Chiral transition-metal complexes as Brønsted-acid catalysts for the asymmetric Friedel-Crafts hydroxyalkylation of indoles.

The Friedel-Crafts reaction between 3,3,3-trifluoropyruvates and indoles is efficiently catalysed by the iridium complex [(η5-C 5Me5)Ir{(R)-Prophos}(H2O)][SbF 6]2 (1) with up to 84% ee. Experimental data and theoretical calculations support a mechanism involving the Brønsted-acid activation of the pyruvate carbonyl by the protons of the coordinated water molecule in 1. Water is not dissociated during the process and, therefore, the catalytic reaction occurs with no direct interaction between the substrates and the metal. This journal is © the Partner Organisations 2014.The authors acknowledge the Ministerio de Economía y Competitividad (MINECO, Grants CTQ2006-03030/BQU, CTQ2009-10303/BQU, CTQ2011-27033 and Consolider Ingenio 2010 CSD2006-003), Gobierno de Aragón (Grupo Consolidado: Catálisis Homogénea Enantioselectiva), Generalitat de Catalunya (2009SGR0259) and the ICIQ foundation for financial support. A. S. and R. R. acknowledge MINECO for predoctoral fellowships. S. D.-G. acknowledges MINECO for a “Torres Quevedo” contract.Peer Reviewe

Hydroformylation of synthetic naphtha catalyzed by a dinuclear gem-dithiolato-bridged rhodium(I) complex

This work focuses on the use of a gem-dithiolato-bridged rhodium(I) Rh 2(µ-S 2CBn 2)(cod) 2 complex (cod = 1,5-cyclooctadiene, Bn 2CS 2 2- = 1,3-diphenyl-2,2-dithiolatopropane) dissolved in toluene in the presence of monodentate phosphite P-donor ligand (P(OPh) 3) under carbon monoxide/hydrogen (1:1, syngas) atmosphere as an effective catalyst for hydroformylation of some olefins (oxo-reactions). The capability of this system to catalyze the hydroformylation of hex-1-ene, cyclohexene, 2,3-dimethyl-but-1-ene and 2-methyl-pent-2-ene and their quaternary mixture (synthetic naphtha) has been demonstrated. This innovative method to perform the in situ hydroformylation of the olefins present in naphthas to oxygenated products would be a promissory work for a future industrial catalytic process applicable to gasoline improving based on oxo-reactions. An important observation is that variation of CO/H 2 pressure (6.8-34.0 atm), temperature (60-80 oC), reaction time (2-10 h), rhodium concentration ((1.0-1.8)x10 -3 mol/L) affect hydroformylation reaction rates. Optimal conversion to oxygenated products were achieved under Rh = 1.8 x10 -2 mol/L, P(CO/H 2) = 34 atm (CO/H 2 = 1:1) at 80 oC for 10 h

Disciplinas de custos: uma análise nos cursos de Ciências Contábeis das IES do sistema ACAFE

A informação de custos, diante de um mercado de competitividade crescente, apresenta-se como uma base importante ao processo decisório, além de implicar novos paradigmas na gestão dos negócios. Desta forma, torna-se relevante o oferecimento de disciplinas de custos no Curso de Ciências Contábeis onde a contabilidade de custos e seu processo de ensino devem direcionar o aluno, a partir do estudo acadêmico, ao processo externo, ou seja, ao mercado tomador do profissional provido de conhecimento contábil.Considerando a relevância das disciplinas de custos no Curso de Ciências Contábeis das Instituições de Ensino Superior (IES), este artigo tem como objetivo verificar as congruências e divergências destas disciplinas ofertadas nos Cursos de Ciências Contábeis das universidades ligadas à Associação Catarinense das Fundações Educacionais (ACAFE). A metodologia da pesquisa consubstancia-se de um estudo exploratório, realizado por meio de levantamento, com abordagem predominantemente qualitativa. Utilizou-se para análise o conteúdo de ementa, a carga horária e a disposição das disciplinas de custos na grade curricular nestas instituições. A técnica estatística empregada foi análise de clusters. Diante deste estudo que teve como objetivo a verificação das congruências e divergências das disciplinas de custos ofertadas nos Cursos de Ciências Contábeis das instituições ligadas à ACAFE, conclui-se que estas instituições estabelecem um agrupamento predominante, mesmo que na análise isolada de algumas variáveis isto não ocorra. Os resultados da pesquisa evidenciam que na variável ementa, o cluster mais representativo apontou 9 instituições, representando o maior grupo com 56,25% do total de instituições pesquisadas. Na variável fase, 10 instituições apresentaram congruência, pois oferecem as disciplinas de custos em períodos semelhantes. Na variável carga horária, 10 instituições apresentam similaridade no oferecimento das disciplinas de custos e análise de custos com 120 h/a. Conclui-se que, num contexto geral, há um acentuado nível de congruência nas disciplinas de custos entre as universidades analisadas, apesar de divergências encontradas na análise isolada de algumas variáveis

Laminin-511 and integrin beta-1 in hair follicle development and basal cell carcinoma formation

<p>Abstract</p> <p>Background</p> <p>Initiation of the hair follicle placode and its subsequent growth, maturation and cycling in post-natal skin requires signaling interactions between epithelial cells and adjacent dermal cells and involves Shh signaling via the primary cilium. Previous reports have implicated laminins in hair follicle epithelial invagination.</p> <p>Results</p> <p>Here we use a human BCC model system and mouse mutants to re-evaluate the role of laminin-511 in epithelial invagination in the skin. Blocking laminin 511 and 332 in BCCs maintains primary cilia and Shh signalling, but prevents invagination. Similarly, in laminin-511 and dermal beta-1 integrin mutants, dermal papilla development and primary cilia formation are normal. Dermal beta-1 integrin mutants have normal hair follicle development.</p> <p>Conclusions</p> <p>Our data provides support for a primary role of laminin-511 promoting hair follicle epithelial downgrowth without affecting dermal primary cilia and Shh target gene induction.</p

