cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
#COVIDisAirborne: AI-enabled multiscale computational microscopy of delta SARS-CoV-2 in a respiratory aerosol
Creators: name: Dommer, Abigail
name: Casalino, Lorenzo
name: Kearns, Fiona
name: Rosenfeld, Mia
name: Wauer, Nicholas
name: Ahn, Surl-Hee
name: Russo, John
name: Oliveira, Sofia
name: Morris, Clare
name: Sztain, Terra
Publisher: name: Freie Universität Berlin
Year: 2023
Subjects: subject: molecular dynamics
subject: deep learning
subject: multiscale simulation
subject: weighted ensemble
subject: computational virology
subject: SARS-CoV-2
subject: aerosols
subject: COVID-19
subject: 600 Technik, Medizin, angewandte Wissenschaften::610 Medizin und Gesundheit::616 Krankheiten

description: We seek to completely revise current models of airborne transmission of respiratory viruses by providing never-before-seen atomic-level views of the SARS-CoV-2 virus within a respiratory aerosol. Our work dramatically extends the capabilities of multiscale computational microscopy to address the significant gaps that exist in current experimental methods, which are limited in their ability to interrogate aerosols at the atomic/molecular level and thus obscure our understanding of airborne transmission. We demonstrate how our integrated data-driven platform provides a new way of exploring the composition, structure, and dynamics of aerosols and aerosolized viruses, while driving simulation method development along several important axes. We present a series of initial scientific discoveries for the SARS-CoV-2 Delta variant, noting that the full scientific impact of this work has yet to be realized.
Monmouth University Poll: August 2015 South Carolina Republican Presidential Primary
Creators: name: Monmouth University Polling Institute
Publisher: name: Roper Center for Public Opinion Research
Year: 2022

description: Registered to vote (1); do you plan to register to vote (1); voter likelihood (1); Republican/Democratic presidential primary (1); Republican presidential primary (3); favorability of Republican presidential candidates (17); important issues in support for Republican presidential nomination (2); president with government experience/knows how to get things done vs. outside of government who can bring a new approach (1); Republican presidential nominee with right positions vs personal qualities and experiences (1); Tea Party.
Mechanisms of peroxisome proliferator-induced DNA hypomethylation in rat liver☆
Creators: name: Pogribny, Igor P.
name: Melnyk, Stepan
name: Boureiko, Anna
name: Tryndyak, Volodymyr P.
name: Bagnyukova, Tetyana V.
name: Rusyn, Ivan
name: Montgomery, Beverly
Publisher: name: The University of North Carolina at Chapel Hill University Libraries
Year: 2008

description: Genomic hypomethylation is a consistent finding in both human and animal tumors and mounting experimental evidence suggests a key role for epigenetic events in tumorigenesis. Furthermore, it has been suggested that early changes in DNA methylation and histone modifications may serve as sensitive predictive markers in animal testing for carcinogenic potency of environmental agents. Alterations in metabolism of methyl donors, disturbances in activity and/or expression of DNA methyltransferases, and presence of DNA single-strand breaks could contribute to the loss of cytosine methylation during carcinogenesis; however, the precise mechanisms of genomic hypomethylation induced by chemical carcinogens remain largely unknown. This study examined the mechanism of DNA hypomethylation during hepatocarcinogenesis induced by peroxisome proliferators WY-14,643 (4-chloro-6-(2,3-xylidino)-pyrimidynylthioacetic acid) and DEHP (di-(2-ethylhexyl)phthalate), agents acting through non-genotoxic mode of action. In the liver of male Fisher 344 rats exposed to WY-14,643 (0.1% (w/w), 5 months), the level of genomic hypomethylation increased by ~2-fold, as compared to age-matched controls, while in the DEHP group (1.2% (w/w), 5 months) DNA methylation did not change. Global DNA hypomethylation in livers from WY-14,643 group was accompanied by the accumulation of DNA single-strand breaks, increased cell proliferation, and diminished expression of DNA methyltransferase 1, while the metabolism of methyl donors was not affected. In contrast, none of these parameters changed significantly in rats fed DEHP. Since WY-14,643 is much more potent carcinogen than DEHP, we conclude that the extent of loss of DNA methylation may be related to the carcinogenic potential of the chemical agent, and that accumulation of DNA single-strand breaks coupled to the increase in cell proliferation and altered DNA methyltransferase expression may explain genomic hypomethylation during peroxisome proliferator-induced carcinogenesis.
(:unas) unassigned
Creators: name: (:Unkn) Unknown
Publisher: name: Universita' degli Studi di Salerno
Year: 2024

description: L’articolo analizza l’ultima creazione del Théâtre du Soleil, L’Île d’Or, attraverso il prisma della relazione fra teatro e mondo, di cui rintraccia le diverse declinazioni nel percorso della compagnia per poi focalizzarsi sullo spettacolo. In uno spazio generativo e metamorfico prende forma un’azione caleidoscopica, metateatrale e autofinzionale, che parla, in maniera diffratta, del mondo di oggi e riflette sul ruolo che può assumere in esso il teatro in generale e il Soleil in particolare.
description: The article analyses the latest creation of the Théâtre du Soleil, L'Île d'Or, through the prism of the relationship between theatre and the world. First, it traces its different declinations in the company's history, and then focuses on the performance. In a generative and metamorphic space, a kaleidoscopic, metatheatrical and self-fictional action takes shape, which talks, in a diffracted manner, about today’s world and reflects on the role that theatre can play in it.
Caso de estudio - SISTEMA PARA LA REVALORIZACIÓN DE DECLARACIONES DE IMPORTACIÓN OBSERVADAS POR LA ADMINISTRACIÓN ADUANERA
Creators: name: Arteaga, Kristiam
Publisher: name: UPDS
Year: 2024

