Search Results - (Author, Cooperation:J. Munch)

2014-05-03

American Association for the Advancement of Science (AAAS)

0036-8075

1095-9203

Biology

Chemistry and Pharmacology

Computer Science

Medicine

Natural Sciences in General

Physics

Agammaglobulinemia/genetics ; *Cell Size ; Chloride Channels/*metabolism ; Gene Knockout Techniques ; Genome-Wide Association Study ; HCT116 Cells ; HEK293 Cells ; Humans ; Membrane Proteins/genetics/*metabolism ; Mutation ; Protein Multimerization ; RNA Interference ; RNA, Small Interfering/genetics ; Taurine/metabolism ; Transfection

2011-06-17

Nature Publishing Group (NPG)

0028-0836

1476-4687

Biology

Chemistry and Pharmacology

Medicine

Natural Sciences in General

Physics

Amino Acid Sequence ; Amino Acids/*chemistry/*pharmacology ; Amyloid/*antagonists & inhibitors/*chemistry/metabolism ; Amyloid beta-Peptides/antagonists & inhibitors/chemistry/metabolism ; Computer-Aided Design ; *Drug Design ; HIV Infections/virology ; Hydrogen Bonding ; Kinetics ; Models, Molecular ; Peptides/*chemistry/*pharmacology ; Polylysine/pharmacology ; Protein Conformation ; tau Proteins/antagonists & inhibitors

1089-7623

AIP Digital Archive

Physics

Electrical Engineering, Measurement and Control Technology

An instrument is being designed and constructed to measure the mass and energy spectrum of ions lost from the end cells of the Mirror Fusion Test Facility (MFTF-B) experiment. The mass and energy analyzer is of an E parallel to B type and is being designed to resolve protons and deuterons in an energy range of 2–200 keV to within ±2% or 200 eV. The magnet is designed to be small and high field (1.2 T) so that it will fit into a radial array on the MFTF-B end dome. To achieve this large energy range in a small magnet, careful attention is paid to the trimming of the poles and electrode near the input edge. The input slit size is adjusted by fast variable apertures to increase the dynamic range. Also, the electronics is designed to be compatible with the high neutron flux rate in the MFTF-B environment. Detailed calculations on particle trajectories and magnet trimming will be presented, as well as detector and electronics design.

Electronic Resource

1089-7623

AIP Digital Archive

Physics

Electrical Engineering, Measurement and Control Technology

We are incorporating a system of fast, variable apertures in our designs for the x-ray, neutral, and ion spectrometers for plasma diagnostics on Mirror Fusion Test Facility B (MFTF-B). The purpose of these apertures is to maintain optimized count rates, and thus optimized measurement statistics during an experimental shot, where flux variations as large as 104–105 may occur in periods as short as 0.1 s. We shall discuss the application of the fast apertures to the x-ray spectrometer in particular, and to the other diagnostic instruments in general. The particular design requirements for the optimized aperture system will be discussed, as will be the influence the system has on the data-handling process. We have performed experiments to test this new concept and shall present the results, including the details of the closed-loop feedback circuit controlling the apertures, optimization of the loop gain, and the engineering issues of the system, such as the effect of vacuum feedthrough, position sensitivity, and alignment criteria.

Electronic Resource

0014-5793

Aggregation ; Crystallization ; Dynamic light scattering ; Lysozyme ; Protein ; Supersaturation

Elsevier Journal Backfiles on ScienceDirect 1907 - 2002

Biology

Chemistry and Pharmacology

Physics

Electronic Resource

0022-0248

Elsevier Journal Backfiles on ScienceDirect 1907 - 2002

Chemistry and Pharmacology

Geosciences

Physics

Electronic Resource

0021-9673

Elsevier Journal Backfiles on ScienceDirect 1907 - 2002

Chemistry and Pharmacology

Electronic Resource

1572-817X

dichromated gelatine ; holography ; notch filters

Springer Online Journal Archives 1860-2000

Electrical Engineering, Measurement and Control Technology

Physics

Abstract We have studied the factors limiting the quality of holographic notch filters. We have employed a novel recording scheme in which the sample is translated during exposure, eliminating flare due to reflections at the boundaries, and simultaneously reducing the scatter of the final hologram. We have also refined a gravity-settling dichromated gelatine (DCG) deposition technique and incorporated hardening of the DCG layers during the drying stage. With this, we have produced high optical quality, uniform, flare-free DCG filters with an optical density, OD 〉 5, bandwidth 〈 20 nm and scatter almost as low as that for state of the art dielectric notch filters.

