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221.
222.
Background
The first microbial genome sequence, Haemophilus influenzae, was published in 1995. Since then, more than 400 microbial genome sequences have been completed or commenced. This massive influx of data provides the opportunity to obtain biological insights through comparative genomics. However few tools are available for this scale of comparative analysis. 相似文献223.
Background
The analysis of biological data is greatly enhanced by existing or emerging databases. Most existing databases, with few exceptions are not designed to easily support large scale computational analysis, but rather offer exclusively a web interface to the resource. We have recognized the growing need for a database which can be used successfully as a backend to computational analysis tools and pipelines. Such database should be sufficiently versatile to allow easy system integration. 相似文献224.
225.
The relation between net dimethyl sulfide (DMS) production and changes in near surface (0-5 mm) oxygen concentrations in a sea grass (Zostera noltii Hornem)-covered intertidal sediment ecosystem was examined during a diel cycle. Sediment covered with Zostera was found to be more oxygenated than uncovered sediment during the period of photosynthesis. This phenomenon was probably caused by radial oxygen loss of the Zostera root-rhizome system. The population sizes of the three functional groups of microbes mainly responsible for the concentration of DMS, the dimethylsulfoniopropionate (DMSP)-demethylating, DMSP-cleaving and DMS-oxidizing bacteria, were quantified by most probable number (MPN) methodologies. Sediments with Zostera supported substantially higher populations of both aerobic (149x10(6) cm(-3) DMSP-utilizing and 0.4x10(6) cm(-3) DMS-oxidizing) and anaerobic (43x10(6) cm(-3) DMSP-utilizing and 0.4x10(6) cm(-3) DMS-oxidizing) microorganisms than sediments without Zostera (DMSP-utilizing aerobes and anaerobes both 2x10(6) cm(-3) and DMS-oxidizing aerobes and anaerobes both 0.2x10(6) cm(-3)). Experiments conducted with sediment cores and sediment slurries suggested that the net production of DMS in these sediments was significantly lower during oxic periods than during anoxic periods. Intact sediment cores with and without Zostera produced DMS when incubated under anoxic/dark conditions (97.0 and 53.6 nmol DMS m(-2) h(-1), respectively), while oxic/light-incubated cores did not produce detectable amounts of DMS. In addition, kinetic parameter values (V(max) and K(m)) for DMSP degradation in cell suspensions of isolated DMSP-demethylating and DMSP-cleaving bacteria were measured and compared to documented values for other strains. Both V(max) and K(m) values for DMSP-demethylating organisms were found to be relatively low (14.4-20.1 nmol DMSP mg protein(-1) min(-1) and 4.1-15.5 μM, respectively) while these parameter values varied widely in the group of the DMSP-cleaving organisms (6.7-1000 nmol DMSP mg protein(-1) min(-1) and 2-2000 μM, respectively). It was hypothesized that a diel rhythm in DMS emission occurred, with a relatively low net production during the day and a high net production during the night. Environmental changes which result in increased anoxic conditions in coastal sediments, such as an increase in eutrophication, may therefore result in increased atmospheric DMS emission rates. 相似文献
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R. A. Zinchenko A. Kh. Makaov V. A. Galkina E. L. Dadali O. V. Khlebnikova G. I. El’chinova L. K. Mikhailova A. V. Marakhonov T. A. Vasilyeva P. Gundorova A. S. Tanas V. V. Strelnikov A. V. Polyakov E. K. Ginter 《Russian Journal of Genetics》2018,54(1):83-90
The paper aims to review the diversity of monogenic hereditary disorders (MHD) in the Circassians of the Karachay-Cherkess Republic (KCR). In total, 50817 Circassians were investigated. The populations of eight districts (Ust-Dzhegutinsky, Karachayevsky, Malokarachayevsky, Prikubansky, Khabezsky, Abazinsky, Nogaysky, and Adyge-Khablsky) and of the city of Cherkessk were studied. Two hundred fifty patients from 167 families were registered. The prevalence of MHD in Circassians happens to be 1: 214. The nosological spectrum of MHD in Circassians includes 70 disorders: 34 with autosomal dominant, 25 with autosomal recessive, and 11 with X-linked inheritance patterns. Confirmatory DNA diagnostics was performed in 56 patients. Accumulation of particular diseases in the Circassian population was revealed in comparison with the previously surveyed ethnic groups/populations of Russia. The cluster analysis was performed on the basis of the prevalence of AD and AR disorders and determined the genogeographic position of the Circassians among eight ethnic groups of Russia (13 populations in total). The total size of the surveyed populations was over 3.5 million people: six Russian regions, Tatars of the Tatarstan, Bashkirs of the Bashkortostan, Chuvashs of the Chuvash Republic, Maris of the Mari El Republic, Udmurts of the Udmurt Republic, Adygeans of the Republic of Adygea, and Circassians of the Karachay-Cherkess Republic. The general pattern for AD and AR diseases was similar: six Russian populations group within a single cluster, being remote from people of the Volga-Ural region and the North Caucasus (Adyghe: Adygeans and Circassians). 相似文献
228.
