Perforations in jet engine supersonic inlet increase shock stability

Modification of a conventional jet engine internal compression supersonic inlet results in increased shock stability and thus, engine instantaneous response to changes in inlet air properties. This technique provides a large amount of bleed near the maximum pressure recovery at the expense of minor bleed flow during critical operation

Carbon isotope anomaly in the major plant C-1 pool and its global biogeochemical implications

We report that the most abundant C-1 units of terrestrial plants, the methoxyl groups of pectin and lignin, have a unique carbon isotope signature exceptionally depleted in C-13. Plant-derived C-1 volatile organic compounds (VOCs) are also anomalously depleted in C-13 compared with Cn+1 VOCs. The results confirm that the plant methoxyl pool is the predominant source of biospheric C-1 compounds of plant origin such as methanol, chloromethane and bromomethane. Furthermore this pool, comprising ca 2.5% of carbon in plant biomass, could be an important substrate for methanogenesis and thus be envisaged as a possible source of isotopically light methane entering the atmosphere. Our findings have significant implications for the use of carbon isotope ratios in elucidation of global carbon cycling. Moreover methoxyl groups could act as markers for biological activity in organic matter of terrestrial and extraterrestrial origin

Gibt es geeignete Legehybriden für die Öko-Haltung?

In einem Feldversuch wurden Eignungs- und Leistungstests an verschiedenen Legehybriden-Herkünften durchgeführt. Wegen verstärkt auftretendem Federpicken bei ihren Legehennen initiierten schleswig-holsteinische Bio-Betriebe und der Ökoring Schleswig Holstein mit Unterstützung der Erna-Graff-Stiftung für Tierschutz Berlin einen Eignungstest für verschiedene Legehennen-Herkünfte, um eine für den ökologischen Landbau geeignete Legehenne zu finden. Die Erfassung von Gefiederschäden, Eiqualität und die Ergebnisauswertung wurden in Zusammenarbeit mit dem HDLGN Tierzuchtzentrum Neu-Ulrichstein durchgeführt

Evidence for Cooper Pair Diffraction on the Vortex Lattice of Superconducting Niobium

We investigated the Abrikosov vortex lattice (VL) of a pure Niobium single crystal with the muon spin rotation (\mu SR) technique. Analysis of the \mu SR data in the framework of the BCS-Gor'kov theory allowed us to determine microscopic parameters and the limitations of the theory. With decreasing temperature the field variation around the vortex cores deviates substantially from the predictions of the Ginzburg-Landau theory and adopts a pronounced conical shape. This is evidence of partial diffraction of Cooper pairs on the VL predicted by Delrieu for clean superconductors.Comment: 9 pages, 6 figure

Magnetic field distribution and characteristic fields of the vortex lattice for a clean superconducting niobium sample in an external field applied along a three-fold axis

The field distribution in the vortex lattice of a pure niobium single crystal with an external field applied along a three-fold axis has been investigated by the transverse-field muon-spin-rotation (TF-$\mu$SR) technique over a wide range of temperatures and fields. The experimental data have been analyzed with the Delrieu's solution for the form factor supplemented by phenomenological formulas for the parameters. This has enabled us to experimentally establish the temperatures and fields for the Delrieu's, Ginzburg-Landau's, and Klein's regions of the vortex lattice. Using the numerical solution of the quasiclassical Eilenberger's equation the experimental results have been reasonably understood. They should apply to all clean BCS superconductors. The analytical Delrieu's model supplemented by phenomenological formulas for its parameters is found to be reliable for analyzing TF-$\mu$SR experimental data for a substantial part of the mixed phase. The Abrikosov's limit is contained in it.Comment: 12 pages, 15 figure

Biting midges (Ceratopogonidae: Diptera) present in aquatic macrophytes from wetlands of Marchantaria Island, Iranduba, Central Amazonia, Brazil

Ceratopogonidae (Diptera) are easily found in both aquatic and semi-aquatic sites under various environmental conditions, where their immature stages develop in areas of nutrient richness. Material was collected from six wetland areas in Ilha da Marchantaria, Iranduba, Amazonas, between July and October 2010 and February and June 2011 throughout the Amazon River’s cycle (receding and flooding stages), in aquatic macrophytes Eichhornia crassipes, Pistia stratiotes and Salvinia auriculata. The collections produced 431 immature individuals: 191 (44.3%) in E. crassipes, 125 (29%) in P. stratiotes and 115 (26.7%) in S. auriculata. After development in the laboratory 16 species were identified belonging to the following genera: Alluaudomyia Kieffer, Bezzia Kieffer, Dasyhelea Kieffer, Forcipomyia Meigen, Heteromyia Say, Neobezzia Wirth and Ratanaworabhan, Palpomyia Meigen, Paryphoconus Enderlein and Stilobezzia Kieffer. Aquatic macrophytes are excellent substrates for immature Ceratopogonidae, which are important because of their value to the balance of biodiversity in ceratofauna in wetlands.Fil: Torreias, Sharlene R. S.. Laboratório de Citotaxonomia e Insetos Aquáticos , Coordenação de Biodiversidade – CBio, Instituto Nacional de Pesquisas da Amazônia – INPA; BrasilFil: Ferreira Keppler, R. L.. Laboratório de Citotaxonomia e Insetos Aquáticos , Coordenação de Biodiversidade – CBio, Instituto Nacional de Pesquisas da Amazônia – INPA; BrasilFil: Ronderos, Maria Marcela. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico La Plata. Centro de Estudios Parasitológicos y de Vectores (i); Argentin

