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21.
Erwin Bergmeier 《Folia Geobotanica》1990,25(1):27-61
The synanthropic vegetation in seven villages of Northern Greece (N Pindhos and Olympus massif)—situated either in theQuercion confertae or in theFagetalia zone—is analyzed on the basis of about 100 phytosociological relevés. The most important vascular plant species of ruderal sites have also been mapped floristically. Nineteen plant communities are discernible, some of which are mentioned for the first time here. Nevertheless, the author refrains from hastily describing new associations, unless a more detailed phytosociological data basis on ruderal vegetation in the Southern Balkans is available. A table refers to differences and similarities between the recognized plant communities in Greek villages and those which correspond to them in Central Europe. Non-industrial methods of agriculture and animal husbandry are among the most important conditions for the remarkable rich vegetation in Greek mountain villages. 相似文献
22.
Patrice Daniel Erwin de Waele Jean-Noël Hallet 《Applied microbiology and biotechnology》1993,38(5):638-641
Genomic DNA of several strains oof oenological lactic bacteria belonging to the species Lactobacillus plantarum, Leuconostoc oenos and Pediococcus pentosaceus was digested by the rare-cutting endonucleases ApaI and SmaI. The restriction products were separated by transverse alternating field electrophoresis (TAFE). The size of the genome of L. oenos estimated by adding the molecular size of the ApaI fragments was on average 1320 kb. A strong polymorphism was observed between the strains, which could be easily differentiated except for two industrial strains of L. oenos. A simple modification of the TAFE apparatus is proposed to improve the separation of the DNA fragments.
Correspondence to: J.-N. Hallet 相似文献
23.
Jrn Elsner Johannes Norgauer Gustav J. Dobos Andreas Emmendrffer Erwin Schpf Alexander Kapp Joachim Roesler 《Journal of cellular physiology》1993,157(3):637-643
Flow cytometric analyses were performed to study intracellular single-cell calcium transients ([Ca2+]i) in suspended human neutrophils during the initial phase of N-formyl peptide stimulation. Thereby, two neutrophil populations became apparent. Early maximally Ca2+-responding (high fluorescence) neutrophils and not-yet Ca2+-responding (low fluorescence) neutrophils, but no neutrophils with intermediate levels of [Ca2+]i, were detected. Within 7 s the number of low fluorescence neutrophils decreased and the number of high fluorescence neutrophils increased maximally. This suggests that [Ca2+]i transients occurred abruptly in individual neutrophils within a time interval below 1 s. At lower N-formyl peptide concentrations the lag times of individual neutrophils and the interval time of maximal activation of the [Ca2+]i-responding neutrophil population increased, however the percentage of [Ca2+]i-responding cells decreased. Surprisingly, no influence of the N-formyl peptide concentration on the [Ca2+]i-induced fluorescence signal of the individual cell was observed: it was always in an almost maximal range or not responding. In parallel, binding studies performed with fluorescein-labeled N-formyl peptide revealed that the heterogeneity of [Ca2+]i-responding cells cannot be explained by different receptor occupancy. In summary, this study demonstrates that [Ca2+]i transients induced by N-formyl peptides in suspended individual human neutrophils occur very rapidly in an almost “all-or-none manner” and that the mean increasing fluorescence signal of a calcium indicator within a whole neutrophil population results from varying lag times of the individual cells, rather than from the mean simultaneous progress of many cells. © 1993 Wiley-Liss, Inc. 相似文献
24.
Mammal Research - Foraging animals must contend with fluctuating environmental variables that affect foraging success, including conditions like wind noise, which could diminish the usefulness of... 相似文献
25.
Andreas Schlosser Angela Hamann Dirk Bossemeyer Erwin Schneider Evert P. Bakker 《Molecular microbiology》1993,9(3):533-543
The nucleotide sequence of trkA, a gene encoding a surface component of the constitutive K+-uptake systems TrkG and TrkH from Escherichia coli, was determined. The structure of the TrkA protein deduced from the nucleotide sequence accords with the view that TrkA is peripherally bound to the inner side of the cytoplasmic membrane. Analysis by a dot matrix revealed that TrkA is composed of similar halves. The M-terminal part of each TrkA half (residues 1–130 and 234–355, respectively) is similar to the complete NAD+-binding domain of NAD+-dependent dehydrogenases. The C-terminal part of each TrkA half (residues 131–233 and 357–458, respectively) aligns with the first 100 residues of the catalytic domain of glyceraldehyde-3-phosphate dehydrogenase. Strong u.v. illumination at 252 nm led to cross-linking of NAD+ or NADH, but not of ATP to the isolated TrkA protein. 相似文献
26.
