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Showing papers by "University of Warsaw published in 1994"


Journal ArticleDOI
TL;DR: In this article, the feasibility of unification of the Yukawa couplings in the framework of the minimal supersymmetric standard model with (assumed) universal mass parameters at the unification scale and with radiative breaking of the electroweak symmetry was investigated.

579 citations


Journal ArticleDOI
26 Aug 1994-Cell
TL;DR: Analysis of the inhibition of pre-mRNA splicing in vitro and in vivo by chemically modified analogs of the cap structure, and of the binding of these analogs to CBC in vitro, suggests a role for the complex in splicing.

497 citations


Journal ArticleDOI
01 Apr 1994-Proteins
TL;DR: A new hierarchical method for the simulation of the protein folding process and the de novo prediction of protein three‐dimensional structure is proposed, which employs lattice discretizations of increasing geometrical resolution and a single ball representation of side chain rotamers.
Abstract: A new hierarchical method for the simulation of the protein folding process and the de novo prediction of protein three-di- mensional structure is proposed. The reduced representation of the protein a-carbon back- bone employs lattice discretizations of increas- ing geometrical resolution and a single ball representation of side chain rotamers. In par- ticular, coarser and finer lattice backbone de- scriptions are used. The coarser (finer) lattice represents Ca traces of native proteins with an accuracy of 1.0 (0.7) A rms. Folding is simulated by means of very fast Monte Carlo lattice dy- namics. The potential of mean force, predomi- nantly of statistical origin, contains several novel terms that facilitate the cooperative as- sembly of secondary structure elements and the cooperative packing of the side chains. Partic- ular contributions to the interaction scheme are discussed in detail. In the accompanying paper (Kolinski, A., Skolnick, J. Monte Carlo simula- tion of protein folding. 11. Application to pro- tein A, ROP, and crambin. Proteins 18:353366, 19941, the method is applied to three small globular proteins. o 1994 Wiley-Liss, hc.

289 citations


Journal ArticleDOI
TL;DR: New renormalization group equations for effective Hamiltonians in quantum field theory are presented and it is shown that these equations do not have to be derived from discrete-time Hamiltonian polynomials.
Abstract: We present new renormalization group equations for effective Hamiltonians in quantum field theory.

258 citations


Journal ArticleDOI
TL;DR: In this article, a systematic on-shell renormalization for the Higgs and gauge boson sectors of the Minimal Supersymmetric Standard Model was carried out for the 2-and 3-point Green's functions.

230 citations


Book ChapterDOI
16 Oct 1994
TL;DR: The results are showing that dynamic reducts can help to extract laws from decision tables, e.g. market data, medical data, textures and handwritten digits.
Abstract: We apply rough set methods and boolean reasoning for knowledge discovery from decision tables. It is not always possible to extract general laws from experimental data by computing first all reducts [12] of a decision table and next decision rules on the basis of these reducts. We investigate a problem how information about the reduct set changes in a random sampling process of a given decision table could be used to generate these laws. The reducts stable in the process of decision table sampling are called dynamic reducts. Dynamic reducts define the set of attributes called the dynamic core. This is the set of attributes included in all dynamic reducts. The set of decision rules can be computed from the dynamic core or from the best dynamic reducts. We report the results of experiments with different data sets, e.g. market data, medical data, textures and handwritten digits. The results are showing that dynamic reducts can help to extract laws from decision tables.

