bluuebunny/crossref_metadata_2025_split huggingface dataset:
Reinforcement Learning for Uncooperative Space Objects Smart Imaging Path-Planning
Authors: Brandonisio Andrea , Lavagna Michèle , Guzzetti Davide 
Published: November 2021

AbstractLeading space agencies are increasingly investing in the gradual automation of space missions. In fact, autonomous flight operations may be a key enabler for on-orbit servicing, assembly and manufacturing (OSAM) missions, carrying inherent benefits such as cost and risk reduction. Within the spectrum of proximity operations, this work focuses on autonomous path-planning for the reconstruction of geometry properties of an uncooperative target. The autonomous navigation problem is called active Simultaneous Localization and Mapping (SLAM) problem, and it has been largely studied within the field of robotics. Active SLAM problem may be formulated as a Partially Observable Markov Decision Process (POMDP). Previous works in astrodynamics have demonstrated that is possible to use Reinforcement Learning (RL) techniques to teach an agent that is moving along a pre-determined orbit when to collect measurements to optimize a given mapping goal. In this work, different RL methods are explored to develop an artificial intelligence agent capable of planning sub-optimal paths for autonomous shape reconstruction of an unknown and uncooperative object via imaging. Proximity orbit dynamics are linearized and include orbit eccentricity. The geometry of the target object is rendered by a polyhedron shaped with a triangular mesh. Artificial intelligent agents are created using both the Deep Q-Network (DQN) and the Advantage Actor Critic (A2C) method. State-action value functions are approximated using Artificial Neural Networks (ANN) and trained according to RL principles. Training of the RL agent architecture occurs under fixed or random initial environment conditions. A large database of training tests has been collected. Trained agents show promising performance in achieving extended coverage of the target. Policy learning is demonstrated by displaying that RL agents, at minimum, have higher mapping performance than agents that behave randomly. Furthermore, RL agent may learn to maneuver the spacecraft to control target lighting conditions as a function of the Sun location. This work, therefore, preliminary demonstrates the applicability of RL to autonomous imaging of an uncooperative space object, thus setting a baseline for future works.
Simulated-Scenario and Peer-Mentorship Curriculum to Train Prehospital Providers in the Practice of Mass Gathering Medicine
Authors: Plaitano Enzo G. , Pate Bianca L. , Everett Elana F. , Golden Sarah K. , Levy Raymond A. , Ryan Kevin M. 
Published: November 2021

Abstract

Objective:
A mass gathering medicine training program was established for a 7,200-seat arena. The objectives of this study were to describe the program schema and determine its impact in preparing novice emergency medical technicians (EMTs) to manage the difficulties of large-venue emergency medical services (EMS).

Methods:
Optional, anonymous surveys were administered to EMTs. Novice EMTs were assessed pre-/post-program implementation, and both novice and experienced EMTs completed self-reported Likert scales. Data were analyzed with nonparametric methods.

Results:
A total of 43/56 responses (response rate = 76.8%) were received. Only 37.2% of providers felt prepared to work mass gatherings before the training, and 60.5% stated that their previous education did not prepare them for large-venue challenges. After the training program, novice EMTs were significantly associated with increased knowledge of large-venue EMS procedures (P = 0.0170), higher proficiency using extrication equipment (P = 0.0248), increased patient care skills (P = 0.0438), and both increased confidence working events (P = 0.0002) and better teamwork during patient encounters (P = 0.0001). The majority of EMTs reported the program as beneficial.

Conclusion:
Upon hire, EMS providers felt unprepared to work large-venue EMS. The analyses demonstrated that this training program improved select large-venue emergency skills for prehospital providers and may fill a gap in the education system regarding mass gathering medicine.
Determination of tissue-specific interaction between vitamin C and vitamin Ein vivousing senescence marker protein-30 knockout mice as a vitamin C synthesis deficiency model
Authors: Sato Ayami , Takino Yuka , Yano Tomohiro , Fukui Koji , Ishigami Akihito 
Published: November 2021

