Effects of turbulent dust grain motion to interstellar chemistry

Theoretical studies have revealed that dust grains are usually moving fast through the turbulent interstellar gas, which could have significant effects upon interstellar chemistry by modifying grain accretion. This effect is investigated in this work on the basis of numerical gas-grain chemical modeling. Major features of the grain motion effect in the typical environment of dark clouds (DC) can be summarised as follows: 1) decrease of gas-phase (both neutral and ionic) abundances and increase of surface abundances by up to 2-3 orders of magnitude; 2) shifts of the existing chemical jumps to earlier evolution ages for gas-phase species and to later ages for surface species by factors of about ten; 3) a few exceptional cases in which some species turn out to be insensitive to this effect and some other species can show opposite behaviors too. These effects usually begin to emerge from a typical DC model age of about 10^5 yr. The grain motion in a typical cold neutral medium (CNM) can help overcome the Coulomb repulsive barrier to enable effective accretion of cations onto positively charged grains. As a result, the grain motion greatly enhances the abundances of some gas-phase and surface species by factors up to 2-6 or more orders of magnitude in the CNM model. The grain motion effect in a typical molecular cloud (MC) is intermediate between that of the DC and CNM models, but with weaker strength. The grain motion is found to be important to consider in chemical simulations of typical interstellar medium.Comment: 20 pages, 10 figures and 2 table

Black Holes, Entropy Bound and Causality Violation

The gravity/gauge theory duality has provided us a way of studying QCD at short distances from straightforward calculations in classical general relativity. Among numerous results obtained so far, one of the most striking is the universality of the ratio of the shear viscosity to the entropy density. For all gauge theories with Einstein gravity dual, this ratio is \eta/s=1/4\pi. However, in general higher-curvature gravity theories, including two concrete models under discussion - the Gauss-Bonnet gravity and the (Riemann)^2 gravity - the ratio \eta/s can be smaller than 1/4\pi (thus violating the conjecture bound), equal to 1/4\pi or even larger than 1/4\pi. As we probe spacetime at shorter distances, there arises an internal inconsistency in the theory, such as a violation of microcausality, which is correlated with a classical limit on black hole entropy.Comment: 8 pages, no figures; Invited contribution to appear in the Proceedings of the 75 Years since Solvay, Singapore, Nov 2008, (World Scientific, Singapore, 2009

Graded reflection equation algebras and integrable Kondo impurities in the one-dimensional t-J model

Integrable Kondo impurities in two cases of the one-dimensional $t-J$ model are studied by means of the boundary ${\bf Z}_2$-graded quantum inverse scattering method. The boundary $K$ matrices depending on the local magnetic moments of the impurities are presented as nontrivial realizations of the reflection equation algebras in an impurity Hilbert space. Furthermore, these models are solved by using the algebraic Bethe ansatz method and the Bethe ansatz equations are obtained.Comment: 14 pages, RevTe

Effects of cordycepin on the microglia-overactivation-induced impairments of growth and development of hippocampal cultured neurons

© 2015 Peng et al. Microglial cells are normally activated in response to brain injury or immunological stimuli to protect central nervous system (CNS). However, over-activation of microglia conversely amplifies the inflammatory effects and mediates cellular degeneration, leading to the death of neurons. Recently, cordycepin, an active component found in Cordyceps militarisa known as a rare Chinese caterpillar fungus, has been reported as an effective drug for treating inflammatory diseases and cancer via unclear mechanisms. In this study, we attempted to identify the anti-inflammatory role of cordycepin and its protective effects on the impairments of neural growth and development induced by microglial over-activation. The results indicate that cordycepin could attenuate the lipopolysaccharide (LPS)-induced microglial activation, evidenced by the dramatically reduced release of TNF-α and IL-1β, as well as the down-regulation of mRNA levels of iNOS and COX-2 after cordycepin treatment. Besides, cordycepin reversed the LPS-induced activation of NF-κB pathway, resulting in antiinflammatory effects. Furthermore, by employing the conditioned medium (CM), we found cordycepin was able to recover the impairments of neural growth and development in the primary hippocampal neurons cultured in LPS-CM, including cell viability, growth cone extension, neurite sprouting and outgrowth as well as spinogenesis. This study expands our knowledge of the anti-inflammatory function of cordycepin and paves the way for the biomedical applications of cordycepin in the therapies of neural injuries

Shear viscosity, instability and the upper bound of the Gauss-Bonnet coupling constant

We compute the dimensionality dependence of $\eta/s$ for charged black branes with Gauss-Bonnet correction. We find that both causality and stability constrain the value of Gauss-Bonnet coupling constant to be bounded by 1/4 in the infinite dimensionality limit. We further show that higher dimensionality stabilize the gravitational perturbation. The stabilization of the perturbation in higher dimensional space-time is a straightforward consequence of the Gauss-Bonnet coupling constant bound.Comment: 16 pages,3 figures+3 tables,typos corrected, published versio

Regional Transport and Its Association with Tuberculosis in the Shandong Province of China, 2009-2011

Human mobility has played a major role in the spread of infectious diseases such as tuberculosis (TB) through transportation; however, its pattern and mechanism have remained unclear. This study used transport networks as a proxy for human mobility to generate the spatial process of TB incidence. It examined the association between TB incidence and four types of transport networks at the provincial level: provincial roads, national roads, highways, and railways. Geographical information systems and geospatial analysis were used to examine the spatial distribution of 2217 smear-positive TB cases reported between 2009 and 2011 in the Shandong province. The study involved factors such as population density and elevation difference in conjunction with the types of transport networks to predict the disease occurrence in space. It identified spatial clusters of TB incidence linked not only with transport networks of the regions but also differentiated by elevation. Our research findings provide evidence of targeting populous regions with well-connected transport networks for effective surveillance and control of TB transmission in Shandong.postprin

Characterization of novel developed expressed sequence tag (EST)-derived simple sequence repeat (SSR) markers and their application in diversity analysis of eggplant

A total of 101,270 eggplant expressed sequence tag (EST) sequences at public databases were used to search for simple sequence repeats (SSRs) and 405 potential SSR loci were identified from 388 sequences. The highest proportion (34.07%, 138) was represented by trinucleotide, followed by dinucleotide (19.51%, 79) and hexanucleotide (15.8%, 64). Among the dinucleotide repeats, AG/CT was the most common (55.69%), followed by AT/AT (31.64%) and AC/GT (12.66%). Further, 288 pairs of primers were developed from these sequences. A random set of 100 EST-SSR primers were amplified in 12 eggplant accessions and 88 successfully amplified expect PCR products. 32 markers revealed 83 polymorphic alleles among the 42 cultivated accessions and the number of allelles per locus varied between 2 and 6 (mean 2.6). Polymorphism information content (PIC) values among the 42 cultivated types were calculated and varied from 0.045 to 0.701 (mean 0.289). The markers showed low frequency transferability in Solanaceae. The 32 SSRs were used to evaluate genetic diversity. These SSRs will be valuable markers for future genetic study, such as genetic diversity estimation, linkage mapping, association mapping and molecular breeding.Key words: Expressed sequence tags, transferability, diversity, dendrogram