cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
Engineering of betabellin-15d: A 64 residue beta sheet protein that forms long narrow multimeric fibrils
Creators: name: Griffith, Jack D.
name: Saderholm, Matthew J.
name: Kroll, Mathias
name: Erickson, Bruce W.
name: Perera, Lalith
name: Makhov, Alexander M.
name: Yan, Yibing
name: Lim, Amareth
Publisher: name: The University of North Carolina at Chapel Hill University Libraries
Year: 1998

description: The betabellin target structure is a beta-sandwich protein consisting of two 32 residue beta-sheets packed against one another by interaction of their hydrophobic faces. The 32 residue chain of betabellin-15S (HSLTAKIpkLTFSIAphTYTCAV pkYTAKVSH, where p=DPro, k=DLys, and h=DHis) did not fold in water at pH 6.5. Air oxidation of betabellin-15S provided betabellin-15D, the 64 residue disulfide bridged two-chain molecule, which also remained unfolded in water at pH 6.5. By circular dichroic spectropolarimetry, the extent of beta structure observed for betabellin-15D increased with the pH and ionic strength of the solution and the betabellin-15D concentration. By electron microscopy, in 5.0 mM MOPS and 0.25 M NaCl at pH 6.9, betabellin-15D formed long narrow multimeric fibrils. A molecular model was constructed to show that the dimensions of these betabellin-15D fibrils are consistent with a single row of beta-sandwich molecules joined by multiple intersheet H-bonds.
Regularization Graphs -- A unified framework for variational regularization of inverse problems
Creators: name: Bredies, Kristian
name: Carioni, Marcello
name: Holler, Martin
Publisher: name: arXiv
Year: 2021
Subjects: subject: Optimization and Control (math.OC)
subject: Functional Analysis (math.FA)
subject: FOS: Mathematics

description: We introduce and study a mathematical framework for a broad class of regularization functionals for ill-posed inverse problems: Regularization Graphs. Regularization graphs allow to construct functionals using as building blocks linear operators and convex functionals, assembled by means of operators that can be seen as generalizations of classical infimal convolution operators. This class of functionals exhaustively covers existing regularization approaches and it is flexible enough to craft new ones in a simple and constructive way. We provide well-posedness and convergence results with the proposed class of functionals in a general setting. Further, we consider a bilevel optimization approach to learn optimal weights for such regularization graphs from training data. We demonstrate that this approach is capable of optimizing the structure and the complexity of a regularization graph, allowing, for example, to automatically select a combination of regularizers that is optimal for given training data.
Ternary complex structure of human hgprtase, prpp, mg 2+ , and the inhibitor HPP reveals the involvement of the flexible loop in substrate binding
Creators: name: Balendiran, Ganesaratnam K.
name: Eakin, Ann E.
name: Molina, JOSÉ A.
name: Stevens, Robert
name: Craig, Sydney P.
name: Sacchettini, James C.
name: Torres-Martinez, Jan
name: Focia, Pamela J.
name: Xu, Yiming
Publisher: name: The University of North Carolina at Chapel Hill University Libraries
Year: 1999

description: Site-directed mutagenesis was used to replace Lys68 of the human hypoxanthine phosphoribosyltransferase (HGPRTase) with alanine to exploit this less reactive form of the enzyme to gain additional insights into the structure activity relationship of HGPRTase. Although this substitution resulted in only a minimal (one- to threefold) increase in the Km values for binding pyrophosphate or phosphoribosylpyrophosphate, the catalytic efficiencies (k(cat)/Km) of the forward and reverse reactions were more severely reduced (6- to 30-fold), and the mutant enzyme showed positive cooperativity in binding of alpha-D-5-phosphoribosyl-1-pyrophosphate (PRPP) and nucleotide. The K68A form of the human HGPRTase was cocrystallized with 7-hydroxy [4,3-d] pyrazolo pyrimidine (HPP) and Mg PRPP, and the refined structure reported. The PRPP molecule built into the [(Fo - Fc)phi(calc)] electron density shows atomic interactions between the Mg PRPP and enzyme residues in the pyrophosphate binding domain as well as in a long flexible loop (residues Leu101 to Gly111) that closes over the active site. Loop closure reveals the functional roles for the conserved SY dipeptide of the loop as well as the molecular basis for one form of gouty arthritis (S103R). In addition, the closed loop conformation provides structural information relevant to the mechanism of catalysis in human HGPRTase.
بررسی بوستان سعدی براساس نظریۀ یادگیری مشاهده  ای بندورا
Publisher: name: دانشگاه کردستان
Year: 2022

description: بیان مسأله:آرای تربیتی سعدی در دو اثر سترگ وی (گلستان و  بوستان) نمود پیدا کرده و وی در انتقال پیام تعلیمی خود از رهیافت  های متعدد تربیتی و تعلیمی بهره برده است\nهدف: نوشتار حاضر در پی آن است بر مبنای نظریه  ی یادگیری مشاهده  ای بندورا کتاب بوستان سعدی را مورد بررسی و مداقّه قرار دهد\nروش:  این پژوهش با رویکردی تلفیقی-بینارشته  ای و با به  کارگیری ابزارهای تربیتی، گفتمانی و معناکاوی و به شیوۀ توصیفی- تحلیلی انجام شده است. ابزار گردآوری داده ­ها فیش است و  ابتدا با استفاده از منابع کتابخانه ه­ای و به روش سندکاوی معیارهای بنیادین نظریۀ بندورا و مصادیق آن در بوستان سعدی استخراج و سپس تحلیل لازم  به صورت تطبیقی انجام شد.\nیافته­ ها: یافته ­های پژوهش بیانگر آن است که علیرغم اختلاف زمانی اثر سعدی با زمان حاضر نظریۀ شناختی اجتماعی بندورا و مفاهیم بنیادین آن، بوستان سعدی در انتقال آموزه  های حکمی-اخلاقی مورد نظر خود به شیوه ­های جدید بسیار نزدیک شده است. سعدی در شیوه یاددهی خود  از میان سه مدل ( زنده، آموزشی و نمادین) مورد نظر بندورا از (مدل آموزشی) شامل سرمشق  گیری مبتنی بر سفر و تعامل با مردمان، سرمشق  گیری مبتنی بر روایت  پردازی و حکایت  های اخلاقی و سرمشق  گیری کلامی مبتنی بر تمثیل و اسلوب معادله و (مدل  نمادین) شامل سرمشق  گیری مبتنی بر الگوی رفتاری شخصیت  های مشهور (رل مدل  ها)، سرمشق  گیری مبتنی بر طبقات و گفتمان  های جامعه  بهره برده است
Organic Pea Starches – I. Comprehensive Investigation of Morphological and Molecular Properties
Creators: name: Terstegen, Tim
name: Grebenteuch, Sandra
name: Rohn, Sascha
name: Müller, Karl‐Josef
name: Flöter, Eckhard
name: Ulbrich, Marco
Publisher: name: Technische Universität Berlin
Year: 2023
Subjects: subject: 600 Technik, Medizin, angewandte Wissenschaften::660 Chemische Verfahrenstechnik::660 Chemische Verfahrenstechnik
subject: amylose content
subject: microscopy
subject: molecular properties
subject: pea cultivars
subject: pea starch

