233 research outputs found

    Adventures in Fair Trade

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    Helping Laotian artisans find larger markets to preserve age-old skills and improve living standardsMark Sloneker,fair trade, Orijyn, Laos, artisans, social enterprise, social entrepreneurship, social business, social entrepreneur, social entrepreneurs, silk, silver, Participatory Development Training Centre, handcrafts, fair trade federation

    Binary Natal Kicks in the Galactic Center: X-ray Binaries, Hypervelocity Stars, and Gravitational Waves

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    Theoretical and observational studies suggest that stellar binaries exist in large numbers in galactic nuclei like our own Galactic Center. Neutron stars (NSs), and debatedly, black holes (BHs) and white dwarfs (WDs), receive natal kicks at birth. In this work we study the effect of two successive natal kicks on a population of stellar binaries orbiting the massive black hole (MBH) in our Galactic Center. These natal kicks can significantly alter the binary orbit in a variety of ways, and also the orbit of the binary around the MBH. We found a variety of dynamical outcomes resulting from these kicks, including a steeper cusp of single NSs relative to the initial binary distribution. Furthermore, hypervelocity star and binary candidates, including hypervelocity X-ray binaries, are a common outcome of natal kicks. In addition, we show that the population of X-ray binaries in the Galactic Center can be used as a diagnostic for the BH natal kick distribution. Finally, we estimate the rate of gravitational wave (GW) events triggered by natal kicks, including binary mergers and EMRIs.Comment: Submitted to Ap

    Designing ad hoc temperature fixed point cells

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    The design of the ad hoc (made of hand-on materials) temperature fixed-point cell (TFPC) is considered in this paper. There was developed a TFPC filled with lead and an apparatus for its investigation. The feature of the considered TFPC is minimization of the stray thermal fluxes distorting the temperature plateau during a phase change. Conclusions about the influence of the design of a TFPC on the temperature plateau of phase change are described

    Characterization of the Exopolysaccharide Produced by Salipiger mucosus A3T, a Halophilic Species Belonging to the Alphaproteobacteria, Isolated on the Spanish Mediterranean Seaboard

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    We have studied the exopolysaccharide produced by the type strain of Salipiger mucosus, a species of halophilic, EPS-producing (exopolysaccharide-producing) bacterium belonging to the Alphaproteobacteria. The strain, isolated on the Mediterranean seaboard, produced a polysaccharide, mainly during its exponential growth phase but also to a lesser extent during the stationary phase. Culture parameters influenced bacterial growth and EPS production. Yield was always directly related to the quantity of biomass in the culture. The polymer is a heteropolysaccharide with a molecular mass of 250 kDa and its components are glucose (19.7%, w/w), mannose (34%, w/w), galactose (32.9%, w/w) and fucose (13.4%, w/w). Fucose and fucose-rich oligosaccharides have applications in the fields of medicine and cosmetics. The chemical or enzymatic hydrolysis of fucose-rich polysaccharides offers a new efficient way to process fucose. The exopolysaccharide in question produces a solution of very low viscosity that shows pseudoplastic behavior and emulsifying activity on several hydrophobic substrates. It also has a high capacity for binding cations and incorporating considerable quantities of sulfates, this latter feature being very unusual in bacterial polysaccharides

    Antiviral Activities of Sulfated Polysaccharides Isolated from Sphaerococcus coronopifolius (Rhodophytha, Gigartinales) and Boergeseniella thuyoides (Rhodophyta, Ceramiales)

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    Water-soluble sulfated polysaccharides isolated from two red algae Sphaerococcus coronopifolius (Gigartinales, Sphaerococcaceae) and Boergeseniella thuyoides (Ceramiales, Rhodomelaceae) collected on the coast of Morocco inhibited in vitro replication of the Human Immunodeficiency Virus (HIV) at 12.5 μg/mL. In addition, polysaccharides were capable of inhibiting the in vitro replication of Herpes simplex virus type 1 (HSV-1) on Vero cells values of EC50 of 4.1 and 17.2 μg/mL, respectively. The adsorption step of HSV-1 to the host cell seems to be the specific target for polysaccharide action. While for HIV-1, these results suggest a direct inhibitory effect on HIV-1 replication by controlling the appearance of the new generations of virus and potential virucidal effect. The polysaccharides from S. coronopifolius (PSC) and B. thuyoides (PBT) were composed of galactose, 3,6-anhydrogalactose, uronics acids, sulfate in ratios of 33.1, 11.0, 7.7 and 24.0% (w/w) and 25.4, 16.0, 3.2, 7.6% (w/w), respectively

    Sequências de culturas em sistema de semeadura direta: II - decomposição e liberação de nutrientes na entressafra

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    Os nutrientes acumulados nos resíduos das culturas, ao serem liberados no processo de decomposição, retornam ao solo e podem ficar disponíveis às culturas em sucessão. O objetivo deste trabalho foi avaliar a decomposição e liberação de nutrientes de resíduos vegetais de espécies utilizadas na entressafra em diferentes sequências de culturas em sistema de semeadura direta. O experimento foi conduzido em Jaboticabal-SP (48° 18' W e 21° 15' S), em um Latossolo Vermelho eutrófico. O delineamento experimental foi em faixas, com três repetições. Os tratamentos constituíram da combinação de três sequências de culturas de verão (rotação soja-milho e monoculturas de milho e de soja) com sete culturas de entressafra (milho, sorgo, girassol, crotalária, guandu, nabo forrageiro e milheto). O experimento foi iniciado em 2002, e o presente estudo refere-se aos anos agrícolas 2007/2008 e 2008/2009. Avaliaram-se a decomposição e a liberação de nutrientes utilizando sacolas de decomposição, com coletas aos 15, 30, 60, 120 e 180 dias após a trituração das culturas. A cobertura do solo foi avaliada após a trituração das culturas e ao final do ano agrícola. Os resíduos de crotalária, milho, sorgo, girassol apresentaram menores taxas de decomposição. Crotalária, guandu, nabo forrageiro e milheto proporcionaram resíduos que liberaram maior quantidade de nutrientes quando comparados ao milho, sorgo e girassol. Crotalária e milheto destacaram-se como as culturas mais adequadas para cultivo na entressafra, em especial a crotalária, devido à baixa taxa de decomposição e à elevada quantidade de nutrientes liberados na decomposição, e o milheto, em razão da elevada quantidade de nutrientes remanescentes nos resíduos no final do ano agrícola. Sequências de culturas que envolveram cultivo de girassol na entressafra proporcionaram menor cobertura do solo pelos resíduos vegetais
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