First determination of f+(0)∣Vus∣f_+(0) |V_{us}| from a combined analysis of τ→Kπντ\tau\to K\pi \nu_\tau decay and πK\pi K scattering with constraints from Kℓ3K_{\ell3} decays

We perform a combined analysis of $\tau\to K\pi \nu_\tau$ decay and $\pi K$ scattering with constraints from $K_{\ell3}$ data using a $N/D$ approach that fulfills requirements from unitarity and analyticity. We obtain a good fit of the $I=1/2$ $\pi K$ amplitude in the $P$ wave using the LASS data above the elastic region while in this region data are generated via Monte Carlo using the FOCUS results based on $D_{\ell 4}$ decay. The spectrum and branching ratio of $\tau\to K\pi \nu_\tau$ constrained by $K_{\ell3}$ decays are also well reproduced leading to $f_+(0) |V_{us}|= 0.2163 \pm 0.0014$. Furthermore, we obtain the slope of the vector form factor $\lambda_+=(25.56 \pm 0.40) \times 10^{-3}$ while the value of the scalar form factor at the Callan-Treiman point is $\ln C=0.2062 \pm 0.0089$. Given the experimental precision our results are compatible with the Standard model.Comment: 30 pages, 7 figures, Updated numerics and discussion slightly extended. Published versio

FUTURE TRADE RESEARCH AREAS THAT MATTER TO DEVELOPING COUNTRY POLICYMAKERS

Income, welfare, poverty, consumer price, compensation

Cultural Experience Copycatting: An Ethnographic Approach of Compostela Copycats

International audienc

An efficient approach for the calculation of frequencies in macromolecules

I. INTRODUCTION. Conformational changes of macromolecules are essential in the understanding of e.g. proteins and drug design. The theoretical prediction is far from trivial, especially for large molecules. In many cases, collective motions are present which occur on a timescale (~ms) that is too long to be accessible through molecular dynamics simulations. Normal mode analysis (NMA) has been proven succesful in exploring the potential energy surface (PES) within the harmonic oscillator approximation. The lowest frequency modes contribute the most to a conformational change. This paper presents a computationally attractive method that selects modes from the lower spectrum

Normal mode analysis of macromolecular systems with the Mobile Block Hessian method

Until recently, normal mode analysis (NMA) was limited to small proteins, not only because the required energy minimization is a computationally exhausting task, but also because NMA requires the expensive diagonalization of a 3Na 3Na matrix with Na the number of atoms. A series of simplified models has been proposed, in particular the Rotation-Translation Blocks (RTB) method by Tama et al. for the simulation of proteins. It makes use of the concept that a peptide chain or protein can be seen as a subsequent set of rigid components, i.e. the peptide units. A peptide chain is thus divided into rigid blocks with six degrees of freedom each. Recently we developed the Mobile Block Hessian (MBH) method, which in a sense has similar features as the RTB method. The main difference is that MBH was developed to deal with partially optimized systems. The position/orientation of each block is optimized while the internal geometry is kept fixed at a plausible – but not necessarily optimized – geometry. This reduces the computational cost of the energy minimization. Applying the standard NMA on a partially optimized structure however results in spurious imaginary frequencies and unwanted coordinate dependence. The MBH avoids these unphysical effects by taking into account energy gradient corrections. Moreover the number of variables is reduced, which facilitates the diagonalization of the Hessian. In the original implementation of MBH, atoms could only be part of one rigid block. The MBH is now extended to the case where atoms can be part of two or more blocks. Two basic linkages can be realized: (1) blocks connected by one link atom, or (2) by two link atoms, where the latter is referred to as the hinge type connection. In this work we present the MBH concept and illustrate its performance with the crambin protein as an example