description: La empresa Global Cruz, parte integrante de la Aduana Nacional de Bolivia, enfrenta importantes desafíos al tratar de actualizar su sistema de control de mercancías provenientes de otros países debido a la diversidad de productos adquiridos, la existencia de más de un precio de referencia por producto, las declaraciones observadas por la administración aduanera y la descripción incompleta de los productos. Y para lograrlo, el siguiente objetivo es desarrollar un sistema de información para mejorar la eficiencia y eficacia del control aduanero en la empresa.

El sistema permitirá el registro, seguimiento y análisis de la mercancía observada, incluyendo información detallada como tipo, lugar de incautación, asignación, descripción, precio de referencia, cantidad, nombre comercial y estado. Se utilizará una arquitectura Modelo-Vista-Controlador (MVC) que se desarrollará con PHP y el framework Laravel, junto con MySQL como sistema de gestión de bases de datos.

El proyecto incluye un análisis de los procesos actuales, la identificación de requisitos, el diseño y el desarrollo del sistema a medida. Se implementarán medidas de seguridad como la autenticación de usuarios y el control de acceso basado en roles para proteger la información confidencial.

El cronograma de trabajo incluye diferentes fases y roles, con un presupuesto estimado de 31.100 Bs. Los requisitos funcionales, las historias de usuario, los diagramas de clases y las relaciones entidad-entidad se presentan como parte de la documentación del proyecto.

En síntesis, el proyecto busca modernizar y optimizar la gestión de mercancías observada por la administración aduanera en Global Cruz, contribuyendo a la eficiencia, transparencia y cumplimiento de la normativa aduanera.
Modification by N-acetyltransferase 1 genotype on the association between dietary heterocyclic amines and colon cancer in a multiethnic study
Creators: name: Winkel, Scott
name: Gammon, Marilie D.
name: Millikan, Robert C.
name: Sinha, Rashmi
name: Harlan, Brent
name: Eaton, Allison
name: Sandler, Robert S.
name: Butler, Lesley M.
name: Keku, Temitope O.
Publisher: name: The University of North Carolina at Chapel Hill University Libraries
Year: 2008

description: Colorectal cancer incidence is greater among African Americans, compared to whites in the U.S., and may be due in part to differences in diet, genetic variation at metabolic loci, and/or the joint effect of diet and genetic susceptibility. We examined whether our previously reported associations between meat-derived heterocyclic amine (HCA) intake and colon cancer were modified by N-acetyltransferase 1 (NAT1) or 2 (NAT2) genotypes and whether there were differences by race.
Modelling Star Cluster Formation: Gas Accretion
Creators: name: Karam, Jeremy
name: Sills, Alison
Publisher: name: arXiv
Year: 2023
Subjects: subject: Astrophysics of Galaxies (astro-ph.GA)
subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: FOS: Physical sciences

description: The formation of star clusters involves the growth of smaller, gas-rich subclusters through accretion of gas from the giant molecular cloud within which the subclusters are embedded. The two main accretion mechanisms responsible for this are accretion of gas from dense filaments, and from the ambient background of the cloud. We perform simulations of both of these accretion processes onto gas-rich star clusters using coupled smoothed particle hydrodynamics to model the gas, and N-body dynamics to model the stars. We find that, for both accretion processes, the accreting star cluster loses some of its original mass while gaining mass from either the ambient background or the dense filament. The amount of mass lost from both these processes is small compared to the total mass of the cluster. However, in the case of accretion from a background medium, the net effect can be a decrease in the total mass of the cluster if it is travelling fast enough through the ambient medium ($> 4$kms$^{-1}$). We find that the amount of mass lost from the cluster through filamentary accretion is independent of the density, width, or number of filaments funneling gas into the cluster and is always such that the mass of the cluster is constantly increasing with time. We compare our results to idealized prescriptions used to model star cluster formation in larger scale GMC simulations and find that such prescriptions act as an upper limit when describing the mass of the star cluster they represent.
description: Accepted for publication in MNRAS, 14 pages, 11 figures
Additional file 1 of Modeling the potential impact of pre-exposure prophylaxis for HIV among men who have sex with men in Cameroon
Creators: name: Lyons, Carrie E.
name: Stokes-Cawley, Owen J.
name: Simkin, Anna
name: Bowring, Anna L.
name: Mfochive Njindam, Iliassou
name: Njoya, Oudou
name: Bissek, Anne Zoung-Kanyi
name: Tamoufe, Ubald
name: Georges, Sandra
name: Kakanou, Florence Zeh
name: Turpin, Gnilane
name: Levitt, Daniel
name: Billong, Serge Clotaire
name: Mishra, Sharmistha
name: Baral, Stefan
Publisher: name: figshare
Year: 2022
Subjects: subject: Medicine
subject: Biotechnology
subject: 59999 Environmental Sciences not elsewhere classified
subject: FOS: Earth and related environmental sciences
subject: Sociology
subject: FOS: Sociology
subject: Immunology
subject: FOS: Clinical medicine
subject: 69999 Biological Sciences not elsewhere classified
subject: FOS: Biological sciences
subject: 80699 Information Systems not elsewhere classified
subject: FOS: Computer and information sciences
subject: 19999 Mathematical Sciences not elsewhere classified
subject: FOS: Mathematics
subject: Cancer
subject: Science Policy
subject: 110309 Infectious Diseases
subject: FOS: Health sciences

