cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
Experiments using sub-wavelength diameter tapered optical fibers in Rubidium vapor
Creators: name: Lai, Meimei
Publisher: name: Maryland Shared Open Access Repository
Year: 2013
Subjects: fiber
nonlinear optics
optical
rubidium
tapered
ultra low power

description: In this work, we describe experimental research on a relatively new nonlinear optics system comprised of a sub-wavelength diameter Tapered Optical Fiber (TOF) suspended in atomic Rubidium (Rb) vapor. The compression of the evanescent optical mode propagating along the TOF enables a dramatic increase in the nonlinear interactions between the fields and the surrounding Rb atoms, thereby allowing the observation of a variety of nonlinear optical effects with very low-power fields. Specifically, we report on the observation of saturated absorption with nW power levels and, more significantly, the observation of two-photon absorption using power-levels corresponding to only 10's to 100's of photons interacting with the Rb atoms at a given time.  One significant drawback to this TOF in Rb system is that at the relatively high atomic densities needed for many of these experiments, Rb atoms accumulating on the TOF surface can cause a significant loss of overall transmission through the fiber. Here we report direct measurements of the time-scale associated with this transmission degradation for various Rb density conditions. We find that transmission is affected almost immediately after the introduction of Rb vapor into the system, and declines rapidly as the density is increased. More significantly, we show how a heating element designed to raise the TOF temperature can be used to reduce this transmission loss and dramatically extend the effective TOF transmission lifetime. Our results indicate that it is possible to achieve relatively high TOF transmission, even in the presence of the relatively high Rb vapor densities that would be needed for many low-power nonlinear optics applications. This study represents a significant step in moving the basic TOF in Rb system from a laboratory setting towards a practical ultra-low-power nonlinear optics device.
Genuine tripartite entanglement monotone of $(2\otimes 2\otimes n)-$ dimensional systems
Creators: name: Yu, Chang-shui
name: Zhou, L.
name: Song, He-shan
Publisher: name: arXiv
Year: 2008
Subjects: subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: A genuine tripartite entanglement monotone is presented for $(2\otimes 2\otimes n)$-dimensional tripartite pure states by introducing a new entanglement measure for bipartite pure states. As an application, we consider the genuine tripartite entanglement of the ground state of the exactly solvable isotropic spin-1/2 chain with three-spin interaction. It is shown that the singular behavior of the genuine tripartite entanglement exactly signals a quantum phase transition.
description: 5 pages
Effects of the quark field on the ghost propagator of Lattice Landau Gauge QCD
Creators: name: Furui, Sadataka
name: Nakajima, Hideo
Publisher: name: arXiv
Year: 2006
Subjects: subject: High Energy Physics - Lattice (hep-lat)
subject: FOS: Physical sciences

description: Infrared features of the ghost propagator of color diagonal and color antisymmetric ghost propagator of quenched SU(2) and quenched SU(3) are compared with those of unquenched Kogut-Susskind fermion SU(3) lattice Landau gauge. We compare 1) the fluctuation of the ghost propagator, 2) the ghost condensate parameter $v$ of the local composite operator (LCO) approach and 3) the Binder cumulant of color anti-symmetric ghost propagator between quenched and unquenched configurations.
description: 9 pages, 15 figures, typos corrected, published in Phys. Rev. D
On the equivalence of molecular graph convolution and molecular wave function with poor basis set
Creators: name: Tsubaki, Masashi
name: Mizoguchi, Teruyasu
Publisher: name: arXiv
Year: 2020
Subjects: subject: Machine Learning (cs.LG)
subject: Materials Science (cond-mat.mtrl-sci)
subject: Chemical Physics (physics.chem-ph)
subject: FOS: Computer and information sciences
subject: FOS: Physical sciences

description: In this study, we demonstrate that the linear combination of atomic orbitals (LCAO), an approximation of quantum physics introduced by Pauling and Lennard-Jones in the 1920s, corresponds to graph convolutional networks (GCNs) for molecules. However, GCNs involve unnecessary nonlinearity and deep architecture. We also verify that molecular GCNs are based on a poor basis function set compared with the standard one used in theoretical calculations or quantum chemical simulations. From these observations, we describe the quantum deep field (QDF), a machine learning (ML) model based on an underlying quantum physics, in particular the density functional theory (DFT). We believe that the QDF model can be easily understood because it can be regarded as a single linear layer GCN. Moreover, it uses two vanilla feedforward neural networks to learn an energy functional and a Hohenberg--Kohn map that have nonlinearities inherent in quantum physics and the DFT. For molecular energy prediction tasks, we demonstrated the viability of an ``extrapolation,'' in which we trained a QDF model with small molecules, tested it with large molecules, and achieved high extrapolation performance. This will lead to reliable and practical applications for discovering effective materials. The implementation is available at https://github.com/masashitsubaki/QuantumDeepField_molecule.
Nonlinear effects in spin relaxation of cavity polaritons
Creators: name: Solnyshkov, D. D.
name: Shelykh, I. A.
name: Glazov, M. M.
name: Malpuech, G.
name: Amand, T.
name: Renucci, P.
name: Marie, X.
name: Kavokin, A. V
Publisher: name: arXiv
Year: 2006
Subjects: subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: Other Condensed Matter (cond-mat.other)
subject: FOS: Physical sciences