description: The comparatively high amylose (AM) content in native pea starch leads to a good functionality in food and non‐food products. Nevertheless, it has also been reported that pea starch tends to cause manufacturing problems more often than other starches. It has been suggested that this is due to substantial variation of the starch qualities originating from different pea starch varieties. Therefore, additional research which explores morphological, physicochemical, molecular, and techno‐/functional properties of starches from multiple pea varieties is necessary. Here, a large variety of pea starches are analyzed. The structure and size of the starch granules is studied using scanning electron microscopy (SEM), laser particle sizing (LPS), and image analysis of optical microscopy (IAOM). The morphological appearance and size do not differ significantly between the pea cultivars. The AM content is determined with two methods, both based on iodine interaction with the AM helix. The method suggested here (SEC‐prep) results in systematically higher AM content. This is due to better solubilization of the starch. Nevertheless, only small differences between the pea cultivars are observed. No differences in morphological appearance, particle size, and only minor differences in AM content, significant variations in the molar mass distribution of the total starch fraction (MwST) and of the AM fraction (MwAM) are found.
Van't Hoff enthalpies without baselines
Creators: name: Weeks, Kevin M.
name: John, Deborah M.
Publisher: name: The University of North Carolina at Chapel Hill University Libraries
Year: 2000

description: Analysis of thermal melting curves represents one important approach for evaluating protein stability and the consequences of amino acid substitution on protein structure. By use of the van't Hoff relationship, the differential melting curve can be robustly fit to only three parameters, two of which are the underlying physical constants of melting temperature (Tm) and van't Hoff enthalpy (deltaHvH). Calculated Tm and deltaHvH values are insensitive to the choice of pre- and post-transition baselines. Consequently, the method accurately computes Tm and deltaHvH for extremely truncated data sets, in the complete absence of baseline information, and for proteins with low melting temperatures, where the traditional direct approach routinely fails. Moreover, agreement between deltaHvH values obtained using points derived from pre- vs. post-transition data provide an independent method for detecting some classes of non-two-state transitions. Finally, fitting of the differential denaturation curve should prove useful for analysis of abbreviated data sets obtained from high throughput array analysis of protein stability.
The development of energy literacy and science communication competence of grade-12 students using 5E inquiry learning model with interactive computer-assisted instruction in the miracle of ethanol from rice straw to smart fuel cell
Creators: name: Vitavas Jumpathong
Publisher: name: Faculty of Science, Ubon Ratchathani University
Year: 2023
Subjects: Interactive Computer-Assisted Instruction
Energy Literacy
Science Communication Competence

description: Journal of Science and Science Education, 6, 1, 91-104
A new exact solution of the relativistic Boltzmann equation and its hydrodynamic limit
Creators: name: Denicol, Gabriel S.
name: Heinz, Ulrich W.
name: Martinez, Mauricio
name: Noronha, Jorge
name: Strickland, Michael
Publisher: name: arXiv
Year: 2014
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: Statistical Mechanics (cond-mat.stat-mech)
subject: High Energy Physics - Theory (hep-th)
subject: Nuclear Theory (nucl-th)
subject: FOS: Physical sciences

description: We present an exact solution of the relativistic Boltzmann equation for a system undergoing boost-invariant longitudinal and azimuthally symmetric transverse flow ("Gubser flow"). The resulting exact non-equilibrium dynamics is compared to 1st- and 2nd-order relativistic hydrodynamic approximations for various shear viscosity to entropy density ratios. This novel solution can be used to test the validity and accuracy of different hydrodynamic approximations in conditions similar to those generated in relativistic heavy-ion collisions.
description: 5 pages, 6 figures. Minor corrections in the text. Accepted for publication in Physical Review Letters
A survey of two analytical wake models for crosswind kite power systems
Creators: name: Karakouzian, Mher Marc
name: Kheiri, Mojtaba
Publisher: name: arXiv
Year: 2021
Subjects: subject: Fluid Dynamics (physics.flu-dyn)
subject: FOS: Physical sciences

description: This paper presents two novel analytical wake models for crosswind kite power systems. One is developed based on the continuity equation, and the other based on both the continuity and momentum equations. For each model, equations for the wake flow speed as well as the wake shape are obtained through a rigorous theoretical approach. Wake models for crosswind kites provide a first step in the understanding of the effects of kite-to-kite aerodynamic interactions on prospective wind energy kite farms. Despite a fair number of computational studies on these wakes, few studies have attempted to provide a concrete analytical solution. Indeed, the primary motivation of this study comes from the fact that analytical models are simple in form and require very little computational power when being solved. The results from the two analytical models are compared with each other and are validated against computational results. Bearing several assumptions, these models are meant to simply offer a preliminary insight that will hopefully see many improvements with added complexity in the near future.
MPEC 2023-U271 : 2023 RS61
Creators: name: Minor Planet Center Staff
Publisher: name: The Minor Planet Center
Year: 2023
Subjects: subject: Small Solar System bodies
valueUri: http://astrothesaurus.org/uat/1469