description: Additional file 1. Figure S1. Calibration. Model structure.
UGT1A1 and UGT1A9 functional variants, meat intake, and colon cancer, among Caucasians and African-Americans
Creators: name: Butler, Lesley M.
name: Girard, Hugo
name: Guillemette, Chantal
name: Sinha, Rashmi
name: Sandler, Robert S.
name: Millikan, Robert C.
name: Villeneuve, Lyne
Publisher: name: The University of North Carolina at Chapel Hill University Libraries
Year: 2008

description: Glucuronidation by the UDP-glucuronosyltransferase enzymes (UGTs) is one of the primary detoxification pathways of dietary heterocyclic amines (HCAs) and polycyclic aromatic hydrocarbons (PAHs). In a population-based case-control study of 537 cases and 866 controls, we investigated whether colon cancer was associated with genetic variations in UGT1A1 and UGT1A9 genes and we determined if those variations modify the association between colon cancer and dietary HCA and PAH exposure. We measured functional UGT1A1 polymorphisms at positions −53 (*28; A(TA)6TAA to A(TA)7TAA), −3156 (G>A), −3279 (T>G) and the UGT1A9-275(T>A) polymorphism, and found no association with colon cancer overall. However, when stratified by race, the UGT1A1-3279 GG/TG intermediate/low activity genotypes were associated with an increased risk of colon cancer (odds ratio (OR) = 1.5, 95% confidence interval (CI)=1.1–2.0) in Caucasians. This finding is also supported by haplotype analyses where the UGT1A1-3279G-allele-bearing haplotype is overrepresented in case group. Overall, UGT1A1-53 and -3156 genotypes modified the association between dietary benzo(a)pyrene (BaP) and colon cancer (P for interaction=0.02 and 0.03, respectively). The strongest association was observed for those with <7.7 ng/day BaP exposure and the low activity genotypes, for both UGT1A1*28/*28 (OR=1.8, 95% CI=1.1–2.9) and −3156AA (OR=1.7, 95% CI=1.0–3.0), compared to ≥7.7 ng/day and combined high/intermediate genotypes. These data support a hypothesis that UGTs modify the association between meat-derived PAH exposure and colon cancer by their role in the elimination of dietary carcinogens.
Ion-photoelectron entanglement in photoionization with chirped laser pulses
Creators: name: Vrakking, Marcus J. J.
Publisher: name: Freie Universität Berlin
Year: 2023
Subjects: subject: attosecond science
subject: photoionization
subject: entanglement
subject: coherence
subject: 500 Naturwissenschaften und Mathematik::530 Physik::539 Moderne Physik

description: The investigation of coherent dynamics induced by photoionization of atoms or molecules by extreme ultra-violet (XUV) attosecond laser pulses requires careful consideration of the degree of ion + photoelectron entanglement that results from the photoionization process. Here, we consider coherent H2+ vibrational dynamics induced by photoionization of neutral H2 by a chirped attosecond laser pulse. We show that chirping the attosecond laser pulse leads to ion + photoelectron entanglement and the transition from a pure to a mixed state. This transition is characterized by evaluating the purity, which is close to unity for a transform-limited attosecond laser pulse and which decreases to a value that is determined by the number of vibrational states populated in the photoionization process for increasing values of the chirp parameter. In the calculations, the vibrational dynamics is probed by calculating time-delayed dissociation of the H2+ cation by a short ultra-violet (UV) laser pulse. Independent of the magnitude of the chirp, the coherent vibrational dynamics can be recovered by recording the XUV-UV delay-dependent kinetic energy release in coincidence with the kinetic energy of the accompanying photoelectron.
Highly confined low-loss plasmons in graphene-boron nitride heterostructures
Creators: name: Woessner, Achim
name: Lundeberg, Mark B.
name: Gao, Yuanda
name: Principi, Alessandro
name: Alonso-González, Pablo
name: Carrega, Matteo
name: Watanabe, Kenji
name: Taniguchi, Takashi
name: Vignale, Giovanni
name: Polini, Marco
name: Hone, James
name: Hillenbrand, Rainer
name: Koppens, Frank H. L.
Publisher: name: arXiv
Year: 2014
Subjects: subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: Materials Science (cond-mat.mtrl-sci)
subject: FOS: Physical sciences

description: Graphene plasmons were predicted to possess ultra-strong field confinement and very low damping at the same time, enabling new classes of devices for deep subwavelength metamaterials, single-photon nonlinearities, extraordinarily strong light-matter interactions and nano-optoelectronic switches. While all of these great prospects require low damping, thus far strong plasmon damping was observed, with both impurity scattering and many-body effects in graphene proposed as possible explanations. With the advent of van der Waals heterostructures, new methods have been developed to integrate graphene with other atomically flat materials. In this letter we exploit near-field microscopy to image propagating plasmons in high quality graphene encapsulated between two films of hexagonal boron nitride (h-BN). We determine dispersion and particularly plasmon damping in real space. We find unprecedented low plasmon damping combined with strong field confinement, and identify the main damping channels as intrinsic thermal phonons in the graphene and dielectric losses in the h-BN. The observation and in-depth understanding of low plasmon damping is the key for the development of graphene nano-photonic and nano-optoelectronic devices.
Structural versus electronic distortions of symmetry-broken IrTe$_2$
Creators: name: Kim, Hyo Sung
name: Kim, Tae-Hwan
name: Yang, Junjie
name: Cheong, Sang-Wook
name: Yeom, Han Woong
Publisher: name: arXiv
Year: 2014
Subjects: subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: FOS: Physical sciences

