bluuebunny/crossref_metadata_2025_split huggingface dataset:
Myxobakterien (Myxobacterales) auf Blattoberflächen
Authors: Rückert G. 
Published: July 2010

Abstract140 leaf samples were examined, 73 of which ( = 52.1%) contained myxobacteria. Three species of the genus Myxococcus, M. virescens, M. fulvus and M. coralloides, could be found more or less frequently in the phyllosphere of woody plants and annuals. Archangium gephyra was observed only once. There was no significant difference in the occurrence of myxobacteria between evergreen leaves and leaves from deciduous trees and shrubs. Fruit‐trees yielded the best results.
Mannan‐Lokalisation durch Concanavalin A im Zusammenhang mit elektronenmikroskopischen und chemisch‐analytischen Untersuchungen an unterschiedlich präparierten Zellwänden der Futtereiweißhefe Candida spec. H
Authors: Fischer W. , Reuter G. 
Published: July 2010

AbstractRegions of different electron densities after concanavalin A‐peroxidase‐reaction have been observed in cell walls of intact cells as well as in isolated cell walls: In the peripheral region of intact cell walls two mannan layers appear. Treating isolated cell walls with pronase, NaOH, ethylendiamine or citrate buffer, respectively, we find con A binding spots in the inner cell wall regions which appear electrontransparent in the untreated cell walls. Apparently the mannan component of the inner cell wall regions is masked by proteins. In correspondence with chemical analysis our results cannot confirm the existence of inner cell wall regions which are free of mannan.
Changes in cytoplasmic ultrastructure during submerged cultivation of a peptide alkaloids‐producing strain of Claviceps purpurea (FR.) TUL
Authors: Lösecke W. , Neumann D. , Schmauder H.‐P. , Gröger D. 
Published: July 2010

AbstractA strain of Claviceps purpurea, designated Pepty 695/S produces ergotoxine alkaloids under particular conditions of fermentation. The onset of alkaloid synthesis occurs around the second day of cultivation. Alkaloid formation is connected with morphological and ultrastructural changes. In the first 3‐5 days of cultivation short thickened, septated hyphae, organized in plectenchymatic pellets as well as large single cells are formed. The hyphae are ultrastructurally characterized by increasing number of lipid droplets, deposits of glycogen and by extended ER membrances, which apparently may form numerous vesicles. The correlations between lipid and alkaloid synthesis are discussed.
Zusammenhang zwischen Protein‐ und Polysaccharidgehalt in zellwandmodifizierten Mutanten von Candida spec. H
Authors: Köllin Ruth , Tröger R. 
Published: July 2010

AbstractThe contents of protein (as total N) and of polysaccharides from 38 mutants of Candida spec. H were analyzed. The results were obtained by calculation iof the correlation‐coefficient. It expresses a significant interrelation between both characters: An increase of one of the contents implied a decrease of the other one. Some mutants show higher concentrations of protein in comparison with the normal ratio between cell wall‐polysaccharides and protein.
Electron microscopic demonstration of negative surface charges on cytoplasmic membrances of Bacillus subtilis with protamine‐ferritin
Authors: Mach F. , Bergmann P. , Pfüller U. , Wölfel L. 
Published: July 2010

AbstractThe application of a protamine‐ferritin conjugate for labelling of isolated protoplast membranes of Bacillus subtilis S 13/1 is desribed. Contrary to Mycoplasma membranes which could only be labelled on the outer side of the membrane, ferrtin was deposited on both membrane sides as a single layer without cluster formation.
Zur Bildung und Wirkung der Epimerase von Azotobacter vinelandii
Authors: Wetzler Chr. , Behrens U. 
Published: July 2010

AbstractAfter exhaustion of the C‐source, terminating the accumulation of the extracellular polysaccharide, the excretion of the epimerase is increased, accordingly the moiety of guluronosyls of the alginate is augmented. Epimerization reactions with an epimerase preparation with commercial alginates from algae lead to higher conversion rates than with alginate from Azotobacter vinelandii. It is reasoned that the acetyl groups of bacterial alginate perform a steric hinderance. Because of the small amount of guluronosyls in Azotobacter alginate, these alginates do not form gels with Ca++.
Einfluß von Phosphatmangel auf Wachstum und makromolekulare Zellzusammensetzung von Candida spec. H
Authors: Brückner B. , Tröger R. 
Published: July 2010

