论大学校报的新闻关系特征

从新闻关系上探讨了大学校报和一般社会性新闻媒体的区别 ,找出了大学校报独有的新闻关系特征 ,在此基础上为提高大学校报的质量提出了一些建议     

从中美关系的正常化看国家利益的作用

2 0世纪 70年代初出现了打开中美两国关系的历史性机会。毛泽东审时度势 ,在中美关系问题上作出了具有转折意义的重大战略决策 ,同美国有远见的政治家尼克松一道打开了封闭已久的中美关系大门。从国家利益出发 ,超越意识形态制定对外政策是中美关系得以正常化的关键。     

浙江地区不同寄主来源的炭疽菌ITS序列PCR-RFLP多态性分析

应用核糖体DNA (ribo-somal DNA,rDNA)的ITS( internal transcribed spacer,ITS)区的RFLP序列的多态性,分析32个不同寄主来源的炭疽菌株的遗传多样性.利用ITS1及ITS4通用引物对扩增各菌株的rDNA的内转录间隔区(ITS1-5.8S-ITS2)获得长约600 bp片段.ITS-RFLP共迁带UPGMA聚类分析的结果表明所有来自不同寄主的炭疽菌菌株(含福建及云南菌株)都以较高的相似系数(＞0.60)聚为一类,具有较近的 亲缘关系;同时试验中所有酶切位点的综合Gst系数达到0.82,说明不同菌株间的ITS具有丰富的多态性.     

Design, synthesis, insecticidal activity and structure-activity relationship of 3,3-dichloro-2-propenyloxy-containing phthalic acid diamide structures

BACKGROUND: Phthalic acid diamide derivatives are among the most important classes of synthetic insecticides. In this study, a 3,3‐dichloro‐2‐propenyloxy group, the essential active group of pyridalyl derivatives, was incorporated into phthalic acid diamide derivatives with the aim of combining the active groups to generate more potent insecticides. RESULTS: Thirty‐one new phthalic acid diamides were obtained, and these were characterised by ¹H and ¹³C NMR. The structure of N²‐[1,1‐dimethyl‐2‐(methoxy)ethyl]‐3‐iodo‐N¹‐[4‐(3,3‐dichloro‐2‐propenyloxy)‐3‐(trifluoromethyl)phenyl]‐1,2‐benzenedicarboxamide was determined by X‐ray diffraction crystallography. The insecticidal activities of the compounds against Plutella xylostella were evaluated. The title compounds exhibited excellent larvicidal activities against P. xylostella. Structure‐activity relationships revealed that varying the combination of aliphatic amide and aromatic amide moieties, or the nature and position of substituent Y on the aniline ring, could aid the design of structures with superior performance. CONCLUSION: A series of novel phthalic acid diamides containing a 3,3‐dichloro‐2‐propenyloxy group at the 4‐position of the aniline ring were designed and synthesised. Structure‐activity relationships with the parent structure provided information that could direct further investigation on structure modification. Copyright © 2012 Society of Chemical Industry     

Water utilization patterns around isolated Acacia karroo trees in the False Thornveld of the eastern Cape

The effect of various vegetation treatments on two soil moisture regimes (i.e. the proportion of the experimental period where the soil had sufficient water for: (a) growth, and (b) to keep the plants turgid in the vicinity of experimentally isolated A. karroo trees) was monitored over a two‐year period. Removal of all vegetation had the greatest effect on soil moisture, increasing the moisture regime by around 200%. Grass removal had the next most significant effect, increasing moisture regimes within 9 m of the tree by around 100%. Removal of the tree had the smallest significant effect, increasing the moisture regime by less than 20%. There was no significant difference in the moisture regime surrounding trees with heights ranging between 1,4 m and 2,5 m, or where various combinations of tree and/or grass defoliations were implemented. We conclude that water supply to the trees is enhanced when soil water extraction is reduced (e.g. during winter or when the sward is harmed) and argue that this may be a mechanism of accelerating bush encroachment in semi‐arid savannas.     

A note on the diet and feeding selectivity of juvenile riverbream,Acanthopagrus berda (Forskal, 1775), in a subtropical mangrove creek

The diet and food selectivity of juvenile (< 100 mm S.L.) Acanthopagrus berda were investigated in Beachwood creek, north of Durban. Fish and benthic samples were taken from November 1986 to September 1987. The diet of juvenile A. berda was varied but crustaceans, mainly amphipods, were the dominant prey item. Ivlev's (1961) electivity index revealed a positive selection for amphipods, tanaids and fish scales.     

Integrated production of semi-finished components in sawmills,part I: External interactions

Abstract

In a changing business landscape, where globalization and new customer requirements create new business opportunities, some Swedish sawmills have taken over the production of components from their industrial customers. In light of the emerging network-centric perspective on business, sawmill managers' perceptions about component customers' operational requirements, customer interaction processes, and their sawmills' offerings are researched and discussed in this article. A multiple case study design, based on face-to-face interviews with Swedish sawmill managers and on various forms of secondary data, produced comprehensive information about sawmills' interaction processes with component purchasing customers. Thematic data coding facilitated the assessment of the research information in relation to the conceptual and empirical findings of previous research. The findings of the study indicate that more process orientation in housing-, joinery-, and furniture-manufacturing implies an opportunity for sawmills to make service-based offerings including not only physical goods, but also administrative services, logistics, and expert advice. The results of the study confirm the network-centric perspective on business where value is created through the interaction between firms. However, noteworthy barriers in the form of process-, culture-, as well as socially related factors at customer firms must be considered.     