description: We investigate atomic and electronic structures of the intriguing low temperature phase of IrTe2 using high-resolution scanning tunneling microscopy and spectroscopy. We confirm various stripe superstructures such as $\times$3, $\times$5, and $\times$8. The strong vertical and lateral distortions of the lattice for the stripe structures are observed in agreement with recent calculations. The spatial modulations of electronic density of states are clearly identified as separated from the structural distortions. These structural and spectroscopic characteristics are not consistent with the charge-density wave and soliton lattice model proposed recently. Instead, we show that the Ir (Te) dimerization together with the Ir 5d charge ordering can explain these superstructures, supporting the Ir dimerization mechanism of the phase transition.
description: 5 pages, 4 figures
Constraining atmospheric parameters and surface magnetic fields with $\texttt{ZeeTurbo}$: an application to SPIRou spectra
Creators: name: Cristofari, P. I.
name: Donati, J. -F.
name: Folsom, C. P.
name: Masseron, T.
name: Fouqué, P.
name: Moutou, C.
name: Artigau, E.
name: Carmona, A.
name: Petit, P.
name: Delfosse, X.
name: Martioli, E.
Publisher: name: arXiv
Year: 2023
Subjects: subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: Earth and Planetary Astrophysics (astro-ph.EP)
subject: FOS: Physical sciences

description: We report first results on a method aimed at simultaneously characterising atmospheric parameters and magnetic properties of M dwarfs from high-resolution nIR spectra recorded with SPIRou in the framework of the SPIRou Legacy Survey. Our analysis relies on fitting synthetic spectra computed from MARCS model atmospheres to selected spectral lines, both sensitive and insensitive to magnetic fields. We introduce a new code, $\texttt{ZeeTurbo}$, obtained by including the Zeeman effect and polarised radiative transfer capabilities to $\texttt{Turbospectrum}$. We compute a grid of synthetic spectra with $\texttt{ZeeTurbo}$ for different magnetic field strengths and develop a process to simultaneously constrain $T_{\rm eff}$, $\log{g}$, [M/H], [$α$/Fe] and the average surface magnetic flux. In this paper, we present our approach and assess its performance using simulations, before applying it to six targets observed in the context of the SPIRou Legacy Survey (SLS), namely AU Mic, EV Lac, AD Leo, CN Leo, PM J18482+0741, and DS Leo. Our method allows us to retrieve atmospheric parameters in good agreement with the literature, and simultaneously yields surface magnetic fluxes in the range 2-4 kG with a typical precision of 0.05 kG, in agreement with literature estimates, and consistent with the saturated dynamo regime in which most of these stars are.
description: 17 pages plus supplementary material. Accepted for publication in MNRAS
Cells deficient in PARP-1 show an accelerated accumulation of DNA single strand breaks, but not AP sites, over the PARP-1-proficient cells exposed to MMS
Creators: name: Afonin, Valeriy
name: Swenberg, James A.
name: Pachkowski, Brian F.
name: Tano, Keizo
name: Nakamura, Jun
name: Takeda, Shunichi
name: Elder, Rhoderick H.
name: Watanabe, Masami
Publisher: name: The University of North Carolina at Chapel Hill University Libraries
Year: 2009

description: Poly(ADP-ribose) polymerase-1 (PARP-1) is a base excision repair (BER) protein that binds to DNA single strand breaks (SSBs) and subsequently synthesizes and transfers poly(ADP-ribose) polymers to various nuclear proteins. Numerous biochemical studies have implicated PARP-1 as a modulator of BER; however, the role of PARP-1 in BER in living cells remains unclear partly due to lack of accurate quantitation of BER intermediates existing in cells. Since DT40 cells, chicken B lymphocytes, naturally lack PARP-2, DT40 cells allow for the investigation of the PARP-1 null phenotype without confounding by PARP-2. To test the hypothesis that PARP-1 is necessary for efficient BER during methylmethane sulfonate (MMS) exposure in vertebrate cells, intact DT40 cells and their isogenic PARP-1 null counterparts were challenged with different exposure scenarios for phenotypic characterization. With chronic exposure, PARP-1 null cells exhibited sensitivity to MMS but with an acute exposure did not accumulate base lesions or AP sites to a greater extent than wild-type cells. However, an increase in SSB content in PARP-1 null cell DNA, as indicated by glyoxal gel electrophoresis under neutral conditions, suggested the presence of BER intermediates. These data suggest that during exposure, PARP-1 impacts the stage of BER after excision of the deoxyribosephosphate moiety from the 5’ end of DNA strand breaks by polymerase β.
Beam Energy Dependence of Dielectron Production in Au+Au Collisions from STAR at RHIC
Creators: name: Huck, Patrick
Publisher: name: arXiv
Year: 2014
Subjects: subject: Nuclear Experiment (nucl-ex)
subject: High Energy Physics - Experiment (hep-ex)
subject: FOS: Physical sciences

