cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
Statistical Methods for Evaluating Exposure-Health Relationships
Creators: name: Orak, Nur H.
Publisher: name: Figshare
Year: 2018
Subjects: subject: 90799 Environmental Engineering not elsewhere classified
subject: FOS: Environmental engineering
subject: 90599 Civil Engineering not elsewhere classified
subject: FOS: Civil engineering

description: Conventional experimental techniques are sometimes limited in their ability to assess the actual risk of chemical exposures. Therefore, there is a rising awareness of mathematical, computational, and statistical approaches to provide insight into the adverse effects of environmental contaminants. Richard Bach once wrote: “Any powerful idea is absolutely fascinating and absolutely useless until we choose to use it.” Likewise, any data may be viewed as absolutely fascinating and absolutely useless until we choose to understand and use it. Recent advances in science and technology provide alternative paths to develop effective risk-assessment methods for environmental contaminants. Moreover, these methods are more efficient in terms of time and cost. Therefore, I develop three Chapters to show the importance of statistical methods in environmental-health risk assessment, and highlight the potency of data-driven knowledge and multidisciplinary research for the future of environmental science and engineering. In Chapter 1, I review the potential risks of missing chemical data and concentration variability on mixture toxicity by developing 27 occurrence scenarios based on data from the literature. The @RISK software simulates random concentrations, assuming multivariate lognormal distributions for the mixture components. In Chapter 2, I demonstrate how a performance analysis can be implemented for a Bayesian Network (BN) representation of a dose-response relationship. I explore the effect of different sample sizes on predicting the strength of the relationship between true responses and true doses of environmental toxicants. In Chapter 3, I characterize the risk factors of a prenatal arsenic exposure network by using Bayesian Network (BN) modeling as a tool for health risk assessment.
THE HYDROGENATION OF ALKENES ENABLED BY ORGANIC PHOTOREDOX CATALYSIS
Creators: name: Toll, Katharine Billings
Publisher: name: The University of North Carolina at Chapel Hill University Libraries
Year: 2021

description: The hydrogenation of alkenes is a prolific reaction in pharmaceutical synthesis and agrochemistry. Despite the broad range of techniques available for this transformation, an ongoing need exists for the development of new methodology under mild conditions that avoids the use of rare-earth metals. Organic photoredox catalysis presents an innovative solution to this problem by enabling new modes of reactivity without utilizing transition metals. In this work, the potent excited state oxidation potential of di-tert-butyl-mesityl acridinium under 390 nm light is leveraged to reduce alkenes to anion radicals. Herein we report work toward reaction optimization and a preliminary substrate scope for organic photoredox-catalyzed alkene hydrogenation. This system hydrogenates electronically-diverse styrenal olefins as well as unsaturated carbonyls in moderate to excellent yields, a significant expansion in scope relative to other photoredox catalytic systems for this transformation.
Storage Physics and Noise Mechanism in Heat-Assisted Magnetic Recording
Creators: name: Li, Hai
Publisher: name: Figshare
Year: 2018
Subjects: subject: Computer Engineering
subject: 90699 Electrical and Electronic Engineering not elsewhere classified
subject: FOS: Electrical engineering, electronic engineering, information engineering

description: As cloud computing and massive-data machine learning are applied pervasively, ultra-high volume data storage serves as the foundation block. Every day, nearly 2.5 quintillion bytes (50000 GB/second in 2018) of data is created and stored. Hard Disk Drive (HDD) takes major part of this heavy duty. However, despite the amazing evolution of HDD technology during the past 50 years, the conventional Perpendicular Magnetic Recording (PMR), the state-of-the-art HDD technique, starts to have less momentum in increasing storage density because of the recording trilemma. To overcome this, Heat-Assisted Magnetic Recording (HAMR) was initially proposed in 1990s. With years of advancement, recent industrial demos have shown the potential of HAMR to actually break the theoretical limit of PMR. However, to fully take advantage of HAMR and realize the commercialization, there are still quite a few technical challenges, which motivated this thesis work. Via thermal coupled micromagnetic simulation based upon Landau-Lifshitz-Bloch (LLB) equation, the entire dynamic recording process has been studied systematically. The very fundamental recording physics theorem is established, which manages to elegantly interpret the previously conflicting experimental observations. The thermal induced field dependence of performance, due to incomplete switching and erase-after-write, is proposed for the first time and validated in industrial lab. The combinational effects form the ultimate physical limit of this technology. Meanwhile, this theorem predicts the novel noise origins, examples being Curie temperature distribution and temperature distribution, which are the key properties but ignored previously. To enhance performance, utilizations of higher thermal gradient, magnetically stiffer medium, optimal field etc. have been suggested based upon the theorem. Furthermore, a novel concept, Recording Time Window (RTW), has been proposed. It tightly correlates with performance and serves as a unified optimization standard, summarizing almost all primary parameters. After being validated via spin stand testing, the theorem has been applied to provide solutions for guiding medium design and relaxing the field and heating requirement. This helps solve the issues around writer limit and thermal reliability. Additionally, crosstrack varying field has been proposed to solve the well-known transition curvature issue, which may increase the storage density by 50%.
Ultraviolet Nanophotonics Enables Autofluorescence Correlation Spectroscopy on Label-Free Proteins With a Single Tryptophan
Creators: name: Roy, Prithu
name: Claude, Jean-Benoît
name: Tiwari, Sunny
name: Barulin, Aleksandr
name: Wenger, Jérôme
Publisher: name: arXiv
Year: 2023
Subjects: subject: Optics (physics.optics)
subject: Biological Physics (physics.bio-ph)
subject: Chemical Physics (physics.chem-ph)
subject: FOS: Physical sciences

