability condition and the saturation. In particular, the exponent relating volumetric flow rate to the excess pressure drop could take on values anywhere between 1.0 and 1.8. The values of the exponent were highest for saturations approaching 0.5, also, the exponent generally increased when the difference in wettability of the two fluids were larger and when this difference was present for a larger fraction of the porous network.
On the Interaction of Viscoelasticity and Waviness in Enhancing the Pull-Off Force in Sphere/Flat Contacts
Authors: Ciavarella Michele , Papangelo Antonio 
Published: August 2021

AbstractMotivated by roughness-induced adhesion enhancement (toughening and strengthening) in low modulus materials, we study the detachment of a sphere from a substrate in the presence of both viscoelastic dissipation at the contact edge, and roughness in the form of a single axisymmetric waviness. We show that the roughness-induced enhancement found by Guduru and coworkers for the elastic case (i.e. at very small detachment speeds) tends to disappear with increasing speeds, where the viscoelastic effect dominates and the problem approaches that of a smooth sphere. This is in qualitative agreement with the original experiments of Guduru’s group with gelatin. The cross-over velocity is where the two separate effects are comparable. Viscoelasticity effectively damps roughness-induced elastic instabilities and makes their effects much less important.
Graphical Abstract
Surface Enhanced Infrared Characterization Using Disordered Slit-Antenna Arrays for the Detection of Electrodeposited Cytochrome C
Authors: Armelles Gaspar , Cebollada Alfonso , Cava Daniel G. , Alvarez-Malmagro Julia , Vélez Marisela 
Published: August 2021

AbstractAn approach which allows both electrochemical studies and surface enhanced infrared characterization of electrodeposited Cytochrome C is presented. This approach is based on in-plane disordered arrays of resonant slits engraved in Au substrates using focused ion beam. For light-polarized perpendicular to the slit, the reflectivity spectra of the slit arrays show dips related to the excitation of the slit plasmon resonance, whose position depends on the slit length. Due to the presence of the continuous Au layer around the slits, the very same substrates can be used to perform electrochemical studies. By varying the slit length, we have tuned the plasmon resonance to match the absorption bands of electrodeposited Cytochrome C, demonstrating the detection of minute amounts of this protein, all the way down to a single monolayer.
A proof of concept study for machine learning application to stenosis detection
Authors: Jones Gareth , Parr Jim , Nithiarasu Perumal , Pant Sanjay 
Published: August 2021

AbstractThis proof of concept (PoC) assesses the ability of machine learning (ML) classifiers to predict the presence of a stenosis in a three vessel arterial system consisting of the abdominal aorta bifurcating into the two common iliacs. A virtual patient database (VPD) is created using one-dimensional pulse wave propagation model of haemodynamics. Four different machine learning (ML) methods are used to train and test a series of classifiers—both binary and multiclass—to distinguish between healthy and unhealthy virtual patients (VPs) using different combinations of pressure and flow-rate measurements. It is found that the ML classifiers achieve specificities larger than 80% and sensitivities ranging from 50 to 75%. The most balanced classifier also achieves an area under the receiver operative characteristic curve of 0.75, outperforming approximately 20 methods used in clinical practice, and thus placing the method as moderately accurate. Other important observations from this study are that (i) few measurements can provide similar classification accuracies compared to the case when more/all the measurements are used; (ii) some measurements are more informative than others for classification; and (iii) a modification of standard methods can result in detection of not only the presence of stenosis, but also the stenosed vessel.
Phosphaturic mesenchymal tumors: radiological aspects and suggested imaging pathway
Authors: Hussein Mohsin A. M. , Cafarelli Francesco Pio , Paparella Maria Teresa , Rennie Winston J. , Guglielmi Giuseppe 
Published: August 2021

AbstractPhosphaturic mesenchymal tumors (PMTs) are rare mesenchymal neoplasms of soft tissue or bone origin that can give rise to a challenge in diagnostic imaging. These tumors are frequently associated with tumor-induced osteomalacia, also called oncogenic osteomalacia, which is a rare paraneoplastic syndrome characterized by ectopic secretion of fibroblast growth factor 23, a hormone that regulates serum phosphate level. PMTs show polymorphic features on both radiological findings and histological examination, causing problems in diagnosis owing to their similarity with other mesenchymal tumors. Thus, this paper aims to describe radiological aspects of PMTs and suggest an imaging pathway for accurate diagnosis throughout the evidence from the literature review.
Non-material nature’s contributions to people from a marine protected area support multiple dimensions of human well-being
Authors: Garcia Rodrigues João , Villasante Sebastián , Sousa Pinto Isabel 
Published: August 2021

