Using Wave-Packet Interferometry to Monitor the External Vibrational Control of Electronic Excitation Transfer

We investigate the control of electronic energy transfer in molecular dimers through the preparation of specific vibrational coherences prior to electronic excitation, and its observation by nonlinear wave-packet interferometry. Laser-driven coherent nuclear motion can affect the instantaneous resonance between site-excited electronic states and thereby influence short-time electronic excitation transfer (EET). We first illustrate this control mechanism with calculations on a dimer whose constituent monomers undergo harmonic vibrations. We then consider the use of nonlinear wave-packet interferometry (nl-WPI) experiments to monitor the nuclear dynamics accompanying EET in general dimer complexes following impulsive vibrational excitation by a sub-resonant control pulse (or control pulse sequence). In measurements of this kind, two pairs of polarized phase-related femtosecond pulses following the control pulse generate superpositions of coherent nuclear wave packets in optically accessible electronic states. Interference contributions to the time- and frequency-integrated fluorescence signal due to overlaps among the superposed wave packets provide amplitude-level information on the nuclear and electronic dynamics. We derive the basic expression for a control-pulse-dependent nl-WPI signal. The electronic transition moments of the constituent monomers are assumed to have a fixed relative orientation, while the overall orientation of the complex is distributed isotropically. We include the limiting case of coincident arrival by pulses within each phase-related pair in which control-influenced nl-WPI reduces to a fluorescence-detected pump-probe difference experiment. Numerical calculations of pump-probe signals based on these theoretical expressions are presented in the following paper

Proteomics Based Process And Cell Line Development Applied To A Mammalian Therapeutic Enzyme

Recombinant human Acid Alpha Glucosidase (GAA) is the therapeutic enzyme used for the treatment of Pompe disease, a rare genetic disorder characterised by GAA deficiency in the cell lysosomes. The manufacturing process for GAA can be challenging, in part due to protease degradation. The overall goal of this project was to understand the effects of GAA overexpression on cell lysosomal phenotype and host cell protein (HCP) release, and any resultant consequences for protease levels and ease of manufacture. To do this we first generated a human recombinant GAA producing stable CHO clonal cell line and then developed a two-step bioprocess based on capture chromatographic step anion exchange (IEX) and intermediate hydrophobic interaction (HIC). The purity of GAA after HIC was determined via LC/MSMS to be above 80%. We then collected images of cell lysosomes via transmission electron microscopy (TEM) and compared the resulting data with that from a Null CHO cell line. TEM imaging revealed 72% of all lysosomes in the GAA cell line were engorged indicating extensive cell stress; by comparison, only 8% of lysosomes in the Null CHO had a similar phenotype. Furthermore, comparison of the HCP profile among cell lines [GAA, mAb and Null] capture eluates, showed that while most HCPs released were common across them, some were unique to the GAA producer, implying that cell stress caused by overexpression of GAA has a molecule specific effect on HCP release. Protease analysis via zymograms showed an overall reduction in proteolytic activity after the capture step but also revealed the presence of co-eluting proteases at approximately 80 KDa, which MS analysis putatively identified as dipeptidyl peptidase 3 and prolyl endopeptidase

Quasiparticle interfacial level alignment of highly hybridized frontier levels: H2_2O on TiO2_2(110)

Knowledge of the frontier levels' alignment prior to photo-irradiation is necessary to achieve a complete quantitative description of H$_2$O photocatalysis on TiO$_2$(110). Although H$_2$O on rutile TiO$_2$(110) has been thoroughly studied both experimentally and theoretically, a quantitative value for the energy of the highest H$_2$O occupied levels is still lacking. For experiment, this is due to the H$_2$O levels being obscured by hybridization with TiO$_2$(110) levels in the difference spectra obtained via ultraviolet photoemission spectroscopy (UPS). For theory, this is due to inherent difficulties in properly describing many-body effects at the H$_2$O-TiO$_2$(110) interface. Using the projected density of states (DOS) from state-of-the-art quasiparticle (QP) $G_0W_0$, we disentangle the adsorbate and surface contributions to the complex UPS spectra of H$_2$O on TiO$_2$(110). We perform this separation as a function of H$_2$O coverage and dissociation on stoichiometric and reduced surfaces. Due to hybridization with the TiO$_2$(110) surface, the H$_2$O 3a$_1$ and 1b$_1$ levels are broadened into several peaks between 5 and 1 eV below the TiO$_2$(110) valence band maximum (VBM). These peaks have both intermolecular and interfacial bonding and antibonding character. We find the highest occupied levels of H$_2$O adsorbed intact and dissociated on stoichiometric TiO$_2$(110) are 1.1 and 0.9 eV below the VBM. We also find a similar energy of 1.1 eV for the highest occupied levels of H$_2$O when adsorbed dissociatively on a bridging O vacancy of the reduced surface. In both cases, these energies are significantly higher (by 0.6 to 2.6 eV) than those estimated from UPS difference spectra, which are inconclusive in this energy region. Finally, we apply self-consistent QP$GW$ (scQP$GW$1) to obtain the ionization potential of the H$_2$O-TiO$_2$(110) interface.Comment: 12 pages, 12 figures, 1 tabl