description: We present the general kinetic formalism for the description of spin and energy relaxation of the cavity polaritons in the framework of the Born-Markov approximation. All essential mechanisms of polaritons redistribution in reciprocal space together with final state bosonic stimulation are taken into account, from our point of view. The developed theory is applied to describe our experimental results on the polarization dynamics obtained in the polariton parametric amplifier geometry (pumping at so-called magic angle). We have experimentally confirmed that the anisotropy of the polariton-polariton interaction is responsible for the build up of the cross-linear polarisation of the signal. The long-living linear polarization is observed at zero detuning. Under elliptical pumping, we have directly measured in the time domain and modelled the effect of self-induced Larmor precession.
description: 21 pages, 4 figures, accepted to Semiconductors
Small Bodies of the Solar System Active at Large Heliocentric Distances: Studies with the 6-Meter Telescope of Sao Ras
Creators: name: Ivanovaa, A. V.
Publisher: name: arXiv
Year: 2021
Subjects: subject: Earth and Planetary Astrophysics (astro-ph.EP)
subject: FOS: Physical sciences

description: A detailed study of comets active at large heliocentric distances (greater than 4 au) which enter the Solar System for the first time and are composed of matter in its elementary, unprocessed state, would help in our understanding of the history and evolution of the Solar System. In particular, contemporary giant planet formation models require the presence of accretion of volatile elements such as neon, argon, krypton, xenon and others, which initially could not survive at the distances where giant planets were formed. Nevertheless, the volatile components could be effectively delivered by the Kuiper-belt and Oort-cloud bodies, which were formed at temperatures below 30 K. This review is dedicated to the results of a multi-year comprehensive study of small bodies of the Solar System showing a comet-like activity at large heliocentric distances. The data were obtained from observations with the 6-meter telescope of SAO RAS equipped with multi-mode focal reducers SCORPIO and SCORPIO-2.
description: 19 pages, 17 figures
Zeno logic gates using micro-cavities
Creators: name: Franson, J. D.
name: Jacobs, B. C.
name: Pittman, T. B.
Publisher: name: arXiv
Year: 2006
Subjects: subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: The linear optics approach to quantum computing has several potential advantages but the logic operations are probabilistic. Here we review the use of the quantum Zeno effect to suppress the intrinsic failure events in these kinds of devices, which would produce deterministic logic operations without the need for ancilla photons or high-efficiency detectors. The potential advantages of implementing Zeno gates using micro-cavities and electromagnetically-induced transparency are discussed.
description: 22 pages, 8 figures
Elicitation on verbal agreement paradigms
Creators: name: Chilel Ramírez, Ovilia Marina
name: Scott, Tessa
name: Sales, Henry
Publisher: name: California Language Archive, University of California, Berkeley
Year: 2023
Subjects: subject: mam

description: This is a remote video interview held using Zoom. Henry Sales, a Mam speaker from San Juan Atitán, provides translation between English and Mam using Mam and Spanish.

The elicitation focuses on verbal agreement paradigms of intransitive verbs "arrive" and "work" as well as the verb "see" with different subject and object combinations.

In this file bundle: 1 Zoom video/audio recording, 1 pdf of typed notes.
A New Approach to Regular & Indeterminate Strings
Creators: name: Louza, Felipe A.
name: Mhaskar, Neerja
name: Smyth, W. F.
Publisher: name: arXiv
Year: 2020
Subjects: subject: Data Structures and Algorithms (cs.DS)
subject: FOS: Computer and information sciences

description: In this paper we propose a new, more appropriate definition of regular and indeterminate strings. A regular string is one that is "isomorphic" to a string whose entries all consist of a single letter, but which nevertheless may itself include entries containing multiple letters. A string that is not regular is said to be indeterminate. We begin by proposing a new model for the representation of strings, regular or indeterminate, then go on to describe a linear time algorithm to determine whether or not a string $x = x[1..n]$ is regular and, if so, to replace it by a lexicographically least (lex-least) string $y$ whose entries are all single letters. Furthermore, we connect the regularity of a string to the transitive closure problem on a graph, which in our special case can be efficiently solved. We then introduce the idea of a feasible palindrome array MP of a string, and prove that every feasible MP corresponds to some (regular or indeterminate) string. We describe an algorithm that constructs a string $x$ corresponding to given feasible MP, while ensuring that whenever possible $x$ is regular and if so, then lex-least. A final section outlines new research directions suggested by this changed perspective on regular and indeterminate strings.
description: Accepted to TCS
The "Mark-Making Book" : catalyst supporting parental involvement in Art Education in early childhood
Creators: name: Pisichko, Maria
Publisher: name: University of British Columbia
Year: 2009

