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略论棕榈科与新分出的省藤科的系统分类、演化、区系地理及主要的经济用途 总被引:6,自引:0,他引:6
棕榈科原省藤亚科因其子房壁及外果皮被倒生、螺旋状排列的鳞片所覆盖,而区别于其他亚科,因而独立分出成一新科--省藤科。作者讨论了棕榈科的祖先种可能在石炭纪时,自原始裸子植物开以顿目在分化、衍生出苏铁目祖先种的进化干上,于白垩纪时分化出的一个分支。在棕榈科的祖先种出现不久后,在其进化的分支上,于白垩纪后期又分化出一旁支,成为棕榈科的姊妹科--省藤科的祖先种。从两祖先种分别再分化、衍生出现今分布地球上该二科的属与种。两科、尤其前者是被子植物、尤其是单子叶植物中最原始的类群之一。作者还提出棕榈科象牙椰亚科与贝叶棕亚科是该科最原始或较原始的两类群;槟榔亚科和腊材榈亚科是较进化的两类群;而水椰亚科祖先种可能源于象牙椰亚科的祖先种,但又演化为该科最进化与特化的类群。省藤科省藤亚科略比鳞果榈亚科原始。作者讨论了两科为泛热带分布的科,指出两科的"现代分布区"在南北两半球热带地区,少数种还延伸分布到两半球暖亚热带、甚至达中亚热带地区,分布区边缘最北达日本中部、中国长江流域及黄河下游的南部,美国加利佛尼亚州与佛罗里达州和地中海北部;最南达智利中部和新西兰南部;而"现代分布中心"在热带与暖亚热带的亚洲,中、南美洲,大洋洲及非洲的东、南、西部;但分布区的"密集中心"则在热带亚洲、热带中及南美洲、南太平洋群岛及非洲东南部。作者还介绍了近50年我国南方引种驯化成功的两科植物近400种(见*图谱),其中少数为耐寒的种类,有的种已引种到长江流域或更北的地区。引种的大部分种都有其重要的经济用途,包括:1. 食用,如淀粉和树液可制"西米"或制糖,酿酒、醋或作饮料;果或种子榨油,供食用或工业用;某些种的嫩芽作蔬菜,甚至种子代咖啡饮用;2. 药用,有消炎、止血、活血、驱虫、抗癌等用;3. 建筑、工艺与日用品,包括不少种的树干供建普通房子、桥梁、小船;少数种可提制工业用蜡;许多种的纤维制高级缆绳和编织品;还制工艺品与日用品等;4. 代表热带景观的园林工程、绿化及美化环境的观赏树和人行道树及建造园林景观生态类型的树种等。 相似文献
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1. In each stage of the differentiation of the growing cones of these two varieties of wheat, their morphological characters are the same as of the general wheat, their fourth stage being the sign of the beginning of their reproductive structures. 2. The sequence of the differentiation in the development of spikelets is as follows: first the outer glume, then the inner glume, the lemma of the first flower, the primordium of the first flower, the lemma of the second flower and finally the primordium of second flower, etc.; while it is the palea, the stamens, the pistil and the lodicules for the flower part. 3. The differentiations of the primordiums of stamens and pistil start at the same time as the appearance of the awn. 4. It was found that in Kansu 96 the rate of the differentiation of the growing cones is more rapid, its volume bigger, the number of its spikelets and flowers, the chance of fruitification and its yield higher, than those of Yu-Chung-Hung, but the average individual weight of the grain is lower than that of the latter. 5. The rate of the differentiation of the growing cones will be slowed, and the numbers of spikelets, flowers and grains increased if a high moisture content of soil is present. The shape of the spike is grand and close under irrigation, but under drought it is slender and soft. Although the yield of Yu-Chung-Hung is lower than that of Kansu 96, but it appears to have a higher hydronasty than the latter. 6. It was shown in our investigation that the Kansu 96 appears to be of drought resistance. 7. Under normal conditions and in the same variety, the appearances of the leaf and the node of the stem, and the developmental phases of plants may be suggested as an indication of the differentiation of the growing cones. It is recommended that they can be used as a field crop. 相似文献
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Mt. Wuyi, located at 27°37‛-27°54‛ N, 117°27‛-117°51‛ E, is the highest mountain
in South-East China. Its main peak, Huanggangshan, is 2158 m above the sea level. In 1955, P.
C. Chen organized the first expedition to Mt. Wuyi, and the authors investigated the different
ravines and the forests of that area in 1976 and from 1979 to 1984 respectively. Up to now
355 species of the bryophytes have been found in Mt. Wuyi.
I. The influence of the factors of geological history on the bryoflora of Mt. Wuyi
Fujian Province, belonging to Cathaysian, one of three Chinese ancient lands, was a part
of ocean until the end of the lower Tertiary. In the early Devonian, Fujian uplifted above the
sea level, but it submerged in the sea later, and then uplifted above the sea level again in the
upper Triassic.