description: Using the ultraviolet autofluorescence of tryptophan aminoacids offers fascinating perspectives to study single proteins without the drawbacks of fluorescence labelling. However, the low autofluorescence signals have so far limited the UV detection to large proteins containing several tens of tryptophan residues. This limit is not compatible with the vast majority of proteins which contain only a few tryptophans. Here we push the sensitivity of label-free ultraviolet fluorescence correlation spectroscopy (UV-FCS) down to the single tryptophan level. Our results show how the combination of nanophotonic plasmonic antennas, antioxidants and background reduction techniques can improve the signal-to-background ratio by over an order of magnitude and enable UV-FCS on thermonuclease proteins with a single tryptophan residue. This sensitivity breakthrough unlocks the applicability of UV-FCS technique to a broad library of label-free proteins.
PATTERN SEPARATION IN CHILDREN AND ADOLESCENTS AT RISK FOR SCHIZOPHRENIA
Creators: name: İmamoğlu, Aslıhan
Publisher: name: The University of North Carolina at Chapel Hill University Libraries
Year: 2022

description: Episodic memory relies critically on the ability to recognize and subsequently organize perceptually similar inputs into distinct, non-overlapping representations, a process termed pattern separation. Prior research has shown that pattern separation arises from the dentate gyrus (DG), a subregion of the hippocampal formation. DG is structurally altered in individuals with schizophrenia who also show related impairments in episodic memory and pattern separation. The current study examined the status of behavioral pattern separation (i.e., mnemonic discrimination) in children and adolescents at high or low familial risk for schizophrenia by utilizing the Mnemonic Similarity Task (MST). High-risk participants demonstrated worse mnemonic discrimination and recognition memory than low-risk (i.e., control) participants. Perceptual discrimination was comparable across both groups. Neither perceptual discrimination nor recognition memory mediated the relationship between risk group and mnemonic discrimination. These results suggest that behavioral pattern separation deficits observed in schizophrenia patients are also present in their high-risk, first-degree relatives.
Statistical behavior of adaptive multilevel splitting algorithms in simple models
Creators: name: Rolland, Joran
name: Simonnet, Eric
Publisher: name: arXiv
Year: 2014
Subjects: subject: Numerical Analysis (math.NA)
subject: Statistical Mechanics (cond-mat.stat-mech)
subject: Computational Physics (physics.comp-ph)
subject: FOS: Mathematics
subject: FOS: Physical sciences

description: Adaptive multilevel splitting algorithms have been introduced rather recently for estimating tail distributions in a fast and efficient way. In particular, they can be used for computing the so-called reactive trajectories corresponding to direct transitions from one metastable state to another. The algorithm is based on successive selection-mutation steps performed on the system in a controlled way. It has two intrinsic parameters, the number of particles/trajectories and the reaction coordinate used for discriminating good or bad trajectories. We investigate first the convergence in law of the algorithm as a function of the timestep for several simple stochastic models. Second, we consider the average duration of reactive trajectories for which no theoretical predictions exist. The most important aspect of this work concerns some systems with two degrees of freedom. They are studied in details as a function of the reaction coordinate in the asymptotic regime where the number of trajectories goes to infinity. We show that during phase transitions, the statistics of the algorithm deviate significatively from known theoretical results when using non-optimal reaction coordinates. In this case, the variance of the algorithm is peaking at the transition and the convergence of the algorithm can be much slower than the usual expected central limit behavior. The duration of trajectories is affected as well. Moreover, reactive trajectories do not correspond to the most probable ones. Such behavior disappears when using the optimal reaction coordinate called committor as predicted by the theory. We finally investigate a three-state Markov chain which reproduces this phenomenon and show logarithmic convergence of the trajectory durations.
description: 23 pages, 11 figures, accepted for publication in the Journal of Computational physics. A sign typo has been corrected in formula 11, at the bottom of page 6
Intra-Unit-Cell magnetic correlations near optimal doping in $\rm YBa_2Cu_3O_{6.85}$
Creators: name: Mangin-Thro, L.
name: Sidis, Y.
name: Wildes, A.
name: Bourges, P.
Publisher: name: arXiv
Year: 2015
Subjects: subject: Superconductivity (cond-mat.supr-con)
subject: FOS: Physical sciences