description: Adult involvement in a young child's artistic learning as an area of study is only beginning to unfold. The intent of this thesis is to lend support to this trend of thought by exploring the "mark-making book" as a catalyst for parental involvement in art education in early childhood. Specifically , it is concerned with examining the role of the "mark-making book" as a link supporting a young child's artistic learning within the school and the home. The "mark-making book" is a sketchbook/scrapbook concept that allows for independent use on the part of the child and guided learning mediated by the parent. It is grounded in social constructivist theory, drawing upon the work of Soviet psychologist Lev Vygotsky and his perspectives on the value of adult interaction, tools, play, and the role of affect in motivation. The research addresses the following questions: 1. How do the parents use the "mark-making book" in the home environment? 2. What are the parental attitudes toward the "mark-making book" experience? 3. How do these attitudes evolve as a result of active engagement over a period of time? 4. What value do parents attribute to the ideas of active involvement in their child's artistic learning? Exploratory descriptive research in the form of multiple cross-case study analysis was used for the purposes of this investigation. The teacher as "investigator" conducted two sets of audio-taped interviews with eight participating parents, whose four year old children attended a nursery program at an inner-city school in Winnipeg. The data resulting from these interviews gives evidence of favourable parental support towards the "mark-making book" concept. Parents also indicated that as they participated in its use with their child, they reflected on their childhood memories and educational experiences, then drew comparisons with the learning experiences associated with school and home use of the mark-making book. Three themes emerged as the result of studying parental and child involvement with the mark-making book. Enjoyment, self-development and understanding are the essence of the mark-making book experience. The study was further supplemented with data collected from parent-teacher interviews at the start of the academic year, field notes collected during in-class use of the mark-making books, parent comment sheets, as well as informal conversations with parents in school hallways and during home visitation . Reflective journals and photo journals were used to document mark-making book activity within the school environment. The study concludes that the mark-making book serves as a manageable and effective means of addressing the needs of both parents and children in terms of their affective, cognitive and artistic learning. These favourable results should encourage further research into mark-making book use, both within the school and the home environments.
Equivalence of non-minimally coupled cosmologies by Noether symmetries
Creators: name: Bajardi, Francesco
name: Capozziello, Salvatore
Publisher: name: arXiv
Year: 2020
Subjects: subject: General Relativity and Quantum Cosmology (gr-qc)
subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: We discuss non-minimally coupled cosmologies involving different geometric invariants. Specifically, actions containing a non-minimally coupled scalar field to gravity described, in turn, by curvature, torsion and Gauss--Bonnet scalars are considered. We show that couplings, potentials and kinetic terms are determined by the existence of Noether symmetries which, moreover, allows to reduce and solve dynamics. The main finding of the paper is that different non-minimally coupled theories, presenting the same Noether symmetries, are dynamically equivalent. In other words, Noether symmetries are a selection criterion to compare different theories of gravity.
description: 16 pages. Accepted for publication in "International Journal of Modern Physics D"
Elicitation on verbal agreement paradigms
Creators: name: Maldonado Sales, Nelly Idalia Nikte
name: Scott, Tessa
name: Sales, Henry
Publisher: name: California Language Archive, University of California, Berkeley
Year: 2023
Subjects: subject: mam

description: This is a remote video interview held using Zoom. Henry Sales, a Mam speaker from San Juan Atitán, provides translation between English and Mam using Mam and Spanish.

The elicitation focuses on verbal agreement paradigms of intransitive verbs "arrive" and "work" as well as the verb "see" with different subject and object combinations.

In this file bundle: 1 Zoom video/audio recording, 1 pdf of typed notes.
Atom Site Selectivity in DNA Alkylation by Primary Diazonium Ions
Creators: name: Lu, Xuefang
Publisher: name: Maryland Shared Open Access Repository
Year: 2009
Subjects: diazonium ions
DNA alkylation
site selectivity

description: Diazonium ions are reactive intermediates derived by metabolites of carcinogenic nitrosamines. They can react with DNA at many heteroatoms and form different adducts, which might eventually lead to cancer. Compared to other classical organic alkylating agents, simple diazonium ions react more selectively at oxygen atoms of nucleobases. The resulting oxygen adducts have been shown to be correlated with the mutagenicity of the parent nitrosamines. Therefore, it is of great importance to understand the factors that account for this preference of diazonium ions for oxygen atoms of nucleobases. This work was carried out to study the site selectivity in DNA alkylation by primary diazonium ions using 1- propyldiazonium ion as a tool. The 1- propyldiazonium ion can generate both n- propylation and iso- propylation products. The yield of iso- propylation and the ratio of n- propylation to iso- propylation at a given heteroatom are roughly measurements of the association constant and nucleophilicity of the site to the diazonium ion, respectively. Therefore, the individual effect of the association constants and nulceophilicities on the product yields can be discussed. Alkylation of DNA as well as its nucleoside monomers by 1- propyldiazonium ion was carried out. After hydrolysis, the percent yields of n- propylation and iso-propylation products were determined by HPLC and LC/ MS. The variation in the iso-propylation yields in nucleoside reactions is small and relatively random. In DNA, however, preferential iso- propylation in the minor groove was observed, indicating that the double helix favors the association of 1- propyldiazonium in the minor groove. In the case of the ratio of n- propylation to iso- propylation, the variation is also small in nucleoside reactions. In DNA, however, the ratios of n- propylation to iso- propylation for some sites show significant enhancement, while the others show much smaller enhancement or remain almost the same as compared to the nucleosides. These results demonstrate that the double helix selectively enhances the nucleophilicities of certain sites. Thus, it is the structure of DNA that dictates the atom site selectivity in DNA alkylation by primary diazonium ions.
Surface Reactions During the Atomic Layer Deposition of High- ? Dielectrics on III-V Semiconductor Surfaces
Creators: name: Ye, Liwang
Publisher: name: Maryland Shared Open Access Repository
Year: 2014
Subjects: Atomic layer deposition
High-k dielectrics
III-V semiconductor
interface
Surface reaction
thin film