Recent and rapid reef recovery around Koh Phangan Island, Gulf of Thailand, driven by plate-like hard corals

Mass bleaching events and local anthropogenic influences have changed the benthic communities of many coral reefs with pronounced spatial differences that are linked to resilience patterns. The Gulf of Thailand is an under-investigated region with only few existing datasets containing long-term developments of coral reef communities using the same method at fixed sites. We thus analyzed benthic community data from seven reefs surrounding the island of Koh Phangan collected between 2014 and 2022. Findings revealed that the average live hard coral cover around Koh Phangan increased from 37% to 55% over the observation period, while turf algae cover decreased from 52% to 29%, indicating some recovery of local reefs. This corresponds to a mean increased rate of coral cover by 2.2% per year. The increase in live hard coral cover was mainly driven by plate-like corals, which quadrupled in proportion over the last decade from 7% to 28% while branching corals decreased in proportion from 9% to 2%. Furthermore, the hard coral genus richness increased, indicating an increased hard coral diversity. While in other reefs, increasing live hard coral cover is often attributed to fast-growing, branching coral species, considered more susceptible to bleaching and other disturbances, the reefs around Koh Phangan recovered mainly via growth of plate-like corals, particularly of the genus Montipora. Although plate-like morphologies are not necessarily more bleaching tolerant, they are important for supporting reef fish abundance and structural complexity on reefs, aiding reef recovery and sturdiness. Hence, our findings indicate that the intensity of local stressors around Kho Phangan allows reef recovery driven by some hard coral species

Formation of the ηc\eta_c in Two-Photon Collisions at LEP

The two-photon width $\Gamma_{\gamma\gamma}$ of the $\eta_c$ meson has been measured with the L3 detector at LEP. The $\eta_c$ is studied in the decay modes $\pi^+\pi^-\pi^+\pi^-$, $\pi^+\pi^-$K$^+$K$^-$, K$_s^0$K$^\pm\pi^\mp$, K$^+$K$^-\pi^{0}$, $\pi^+\pi^-\eta$, $\pi^+\pi^-\eta'$, and $\rho^+\rho^-$ using an integrated luminosity of 140 pb$^{-1}$ at $\sqrt{s} \simeq 91$ GeV and of 52 pb$^{-1}$ at $\sqrt{s} \simeq 183$ GeV. The result is $\Gamma_{\gamma\gamma}(\eta_c) = 6.9 \pm 1.7 (stat.) \pm 0.8 (sys.) \pm 2.0$(BR) keV. The $Q^2$ dependence of the $\eta_c$ cross section is studied for $Q^2 < 9$ GeV$^{2}$. It is found to be better described by a Vector Meson Dominance model form factor with a J-pole than with a $\rho$-pole. In addition, a signal of $29 \pm 11$ events is observed at the $\chi_c0$ mass. Upper limits for the two-photon widths of the $\chi_c0$, $\chi_c2$, and $\eta_c'$ are also given

Measurement of Mass and Width of the W Boson at LEP

We report on measurements of the mass and total decay width of the W boson with the L3 detector at LEP. W-pair events produced in $\mathrm{e^+e^-}$ interactions between 161 GeV and 183 GeV centre-of-mass energy are selected in a data sample corresponding to a total luminosity of 76.7 pb$^{-1}$. Combining all final states in W-pair production, the mass and total decay width of the W boson are determined to be $\mathrm{M_W}=80.61\pm0.15$ GeV and $\Gamma_{\mathrm{W}}=1.97\pm0.38$ GeV, respectively

Search for Heavy Neutral and Charged Leptons in e+^+e−^- Annihilation at s\sqrt{s} = 183 and 189 GeV

A search for unstable neutral and charged heavy leptons as well as for stable charged heavy leptons is performed at center-of-mass energies $\sqrt{s}$ = 183 and 189 GeV with the L3 detector at LEP. No evidence for their existence is found. We exclude neutral heavy leptons which couple to the electron, muon or tau family, of the Dirac type for masses below 92.4, 93.3 and 83.3 GeV, and of the Majorana type for masses below 81.8, 84.1 and 73.5 GeV, respectively. We exclude unstable charged heavy leptons for masses below 93.9 GeV for a wide range of the associated neutral heavy lepton mass. If the unstable charged heavy lepton decays to a light neutrino, we exclude masses below 92.4 GeV. The production of stable charged heavy leptons with mass less than 93.5 GeV is also excluded

Measurement of an Elongation of the Pion Source in Z Decays

We measure Bose-Einstein correlations between like-sign charged pion pairs in hadronic Z decays with the L3 detector at LEP. The analysis is performed in three dimensions in the longitudinal center-of-mass system. The pion source is found to be elongated along the thrust axis with a ratio of transverse to longitudinal radius of $0.81\pm 0.02 ^{+0.03}_{-0.19}$

