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21.
To evaluate the impact of temporal variation of primary productivity on the recruitment of Japanese sardine (Sardinops melanostictus) in the Sea of Japan, the phenology of sea surface phytoplankton abundance was estimated from 8 day multiple satellite (SeaWiFS, MODIS‐Aqua, MERIS, and VIIRS) derived sea surface chlorophyll (SSChl) a concentrations from January 1998 to December 2015. Because relationships between SSChl a and in situ chlorophyll a concentrations were significantly different among periods based on the satellite combinations used, maximum and minimum SSChl a concentrations of 1 year were relativized as 1 and 0, respectively. Spatio‐temporal variation of relativized SSChl a concentrations was determined by using empirical orthogonal function (EOF) analysis. Scores in the first EOF mode denoted the basin‐scale variations of SSChl a concentrations in the Sea of Japan, and the major peak from the end of February to the end of May displayed the spring bloom. The logarithm of recruitment per spawner (LNRPS) for sardine was positively affected by delays in the start and end dates of the spring phytoplankton bloom. The delay of the date of the lowest sea surface temperature contributed to the delay of the end of the spring bloom during the period 1998–2015 and elevated the LNRPS during the period 1982–2015. Sardine spawns in the southern Sea of Japan from April to May, hence, delays of the spring bloom prolonged its overlap with sardine larval periods, and thus improved the recruitment of Japanese sardine in the Sea of Japan.  相似文献   
22.
Glutaredoxins (Grxs) play important roles in the redox system via reduced glutathione as a reductant. A TcmonoGrx cDNA (1039 bp, EU158772) encoding a putative monothiol Grx was cloned from Taiwanofungus camphorata (formerly named Antrodia camphorata). The deduced amino acid sequence is conserved among the reported monothiol Grxs. Two 3-D homology structures of the TcmonoGrx based on known structures of human Grx3 (pdb: 2DIY_A) and Mus musculus Grx3 (pdb: 1WIK_A) have been created. To characterize the TcmonoGrx protein, the coding region was subcloned into an expression vector pET-20b(+) and transformed into E. coli C41(DE3). The recombinant His6-tagged TcmonoGrx was overexpressed and purified by Ni(2+)-nitrilotriacetic acid Sepharose. The purified enzyme showed a predominant band on 10% sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE). The enzyme exhibited glutathione reductase (GR) activity via dithionitrobenzoate (DTNB) assay. The Michaelis constant (K(M)) values for GSSG and NADPH were 0.064 and 0.041 mM, respectively. The enzyme's half-life of deactivation at 60 °C was 10.5 min, and its thermal inactivation rate constant (k(d)) was 5.37 × 10(-2) min(-1). The enzyme was active under a broad pH range from 6 to 8. The enzyme retained 50% activity after trypsin digestion at 37 °C for 40 min. Both mutants C(40)→S(40) and C(165)→S(165) lost 40-50% GR activity, whereas the mutant S(168)→C(168) showed a 20% increase in its GR activity.  相似文献   
23.
蔡肯  王克强  何纯飞 《中国农机化》2012,(2):158-161,150
信息技术飞速发展,农业不再是简单的田间的播种、收割农作物,而是对于农作物成长过程的更多的管理。面对多变的天气,及时快速的发现异常,则能够让农户减少损失。本设计是用PHP+MySQL数据库开发的,基于B/S结构的田间环境参数动态监测系统平台,它将网络应用技术运用到农业生产中来,使之能够监测农作物生产环境的动态并及时反馈,让农户能够随时随地查看农场环境信息。通过提供农业相关资讯,环境监测以及农户们交流的服务平台,本平台让农民们可以利用信息技术进行科学化管理,学习更多的技术和知识,最终实现提高单位面积产量的目标。  相似文献   
24.