219 citations


Journal ArticleDOI
TL;DR: The weak-coupling approach potentially reconciles the simplicity of the Constituent Quark Model with the complexities of QuantumChromodynamics, and the necessity of formulating the dynamic QCD in light-front coordinates and of dealing with the complications of renormalization which such a formulationentails.
Abstract: In this work the determination of low-energy bound states in quantum chromodynamics is recast so that it is linked to a weak-coupling problem. This allows one to approach the solution with the same techniques which solve quantum electrodynamics: namely, a combination of weak-coupling diagrams and many-body quantum mechanics. The key to eliminating necessarily nonperturbative effects is the use of a bare Hamiltonian in which quarks and gluons have nonzero constituent masses rather than the zero masses of the current picture. The use of constituent masses cuts off the growth of the running coupling constant and makes it possible that the running coupling never leaves the perturbative domain. For stabilization purposes an artificial potential is added to the Hamiltonian, but with a coefficient that vanishes at the physical value of the coupling constant. The weak-coupling approach potentially reconciles the simplicity of the constituent quark model with the complexities of quantum chromodynamics. The penalty for achieving this perturbative picture is the necessity of formulating the dynamics of QCD in light-front coordinates and of dealing with the complexities of renormalization which such a formulation entails. We describe the renormalization process first using a qualitative phase space cell analysis, and we then set up a precise similarity renormalization scheme with cutoffs on constituent momenta and exhibit calculations to second order. We outline further computations that remain to be carried out. There is an initial nonperturbative but nonrelativistic calculation of the hadronic masses that determines the artificial potential, with binding energies required to be fourth order in the coupling as in QED. Next there is a calculation of the leading radiative corrections to these masses which requires our renormalization program. Then the real struggle of finding the right extensions to perturbation theory to study the strong-coupling behavior of bound states can begin.

210 citations


Journal ArticleDOI
TL;DR: It is shown how to speed up two string-matching algorithms: the Boyer-Moore algorithm (BM algorithm), and its version called here the reverse factor algorithm (RF algorithm), based on factor graphs for the reverse of the pattern.
Abstract: We show how to speed up two string-matching algorithms: the Boyer-Moore algorithm (BM algorithm), and its version called here the reverse factor algorithm (RF algorithm). The RF algorithm is based on factor graphs for the reverse of the pattern. The main feature of both algorithms is that they scan the text right-to-left from the supposed right position of the pattern. The BM algorithm goes as far as the scanned segment (factor) is a suffix of the pattern. The RF algorithm scans while the segment is a factor of the pattern. Both algorithms make a shift of the pattern, forget the history, and start again. The RF algorithm usually makes bigger shifts than BM, but is quadratic in the worst case. We show that it is enough to remember the last matched segment (represented by two pointers to the text) to speed up the RF algorithm considerably (to make a linear number of inspections of text symbols, with small coefficient), and to speed up the BM algorithm (to make at most 2 ·n comparisons). Only a constant additional memory is needed for the search phase. We give alternative versions of an accelerated RF algorithm: the first one is based on combinatorial properties of primitive words, and the other two use the power of suffix trees extensively. The paper demonstrates the techniques to transform algorithms, and also shows interesting new applications of data structures representing all subwords of the pattern in compact form.

190 citations


Journal ArticleDOI
TL;DR: In this paper, a condition number estimate for the iterative operator, which is independent of the coefficients, and grows at most as the square of the number of levels, is established.
Abstract: Multilevel Schwarz methods are developed for a conforming finite element approximation of second order elliptic problems. We focus on problems in three dimensions with possibly large jumps in the coefficients across the interface separating the subregions. We establish a condition number estimate for the iterative operator, which is independent of the coefficients, and grows at most as the square of the number of levels. We also characterize a class of distributions of the coefficients, called quasi-monotone, for which the weighted\(L^{2}\) -projection is stable and for which we can use the standard piecewise linear functions as a coarse space. In this case, we obtain optimal methods, i.e. bounds which are independent of the number of levels and subregions. We also design and analyze multilevel methods with new coarse spaces given by simple explicit formulas. We consider nonuniform meshes and conclude by an analysis of multilevel iterative substructuring methods.

189 citations


Journal ArticleDOI
TL;DR: Domain decomposition methods provide powerful preconditioners for the iterative solution of the large systems of algebraic equations that arise in finite element or finite difference approximations as discussed by the authors.
Abstract: Domain decomposition methods provide powerful preconditioners for the iterative solution of the large systems of algebraic equations that arise in finite element or finite difference approximations...

189 citations


Journal ArticleDOI
TL;DR: In this article, it was shown that the motion of a curve selects hierarchies of integrable dynamics, such as the Korteweg-de Vries hierarchy, the Schrodinger hierarchy, and the Schroff hierarchy.