description: The quality of the dielectric/semiconductor interface is one of the most critical parameters for the fabrication of high-speed and low-power-consumption III-V semiconductor based metal-oxide-semiconductor field effect transistors (MOSFETs), as it determines the device performance. This dissertation contains investigations of the deposition and interface of binary oxide films on GaAs(100) and InAs(100) surfaces aiming at understanding the removal of the surface native oxides during certain atomic layer deposition (ALD) processes. To accomplish that, two complementary experimental approaches have been used. Initially, films were deposited in a conventional ALD reactor and characterized ex situ using spectroscopic ellipsometry (SE), X-ray photoelectron spectroscopy (XPS), high-resolution transmission electron microscopy (HRTEM), and atomic force microscopy (AFM). The systems examined were Ta2O5  on GaAs(100) surfaces from pentakis(dimethylamino) tantalum (Ta(N(CH3)2)5, PDMAT) and TiO2 on GaAs(100) and InAs(100) surfaces from tetrakis(dimethylamino) titanium (Ti(N(CH3)2)4, TDMAT). For these systems, deposition at the optimal ALD temperature resulted in practically sharp interfaces. Indium oxides were found to diffuse through ~ 6 nm of TiO2 film and accumulate on the topmost film layer. For the ALD of Ta2O5 on GaAs(100) surfaces, native oxide removal was enhanced at deposition temperatures above the ALD window; for ALD of TiO2 on both GaAs(100) and InAs(100) surfaces, native oxide removal was enhanced as the deposition temperatures increased up to 250 ?C, while oxidation of the interface was observed for deposition above 300 ?C due to the formation of noncontinuous films. To elucidate the surface reactions occurring during the deposition, an in situ attenuated total reflectance Fourier transform infrared (ATR-FTIR) spectroscopy apparatus was constructed and used to investigate the surface reactions during the ALD of TiO2 and HfO2 on GaAs(100) surfaces. The existence of a ligand exchange mechanism was verified for both processes. Additionally, the formation of methylmethyleneimine (CH3N=CH2, MMI) was observed, indicating the existence of a beta hydride reaction pathway. Additionally, at 275 ?C continuous removal of arsenic oxides was observed during the first 20 process cycles, an observation that challenges the prevailing understanding of the native oxide removal and indicates a much more complex surface chemistry.
Heterocoryne Wedler & Larson 1986
Creators: name: Maggioni, Davide
name: Schuchert, Peter
name: Arrigoni, Roberto
name: Hoeksema, Bert W.
name: Huang, Danwei
name: Strona, Giovanni
name: Seveso, Davide
name: Berumen, Michael L.
name: Montalbetti, Enrico
name: Collins, Richard
name: Galli, Paolo
name: Montano, Simone
Publisher: name: Zenodo
Year: 2021
Subjects: Biodiversity
Taxonomy
Animalia
Cnidaria
Hydrozoa
Anthoathecata
Sphaerocorynidae
Heterocoryne

description: Heterocoryne Wedler & Larson, 1986
Diagnosis: Hydroid colony stolonal; hydrocaulus unbranched; hydranth vasiform, with one whorl of long capitate tentacles and one whorl of tentacles that are composed of two to four parallel, partially-fused capitate tentacles. Gonophores single, on short pedicel, among upper whorl of simple capitate tentacles. Gonophores developing into eumedusoids.
Genetic diagnosis: 87 molecular diagnostic characters differentiate Heterocoryne from other genera in the family, specifically 21 in the 16S, 23 in the COX1, 33 in the COX3, 6 in the 18S, and 4 in the 28S (table 2).
Remarks: Heterocoryne is a monotypic genus.
description: Published as part of Maggioni, Davide, Schuchert, Peter, Arrigoni, Roberto, Hoeksema, Bert W., Huang, Danwei, Strona, Giovanni, Seveso, Davide, Berumen, Michael L., Montalbetti, Enrico, Collins, Richard, Galli, Paolo & Montano, Simone, 2021, Integrative systematics illuminates the relationships in two sponge-associated hydrozoan families (Capitata: Sphaerocorynidae and Zancleopsidae), pp. 487-525 in Contributions to Zoology 90 on page 508, DOI: 10.1163/18759866-BJA10023, http://zenodo.org/record/8343324
Relative entropy, Haar measures and relativistic canonical velocity distributions
Creators: name: Dunkel, Jörn
name: Talkner, Peter
name: Hänggi, Peter
Publisher: name: arXiv
Year: 2006
Subjects: subject: Statistical Mechanics (cond-mat.stat-mech)
subject: Astrophysics (astro-ph)
subject: Mathematical Physics (math-ph)
subject: FOS: Physical sciences

