cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
The potential of Red Supergiants as extra-galactic abundance probes at low spectral resolution
Creators: name: Davies, Ben
name: Kudritzki, Rolf-Peter
name: Figer, Donald F.
Publisher: name: arXiv
Year: 2010
Subjects: subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: Astrophysics of Galaxies (astro-ph.GA)
subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: FOS: Physical sciences

description: Red Supergiants (RSGs) are among the brightest stars in the local universe, making them ideal candidates with which to probe the properties of their host galaxies. However, current quantitative spectroscopic techniques require spectral resolutions of R>17,000, making observations of RSGs at distances greater than 1Mpc unfeasible. Here we explore the potential of quantitative spectroscopic techniques at much lower resolutions, R ~2-3000. We take archival J-band spectra of a sample of RSGs in the Solar neighbourhood. In this spectral region the metallic lines of FeI, MgI, SiI and TiI are prominent, while the molecular absorption features of OH, H_2O, CN and CO are weak. We compare these data with synthetic spectra produced from the existing grid of model atmospheres from the MARCS project, with the aim of deriving chemical abundances. We find that all stars studied can be unambiguously fit by the models, and model parameters of log g, effective temperatures Teff, microturbulence and global metal content may be derived. We find that the abundances derived for the stars are all very close to Solar and have low dispersion, with an average of [logZ]=0.13+/-0.14. The values of Teff fit by the models are ~150K cooler than the stars' literature values for earlier spectral types when using the Levesque et al. temperature scale, though this temperature discrepancy has very little systematic effect on the derived abundances as the equivalent widths (EWs) of the metallic lines are roughly constant across the full temperature range of RSGs. Instead, elemental abundances are the dominating factor in the EWs of the diagnostic lines. Our results suggest that chemical abundance measurements of RSGs are possible at low- to medium-resolution, meaning that this technique is a viable infrared-based alternative to measuring abundance trends in external galaxies. [Abridged]
description: 10 pages, 7 figures. Accepted for publication in MNRAS.
Recovery of geochemical processes in komatiites using linear algebraic methods
Creators: name: Hilchie, Luke
Publisher: name: University of British Columbia
Year: 2017

description: The metasomatic reactions responsible for the mineralogical and chemical alteration of komatiites have not been fully identified. The geochemical effects of these reactions inhibit recovery of the nature and extent of magmatic processes recorded by komatiite rocks. Metasomatism is a challenge in lithogeochemical research because protolith variability and metasomatism together define high-dimensional geochemical spaces. Standard methods that require a conserved element are of limited use, as conserved elements may not be present. This work develops and applies linear algebraic techniques to test mass transfer hypotheses against whole rock compositions without assumptions of elemental behaviour. The methods enabled quantification of the stoichiometry and the relative effects of magmatic and metasomatic processes in komatiites. Such processes include magmatic differentiation, serpentinization, and breakdown of clinopyroxene to actinolite. Three main findings are: (1) geochemical and petrological evidence exists for within-flow differentiation and the possibility of lateral continuity between komatiite and komatiitic basalt flows; (2) serpentinization occurred neither by isochemical nor fully metasomatic processes in a lava flow from Pyke Hill in the Abitibi greenstone belt; and (3) small magnitudes of metasomatic reactions are sufficient to modify primary geochemical signals, such that their neglect in geochemical interpretation could lead to incorrect conclusions. Future studies could delve deeper into the possibility of lateral continuity between komatiites and komatiitic basalts, and expand determination of viable serpentinization reactions to a wider range of localities and lithologies.
Unusual Coordination Behaviour of Pn-Ligand Complexes with Tl+ [Ungewöhnliches Koordinationsverhalten von Pn-Ligandkomplexen gegenüber Tl+]
Creators: name: Welsch, Stefan
name: Gregoriades, Laurence John
name: Sierka, Marek
name: Zabel, Manfred
name: Virovets, Alexander
name: Scheer, Manfred
Publisher: name: Universität Regensburg
Year: 2007
Subjects: subject: pi interactions; coordination polymers; phosphorus; thallium; weakly coordinating anions
subject: 540 Chemie

description: Pentaphosphaferrocene coordinates as a ligand to the large monocation Tl+. In addition, one of the phosphorus atoms of each cyclo-P5 moiety coordinates to a neighboring Tl+ ion to give a one-dimensional polymer. Even at low temperatures, fast rotation of the P5 rings is observed in solution and in the solid state.
Coordination Behavior of the 1,2,3-Triphosphaferrocene [Cp′′′Fe(η5-P3C2(H)Ph)] with Organometallic Moieties
Creators: name: Deng, Shining
name: Schwarzmaier, Christoph
name: Zabel, Manfred
name: Nixon, John F.
name: Timoshkin, Alexey Y.
name: Scheer, Manfred
Publisher: name: Universität Regensburg
Year: 2009
Subjects: subject: 540 Chemie

description: The reaction of the 1,2,3-triphosphaferrocene [Cp′′′Fe(η5-P3C2(H)Ph)] (1) with the Lewis acidic complex [PtCl2(PEt3)]2 yields the monosubstituted derivative [Cp′′′Fe(η5-P3C2(H)Ph){PtCl2(PEt3)}] (2), in which the Pt moiety is located at the P atom adjacent to the C(H) group of the cyclo-P3C2 ring. Using an excess of the Pt complex no multiple substitution occurs. In contrast, using [W(CO)5] units as Lewis acids results in mono-, di-, and tricoordination at the cyclo-P3C2 ring. The products, [Cp′′′Fe(η5-P3C2(H)Ph){W(CO)5}n] (n = 1 (3), 2 (4), 3 (5)), have all been spectroscopically characterized, and the substitution patterns of the experimentally found (mono- and disubstituted) isomers are found to be in accordance with the energetically favored derivatives calculated by DFT methods. For these structures the energetically favored rotational conformers have also been calculated. The energetically favored 2,3-coordinated isomer 4b could be crystallized, and its structure and that of the tricoordinated derivative 5 were determined by X-ray diffraction methods.
Synthesis and Crystal Structures of Novel Copper(I) Complexes of a Phosphanylborane
Creators: name: Schwan, Karl-Christian
name: Adolf, Ariane
name: Bodensteiner, Michael
name: Zabel, Manfred
name: Scheer, Manfred
Publisher: name: Universität Regensburg
Year: 2008
Subjects: subject: Boron; Phosphorus; Copper; Iodide; Cluster compounds
subject: 540 Chemie

