562 research outputs found

    The effect of inoculum source and fluid shear force on the development of in vitro oral multispecies biofilms

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    AimsSaliva has been previously used as an inoculum for in vitro oral biofilm studies. However, the microbial community profile of saliva is markedly different from hardâ and softâ tissueâ associated oral biofilms. Here, we investigated the changes in the biofilm architecture and microbial diversity of in vitro oral biofilms developed from saliva, tongue or plaqueâ derived inocula under different salivary shear forces.Methods and ResultsFour inoculum types (saliva, bacteria harvested from the tongue, toothbrush and curetteâ harvested plaque) were collected and pooled. Biofilms (n ⠥ 15) were grown for 20 h in cellâ free human saliva flowing at three different shear forces. Stained biofilms were imaged using a confocal laser scanning microscope. Biomass, thickness and roughness were determined by image analysis and bacterial community composition analysed using Ion Torrent. All developed biofilms showed a significant reduction in observed diversity compared with their respective original inoculum. Shear force altered biofilm architecture of saliva and curetteâ collected plaque and community composition of saliva, tongue and curetteâ harvested plaque.ConclusionsDifferent intraoral inocula served as precursors of in vitro oral polymicrobial biofilms which can be influenced by shear.Significance and Impact of the StudyInoculum selection and shear force are key factors to consider when developing multispecies biofilms within in vitro models.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/136333/1/jam13376-sup-0001-FigS1.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/136333/2/jam13376-sup-0002-TableS1.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/136333/3/jam13376_am.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/136333/4/jam13376.pd

    The metallogenic evolution of the Greater Antilles

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    The Greater Antilles host some of the world’s most important deposits of bauxite and lateritic nickel as well as significant resources of gold and silver, copper, zinc, manganese, cobalt and chromium. Beginning in Jurassic time, sedimentary exhalative base metal deposits accumulated in marine sedimentary rift basins as North and South America drifted apart. With the onset of intraoceanic subduction during the Early Cretaceous, a primitive (tholeiitic) island arc formed above a southwesterly-dipping subduction zone. Podiform chromite deposits formed in the mantle portion of the supra-subduction zone, directly above subducted Proto-Caribbean oceanic lithosphere. Within the nascent island arc, bimodal-mafic volcanogenic massive sulfide deposits formed in a fore-arc setting; mafic volcanogenic massive sulfide deposits formed later in mature back-arc basins. The Pueblo Viejo gold district, with five million ounces in production and twenty million ounces in mineable reserves, formed at 108-112Ma, in an apical rift or back-arc setting. By Late Cretaceous time, calc-alkaline volcanism was well established along the entire length of the Greater Antilles. Volcanogenic massive sulfide deposits including shallow submarine deposits characteristic of the primitive island arc gave way to porphyry copper and epithermal precious metal deposits typical of the mature island arc. Oblique collision of the Greater Antilles with North America began in the Late Cretaceous in Cuba and migrated eastward. Orogenic gold and tungsten deposits that formed during the collision event are preserved in ophiolites and in metamorphic core complexes. Since the Eocene, regional tectonism has been dominated by strike-slip motion as the North American continent moved westward relative to the Caribbean Plate. Large nickel-cobalt laterite deposits were formed when serpentinites were exposed to weathering and erosion during the mid-Tertiary. Bauxite deposits were derived from the weathering of volcanic ash within a carbonate platform of Eocene to Miocene ag

    Sustainable management of peel waste in the small-scale orange juice industries: A Colombian case study

