Alpha-CIR Model with Branching Processes in Sovereign Interest Rate Modelling

We introduce a class of interest rate models, called the $\alpha$-CIR model, which gives a natural extension of the standard CIR model by adopting the $\alpha$-stable L{\'e}vy process and preserving the branching property. This model allows to describe in a unified and parsimonious way several recent observations on the sovereign bond market such as the persistency of low interest rate together with the presence of large jumps at local extent. We emphasize on a general integral representation of the model by using random fields, with which we establish the link to the CBI processes and the affine models. Finally we analyze the jump behaviors and in particular the large jumps, and we provide numerical illustrations

Limit theorems for continuous-state branching processes with immigration

We prove and extend some results stated by Mark Pinsky: Limit theorems for continuous state branching processes with immigration [Bull. Amer. Math. Soc. 78(1972), 242--244]. Consider a continuous-state branching process with immigration $(Y_t,t\geq 0)$ with branching mechanism $\Psi$ and immigration mechanism $\Phi$ (CBI$(\Psi,\Phi)$ for short). We shed some light on two different asymptotic regimes occurring when $\int_{0}\frac{\Phi(u)}{|\Psi(u)|}du<\infty$ or $\int_{0}\frac{\Phi(u)}{|\Psi(u)|}du=\infty$. We first observe that when $\int_{0}\frac{\Phi(u)}{|\Psi(u)|}du<\infty$, supercritical CBIs have a growth rate dictated by the branching dynamics, namely there is a renormalization $\tau(t)$, only depending on $\Psi$, such that $(\tau(t)Y_t,t\geq 0)$ converges almost-surely to a finite random variable. When $\int_{0}\frac{\Phi(u)}{|\Psi(u)|}du=\infty$, it is shown that the immigration overwhelms the branching dynamics and that no linear renormalization of the process can exist. Asymptotics in the second regime are studied in details for all non-critical CBI processes via a nonlinear time-dependent renormalization in law. Three regimes of weak convergence are then exhibited, where a misprint in Pinsky's paper is corrected. CBI processes with critical branching mechanisms subject to a regular variation assumption are also studied

A novel and simple method for construction of recombinant adenoviruses

Recombinant adenoviruses have been widely used for various applications, including protein expression and gene therapy. We herein report a new and simple cloning approach to an efficient and robust construction of recombinant adenoviral genomes based on the mating-assisted genetically integrated cloning (MAGIC) strategy. The production of recombinant adenovirus serotype 5-based vectors was greatly facilitated by the use of the MAGIC procedure and the development of the Adeasy™ adenoviral vector system. The recombinant adenoviral plasmid can be generated by a direct and seamless substitution, which replaces the stuff fragment in a full-length adenoviral genome with the gene of interest in a small plasmid in Escherichia coli. Recombinant adenoviral plasmids can be rapidly constructed in vivo by using the new method, without manipulations of the large adenoviral genome. In contrast to other traditional systems, it reduces the need for multiple in vitro manipulations, such as endonuclease cleavage, ligation and transformation, thus achieving a higher efficiency with negligible background. This strategy has been proven to be suitable for constructing an adenoviral cDNA expression library. In summary, the new method is highly efficient, technically less demanding and less labor-intensive for constructing recombinant adenoviruses, which will be beneficial for functional genomic and proteomic researches in mammalian cells

Neuroprotective and anti-inflammatory effects of myricetin 3-glucoside in a rat model of cerebral ischemia

Purpose: To investigate the effect of myricetin 3-glucoside (M3GLS) on middle cerebral artery occlusion (MCAO)-induced cerebral ischemia in a rat model, and the mechanism of action involved.Methods: A cerebral ischemia rat model was established using MCAO under 10 % chloral hydrate anesthesia. Neurological severity score was determined by analyzing reflex, motor and sensory functions, as well as balancing potential. Infarction volume was determined using triphenyl tetrazolium chloride dye, while counting of Nissl bodies was done after toluidine blue staining. The protein expression levels of Bax and Bcl-2 were assayed using western blotting, while cytokine levels were determined by enzyme-linked immunosorbent assay (ELISA).Results: Treatment of cerebral ischemia rats with M3GLS effectively reduced infarct volume, when compared to vehicle-treated group (p &lt; 0.05). Moreover, M3GLS treatment significantly increased the population of Nissl bodies and effectively improved neurologic scores (p &lt; 0.05). In M3GLS-pretreated rats, cerebral ischemia-induced elevation of protein expressions of TNF-α, IL-6 and IL-1β were significantly suppressed. M3GL treatment significantly reversed cerebral ischemia-mediated downregulation of Bcl-2 protein level, but markedly reduced cerebral ischemia-induced upregulation of Bax protein level (p &lt; 0.05).Conclusion: M3GLS exerts protective effect against cerebral ischemia-induced brain injury in rats via downregulation of inflammatory cytokines. It reduces infarction volume in the brain of cerebral ischemia rats, and regulates Bcl-2/Bax protein ratio. Thus, M3GLS has a potential for use in the clinical management of cerebral ischemia. Keywords: Myricetin, Neuroprotection, Anti-inflammation, Cerebral ischemia, Cytokines, Infarctio