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1.
The Late Glacial and early Holocene palaeovegetation is reconstructed by analysis of pollen and macroscopic plant remains from sediments of the lower river Erft valley, near Cologne, exposed by the Garzweiler opencast lignite mine. The study was carried out in parallel with the archaeological excavation of the Mesolithic site of Bedburg-Königshoven, located within a former meander of the Erft. During the Younger Dryas period, the study region was thinly wooded. Relatively open pine woods existed during the Preboreal, becoming more closed during the Boreal. Later in the Boreal,Corylus and taxa of the mixed oak woodland (Ulmus, Quercus, Tilia andFraxinus) appeared. The Atlantic period was characterised by mixed oak woods with dominantUlmus. At the beginning of the Subboreal,Ulmus declined andTilia became the predominant element of the woods. The Mesolithic settlement existed during the early and middle part of the Preboreal period. At that time, the woodland of the Erft valley was mainly composed ofPinits, Belula and somePopulus. The pollen results do not show any evidence of the activity of Mesolithic people. Local vegetational changes of the filling process of the Erft meander were described and interpreted. The vegetational development of the study region is compared with that of neighbouring regions.  相似文献   

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Butterbach-Bahl  K.  Gasche  R.  Willibald  G.  Papen  H. 《Plant and Soil》2002,240(1):117-123
During 4 years continuous measurements of N-trace gas exchange were carried out at the forest floor-atmosphere interface at the Höglwald Forest that is highly affected by atmospheric N-deposition. The measurements included spruce control, spruce limed and beech sites. Based on these field measurements and on intensive laboratory measurements of N2-emissions from the soils of the beech and spruce control sites, a total balance of N-gas emissions was calculated. NO2-deposition was in a range of –1.6 –2.9 kg N ha–1 yr–1 and no huge differences between the different sites could be demonstrated. In contrast to NO2-deposition, NO- and N2O-emissions showed a huge variability among the different sites. NO emissions were highest at the spruce control site (6.4–9.1 kg N ha–1 yr–1), lowest at the beech site (2.3–3.5 kg N ha–1 yr–1) and intermediate at the limed spruce site (3.4–5.4 kg N ha–1 yr–1). With regard to N2O-emissions, the following ranking between the sites was found: beech (1.6–6.6 kg N ha–1 yr–1) >> spruce limed (0.7–4.0 kg N ha–1 yr–1) > spruce control (0.4–3.1 kg N ha–1 yr–1). Average N-trace gas emissions (NO, NO2, N2O) for the years 1994–1997 were 6.8 kg N ha–1 yr–1 at the spruce control site, 3.6 kg N ha–1 yr–1 at the limed spruce site and 4.5 kg N ha–1 yr–1 at the beech site. Considering N2-losses, which were significantly higher at the beech (12.4 kg N ha–1 yr–1) than at the spruce control site (7.2 kg N ha–1 yr–1), the magnitude of total gaseous N losses, i.e. N2-N + NO-N + NO2-N + N2O-N, could be calculated for the first time for a forest ecosystem. Total gaseous N-losses were 14.0 kg N ha–1 yr–1 at the spruce control site and 15.5 kg N ha–1 yr–1 at the beech site, respectively. In view of the huge interannual variability of N-trace gas fluxes and the pronounced site differences in N-gas emissions it is concluded that more research is needed in order to fully understand patterns of microbial N-cycling and N-gas production/emission in forest ecosystems and mechanisms of reactions of forest ecosystems to the ecological stress factor of atmospheric N-input.  相似文献   

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Objective: This study was undertaken to assess the presence and degree of anxiety and depression in a group of UK patients with primary Sjögren's syndrome (1°SS). Design: Cross‐sectional. Setting: Department of Oral Medicine, Liverpool University Dental Hospital. Subjects: Eighty adult patients; 40 diagnosed with 1°SS according to the revised European Criteria and 40 age/gender‐matched controls with no history of chronic illness. Intervention: Hospital Anxiety and Depression Scale (HADS), a self‐administered questionnaire designed to evaluate the presence and degree of anxiety and depression in a clinical setting. Main outcome measures: Age, gender, Hospital Anxiety and Depression Scale (HADS). Results: Forty patients with 1°SS and 40/age/gender‐matched controls completed the HADS. Scores for anxiety in both the 1°SS and control groups showed no statistically significant difference. Patients with 1°SS had statistically significant higher, mean HADS scores for depression than the controls. There was an increased prevalence of ‘definite’ clinical depression in the 1°SS group. Conclusion: Patients with 1°SS appear to be at increased risk from clinical depression. Early recognition and appropriate intervention is therefore essential to reduce the negative impact of depression on the patient's quality of life and outcome of their disease.  相似文献   

