Zoosporic aquatic fungi growing on dead specimens of 29 freshwater crustacean species   总被引：1，自引：0，他引：1  

Bazyli Czeczuga  Mariola Koz&#x;owska  Anna Godlewska 《Limnologica》2002,32(2)

The authors investigated aquatic fungi growing on the carapaces of 29 species of dead crustaceans (13 species of Copepoda, 13 species of Cladocera and 3 species of Ostracoda) in the water from six limnological and trophical different water bodies (two springs, one river, one lake and two ponds). All of these waterbodies are strongly loaded. 146 species of aquatic fungi were found on the carapaces: 40 Chytridiomycetes, 1 Hyphochytriomycete and 105 Oomycetes. The most common fungus species were Karlingia chitinophila, Myzocytium microsporum, Myzocytium zoophthorum, Pythium acanthicum, Pythium butleri and Pythium myriotylum. Most zoosporic fungus species were observed on the specimens of Daphnia pulex (50 fungus species), Daphnia magna (48) and Cyclocypris laevis (44), fewest on Cyclops fuscus and Cyclops vicinus (each 10).The most fungi were growing in the water from River Supraśl (86), the fewest in the water from Pond Fosa (53). Cluster analysis of the investigated parameters carried out in water bodies during the experiment on zoosporic fungus species has revealed that in the water from springs and Pond Fosa the number of fungus species is closely associated with the concentration of sulphates, in water from River Supraśl and Lake Komosa with calcium and in the water from Pond Dojlidy with chlorides. Out of these 146 species, 21 are known as parasites or necrotrophs of fish. Some dead specimens of crustacean species are a new substrate for some fungus species.  相似文献   

Paleo-environmental and volcano-tectonic evolution of the southeastern flank of Mt. Etna during the last 225 ka inferred from the volcanic succession of the ‘Timpe’, Acireale, Sicily     

Rosa Anna Corsaro  Marco Neri  Massimo Pompilio   《Journal of Volcanology and Geothermal Research》2002,113(1-2)

The tectonic escarpments locally known as ‘Timpe’ cut a large sector of the eastern flank of Etna, and allow an ancient volcanic succession dating back to 225 ka to be exposed. Geological and volcanological investigations carried out on this succession have allowed us to recognize relevant angular unconformities and volcanic features which are the remnants of eruptive fissures, as well as important changes in the nature, composition and magmatic affinity of the exposed volcanics. In particular, the recognition in the lower part of the succession of important and unequivocal evidence of ancient eruptive fissures led us to propose a local origin for these volcanics and to revise previous interpretations which attributed their westward-dipping to the progressive tectonic tilting of strata. These elements led us to reinterpret the main features of the volcanic activity occurring since 250 ka BP and their relationship with tectonic structures active in the eastern flank of Etna. We propose a complex paleo-environmental and volcano-tectonic evolution of the southeastern flank of Mt. Etna, in which the Timpe fault system played the role of the crustal structure that allowed the rise and eruption of magmas in the above considered time span.  相似文献   

Peat-forming environments of Westphalian A coal seams from the Lower Silesian Coal Basin of SW Poland based on petrographic and palynologic data     

Grzegorz J. Nowak  Anna Grecka-Nowak 《International Journal of Coal Geology》1999,40(4):15

The petrographic and palynologic compositions of coal seams of the acler formation (Upper Carboniferous, Westphalian A) from northwestern and southeastern part of the Lower Silesian Coal Basin (LSCB) were examined. Coals studied are highly volatile bituminous coal, where R_o ranges from 0.91% to 1.09%. Seam 430 from the northwestern part of the basin contains high vitrinite percentage with rather low inertinite and liptinite contents, while percentage of mineral matter is variable. This petrographic composition is associated either with a predominance of Lycospora in miospore assemblage, or with a miospore assemblage of mixed character. The abundance of Lycospora reflects vegetation composed of the arborescent lycopsids while the mixed miospore assemblage is connected with diverse palaeoplant communities, namely, arborescent lycopsids, calamites and ferns. Seams 409 and 412/413 from the southeastern part of the LSCB are rich in inertinite and liptinite, while the vitrinite content is moderate. Their characteristic feature is the occurrence of a diagnostic crassisporinite (densosporinite). Amount of the mineral components in these coals is very low. Densosporites and related crassicingulate genera are main components of these miospore assemblages and were produced by herbaceous and/or sub-arborescent lycopsids. These petrographic and palynologic features were the basis for distinguishing three maceral–miospore associations: an arborescent lycopsid and mixed associations, occurring in the seam 430 and a herbaceous and/or sub-arborescent lycopsid association which was recorded in seams 409 and 412/413. The first two assemblages are interpreted as having been deposited in a planar rheotrophic mire, whereas the herbaceous and/or sub-arborescent lycopsid association is thought to have developed in an ombrotrophic, domed mire.  相似文献   

