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71.
Meherzia Mokni Mohamed Amri Ferid Limam Ezzedine Aouani 《Tropical animal health and production》2017,49(1):131-137
In the present study, we investigated the effect of grape seed and skin supplement (GSSS), on lactating dairy ewes’ production. Ten dairy pregnant ewes from northern Tunisia were allocated to two groups: control diet (C) and supplemented with 20 % (w/w) GSSS. The experiment lasted for 8 weeks and took place after 2 months of lambing. During the experiment, daily milk yield and milk composition were determined. Supplementation of the diet with GSSS increased milk production (P?<?0.001), calcium (P?<?0.01), free iron (P?<?0.01) and urea content (P?<?0.001) but had no effect on milk fat nor protein. From these data, it is concluded that the inclusion of GSSS in sheep diets increased significantly ewes’ milk yield. 相似文献
72.
鸡传染性支气管炎病毒地方分离株S1、N和M基因的克隆与表达 总被引:1,自引:0,他引:1
摘要:将IBVSX16株的S1、N和M基因克隆入真核表达载体pVAX1,构建IBV真核表达载体pVAX1-16S1、pVAX1-16N和pVAX1-16M。体外转染BHK-21细胞,用间接ELISA检测到目的蛋白表达,用构建的3个表达载体免疫小鼠,从小鼠血清中检测到了抗IBV抗体,初步证实用IBVS1、N和M基因作为核酸疫苗免疫动物,可以激活机体免疫应答。 相似文献
73.
Liu Yang Shaohua Chen Meiying Hu Weining Hao Peng Geng Yanbo Zhang 《Biology and Fertility of Soils》2011,47(8):917-923
A novel yeast named HQ-C-01 was isolated from activated sludge and identified as Pichia anomala based on the morphology and 18S rDNA sequence analysis. The HQ-C-01 strain degraded 95.2% of carbofuran when the insecticide
was used as the only C source and added at 50 mg/L in a mineral salts medium within 48 h. The optimal concentration, temperature,
and pH of medium for degradation of carbofuran were 50 mg/L, 30°C, and pH 7.5, respectively. Strain HQ-C-01 could also effectively
degrade other carbamate insecticides including carbaryl, indoxacarb, and fenobucarb, and the degradation rates were 99%, 85%,
and 67%, respectively. Gas chromatography–mass spectrometry analysis showed that the strain metabolized carbofuran to produce
benzofuranol as the intermediate metabolite, which was further degraded. Degradation of carbofuran added at 50 mg/kg of soil
was higher in yeast-inoculated soil than in the control. These results indicated that strain HQ-C-01 may potentially be used
in bioremediation of carbofuran-contaminated soil. 相似文献
74.
Iman Tahmasbian Zhihong Xu Kadum Abdullah Jun Zhou Roya Esmaeilani Thi Thu Nhan Nguyen Shahla Hosseini Bai 《Journal of Soils and Sediments》2017,17(8):2091-2103
Purpose
The main objective of this study was to examine the potential of using hyperspectral image analysis for prediction of total carbon (TC), total nitrogen (TN) and their isotope composition (δ13C and δ15N) in forest leaf litterfall samples.Materials and methods
Hyperspectral images were captured from ground litterfall samples of a natural forest in the spectral range of 400–1700 nm. A partial least-square regression model (PLSR) was used to correlate the relative reflectance spectra with TC, TN, δ13C and δ15N in the litterfall samples. The most important wavelengths were selected using β coefficient, and the final models were developed using the most important wavelengths. The models were, then, tested using an external validation set.Results and discussion
The results showed that the data of TC and δ13C could not be fitted to the PLSR model, possibly due to small variations observed in the TC and δ13C data. The model, however, was fitted well to TN and δ15N. The cross-validation R2 cv of the models for TN and δ15N were 0.74 and 0.67 with the RMSEcv of 0.53% and 1.07‰, respectively. The external validation R2 ex of the prediction was 0.64 and 0.67, and the RMSEex was 0.53% and 1.19 ‰, for TN and δ15N, respectively. The ratio of performance to deviation (RPD) of the predictions was 1.48 and 1.53, respectively, for TN and δ15N, showing that the models were reliable for the prediction of TN and δ15N in new forest leaf litterfall samples.Conclusions
The PLSR model was not successful in predicting TC and δ13C in forest leaf litterfall samples using hyperspectral data. The predictions of TN and δ15N values in the external litterfall samples were reliable, and PLSR can be used for future prediction.75.
萘醌类化合物普遍被报道具备较好的抗肿瘤能力。以1,5-二羟基萘为原料,经五步反应得到了4个末端含有羟基的萘醌类衍生物(6a-d)和1个未含羟基的萘醌类衍生物(6e),并通过质谱和1H NMR进行结构鉴定,采用MTT法评价了5种化合物对人肝癌细胞Hep3B细胞系的生长抑制作用。结果显示取代基末端含羟基的萘醌类衍生物的抗肿瘤活性与碳链长度有密切关系。研究中的6 d对肿癌细胞Hep3B抑制活性最强,IC50为9.1μmol·m L~(-1)。 相似文献
76.