By the end of the lower Triassic the Himalayan movement influenced the paleogeography
of China deeply, and the eastern and central mountains of Fujian uplifted again. In the Tertiary, Fujian was influenced by the hot maritime weather, so the tropical evergreen forests existed
in southern Fujian at that time. The conclusion was made by Z. B. Zhao in 1983 after his long
period of study on geological history of Fujian Province since the Yanshan movement.
According to the morden geographical distribution of Chinese bryophytes, it seems that the
above influence might be related to the bryophytes of Mt. Wuyi and also the southern part of
Zhejian Province. By the end of the Tertiary the weather became cold in most parts of China.
Since then the cold weather and hot weather alternated several times. One kind of the endemic elements of the bryoflora formed in the area from the south-eastern coast of China to the
southeastern Xizang (Tibet), including Japan. They are not specialized at the family level or
closely related to each other, but they have similar distribution and belong to different families.
In the Quaternary, Mt. Wuyi gradually uplifted following the Himalayan movement. As the
weather cooled down in the upper part of the mountain, deciduous broad-leaved and needleleaved trees increased there. Meanwhile, temperate genera and species of the bryophytes spread and
invaded South China and entered Mr. Wuyi. Rhytidiadelphus and Hvlocomium probably began to grow in Mt. Wuyi at that time, and their distribution is quite different from their primary one. On the other hand, a part of tropical and subtropical bryophytes might enjoy the
changed weather and environment in the Quaternary and existed in a few small localities of Mt.
Wuyi, and the genera Haplomitrium, Endotrichella and Floribundaria are probably their representatives. From the point of view of geological history we are now living in the interglacial
period and the present natural conditions will last continuously, so they will steadily influence
the bryoflora of Mt. Wuyi in a long period of time.
2. Essential characteristics of the bryoflora in Mt. Wuyi
Due to the geographical position and the other factors of Mt. Wuyi the bryoflora is represented by numerous tropical and subtropical elements (34.1%), but the East-Asiatic endemic ones
(79.2%) are characteristic of the bryoflora in Mt. Wuyi (Tab. 1). The tropical and subtropical
families of the bryophytes, found south of Changjiang (Yangtzi) River, are Haplomitriaceae (1
genus, 3 species), Porellaceae (2 genera, 8 species), Frullaniaceae (2 genera, 10 species), Lejeun eaceae (21 genera, 35 species), Trachypodaceae (3 genera, 4 species), Meteoriaceae (10 genera, 17
species), Neckeraceae (5 genera, 8 species) and Hookeriaceae (3 genera, 3 species). The above
8 families, including 46 genera and 85 species, represent about 1/4 genera (24.3%) and less than
1/4 species (23.9%) of the bryoflora of Mt. Wuyi.
Most species of East-Asiatic elements show very close relationships with Japan, and are
widely distributed from the low altitude of Mt. Wuyi to the summit of Mt. Huanggangshan.
However, the Holarctic species (26.8%) are also important elements of the bryoflora in Mt.
Wuyi, showing its transition nature, although it is located in the subtropics. Moreover, the in fluence of the Himalayas also exists in Mt. Wuyi, and the Himalayan elements cover 14.4% in
the bryoflora of Mt. Wuyi. The similarity coefficients between the bryofloras of Central and
South America, Africa and Oceania and that of Mt. Wuyi are from 5.0-9.2% respectively. The
endemic species are not very many and cosmopolitan species are only 7 there.
In 1958, P. C. Chen designated Mt. Wuyi as “the transition region of South and North
China rich in East-Asiatic genera and species”. His very important conclusion is essentially in
accordance with the fact of the bryoflora on Mt. Wuyi. Recently, some of the new records fur ther show the characteristics of the bryoflora in Wuyi. Two facts are worth being mentioned.
One is that East-Asiatic genera are only five in Mt. Wuyi. However, there are 9 East-Asiatic
genera in Mt. Huangshan more than in Mt. Wuyi; 4 East-Asiatic genera are recorded in Mt.
Shennongjia. The other is that epiphyllous liverworts in Mt. Wuyi, consisting of 7 families, 21
genera and 36 species, are less than on Hainan Island and Xishuangbannan, located in the tro pics in China.
