Transgene for growth hormone in common carp（Cyprinus carpio L.） promotes thymus development

The transgenic carp were produced by micro-injection of CAgcGHc into the fertilized eggs. Observation of the thymus development between the transgenics and non- transgenic controls was carried out. The thymus of one-year- old transgenics F1 showed a great increase in both size and weight. The unilateral thymus of the transgenics weighed from 190 to 295 mg with average 218.6 mg, whereas the uni-lateral thymus of the controls weighed 20—81 mg with av-erage 42.5 mg; i.e. the thymus weight in the transgenics was 5.14 fold over that in the controls. The index of thymus/body weight in the transgenics was 2.97 fold over the controls. Light microscopy observation indicated that the thymus of the transgenics well developed with the thickened outer re-gion and compactly arranged thymocytes, while the thymus in the controls were degenerating with the thinned outer region, scattered thymocytes and groups of fatty cells. Fur-ther analysis with the electron microscopy revealed that pro-liferous cells in the transgenics were mainly small lympho-cytes and no pathological changes were found. The results confirmed that the 揂ll-fish?GH-transgene promotes thy-mus development and thymocyte proliferation, and retards thymus degeneration. The study has laid a foundation for further analysis of the immunobiological function in GH- transgenic carp.     

Induction of gynogenesis in red crucian carp using spermatozoa of blunt snout bream

Gynogenetic diploid was induced in red crucian carp (RCC) ( Carassius auratus Red Variety) eggs using UV-irradiated spermatozoa from blunt snout bream (B) (Megalobrama amblycephaia) or from mirror carp (C) (Cyprinus carpio. L) . Spermatozoa were genetically inactivated by an appropriate UV dosage, and then the maternal DNA was duplicated with cold shock at 0-4℃. When using the spermatozoa of B, the fertilization rate, hatching rate and survival at first feeding were 52. 6±3. 0 %, 23.6±4.1 % and15.7±3.4 % , respectively, and the survival at first feeding was significantly higher than that (11.3±2.2%) when using the spermatozoa of C (Cyprinus carpio. L). According to the morphological characteristics, the chromosome number and the degree of gonadal development, gynogenetic RCC could be distinguished from the control hybrids of RCC♀×B♂. The individuals with red body color, 100 chromosomes and normal gonadal development were successful gynogenetic RCC, while the individuals with 124 or 148 chromosomes and delayed gonadal development were hybrids of (RCC×B). The triploid hybrids (RCC×B) (2 years old) were sterile, but the tetraploid hybrids (RCC×B) were sexually mature age of two. In the present study, compared to the spermatozoa of C, the advantages of spermatozoa of B as the activation source were that could increase the survival at first feeding of gynogenetic individuals and simplify the confirmation of gynogenetic status, which suggested that the sperm of B was an effective activation source for inducing gynogenesis in crucian carp.     

Induction of gynogenesis in red crucian carp using spermatozoa of blunt snout bream

Gynogenetic diploid was induced in red crucian carp (RCC) (Carassius auratus Red Variety) eggs using UV-irradiated spermatozoa from blunt snout bream (B) (Megalobrama amblycephala) or from mirror carp (C) (Cyprinus carpio. L). Spermatozoa were genetically inactivated by an appropriate UV dosage, and then the maternal DNA was duplicated with cold shock at 0-4℃. When using the spermatozoa of B, the fertilization rate, hatching rate and survival at first feeding were 52.6±3.0 %, 23.6±4.1 % and 15.7±3.4 %, respectively, and the survival at first feeding was significantly higher than that (11.3±2.2%) when using the spermatozoa of C (Cyprinus carpio. L). According to the morphological characteristics, the chromosome number and the degree of gonadal development, gynogenetic RCC could be distinguished from the control hybrids of RCC♀× B♂. The individuals with red body color, 100 chromosomes and normal gonadal development were successful gynogenetic RCC, while the individuals with 124 or 148 chromosomes and delayed gonadal development were hybrids of (RCC× B). The triploid hybrids (RCC× B) (2 years old) were sterile, but the tetraploid hybrids (RCC× B) were sexually mature age of two. In the present study, compared to the spermatozoa of C, the advantages of spermatozoa of B as the activation source were that could increase the survival at first feeding of gynogenetic individuals and simplify the confirmation of gynogenetic status, which suggested that the sperm of B was an effective activation source for inducing gynogenesis in crucian carp.     