description: The novel copper iodide clusters [Cu3(-I)(3-I)2(PH2BH2·NMe3)3] (2) and [Cu4(-I)2(3-I)2(PH2BH2·NMe3)3] (3) were synthesized by treating CuI with the primary phosphine (H2PBH2·NMe3). The novel features of both compounds, which have been characterized by X-ray crystallography, are the unsymmetrical constitution of the copper iodide core due to the influence of the monodentate phosphorus ligand. This results in copper atoms with different coordination numbers within the compound. Complex 2, the major product of the reaction, contains a distorted octahedral Cu3I3-core, in which one vertex is missing. Complex 3 was isolated as a by-product and is composed of a Cu4I4-core in a distorted octahedral coordination.
The coordination chemistry of group 15 element ligand complexes—a developing area
Creators: name: Scheer, Manfred
Publisher: name: Universität Regensburg
Year: 2008
Subjects: subject: 540 Chemie

description: A survey of the contemporary challenges of the field of unsubstituted group 15 element ligand complexes (excluding N) is given. The focus of the article is on the coordination chemistry behaviour of such En ligand complexes. This field is subdivided into two areas of reactivity: En ligand complexes with (i) noncoordinated Lewis-acidic cations and (ii) Lewis-acidic coordination compounds containing at least one permanently coordinating ligand. In the latter case, insoluble 1D and 2D polymers respectively are obtained; however, under special conditions soluble, spherical, fullerene-like giant molecules are formed. These nano-sized molecules are up to 2.4 nm in diameter and are able to encapsulate small molecules in their holes. In contrast, the first-mentioned field uses weakly coordinating anions to obtain readily soluble di- and polycationic products. These show depolymerisation tendencies in solution under the formation of oligomer–monomer equilibria and thus reveal dynamic supramolecular aggregation processes.
Undergraduate Bioinformatics Workshops Provide Perceived Skills
Creators: name: Cresiski, Robin H.
Publisher: name: ASM
Year: 2014

description: Bioinformatics is becoming an important part of undergraduate curriculum, but expertise and well-evaluated teaching materials may not be available on every campus. Here, a guest speaker was utilized to introduce bioinformatics and web-available exercises were adapted for student investigation. Students used web-based nucleotide comparison tools to examine the medical and evolutionary relevance of a unidentified genetic sequence. Based on pre- and post-workshop surveys, there were significant gains in the students understanding of bioinformatics, as well as their perceived skills in using bioinformatics tools. The relevance of bioinformatics to a student’s career seemed dependent on career aspirations.
title: A Case Study of Professional Boundary Issues Experienced by Undergraduate Psychology Students in a Supervised Field Experience Course
title: Boundary issues in undergraduate psychology field experience courses
titleType: AlternativeTitle
Creators: name: Sharp, Gwen
name: Yao, Richard
name: Cresiski, Robin H.
name: Hahn, Kate
Publisher: name: Sage
Year: 2013

description: There has been little research on the types of boundary issues encountered in undergraduate psychology field experience courses, despite the increased popularity of such courses. This case study identifies the frequency and types of boundary issues faced by undergraduate psychology students enrolled in such a course, including the most common issues experienced at different types of placements. The case study included 50 students enrolled in a supervised undergraduate psychology field experience course at a small public teaching institution. Boundary issues, including inappropriate comments, behavior, or physical contact from employees or clients, were not uncommon, but varied based on student characteristics and type of placement. Women reported more frequent, and serious, inappropriate comments and behavior than men. Boundary issues were most common in drug and alcohol rehabilitation agencies. The findings from this case study suggest several steps field experience supervisors may take to improve the learning experience for students.
Ag Bimetallic Molecular Clips with Adaptive Coordination Behavior for Supramolecular Chemistry
Creators: name: Welsch, Stefan
name: Lescop, Christophe
name: Scheer, Manfred
name: Réau, Régis
Publisher: name: Universität Regensburg
Year: 2008
Subjects: subject: 540 Chemie

description: An Ag dimer featuring a bridging phosphane ligand acts as an adaptive molecular clip for the coordination-driven synthesis of π-stacked metallocyclophanes.
First Kepler results on compact pulsators III: Subdwarf B stars with V1093~Her and hybrid (DW~Lyn) type pulsations
Creators: name: Reed, M. D.
name: Kawaler, S. D.
name: Ostensen, R. H.
name: Bloemen, S.
name: Baran, A.
name: Telting, J. H.
name: Silvotti, R.
name: Charpinet, S.
name: Quint, A. C.
name: Handler, G.
name: Gilliland, R. L.
name: Borucki, W. J.
name: Koch, D. G.
name: Kjeldsen, H.
name: Christensen-Dalsgaard, J.
Publisher: name: arXiv
Year: 2010
Subjects: subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: FOS: Physical sciences