AbstractVitamin E (α-tocopherol; VE) is known to be regenerated from VE radicals by vitamin C (L-ascorbic acid; VC)in vitro. However, theirin vivointeraction in various tissues is still unclear. Therefore, we alternatively examined thein vivointeraction of VC and VE by measurement of their concentrations in various tissues of senescence marker protein-30 (SMP30) knockout (KO) mice as a VC synthesis deficiency model. Male SMP30-KO mice were divided into four groups (VC+/VE+, VC+/VE–, VC–/VE+ and VC–/VE–), fed diets with or without 500 mg/kg VE and given water with or without 1·5 g/l VCad libitum. Then, VC and VE concentrations in the plasma and various tissues were determined. Further, gene expression levels of transporters associated with VC and VE, such asα-tocopherol transfer protein (α-TTP) and sodium-dependent vitamin C transporters (SVCTs), were examined. These results showed that the VE levels in the VC-depleted (VC–/VE+) group were significantly lower than those in the VC+/VE+ group in the liver and heart; the VC levels in the VE-depleted (VC+/VE–) group were significantly lower than those in the VC+/VE+ group in the kidneys. Theα-TTP gene expression in the liver and kidneys was decreased by VC and/or VE depletion. Moreover, SVCT1 gene expression in the liver was decreased by both VC and VE depletion. In conclusion, these results indicate that VC spares VE mainly in the liver and heart and that VE spares VC in the kidneys of SMP30-KO mice. Thus, interaction between VC and VE is likely to be tissue specific.
First whole-genome analysis of the novel coronavirus (SARS-CoV-2) obtained from COVID-19 patients from five districts in Western Serbia
Authors: Vidanović Dejan , Tešović Bojana , Volkening Jeremy D. , Afonso Claudio L. , Quick Joshua , Šekler Milanko , Knežević Aleksandra , Janković Marko , Jovanović Tanja , Petrović Tamaš , Đeri Bojana Banović 
Published: November 2021

Abstract
This study was endeavoured to contribute in furthering our understanding of the molecular epidemiology of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) by sequencing and analysing the first full-length genome sequences obtained from 48 coronavirus disease-2019 (COVID-19) patients in five districts in Western Serbia in the period April 2020–July 2020. SARS-CoV-2 sequences in Western Serbia distinguished from the Wuhan sequence in 128 SNPs in total. The phylogenetic structure of local SARS-CoV-2 isolates suggested the existence of at least four distinct groups of SARS-CoV-2 strains in Western Serbia. The first group is the most similar to the strain from Italy. These isolates included two 20A sequences and 15−30 20B sequences that displayed a newly occurring set of four conjoined mutations. The second group is the most similar to the strain from France, carrying two mutations and belonged to 20A clade. The third group is the most similar to the strain from Switzerland carrying four co-occurring mutations and belonging to 20B clade. The fourth group is the most similar to another strain from France, displaying one mutation that gave rise to a single local isolate that belonged to 20A clade.
Impact of front-of-pack labels on the perceived healthfulness of a sweetened fruit drink: a randomised experiment in five countries
Authors: Jáuregui Alejandra , White Christine M , Vanderlee Lana , Hall Marissa G , Contreras-Manzano Alejandra , Nieto Claudia , Sacks Gary , Thrasher James F , Hammond David , Barquera Simón 
Published: November 2021

AbstractObjective:Front-of-pack (FOP) nutrition labelling is a globally recommended strategy to encourage healthier food choices. We evaluated the effect of FOP labels on the perceived healthfulness of a sweetened fruit drink in an international sample of adult consumers.Design:Six-arm randomised controlled experiment to examine the impact of FOP labels (no label control, Guideline Daily Amounts (GDA), Multiple Traffic Lights, the Health Star Ratings (HSR), Health Warning Labels, and ‘High-in’ Warning Labels (HIWL)) on the perceived healthfulness of the drink. Linear regression models by country examined healthfulness perceptions on FOP nutrition labels, testing for interactions by demographic characteristics.Setting:Online survey in 2018 among participants from Australia, Canada, Mexico, United Kingdom (UK) and United States.Participants:Adults (≥18 years, n 22 140).Results:Compared with control, HIWL had the greatest impact in lowering perceived healthfulness (β from −0·62 to −1·71) across all countries. The HIWL and the HSR had a similar effect in Australia. Other labels were effective in decreasing the perceived healthfulness of the drink within some countries only, but to a lower extent. The GDA did not reduce perceived healthfulness in most countries. In the UK, the effect of HIWL differed by age group, with greater impact among older participants (> 40 years). There were no other variations across key demographic characteristics.Conclusions:HIWL, which communicates clear, non-quantitative messages about high levels of nutrients of concern, demonstrated the greatest efficacy to decrease the perceived healthfulness of a sweetened fruit drink across countries. This effect was similar across demographic characteristics.
BOUNDS ON THE CRITICAL TIMES FOR THE GENERAL FISHER–KPP EQUATION
Authors: RODRIGO MARIANITO R. 
Published: November 2021