AbstractWith Candida spec. H during phosphate starvation the changes occurring in the macromolecular cell composition and growth parameters were studies. In the absence of exogenous phosphate, but in the presence of carbon source (n‐alkanes or glucose) and nitrogen source, the cells exponentially grow some time, whereas cell composition undergoes several changes. Both the lated, especially with n‐alkanes as carbon source. The carbohydrate content increased only slight, although the carbon source was in excess. The results were discussed.
A screening method for autoregulators of anthracycline‐producing streptomycetes
Authors: Eritt Inge , Gräfe U. , Fleck W. F. 
Published: July 2010

AbstractA novel method was proposed for screening of autoregulators by anthracycline‐producing strains of Streptomyces griseus. By means of a modified cosynthesis procedure, an indicator strain was detected capable of producing both leukaemomycin and aerial mycelium only in the presence yielding organisms and their mutants, but also by a streptomycin‐producing strain of Streptomyces griseus as well as its non‐differentiation derivative.
Biochemical characteristic of non‐streptomycin‐producing mutants of Streptomyces griseus. II. Lipids and fatty acid composition of vegetative mycelia
Authors: Gräfe U. , Reinhardt G. , Krebs D. , Roth M. , Bormann E. J. 
Published: July 2010

AbstractFive non‐streptomycin‐producing non‐aerial‐mycelium‐forming mutants (Str‐Amy‐) of Streptomyces griseus obtained either by spontaneous degeneration or during continuous cultivation of the high‐producing aerial‐mycelium‐forming parent strain HP (Str+Amy+) were checked with regard to the composition of mycelial lipid material. All the Str‐Amy‐derivatives differed from their ancestor strain HP by an increased ration of 12‐methyltetradecanoic acid (aC15:0) to isopalmitic acid (iC16:0) during growth on a chemically defined medium lacking branched‐chain amino acids. This finding attests alterations in the availability of precursors for the biosynthesis of methyl‐ branched fatty acids. The qualitative composition of phospholipids and other polar lipids in one mutant group was found to be similar to the progenitor strain but, additionally, both a yellow pigment and a neutral lipid component were produced in excess. A second type of mutant differed by its incapability to form ornithinolipids even under phosphate limitation. Changes of phospholipid composition were demonstrated in the course of fermentation. Formation of ornithinolipid was suppressed by an excess of inorganic phosphate in the medium, while the portions of phosphatidylethanolamine and cardiolipin increased strongly. Furthermore, the formation of ornithinolipids was influenced by nitrogen sources. These results suggest that the composition of membrane of S. griseus varies in dependence upon the composition of the medium and the age of the mycelium.
Formation of fertile aerial mycelium within asporogenous streptomycetes as induced by fungal metabolites
Authors: Küster E. , Attaby H. S. H. 
Published: July 2010

AbstractAsporogenous streptomycetes, e. g. Streptomyces flavochromogenes and S. luteolutescens, become able to form fertile aerial mycelium when they are cultivated in close contact with fungi. This may be caused by the production and secretion of fungal metabolites which induce or stimulate the aerial mycelium formation. An attempt was made to characterize the stimulatory factor. Among the numerous fungi tested the most active ones were Cladosporium cladosporioides and Drechslera erythrospila.
Fatty acid composition of lipids of Escherichia coli W 1655 F+ and its stable protoplast type L‐form
Authors: Gumpert J. , Schade W. , Krebs D. , Baykousheva S. , Ivanova E. , Toshkov As. 
Published: July 2010

AbstractThe comparative fatty acid analysis of extractable and non‐extractable lipids of Escherichia coli W 1655 F+ and its stable protoplast type L‐form shows quantitative as well as qualitative differences. From 10 different fatty acids obtained 16:0, 17:0, and 18:0 are present at about the same quantities in the lipid fractions of the bacterial and L‐form. The absence of larger amounts of 12:0, 14:0, and 14:βOH fatty acids in non‐extractable L‐form lipids reflects the loss of the cell wall in L‐form cells. 16:1 fatty acid was found in L‐form lipids only. This qualitative difference and the 2–3 times higher content of 18:1 in L‐form lipids and the 7 times lower content of cyc 19:0 in extractable lipids of the L‐form may be interpreted as alterations characteristic for the changed composition of the cytoplasmic membrane in L‐form cells.
Bistability in the glucose and energy metabolism of ammonia‐limited chemostat cultures of Escherichia coli ML 30
Authors: Müller P. J. , Von Frommannshausen Beate 
Published: July 2010