description: We present the discovery of nonradial pulsations in five hot subdwarf B (sdB) stars based on 27 days of nearly continuous time-series photometry using the Kepler spacecraft. We find that every sdB star cooler than $\approx 27\,500\,$K that Kepler has observed (seven so far) is a long-period pulsator of the V1093~Her (PG~1716) class or a hybrid star with both short and long periods. The apparently non-binary long-period and hybrid pulsators are described here. The V1093~Her periods range from one to 4.5~h and are associated with $g-$mode pulsations. Three stars also exhibit short periods indicative of $p-$modes with periods of 2 to 5~m and in addition, these stars exhibit periodicities between both classes from 15 to 45~m. We detect the coolest and longest-period V1093~Her-type pulsator to date, KIC010670103 ($T_eff\approx 20\,900\,$K, $P_max\approx 4.5$~h) as well as a suspected hybrid pulsator, KIC002697388 which is extremely cool ($T_{\rm eff}\approx 23\,900\,$K) and for the first time hybrid pulsators which have larger $g-$mode amplitudes than $p-$mode ones. All of these pulsators are quite rich with many frequencies and we are able to apply asymptotic relationships to associate periodicities with modes for KIC010670103. Kepler data are particularly well-suited for these studies as they are long-duration, extremely high duty cycle observations with well-behaved noise properties.
description: 23 pages, 10 figures, 5 tables, accepted to MNRAS
Sparticle Spectrum of Large Volume Compactification
Creators: name: Choi, Kiwoon
name: Nilles, Hans Peter
name: Shin, Chang Sub
name: Trapletti, Michele
Publisher: name: arXiv
Year: 2010
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: We examine the large volume compactification of Type IIB string theory or its F theory limit and the associated supersymmetry breakdown and soft terms. It is crucial to incorporate the loop-induced moduli mixing, originating from radiative corrections to the Kahler potential. We show that in the presence of moduli mixing, soft scalar masses generically receive a D-term contribution of the order of the gravitino mass m_{3/2} when the visible sector cycle is stabilized by the D-term potential of an anomalous U(1) gauge symmetry, while the moduli-mediated gaugino masses and A-parameters tend to be of the order of m_{3/2}/8pi^2. It is noticed also that a too large moduli mixing can destabilize the large volume solution by making it a saddle point.
description: 29 pages
Mono-, di- and polymetallic TlI complexes stabilized by a 2,5-bis(2-pyridyl)-1-phenyl-phosphole ligand
Creators: name: Welsch, Stefan
name: Lescop, Christian
name: Réau, Régis
name: Scheer, Manfred
Publisher: name: Universität Regensburg
Year: 2009
Subjects: subject: 540 Chemie

description: Depending on the nature of the counterion and of the solvent, novel TlI complexes of different nuclearity featuring a 2,5-bis(2-pyridyl)phosphole ligand were synthesized.
Desynchronization transitions in nonlinearly coupled phase oscillators
Creators: name: Burylko, Oleksandr
name: Pikovsky, Arkady
Publisher: name: arXiv
Year: 2011
Subjects: subject: Adaptation and Self-Organizing Systems (nlin.AO)
subject: FOS: Physical sciences

description: We consider the nonlinear extension of the Kuramoto model of globally coupled phase oscillators where the phase shift in the coupling function depends on the order parameter. A bifurcation analysis of the transition from fully synchronous state to partial synchrony is performed. We demonstrate that for small ensembles it is typically mediated by stable cluster states, that disappear with creation of heteroclinic cycles, while for a larger number of oscillators a direct transition from full synchrony to a periodic or quasiperiodic regime occurs.
description: 25 pages, 8 figures
Min-Rank Conjecture for Log-Depth Circuits
Creators: name: Jukna, S.
name: Schnitger, G.
Publisher: name: arXiv
Year: 2010
Subjects: subject: Computational Complexity (cs.CC)
subject: FOS: Computer and information sciences

description: A completion of an m-by-n matrix A with entries in {0,1,*} is obtained by setting all *-entries to constants 0 or 1. A system of semi-linear equations over GF(2) has the form Mx=f(x), where M is a completion of A and f:{0,1}^n --> {0,1}^m is an operator, the i-th coordinate of which can only depend on variables corresponding to *-entries in the i-th row of A. We conjecture that no such system can have more than 2^{n-c\cdot mr(A)} solutions, where c>0 is an absolute constant and mr(A) is the smallest rank over GF(2) of a completion of A. The conjecture is related to an old problem of proving super-linear lower bounds on the size of log-depth boolean circuits computing linear operators x --> Mx. The conjecture is also a generalization of a classical question about how much larger can non-linear codes be than linear ones. We prove some special cases of the conjecture and establish some structural properties of solution sets.
description: 22 pages, to appear in: J. Comput.Syst.Sci.
Species-specific and seasonal differences in the resistance of salt-marsh vegetation to wave impact
Creators: name: Reents, Svenja
name: Möller, Iris
name: Evans, Ben R.
name: Schoutens, Ken
name: Jensen, Kai
name: Paul, Maike
name: Bouma, Tjeerd J.
name: Temmerman, Stijn
name: Lustig, Jennifer
name: Kudella, Matthias
name: Nolte, Stefanie
Publisher: name: Lausanne : Frontiers Media
Year: 2022
Subjects: subject: flume experiment
subject: plant properties
subject: salt marshes
subject: seasonality
subject: wave-induced damage
subject: Dewey Decimal Classification::500 | Naturwissenschaften::550 | Geowissenschaften