Journal ArticleDOI
M. Derrick1, M. Derrick2, D. Krakauer3, D. Krakauer2  +453 moreInstitutions (40)
TL;DR: In this article, the authors measured the elastic light vector meson cross sections at an average υp center of mass energy of 180 GeV with the ZEUS detector at HERA.
Abstract: Photon proton cross sections for elastic light vector meson production, σelνp, inelastic diffractive production, σndνp, non-diffractive production, σdνp, as well as the total cross section, σtotνp, have been measured at an average υp center of mass energy of 180 GeV with the ZEUS detector at HERA. The resulting values are σelνp = 18 ± 7 μb, σdνp = 33 ± 8 μb, σndνp = 91 ± 11 μb, and σtotνp 143 ± 17 μb, where the errors include statistical and systematic errors added in quadrature.

Journal Article
TL;DR: In this paper, the first two years of the OGLE search for gravitational lenses towards the Galactic bulge were analyzed. And they found that the optical depth to microlensing is larger than 3.3 ± 1.2 × 10−6.
Abstract: We present the analysis of the first two years of the OGLE search for gravitational lenses towards the Galactic bulge. We detected 9 microlensing events in an algorithmic search of $ \\sim 10^8 $ measurements of $ \\sim 10^6 $ stars. The characteristic time scales are in the range $ 8.6 < t_0 < 62 $ days, where $ t_0 = R_E / V $. The distribution of amplitudes is consistent with theoretical expectation. The stars seem to be drawn at random from the overall distribution of the observed bulge stars. We find that the optical depth to microlensing is larger than $ ( 3.3 \\pm 1.2 ) \\times 10^{-6}$, in excess of current theoretical estimates.

Journal ArticleDOI
TL;DR: In this article, the authors describe the event generator DJANGO6, which simulates deep inelastic lepton-proton scattering including both QED and QCD radiative effects.

Journal ArticleDOI
TL;DR: Three system order parameters are derived, dynamism, polarization, and clustering, to describe global states of attitude distribution and change for human social systems, which suggest a conception of human systems rooted in time and space that is distinct from other approaches.
Abstract: We derive three system order parameters: dynamism, polarization, and clustering, to describe global states of attitude distribution and change for human social systems. Dynamism (f) captures the rate of change in a system, while polarization (Pt) refers to the increase or decrease of a minority position over time. Clustering (e) defines the spatial segregation of opinion based on system topography. These measures suggest a conception of human systems rooted in time and space that is distinct from other approaches. Their utility is illustrated through computer simulations showing that under a wide variety of circumstances, social influence models incorporating spatial distributions lead to unexpected outcomes of incomplete polarization and clustering, with alternative theories of how individuals encode information leading to quantitatively distinct results. A second set of simulations describes the intrusion of temperature, or unexplained randomness into these systems. Surprisingly, the self-organizational tendencies emerging from the iteration of simple laws of individual attitude change derived from Latane's (1981) metatheory of social impact appear to increase with moderate levels of randomness. We consider other approaches for measuring group level processes, among them network analysis-inspired indices and spatial autocorrelation, and suggest how our system order parameters could be used to predict political elections.

Journal ArticleDOI
TL;DR: These first applications to human intracranial recordings demonstrated that the DTF method can accurately determine patterns of seizure onset and propagation and can provide evidence regarding patterns of flow of seizure activity that are not readily apparent from visual inspection of the EEG recordings.

Journal ArticleDOI
TL;DR: In this paper, the authors compared the Minimal Supersymmetric Standard Model (MSSM) and the standard model with the light Higgs boson mass Mh.

Journal ArticleDOI
TL;DR: In this paper, the authors proposed a modified single-reference coupled-cluster (CC) procedure for the calculation of non-dynamical electron correlation effects by the complete active space self-consistent field (CASSCF) method.


Journal ArticleDOI
TL;DR: In this paper, it was shown that the convergence of the top quark mass to its fixed point value has relevant consequences for the universal soft supersymmetry breaking parameters at the grand unification scale.

Journal ArticleDOI
TL;DR: This work provides necessary and sufficient conditions for linear multivariate problems to be tractable or strongly tractable in the worst case, average case, randomized, and probabilistic settings, and considers linearMultivariate problems over reproducing kernel Hilbert spaces, showing that such problems are strong tractable even in the best case setting.