satFRET: estimation of Forster resonance energy transfer by acceptor saturation

We demonstrate theoretically and experimentally the quantification of Förster resonance energy transfer (FRET) by direct and systematic saturation of the excited state of acceptor molecules. This version of acceptor depletion methods for FRET estimation, denoted as “satFRET” is reversible and suitable for time-resolved measurements. The technique was investigated theoretically using the steady-state solution of the differential equation system of donor and acceptor molecular states. The influence of acceptor photobleaching during measurement was included in the model. Experimental verification was achieved with the FRET-pair Alexa 546- Alexa 633 loaded on particles in different stoichiometries and measured in a confocal microscope. Estimates of energy transfer efficiency by excited state saturation were compared to those obtained by measurements of sensitised emission and acceptor photobleaching. The results lead to a protocol that allows time-resolved FRET measurements of fixed and living cells on a conventional confocal microscope. This procedure was applied to fixed Chinese hamster ovary cells containing a cyan fluorescent protein and yellow fluorescent protein pair. The time resolution of the technique was demonstrated in a live T cell activation assay comparing the FRET efficiencies measured using a genetically encoded green and red fluorescent protein biosensor for GTP/GDP turnover to those measured by acceptor photobleaching of fixed cells

Bulk rock elastic moduli at high pressures, derived from the mineral textures and from extrapolated laboratory data

The elastic anisotropy of bulk rock depends on the mineral textures, the crack fabric and external parameters like, e.g., confining pressure. The texture-related contribution to elastic anisotropy can be predicted from the mineral textures, the largely sample-dependent contribution of the other parameters must be determined experimentally. Laboratory measurements of the elastic wave velocities are mostly limited to pressures of the intermediate crust. We describe a method, how the elastic wave velocity trends and, by this means, the elastic constants can be extrapolated to the pressure conditions of the lower crust. The extrapolated elastic constants are compared to the texture-derived ones. Pronounced elastic anisotropy is evident for phyllosilicate minerals, hence, the approach is demonstrated for two phyllosilicate-rich gneisses with approximately identical volume fractions of the phyllosilicates but different texture types

Binding of Antitumor Ruthenium(III) Complexes to Plasma Proteins

Presently, there is large interest in analysing the interactions in vitro with plasma proteins of some novel antitumor ruthenium(III) complexes that are in preclinical or clinical phase. The joint application of separation and spectroscopic techniques provides valuable information on the nature and the properties of the resulting ruthenium/protein adducts. Recent work carried out in our laboratory points out that, under physiological conditions, some selected ruthenium(III) complexes bind plasma proteins tightly with a marked preference for surface imidazole groups. Representative examples of interactions of antitumor ruthenium(III) complexes with plasma proteins such as albumin and transferrin are given. Notably the antitumor ruthenium(III) complexes considered here bind proteins much tighter than DNA; it is proposed that protein binding of ruthenium(III) complexes will have a large impact on the biodistribution, the pharmacokinetics and the mechanism of action of these experimental drugs

New insight into the atmospheric chloromethane budget gained using gained using

International audienceAtmospheric chloromethane (CH3Cl) plays an important role in stratospheric ozone destruction, but many uncertainties still exist regarding strengths of both sources and sinks and the processes leading to formation of this naturally occurring gas. Recent work has identified a novel chemical origin for CH3Cl, which can explain its production in a variety of terrestrial environments: The widespread structural component of plants, pectin, reacts readily with chloride ion to form CH3Cl at both ambient and elevated temperatures (Hamilton et al., 2003). It has been proposed that this abiotic chloride methylation process in terrestrial environments could be responsible for formation of a large proportion of atmospheric CH3Cl. However, more information is required to determine the global importance of this new source and its contribution to the atmospheric CH3Cl budget. A potentially powerful tool in studying the atmospheric CH3Cl budget is the use of stable carbon isotope ratios. In an accompanying paper it is reported that the reaction of CH3Cl with OH radical, the dominant sink for atmospheric CH3Cl, is accompanied by an unexpectedly large fractionation factor (Gola et al., 2005). Another recently published study shows that CH3Cl formed by the abiotic methylation process at ambient temperatures has a unique stable carbon isotope signature, extremely depleted in 13C, unequivocally distinguishing it from all other known sources (Keppler et al., 2004). Using these findings together with data existing in the literature, we here present three scenarios for an isotopic mass balance for atmospheric CH3Cl. Our calculations provide strong support for the proposal that the bulk fraction of atmospheric CH3Cl (1.8 to 2.5Tg yr?1) is produced by an abiotic chloride methylation process in terrestrial ecosystems, primarily located in tropical and subtropical areas, where turnover of biomass is highest. Furthermore our calculations also indicate that the microbial soil sink for CH3Cl is likely to be much larger (>1Tg yr?1) than that previously assumed