Water dimer diffusion on Pd{111} assisted by an H-bond donor-acceptor tunneling exchange

Based on the results of density functional theory calculations, a novel mechanism for the diffusion of water dimers on metal surfaces is proposed, which relies on the ability of H bonds to rearrange through quantum tunneling. The mechanism involves quasifree rotation of the dimer and exchange of H-bond donor and acceptor molecules. At appropriate temperatures, water dimers diffuse more rapidly than water monomers, thus providing a physical explanation for the experimentally measured high diffusivity of water dimers on Pd{111} [Mitsui et al., Science 297, 1850 (2002)]

Gemini/GMOS photometry of intermediate-age star clusters in the Large Magellanic Cloud

We present Gemini South GMOS g,i photometry of 14 intermediate-age Large Magellanic Cloud (LMC) star clusters, namely: NGC 2155, 2161, 2162, 2173, 2203, 2209, 2213, 2231, 2249, Hodge 6, SL 244, 505, 674, and 769, as part of a continuing project to investigate the extended Main Sequence Turnoff (EMSTO) phenomenon. Extensive artificial star tests were made over the observed field of view. These tests reveal the observed behaviour of photometric errors with magnitude and crowding. The cluster stellar density radial profiles were traced from star counts over the extent of the observed field. We adopt clus- ter radii and build colour-magnitude diagrams (CMDs) with cluster features clearly identified. We used the cluster (g,g-i) CMDs to estimate ages from the matching of theoretical isochrones. The studied LMC clusters are confirmed to be intermediate-age clusters, which range in age 9.10 < log(t) < 9.60. NGC 2162 and NGC 2249 look like new EMSTO candidates, in addition to NGC 2209, on the basis of having dual red clumps.Comment: MNRAS, accepte

Innovation in the subsistence marketplace: an analysis considering multiple concepts and approaches

Purpose – The purpose of this paper is to explore the different concepts of innovation in thesubsistence marketplace from top-down and bottom-up approaches. This study analyzes the literatureon the theme and identified research gaps by constructing a framework based on approaches andinnovation concepts, which can guide future research efforts. Additionally, this paper presents two casestudies, which can improve the way innovation is developed and diffused in the subsistencemarketplace.Design/methodology/approach – Through a literature review, this study develops a framework byanalyzing innovation concepts in the subsistence marketplace (i.e. base of the pyramid innovation, disruptiveinnovation, frugal innovation, reverse innovation and inclusive innovation) in light of subsistencemarketplace approaches (top-down and bottom-up).Findings – The analysis showed critical research gaps, especially a lack of studies involvingdisruptive and frugal innovations from a bottom-up approach. This paper also concludes that the topdown approach is more common than the bottom-up one. To fill these gaps, this study presents twobusiness plans by illustrating disruptive innovation vs bottom-up approach and frugal innovation vsbottom-up approach.Originality/value – The use of real business plans to illustrate proposals having an actual impact onsubsistence marketplace regions sheds light on how to address these challenges. By doing so, this paperintends to fill the theoretical gap in disruptive and frugal innovations within a bottom-up approach to promote the development and diffusion of different types of innovation in the subsistence marketplace, andthus provide solutions to alleviate povert

DISRUPTIVE INNOVATION IN LOW-INCOME CONTEXTS: CHALLENGES AND STATE-OF-THE-ART NATIONAL RESEARCH IN MARKETING

The low-income market has become the focus of many companies since the economic growth of emerging countries has been highlighted nationally and internationally. Thus, the development of innovations for this segment has also become a central issue in academia and management. Literature on disruptive innovation presents assumptions that justify its analysis in light of the low-income market. Thus, this article analyzes the concept of disruptive innovation in this market. For this purpose, the article is divided into two parts: the first focuses on a theoretical review of disruptive innovation, whilst the second presents a review of national publications dealing with this concept. The national literature review shows that few studies have been concerned with addressing these concepts in Business Administration and Marketing, especially considering aspects of the low-income context

Ação de regulador do metabolismo de etileno sobre a produtividade de soja cultivada em terras baixas.

bitstream/item/30414/1/boletim-68.pd

Condensation in ducts

Phase changing flows are being considered for thermal management in space platforms. The resulting flow patterns are very complicated and extremely sensitive to gravity action. Concerning fluid flow in ducts, the available evidence indicates that although the pressure loss does not depend too much on the fluid flow pattern,the heat transfer (and resulting phase change) does. A simple exercise to illustrate this point is presented in this paper. It deals with condensing flow in straight circular cross-sectional ducts. Two extreme configurations are considered here, one corresponds to a stratified flow and the other to an annular flow. Both types of flow patterns have been extensively considered in the past and from this point of view almost nothing is new in the paper, but past results look conflictive and this could be due to the limitations and computational intricacies of the models used. Thus the problem has been reformulated from the onset and the results are presented as the evolution of the vapor quality (vapor to total mass flow rate) along the duct, in typical cases. The results presented here indicate that within the validity of the present models and the assumed ranges of mass flow rate, duct diameter, thermal conditions and fluid characteristics,the length of the ducts required to achieve complete condensation under zero gravity are an order of magnitude larger than in horizontal tubes under normal terrestrial conditions

Geranylgeraniol overcomes the block of cell proliferation by lovastatin in C6 glioma cells

It is well documented that 3-hydroxy-3-methylglutaryl-CoA reductase inhibitors prevent cultured mammalian cells from progressing through the cell cycle, suggesting a critical role for a mevalonate-derived product. Recently, it has been shown that free geranylgeraniol (GG-OH) and farnesol (F-OH) can be utilized by C6 glioma cells for protein isoprenylation. The ability of CC-OH and F-OH to restore protein geranylgeranylation or farnesylation selectively has enabled us to examine the possibility that mevalonate is essential for cell proliferation because it is a precursor of farnesyl pyrophosphate or geranylgeranyl pyrophosphate, the isoprenyl donors involved in the posttranslational modification of key regulatory proteins. In this study we report that CC-OH, as well as mevalonate, overcomes the arrest of cell proliferation of C6 glioma cells treated with lovastatin, as assessed by increased cell numbers and a stimulation in [H-3]thymidine incorporation. The increase in cell number and [H-3]thymidine incorporation were significantly lower when F-OH was added. Under these conditions [H-3]mevalonate and [H-3]GG-OH are actively incorporated into a set of isoprenylated proteins in the size range of small, GTP-binding proteins (19-27 kDa) and a polypeptide with the molecular size (46 kDa) of the smaller isoform of 2',3'-cyclic nucleotide 3'-phosphodiesterase. Analysis of the proteins metabolically labeled by [H-3]mevalonate and [H-3]GG-OH reveals the presence of labeled proteins containing geranylgeranylated cysteinyl residues. Consistent with geranylgeranylated proteins playing a critical role in the entry of C6 cells into the cell cycle, a (phosphonoacetamido) oxy derivative of GG-OH, a drug previously shown to interfere with protein geranylgeranylation, prevented the increase in cell number when mevalonate or GG-OH was added to lovastatin-treated cells. These results strongly suggest that geranylgeranylated proteins are essential for progression of C6 cells into the S phase of the cell cycle and provide the first evidence that the "salvage" pathway for the utilization of the free isoprenols is physiologically significant in the CNS