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1.
内蒙古巴特敖包地区早泥盆世牙形刺   总被引:2,自引:1,他引:1  
内蒙古达茂旗(达尔罕茂明安联合旗)巴特敖包地区以碳酸岩相古生代地层发育而引人注意。经多年研究,特别是李文国等(1985)的研究,使本区珊瑚、腕足类、层孔虫、鹦鹉螺等大化石的研究工作已有一定基础,并依据牙形刺首先确定了在阿鲁共剖面有泥盆纪地层的存在。但本区泥盆纪地层仍存在很多问题,必须通过对牙形刺的研究加以解决。在王成源研究员的精心安排和亲自指导下,作者等在巴特敖包地区的七个剖面进行了系统取样研究。经对158个样品(重667kg)的分析,在本区发现了大量的原定为志留纪的早泥盆世地层,包括西别河组命名剖面。分析结果同时证明,本区不存在志留系温洛克统的沉积。巴特敖包剖面断层发育,志留—泥盆纪地层交替出现,巴特敖包组应取消,原定的阿鲁共剖面层序颠倒。本区地层应厘订为志留系的西别河组(罗德洛统—普里道利统)和下泥盆统的阿鲁共组(Lochkovian阶),前者以包尔汉图剖面为标准剖面,后者应寻找更好的标准剖面。本文重点总结巴特敖包地区早泥盆世的牙形刺。本区共建立了4个牙形刺带,文中共描述了8牙形刺属,21种,其中包括4亚种、1新种(Belodellataeniocuspidatasp.nov.)和1未定种。  相似文献   

2.
R Jander  D Troyer  J Rauterberg 《Biochemistry》1984,23(16):3675-3681
The 140 000-dalton collagenous glycoprotein (CGP) from calf aorta and ligament characterized by Gibson & Cleary (1982) [Gibson, M.A., & Cleary, E.G. (1982) Biochem. Biophys. Res. Commun. 105, 1288-1295] has been studied. In the electron microscope, rotary-shadowed CGP molecules appear similar to the dimers of type VI collagen (short-chain collagen, intima collagen) described by other authors [Furthmayr, H., Wiedemann, H., Timpl, R., Odermatt, E., & Engel, J. (1983) Biochem. J. 211, 303-311] except that they have larger globular domains. As shown by gel electrophoresis, pepsin treatment of CGP at 4 degrees C either before or after reduction releases polypeptide chains corresponding in size to those of type VI collagen. Electron microscopic examination shows that pepsin digestion of nonreduced CGP removes the outer globular domains, reduces the size of the inner ones, and separates the paired central strands. The residual structures look like type VI collagen dimers. When intact CGP is reduced, monomers with two large globular ends are obtained. Pepsin digestion of monomers removes most or all of both globular domains. In immunoblots, CGP and its pepsin-derived fragments react with antibodies directed against type VI collagen. The results indicate that type VI collagen is an integral component of CGP.  相似文献   

3.
The karyotype of Echinostoma caproni Richard, 1964 is studied. There are eleven pairs of chromosomes (2n=22). Two pairs are submetacentric (Nos. 4 and 5). C-banding methods revealed a large block of heterochromatin in No. 3 and two blocks in No. 5. E. cinetorchis (see Terasaki et al., 1982) and E. barbosai (see Mutafova & Kanev, 1983) also have 22 chromosomes, but the metacentric or submetacentric chromosomes are Nos. 8 and 11 for the former and No. 10 for the latter. ac]19860425  相似文献   

4.
Lactic acid bacteria are considered indigenous members of the gastrointestinal microflora in a number of animal species (Savage 1977a). Some intestinal strains of lactobacilli and streptococci are aWe to adhere to stratified squamous epithelium of some animals (Tannock et al. 1987), in the non-secreting part of the stomach of piglets (Barrow et al. 1980, Fuller et al. 1978) and rodents (Tannock et al. 1982), and in the crop of poultry (Fuller 1978). The presence of lactic acid bacteria in the digestive tract is believed to be of beneficial value to the host animal (Fuller 1989). The production of organic acids in the stomach or the crop helps maintaining a low pH which may be important for inhibiting the colonization of potentially pathogenic bacteria, particularly in the newborn animal (Barrow et al 1980, Fuller 1977, Fuller 1978). The adhesion of lactobacilli to squamous epithelium is host specific: strains capable of adhering to the epithelium of piglets are usually not able to adhere in rodents or poultry and vice versa (Fuller 1978, Lin & Savage 1984, Tannock et al 1982). Adhesion of lactic acid bacterial strains to other epithelia than stratified squamous epithelium has been reported. Thus, the attachment of lactobacilli to cells from the secreting epithelium of the murine stomach (Kotarski & Savage 1979), to intestinal cells of humans (Goldin & Gorbach 1987), and to columnar epithelial cells of piglets and calves (Mäyrä-Mäkinen et al 1983) has been demonstrated using in vitro methods. In another study the in vivo attachment of Enterococcus faecium to duodenal epithelium of gnotobi-otic chickens was demonstrated (Fuller et al 1981). Recent research indicated that in adult mink lactic acid bacteria are not indigenous members of the intestinal flora, and they do not attach to epithelium in any part of the gastrointestinal tract (Federsen & Jørgensen 1992). The present paper presents evidence that Gram positive cocci may colonize the gut of suckling mink kits and attach to the gut mucosa.  相似文献   