3. Comparison between the bryoflora of Mt. Wuyi and those of the neighbouring regions
As China covers a very large area, bryofloristic elements are quite different in the diffe rent regions. In this section, we are concentrated on making a comparison between the bryof loras of Mt. Wuyi and the regions belonging to the Central China of the bryoflora named by
P. C. Chen.
Huaping Forest Region, Guangxi Zhuang Autonomous Region in South China, with both
latitute and altitude very similar to Mt. Wuyi, is included in this comparison (Fig. 1). According to the rough estimation, the similarity coefficient of moss genera between Mt. Wuyi and
Huaping is 56.3%, and those between the mountain and southern Zhejian and Mt. Huangshan,
Anhui, are 62.7% and 51.6% respectively, while the similarity coefficient of the genera of the
mossfloras between Mt. Shennongjia and Mt. Wuyi is 46.8%. Table 2 shows the statistics of
mosses in Mt. Wuyi and the others, but the bryoflora of Huaping needs further study However,
it is very interesting to note that Haplomitrium and Pleurozia of liverworts are both found in
Mt. Wuyi and Huaping Forest Region, and the similarity coefficient between the mossfloras of
Mt. Wuyi and Zhejian Province is also higher than those mentioned above.
Tropical and subtropical elements reduce towards the north in China, and temperate ones
increase. Huaping is located in the south, and, as expected, some tropical and subtropical
genera such as Hookeriopsis and Symphyodon have been found there, but not in Mt. Wuyi; several
temperate genera, such as Schwetschkeopsis and Fauriella, have been recorded in Mt. Huangshan,
but not in Mt. Wuyi. For some unknown reasons, Octoblepharum and Neckeropsis are only
found in southern Zhejiang, but not in Mt. Wuyi. Mt. Shennongjia, with its main peak over
1000 m higher than that of Mt. Wuyi, is located in its northwest, and more than ten temperate
genera, such as, Ceratodon, Aulacomnium Myurella, Bryonoguchia and Abietinella have been
found there.
Generally, Mt. Wuyi belongs to the central subtropical region of China, and East-Asiatic
endemic genera are the main elements of its bryoflora, but the bryoflora also consists of tropical and subtropical elements with some temperate ones.
4. East-Asiatic endemic genera in the bryoflora of Mt. Wuyi
In the bryoflora of Mt. Wuyi, one of the main elements, East-Asiatic endemic genera, should
not be neglected (Tab. 4). East-Asiatic endemic genera in Mt. Wuyi (five) are less than in Mt.
Huangshan and Mt. West Tianmu, although the positions of the latter two are very close to Mt.
Wuyi. East-Asiatic endemic genera of liverworts are Trichocolea and Macvicaria so far found
in Mt. Wuyi, and the mosses are Myuriopsis, Meteoriella, Pseudospiridentopsis (Fig. 1). Myuriopsis is only distributed in Taiwan Province and Mt. Wuyi, and the other four are distributed in Mt.
Huangshan or Mt. West Tianmu, and also in Taiwan, besides in Mt. Wuyi. About thirty EastAsiatic endemic genera have so far been known in China, which means that about one sixth of
East- Asiatic endemic genera of the bryophytes occur in Mt. Wuyi. We may notice that nine
and seven East-Asiatic endemic genera of the bryophytes have been recorded in Mt. Huangshan
and Mt. West Tianmu respectively. In Mt. Shennongjia, Central China, there are four East
Asiatic endemic genera, but only two have been found in the Huaping Forest Region, South
China. In Mt. Dinghua, located south of Mt. Wuyi, on East-Asiatic endemic genus of the bryophytes has so far been found.
East-Asiatic endemic genera of the bryophytes are mainly limited to China, Korea and Japan,
including the East Himalayas, rarely occur in South Asia, Siberia of the Soviet Union. Therefore,
these genera enjoy a warm and moist environment. In Mt. Wuyi, all the East-Asiatic endemic
genera are monotypic ones with a disjunct distribution. Now in Taiwan Province five of six
recorded East-Asiatic endemic genera are common to Mt. Wuyi. In Japan, about eleven, i.e.
one third of, East Asiatic endemic genera so far found are common to China, which shows a
long history of the phytogeographical relationships between Japan and China. East Asiatic endemic genera of the bryophytes might therefore exist on islands of Taiwan Province and Japan
before they were separated from the mainland of Asia. However the fossil evidence is still
lacking in the bryophytes, so we are not able to discuss about the distribution area and the distribution center of the East-Asiatic bryoflora in detail. The above estimation is more or less
related to geological history, and we assume that the East-Asiatic endemic genera have existed at
least since the end of the Tertiary. Starting from the Quaternary, the climatic change during
glacial epoch has been possibly the most important factor affecting the bryoflora in Asia, and
the upheaval of the Himalayas has stimulated the diversity and the specialization of the bryophy tes. Considering these factors, East-Asiatic endemic genera might be the “Tertiary fossil
plants”.
Another problem is difficult to explain, because Mts. Huangshan, West Tianmu and Shen nongjia were once influenced by glaciation directly, although Chinese geologists hold different
views. However, no evidence of glaciation has been found in Mt. Wuyi. It is worth to study the
close relationships between Mt. Wuyi, Mt. Huangshan and Mt. West Tianmu, where is the distri bution center of the East-Asiatic endemic genera. The above three mountain regions share half
of the East-Asiatic endemic genera, and about 32% genera of the others are found in two of
them (Fig. 2). Myuriopsis, one of the East Asiatic types, was only recorded in Taiwan Pro vince, Japan and Korea. Neodolichomitra, occuring in Taiwan Province, is endemic to China.