description: Understanding high-temperature superconductivity requires a prior knowledge of the nature of the enigmatic pseudogap metallic state, out of which the superconducting state condenses. In addition to the electronic orders involving charge degrees of freedoms recently reported inside the pseudogap state, a magnetic intra-unit-cell (IUC) order was discovered in various cuprates to set in just at the pseudogap temperature, T*. In nearly optimally doped YBa$_2$Cu$_3$O$_{6.85}$, polarized neutron scattering measurements, carried out on two different spectrometers, reveal new features. The order is made of finite size planar domains, hardly correlated along the c-axis. At high temperature, only the out-of-plane magnetic components correlate, revealing a strong Ising anistropy, as originally predicted in the loop current model. Below T*, a correlated in-plane response develops, giving rise the apparent tilt of the magnetic moment at low temperature. The discovery of these two regimes put stringent constraints on the intrinsict nature of IUC order, tightly bound to the pseudogap physics.
description: 3 figures + supplementary information
The supernova remnant SN 1006 as a Galactic particle accelerator
Creators: name: Giuffrida, Roberta
name: Miceli, Marco
name: Caprioli, Damiano
name: Decourchelle, Anne
name: Vink, Jacco
name: Orlando, Salvatore
name: Bocchino, Fabrizio
name: Greco, Emanuele
name: Peres, Giovanni
Publisher: name: arXiv
Year: 2022
Subjects: subject: High Energy Astrophysical Phenomena (astro-ph.HE)
subject: FOS: Physical sciences

description: The origin of cosmic rays is a pivotal open issue of high-energy astrophysics. Supernova remnants are strong candidates to be the Galactic factory of cosmic rays, their blast waves being powerful particle accelerators. However, supernova remnants can power the observed flux of cosmic rays only if they transfer a significant fraction of their kinetic energy to the accelerated particles, but conclusive evidence for such efficient acceleration is still lacking. In this scenario, the shock energy channeled to cosmic rays should induce a higher post-shock density than that predicted by standard shock conditions. Here we show this effect, and probe its dependence on the orientation of the ambient magnetic field, by analyzing deep X-ray observations of the Galactic remnant of SN 1006. By comparing our results with state-of-the-art models, we conclude that SN 1006 is an efficient source of cosmic rays and obtain an observational support for the quasi-parallel acceleration mechanism.
description: Published in Nature Communications. The published version of the paper, including supplementary material, is freely available online here https://doi.org/10.1038/s41467-022-32781-4 or as a PDF here https://www.nature.com/articles/s41467-022-32781-4.pdf
Structural Analysis of Large Networks: Observations and Applications
Creators: name: McGlohon, Mary
Publisher: name: Figshare
Year: 2018
Subjects: subject: 170203 Knowledge Representation and Machine Learning
subject: FOS: Psychology

description: Network data (also referred to as relational data, social network data, real graph
data) has become ubiquitous, and understanding patterns in this data has become an
important research problem. We investigate how interactions in social networks are
formed and how these interactions facilitate diffusion, model these behaviors, and
apply these findings to real-world problems.

We examined graphs of size up to 16 million nodes, across many domains from
academic citation networks, to campaign contributions and actor-movie networks.
We also performed several case studies in online social networks such as blogs and
message board communities.

Our major contributions are the following: (a) We discover several surprising
patterns in network topology and interactions, such as Popularity Decay power law
(in-links to a blog post decay with a power law with -1:5 exponent) and the oscillating
size of connected components; (b) We propose generators such as the Butterfly
generator that reproduce both established and new properties found in real networks;
(c) several case studies, including a proposed method of detecting misstatements in
accounting data, where using network effects gave a significant boost in detection
accuracy.
Anisotropic satellite accretion onto the Local Group with HESTIA
Creators: name: Dupuy, Alexandra
name: Libeskind, Noam I.
name: Hoffman, Yehuda
name: Courtois, Hélène M.
name: Gottlöber, Stefan
name: Grand, Robert J. J.
name: Knebe, Alexander
name: Sorce, Jenny G.
name: Tempel, Elmo
name: Tully, R. Brent
name: Vogelsberger, Mark
name: Wang, Peng
Publisher: name: arXiv
Year: 2022
Subjects: subject: Astrophysics of Galaxies (astro-ph.GA)
subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: FOS: Physical sciences

description: How the cosmic web feeds halos, and fuels galaxy formation is an open question with wide implications. This study explores the mass assembly in the Local Group within the context of the local cosmography by employing simulations whose initial conditions have been constrained to reproduce the local environment. The goal of this study is to inspect whether the direction of accretion of satellites on to the Milky Way and Andromeda galaxies, is related to the cosmic web. The analysis considers the three high-resolution simulations available in the HESTIA simulation suite, as well as the derived velocity shear and tidal tensors. We notice two eras in the Local Group accretion history, delimited by an epoch around $z \approx 0.7$. We also find that satellites can travel up to $\sim 4$ Mpc, relative to their parent halo before crossing its viral radius $R_{200}$. Finally, we observe a strong alignment of the infall direction with the axis of slowest collapse $\vec{e_3}$ of both tidal and shear tensors, implying satellites of the Local Group originated from one particular region of the cosmic web and were channeled towards us via the process of accretion.This alignment is dominated by the satellites that enter during the early infall era, i.e $z>0.7$.
description: 10 pages, 11 figures, accepted for publication in MNRAS
Additional file 1 of Contaminants from dredged sediments alter the transcriptome of Manila clam and induce shifts in microbiota composition
Creators: name: Bernardini, Ilaria
name: Quagliariello, Andrea
name: Peruzza, Luca
name: Martino, Maria Elena
name: Dalla Rovere, Giulia
name: Iori, Silvia
name: Asnicar, Davide
name: Ciscato, Maria
name: Fabrello, Jacopo
name: Corami, Fabiana
name: Cecchetto, Martina
name: Giubilato, Elisa
name: Carrer, Claudio
name: Bettiol, Cinzia
name: Semenzin, Elena
name: Marcomini, Antonio
name: Matozzo, Valerio
name: Bargelloni, Luca
name: Milan, Massimo
name: Patarnello, Tomaso
Publisher: name: figshare
Year: 2024
Subjects: subject: Ecology
subject: FOS: Biological sciences