AbstractThe Fisher–Kolmogorov–Petrovsky–Piskunov (Fisher–KPP) equation is one of the prototypical reaction–diffusion equations and is encountered in many areas, primarily in population dynamics. An important consideration for the phenomena modelled by diffusion equations is the length of the diffusive process. In this paper, three definitions of the critical time are given, and bounds are obtained by a careful construction of the upper and lower solutions. The comparison functions satisfy the nonlinear, but linearizable, partial differential equations of Fisher–KPP type. Results of the numerical simulations are displayed. Extensions to some classes of reaction–diffusion systems and an application to a spatially heterogeneous harvesting model are also presented.
Refactoring the Whitby Intelligent Tutoring System for Clean Architecture
Authors: BROWN PAUL S. , DIMITROVA VANIA , HART GLEN , COHN ANTHONY G. , MOURA PAULO 
Published: November 2021

AbstractWhitby is the server-side of an Intelligent Tutoring System application for learning System-Theoretic Process Analysis (STPA), a methodology used to ensure the safety of anything that can be represented with a systems model. The underlying logic driving the reasoning behind Whitby is Situation Calculus, which is a many-sorted logic with situation, action, and object sorts. The Situation Calculus is applied to Ontology Authoring and Contingent Scaffolding: the primary activities within Whitby. Thus many fluents and actions are aggregated in Whitby from these two sub-applications and from Whitby itself, but all are available through a common situation query interface that does not depend upon any of the fluents or actions. Each STPA project in Whitby is a single situation term, which is queried for fluents that include the ontology, and to determine what pedagogical interventions to offer. Initially Whitby was written in Prolog using a module system. In the interest of a cleaner architecture and implementation with improved code reuse and extensibility, the initial application was refactored into Logtalk. This refactoring includes decoupling the Situation Calculus reasoner, Ontology Authoring framework, and Contingent Scaffolding framework into third-party libraries that can be reused in other applications. This extraction was achieved by inverting dependencies via Logtalk protocols and categories, which are reusable interfaces and components that provide functionally cohesive sets of predicate declarations and predicate definitions. In this paper the architectures of two iterations of Whitby are evaluated with respect to the motivations behind the refactor: clean architecture enabling code reuse and extensibility.
Electron Pitch Angle Distributions in Compressional Pc5 Waves by THEMIS‐A Observations
Authors: Ma X. , Tian A. M. , Shi Q. Q. , Bai S. C. , Yao S. T. , Shen X. C. , Sun W. J. , Guo R. L. , Nowada M. , Degeling A. W. , Liu J. , Li L. , Zhang S. , Li W. 
Published: October 2021

AbstractAlthough compressional Pc5 waves are well known in the energy conversion and regulation of charged particles in the magnetosphere, the detailed features of associated electron pitch angle distributions (ePADs) are poorly understood. Based on Time History of Events and Macroscale Interactions during Substorms (THEMIS) observations from 2010 to 2016, ePADs in the magnetic decreases (troughs) of compressional Pc5 waves are classified into three types: cigar, butterfly, and pancake. They are found in the electrons with respective energy ranges of 100–1,000 eV (larger than 10 keV), 1–10 keV (larger than 1 keV), and 6–30 keV (100 eV–10 keV) in (non)whistler‐type compressional Pc5 waves, that is, cases where whistler‐mode waves are present (absent) in the magnetic troughs. These statistical ePAD features observed in the whistler‐ and nonwhistler‐type waves are suggested to be associated with the Landau resonance of whistler‐mode waves and drift‐shell splitting effect.
Absolute characterization of high numerical aperture microscope objectives utilizing a dipole scatterer
Authors: Eismann Jörg S. , Neugebauer Martin , Mantel Klaus , Banzer Peter 
Published: November 2021

