猪圆环病毒3型近五年的研究进展

猪圆环病毒3型(porcine circovirus type 3,PCV3)属于圆环病毒科，是一种无包膜、环状、单链DNA病毒。猪圆环病毒属成员最初于2016年被报道，能够感染猪，其结构特征、临床症状、发病机制和猪感染后的免疫反应在之后的研究中得到了进一步的阐述。本综述旨在总结PCV3相关研究在病毒基因组特征、流行病学、发病机制、免疫应答和诊断方法方面的进展。PCV3在全球各年龄段的猪上均有检出，并与一系列临床症状相关，包括多系统炎症综合征、繁殖障碍、猪皮炎与肾病综合征以及亚临床感染。实验性研究发现猪感染PCV3后成功地再现了多系统炎症，但并未暴发临床疾病。这些发现，再加上大量关于PCV3并发感染的报道，表明仅感染PCV3可能不足以导致猪出现明显的临床疾病。目前尚未充分阐明PCV3的发病机制，也未能确定促进病毒入侵细胞的受体，但已证实PCV3可在受感染猪的滋养层细胞、心肌细胞、皮肤脂肪细胞和神经元等多种类型的细胞中复制。PCV3似乎可以逃避宿主的免疫反应，在实验性和田间研究中，猪感染病毒42 d后会出现持续性毒血症就证明了这一现象，不过感染猪有强烈的体液反应。已经观察到宿主细胞因子谱...     

Tree ecophysiology in the context of climate change

Forest structure and function strongly depend on and concurrently influence environmental conditions.Tree performance is generally governed by its genetics and environment;thus,recent hotspots in this field include tree genotype × environment,phenotype × environment,and functional trait × environment interactions.The editorial,review,and 22 original research articles in this Special Issue, "Tree ecophysiology in the context of climate change",highlight ecophysiological phenomena(e.g.,climate hor...     

不同有机物料腐熟剂对农业废弃物堆肥腐熟效率的影响

为提高农业废弃物资源化利用效率,选择6种不同有机物料腐熟剂进行牛粪和棉花秸秆的堆肥试验,监测堆肥温度、pH值、碳氮比、含水量、种子发芽指数等指标.结果表明:添加有机物料腐熟剂后,堆肥沤制初期升温快,堆肥沤制后期腐熟效率高;添加有机物料腐熟剂能缩短堆肥腐熟周期;根据试验结果和使用成本判断6种有机物料腐熟剂性价比,以四川绿微公司生产的有机肥发酵剂和鹤壁人元生物公司生产的促腐剂应用于牛粪和秸秆堆肥发酵效果较好.     

The interplay between leaf water potential and osmotic adjustment on photosynthetic and growth parameters of tropical dry forest trees

Mimosa tenuiflora and Piptadenia stipulacea are commonly accepted as drought-tolerant species but little is known about their response to drought followed by rehydration.Therefore,the interplay between leaf water potential and osmotic adjustment on photo synthetic and growth parameters of these species was examined.A greenhouse study was conducted in a split-plot design with two water conditions in the main plots(control;drought followed by rehydration),and eight sampling times in the subplots(1...     

Ecophysiology and multivariate analysis for production of Tachigali vulgaris in Brazil:Influence of rainfall seasonality and fertilization

Studies on fertilization management of species native to the Amazon for energy plantations contribute to the diversity of species use and reduce biological risk due to the excessive use of clones or hybrids of Eucalyptus.This study evaluates the effect of precipitation seasonality and phosphorus and potassium fertilization on gas exchange in a Tachigali vulgaris plantation.Three levels of P(zero,65.2,130.4 kg ha^-1) and three of K(zero,100.0,200.0 kg ha^-1)were applied in a 3...     

Response of photosynthesis,growth, and acorn mass of pedunculate oak to diff erent levels of nitrogen in wet and dry growing seasons

The objective was to examine the effects of optimal leaf nitrogen levels> 2.0% and suboptimal levels <2.0%,nitrogen nutrition on net photo synthetic rate,stem diameter increment,height growth increment and acorn mass of pedunculate oak during 2010 in the absence of drought stress and during 2011 under the impact of moderate drought stress.According to the results,moderate drought stress significantly reduced net photo synthetic rate,stem diameter increment and height growth increment,while...     

Influence of fire on woody vegetation of savanna and forest formations in the Cerrado biome

Wildfires have environmental,economic,and social impacts,and can shape the landscape and benefit ecosystems such as the Cerrado.This study evaluated the diversity,similarity,and floristic and structural differences of woody savanna and forest formations of the Cerrado,when affected and not affected by fire.Twenty-eight 25-400m2 plots were randomly allocated and divided into Burnt Cerrado and Unburnt Cerrado,Burnt Forest,and Unburnt Forest,and divided into three levels of inclusion according to d...     

无人机棉花脱叶关键技术及应用分析

棉花催熟、脱叶是棉花采收环节中不可或缺的一项主要技术措施,其中,脱叶剂品种选择、喷施时期是否得当及喷施质量决定着脱叶效果和棉花采收质量.无人机因其独特的优势,在阿克苏地区棉花生产上的应用越来越广泛,但也存在一些问题.本文从脱叶剂选择、作业时间的确定、关键技术建议等方面总结阿克苏地区无人机棉花脱叶催熟关键技术,以供棉农参考.