description: Additional file 1: Table S1. Organic matter content and grain-size distribution in sediments collected from the six sampling sites (one replicate for each site). Table S2. Chemical analyses of metals and organic contaminants in sediments (one replicate for each site). Table S3. Bioaccumulation of metals (mg/kg dw; Table A) and organic pollutants (Table B) in clams before exposure (T0) and at the end of sediment exposure (Day 14) (one replicate for each site). Table S4. Pairwise Adonis values on Unweighted and Weighted Unifrac distances at different time-points (Table A) and among different sites for each time-point (Table B). Data collected from a total of 10 biological replicates for each site/sampling time were considered. Figure S1. Pearson’s correlation between the coordinates along the first component of variation of the sediment’s PCA and of the gene expression’s PCA. Figure S2. Principal Coordinate Analysis (PcoA) plot using Unweighted and Weighted UniFrac dissimilarities (ASV level) of the digestive gland and sediment microbiota. Data collected from a total of 10 biological replicates for each site/sampling time were considered. Figure S3. DESeq2 results by collection date. Data collected from a total of 10 biological replicates for each site/sampling time were considered. Figure S4. Alpha diversity in Manila clam microbiota and sediments. Figure S5. Barplot representing the number of unique ASVs for each bacteria Phylum in group I and group II, A and B respectively. Figure S6. Changes in relative abundance of the significant ASVs for the two groups and for every site considered: Site I (A); Site II (B,C); Site III (D,E); Site IV (F,G); Site V (H,I); Site VI (L,M). Green and Red lines identify ASVs belonging to group I and II, respectively.
Multiple flares caused by mass ejection episodes during the advanced nebular phase of Nova Scuti 2019
Creators: name: Munari, U.
name: Righetti, G. L.
name: Dallaporta, S.
Publisher: name: arXiv
Year: 2022
Subjects: subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: High Energy Astrophysical Phenomena (astro-ph.HE)
subject: FOS: Physical sciences

description: Our photometric and spectroscopic monitoring shows that starting with 2020 June 4, day +217 from optical maximum and well into its advanced nebular stage, Nova Sct 2019 began displaying a series of nine large amplitude flares (up to Delta(m)~1.7 mag), characterized by a rapid rise to peak (=<10 hours) and a fast exponential decline (e-folding time =<50 hours). The time interval Delta(t) between flares follows an ordered sequence, declining from 8.43 to 4.90 days, that safely allows to exclude that any other flare occured without being recorded by the observations. When the sequence of flares was over by 2020 July 28 (day +271), Nova Sct 2019 slowed its overall decline rate from Delta(m)=0.0067 mag/day to 0.0027 mag/day. The flares were caused by material expelled at high velocity (~1000 km/s) from the still burning WD. The cooler pseudo-photosphere forming at each flare in the expelled material, resulted in a recombination wave to spread through the original nova ejecta (at ~170 AU from the WD), quenching emission from [FeX] and [FeVII] and boosting that from lower ionization species. After each flare, once the small amount of expelled material had turned optically thin, the original nova ejecta resumed displaying [FeX] and [FeVII] emission lines, a fact that clearly proves the direct photo-ionization action exerted on the ejecta by the burning WD. While the other known flaring novae (V458 Vul, V4745 Sgr, and V5588 Sgr) presented the flares close to maximum brightness and with increasing Delta(t), Nova Sct 2019 is unique in having displayed them during the advanced nebular stage and with decreasing Delta(t).
description: Accepted for publication in MNRAS
Attosecond streaking of photoelectrons emitted from metal surfaces
Creators: name: Obreshkov, Boyan
Publisher: name: arXiv
Year: 2014
Subjects: subject: Quantum Physics (quant-ph)
subject: Atomic Physics (physics.atom-ph)
subject: FOS: Physical sciences

description: We numerically investigate attosecond streaking time delays in the photoemission of valence and 2p core electrons of aluminum surface. We find that electron emission from the core level band is delayed by $Δτ=100$ attoseconds relative to the release of electrons from the valence band. We show that this relative time offset in electron emission is caused by the screening of the streaking laser field by conduction electrons.
description: Contribution to IWNT-33, Proceedings of the 33rd Internatioanl Workshop on Nuclear Theory, 22-28 June 2014, Rila Mountains, Bulgaria
Neural correlates of RDoC-specific cognitive processes in a high-functional autistic patient: a statistically validated case report
Creators: name: Daedelow, Laura Stefanie
name: Beck, Anne
name: Romund, Lydia
name: Mascarell Maricic, Lea
name: Dziobek, Isabel
name: Romanczuk-Seiferth, Nina
name: Wüstenberg, Torsten
name: Heinz, Andreas
Publisher: name: Humboldt-Universität zu Berlin
Year: 2021
Subjects: subject: Autism spectrum disorder
subject: Research Domain Criteria
subject: Emotion processing
subject: Reward processing
subject: Working memory
subject: Neuroimaging
subject: 150 Psychologie

