干扰素刺激基因对羊口疮病毒在OFTu细胞中增殖的抑制效应

羊口疮病毒（ORFV）是重要的人兽共患病病原,不仅严重危害养羊业,而且威胁人类健康。干扰素刺激基因（stimulator of interferon genes,STING）作为细胞的DNA感受器,在机体天然免疫中起重要作用。为探索STING在ORFV感染中的作用及其对病毒复制的影响,本研究构建了ORFV感染羊胚胎鼻甲细胞（OFTu）的模型,分析了ORFV感染细胞后对STING及其相关基因的动态表达,探索了STING基因在干扰表达和过表达状态下对ORFV在细胞上增殖的影响。结果表明,ORFV感染OFTu细胞后,STING、cGAS、TBK1、IRF3、IRF7、IL-6、IFN-β、IL-1β和TNF-α的转录明显升高。OFTu细胞过表达STING可导致RIG-1、DDX41、IFI16、IRF3、IRF7、IL-6、TNF-α、IFN-α和IFN-β等基因转录上调。OFTu细胞在STING过表达状态下感染ORFV可介导TBK-1、IRF3、IFN-β和TNF-α的转录升高,抑制ORFV的复制;在STING表达干扰的状态下,ORFV感染OFTu细胞降低了TBK-1、IRF3、IFN-β和TNF-α的转录,增加了ORFV的复制。这表明STING蛋白能够增强抗病毒细胞因子的表达,抑制ORFV在OFTu细胞中的增殖,研究结果为深入理解STING在羊口疮病毒感染和复制中的作用提供了科学的理论依据,也为深入探索ORFV感染和致病的分子机制提供了基础数据。     

我国设施蔬菜专家系统开发的研究进展

设施蔬菜专家系统是提高设施蔬菜栽培管理和设施环境控制智能化水平,实现设施蔬菜标准化生产的重要手段。本文介绍了农业专家系统的结构及其开发平台,对目前国内设施蔬菜栽培管理专家系统和温室环境控制专家系统的研究现状进行分析,就如何加强我国设施蔬菜专家系统开发提出了建议。     

Leaching and Recovering of Nitrogen Following N Fertilizers Application to the Soil in a Laboratory Study

Following soil fertilization, nitrogen (N) is partially lost. The objective of this study was to evaluate leaching and recovery of N after addition of fertilizers to the soil. Two experiments were conducted in leaching columns submitted to frequent water percolations. In the leaching experiment, urea, ammonium nitrate, and six coated N fertilizers were utilized; in the N recovery experiment, treatments consisted of urea, potassium nitrate, ammonium sulfate, and ammonium nitrate, combined or not with percolation. Percolations were performed weekly with quantification of ammonium and nitrate in the percolated. The recovered N was obtained by summing total N percolated with N in the soil. Nitrate leaching was highest from amide-N fertilizers, with no differences between them showing that coating urea was not efficient to decrease N leaching. Nitric fertilizers had the lowest recovery of N, probably due to the occurrence of denitrification caused by the frequent water percolation.     

Spatial variability in commercial orange groves. Part 2: relating canopy geometry to soil attributes and historical yield

Precision Agriculture - Site-specific management strategies are usually dependant on the understanding of the underlying cause and effect relationships that occur at the within-field level. The...     

Participative site-specific agriculture analysis for smallholders

Site-specific agriculture has been adopted in a high-tech context using, for instance, in situ sensors, satellite images for remote sensing analysis, and some other technological devices. However, farmers and smallholders without the economic resources and required knowledge to use and to access the latest technology seem to find an impediment to precision agricultural practices. This article discusses the possibility of adopting precision agriculture (PA) principles for site-specific management but in a low technology context for such farmers. The proposed methodology to support PA combines low technology dependency and a participatory approach by involving smallholders, farmers and experts. The case studies demonstrate how the interplay of low technology and a participative approach may be suitable for smallholders for site-specific agriculture analysis.     

Spatial determinants of Atlantic Forest loss and recovery in Brazil

Context

Despite continued forest cover losses in many parts of the world, Atlantic Forest, one of the largest of the Americas, is increasing in some locations. Economic factors are suggested as causes of forest gain, while enforcement has reduced deforestation.

Objectives

We examine three aspects of this issue: the relative importance of biophysical versus anthropogenic factors in driving forest dynamics; role of forest mean patch age influencing areas targeted for losses; and what future forest mean patch age mosaic we can expect (more forest cover and full forest maturity?).

Methods

Three land cover maps from 1990, 2000 and 2010, were used in the study. We selected six biophysical and six anthropogenic spatial determinants to analyze by means of weights of evidence, using Dinamica software.

Results

Results show that forest regrowth is influenced by multiple factors, working in synergy. Biophysical variables are related to forest gain while anthropogenic are associated with loss. Clear patterns of regrowth on pasture and sugarcane plantations occurred, especially near rivers and forest patches, on steeper slopes and with sufficient rainfall. Forest loss has targeted both older and newer forests. Future projections reveal forest gain in a slow pace, followed by specific ecosystem service losses, due to continuous trends of older mature forest loss.

Conclusions

Regrowth is linked to land abandonment, and to neighboring environmental conditions. It is important to question which mechanisms will guarantee and potentiate new regrowth, thus contributing to landscape restoration and reestablishment of ecosystem services in the Atlantic Forest.