CAREX GRACEII SP. N., CYPEROCARPUS ELIASII SP. N., CYPEROCARPUS TERRESTRIS SP. N., AND CYPEROCARPUS PULCHERRIMA SP. N. (CYPERACEAE) FROM THE MIOCENE OF NEBRASKA

Silicified achenes and some perigynia of four new sedges are described from the late middle or late Miocene Ash Hollow (Clarendonian or Hemphillian) and early middle Miocene Sheep Creek (Late Hemingfordian) Formations of Nebraska. Carex graceii, sp. n., Cyperocarpus terrestris, sp. n., and Cyperocarpus pulcherrima, sp. n., were collected from strata in Garden and Antelope Counties and Cyperocarpus eliasii, sp. n., was collected from strata in Sioux County. Certain of the newly discovered taxa exhibit considerable anatomical detail of the pericarp wall of the achene. In two taxa, Carex graceii and Cyperocarpus pulcherrima, the achene pericarp exhibits four topographic regions: a cuticle, an outer layer of pentagonally to hexagonally shaped epidermal cells containing silica bodies, a middle layer of sclerenchyma cells, and an inner layer of sclerenchyma cells whose long axes are perpendicular to the long axes of the cells of the middle layer. Similar pericarp anatomy was found in Cyperocarpus terrestris except that the inner layer was not observed. In the fourth taxon, Cyperocarpus eliasii, only an outer epidermal layer of elongate cells with small protuberances is preserved. The ultrastructure of the pericarp of the fossil taxa is similar to that of living forms. Associated flora and fauna indicate widespread savanna environments with significant riparian elements. This is the first systematic treatment of sedges from the Miocene of North America.     

窄口螺侧殖吸虫的发育史及早熟现象

1.本文描述从福州闽江泥滩采集的图氏窄口螺体中发现一新种侧殖吸虫,定名为窄口螺侧殖吸虫(Asymphylodora stenothyrae sp.nov.)并与其他相近虫种作详细比较。2.窄口螺侧殖吸虫的生活史各期发育经详细观察,本文简单介绍其各发育期形态特征。3.本文对窄口螺侧殖吸虫早熟现象及其他吸虫类的提早发育现象进行讨论,并将复殖吸虫亚纲曾经发现有提早发育现象的虫种及其中间宿主列表比较。我们的结论:早熟现象在吸虫类中是相当普遍的一种现象。       

Early development of bacteriophages SP01 and SP82G in minicells of Bacillus subtilis.

SP01- and SP82G-infected Bacillus subtilis CU403 divIVBI minicells synthesize 13 easily detectable early RNA species with molecular weights ranging from 60 × 10³ to 430 × 10³. Comparison of in vivo and in vitro translation of early messenger RNA indicates that five early mRNAs of SP01 are synthesized but not translated unless protein synthesis has been permitted in the infected minicell, providing evidence for a translation control mechanism. A sequential appearance of 48 polypeptides has been determined in SP01-infected minicells. The polypeptides have been grouped into two classes of early polypeptides, i.e. those encoded by early mRNA and three subsequent classes as demonstrated by the analysis of polypeptides synthesized in minicells infected with the SP01 mutants, susF21, susF4 and susF14. Phage capsid proteins are not synthesized in minicells. RNA synthesized in infected minicells is subject to turnover. The individual mRNA species have differing functional stabilities ranging from a loss of only 50% functional activity, in 20 minutes at 37 °C, to loss of over 99% activity.Infection of anucleate minicells has been shown to be a very simple method for comparison of closely related phages (slight differences are detected between SP01- and SP82G-encoded mRNA and polypeptides), detection of polypeptides affected by amber mutations and the analysis of early events in phage development in the absence of host syntheses.     

Nicotiana Deformis N. SP. und die Enzymtheorie der Erblichkeit

Ohne Zusammenfassung     

Studies on the ATPase of Bacillus cereus.