description: The level of functioning of individuals with autism spectrum disorder (ASD) varies widely. To better understand the neurobiological mechanism associated with high-functioning ASD, we studied the rare case of a female patient with an exceptional professional career in the highly competitive academic field of Mathematics. According to the Research Domain Criteria (RDoC) approach, which proposes to describe the basic dimensions of functioning by integrating different levels of information, we conducted four fMRI experiments targeting the (1) social processes domain (Theory of mind (ToM) and face matching), (2) positive valence domain (reward processing), and (3) cognitive domain (N-back). Patient’s data were compared to data of 14 healthy controls (HC). Additionally, we assessed the subjective experience of our case during the experiments. The patient showed increased response times during face matching and achieved a higher total gain in the Reward task, whereas her performance in N-back and ToM was similar to HC. Her brain function differed mainly in the positive valence and cognitive domains. During reward processing, she showed reduced activity in a left-hemispheric frontal network and cortical midline structures but increased connectivity within this network. During the working memory task patients’ brain activity and connectivity in left-hemispheric temporo-frontal regions were elevated. In the ToM task, activity in posterior cingulate cortex and temporo-parietal junction was reduced. We suggest that the high level of functioning in our patient is rather related to the effects in brain connectivity than to local cortical information processing and that subjective report provides a fruitful framework for interpretation.
Intracluster light is already abundant at redshift beyond unity
Creators: name: Joo, Hyungjin
name: Jee, Myungkook James
Publisher: name: arXiv
Year: 2023
Subjects: subject: Astrophysics of Galaxies (astro-ph.GA)
subject: FOS: Physical sciences

description: Intracluster light (ICL) is diffuse light from stars that are gravitationally bound not to individual member galaxies, but to the halo of galaxy clusters. Leading theories predict that the ICL fraction, defined by the ratio of the ICL to the total light, rapidly decreases with increasing redshift, to the level of a few per cent at z > 1. However, observational studies have remained inconclusive about the fraction beyond redshift unity because, to date, only two clusters in this redshift regime have been investigated. One shows a much lower fraction than the mean value at low redshift, whereas the other possesses a fraction similar to the low-redshift value. Here we report an ICL study of ten galaxy clusters at 1 \lesssim z \lesssim 2 based on deep infrared imaging data. Contrary to the leading theories, our study finds that ICL is already abundant at z \lesssim 1, with a mean ICL fraction of approximately 17\%. Moreover, no significant correlation between cluster mass and ICL fraction or between ICL color and cluster-centric radius is observed. Our findings suggest that gradual stripping can no longer be the dominant mechanism of ICL formation. Instead, our study supports the scenario wherein the dominant ICL production occurs in tandem with the formation and growth of the brightest cluster galaxies and/or through the accretion of preprocessed stray stars.
description: 27 pages, 9 figures, 3 tables, accepted to Nature
Boosting terahertz generation in laser-field ionized gases using a sawtooth wave shape
Creators: name: Martínez, P. González de Alaiza
name: Babushkin, I.
name: Bergé, L.
name: Skupin, S.
name: Cabrera-Granado, E.
name: Köhler, C.
name: Morgner, U.
name: Husakou, A.
name: Herrmann, J.
Publisher: name: arXiv
Year: 2014
Subjects: subject: Optics (physics.optics)
subject: Plasma Physics (physics.plasm-ph)
subject: FOS: Physical sciences

description: Broadband ultrashort terahertz (THz) pulses can be produced using plasma generation in a noble gas ionized by femtosecond two-color pulses. Here we demonstrate that, by using multiple-frequency laser pulses, one can obtain a waveform which optimizes the free electron trajectories in such a way that they reach the highest velocity at the electric field extrema. This allows to increase the THz conversion efficiency to the percent level, an unprecedented performance for THz generation in gases. Besides the analytical study of THz generation using a local current model, we perform comprehensive 3D simulations accounting for propagation effects which confirm this prediction. Our results show that THz conversion via tunnel ionization can be greatly improved with well-designed multicolor pulses.
Subdimensional Expansion: A Framework for Computationally Tractable Multirobot Path Planning
Creators: name: Wagner, Glenn
Publisher: name: Figshare
Year: 2018
Subjects: subject: 80101 Adaptive Agents and Intelligent Robotics
subject: FOS: Computer and information sciences

description: Planning optimal paths for large numbers of robots is computationally expensive. In this thesis, we present a new framework for multirobot path planning called subdimensional expansion, which initially plans for each robot individually, and then coordinates motion among the robots as needed. More specifically subdimensional expansion initially creates a one-dimensional search space embedded in the joint configuration space of the multirobot system. When the search space is found to be blocked during planning by a robot-robot collision, the dimensionality of the search space is locally increased to ensure that an alternative path can be found. As a result, robots are only coordinated when necessary, which reduces the computational cost of finding a path. Subdimensional expansion is a exible framework that can be used with multiple planning algorithms. For discrete planning problems, subdimensional expansion can be combined with A* to produce the M* algorithm, a complete and optimal multirobot path planning problem. When the configuration space of individual robots is too large to be explored effectively with A*, subdimensional expansion can be combined with probabilistic planning algorithms to produce sRRT and sPRM. M* is then extended to solve variants of the multirobot path planning algorithm. We present the Constraint Manifold Subsearch (CMS) algorithm to solve problems where robots must dynamically form and dissolve teams with other robots to perform cooperative tasks. Uncertainty M* (UM*) is a variant of M* that handles systems with probabilistic dynamics. Finally, we apply M* to multirobot sequential composition. Results are validated with extensive simulations and experiments on multiple physical robots.
Robust Control for Dynamical Systems With Non-Gaussian Noise via Formal Abstractions
Creators: name: Badings, Thom
name: Romao, Licio
name: Abate, Alessandro
name: Parker, David
name: Poonawala, Hasan A.
name: Stoelinga, Marielle
name: Jansen, Nils
Publisher: name: arXiv
Year: 2023
Subjects: subject: Systems and Control (eess.SY)
subject: Artificial Intelligence (cs.AI)
subject: FOS: Electrical engineering, electronic engineering, information engineering
subject: FOS: Computer and information sciences

