2,802 research outputs found

    The “Indy Way”: Lessons from Brazilian Sugarcane Ethanol and Indycar Partnership

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    This paper explores how the Brazilian sugar-energetic processors used Indycar racing to increase exports to the United States and create value by transforming the Brazilian ethanol from a commodity fuel to an advanced biofuel, between 2009 to 2012. This case study uses the relationship between Brazilian Sugar-cane Industry Association (UNICA), Brazilian Trade and Investment Promotion Agency (APEX-Brazil), and the IndyCar Racing League (IRL), to show the ability to learn and perform in a competitive scenario. Absorptive Capacity (ACAP) theory is used to understand how the Brazilian sugar-energetic processors identified, assimilated, transformed, and exploited knowledge from this relationship, as well as how this experience could be used in other industries. As a trading result, Brazilian biofuel exports to the United States increased 758.22% during the studied period and the Volumetric Ethanol Excise Tax Credit (VEETC), an American tax act in vigor since the 1970’s, was extinguished at the end of 2011. The main contribution of this study: Identify how the Absorptive Capacity Theory can explain such impacts in the Brazilian Biofuel exports through the relationship between partners in the U.S. and Brazil

    ‘Who are you to judge my writing?’: Student collaboration in the co-construction of assessment rubrics

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    Collaborative models of involving students in the co-construction of assessment rubrics are rare. Inviting students to take part actively in the design of assessment rubrics is one method of filling this research gap, potentially garnering a shared understanding of assessment requirements. Rubrics traditionally are constructed by educators, based on set criteria, in order to streamline grading more cohesively and equitably. But research demonstrates that assessment rubric use is usually of more benefit to the educator in grading, than to the student in undertaking the assessment task – the educator understands requirements but often specific requirements are not clear to the student. Using a multiple case study research approach which incorporated a modified Delphi method to gather expert views on rubrics, the study outlined in this paper explores the outcomes of collaborating with students at the rubric design stage of the assessment process. This paper discusses the rubric co-construction process facilitated by a writing lecturer and a team of students from one university who took part in collaborating and developing an assessment rubric. The processes adopted to implement this co-construction process are reported, the products of which were distributed to a 250-student cohort, and reflects on the value of this pedagogical innovation

    Phase-field crystal modelling of crystal nucleation, heteroepitaxy and patterning

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    We apply a simple dynamical density functional theory, the phase-field-crystal (PFC) model, to describe homogeneous and heterogeneous crystal nucleation in 2d monodisperse colloidal systems and crystal nucleation in highly compressed Fe liquid. External periodic potentials are used to approximate inert crystalline substrates in addressing heterogeneous nucleation. In agreement with experiments in 2d colloids, the PFC model predicts that in 2d supersaturated liquids, crystalline freezing starts with homogeneous crystal nucleation without the occurrence of the hexatic phase. At extreme supersaturations crystal nucleation happens after the appearance of an amorphous precursor phase both in 2d and 3d. We demonstrate that contrary to expectations based on the classical nucleation theory, corners are not necessarily favourable places for crystal nucleation. Finally, we show that adding external potential terms to the free energy, the PFC theory can be used to model colloid patterning experiments.Comment: 21 pages, 16 figure

    Electric Field Control of Spin Transport

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    Spintronics is an approach to electronics in which the spin of the electrons is exploited to control the electric resistance R of devices. One basic building block is the spin-valve, which is formed if two ferromagnetic electrodes are separated by a thin tunneling barrier. In such devices, R depends on the orientation of the magnetisation of the electrodes. It is usually larger in the antiparallel than in the parallel configuration. The relative difference of R, the so-called magneto-resistance (MR), is then positive. Common devices, such as the giant magneto-resistance sensor used in reading heads of hard disks, are based on this phenomenon. The MR may become anomalous (negative), if the transmission probability of electrons through the device is spin or energy dependent. This offers a route to the realisation of gate-tunable MR devices, because transmission probabilities can readily be tuned in many devices with an electrical gate signal. Such devices have, however, been elusive so far. We report here on a pronounced gate-field controlled MR in devices made from carbon nanotubes with ferromagnetic contacts. Both the amplitude and the sign of the MR are tunable with the gate voltage in a predictable manner. We emphasise that this spin-field effect is not restricted to carbon nanotubes but constitutes a generic effect which can in principle be exploited in all resonant tunneling devices.Comment: 22 pages, 5 figure

    On your bike! a cross-sectional study of the individual, social and environmental correlates of cycling to school

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    Background : Active school transport (AST) has declined rapidly in recent decades. While many studies have examined walking, cycling to school has received very little attention. Correlates of cycling are likely to differ to those from walking and cycling enables AST from further distances. This study examined individual, social and environmental factors associated with cycling to school among elementary school-aged children, stratified by gender. Methods : Children (n = 1197) attending 25 Australian primary schools located in high or low walkable neighborhoods, completed a one-week travel diary and a parent/child questionnaire on travel habits and attitudes. Results : Overall, 31.2% of boys and 14.6% of girls cycled &ge; 1 trip/week, however 59.4% of boys and 36.7% of girls reported cycling as their preferred school transport mode. In boys (but not girls), school neighborhood design was significantly associated with cycling: i.e., boys attending schools in neighborhoods with high connectivity and low traffic were 5.58 times more likely to cycle (95% CI 1.11-27.96) and for each kilometer boys lived from school the odds of cycling reduced by 0.70 (95% CI 0.63-0.99). Irrespective of gender, cycling to school was associated with parental confidence in their child\u27s cycling ability (boys: OR 10.39; 95% CI 3.79-28.48; girls: OR 4.03; 95% CI 2.02-8.05), parental perceived convenience of driving (boys: OR 0.42; 95% CI 0.23-0.74; girls: OR 0.40; 95% CI 0.20-0.82); and child\u27s preference to cycle (boys: OR 5.68; 95% CI 3.23-9.98; girls: OR 3.73; 95% CI 2.26-6.17). Conclusion : School proximity, street network connectivity and traffic exposure in school neighborhoods was associated with boys (but not girls) cycling to school. Irrespective of gender, parents need to be confident in their child\u27s cycling ability and must prioritize cycling over driving. <br /