More or less the differentiation has taken place in Mt. Huangshan, Mt. West Tianmu and Mt.
Wuyi. The number of the East-Asiatic endemic genera is smaller in Mt. Wuyi, so it is possibly
located on the border of the distributional center of the East-Asiatic endemic genera. Moreo ver, three of four East-Asiatic endemic genera in Mt. Shennongjia are also found in Mt. Huang shan and Mt. West Tianmu, but the other East-Asiatic genus in Mt. Wuyi is common to the
mountain areas in SW China, the Qinglin Range of NW China, and the isolated mountain areas
of NE China. Considering all the characteristics of the bryoflora of Mt. Shennongjia, we assume
that Mt. Shennongjia may belong to another distribution center, including SW part of Sichuan
Province, and the other neighbouring mountains. 相似文献
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C. J. Tsai S. Kumar B. Ma R. Nussinov 《Protein science : a publication of the Protein Society》1999,8(6):1181-1190
Folding funnels have been the focus of considerable attention during the last few years. These have mostly been discussed in the general context of the theory of protein folding. Here we extend the utility of the concept of folding funnels, relating them to biological mechanisms and function. In particular, here we describe the shape of the funnels in light of protein synthesis and folding; flexibility, conformational diversity, and binding mechanisms; and the associated binding funnels, illustrating the multiple routes and the range of complexed conformers. Specifically, the walls of the folding funnels, their crevices, and bumps are related to the complexity of protein folding, and hence to sequential vs. nonsequential folding. Whereas the former is more frequently observed in eukaryotic proteins, where the rate of protein synthesis is slower, the latter is more frequent in prokaryotes, with faster translation rates. The bottoms of the funnels reflect the extent of the flexibility of the proteins. Rugged floors imply a range of conformational isomers, which may be close on the energy landscape. Rather than undergoing an induced fit binding mechanism, the conformational ensembles around the rugged bottoms argue that the conformers, which are most complementary to the ligand, will bind to it with the equilibrium shifting in their favor. Furthermore, depending on the extent of the ruggedness, or of the smoothness with only a few minima, we may infer nonspecific, broad range vs. specific binding. In particular, folding and binding are similar processes, with similar underlying principles. Hence, the shape of the folding funnel of the monomer enables making reasonable guesses regarding the shape of the corresponding binding funnel. Proteins having a broad range of binding, such as proteolytic enzymes or relatively nonspecific endonucleases, may be expected to have not only rugged floors in their folding funnels, but their binding funnels will also behave similarly, with a range of complexed conformations. Hence, knowledge of the shape of the folding funnels is biologically very useful. The converse also holds: If kinetic and thermodynamic data are available, hints regarding the role of the protein and its binding selectivity may be obtained. Thus, the utility of the concept of the funnel carries over to the origin of the protein and to its function. 相似文献
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基于构件理论,采用灰色关联度分析技术,对四川缙云山1989年风灾迹地林窗内大头茶(Gordoniaacumenata)幼苗种群构件结构及其与环境因子的关系进行了研究。结果表明,四川缙云山大头茶幼苗种群构件结构主要分为一级枝、二级枝、当年生枝、空间结构、叶片等几大部分,分别可以以一级枝数或茎粗或长度、二级枝数或基粗或长度、当年生枝数、3年生一级枝数、总叶数等的变化特征来表达其动态特点。前四者间的相关性亦很高,后者(包括主茎上叶面积)和主茎上第一一级枝离地面高、主茎上第一叶距地高为比较稳定的特征,受其它生态因子作用影响不十分显著。相对而言,土壤全N、全P、全K、有机质含量及其pH值是比较关键的环境因子;而海拔高度和林自大小及地形坡度却比较次要。灰色关联度分析不失为一种比较简捷而有效的分析植物种群构件结构特征间及与环境因子间关系的方法。关键词 相似文献
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国家大型煤电基地生态环境监测技术体系研究——以内蒙古锡林郭勒盟煤电基地为例 总被引:2,自引:0,他引:2
随着我国煤电基地建设进程的不断加快,煤电基地建设与开发活动引起的环境问题也日趋严重。了解生态环境质量现状,评估其对生态系统与人民健康水平的影响,制定合理的保护、治理、恢复策略是煤电基地环境保护工作的重中之重,而生态环境监测是解决上述问题的基础。然而,现有的监测技术体系普遍存在自动化水平较低、成本较高、时空覆盖面较低等问题。鉴于物联网技术在提高信息采集效率和改善信息获取方式方面的作用日益显著,所以将物联网技术应用于煤电基地生态环境监测,从感知层、传输层、支撑层、应用层、用户层的角度明确生态环境监测技术体系,为解决上述问题提供有效途径。 相似文献
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基于构件理论,采用灰色关联度分析技术,对四川缙云山1989年风灾迹地林窗内大头茶(Gordonia acumenata)幼苗种群构件结构及其与环境因子的关系进行了研究。结果表明,四川缙云山大头茶幼苗种群构件结构主要分为一级枝、二级枝、当年生枝、空间结构、叶片等几大部分。分别可以以一级枝数或茎粗或长度、二级枝数或茎粗或长度、当年生枝数、3年生一级枝数、总叶数等的变化特征来表达其动态特点。前四者间的相关性亦很高,后者(包括主茎上叶面积)和主茎上第一级枝离地面高、主茎上第一叶距地高为比较稳定的特征,受其它生态因子作用影响不十分显著。相对而言,土壤全N、全P、全K、有机质含量及其pH值是比较关键的环境因子;而海拔高度和林窗大小及地形坡度却比较次要。灰色关联度分析不失为一种比较简捷而有效的分析植物种群构件结构特征间及与环境因子间关系的方法。 相似文献
11.