Context
Common indicators are needed to monitor biodiversity loss and the implications for the sustainable provision of ecosystem services (ES). A plethora of different sets of indicators may hinder the identification of major endpoints for large-scale assessments of biodiversity and ecosystem services (BES).Objectives
We aim to describe the main challenges of indicators for BES assessment and provide suggestions for establishing a comprehensive indicator system.Methods
An extensive literature review was conducted in this study. We review the main challenges of indicators for BES assessment and propose corresponding improvements from our perspectives of theory and practical applications.Results
The main theoretical challenges of existing indicators include inconsistent definitions and classifications of ES, misunderstanding of linkages among biodiversity, ecosystem structure, functions and services, and practical problems relate to such issues as indicator representativeness, data availability, and uncertainty. Our suggested improvements include clarifying the main terms, concepts and classification of indicators, establishing a robust conceptual framework with clear interactions among different components and indicators, selecting indicators based on ecosystem properties, streaming existing data into one platform, and strengthening validation of proxies. The steps for constructing a comprehensive indicator system for BES assessment are summarized.Conclusions
Clear definitions of key terms are indispensable to classify indicators and construct a conceptual framework. Improved understanding of the relations among indicators of biodiversity, ecosystem functions, and ES across multiple scales can guide the development of the indicator system. The integrated indicator system is an important tool for BES assessment to support decision making for sustainable development.77.
78.
基于时序归一化植被指数的冬小麦收获指数空间信息提取 总被引:5,自引:1,他引:5
为获取农作物收获指数(HI)空间分布信息,该研究充分利用遥感技术,以冬小麦为例,利用时序归一化植被指数NDVI构成的作物生长过程曲线提取MODIS NDVI阶段性累积特征参数,并用生殖生长关键阶段和营养生长关键阶段对应的NDVI累积参数比值HINDVI_SUM构建了用于反演冬小麦收获指数的参数,并建立了参数HINDVI_SUM与冬小麦实测收获指数的定量关系,利用上述定量关系实现作物收获指数空间信息的提取。经过对反演冬小麦收获指数的精度验证,结果表明,利用构建参数HINDVI_SUM在区域范围内反演冬小麦收获指数取得了较好的效果。其中,冬小麦收获指数预测的平均相对误差为2.40%,均方根误差(RMSE)为0.02,证明了该研究利用时序NDVI构建参数HINDVI_SUM反演区域冬小麦收获指数空间信息的方法准确性和可行性。 相似文献
79.
Dynamics of forest biomass carbon stocks from 1949 to 2008 in Henan Province,east-central China 总被引:1,自引:0,他引:1
We estimated forest biomass carbon storage and carbon density from 1949 to 2008 based on nine consecutive forest inventories in Henan Province,China.According to the definitions of the forest inventory,Henan forests were categorized into five groups: forest stands,economic forests,bamboo forests,open forests,and shrub forests.We estimated biomass carbon in forest stands for each inventory period by using the continuous biomass expansion factor method.We used the mean biomass density method to estimate carbon stocks in economic,bamboo,open and shrub forests.Over the 60-year period,total forest vegetation carbon storage increased from34.6 Tg(1 Tg = 1×10~(12)g) in 1949 to 80.4 Tg in 2008,a net vegetation carbon increase of 45.8 Tg.By stand type,increases were 39.8 Tg in forest stands,5.5 Tg in economic forests,0.6 Tg in bamboo forests,and-0.1 Tg in open forests combine shrub forests.Carbon storageincreased at an average annual rate of 0.8 Tg carbon over the study period.Carbon was mainly stored in young and middle-aged forests,which together accounted for 70–88%of the total forest carbon storage in different inventory periods.Broad-leaved forest was the main contributor to forest carbon sequestration.From 1998 to 2008,during implementation of national afforestation and reforestation programs,the carbon storage of planted forest increased sharply from 3.9 to 37.9 Tg.Our results show that with the growth of young planted forest,Henan Province forests realized large gains in carbon sequestration over a 60-year period that was characterized in part by a nation-wide tree planting program. 相似文献
80.
油菜花上真菌种类及其对菌核菌拮抗作用的研究 总被引:4,自引:0,他引:4
于油菜初花期与盛花期采取油菜不同部位花瓣和花药进行真菌分离.除菌核病菌(Sclerotinia sclerotiorum)外,还以不同的频率分离到葡萄孢菌(Botrytis spp.),交链孢菌(Alternaria spp.),芽枝霉菌(Cladosporium spp.),叶点霉菌(Phyllosticta sp.),附球孢菌(Epicoccum sp.),镰刀菌(Fusarium spp.).其中葡萄孢菌、交链孢菌、芽枝霉菌出现较早,为初花期主要真菌群;盛花期还分离到叶点霉菌和附球孢菌,以镰刀菌出现最迟.1991年从分离真菌中选择101个菌株.通过培养皿法和花瓣法测定对菌核菌的拮抗作用,初步筛选出A_3,A_(25),A_(26),B_(10),B_(13),B_(11),B_(26),B_(31),B_(3(?)),C_8,E_1和E_2 12个对菌核菌拮抗作用较强的菌株.用以上拮抗菌和菌核菌的孢子悬液于24h 时内在实验室条件下先后喷雾接种开花的油菜植株,所有拮抗菌占领花朵百分率为63%~96%不等,而菌核菌不能定殖其上.1992年从151个分离菌株中,筛选出59个对核盘菌具有拮抗作用的真菌菌株,其中葡萄孢菌41个占69.49%,交链孢菌5个占8.47%,芽枝霉菌1个占1.69%,镰刀菌12个占20.34%. 相似文献