Aniko Pay Claudia Jonak Laszlo Bögre Irute Meskiene Theresia Mairinger Aladar Szalay Erwin Heberle-Bors Heribert Hirt 《The Plant journal : for cell and molecular biology》1993,3(6):847-856
This paper reports on the isolation of a novel class of plant serine/threonine protein kinase genes, MsK-1 , MsK-2 and MsK-3 . They belong to the superfamily of cdc2 -like genes, but show highest identity to the Drosophila shaggy and rat GSK-3 proteins (66–70%). All of these kinases share a highly conserved catalytic protein kinase domain. Different amino-terminal extensions distinguish the different proteins. The different plant kinases do not originate from differential processing of the same gene as is found for shaggy , but are encoded by different members of a gene family. Similarly to the shaggy kinases, the plant kinases show different organ-specific and stage-specific developmental expression patterns. Since the shaggy kinases play an important role in intercellular communication in Drosophila development, the MsK kinases are expected to perform a similar function in plants. 相似文献
27.
Samantha G. Robinson Katie M. Walker Henrietta A. Bellman Daniel Gibson Daniel H. Catlin Sarah M. Karpanty Shannon J. Ritter James D. Fraser 《The Journal of wildlife management》2023,87(1):e22325
Population declines of disturbance-dependent species due to suppression of natural disturbances are realized across ecosystems. The piping plover (Charadrius melodus; plover), a disturbance-dependent and conservation-reliant shorebird that nests on sandy beaches and barrier islands on the Atlantic Coast, was listed under the United States Endangered Species Act in 1986. In 2012, Hurricane Sandy landed on Fire and Westhampton islands, barrier island nesting sites for plovers in New York, USA. Hurricane Sandy was a natural disturbance in this system, creating abundant nesting habitat. The number of chicks produced by a pair, or a population, is a direct measure of reproductive output, and gaining a better understanding of productivity and chick behavior following large-scale habitat creation may improve plover habitat management and potentially species persistence. We evaluated the effects of landscape features on habitat selection, behavior, and survival of plover broods using logistic regression, generalized linear mixed effects models, and survival models. Plover broods selected flatter sites with less dense vegetation than available at random. Chick foraging rates were highest in moist substrates and were lower in areas of higher nesting plover density. Chick survival was greater for broods that hatched earlier in the breeding season and increased as chicks aged. Generally, providing access to sites with flatter, moist substrates will likely result in higher quality brood rearing habitat on the landscape. Ultimately, vegetation removal and habitat management may be needed to reduce plover nesting density and ensure sufficient habitat, which may in turn improve plover chick survival. Moreover, sustaining natural landscape disturbances such as those resulting from storms, and not taking actions to prevent hurricane-created overwash, will allow these landscape features to persist. 相似文献
28.
Erwin Stresemann und Eugeniusz Nowak 《Journal of Ornithology》1958,99(3):243-296
Zusammenfassung Die Türkentaube war ursprünglich auf semi-aride Gebiete Südasiens beschränkt. Dort lassen sich drei geographische Rassen unterscheiden. Eine davon,Streptopelia decaocto decaocto, bewohnte bis zum Beginn des historischen Zeitalters nur Indien, nordwärts bis zum Himalaya, ostwärts etwa bis zum Brahmaputra. Später ist sie, vermutlich auf dem Seewege, nach Nord-China eingeführt worden, wo sie sich stark ausgebreitet hat.Auch nach Vorder-Asien ist sie von Indien her erst in historischer Zeit gelangt. Es ist wahrscheinlich, aber nicht sicher, daß sie nach Mesopotamien durch den Menschen gebracht wurde. Von dort aus ist sie nach Syrien und (schwerlich vor der Mitte des 16. Jahrhunderts) nach Anatolien und weiter nach Südost-Europa vorgedrungen, wo die Türken ihr eine besondere Hege angedeihen ließen. In der europäischen Türkei entwickelten sich Populationen in sehr vielen Städten und Dörfern. Einige davon (z. B. in Mostar und Bessarabien) sind