AbstractThe non-material aspects of nature are frequently the most socially valued and demanded nature’s contributions to people (NCP). This is because non-material NCP often lay the foundations of key human well-being dimensions such as identities, experiences, and capabilities. Yet, while research on material NCP such as food and water abound, studies of non-material NCP are relatively scarce. This research gap results in a limited understanding of the relationships between non-material NCP and human well-being, especially in the marine and coastal environment. To understand the relationships between non-material NCP and subjective human well-being, we surveyed 453 users of Litoral Norte—a multiple-use marine protected area in Portugal. Our survey included 16 statement indicators reflecting theoretical constructs of subjective well-being. Using factor analysis, we found that subjective well-being derived from relating to, interacting with, and experiencing marine and coastal sites can be grouped into four interpretable cultural dimensions of well-being. These dimensions are ‘engagement with nature & health’, ‘sense of place’, ‘solitude in nature’, and ‘spirituality’. We also found statistically significant differences in reported levels of the four dimensions of well-being. Reported levels of well-being varied with interviewees’ socio-economic characteristics and environmental behaviour. Our findings offer interesting insights for marine conservation practice and policy that aims to foster both biodiversity and human well-being.
Nitrogen dioxide decline and rebound observed by GOME-2 and TROPOMI during COVID-19 pandemic
Authors: Liu Song , Valks Pieter , Beirle Steffen , Loyola Diego G. 
Published: August 2021

AbstractSince its first confirmed case in December 2019, coronavirus disease 2019 (COVID-19) has become a worldwide pandemic with more than 90 million confirmed cases by January 2021. Countries around the world have enforced lockdown measures to prevent the spread of the virus, introducing a temporal change of air pollutants such as nitrogen dioxide (NO2) that are strongly related to transportation, industry, and energy. In this study, NO2 variations over regions with strong responses to COVID-19 are analysed using datasets from the Global Ozone Monitoring Experiment-2 (GOME-2) sensor aboard the EUMETSAT Metop satellites and TROPOspheric Monitoring Instrument (TROPOMI) aboard the EU/ESA Sentinel-5 Precursor satellite. The global GOME-2 and TROPOMI NO2 datasets are generated at the German Aerospace Center (DLR) using harmonized retrieval algorithms; potential influences of the long-term trend and seasonal cycle, as well as the short-term meteorological variation, are taken into account statistically. We present the application of the GOME-2 data to analyze the lockdown-related NO2 variations for morning conditions. Consistent NO2 variations are observed for the GOME-2 measurements and the early afternoon TROPOMI data: regions with strong social responses to COVID-19 in Asia, Europe, North America, and South America show strong NO2 reductions of $\sim $
∼
30–50% on average due to restriction of social and economic activities, followed by a gradual rebound with lifted restriction measures.
Measuring aggregate electricity savings from the diffusion of more efficient lighting technologies
Authors: Moral-Carcedo Julián , Pérez-García Julián 
Published: August 2021

AbstractIncreasing concerns about sustainability and energy conservation, coupled with the proliferation of incentives in the EU to achieve energy savings, suggest that significant improvements in energy efficiency should be realized. A policy measure that should have a direct impact on energy savings is the replacement of incandescent and halogen light bulbs by more efficient lighting technologies, which was implemented in 2009. Due to the lack of detailed data, it is not feasible to measure the effect of energy-efficient improvements on electricity consumption at the aggregate level using a bottom-up approach. To overcome this limitation, this paper analyzes hourly electricity demand in a very specific period of the day: the transition from day to night. In this short period, it is plausible that lighting is the main driver of changes in electricity demand, thus making it possible to estimate the increase in electricity consumption when lights are switched on and to analyze the effects of higher energy efficiency in lighting, if any. The results of the analysis for Spain show that during the periods 2009–2011 and 2015–2016, an estimated energy savings of 251 GWh can be attributed to a reduction in the magnitude of the lighting effect, which accounts for 20.3% of the observed decrease in electricity consumption during these two periods.
1H, 13C and 15N assignment of stem-loop SL1 from the 5'-UTR of SARS-CoV-2
Authors: Richter Christian , Hohmann Katharina F. , Toews Sabrina , Mathieu Daniel , Altincekic Nadide , Bains Jasleen Kaur , Binas Oliver , Ceylan Betül , Duchardt-Ferner Elke , Ferner Jan , Fürtig Boris , Grün J. Tassilo , Hengesbach Martin , Hymon Daniel , Jonker Hendrik R. A. , Knezic Bozana , Korn Sophie M. , Landgraf Tom , Löhr Frank , Peter Stephen A. , Pyper Dennis J. , Qureshi Nusrat S. , Schlundt Andreas , Schnieders Robbin , Stirnal Elke , Sudakov Alexey , Vögele Jennifer , Weigand Julia E. , Wirmer-Bartoschek Julia , Witt Kerstin , Wöhnert Jens , Schwalbe Harald , Wacker Anna 
Published: August 2021

AbstractThe stem-loop (SL1) is the 5'-terminal structural element within the single-stranded SARS-CoV-2 RNA genome. It is formed by nucleotides 7–33 and consists of two short helical segments interrupted by an asymmetric internal loop. This architecture is conserved among Betacoronaviruses. SL1 is present in genomic SARS-CoV-2 RNA as well as in all subgenomic mRNA species produced by the virus during replication, thus representing a ubiquitous cis-regulatory RNA with potential functions at all stages of the viral life cycle. We present here the 1H, 13C and 15N chemical shift assignment of the 29 nucleotides-RNA construct 5_SL1, which denotes the native 27mer SL1 stabilized by an additional terminal G-C base-pair.