description: The coastal protection function provided by the vegetation of tidal wetlands (e.g. salt marshes) will play an important role in defending coastlines against storm surges in the future and depend on how these systems respond to such forcing. Extreme wave events may induce vegetation failure and thereby risking loss of functionality in coastal protection. However, crucial knowledge on how hydrodynamic forces affect salt-marsh vegetation and whether plant properties might influence plant resistance is missing. In a true-to-scale flume experiment, we exposed two salt-marsh species to extreme hydrodynamic conditions and quantified wave-induced changes in plant frontal area, which was used to estimate plant damage. Moreover, half of the plants were artificially weakened to induce senescence, thus allowing us to examine potential seasonal effects on plant resistance. Morphological, biomechanical as well as biochemical plant properties were assessed to better explain potential differences in wave-induced plant damage. Our results indicate that the plants were more robust than expected, with pioneer species Spartina anglica showing a higher resistance than the high-marsh species Elymus athericus. Furthermore, wave-induced plant damage mostly occurred in the upper part of the vegetation canopy and thus higher canopies (i.e. Elymus athericus) were more vulnerable to damage. Besides a taller canopy, Elymus athericus had weaker stems than Spartina anglica, suggesting that biomechanical properties (flexural stiffness) also played a role in defining plant resistance. Under the highest wave conditions, we also found seasonal differences in the vulnerability to plant damage but only for Elymus athericus. Although we found higher concentrations of a strengthening compound (biogenic silica) in the plant material of the weakened plants, the flexibility of the plant material was not affected indicating that the treatment might not has been applied long enough. Nevertheless, this study yields important implications since we demonstrate a high robustness of the salt-marsh vegetation as well as species-specific and seasonal differences in the vulnerability to plant damage.
Colourings of lattices and coincidence site lattices
Creators: name: Loquias, Manuel Joseph C.
name: Zeiner, Peter
Publisher: name: arXiv
Year: 2010
Subjects: subject: Metric Geometry (math.MG)
subject: FOS: Mathematics
subject: 52C07, 52C23, 11H06, 20G45, 20H15

description: The relationship between the coincidence indices of a lattice $Γ_1$ and a sublattice $Γ_2$ of $Γ_1$ is examined via the colouring of $Γ_1$ that is obtained by assigning a unique colour to each coset of $Γ_2$. In addition, the idea of colour symmetry, originally defined for symmetries of lattices, is extended to coincidence isometries of lattices. An example involving the Ammann-Beenker tiling is provided to illustrate the results in the quasicrystal setting.
description: 9 pages, 6 figures
Characterization and identification of hepatic mesenchymal stromal cell populations
Creators: name: Tausan, Daniel
Publisher: name: University of British Columbia
Year: 2021

description: Mesenchymal stromal or stem cells (MSCs) play central roles in numerous physiological processes including tissue development, regeneration and homeostasis. In this study, the homeostatic properties of hepatic MSC’s were characterized by next generation sequencing (NGS) technology at single cell resolution. Hic1 (Hypermethylated in Cancer 1) was found to be a systemic marker of MSCs, and mouse models incorporating a CreERT2 knock-in into this locus were used to genetically trace and characterize labeled hepatic MSCs (HMSCs). Three hepatic mesenchymal cell types were marked by Hic1-expression, the vitamin A storing hepatic stellate cells (HSC), portal fibroblasts (PF) and the hepatic capsule lining mesothelial cell (MC). These HMSCs were known to contribute to regeneration and renewal, and herein data is provided to show that Hic1-expressing cells proliferate in response to liver injury and acquire a pro-regenerative myofibroblastic-like phenotype. Additionally, analysis of Hic1-lineage marked cells from liver with single cell RNA-seq showed that the liver sinusoidal endothelial cell (LSEC) compartment also appeared to be labelled. Hic1-expression within LSECs remains inconclusive and requires further investigation. No marker to date has captured the full spectrum of HMSCs making Hic1 a unique candidate to study the liver stroma.
Minimal symmetric Darlington synthesis
Creators: name: Baratchart, Laurent
name: Enqvist, Per
name: Gombani, Andrea
name: Olivi, Martine
Publisher: name: arXiv
Year: 2011
Subjects: subject: Optimization and Control (math.OC)
subject: Systems and Control (eess.SY)
subject: FOS: Mathematics
subject: FOS: Electrical engineering, electronic engineering, information engineering

description: We consider the symmetric Darlington synthesis of a p x p rational symmetric Schur function S with the constraint that the extension is of size 2p x 2p. Under the assumption that S is strictly contractive in at least one point of the imaginary axis, we determine the minimal McMillan degree of the extension. In particular, we show that it is generically given by the number of zeros of odd multiplicity of I-SS*. A constructive characterization of all such extensions is provided in terms of a symmetric realization of S and of the outer spectral factor of I-SS*. The authors's motivation for the problem stems from Surface Acoustic Wave filters where physical constraints on the electro-acoustic scattering matrix naturally raise this mathematical issue.
Halogenation of Lewis acid/base stabilised phosphanylboranes
Creators: name: Schwan, Karl-Christian
name: Vogel, Ulf
name: Adolf, Ariane
name: Zabel, Manfred
name: Scheer, Manfred
Publisher: name: Universität Regensburg
Year: 2009
Subjects: subject: Lewis-acid/base-stabilised phosphanylborane; Phosphorous; Boron; Halogenation; Iodine; Bromine
subject: 540 Chemie

description: The reaction pattern of the Lewis-acid/base stabilised phosphanylborane [(CO)5W(H2PBH2 · NMe3)] (1) with elemental halogens is comprehensively studied. The reaction with iodine and bromine leads to a selective halogenation at the tungstencarbonyl moiety under formation of [WX2(CO)4(H2PBH2 · NMe3)] (X = I (2), Br (3)). Whereas 2 is a stable product the brominated compound 3 dimerises easily to [WBr2(CO)3(H2PBH2 · NMe3)]2 (4) under lost of CO. The CO elimination reaction of 3 is extensively studied. If 3 is reacted with [Et4N][Br] the ionic compound [Et4N][WBr3(CO)3(H2PBH2 · NMe3)] (5) is formed. Otherwise, if 3 is combined with the donor ligand [H2PBH2 · NMe3], the complex [WBr2(CO)3(H2PBH2 · NMe3)2] (6) is obtained. Compounds 2–6 are comprehensively characterised by X-ray diffraction analysis, NMR, and IR spectroscopy.
Crosstalk between somatostatin receptor subtypes and cannabinoid receptor 1 in excitotoxicity
Creators: name: Zou, Shenglong
Publisher: name: University of British Columbia
Year: 2020

