1991-2010年宁夏水稻病虫害发生特征与经济损失分析

水稻病虫害发生种类繁多、暴发频繁,是威胁宁夏水稻稳产、高产的重要因素,但对其变化趋势与实际危害损失不清楚.基于宁夏水稻统计数据、稻田覆盖类型遥感数据和水稻产量数据,分析1991年至2010年宁夏水稻病虫害发生特征与经济损失情况.结果表明:1991年到2010年期间,宁夏水稻病害、虫害年均发生面积分别为5.3万hm2和2.0万hm2,其年均防治面积分别为8.4万hm2和1.6万hm2;水稻病害的发生程度下降了23.10％,防治程度上升了77.30％.20年间宁夏水稻虫害的发生面积、发生程度、防治面积和防治程度均显著增加.防治水稻病害、虫害后,分别挽回稻谷为2.67万吨、0.28万吨,其挽回损失量在20年期间分别增加了55.15％、2775.0％,表明水稻病虫害防治意义重大.由于气候变化等诸多因子,导致1991年到2010年宁夏水稻病害、虫害年均造成的实际稻谷损失量分别为0.71万吨与0.13万吨,水稻病害实际损失量在0值附件波动、虫害呈现波动增加趋势,说明水稻病害防控效果好、虫害的防控还有提升的空间.从全区各市县分布来看,水稻病虫害主要分布在宁夏的银北地区.为有效地防止或减少病虫害对水稻产量的损失,应加强农田景观变化和气候变化等对水稻病虫害发生与灾变的风险评估和监测预警,开展区域性水稻病虫害综合治理研究,并建立相应的防控新对策与技术体系.     

种子物理休眠研究进展

种子物理休眠是由种皮不透水层引起的一种休眠类型,是植物在长期系统发育进程中获得的一种适应环境变化的特性。该文简述了种子物理休眠的定义与概念;从不透水层、种皮的特殊水孔器结构以及胚的形态特异性等方面,综述了物理休眠种子的形态特征、物理休眠与综合休眠的解除方法以及物理休眠的可能解除机制;利用Angiosperm Phylogeny Group Ⅲ(APG Ⅲ)系统分析了种子物理休眠的植物在系统发育中的位置;最后提出了今后种子物理休眠有待研究的主要问题。     

Nonlocal Immunized Mid-Infrared Magnetic Hot Spots in Graphene Junctions

Magnetic hot spots, which implies confinements and enhancements of magnetic fields, are demonstrated in graphene junctions (GJs) in the mid-infrared range. The appearance of magnetic hot spots in GJs comes from the conduction currents in the junction. In further, the extinction resonance peaks suffer blue shift, along with the increases in the magnetic fields inside junction area, when the junction width reduces. In opposite to the circumstances for electric field enhancements, neither magnetic field enhancements nor resonance frequency of GJs is perturbed by the intrinsic nonlocal electronic response of graphene. Such nonlocality immunized magnetic enhancement could be explained by the polarization dependent property of nonlocal effect.     

Tailoring of Localized Surface Plasmon Resonances of Core-Shell Au@Ag Nanorods by Changing the Thickness of Ag Shell

We report the synthesis and the characterization of core-shell Au@Ag nanorods through reduction by the wet chemical method. UV-visible absorption spectra of core-shell Au@Ag nanorods demonstrate the longitudinal mode of localized surface plasmon resonances (LSPRs) can be tailored from 724 to 786 nm by controlling the thickness of the silver shell, as is assessed by transmission electron microscope (TEM). Furthermore, the tunable and well-controlled LSPRs of core-shell Au@Ag nanorods are also investigated by numerical simulation using the finite difference time domain (FDTD) method, which strongly supports the experimental observations. The growth mechanism for core-shell Au@Ag nanorods is proposed, according to experimental observations and numerical calculations.     

FUNDC1 is a novel mitochondrial-associated-membrane (MAM) protein required for hypoxia-induced mitochondrial fission and mitophagy

Mitochondria need to be fragmented prior to engulfment by phagophores, the precursors to autophagosomes. However, how these 2 processes are finely regulated and integrated is poorly understood. We have shown that the outer mitochondrial membrane protein FUNDC1 is a novel mitochondrial-associated membrane (MAM) protein, enriched at the MAM by interacting with the ER resident protein CANX (calnexin) under hypoxia. As mitophagy proceeds, it dissociates from CANX and preferably recruits DNM1L/DRP1 to drive mitochondrial fission in response to hypoxic stress. In addition, knocking down of FUNDC1, DNM1L or CANX in hypoxic cells increases the number of elongated mitochondria and also reduces the colocalization of autophagosome and mitochondria, thus preventing mitophagy. These findings identify FUNDC1 as a molecular hub integrating mitochondrial fission and mitophagy at the MAM in response to hypoxia.     

Effects of BmCPV Infection on Silkworm Bombyx mori Intestinal Bacteria

The gut microbiota has a crucial role in the growth, development and environmental adaptation in the host insect. The objective of our work was to investigate the microbiota of the healthy silkworm Bombyx mori gut and changes after the infection of B. mori cypovirus (BmCPV). Intestinal contents of the infected and healthy larvae of B. mori of fifth instar were collected at 24, 72 and 144 h post infection with BmCPV. The gut bacteria were analyzed by pyrosequencing of the 16S rRNA gene. 147(135) and 113(103) genera were found in the gut content of the healthy control female (male) larvae and BmCPV-infected female (male) larvae, respectively. In general, the microbial communities in the gut content of healthy larvae were dominated by Enterococcus, Delftia, Pelomonas, Ralstonia and Staphylococcus, however the abundance change of each genus was depended on the developmental stage and gender. Microbial diversity reached minimum at 144 h of fifth instar larvae. The abundance of Enterococcus in the females was substantially lower and the abundance of Delftia, Aurantimonas and Staphylococcus was substantially higher compared to the males. Bacterial diversity in the intestinal contents decreased after post infection with BmCPV, whereas the abundance of both Enterococcus and Staphylococcus which belongs to Gram-positive were increased. Therefore, our findings suggested that observed changes in relative abundance was related to the immune response of silkworm to BmCPV infection. Relevance analysis of plenty of the predominant genera showed the abundance of the Enterococcus genus was in negative correlation with the abundance of the most predominant genera. These results provided insight into the relationship between the gut microbiota and development of the BmCPV-infected silkworm.     