Resonance properties from the finite-volume energy spectrum

A new method based on the concept of probability distribution is proposed to analyze the finite volume energy spectrum in lattice QCD. Using synthetic lattice data, we demonstrate that for the channel with quantum numbers of the Delta-resonance a clear resonance structure emerges in such an analysis. Consequently, measuring the volume-dependence of the energy levels in lattice QCD will allow to determine the mass and the width of the Delta with reasonable accuracy.Comment: 26 pages, 9 figures, 5 tables, tex typos in formulae A.1 and A.5 remove

On the development of a partial vibrational analysis within a QM/MM approach

In molecular modeling extended systems are often only partially optimized in order to restrict the computational cost. For instance in a first step the whole system is optimized at a low level-of-theory, and in the next step only part of the atoms, usually the chemically active region, is optimized at a high level-of-theory, while atoms in the passive region are kept fixed at their original positions. However, partially optimized geometries are non-equilibrium structures and the standard normal mode analysis (NMA) shows some serious defects, e.g. spurious imaginary frequencies may appear. In the Partial Hessian Vibrational Analysis [1],[2] these defects are surmounted by giving the fixed part an infinite mass. We propose a new model, the Mobile Block Hessian (MBH) approach, which takes into account the finite mass of the fixed block and avoids the spurious frequencies and the coordinate dependence [3]. The approach was generalized to the case of several mobile blocks. The MBH has been validated by comparing eigenfrequencies and eigenvectors, vibrational entropy and enthalpy, and recently reaction rate constants [4], with remarkably satisfying results. One of the main advantages is that the implementation of the MBH allows a considerable reduction of computer time [5]. After several tests with smaller QM systems, the method is now also included in the CHARMM package, allowing the simulation of more extended (bio)systems. The next step is combining the MBH approach with QM/MM, currently in a developing stage, which will broaden the range of applications. MBH in QM/MM is a very promising methodology for extended systems. Whereas a full normal mode analysis is unfeasible even if only the MM part of the system increases, because of the high number of expensive second derivatives of the QM/MM interaction terms in the Hamiltionian, the MBH can considerably reduce this cost, thereby opening the path to vibrational analysis in extended QM/MM systems. [1] J. D. Head, Int. J. of Quantum Chem. 65, 827 (1997) [2] H. Li and J. H. Jensen, Theor. Chem. Accounts. 107(4): 211-219 (2002) [3] A. Ghysels, D. Van Neck, V. Van Speybroeck, T. Verstraelen, M. Waroquier, J. Chem. Phys. 126, 224102 (2007) [4] A. Ghysels, V. Van Speybroeck, T. Verstraelen, D. Van Neck, M. Waroquier, J. Chem. Theor. Comp. 4 (4), 614-625 (2008) [5] A. Ghysels, D. Van Neck, M. Waroquier, J. Chem. Phys. 127, 164108 (2007

Effects of poor sanitation on public health: Case of Yopougon town (Abidjan)

Effects of poor environmental hygiene on population health were studied in the precarious living quarters of Doukoure, the village of Niangon-adjame and the viable living quarters of millionaire’s in Yopougon town. This study included sanitation, water sources, as well as, population health. It appears that excreta management is from self-purification works (WC with septic tank) (60%), collective purification work (gutter storm water, sewer) (26%), anarchic connections (30%) and defecation in nature relatively less important (2%) for all living quarters visited. Furthermore, almost 90% of the populations have access to the drinking water, which is rather used. In Doukouré’s living quarters and Niangon-Adjamé’s village, public tap water (7%) and traditional wells (3%) are used for domestic needs. Data collected in 15 health centers in the town on 125 446 cases of morbidity, revealed that malaria is much contracted by populations with 58% cases against 14% for diarrhea and 28% for acute respiratory infections. Under-five children are much affected with 24% of the patients among which 43% were cases of the diarrheic diseases. Also, malaria and respiratory infections are more important during rainy seasons, in contrast to diarrheal diseases caused by poor hygiene of people.Key words: Public health, malaria, diarrhea, respiratory infections, sanitation, risk