description: Both somatostatin (SST) and cannabinoid receptor 1 (CB1R) are critical components modulating neurotransmission in the central nervous system (CNS), with sharing functional properties in various neurological activities. To explore their potential crosstalk, first we investigated the expression of SST and CB1R in rat brain hypothalamus and hippocampus. The distributional patterns and colocalization of CB1R and SST were selective and region specific. Neuronal population expressing either SST or CB1R alone, as well as colocalization were seen in various intensities in different regions, suggesting a possible interaction. SST exerts its biological effects via binding to somatostatin receptors (SSTRs). Both SSTRs and CB1R belong to G-protein coupled receptor family that are known to function as oligomers. Accordingly, we investigated the colocalization of CB1R and SSTR5 in rat brain and HEK-293 cells cotransfected with hCB1R and hSSTR5. Our results showed that CB1R and SSTR5 colocalized in rat brain regions. In cotransfected HEK-293 cells, SSTR5 and CB1R existed in a constitutive heteromeric complex under basal condition. Agonist treatments lead to the disruption of CB1R/SSTR5 heterodimer, along with preferential formation of SSTR5 homodimer and dissociation of CB1R homodimer. cAMP and ERK1/2 signaling was modulated in a SSTR5-dominant manner in co-transfected cells. To explore pathological significance of such interaction, we further expanded our study in HD transgenic mice and Huntingtin (Htt) knock-in striatal neuronal cells. We observed significant loss of neuronal subpopulation displaying colocalization between SSTRs and CB1R with selective sparing of SSTR positive neurons in cortex and hippocampus but not in striatum of 11-week-old R6/2 mice, in comparison to wild-type and 7-week-old R6/2 mice. Using mHtt knock-in (STHdhQ¹¹¹/¹¹¹) and wild-type (STHdhQ⁷/⁷) striatal cells, we discovered that STHdhQ¹¹¹/¹¹¹ cells were more vulnerable to QUIN and displayed suppressed cell survival signalings. Receptor-specific agonist protected cells against QUIN-induced toxicity and selectively activated ERK1/2 in both STHdh cells. Co-activation of SSTR subtypes and CB1R resulted in diminished protective effects, delayed ERK1/2 phosphorylation and altered receptor complex composition, with more pronounced effects in STHdhQ¹¹¹/¹¹¹ cells than STHdhQ⁷/⁷ cells. Taken together, our results provide evidence for functional interaction between SSTR and CB1R, emphasizing its therapeutic potentials in excitotoxicity and associated neurological disorders.
Сравнительный анализ марок сталей магнитных систем авиационных двигателей
Creators: name: Владимировна, Шевченко Валентина
name: Зубань Евгений Станиславович
Publisher: name: Zenodo
Year: 2017
Subjects: авиационные двигатели
гистерезис
стали для двигателей

description: На русском: [Шевченко В.В., Зубань Е.С. Сравнительный анализ марок сталей магнитных систем авиационных двигателей // Тезисы докладов 25-й международной научно-практической конференции "Информационные технологии: наука, техника, технология, образование, здоровье" (MicroCAD-2017), 17-19 мая 2017 года, Харьков (ISSN 2222-2944), в 4-х частях, часть 2, cекция 9 "Электромеханическое и электрическое преобразование энергии". – Украина,  Харьков: НТУ "ХПИ", 2017. – С. 178. https://doi.org/10.5281/zenodo.2600278]

Ключевые слова: авиационные двигатели,  гистерезис, стали для двигателей.

Репозиторий НТУ "ХПИ" - открыть pdf. Архив НТУ "ХПИ" - открыть pdf (http, https).

Сертификат участника конференции MicroCAD-2017 Шевченко В.В.

Сборник: в репозитории НТУ "ХПИ" - открыть pdf (все части сборника), на zenodo - скачать pdf.
Chemistry of Bridging Phosphanes: A Comparative Study within CuI-AgI-AuI Triad-Based Homonuclear Dimers
Creators: name: Welsch, Stefan
name: Nohra, Brigitte
name: Peresypkina, Eugenia V.
name: Lescop, Christian
name: Scheer, Manfred
name: Réau, Régis
Publisher: name: Universität Regensburg
Year: 2009
Subjects: subject: bridging ligands; coordination modes; gold; P ligands; silver
subject: 540 Chemie

