纳西族和普米族的红细胞血型分布

调查了云南纳西族和普米族各１０４人的ＡＢＯ、ＮＭＳｓ、Ｒｈ和Ｐ血型系统。结果表明,ＡＢＯ血型系统中,纳西族和普米族有较高的基因频率ｒ,分别为０．６０８２和０．６８８２,且基因频率ｐ＝ｑ,纳西族均为０．１９５９,普米族均为０．１５５９。ＭＮＳｗ系统中两个民族都表现ｍ〉ｎ、ｓ〉ｓ,Ｍｓ〉Ｎｓ、ＭＳ〉ＮＳ,其中纳西族的基因频率在国内报道的相应值中是比较高的,且ＮＳ为零。     

畜禽遗传资源系统保存的理论与模拟实验研究──I．畜禽遗传资源系统保存的理论分析

本文提出了畜禽遗传资源系统保存的概念、基本思想及其群体遗传结构变化的数学模型。该理论是将一定时空内某一畜种所拥有的全部基因作为保存对象,既将活体保存作为基本方法,又将其有机地与高新生物技术结合在一起;既追求系统地保存控制畜种特性的基因资源,又可达到保存地方品种的目的。在假定无世代重叠,群体内存在选择、突变、迁移,且考虑漂变效应的情况下,本文所构建的两个数学模型可分别用来描述一个座位上多个主基因频率或数量性状群体均数的动态变化。     

Electromyographic correlates of the transition from aerobic to anaerobic metabolism in treadmill running

This study analysed the changes in electromyographic (EMG) activity of the vastus lateralis, biceps femoris and gastrocnemius muscles during incremental treadmill running. The changes in EMG were related to the lactate and ventilatory thresholds. Ten trained subjects participated in the study. Minute ventilation, oxygen consumption, carbon dioxide expired and the fraction of oxygen in the expired gas were recorded continuously. Venous blood samples were collected at each exercise intensity and analysed for lactate concentration. The EMG were recorded at the end of each exercise intensity using surface electrodes. The EMG were quantified through integration (iEMG) and by calculating the mean power frequency (MPF). The iEMG measurements were characterized by a breakpoint in the vastus lateralis and/or gastrocnemius muscles in eight of the subjects tested. However, the results indicated that blood lactate concentrations had already begun to increase in a nonlinear fashion before the iEMG breakpoint had been surpassed. Consequently, the occurence of the lactate threshold cannot be attributed solely to the change in motor unit recruitment or rate coding patterns demonstrated by the iEMG breakpoint. The ventilatory threshold was shown to be a far more reliable and convenient noninvasive predictor of the lactate threshold in comparison with EMG techniques. In conclusion, the EMG measurements used in this study (i.e. iEMG and MPF) were not considered to be viable noninvasive determinants of the aerobic-anaerobic transition phase in treadmill running.     

云南阿昌族的红细胞血型分布

调查了１０２名云南阿昌族的ＡＢＯ,ＮＮＳｓ,Ｒｈ和Ｐ系统的红细胞血型,结果表明,阿昌族的基因频率ｐ（０．３８７４）是迄今国内调查过人群中的最高值,Ｅ（０．２４５９）和ＣＤｅ（０．６９３６）基因或染色体频率较高,而Ｓ（０．０６８６）和Ｐ１（０．１０８９）频率较低;Ｍｓ（０．５９５０）连锁率高于Ｎｓ（０．３３５３）;未发现ＳＳ和Ｒｈ（－Ｄ）阴性表现型。     

Analysis of the frequency of inheritance of transposed Ds elements in Arabidopsis after activation by a CaMV 35S promoter fusion to the Ac transposase gene

The Ac/Ds transposon system of maize shows low activity in Arabidopsis. However, fusion of the CaMV 35S promoter to the transposase gene (35S::TPase) increases the abundance of the single Ac mRNA encoded by Ac and increases the frequency of Ds excision. In the experiments reported here it is examined whether this high excision frequency is associated with efficient re-insertion of the transposon. This was measured by using a Ds that carried a hygromycin resistance gene (HPT) and was inserted within a streptomycin resistance gene (SPT). Excision of Ds therefore gives rise to streptomycin resistance, while hygromycin resistance is associated with the presence of a transposed Ds or with retention of the element at its original location. Self-fertilisation of most individuals heterozygous for Ds and 35S::TPase produced many streptomycin-resistant (strep^r) progeny, but in many of these families a small proportion of strep^r seedlings were also resistant to hygromycin (hyg^r). Nevertheless, 70% of families tested did give rise to at least one strep^r, hyg^r seedling, and over 90% of these individuals carried a transposed Ds. In contrast, the Ac promoter fusion to the transposase gene (Ac::TPase) produced fewer strep^rhyg^r progeny, and only 53% of these carried a transposed Ds. However, a higher proportion of the strep^r seedlings were also hyg^r than after activation by 35S::TPase. We also examined the genotype of strep^r, hyg^r seedlings and demonstrated that after activation by 35S::TPase many of these were homozygous for the transposed Ds, while this did not occur after activation by Ac::TPase. From these and other data we conclude that excisions driven by 35S::TPase usually occur prior to floral development, and that although a low proportion of strep^r progeny plants inherit a transposed Ds, those that do can be efficiently selected with an antibiotic resistance gene contained within the element. Our data have important implications for transposon tagging strategies in transgenic plants and these are discussed.     