description: Controllers for dynamical systems that operate in safety-critical settings must account for stochastic disturbances. Such disturbances are often modeled as process noise in a dynamical system, and common assumptions are that the underlying distributions are known and/or Gaussian. In practice, however, these assumptions may be unrealistic and can lead to poor approximations of the true noise distribution. We present a novel controller synthesis method that does not rely on any explicit representation of the noise distributions. In particular, we address the problem of computing a controller that provides probabilistic guarantees on safely reaching a target, while also avoiding unsafe regions of the state space. First, we abstract the continuous control system into a finite-state model that captures noise by probabilistic transitions between discrete states. As a key contribution, we adapt tools from the scenario approach to compute probably approximately correct (PAC) bounds on these transition probabilities, based on a finite number of samples of the noise. We capture these bounds in the transition probability intervals of a so-called interval Markov decision process (iMDP). This iMDP is, with a user-specified confidence probability, robust against uncertainty in the transition probabilities, and the tightness of the probability intervals can be controlled through the number of samples. We use state-of-the-art verification techniques to provide guarantees on the iMDP and compute a controller for which these guarantees carry over to the original control system. In addition, we develop a tailored computational scheme that reduces the complexity of the synthesis of these guarantees on the iMDP. Benchmarks on realistic control systems show the practical applicability of our method, even when the iMDP has hundreds of millions of transitions.
description: To appear in the Journal of Artificial Intelligence Research (JAIR). arXiv admin note: text overlap with arXiv:2110.12662
Super-enantiospecific Autocatalytic Decomposition of Tartaric Acid and Aspartic Acid on Cu Surfaces
Creators: name: Mhatre, Bharat Suresh
Publisher: name: Figshare
Year: 2018
Subjects: subject: 90499 Chemical Engineering not elsewhere classified
subject: FOS: Chemical engineering

description: Autocatalytic reaction mechanisms are observed in a range of important chemical processes including catalysis, radical-mediated explosions, and biosynthesis. Because of their complexity, the microscopic details of autocatalytic reaction mechanisms have been difficult to study on surfaces and heterogeneous catalysts. Autocatalytic decomposition reactions of tartaric acid (TA) enantiomers adsorbed on Cu(110) offer molecular-level insight into these processes, which until now, were largely a matter of speculation. The decomposition of TA/Cu(110) is initiated by a slow, irreversible process that forms vacancies in the adsorbed TA layer, followed by a vacancy-mediated, explosive decomposition process that yields CO2 and small hydrocarbon products. Initiation of the explosive decomposition of TA/Cu(110) was studied by measurement of the reaction kinetics, time-resolved low energy electron diffraction (LEED), and time-resolved scanning tunneling microscopy (STM). Initiation results in a decrease in the local coverage of TA and a concomitant increase in the areal vacancy concentration. Once the vacancy concentration reaches a critical value, the explosive, autocatalytic decomposition step dominates the subsequent TA decomposition rate.
Aspartic acid is an excellent probe molecule for investigating the surface chemistry of autocatalytic reactions . Because a wide range of isotopically labeled varieties of aspartic acid are commercially available, we have been able to conduct a detailed investigation of its autocatalytic reaction mechanism. Experimental data obtained for variable initial coverage, variable heating rate and isothermal TPRS experiments, while monitoring CO2 desorption is in excellent agreement with a rate law which explicitly accounts for an initiation step and an explosion step which is second order in vacancy concentration
Autocatalytic surface explosion mechanisms can be exploited to attain extremely high enantiospecificities in the case of TA decomposition on naturally chiral Cu(hkl)R&S surfaces. Interaction energies of chiral molecules with naturally chiral surfaces are small and typically lead to modest enantioselectivities. However, the highly non-linear kinetics of autocatalytic reaction mechanism amplifies these small differences to result in high enantiospecificities. The observed phenomenon has the characteristics of autocatalytic processes that have been postulated to lead to biomolecular homochirality in life on Earth; processes with relatively small differences in reaction energetics that, nonetheless, lead to extremely high enantioselectivity.
Dielectric relaxation induced by oxygen vacancies in Na$_{0.5}$Bi$_{0.5}$TiO$_{3}$ ceramics
Creators: name: Sidak, V. M.
name: Trubitsyn, M. P.
name: Panchenko, T. V.
Publisher: name: arXiv
Year: 2023
Subjects: subject: Materials Science (cond-mat.mtrl-sci)
subject: FOS: Physical sciences