AbstractRecently bistability in the pyruvate production of ammonia‐limited glucose‐grown Escherichia coli ML 30 chemostat cultures was evidenced. The present investigation shows that the state of higher pyruvate production is connected with a lower glycogen content than in cells in the state of lower pyruvate production.The results support the view of a regulation of bistability on the step of pyruvate consumption by the citric acid cycle.Pronounced differences in energy formation in the two states of glucose bistability are discussed.
Spore differentiation in relation to certain antibiotics in the blue‐green alga Nodularia spumigena MERTENS
Authors: Pandey R. K. , Talpasayi E. R. S. 
Published: July 2010

AbstractInduction of spore differentiation is achieved within three days in Nodularia spumigena by incubating the cultures at 35°C in the light. Morphologically detectable sporulation and spore germination could not occur in the presence of chloramphenicol, streptomycin and penicillin. But chloramphenicol‐supplemented cultures developed prominent cyanophycin granules. Synthesis of these granules seems to be a non‐ribosomal phenomenon.
Characterization of two strains of Tobacco Mosaic Virus by biological, biochemical, immunological and electron microscopical techniques
Authors: El‐Ahdal A. M. E. , Mayer F. , El Afifi S. I. , Allam E. K. 
Published: July 2010

AbstractTwo strains of Tobacco Mosaic Virus (TMV) isolated from tomato plants were characterized by biological, biochemical, immunological and electron microscopical techniques including immuno‐electron microscopy. The biological tests indicated, on the basis of symptoms observed on differential hosts, differences between the two strains. However, detailed studies with the other techniques mentioned above did not reveal significant differences.
Leukaemomycin‐geblockte Mutanten des Streptomyces griseus und ihre Pigmente II. Neue 7‐Hydroxy‐bisanhydro‐rhodomycinone aus der Mutante ZIMET 41707/1P
Authors: Ihn W. , Wagner C. , Fleck W. F. , Tresselt D. , Eritt I. , Sedmera P. 
Published: July 2010

AbstractVarious blocked mutants were isolated from three leukaemomycin‐(daunomycin‐)producing strains IMET JA 3933, IMET JA 5142 and IMET JA 5570 of Streptomyces griseus by NTG and UV treatments. Among them, one class of four mutants ZIMET 43707/1P, IMET JA 5570/3P, IMET JA 5570/10P and IMET JA 5142/01P1 produced new blue and red pigments. Two red compounds designated 1PI and 1PII are the main components of the pigment complex produced by culture of the blocked mutant ZIMET 43707/1P. This paper describes the isolation of 1PI and IPII; furthermore, the spectral and physicochemical properties of these anthracyclinones and the elucidation of their structures are reported.
Hybridization of yeasts by protoplast fusion: Ploidy level of hybrids resulting from fusions in haploid strains of Pichia guilliermondii
Authors: Klinner U. , Böttcher F. 
Published: July 2010

AbstractHybrids produced by protoplast fusion between auxotrophic mutants of the same strain contained the parental markers heterozygously, as indicated by induced mitotic segregation. Even within the same fusion combination the hybrids differed in their mitotic stability and their induced mitotic segregation pattern. The occurrence of aneuploids was proved. The ploidy of the hybrids did not exceed the diploid level in any case.
The katabatic wind regime at Adelie Land, Antarctica
Authors: Parish Thomas R. , Wendler Gerd 
Published: July 2010

AbstractThe coastal sections of Adelie Land in East Antarctica experience the strongest and most persistent slope (katabatic) winds recorded about the continental periphery. The area was first explored during Mawson's 1911–14 Australasian Antarctic Expedition; the annual average surface wind speed at the base camp of Cape Denison was approximately 20 m s−1 during the course of the 2‐year stay in Antarctica. Field traverses conducted by the Mawson group and the subsequent establishment of additional bases and more recent deployment of automatic weather stations suggest that the zone of extreme katabatic winds is not confined to the Cape Denison site, but rather, extends several hundred kilometres inland from the coast and at least 60 km west along the coast. Numerical simulations of the Adelie Land katabatic wind regime have been conducted using a primitive equation three‐dimensional model. Results confirm the extreme wind conditions over the Adelie Land region and strongly suggest that the confluence of cold air drainage currents from the interior towards Adelie Land is responsible for the anomalous katabatic wind intensity.
The effect of domain shape on principal components analyses
Authors: Legates David R. 
Published: July 2010