Genetic variations and interrelationships in Vanilla planifolia and few related species as expressed by RAPD polymorphism

Vanilla is naturally distributed in Mexico and parts of Central America and the history of origin of cultivated vanilla suggests that the entire stock outside Mexico may be from a single genetic source. In the present study, RAPD polymorphism was used to estimate the level of genetic diversity and interrelationships among different collections of Vanilla planifolia Andr., and few related species, including both leafy and leafless types such as V. tahitensis J.W.Moore, V. andamanica, Rolfe, V. pilifera Holtt., and V. aphylla Blume. Studies revealed that there are very limited variation within collections of V. planifolia, indicative of its narrow genetic base, and of the related species we tested, V. tahitensis is nearest to V. planifolia. The species studied are diverse and have a similarity ranging from 1.2 to 57.3 %. Of the sampled taxa, V. andamanica is the most divergent and there is also reasonable variability within its collections, indicating the possibility of natural seed set. A total of 82 polymorphic bands expressed in the RAPD profiles were used to generate a genetic distance matrix, which was then used in cluster analysis. Specific groupings were revealed by the cluster analysis whereby the leafless forms (V. aphylla, V. pilifera and the new species) and V. andamanica formed separate clusters. This is the first report of species interrelationship studies, including both cultivated and wild vanilla species.     

Live weight, body size and carcass characteristics of young bulls of fifteen European breeds

A total of 436 young bulls from fifteen Western European breeds, including beef, dairy and local types from five countries, were studied to assess variability in live weight, live weight gain, body measurements and carcass traits. Animals were logged indoors, and fed a diet based on concentrate and straw offered ad libitum from 9 months of age to slaughter at 15 months of age. The weight, body length, height at withers and pelvis width, of the animals were recorded at 9, 12 and 15 months of age. After slaughter, 15 carcass variables were recorded, including carcass weight, EU classification scores, morphological measurements and dissection data. Data were analysed by GLM, regression and principal component analysis procedures.Significant differences were found between breeds for all variables studied, however, the body size measurements and the carcass traits were more useful to discriminate among cattle breeds, than either live weight or daily gain. With respect to the body size and carcass traits the studied breeds could be grouped as:

– Specialized beef breeds, comprising Piemontese, Asturiana de los Valles, Pirenaica, Limousin, South Devon, Charolais and Aberdeen Angus, all of which were characterized by high muscularity, wide pelvis and medium height and a low to medium level of fatness.

– Local and dairy breeds, comprising Jersey, Casina, Highland, Holstein and Danish Red, the latter two breeds were tall animals, while the former three breeds were small in size. In general the group was poorly muscled and tended to have a high or medium level of fat.

– Intermediate group, Avileña, Marchigiana and Simmental: these breeds were characterized by an intermediate muscle conformation and fatness level and were relatively tall.

This study provides a detailed assessment or a wide range of variables in the major breeds, and several minor breeds, that are used in breeding programmes across Europe and elsewhere, and will provide information that will be of use to define breeding strategies to meet the demands of the European beef market.     

Genetic diversity and relationships of lotus (Nelumbo) cultivars based on allozyme and ISSR markers

Genetic diversity and genetic relationships of lotus (Nelumbo Adanson) cultivars were evaluated using allozyme and ISSR markers. The samples used covered 11 accessions of possible hybrids between Nelumbo nucifera and Nelumbo lutea and 92 accessions of N. nucifera including 69 flower lotus, 13 rhizome lotus, 5 seed lotus and 5 wild lotus. For allozyme studies, a total of 31 alleles at 23 loci of 18 enzyme systems were detected of which 5 (21.7%) loci Aat, Idh, Mdh-2, Pgd, Sod were polymorphic. The loci of Aat and Idh included two alleles, Mdh-2, Pgd and Sod included three alleles. Eighteen genotypes were detected with the 13 alleles of the 5 polymorphic loci. The parameters of average allele number, observed heterozygosity, expected heterozygosity and Shannon information index of 92 N. nucifera samples were 1.35 ± 0.71, 0.06 ± 0.21, 0.05 ± 0.14, 0.10 ± 023, respectively. Thirteen ISSR primers generated 93 loci, of which 37.63% were polymorphic across all samples. The percentage of polymorphic loci, average allele number, expected heterozygosity and Shannon information index of 92 N. nucifera samples were 26.67%, 1.30 ± 0.46, 0.10 ± 0.18 and 0.15 ± 0.25, respectively for the ISSR data. The ‘Bottleneck effect’ and rapid propagation of clones after the ice ages may explain the low genetic diversity of lotus. The dendrograms based on ISSR and allozymes were not congruent. Based on the ISSR data, the 103 samples were divided into the N. nucifera group (Group I), and the group containing inter-specific hybrids between N. nucifera and N. lutea (Group II). The flower lotus, rhizome lotus, and seed lotus each has multiple sources of origin. Plant size, a criterion commonly used in the classification of cultivars of lotus, is not correlated with genetic variation. Flower color is correlated with the cultivar classification to some degree, but its variation is complex in the hybrids.