description: Bridging ligands in AgI and AuI bimetallic complexes: The P moiety of bis(2-pyridyl)phosphole acts as a symmetrically, semi-, or non-bridging donor in AgI dimers (see figure). In related AuI complexes, only the non-bridging mode is observed. An unsaturated AgI dimer is used as an adaptive molecular clip for the synthesis of -stacked metallocyclophanes. Bis(2-pyridyl)phosphole C reacted with AgPF6 and dppm giving rise to dicationic dimer 1 in which C acts as a 1N:1,2P:2N-donor with a symmetrically bridging P-centre. This complex gives the first example of dimers based on trigonal planar metal centres bearing a bridging 3,3-phosphane ligand. The reaction of two equivalents of C with AgPF6 and Ag{Al[OC(CF3)3]4} afforded dicationic dimers 2 and 3 of general formula Ag2(C)22+, respectively. X-ray diffraction studies showed that one ligand C acts as a 1N:1,2P:2N-donor with a symmetrically bridging P-centre and one behaves as a 1N:2P-chelate. In complex 3, one toluene molecule interacts with an Ag centre, giving the first example of a mixed coordination dimer featuring a bridging P-donor. AgI-dimers 4 a-c of the general formula Ag2(C)32+, 2 X- (X=PF6, BF4, Al[OC(CF3)3]4) have been prepared according to different routes and characterised by X-ray diffraction study. In these derivatives, C exhibits a variety of coordination modes depending on the nature of the counteranion and of the solvent molecules included in the asymmetric units. These complexes can feature 0, 1, or 2 bridging P-donors. These results definitively demonstrate that the P-centre of phosphane ligands can easily switch from a bridging to a semi-bridging and a non-bridging coordination mode. Dimer 2 is used as an adaptive molecular clip for the synthesis of -stacked metallocyclophanes 7 a, b and 8 upon reaction with ditopic linkers. X-ray diffraction studies revealed that these supramolecular species behave as receptors for the counteranions (PF6, BF4) and that the nature of the anion impacts the stereochemistry of the supramolecular metallocyclophanes. AuI-Dimers 10 a, b bearing two ligands C acting as 1N:2P-chelates are prepared and characterised in the solid-state.
Eine Familie mit komplexiertem Triphosphaallyl-Radikal, -Kation und -Anion [The Complexed Triphosphaallyl Radical, Cation, and Anion Family]
Creators: name: Scheer, Manfred
name: Kuntz, Christian
name: Stubenhofer, Markus
name: Linseis, Michael
name: Winter, Rainer F.
name: Sierka, Marek
Publisher: name: Universität Regensburg
Year: 2009
Subjects: subject: Allylliganden; Dichtefunktionalrechnungen; Phosphinidene; Phosphor; Radikale
subject: 540 Chemie

description: Radikal für Redoxstudien: Die Photolyse von [Cp*P{W(CO)5}2] mit einem Diphosphen verläuft über ein radikalisches Intermediat und liefert ein luftstabiles komplexiertes Triphosphaallylradikal, in dem das ungepaarte Elektron gleichmäßig über beide terminale P-Atome verteilt ist. Die Oxidation des Radikals führt zu dem lediglich bei tiefen Temperaturen in Lösung stabilen Triphosphaallylkation, während bei der Reduktion das stabile Triphosphaallylanion gebildet wird. Mes*=2,4,6-Tri-tert-butylphenyl.
T Cell-Independent and Toll-like Receptor-Dependent Antigen-Driven Activation of Autoreactive B Cells
Creators: name: Cresiski, Robin H.
name: Christensen, Sean R.
name: Sweet, Rebecca A.
name: Hershberg, Uri
name: Shlomchik, Mark J.
Publisher: name: Elsevier
Year: 2008
Subjects: MOLIMMUNO
CELLIMMUNO

description: On the lupus-prone MRL-lpr/lpr (MRL-lpr) background, AM14 rheumatoid factor (RF) B cells are activated, differentiate into plasmablasts, and undergo somatic hypermutation outside of follicles. Using multiple strategies to impair T cells, we found that such AM14 B cell activation did not require T cells but could be modulated by them. In vitro, the signaling adaptor MyD88 is required for IgG anti-chromatin to stimulate AM14 B cell proliferation when T cells are absent. However, the roles of Toll-like receptors (TLRs) in AM14 B cell activation in vivo have not been investigated. We found that activation, expansion, and differentiation of AM14 B cells depended on MyD88; however, mice lacking either TLR7 or TLR9 displayed partial defects, indicating complex roles for these receptors. T cell-independent activation of certain autoreactive B cells, which gain stimuli via endogenous TLR ligands instead of T cells, may be the initial step in the generation of canonical autoantibodies.
Reactivity of Transition Metal-Phosphorus Triple Bonds towards Triply Bonded [{CpMo(CO)2}2]: Formation of Heteronuclear Cluster Compounds
Creators: name: Scheer, Manfred
name: Himmel, Daniel
name: Kuntz, Christian
name: Zhan, Shuzhong
name: Leiner, Eva
Publisher: name: Universität Regensburg
Year: 2008
Subjects: subject: cluster compounds; molybdenum; phosphorus; reactive intermediates; tungsten
subject: 540 Chemie

description: Thermolysis of [Cp*P{W(CO)5}2] (1) in the presence of [{CpMo(CO)2}2] leads to the novel complexes [{(CO)2Cp*W}{CpMo(CO)2}(,2:1:1-P2{W(CO)5}2)] (6; Cp=5-C5H5, Cp*=5-C5Me5), [{(-O)(CpMoWCp*)W(CO)4}{3-PW(CO)5}2] (7), [{CpMo(CO)2}2{Cp*W(CO)2}{3-PW(CO)5}] (8) and [{CpMo(CO)2}2{Cp*W(CO)2}(3-P)] (9). The structural framework of the main products 8 and 9 can be described as a tetrahedral Mo2WP unit that is formed by a cyclisation reaction of [{CpMo(CO)2}2] with an [Cp*(CO)2WPW(CO)5] intermediate containing a WP triple bond and subsequent metal-metal and metal-phosphorus bond formation. Photolysis of 1 in the presence of [{CpMo(CO)2}2] gives 8, 9 and phosphinidene complex [(3-PW(CO)5){CpMo(CO)2W(CO)5}] (10), in which the P atom is in a nearly trigonal-planar coordination environment formed by one {CpMo(CO)2} and two {W(CO)5} units. Comprehensive structural and spectroscopic data are given for the products. The reaction pathways are discussed for both activation procedures, and DFT calculations reveal the structures with minimum energy along the stepwise Cp* migration process under formation of the intermediate [Cp*(CO)2WPW(CO)5].
Temperature Controlled Reversible Change of the Coordination Modes of the Highly Symmetrical Multitopic Ligand To Construct Coordination Assemblies: Experimental and Theoretical Studies
Creators: name: Zheng, Bo
name: Dong, Hao
name: Bai, Junfeng
name: Li, Yizhi
name: Li, Shuhua
name: Scheer, Manfred
Publisher: name: Universität Regensburg
Year: 2008
Subjects: subject: 540 Chemie

