Product Life Cycles and Innovation in the US Seed Corn Industry

The purpose of this study is to evaluate potential changes in the length of product life cycles in the US seed corn industry. We use the observed survival time on the market for hybrids sold during 1997-2009 to conduct a survival analysis. Our empirical results show that the average lifetimes of conventional and biotech corn hybrids have decreased over the last twelve years at similar rates and that the rate of decline in the life cycle length increased since 2004. We also find that the shorter product life cycles are closely linked to the accelerated levels of biotech product innovation in the US seed corn industry observed over the period of the analysis.Crop Production/Industries, Research and Development/Tech Change/Emerging Technologies,

Product Life Cycles and Innovation in the US Seed Corn Industry

The purpose of this study is to evaluate potential changes in the length of product life cycles in the US seed corn industry. We use the observed survival time on the market for hybrids sold during 1997-2009 to conduct a survival analysis. Our empirical results show that the expected lifetimes for corn hybrids with single biotech traits are 5-15% longer than for hybrids with multiple (stacked) traits, and the expected lifetimes for conventional corn are 13-17% longer than stacked hybrids. Also, the product life cycles for all types of hybrids have decreased over the past twelve years (especially after 2004), but the rate of decline is roughly similar across hybrid types. Based on this evidence, we conclude that the shorter product life cycles are closely linked to the accelerated levels of biotech product innovation in the US seed corn industry over the period of analysis.accelerated failure time, biotechnology, product life cycle, survival analysis, Productivity Analysis, Research and Development/Tech Change/Emerging Technologies, Research Methods/ Statistical Methods, Risk and Uncertainty,

How are the guards watched out? Institutional limits of the judicial independence in Brazil and Spain

[spa] Este documento recopila datos sobre el diseño normativo, la composición, la organización y el desempeño de los Consejos de Justicia de Brasil y España, e identifica las principales trabas al funcionamiento de ambos con el fin de acercar su experiencia institucional. La atención se centra en buscar si la institucionalización de los Consejos de Justicia en las experiencias constitucionales post-autoritarias de estos países proporciona parámetros comunes para comprender las prácticas judiciales. Siguiendo un enfoque sistémico-constructivista que confronta discursos y prácticas judiciales, el artículo cuestiona el dogma según el cual la autonomía de los jueces amplía el ámbito de los derechos. La hipótesis es que la preservación de la estructura corporativa y la falta de conexión entre la independencia y la accountability han contribuido a la disfuncionalidad de dichos órganos en perjuicio de todo el Poder Judicial.[cat] Aquest document recopila dades sobre el disseny normatiu, la composició, l'organització i l'acompliment dels Consells de Justícia de Brasil i Espanya, i identifica els principals traves al funcionament de tots dos amb la finalitat d'acostar la seva experiència institucional. L'atenció es centra en cercar si la institucionalització dels Consells de Justícia en les experiències constitucionals post-autoritàries d'aquests països proporciona paràmetres comuns per comprendre les pràctiques judicials. Seguint un enfocament sistèmicconstructivista que confronta discursos i pràctiques judicials, l'article qüestiona el dogma segons el qual l'autonomia dels jutges amplia l'àmbit dels drets. La hipòtesi és que la preservació de l'estructura corporativa i la falta de connexió entre la independència i la accountability han contribuït a la disfuncionalitat d'aquests òrgans en perjudici de tot el Poder Judicial.[eng] This paper collects data on normative design, composition, organization and performance of the Councils of Justice of Brazil and Spain, and identifies the main obstacles to the functioning of both in order to bring closer their institutional experience. The attention is focused on seeking whether the institutionalization of the Councils of Justice in the postauthoritarian constitutional experiences of these countries provides common parameters for understanding judicial practices. By following a systemic-constructivist approach that confronts judicial discourses and practices, the paper calls into question the dogma according to which judges’ autonomy widens the ambit of rights. The hypothesis is that the preservation of the corporate structure and the lack of connection between independence and accountability have contributed to the dysfunctions of such bodies to the detriment of the entire Judicial Power

The Structure of Graphene on Graphene/C60/Cu Interfaces: A Molecular Dynamics Study