description: Dielectric permittivity was studied in ceramics of relaxor ferroelectric bismuth-sodium titanate Na$_{0.5}$Bi$_{0.5}$TiO$_{3}$. The measurements were performed on as sintered and heat treated in vacuum samples. The diffuse dielectric anomalies associated with the structural phase transitions were observed in as sintered samples. The intense peak of permittivity ($ \varepsilon_{\text{max}} \sim 10^{4}$) appeared after heat treating in vacuum. The anomaly of $\varepsilon(T)$ was contributed by slow polarization processes ($f<10$ kHz) and was non-stable, vanishing on heating in air up to $\sim 800$ K. Temperature and frequency dependencies of $\varepsilon$ were described by using Cole-Cole model with accounting thermally stimulated decay of the non-stable polarization. It is supposed that the dielectric anomaly is determined by space charge polarization mechanism. Oxygen vacancies V$_{\rm{O}}^{\bullet \bullet}$ and electrons localized on titanium ions Ti$'_{\rm{Ti}}$ are assumed to be responsible for the phenomenon observed.
description: 10 pages, 6 figures, 1 table
Ukaliq: Seeing Long-Term with Small, Precise Arctic Telescopes
Creators: name: Steinbring, Eric
name: Leckie, Brian
name: Murowinski, Rick
Publisher: name: arXiv
Year: 2014
Subjects: subject: Instrumentation and Methods for Astrophysics (astro-ph.IM)
subject: FOS: Physical sciences

description: Time-domain astrophysics benefits from extreme-latitude sites, which can combine intrinsically extended nighttime with good sky conditions. One such location is the Polar Environment Atmospheric Research Laboratory (PEARL), at 80 degrees North latitude, on the northwestern edge of Ellesmere Island, Canada. Experience gained deploying seeing monitors there has been incorporated into an automated system called "Ukaliq" after the common arctic hare, which is also very well suited to its local environment. Even with modest aperture, high photometric reliability may be achieved using simple adaptive optics together with observing strategies that best fit the unique set of advantages available at PEARL: excellent image quality maintained during many clear, calm, dark periods of 100 hours or more. A potential multi-year search for gravitational microlensing of quasars with Ukaliq helps illustrate this niche in the era of large wide-field survey facilities.
description: 6 pages, to appear in IoPCS Conf. Series "Adapting to the Atmosphere"
Finite frequency noise for Laughlin state investigated by a resonant circuit
Creators: name: Carrega, M.
name: Ferraro, D.
name: Braggio, A.
name: Sassetti, M.
Publisher: name: arXiv
Year: 2014
Subjects: subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: FOS: Physical sciences

description: We study the finite frequency (F.F.) noise properties of edge states in the Laughlin state. We investigate the model of a resonant detector coupled to a quantum point contact in the weak-backscattering limit. In particular we discuss the impact of possible renormalization of the Luttinger exponent, due to environmental effects, on the measured quantities and we propose a simple way to extract such non-universal parameters from noise measurements.
description: Proceeding of the conference LT27 (Buenos Aires)
Slow and fast relaxation times of quantum lattice model with local multi-well potentials: phenomenological dynamics for Sn$_{2}$P$_{2}$S$_{6}$ ferroelectric crystals
Creators: name: Erdem, R.
name: Özüm, S.
name: Güçlü, N.
Publisher: name: arXiv
Year: 2023
Subjects: subject: Statistical Mechanics (cond-mat.stat-mech)
subject: FOS: Physical sciences

description: As a continuation of the previously published work [Velychko O. V., Stasyuk I. V., Phase Transitions, 2019, 92, 420], a phenomenological framework for the relaxation dynamics of quantum lattice model with multi-well potentials is given in the case of deformed Sn$_{2}$P$_{2}$S$_{6}$ ferroelectric lattice. The framework is based on the combination of statistical equilibrium theory and irreversible thermodynamics. In order to study these dynamics in a connected way we assume that the dipole ordering or polarization ($η$) and volume deformation ($u$) can be treated as fluxes and forces in the sense of Onsager theory. From the linear relations between the forces and fluxes, the rate equations are derived and characterized by two relaxation times ($τ_{S}, τ_{F}$) which describe the irreversible process near the equilibrium states. The behaviors of $τ_{S}$ and $τ_{F}$ in the vicinity of ferroelectric phase transitions are studied.
description: 8 pages, 4 figures
Statistical Investigation of the Kinematic and Thermal Properties of Supra-arcade Downflows Observed During a Solar Flare
Creators: name: Tan, Guangyu
name: Hou, Yijun
name: Tian, Hui
Publisher: name: arXiv
Year: 2022
Subjects: subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: FOS: Physical sciences