胡蜂与蜜蜂的防御行为研究   总被引:3,自引:0,他引:3  
 在19.4℃气温条件下,选择东方蜜蜂和西方蜜蜂各3群进行蜜蜂激怒时的结团温度的试验研究,刺激物分别为半导体点温仪器的铜线头和活体胡蜂,在蜂群内放入刺激物后每隔15 s做一次温度记录。结果发现,在东方蜜蜂群内,蜂群对两种刺激物的结团蜜蜂数在25~32只之间;温度在210 s左右的时间内分别达到44.6 ℃和45.0 ℃,其中,刺激物为铜线头的结团温度最高可以达到45.0 ℃, 而刺激物为活体胡蜂的结团温度最高可以达到45.6 ℃;在西方蜜蜂群内,蜂群对两种刺激物的结团蜜蜂数在18~26只之间;蜂群对两种刺激物的结团温度在210 s左右的时间内分别达到42.2 ℃和 44.1 ℃,其中刺激物为铜线头的结团温度最高可以达到42.7 ℃,而刺激物为活体胡蜂的结团温度最高可以达到44.4 ℃.在恒温箱的耐温试验里,20 min内,黑盾胡蜂的最高耐温极限温度为46 ℃,而东方蜜蜂和西方蜜蜂的最高耐温极限温度却分别为51 ℃和52 ℃.另外, 选择云南高原温带型东方蜜蜂和云南低海拔热带型东方蜜蜂各2群,在蜂箱门口用活体黑盾胡蜂(Vespa velutina)干扰蜜蜂采集活动,干扰的时间分别为3 min,6 min和12 min. 每 min为一计数单位,记录蜜蜂采集蜂飞出的数量。结果发现:蜜蜂采集蜂飞出的数量随干扰时间的增加而明显下降,干扰的时间越长,蜜蜂采集蜂恢复到正常数量的时间就越长;高原温带型东方蜜蜂和低海拔热带型东方蜜蜂在胡蜂干扰时的在数量变化有着明显的差异,后者对胡蜂的干扰比前者更为敏感(P<0.05)。  相似文献   
25.
通过对枸杞种质的光合特性进行综合评价,以期筛选出高光效种质,为枸杞品种选育提供参考依据。采用大田试验,连续2 a对76份枸杞种质材料的光合气体交换参数、叶片物理性状指标进行测定,利用主成分分析、层次分析法、聚类分析法对枸杞种质的光合特性进行综合评价,筛选出合理的高光效评价指标。结果表明:枸杞种质间净光合速率、气孔导度、胞间CO2浓度、蒸腾速率、水分利用率、叶面积、叶鲜质量、叶干质量均存在极显著差异,其中气孔导度、叶鲜质量、叶干质量、比叶重、叶面积的变异系数大,为46.3%~57.6%,胞间CO2浓度、水分利用率的变异系数小,在10.9%~27.4%。利用主成分分析,提取到3个主成分,累计贡献率达86.88%,具有代表性,筛选出净光合速率、气孔导度、胞间CO2浓度、蒸腾速率、叶面积、叶鲜质量、比叶重作为评价指标,通过层次分析法得出权重值依次为蒸腾速率>比叶重>叶鲜质量>气孔导度>叶面积>净光合速率>胞间CO2浓度。通过聚类分析将76份材料划分为3种类型,低光效型6个,中等光效型51个,高光效型19个。利用判别分析对聚类结果重新进行分类,只有1个材料被误判,总误判率为1.32%,判对的概率为98.68%,分类结果可靠,可为后续新品种选育提供材料。  相似文献   
26.
为研究硒浸种对春小麦种子活力和幼苗生长特性的影响,分别设置0,0.5,1.0,2.5,3.5,5.0,10.0,50.0 mg/L共8个亚硒酸钠溶液浓度,通过发芽试验,比较研究了不同浓度的亚硒酸钠浸种对春小麦种子萌发和幼苗生长的影响.结果表明:随着亚硒酸钠溶液浓度升高,春小麦种子的发芽率、发芽势、发芽指数、活力指数、幼苗和根长以及干鲜重等指标均呈先升高后下降的趋势;1.0 mg/L的亚硒酸钠溶液对小麦种子萌发和幼苗生长有促进作用;随着亚硒酸钠浓度的升高(≥2.5 mg/L),其各项指标显著下降,并对根和苗的生长表现出抑制作用;因此在实际生产中,掌握合适的硒浸种浓度非常关键.  相似文献   
27.
