期刊文献+
共找到9篇文章
< 1 >
每页显示 20 50 100
The Special Expression and Comparison of the c-kit Protein in Spermatogenesis of Three Species of Locusts of Arcypteridae 被引量:1
1
作者 ZHAO Zhuo XI Geng-si 《Agricultural Sciences in China》 CAS CSCD 2007年第7期825-831,共7页
The aim of this study was to elucidate the expression and regulation of the c.kit protein in spermatogenesis of locusts. Immunohistochemistry and biological statistics were used to investigate the expression of the c-... The aim of this study was to elucidate the expression and regulation of the c.kit protein in spermatogenesis of locusts. Immunohistochemistry and biological statistics were used to investigate the expression of the c-kit protein in four representative phases of spermatogenesis of three dominant species of locusts of Arcypteridae (Orthoptera: Acridoidea), namely, Omocestus viridulus (Linnaeus), Euchorthippus unicolor (Ikonn.), and Euchorthippus vittatus Zheng, and so on, in Siping area of Jilin Province, China. The results revealed the following: (1) There was weak positive expression of the c-kit protein in spermatogonia and the positive granules were thinner; (2) there was a strong positive expression of the c-kit protein in primary spermatocyte and the positive granules became the largest than in all developmental stages; (3) the c-kit protein positive expression became stronger in secondary spermatocyte, while the positive granules became thinner; (4) there was strong positive expression of the c-kit protein and the positive granules were thinner in mature sperm, which were distributed on its head and tail; (5) there were strong positive protein granules massing at the end of spermary; (6) the positive intensity of the c-kit protein in spermatogenesis was significantly different among different species of locusts. The data suggested that the c-kit protein may play a crucial role in spermatogenesis as well as maintain the physiological action of sperms and fertilization, regulate the developmental speed of spermatogenesis, and/or maintain species isolation, etc. 展开更多
关键词 locust SPERMATOGENESIS c-kit protein special expression significant difference
下载PDF
Are University Rankings Statistically Significant?A Comparison among Chinese Universities and with the USA 被引量:1
2
作者 Loet Leydesdorff Caroline SWagner Lin Zhang 《Journal of Data and Information Science》 CSCD 2021年第2期67-95,共29页
Purpose:Building on Leydesdorff,Bornmann,and Mingers(2019),we elaborate the differences between Tsinghua and Zhejiang University as an empirical example.We address the question of whether differences are statistically... Purpose:Building on Leydesdorff,Bornmann,and Mingers(2019),we elaborate the differences between Tsinghua and Zhejiang University as an empirical example.We address the question of whether differences are statistically significant in the rankings of Chinese universities.We propose methods for measuring statistical significance among different universities within or among countries.Design/methodology/approach:Based on z-testing and overlapping confidence intervals,and using data about 205 Chinese universities included in the Leiden Rankings 2020,we argue that three main groups of Chinese research universities can be distinguished(low,middle,and high).Findings:When the sample of 205 Chinese universities is merged with the 197 US universities included in Leiden Rankings 2020,the results similarly indicate three main groups:low,middle,and high.Using this data(Leiden Rankings and Web of Science),the z-scores of the Chinese universities are significantly below those of the US universities albeit with some overlap.Research limitations:We show empirically that differences in ranking may be due to changes in the data,the models,or the modeling effects on the data.The scientometric groupings are not always stable when we use different methods.Practical implications:Differences among universities can be tested for their statistical significance.The statistics relativize the values of decimals in the rankings.One can operate with a scheme of low/middle/high in policy debates and leave the more fine-grained rankings of individual universities to operational management and local settings.Originality/value:In the discussion about the rankings of universities,the question of whether differences are statistically significant,has,in our opinion,insufficiently been addressed in research evaluations. 展开更多
关键词 RANKING UNIVERSITY China significance of differences INDICATORS
下载PDF
Seed and Wasp Production in the Mutualism of Figs and Fig Wasps 被引量:1
3
作者 YaoJin-yan ZhaoNan-xian +3 位作者 ChenYi-zhu JiaXiao-cheng DengYuan YuHui 《Forestry Studies in China》 CAS 2005年第1期25-28,共4页