description: Supra-arcade downflows (SADs) are dark structures descending towards post-reconnection flare loops observed in extreme ultraviolet or X-ray observations and are closely related to magnetic reconnection during solar flares. Due to the lack of statistical study on SADs in a single flare, evolutions of kinematic and thermal properties of SADs during the flare process still remain obscure. In this work, we identified 81 SADs in a flare that occurred on 2013 May 22 using observations of the Atmospheric Imaging Assembly (AIA) on the Solar Dynamics Observatory (SDO). The kinematic properties of each SAD, including the appearance time, height, projective velocity, and acceleration were recorded. We found that the appearance heights of SADs become larger during the flare, which is likely due to the lift of the bottom of the plasma sheet. In the flare decay phase, the region where SADs mainly appear moves from the north part to the south side possibly related to a secondary eruption in the south side. The trajectories of most SADs can be fitted by one or two deceleration processes, while some special ones have positive accelerations during the descent. For the thermal properties, we selected 54 SADs, whose front and body could be clearly distinguished from the surrounding during the entire descent, to perform Differential Emission Measure analysis. It is revealed that the temperatures of the SAD front and body tend to increase during their downward courses, and the relationship between the density and temperature indicates that the heating is mainly caused by adiabatic compression.
description: 11 pages, 6 figures, 1 table, 1 animation as supplementary material. Accepted for publication in MNRAS
Progress on a Miniature Cold-Atom Frequency Standard
Creators: name: Scherer, David R.
name: Lutwak, Robert
name: Mescher, Mark
name: Stoner, Richard
name: Timmons, Brian
name: Rogomentich, Fran
name: Tepolt, Gary
name: Mahnkopf, Sven
name: Noble, Jay
name: Chang, Sheng
name: Taylor, Dwayne
Publisher: name: arXiv
Year: 2014
Subjects: subject: Atomic Physics (physics.atom-ph)
subject: FOS: Physical sciences

description: Atomic clocks play a crucial role in timekeeping, communications, and navigation systems. Recent efforts enabled by heterogeneous MEMS integration have led to the commercial introduction of Chip-Scale Atomic Clocks (CSAC) with a volume of 16 cm3, power consumption of 120 mW, and instability (Allan Deviation) of σ(τ = 1 sec) < 2e-10. In order to reduce the temperature sensitivity of next-generation CSACs for timing applications, the interaction of atoms with the environment must be minimized, which can be accomplished in an architecture based on trapped, laser-cooled atoms. In this paper, we present results describing the development of a miniature cold-atom apparatus for operation as a frequency standard. Our architecture is based on laser-cooling a sample of neutral atoms in a Magneto-Optical Trap (MOT) using a conical retro-reflector in a miniature vacuum chamber. Trapping the atoms in vacuum and performing microwave interrogation in the dark reduces the temperature sensitivity compared to vapor-cell CSACs. We present details of the component development associated with the laser systems, opto-electronics, and vacuum package for miniature cold-atom technology. Finally, we conclude by characterizing the optimum alkali background pressure for such a cold-atom frequency standard.
description: 10 pages, 17 figures, to be published in the proceedings of ION PTTI 2014
Additional file 2 of Comprehensive in silico analysis of the underutilized crop tef (Eragrostis tef (Zucc.) Trotter) genome reveals drought tolerance signatures
Creators: name: Bekele-Alemu, Abreham
name: Ligaba-Osena, Ayalew
Publisher: name: figshare
Year: 2024
Subjects: subject: Genetics
subject: FOS: Biological sciences
subject: Plant Biology

description: Additional file 2: Supplementary Table 1. Lists of 505 ESTs mapped on teff and submitted to Blast2GO. Supplementary Table 2. Lists of 224 genes submitted to DAVID for GO analysis. Supplementary Table 3. Lists of 29 ESTs annotated using Blast2GO. Supplementary Table 4. 160 genes with Gene ontology term for molecular function. Supplementary Table 5. 130 genes with Gene ontology term for biological process. Supplementary Table 6. 87 Genes with known GO terms enriched in different biological processes using UP_KW_BIOLOGICAL_PROCESS. Supplementary Table 7. 102 Genes with known GO terms enriched in different molecular function using UP_KW_MOLECULAR_FUNCTION. Supplementary Table 8. UP_tissue report of gene expression analysis. Supportive Table 9. List of genes highly enrich in biological process using ShniyGO. Supplementary Table 10. Genes significantly enriched in different molecular Function using shinyGO and using Arabidopsis model. Supplementary Table 11. Cluster of genes using gene set enrichment score in several molecular function. Supplementary Table 12. Cluster of genes having critical function in several molecular function using Kappa score. Supplementary Table 13 A. Genes involved in several biological pathways using KEGG pathway enrichment analysis. Supplementary Table 13 B. Pathway analysis using KEGG with ShinyGO. Supplementary Table 14. Genes grouped by functional categories defined by high-level GO terms.
Lack of Participation by Black Male Student-Athletes in Academic and Life Skills Programming
Creators: name: Wilson, Camille Alexandra
Publisher: name: The University of North Carolina at Chapel Hill University Libraries
Year: 2022

description: ABSTRACTCamille Wilson: Lack of Participation by Black Student-Athletes in Academic and Life Skills Programming(Under the direction of Barbara Osborne)      This thesis investigated the obstacles that Black male football student-athletes face when attending academic, leadership, career, and life skills development programs. Using a survey and semi-structured interviews, this study provides qualitative data about these student-athletes’ experiences which will be helpful for athletics administrators when designing programming to attract this specific demographic. The research suggests that Black male student-athletes continue to struggle with grades in the classroom as well as life after sport, especially football. Coaches, teammates, and family continue to make-up these student-athletes support systems. Having people on staff that look like this demographic of student-athletes and are willing to educate and support them may be the start to navigating how to get these young men involved with programming.