A detailed study of the generation of optically detectable watermarks using the logistic map

A digital watermark is a visible, or preferably invisible, identification code that is permanently embedded in digital media, to prove owner authentication and provide protection for documents. Given the interest in watermark generation using chaotic functions a detailed study of one chaotic function for this purpose is performed. In this paper, we present an approach for the generation of watermarks using the logistic map. Using this function, in conjunction with seed management, it is possible to generate chaotic sequences that may be used to create highpass or lowpass digital watermarks. In this paper we provide a detailed study on the generation of optically detectable watermarks and we provide some guidelines on successful chaotic watermark generation using the logistic map, and show using a recently published scheme, how care must be taken in the selection of the function seed.     

Observation of two resonant structures in e+ e- -->pi+ pi- psi(2S) via initial-state radiation at Belle

The cross section for e+ e- --> pi+ pi- psi(2S) between threshold and sqrt[s]=5.5 GeV is measured using 673 fb(-1) of data on and off the Upsilon(4S) resonance collected with the Belle detector at KEKB. Two resonant structures are observed in the pi+ pi- psi(2S) invariant-mass distribution, one at 4361 +/- 9 +/- 9 MeV/c2 with a width of 74 +/- 15 +/- 10 MeV/c2, and another at 4664 +/- 11 +/- 5 MeV/c2 with a width of 48 +/- 15 +/- 3 MeV/c2, if the mass spectrum is parametrized with the coherent sum of two Breit-Wigner functions. These values do not match those of any of the known charmonium states.     

Measurement of Einstein-Podolsky-Rosen-type flavor entanglement in Upsilon(4S) --> B0 B0 decays

The neutral B meson pair produced at the Upsilon(4S) should exhibit a nonlocal correlation of the type discussed by Einstein, Podolsky, and Rosen. We measure this correlation using the time-dependent flavor asymmetry of semileptonic B(0) decays, which we compare with predictions from quantum mechanics and two local realistic models. The data are consistent with quantum mechanics, and inconsistent with the other models. Assuming that some B pairs disentangle to produce B(0) and B(0) with definite flavor, we find a decoherent fraction of 0.029 +/ -0.057, consistent with no decoherence.     

Measurements of branching fractions for B --> K pi and B --> pi pi decays

We report measurements of branching fractions for B --> K pi and B --> pi pi decays based on a data sample of 449 x 10(6) BB[over] pairs collected at the Upsilon(4S) resonance with the Belle detector at the KEKB asymmetric-energy e(+)e(-) collider. We also measure the ratios of partial widths for B-->Kpi decays, namely R(c) identical with 2Gamma(B(+) --> K(+) pi(0))/Gamma(B(+) --> K(0) pi(+)) = 1.08+/-0.06+/-0.08 and R(n) identical with Gamma(B(0) --> K(+) pi(-))/2 Gamma(B(0) --> K(0) pi(0)) = 1.08+/-0.08+/-0.08, where the first and the second errors are statistical and systematic, respectively. These ratios are sensitive to enhanced electroweak penguin contributions from new physics; the new measurements are, however, consistent with standard model expectations.     

Measurement of inclusive Ds, D0, and J/psi rates and determination of the Bs(*)Bs(*) production fraction in bb Events at the Upsilon(5S) resonance

The inclusive production of D(s), D(0), and J/psi mesons is studied using a 1.86 fb(-1) data sample collected on the Upsilon(5S) resonance with the Belle detector at the KEKB asymmetric-energy e(+)e(-) collider. The number of bb events in this Upsilon(5S) data sample is determined. We measure the branching fractions B(Upsilon(5S)-->D(s)X)/2=(23.6+/-1.2+/-3.6)%, B(Upsilon(5S)-->D(0)X)/2=(53.8+/-2.0+/-3.4)%, and B(Upsilon(5S)-->J/psiX)/2=(1.030+/-0.080+/-0.067)%. From the D(s) and D(0) inclusive branching fractions the ratio f(s)=(18.0+/-1.3+/-3.2)% of B(s)(*)B(s)(*) to the total bb quark pair production at the Upsilon(5S) energy is obtained in a model-dependent way.     