R. A. Zinchenko A. Kh. Makaov V. V. Kadyshev V. A. Galkina E. L. Dadali M. F. Shurygina G. I. El’chinova L. K. Mikhailova A. V. Marakhonov T. A. Vasilyeva N. V. Petrova P. Gundorova A. S. Tanas V. V. Strelnikov A. V. Polyakov E. K. Ginter 《Russian Journal of Genetics》2018,54(6):703-711
This paper estimates the load and nosological spectrum of monogenic hereditary diseases (HDs) in Abazins of the Karachay-Cherkess Republic (KChR), identified in Cherkessk and ten districts, Abazinsky, Ust-Dzhegutinsky, Malokarachaevsky, Karachaevsky, Prikubansky, Khabezsky, Nogaysky, Adyge-Khablsky, Urupsky, and Zelenchuksky. The number of the investigated population was 387231 individuals (including 33264 Abazins). We detected 153 patients from 105 families with 45 nosological forms of HDs: 83 patients from 50 families with 23 AD diseases, 47 patients from 42 families with 15 AR diseases, and 23 patients from 13 families with 7 X-linked diseases. The total load of HDs in Abazins was 1: 218 individuals (in the rural population 1: 162, in the urban population 1: 305). Frequent and rare nosological forms of HDs and the accumulation of certain diseases in Abazins in comparison with the previously surveyed populations of Russia were determined. On the basis of the prevalence of AD and AR hereditary diseases, a principal component analysis was carried out, which determined the genogeographical position of Abazins among nine ethnic groups (13 populations) of Russian Federation: six Russian regions, Bashkirs of the Bashkortostan, Tatars of the Tatarstan, Chuvashes of the Chuvashia, Maris of the Mari El, Udmurts of the Udmurtia, Adygeans of the Adygea, and Circassians and Abazins of the KChR. 相似文献
229.
为进一步阐明盐生植物白刺耐盐性与多胺的关系,通过水培试验研究了叶面喷施亚精胺(Spd)对不同浓度NaCl胁迫下西伯利亚白刺幼苗叶片丙二醛(MDA)和超氧阴离子(O2)产生速率,以及抗氧化物酶系统和根系活力的影响.结果表明:叶面喷施0.1 mmol·L1 Spd 5 d后,可显著提高100和200 mmol·L1 NaCl胁迫下白刺幼苗叶片超氧化物歧化酶(SOD)、过氧化物酶(POD)和过氧化氢酶(CAT)的活性以及根系活力,降低了叶片MDA含量和O2的产生速率;而在0、50、300 mmol·L-1 NaC1处理下,外施Spd对白刺幼苗叶片上述指标无显著影响.研究结果证实,在100~200 mmol·L-1 NaCl胁迫范围内,外施亚精胺可能通过增强体内保护酶活性来显著降低活性氧水平,有效减轻盐胁迫对盐生植物白刺幼苗造成的过氧化伤害,从而增强白刺对盐环境的适应性. 相似文献
230.
报道了豆科Leguminosae昆仑岩黄耆Hedysarum krassnovii B.Fedtsch.在中国的分布。昆仑岩黄耆与近缘种红花岩黄耆H.multijugum Maxim.形态易混淆,但以其小叶3-9×3-7mm;旗瓣倒卵形,顶端凹陷约2mm深;翼瓣狭披针形;龙骨瓣近半圆形或矩圆形;花萼二唇彤;荚果具1-2节荚等性状易于区分。另外,此二种的物候期、生境及地理分布亦有区别。 相似文献