description: By fine-tuning the reaction temperature to 5, 15, 30, and 50 °C, respectively, four different complexes, [Cd(HC4O4)2(H2O)4] (1), [Cd4(C4O4)4(H2O)16]•(H2O)2 (2), [Cd(C4O4)(H2O)2] (3), and [Cd(C4O4)(H2O)2] (4), were formed successfully from the identical initial reaction mixture. Moreover, an unprecedented reversible interconversion among the four complexes at the corresponding reaction temperatures mediated by the mother liquor was observed.
Molecular transport and flow past hard and soft surfaces: Computer simulation of model systems
Creators: name: Léonforte, F.
name: Servantie, J.
name: Pastorino, C.
name: Müller, M.
Publisher: name: arXiv
Year: 2010
Subjects: subject: Soft Condensed Matter (cond-mat.soft)
subject: Fluid Dynamics (physics.flu-dyn)
subject: FOS: Physical sciences

description: The properties of polymer liquids on hard and soft substrates are investigated by molecular dynamics simulation of a coarse-grained bead-spring model and dynamic single-chain-in-mean-field (SCMF) simulations of a soft, coarse-grained polymer model. Hard, corrugated substrates are modelled by an FCC Lennard-Jones solid while polymer brushes are investigated as a prototypical example of a soft, deformable surface. From the molecular simulation we extract the coarse-grained parameters that characterise the equilibrium and flow properties of the liquid in contact with the substrate: the surface and interface tensions, and the parameters of the hydrodynamic boundary condition. The so-determined parameters enter a continuum description like the Stokes equation or the lubrication approximation.
description: 41 pages, 13 figures
Dependence of time-lags upon luminosity in neutron-star low-mass X-ray binaries
Creators: name: Peirano, Valentina
name: Méndez, Mariano
Publisher: name: Zenodo
Year: 2021

description: Kilohertz quasi-periodic oscillations (kHz QPOs) are fast variability features in the emission of neutron-star low-mass X-ray binaries (LMXBs) that are believed to have their origin in the innermost regions of binary systems, close to the central object. Studying this variability allows us to probe the extreme conditions under which matter interacts with the system, helping us understand the mechanism responsible for the kHz QPOs and the way matter behaves as it gets closer to the neutron star. Using timing analysis techniques, it has been shown that the fractional rms amplitude of the lower kHz QPOs decreases exponentially with the luminosity of the source in which the QPOs occur. We show here, for the first time, that the slope of the time-lag spectrum of the lower kHz QPO in 8 neutron-star LMXBs follows the same trend with luminosity. This strong correlation suggests that a single property of the system is responsible for the energy-dependent rms amplitude and time lags of the kHz QPOs in these sources. Since time-dependent Comptonisation with feedback between the corona and the accretion disc is currently the only mechanism that can explain both the lags and rms spectra of the QPO, and since the properties of the corona in these sources change with luminosity, we propose that the QPOs arise from the onset of resonance in a coupled oscillation between the disc and the corona. This resonance would be excited over a narrow range of sizes, electron temperatures and optical depths of the corona when variability at the appropriate frequency appears in the disc.
Anti-chromatin antibodies drive in vivo antigen-specific activation and somatic hypermutation of rheumatoid factor B cells at extrafollicular sites
Creators: name: Cresiski, Robin H.
name: William, Jacqueline
name: Hershberg, Uri
name: Shlomchik, Mark J.
Publisher: name: Wiley
Year: 2007
Subjects: B cells
Systemic lupus erythematosus
Autoantibodies

description: A dominant type of spontaneous autoreactive B cell activation in murine lupus is the extrafollicular generation of plasmablasts. The factors governing such activation have been difficult to identify due to the stochastic onset and chronic nature of the response. Thus, the ability to induce a similar autoreactive B cell response with a known autoantigen in vivo would be a powerful tool in deciphering how autoimmune responses are initiated. We report here the establishment and characterization of a system to initiate autoreactive extrafollicular B cell responses, using IgG anti-chromatin antibodies, that closely mirrors the spontaneous response. We demonstrate that exogenously administered anti-chromatin antibody, presumably by forming immune complexes with released nuclear material, drives activation of rheumatoid factor B cells in AM14 Tg mice. Anti-chromatin elicits autoreactive B cell activation and development into antibody-forming cells at the T zone/red pulp border. Plasmablast generation occurs equally in BALB/c, MRL/+ and MRL/lpr mice, indicating that an autoimmune-prone genetic background is not required for the induced response. Importantly, infused IgG anti-chromatin induces somatic hypermutation in the absence of a GC response, thus proving the extrafollicular somatic hypermutation pathway. This system provides a window on the initiation of an autoantibody response and reveals authentic initiators of it.
Cataclysmic Variables and Other Compact Binaries in the Globular Cluster NGC 362: Candidates from Chandra and HST
Creators: name: Margon, Bruce
name: Beck-Winchatz, B.
name: Homer, L.
name: Pooley, D.
name: Bassa, C. G.
name: Anderson, S. F.
name: Lewin, W. H. G.
name: Verbunt, F.
name: Kong, A. K. H.
name: Plotkin, R. M.
Publisher: name: arXiv
Year: 2010
Subjects: subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: FOS: Physical sciences