Expression Profiles of Long Noncoding RNAs and Messenger RNAs in Mn-Exposed Hippocampal Neurons of Sprague–Dawley Rats Ascertained by Microarray: Implications for Mn-Induced Neurotoxicity

Manganese (Mn) is an essential trace element, while excessive expose may induce neurotoxicity. Recently, lncRNAs have been extensively studied and it has been confirmed that lncRNAs participate in neural functions and aberrantly expressed lncRNAs are involved in neurological diseases. However, the pathological effects of lncRNAs on Mn-induced neurotoxicity remain unclear. In this study, the expression profiles of lncRNAs and messenger RNAs (mRNAs) were identified in Mn-treated hippocampal neurons and control neurons via microarray. Bioinformatic methods and intersection analysis were also employed. Results indicated that 566, 1161, and 1474 lncRNAs meanwhile 1848, 3228, and 4022 mRNAs were aberrantly expressed in low, intermediate, and high Mn-exposed groups compared with the control group, respectively. Go analysis determined that differentially expressed mRNAs were targeted to biological processes, cellular components, and molecular functions. Pathway analysis indicated that these mRNAs were enriched in insulin secretion, cell cycle, and DNA replication. Intersection analysis denominated that 135 lncRNAs and 373 mRNAs were consistently up-regulated while 150 lncRNAs and 560 mRNAs were consistently down-regulated. Meanwhile, lncRNA {"type":"entrez-nucleotide","attrs":{"text":"BC079195","term_id":"50926238"}}BC079195 was significantly up-regulated while lncRNAs uc.229- and {"type":"entrez-nucleotide","attrs":{"text":"BC089928","term_id":"59808777"}}BC089928 were significantly down-regulated in three comparison groups. The relative expression levels of 3 lncRNAs and 4 mRNAs were validated through qRT-PCR. To the best of our knowledge, this study is the first to identify the expression patterns of lncRNAs and mRNAs in hippocampal neurons of Sprague–Dawley rats. The results may provide evidence on underlying mechanisms of Mn-induced neurotoxicity, and aberrantly expressed lncRNAs/mRNAs may be useful in further investigations to detect early symptoms of Mn-induced neuropsychiatric disorders in the central nervous system.     

Genome-Wide Identification,Characterization and Phylogenetic Analysis of ATP-Binding Cassette (ABC) Transporter Genes in Common Carp (Cyprinus carpio)

The ATP-binding cassette (ABC) gene family is considered to be one of the largest gene families in all forms of prokaryotic and eukaryotic life. Although the ABC transporter genes have been annotated in some species, detailed information about the ABC superfamily and the evolutionary characterization of ABC genes in common carp (Cyprinus carpio) are still unclear. In this research, we identified 61 ABC transporter genes in the common carp genome. Phylogenetic analysis revealed that they could be classified into seven subfamilies, namely 11 ABCAs, six ABCBs, 19 ABCCs, eight ABCDs, two ABCEs, four ABCFs, and 11 ABCGs. Comparative analysis of the ABC genes in seven vertebrate species including common carp, showed that at least 10 common carp genes were retained from the third round of whole genome duplication, while 12 duplicated ABC genes may have come from the fourth round of whole genome duplication. Gene losses were also observed for 14 ABC genes. Expression profiles of the 61 ABC genes in six common carp tissues (brain, heart, spleen, kidney, intestine, and gill) revealed extensive functional divergence among the ABC genes. Different copies of some genes had tissue-specific expression patterns, which may indicate some gene function specialization. This study provides essential genomic resources for future studies in common carp.     

The Role of Physical Activity in Harm Reduction among Betel Quid Chewers from a Prospective Cohort of 419,378 Individuals

ObjectiveTo assess the benefits of regular exercise in reducing harms associated with betel quid (BQ) chewing.MethodsThe study cohort, 419,378 individuals, participated in a medical screening program between 1994 and 2008, with 38,324 male and 1,495 female chewers, who consumed 5–15 quids of BQ a day. Physical activity of each individual, based on “MET-hour/week”, was classified as “inactive” or “active”, where activity started from a daily 15 minutes/day or more of brisk walking (≥3.75 MET-hour/week). Hazard ratios for mortality and remaining years in life expectancy were calculated.ResultsNearly one fifth (18.7%) of men, but only 0.7% of women were chewers. Chewers had a 10-fold increase in oral cancer risk; and a 2-3-fold increase in mortality from lung, esophagus and liver cancer, cardiovascular disease, and diabetes, with doubling of all-cause mortality. More than half of chewers were physically inactive (59%). Physical activity was beneficial for chewers, with a reduction of all-cause mortality by 19%. Inactive chewers had their lifespan shortened by 6.3 years, compared to non-chewers, but being active, chewers improved their health by gaining 2.5 years. The improvement, however, fell short of offsetting the harms from chewing.ConclusionsChewers had serious health consequences, but being physically active, chewers could mitigate some of these adverse effects, and extend life expectancy by 2.5 years and reduce mortality by one fifth. Encouraging exercise, in addition to quitting chewing, remains the best advice for 1.5 million chewers in Taiwan.