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    Appropriate waste management in emerging economies like Colombia should be an asset for the overall sustainability. In the Orange Peel Waste case, incineration and Anaerobic Digestion are challenging solutions for the orange juice agro-industrial sector for avoiding the landfill, which is the conventional practice. However, these alternatives should be assessed in order to determine their feasibility. This paper aims to understand if incineration and Anaerobic Digestion are potential alternatives to landfill form a techno-economic and environmentally perspective. To this aim, a comparative Life Cycle Assessment was carried out in four scenarios. In the first scenario coal and landfill are used as source of energy and landfill disposal in the actual orange juice process. In the second scenario, the peels are incinerated to avoid landfill and reduce the need for coal. The third scenario includes the valorization of the peels by means of Anaerobic Digestion which produces biogas for the plant energy requirements. In the fourth scenario, apart from the energy from biogas, the digestate becomes a fertilizer for use in the orange crops. The results revealed that scenario III and IV are environmentally friendly options compared to Scenario I, but they incur higher costs than Scenario II. Carbon footprint found that 1.55 kg of CO2 are saving when coal substitution is reduced from 0.493 kg in SI to 0.279 kg in SII. Therefore, Scenario II is more suitable for the Colombian socioeconomic reality since Scenario II is not only techno-environmentally achievable, but also economically feasible. The methodology used in this case study could be applied to other countries or small and medium scale technologies and could also be useful for the scientific community, enterprises and policy-makers.The authors wish to acknowledge the financial support of the Fondo Regional de Tecnología Agropecuaria FONTAGRO [Contract:ATN/RF 16111RG, 2016] and of the Departamento Administrativo de Ciencia, Tecnología e Innovación, Doctorados Nacionales [Contract:727, 2015]. Also this article is the result of the work developed through the "Programa de investigación reconstrucción del tejido social en zonas de pos-conflicto en Colombia" [SIGP 57579] withthe research project "Competencias empresariales y de innovación para el desarrollo económico y la inclusión productiva de las regiones afectadas por el conflicto colombiano" [SIGP 58907]. Finally, the authors would like to express their appreciation to FLP Procesados Company for providing the data for the case study

    Re-establishment of the genus Pseudalbizzia (Leguminosae, Caesalpinioideae, mimosoid clade): the New World species formerly placed in Albizia

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    Following recent mimosoid phylogenetic and phylogenomic studies demonstrating the non-monophyly of the genus Albizia, we present a new molecular phylogeny focused on the neotropical species in the genus, with much denser taxon sampling than previous studies. Our aims were to test the monophyly of the neotropical section Arthrosamanea, resolve species relationships, and gain insights into the evolution of fruit morphology. We perform a Bayesian phylogenetic analysis of sequences of nuclear internal and external transcribed spacer regions and trace the evolution of fruit dehiscence and lomentiform pods. Our results find further support for the non-monophyly of the genus Albizia, and confirm the previously proposed segregation of Hesperalbizia, Hydrochorea, Balizia and Pseudosamanea. All species that were sampled from section Arthrosamanea form a clade that is sister to a clade composed of Jupunba, Punjuba, Balizia and Hydrochorea. We find that lomentiform fruits are independently derived from indehiscent septate fruits in both Hydrochorea and section Arthrosamanea. Our results show that morphological adaptations to hydrochory, associated with shifts into seasonally flooded habitats, have occurred several times independently in different geographic areas and different lineages within the ingoid clade. This suggests that environmental conditions have likely played a key role in the evolution of fruit types in Albizia and related genera. We resurrect the name Pseudalbizzia to accommodate the species of section Arthrosamanea, except for two species that were not sampled here but have been shown in other studies to be more closely related to other ingoid genera and we restrict the name Albizia s.s. to the species from Africa, Madagascar, Asia, Australia, and the Pacific. Twenty-one new nomenclatural combinations in Pseudalbizzia are proposed, including 16 species and 5 infraspecific varietal names. In addition to the type species Pseudalbizzia berteroana, the genus has 17 species distributed across tropical regions of the Americas, including the Caribbean. Finally, a new infrageneric classification into five sections is proposed and a distribution map of the species of Pseudalbizzia is presented

    Neutron structure function and inclusive DIS from H-3 and He-3 at large Bjorken-x

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    A detailed study of inclusive deep inelastic scattering (DIS) from mirror A = 3 nuclei at large values of the Bjorken variable x is presented. The main purpose is to estimate the theoretical uncertainties on the extraction of the neutron DIS structure function from such nuclear measurements. On one hand, within models in which no modification of the bound nucleon structure functions is taken into account, we have investigated the possible uncertainties arising from: i) charge symmetry breaking terms in the nucleon-nucleon interaction, ii) finite Q**2 effects neglected in the Bjorken limit, iii) the role of different prescriptions for the nucleon Spectral Function normalization providing baryon number conservation, and iv) the differences between the virtual nucleon and light cone formalisms. Although these effects have been not yet considered in existing analyses, our conclusion is that all these effects cancel at the level of ~ 1% for x < 0.75 in overall agreement with previous findings. On the other hand we have considered several models in which the modification of the bound nucleon structure functions is accounted for to describe the EMC effect in DIS scattering from nuclei. It turns out that within these models the cancellation of nuclear effects is expected to occur only at a level of ~ 3%, leading to an accuracy of ~ 12 % in the extraction of the neutron to proton structure function ratio at x ~ 0.7 -0.8$. Another consequence of considering a broad range of models of the EMC effect is that the previously suggested iteration procedure does not improve the accuracy of the extraction of the neutron to proton structure function ratio.Comment: revised version to appear in Phys. Rev. C; main modifications in Section 4; no change in the conclusion

