56 research outputs found

    Herbicide and Additive Impacts on \u3cem\u3eBradyrhizobium japonicum\u3c/em\u3e Growth in Solution

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    Plant biostimulants include beneficial fungi and bacteria, and are often applied to foliage to improve crop growth, yield, and/or crop quality. Crop improvements due to biostimulant addition may be modest; therefore, solo applications may not be economical or climate smart. However, biostimulants combined with other postemergence treatments, such as herbicides, may provide an alternative application method, if mixtures do not harm the living organism(s). The growth of Bradyrhizobium japonicum, as a biostimulant surrogate, was assessed in solutions of glyphosate [N-(phosphonomethyl)glycine] and dicamba (3,6-dichloro-2-methoxybenzoic acid), with and without common spray additives (ammonium sulfate [AMS] and nonionic surfactant) in laboratory studies over 72 h. Solution turbidity, using optical density as a surrogate of bacterial growth, was measured at 600 nm at 24, 48, and 72 h after inoculation, and colony forming units (CFUs) per milliliter were estimated. Growth was not detected in either the glyphosate or AMS solutions, most likely due to the low pH and high electrical conductivity of the solutions, respectively. When herbicides were mixed with a nonionic surfactant, CFUs per milliliter were about 25% greater than the positive control. These data suggest that mixing bacteria with postemergence herbicide + surfactants/additives combinations can hinder or maintain growth when preparing for agrochemical applications. Biostimulant type and the agrichemical combination(s) should be evaluated prior to tank mixing to determine if detrimental interactions occur. After application, an evaluation of the effectiveness of the biostimulant to the crop and efficacy of the agrichemical to the target organism should be conducted

    Factors Affecting the Radii of Close-in Transiting Exoplanets

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    The radius of an exoplanet may be affected by various factors, including irradiation, planet mass and heavy element content. A significant number of transiting exoplanets have now been discovered for which the mass, radius, semi-major axis, host star metallicity and stellar effective temperature are known. We use multivariate regression models to determine the dependence of planetary radius on planetary equilibrium temperature T_eq, planetary mass M_p, stellar metallicity [Fe/H], orbital semi-major axis a, and tidal heating rate H_tidal, for 119 transiting planets in three distinct mass regimes. We determine that heating leads to larger planet radii, as expected, increasing mass leads to increased or decreased radii of low-mass (<0.5R_J) and high-mass (>2.0R_J) planets, respectively (with no mass effect on Jupiter-mass planets), and increased host-star metallicity leads to smaller planetary radii, indicating a relationship between host-star metallicity and planet heavy element content. For Saturn-mass planets, a good fit to the radii may be obtained from log(R_p/R_J)=-0.077+0.450 log(M_p/M_J)-0.314[Fe/H]+0.671 log(a/AU)+0.398 log(T_eq/K). The radii of Jupiter-mass planets may be fit by log(R_p/R_J)=-2.217+0.856 log(T_eq/K)+0.291 log(a/AU). High-mass planets' radii are best fit by log(R_p/R_J)=-1.067+0.380 log(T_eq/K)-0.093 log(M_p/M_J)-0.057[Fe/H]+0.019 log(H_tidal/1x10^{20}). These equations produce a very good fit to the observed radii, with a mean absolute difference between fitted and observed radius of 0.11R_J. A clear distinction is seen between the core-dominated Saturn-mass (0.1-0.5M_J) planets, whose radii are determined almost exclusively by their mass and heavy element content, and the gaseous envelope-dominated Jupiter-mass (0.5-2.0M_J) planets, whose radii increase strongly with irradiating flux, partially offset by a power-law dependence on orbital separation.Comment: 14 pages, 14 figures, accepted in A&

    An Open, Large-Scale, Collaborative Effort to Estimate the Reproducibility of Psychological Science

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    Reproducibility is a defining feature of science. However, because of strong incentives for innovation and weak incentives for confirmation, direct replication is rarely practiced or published. The Reproducibility Project is an open, large-scale, collaborative effort to systematically examine the rate and predictors of reproducibility in psychological science. So far, 72 volunteer researchers from 41 institutions have organized to openly and transparently replicate studies published in three prominent psychological journals in 2008. Multiple methods will be used to evaluate the findings, calculate an empirical rate of replication, and investigate factors that predict reproducibility. Whatever the result, a better understanding of reproducibility will ultimately improve confidence in scientific methodology and findings

    The Winchcombe meteorite, a unique and pristine witness from the outer solar system.