Electronic Resource

1572-817X

intracavity SBS ; MOPA ; phase conjugate oscillator ; phase conjugation ; Q-switching ; stimulated Brillouin scattering

Springer Online Journal Archives 1860-2000

Electrical Engineering, Measurement and Control Technology

Physics

Abstract A method for increasing the output power of a phase conjugated oscillator (PCO) by using two stimulated-Brillouin-scattering (SBS) cells is described. The average power has been more than doubled and the peak power has been increased by twenty times compared to the single-SBS-cell PCO. Near unity beam quality has been measured.

Electronic Resource

1432-1890

Key words Alder mycorrhizas ; Characterisation of ectomycorrhizas ; Morphology ; Anatomy ; Alnus glutinosa

Springer Online Journal Archives 1860-2000

Biology

Abstract  Ectomycorrhizal types of black alder [Alnus glutinosa (L.) Gaertn.] collected over a 3-year period within an alder forest were characterised by morphological and anatomical features. Of the total of 16 types, 14 are described for the first time in this paper. Eight identified types belong to the genera Russula, Lactarius, Naucoria, and Cortinarius, while eight further types remained unidentified. In some cases, similarities of mantle features indicate relationships to identified mycorrhizas. Mycorrhizas of Naucoria escharoides and N. subconspersa were not distinguished. Two unidentified mycorrhizal types exhibited hyphal mantle structures very similar to these Naucoria species. Within the genus Cortinarius, mycorrhizas of C. cf. helvelloides were easily distinguished from all other Cortinarius-like mycorrhizas described on Alnus, which in general showed little anatomical variation. Two further unidentified mycorrhizas, "Alnirhiza lilacina" and "A. violacea", probably also belong to Cortinarius. The ectomycorrhiza of Russula pumila was the only identified type within the genus Russula, but the unidentified type "Alnirhiza cremicolor" also likely belongs to this genus. Three Lactarius species were present in the experimental plot. Two species (L. obscuratus and L. omphaliformis) had indistinguishable mycorrhizal types, but were easily differentiated from the mycorrhizas of L. lilacinus, which caused intracellular penetration of Hartig net hyphae into epidermal and cortical cells. All other mycorrhizal types of black alder exhibited a paraepidermal Hartig net without penetration of root cells. Two unidentified mycorrhizal types "Alnirhiza atroverrucosa" and "A. cystidiobrunnea", already described from North American Alnus rubra as unnamed morphotypes, showed no similarity to identified mycorrhizas. All 16 mycorrhizal types appeared to be specific or at least typical for alders, since they have not yet been reported from other tree species.

Electronic Resource

1432-0649

PACS: 42.55.Rz; 42.60.Lh; 95.55.Ym

Springer Online Journal Archives 1860-2000

Physics

Abstract. Measurements of intensity and frequency noise of an injection-locked 5-W Nd:YAG laser are presented and compared with the predictions of models. We show that the output of the injection-locked laser has very low levels of noise, and that the measurements support the predictions of the models. Thus these models can confidently be used to predict the performance of high-power, injection-locked lasers being developed for gravity wave detection.

Electronic Resource

1432-0800

Springer Online Journal Archives 1860-2000

Energy, Environment Protection, Nuclear Power Engineering

Medicine

Electronic Resource

1432-0789

Key wordsRhizobium meliloti ; Genetically engineered microorganisms ; Ecological risk assessment ; Soil column model system ; Polymerase chain reaction