Rapid establishment of pure lines of silver carp (Hypophthalmichthys molirix) and bighead carp (Aristichthys nobilis)

The diversity of gynogenetic, artificial sex reversal and natural silver carp and bighead carp is examined using randomly amplified polymorphic DNA (RAPD) method.All of the 187 bands are obtained and 19 (10.16%) of them are polymorphic in gynogenetic silver carp.Meanwhile 32 (15.61%) out of 205 bands are polymorphic in control group.In gynogenetic bighead carp a total of 232 bands are identified and 11 (4.74%) out of them are polymorphic, while 25 (10.37%) out of 241 bands are polymorphic in control group.The genetic distance of four populations is calculated and it is 0.102 and 0.023 for gynogenetic silver carp and gynogenetic bighead carp respectively.The values of natural silver carp and bighead carp are 0.161 and 0.104.From the UPGMA trees constructed based on genetic distance, the sex reversal individuals that match with the gynogenetic female individuals are picked out.A new breeding process of establishing a pure line is developed.     

Rapid growth cost in “all-fish” growth hormone gene transgenic carp:Reduced critical swimming speed

Evidence has accumulated that there is a trade-off between benefits and costs associated with rapid growth. A trade-off between growth rates and critical swimming speed (Ucrit) had been also reported to be common in teleost fish. We hypothesize that growth acceleration in the F3 generation of "all-fish" growth hormone gene (GH) transgenic common carp (Cyprinus carpio L.) would reduce the swimming abilities. Growth and swimming performance between transgenic fish and non-transgenic controls were compared. The results showed that transgenic fish had a mean body weight 1.4―1.9-fold heavier,and a mean specific growth rate (SGR) value 6%―10% higher than the controls. Transgenic fish,however,had a mean absolute Ucrit (cm/s) value 22% or mean relative Ucrit (BL/s) value 24% lower than the controls. It suggested that fast-growing "all-fish" GH-transgenic carp were inferior swimmers. It is also supported that there was a trade-off between growth rates and swimming performance,i.e. faster-growing individuals had lower critical swimming speed.     

Rapid growth cost in ＂all-fish＂ growth hormone gene transsenic carp： Reduced critical swimming speed

Evidence has accumulated that there is a trade-off between benefits and costs associated with rapid growth. A trade-off between growth rates and critical swimming speed （Uc,t） had been also reported to be common in teleost fish. We hypothesize that growth acceleration in the F3 generation of ＂all-fish＂ growth hormone gene （GH） transgenic common carp （Cyprinus carpio L.） would reduce the swimming abilities. Growth and swimming performance between transgenic fish and non-transgenic controls were compared. The results showed that transgenic fish had a mean body weight 1.4--1.9-fold heavier, and a mean specific growth rate （SGR） value 6%-10% higher than the controls. Transgenic fish, however, had a mean absolute Ucr, （cm/s） value 22% or mean relative Ucrit （BL/s） value 24% lower than the controls. It suggested that fast-growing ＂all-fish＂ GH-transgenic carp were inferior swimmers. It is also supported that there was a trade-off between growth rates and swimming performance, i.e. faster-growing individuals had lower critical swimming speed.     

印度国家网站:India.gov.in

鉴于印度在信息技术领域中的全球地位,印度政府在信息化方面也一直不懈努力。其中很大的举措就是开通了"India.gov.in"网站,它是印度的政府网站。印度政府对这个网站的认真程度从给予它"国家电子政府     

Confidence Problems in the Classroom.

This article discusses the causes of shyness and reluctance of Chinese students to speak English, both inside and outside the classroom, and offers possible solutions to the problem.     

Introduction of firefighting methods in U.S. underground mines

Underground mine fire always exists since the mining activity was practiced.It poses a severe safety hazard to the mine workers and may also cause a tremendous economic loss to the mines.Methods for controlling and extinguishing fires in underground mine have long been studied and there have been significant improvements.In order to know clearly about the firefighting technology used,this paper summarizes most of the underground mine firefighting methods used in the United States the past 150 years.This paper describes not only the accepted firefighting theories,but also the technologies,both direct and indirect attacking,in accordance to regulations or codes,with special attention is given to the indirect attack method and its related technologies.Further research needed is also briefly discussed at the end of this paper.     