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Abstract

A Paddyfield Warbler was mist-netted at Van in eastern Anatolia on 8.5 1987. This is the second record for Turkey.  相似文献   

8.
Full analysis of eight seed samples collected in the 1960's excavations at Neolithic Çatalhöyük East, Turkey, is presented. Detailed investigation of the composition and context of the samples suggests that the Neolithic population collected, processed and stored seeds from Capsella sp. and Descurainia sp. (wild crucifers) for food use. In addition seeds of Vicia/Lathyrus sp. (wild vetch), Helianthemum spp. and Taeniatherum caput-medusae mixed with Eremopyrum type (grasses) were also found, some of which may have been used for food or other purposes. The analysis demonstrates that wild seed exploitation was a regular part of subsistence practice alongside the economic staple of crop production, and again demonstrates how diverse plant use practices were at the site.  相似文献   

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Oxygen availability is considered to have been a major factor in shaping the sedimentary facies and biofacies of a Late Miocene (8–8.5 Ma old) Lake Pannon sequence studied in the Kozma-street outcrop in Budapest-Köbánya. The sequence contains blue clays deposited in low-oxygen conditions between the storm and the fair-weather wave bases and thin intercalations of laminated fine sand interpreted as tempestites. The storms caused temporary oxygenation of the bottom and thus promoted bioturbation, as indicated by the presence of trace fossils belonging to the Arenicolites ichnofacies or a lacustrine equivalent of the marine Skolithos ichnofacies. Fully bioturbated sand layers with the infaunal Dreissenomya and other littoral molluscs indicate longer periods of bottom ventilation. The blue clays immediately above these sand layers also contain abundant and diverse mollusc fauna. Oxygen deficiency on the “shelf” of Lake Pannon was a local phenomenon probably caused by a high organic loading and/or a salinity-induced stratification.  相似文献   

10.
Zusammenfassung Alle 3 untersuchten Prosobranchier wachsen isometrisch und zeigen einen O2-Konsum, der dem Quadrat der mittleren Linearausdehnung parallel geht. Als RQ ergab sich für Paludina fasciata (Herbstversuche) ein plausibler, knapp unter 0,7 liegender Wert. Die normale Lokomotionsgeschwindigkeit, geprüft an Paludina und Bythinia, ist von der Körperlänge unabhängig (konstante Absolutgeschwindigkeit), in Übereinstimmung mit den Befunden Ludwigs (I) für Lithoglyphus und der Muschel Dreissensia. Somit verhalten sich bisher alle kiemenatmenden Mollusken konform. Die Frage nach dem Sinn der Größe (O2)/G·t, d.h. des O2-Konsums je Gewichts-Zeiteinheit bei Formen mit einem zur Oberfläche proportionalen Energiekonsum, wird erörtert.  相似文献   

11.
Analysis of charred plant macro-remains, including wood charcoals, cereals, seeds, tubers and fruits from the Neolithic site of ?atalh?yük has indicated complex patterns of plant resource use and exploitation in the Konya plain during the early Holocene. Evidence presented in this paper shows that settlement location was not dictated by proximity to high quality arable land and direct access to arboreal resources (firewood, timber, fruit producing species). A summary of the patterns observed in sample composition and species representation is outlined here together with preliminary interpretations of these results within their broader regional context. Received September 4, 2001 / Accepted April 9, 2002  相似文献   