A common repressor pool results in indeterminacy of extrinsic noise

For just over a decade, stochastic gene expression has been the focus of many experimental and theoretical studies. It is now widely accepted that noise in gene expression can be decomposed into extrinsic and intrinsic components, which have orthogonal contributions to the total noise. Intrinsic noise stems from the random occurrence of biochemical reactions and is inherent to gene expression. Extrinsic noise originates from fluctuations in the concentrations of regulatory components or random transitions in the cell's state and is imposed to the gene of interest by the intra- and extra-cellular environment. The basic assumption has been that extrinsic noise acts as a pure input on the gene of interest, which exerts no feedback on the extrinsic noise source. Thus, multiple copies of a gene would be uniformly influenced by an extrinsic noise source. Here, we report that this assumption falls short when multiple genes share a common pool of a regulatory molecule. Due to the competitive utilization of the molecules existing in this pool, genes are no longer uniformly influenced by the extrinsic noise source. Rather, they exert negative regulation on each other and thus extrinsic noise cannot be determined by the currently established method.     

Hyperconifold transitions,mirror symmetry,and string theory

Multiply-connected Calabi–Yau threefolds are of particular interest for both string theorists and mathematicians. Recently it was pointed out that one of the generic degenerations of these spaces (occurring at codimension one in moduli space) is an isolated singularity which is a finite cyclic quotient of the conifold; these were called hyperconifolds. It was also shown that if the order of the quotient group is even, such singular varieties have projective crepant resolutions, which are therefore smooth Calabi–Yau manifolds. The resulting topological transitions were called hyperconifold transitions, and change the fundamental group as well as the Hodge numbers. Here Batyrev?s construction of Calabi–Yau hypersurfaces in toric fourfolds is used to demonstrate that certain compact examples containing the remaining hyperconifolds — the Z₃${\mathbb{Z}}_3$ and Z₅${\mathbb{Z}}_5$ cases — also have Calabi–Yau resolutions. The mirrors of the resulting transitions are studied and it is found, surprisingly, that they are ordinary conifold transitions. These are the first examples of conifold transitions with mirrors which are more exotic extremal transitions. The new hyperconifold transitions are also used to construct a small number of new Calabi–Yau manifolds, with small Hodge numbers and fundamental group Z₃${\mathbb{Z}}_3$ or Z₅${\mathbb{Z}}_5$. Finally, it is demonstrated that a hyperconifold is a physically sensible background in Type IIB string theory. In analogy to the conifold case, non-perturbative dynamics smooth the physical moduli space, such that hyperconifold transitions correspond to non-singular processes in the full theory.     

A delay-dependent model with HIV drug resistance during therapy

The use of combination antiretroviral therapy has proven remarkably effective in controlling HIV disease progression and prolonging survival. However, the emergence of drug resistance can occur. It is necessary that we gain a greater understanding of the evolution of drug resistance. Here, we consider an HIV viral dynamical model with general form of target cell density, drug resistance and intracellular delay incorporating antiretroviral therapy. The model includes two strains: wild-type and drug-resistant. The basic reproductive ratio for each strain is obtained for the existence of steady states. Qualitative analysis of the model such as the well-posedness of the solutions and the equilibrium stability is provided. Global asymptotic stability of the disease-free and drug-resistant steady states is shown by constructing Lyapunov functions. Furthermore, sufficient conditions related to the properties of the target cell density are obtained for the local asymptotic stability of the positive steady state. Numerical simulations are conducted to study the impact of target cell density and intracellular delay focusing on the stability of the positive steady state. The occurrence of Hopf bifurcation of periodic solutions is shown to depend on the target cell density.