Hartmann,K.J,Soziologie.Ferdinand Hirt in Breslau.1933.104 Seiten

在这篇书评里面,我除介绍哈特曼的社会学之外,还想借这个机会,附带的提到一些研究德国社会学的资料,以供有志于此道的人的参予。 哈特曼的书,虽然以社会学命名;但是他的内容,与美国一般的社会学书籍,大有分别。在美国出版的社会学书籍,内容大约偏于理论的探讨,很少讲到社会学史的。这本书里面,有四分之三的地位,是讲社会学史,而且是德国的社会学史。在哈特曼以前,这种工作也有人做过,如维塞(Leopold von Wiese,1876-)在一九二六年出版的社会学,(1)如富莱尔(Hans Freyer,1887-)在一九三一年出版的社会学入门,(2)都可以说是叙述德国的社会学…     

Die philosophischen Stroemungen der Gegenwart in Grossbritannien.Von Rudolf Metz.2 Bde.

梅慈博士这部大作是现有的最详细的现代英国哲学史。有了这部大作之後,英国现代哲学与法国现代国现代哲学,算是都有了详尽的历史了。但两书虽都是德文的,德国现代哲学的详书历史,却是还在阙如。庞罗比I.Benrubi所作,1928出版,与此书为姊妹篇的“法国现代哲学潮流”(已有法文本)是把现代法国哲学分为三个主潮,而从孔德讲起。梅慈这部,更博大,全书两大本,先分为两主分,第一主分十九世纪的旧潮流,第二主分才是十九世纪末二十世纪初的新潮流。第一卷的後半与第二卷都是讲的第二主分。 在第一生分中又分为四分。第一是苏格兰派(pp.3-19),由黎德…     

Evolutionary analysis of allotetraploid hybrids of red crucian carp × common carp, based on ISSR, AFLP molecular markers and cloning of cyclins genes

The allotetraploid hybrids of red crucian carp x common carp are the first reported artificially cultured polyploid fish with bisexual fertility and stable inheritance in vertebrate. Using ISSR and AFLP markers and the cyclins genes, the genomes and cyclin gene sequence changes were analyzed between the allotetraploid hybrids and their parents. The results indicated that the allotetraploids inherited many genetic characteristics from their parents and the genetic characteristics were stable after 15 generations. However, the allotetraploids had a closer genetic relationship with their original female parents and represented a bias toward the maternal progenitor. DNA fingerprinting analysis showed that the allotetraploids had undergone sequences deletion from their original parents and that the deleted sequences were mostly from the male parent＇s genome. Some non-parental bands were found in the allotetraploid hybrids. Sequences analysis of the cyclin A1 and B1 genes showed nonsynonymous substitutions of single nucleotides in codons that were different from their original parents, leading to non-parental amino acid loci. We speculate that the non-additivity in the allotetraploids, compared with their progenitors, could be an adjustment to the genomic shock from heterozygosity and polyploidy, allowing maintenance of genetic stability.     

A.C. conductivity and relaxation dynamics in zinc–borate glasses

The frequency-dependent dielectric dispersion of ZnO–Na2O–Al2O3–B2O3(in mol%) glass prepared by the melt quenching technique is investigated in the temperatur e ranges from room temperature to 420 K. Dielectric relaxation has been analyzed based on the behavior of electric modulus behavior. An analysis of the real and imaginary parts of dielectric is performed assuming the ideal Debye behavior as confirmed by Cole–Cole plot. The activation energy associated with the dielectric relaxation determined from the electric modulus spectra was found to be 1.863 eV, which is close to that the activation energy for d.c. conductivity (1.871 eV), indicating the similar nature of relaxation and conductivity.     

Security Issues in VolP Based on H. 323

We first discusses some threats to VolP system and H. 323 architectures designed for VolP communications on security point of view. Continues with presenting security requirements of VolP, and explaining the essential security constraints surrounding a successful VolP deployment. Finally, suggests some strategies to implement the security and encryption functions of VolP system based on H. 323.