Phylogenetic analysis of Adephaga (Coleoptera) based on characters of the larval head 总被引:5,自引:0,他引:5
R. G. BEUTEL 《Systematic Entomology》1993,18(2):127-147
Abstract. Characters of the head of adephagan larvae were examined and analysed phylogenetically. A labrum which is completely fused to the clypeofrons and the presence of a closed prepharyngeal tube are autapomorphies of Adephaga. Partial reduction of the fossa maxillaris, cardo and stipes forming a functional unit, the immobilization of the lacinia, attachment of M. craniolacinialis to the lateral stipital wall, and loss of one stipitopalpal muscle, are considered autapomorphies of Adephaga excluding Gyrinidae. Complete reduction of the fossa maxillaris and the presence of M. craniostipitalis medialis are possible autapomorphies of Adephaga excluding Gyrinidae and Haliplidae. The presence of caudal tentorial arms, insertion of the galea on the mesal side of palpomere I, and absence of the lacinia are considered synapomorphies of Trachypachidae and Dytiscoidea (Noteridae, Amphizoidae, Hygrobiidae, Dytiscidae). The presence of a slender, elongated process of the head capsule, which articulates with a corresponding socket of the cardo, is a possible autapomorphy of Dytiscoidea. The sinuate frontal sutures, distinctly protruding prementum, shortened M. craniostipitalis medialis, and absence of M. submentopraementalis are considered autapomorphies of Geadephaga excluding Trachypachidae. The presence of a regular row of hairs along the anterior hypopharyngeal margin is a possible autapomorphy of Geadephaga excluding Trachypachidae and Rhysodidae. Improvement of the hypopharyngeal filter apparatus suggests the monophyly of Anisochaeta. Presence of a penicillum and partial reduction of the lacinia are possible autapomorphies of Anisochaeta excluding Omophronini. Larvae of Cychrini, Carabini, Nebriini and Notiophilini are characterized by a strongly developed, cone-shaped hypodon. Postocular and cervical ridges, crosswise arrangement of antennal muscles, and a completely flattened hypopharynx are considered autapomorphies of Caraboidea Limbata. 相似文献
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扶桑绵粉蚧的过冷却点和体液结冰点测定 总被引:5,自引:0,他引:5
本文测定了扶桑绵粉蚧Phenacoccus solenopsis Tinsley除卵期以外其它各虫态的过冷却点和结冰点.结果表明,该虫过冷却点以1龄若虫最低,为-24.02℃;雄虫预蛹次之,为-22.13℃;雄虫蛹、雄虫2龄若虫、雌虫3龄若虫、雄成虫、雌虫2龄若虫、雌成虫过冷却点逐渐升高,分别为-21.08℃、-20.25℃、-19.05℃、-18.42℃、-17.91℃、-16.89℃.体液结冰点也以1龄若虫最低,为-23.2℃;雄虫预蛹次之,为-19.09℃;雄虫蛹、雄虫2龄若虫、雌虫3龄若虫、雌虫2龄若虫、雌成虫、雄成虫体液结冰点逐渐升高,分别为-16.64%、-15.81℃、-13.92℃、-13.20℃、-12.85℃、-12.79℃.试验结果表明扶桑绵粉蚧过冷却点低,耐寒性较强,可能适宜在中国北部更广泛的区域生存. 相似文献
13.