    Redução na adubação nitrogenada em Triticum sp. inoculado e coinoculado

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    Using techniques of inoculation and co-inoculation of plant growth-promoting rhizobacteria (PGPR) could be an alternative with great potential for the wheat agricultural market, aiming towards a higher fertilizer efficiency and a subsequent reduction in environmental impacts. The objective of this study was to evaluate the efficiency of rhizobia symbiont inoculants isolated from legumes, individually and combined with Azospirillum brasilense, in promoting the growth of the wheat crop. The experiments were performed with the cultivars BRS Parrudo and TBIO Sossego, both inoculated and co-inoculated with the rhizobia UFRGS Vp16 and UFRGS Lc348, and A. brasilense, and under nitrogen dosage levels recommended for wheat plants. Inoculation of rhizobia, isolated or combined with A. brasilense, promotes increases in the production of wheat grains with half of the nitrogen dose recommended in the two evaluated cultivars, standing as an economically viable and ecologically sustainable alternative for the agricultural market.A utilização das técnicas de inoculação e coinoculação de rizobactérias promotoras do crescimento de plantas (RPCPs) pode ser uma alternativa com grande potencial para o mercado agrícola do trigo, visando uma maior eficiência no uso de fertilizantes e consequentemente redução do impacto ambiental. O objetivo deste trabalho foi avaliar a eficiência da inoculação de rizóbios simbiontes em leguminosas, isoladamente e em conjunto com Azospirillum brasilense, na promoção de crescimento da cultura do trigo. Os experimentos foram realizados com as cultivares BRS Parrudo e a TBIO Sossego, inoculadas e coinoculadas com os rizóbios UFRGS Vp16 e UFRGS Lc348, e A. brasilense, e sob níveis de doses de nitrogênio recomendadas para plantas de trigo. A inoculação de rizóbios, isoladamente ou em coinoculação com A. brasilense promove aumentos de produção de grãos de trigo com metade da dose de nitrogênio recomendada nas duas cultivares avaliadas, sendo uma alternativa economicamente viável e ecologicamente sustentável para o mercado agrícola

    Liver resection or combined chemoembolization and radiofrequency ablation improve survival in patients with hepatocellular carcinoma

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    Background/ Aims: To evaluate the long-term outcome of surgical and non-surgical local treatments of patients with hepatocellular carcinoma (HCC). Methods: We stratified a cohort of 278 HCC patients using six independent predictors of survival according to the Vienna survival model for HCC (VISUM- HCC). Results: Prior to therapy, 224 HCC patients presented with VISUM stage 1 (median survival 18 months) while 29 patients were classified as VISUM stage 2 (median survival 4 months) and 25 patients as VISUM stage 3 (median survival 3 months). A highly significant (p < 0.001) improved survival time was observed in VISUM stage 1 patients treated with liver resection ( n = 52; median survival 37 months) or chemoembolization (TACE) and subsequent radiofrequency ablation ( RFA) ( n = 44; median survival 45 months) as compared to patients receiving chemoembolization alone (n = 107; median survival 13 months) or patients treated by tamoxifen only (n = 21; median survival 6 months). Chemoembolization alone significantly (p <= 0.004) improved survival time in VISUM stage 1 - 2 patients but not (p = 0.341) in VISUM stage 3 patients in comparison to those treated by tamoxifen. Conclusion: Both liver resection or combined chemoembolization and RFA improve markedly the survival of patients with HCC

    Identification of sex hormone-binding globulin in the human hypothalamus

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    Gonadal steroids are known to influence hypothalamic functions through both genomic and non-genomic pathways. Sex hormone-binding globulin ( SHBG) may act by a non-genomic mechanism independent of classical steroid receptors. Here we describe the immunocytochemical mapping of SHBG-containing neurons and nerve fibers in the human hypothalamus and infundibulum. Mass spectrometry and Western blot analysis were also used to characterize the biochemical characteristics of SHBG in the hypothalamus and cerebrospinal fluid (CSF) of humans. SHBG-immunoreactive neurons were observed in the supraoptic nucleus, the suprachiasmatic nucleus, the bed nucleus of the stria terminalis, paraventricular nucleus, arcuate nucleus, the perifornical region and the medial preoptic area in human brains. There were SHBG-immunoreactive axons in the median eminence and the infundibulum. A partial colocalization with oxytocin could be observed in the posterior pituitary lobe in consecutive semithin sections. We also found strong immunoreactivity for SHBG in epithelial cells of the choroid plexus and in a portion of the ependymal cells lining the third ventricle. Mass spectrometry showed that affinity-purified SHBG from the hypothalamus and choroid plexus is structurally similar to the SHBG identified in the CSF. The multiple localizations of SHBG suggest neurohypophyseal and neuroendocrine functions. The biochemical data suggest that CSF SHBG is of brain rather than blood origin. Copyright (c) 2005 S. Karger AG, Base
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