144 research outputs found

    Genetic diversity and character association analysis based on pomological traits in olive (Olea europaea L.)

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    Thirteen exotic genotypes of olive (Olea europaea L.) were studied for the genetic variability, correlation and path coefficient analysis for fruit quality, yield and yield contributing traits at experimental farm of ICAR-CITH, Srinagar during 2009-2013. Maximum variability was recorded for fruit yield and oil content, however, low differ-ences between the phenotypic and genotypic coefficients of variations indicated low environmental influences on the expression of these characters. High heritability coupled with high genetic advance was obtained with fruit yield per plant, acidity, fruit pulp weight, fruit weight and stone weight. Fruit weight (r=0.329), stone weight (r=0.405) and oil content (r=0.841) were the most important traits, which possessed significant positive association with fruit yield per plant. Path coefficient analysis revealed that among the different yield contributing characters oil content (0.875), fruit weight (0.797) followed by acidity (0.501), peroxides value ( 0.199) and fruit length (0.054) influenced fruit yield per plant directly. The direct effects of these characters on fruit yield were found positive and considerably very high.The selection based on fruit weight, stone weight oil content and yield per plant will be effective for enhancing the fruit and oil yieldand making future olive breeding strategies

    Costimulatory molecule-deficient dendritic cell progenitors (MHC class II<sup>+</sup>, CD80(dim), CD86<sup>-</sup>) prolong cardiac allograft survival in nonimmunosuppressed recipients

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    We have shown previously that granulocyte-macrophage colony-stimulating factor-stimulated mouse bone marrow-derived MHC class II+ dendritic cell (DC) progenitors that are deficient in cell surface expression of the costimulatory molecules B7-1 (CD8O) and B7-2 (CD86) can induce alloantigen- specific T-cell anergy in vitro. To test the in vivo relevance of these findings, 2 x 106 B10 (H2(b)) mouse bone marrow-derived DC progenitors (NLDC 145+, MHC class II+, B7-1(dim), B7-2(-/dim)) that induced T-cell hyporesponsiveness in vitro were injected systemically into normal C3H (H2(k)) recipients. Seven days later, the mice received heterotopic heart transplants from B10 donors. No immunosuppressive treatment was given. Median graft survival time was prolonged significantly from 9.5 to 22 days. Median graft survival time was also increased, although to a lesser extent (16.5 days), in mice that received third-party (BALB/c; H2(d)) DC progenitors. Ex vivo analysis of host T-cell responses to donor and third-party alloantigens 7 days after the injection of DC progenitors (the time of heart transplant) revealed minimal anti-donor mixed leukocyte reaction and cytotoxic T lymphocyte reactivity. These responses were reduced substantially compared with those of spleen cells from animals pretreated with 'mature' granulocyte- macrophage colony-stimulating factor + interleukin-4-stimulated DC (MHC class II(bright), B7-1+, B7-2(bright)), many of which rejected their heart grafts in an accelerated fashion. Among the injected donor MHC class II+ DC progenitors that migrated to recipient secondary lymphoid tissue were cells that appeared to have up-regulated cell surface B7-1 and B7-2 molecule expression. This observation may explain, at least in part, the temporary or unstable nature of the hyporesponsiveness induced by the DC progenitors in nonimmunosuppressed recipients

    Synergistic Catalysis of Ruthenium Nanoparticles and Polyoxometalate Integrated Within Single UiO−66 Microcrystals for Boosting the Efficiency of Methyl Levulinate to γ-Valerolactone

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    The synthesis of heterogeneous cooperative catalysts in which two or more catalytically active components are spatially separated within a single material has generated considerable research efforts. The multiple functionalities of catalysts can significantly improve the efficiency of existing organic chemical transformations. Herein, we introduce ruthenium (Ru) nanoparticles (NPs) on the surfaces of a metal–organic framework pre-encapsulated with polyoxometalate silicotungstic acid (SiW) UiO−66 (University of Oslo [UiO]) and prepared a 2.0% Ru/11.7% SiW@UiO−66 porous hybrid using the impregnation method. The close synergistic effect of metal Ru NPs, SiW, and UiO-66 endow 2.0% Ru/11.7% SiW@UiO-66 with increased activity and stability for complete methyl levulinate (ML) conversion and exclusive γ-valerolactone (GVL) selectivity at mild conditions of 80°C and at a H2 pressure of 0.5 MPa. Effectively, this serves as a model reaction for the upgrading of biomass and outperforms the performances of the constituent parts and that of the physical mixture (SiW + Ru/UiO−66). The highly dispersed Ru NPs act as active centers for hydrogenation, while the SiW molecules possess Brønsted acidic sites that cooperatively promote the subsequent lactonization of MHV to generate GVL, and the UiO−66 crystal accelerates the mass transportation facilitated by its own porous structure with a large surface area