description: Highly sensitive and precise X-ray imaging from Chandra, combined with the superb spatial resolution of HST optical images, dramatically enhances our empirical understanding of compact binaries such as cataclysmic variables and low mass X-ray binaries, their progeny, and other stellar X-ray source populations deep into the cores of globular clusters. Our Chandra X-ray images of the globular cluster NGC 362 reveal 100 X-ray sources, the bulk of which are likely cluster members. Using HST color-magnitude and color-color diagrams, we quantitatively consider the optical content of the NGC 362 Chandra X-ray error circles, especially to assess and identify the compact binary population in this condensed-core globular cluster. Despite residual significant crowding in both X-rays and optical, we identify an excess population of Hα-emitting objects that is statistically associated with the Chandra X-ray sources. The X-ray and optical characteristics suggest that these are mainly cataclysmic variables, but we also identify a candidate quiescent low mass X-ray binary. A potentially interesting and largely unanticipated use of observations such as these may be to help constrain the macroscopic dynamic state of globular clusters.
description: 6 pages, 6 figures, to appear in the proceedings of the conference "Binary Star Evolution: Mass Loss, Accretion, and Mergers," Mykonos, Greece, June 22-25, 2010
Unexpected Differences in the Coordination Behaviour of 1,2,4-Triphosphaferrocenes towards Cu Chloride
Creators: name: Deng, Shining
name: Schwarzmaier, Christoph
name: Vogel, Ulf
name: Zabel, Manfred
name: Nixon, John F.
name: Scheer, Manfred
Publisher: name: Universität Regensburg
Year: 2009
Subjects: subject: Supramolecular chemistry; Copper; Fragmentation reactions; Tri­phosphaferrocenes; Tetraphosphabutadiene ligand
subject: 540 Chemie

description: The coordination behaviour of 1,2,4-triphosphaferrocenes [FeCpR(5-P3C2tBu2)] [CpR = Cp (1), Cp (2)] towards CuI chloride is significantly influenced by the substitution pattern of the cyclopentadienyl ring attached to iron. The dimeric copper complexes [{FeCp(5:1:1-P3tBu2C2)}{-CuCl(MeCN)}]2 (3) and [{FeCp (5:1:1-P3tBu2C2)}(-CuCl)]2 (4), in which two 1,2,4-triphosphaferrocenes are linked by two CuCl centres to form dimeric complexes were obtained in reactions using a 1:1 stoichiometry. Whereas in 3 a tetra-coordinated Cu atom is revealed, 4 possesses a threefold-coordinated Cu atom due to the steric influence of the bulkier Cp ligand. However, if the reaction is carried out with an excess of CuCl in a 1:2 stoichiometry for the Cp derivative 1 the same product 3 is obtained, whereas in the case of a tri-tert-butyl-substituted Cp ligand complex 2 the triphospholyl ring is fragmented under mild conditions to a tetraphosphabutadiene moiety within an iron triple-decker sandwich complex [{(FeCp)2(,4:4:1:1-P4)}{-CuCl(MeCN)}] (5) embedded in a CuCl polymer matrix.
Stellar weak decay rates in neutron-deficient medium-mass nuclei
Creators: name: Sarriguren, P.
Publisher: name: arXiv
Year: 2011
Subjects: subject: Nuclear Theory (nucl-th)
subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: FOS: Physical sciences

description: Weak decay rates under stellar density and temperature conditions holding at the rapid proton capture process are studied in neutron-deficient medium-mass waiting point nuclei extending from Ni up to Sn. Neighboring isotopes to these waiting point nuclei are also included in the analysis. The nuclear structure part of the problem is described within a deformed Skyrme Hartree-Fock + BCS + QRPA approach, which reproduces not only the beta-decay half-lives but also the available Gamow-Teller strength distributions, measured under terrestrial conditions. The various sensitivities of the decay rates to both density and temperature are discussed. In particular, we study the impact of contributions coming from thermally populated excited states in the parent nucleus, as well as the competition between beta decays and continuum electron captures.
description: 24 pages, 16 figures
A spherical molecule with a carbon-free Ih-C80 topological framework [Ein sphärisches Molekül mit einem Kohlenstoff-freien Ih-C80-topologischen Gerüst]
Creators: name: Scheer, Manfred
name: Schindler, Andrea
name: Gröger, Christian
name: Virovets, Alexander V.
name: Peresypkina, Eugenia V.
Publisher: name: Universität Regensburg
Year: 2009
Subjects: subject: carborane; fullerenes; phosphorus; self-assembly; supramolecular chemistry
subject: 540 Chemie

description: The complete encapsulation of ortho-carborane by a fullerene-like building-block system consisting of pentaphosphaferrocene and CuICl leads to the formation of the spherical supermolecule C2B10H12§[{Cp*Fe(5-P5)}12(CuCl)20]. This product of template-controlled aggregation represents the first example of a carbon-free C80 analogue possessing icosahedral symmetry.
Sex differences in the effects of aerobic exercise on neurogenesis and cognitive function in adult C57BL/6 mice
Creators: name: Gheorghe, Ana-Stefania
Publisher: name: University of British Columbia
Year: 2018

description: Aerobic exercise has positive effects on the brain and is associated with improved cognition. One mechanism through which exercise can promote brain health is by increasing adult hippocampal neurogenesis, a phenomenon that produces new function brain cells after the developmental period and throughout life. Meta-analyses of exercise interventions have shown a sex-difference in the efficacy of exercise on cognition in older adults. This current study sought to determine whether there are sex-differences in the efficacy of exercise for promoting neurogenesis and improving cognition in healthy, adult mice. Adult male and female mice were given access to a running wheel (or a disassembled wheel) for 28 days and on day 22 were given 6 days in the Morris water maze, for spatial learning, memory and reversal training. Mice were then sacrificed and examined for neurogenesis in the dentate gyrus using the endogenous protein doublecortin (DCX), a marker for immature neurons. Mice that ran for 28 days showed increased hippocampal neurogenesis, regardless of sex. All mice, irrespective of exercise intervention or sex, showed learned the reference memory version of the Morris water maze. There was a positive correlation between time spent in the platform zone and doublecortin-expressing neurons in the dorsal dentate gyrus in males, but not females. Future studies should continue to address sex-differences in the effects of exercise on neurogenesis and cognition by using more specific and challenging cognitive tests for young, healthy rodents, or using animals with impaired or naturally decreased levels of neurogenesis.