description: We present the energy-dependent study of dielectron production in 0-80% minimum-bias Au+Au collisions at $\sqrt{s_{NN}}$ energies of 19.6, 27, 39, and 62.4 GeV in STAR. Invariant mass ($M_{ee}$) and transverse momentum ($p_T$) differential measurements of dielectron yields are compared to cocktail simulations of known hadronic sources and semi-leptonic charmed decays. The enhancement (excess yield) prominent in the Low-Mass Region (LMR) over the cocktail at all energies, is further compared to calculations of $ρ$ in-medium modifications. Within statistical and systematic uncertainties, we find that the model consistently describes this enhancement from SPS up to top RHIC energies in its $M_{ee}$- as well as $p_T$-dependence. Dielectron measurements drive the statistics for the future BES Phase-II program, which promises to improve our understanding of the LMR enhancement's trend with total baryon densities.
description: 4 pages, 3 figures, to be published in Nuclear Physics A, Proceedings of Quark Matter Conference 2014, see http://qm2014.gsi.de/
Mutagenicity, stable DNA adducts, and abasic sites induced in Salmonella by phenanthro[3,4-b]- and phenanthro[4,3-b]thiophenes, sulfur analogs of benzo[c]phenanthrene
Creators: name: Nesnow, Stephen
name: Swartz, Carol D.
name: King, Leon C.
name: Kumar, Subodh
name: Umbach, David M.
name: DeMarini, David M.
Publisher: name: The University of North Carolina at Chapel Hill University Libraries
Year: 2009

description: Sulfur-containing polycyclic aromatic hydrocarbons (thia-PAHs or thiaarenes) are common constituents of air pollution and cigarette smoke, but only a few have been studied for health effects. We evaluated the mutagenicity in Salmonella TA98, TA100, and TA104 of two sulfur-containing derivatives of benzo[c]phenanthrene, phenanthro[3,4-b]thiophene (P[3,4-b]T), and phenanthro[4,3-b]thiophene (P[4,3-b]T) as well as their dihydrodiol and sulfone derivatives. In addition, we assessed levels of stable DNA adducts (by 32P-postlabeling) as well as abasic sites (by an aldehydic-site assay) produced by six of these compounds in TA100. P[3,4-b]T and its 6,7- and 8,9-diols, P[3,4-b]T sulfone, P[4,3-b]T, and its 8,9-diol were mutagenic in TA100. P[3,4-b]T sulfone, the most potent mutagen, was approximately twice as potent as benzo[a]pyrene in both TA98 and TA100. Benzo-ring dihydrodiols were much more potent than K-region dihydrodiols, which had little or no mutagenic activity in any strain. P[3,4-b]T sulfone produced abasic sites and not stable DNA adducts; the other five compounds examined, B[c]P, B[c]P 3,4-diol, P[3,4-b]T, P[3,4-b]T 8,9-diol, and P[4,3-b]T 8,9-diol, produced only stable DNA adducts. P[3,4-b]T sulfone was the only compound that produced significant levels of frameshift mutagenicity and induced mutations primarily at GC sites. In contrast, B[c]P, its 3,4-diol, and the 8,9 diols of the phenanthrothiophenes induced mutations primarily at AT sites. P[3,4-b]T was not mutagenic in TA104, whereas P[3,4-b]T sulfone was. The two isomeric forms (P[3,4-b]T and P[4,3-b]T) are apparently activated differently, with the latter, but not the former, involving a diol pathway. This study is the first illustrating the potential importance of abasic sites in the mutagenicity of thia-PAHs.
Analytic Classes of Metastable de Sitter Vacua
Creators: name: Kallosh, Renata
name: Linde, Andrei
name: Vercnocke, Bert
name: Wrase, Timm
Publisher: name: arXiv
Year: 2014
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: General Relativity and Quantum Cosmology (gr-qc)
subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: In this paper, we give a systematic procedure for building locally stable dS vacua in $\mathcal{N}=1$ supergravity models motivated by string theory. We assume that one of the superfields has a Kahler potential of no-scale type and impose a hierarchy of supersymmetry breaking conditions. In the no-scale modulus direction the supersymmetry breaking is not small, in all other directions it is of order $ε$. We establish the existence of an abundance of vacua for large regions in the parameter space spanned by $ε$ and the cosmological constant. These regions exist regardless of the details of the other moduli, provided the superpotential can be tuned such that the off-diagonal blocks of the mass matrix are parametrically small. We test and support this general dS landscape construction by explicit analytic solutions for the STU model. The Minkowski limits of these dS vacua either break supersymmetry or have flat directions in agreement with a no-go theorem that we prove, stating that a supersymmetric Minkowski vacuum without flat directions cannot be continuously deformed into a non-supersymmetric vacuum. We also describe a method for finding a broad class of stable supersymmetric Minkowski vacua that can be F-term uplifted to dS vacua and which have an easily controllable SUSY breaking scale.
description: 30 pages
Accumulation of true single strand breaks and AP sites in base excision repair deficient cells
Creators: name: Kaufman, David G.
name: Afonin, Valeriy
name: Pachkowski, Brian F.
name: Luke, April M.
name: Takeda, Shunichi
name: Nakamura, Jun
name: Swenberg, James A.
name: Chastain, Paul D.
Publisher: name: The University of North Carolina at Chapel Hill University Libraries
Year: 2010

