Temporal-spatial analysis of an age-space structured foot-and-mouth disease model with Dirichlet boundary condition.

Foot-and-mouth disease is a highly contagious and economically devastating disease of cloven-hoofed animals. The historic occurrences of foot-and-mouth diseases led to huge economic losses and seriously threatened the livestock food security. In this paper, a novel age-space diffusive foot-and-mouth disease model with a Dirichlet boundary condition, coupling the virus-to-animals and animals-to-animals transmission routes, has been proposed. The basic reproduction number R0 is defined as the spectral radius of a next generation operator K, which is calculated in an explicit form, and it serves as a vital value determining whether or not the disease persists. The existence of a unique trivial nonconstant steady state and at least one nonconstant endemic steady state of the system is established by a smart Lyapunov functional and the Kronoselskii fixed point theorem. An application to a foot-and-mouth outbreak in China is presented. The findings suggest that increasing the movements and disinfection of the environment for animals apparently reduce the risk of a foot-and-mouth infection.

Aspartic proteases gene family: Identification and expression profiles during stem vascular development in tobacco.

Aspartic proteases (APs) constitute a large family in plants and are widely involved in diverse biological processes, like chloroplast metabolism, biotic and abiotic stress responses, and reproductive development. In this study, we focused on overall analysis of the APs genes in tobacco. Our analysis included the phylogeny and cis-elements in the cell wall-associated promoters of these genes. To characterize the expression patterns of APs genes in stem vascular development. The tissue expression analysis showed that NtAED3-like was preferentially expressed in the differentiating xylem and phloem cells of the vascular system. Based on histochemical staining analysis showed that the NtAED3-like gene was specifically expressed in stem vascular tissue, root vascular tissue, and petiole vascular tissue. The TdT-mediated dUTP nick-end labeling (TUNEL) assay illustrated a delayed progression of programmed cell death (PCD) within the xylem of the ko-ntaed3a-like mutant, relative to the wild type. The mutant ko-ntaed3a-like exhibited a phenotype of thinning stem circumference and changed in xylem structure and lignin content. In addition, the two-dimension heteronuclear single quantum coherent nuclear magnetic resonance (2D-HSQC) analysis of three milled wood lignins (MWLs) showed that the content of ß-O-4 connection in ko-ntaed3a-like decreased slightly compared with wild type. In conclusion, this study provides our understanding of the regulation of vascular tissue development by the NtAED3-like gene in tobacco and provides a better basis for determining the molecular mechanism of the aspartic protease in secondary cell wall (SCW) development.

[Comparison among remotely sensed image fusion methods based on spectral response function].

Remotely sensed image fusion is a critical issue, and many methods have been developed to inject features from a high spatial resolution panchromatic sensor into low spatial resolution multi-spectral images, trying to preserve spectral signatures while improving spatial resolution of multi-spectral images. However, no explicit physical information of the detection system has been taken into account in usual methods, which might lead to undesirable effects such as severe spectral distortion. Benefiting from the proper decomposition of the image fusion problem by a concise image fusion mathematical model, the present paper focuses on comparing reasonable modulation coefficient of spatial details based on analysis of the spectral response function (SRF). According to the classification of former methods, three modulation coefficients based on SRF of sensors were concluded, which lead to three image fusion methods incorporating spatial detail retrieved by Gaussian high-pass filter. All these methods were validated on Ikonos data compared to GS and HPM method.

Effect of ginsenoside-Rg3 on the expression of VEGF and TNF-α in retina with diabetic rats.

AIM: To investigate the effect of ginsenoside-Rg3 on the expression of vascular endothelial growth factor (VEGF) and tumor necrosis factor-α (TNF-α) in retina with diabetic rats and its roles in preventing neovascularization in diabetes. METHODS: Sixty male Wistar rats were divided into 3 groups randomly: negative control group, diabetic control group and ginsenoside-Rg3 treatment group (5mg/kg, 0.2mg/mL) followed by establishing diabetic model. The expression of VEGF and TNF-α were measured after 8 weeks. RESULTS: There were significant differences among negative control group, diabetic control group and ginsenoside-Rg3 treatment group in the expression of VEGF and TNF-α (F=129.363, 211.992; all the P<0.01). VEGF and TNF-α expression were significantly higher in diabetic control group and ginsenoside-Rg3 treatment group than that in negative control group (P<0.01), with a significant reduction in ginsenoside-Rg3 treatment group than that in diabetic control group (P<0.01). CONCLUSION: Ginsenoside-Rg3 can down-regulate the expression of VEGF and TNF-α in retina, which may interfere in the development of diabetic retinopathy.