Two experimental studies reported the spontaneous formation of amorphous and crystalline structures of C60 intercalated between graphene and a substrate. They observed interesting phenomena ranging from reaction between C60 molecules under graphene to graphene sagging between the molecules and control of strain in graphene. Motivated by these works, we performed fully atomistic reactive molecular dynamics simulations to study the formation and thermal stability of graphene wrinkles as well as graphene attachment to and detachment from the substrate when graphene is laid over a previously distributed array of C60 molecules on a copper substrate at different values of temperature. As graphene compresses the C60 molecules against the substrate, and graphene attachment to the substrate between C60s ("C60s" stands for plural of C60) depends on the height of graphene wrinkles, configurations with both frozen and non-frozen C60s structures were investigated in order to verify the experimental result of stable sagged graphene when the distance between C60s is about 4 nm and height of graphene wrinkles is about 0.8 nm. Below the distance of 4 nm between C60s, graphene becomes locally suspended and less strained. We show that this happens when C60s are allowed to deform under the compressive action of graphene. If we keep the C60s frozen, spontaneous "blanketing" of graphene happens only when the distance between them are equal or above 7 nm. Both above results for the existence of stable sagged graphene for C60 distances of 4 or 7 nm are shown to agree with a mechanical model relating the rigidity of graphene to the energy of graphene-substrate adhesion. In particular, this study might help the development of 2D confined nanoreactors that are considered in literature to be the next advanced step on chemical reactions.Comment: 7 pages, 4 figure

Polycyclic aromatic hydrocarbons (PAHS) in cachaça, rum, whiskey and alcohol fuel

The concentration of 15 polycyclic aromatic hydrocarbons (PAHs) in 57 samples of distillates (cachaça, rum, whiskey, and alcohol fuel) has been determined by HPLC-Fluorescence detection. The quantitative analytical profile of PAHs treated by Partial Least Square - Discriminant Analysis (PLS-DA) provided a good classification of the studied spirits based on their PAHs content. Additionally, the classification of the sugar cane derivatives according to the harvest practice was obtained treating the analytical data by Linear Discriminant Analysis (LDA), using naphthalene, acenaphthene, fluorene, phenanthrene, anthracene, fluoranthene, pyrene, benz[a]anthracene, benz[b]fluoranthene, and benz[g,h,i]perylene, as a chemical descriptors.CNPqCoordenacao de Aperfeicoamento de Pessoal de Nivel Superior (CAPES)FAPES

Operator growth in the SYK model

We discuss the probability distribution for the "size" of a time-evolving operator in the SYK model. Scrambling is related to the fact that as time passes, the distribution shifts towards larger operators. Initially, the rate is exponential and determined by the infinite-temperature chaos exponent. We evaluate the size distribution numerically for $N = 30$, and show how to compute it in the large-$N$ theory using the dressed fermion propagator. We then evaluate the distribution explicitly at leading nontrivial order in the large-$q$ expansion.Comment: 18 pages, 2 official figures, many unofficial figure

Investigation of the hydrolytic stability of polyurethane applied to vehicle suspension components

Process parameters such as temperature and humidity, as well as formulation are the main factors in the manufacture of a polymeric component through a polyurethane prepolymer, which define the reaction kinetics as well as the bonds and the resulting chemical interactions, determining the final characteristics of the material. One of the expected skills of polyurethane, when applied to components used in contact with water, is hydrolysis resistance. Being this research constituted by the exposure of a polymerized TDI polyether polyurethane to different proportions of the curing agent, MOCA, in an environment susceptible to reactions with water at 70 °C. In this case, this material is applied in the manufacture of coil spring solid axle with trailing arms and Panhard rod suspension bushings. Mechanical tests and DSC, TGA and FTIR evaluations of the samples and prepolymer are conducted for the characterization of the different formulations, showing the negative relationship of the curing agent proportion parameters with the hydrolysis resistance, where it is verified. depolymerization of the urethane and ether groups, as well as lower retention of yield stress. These findings can subsidize developing predictive models for performance and lifetime of polyurethanes