AbstractIn a recent article, Richman criticized principal components analysis for not reflecting the spatial covariance structure observed in the data owing to an overdependence on the shape of the domain. This assertion, originally posited by Buell, is re‐examined using Buell's correlation functions and the geophysically based studies cited by Richman. Two examples—gauge‐corrected, global precipitation and global surface air temperature—are given to illustrate that even though both fields are from the same domain, maps of the spatial distribution of the loadings on the first four principal components are highly dissimilar. These fields are mapped using a rectangular (cylindrical equal‐area) projection and compared with other geophysically based studies that have employed rectangularly shaped domains as well as the rectangular domain mapping of Buell's correlation functions. Results indicate that component loading patterns are mainly determined by the structure exhibited in the dispersion matrix and only influenced by the domain shape (through spatial autocorrelation) to a limited degree.
Rainfall anomaly patterns in dry and wet years over Nigeria
Authors: Olaniran O. J. 
Published: July 2010

AbstractRainfall amount and rainfall frequency for five individual dry and five individual wet years were compared with the 1941–1987 averages for Nigeria. Five spatial‐anomaly types were found to emerge for dry years, namely above average rainfall in southern Nigeria but below average rainfall in northern Nigeria (spatial type I), above average rainfall in the centre but below average rainfall in the coastal and extreme northern parts of the country (spatial type II) and below average rainfall in southern Nigeria but above average rainfall in northern Nigeria (spatial type III). The other two anomaly types are country‐wide occurrence of below average rainfall (spatial type IV) and country‐wide occurrence of above average rainfall (spatial type V). These spatial‐anomaly types also hold true for wet years, except that the spatial type II is replaced by the occurrence of below average rainfall in the centre but above average rainfall in the coastal and extreme northern parts of the country (spatial type VI).The spatial type I and II anomalies support the hypothesis of a restricted northward advance of the Inter Tropical Discontinuity (ITD) in dry years and on a complementary basis the spatial patterns for the rainfall amount anomaly (RAA) and the rainfall frequency anomaly (RFA) depicted these two anomaly types in 40 per cent of the monthly periods for the set of dry years considered. The spatial type IV anomaly, which occurs during the peak of the rainy season, supports the hypothesis of a weakening of the rainy season intensity and on a complementary basis the spatial patterns for the RAA and the RFA depicted this pattern in 30 per cent of the monthly periods for the dry years studied. This shows that both hypotheses are valid for explaining dry years in subtropical West Africa.The spatial type III and V anomalies support the hypothesis of a considerable northward incursion of the ITD in wet years. It was found that the spatial patterns of the RAA depicted these anomaly types in 53.3 per cent of the monthly periods whilst the spatial patterns of the RFA depicted the anomaly types in 66.7 per cent of the monthly periods for the set of wet years considered.
Some updated statistical assessments of the surface temperature response to increased greenhouse gases
Authors: Schönwiese Christian‐D. , Runge Kirsten 
Published: July 2010

AbstractIn an earlier study we analysed the surface temperature response to increasing atmospheric carbon dioxide (CO2) concentrations based on long‐term observational climate time series using multiple regression statistical techniques. Moreover, these assessments were compared with the results from general circulation model experiments. Recently we have used improved climate data sets, added ENSO (El Niño/Southern Oscillation) forcing to our multiple regression models, improved the volcanic forcing parameters and introduced phase shifts of the temperature response to the forcing parameter time series. In addition, we used not only CO2 but also ‘equivalent’ CO2 concentrations accounting for additional greenhouse gases. The results of these updated assessments are briefly summarized.
Modelling the differential impact of 1984 and 1950 sea‐surface temperatures on sahel rainfall
Authors: Druyan Leonard M. , Hastenrath Stefan 
Published: July 2010