The “schizohaline” environment: Its sedimentary and diagenetic fabrics as exemplified by Late Paleozoic rocks of Bear Island,Svalbard     

Robert L. Folk  Anna Siedlecka 《Sedimentary Geology》1974,11(1):1-15

Environments characterized by fluctuating hypersaline to fresh-water conditions are defined as “schizohaline” and examples are given of situations in which “schizohaline” environments can arise. Fabrics diagnostic for the occurrence of both hyper- and hyposalinity have been recorded in Late Paleozoic rocks from Bear Island (74°30′N, 19°E): evaporite nodules, length-slow chalcedony and very finely crystalline penecontemporaneous dolomite are considered as indicators of hypersaline conditions while euhedral limpid dolomite crystals, coarse poikilitic sparry calcite and microspar calcite are thought to have originated under the hyposaline regime. Zoned dolomite crystals and euhedral crystals of authigenic mega-quartz replacing sulphates have also been recorded in the same rocks; their diagnostic importance for the schizohaline environment is, however, uncertain.Internal structural pores of some crinoid and bryozoan skeletal grains of biosparites from Bear Island are either empty or infilled with very finely crystalline dolomite. Expulsion of Mg²⁺ ions from the magnesian-calcite skeletons and either: (1) “poisoning” of the micro-environment of the pores; or (2) formation of stagnant “micro-sabkha” conditions in the pores are proposed as an explanation for these phenomena.  相似文献   

Die Verteilung des SO2-Gehaltes der Luft im Stadtgebiet von Wien     

Anna Bangerl  Ferdinand Steinhauser 《Theoretical and Applied Climatology》1959,10(1):132-153

Zusammenfassung An zahlreichen über das ganze Stadtgebiet von Wien verteilten Beobachtungsstellen wurden vom September 1956 bis September 1957 an je vier Wochen lang ausgesetzten, mit einem Absorptionsmittel getränkten Baumwollappen SO₂-Ablagerungen gesammelt. Die gefundenen SO₂-Mengen zeigen eine stark unterschiedliche Verteilung im Stadtbereich und einen deutlichen Jahresgang mit einem Maximum im Winter und einem Minimum im Juli. Der Einfluß meteorologischer Faktoren auf den SO₂-Gehalt der Luft und seine Änderungen wird unter besonderer Berücksichtigung der orographischen Verhältnisse und örtlicher SO₂-Quellen eingehend diskutiert. Abschließend wird auch über eine Analyse von Schneeproben auf berichtet.

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Summary During the period September 1956 to September 1957 the amount of SO₂ deposited from the atmosphere was observed at numerous locations in the town of Vienna. The observations were made by means of cotton rags, soaked with an absorbing chemical, and each rag was exposed for four weeks. The amounts of SO₂ show great differences within the area, and a pronounced annual variation, with a maximum in winter and a minimum in July. The influence on the SO₂ content of the air of meteorological factors is discussed in detail, with special regard to variations by orographic conditions and local SO₂ sources. Additional determinations on snow samples are reported.

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Résumé Des prélèvements de SO₂ par absorption sur des bandes de coton imprégné, laissées sur place pendant quatre semaines, ont été faits en de nombreux endroits de l'agglomération viennoise de septembre 1956 à septembre 1957. Les quantités de SO₂ varient beaucoup selon les endroits et la saison; elles sont maximum en hiver et minimum en juillet. Etude des facteurs météorologiques agissant sur la répartition du gaz en tenant compte en particulier du relief et des sources locales d'anhydride sulfureux. On a également déterminé la teneur de d'échantillons de neige.

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Mit 4 Textabbildungen  相似文献   

Data rescue in manuscripts: a hydrological modelling study example     

Xuan Yu  Anna Lamačová  Lele Shu  Christopher Duffy  Pavel Krám  Jakub Hruška 《水文科学杂志》2020,65(5):763-769

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Projection of runoff characteristics as a response to regional climate change in a Central/Eastern European catchment     

Anna Kis  Rita Pongrácz  Judit Bartholy  János Adolf Szabó 《水文科学杂志》2020,65(13):2256-2273

