4,919 research outputs found
Role Of Suspension Media For Electrophoretic Deposition: The Case Of Functional Oxides
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The Performance of Several Docking Programs at Reproducing Protein-Macrolide-Like Crystal Structures
The accuracy of five docking programs at reproducing crystallographic structures of complexes of 8 macrolides and 12 related macrocyclic structures, all with their corresponding receptors, was evaluated. Self-docking calculations indicated excellent performance in all cases (mean RMSD values ≤ 1.0) and confirmed the speed of AutoDock Vina. Afterwards, the lowest-energy conformer of each molecule and all the conformers lying 0-10 kcal/mol above it (as given by Macrocycle, from MacroModel 10.0) were subjected to standard docking calculations. While each docking method has its own merits, the observed speed of the programs was as follows: Glide 6.6 > AutoDock Vina 1.1.2 > DOCK 6.5 >> AutoDock 4.2.6 > AutoDock 3.0.5. For most of the complexes, the five methods predicted quite correct poses of ligands at the binding sites, but the lower RMSD values for the poses of highest affinity were in the order: Glide 6.6 ≈ AutoDock Vina ≈ DOCK 6.5 > AutoDock 4.2.6 >> AutoDock 3.0.5. By choosing the poses closest to the crystal structure the order was: AutoDock Vina > Glide 6.6 ≈ DOCK 6.5 ≥ AutoDock 4.2.6 >> AutoDock 3.0.5. Re-scoring (AutoDock 4.2.6//AutoDock Vina, Amber Score and MM-GBSA) improved the agreement between the calculated and experimental data. For all intents and purposes, these three methods are equally reliable
High-Resolution Spectroscopic Study of Extremely Metal-Poor Star Candidates from the SkyMapper Survey
The SkyMapper Southern Sky Survey is carrying out a search for the most
metal-poor stars in the Galaxy. It identifies candidates by way of its unique
filter set that allows for estimation of stellar atmospheric parameters. The
set includes a narrow filter centered on the Ca II K 3933A line, enabling a
robust estimate of stellar metallicity. Promising candidates are then confirmed
with spectroscopy. We present the analysis of Magellan-MIKE high-resolution
spectroscopy of 122 metal-poor stars found by SkyMapper in the first two years
of commissioning observations. 41 stars have [Fe/H] <= -3.0. Nine have [Fe/H]
<= -3.5, with three at [Fe/H] ~ -4. A 1D LTE abundance analysis of the elements
Li, C, Na, Mg, Al, Si, Ca, Sc, Ti, Cr, Mn, Co, Ni, Zn, Sr, Ba and Eu shows
these stars have [X/Fe] ratios typical of other halo stars. One star with low
[X/Fe]
[X/Fe values appears to be "Fe-enhanced," while another star has an extremely
large [Sr/Ba] ratio: >2. Only one other star is known to have a comparable
value. Seven stars are "CEMP-no" stars ([C/Fe] > 0.7, [Ba/Fe] < 0). 21 stars
exhibit mild r-process element enhancements (0.3 <=[Eu/Fe] < 1.0), while four
stars have [Eu/Fe] >= 1.0. These results demonstrate the ability to identify
extremely metal-poor stars from SkyMapper photometry, pointing to increased
sample sizes and a better characterization of the metal-poor tail of the halo
metallicity distribution function in the future.Comment: Minor corrections to text, missing data added to Tables 3 and 4;
updated to match published version. Complete tables included in sourc
Effects of Housing System on Dairy Heifer Replacement Cost from Birth to Calving: Evaluating Costs of Confinement, Dry-Lot, and Pasture-Based Systems and Their Impact on Total Rearing Investment
Replacement heifer rearing is critical for the future of dairy operations, to improve genetic merit and maintain herd size. A myriad of options exist on how to manage, feed, and ultimately raise replacement heifers. Pasture is perceived to offer optimal welfare and an economical housing system for replacement animals, but confinement systems are gaining popularity. This study investigates the costs associated with replacement heifer management decisions from birth to calving, considering the factors of housing systems, labor, feed, and health. The objective of this study was to develop an economic model to determine the cost of raising a replacement heifer managed in confinement, dry-lot, and pasture-based scenarios post-weaning. We accounted for variation in feed, labor, and health inputs and quantified the impact of these individual management decisions. An economic simulation with 10,000 iterations were completed for each situation using @Risk and PrecisionTree add-ons (Palisade Corporation, Ithaca, NY) where health incidence, commodity prices, and management variables were made stochastic. Published literature or sample farm data created parameters used in Pert distributions. Costs and biological responses were reflective of published surveys, literature, and market conditions. Management decision inputs had 3 main factors: housing type, ration composition, and labor utilization. Housing systems were calculated separately for confinement, dry-lot, and pasture scenarios. The mean total cost (min, max) to raise a replacement heifer from birth to calving, assuming the same pre-weaning strategy of group housing with an automatic calf feeder, was found to be 1,777.25, 1,593.57 (1,737.26), and 1,266.69, 423.05, 207.96 for confinement, dry-lot, and pasture management systems, respectively. When compared to total cost, housing contributed 21% for confinement, 7% for dry-lot, and 15% for pasture. Upon analysis of all scenarios, utilizing pasture to raise heifers resulted in a lower overall cost when compared to confinement housing options. Percentage breakdowns of feed, labor, housing, and fixed and variable costs provided more information on efficiency rather than total cost, which makes each situation different in relation to on-farm cost. This cost analysis is critical to assisting farms in making decisions in the utilization of their resources for replacement dairy heifers
