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931.
黄山雄性短尾猴换群行为的研究 总被引:5,自引:2,他引:3
1986至1992年对安徽黄山一群短尾猴连续进行7年的换群行为研究表明:雄性的换群行为发生在临近交配期开始前后,大多数为成年个体;这些个体与换群前的顺位无关,且未受到迁入新群的其它个体更多的攻击,迁入雄体还倍受雌体青睐。据此推测,外群雌性的性吸引是雄性短尾猴换群的直接原因。雄性短尾猴换群的结果,降低了种群的近亲繁殖率,增加了不同种群间的基因交流,对种群遗传多样性的保存和发展具有重要意义.因此,进化选择压力有利于换群行为的发展。 相似文献
932.
野生猕猴声行为的研究 总被引:4,自引:2,他引:2
本文通过在华南四省区对四个野生种群猕猴声行为的观察和现场录音,对它们的叫声声学特性,行为模式和其它个体对其相应的行为反应进行了定量的分析研究,并得出11种不同的声行为,这些声行为有相互不同的声学特性,不同的行为模式并引起其它个体相应的行为反应,从而起着通讯的作用。叫声在猕猴的声行为通讯中,一些借助视觉提示,至少以不同的刺激度来“表示”某一类事物,并得到个体间的“共识”有些甚至无需视觉提示而单独传递 相似文献
933.
Methyl , a 3-O hexyl analogue of the octaosyl component of fungal lipooligosaccharide HS-142-1, was stereo- and regioselectively synthesized as a potent antagonist for the tetrameric atrial natriuretic peptide (ANP) receptors. 相似文献
934.
935.
Cynthia G. Fields Beate Grab Janelle L. Lauer Andrew J. Miles Ying-Ching Yu Gregg B. Fields 《Letters in Peptide Science》1996,3(1):3-16
Summary The triple-helical conformation of collagen has been proposed to be important for mediation of cellular activities, such as adhesion and activation, extracellular matrix assembly, and enzyme function. We have developed synthetic protocols that allow for the study of biological activities of specific collagen sequences in triple-helical conformation. These methods primarily involve solid-phase assembly and covalent linkage of three peptide chains. The resultant triple-helical peptides have sufficient thermal stabilities to permit structural and biological characterization under physiological conditions. The present article critically reviews the various approaches for constructing synthetic triple-helices.This paper is based on a presentation given at the Symposium on Peptide Structure and Design as part of the 31st Annual ACS Western Regional Meeting held in San Diego, CA, USA, October 18–21, 1995. 相似文献
936.
Production of congenic mouse strains carrying genomic intervals containing SLE-susceptibility genes derived from the SLE-prone NZM2410 strain 总被引:12,自引:0,他引:12
Systemic lupus erythematosus is inherited as a complex polygenic trait. Four genomic intervals containing major SLE-susceptibility
loci were previously identified by interval mapping in the NZM2410 mouse model. In this paper, we utilized a marker-assisted
selection protocol to produce four congenic mouse strains, each carrying an NZM2410-derived SLE-susceptibility interval on
a C57BL/6-resistant background. Each strain carries only one susceptibility allele derived from this polygenic model and consequently
can be used to characterize the specific component phenotypes contributed by individual SLE-susceptibility genes. We illustrate
the efficacy of this approach with phenotypic data for one of our congenic strains, B6.NZMH2
z
. Our results indicate that this single genomic interval from Chromosome (Chr) 17 of NZM2410 can mediate increased levels of
IgG autoantibodies specific for chromatin and that, similar to results obtained in our original genetic cross, B6.NZMH2
z/b
heterozygotes are more prone than B6.NZMH2
z
homozygotes to the development of humoral autoimmunity to nuclear antigens. These results illustrate the feasibility of using
congenic strains to dissect the complex pathogenic mechanisms that mediate polygenic SLE. These congenic strains will be valuable
tools in the genetic analysis of SLE susceptibility. In future studies, these congenic strains will be interbred to produce
bi- and tri-congenic strains in order to assess the role of genetic interactions in the expression of specific components
of SLE pathogenesis. They will also be instrumental to the positional cloning and identification of the genes responsible
for SLE susceptibility, via the production of congenic recombinants.
Received: 1 September 1995 / Accepted: 20 December 1995 相似文献
937.
938.
T. Hishinuma Grace S. P. Yu M. Takabatake Y. Nakagawa K. Ito M. Nishikawa M. Ishibashi K. Suzuki M. Matsumoto T. Toyoda M. Mizugaki 《Prostaglandins, leukotrienes, and essential fatty acids》1996,54(6):445-449
We microanalyzed 2,3-dinor-6-keto-prostaglandin F1α (2,3-dinor-6-keto-PGF1α 1) and 11-dehydrothromboxane B2 (11-dehydro-TXB2, 2) in human urine. Samples containing a [2H4]-analogue as an internal standard were extracted by chromatography using Sep Pak tC18 and silica gel. The compounds were then analysed by means of the lactone ring opening reaction and dimethylisopropylsilylation. The conversion of 1 to 1-methyl ester (ME)-propylamide (PA)-9,12,15-dimethylisopropylsilyl (DMIPS) ether derivative and of 2 to 1-ME-6-methoxime (MO)-9,12,15-tris-DMIPS ether derivative was followed by gas chromatography/selected ion monitoring (GC/SIM). Interfering substances from the urine matrix were eliminated during GC/SIM analysis using a DB-5 column. We were able to detect 1 (222–1031 pg/mg creatinine) and 2 (18–155 pg/mg creatinine) in human urine. Furthermore, the thromboxane/prostacyclin (IX/PGI) ratio in the urine of diabetics was higher than that of healthy volunteers. This method can be used to determine the TX/PGI balance in human urine. 相似文献
939.
A pentachlorophenol (PCP) degrading mixed culture contained three predominant strains identified as Flavobacterium gleum, Agrobacterium radiobacter and Pseudomonas sp. The relative abilities of the three strains to degrade PCP were tested individually and in combination. Rates of PCP degradation by individual isolates were lower than that observed for the three isolates combined. Of the individual strains, Flavobacterium gleum manifested highest PCP degradation ability. A biodegradation medium inoculated with a combination of the three isolates exhibited PCP degradation patterns similar to the original mixed culture. Varying low amounts of tetrachlorophenol were found in degradation medium inoculated with individual isolates, but this intermediate was absent from media inoculated with the mixed culture. 相似文献
940.
中国异皮属线虫一新种(线虫纲:垫刃目:异皮科) 总被引:1,自引:0,他引:1
本文描述采自河北省滦县寄生于白茅Imperate cylindrica var.Major的异皮属线虫一新种,中华异皮线虫Heterodera sinensis sp.nov.;新种孢囊为柠檬形,阴门膜孔为两侧单膜孔型,下桥发达有泡状突;二龄幼虫口针基部球前部略凹陷,口孔侧唇外缘融合王头晕第1环纹内,即无明显侧唇,其体侧区有3条侧线与体环纹呈不完全网格状交叉;雄虫侧区有3条侧线与体环纹呈完全网格状 相似文献