黄海辐射沙洲颗石的分布及海底沉积性质的研究

以工作区南黄海辐射沙洲海区为例,探讨了颗石的滨浅海环境中的标准分布,并以这种标准分布模式为基础,通过工作区采集的大量样品,得出该海区各主要潮流深槽及沙脊的沉积特征。     

THE ROLE OF DETRITUS IN THE NUTRITION OF TWO MARINE DEPOSIT FEEDERS, THE PROSOBRANCH HYDROBIA ULVAE AND THE BIVALVE MACOMA BALTHICA

Observation on the shore show that the density of the population of the prosobranch Hydrobia ulvae and of the bivalve Macoma balthica at Whitstable varies considerably With the grade of deposit, dense populations being found in fine deposits and sparse populations in coarse deposits. From laboratory experiments it seems probable that these animals feed by abstracting proteins, which can be assessed as nitrogen, from the bodies of microorganisms in the deposits and that the micro-organisms are more abundant in fine deposits than in coarse ones.
As a result of these conclusions it is suggested that the rapid increase in population density of Hydrobia ulvae and Macoma balthica , and by inference of other deposit-feeders, towards regions of fine-grained deposits is attributable to the increase in density of the micro-organism population. this, in turn, is related to the surface area of the deposits rather than to the abundance of organic debris.
Finally, the nature of detritus is discussed and it is recommended that this term is replaced by organic debris.     

马科在中国的分布与现状

蒙古野驴(Asinus h．hemionus)分布于内蒙和甘肃西北角、新疆东北部至准噶尔盆地西部。1982年航调,卡拉麦里山保护区内有356头,O.02头／平方公里;1986年调查为O.03头／平方公里。估计目前我国境内不超过2000头。西藏野驴(Asinus k.kiang)分布于西藏西部、新疆南缘山地;A.k.holdereri分布于除湟水河谷外青海全境、四川西北角、甘肃祁连山。1984年调查,阿尔金山保护区内有41,262头,0.917头／平方公里。估计我国境内种群约在20万头上。多年考察未发现野马(Equus przewalskii),目前可能在北塔山以东尚有少数残存。     

THE NUMBER AND DISTRIBUTION OF PHYSICIANS IN CALIFORNIA

The ratio of physicians to general population in California has been approximately the same for many years, the influx of physicians having kept pace with the population trend.For many years California has licensed more physicians than any other state.The five medical schools in this state have been increasing the number of candidates admitted to the freshman class. Attempts are being made to increase the number of medical schools in this state to seven in anticipation of the future growth and medical needs of the population.The heaviest concentration of physicians is as always in the thickly populated areas as determined by the population physician ratio.A study of the detailed statistics presented in this paper should be of interest to all California physicians.     

THE DISTRIBUTION AND PROPERTIES OF THE NONSPECIFIC N-METHYLTRANSFERASE IN BRAIN

Abstract— The distribution and properties of a nonspecific N -methyltransferase in the rat brain are described. The enzyme N -methylates tryptamine and N -methyltryptamine as well as β-phenylethylamine, phenylethanolamine, tyramine and octopamine. The enzyme exhibits a pH optimum of 7·9 with phosphate buffer and has a K_m for tryptamine of 28 μM. There are potent inhibitors to the enzyme that can be removed by dialysis. Enzymatic activity is present in the brains of a number of species including man, rat, mouse, guinea-pig and frog. Its activity is unevenly distributed in the brain with the highest activity in the cerebral cortex and striaturn of the rat and in the subcortical white matter in man. Studies of its subcellular distribution indicate that most of the N -methylation activity is released into the soluble fraction. Enzymatic activity is also present in a number of peripheral tissues of the rat.     

THE DISTRIBUTION AND TAXONOMIC SIGNIFICANCE OF LIGNIN IN THE LEMNACEAE

Lignification characteristics of 14 species of Lemnaceae were studied by the alkaline oxidation technique in an attempt to resolve conflicting reports of the presence of lignin and to provide chemotaxonomic data for supplementing previous systematic treatments. Four species of Spirodela, eight of Lemna, Wolffiella oblonga, and Wolffia microscopica were clonally subcultured, homogenized, exhaustively extracted and the insoluble residue oxidized in alkaline cupric hydroxide. Barley (Hordeum vulgare), Elodea densa and Spirogyra sp. were examined to validate the technique. The benzaldehydes were extracted, separated by thin-layer chromatography, and quantitated spectrophotometrically. Recovery of syringaldehyde, vanillin, and to a lesser extent p-hydroxybenzaldehyde, was accepted as evidence that these plants are lignified. The highest yields of syringaldehyde and vanillin were recovered from S. intermedia, the largest member of the Lemnaceae. Lesser amounts were obtained from S. polyrhiza and S. oligorhiza. Spirodela biperforata yielded no syringaldehyde which substantiates its distinctiveness from the morphologically similar S. polyrhiza. All Lemna species are nerved, yet vanillin (but not syringaldehyde) was recovered only from L. trinervis, L. perpusilla, L. minor, and L. minima. The species L. trisulca, L. gibba, L. obscura, and L. valdiviano yielded only p-hydroxybenzaldehyde. Thus the presence of nerves is not evidence for lignification within the genus Lemna, and the relationships suggested by their gross morphology are not supported by their lignin chemistry. Wolffiella is non-lignified by these criteria. Wolffia microscopica is the smallest flowernig plant and it has no nerves; vanillin was unexpectedly recovered and microscopic examination showed highly lignified anther walls.     