description: The Minor Planet Electronic Circulars contain information on unusual minor planets, routine data on comets and natural satellites, and occasional editorial announcements.  They are published on behalf of Division F of the International Astronomical Union by the Minor Planet Center, Smithsonian Astrophysical Observatory, Cambridge, MA 02138, U.S.A.
Free energies of protein decoys provide insight into determinants of protein stability
Creators: name: Hermans, Jan
name: Vorobjev, Yury N.
Publisher: name: The University of North Carolina at Chapel Hill University Libraries
Year: 2001

description: We have calculated the stability of decoy structures of several proteins (from the CASP3 models and the Park and Levitt decoy set) relative to the native structures. The calculations were performed with the force field–consistent ES/IS method, in which an implicit solvent (IS) model is used to calculate the average solvation free energy for snapshots from explicit simulations (ESs). The conformational free energy is obtained by adding the internal energy of the solute from the ESs and an entropic term estimated from the covariance positional fluctuation matrix. The set of atomic Born radii and the cavity-surface free energy coefficient used in the implicit model has been optimized to be consistent with the all-atom force field used in the ESs (cedar/gromos with simple point charge (SPC) water model). The decoys are found to have a consistently higher free energy than that of the native structure; the gap between the native structure and the best decoy varies between 10 and 15 kcal/mole, on the order of the free energy difference that typically separates the native state of a protein from the unfolded state. The correlation between the free energy and the extent to which the decoy structures differ from the native (as root mean square deviation) is very weak; hence, the free energy is not an accurate measure for ranking the structurally most native-like structures from among a set of models. Analysis of the energy components shows that stability is attained as a result of three major driving forces: (1) minimum size of the protein-water surface interface; (2) minimum total electrostatic energy, which includes solvent polarization; and (3) minimum protein packing energy. The detailed fit required to optimize the last term may underlie difficulties encountered in recovering the native fold from an approximate decoy or model structure.
Spin‐Lasing in Bimodal Quantum Dot Micropillar Cavities
Creators: name: Heermeier, Niels
name: Heuser, Tobias
name: Große, Jan
name: Jung, Natalie
name: Kaganskiy, Arsenty
name: Lindemann, Markus
name: Gerhardt, Nils C.
name: Hofmann, Martin R.
name: Reitzenstein, Stephan
Publisher: name: Technische Universität Berlin
Year: 2022
Subjects: subject: 500 Naturwissenschaften und Mathematik::530 Physik::530 Physik
subject: bimodal micropillar cavities
subject: cavity quantum electrodynamics
subject: microlasers
subject: quantum dots
subject: spin‐lasers

description: Spin‐controlled lasers are highly interesting photonic devices and have been shown to provide ultrafast polarization dynamics in excess of 200 GHz. In contrast to conventional semiconductor lasers their temporal properties are not limited by the intensity dynamics, but are governed primarily by the interaction of the spin dynamics with the birefringent mode splitting that determines the polarization oscillation frequency. Another class of modern semiconductor lasers are high‐β emitters, which benefit from enhanced light–matter interaction due to strong mode confinement in low‐mode‐volume microcavities. In such structures, the emission properties can be tailored by the resonator geometry to realize for instance bimodal emission behavior in slightly elliptical micropillar cavities. This attractive feature is utilized to demonstrate and explore spin‐lasing effects in bimodal high‐β quantum dot micropillar lasers. The studied microlasers with a β‐factor of 4% show spin‐laser effects with experimental polarization oscillation frequencies up to 15 GHz and predicted frequencies up to about 100 GHz, which are controlled by the ellipticity of the resonator. These results reveal appealing prospects for very compact, ultrafast, and energy‐efficient spin‐lasers and can pave the way for future purely electrically injected spin‐lasers enabled by short injection path lengths.
The developmentteamwork and collaborationcompetenceof learnersusingthe 6E model in STEM education merge with the BCG economic modelfor grade-7 students in ChumchonBankampokThadokkeaw schoo
Creators: name: Wuttichai Phoode
Publisher: name: Faculty of Science, Ubon Ratchathani University
Year: 2023
Subjects: STEM Education
Teamwork and collaboration competence of learners
BCG Economic Mode

description: Journal of Science and Science Education, 6, 1, 105-119
s- and p-superfluidity of Fermi atoms in Bose-Fermi mixtures
Creators: name: Gorbar, E. V.
name: Nikolaieva, Y. O.
name: Oleinikova, I. V.
name: Vilchinskii, S. I.
name: Yakimenko, A. I.
Publisher: name: arXiv
Year: 2021
Subjects: subject: Quantum Gases (cond-mat.quant-gas)
subject: FOS: Physical sciences

description: The p-wave superfluid is characterized by nontrivial topological characteristics essential for fault-tolerant quantum state manipulation. However, the practical realization of the p-wave state remains a challenging problem. We study the s- and p-wave superfluidity in mixtures of fermionic and spinor bosonic gases and derive a general set of the gap equations for these superfluid states. Numerically solving the gap equations for the s-wave state, we quantify the physical conditions for the realization of the pure p-wave state in a well-controlled environment of atomic physics in the absence of an admixture of the s-wave state.
description: 9 pages, 2 figures
Reviving Oxygen Evolution Electrocatalysis of Bulk La–Ni Intermetallics via Gaseous Hydrogen Engineering
Creators: name: Chen, Ziliang
name: Yang, Hongyuan
name: Mebs, Stefan
name: Dau, Holger
name: Driess, Matthias
name: Wang, Zhaowu
name: Kang, Zhenhui
name: Menezes, Prashanth W.
Publisher: name: Technische Universität Berlin
Year: 2023
Subjects: subject: 500 Naturwissenschaften und Mathematik::540 Chemie::540 Chemie und zugeordnete Wissenschaften
subject: heterostructures
subject: hydrogen storage intermetallics
subject: oxygen evolution reaction
subject: phase reconstruction
subject: rare‐earth metals

