Weak interaction Research Papers - Academia.edu (original) (raw)

Fragment-based drug discovery (FBDD) has become a widely accepted tool that is complementary to high-throughput screening (HTS) in developing small-molecule inhibitors of pharmaceutical targets. Because a fragment campaign can only be as... more

Fragment-based drug discovery (FBDD) has become a widely accepted tool that is complementary to high-throughput screening (HTS) in developing small-molecule inhibitors of pharmaceutical targets. Because a fragment campaign can only be as successful as the hit matter found, it is critical that the first stage of the process be optimized. Here the authors compare the 3 most commonly used methods for hit discovery in FBDD: high concentration screening (HCS), solution ligand-observed nuclear magnetic resonance (NMR), and surface plasmon resonance (SPR). They selected the commonly used saturation transfer difference (STD) NMR spectroscopy and the proprietary target immobilized NMR screening (TINS) as representative of the array of possible NMR methods. Using a target typical of FBDD campaigns, the authors find that HCS and TINS are the most sensitive to weak interactions. They also find a good correlation between TINS and STD for tighter binding ligands, but the ability of STD to detect ...

We consider mathematical models of the weak decay of the vector bosons [Formula: see text] into leptons. The free quantum field Hamiltonian is perturbed by an interaction term from the standard model of particle physics. After the... more

We consider mathematical models of the weak decay of the vector bosons [Formula: see text] into leptons. The free quantum field Hamiltonian is perturbed by an interaction term from the standard model of particle physics. After the introduction of high energy and spatial cut-offs, the total quantum Hamiltonian defines a self-adjoint operator on a tensor product of Fock spaces. We study the scattering theory for such models. First, the masses of the neutrinos are supposed to be positive: for all values of the coupling constant, we prove asymptotic completeness of the wave operators. In a second model, neutrinos are treated as massless particles and we consider a simpler interaction Hamiltonian: for small enough values of the coupling constant, we prove again asymptotic completeness, using singular Mourre’s theory, suitable propagation estimates and the conservation of the difference of some number operators.

Axions and axionlike particles are strongly motivated dark-matter candidates that are the subject of many current ground based dark-matter searches. We present first results from the Axion Dark-Matter Birefringent Cavity (ADBC)... more

Axions and axionlike particles are strongly motivated dark-matter candidates that are the subject of many current ground based dark-matter searches. We present first results from the Axion Dark-Matter Birefringent Cavity (ADBC) experiment, which is an optical bow-tie cavity probing the axion-induced birefringence of electromagnetic waves. Our experiment is the first optical axion detector that is tunable and quantum noise limited, making it sensitive to a wide range of axion masses. We have iteratively probed the axion mass ranges 40.9-43.3 neV=c 2 , 49.3-50.6 neV=c 2 , and 54.4-56.7 neV=c 2 , and found no darkmatter signal. On average, we constrain the axionlike particle and photon coupling at the level g aγγ ≤ 1.9 × 10 −8 GeV −1. We also present prospects for future axion dark-matter detection experiments using optical cavities.

Results from numerical simulations of weak magnetohydrodynamic (MHD) turbulence in steady-state are presented, with resolutions as high as 1024^2x256 grid points. Weak turbulence refers to the limit of MHD turbulence in which the energy... more

Results from numerical simulations of weak magnetohydrodynamic (MHD) turbulence in steady-state are presented, with resolutions as high as 1024^2x256 grid points. Weak turbulence refers to the limit of MHD turbulence in which the energy transfer toward smaller scales results from the weak interaction between Alfv'en waves moving along of against a strong guide magnetic field. The energies of the Alfven waves moving in the opposite directions can be either equal, in which case the turbulence is called balanced, or unequal, in which case it is unbalanced. The numerical set up is optimized as to drive either balanced or unbalanced turbulent cascades. We obtain the spectra of Alfv'en waves for various degrees of imbalance and Reynolds numbers. We discuss our results and compare with recent theories of weak MHD turbulence.

We propose a methodology for constructing confldence regions with partially iden- tifled models of general form. The region is obtained by inverting a test of internal consistency of the econometric structure. We develop a dilation... more

We propose a methodology for constructing confldence regions with partially iden- tifled models of general form. The region is obtained by inverting a test of internal consistency of the econometric structure. We develop a dilation bootstrap method- ology to deal with sampling uncertainty without reference to the hypothesized eco- nomic structure, and apply a duality principle to reduce the dimensionality of the remaining deterministic problem. As a result, the confldence region becomes easily computable, and the methodology can be applied to the estimation of models with sample selection, censored observations and to games with multiple equilibria.

