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

The emergence of order in natural systems is a constant source of inspiration for both physical and biological sciences. While the spatial order characterizing for example the crystals has been the basis of many advances in contemporary physics, most complex systems in nature do not offer such high degree of order. Many of these systems form complex networks whose nodes are the elements of the system and edges represent the interactions between them. 
Traditionally complex networks have been described by the random graph theory founded in 1959 by Paul Erdohs and Alfred Renyi. One of the defining features of random graphs is that they are statistically homogeneous, and their degree distribution (characterizing the spread in the number of edges starting from a node) is a Poisson distribution. In contrast, recent empirical studies, including the work of our group, indicate that the topology of real networks is much richer than that of random graphs. In particular, the degree distribution of real networks is a power-law, indicating a heterogeneous topology in which the majority of the nodes have a small degree, but there is a significant fraction of highly connected nodes that play an important role in the connectivity of the network. 
The scale-free topology of real networks has very important consequences on their functioning. For example, we have discovered that scale-free networks are extremely resilient to the random disruption of their nodes. On the other hand, the selective removal of the nodes with highest degree induces a rapid breakdown of the network to isolated subparts that cannot communicate with each other. 
The non-trivial scaling of the degree distribution of real networks is also an indication of their assembly and evolution. Indeed, our modeling studies have shown us that there are general principles governing the evolution of networks. Most networks start from a small seed and grow by the addition of new nodes which attach to the nodes already in the system. This process obeys preferential attachment: the new nodes are more likely to connect to nodes with already high degree. We have proposed a simple model based on these two principles wich was able to reproduce the power-law degree distribution of real networks. Perhaps even more importantly, this model paved the way to a new paradigm of network modeling, trying to capture the evolution of networks, not just their static topology.

/pdf/statistical-mechanics-of-complex-networks-1zfjpvxipu.pdf

Statistical mechanics of complex networks

Preface to the Princeton Landmarks in Biology Edition vii Preface xi Symbols Used xiii 1. The Importance of Islands 3 2. Area and Number of Speicies 8 3. Further Explanations of the Area-Diversity Pattern 19 4. The Strategy of Colonization 68 5. Invasibility and the Variable Niche 94 6. Stepping Stones and Biotic Exchange 123 7. Evolutionary Changes Following Colonization 145 8. Prospect 181 Glossary 185 References 193 Index 201

The Theory of Island Biogeography

http://www.maths.qmul.ac.uk/%7Elatora/report_06.pdf

Complex networks: Structure and dynamics

https://www.tau.ac.il/%7Eklafter1/258.pdf

The random walk's guide to anomalous diffusion: a fractional dynamics approach

In a recent analysis of number counts in the ESP sur- vey Scaramella et al. (1998) claim to find evidence for a cross- over to homogeneity at large scales, and against a fractal be- haviour with dimension D 2. In this comment we note firstly that, if such a cross-over exists as described by the authors, the scale characterizing it is 100300h 1 Mpc. This invalidates the "standard" analysis of the same catalogue given elsewhere by the authors which results in a "correlation length" of only r0 =4 h 1 Mpc. Furthermore we show that the evidences for a cross-over to homogeneity rely on the choice of cosmological model, and most crucially on the so called K corrections. We show that the D 3 behaviour seen in the K-corrected data of Scaramella et al. is in fact unstable, increasing systemati- cally towards D =4 as a function of the absolute magnitude limit. This behaviour can be quantitatively explained as the ef- fect of unphysical K-correction in the relevant range of red-shift (z 0:10:3). A more consistent interpretation of the number counts is that D is in the range 2 2:5, depending on the cos- mological model, consistent with the continuation of the fractal D 2 behaviour observed at scales up to 100h 1 Mpc. This implies a smaller K-correction. Given, however, the uncertainty in the effect of intrinsic fluctuations on the number counts statis- tic, and its sensitivity on these large scales to the uncertain K corrections, we conclude that it is premature to put a definitive constraint on the galaxy distribution using the ESP data alone.