description: The thermodynamic maximum principle for the Boltzmann-Gibbs-Shannon (BGS) entropy is reconsidered by combining elements from group and measure theory. Our analysis starts by noting that the BGS entropy is a special case of relative entropy. The latter characterizes probability distributions with respect to a pre-specified reference measure. To identify the canonical BGS entropy with a relative entropy is appealing for two reasons: (i) the maximum entropy principle assumes a coordinate invariant form; (ii) thermodynamic equilibrium distributions, which are obtained as solutions of the maximum entropy problem, may be characterized in terms of the transformation properties of the underlying reference measure (e.g., invariance under group transformations). As examples, we analyze two frequently considered candidates for the one-particle equilibrium velocity distribution of an ideal gas of relativistic particles. It becomes evident that the standard Jüttner distribution is related to the (additive) translation group on momentum space. Alternatively, imposing Lorentz invariance of the reference measure leads to a so-called modified Jüttner function, which differs from the standard Jüttner distribution by a prefactor, proportional to the inverse particle energy.
description: 15 pages: extended version, references added
Ram Pressure Induced Star Formation in Abell 3266
Creators: name: Bonsall, Brittany
Publisher: name: Maryland Shared Open Access Repository
Year: 2014
Subjects: Galaxy Clusters
Merger
Ram Pressure

description: An X-ray observation of the merging galaxy cluster Abell 3266 was obtained via the ROSAT PSPC. This information, along with spectroscopic data from the WIde-field Nearby Galaxy-clusters Survey (i.e. WINGS), were used to investigate whether ram pressure is a mechanism that influences star formation. Galaxies exhibiting ongoing star formation are identified by the presence of strong Balmer lines (Hβ), known to correspond to early type stars. Older galaxies where a rapid increase in star formation has recently ceased, known as E+A galaxies, are identified by strong Hβ absorption coupled with little to no [OII] emission. The correlation between recent star formation and high ram pressure, as defined by Kapferer et al. (2009) as ≥ 5 x 10-11 dyn cm-2, was tested and lead to a contradiction of the previously held belief that ram pressure influences star formation on the global cluster scale.
Measurement Analysis and Quantum Gravity
Creators: name: Albers, Mark
name: Kiefer, Claus
name: Reginatto, Marcel
Publisher: name: arXiv
Year: 2008
Subjects: subject: General Relativity and Quantum Cosmology (gr-qc)
subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: We consider the question of whether consistency arguments based on measurement theory show that the gravitational field must be quantized. Motivated by the argument of Eppley and Hannah, we apply a DeWitt-type measurement analysis to a coupled system that consists of a gravitational wave interacting with a mass cube. We also review the arguments of Eppley and Hannah and of DeWitt, and investigate a second model in which a gravitational wave interacts with a quantized scalar field. We argue that one cannot conclude from the existing gedanken experiments that gravity has to be quantized. Despite the many physical arguments which speak in favor of a quantum theory of gravity, it appears that the justification for such a theory must be based on empirical tests and does not follow from logical arguments alone.
description: 31 pages, many conceptual clarifications included, new appendix added, to appear in Phys. Rev. D
A General Algorithm for Gridding Earth Sensing Scanning Instruments
Creators: name: Chapman, David Raymond
Publisher: name: Maryland Shared Open Access Repository
Year: 2008
Subjects: Computer Science (0984)
Gridding
Obscov
Climate
AIRS
Remote Sensing
Footprint

description: Gridding in remote sensing must re-project observations from their original coordinate system based on satellite orbit and attitude to a grid defined by Earth coordinates. Primitive methods assume that observations are located at points on Earth and typically average observations in grid cells, or interpolate geolocated observations. These approaches are inaccurate, because they do not make use of the instrument's footprint geometry, and spatial response. Observation Coverage (Obscov) gridding techniques make use of the satellite optics and geometry to more accurately describe coverage of a footprint on within each grid cell. Obscov gridding provides significant accuracy improvements exceeding 1 Kelvin Brightness Temperature over most regions on Earth for a 12 micron window channel on-board the Atmospheric Infrared Sounder (AIRS). Existing Obscov algorithms are only applicable to specific instruments and depend heavily on implicitly defined spatial response functions. We make use of raycasting and adaptive grid numerical integration to compute Obscov for the spatial response function of any instrument while processing streaming satellite observation data faster than 400 Megabits/second on a 6 machine cluster. We discuss the quality benefits of our algorithm by analyzing the results of gridded AIRS infrared sensor data with 324 operational spectral channels. Obscov gridding has improved coverage, and distorted regions such as poles no longer suffer from stippling artifacts. Secondly, Obscov gridding has improved accuracy, as our difference images show second order aliasing effects are corrected with the technique. We also address parallel processing issues to integrate AIRS Obscov gridding with SOAR, an on demand climate processing system built on a 122 processor blade server.
The Quality Control of Ethyl Glucuronide Standards
Creators: name: Grimm, Ivy
Publisher: name: Maryland Shared Open Access Repository
Year: 2009
Subjects: Alcohol
Ethyl Glucuronide
High Performance Liquid Chromatography
Method Validation
Pulsed Electrochemical Detection