5.
H. Källander 《Ibis》1993,135(1):97-100
Commensal 'beating' associations in which one party exploits prey disturbed by the other seem to be fairly common in terrestrial habitats (e.g. Dean and MacDonald 1981). Most such commensal relations appear to be opportunistic phenomena, rather than regularly occurring associations with possible fitness effects for the commensal, but few of them have been studied in detail. Exceptions are a few apparently very regular associations, for example those between birds and army ants (e.g. Willis 1966, Willis & Oniki 1978), between anis Crotophaga spp and cattle (Rand 1953, Smith 1971) and, especially, between Cattle Egrets Bubulcus ibis and large herbivorous mammals (for references, see Kushlan 1978). In the latter two cases, clear advantages in the form of higher food intake rates have been demonstrated for individuals foraging commensally (Rand 1953, Heatwole 1965, Smith 1971, Dinsmore 1973, Grubb 1976, Burger & Gochfeld 1982).  相似文献   

6.
The anthelminthic Praziquantel is found to be effective against trematodes and cestodes (for a comprehensive review of various aspects of this drug, see Andrews et al. 1983). Praziquantel has been reported to affect fish cestodes (Pool et al. 1984, Moser et al. 1986, Ward et al. 1986), fish digeneans (Bylund & Sumari 1981) and fish monogeneans (Schmahl & Mehlhorn 1985). Therefore Praziquantel could be a potential drug against Pseudodactylogyrus spp. parasitizing the gills of eels. Infections with these monogeneans cause problems in eel farms (Ogawa & Egusa 1976, Egusa 1979, Chan & Wu 1984, Mellergaard & Dalsgaard 1986). Köhler & Bachmann (1978) tested the effect of Praziquantel on the activity of succinate dehydrogenase and NADH-diaphorase (NADH-oxidase) from Ascaris suum and reported that the latter enzyme was inhibited by Praziquantel.  相似文献   

7.
Book reviews     
Book reviewed in this article:
B acterial C ell S tructure (Aspects of Microbiology 6) (1983). H.J. Rogers.
T he E lisa : E nzyme -L inked I mmunosorbent A ssay in V eterinary R esearch and D iagnosis (1982). Edited by R.C Wardley & J.R. Crowther.
G enetic R ecombination : U nderstanding the M echanisms (1982). H.L.K. Whitehouse.
M icrobial C ontrol of P lant P ests & D iseases (Aspects of Microbiology 7) (1983). J.W. Deacon.
M ethods in F ood and D airy M icrobiology (1982)  相似文献   

8.
Overwintering larvae of the Cucujid beetle, Cucujus clavipes, were freeze tolerant, able to survive the freezing of their extracellular body fluids, during the winter of 1978–1979. These larvae had high levels of polyols (glycerol and sorbitol), thermal hysteresis proteins and haemolymph ice nucleators that prevented extensive supercooling (the supercooling points of the larvae were ? 10°C), thus preventing lethal intracellular ice formation. In contrast, C. clavipes larvae were freeze suspectible, died if frozen, during the winter of 1982–1983, but supercooled to ~ ? 30°C. The absence of the ice nucleators in the 1982–1983 larvae, obviously essential in the now freeze-susceptible insects, was the major detected difference in the larvae from the 2 years. However, experiments in which the larvae were artifically seeded at ? 10°C (the temperature at which the natural haemolymph ice nucleators produced spontaneous nucleation in the 1978–1979 freeze tolerant larvae) demonstrated that the absence of the ice nucleators was not the critical factor, or at least not the only critical factor, responsible for the loss of freeze tolerance in the 1982–1983 larvae. The lower lethal temperatures for the larvae were approximately the same during the 2 winters in spite of the change in overwintering strategy.  相似文献   