description: Single strand breaks (SSBs) are one of the most frequent DNA lesions caused by endogenous and exogenous agents. The most utilized alkaline-based assays for SSB detection frequently give false positive results due to the presence of alkali-labile sites that are converted to SSBs. Methoxyamine, an acidic O-hydroxylamine, has been utilized to measure DNA damage in cells. However, the neutralization of methoxyamine is required prior to usage. Here we developed a convenient, specific SSB assay using alkaline gel electrophoresis (AGE) coupled with a neutral O-hydroxylamine, O-(tetrahydro-2H-pyran-2-yl)hydroxylamine (OTX). OTX stabilizes abasic sites (AP sites) to prevent their alkaline incision while still allowing for strong alkaline DNA denaturation. DNA from DT40 and isogenic polymerase β null cells exposed to methyl methanesulfonate were applied to the OTX-coupled AGE (OTX-AGE) assay. Time-dependent increases in SSBs were detected in each cell line with more extensive SSB formation in the null cells. These findings were supported by an assay that indirectly detects SSBs through measuring NAD(P)H depletion. An ARP-slot blot assay demonstrated a significant time-dependent increase in AP sites in both cell lines by 1 mM MMS compared to control. Furthermore, the Pol β-null cells displayed greater AP site formation than the parental DT40 cells. OTX use represents a facile approach for assessing SSB formation, whose benefits can also be applied to other established SSB assays.
Comparative analysis of promoter methylation and gene expression endpoints between tumorous and non-tumorous tissues from HCV-positive patients with hepatocellular carcinoma
Creators: name: Rusyn, Ivan
name: Shpyleva, Svitlana
name: Formeister, Eric J.
name: Pogribny, Igor P.
name: Tsuchiya, Masato
name: Fujii, Hideki
Publisher: name: The University of North Carolina at Chapel Hill University Libraries
Year: 2010

description: Transcriptional silencing of tumor suppressor genes and other cancer-related genes induced by promoter CpG island hypermethylation is an important epigenetic mechanism of hepatocarcinogenesis. Previous studies have established methylation profiles of hepatocellular carcinomas (HCCs) and demonstrated that methylation of several candidate genes in resected tissues may be associated with time to recurrence. The goals of our study were to test whether specific promoter methylation and mRNA levels of candidate genes, as well as global changes in DNA methylation, can be linked with time to recurrence and clinicopathological variables in a homogenous study group of HCC patients. Forty-three tumorous and 45 non-tumorous liver tissue samples from the surgical margin were obtained from HCV-positive, HBV-negative HCC patients who underwent tumor resection surgery and who were monitored for tumor recurrence thereafter (median follow-up time: 16 months (range, 0 – 79 months)). Methylation-specific PCR was used to assess the promoter methylation status of P16(INK4a), SOCS-1, RASSF1A, APC, GSTP1, RIZ1, and MGMT genes, while the level of LINE-1 methylation was used as marker of global DNA methylation levels. Methylation frequencies in P16(INK4a), RASSF1A, APC, GSTP1, and RIZ1 genes were significantly greater in tumorous versus non-tumorous tissues. Methylation of RIZ1 in non-tumorous tissues was significantly associated with time to recurrence. Additionally, genomic DNA was significantly more hypomethylated in tumorous tissues, and this change was associated with shorter recurrence, but not with clinicopathological features. In conclusion, this study supports the role of aberrant methylation in the pathobiology of HCV-positive HCCs. The finding that RIZ1 methylation and increased levels of LINE-1 hypomethylation in non-tumorous tissues are associated with time to recurrence underscores the importance of assessing the epigenetic state of the liver remnant.
Attosecond investigation of extreme-ultraviolet multi-photon multi-electron ionization
Creators: name: Kretschmar, M.
name: Hadjipittas, A.
name: Major, B.
name: Tümmler, J.
name: Will, I.
name: Nagy, T.
name: Vrakking, Marcus
name: Emmanouilidou, A.
name: Schütte, B.
Publisher: name: Freie Universität Berlin
Year: 2023
Subjects: subject: Atoms
subject: Attosecond pulses
subject: Multiphoton ionization
subject: Optical parametric chirped pulse amplification
subject: Photoelectron spectra
subject: Photons
subject: 500 Naturwissenschaften und Mathematik::530 Physik::539 Moderne Physik

description: Multi-electron dynamics in atoms and molecules very often occur on sub- to few-femtosecond time scales. The available intensities of extreme-ultraviolet (XUV) attosecond pulses have previously allowed the time-resolved investigation of two-photon, two-electron interactions. Here we study double and triple ionization of argon atoms involving the absorption of up to five XUV photons using a pair of intense attosecond pulse trains (APTs). By varying the time delay between the two APTs with attosecond precision and the spatial overlap with nanometer precision, we obtain information on complex nonlinear multi-photon ionization pathways. Our experimental and numerical results show that Ar2+ is predominantly formed by a sequential two-photon process, whereas the delay dependence of the Ar3+ ion yield exhibits clear signatures of the involvement of a simultaneous two-photon absorption process. Our experiment suggests that it is possible to investigate multi-electron dynamics using attosecond pulses for both pumping and probing the dynamics.
On excess entropy and latent heat in crystallizing white dwarfs
Creators: name: Baiko, D. A.
Publisher: name: arXiv
Year: 2023
Subjects: subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: High Energy Astrophysical Phenomena (astro-ph.HE)
subject: Nuclear Theory (nucl-th)
subject: FOS: Physical sciences

