1,969 research outputs found
Coupled effects of local movement and global interaction on contagion
By incorporating segregated spatial domain and individual-based linkage into
the SIS (susceptible-infected-susceptible) model, we investigate the coupled
effects of random walk and intragroup interaction on contagion. Compared with
the situation where only local movement or individual-based linkage exists, the
coexistence of them leads to a wider spread of infectious disease. The roles of
narrowing segregated spatial domain and reducing mobility in epidemic control
are checked, these two measures are found to be conducive to curbing the spread
of infectious disease. Considering heterogeneous time scales between local
movement and global interaction, a log-log relation between the change in the
number of infected individuals and the timescale is found. A theoretical
analysis indicates that the evolutionary dynamics in the present model is
related to the encounter probability and the encounter time. A functional
relation between the epidemic threshold and the ratio of shortcuts, and a
functional relation between the encounter time and the timescale are
found
A generalized public goods game with coupling of individual ability and project benefit
Facing a heavy task, any single person can only make a limited contribution
and team cooperation is needed. As one enjoys the benefit of the public goods,
the potential benefits of the project are not always maximized and may be
partly wasted. By incorporating individual ability and project benefit into the
original public goods game, we study the coupling effect of the four
parameters, the upper limit of individual contribution, the upper limit of
individual benefit, the needed project cost and the upper limit of project
benefit on the evolution of cooperation. Coevolving with the individual-level
group size preferences, an increase in the upper limit of individual benefit
promotes cooperation while an increase in the upper limit of individual
contribution inhibits cooperation. The coupling of the upper limit of
individual contribution and the needed project cost determines the critical
point of the upper limit of project benefit, where the equilibrium frequency of
cooperators reaches its highest level. Above the critical point, an increase in
the upper limit of project benefit inhibits cooperation. The evolution of
cooperation is closely related to the preferred group-size distribution. A
functional relation between the frequency of cooperators and the dominant group
size is found
New Frontiers in Cancer Chemotherapy — Targeting Cell Death Pathways
Cell death plays an important role in tumorigenesis, growth, and progression and affects the efficiency of chemotherapy to a great extent. Apoptosis is usually regarded as the principal mechanism of chemotherapy-induced cell death. However, the dysregulation of apoptosis occurs commonly in many cancers, which lowers the effectiveness of therapy and allows cells to survive. The mechanisms by which cells acquire this resistance to chemotherapy are not fully understood. Several studies uncovered alternative cell death pathways that are mechanistically distinct from apoptosis. These pathways, including autophagy and necrosis, represent potential targets for novel cancer treatment. By modulating the key regulatory molecules involved in the different types of cell death, more effective and less toxic chemotherapy might be developed. In this chapter, we describe the signaling pathways and the molecular events that are involved in these three major forms of programmed cell death. Additionally, we also discuss the emerging therapies targeting these cell death pathways as new strategies against cancer
A multivariate cointegration time series model and its applications in analysing stock markets in China
This paper explores nonlinear cointegration between Chinese
mainland stock markets and Hong Kong stock market in a multivariate
framework for the period January, 1998 to December, 2014
by a nonparametric method. The local linear kernel smoothing
method is developed to estimate the unknown function, and the
practical problem of implementation is also addressed. Then, a
simple nonparametric version of a bootstrap test is adapted for
testing misspecification. Furthermore, Some Monte Carlo experiments
are presented to examine the finite sample performance
of the proposed procedure. Finally, the stock markets data set
is discussed in detail by using proposed procedures, showing
that Shanghai Stock Index (SHSI) and Shenzhen Component
Index (SZCI) can affect Hang Seng Index (HSI), and the influence
appears to be a strong nonlinear characteristics
Limitation of network inhomogeneity in improving cooperation in coevolutionary dynamics
Cooperative behavior is common in nature even if selfishness is sometimes
better for an individual. Empirical and theoretical studies have shown that the
invasion and expansion of cooperators are related to an inhomogeneous
connectivity distribution. Here we study the evolution of cooperation on an
adaptive network, in which an individual is able to avoid being exploited by
rewiring its link(s). Our results indicate that the broadening of connectivity
distribution is not always beneficial for cooperation. Compared with the
Poisson-like degree distribution, the exponential-like degree distribution is
detrimental to the occurrence of a higher level of cooperation in the
continuous snowdrift game (CSG)
A new species and a new provincial record of the genus Acidota Stephens from China (Coleoptera, Staphylinidae, Omaliinae)
New taxonomic and faunistic data for two species of the genus Acidota Stephens, 1829 from China are provided. A new species from Xizang (Linzhi) is described and illustrated: A. dawai Peng & Chen, sp. nov. Additional data (including photographs of the habitus and the type labels) on the type specimens of taxa described from Japan (A. crenata japonica Watanabe, 1990) and Taiwan (A. montana Smetana, 1993 and A. nivicola Smetana, 1993) are given. A key to Chinese species of Acidota is given. Acidota crenata (Fabricius, 1792) is recorded from Heilongjiang for the first time
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