Springer Online Journal Archives 1860-2000

Biology

Geosciences

Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition

Abstract In order to identify potential ecological risks associated with the environmental release of two Rhizobium meliloti strains, genetically engineered with the firefly-derived luciferase gene (luc), a pre-release greenhouse investigation was conducted. The upper 4 cm of soil columns (30 cm diameter; 65 cm depth), which were filled according to the horizons of an agricultural field (loamy sand), were inoculated with seeds of Medicago sativa (alfalfa) and R. meliloti cells at approximately 5×106 cells·g–1 soil. Four treatments were tested: inoculation with a non-engineered wild type strain (2011), strain L33 (luc +), strain L1(luc +, recA–) and non-inoculated controls. The fate of the engineered strains was followed by two methods: (1) selective cultivation and subsequent detection of bioluminescent colonies and (2) PCR detection of the luc gene in DNA, directly extracted from soil. Strain R. meliloti L33 declined to 9.0×104 cfu·g–1 soil within 24 weeks and to 2.8×103 cfu·g–1 soil within 85 weeks in the upper 25 cm of the soil columns. Decline rates for R. meliloti L1 were not significantly different. Vertical distribution analysis of the recombinant cells after 37 weeks revealed that in three of four columns tested, the majority of cells (〉98%) remained above 10 cm soil depth and no recombinant cells occurred below 20 cm depth. However, in one column all horizons below 20 cm were colonized with 2.2×104 to 6.8×104 cfu g–1 soil. Ecological monitoring parameters included organic substance, total nitrogen, ammonium and nitrate, microbial biomass, culturable bacteria on four different growth media and the immediate utilization of 95 carbon sources (BiologGN) by soil-extracted microbial consortia. None of the parameters was specifically affected by the genetically engineered cells.

Electronic Resource

1432-0789

Key words Arginine-ammonification rate ; Microbial biomass content ; Microbial activities ; Metabolic quotient ; Ecosystem research

Springer Online Journal Archives 1860-2000

Biology

Geosciences

Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition

Abstract  The content levels and activities of the microbiota were estimated in topsoils and in one soil profile at agricultural and forest sites of the Bornhöved Lake district in northern Germany. Discrepancies between data achieved by fumigation-extraction (FE) and substrate-induced respiration (SIR), both used for the quantification of microbial biomass, were attributed to the composition of the microbial populations in the soils. In the topsoils, the active, glucose-responsive (SIR) versus the total, chloroform-sensitive microbial (FE) biomass decreased in the order; field maize monoculture (field-MM)〉field crop rotation (field-CR) and dry grassland〉beech forest. This ratio decreased within the soil profile of the beech forest from the litter horizon down to the topsoil. Differences between microbial biomass and activities suggested varying biomass-specific transformation intensities in the soils. The metabolic quotient (qCO2), defined as the respiration rate per unit of biomass, indicates the efficiency in acquiring organic C and the intensity of C mineralization, while biomass-specific arginine-ammonification (arginine-ammonification rate related to microbial biomass content) seems to be dependent on N availability. The qCO2, calculated on the basis of the total microbial biomass, decreased for the topsoils in the same order as did the ratio between the active, glucose-responsive microbial biomass to the total, chloroform-sensitive microbial biomass, in contrast to qCO2 values based on the glucose-responsive microbial biomass, which did not. There was no difference between the levels of biomass-specific arginine-ammonification in topsoils of the fertilized field-CR, fertilized field-MM, fertilized dry grassland and eutric alder forest, but levels were lower in the beech forest, dystric alder forest, and unfertilized wet grassland topsoils. Ratios between values of different microbiological features are suggested to be more useful than microbiological features related to soil weight when evaluating microbial populations and microbially mediated processes in soils.

Electronic Resource

1432-0789

Key words Nitrous oxide ; Forage crops ; Spring barley ; Nitrogen fertiliser ; Thawing and freezing cycles

Springer Online Journal Archives 1860-2000

Biology

Geosciences

Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition

Abstract  N2O emission rates from a sandy loam soil were measured in a field experiment with 2 years of perennial forage crops (ryegrass, ryegrass-red clover, red clover) and 1 year of spring barley cultivation. Spring barley was sown after the incorporation of the forage crop residues. All spring barley plots received 40 kg N ha–1 N fertiliser. Ryegrass, ryegrass-red clover and red clover plots were fertilised with 350 kg N ha–1, 175 kg N ha–1 and 0 kg N ha–1, respectively. From June 1994 to February 1997, N2O fluxes were continuously estimated using very large, closed soil cover boxes (5.76 m2). In order to compare the growing crops, the 33 months of investigation were separated into three vegetation periods (March–September) and three winter periods (October–February). All agronomic treatments (fertilisation, harvest and tillage) were carried out during the vegetation period. Large temporal changes were found in the N2O emission rates. The data were approximately log-normally distributed. Forty-seven percent of the annual N2O losses were observed to occur during winter, and mainly resulted from N2O production during daily thawing and freezing cycles. No relationship was found between the N2O emissions during the winter and the vegetation period. During the vegetation period, N2O losses and yields were significantly different between the three forage crops. The unfertilised clover plot produced the highest yields and the lowest N2O losses on this soil compared to the highly fertilised ryegrass plot. Total N2O losses from soil under spring barley were higher than those from soil under the forage crops; this was mainly a consequence of N2O emissions after the incorporation of the forage crop residues.