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    Direct links between carbonaceous chondrites and their parent bodies in the solar system are rare. The Winchcombe meteorite is the most accurately recorded carbonaceous chondrite fall. Its pre-atmospheric orbit and cosmic-ray exposure age confirm that it arrived on Earth shortly after ejection from a primitive asteroid. Recovered only hours after falling, the composition of the Winchcombe meteorite is largely unmodified by the terrestrial environment. It contains abundant hydrated silicates formed during fluid-rock reactions, and carbon- and nitrogen-bearing organic matter including soluble protein amino acids. The near-pristine hydrogen isotopic composition of the Winchcombe meteorite is comparable to the terrestrial hydrosphere, providing further evidence that volatile-rich carbonaceous asteroids played an important role in the origin of Earth's water

    Preventing Violence in Seven Countries: Global Convergence in Policies

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    Do governments take the measures that are supported by the best scientific evidence available? We present a brief review of the situation in: Australia, Canada, Germany, the Netherlands, Spain, the United Kingdom, and the United States. Our findings show surprisingly similar developments across countries. While all seven countries are moving towards evidence-based decision making regarding policies and programs to prevent violence, there remain a number of difficulties before this end can be achieved. For example, there continue to be few randomized controlled trials or rigorous quasi-experimental studies on aggression and violence. Results from experimental research are essential to both policy makers and researchers to determine the effectiveness of programs as well as increase our knowledge of the problem. Additionally, all noted that media attention for violence is high in their country, often leading to management by crisis with the result that policies are not based on evidence, but instead seek to appease public outrage. And perhaps because of attendant organizational problems (i.e., in many countries violence prevention was not under the guise of one particular agency or ministry), most have not developed a coordinated policy focusing on the prevention of violence and physical aggression. It is hypothesized that leaders in democratic countries, who must run for election every 4 to 6 years, may feel a need to focus on short-term planning rather than long-term preventive policies since the costs, but not the benefits for the latter would be incurred while they still served in office. We also noted a general absence of expertise beyond those within scientific circles. The need for these ideas to be more widely accepted will be an essential ingredient to real and sustaining change. This means that there must be better communication and increased understanding between researchers and policy makers. Toward those ends, the recent establishment of the Campbell Collaboration, formed to provide international systematic reviews of program effectiveness, will make these results more available and accessible to politicians, administrators and those charged with making key policy decision

    Finishing the euchromatic sequence of the human genome

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    The sequence of the human genome encodes the genetic instructions for human physiology, as well as rich information about human evolution. In 2001, the International Human Genome Sequencing Consortium reported a draft sequence of the euchromatic portion of the human genome. Since then, the international collaboration has worked to convert this draft into a genome sequence with high accuracy and nearly complete coverage. Here, we report the result of this finishing process. The current genome sequence (Build 35) contains 2.85 billion nucleotides interrupted by only 341 gaps. It covers ∼99% of the euchromatic genome and is accurate to an error rate of ∼1 event per 100,000 bases. Many of the remaining euchromatic gaps are associated with segmental duplications and will require focused work with new methods. The near-complete sequence, the first for a vertebrate, greatly improves the precision of biological analyses of the human genome including studies of gene number, birth and death. Notably, the human enome seems to encode only 20,000-25,000 protein-coding genes. The genome sequence reported here should serve as a firm foundation for biomedical research in the decades ahead

    Herbicide and additive impacts on Bradyrhizobium japonicum growth in solution

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    Abstract Plant biostimulants include beneficial fungi and bacteria, and are often applied to foliage to improve crop growth, yield, and/or crop quality. Crop improvements due to biostimulant addition may be modest; therefore, solo applications may not be economical or climate smart. However, biostimulants combined with other postemergence treatments, such as herbicides, may provide an alternative application method, if mixtures do not harm the living organism(s). The growth of Bradyrhizobium japonicum, as a biostimulant surrogate, was assessed in solutions of glyphosate [N‐(phosphonomethyl)glycine] and dicamba (3,6‐dichloro‐2‐methoxybenzoic acid), with and without common spray additives (ammonium sulfate [AMS] and nonionic surfactant) in laboratory studies over 72 h. Solution turbidity, using optical density as a surrogate of bacterial growth, was measured at 600 nm at 24, 48, and 72 h after inoculation, and colony forming units (CFUs) per milliliter were estimated. Growth was not detected in either the glyphosate or AMS solutions, most likely due to the low pH and high electrical conductivity of the solutions, respectively. When herbicides were mixed with a nonionic surfactant, CFUs per milliliter were about 25% greater than the positive control. These data suggest that mixing bacteria with postemergence herbicide + surfactants/additives combinations can hinder or maintain growth when preparing for agrochemical applications. Biostimulant type and the agrichemical combination(s) should be evaluated prior to tank mixing to determine if detrimental interactions occur. After application, an evaluation of the effectiveness of the biostimulant to the crop and efficacy of the agrichemical to the target organism should be conducted
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