description: A hydrogen processing strategy is developed to enable bulk LaNi5 to attain high activity and long‐term stability toward the electrocatalytic oxygen evolution reaction (OER). By a combination of in situ Raman and quasi in situ X‐ray absorption (XAS) spectra, secondary‐electron‐excited scanning transmission electron microscopy (STEM) patterns as well as the Rietveld method and density functional theory (DFT) calculations, it is discovered that hydrogen‐induced lattice distortion, grain refinement, and particle cracks dictate the effective reconstruction of the LaNi5 surface into a porous hetero‐nanoarchitecture composed of uniformly confined active γ‐NiOOH nanocrystals by La(OH)3 layer in the alkaline OER process. This significantly optimizes the charge transfer, structural integrity, active‐site exposure, and adsorption energy toward the reaction intermediates. Benefiting from these merits, the overpotential (322 mV) at 100 mA cm−2 for the hydrogen‐processed OER catalyst deposited on nickel foam is reduced by 104 mV as compared to the original phase. Notably, it exhibits remarkable stability for 10 days at an industrial‐grade current density of more than 560 mA cm−2 in alkaline media.
H-principle for 4-dimensional contact foliations
Creators: name: Casals, Roger
name: del Pino, Alvaro
name: Presas, Francisco
Publisher: name: arXiv
Year: 2014
Subjects: subject: Symplectic Geometry (math.SG)
subject: FOS: Mathematics
subject: 53D10

description: In this article we introduce the topological study of codimension-1 foliations which admit contact or symplectic structures on the leaves. A parametric existence h-principle for foliated contact structures is provided for any cooriented foliation in a closed oriented 4-fold.
description: 18 pages, 3 figures
Drop Size Distributions as a Function of Dispersed Phase Viscosity: Experiments and Modeling
Creators: name: Hohl, Lena
name: Röhl, Susanne
name: Kraume, Matthias
Publisher: name: Technische Universität Berlin
Year: 2023
Subjects: subject: 600 Technik, Medizin, angewandte Wissenschaften::660 Chemische Verfahrenstechnik::660 Chemische Verfahrenstechnik
subject: dispersions
subject: endoscopes
subject: liquid phases
subject: population balance equations
subject: stirred tanks

description: Detailed measurements of dynamic and steady-state drop size distributions were performed in liquid-liquid systems with water and different silicone oils using an in situ endoscope technique in a discontinuously operated stirred tank. The oils used as the dispersed phase vary in dynamic viscosity, while density and interfacial tension are nearly constant. The performance of a population balance model for partially mobile interfaces and its ability to predict steady-state and dynamic Sauter mean diameters and the complete drop size distributions as a function of dispersed phase viscosity and different process parameters are evaluated. Furthermore, the impact of different daughter drop size distribution shapes on simulation results is quantified.
Effect of Learning activities by using STAD technique with KWDL technique on Mathematical problem solving and connection abilities in linear equation of one variable of grade-7 students
Creators: name: Thanapon Namlai
Publisher: name: Faculty of Science, Ubon Ratchathani University
Year: 2023
Subjects: Mathematical problems ability
Mathematical connection ability
STAD Technique
KWDL technique

description: Journal of Science and Science Education, 6, 1, 120-134
Identification of four proteins from the small subunit of the mammalian mitochondrial ribosome using a proteomics approach
Creators: name: Koc, E. C.
Publisher: name: The University of North Carolina at Chapel Hill University Libraries
Year: 2001

description: Proteins in the small subunit of the mammalian mitochondrial ribosome were separated by two-dimensional polyacrylamide gel electrophoresis. Four individual proteins were subjected to in-gel Endoprotease Lys-C digestion. The sequences of selected proteolytic peptides were obtained by electrospray tandem mass spectrometry. Peptide sequences obtained from in-gel digestion of individual spots were used to screen human, mouse, and rat expressed sequence tag databases, and complete consensus cDNAs for these species were deduced in silico. The corresponding protein sequences were characterized by comparison to known ribosomal proteins in protein databases. Four different classes of mammalian mitochondrial small subunit ribosomal proteins were identified. Only two of these proteins have significant sequence similarities to ribosomal proteins from prokaryotes. These proteins are homologs to Escherichia coli S9 and S5 proteins. The presence of these newly identified mitochondrial ribosomal proteins are also investigated in the Drosophila melanogaster, Caenorhabditis elegans, and in the genomes of several fungi.
رابطه ویژگی های دانشجویان با نظر آنان نسبت به سامانه درسی الکترونیکی: مورد دوره کارشناسی علوم ارتباطات
Publisher: name: دانشگاه کردستان
Year: 2022

