849 research outputs found

    MODELING ANIMAL AND FORAGE RESPONSE TO FERTILIZATION OF ANNUAL RANGELANDS

    Get PDF
    The response functions for forage, animal gain, and stocking rate were estimated from data obtained in a three-year fertilization experiment on California annual range. Degree-days; the interactions between degree-days and nitrogen, between degree-days and phosphorus-sulphur, and between nitrogen and phosphorus-sulphur; and the lagged forage variable were significant in explaining the variations in forage growth, animal gain, and stocking rate. The impact of PS was more important in interaction with DD or N than by itself. The correct impact of moisture was not found due to misspecification of the variable in the model. The models for the first year and the three years combined were well behaved; however, the models for the last two years combined neither explained adequately nor behaved well.Livestock Production/Industries,

    "Killing them softly" … challenges in the Bacillus subtilis spore inactivation by plasma sterilization

    Get PDF
    The elimination of bacterial endospores is absolutely essential in numerous fields, ranging from hospital hygiene, the food processing industry, all the way to the space industry. A major goal of space exploration is the search for signatures of life forms and biomolecules on other planetary bodies and moons in our solar system. The transfer of microorganisms or biomolecules of terrestrial origin to critical areas of exploration is of particular risk to impact the development and integrity of life-detection missions.1 Plasma sterilization is a promising alternative to conventional sterilization methods for spaceflight purposes. Due to their extraordinary resistance properties, spores of the Gram-positive bacterium Bacillus subtilis are used as biological indicators for decontamination studies to identify the relevant mechanism that leads to the rapid bacterial inactivation.1,3 Here, we present novel insights into the key factors involved in spore inactivation by low pressure plasma sterilization using a double inductively-coupled plasma reactor. (2,4) In order to standardize the assessment of inactivation efficiencies by plasma discharges, an electrically driven spray deposition device was developed, allowing fast, reproducible, and homogeneous preparation of B. subtilis spore monolayers. We demonstrate that plasma discharges caused significant physical damage to spore surface structures as visualized by atomic force microscopy. A systematic analysis of B. subtilis spores lacking individual coat and crust layers - the first barrier to environmental influences – revealed the coat to be one of the contributing factors in the spore resistance to plasma sterilization. (2-4) Furthermore, we identified spore-specific and general protection mechanisms and DNA repair pathways during spore germination and outgrowth after plasma treatment, leading to a better understanding of the complex molecular mechanisms involved in the inactivation by plasma sterilization processes

    Optical properties of dense self-assembled gold nanoparticle layers with organic linker molecules

    Full text link
    Films consisting of self-assembled gold nanoparticles cross-linked with alkane-dithiols were prepared by a filtration method and studied with scanning electron microscopy to determine the structure of the films and spectrophotometry and ellipsometry to ascertain their optical properties. The structural characterization showed the existence of nanometer-sized voids within the films. This previously unmentioned feature is responsible for the previous difficulties in modelling the optical properties with effective medium models. This can be remedied, using a two-tiered hierarchical effective medium model, which takes into account the existence of the voids. Using this model we were able to fit the experimental data, with only the void volume fraction to be determined by the overall fit, while the gold volume fraction in the linker medium is fixed by the wavelength of the resonance peak. Our model should be applicable to all such films, when the deposition method, which determines the microstructure, is properly taken into account

    Redskaber til monitorering af trafikken (REMOTE)

    Get PDF
    GPS data fra kørende biler vil sandsynligvis i fremtiden erstatte traditionelle spoler i vejene som grundlaget for realtidstrafikinformation. I denne artikel beskrives et projekt under EU’s VIKING program, hvor der er udviklet udstyr til indsamling og behandling af GPS data fra kørende biler med henblik på realtidstrafikinformation. Endvidere beskrives et feltforsøg med 10 taxier