REGIONAL DISTRIBUTION OF PUTRESCINE, SPERMIDINE AND SPERMINE IN RELATION TO THE DISTRIBUTION OF RNA AND DNA IN THE RAT NERVOUS SYSTEM

—Putrescine, spermidine, spermine, RNA, DNA and protein concentrations were determined in 14 parts of the rat nervous system. If the concentrations are expressed in DNA units, putrescine and spermidine concentrations change concomitantly in the different brain parts, with the exception of hypothalamus, where relatively higher putrescine than spermidine concentrations are observed. The constancy of putrescine/spermidine ratios indicates the value of putrescine concentration as an index of spermidine biosynthesis. Spermidine correlates with RNA, except in medulla, spinal cord and peripheral nerves. It is assumed that the relative excess of spermidine in these structures indicates an additional functional role. Spermine/DNA ratios are remarkably constant in the diencephalic and telencephalic regions; they are also nearly constant, but significantly lower in midbrain, medulla, spinal cord and cerebellum. This observation gives additional support for the preferential interrelation of spermidine with RNA and spermine with DNA; i.e. for different functional roles of these two narrowly related polycations.     

中国麻黄属的地理分布与演化

中国现有麻黄属植物１５种,２变种和１变型,这些种属于膜果麻黄组和麻黄组中的麻黄亚组,没有原始类型藤麻黄亚组的代表。我国除长江中下游及珠江流域的省区处,其他省区都有分布。麻黄花粉的化石－麻分在地层中的分布说明,麻黄在过去曾遍布我国各地,发现的最早时期是在侏罗纪,到白垩纪－早第三纪时,种类较现在丰富,将近５０种,根据麻黄粉在世界各地地层中的分布和时期,结合大陆飘移和海底扩张板块构造学说推断,原麻黄在各     

中国腐霉属的生态和分布

腐霉属PytMum真菌全世界已报道约100种。本文记载我国的腐霉45种,以及它们的生态及地理分布。腐霉喜栖息于富含有机质的潮湿土壤里,以菜园土中为最多,其次是大田土、水畔土和陵园土,干旱的沙质土、森林土和含盐碱的沼泽土一般均较少,最贫乏的是草丘土,如草原、牧场、山坡、荒丘及道旁等土壤。在我国的土壤中,以绚丽腐霉P．Pulchrum和瓜果腐霉P. aphanidermatum最为常见,其次是刺腐霉Spinosum、中国腐霉P．Sinense和卡地腐霉P. carolinianum,而顶生腐霉P．Acrogenum、色孢腐霉P．Coloratum、壁台腐霉P connatura等10个种却较罕见,仅出现过一次。腐霉在土壤中的垂直分布以5—10㈨深处为最多。腐霉在土壤中的活动有着明显的季节性变化：春季最多,秋季次之,夏季最少。在我国的30个省市自治区中,北京发现的腐霉最多,已报道22种;河北、广东、云南省次之,各有13种;台湾省已记录12个种;山西省、甘肃省和新疆维吾尔自治区均仅发现一个种;而青海省、宁夏回族自治区和西藏自治区迄今尚未见有腐霉报道。     

DIGESTION AND THE DISTRIBUTION OF ACID PHOSPHATASE IN BLEPHARISMA

Suspensions of Blepharisma intermedium were fed latex particles for 5 min and then were separated from the particles by filtration. Samples were fixed at intervals after separation and incubated to demonstrate acid phosphatase activity. They were subsequently embedded and sectioned for electron microscopy. During formation of the food vacuole, the vacuolar membrane is acid phosphatase-negative. Within 5 min, dumbbell-shaped acid phosphatase-positive bodies, possibly derived from the the acid phosphatase-positive Golgi apparatus, apparently fuse with the food vacuole and render it acid phosphatase-positive. A larger type of acid phosphatase-positive, vacuolated body may also fuse with the food vacuole at later stages. At about 20 min after formation, acid phosphatase-positive secondary pinocytotic vesicles pinch off from the food vacuoles and approach a separate system of membrane-bounded spaces. By 1 hr after formation, the food vacuole becomes acid phosphatase-negative, and the undigested latex particles are voided into the membrane-bounded spaces. The membrane-bounded spaces are closely associated with the food vacuole at all stages of digestion and are generally acid phosphatase-negative. Within the membrane-bounded spaces, dense, pleomorphic, granular bodies are found, in which are embedded mitochondria, paraglycogen granules, membrane-limited acid phosphatase-containing structures, and Golgi apparatuses. The granular bodies may serve as vehicles for the transport of organelles through the extensive, ramifying membrane-bounded spaces.     

南方鲇消化道杯状细胞分布及类型探讨

本研究应用阿利新蓝－过碘酸雪夫氏（ＡＢ－ＰＡＳ）染色方法对南方鲇（Ｓｉｌｕｒｕｓ　ｍｅｒｉｄｉｏｎａｌｉｓ）消化道杯状细胞的分布特点进行了分类研究,结果表明：南方鲇消化道杯状细胞的数量从肠前段、肠中段到肠后段,呈现递增趋势,有杯状、囊状和梨形三种不同的形态,ＡＢ反应阳性,ＰＡＳ反应阴性,分泌物主要含酸性粘多糖,属Ⅱ型粘液细胞。     

富硒螺旋藻中硒的有机化及其分布特性

作者已对螺旋藻生物富集硒和铬(Ⅲ)的条件及相关技术进行了详细研究1,2。