AbstractMeasuring the aberrations of optical systems is an essential step in the fabrication of high precision optical components. Such a characterization is usually based on comparing the device under investigation with a calibrated reference object. However, when working at the cutting-edge of technology, it is increasingly difficult to provide an even better or well-known reference device. In this manuscript we present a method for the characterization of high numerical aperture microscope objectives, functioning without the need of calibrated reference optics. The technique constitutes a nanoparticle, acting as a dipole-like scatterer, that is placed in the focal volume of the microscope objective. The light that is scattered by the particle can be measured individually and serves as the reference wave in our system. Utilizing the well-characterized scattered light as nearly perfect reference wave is the main idea behind this manuscript.
Fluorescence lifetime imaging for studying DNA compaction and gene activities
Authors: Levchenko Svitlana M. , Pliss Artem , Peng Xiao , Prasad Paras N. , Qu Junle 
Published: November 2021

AbstractOptical imaging is a most useful and widespread technique for the investigation of the structure and function of the cellular genomes. However, an analysis of immensely convoluted and irregularly compacted DNA polymer is highly challenging even by modern super-resolution microscopy approaches. Here we propose fluorescence lifetime imaging (FLIM) for the advancement of studies of genomic structure including DNA compaction, replication as well as monitoring of gene expression. The proposed FLIM assay employs two independent mechanisms for DNA compaction sensing. One mechanism relies on the inverse quadratic relation between the fluorescence lifetimes of fluorescence probes incorporated into DNA and their local refractive index, variable due to DNA compaction density. Another mechanism is based on the Förster resonance energy transfer (FRET) process between the donor and the acceptor fluorophores, both incorporated into DNA. Both these proposed mechanisms were validated in cultured cells. The obtained data unravel a significant difference in compaction of the gene-rich and gene-poor pools of genomic DNA. We show that the gene-rich DNA is loosely compacted compared to the dense DNA domains devoid of active genes.
Localized extension in megathrust hanging wall following great earthquakes in western Nepal
Authors: Riesner Magali , Bollinger Laurent , Hubbard Judith , Guérin Cyrielle , Lefèvre Marthe , Vallage Amaury , Basnet Shah Chanda , Kandel Thakur Prasad , Haines Samuel , Sapkota Soma Nath 
Published: November 2021

AbstractThe largest (M8+) known earthquakes in the Himalaya have ruptured the upper locked section of the Main Himalayan Thrust zone, offsetting the ground surface along the Main Frontal Thrust at the range front. However, out-of-sequence active structures have received less attention. One of the most impressive examples of such faults is the active fault that generally follows the surface trace of the Main Boundary Thrust (MBT). This fault has generated a clear geomorphological signature of recent deformation in eastern and western Nepal, as well as further west in India. We focus on western Nepal, between the municipalities of Surkhet and Gorahi where this fault is well expressed. Although the fault system as a whole is accommodating contraction, across most of its length, this particular fault appears geomorphologically as a normal fault, indicating crustal extension in the hanging wall of the MHT. We focus this study on the reactivation of the MBT along the Surkhet-Gorahi segment of the surface trace of the newly named Reactivated Boundary Fault, which is ~ 120 km long. We first generate a high-resolution Digital Elevation Model from triplets of high-resolution Pleiades images and use this to map the fault scarp and its geomorphological lateral variation. For most of its length, normal motion slip is observed with a dip varying between 20° and 60° and a maximum cumulative vertical offset of 27 m. We then present evidence for recent normal faulting in a trench located in the village of Sukhetal. Radiocarbon dating of detrital charcoals sampled in the hanging wall of the fault, including the main colluvial wedge and overlying sedimentary layers, suggest that the last event occurred in the early sixteenth century. This period saw the devastating 1505 earthquake, which produced ~ 23 m of slip on the Main Frontal Thrust. Linked or not, the ruptures on the MFT and MBT happened within a short time period compared to the centuries of quiescence of the faults that followed. We suggest that episodic normal-sense activity of the MBT could be related to large earthquakes rupturing the MFT, given its proximity, the sense of motion, and the large distance that separates the MBT from the downdip end of the locked fault zone of the MHT fault system. We discuss these results and their implications for the frontal Himalayan thrust system.
Hypoxia induces stress fiber formation in adipocytes in the early stage of obesity
Authors: Anvari Golnaz , Bellas Evangelia 
Published: November 2021