wahrscheinlich auf importierte Paare zurückzuführen.Nach dem Zusammenbruch der türkischen Herrschaft in Bessarabien (1812), Griechenland (1828), Rumelien, Bulgarien, Serbien, Albanien, Montenegro, Herzegowina (1878), verloren die Türkentauben dort ihre Beschützer. Ihr Bestand ging sehr stark zurück, in weiten Gebieten (Bessarabien, Griechenland), wurden sie gänzlich ausgerottet. Erst nach 1900 breiteten sie sich in Bulgarien und wohl auch in Serbien wieder aus. Das war nach Ansicht der Verff. die Folge oekologischer Umstellung vom Nisten an Häusern und unter Dächern zum Brüten auf Bäumen.Von vorgeschobenen, dicht besiedelten Kolonien (Mostar, Belgrad, Orten an der bulgarisch-rumänischen Grenze) aus drangen Türkentauben um 1930 über die Grenzen des einstigen osmanischen Reiches in drei Richtungen vor, und zwar nach der Küste Dalmatiens, nach Ungarn und nach der Walachei.Infolge der dort einsetzenden starken Vermehrung (wahrscheinlich ermöglicht durch verminderten Feinddruck) hat sich die Türkentaube schnell weiter verbreitet. In einem günstigen Jahr kann eine örtliche Population, wie nachgewiesen, um mehr als 250% zunehmen.Zur Zeit ist die Türkentaube in der Po-Ebene bis nach Turin, nördlich der Alpen bis an die Küste der Nordsee (Belgien, Holland, Cuxhaven), des Skagerrak (Skagen) und der Ostsee (Wismar, Rostock, Danzig, Reval), und über Rumänien bis zum Dnjestr und sogar bis Kiew vorgedrungen. Schon haben einzelne Paare in Ost-England, Schottland und Süd-Schweden mit Erfolg gebrütet.Bisher sind 15, meist am Geburtsort beringte Türkentauben in größerer Entfernung (bis 720 km) wiedergefunden worden. Sie beweisen, daß die von ihrer Stamm-Kolonie abwandernden (wohl meist noch nicht einjährigen) Individuen dies ohne Bevorzugung einer Himmelsrichtung tun, also wahllos streuen. Das kann zu jeder Jahreszeit geschehen. Der Ort der endgültigen Ansiedlung abgewanderter Individuen oder Paare ist mitunter über 700 km weit vom Geburtsort entfernt.Daß das Vordringen der Türkentaube infolge ihrer Eigenschaft, den Winter am Brutplatz oder in dessen Nähe zu verbringen, an einer klimatisch bedingten Ausbreitungsgrenze (Winter-Isotherme?) enden wird, ist wahrscheinlich. Diese Grenze scheint bisher noch nicht erreicht zu sein. Der nördlichste bisherige Brut- und zugleich Überwinterungsort liegt dicht bei Reval (= Tallinn), 59° 45 N (südlichstes Siedlungsgebiet ist Nord-Ceylon, 9° 45 N).Man kennt weder morphologische noch ethologische Unterschiede zwischen den nördlichsten und den südlichsten, durch 50 Breitengrade getrennten Populationen. Starker Frost kann bei den europäischen Türkentauben eine Schädigung der Zehen bewirken, die dem Vogel das Umfassen von Zweigen und das Laufen erschwert. Ob die indischen noch empfindlicher gegen Kälte sind, wurde bisher noch nicht untersucht. 相似文献
29.
Inhibition of cholinesterase (ChE) activity produced by a single acute intraperitoneal administration of dimethoate was studied in the wood mouse, Apodemus sylvaticus, and the common shrew, Sorex araneus, under laboratory conditions. ChE values from serum and whole blood were compared with those obtained from brain in order to obtain a non-destructive tool for predicting the severity of brain acetylcholinesterase (AChE) inhibition. In addition, serum and brain inhibition following oral exposure to dimethoate was also measured in the wood mouse. Normal ChE activity was higher in the brain and whole blood of the shrews than in wood mice. There was no difference between species in serum ChE activity. Exposure to dimethoate caused a dose-dependent reduction in ChE activity and there was a significant recovery in activity with increasing time after administration. In both species, serum and whole blood were more sensitive than brain for revealing organophosphate-induced ChE inhibition and serum was more sensitive than whole blood. Statistically significant relationships were defined between whole blood and brain ChE activity and between serum and brain ChE activity. Compared with serum, whole blood ChE activity was the more accurate predictor of brain AChE levels. The relationships between brain and serum ChE activity did not appear to be affected by the route of administration of the pesticide. 相似文献
30.