description: Alcohol is a commonly abused drug and can lead to occupational,  pregnancy and driving hazards. It is important to monitor alcohol consumption to  attempt to avoid these potentially hazardous situations. Ethyl glucuronide ( EtG)  is a direct metabolite of ethanol and its determination in biological samples,  especially urine, has gained popularity as a biomarker of alcohol consumption.  Monitoring ethanol metabolites helps to distinguish between alcohol consumption  and post- mortem production of ethanol. Recently, there has been a growing  need for commercially available analytical standards for the target compound,  EtG. The legal ramifications of challenge testing for alcohol abuse require  stringent quality control of these reagents. High performance liquid  chromatography followed by pulsed electrochemical detection ( HPLC- PED),  offers unique advantages for assessing the purity of ethyl glucuronide standards.  This thesis discusses in detail the development and validation of an  HPLC- PED method. The method was validated for the purity assay of EtG  standards in DI water. Additionally, purity assays of three commercially- available  EtG standards are shown to highlight the successful application of this method.  Results obtained from the HPLC- PED method were compared to those obtained  using refractive index detection, a universal method of detection. HPLC- PED  was found to be a valid method for sensitive and selective determination of EtG  standards. Overall, this method meets the needs of quality control in the  production of EtG to ensure the consumer obtains the highest possible quality  standards achievable.
Vibrational Self Consistent Field Theory of Condensed Phase Bio-Organic Crystals
Creators: name: Balu, Radhakrishnan
Publisher: name: Maryland Shared Open Access Repository
Year: 2008
Subjects: Chemistry, Physical (0494)

description: High resolution THz (THz) spectroscopy in condensed phases is an emerging technique that can fingerprint molecules, such as the explosives found in IEDs, and active ingredients found in imported drug formulations. To date, large amounts of THz spectroscopic data are available for molecules in solid environments ranging from simple amino acid and peptide based systems to soft nanotubes. However, the theoretical methods to describe these systems and to predict spectroscopic features for new systems are not fully developed. Methods that take into account anharmonicity in vibrational motions and calculations based on anharmonic theory can be used to compare resulting spectra with experimental data. Such an analysis can then provide useful insight into the intramolecular force field of the molecular crystals in addition to predicting spectroscopic features. The methods have to go beyond the usually harmonic approximations under which vibrational spectroscopic data are analyzed. In our laboratory, we use the vibrational self-consistent field (VSCF) approach to model anharmonicity that has been successfully applied to systems in the gas-phase. The objective is to develop a generic algorithm for the calculations of vibrational spectroscopy of molecules in crystalline form. In summary, we have used molecular force fields to describe the potentials of the systems studied and we have calculated the spectral features at a harmonic level. We then used quantum force fields to study anharmonicity due to the potential.  Finally, we have treated anharmonicity due to vibrational mode-coupling using the VSCF approach. In essence, the present study extends the VSCF method to periodic systems containing molecular repeating units, and applies appropriate boundary conditions for the systems studied. We have tested our methods on the following systems: trialanine in parallel, anti-parallel, and hydrated configurations, nanotubes made of alanine-isoleucine and simple amino acid based crystals. We find in general good agreement with the experimental data in terms of the spectral features.
Physical Processes in the Atmospheric Boundary Layer with Implications for Air Quality
Creators: name: Baker, Barry Dean
Publisher: name: Maryland Shared Open Access Repository
Year: 2014
Subjects: Air Quality
Boundary Layer
Boundary Layer Height
CAMx
ozone
WRF

description: Ozone (O3) is a secondary pollutant dependent on complex photochemical reactions of nitrogen oxides (NOx) and volatile organic compounds (VOCs) and is sensitive to meteorological conditions that govern solar radiation, temperature, and wind speed/direction (Stockwell, 2011). The U.S. Environmental Protection Agency (USEPA) has classified O3 as one of the six criteria pollutants that is considered harmful to both plants and human health (Hollingsworth, 2007).   The current study investigates the influence of the diurnal cycle of the BL on the surface air pollutants. Specifically, it examines how the nighttime and transition period turbulence impacts the concentration of ozone at the surface and in the atmospheric column during the following day.   In order to complete the study, a series of models including the Weather Research and Forecasting (WRF) model and the Comprehensive Air Quality model with Extensions (CAMx) are used to simulate atmospheric conditions in the Maryland and Texas areas.  BL processes such as the minimum diffusivity or BL parameterization within CAMx are investigated.  The Blackadar scheme was found to artificially suppress the nocturnal BL height and appears to be the cause of a 15 ppbv high model bias.  An experiment is then conducted where a minimum BL height of 160 m and an improvement of 7% in the median model bias are found in the Maryland area.  With Maryland being in a NOx-limited regime, the same process of setting a minimum height is tested in the Texas area using the YSU scheme but minimal differences produced minuscule changes in the vertical diffusivity.  The use of the Ri number improved the model bias by another 5 ppbv or 13% over using the Blackadar BL scheme.   A new algorithm to predict the nocturnal BL depth is implemented into the WRF YSU scheme, which scales the Ribc with the Obukhov length adding a dependency on near surface properties of the flow.  The algorithm is tested using meteorological surface measurements and tower measurements, along with pollutant measurements in the Texas and Maryland areas.  The median model bias improved by 10% compared to using a static critical bulk Ri number.
THE EXAMINATION OF HYDROGEN PEROXIDE AS A GENERAL SIGNALING AGENT OF DITHIOLETHIONE CANCER CHEMOPREVENTIVES AND ITS EFFECTS ON HUMAN KEAP1
Creators: name: Holland, Ryan John
Publisher: name: Maryland Shared Open Access Repository
Year: 2009
Subjects: ADT
D3T
Dithiolethione
Hydrogen Peroxide
Keap1
Oltipraz

