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71.
AIM: To investigate the role of miR-181b in the expression of Bcl-2 and SP1 at mRNA and protein levels in the human hepatoma G2 cells (HepG2), and to explore the effect of miR-181b on the regulation of HepG2 cell proliferation. METHODS: The synthetic double-strand complementary DNA based on the sequence of miR-181b was inserted into the vector of miRNASelectTM pEGP-miR. The microRNA high-expression plasmid was cloned, and the sequences were identified. The miR-181b plasmid was transfected into HepG2 cells with liposomes. The stable cell line was screened by puromycin. The mRNA and protein levels of Bcl-2 and SP1 were measured by RT-PCR and Western blotting, respectively. Methyl thiazolyl tetrazolium (MTT) method was used to analyze the proliferation of HepG2 cells. RESULTS: The Western blotting results showed that miR-181b inhibited the protein expression of Bcl-2 and SP1. The result of RT-PCR also indicated that the mRNA expression of Bcl-2 and SP1 was suppressed. Compared with the control, the growth rate of HepG2 with high expression of miR-181b was significantly decreased.CONCLUSION: miR-181b inhibits the proliferation of HepG2, which may be related to the down-regulation of Bcl-2 and SP1. 相似文献
72.
马蹄金是一种重要的地被植物,然而目前利用的种子依赖于进口,如何减少种子利用是生产中面临的问题。试验以马蹄金作为材料,按10、13、16、19、22g/m2进行播种,采用随机区组设计,通过相对生长速率、盖度、密度及草坪综合质量等指标测定,筛选出适宜亚热带地区的播种量。结果表明:播种量为19g/m2的条件下,生长80d后马蹄金草坪密度达到165.57株/米2,盖度为69.78%;与其他处理相比,播种量为19g/m2杂草发生率少,且盖度增加快,均一性好,综合质量最高(P0.05)。因而,19g/m2可以作为马蹄金在亚热带地区建植草坪时的适宜播种量。 相似文献
73.
Abbas Safari Navid Ghavi Hossein-Zadeh Abdol Ahad Shadparvar Rostam Abdollahi Arpanahi 《Tropical animal health and production》2018,50(4):707-714
The aim of current study was to review breeding progress and update information on genetic strategies in Iranian buffaloes. Iranian buffalo is one of the vital domestic animals throughout north, north-west, south and south-west of Iran with measurable characteristics both in milk and meat production. The species plays an important role in rural economy of the country due to its unique characteristics such as resistance to diseases and parasites, having long productive lifespan and showing higher capability of consuming low-quality forage. In Iran, total production of milk and meat devoted to buffaloes are 293,000 and 24,700 tons, respectively. Selection activities and milk yield recording are carrying out by the central government through the Animal Breeding Centre of Iran. The main breeding activities of Iranian buffaloes included the estimation of genetic parameters and genetic trends for performance traits using different models and methods, estimation of economic values and selection criteria and analysis of population structure. Incorporating different aspects of dairy buffalo management together with improved housing, nutrition, breeding and milking, is known to produce significant improvements in buffalo production. Therefore, identifying genetic potential of Iranian buffaloes, selection of superior breeds, improving nutritional management and reproduction and developing the education and increasing the skills of practical breeders can be useful in order to enhance the performance and profitability of Iranian buffaloes. 相似文献
74.
75.
The tallgrass prairie of North America has undergone widespread habitat loss and fragmentation (<4% remains). The Flint Hills
region of Kansas and Oklahoma is the largest tallgrass prairie remaining and therefore provides an opportunity to study the
population genetic structure of grassland species in a relatively contiguous landscape and set a baseline for evaluating changes
when the habitat is fragmented. We adopted a landscape genetics approach to identify how landscape structure affected dispersal,
population genetic structure, and landscape connectivity of the Eastern Yellowbelly Racer (Coluber constrictor flaviventris) across a 13,500-km2 landscape in northeastern Kansas, USA. The racer population had high allelic diversity, high heterozygosity, and was maintaining
migration-drift equilibrium. Autocorrelation between genetic and geographic distance revealed that racers exhibited restricted
dispersal within 3 km, and isolation-by-distance. Significant isolation-by-distance occurred at broad regional scales (>100 km),
but because of sufficient gene flow between locations, we were unable to define discrete subpopulations using Bayesian clustering
analyses. Resistance distance, which considers the permeability of habitats, did not explain significant variation in genetic
distance beyond Euclidean distance alone, suggesting that racers are not currently influenced by landscape composition. In
northeastern Kansas, racers appear to be an abundant and continuously distributed snake that perceives the landscape as well
connected with no cover type currently impeding snake dispersal or gene flow. 相似文献
76.
77.