9.
Plastome mutants     
Summary Since the first reports seventy-five years ago on the non-Mendelian inheritance of variegation in plants, chloroplast gene mutations have been useful for genetical and physiological investigations. The mutations have been shown to affect the chloroplast translational apparatus, photosystem I, photosystem II, the cytochrome f/b6 complex, carbon fixation, or the ATP synthase. They arose spontaneously or were induced by mutagens or by the action of nuclear mutator genes. Alterations of chloroplast DNA include point mutations, deletions, duplications, and inversions. In 1909, Correns discovered uniparental transmission of chloroplasts when he observed the maternal inheritance of a chlorophyll deficiency inMirabilis jalapa. At the same time, Baur (1909) reported crosses ofPelargonium zonale in which the offspring inherited chloroplasts from both parents (biparental transmission) with variegated leaves resulting as the green and white plastids sorted out. since the experiments of Baur and Correns, many non-Mendelian mutants have been isolated in both higher plants and algae (for reviews see Hagemann, 1964; Kirk and Tilney-Bassett, 1978; Gillham, 1978). Some of these are mitochondrial traits, including cytoplasmic male sterility in maize and several other plants (Hanson and Conde, 1985; Pring and Lonsdale, 1985). Several other traits have been tentatively identified as mitochondrial since their inheritance pattern differs from that of both nuclear and chloroplast genes, including the deformed leaf (“falsifolia”) syndrome ofOenothera (Stubbe, 1970), non-chromosomal stripe of maize (Coe, 1983), and inChlamydomonas, photoautotropism (Wiseman et al., 1977) and a minute colony phenotype (Alexander et al., 1974). A far larger number of extranuclear mutations affect the plastome (plastid genome). Among the algae,Euglena gracilis (Russell and Lyman, 1982),Scenedesmus obliquus (Bishop, 1982) andChlorella (Galling, 1982) have yielded interesting mutants, but unlikeChlamydomonas, they are not known to undergo sexual reproduction, and thus the Mendelian or non-Mendelian nature of the mutations has not been determined. Most of the plastome mutations which have been characterized have been isolated in higher plant lines or fromChlamydomonas.  相似文献   

10.
Book reviewed in this article: Bücher/Books: Barnard, C. J. (1983): Animal behaviour: ecology and evolution (Verhalten der Tiere: Ökologie und Evolution). Gwynne, D. T., and G. K. Morris, eds. (1983): Orthopteran mating systems. Brian, M. V. (1983): Social insects, ecology and behavioural biology (Soziale Insekten: Ökologie, Lebensweise, Verhalten). Hasler, H. D., und A. T. Scholl (1983): Olfactory imprinting and homing in salmon (Duftprägung und Heimfinden bei Lachsen). Papi, F., and H. G. Wallraff, eds. (1982): Avian navigation (Orientierungsverhalten von Vögeln). Simons, D. (1984): Problemverständnis und Problemlöseverhalten bei Primaten (Cognitive skills and problem solving in primates). Wolf, G., und J. Hess (1983): Seele oder Programm? (Soul or program?). Koenig, O. (1980): Tier und Mensch (Animals and men). Rensch, B. (1979): Lebensweg eines Biologen in einem turbulenten Jahrhundert (Life of a biologist in a troublesome century). Herter, K. (1979): Begegnungen mit Menschen und Tieren. Erinnerungen eines Zoologen 1891–1978 (Memories of a zoologist). Mohr, H. (1983): Biologische Wurzeln der Ethik (The natural roots of ethics).  相似文献   

11.
An abiotic system is described which chemically catalyzes the formation of less than Glu-His-Pro-NH2 (thyrotropin-releasing hormone) from less than Glu-His-Pro-amino acid in the presence of copper, ascorbate, and molecular oxygen. Evidence is presented to support the participation of hydroxyl and carbon radicals as reaction intermediates in the production of a peptide amide and an aldehyde or ketone. The characteristics of this model system closely mimic the characteristics of enzymatic peptide amidation, and an oxidative, free-radical mechanism for enzymatic peptide amidation is proposed as an alternative to the mechanism for enzymatic amidation offered by Bradbury et al. (Bradbury, A. F., Finnie, M. D. A., and Smyth, D. G. (1982) Nature 298, 686-688).  相似文献   