The dynamics of cultivation and floods in arable lands of Central Argentina

Although floods in watersheds have been associated with land-use change since ancient times, the dynamics of flooding is still incompletely understood. In this paper we explored the relations between rainfall, groundwater level, and cultivation to explain the dynamics of floods in the extremely flat and valuable arable lands of the Quinto river watershed, in central Argentina. The analysis involved an area of 12.4 million hectare during a 26-year period (1978–2003), which comprised two extensive flooding episodes in 1983–1988 and 1996–2003. Supported by information from surveys as well as field and remote sensing measurements, we explored the correlation among precipitation, groundwater levels, flooded area and land use. Flood extension was associated to the dynamics of groundwater level. While no correlation with rainfall was recorded in lowlands, a significant correlation (&lt;i&gt;P&lt;/i&gt;&amp;lt;0.01) between groundwater and rainfall in highlands was found when estimations comprise a time lag of one year. Correlations between groundwater level and flood extension were positive in all cases, but while highly significant relations (&lt;i&gt;P&lt;/i&gt;&amp;lt;0.01) were found in highlands, non significant relations (&lt;i&gt;P&lt;/i&gt;&amp;gt;0.05) predominate in lowlands. Our analysis supports the existence of a cyclic mechanism driven by the reciprocal influence between cultivation and groundwater in highlands. This cycle would involve the following stages: (a) cultivation boosts the elevation of groundwater levels through decreased evapotranspiration; (b) as groundwater level rises, floods spread causing a decline of land cultivation; (c) flooding propitiates higher evapotranspiration favouring its own retraction; (d) cultivation expands again following the retreat of floods. Thus, cultivation would trigger a destabilizing feedback self affecting future cultivation in the highlands. It is unlikely that such sequence can work in lowlands. The results suggest that rather than responding directly and solely to the same mechanism, floods in lowlands may be the combined result of various factors like local rainfall, groundwater level fluctuations, surface and subsurface lateral flow, and water-body interlinking. Although the hypothetical mechanisms proposed here require additional understanding efforts, they suggest a promising avenue of environmental management in which cultivation could be steered in the region to smooth the undesirable impacts of floods

Estimating the cumulative effects of the nature-based tourism in a coastal dolphin population from southern Kenya

Due to the growth of nature-based tourism worldwide, behavioural studies are needed to assess the impact of this industry on wildlife populations and understand their short-term effect. Tourism impact on dolphin populations remain poorly documented in developing countries. This study investigates the effects of nature-based tourism on the behaviour of the Indo-Pacific bottlenose dolphins (Tursiops aduncus) in southern Kenya. We used Markov chain models to estimate transition probabilities between behavioural states in the presence and absence of tourist boats, and assess the overall behavioural budgets. Based on these data and the tourism intensity in the area, we quantified the potential tourist boat disturbance over the period 2006-2013. Our results demonstrated that tourist boat interactions affected dolphins' behavioural budgets, with a significant decrease in the overall amount of time travelling and an increase in diving. The average duration of travelling and resting decreased significantly in the presence of boats. Although the cumulative tourism exposure was not significant for the dolphin population at their current levels, these impacts should be taken into consideration with the potential tourism growth in the area. This is particularly important if tourism reaches periods of high intensity, as we have shown that these periods could have a significant impact for the species, particularly where home-range and core areas are highly overlap by this activity. Understanding the effect of human disturbance variations from previous years may help to predict the consequences on dolphin populations, towards achieving a more ecological and economic sustainability of the activity

Synthesis of oxazolidinones in supercritical CO2 under heterogeneous catalysis

Basic alumina efficiently promotes the reaction of propargylamines with scCO2 for the synthesis of variously substituted oxazolidinones that, after catalyst filtration, are easily isolated by methanol crystallization

Use of the Richtmyer-Meshkov Instability to Infer Yield Stress at High-Energy Densities

We use the Richtmyer-Meshkov instability (RMI) at a metal-gas interface to infer the metal’s yield stress (Y) under shock loading and release. We first model how Y stabilizes the RMI using hydrodynamics simulations with a perfectly plastic constitutive relation for copper (Cu). The model is then tested with molecular dynamics (MD) of crystalline Cu by comparing the inferred Y from RMI simulations with direct stress-strain calculations, both with MD at the same conditions. Finally, new RMI experiments with solid Cu validate our simulation-based model and infer Y~0.47 GPa for a 36 GPa shock

Mitochondrial Function in Antarctic Nototheniids with ND6 Translocation

Fish of the suborder Notothenioidei have successfully radiated into the Southern Ocean and today comprise the dominant fish sub-order in Antarctic waters in terms of biomass and species abundance. During evolution in the cold and stable Antarctic climate, the Antarctic lineage of notothenioids developed several unique physiological adaptations, which make them extremely vulnerable to the rapid warming of Antarctic waters currently observed. Only recently, a further phenomenon exclusive to notothenioid fish was reported: the translocation of the mitochondrial gene encoding the NADH Dehydrogenase subunit 6 (ND6), an indispensable part of complex I in the mitochondrial electron transport system