627 research outputs found

    Nearfield RCS Measurements of Full Scale Targets Using ISAR

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    Nearfield Radar Cross Section (RCS) measurements and Inverse Synthetic Aperture Radar (ISAR) processing are used in this study to obtain geometrically correct images and farfield RCS. The back projection algorithm is used to determine the amplitudes and locations for the scatterers in a point by point imaging process. Different approximations are used to sum the nearfield RCS recorded at an azimuthal interval of angles when forming the farfield image. The images obtained show the geometrically correct locations of the target scatterers with exceptions for some target features e.g., when there are multiple or resonance scattering features. Separate features in the images are gated and an inverse processing step is performed to obtain the farfield RCS of the full target or selected parts of the target. Examples of images and farfield RCS extracted from simulations and measurements on small and full scale targets using the ISAR processing techniques described in this paper are given

    Baseline heterogeneity in glucose metabolism marks the risk for type 1 diabetes and complicates secondary prevention.

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    Non-diabetic children with multiple islet autoantibodies were recruited to a secondary prevention trial. The objective was to determine the predictive value of baseline (1) HbA1c and metabolic variables derived from intravenous (IvGTT) and oral glucose tolerance tests (OGTT), (2) insulin resistance and (3) number, type and levels of islet autoantibodies, for progression to type 1 diabetes

    An avalanche forecasting program based on a modified nearest neighbour method.

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    As a part of an avalanche forecasting system, a modified nearest neighbour program is described. The system is intended to be used with forecast values for most ofthe parameters. The modifications consist of 1) the use of a parameter set that better reflects the course of the weather situation, 2) the setting of initial selection criteria for certain parameters 3) a method for normalizing the distances and 4) a weighting of the avalanche probability based on the avalanche activity and the similarity of the weather situations

    SAR-ISAR Blending Using Compressed Sensing Methods

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    Inverse Synthetic Aperture Radar (ISAR) target images are extracted using compressed sensing methods. The extracted images are edited and merged into measured Synthetic Aperture Radar (SAR) images. A noise free image of the target is extracted from the Radar Cross Section (RCS) measurement by using the Basis Pursuit Denoise (BPDN) method and then solving for a model consisting of point scatterers. The target signature point scatterers are then merged into a point scatterer representation of the SAR background scene. This method means that SAR images acquired in expensive airborne field trials can be used efficiently to evaluate different targets and camouflage measured separately in a ground based setup. The method is demonstrated with turntable measurements of a full scale target, with and without camouflage, signature extraction and blending into a SAR background. We find that the method provides an efficient way of evaluating measured target signatures in SAR backgrounds

    A Novel and Simple Method for Laboratory Diagnosis of Relapsing Fever Borreliosis

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    Relapsing fever caused by Borrelia bacteria is often obscured by malaria and incorrectly treated. Here a novel method for diagnosis is presented. The method is cheap, simple and requires minimal laboratory material. Despite its simplicity, the method shows surprisingly high sensitivity, detecting concentrations less than 10 bacteria/ml blood

    2-Butanol and Butanone Production in Saccharomyces cerevisiae through Combination of a B-12 Dependent Dehydratase and a Secondary Alcohol Dehydrogenase Using a TEV-Based Expression System

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    2-Butanol and its chemical precursor butanone (methyl ethyl ketone -MEK) are chemicals with potential uses as biofuels and biocommodity chemicals. In order to produce 2-butanol, we have demonstrated the utility of using a TEV-protease based expression system to achieve equimolar expression of the individual subunits of the two protein complexes involved in the B-12-dependent dehydratase step (from the pdu-operon of Lactobacillus reuterii), which catalyze the conversion of meso-2,3-butanediol to butanone. We have furthermore identified a NADH dependent secondary alcohol dehydrogenase (Sadh from Gordonia sp.) able to catalyze the subsequent conversion of butanone to 2-butanol. A final concentration of 4 +/- 0.2 mg/L 2-butanol and 2 +/- 0.1 mg/L of butanone was found. A key factor for the production of 2-butanol was the availability of NADH, which was achieved by growing cells lacking the GPD1 and GPD2 isogenes under anaerobic conditions