The results of the analysis of the literature data on the ethnic distribution of xenobiotic biotransformation phenotypes and on tumor incidence (for all organs in total) are presented from the standpoint of the concept by L.A. Piruzyan [1]. For a number of ethnic groups, a possibility is theoretically shown of the metabolic populational in vivo construction of tumors (depending on the genetically determined metabolic status of certain populations), i.e., of the ethnic dependence of tumors. In the American population, the higher incidence of the slow acetylation phenotype than in Swedes and in the Chinese was associated with the higher incidence of morbidity. In populations of the English, the Germans, the Swedes, and the Swiss, characterized by a low incidence of the slow acetylation phenotype, the tumor morbidity was higher than in the Chinese with a higher incidence of slow acetylators. Americans are more predisposed to tumors than the Swedes. Caucasoids with either the slow or the fast acetylation phenotype are more predisposed to tumors than the Chinese. The prevalence of the fast acetylation phenotype in the Chinese and Japanese populations was associated with the lower cancer morbidity: in the Chinese compared to Australians, Danes, Swedes; in the Japanese compared to Australians, Americans, the English, Danes, Canadians, the German, the Portuguese, Finns, Czechs, and Slovaks. The lower incidence of the slow acetylators in the Chinese than in Americans, English, Danes, Canadians, Germans, Finns, Czechs, Slovaks, and Swedes was associated with a lower rate of morbidity. In the Portuguese, the higher incidence of fast acetylators than in Danes and the lower incidence of slow acetylators than in Czechs, Slovaks, and Afro-Americans was associated with the lower rate of morbidity. In the Hong Kong and Singapore Chinese with the lower incidence of slow acetylators than in the Madras Negroids, the morbidity was higher. In Australians and Swedes, the greater fraction of slow acetylators was associated with a lower morbidity than in Afro-Americans. In the Russian population of St. Petersburg, the higher incidence of slow acetylators was associated with the lower morbidity compared to the Hong Kong Chinese. Among Poles, the slow acetylator incidence was higher and the morbidity was lower than in the Portuguese. The Japanese and the Chinese (fast acetylators) are less predisposed to cancer than the above-listed Caucasoids; among Caucasoids, the Portuguese (fast acetylators) were less predisposed to cancer than the Danes, Czechs, Slovaks, and Afro-Americans. The tumor predisposition of the Hong Kong and Singapore Chinese was higher than the predisposition of the Madras Negroids. Australians, Russians (St. Petersburg residents), and Poles were less predisposed to cancer than Afro-Americans, the Hong Kong Chinese, and the Portuguese. The morbidity of the Madras Negroids with the higher incidence of the slow acetylation phenotype was lower than the morbidity of the Hong Kong and Singapore Chinese. The incidence of the slow acetylation phenotype in Afro-Americans was lower than in the Australians and Swedes and higher than in the Portuguese, Chinese, and Japanese; this was associated with the higher cancer morbidity, i.e., with the increased predisposition to tumors. The lower incidence of the T1-0 phenotype of glutathione-S-transferase in the English than in the Singapore and Shanghai Chinese and in the Japanese was associated with the higher morbidity of the English. In the Singapore Chinese, the higher incidence of the M1-0 and of T1-0 phenotypes of glutathione-S-transferase than in the Japanese was associated with the increased morbidity. In some populations, different morbidities were associated with similar incidences of one or another metabolic phenotype, or different phenotype incidences in different populations were associated with similar morbidities. The morbidity under consideration did not include chemical carcinogenesis, i.e., the conversion of procarcinogens to true carcinogens or the carcinogen inactivation. Because the results presented are preliminary, this article outlines the directions of theoretical studies that are required for definite conclusions concerning the ethnic dependence of tumors. 相似文献
14.
赤松毛虫越冬幼虫生化物质变化与抗寒性的关系 总被引:12,自引:2,他引:12
昆虫的抗寒性与其体内生化物质的种类、含量密切相关。测定了赤松毛虫(Dendrolimusspectabilis)越冬幼虫体内和血淋巴内抗寒物质含量的变化,结果表明,血淋巴内小分子碳水化合物总量1月份为10月份的3.8倍,其中以葡萄糖、海藻糖和山梨醇增加幅度较大,依次为10月份的10.08倍、2.84倍、7.44倍。3月份有较大幅度的下降,虫体内糖原含量下降了56.5%。越冬期苏氨酸、丝氨酸、谷氨酸、丙氨酸、胱氨酸增加幅度较大,分别比越冬前增加了493.8%、433.7%、474.2%、21.5%和47.1%,甘氨酸、天门冬氨酸、蛋氨酸、亮氨酸、酪氨酸、苯丙氨酸、组氨酸、精氨酸、脯氨酸含量则有较大幅度的降低。越冬幼虫体内脂肪含量下降,蛋白质含量上升。应用蛋白质垂直平板电泳法对糖蛋白进行电泳分析发现糖蛋白含量增加,为越冬前的300%。综合分析认为赤松毛虫越冬幼虫体内抗寒物质系统为小分子碳水化合物类(山梨醇、海藻糖、葡萄糖)-糖蛋白-氨基酸类(丙氨酸、苏氨酸、谷氨酸等)。该系统可随生态条件的改变而变化。 相似文献
15.
