Three parallel algorithms for classical molecular dynamics are presented. The first assigns each processor a fixed subset of atoms; the second assigns each a fixed subset of inter-atomic forces to compute; the third assigns each a fixed spatial region. The algorithms are suitable for molecular dynamics models which can be difficult to parallelize efficiently—those with short-range forces where the neighbors of each atom change rapidly. They can be implemented on any distributed-memory parallel machine which allows for message-passing of data between independently executing processors. The algorithms are tested on a standard Lennard-Jones benchmark problem for system sizes ranging from 500 to 100,000,000 atoms on several parallel supercomputers--the nCUBE 2, Intel iPSC/860 and Paragon, and Cray T3D. Comparing the results to the fastest reported vectorized Cray Y-MP and C90 algorithm shows that the current generation of parallel machines is competitive with conventional vector supercomputers even for small problems. For large problems, the spatial algorithm achieves parallel efficiencies of 90% and a 1840-node Intel Paragon performs up to 165 faster than a single Cray C9O processor. Trade-offs between the three algorithms and guidelines for adapting them to more complex molecular dynamics simulations are also discussed.

Fast parallel algorithms for short-range molecular dynamics

다중혈관 관상동맥 환자에서 y-문합을 이용하여 양쪽 내흉동맥만을 사용한 우회술의 조기 성적

抗原变异可使得多种致病微生物易于逃避宿主免疫应答。表达在感染红细胞表面的恶性疟原虫红细胞表面蛋白1（PfPMP1）与感染红细胞、内皮细胞、树突状细胞以及胎盘的单个或多个受体作用，在黏附及免疫逃避中起关键的作用。每个单倍体基因组var基因家族编码约60种成员，通过启动转录不同的var基因变异体为抗原变异提供了分子基础。

疟原虫var基因转换速率变化导致抗原变异[英]／Paul H, Robert P, Christodoulou Z, et al//Proc Natl Acad Sci U S A

[신간의 별자리x] 우리/미술, 그리고 ‘슬픔의 박물관’

We investigate whether income inequality affects subsequent growth in a cross-country sample for 1965-90, using the models of Barro (1997), Bleaney and Nishiyama (2002) and Sachs and Warner (1997), with negative results. We then investigate the evolution of income inequality over the same period and its correlation with growth. The dominating feature is inequality convergence across countries. This convergence has been significantly faster amongst developed countries. Growth does not appear to influence the evolution of inequality over time. Outline

https://www.econstor.eu/bitstream/10419/81822/1/02-28.pdf

Economic growth and income inequality

The problem of spontaneous evolution of morphological patterns in thin ( $l100\mathrm{nm}$) unstable liquid films on homogeneous solid substrates is resolved based on a 3D nonlinear equation of motion. Initially, a small amplitude bicontinuous structure emerges, which either grows and fragments into a collection of microdroplets (for relatively thinner films), or leads directly to isolated circular holes (for thicker films) which dewet the surface. The characteristics of a pattern, and its pathway of evolution, thus depend crucially on the form of the intermolecular potential in an extended neighborhood of the initial thickness. The linear and 2D nonlinear analyses used hitherto fail completely in prediction of morphological patterns, but can predict their length scales rather well.

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Pattern formation in unstable thin liquid films

Instability of thin polymer films on coated substrates : Rupture, dewetting, and drop formation

Relationship of thin film stability and morphology to macroscopic parameters of wetting in the apolar and polar systems

A new mechanism for the surface instability and dewetting of thin films on chemically heterogeneous substrates is identified and simulated. The time scale for instability varies inversely with the potential difference due to the heterogeneity. Heterogeneities can even destabilize spinodally stable films, reduce the time of rupture substantially for thicker films, and produce complex and locally ordered morphological features (e.g., ripples and castle-moat structures, lack of undulations before hole formation) that are not predicted by the spinodal mechanism.

Instability and morphology of thin liquid films on chemically heterogeneous substrates

Dispersion forces are present everywhere. Their importance, however, is largely neglected because directly at a surface or at an interface they are mostly weak compared with specific interaction of short range. Here, we show that these forces are nonetheless extremely relevant and may have drastic consequences on the stability of thin films. We demonstrate that a force (per unit area) of <1 Pa is capable of “destroying” 100 nm (!) thick films, even if they are “glued” to the substrate by end-grafted polymers. We present the temporal evolution of different morphologies of unstable thin liquid polymer films caused by destabilizing intermolecular forces.

Ashutosh Sharma

Papers

Pattern formation in unstable thin liquid films

Instability of thin polymer films on coated substrates : Rupture, dewetting, and drop formation

Relationship of thin film stability and morphology to macroscopic parameters of wetting in the apolar and polar systems

Instability and morphology of thin liquid films on chemically heterogeneous substrates

Thin film instability induced by long-range forces