Evaluating the effect of 3D urban form on neighborhood land surface temperature using Google Street View and geographically weighted regression

Landscape Ecology - Land surface temperature (LST) directly responds to incoming solar radiation and is strongly influenced by vertical urban structures, such as trees and buildings that provide...     

黄颡鱼毒棘结构研究

黄颡鱼（Pelteobagrus fulvidraco）是较为典型的淡水刺毒鱼类,本研究结合宏观毒棘骨骼标本制作和微观组织切片等方法,深入探究黄颡鱼的毒棘结构。研究结果表明,黄颡鱼的胸鳍和背鳍均具有尖锐的倒刺棘骨,棘骨外包围着皮膜,皮膜拥有能分泌毒液的毒腺细胞,它们共同组成了黄颡鱼毒棘装置。毒棘骨骼宏观结构表明,黄颡鱼的背鳍和胸鳍毒棘均具有贯穿全棘骨的中央管和包围棘骨的皮膜;背鳍棘骨细长、锥形,且轻微拱起,顶部骤尖,后缘为弱锯齿;胸鳍棘骨前后缘均有锯齿,但后缘为强锯齿。背鳍和胸鳍毒棘基部结构的髁突形状、大小、位置全然不同。微观结构显示,皮膜中的毒腺细胞聚集成层,位于鳞状上皮与色素层之间,未见导管与之相连,背鳍和胸鳍毒棘的分支性骨管中均未发现毒腺细胞。胸鳍和背鳍锁紧装置可让毒棘保持倒伏或者直立的锁定状态,降低猎物挣脱几率。本研究可深入了解黄颡鱼的毒棘结构和特征,增强人们对刺毒鱼类的认知,同时为淡水刺毒鱼类深入研究奠定基础。     

High-Quality de novo Genome Assembly of Huajingxian 74, a Receptor Parent of Single Segment Substitution Lines

Rice(Oryza sativa L.)is grown nearly worldwide and provides the staple food for more than half of the global population(Luo et al,2017).The genomes of several cultivated rice varieties including Nipponbare(NPB)(Kawahara et al,2013;Sakai et al,2013),IR64(Tanaka et al,2020),93-11(Zhang et al,2018)and R498(Du et al,2017)at chromosome level,and Minghui 63 and Zhenshan 97(Zhang et al,2016)at scaffold level have been assembled,annotated and released,among which the R498 and NPB genomes are widely used as reference genomes in rice research.However,there are thousands of rice cultivars,landraces and wild rice varieties in the world with dramatically different genetic backgrounds,and the genomes of native rice varieties in South China,which is one of the major rice production areas in China,have not been de novo assembled.Huajingxian 74(HJX74)is an indica rice variety bred in South China Agricultural University,Guangdong Province with widely environmental adaptability and high yield(www.ricedata.cn/variety/varis/602548.htm).HJX74 exhibits significant phenotypic and genetic differences from those varieties whose whole genomes have been properly sequenced and assembled(Fig.1).     

苋菜、马唐出土对温度、水分的反应

本研究于１９９５～１９９７ 年在中国农业大学杂草研究室完成。研究结果表明：马唐（Ｄｉｇｉｔａｒｉａｓａｎｇｕｉｎａｌｉｓ）、苋菜（Ａｍ ａｒａｎｔｈｕｓｒｅｔｒｏｆｌｅｘｕｓ）室内出土的温度极限点：最低温度５℃,最高４０℃,适宜温度是３０～３５℃。５～５０℃温度段内,在相邻温度间杂草出土率显著变化的段是２０～２５℃和３５～４０℃,出土最快的温度是４０℃;这两种杂草出土的水分极限点是２０％ ,适宜水分是８０％ ,２０％ ～１００％ 含水量段内,在相邻的水分含量间杂草出土率显著变化段是４０％ ～６０％ ,出土最快的水分含量是１００％ 。温度和水分在对苋菜和马唐出土的作用中,二者之间存在一定程度的互补作用,温度对水分的互补作用尤为明显     

Identification of eggs from different production systems based on hyperspectra and CS-SVM

1. To identify the origin of table eggs more accurately, a method based on hyperspectral imaging technology was studied.

2. The hyperspectral data of 200 samples of intensive and extensive eggs were collected. Standard normalised variables combined with a Savitzky–Golay were used to eliminate noise, then stepwise regression (SWR) was used for feature selection. Grid search algorithm (GS), genetic search algorithm (GA), particle swarm optimisation algorithm (PSO) and cuckoo search algorithm (CS) were applied by support vector machine (SVM) methods to establish an SVM identification model with the optimal parameters. The full spectrum data and the data after feature selection were the input of the model, while egg category was the output.