    Cosmological distance indicators

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    We review three distance measurement techniques beyond the local universe: (1) gravitational lens time delays, (2) baryon acoustic oscillation (BAO), and (3) HI intensity mapping. We describe the principles and theory behind each method, the ingredients needed for measuring such distances, the current observational results, and future prospects. Time delays from strongly lensed quasars currently provide constraints on H0H_0 with < 4% uncertainty, and with 1% within reach from ongoing surveys and efforts. Recent exciting discoveries of strongly lensed supernovae hold great promise for time-delay cosmography. BAO features have been detected in redshift surveys up to z <~ 0.8 with galaxies and z ~ 2 with Ly-α\alpha forest, providing precise distance measurements and H0H_0 with < 2% uncertainty in flat Λ\LambdaCDM. Future BAO surveys will probe the distance scale with percent-level precision. HI intensity mapping has great potential to map BAO distances at z ~ 0.8 and beyond with precisions of a few percent. The next years ahead will be exciting as various cosmological probes reach 1% uncertainty in determining H0H_0, to assess the current tension in H0H_0 measurements that could indicate new physics.Comment: Review article accepted for publication in Space Science Reviews (Springer), 45 pages, 10 figures. Chapter of a special collection resulting from the May 2016 ISSI-BJ workshop on Astronomical Distance Determination in the Space Ag

    Microstructure and Phase Formation in a Rapidly Solidified Laser-Deposited Ni-Cr-B-Si-C Hardfacing Alloy

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    In this study, microstructural evolutions and phase selection phenomena during laser deposition of a hardfacing Ni-Cr-B-Si-C alloy at different processing conditions are experimentally investigated. The results show that even minor variations in the thermal conditions during solidification can modify the type and morphology of the phases. Higher undercoolings obtained at faster cooling rates suppressed the primary borides and encouraged floret-shape mixtures of Ni and Cr5B3 via a metastable reaction. Variations in the boride phases are discussed in terms of nucleation-and growth-controlled phase selection mechanisms. These selection processes also influenced the nature and proportion of the Ni-B-Si eutectics by changing the amount of the boron available for the final eutectic reactions. The results of this work emphasize the importance of controlling the cooling rate during deposition of these industrially important alloys using laser beam or other rapid solidification techniques. (C) The Minerals, Metals & Materials Society and ASM International 201

    Deep Molecular Characterization of Milder Spinal Muscular Atrophy Patients Carrying the c.859G&gt;C Variant in SMN2

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    Spinal muscular atrophy (SMA) is a severe neuromuscular disorder caused by biallelic loss or pathogenic variants in the SMN1 gene. Copy number and modifier intragenic variants in SMN2, an almost identical paralog gene of SMN1, are known to influence the amount of complete SMN proteins. Therefore, SMN2 is considered the main phenotypic modifier of SMA, although genotype-phenotype correlation is not absolute. We present eleven unrelated SMA patients with milder phenotypes carrying the c.859G>C-positive modifier variant in SMN2. All were studied by a specific NGS method to allow a deep characterization of the entire SMN region. Analysis of two homozygous cases for the variant allowed us to identify a specific haplotype, Smn2-859C.1, in association with c.859G>C. Two other cases with the c.859G>C variant in their two SMN2 copies showed a second haplotype, Smn2-859C.2, in cis with Smn2-859C.1, assembling a more complex allele. We also identified a previously unreported variant in intron 2a exclusively linked to the Smn2-859C.1 haplotype (c.154-1141G>A), further suggesting that this region has been ancestrally conserved. The deep molecular characterization of SMN2 in our cohort highlights the importance of testing c.859G>C, as well as accurately assessing the SMN2 region in SMA patients to gain insight into the complex genotype-phenotype correlations and improve prognostic outcomes
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