12.
Huber  C.  Oberhauser  A.  Kreutzer  K. 《Plant and Soil》2002,240(1):3-11
Laboratory and field measurements of the flux of ammonia to forest floor canopies of spruce and beech stands at the Höglwald site in southern Bavaria are reported. Measurements were performed with an open chamber method. A linearity between ammonia concentration and ammonia flux from the atmosphere to the ground floor canopy was detected. Deposition of ammonia showed no saturation even at air concentrations up to 50 g NH3 m–3 air. Temperature, water content and the moss layer of the ground floor canopy had a minor influence on the deposition velocity in laboratory experiments. Deposition velocity of ammonia was higher to the spruce (1.3 cm s–1), and limed spruce ground floor canopy (1.17 cm s–1) compared to the beech stand (0.79 cm s–1). In field studies, a diurnal course of the deposition velocity was detected with highest velocities in midday and minor during night times, but not in the climatic chamber. The flux of ammonia to the ground floor canopy was estimated of app. 10 kg N ha–1 yr–1 for the soil under spruce, 9 kg N ha–1 yr–1 for the limed spruce and 6 kg N ha–1yr–1 for the soil under beech. The fluxes are interpreted as fluxes from the atmosphere to the ground canopies of the stands.  相似文献   

13.
Ohne ZusammenfassungD 3. Teil I (Ludwig): Z. vergl. Physiol. 24, 319–342 (1937).Herrn Prof. Dr. W. Ludwig, der mir die Anregung zu dieser Arbeit gab und mir auch weiterhin viele Ratschläge zuteil werden ließ, möchte ich an dieser Stelle meinen herzlichsten Dank aussprechen.Ausgeführt mit Unterstützung durch Mittel der Deutschen Forschungsgemeinschaft (Prof. Dr. W. Ludwig).  相似文献   

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Wang G  Lu L  Zhang CY  Singapuri A  Yuan S 《Protoplasma》2006,228(4):159-166
The calmodulin (CaM) localization pattern in the growing hyphal tip of Aspergillus nidulans was studied with the functional GFP::CaM fusion protein. A faint tip-high gradient of CaM was found in the growing hyphal tip, with CaM highly localized in the region corresponding to the Spitzenk?rper forming a bright granule. The position of highly concentrated CaM in the extreme apex seemed to determine the orientation of the hypha. The normal pattern of CaM localization was also shown to be dependent on the integrated actin cytoskeleton. When the growth of the hyphal tip ceased, CaM failed to localize in the bright granule and was evenly distributed in the hyphal tip. These findings suggest that CaM may play an important role in establishing and maintaining apical organization, morphogenesis, and growth in Aspergillus nidulans.  相似文献   

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Zusammenfassung An zahlreichen Exemplaren von Noctuiden, Geometriden, Notodontiden und Arctiiden wurden Reaktionen auf Schallwellen des Frequenzbereiches 15–175 kHz beobachtet, die sämtlich Flucht- oder Totstellreaktionen waren und nach Häufigkeit und Intensität ihre niedrigste Schwelle im Bereich von 40–80 kHz haben.Die Reaktionen sind nicht artspezifisch.Durch Exstirpationsversuche konnte gezeigt werden, daß die Schallreize peripher in den Tympanalorganen aufgenommen, zentral kritisch verarbeitet werden und dann zu den beschriebenen Reaktionen führen. Diese sind also nicht reflektorisch entstanden, sondern müssen als Ausdruck echten Hörens aufgefaßt werden.Dieselben Reaktionen werden beobachtet, wenn Nachtfalter mit Fledermäusen konfrontiert werden, deren Orientierungslaute im selben Frequenzbereich liegen wie die niedrigsten Schwellen der Nachtfalter.Aus allem wird der Schluß gezogen, daß Nachtfalter Fledermäuse hören können, sich ihrem Zugriff durch Flucht oder Totstellen entziehen und dadurch einen relativen Schutz vor ihren Feinden besitzen.  相似文献   