12.
Quantitative defense theory and patterns of feeding by oak insects   总被引:3,自引:0,他引:3  
Summary Patterns of herbivory over a two year period on Quercus emoryi (Fagaceae) were correlated with seasonal and yearly changes in tannin and protein content. Quantitative defense theory predicts that tannin and protein content in apparent plants should be negatively and positively correlated, respectively, with degree of herbivory. Most herbivory occurred early in the growing season, but the pattern varied between the two years. Tannin and protein content sometimes varied negatively and sometimes positively with degree of herbivory; they did not consistently covary with herbivory. Protein content was positively correlated with herbivory in 1981–1982 but not in 1982–1983. Condensed tannin content was negatively correlated with herbivory in 1981–1982 but not in 1982–1983. Hydrolysable tannin content was positively correlated with herbivory activity. Multiple regression analyses indicated these phytochemical variables explained either no significant variation in herbivory (1982–1983) or did so in a fashion opposite (1981–1982) to the predictions of the theory of quantitative defense.Feeding by oak insects was not solely a function of seasonal changes in quantitative defenses and nutrients. Obviously, population dynamics of the insects are sensitive to factors other than phytochemistry of the trees and I discuss other factors that can influence patterns of herbivory.  相似文献   

13.
Book Reviews     
《Freshwater Biology》1985,15(1):121-126
Merilainen, J., Huttunen, P. & Battarbee, R.W. (Eds.) (1983) Paleolimnology.
Wetzel, R.G. (Ed,) (1983) Periphyton of Fresh-water Ecosystems. (Developments in Hyd-robiology
Elster, H.J. & Ohle, W. (Eds,) (1982) Nutrient Remobilization from Sediments and its Lim-nological Effects.
Elster, H.J. & Ohle, W. (Eds,) (1982) Nutrient Remobilization from Sediments and its Lim-nological Effects.
Caljon, A.G. (1984) Brackish-water Phyto-plankton of the Flemish Lowland.
Golterman, H.L., Sly, P.G. & Thomas, R.L. (1983) Study of the Relationship between Water Quality and Sediment Transport.
Hakanson, L. & Jansson, M. (1983) Principles of Lake Sedimentology.  相似文献   

14.
The c-myc gene is expressed in a variety of actively growing cells and tissues including lymphoblastoid cell lines made in vitro by EBV infection (Hamlyn & Rabbitts 1983). The gene is implicated in the derivation of Burkitt's lymphoma because of its association with consistent chromosomal translocations (Dalla-Favera et al. 1982; Neel et al. 1982; Taub et al. 1982) and in, for example, some colon carcinomas where the gene is amplified (Alitalo et al. 1983). To understand the formation of these cancers, we must determine the function of the c-myc protein in the cell. In this discussion we describe some features of c-myc metabolism which indicate that its expression may normally be strictly modulated; it is possible that the potential oncogenic effect of c-myc in various tumours is the result of loss of this ability to modulate its activity.  相似文献   

15.
Summary We studied the invasion of a California annual grassland by the shrub, Baccharis pilularis ssp. consanguinea (DC) C.B. Wolf. A series of aerial photographs indicated that the shrub had been present at the study site for 35–45 years but spread very little until the early 1970's. A period of slow expansion was followed by rapid outward spread of the shrub population and large increases in shrub density. Detailed demographic studies showed a period of rapid population increase from 1978 to 1983, with the highest stablishment rates in 1982–83. Establishment was strongly correlated with annual and spring rainfall amounts. An iniiall period of slow outward spread is thought to have profided foci for rapid spread during years of high rainfall.  相似文献   

16.
Book review     
Clinical and Biochemical Luminescence (1982). Edited by L.J. Kricka & T.J.N. Carter. 289 pp. New York & Basel: Marcel Dekker, Inc. S.Fr. 135.
Microbial and Viral Pesticides (1982). Edited by E. Kurstak. 720 pp. New York & Basel: Marcel Dekker, Inc. S.Fr. 284.
The Control of Antibiotic-Resistant Bacteria (1982). Edited by Sir Charles H. Stuart-Harris & D.M. Harris. 284 pp. London & New York: Academic Press. £20.00, US$37.00.
Economic Microbiology Vol. 7. Fermented Foods (1983). Edited by A.H. Rose. 337 pp. London & New York: Academic Press. £29.20, $60.00.
Current Developments in Malting, Brewing and Distilling (1983). Edited by F.G. Priest & I. Campbell. 311 pp. London: The Institute of Brewing, 33 Clarges St, London W1Y 8EE. Price not stated.  相似文献   