Figs (Moracea: Ficus) and fig wasps (Hymenoptera: Chlocloids: Agaonideae) depend on each other to complete their reproduction. Monoecious fig species and their pollinating wasps are in conflict over the use of fig ov... Figs (Moracea: Ficus) and fig wasps (Hymenoptera: Chlocloids: Agaonideae) depend on each other to complete their reproduction. Monoecious fig species and their pollinating wasps are in conflict over the use of fig ovaries which can either produce one seed or one wasp. From observation on Ficus virens Ait., we showed that female flowers with outer layer of ovaries (near to the wall of syconium) had no significant difference from that with inner and interval layer of ovaries (near to the syconium cavity), in which most seeds and wasps were produced. This meant that fig tree provided the same potential resource for seed and wasps production. Observation indicated that there was usually only one foundress in syconium at female flower phase and no com- petition pollinators. Measurement of the style length of female flowers and the ovipositor of pollinators indicated that most ovaries could be reached by pollinator’s ovipositor. However, at the male flower phase, production of seeds was significantly more than that of wasps including non-pollinating wasps but there was no significant difference between seed and pollinating wasp production when without non-pollinating wasps produced. This result indicated that non-pollinating wasps competed ovaries not with seeds but with pollinating wasps for ovipositing. Bagged experiment showed that the sampling fig species was not self-sterile which was important for figs and wasps to survive bad season. Seed production in self-pollinated figs was not significantly different from total wasps in- cluding non-pollinating ones. This might be related with the weaker competition among wasps since bagged figs were not easy to reach by wasps from outside. 展开更多
关键词 FICUS Ficus wasp mutualism conflicts seed and wasp production Seed and Wasp Production in the Mutualism of Figs and Fig Wasps Yao Jin-yan1 2 Zhao Nan-xian1 Chen Yi-zhu1* Jia Xiao-cheng1 2 Deng Yuan1 2 Yu Hui1 2 1South China Botanical Garden Chinese Academy of Sciences Guangzhou 510650 P. R. China 2Graduate School of the Chinese Academy of Sciences Beijing 100039 P. R. China ABSTRACT Figs (Moracea: Ficus) and fig wasps (Hymenoptera: Chlocloids: Agaonideae) depend on each other to complete their reproduction. Monoecious fig species and their pollinating wasps are in conflict over the use of fig ovaries which can either produce one seed or one wasp. From observation on Ficus virens Ait. we showed that female flowers with outer layer of ovaries (near to the wall of syconium) had no significant difference from that with inner and interval layer of ovaries (near to the syconium cavity) in which most seeds and wasps were produced. This meant that fig tree provided the same potential resource for seed and wasps production. Observation indicated that there was usually only one foundress in syconium at female flower phase and no com- petition pollinators. Measurement of the style length of female flowers and the ovipositor of pollinators indicated that most ovaries could be reached by pollinator’s ovipositor. However at the male flower phase production of seeds was significantly more than that of wasps including non-pollinating wasps but there was no significant difference between seed and pollinating wasp production when without non-pollinating wasps produced. This result indicated that non-pollinating wasps competed ovaries not with seeds but with pollinating wasps for ovipositing. Bagged experiment showed that the sampling fig species was not self-sterile which was important for figs and wasps to survive bad season. Seed production in self-pollinated figs was not significantly different from total wasps in- cluding non-pollinating
下载PDF
Normalization strategy of microarray gene expression data
4
作者 伍亚舟 张玲 +2 位作者 黄明辉 杨梦苏 易东 《Journal of Medical Colleges of PLA(China)》 CAS 2007年第4期195-200,共6页
Objective: To discuss strategies and methods of normalization on how to deal with and analyze data for different chips with the combination of statistics, mathematics and bioinformatics in order to find significant d... Objective: To discuss strategies and methods of normalization on how to deal with and analyze data for different chips with the combination of statistics, mathematics and bioinformatics in order to find significant difference genes. Methods: With Excel and SPSS software, high or low density chips were analyzed through total intensity normalization (TIN) and locally weighted linear regression normalization (LWLRN). Results: These methods effectively reduced systemic errors and made data more comparable and reliable. Conclusion: These methods can search the genes of significant difference, although normalization methods are being developed and need to be improved further. Great breakthrough will be obtained in microarray data normalization analysis and transformation with the development of non-linear technology, software and hardware of computer. 展开更多
关键词 gene chip normalization factor expression ratio significant difference
下载PDF
Influence of Elevation on the Growth of Platycladus orientalis
5
作者 王英伟 张靖 +2 位作者 王一辰 乔洪波 王克华 《Agricultural Science & Technology》 CAS 2017年第6期1055-1057,共3页
Based on the survey data of forest assessment in Shandong province, mathematics statistic method was used to analyze the significance tests within the elevation distance of 100 m and the overall performance, concludin... Based on the survey data of forest assessment in Shandong province, mathematics statistic method was used to analyze the significance tests within the elevation distance of 100 m and the overall performance, concluding that elevation had a significant effect on the growth of Platycladus orientalis. The methods, pro- cess, and analysis on survey results were introduced, and the direction of its appli- cation was pointed out, as well as the limitations of the study. 展开更多
关键词 GROWTH Elevation section Significant difference
下载PDF