19.
Das Auflösungsvermögen elektronenmikroskopischer Autoradiographien   总被引:5,自引:0,他引:5  
Zusammenfassung Zur Bestimmung des autoradiographischen Auflösungsvermögens wurde mit Hilfe eines einfachen Testpräparates die Verteilung der entwickelten Silberkörner um eine mit Tritium markierte 500 Å breite lineare Strahlungsquelle gemessen. Als Kenngröße für das Auflösungsvermögen diente die Halbwertsdistanz, d.i. diejenige Entfernung von der aktiven Linie, innerhalb der die Hälfte aller Körner liegt. Der Einfluß der Entwicklung sowie der Dicke von Emulsionsschicht und Schnitt auf die Halbwertsdistanz wurde unter Verwendung von zentrifugierter Kodak NTE- und Ilford L 4-Emulsion bestimmt. Es wurde gefunden, daß die Kornverteilung bei allen untersuchten Methoden durch eine gemeinsame Universalkurve und die jeweilige Halbwertsdistanz beschrieben werden kann. Bei Kenntnis dieser Größe läßt sich die Kornverteilung auch um anders geformte Quellen berechnen, was wiederum Voraussetzung ist zur Beurteilung der Auflösbarkeit markierter Strukturen.Die gemessenen Verteilungskurven stimmen grundsätzlich mit einer früher publizierten Rechnung überein, sie zeigen jedoch, daß das autoradiographische Auflösungsvermögen in der Literatur oft zu optimistisch beurteilt wird. Die Halbwertsdistanzen für Emulsions-Einkornschichten und 500 Å dicke Schnitte betragen 800 Å bei Verwendung von Kodak NTE/ Dektol, 1300 Å für Ilford L 4/Paraphenylendiamin und 1450 Å für Ilford L 4/Microdol X. Der in der Literatur häufig verwendete Auflösungswert nach Rayleigh beträgt in allen Fällen das 1,5fache der Halbwertsdistanz.
The resolution of electron microscope autoradiography
Summary The resolution of EM autoradiography was studied by measuring the distribution of developed grains around a linear radioactive source (500 Å wide, H–3-labeled). The resolving power of a method was characterized by its half-distance, i.e. the distance from the linear source within which half the developed grains were found. The influence of emlusion thickness, section thickness and developing procedures was studied using centrifuged Kodak NTE and Ilford L 4 emulsion. It was found that in each case the grain distribution can be characterized by the half-distance of the particular method plus a universal distribution curve which is valid for all preparations. If the half-distance is known the grain distribution around sources of different shapes and sizes can be calculated and used to determine wether labeled structures can be resolved by autoradiography or not.The experimental grain distribution curves are in good agreement with our previous calculations. The measurements show however that autoradiographic resolution is often judged too optimistically in the literature. The half-distances for 500 Å thick sections with emulsion monolayers are 800 Å using centrifuged Kodak NTE/Dektol, 1300 Å using Ilford L4/ paraphenylendiamine and 1450 Å using Ilford L 4/Microdol X. The more commonly used criterion for resolution, the so-called Rayleigh criterion (see Caro, 1962) is in each case 1.5 times the half-distance.


Auszugsweise vorgetragen auf der 13. Tagung für Elektronenmikroskopie, Marburg, September 1967.  相似文献   

20.
M. Sager  R. Pucsko 《Hydrobiologia》1991,226(1):39-49
Summary The sediments of the River Danube in the Reservoir at Altenwörth/Lower Austria, are moderately polluted with Zn, Pb, and Cd, whereas concentrations of As, Co, Cr, Cu and Ni are typical of background values. Deposit-feeding oligochaetes living in these sediments were analyzed for their trace element concentrations (As, Cd, Cu, Pb, Zn) to study pathways of recycling of sediment bound amounts to the food web. Compared with background values of benthic deposit feeders from the literature, Cu and As are low, whereas some samples were enhanced in Pb, Cd and Zn. Within the rather narrow concentration ranges, relations of tissue concentrations with chemical and mineralogical compositions of the sediment were hardly found. Increase of clay mineral contents went in parallel with increasing Cd, Zn, and Cu in the tissues, and As in the tissues with total As content. Pb in the tissues was closely related to Pb-concentrations in the pore water. By means of sequential leaching, some further relations between trace element contents in the tissues and solid phases were found. The organic detrital phase positively correlates with As-uptake, whereas hydroxylamine-reducible Mn/Fe-oxyhydroxides influence the Pb-level, and dithionite-reducible Fe/Mn influence the Cu-level. Exchangeable and weak-acid-mobile fractions of the respective metals, however, did not correlate with tissue-levels, nor did the oxalate-extractable Fe-hydroxide coatings, which carry a major part of the heavy metals at fine grain sizes in the Danube sediments investigated. Zn in the tissues was largely independent from all investigated parameters.  相似文献   

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