The radiative lifetime of the A 2 1/2 (v = 0) state in radium monofluoride (RaF) is measured to be 35(1) ns. The lifetime of this state and the related decay rate = 2.86(8) × 10 7 s −1 are of relevance to the laser cooling of RaF via the... more

The radiative lifetime of the A 2 1/2 (v = 0) state in radium monofluoride (RaF) is measured to be 35(1) ns. The lifetime of this state and the related decay rate = 2.86(8) × 10 7 s −1 are of relevance to the laser cooling of RaF via the optically closed A 2 1/2 ← X 2 1/2 transition, which makes the molecule a promising probe to search for new physics. RaF is found to have a comparable photon-scattering rate to homoelectronic laser-coolable molecules. Owing to its highly diagonal Franck-Condon matrix, it is expected to scatter an order of magnitude more photons than other molecules when using just three cooling lasers, before it decays to a dark state. The lifetime measurement in RaF is benchmarked by measuring the lifetime of the 8P 3/2 state in Fr to be 83(3) ns, in agreement with literature.

The nature of Dark Matter remains one of the outstanding questions of modern astrophysics. The success of the Cold Dark Matter cosmological model argues strongly in favor of a major component of the dark matter being in the form of... more

The nature of Dark Matter remains one of the outstanding questions of modern astrophysics. The success of the Cold Dark Matter cosmological model argues strongly in favor of a major component of the dark matter being in the form of elementary particles, not yet discovered. Based on earlier theoretical considerations, a possible link between the recent SPI/INTEGRAL measurement of an

Description/Abstract We develop the scattering approach for the dispersive force on a ground state atom on top of a corrugated surface. We present explicit results to first order in the corrugation amplitude. A variety of analytical... more

Description/Abstract We develop the scattering approach for the dispersive force on a ground state atom on top of a corrugated surface. We present explicit results to first order in the corrugation amplitude. A variety of analytical results are derived in different limiting ...

Thymidylate synthase (TS) catalyzes the reductive methylation of dUMP, the reaction being the sole intracellular de novo source of thymidylate required for DNA synthesis. TS is an important target in chemotherapy, as its inhibition blocks... more

Thymidylate synthase (TS) catalyzes the reductive methylation of dUMP, the reaction being the sole intracellular de novo source of thymidylate required for DNA synthesis. TS is an important target in chemotherapy, as its inhibition blocks DNA synthesis and prevents cellular proliferation. An analogue of dUMP, N(4)–hydroxy–2'–deoxycytidine 5'–monophosphate (N(4)–OH–dCMP), exhibited in the presence of the cofactor, N,N-methylenetetrahydrofolate (mTHF), a strong, time-dependent inhibition of TS [1]. In order to elucidate the inhibitory mechanism of N(4)–OH–dCMP on TS, X-ray crystallographic and molecular modeling studies were carried out. The protein complex of mouse thymidylate synthase (mTS) with N(4)–OH–dCMP was crystallized by the vapor diffusion method. Diffraction data to 1.75 A resolution were collected on the BESSY synchrotron in Berlin and processed with DENZO and SCALEPACK. The structure was refined with REFMAC5 of the CCP4 program suite using the 3IHI crystal structu...

The idea for this paper arose from discussions with P. Pfaffelhuber and A. Wakolbinger dur-

We consider the evolution of the genealogy of the population currently alive in a Feller branching diffusion model. In contrast to the approach via labeled trees in the continuum random tree world, the genealogies are modeled as... more

We consider the evolution of the genealogy of the population currently alive in a Feller branching diffusion model. In contrast to the approach via labeled trees in the continuum random tree world, the genealogies are modeled as equivalence classes of ultrametric measure spaces, the elements of the space mathbbU\mathbb{U}mathbbU. This space is Polish and has a rich semigroup structure for the genealogy. We focus on the evolution of the genealogy in time and the large time asymptotics conditioned both on survival up to present time and on survival forever. We prove existence, uniqueness and Feller property of solutions of the martingale problem for this genealogy valued, i.e., mathbbU\mathbb{U}mathbbU-valued Feller diffusion. We give the precise relation to the time-inhomogeneous mathbbU_1\mathbb{U}_1mathbbU_1-valued Fleming-Viot process. The uniqueness is shown via Feynman-Kac duality with the distance matrix augmented Kingman coalescent. Using a semigroup operation on mathbbU\mathbb{U}mathbbU, called concatenation, together with the...