Simulating the cumulative effects of multiple forest management strategies on landscape measures of forest sustainability 总被引:1,自引:2,他引:1
While the cumulative effects of the actions of multiple owners have long been recognized as critically relevant to efforts
to maintain sustainable forests at the landscape scale, few studies have addressed these effects. We used the HARVEST timber
harvest simulator to predict the cumulative effects of four owner groups (two paper companies, a state forest and non-industrial
private owners) with different management objectives on landscape pattern in an upper Michigan landscape managed primarily
for timber production. We quantified trends in landscape pattern metrics that were linked to Montreal Process indicators of
forest sustainability, and used a simple wildlife habitat model to project habitat trends. Our results showed that most trends
were considered favorable for forest sustainability, but that some were not. The proportion of all age classes and some forest
types moved closer to presettlement conditions. The trend for the size of uneven-aged patches was essentially flat while the
average size of patches of the oldest and youngest age classes increased and the size of patches of the remaining age classes
decreased. Forest fragmentation generally declined, but edge density of age classes increased. Late seral forest habitat increased
while early successional habitat declined. The owners use different management systems that cumulatively produce a diversity
of habitats. Our approach provides a tool to evaluate such cumulative effects on other landscapes owned by multiple owners.
The approach holds promise for helping landowner groups develop and evaluate cooperative strategies to improve landscape patterns
for forest sustainability. 相似文献
78.
Twelve male buffalo calves of 10 to 12 months of age were divided into 3 groups of four each. They were fed wheat straw+concentrate
mixture +3 Kg greens. The chemical composition of the diet was same in all the three groups except fluoride which was added
(as NaF) in concentrate mixture of group B and C to make the final fluoride concentration 30 ppm and 60 ppm respectively.
The animals were kept on scheduled diet for a period of 90 days. Body weights were recorded at the start of the experiment
and at fortnightly interval thereafter. Analysis of data revealed that the dry matter intake decreased non significantly in
group B and C as compared to control group. A significant decrease in serum calcium and a significant increase in phosphorus
concentration were observed in group C animals. A significant increase was observed in alkaline phosphatase activity in group
C animals. A non significant decrease was observed in T4 values in group C animals. On the basis of these results it could be concluded that fluoride in the diet of buffalo calves
@ 30 ppm is a safe level whereas 60 ppm has affected the blood metabolites. 相似文献
79.
Robert A. Mccleery 《Landscape Ecology》2009,24(4):483-493
Predator stimuli created by humans in the urban environment may alter animals’ anti-predator behaviors. I hypothesized that
habituation would cause anti-predator behaviors to decrease in urban settings in response to humans. Additionally, I hypothesized
that populations habituated to humans would show reduced responses to other predator stimuli. I observed three populations
of squirrels (urban, suburban and rural) responses to human approaches, red-tailed hawk vocalizations (Buteo jamaicensis) and coyote (Canis latrans) vocalizations. Mahalanobis distances of anti-predator behaviors in response to human approaches were consistent with the
urban–rural gradient. Flight initiation distances (X
2 = 26.33, df = 2, P < 0.001) and amount of time dedicated to anti-predator behavior (X
2 = 10.94, df = 2, P = 0.004) in response to human approaches were also consistent with the urban–rural gradient. Supporting the habituation hypothesis,
naive juvenile squirrels increased flight initiation distances (X
2 = 35.89, df = 1, P < 0.001) and time dedicated to anti-predator behaviors (X
2 = 9.46, df = 1, P = 0.002) relative to adult squirrels in the same urban environment. Time dedicated to anti-predator behaviors differed among
all three sites in response to both coyote (X
2 = 9.83, df = 2, P = 0.007) and hawk (X
2 = 6.50, df = 2, P = 0.035) vocalizations. Responses to both vocalizations on rural sites (coyote = 45%, hawk = 55%) greater than twice that
found on the urban sites (coyote = 11%, hawk = 20%). This is possibly the first case of a transfer of habituation demonstrated
under field conditions. 相似文献
80.
莴苣花叶病毒病的研究Ⅰ。病原鉴定 总被引:2,自引:0,他引:2
由山东济南和泰安两市郊区大面积受害的莴苣(Lactuca sativa L.var.asparagina L.)上分离到一株病毒。莴苣上症状为系统花叶,畸型和褐色斑点。人工接种,在昆诺阿藜和苋色藜上产生局部枯斑和系统症状,千日红上呈不规则斑块,不侵染普通烟、心叶烟、曼陀罗、豇豆、菜豆和黄瓜。传毒试验证明经汁液和蚜虫传播,种子带毒。病毒稀释限点5×10-1~5×10-2;失活温度55~60℃;体外保毒期(22~23℃)24小时,经有机溶剂澄清,聚乙二醇沉淀和差速离心可部分提纯。病毒粒子线状,长约750毫微米;病组织超薄切片可见风轮状内含体。试管沉淀法初步测定与马铃薯Y病毒血清呈阳性反应。 相似文献