AbstractIn obese adipose tissue (AT), hypertrophic expansion of adipocytes is not matched by new vessel formation, leading to AT hypoxia. As a result, hypoxia inducible factor-1⍺ (HIF-1⍺) accumulates in adipocytes inducing a transcriptional program that upregulates profibrotic genes and biosynthetic enzymes such as lysyl oxidase (LOX) synthesis. This excess synthesis and crosslinking of extracellular matrix (ECM) components cause AT fibrosis. Although fibrosis is a hallmark of obese AT, the role of fibroblasts, cells known to regulate fibrosis in other fibrosis-prone tissues, is not well studied. Here we have developed an in vitro model of AT to study adipocyte-fibroblast crosstalk in a hypoxic environment. Further, this in vitro model was used to investigate the effect of hypoxia on adipocyte mechanical properties via ras homolog gene family member A (RhoA)/Rho-associated coiled-coil kinases (ROCK) signaling pathways. We confirmed that hypoxia creates a diseased phenotype by inhibiting adipocyte maturation and inducing actin stress fiber formation facilitated by myocardin-related transcription factor A (MRTF-A/MKL1) nuclear translocation. This work presents new potential therapeutic targets for obesity by improving adipocyte maturation and limiting mechanical stress in obese AT.
The educational community and its knowledge and perceptions of native and invasive alien species
Authors: Sosa Alejandro J. , Jiménez Nadia L. , Faltlhauser Ana C. , Righetti Tomás , Mc Kay Fernando , Bruzzone Octavio A. , Stiers Iris , Fernández Souto Adriana 
Published: November 2021

AbstractEnvironmental education seeks to foster an appreciation for nature and the impact of humans on it while introducing citizens to scientific thinking. Biological invasions affect different aspects of life on earth and mandate urgent management actions. Education and public awareness are strongly recommended for successful prevention and management of invasive alien species (IAS). This work presents a study on knowledge and perception of the educational community of Argentina about native species and IAS. We designed an on-line semi-structured questionnaire to examine perception of the environment, recognition of native species and IAS and awareness about biological invasions. Educators recognised an important number of biotic components, mostly represented by trees, birds and mammals. Recognition of native species and IAS, and awareness of biological invasions were different between NST (Natural Science Teachers) and non-NST. Respondents had different performances when they were exposed to recognising native species though written names or photographs. Out of 532 respondents, 56% knew what biological invasions are, 21% answered “Maybe” and 23% had never heard about them. We need to foster capacity-building and encourage a two-way communication between educators and scientists, formally and informally, to engage the participation of the whole society in recognition, prevention and management of IAS.
Adaptive auditory brightness perception
Authors: Siedenburg Kai , Barg Feline Malin , Schepker Henning 
Published: November 2021

AbstractPerception adapts to the properties of prior stimulation, as illustrated by phenomena such as visual color constancy or speech context effects. In the auditory domain, only little is known about adaptive processes when it comes to the attribute of auditory brightness. Here, we report an experiment that tests whether listeners adapt to spectral colorations imposed on naturalistic music and speech excerpts. Our results indicate consistent contrastive adaptation of auditory brightness judgments on a trial-by-trial basis. The pattern of results suggests that these effects tend to grow with an increase in the duration of the adaptor context but level off after around 8 trials of 2 s duration. A simple model of the response criterion yields a correlation of r = .97 with the measured data and corroborates the notion that brightness perception adapts on timescales that fall in the range of auditory short-term memory. Effects turn out to be similar for spectral filtering based on linear spectral filter slopes and filtering based on a measured transfer function from a commercially available hearing device. Overall, our findings demonstrate the adaptivity of auditory brightness perception under realistic acoustical conditions.