17.
To establish those environmental conditions which promote the growth of aflatoxin (AFT)-producing Aspergillus spp. on peanuts, a four-year (1982–1986) investigation was undertaken to examine possible relationships between air temperature (AT), precipitation (P), and AFT contamination of stored nuts. The mean percentages of nuts that possessed various AFT levels for the years 1982–1986 (June–July) ranged from 74·2 to 88·0 for 0–4 ppb, 6·3 to 14·9 for 5–15 ppb, 2·4 to 5·9 for 16–25 ppb, 2·3 to 6·4 for 26–100 ppb, and 0 to 4·7 for > 100 ppb. The mean percentages for the years which exceeded USDA/FDA regulations were 7·1 (1982–1983), 7·6 (1983–1984), 11·6 (1984–1985), and 17·0 (1985–1986). Examination of the mean percentage > 15 ppb for each month during these four years revealed that the following months fell within that range; Septtember, November, December, January, February, and May (1982–1983); July, October, April, and June (1983–1984); August, and June, (1984–1985); and July, April, and May (1985–1986). Comparisons of pooled-AFT levels, rainfall, and temperature over four years suggested a ‘better fit’ between mean monthly P and mean percentage AFTs > 15 ppb, than between the latter and mean monthly AT. However, application of a predictor equation suggested a correlation between AFT levels and monthly AT.  相似文献   

18.
ABSTRACT. Seabottom sediments from a discontinued Philadelphia-Camden 40-Mile ocean sewage disposal site were cultured for cyst-forming free-living amoebae. Barge delivered wastes were discharged at the site from 1973 until 1980 when the site was closed. One station at the southeast margin of the site was sampled at a depth of approximately 50 m, twice in 1978 and once in 1982, 1983 and 1984. Sediment from the 1978 collection yielded Acanthamoeba polyphaga, Vahlkampfia sp., and an unknown amoeba with stellate endocysts similar to those of A. astronyxis. Trophozoites and cysts of the isolate were typical of those described for the genus Acanthamoeba. Biochemical tests employing enzyme electrophoresis and morphological studies on live and stained specimens showed that the isolate was distinct from other well-described species within the family Acanthamoebidae Sawyer & Griffin, 1975.  相似文献   

19.
The plankton of the Prince Edward Islands   总被引:4,自引:3,他引:1  
Summary The Prince Edward Islands (47°S, 38°E) are situated very close to the border between the antarctic and subantarctic zones. There is, indeed, some difference of opinion whether this border, the Antarctic covergence or Polar front, should be drawn at 46° or 50°S (see Discussion). Deacon (1983) claims that the complexity of the currents in this area leads to more interchange and less clear gradation between Antarctic and subantarctic waters than in most longitudes. This is a study of the species composition, and a very rough estimate of the standing stock, of the plankton fauna of the waters surrounding the Prince Edward Islands during two surveys conducted by us in 1982 and 1983. They are compared with each other and with a third survey by Grindley and Lane in 1979 and data presented by Miller (1985). The plankton is mainly antiboreal (Systematic Account and Table 1). However, entrants of tropical, sub-tropical and antarctic origin are noted. The means of advection of these aliens into the region are hypothesized and it is further speculated that they may be, at times, relics of decayed biocoenoses.  相似文献   

20.
Book reviewed in this article: Seidel , F., ed. (1982): Morphogenese der Tiere (Morphogenesis in animals). Handbuch der ontogenetischen Morphologie und Physiologie in Einzeldarstellungen. Noakes , D. I. G., D. G. Lindquist , G. S. Helfman and J. A. Ward (1983): Predators and prey in fishes (Räuber und Beute bei Fischen). Burghardt , G. M., and A. S. Rand, eds. (1982): Iguanas of the world. Their behavior, ecology and conservation (Leguane der Welt. Jenkins , J. M. (1983): The native forest birds of Guam (Die einheimischen Waldvögel von Guam). Boag , D. (1982):The Kingfisher (Der Eisvogel). Bezzel , E., und F. Pölking (1979): Kleinod Eisvogel. O'Donald , P. (1983): The Arctic skua. A study of the ecology and evolution of a seabird (Die Schmarotzerraubmöwe. Nelson , B. (1980): Seabirds, their biology and ecology (Meeresvögel, ihre Lebensweise und Umweltbeziehungen). Grant , G. S. (1982): Avian incubation: egg temperature, nest humidity, and behavioral thermoregulation in a hot environment (Das Brüten von Vögeln: Temperatur der Eier, Feuchtigkeit des Nestes und Wärmeregulierung durch Verhalten). Perrins , C. M., and T. R. Birkhead (1983): Avian ecology (Ökologie der Vögel). Brush , A. H., and G. A. Clark, eds. (1983): Perspectives in ornithology (Ornithologische Ausblicke).  相似文献   

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