448 research outputs found

    Fiber and Insulin Sensitivity

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    Variations in the structure of airborne bacterial communities in Tsogt-Ovoo of Gobi desert area during dust events

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    Asian dust events transport the airborne bacteria in Chinese desert regions as well as mineral particles and influence downwind area varying biological ecosystems and climate changes. However, the airborne bacterial dynamics were rarely investigated in the Gobi desert area, where dust events are highly frequent. In this study, air samplings were sequentially performed at a 2-m high above the ground at the sampling site located in desert area (Tsogt-Ovoo of Gobi desert; Mongolia 44.2304°N, 105.1700°E). During the dust event days, the bacterial cells and mineral particles increased to more than tenfold of concentrations. MiSeq sequencing targeting 16S ribosomal DNA revealed that the airborne bacteria in desert area mainly belonged to the classes Acidobacteria, Actinobacteria, Bacteroidetes, Chloroflexi, Bacilli, Alpha-proteobacteria, Beta-proteobacteria, and Gamma-proteobacteria. The bacterial community structures were different between dust events and non-dust events. The air samples collected at the dust events indicated high abundance rates of Alpha-proteobacteria, which were reported to dominate on the leaf surfaces of plants or in the saline lake environments. After the dust events, the members of Firmicutes (Bacilli) and Bacteroidetes, which are known to form endospore and attach with coarse particles, respectively, increased their relative abundances in the air samples. Presumably, the bacterial compositions and diversities in atmosphere significantly vary during dust events, which carry some particles from grassland (phyllo-sphere), dry lake, and sand surfaces, as well as some bacterial populations such as Firmicutes and Bacteroidetes maintain in the atmosphere for longer time. © 2016 The Author(s)Embargo Period 12 month

    Airborne microbial transport limitation to isolated Antarctic soil habitats

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    Dispersal is a critical yet poorly understood factor underlying macroecological patterns in microbial communities. Airborne microbial transport is assumed to occupy a central role in determining dispersal outcomes, and extra-range dispersal has important implications for predicting ecosystem resilience and response to environmental change. One of the most pertinent biomes in this regard is Antarctica, given its geographic isolation and vulnerability to climate change and human disturbance. Here, we report microbial diversity in near-ground and high-altitude air above the largest ice-free Antarctic habitat, as well as that of underlying soil microbial communities. We found that persistent local airborne inputs were unable to fully explain Antarctic soil community assembly. Comparison with airborne microbial diversity from high-altitude and non-polar sources suggests that strong selection occurs during long-range atmospheric transport. The influence of selection during airborne transit and at sink locations varied between microbial phyla. Overall, the communities from this isolated Antarctic ecosystem displayed limited connectivity to the non-polar microbial pool, and alternative sources of recruitment are necessary to fully explain extant soil diversity. Our findings provide critical insights into the role of airborne transport limitation in determining microbial biogeographic patterns.The New Zealand Ministry of Business, Innovation & Employment (UOWX1401) and the Yale-NUS College Start-Up Fund.https://www.nature.com/nmicrobiolhj2019Genetic

    Atmospheric aerosol deposition influences marine microbial communities in oligotrophic surface waters of the western Pacific Ocean

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    Atmospheric aerosols contain particulates that are deposited to oceanic surface waters. These can represent a major source of nutrients, trace metals, and organic compounds for the marine environment. The Japan Sea and the western Pacific Ocean are particularly affected by aerosols due to the transport of desert dust and industrially derived particulate matter with aerodynamic diameter less than 2.5 µm (PM2.5) from continental Asia. We hypothesized that supplementing seawater with aerosol particulates would lead to measurable changes in surface water nutrient composition as well as shifts in the marine microbial community. Shipboard experiments in the Pacific Ocean involved the recovery of oligotrophic oceanic surface water and subsequent supplementation with aerosol particulates obtained from the nearby coastal mountains, to simulate marine particulate input in this region. Initial increases in nitrates due to the addition of aerosol particulates were followed by a decrease correlated with the increase in phytoplankton biomass, which was composed largely of Bacillariophyta (diatoms), including Pseudo-nitzschia and Chaetoceros species. This shift was accompanied by changes in the bacterial community, with apparent increases in the relative abundance of heterotrophic Rhodobacteraceae and Colwelliaceae in aerosol particulate treated seawater. Our findings provide empirical evidence revealing the impact of aerosol particulates on oceanic surface water microbiology by alleviating nitrogen limitation in the organisms. © 2016 Elsevier LtdEmbargo Perion 12 month