description: سامانه های درسی الکترونیکی در مدت نزدیک به دو سال تحصیلی (1400-1398)، مصادف با همه گیری کوید-19، در دانشگاه ها در سراسر جهان جایگزین کلاس های درس حضوری گردید. بدین جهت،مدرسان مجبور شدند به تدریس در محیط های مجازی روی آورند. این جایگزینی مشکلات چندی در فرایند یاددهی- یادگیری به وجود آورد و کیفیت یادگیری را متأثر نمود. ازاین رو، این سؤال ها را می توان مطرح که «نظر دانشجویان نسبت به سیستم ها و سامانه های یادگیری الکترونیکی چیست؟» و «آیا نظر دانشجویان با ویژگی های فردی آنان رابطه دارد؟» برای پاسخ دادن به این سؤال ها، یک طرح پژوهشی تدوین شد و در جامعه دانشجویان دریکی از سامانه های درسی در رشته علوم ارتباطات در یک دانشگاه پژوهشی به اجرا درآمد. حجم جامعه موردمطالعه 43 نفر بود که به عنوان نمونه آماری موردنظر قرار گرفت. سپس با استفاده از روش تحقیق توصیفی- تحلیلی داده های موردنیاز گردآوری، تنظیم و تحلیل گردید. یافته ها و نتایج پژوهش نشان می دهد که اکثریت دانشجویان موردمطالعه (72٪) نسبت به سامانه درسی الکترونیکی نظرشان مثبت نبوده است و از آن رضایت نداشته اند. علاوه بر آن، میان نظر دانشجویان و ویژگی های فردی آنان (جنسیت و علاقه به رشته تحصیلی) رابطه ای وجود ندارد. آزمون آماری  در سطح معنی داری  عدم رابطه یادشده را مورد تأیید قرار داد. در پایان مقاله پیشنهادهای اجرائی و نیز پیشنهاد برای پژوهش های دیگر عرضه شده است
Covariant constraints for generic massive gravity and analysis of its characteristics
Creators: name: Deser, S.
name: Sandora, M.
name: Waldron, A.
name: Zahariade, G.
Publisher: name: arXiv
Year: 2014
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: General Relativity and Quantum Cosmology (gr-qc)
subject: FOS: Physical sciences

description: We perform a covariant constraint analysis of massive gravity valid for its entire parameter space, demonstrating that the model generically propagates five degrees of freedom; this is also verified by a new and streamlined Hamiltonian description. The constraint's covariant expression permits computation of the model's caustics. Although new features such as the dynamical Riemann tensor appear in the characteristic matrix, the model still exhibits the pathologies uncovered in earlier work: superluminality and likely acausalities.
description: 26 pages LaTeX, references added, version to appear in Phys. Rev. D
Full and Reduced Order Model Consistency of the Nonlinearity Discretization in Incompressible Flows
Creators: name: Ingimarson, Sean
name: Rebholz, Leo G.
name: Iliescu, Traian
Publisher: name: arXiv
Year: 2021
Subjects: subject: Numerical Analysis (math.NA)
subject: FOS: Mathematics

description: We investigate both theoretically and numerically the consistency between the nonlinear discretization in full order models (FOMs) and reduced order models (ROMs) for incompressible flows. To this end, we consider two cases: (i) FOM-ROM consistency, i.e., when we use the same nonlinearity discretization in the FOM and ROM; and (ii) FOM-ROM inconsistency, i.e., when we use different nonlinearity discretizations in the FOM and ROM. Analytically, we prove that while the FOM-ROM consistency yields optimal error bounds, FOM-ROM inconsistency yields additional terms dependent on the FOM divergence error, which prevent the ROM from recovering the FOM as the number of modes increases. Computationally, we consider channel flow around a cylinder and Kelvin-Helmholtz instability, and show that FOM-ROM consistency yields significantly more accurate results than FOM-ROM inconsistency.
Influence of the Distance between Two Catalysts for CO2 to Dimethyl Ether Tandem Reaction
Creators: name: Javed, Mudassar
name: Brösigke, Georg
name: Schomäcker, Reinhard
name: Repke, Jens-Uwe
Publisher: name: Technische Universität Berlin
Year: 2023
Subjects: subject: 600 Technik, Medizin, angewandte Wissenschaften::660 Chemische Verfahrenstechnik::660 Chemische Verfahrenstechnik
subject: dimethyl ether tandem system
subject: HZSM‐5 deactivation
subject: mass transfer
subject: methanol
subject: tandem catalysis

description: Tandem reactions, with their great potential for reduction of capital and operational costs, reaction time, and byproducts are becoming more prominent. Among possible tandem reaction systems for direct conversion of CO2 to green fuel, dimethyl ether synthesis via methanol route is of vital importance. However, there are several parameters which must be considered for the combination of two catalysts to achieve promising performance, of those, the distance between the two catalysts is a crucial one. This distance can affect the overall performance of the tandem system by causing external mass transfer limitations or the poisoning of the catalysts. This work presents a systematic study on the influence of the distance between the two catalysts for the CO2 to dimethyl ether tandem system.
Identification of overlapping but distinct cAMP and cGMP interaction sites with cyclic nucleotide phosphodiesterase 3A by site-directed mutagenesis and molecular modeling based on crystalline PDE4B
Creators: name: Tretiakova, Anna P.
name: Jameson, Bradford
name: Colman, Robert W.
name: Zhang, Wei
name: Ke, Hengming
Publisher: name: The University of North Carolina at Chapel Hill University Libraries
Year: 2001

description: Cyclic nucleotide phosphodiesterase 3A (PDE3A) hydrolyzes cAMP to AMP, but is competitively inhibited by cGMP due to a low kcat despite a tight Km. Cyclic AMP elevation is known to inhibit all pathways of platelet activation, and thus regulation of PDE3 activity is significant. Although cGMP elevation will inhibit platelet function, the major action of cGMP in platelets is to elevate cAMP by inhibiting PDE3A. To investigate the molecular details of how cGMP, a similar but not identical molecule to cAMP, behaves as an inhibitor of PDE3A, we constructed a molecular model of the catalytic domain of PDE3A based on homology to the recently determined X-ray crystal structure of PDE4B. Based on the excellent fit of this model structure, we mutated nine amino acids in the putative catalytic cleft of PDE3A to alanine using site-directed mutagenesis. Six of the nine mutants (Y751A, H840A, D950A, F972A, Q975A, and F1004A) significantly decreased catalytic efficiency, and had kcat/Km less than 10% of the wild-type PDE3A using cAMP as substrate. Mutants N845A, F972A, and F1004A showed a 3- to 12-fold increase of Km for cAMP. Four mutants (Y751A, H840A, D950A, and F1004A) had a 9- to 200-fold increase of Ki for cGMP in comparison to the wild-type PDE3A. Studies of these mutants and our previous study identified two groups of amino acids: E866 and F1004 contribute commonly to both cAMP and cGMP interactions while N845, E971, and F972 residues are unique for cAMP and the residues Y751, H836, H840, and D950 interact with cGMP. Therefore, our results provide biochemical evidence that cGMP interacts with the active site residues differently from cAMP.
Revealing the Chemical State of Palladium in Operating In2O3 Gas Sensors: Metallic Pd Enhances Sensing Response and Intermetallic InxPdy Compound Blocks It
Creators: name: Ovsianytskyi, Oleksandr
name: Bekheet, Maged F.
name: Gili, Albert
name: Gurlo, Aleksander
Publisher: name: Technische Universität Berlin
Year: 2023
Subjects: subject: 500 Naturwissenschaften und Mathematik::540 Chemie::540 Chemie und zugeordnete Wissenschaften
subject: indium oxide
subject: palladium
subject: in situ X-ray diffraction
subject: gas sensors
subject: hydrogen