Book ChapterDOI
TL;DR: Waters of Lake Łuknajno (623 ha, 3 m max. depth postglacial basin in Masurian Lakeland) are of meso-eutrophic type in spite of an intensive land impact and substantial phosphorus loading because of an abundance of 4 species of charophytes.
Abstract: Waters of Lake Luknajno (623 ha, 3 m max. depth postglacial basin in Masurian Lakeland) are of meso-eutrophic type in spite of an intensive land impact and substantial phosphorus loading. The reason of this peculiarity is an abundance of 4 species of charophytes (Chara aculeolata, C. aspera, C. contraria and C. tomentosa) which dominate the submerged vegetation of the lake and yielded 417 g m−2 dry biomass in summer 1991. The plants have high potential for phosphorus uptake and accumulation as was checked in laboratory experiments. Due to this potential Chara can outcompete planktonic algae in mixed cultures at different mineral P supplies.

Journal ArticleDOI
TL;DR: In this article, a di-and tetrathioamide functionalized calix arene as ionophores were used as lead selective electrodes and the Pb(II)-response functions exhibited almost theoretical Nernstian slopes in the activity range 10?6?10?2M of lead ions.

Journal ArticleDOI
TL;DR: Bean plants (Phaseolus vulgaris) grown in phosphate-deficient (-P) medium display deficiency symptoms after about 2 weeks of culture, and the sucrose level in -P roots almost doubled compared to control roots.
Abstract: Bean plants (Phaseolus vulgaris) grown in phosphate-deficient (-P) medium display deficiency symptoms after about 2 weeks of culture. A decrease in inorganic phosphate level in roots was observed after 10 days of culture, and after 17 days it was more than 30 times less than control. The dry weight of the roots was higher as compared to the control roots. After 2 weeks of culture, the sucrose level in -P roots almost doubled compared to control roots

Journal ArticleDOI
TL;DR: In this article, the authors investigated the performance of selective electrodes based on thioether functionalized calix[4]arenes 1 and 2 as ionophores and found that the Ag(I)-response functions exhibited almost theoretical Nernstian slopes in the activity range 10−6−10−1M of silver ions.

Journal ArticleDOI
TL;DR: Root growth and mitotic activity were gradually inhibited during the initial hours of incubation and were accompanied by a rise in the incidence of abnormal mitoses (c-mitoses) to about 40%.

Journal ArticleDOI
TL;DR: In this paper, it is shown that the density distribution at the third, hyperdeformed minimum resembles a di-nucleus consisting of a nearly-spherical nucleus around the doubly-magic nucleus 132Sn, and a well-deformed fragment from the neutron-rich A ≈ 100 region.

Posted Content
TL;DR: In this article, the authors extended the Hall transform to the infinite dimensional context of non-Abelian gauge theories by replacing the Lie group $G$ by (a certain extension of) the space of connections modulo gauge transformations.
Abstract: The Segal-Bargmann transform plays an important role in quantum theories of linear fields. Recently, Hall obtained a non-linear analog of this transform for quantum mechanics on Lie groups. Given a compact, connected Lie group $G$ with its normalized Haar measure $\mu_H$, the Hall transform is an isometric isomorphism from $L^2(G, \mu_H)$ to ${\cal H}(G^{\Co})\cap L^2(G^{\Co}, u)$, where $G^{\Co}$ the complexification of $G$, ${\cal H}(G^{\Co})$ the space of holomorphic functions on $G^{\Co}$, and $ u$ an appropriate heat-kernel measure on $G^{\Co}$. We extend the Hall transform to the infinite dimensional context of non-Abelian gauge theories by replacing the Lie group $G$ by (a certain extension of) the space ${\cal A}/{\cal G}$ of connections modulo gauge transformations. The resulting ``coherent state transform'' provides a holomorphic representation of the holonomy $C^\star$ algebra of real gauge fields. This representation is expected to play a key role in a non-perturbative, canonical approach to quantum gravity in 4-dimensions.


Journal ArticleDOI
TL;DR: In this paper, the adsorption of carbon oxides from sulfuric acid solution on a palladium electrode was investigated with electrochemical and radiometric methods, and a strong correlation between the decrease in the real surface of the palladium electrodes and the currents of sorbed hydrogen during its oxidation has been found.