研究沿用不可转移生态足迹反映旅游城镇化地区所承受的生态压力,利用偏最小二乘法构建足迹与驱动因子之间的回归模型,并通过构建驱动指数模型,比较各驱动因素对不可转移生态足迹变化的贡献。以张家界为案例地,研究旅游城镇化各阶段足迹演变及驱动规律。研究结果显示:(1)旅游城镇化地区不可转移生态足迹、人均不可转移生态足迹总体上呈现出平缓增长的动态变化,发展能力具有不稳定性。对外开放程度的提高,并不能抑制足迹的增长。在不控制生产总量的情况下,资源生产效率的提高会带来更多的不可转移足迹。(2)各因素对人均不可转移生态足迹影响的弹性系数由大到小分别为城镇居民人均可支配收入、第二产业增加值、城镇化率、第三产业增加值、资源生产效率、城市建设用地、第一产业增加值、旅游人口密度。产业内部结构会影响产业增加值对人均不可转移足迹的弹性系数。(3)旅游城镇化初级阶段,不可转移生态足迹增加,最主要的驱动因素是第二产业增加值、旅游人口密度、第三产业增加值;旅游城镇化高级阶段,不可转移生态足迹增加,最主要的驱动因素是第三产业增加值、第二产业增加值、第一产业增加值。建议如下:在旅游城镇发展的初级阶段,合理推进城镇化进程,控制旅... 相似文献
16.
Babesia gibsoni multiplies well in canine red blood cells (RBCs) containing high concentrations of potassium (HK), reduced glutathione, and free amino acids as a result of an inherited high Na,K-ATPase activity, i.e., HK RBCs. To determine the role of Na,K-ATPase in the multiplication of B. gibsoni, the effect of ouabain on the proliferation of the parasites in HK RBCs was investigated. To determine the direct effect of ouabain on the parasites, the proliferation of the parasites in normal canine RBCs containing low potassium (LK) and high sodium concentrations, i.e., LK RBCs, which completely lack Na,K-ATPase activity, was observed. Ouabain at 0.1 mM significantly suppressed the multiplication of B. gibsoni in HK RBCs in vitro, whereas it had no effect on the parasites in LK RBCs. The results suggest that the multiplication of B. gibsoni in HK RBCs depends mainly on the presence of Na,K-ATPase in the cells. Therefore, the effects of ouabain on the intracellular cation and free amino acid composition of the HK RBCs were examined. In HK RBCs incubated with ouabain, a marked decrease in the concentration of potassium and an increase in sodium were observed, together with a decrease in the number of parasitized cells. These results suggest that the intracellular cation composition maintained by Na,K-ATPase might be advantageous to the parasites. Moreover, the concentrations of some free amino acids, i.e., asparagine, aspartate, glutamate, glutamine, glycine, and histidine, were markedly decreased in HK RBCs incubated with ouabain. Decreased concentrations of the free amino acids induced by inhibition of Na,K-ATPase seemed to affect the multiplication of B. gibsoni in HK RBCs. Based on these results, it is clear that the high Na,K-ATPase activity in HK RBCs contributes to the proliferation of B. gibsoni by maintaining high potassium and low sodium concentrations, as well as high concentrations of some free amino acids in the cells. 相似文献
17.
An electrocorticographic method of recording after-potentials in response to electrical stimulation of the thalamic nuclei in limbic structures during stereotaxic operations was developed. Altogether 42 patients undergoing operations for subcortical hyperkinesia, pain syndromes, and Kozhevnikov's epilepsy were investigated. The character of the cortical after-discharges in response to stimulation of the ventro-oral nuclear complex (V.o.) and the centrum medianum (Ce) of the thalamus and the amygdala differs in its character. These differences affected the area of spread of after-synchronization of the slow rhythms in regions of the hemispheres, the duration of the bursts of after-activity, and the expression of the accompanying autonomic responses. During the after-response to electrical stimulation of V.o. a relatively local after-synchronization of the slow rhythms in the ECoG was observed in the premotor area on the side of stimulation. The off-response to electrical stimulation of Ce, by contrast with V.o. was bilateral synchronization of the slow rhythm, coinciding in some cases with the appearance of bradypnea, bradycardia, and vasomotor and pilomotor responses. The most marked autonomic responses, associated with long volleys of after-hypersynchronization of slow waves or epileptoid discharges, were observed after stimulation of the amygdala. Problems connected with the mechanisms of after-synchronization of the cortical rhythm and the role of the various thalamic and limbic structures in these mechanisms are discussed.N. N. Burdenko Institute of Neurosurgery, Academy of Medical Sciences of the USSR, Moscow. Translated from Neirofiziologiya, Vol. 5, No. 3, pp. 227–235, May–June, 1973. 相似文献
18.