The membrane ATPase (EC 3.6.1.3) of Bacillus cereus was solubilized by a 'shock-wash' process and purified. The non-specific phosphatase contaminant was separated by glycerol density gradient centrifugation. The optimum temperature was 39.5 degrees C and the pH optimum at 7.5. On SDS-polyacrylamide gel electrophoresis two classes of subunits were observed in equal proportions with molecular weights of 70 K and 83 K. The effect of various compounds on the enzymatic activity was studied. The enzyme was insensitive to NaN3, oligomycin and to divalent cations, but was inhibited by citrate and oxalate.     

NITZSCHIA ALICAE SP. NOV. AND N. PURIFORMIS SP. NOV., NEW DIATOMS FROM EUROPEAN RIVERS AND COMPARISON WITH THE TYPE MATERIAL OF N. SUBLINEARIS AND N. PURA1

Nitzschia sublinearis Hustedt and N. pura Hustedt are common oligosaprobic freshwater diatom species that frequently occur in diatom inventories, thus being important in water quality studies. Both are considered as species with overlapping diagnostic criteria in several floras, which is typical of the whole genus Nitzschia. The type material of Hustedt of N. sublinearis and N. pura was examined using LM and EM in order to document the range of variation within the type populations and to compare it with populations occurring in different European rivers. Detailed observations allowed recognition of two new freshwater diatom species: N. alicae sp. nov., occurring in mesotrophic up to eutrophic conditions, and N. puriformis sp. nov., mostly occurring in oligotrophic habitats, both in rivers and streams at middle and high altitudes. The most reliable taxonomic features that separate both new species from the most similar taxa are the density of fibulae and striae, valve shape, and valve width as well as the shape of areolae. Morphological examination of different populations indicates that N. puriformis is relatively common in European rivers and has been overlooked to date and confounded with N. pura by several researchers. By contrast, N. alicae has, to date, been collected only in Slovakia and Northern Italy, but with a high frequency of occurrence and sometimes in high abundance at sites.     

THE ANATOMY AND THREE-DIMENSIONAL MORPHOLOGY OF ANNULARIA HOSKINSII SP. N.

Foliage attached to calamitean shoots is described from coal ball petrifactions of Middle and Late Pennsylvanian age. Leaves correspond to the compression-impression genus Annularia and thus represent the first attached members of this genus to be recognized as petrifactions. Individual leaves contain a single unbranched vascular bundle flanked by wide lateral laminar areas which occupy more than half the leaf cross sectional area. Stomata are confined to broad bands within concave furrows which parallel the vascular bundle on the abaxial leaf surface. Epidermal cells within these furrows are in rows aligned obliquely to the leaf axis, and the rows angle outward at a slight angle towards the leaf margin. Convolutions of the leaf-bearing axes result from nodal diaphragms which are oblique to the shoot axis. Whorled leaves apparently radiate outward in the plane of each obliquely positioned nodal diaphragm. This petrified material helps explain the apparent flattening of entire nodal diaphragms and leaf whorls within the same plane as seen in compression specimens. Annularia hoskinsii sp. n. is proposed, and the systematic position of structurally preserved Annularia foliage relative to the genus Dicalamophyllum is discussed.     

BA-25菌株碱性纤维素酶产酶条件优化研究

试验研究了分离自烟草调制过程中的产芽孢细菌Bacillussp.BA-25菌株碱性纤维素酶产生的优化条件.结果表明:麸皮是最佳碳源,豆饼粉是最佳的氮源,且当碳氮比为2∶1时产酶活性最高;NaCl和KH2PO4对纤维素酶的合成具有重要作用,其适宜用量分别为0.5%～1.0%和0.1%;培养液的初始pH会极大地影响产酶活性,其最适pH为10.最优化的发酵工艺参数为:种子菌龄为24h,在300mL摇瓶中,装入30mL培养基培养温度为37℃,摇床转速为160r/min,在发酵24h后补充1%的葡萄糖,培养48h,该菌产碱性纤维素酶活力可以达到68.4U/mL.