We present the details of a lattice Boltzmann approach to phase separation in nonideal one- and two-component fluids. The collision rules are chosen such that the equilibrium state corresponds to an input foe energy and the bulk flow is governed by the continuity, Navier-Stokes, and, for the binary fluid, a convection-diffusion equation. Numerical results are compared to simple analytic predictions to confirm that the equilibrium state is indeed thermodynamically consistent and that the kinetics of the approach to equilibrium lie within the expected universality classes. The approach is compared to other lattice Boltzmann simulations of nonideal systems

A lattice Boltzmann scheme able to model the hydrodynamics of phase separation and two-phase How is described. Thermodynamic consistency is ensured by introducing a nonideal pressure tensor directly into the collision operator. We also show how an external chemical potential can be used to supplement standard boundary conditions in order to investigate the effect of wetting on phase separation and fluid Aow in confined geometries.The approach has the additional advantage of reducing many of the unphysical discetrization problems common to previous lattice Boltzmann methods. The hydrodynamics and kinetics of two-component Auids present a wealth of physical problems of both fundamental and technological importance [1]. There is much current interest in the relevance of hydrodynamics to spinodal decomposition [2] and the effects of substrates with different wetting properties on phase separation and domain growth [3]. In addition, the fiow properties of multicomponent systems, particularly in porous media, have been intensively studied and are of great relevance to oil recovery [4]. Conventional methods for simulating two-phase How include numerical integration of the Navier-Stokes equations and molecular dynamics simulations [5]. These techniques are extremely computationally intensive and particularly difficult to implement in random geometries. A newer approach, the lattice Boltzmann method, has recently proved competitive [6]. Here a set of distribution functions defined on a lattice is allowed to relax to equilibrium via a Boltzmann equation, discrete in both space and time. The correct choice of equilibrium distribution ensures that in the long wavelength limit the Navier-Stokes equations are recovered. Several authors have set up lattice Boltzmann schemes for two-phase systems. In most approaches interface formation has been introduced phenomenologically by modifying the Boltzmann collision operator to impose phase separation [7]. Recent work by Shan and Chen [8] has attempted to relate phase separation to microscopic interactions by redefining the equilibrium velocity distribution so as to simulate a Quid with a nonideal equation of state. However, their approach leads to inconsistent thermodynamics unless a particular equation of state is chosen. In addition, all current schemes reach equilibrium distributions which have unphysical velocity fluctuations within the interfacial region [9].In this Letter we show for the first time that it is possible to set up a lattice Boltzmann scheme modeling isothermal hydrodynamics for two-phase systems. This is achieved by introducing directly into the collision operator the equilibrium pressure tensor for a nonideal quid. The resulting phase transition is pressure driven, as pertinent to a liquid-vapor system quenched to well below the critical point [10]. The lluid reaches the correct thermodynamic equilibrium as determined by the equation of state and a Maxwell construction.We first summarize the relevant results from the van der Waals formulation of quasilocal thermo...

The ataxia-telangiectasia gene predisposes heterozygotes to cancer, particularly breast cancer in women. There is also excess mortality from all causes in adults under the age of 60. Diagnostic or occupational exposure to ionizing radiation probably increases the risk of breast cancer in women heterozygous for ataxia-telangiectasia.

Patients who are homozygous for ataxia-telangiectasia have an exceptionally high incidence of cancer. In a group of families expected to have a high proportion of heterozygotes for ataxia-telangiectasia, we tested the hypothesis that such heterozygotes, estimated to make up 0.68 to 7.7 percent of the U.S. white population, also have an excess cancer risk. Retrospective cancer incidence rates in adult blood relatives of patients with ataxia-telangiectasia in 110 white non-Amish families were significantly elevated over the incidence rates in spouse controls (rate ratios, 1.6 for men [P = 0.032]; 2.0 for women [P = 0.013]). For persons who are heterozygous for ataxia-telangiectasia, the relative risk of cancer was estimated to be 2.3 for men (P = 0.014) and 3.1 for women (P = 0.004). Breast cancer in women was the cancer most clearly associated with heterozygosity for ataxia-telangiectasia (rate ratio, 3.0 [P = 0.028]; heterozygote relative risk, 6.8 [P = 0.006]). On the basis of this estimated relative risk of 6.8 and an estimated heterozygote frequency in the general population of 1.4 percent, 8.8 percent of patients with breast cancer in the U.S. white population would be heterozygous for ataxia-telangiectasia. We conclude that heterozygous carriers of the gene for ataxia-telangiectasia have an excess risk of cancer, particularly breast cancer in women.

The scaling of physical forces to the extremely low ambient gravitational acceleration regimes found on the surfaces of small asteroids is performed. Resulting from this, it is found that van der Waals cohesive forces between regolith grains on asteroid surfaces should be a dominant force and compete with particle weights and be greater, in general, than electrostatic and solar radiation pressure forces. Based on this scaling, we interpret previous experiments performed on cohesive powders in the terrestrial environment as being relevant for the understanding of processes on asteroid surfaces. The implications of these terrestrial experiments for interpreting observations of asteroid surfaces and macro-porosity are considered, and yield interpretations that differ from previously assumed processes for these environments. Based on this understanding, we propose a new model for the end state of small, rapidly rotating asteroids which allows them to be comprised of relatively fine regolith grains held together by van der Waals cohesive forces.

BACKGROUND X-linked cardiomyopathy (XLCM) is a rapidly progressive primary myocardial disorder presenting in teenage males as congestive heart failure. Manifesting female carriers have later onset (fifth decade) and slower progression. The purpose of this study was to localize the XLCM gene locus in two families using molecular genetic techniques. METHODS AND RESULTS Linkage analysis using 60 X-chromosome-specific DNA markers was performed in a previously reported large XLCM pedigree and a smaller new pedigree. Two-point and multipoint linkage was calculated using the LINKAGE computer program package. Deletion analysis included multiplex polymerase chain reaction (PCR). Dystrophin protein was evaluated by Western blotting with N-terminal and C-terminal dystrophin antibody. Linkage of XLCM to the centromeric portion of the dystrophin or Duchenne muscular dystrophy (DMD) locus at Xp21 was demonstrated with combined maximum logarithm of the scores of +4.33, theta = 0 with probe XJ1.1 (DXS206) using two-point linkage and +4.81 at XJ1.1 with multipoint linkage analysis. LOD scores calculated using other proximal DMD genomic and cDNA probes and polymerase chain reaction polymorphisms supported linkage. No deletions were observed. Abnormalities of cardiac dystrophin were shown by Western blotting with N-terminal dystrophin antibody, whereas skeletal muscle dystrophin was normal, suggesting primary involvement of the DMD gene with preferential involvement of cardiac muscle. CONCLUSIONS XLCM is due to an abnormality within the centromeric half of the dystrophin genomic region in heart. This abnormality could be due to 1) a point mutation in the 5' region of the DMD coding sequence preferentially affecting cardiac function, 2) a cardiac-specific promoter mutation that alters expression in this tissue, 3) splicing abnormalities, resulting in an abnormal cardiac protein, or 4) deletion mutations undetectable by Southern and multiplex polymerase chain reaction analysis.

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We introduce a lattice Boltzmann model for simulating an immiscible binary fluid mixture. Our collision rules are derived from a macroscopic thermodynamic description of the fluid in a way motivated by the Cahn-Hilliard approach to non-equilibrium dynamics and ensure that a thermodynamically consistent state is reached in equilibrium. The non-equilibrium dynamics is investigated numerically and found to agree with simple analytic predictions in both the one-phase and the two-phase region of the phase diagram.