Electronic Resource

1432-0789

Ecosystem research ; Agricultural soils ; Forest soils ; Microbial biomass ; Microbial activities

Springer Online Journal Archives 1860-2000

Biology

Geosciences

Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition

Abstract The soil microbial biomass and activity were estimated for seven field (intensive and extensive management), grassland (dry and wet), and forest (beech, dry and wet alder) sites. Three of the sites (wet grassland, dry and wet alder) are located on a lakeshore and are influenced by lake water and groundwater. Four different methods were selected to measure and characterize the microbial biomass. Values of microbial biomass (weight basis) and total microbial biomass per upper horizon and hectare (volume basis) were compared for each site. Fumigation-extraction and substrate-induced respiration results were correlated but dit not give the same absolute values for microbial biomass content. When using the original conversion factors, substrate-induced respiration gave higher values in field and dry grassland soils, and fumigation-extraction higher values in soils with low pH and high water levels (high organic content). Results from dimethylsulfoxide reduction and arginine ammonification, two methods for estimating microbial activity, were not correlated with microbial biomass values determined by fumigation-extraction or substrate-induced respiration in all soils examined. In alder forest soils dimethylsulfoxide reduction and arginine ammonification gave higher values on the wet site than on the dry site, contrary to the values estimated by fumigation-extraction and substrate-induced respiration. These microbial activities were correlated with microbial biomass values only in field and dry grassland soils. Based on soil dry weight, microbial biomass values increased in the order intensive field, beech forest, extensive field, dry grassland, alder forest, wet grassland. However, microbial biomass values per upper horizon and hectare (related to soil volume) increased in agricultural soils in the order intensive field, dry grassland, extensive field, wet grassland and in forest soils in the order beech, wet alder, dry alder. We conclude that use of the original conversion factors with the soils in the present study for fumigation-extraction and substrate-induced respiration measurements does not give the same values for the microbial biomass. Furthermore, dimethylsulfoxide reduction and arginine ammonification principally characterize specific microbial activities and can be correlated with microbial biomass values under specific soil conditions. Further improvements in microbial biomass estimates, particularly in waterlogged soils, may be obtained by direct counts of organisms, ATP estimate, and the use of 14C-labelled organic substrates. From the ecological viewpoint, data should also be expressed per horizon and hectare (related to soil volume) to assist in the comparison of different sites.

Electronic Resource

1432-0789

Key words Global warming ; Nitrous oxide ; Soil warming ; Agriculture ; Ecosystem manipulation

Springer Online Journal Archives 1860-2000

Biology

Geosciences

Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition

Abstract  In order to determine the effects of increased soil temperature resulting from global warming on microbiological reactions, a 21-month field experiment was carried out in the Bavarian tertiary hills. The major objective was to focus on N2O releases as either a positive or negative feedback in response to global warming. The soils of a fallow field and a wheat field were heated 3  °C above ambient temperature and N2O fluxes were measured weekly from June 1994 to March 1996. During the experimental period, measured temperature differences between the control plots and the heated plots were 2.9±0.3  °C at a depth of 0.01 m and 1.0–1.8  °C at a depth of 1 m. Soil moisture decreased with the elevated soil temperatures of the heated plots. The mean differences in soil moisture between the treatments were 6.4% (fallow field) and 5.2%DW (wheat field dry weight, DW), respectively. Overall N2O releases during the experimental period from the fallow field were 4.8 kg N2O–N ha–1 in the control plot against 5.0 kg N2O–N ha–1 in the heated plot, and releases from the wheat field were 8.0 N2O–N ha–1 in the control plot and 7.6 N2O–N kg ha–1 in the heated plot. However, on a seasonal basis, cumulated N2O emissions differed between the plots. During the summer months (May–October), releases from the heated fallow plot were 3 times the rates from the control plot. In the winter months, N2O releases increased in both the fallow and wheat fields and were related to the number of freezing and thawing cycles.