    Lineage diversification and historical demography of a montane bird Garrulax elliotii - implications for the Pleistocene evolutionary history of the eastern Himalayas

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    <p>Abstract</p> <p>Background</p> <p>Pleistocene climate fluctuations have shaped the patterns of genetic diversity observed in many extant species. In montane habitats, species' ranges may have expanded and contracted along an altitudinal gradient in response to environmental fluctuations leading to alternating periods of genetic isolation and connectivity. Because species' responses to climate change are influenced by interactions between species-specific characteristics and local topography, diversification pattern differs between species and locations. The eastern Himalayas is one of the world's most prominent mountain ranges. Its complex topography and environmental heterogeneity present an ideal system in which to study how climatic changes during Pleistocene have influenced species distributions, genetic diversification, and demography. The Elliot's laughing thrush (<it>Garrulax elliotii</it>) is largely restricted to high-elevation shrublands in eastern Himalayas. We used mitochondrial DNA and microsatellites to investigate how genetic diversity in this species was affected by Pleistocene glaciations.</p> <p>Results</p> <p>Mitochondrial data detected two partially sympatric north-eastern and southern lineages. Microsatellite data, however, identified three distinct lineages congruent with the geographically separated southern, northern and eastern eco-subregions of the eastern Himalayas. Geographic breaks occur in steep mountains and deep valleys of the Kangding-Muli-Baoxin Divide. Divergence time estimates and coalescent simulations indicate that lineage diversification occurred on two different geographic and temporal scales; recent divergence, associated with geographic isolation into individual subregions, and historical divergence, associated with displacement into multiple refugia. Despite long-term isolation, genetic admixture among these subregional populations was observed, indicating historic periods of connectivity. The demographic history of <it>Garrulax elliotii </it>shows continuous population growth since late Pleistocene (about 0.125 mya).</p> <p>Conclusion</p> <p>While altitude-associated isolation is typical of many species in other montane regions, our results suggest that eco-subregions in the eastern Himalayas exhibiting island-like characteristics appear to have determined the diversification of <it>Garrulax elliotii</it>. During the Pleistocene, these populations became isolated on subregions during interglacial periods but were connected when these expanded to low altitude during cooler periods. The resultant genetic admixture of lineages might obscure pattern of genetic variation. Our results provide new insights into sky island diversification in a previously unstudied region, and further demonstrate that Pleistocene climatic changes can have profound effects on lineage diversification and demography in montane species.</p

    A solution of aluminum substrate drilling

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    PurposeThe purpose of this paper is to present and describe a solution of aluminum substrate drilling.Design/methodology/approachThe development of LED and printed circuit board with metal substrate are reviewed first. Then the challenges of drilling metal substrate, particularly the aluminum substrate, are described. To find the solution, coated micro drill bit with optimized helix angle is developed. The performance of developed micro drill bit is examined via drilling force investigation. Finally, the drilling tests are conducted to verify the solution of aluminum substrate drilling.FindingsCoated drill bit is a very good choice to solve the problems of drilling burr and chip clogging in aluminum substrate drilling. The reason is that the drilling force can be obviously reduced by using a coated drill bit. The drill bit with medium helix angle is beneficial to prevent chip clogging. A satisfactory solution of aluminum substrate drilling can be achieved by applying coated drill bit with medium helix angle together with appropriate entry board.Originality/valueThe paper presents a satisfactory solution of aluminum substrate drilling. By employing the presented solution, the problems of drilling burr and chip clogging can be avoided in aluminum substrate drilling.</jats:sec

    MoS<sub>2</sub>-based broadband and highly efficient solar absorbers

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    In order to obtain broadband, highly efficient, wide-angle, and polarization-insensitive solar absorbers, we propose a universal configuration consisting of monolayer molybdenum disulfide ( M o S 2 ) and the metal-insulator-metal structure, which gives rise to significant absorption enhancement of the M o S 2 layer. Light trapping structures with silver square-, circle-, and crossed-shaped resonators are investigated. The localized surface plasmon resonances among the silver resonators induce prominent interaction between the incident photon and M o S 2 layer, contributing to efficient absorption of light energy. Simulation results show that the absorber made of square patches enables the best performance and realizes absorptance higher than 90% from 400 to 666 nm and an average absorptance greater than 91% in the range of 400–700 nm. The average light absorption within the M o S 2 layer reaches 74% in the visible spectrum, which is one of the highest levels for the existing M o S 2 -based absorbers. Meanwhile, the polarization-independent designs exhibit good angle tolerance within 50° incidences. Such a universal structure can also obtain broadband and highly efficient absorption by using other transition metal dichalcogenides such as M o S e 2 , W S 2 , and W S e 2 , which indicates that the configuration has great applicability in solar energy absorption of 2D materials. The proposed solar absorbers with simple configuration and broadband absorption in wide incident angles have potential in applications such as solar cells, photovoltaic devices, and blackbody materials.</jats:p
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