AbstractExperiments with the GISS general circulation model are analysed to evaluate the differential impact of the contrastingly different 1984 and 1950 sea‐surface temperature (SST) patterns on simulated precipitation over sub‐Saharan Africa. Simulations yielded significantly lower August rainfall with 1984 SST as compared with 1950 SST. Differences in the moisture convergence into the Sahel responsible for the different resultant precipitation conditions are related to different evolutions of key circulation features. These are, in turn, consistent with some 1984 vs. 1950 SST differences in the Atlantic Ocean. In the model scenario, anomalously warm surface waters in July 1984 deepened the near‐equatorial trough over the coastal waters adjacent to north‐west Africa, promoting a circulation that eventually inhibited moisture advection from the Gulf of Guinea to the Sahel. This atmospheric evolution included a southward expansion of the West African Mid‐tropospheric jet, which has been observed to occur during dry summers. The study suggests that this structure is a symptom of drought rather than a cause.
An approach to reconstruction of temperature on a seasonal basis using historical documents from China
Authors: Wang Risheng , Wang Shaowu , Fraedrich Klaus 
Published: July 2010

AbstractA methodology is presented for reconstructing past climates on a seasonal basis using historical data from chronicles and documents in China. This procedure consists of three steps: first, individual climate indicators are identified and scaled by ordinal numbers (or grades) based on their individual statistics; secondly, the cold (warm) climate index is defined as a function of the scaled indicators. Finally, the climate index is calibrated in terms of temperatures by regression with recent observations. This methodology is applied to constructing the temperature series of the last 500 years in China, based on which climate variations are studied. Spectrum analysis shows variability in about 200, 80, 30, and 22–year cycles.
Nocturnal air and road surface temperature variations in complex terrain
Authors: Bogren Jörgen , Gustavsson Torbjörn 
Published: July 2010

AbstractThis paper is part of an ongoing project dealing with the modelling of local climate for predicting temperature variations and risks of road slipperiness under various synoptic conditions. Temperature recordings from mobile measurements taken along road stretches have been analysed to determine the influence of valleys on the variation in air and road surface temperatures. During clear, calm nights, the variation in air temperature between valley bottoms and surrounding areas can be related to geometric properties of valleys, such as depth and width. It is seen that temperature differences between valleys and surrounding areas increase with increasing depth and width. The prevailing wind speed has been found to be a major factor controlling the variation in temperature. The variation in air temperature is totally smoothed out in situations in which there is an ambient wind speed exceeding 3 m s−1. In the interval 2–3 m s−1, the degree of wind exposure in valleys is of importance for the magnitude of the air temperature differences. Counter‐radiation from clouds has been found to significantly reduce the intensity of cold air pools. Under partly cloudy situations (3–5 octas) with no wind, the temperature difference between valley bottoms and surrounding areas differs by approximately 6°C in comparison with clear, calm situations. The relationship between differences in air and road surface temperature has also been studied. In general, an increase in cold air pool intensity of 1°C lowers the road surface temperature by 0·4°C.
Tropical perturbations in the Eastern Pacific and the Precipitation field over North‐Western Mexico in relation to the enso phenomenon
Authors: Reyes Sergio , Mejía‐Trejo Adan 
Published: July 2010

AbstractMonthly time series of the number of tropical perturbations (TP) for the eastern tropical Pacific Ocean, the Southern Oscillation Index (SOI), the north‐eastern tropical sea‐surface temperature (SST), and the precipitation field over north‐western Mexico for the period 1966–1988 are analysed by using power spectral techniques. It is found that a significant coherence exists at the frequency bands of 0.015–0.025 cycles per month and 0.035–0.040 cycles per month. These signals are associated with the El Niño/Southern Oscillation (ENSO) and the Quasi‐Biennial Oscillation (QBO) phenomena, respectively. As reported elsewhere, fewer tropical storms over the Atlantic and western Pacific Oceans tend to be associated with negative values of the SOI (or positive anomalies of the eastern Pacific SST); however, for the eastern Pacific, only the period 1966–1979 coincides with the above conclusion. The period 1980–1987, with two observed ENSO phenomena, shows an above normal number of TP coincident with negative values of the SOI and positive SST anomalies. Briefly, the controlling mechanisms lie in the atmospheric and oceanic interactions. That is, during the period 1966–1979, the thermal potential was relatively weak, while for the period 1980–1988 the thermal potential was stronger, with more frequent tropical cyclone formation. The summer precipitation field over the Sonoran Desert, Mexico, is largely influenced by the nearby presence of eastern Pacific tropical perturbations, especially during the ENSO years, while summer precipitation over the Sierras (south‐east of the Sonoran Desert) always shows an influence from both the Atlantic and Pacific atmospheric phenomena.