http://aa.springer.de/papers/9344002/2300387.pdf

Comment on the paper "The ESO Slice Project galaxy redshift survey: V. Evidence for a D=3 sample dimensionality"

We use the fixed scale transformation method, developed for fractal growth, to investigate analytically the nature of clusters in self-organized criticality (SOC). In two dimensions the clusters of sites involved in a relaxation process turn out to be compact (D=2) because of the absence of effective screening. Therefore they are more similar to Eden-type clusters (possibly with a rough surface) than to those of the usual fractal growth models. This result is in good agreement with the computer simulations and one can conjecture that it should hold for any dimensions. The critical state corresponding to SOC dynamics is therefore of much simpler nature with respect to those of the usual fractal growth models.

Fixed scale transformation approach to the nature of relaxation clusters in self-organized criticality

The origin of fractal properties in diffusion limited aggregation is related to the persistence of screening in the scale invariant growth regime. This effect is described by the effective noise reduction parameter S spontaneously generated by the scale invariant dynamics. The renormalization of this parameter under scale transformation shows the following: (i) The fixed point is attractive, implying the self-critical nature of the process. (ii) The fixed point value ${\mathit{S}}^{\mathrm{*}}$ is of the order of unity, showing that the small scale growth rules are already close to the scale invariant ones and that screening effects persisit in the asympotic regime.

https://repository.library.northeastern.edu/files/neu:331447/fulltext.pdf

Persistence of screening and self-criticality in the scale invariant dynamics of diffusion limited aggregation.

In this paper we address the possibility of high-${T}_{c}$ superconductivity ${(T}_{c}\ensuremath{\sim}100\mathrm{K})$ in hypothetical hole doped ${\mathrm{C}}_{60}$ within the context of the nonadiabatic theory of superconductivity. Our analysis shows that electron doped fullerenes, represented by the ${A}_{3}{\mathrm{C}}_{60}$ family, are characterized by relatively small values of the electron--phonon coupling constant \ensuremath{\lambda}, which can thus be further increased by hole doping before lattice instabilities occur. In particular we show that ${T}_{c}$ larger than 100 K are compatible in the nonadiabatic context with microscopic parameters ${\ensuremath{\lambda}}_{h}\ensuremath{\simeq}0.5--1.0,$ ${\ensuremath{\mu}}^{*}\ensuremath{\simeq}0.3--0.5$ and phonon frequencies ${\ensuremath{\omega}}_{\mathrm{ph}}\ensuremath{\simeq}1500--2000\mathrm{K}.$ These results provide a stimulus for material engineering and optimization along the lines indicated.

/pdf/nonadiabatic-high-t-c-superconductivity-in-hole-doped-4i55xq22o1.pdf

Nonadiabatic high- T c superconductivity in hole-doped fullerenes

The depinning transition of a charge density wave pinned by random impurities gives rise to a dynamical critical behaviour of new type with properties analogous to those of glassy systems. In order to discuss these properties, it is convenient to introduce a coarse-grained model that should belong to the same class of universality of the usual models. This allows to derive analytical results for the critical exponents and for the stretched exponential relaxation below threshold. These results are in excellent agreement with computer simulations and elucidate the nature of this dynamical phase transition and of the glassy-type relaxation in the pinned region.

http://iopscience.iop.org/article/10.1209/0295-5075/16/4/001/pdf

Luciano Pietronero

Papers

Comment on the paper "The ESO Slice Project galaxy redshift survey: V. Evidence for a D=3 sample dimensionality"

Fixed scale transformation approach to the nature of relaxation clusters in self-organized criticality

Persistence of screening and self-criticality in the scale invariant dynamics of diffusion limited aggregation.

Nonadiabatic high- T c superconductivity in hole-doped fullerenes

Theory of the depinning transition in charge density waves.