description: Dithiolethiones are a class of cancer chemopreventives which manifest some of their biological activity through the activation of transcription factor Nrf2, resulting in the stimulation of ARE dependant transcription of a large family of cytoprotective enzymes. In determining the mechanism by which these compounds activate Nrf2 it was observed that all dithiolethiones undergo reductive metabolism. These reductive metabolites can reduce molecular oxygen forming superoxide anion. Subsequent dismutation of superoxide anion results in the formation of hydrogen peroxide which has been shown to be a second messenger for enzyme induction of dithiolethiones. Oxidants such as hydrogen peroxide have been hypothesized to encumber Keap1, a negative regulator of Nrf2, thus enhancing Nrf2 activity. Low levels of hydrogen peroxide can react directly with Keap1 forming three Type 2 disulfides, Cys23- Cys38, Cys257- Cys297 and Cys319- Cys319, all of which lie in functional domains of Keap1. Higher levels of hydrogen peroxide which lead to a perturbation of the GSH/ GSSG redox couple also cause multiple modifications to Keap1. Some of the modifications, Type 1 disulfides at Cys77, Cys297, Cys319, Cys368 and Cys434, and Type 2 disulfides involving Cys23- Cys38, Cys257- Cys297 and Cys319- Cys319, form in a physiologically relevant range of redox potentials, and again lie in functional domains of Keap1. Through mathematical modeling Type 1 disulfides Cys368 and Cys434 have been shown to alter the structure of the kelch domain, the Nrf2 binding domain, of Keap1. These modifications may cause the observed activation of Nrf2 and subsequent induction of cytoprotective enzymes, which give dithiolethiones their cancer chemopreventive characteristics.
SWISS-MODEL – automated structure prediction of protein complexes in a web-based system
Creators: name: Waterhouse, Andrew
name: Bertoni, Martino
name: Bienert, Stefan
name: Studer, Gabriel
name: Tauriello, Gerardo
name: Robin, Xavier
name: Gumienny, Rafal
name: Heer, Florian
name: Beer, Tjaart De
name: Rempfer, Christine
name: Bordoli, Lorenza
name: Lepore, Rosalba
name: Schwede, Torsten
Publisher: name: F1000 Research Limited
Year: 2019

description: Since 25 years, SWISS-MODEL has been providing life science researchers worldwide with high-quality protein structure models. In total, it was referenced in 19'642 scientific publications. In the past 12 months, the server generated approximately 1.7 million protein structure models, i.e. 3.2 models per minute have been requested by users through the interactive modelling web interface. The SWISS-MODEL Repository provides weekly updated models for the complete proteomes of 13 selected model organisms.

Here we present recent advances in SWISS-MODEL: enhanced capabilities for automated modelling of homo- and hetero-oligomeric protein complexes, the open source modelling engine ProMod3 which lies at the core of SWISS-MODEL, and a new web service for assessing the quality of protein structures which offers an intuitive way to identify structural irregularities.

The automated SWISS-MODEL pipeline is continuously benchmarked with other state-of-the-art methods within the CAMEO project, where we observe that SWISS-MODEL is generating accurate models in their biologically relevant oligomeric state with accurate estimations of model quality, and nevertheless has by far the lowest response time in this benchmark.
Investigation of stable and unstable boundary layer  phenomena using observations and a numerical weather prediction model
Creators: name: Weldegaber, Mengsteab Habtegiorgis
Publisher: name: Maryland Shared Open Access Repository
Year: 2009
Subjects: Boundary layer
Dryline
Low level jet
Stable boundary layer
Unstable boundary layer
WRF modeling

description: Despite significant advances in the simulation of synoptic scale weather events, current numerical weather prediction models show poor skill in their capability to accurately simulate sub- grid scale processes, such as cloud- precipitation processes and planetary boundary layer ( PBL) evolution, because too many semi- empirical parameterizations are involved. The goal of the work presented here is to evaluate the next- generation mesoscale Weather Research and Forecasting ( WRF) model in simulating mesoscale weather phenomena under different PBL stratifications. The work presented in this thesis investigates the performance of the state- of- the- art mesoscale WRF model in simulating the structure and development of a daytime convective boundary layer phenomenon, ( the dryline over the Southern Great Plains), and a nocturnal stable boundary layer phenomenon, ( the low level jet ( LLJ) over the Mid- Atlantic region). The dryline and LLJ are two examples of boundary layer phenomena that occur under very different conditions and thus  together they provide a good test of the PBL dynamics in the model. Extensive, high spatial and temporal resolution data collected during these case studies is used to evaluate the numerical results. For the unstable boundary layer, a detailed observational analysis of a non- convective dryline investigates an incorrect forecast. For the stable boundary layer, the accuracy of the timing and spatial characteristics of the LLJ for different PBL parameterizations is investigated and discussed in terms of the LLJ forcing mechanisms.
Hodge genera of algebraic varieties, I
Creators: name: Cappell, Sylvain E.
name: Maxim, Laurentiu G.
name: Shaneson, Julius L.
Publisher: name: arXiv
Year: 2006
Subjects: subject: Algebraic Geometry (math.AG)
subject: Algebraic Topology (math.AT)
subject: FOS: Mathematics
subject: 57R20, 32S20, 14C30, 32S35, 32S50, 32S60, 55N33