ABSTRACT

The impact of climate change on runoff characteristics is investigated for the Upper Tisza basin, in eastern Central Europe. For a reliable estimation of uncertainty, an appropriate stochastic weather generator is embedded into a Monte Carlo cycle capable of generating any large number of independent, equally probable, 100-year-long daily sequences of synthetic data with which a hydrological model is driven in order to obtain the hydrological responses to the meteorological data sequences. According to our results, a decrease of daily average runoff is likely to occur in the future in the Upper Tisza basin, especially in July and August. The occurrence of water levels below the critical low level is estimated to increase between July and October. Level-3 flood warnings are projected to be less frequent in the future; however, they will tend to be more severe than in the historical period.  相似文献   

应用主分量分析法研究唐山Ms7.8地震前的地磁异常     

杜安娜  高惠璇 《地震》1995,(3):291-297

应用主分量分析法对昌黎、青光、宝坻、红山等台站(1975—1977年)三年的每月五个静日地磁绝对磁场的资料及相应时间的太阳黑子相对数的资料进行计算。结果表明,第一主分量与太阳黑子相对数对应很好,相关系数为0.9以上,而第二主分量与太阳黑子相对数的相关系数为0.03左右。对于在某一固定频率而变化的地磁外源场,内外场的比例几乎恒定在一定水平上,而在唐山地震前内外场比值有明显的异常变化,笔者认为,这个恒定水平的偏离可能是由于地壳内应力不断积累导致的地下电导率的变化而引起的。用这种方法不仅可以消除地磁场的非局部变化,而且利用内外场比值的偏离或监视内场的变化可能为使用地磁场预报地震提供一个依据。  相似文献   

Stability and dynamics of beams on winkler elastic foundations     

Maria Anna De Rosa 《地震工程与结构动力学》1989,18(3):377-388

The dynamical properties of a foundation beam on a Winkler soil have been recently discussed by using the power series method¹⁴ and the finite element method.^{15, 17 – 19} The first method can be applied only if the Winkler soil is linearly distributed along the whole span: on the contrary, the second method is more general, but it requires considerable computational efforts. In this paper a recently developed discretization method has been shown to be particularly well suited for dynamic analysis of foundation beams, in the presence of second order destabilizing effects. The procedure is based on the Hamilton principle, and the equation of motion is deduced from the corresponding Lagrange equations. According to the proposed method, the structure is reduced to a set of rigid bars, connected together by elastic cells. The convergence of the method is shown to be quite rapid, so that a small number of Lagrangian coordinates has to be introduced, and the resulting eigenvalue problem can be easily solved. Numerical comparisons are also performed with the available data of the literature, and the agreement is shown to be excellent. Two particularly unusual cases are illustrated, in order to emphasize the method's peculiarities. Finally, the influence of the axial forces on the fundamental vibration frequency is discussed, both for conservative and non-conservative forces.  相似文献   

Fault-generated mountain fronts in the central apennines (Central Italy): Geomorphological features and seismotectonic implications     

Anna Maria Blumetti  Francesco Dramis  Alessandro Maria Michetti 《地球表面变化过程与地形》1993,18(3):203-223

The morphotectonic framework of the Central Apennines is given by faulted blocks bounded by normal faults, mostly trending NW–SE, NNW–SSE and NE–SW, which cut previous compressive structures. Such a structural setting is consistent with the focal mechanisms of the earthquakes which often occur in this area. In this paper, three lithologically different normal fault-generated mountain fronts are analysed in order to assess the relations between their geomorphic features and active tectonics. They border the Norcia depression (Sibillini Mts, Umbria), the Amatrice–Campotosto plateau (Laga Mts, Lazio) and the Fucino basin (Marsica Mts, Abruzzi). The Norcia depression is bounded by a N20°W trending normal fault to the east and by a parallel antithetic fault to the west. The main fault has a 1000 m throw and gives rise to a wide fault escarpment, characterized by: (1) sharp slope breaks due to low angle gravity faults; (2) important paleolandslides; and (3) several fault scarplets on the piedmont belt affecting Quaternary deposits. The Amatrice–Campotosto plateau is delimited by the western slope of Mt Gorzano which runs along a N20°W trending normal fault having a 1500m throw. Minor parallel faults dislocate Quaternary landforms. Large-scale massmovements also occur here. The Fucino basin was struck by the 1915 Avezzano earthquake (I=XI MCS) which produced extensive surface faulting along two parallel NW trending normal fault escarpments on the eastern border of the basin. There is paleoseismic evidence including buried gravity graben in Late Glacial gravels and tectonic dip-slip striations on Holocene calcitic crusts covering bedrock normal fault planes. These data suggest that active extensional tectonics plays a major role in the slope morphogenesis of the Central Apennines and they indicate the importance of geomorphic analysis in seismic zonation of this area.  相似文献