截至2021年底, 中国共记载591种两栖类(不包括外来入侵种), 是世界上两栖类物种数最多的国家之一。物种特征影响和决定了物种在环境中的生存能力, 在进化生物学、生态学和保护生物学研究中具有重要作用。目前, 中国两栖类在线数据库(https://www.amphibiachina.org )已经整理了我国两栖类的形态特征、生物学信息和地理分布等部分物种特征, 但仍缺乏一个完整的、可自由检索的数据集。通过系统查阅文献和数据检索, 本文收集整理了中国全部591种本土两栖类的22个特征数据, 包括物种发现时间(最早发现和描述新物种文章的发表时间)、模式产地、中国受威胁等级、全球受威胁等级、致危因子、是否中国特有种、是否岛屿特有种、雄性体长、雌性体长、窝卵数、卵径、产卵地点、幼体主要生境、成体微生境、活动模式、生殖周期、繁殖时间、是否有亲本照顾、受精方式、海拔范围、分布地区、分布省份数。除了物种发现时间、是否岛屿特有种、分布地区、分布省份数外, 其余特征数据都有不同程度的缺失, 数据完整度为27.92%-100%, 平均完整度为71.72%, 标准差为24%。本数据集是目前我国两栖类最新和最全的物种特征数据库, 希望可以为我国两栖类生态学、保护生物学、生物地理学等研究提供数据支持。 相似文献
19.
David W. Barnes Ph. D. Dr. Robert E. Stevenson 《In vitro cellular & developmental biology. Plant》1989,25(1):6-8
Summary On September 14 through 16, 1988, a meeting on the use of human fetal tissue in transplantation was held at the National Institutes
of Health, Bethesda Maryland, USA. The meeting sponsored by NIH for the Human Fetal Tissue Transplantation Research Panel,
a consultant group to the Advisory Committee to the Director. The consultant group was convened to deal with the scientific,
judicial and moral questions associated with research involving transplantation of human fetal tissue obtained after induced
abortions. The first day of the meeting was devoted to presentations addressing scientific issues. Included among the speakers
was Dr. Lars Olson, Professor of Neurobiology, Karolinska Institute, Stockholm, who described the use of transplanted human
fetal tissue in the treatment of patients with Parkinkson's disease and Dr. Eugene Redmond, Professor of Psychiatry, Yale
University School of Medicine, who showed results of work with transplantation of tissue to correct induced Parkinson-like
disease in monkeys. Other speakers addressed the present, past or potential use of fetal tissue in the treatment of diabetes,
immune disorders, and other diseases, as well as the use of fetal cells in the production of biologicals.
At the conclusion of the meeting the panel did not recommend that research be halted on fetal tissue within the context discussed,
although the recommendation of the committee is not binding, and an additional assembly of the panel will probably occur before
the final recommendation to an NIH advisory committee is made in November. Other meetings on this subject include a meeting
on the use of fetal tissue sponsored by the American Association of Tissue Banks, March 6–7, 1989, in Washington D. C. (Crystal
City) and a meeting June 10, 1989, the day before the annual meeting of the Tissue Culture Association, USA, in Orlando, Florida,
on fetal cells and ownership of cultured cells and products derived from clinical specimens. Following are statements to the
Human Fetal Tissue Transplantation Research Panel presented September 14, 1988, by Dr. David Barnes, Associate Professor of
Biochemistry and Biophysics in the Environmental Health Sciences Center at Oregon State University, USA, who was asked to
address for the panel recent advances in cell culture related to fetal tissue, and Dr. Robert E. Stevenson, Director of the
American Type Culture Collection, President of the Tissue Culture Association, USA, and Chairman of the Committee on Cells
and Tumors of the American Association of Tissue Banks. 相似文献
20.
The interactions between the substrates of the 2E1 isoform of the human cytochrome P450 and receptor were simulated. It was found that the CP4 isoform of the cytochrome of the bacterial cell is highly homologous to the 2E1 isoform of the human cytochrome P450. The orientation of the substrates of the 2E1 isoform in the CP4 isoform of the bacterial cell cytochrome was performed. A cavity in the receptor was found that is responsible for the binding of the substrate. Amino acid residues Phe87, Pro89, Val119, Thr185, Leu244, Leu245, Leu246, Val247, Gly248, Gly249, Thr252, Val295, Asp297, Cys357, Ile395, and Val396, the heme, and water molecules are involved in the formation of the cavity. The mode of the interactions of the substrate molecule with cytochrome was analyzed. Active sites of the receptor, and a part of the substrate molecule responsible for the binding to cytochrome were found. Equations for the dependence of the Michaelis constant on the structural parameters of complexes of substrates with cytochrome were derived. 相似文献