description: The aim of this paper is to study the behavior of Hodge-theoretic (intersection homology) genera and their associated characteristic classes under proper morphisms of complex algebraic varieties. We obtain formulae that relate (parametrized families of) global invariants of a complex algebraic variety $X$ to such invariants of singularities of proper algebraic maps defined on $X$. Such formulae severely constrain, both topologically and analytically, the singularities of complex maps, even between smooth varieties. Similar results were announced by the first and third author in \cite{CS1, S}.
description: to appear in Comm. in Pure and Applied Math
Magnetic, superconducting, and topological surface states on Fe$_{1+y}$Te$_{1-x}$Se$_{x}$
Creators: name: Li, Yangmu
name: Zaki, Nader
name: Garlea, Vasile O.
name: Savici, Andrei T.
name: Fobes, David
name: Xu, Zhijun
name: Camino, Fernando
name: Petrovic, Cedomir
name: Gu, Genda
name: Johnson, Peter D.
name: Tranquada, John M.
name: Zaliznyak, Igor A.
Publisher: name: arXiv
Year: 2020
Subjects: subject: Superconductivity (cond-mat.supr-con)
subject: Materials Science (cond-mat.mtrl-sci)
subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: FOS: Physical sciences

description: The idea of employing non-Abelian statistics for error-free quantum computing ignited interest in recent reports of topological surface superconductivity and Majorana zero modes (MZMs) in FeTe$_{0.55}$Se$_{0.45}$. An associated puzzle is that the topological features and superconducting properties are not observed uniformly across the sample surface. Understanding and practical control of these electronic inhomogeneities present a prominent challenge for potential applications. Here, we combine neutron scattering, scanning angle-resolved photoemission spectroscopy (ARPES), and microprobe composition and resistivity measurements to characterize the electronic state of Fe$_{1+y}$Te$_{1-x}$Se$_{x}$. We establish a phase diagram in which the superconductivity is observed only at sufficiently low Fe concentration, in association with distinct antiferromagnetic correlations, while the coexisting topological surface state occurs only at sufficiently high Te concentration. We find that FeTe$_{0.55}$Se$_{0.45}$ is located very close to both phase boundaries, which explains the inhomogeneity of superconducting and topological states. Our results demonstrate the compositional control required for use of topological MZMs in practical applications.
description: Main text (18 pages, 5 figures, 50 references) combined with Supplementary (18 pages, 12 figures). Nat. Mater. (2021)
Detection of HCO+ Emission toward the Planetary Nebula K 3-35
Creators: name: Tafoya, D.
name: Gomez, Y.
name: Anglada, G.
name: Loinard, L.
name: Torrelles, J. M.
name: Miranda, L. F.
name: Osorio, M.
name: Franco-Hernandez, R.
name: Nyman, L. -A.
name: Nakashima, J.
name: Deguchi, S.
Publisher: name: arXiv
Year: 2006
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: We report the detection, for the first time, of HCO+ (J=1-0) emission as well as marginal CO (J=1-0) emission toward the planetary nebula (PN) K3-35 as a result of a molecular survey carried out toward this source. We also report new observations of the previously detected CO (J=2-1) and water maser emission, as well as upper limits for the emission of the SiO, H13CO+, HNC, HCN, HC3OH, HC5N, CS, HC3N, 13CO, CN, and NH3 molecules. From the ratio of CO (J=2-1) to CO (J=1-0) emission we have estimated the kinetic temperature of the molecular gas, obtaining a value of ~20 K. Using this result, we have estimated a molecular mass for the envelope of ~ 0.017 M_Sun, and an HCO+ abundance relative to H_2 of 6 X 10^-7, similar to the abundances found in other PNe. K~3-35 is remarkable because it is one of the two PNe reported to exhibit water maser emission, which is present in the central region as well as at a distance of $\simeq$ 5000 AU away from the center. The presence of molecular emission provides some clues that could help to understand the persistence of water molecules in the envelope of K 3-35. The HCO$^{+}$ emission could be arising in dense molecular clumps, that may provide the shielding mechanism which protects water molecules in this source.
description: 16 pages, 6 figures, accepted in AJ, in press
Quality assessment of in situ plasma etched diamond surfaces for CVD overgrowth
Creators: name: Langer, J.
name: Cimalla, V.
name: Prescher, M.
name: Ligl, J.
name: Tegetmeyer, B.
name: Schreyvogel, C.
name: Ambacher, O.
Publisher: name: arXiv
Year: 2021
Subjects: subject: Materials Science (cond-mat.mtrl-sci)
subject: FOS: Physical sciences

description: In situ plasma etching is a common method to prepare diamond substrates for epitaxial overgrowth to effectuate higher quality. However, there is no practical, direct, qualitative method established so far to assess the performance of the etching pretreatment. We propose an optimization of the pretreatment process on grounds of high-resolution X-ray diffraction measurements to judge the structural quality gain of the diamond substrates and the effectiveness of the polishing-induced subsurface damage removal. The obtained data shows, that parameters like thickness nor misorientation angle of the diamond substrates seem to influence the gain of the structural quality. The process duration, however, is an important key factor, when the amount of material removal and the arising roughness are discussed. Furthermore, the impact of the oxygen-to-hydrogen ratio is examined. And with rising oxygen percentage, the structural quality gain remains similar, only the overall as well as local mean roughness increases exponentially. Within the utilized reactor setup, the best results are obtained after a 20-minute in situ hydrogen plasma-etching step. The optimal pretreatment process, however, will always embody a tradeoff and needs to be optimized for each reactor type. Due to the introduced method a better evaluation and comparison of the achievements is accomplishable.
description: 10 pages, 7 figures