description: The sensing response of metal oxides activated with noble metal nanoparticles is significantly influenced by changes to the chemical state of corresponding elements under operating conditions. Here, a PdO/rh-In2O3 consisting of PdO nanoparticles loaded onto rhombohedral In2O3 was studied as a gas sensor for H2 gas (100–40000 ppm in an oxygen-free atmosphere) in the temperature range of 25–450 °C. The phase composition and chemical state of elements were examined by resistance measurements combined with synchrotron-based in situ X-ray diffraction and ex situ X-ray photoelectron spectroscopy. As found, PdO/rh-In2O3 undergoes a series of structural and chemical transformations during operation: from PdO to Pd/PdHx and finally to the intermetallic InxPdy phase. The maximal sensing response (RN2/RH2) of ∼5 ⋅ 107 towards 40000 ppm (4 vol %) H2 at 70 °C is correlated with the formation of PdH0.706/Pd. The InxPdy intermetallic compounds formed around 250 °C significantly decrease the sensing response.
Gravity factorized
Creators: name: Blommaert, Andreas
name: Iliesiu, Luca V.
name: Kruthoff, Jorrit
Publisher: name: arXiv
Year: 2021
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: General Relativity and Quantum Cosmology (gr-qc)
subject: FOS: Physical sciences

description: We find models of two-dimensional gravity that resolve the factorization puzzle and have a discrete spectrum, whilst retaining a semiclassical description. A novelty of these models is that they contain non-trivially correlated spacetime branes or, equivalently, nonlocal interactions in their action. Such nonlocal correlations are motivated in the low-energy gravity theory by integrating out UV degrees of freedom. Demanding factorization fixes almost all brane correlators, and the exact geometric expansion of the partition function collapses to only two terms: the black hole saddle and a subleading ``half-wormhole'' geometry, whose sum yields the desired discrete spectrum. By mapping the insertion of correlated branes to a certain double-trace deformation in the dual matrix integral, we show that factorization and discreteness also persist non-perturbatively. While in our model all wormholes completely cancel, they are still computationally relevant: self-averaging quantities, like the Page curve, computed in the original theory with wormholes, accurately approximate observables in our theory, which accounts for UV corrections. Our models emphasize the importance of correlations between different disconnected components of spacetime, providing a possible resolution to the factorization puzzle in any number of dimensions.
description: 43 pages, 35 figures
Interaction energies between β-lactam antibiotics and E. coli penicillin-binding protein 5 by reversible thermal denaturation
Creators: name: Beadle, Beth M.
name: Shoichet, Brian K.
name: Nicholas, Robert A.
Publisher: name: The University of North Carolina at Chapel Hill University Libraries
Year: 2001

description: Penicillin-binding proteins (PBPs) catalyze the final stages of bacterial cell wall biosynthesis. PBPs form stable covalent complexes with β-lactam antibiotics, leading to PBP inactivation and ultimately cell death. To understand more clearly how PBPs recognize β-lactam antibiotics, it is important to know their energies of interaction. Because β-lactam antibiotics bind covalently to PBPs, these energies are difficult to measure through binding equilibria. However, the noncovalent interaction energies between β-lactam antibiotics and a PBP can be determined through reversible denaturation of enzyme–antibiotic complexes. Escherichia coli PBP 5, a d-alanine carboxypeptidase, was reversibly denatured by temperature in an apparently two-state manner with a temperature of melting (Tm) of 48.5°C and a van't Hoff enthalpy of unfolding (ΔHVH) of 193 kcal/mole. The binding of the β-lactam antibiotics cefoxitin, cloxacillin, moxalactam, and imipenem all stabilized the enzyme significantly, with ΔTm values as high as +4.6°C (a noncovalent interaction energy of +2.7 kcal/mole). Interestingly, the noncovalent interaction energies of these ligands did not correlate with their second-order acylation rate constants (k2/K′). These rate constants indicate the potency of a covalent inhibitor, but they appear to have little to do with interactions within covalent complexes, which is the state of the enzyme often used for structure-based inhibitor design.
Measuring the surface magnetic fields of magnetic stars with unresolved Zeeman splitting
Creators: name: Bailey, J. D.
Publisher: name: arXiv
Year: 2014
Subjects: subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: FOS: Physical sciences

description: High-dispersion, archival spectra of magnetic Ap stars with resolved Zeeman components in Stokes I are used to derive a simple relation that can be utilised to estimate the mean surface field strengths of stars with v sin i > 10 km/s. For each star, the mean surface field, as measured from the observed splitting in Fe II at 6149 A, is compared to the differential broadening of spectral lines with large and small Lande factors in order to produce a relation to estimate the field strengths of magnetic stars with unresolved Zeeman patterns. The method is shown to be reliable for rotational velocities up to about 50 km/s for field strengths down to about 5 kG. These results should allow for better constraints to be placed on the mean surface magnetic fields of Ap stars where Zeeman patterns are unresolved.
description: Accepted for publication in A&A
Cyclic Nanoindentation for Local High Cycle Fatigue Investigations: A Methodological Approach Accounting for Thermal Drift
Creators: name: Schmahl, Merle
name: Müller, Cecilia
name: Meinke, Reinhard
name: Alves Alcantara, Erika G.
name: Hangen, Ude D.
name: Fleck, Claudia
Publisher: name: Technische Universität Berlin
Year: 2023
Subjects: subject: 600 Technik, Medizin, angewandte Wissenschaften::620 Ingenieurwissenschaften::620 Ingenieurwissenschaften und zugeordnete Tätigkeiten
subject: aluminum foam
subject: cyclic nanoindentation
subject: nanofatigue
subject: thermal drift correction
subject: zirconia