3. The SWR–CS–SVM model performed better than the other models, including SWR–GS–SVM, SWR–GA–SVM, SWR–PSO–SVM and others based on full spectral data. The training and test classification accuracy of the SWR–CS–SVM model were respectively 99.3% and 96%.

4. SWR–CS–SVM proved effective for identifying egg varieties and could also be useful for the non-destructive identification of other types of egg.     

乐都山羊红细胞钾型的研究

采用火焰光度法对７５只乐都山羊的红细胞钾型进行了调查研究。结果发现：①按红细胞钾浓度，乐都山羊有高钾和低钾两种表型，以高钾为优势表型（８８％）；②高钾型山羊的红细胞钾浓度在４３．５９￣８１．３０ｍｍｏｌ／Ｌ之间，低钾型的在９．３７￣２１．２１ｍｍｏｌ／Ｌ之间；③Ｋ＾ｈ和Ｋ＾Ｌ等位基因频率分别为０．９３８７和０．０６１９，基因杂合度为０．１１６１。     

2008—2009年度我国大豆和豆粕供需状况分析

2008—2009年度,我国大豆产量出现恢复性增长,进口量继续呈现增加的态势,供需节余量将大幅增加。2008—2009年度我国大豆压榨量和豆粕供应量将继续增加,但由于饲料养殖业对豆粕需求持续强劲,供需将保持基本平衡的局面。     

LPS-TLR4/MD-2–TNF-α signaling mediates alcohol-induced liver fibrosis in rats

Liver fibrosis results from liver inflammation and progresses to liver cirrhosis or liver cancer. It is known that nonalcoholic liver disease is mediated by the Toll-like receptor 4 (TLR4)/myeloid differentiation factor-2 (MD-2)–tumor necrosis factor-alpha (TNF-α) signaling pathway. This study aimed to investigate whether alcoholic liver disease is also mediated by this pathway. To this end, we first established rat models of liver fibrosis by administering alcohol. Next, the rats were injected with anti-TLR4 and anti-MD-2 antibodies. Real Time Quantitative PCR (RT-qPCR) and Western blotting were used to detect the activation of the TLR4/MD-2–TNF-α signaling pathway and hepatic stellate cells (HSCs). Moreover, the expression of molecules related to liver fibrosis was estimated. The morphology of rat liver tissue was observed through hematoxylin–eosin staining and Masson staining. For in vitro studies, Kupffer cells (KCs) isolated from the liver were transfected with si-TLR4 and si-MD-2 and co-cultured with HSCs to determine the activity of HSCs. It was found that alcohol treatment activated the TLR4/MD-2–TNF-α signaling pathway and upregulated the molecules associated with liver fibrosis. However, inhibition of TLR4 and MD-2 partially reversed this trend. Notably, in vitro studies indicated that knockdown of TLR4 and MD-2 in KCs partially inhibited LPS-induced activation of KCs and HSCs. Overall, this study showed that alcohol induces liver fibrosis via the LPS-TLR4/MD-2–TNF-α signaling pathway.     

Genome architecture changes and major gene variations of Andrias davidianus ranavirus (ADRV)

Ranaviruses are emerging pathogens that have led to global impact and public concern. As a rarely endangered species and the largest amphibian in the world, the Chinese giant salamander, Andrias davidianus, has recently undergone outbreaks of epidemic diseases with high mortality. In this study, we isolated and identified a novel ranavirus from the Chinese giant salamanders that exhibited systemic hemorrhage and swelling syndrome with high death rate in China during May 2011 to August 2012. The isolate, designated Andrias davidianus ranavirus (ADRV), not only could induce cytopathic effects in different fish cell lines and yield high viral titers, but also caused severely hemorrhagic lesions and resulted in 100% mortality in experimental infections of salamanders. The complete genome of ADRV was sequenced and compared with other sequenced amphibian ranaviruses. Gene content and phylogenetic analyses revealed that ADRV should belong to an amphibian subgroup in genus Ranavirus, and is more closely related to frog ranaviruses than to other salamander ranaviruses. Homologous gene comparisons show that ADRV contains 99%, 97%, 94%, 93% and 85% homologues in RGV, FV3, CMTV, TFV and ATV genomes respectively. In addition, several variable major genes, such as duplicate US22 family-like genes, viral eukaryotic translation initiation factor 2 alpha gene and novel 75L gene with both motifs of nuclear localization signal (NLS) and nuclear export signal (NES), were predicted to contribute to pathogen virulence and host susceptibility. These findings confirm the etiologic role of ADRV in epidemic diseases of Chinese giant salamanders, and broaden our understanding of evolutionary emergence of ranaviruses.