长白山东方蜜蜂形态特征研究*   总被引:1,自引:0,他引:1  
 通过测定长白山6个不同样点17群东方蜜蜂的38个形态特征并采用计算机进行数据分析,得出长白山东方蜜蜂可分为3个类群。同邻近国家(日本、韩国)及中国部分地区的东方蜜蜂形态数据进行分析发现,长白山东方蜜蜂与日本、韩国的东方蜜蜂归于1个类群,由于长白山的气候及自然地理条件而形成多个小的生态区域,长白山东方蜜蜂在小区域内自成繁殖体系,各个生态区域间蜜蜂个体体色差异较大,体型大小差异不大。  相似文献   
28.
湖北神农架中蜂的数值分类研究   总被引:2,自引:3,他引:2  
 通过测定湖北神农架6 个不同样点的18群东方蜜蜂,每群15只工蜂,每只蜜蜂样共38个形态特征,测定的性状特征的数据进行因素分析,集合分析和区辨分析;形态性状与生态环境因子相关性分析;并与周边省份东方蜜蜂的相关数据进行比较,发现: 神农架蜜蜂种群内遗传变异丰富,种群中许多形态性状特征表现出较明显的地理变异性;蜜蜂个体增大、体色变深, 具体是:前翅长、前翅宽、背板3,4宽; 后腿长、蜡镜长、蜡镜宽、蜡镜间距、腹片3,6的长和宽逐渐增加;而背板3,4的色素度、小盾片的色素度逐渐加深。神农架东方蜜蜂种群形态性状的多态性、多型性及其生态地理变异式样,均具有生态适应意义  相似文献   
29.
A principal nuclear transfer procedure is to inject a donor cell into the perivitelline space in an enucleated oocyte and then electric fusion is performed (cell fusion method). The effects of activation methods in reconstructed oocytes for the serum-starved somatic cell cloning procedure were investigated in this study by means of intracytoplasmic injection (i.c.i.). Bovine oocytes were enucleated at 18-22 h for in vitro maturation, and subsequently the nucleus of cumulus cell collected from Japanese Black Bulls (JBCC) after 5-7 days of starved culture was injected into the recipient cytoplast with a piezo-micromanipulator. At 1 h after i.c.i., reconstructed oocytes were stimulated with ethanol (ET) or calcium ionophore (CaI) as the first activation treatment, followed by cycloheximide (CHX) or 6-dimethylaminopurin (DMAP) treatment as the second activation. In the experiment on the first activation method, the proportion of reconstructed oocytes developing to the blastocyst stage was significantly (p<0.01) higher in the ET activation method than that with CaI (10.5% and 4.7%, respectively). And the experiment on the second activation method after ET treatment showed similar proportions of blastocyst development in both CHX and DMAP treatments (5.9% and 2.8%, respectively). The present results indicated that combined activation treatment with ET and CHX was efficient for reconstructed bovine oocytes by i.c.i.  相似文献   
30.
We investigated the therapeutic effects of a progesterone releasing intravaginal device (PRID) on cystic ovarian disease (COD) and reproduction performance of cows. The possible influence of PRID on metabolic and/or health status was also examined. A total of 40 Holstein-Friesian cattle, with ovarian cystic structures, > or =2.5 cm in diameter, persisting for more than 7-14 days, without a corpus luteum (CL) were used for the study. PRID or placebos were inserted into the vagina for 12 days. Five animals lost the intravaginal device before removal and one was culled. Based on plasma progesterone concentration on the day of treatment, 20 (17 PRID and 3 placebos) of the remaining 34 cows had follicular cysts (progesterone < or =1 ng/ml) and 14 (10 PRID and 4 placebos) had luteal cysts (progesterone >1 ng/m l). Fourteen (82%) of the PRID-treated follicular cystic cows responded with formation of a CL within 14 days after treatment, and an overall conception rate of 53.8%. Likewise, 70% of the treated luteal cystic cows responded with CL formation and 71.4% conception rate. No significant differences were observed in hematocrit (Ht), white blood cell count and serum levels of glucose, blood urea nitrogen, aspartate aminotransferase, and alanine aminotransferase, between the day of PRID insertion and removal, in animals with follicular and luteal cysts. PRID treatment resulted in ovulation 2-4 days later and formation of a CL in cows that recovered.  相似文献   
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