Evaluating Writing Strategy Instruction in a Chinese EFL University Context
6
作者 WANG Yu-wen 《Sino-US English Teaching》 2007年第2期11-17,共7页
The study aims to find out the effects of writing strategy instruction on non-English major graduate students by means of an empirical study. The results of Kruskal-Wallis Test show no significant differences at the p... The study aims to find out the effects of writing strategy instruction on non-English major graduate students by means of an empirical study. The results of Kruskal-Wallis Test show no significant differences at the pre-test, but at the post-test, there are significant differences in terms of content and organization among three groups. These significant differences suggest that pre-writing strategy instruction help learners generate richer ideas and organize information logically in a Chinese EFL university context 展开更多
关键词 pre-writing strategy revising strategy significant differences
下载PDF
Assessing the incidence of common bean(Phaseolus vulgaris L.)infection by fungi during harvest and storage in Cameroon
7
作者 Akwa TE Maingi JM Birgen JK 《Studies in Fungi》 2020年第1期435-446,共12页
In most parts of Cameroon particularly the Menoua Division,common bean(Phaseolus vulgaris L.)is usually consumed immediately after harvest or after a few months of storage.Contamination of common bean by fungi usually... In most parts of Cameroon particularly the Menoua Division,common bean(Phaseolus vulgaris L.)is usually consumed immediately after harvest or after a few months of storage.Contamination of common bean by fungi usually occurs in the field and during storage.It is possible that the incidence of food contamination by fungi varies between field and storage.The study aimed at determining the incidence of common bean infection by fungi during harvest and during storage.Six common bean cultivars both during harvest and storage were evaluated.Analysis of variance showed no significant difference(P˃0.05)between their incidences of infection by fungi during harvest.The incidence of common bean infection during storage was shown to differ significantly between each cultivar(P≤0.05).A comparison of the mean incidence level of infection by fungi in the two groups of bean cultivars(cultivars during harvest and cultivars during storage)using the independent t-test analysis revealed a significant difference between their mean incidence of infection.The findings conclude that the incidence of common bean infection by fungi during storage is higher than during harvest in the Menoua Division.These findings will help to sensitise farmers on the improvement of bean storage conditions. 展开更多
关键词 AFRICA Identification Menoua Division MOLD Significant difference
下载PDF
Design,synthesis and bioassay of the emerging photo-responsive fungicides
8
作者 Wen Fu Xinyue Hu +4 位作者 Qinglong Yuan Zhiping Xu Jiagao Cheng Zhong Li Xusheng Shao 《Chinese Chemical Letters》 SCIE CAS CSCD 2023年第8期223-226,共4页
Precise and spatiotemporal control over the pesticide remains to be a challenge.More efficient controlled release systems(CRSs)have been developed to support the precise delivery of active ingredients.Herein,we incorp... Precise and spatiotemporal control over the pesticide remains to be a challenge.More efficient controlled release systems(CRSs)have been developed to support the precise delivery of active ingredients.Herein,we incorporated the photoremovable protecting groups(PRPGs)into phenamacril(PHE)and obtained two photo-responsive fungicides of NV-PHE and DEACM-PHE.The 4,5-dimethoxy-o-nitrobenzyl(NV)or 7-diethylaminocoumarin(DEACM)-caged PHE could release the active molecule PHE after irradiation of UV light and blue light,respectively.Optical properties and in-vitro/vivo fungicidal activities of NV-PHE and DEACM-PHE demonstrated the feasibility for light controlled release of PHE.DEACM-PHE could release 98%PHE by illumination of blue light.The irradiated DEACM-PHE could preserve the similar bioactivity of PHE,and significantly improve the in-vitro/vivo fungicidal activities compared to the non-irradiated DEACM-PHE.The optical controlled release of PHE from DEACM-PHE enabled the precise and spatiotemporal delivery of PHE,diversifying the development of CRSs for pesticide,and providing environmentfriendly agricultural applications with high pesticide efficiency. 展开更多
关键词 Phenamacril Controlled release Photoremovable protecting groups SPATIOTEMPORAL Significant difference
原文传递
THE EFFECT OF EXPOSURE TO MEANINGS OF UNKNOWN VOCABULARY ON READING COMPREHENSION IN THE TARGET LANGUAGE OF SECOND-YEAR CHINESE COLLEGE STUDENTS
9
作者 余苏凌 《Chinese Journal of Applied Linguistics》 2005年第5期33-39,128,共8页
This paper presents a study of the effect of exposure to meanings of unknown vocabulary on reading comprehension in the target language (in this case, English). The subjects are 30 second-year Chinese college students... This paper presents a study of the effect of exposure to meanings of unknown vocabulary on reading comprehension in the target language (in this case, English). The subjects are 30 second-year Chinese college students. The results illustrate that the subjects' being exposed to the meanings of unknown words in a passage does exert a significant effect on their reading comprehension in the target language. 展开更多
关键词 exposure unknown vocabulary PRE-TEST post-test reading comprehension significant difference
原文传递
上一页 1 下一页 到第
使用帮助 返回顶部