    Electroluminescence of thin-film CdTe solar cells and modules

    Get PDF
    Includes bibliographical references.2015 Summer.Thin-film photovoltaics has the potential to be a major source of world electricity. Mitigation of non-uniformities in thin-film solar cells and modules may help improve photovoltaic conversion efficiencies. In this manuscript, a measurement technique is discussed in detail which has the capability of detecting such non-uniformities in a form useful for analysis. Thin-film solar cells emit radiation while operating at forward electrical bias, analogous to an LED, a phenomena known as electroluminescence (EL). This process relatively is inefficient for polycrystalline CdTe devices, on the order of 10⁻⁴%, as most of the energy is converted into heat, but still strong enough for many valuable measurements. A EL system was built at the Colorado State University Photovoltaics Laboratory to measure EL from CdTe cells and modules. EL intensity normalized to exposure time and injection current density has been found to correlate very well with the difference between ideal and measured open-circuit voltage from devices that include a GaAs cell, an AlGaAs LED, and several CdTe cells with variations in manufacturing. Furthermore, these data points were found to be in good agreement when overlaid with calibrated data from two additional sources. The magnitude of the inverse slope of the fit is in agreement with the thermal voltage and the intercept was found to have a value near unity, in agreement with theory. The expanded data set consists of devices made from one of seven different band gaps and spans eight decades of EQELED efficiencies. As expected, cells which exhibit major failure of light-dark J-V superposition did not follow trend of well-behaved cells. EL images of selected defects from CdTe cells and modules are discussed and images are shown to be highly sensitive to defects in devices, since the intensity depends exponentially on the cells' voltages. The EL technique has proven to be a useful high-throughput tool for screening of cells. In addition to EL images, other opto-electronics characterization techniques were used to analyze defects in cells and modules such as weak-diode areas, cell delineation near substrate edge, non-uniform chlorine passivation, holes in back contact, high-resistance foreign layer, high back-contact sheet resistance, a discontinuous P3 line scribe (intercell shunt) and shunt through a cell (intracell shunt). Although EL images are proficient at illustrating the location and severity of defects with potentially high spatial resolution and short measurement times, their ability to identify the cause of such defects is limited. EL in concert with Light-Beam-Induced Current (LBIC), however, makes for a powerful ensemble as LBIC can probe different film layers at arbitrary voltage bias conditions, albeit with increased measurement times and potentially reduced spatial resolution

    Antibacterial activity of blue light against nosocomial wound pathogens growing planktonically and as mature biofilms

    Get PDF
    The blue wavelengths within the visible light spectrum are intrinisically antimicrobial and can photodynamically inactivate the cells of a wide spectrum of bacteria (Gram positive and negative) and fungi. Furthermore, blue light is equally effective against both drug-sensitive and -resistant members of target species and is less detrimental to mammalian cells than is UV radiation. Blue light is currently used for treating acnes vulgaris and Helicobacter pylori infections; the utility for decontamination and treatment of wound infections is in its infancy. Furthermore, limited studies have been performed on bacterial biofilms, the key growth mode of bacteria involved in clinical infections. Here we report the findings of a multicenter in vitro study performed to assess the antimicrobial activity of 400-nm blue light against bacteria in both planktonic and biofilm growth modes. Blue light was tested against a panel of 34 bacterial isolates (clinical and type strains) comprising Acinetobacter baumannii, Enterobacter cloacae, Stenotrophomonas maltophilia, Pseudomonas aeruginosa, Escherichia coli, Staphylococcus aureus, Enterococcus faecium, Klebsiella pneumoniae, and Elizabethkingia meningoseptica. All planktonic-phase bacteria were susceptible to blue light treatment, with the majority (71%) demonstrating a ≥ 5-log10 decrease in viability after 15 to 30 min of exposure (54 J/cm2 to 108 J/cm2). Bacterial biofilms were also highly susceptible to blue light, with significant reduction in seeding observed for all isolates at all levels of exposure. These results warrant further investigation of blue light as a novel decontamination strategy for the nosocomial environment, as well as additional wider decontamination applications

    To What Extent Are Uninsured Depositors At Risk?

    Get PDF
    Recent bank failures prompt the important question, \u27\u27To what extent are uninsured depositors at monetary risk? The purpose of this study is to examine the historical loss rates associated with being an uninsured/exposed depositor at a failed banking institution. This paper will also explore the returns on bank deposits compared to the returns of alternative marketable investments. The purpose of comparing the various marketable instruments to bank time deposits is to explore the amount of risk and return, measured through yearly average returns and standard deviation, associated with both. By using difference of means tests, as well as accounting for differences in maturities, it was proven in this study that the mean average return of CDs is statistically significantly higher than that of T-bills between 1986 and 2000. Thus, although investors are at monetary risk in the event of a bank failure, they are being compensated. Results suggest that further research is needed to explain the amount of specific CD interest rates prior to an institution\u27s failure

    Primary oral manifestation of Langerhans cell histiocytosis refractory to conventional therapy but susceptible to BRAF-specific treatment: a case report and review of the literature

    Get PDF
    Langerhans cell histiocytosis (LCH) is a diagnostic and therapeutic challenge. We report on a rare case of its primary oral manifestation that was treated successfully with the BRAF-specific agent, vemurafenib, after insufficient standard LCH treatment. This case underlines the importance of proper diagnosis and the evaluation of targeted therapy as a valuable tool in LCH treatment. Furthermore, the close collaboration of surgeons, oncologists, and dentists is mandatory to ensure adequate treatment, restore the stomatognathic system in debilitating post-treatment situations, improve quality of life, and ensure effective disease control in infants and young patients
    corecore