Electronic Resource

1432-0789

Key words Proteolytic soil bacteria ; Pseudomonas fluorescens ; Bacillus cereus ; Bacillus mycoides ; Metallopeptidases

Springer Online Journal Archives 1860-2000

Biology

Geosciences

Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition

Abstract  Four topsoils and three subsoils from an arable field, two grasslands and a beech forest with different ecophysiological properties were investigated for the most abundant proteolytic bacteria. The number of proteolytic bacteria was estimated with the most probable number (MPN) assay using a gelatin-based medium. Subsequent isolations of bacteria were performed on a gelatin-based agar medium. No coherence was observed between site specific properties, MPN counts of proteolytic bacteria and proteolytic activities at the different sites. In the subsoils proteolytic activity was considerably lower than in the corresponding topsoils. Differences in MPN counts of proteolytic bacteria were only significant for the arable field profile in March, with lower values in the subsoil. Pseudomonas fluorescens was the most abundant proteolytic species in all investigated horizons except for the acidic topsoil of the beech forest. Bacillus cereus and B. mycoides were also prominent especially in the topsoils and were less abundant in the subsoils. Flavobacterium-Cytophaga bacteria were enriched in autumn, but were lacking in the beech forest horizons and in the topsoil of the arable field. The results of inhibition assays suggest that the extracellular peptidases formed by these species were metalloenzymes.

Electronic Resource

1432-0614

Springer Online Journal Archives 1860-2000

Biology

Process Engineering, Biotechnology, Nutrition Technology

Abstract The potential for reductive dechlorination of hexachlorobenzene was investigated in samples of three different, naturally oxic soils held under conditions of high oxygen deficiency. The soils were water-saturated and the influence on dechlorination of adding different electron donors, a surfactant and an anaerobic microbial consortium was tested. The influence of supplied electron donors seems to depend on the organic matter content of the soils. Dechlorination in the organic-matter-rich soil from Maulach was not affected by amendment with organic electron donors. A release of about 40% chloride within 140 days was observed for this soil in all biotic-treated assays. By contrast, the organic-matter-poor soil of Eppingen showed no dechlorination in unamended assays. However, when it was supplemented with organic electron donors dechlorination of 2%–37% occurred within 140 days, depending on the type of electron donor. Complex substrate (wheat strawdust), from which carbon is slowly liberated, gave the best results. These two soils had an indigenous dechlorinating anaerobic microflora, whereas the third soil (Rastatt) required inoculation with an anaerobic consortium for dechlorination. The addition of electron donors alone did not cause dechlorination in this sandy soil. The addition of a surfactant (Tween 80) to increase the bioavailability of hexachlorobenzene did not enhance dechlorination. This process was not inhibited by inherent alternative electron acceptors in soil (NO3−, SO4 2−, Fe3+). The dechlorination did not require methanogenic conditions.

Electronic Resource

1432-0614

Springer Online Journal Archives 1860-2000

Biology

Process Engineering, Biotechnology, Nutrition Technology

Abstract The potential for aerobic mineralization of [U-14C]dibenzo-p-dioxin (DD) was investigated in samples of three different agricultural soils already contaminated with polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/F) by industrial activities. The influence of amendments, i.e. wheat straw and compost, and of soil treatment by inoculation with lignolytic fungi, grown on wheat straw substrate, was tested. All the soils tested contained an indigenous DD-mineralizing microflora. The soil characterized by the highest organic matter content and the highest content of soil microbial biomass displayed the best DD mineralization of 36.6% within 70 days, compared with the two organic-matter-poor soils with an endogenous DD mineralization of 19.5% and 23.3% respectively. Amendments with compost increased DD mineralization up to 28% in both soils with low organic matter and microbial biomass content, but did not affect mineralization in the organic-matter-rich soil. Addition of wheat straw had no constant influence on DD mineralization in the soils tested. The best DD mineralization resulted from inoculation with lignolytic white-rot fungi (Phanerochaete chrysosporium, Pleurotus sp. Florida, Dichomitus squalens) and with an unidentified lignolytic fungus, which was isolated originally from a long-term PCDD/F-contaminated soil. A mineralization of up to 50% within 70 days was reached by this treatment. The influence of inoculated fungi on mineralization differed between the soils investigated.

Electronic Resource