description: Based on the linear mixing approach, we calculate the latent heat for crystallizing fully-ionized $^{12}$C/$^{16}$O and $^{16}$O/$^{20}$Ne mixtures in white dwarf (WD) cores for two different parametrizations of the corrections to the linear-mixing energies and with account of ion quantum effects. We report noticeable composition-dependent deviations of the excess entropy in both directions from the standard value of 0.77 per ion. Within the same framework, we evaluate the excess entropy and released or absorbed heat accompanying the exsolution process in solidified WD layers. The inclusion of this effect is shown to be important for reliable interpretation of WD cooling data. We also analyze the latent heat of crystallizing eutectic $^{12}$C/$^{22}$Ne mixture, where we find a qualitative dependence of both the phase diagram and the latent heat behaviour on ion quantum effects. This may be important for the model with $^{22}$Ne distillation in cooling C/O/$^{22}$Ne WD proposed as a solution for the ultramassive WD multi-Gyr cooling anomaly. Astrophysical implications of our findings for crystallizing WD are discussed.
description: 5 pages, 2 figures. Letter to MNRAS, in press
(:unas) unassigned
Creators: name: (:Unkn) Unknown
Publisher: name: Universita' degli Studi di Salerno
Year: 2024

description: In for colored girls who have considered suicide/ when the rainbow is enuf, Ntozake Shange deconstructs patriarchal ideology through language by sharing the experiences of empowerment and disempowerment of seven women that belong to the black community in the 1970s. She employs an innovative genre, the “choreopoem” which combines poetry, prose and stage performance. This paper is highly vested in gender politics as the stories of these seven women revolve around feminism. The play brings to the forefront the racial tensions that black women faced outside the black community but most importantly, it unravels the forces of subjugation that they experienced from within the very black community they are part of, through the violent behavior of black men towards their body. Issues such as rape, abortion, assuming non-normative roles are explored. Attentive to the multiplicity of voices, Shange yearns for the decolonization of black women from the double oppression they experience outside and within the black community by attaining agency through language and through projecting their voice..
Actor Ecosystem Readiness: Understanding the Nature and Role of Human Abilities and Motivation in a Service Ecosystem
Creators: name: Danatzis, Ilias
name: Karpen, Ingo O.
name: Kleinaltenkamp, Michael
Publisher: name: Freie Universität Berlin
Year: 2022
Subjects: subject: customer readiness
subject: employee readiness
subject: service ecosystem
subject: microfoundations
subject: multi-actor service provision
subject: 300 Sozialwissenschaften::330 Wirtschaft::330 Wirtschaft

description: Fueled by technological advances, service delivery today is increasingly realized among multiple actors beyond dyadic service encounters. Customers, for example, often collaborate with peers, service employees, platform providers, or other actors in a service ecosystem to realize desired outcomes. Yet such multi-actor settings pose greater demands for both customers and employees given added connectivity, changing roles, and responsibilities. Advancing prior dyadic readiness conceptualizations, this article lays the theoretical ground for an ecosystem-oriented understanding of readiness, which we refer to as actor ecosystem readiness (AER). Grounded in a six-stage systematic synthesis of literature from different disciplines, our AER concept unpacks the cognitive, emotional, interactional, and motivational conditions that enable a customer or an employee to navigate a service ecosystem effectively. Building on human capital resource literature, we propose a multilevel framework around five sets of propositions that theorize AER’s nomological interdependencies across ecosystem levels. In articulating the process of how AER results in higher-level ecosystem outcomes, we demonstrate how AER serves as a microfoundation of service ecosystem effectiveness. By bridging this micro–macro divide, our AER concept and framework advance multilevel theory on human readiness and critically refine the service ecosystem concept itself while providing managerial guidance and an extensive future research agenda.
HD 42477: coupled r modes, g modes and a p mode in an A0Vnne star
Creators: name: Kurtz, D. W.
name: Jayaraman, R.
name: Sowicka, P.
name: Handler, G.
name: Saio, H.
name: Labadie-Bartz, J.
name: Lee, U.
Publisher: name: arXiv
Year: 2023
Subjects: subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: FOS: Physical sciences

description: Several studies have shown that a number of stars pulsating in p modes lie between the $β$ Cep and $δ$ Sct instability strips in the Hertzsprung-Russell (HR) Diagram. At present, there is no certain understanding of how p~modes can be excited in this $T_{\rm eff}$ range. The goal of this work is to disprove the conjecture that all stars pulsating in p modes and lying in this $T_{\rm eff}$ range are the result of incorrect measurements of $T_{\rm eff}$, contamination, or the presence of unseen cooler companions lying in the $δ$ Sct instability strip (given the high binary fraction of stars in this region of the HR Diagram). Using TESS data, we show that the A0Vnne star HD 42477 has a single p mode coupled to several r modes and/or g modes. We rule out a contaminating background star with a pixel-by-pixel examination, and we essentially rule out the possibility of a companion $δ$ Sct star in a binary. We model the pulsations in HD 42477 and suggest that the g modes are excited by overstable convective core modes. We also conjecture that the single p mode is driven by coupling with the g modes, or that the oblateness of this rapidly-rotating star permits driving by He II ionization in the equatorial region.
description: 11 pages, 6 figures, 2 tables, accepted to MNRAS
Short-lived radioisotope enrichment in star-forming regions from stellar winds and supernovae
Creators: name: Parker, Richard J.
name: Lichtenberg, Tim
name: Patel, Miti
name: Polius, Cheyenne K. M.
name: Ridsdill-Smith, Matthew
Publisher: name: arXiv
Year: 2023
Subjects: subject: Earth and Planetary Astrophysics (astro-ph.EP)
subject: Astrophysics of Galaxies (astro-ph.GA)
subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: FOS: Physical sciences