    Inside-out plant plasma membrane vesicles of high purity obtained by aqueous two-phase partitioning

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    AbstractHighly purified plasma membranes obtained from leaves of sugar beet (Beta vulgaris L.) by aqueous two-phase partitioning were separated into two fractions by further phase partition steps. The vesicles partitioning to the interface showed an ATP-dependent H+-uptake (measured using the pH probe acridine orange) and a negligible K+,Mg2+-ATPase latency, while the vesicles partitioning in the upper phase showed only slow H+-uptake and a high ATPase latency on addition of Triton X-100. Based on these results the material at the interface is estimated to contain ∼90% sealed, inside-out vesicles, and the material in the upper phase ∼90% sealed, right-side-out vesicle

    Fermentation performance and physiology of two strains of Saccharomyces cerevisiae during growth in high gravity spruce hydrolysate and spent sulphite liquor

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    Background: Lignocellulosic materials are a diverse group of substrates that are generally scarce in nutrients, which compromises the tolerance and fermentation performance of the fermenting organism. The problem is exacerbated by harsh pre-treatment, which introduces sugars and substances inhibitory to yeast metabolism. This study compares the fermentation behaviours of two yeast strains using different types of lignocellulosic substrates; high gravity dilute acid spruce hydrolysate (SH) and spent sulphite liquor (SSL), in the absence and presence of yeast extract. To this end, the fermentation performance, energy status and fermentation capacity of the strains were measured under different growth conditions. Results: Nutrient supplementation with yeast extract increased sugar uptake, cell growth and ethanol production in all tested fermentation conditions, but had little or no effect on the energy status, irrespective of media. Nutrient-supplemented medium enhanced the fermentation capacity of harvested cells, indicating that cell viability and reusability was increased by nutrient addition. Conclusions: Although both substrates belong to the lignocellulosic spruce hydrolysates, their differences offer specific challenges and the overall yields and productivities largely depend on choice of fermenting strain

    Down Regulation of CLDND1 Induces Apoptosis in Breast Cancer Cells.

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    Identification of targets for apoptosis induction is important to provide novel therapeutic approaches in breast cancer. Our earlier studies showed that down regulation of protein kinase C δ (PKCδ) induces death in breast cancer cells. In this study we set out to identify previously unrecognized apoptosis regulators in breast cancer cells. To identify candidates, global expression analysis with microarray was performed after down regulation of PKCδ in the basal-like breast cancer cell lines MDA-MB-231, MDA-MB-468 and BT-549. Genes that were down regulated in all cell lines were further studied for survival-supporting effects. The claudin-like CLDND1 was singled out since several independent siRNAs targeting CLDND1 induced cell death in several cell lines. The cell death induced by CLDND1 knockdown was caspase-dependent, suggesting induction of apoptosis. Nuclear fragmentation, cleavage of caspase-3 and PARP and release of cytochrome C from the mitochondria upon CLDND1 depletion demonstrated involvement of the intrinsic apoptotic pathway. Inhibition of MEK1/2 and JNK further potentiated the cell death induction by CLDND1 knockdown. However, CLDND1 down regulation augmented ERK1/2 phosphorylation, which thereby may protect against the apoptosis inducing effects of CLDND1 down regulation. A concomitant inhibition of MEK1/2 suppresses the ERK1/2 phosphorylation and markedly potentiates the cell death following CLDND1 siRNA treatment. There is today little information on the function of CLDND1. These data provide novel information on CLDND1 and highlight it as a novel survival factor in basal-like breast cancer cell lines

    Waveguide measurements of the permittivity and permeability at temperatures up to 1000 C

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    This paper describes a method to measure the permittivity and the permeability at temperatures from room temperature up to 1000 C using a single rectangular waveguide. The hardware design of the setup that can handle these temperatures and the procedure that is required to correct for the thermal expansion is developed. This includes the sample displacement, the displacement of the calibration reference planes, the thermal expansion of the waveguide and the gap between the sample and the waveguide wall. Measurements on Macor\textregistered and NiZn Ferrite samples are performed in order to evaluate the performance of the setup and the procedure that is used to determine the permittivity and permeability from the measured S-parameters
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