Size and Shape Constraints of (486958) Arrokoth from Stellar Occultations

We present the results from four stellar occultations by (486958) Arrokoth, the flyby target of the New Horizons extended mission. Three of the four efforts led to positive detections of the body, and all constrained the presence of rings and other debris, finding none. Twenty-five mobile stations were deployed for 2017 June 3 and augmented by fixed telescopes. There were no positive detections from this effort. The event on 2017 July 10 was observed by the Stratospheric Observatory for Infrared Astronomy with one very short chord. Twenty-four deployed stations on 2017 July 17 resulted in five chords that clearly showed a complicated shape consistent with a contact binary with rough dimensions of 20 by 30 km for the overall outline. A visible albedo of 10% was derived from these data. Twenty-two systems were deployed for the fourth event on 2018 August 4 and resulted in two chords. The combination of the occultation data and the flyby results provides a significant refinement of the rotation period, now estimated to be 15.9380 ± 0.0005 hr. The occultation data also provided high-precision astrometric constraints on the position of the object that were crucial for supporting the navigation for the New Horizons flyby. This work demonstrates an effective method for obtaining detailed size and shape information and probing for rings and dust on distant Kuiper Belt objects as well as being an important source of positional data that can aid in spacecraft navigation that is particularly useful for small and distant bodies.Fil: Buie, Marc W.. Southwest Research Institute.; Estados UnidosFil: Porter, Simon B.. Southwest Research Institute.; Estados UnidosFil: Tamblyn, Peter. Southwest Research Institute.; Estados UnidosFil: Terrell, Dirk. Southwest Research Institute.; Estados UnidosFil: Parker, Alex Harrison. Southwest Research Institute.; Estados UnidosFil: Baratoux, David. Géosciences Environnement Toulouse; Francia. Centre National de la Recherche Scientifique; FranciaFil: Kaire, Maram. Ministry of Higher Education Research and Innovation; Senegal. Asociación Senegalesa para la Promoción de la Astronomía; SenegalFil: Leiva, Rodrigo. Southwest Research Institute.; Estados UnidosFil: Verbiscer, Anne J.. University of Virginia; Estados UnidosFil: Zangari, Amanda M.. Southwest Research Institute.; Estados UnidosFil: Colas, François. Centre National de la Recherche Scientifique. Observatoire de Paris; Francia. Sorbonne University; Francia. Centre National de la Recherche Scientifique; FranciaFil: Diop, Baidy Demba. Direction de la Formation et de la Communication; SenegalFil: Samaniego, Joseph I.. University of Colorado; Estados UnidosFil: Wasserman, Lawrence H.. Lowell Observatory; Estados UnidosFil: Benecchi, Susan D.. Planetary Science Institute; Estados UnidosFil: Caspi, Amir. Southwest Research Institute.; Estados UnidosFil: Gwyn, Stephen. Herzberg Astronomy and Astrophysics Research Centre; CanadáFil: Kavelaars, J. J.. Herzberg Astronomy and Astrophysics Research Centre; CanadáFil: Ocampo Uría, Adriana C.. National Aeronautics and Space Administration; Estados UnidosFil: Rabassa, Jorge Oscar. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Austral de Investigaciones Científicas; ArgentinaFil: Skrutskie, M. F.. University of Virginia; Estados UnidosFil: Soto, Alejandro. Southwest Research Institute.; Estados UnidosFil: Tanga, Paolo. Université Côte d’Azur; Francia. Centre National de la Recherche Scientifique; FranciaFil: Young, Eliot F.. Southwest Research Institute.; Estados UnidosFil: Stern, S. Alan. Southwest Research Institute.; Estados UnidosFil: Andersen, Bridget C.. University of Virginia; Estados UnidosFil: Arango Pérez, Mauricio E.. Universidad de Antioquia; ColombiaFil: Arredondo, Anicia. Massachusetts Institute of Technology; Estados UnidosFil: Artola, Rodolfo Alfredo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Astronomía Teórica y Experimental. Universidad Nacional de Córdoba. Observatorio Astronómico de Córdoba. Instituto de Astronomía Teórica y Experimental; ArgentinaFil: García Migani, Esteban Andrés. Universidad Nacional de San Juan. Facultad de Ciencias Exactas, Físicas y Naturales. Departamento de Geofísica y Astronomía; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Juan; Argentin

Cerium Oxide Nanoparticles Protect Cardiac Progenitor Cells from Oxidative Stress

Cardiac progenitor cells (CPCs) are a promising autologous source of cells for cardiac regenerative medicine. However, CPC culture in vitro requires the presence of microenvironmental conditions (a complex array of bioactive substance concentration, mechanostructural factors, and physicochemical factors) closely mimicking the natural cell surrounding in vivo, including the capability to uphold reactive oxygen species (ROS) within physiological levels in vitro. Cerium oxide nanoparticles (nanoceria) are redox-active and could represent a potent tool to control the oxidative stress in isolated CPCs. Here, we report that 24 h exposure to 5, 10, and 50 !g/mL of nanoceria did not a!ect cell growth and function in cardiac progenitor cells, while being able to protect CPCs from H2O2-induced cytotoxicity for at least 7 days, indicating that nanoceria in an e!ective antioxidant. Therefore, these "ndings con"rm the great potential of nanoceria for controlling ROS-induced cell damage