description: The abundance of the short-lived radioisotopes 26-Al and 60-Fe in the early Solar system is usually explained by the Sun either forming from pre-enriched material, or the Sun's protosolar disc being polluted by a nearby supernova explosion from a massive star. Both hypotheses suffer from significant drawbacks: the former does not account for the dynamical evolution of star-forming regions, while in the latter the time for massive stars to explode as supernovae can be similar to, or even longer than, the lifetime of protoplanetary discs. In this paper, we extend the disc enrichment scenario to include the contribution of 26-Al from the winds of massive stars before they explode as supernovae. We use N-body simulations and a post-processing analysis to calculate the amount of enrichment in each disc, and we vary the stellar density of the star-forming regions. We find that stellar winds contribute to disc enrichment to such an extent that the Solar system's 26-Al/60-Fe ratio is reproduced in up to 50 per cent of discs in dense (rho = 1000Msun pc^-3) star-forming regions. When winds are a significant contributor to the SLR enrichment, we find that Solar system levels of enrichment can occur much earlier (before 2.5 Myr) than when enrichment occurs from supernovae, which start to explode at later ages (>4 Myr). We find that Solar system levels of enrichment all but disappear in low-density star-forming regions (rho < 10Msun pc^-3), implying that the Solar system must have formed in a dense, populous star-forming region if 26-Al and 60-Fe were delivered directly to the protosolar disc from massive-star winds and supernovae.
description: 16 pages, 10 figures, 1 appendix with 3 further figures, accepted for publication in MNRAS
Unveiling new stellar companions from the PIONIER exozodi survey
Creators: name: Marion, Lindsay
name: Absil, Olivier
name: Ertel, Steve
name: Bouquin, Jean-Baptiste Le
name: Defrere, Denis
Publisher: name: arXiv
Year: 2014
Subjects: subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: FOS: Physical sciences

description: The main goal of the EXOZODI survey is to detect and characterize circumstellar dust and to propose the first statistical study of exozodiacal disks in the near-infrared using telescopes in both hemispheres. For this purpose, Ertel et al. have conducted in 2012 a survey of nearby main sequence stars with VLTI/PIONIER to search for the presence of circumstellar dust. This survey, carried out during 12 nights, comprises about 100 stars. For each star, we obtained typically three OBs and we searched for circumstellar emission based on the measurement of squared visibilities at short baselines. A drop in the measured visibilities with respect to the expected photospheric visibility indicates the presence of resolved emission around the target star. It is however generally not possible to conclude on the morphology of the detected emission based solely on the squared visibilities. Here, we focus on closure phases to search for faint companions around the whole sample. Indeed, to derive robust statistics on the occurrence rate of bright exozodiacal disks, we need to discriminate between companions and disks. For this reason, the main goal of this paper is to discriminate between circumstellar disks (which show no closure phase provided that they are point-symmetric) and faint companions (point-like sources, creating non-zero closure phases). We also aim to reveal new companions that do not necessarily produce a significant signature in the squared visibilities, as the signature of the companion may show up more prominently in the closure phases. In this process, we reveal four new stellar companions with contrasts ranging from 2% to 95% (i.e., up to equal flux binaries). We also tentatively detect faint companions around one other target that will require follow-up observations to be confirmed or infirmed. We discuss the implications of these discoveries on the results of the exozodi survey.
description: To appear in SPIE proceedings vol. 9146
Bot, or not? Comparing three methods for detecting social bots in five political discourses
Creators: name: Martini, Franziska
name: Samula, Paul
name: Keller, Tobias R.
name: Klinger, Ulrike
Publisher: name: Freie Universität Berlin
Year: 2021
Subjects: subject: Social bots
subject: bot detection
subject: Twitter
subject: comparative research
subject: political discourse
subject: 000 Informatik, Informationswissenschaft, allgemeine Werke::070 Publizistische Medien, Journalismus, Verlagswesen::070 Publizistische Medien, Journalismus, Verlagswesen

description: Social bots – partially or fully automated accounts on social media platforms – have not only been widely discussed, but have also entered political, media and research agendas. However, bot detection is not an exact science. Quantitative estimates of bot prevalence vary considerably and comparative research is rare. We show that findings on the prevalence and activity of bots on Twitter depend strongly on the methods used to identify automated accounts. We search for bots in political discourses on Twitter, using three different bot detection methods: Botometer, Tweetbotornot and “heavy automation”. We drew a sample of 122,884 unique user Twitter accounts that had produced 263,821 tweets contributing to five political discourses in five Western democracies. While all three bot detection methods classified accounts as bots in all our cases, the comparison shows that the three approaches produce very different results. We discuss why neither manual validation nor triangulation resolves the basic problems, and conclude that social scientists studying the influence of social bots on (political) communication and discourse dynamics should be careful with easy-to-use methods, and consider interdisciplinary research.