Directional mutation pressure,mutator mutations,and dynamics of molecular evolution

Using a general form of the directional mutation theory, this paper analyzes the effect of mutations in mutator genes on the G + C content of DNA, the frequency of substitution mutations, and evolutionary changes (cumulative mutations) under various degrees of selective constraints. Directional mutation theory predicts that when the mutational bias between A/T and G/C nucleotide pairs is equilibrated with the base composition of a neutral set of DNA nucleotides, the mutation frequency per gene will be much lower than the frequency immediately after the mutator mutation takes place. This prediction explains the wide variation of the DNA G + C content among unicellular organisms and possibly also the wide intragenomic heterogeneity of third codon positions for the genes of multicellular eukaryotes. The present analyses lead to several predictions that are not consistent with a number of the frequently held assumptions in the field of molecular evolution, including belief in a constant rate of evolution, symmetric branching of phylogenetic trees, the generality of higher mutation frequency for neutral sets of nucleotides, the notion that mutator mutations are generally deleterious because of their high mutation rates, and teleological explanations of DNA base composition. Presented at the NATO Advanced Research Workshop onGenome Organization and Evolution, Spetsai, Greece, 16–22 September 1992     

Chloroplast DNA variation and phylogeny of theRanunculaceae

Restriction site mapping of chloroplast DNA from 31 species representing 26 genera of theRanunculaceae was performed using eleven restriction endonucleases. The chloroplast genome varies in length from approximately 152 to 160 kb. Length variants are frequent in theRanunculaceae and range from usually less than 300 bp to rarely 1.5 kb. The inverted repeat is extended into the large single copy (LSC) region by 4–4.5 kb inAnemone, Clematis, Clematopsis, Hepatica, Knowltonia, andPulsatilla. Several inversions are present in the LSC-region of the cpDNA in all these genera and inAdonis. The frequency of restriction site mutations varies within the chloroplast genome in theRanunculaceae between 4 and 32 mutations per kilobase, and is lowest in the inverted repeat and the regions containing the ATPase-genes and the genespsaA, psaB, psbA, rpoB, andrbcL. A total of 547 phylogenetically informative restriction sites was utilized in cladistic analyses of the family using Wagner, Dollo, and weighted parsimony. These three parsimony analyses result in different tree topologies. Four, six, and one equally most parsimonious trees were obtained with Wagner, Dollo, and weighted parsimony, respectively. The amount of support for the monophyletic groups was evaluated using bootstrapping and decay analysis. All three parsimony methods suggest thatHydrastis is the sister group to the remainder of theRanunculaceae, and that theAnemone-Clematis group, which shares several derived cpDNA rearrangements, is monophyletic. Only a few of the traditional groups in theRanunculaceae are supported by cpDNA restriction side data. Only Dollo parsimony provides support for the hypothesis thatThalictroideae andRanunculoideae are monophyletic.     

Small-scale plant species turnover in a limestone grassland: the carousel model and some comments on the niche concept

Abstract. This study reports on small-scale changes in the distribution of plant species in a 2.5 m² plot of grazed, species-rich Veronica spicata - Avenula pratensis grassland on shallow, dry, nutrient-poor soil in the Great Alvar area (Stora Alvaret) of southern Öland, southeastern Sweden. Multivari-ate analysis of 0.001 m² and 0.25 m² quadrats within the plot showed that there is little floristic variation without any trend in the plot. Average species richness varied little throughout the study period from 1986 to 1991 with 1986 averages of 7.0 on 0.001m², 16.3 on 0.01 m², and 26.1 on 0.25 m². On 0.001 m²the highest species number found was 12, on 0.01 m², 27. However, cumulative species richness, i.e. species number in the first year plus new species appearing in later years (averaged over 40 quadrats) increased over the same period, on 0.001 m² from 7.0 in 1986 to 14.9 in 1991, and on 0.01 m² from 16.3 to 24.1. Cumulative frequency, i.e. number of quadrats out of 40 where a species occurred in the first year or/and in later years, increased as well; the number of cumulatively highly frequent (> 80%) species increased from 5 in 1986 to 18 in 1991. Species mobility on the scale of the small quadrats used implies both appearance and disappearance from these quadrats. Using six examples, species mobility is shown to vary individualistically, both in rate and degree. We postulate that in homogeneous, grazed, nutrient- and water-deficient environments many species can reach virtually all microsites within the plot, which we express through the idea of the ‘carousel model’. We also question the usefulness of the niche concept and re-interpret it by stating that all species of this plant community have the same habitat niche, while most of them are short-lived and have the same regeneration niche. The essential variation amongst the species is their individual ability to establish or re-establish by making use of favourable conditions appearing in microsites in an unknown, complex spatio-temporal pattern.     

高频重复经颅磁刺激联合Brunnstrom分期训练对脑卒中恢复期患者康复效果的影响

摘要 目的：探讨高频重复经颅磁刺激（rTMS）联合Brunnstrom分期训练对脑卒中恢复期患者康复效果的影响。方法：根据随机数字表法将新疆医科大学第一附属医院2020年1月~2022年2月期间收治的脑卒中恢复期患者80例分为对照组（40例,Brunnstrom分期训练）和研究组（40例,高频rTMS联合Brunnstrom分期训练）。对比两组疗效、美国国立卫生研究院卒中量表（NIHSS）评分、功能独立性量表（FIM）评分、生活质量评分、血清神经因子指标[髓鞘碱性蛋白（MBP）、神经元特异性烯醇化酶（NSE）、神经生长因子-1（NGF-1）]。结果：研究组的临床总有效率（92.50%）明显高于对照组（70.00%）（P<0.05）。治疗4周后,研究组MBP、NSE低于对照组,NGF-1高于对照组（P<0.05）。与对照组比较,治疗4周后,研究组NIHSS评分降低,FIM评分升高（P<0.05）。治疗4周后,研究组心理/躯体/物质/社会功能评分较对照组高（P<0.05）。结论：高频rTMS联合Brunnstrom分期训练有助于提高脑卒中恢复期患者的康复效果,同时还可调节血清神经指标,提高生活质量。