description: Cyclic nanoindentation allows characterizing the influence of single phases and their interactions on fatigue mechanisms. Herein, a method for high cycle fatigue testing by nanoindentation is presented. By combining high- and low-frequency indentation modes, high cycle numbers are achieved while obtaining sufficient data points to reconstruct force–displacement hysteresis loops. A challenge is the stochastic course of thermal drift which is addressed by measuring drift rate in regular low-force holding segments. Drift rates are used to correct the displacement values, yielding reproducible cyclic deformation data as it is shown for two very different materials, a ductile metal and a brittle ceramic.
Model functions and robustness analysis from Competition among small individuals hinders adaptive radiation despite ecological opportunity
Creators: name: ten Brink, Hanna
name: Seehausen, Ole
Publisher: name: The Royal Society
Year: 2022
Subjects: subject: Evolutionary Biology
subject: FOS: Biological sciences
subject: Ecology
subject: 60102 Bioinformatics
subject: FOS: Computer and information sciences
subject: 10202 Biological Mathematics
subject: FOS: Mathematics

description: Additional tables and figures, including results from the robustness analysis
title: Climate change impacts on the waters around the UK and Ireland: Salinity
Creators: name: Dye, Stephen R.
name: Holliday, N. Penny
name: Hughes, Sarah L.
name: Inall, Mark
name: Kennington, Kevin
name: Smyth, Tim
name: Tinker, Jonathan
name: Andres, Olga
name: Beszczynska-Möller, Agnieszka
Publisher: name: Marine Climate Change Impacts Partnership (MCCIP), Lowestoft, UK
Year: 2013

description: MCCIP Science Review 2013, 60-66
Development of Scientific Creative Thinking and Academic Achievement of Grade 11 Students using Inquiry Learning with Scientific Creativity: PIEGA MODEL in the Topic of Electrochemistry
Creators: name: Wannapa Thuwawit
Publisher: name: Faculty of Science, Ubon Ratchathani University
Year: 2023
Subjects: Inquiry Learning with Scientific Creativity
Scientific Creative Thinking
Academic Achievement

description: Journal of Science and Science Education, 6, 1, 135-149
Gas-phase spectroscopy of photostable PAH ions from the mid- to far-infrared
Creators: name: Wiersma, Sandra D.
name: Candian, Alessandra
name: Bakker, Joost M.
name: Petrignani, Annemieke
Publisher: name: arXiv
Year: 2021
Subjects: subject: Chemical Physics (physics.chem-ph)
subject: Astrophysics of Galaxies (astro-ph.GA)
subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: FOS: Physical sciences

description: We present gas-phase InfraRed Multiple Photon Dissociation (IRMPD) spectroscopy of cationic phenanthrene, pyrene, and perylene over the 100$-$1700 cm$^{-1}$ (6-95 $μ$m) spectral range. This range covers both local vibrational modes involving C$-$C and C$-$H bonds in the mid-IR, and large-amplitude skeletal modes in the far-IR. The experiments were done using the 7T Fourier-Transform Ion Cyclotron Resonance (FTICR) mass spectrometer integrated in the Free-Electron Laser for Intra-Cavity Experiments (FELICE), and findings were complemented with Density Functional Theory (DFT) calculated harmonic and anharmonic spectra, matching the experimental spectra well. The experimental configuration that enables this sensitive spectroscopy of the strongly-bound, photo-resistant Polycyclic Aromatic Hydrocarbons (PAHs) over a wide range can provide such high photon densities that even combination modes with calculated intensities as low as 0.01 km$\cdot$mol$^{-1}$ near 400 cm$^{-1}$ (25 $μ$m) can be detected. Experimental frequencies from this work and all currently available IRMPD spectra for PAH cations were compared to theoretical frequencies from the NASA Ames PAH IR Spectroscopic Database to verify predicted trends for far-IR vibrational modes depending on PAH shape and size, and only a relatively small redshift (6$-$11 cm$^{-1}$) was found between experiment and theory. The absence of spectral congestion and the drastic reduction in bandwidth with respect to the mid-IR make the far-IR fingerprints viable candidates for theoretical benchmarking, which can aid in the search for individual large PAHs in the interstellar medium.
description: to be submitted to the Monthly Notices of the Royal Astronomical Society
Evolution of Carbonate‐Intercalated γ‐NiOOH from a Molecularly Derived Nickel Sulfide (Pre)Catalyst for Efficient Water and Selective Organic Oxidation
Creators: name: Ghosh, Suptish
name: Dasgupta, Basundhara
name: Kalra, Shweta
name: Ashton, Marten L. P.
name: Yang, Ruotao
name: Kueppers, Christopher J.
name: Gok, Sena
name: Alonso, Eduardo Garcia
name: Schmidt, Johannes
name: Laun, Konstantin
name: Zebger, Ingo
name: Walter, Carsten
name: Driess, Matthias
name: Menezes, Prashanth W.
Publisher: name: Technische Universität Berlin
Year: 2023
Subjects: subject: 500 Naturwissenschaften und Mathematik::540 Chemie::540 Chemie und zugeordnete Wissenschaften
subject: active γ‐NiOOH phase
subject: CO 3 2−‐intercalation
subject: nickel sulfide
subject: oxygen evolution reaction
subject: selective organic oxidation
subject: single‐source precursors