(Z)-Oxopropene-1,3-diyl, a linker for the conjugation of the thiol group of cysteine with amino-derivatized drugs
We have developed a conjugation reaction based on the thia-Michael addition to activated triple bonds, which can be an alternative to maleimides, the most commonly used reagents to link thiol groups (of Cys) to drugs and labels. An amino group is converted into its propynamide and, in aqueous media at 37 °C and pH 7.4, Cys derivatives are added. The oxopropene-1,3-diyl linker is formed with excellent Z selectivity without secondary reactions. No exchange with other thiols is observed
Aldeia Sowante: exploração, colonialismo e reconquista territorial
O recente ordenamento territorial dos índios Nambiquara da Serra do Norte que se identificaram durante os trabalhos de campo como Sabanê, Kolimisí, Idalamarê, Lakondê, Niyahlosu, Siwaihsu e Hinkatesu consite no objeto deste estudo. O que se quer evidenciar é a dinâmica cultural desses grupos que há mais de uma década decidiram retornar ao seu antigo território de ocupação tradicional. O contato dos índios com os não índios encontra-se enlaçado em dimensões culturais e políticas, resultantes de uma distribuição desigual de poder. Com base na pesquisa etnográfica, este artigo pretende lançar luz ao retorno de famílias pertencentes aos grupos Nambiquara da Serra do Norte, anteriormente localizadas na Terra Indígena Pyreneus de Souza, município de Comodoro, Mato Grosso. Daí retornaram ao seu território tradicional, à margem direita do rio Roosevelt, no Sul da Terra Indígena Parque do Aripuanã. Afora a pesquisa etnográfica adotada para resolver a problemática indicada, a metodologia utilizada consistiu também na pesquisa documental, quando foram analisados documentos do SPI e os poucos produzidos pelas lideranças indígenas que conduziram o processo de retorno ao Sul do Parque do Aripuanã. O percurso teórico seguiu especialmente as trilhas de Junqueira (2002), Boaventura de Sousa Santos e Maria Paula Meneses (2010), Anibal Quijano (2005), Georges Balandier (1976 e 1997) para investigar outras lógicas de produção de conhecimento e ideias, com padrões próprios de expressão intelectual indígena
Aldeia Sowante: exploração, colonialismo e reconquista territorial
O recente ordenamento territorial dos índios Nambiquara da Serra do Norte que se identificaram durante os trabalhos de campo como Sabanê, Kolimisí, Idalamarê, Lakondê, Niyahlosu, Siwaihsu e Hinkatesu consite no objeto deste estudo. O que se quer evidenciar é a dinâmica cultural desses grupos que há mais de uma década decidiram retornar ao seu antigo território de ocupação tradicional. O contato dos índios com os não índios encontra-se enlaçado em dimensões culturais e políticas, resultantes de uma distribuição desigual de poder. Com base na pesquisa etnográfica, este artigo pretende lançar luz ao retorno de famílias pertencentes aos grupos Nambiquara da Serra do Norte, anteriormente localizadas na Terra Indígena Pyreneus de Souza, município de Comodoro, Mato Grosso. Daí retornaram ao seu território tradicional, à margem direita do rio Roosevelt, no Sul da Terra Indígena Parque do Aripuanã. Afora a pesquisa etnográfica adotada para resolver a problemática indicada, a metodologia utilizada consistiu também na pesquisa documental, quando foram analisados documentos do SPI e os poucos produzidos pelas lideranças indígenas que conduziram o processo de retorno ao Sul do Parque do Aripuanã. O percurso teórico seguiu especialmente as trilhas de Junqueira (2002), Boaventura de Sousa Santos e Maria Paula Meneses (2010), Anibal Quijano (2005), Georges Balandier (1976 e 1997) para investigar outras lógicas de produção de conhecimento e ideias, com padrões próprios de expressão intelectual indígena
Las emociones: punto de partida y llegada en el practicum de educación social
Podeu consultar el document complet a: http://hdl.handle.net/2445/58585Sin emoción no hay educación, esta es la premisa que nos convoca y que quiere
dar cuenta esta comunicación. Como tutoras del practicum de educación social y por el hecho
también de haber participado en el equipo de coordinación del mismo, hemos trabajado desde
las emociones, con las emociones y hemos crecido profesionalmente a través de ellas. Esta
comunicación quiere dar cuenta de la importancia de las emociones en el practicum de educación
social, en el aprendizaje de los estudiantes, en su acompañamiento, pero también las
emociones de los tutores y de nuestra relación pedagógica. Una relación pedagógica sostenida
por las emociones. Por tanto vamos a presentar las voces de nuestra vivencia emocional y el
trabajo realizado con los estudiantes de educación social en su proceso de prácticas, en su acompañamiento en las sesiones de seminario en la universidad y las tutorías
High Frequency Characterization and Nonlinear Analysis of BST Thick Films Produced by Electrophoretic Deposition
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Computer-aided insight into the relative stability of enamines
Venerable aldol, Michael, and Mannich reactions have undergone a renaissance in the past fifteen years, as a consequence of the development of direct organocatalytic versions, mediated by chiral amines. Chiral enamines are key intermediates in these reactions. This review focuses on the formation of enamines from secondary amines and their relative thermodynamic stability, as well as on the reverse reactions (hydrolysis). Experimental results and predictions based on MO calculations are reviewed to show which enamine forms may predominate in the reaction medium and to compare several secondary amines as organocatalysts.1 Introduction2 Relative Stability of Enamines as Determined Experimentally3 Pyrrolidine Enamines4 Enamines of the Jorgensen-Hayashi Catalyst5 Proline Enamines6 Free Enthalpies and Polar Solvent Effects7 Comparison of Organocatalysts8 Summary and Outlook9 Appendi
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