description: The development of a competent (pre)catalyst for the oxygen evolution reaction (OER) to produce green hydrogen is critical for a carbon-neutral economy. In this aspect, the low-temperature, single-source precursor (SSP) method allows the formation of highly efficient OER electrocatalysts, with better control over their structural and electronic properties. Herein, a transition metal (TM) based chalcogenide material, nickel sulfide (NiS), is prepared from a novel molecular complex [NiII(PyHS)4][OTf]2 (1) and utilized as a (pre)catalyst for OER. The NiS (pre)catalyst requires an overpotential of only 255 mV to reach the benchmark current density of 10 mA cm−2 and shows 63 h of chronopotentiometry (CP) stability along with over 95% Faradaic efficiency in 1 m KOH. Several ex situ measurements and quasi in situ Raman spectroscopy uncover that NiS irreversibly transformed to a carbonate-intercalated γ−NiOOH phase under the alkaline OER conditions, which serves as the actual active structure for the OER. Additionally, this in situ formed active phase successfully catalyzes the selective oxidation of alcohol, aldehyde, and amine-based organic substrates to value-added chemicals, with high efficiencies.
Second virial coefficients as a measure of protein-osmolyte interactions
Creators: name: Weatherly, G. T.
Publisher: name: The University of North Carolina at Chapel Hill University Libraries
Year: 2001

description: The cytoplasm contains high concentrations of cosolutes. These cosolutes include macromolecules and small organic molecules called osmolytes. However, most biophysical studies of proteins are conducted in dilute solutions. Two broad classes of models have been used to describe the interaction between osmolytes and proteins. One class focuses on excluded volume effects, while the other focuses on binding between the protein and the osmolyte. To better understand protein–smolyte interactions, we have conducted sedimentation equilibrium analytical ultracentrifugation experiments using ferricytochrome c as a model protein. From these experiments, we determined the second virial coefficients for a series of osmolytes. We have interpreted the second virial coefficient as a measure of both excluded volume and protein–osmolyte binding. We conclude that simple models are not sufficient to understand the interactions between osmolytes and proteins.
Renormalization and forcing of horseshoe orbits
Creators: name: Mendoza, Valentín
Publisher: name: arXiv
Year: 2014
Subjects: subject: Dynamical Systems (math.DS)
subject: FOS: Mathematics

description: In this paper we deal with the Boyland order of horseshoe orbits. We prove that there exists a set $\mathcal{R}$ of renormalizable horseshoe orbits containing only quasi-one-dimensional ones, that is, for these orbits the Boyland order coincides with the unimodal order.
استفاده از منحنی های هم اثر در بررسی اثرات اختلاط متری بوزین با هالوسولفورون و فلومیوکسازین در کنترل علف های هرز سیب زمینی
Publisher: name: دانشگاه کردستان
Year: 2022

description: یکی از مؤثرترین روش­ها برای جلوگیری و به تأخیر انداختن بروز مقاومت به علف­کش­ها و  افزایش طیف کنترلی علف­های­ هرز، اختلاط علف­کش­ها می­باشد. به منظور بررسی تأثیر اختلاط علف­کش­های متری­بوزین با هالوسولفورون و فلومیوکسازین، آزمایشی بصورت فاکتوریل در قالب طرح بلوک­های کامل تصادفی در اردبیل در سال 1398 انجام شد. در اختلاط متری­بوزین با هالوسولفورون، علف­کش متری­بوزین با دزهای 93/10، 87/21، 75/43، 5/87، 175، 350 و 700 گرم ماده مؤثره در هکتار و هالوسولفورون با دزهای 78/0، 562/1، 125/3، 25/6، 5/12، 25 و 50 گرم ماده مؤثره در هکتار در نسبت­های اختلاط (0:100)، (2:98)، (7:93)، (18:82) و (100:0) درصد در سه تکرار استفاده شد. در اختلاط متری­بوزین با فلومیوکسازین، علف­کش متری­بوزین با دزهای 93/10، 87/21، 75/43، 5/87، 175، 350 و 700 گرم ماده مؤثره در هکتار و فلومیوکسازین با دزهای  97/0، 95/1، 9/3، 81/7، 62/15، 25/31 و 5/62 گرم ماده مؤثره در هکتار در نسبت­های اختلاط (0:100)، (3:97)، (8:92)، (21:79) و (100:0) درصد در سه تکرار بکار برده شد. آزمایش در دو مرحله­ی پیش­رویشی (هفت روز پس از کاشت سیب­زمینی) و پس­رویشی (مرحله­ی سبز شدن 75 درصد سیب­زمینی، 35 روز پس از کاشت) مورد ارزیابی قرار گرفت. مقادیر  ED50و  ED90نشان داد که نسبت اختلاط (100:0) درصد متری­بوزین با هالوسولفورون و متری­بوزین با فلومیوکسازین در مرحله­ی پیش­رویشی بیشترین تأثیر را در کاهش وزن خشک کل علف­های­هرز پیچک صحرایی و چسبک داشت. منحنی­های هم اثر نشان داد که بر همکنش اختلاط متری­بوزین با هالوسولفورون و متری­بوزین با فلومیوکسازین، با استفاده از مدل افزایش غلظت، بصورت همکاهی می­باشد
Atomic force microscopy calibration of standing surface acoustic wave amplitudes
Creators: name: Hellemann, Jan
name: Müller, Filipp
name: Msall, Madeleine
name: Santos, Paulo V.
name: Ludwig, Stefan
Publisher: name: arXiv
Year: 2021
Subjects: subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: FOS: Physical sciences

description: Atomic force microscopy is an important tool for characterizing surface acoustic waves, in particular for high frequencies, where the wavelength is too short to be resolved by laser interferometry. A caveat is, that the cantilever deflection is not equal to the amplitude of the surface acoustic wave. We show, that the energy transfer from the moving surface to the cantilever instead leads to a deflection exceeding the surface modulation. We present a method for an accurate calibration of surface acoustic wave amplitudes based on comparing force-curve measurements with the equation of motion of a driven cantilever. We demonstrate our method for a standing surface acoustic wave on a GaAs crystal confined in a focusing cavity with a resonance frequency near 3 GHz.
description: 9 pages, 11 figures