    Tolerance, bioavailability, and potential cognitive health implications of a distinct aqueous spearmint extract

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    Background: Cognitive function can decline during the aging process and significantly reduce quality of life. Although a number of interventions have been investigated for cognitive dysfunction, including antioxidants, this prominent health concern emphasizes a need to explore methods to support cognitive health later in the life span. An aqueous extract from a proprietary spearmint line has been developed which contains a number of antioxidant compounds, including rosmarinic acid, at levels that are higher than found in commercially-bred spearmint. Therefore, this pilot trial assessed the tolerance, bioavailability, and potential cognitive health implications of a proprietary spearmint extract in men and women with self-reported memory impairment. Methods: Subjects consumed 900 mg/day spearmint extract for 30 days. The sample population (N = 11) was 73% female and 27% male with a mean age of 58.7 ± 1.6 y. Tolerability parameters were assessed at baseline and end of treatment visits. Computerized cognitive function tests were completed and blood was drawn at pre- and post-dose (0.5 to 4 h) timepoints during baseline and end of treatment visits. Subjective cognition was also assessed at end of treatment. Results: No serious adverse events or clinically relevant findings were observed in any tolerability parameters. Plasma vanillic, caffeic, and ferulic acid sulfates, rosmarinic acid, and methyl rosmarinic acid glucuronide were detected in plasma following acute administration of the spearmint extract. Computerized cognitive function scores improved in reasoning (P = 0.023) and attention/concentration (P = 0.002) after 30 days of supplementation. After acute administration, subjects had improved attention/concentration in two tests at 2 (P = 0.042 and P = 0.025) and 4 h (P = 0.001 and P = 0.002). Conclusions: The results from this pilot trial suggest that the spearmint extract, which contains higher rosmarinic acid content relative to extracts from typical commercial lines, was welltolerated at 900 mg/day. In addition, the extract was bioavailable and further investigation is warranted regarding its potential for supporting cognitive healt

    Indices of insulin sensitivity and secretion from a standard liquid meal test in subjects with type 2 diabetes, impaired or normal fasting glucose

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    <p>Abstract</p> <p>Background</p> <p>To provide an initial evaluation of insulin sensitivity and secretion indices derived from a standard liquid meal tolerance test protocol in subjects with normal (NFG), impaired fasting glucose (IFG) or type 2 diabetes mellitus.</p> <p>Methods</p> <p>Areas under the curve (AUC) for glucose, insulin and C-peptide from pre-meal to 120 min after consumption of a liquid meal were calculated, as were homeostasis model assessments of insulin resistance (HOMA2-IR) and the Matsuda index of insulin sensitivity.</p> <p>Results</p> <p>Subjects with NFG (n = 19), IFG (n = 19), and diabetes (n = 35) had mean ± SEM HOMA2-IR values of 1.0 ± 0.1, 1.6 ± 0.2 and 2.5 ± 0.3 and Matsuda insulin sensitivity index values of 15.6 ± 2.0, 8.8 ± 1.2 and 6.0 ± 0.6, respectively. The log-transformed values for these variables were highly correlated overall and within each fasting glucose category (r = -0.91 to -0.94, all p < 0.001). Values for the product of the insulin/glucose AUC ratio and the Matsuda index, an indicator of the ability of the pancreas to match insulin secretion to the degree of insulin resistance, were 995.6 ± 80.7 (NFG), 684.0 ± 57.3 (IFG) and 188.3 ± 16.1 (diabetes) and discriminated significantly between fasting glucose categories (p < 0.001 for each comparison).</p> <p>Conclusion</p> <p>These results provide initial evidence to support the usefulness of a standard liquid meal tolerance test for evaluation of insulin secretion and sensitivity in clinical and population studies.</p

    Sloan Digital Sky Survey Imaging of Low Galactic Latitude Fields: Technical Summary and Data Release

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    The Sloan Digital Sky Survey (SDSS) mosaic camera and telescope have obtained five-band optical-wavelength imaging near the Galactic plane outside of the nominal survey boundaries. These additional data were obtained during commissioning and subsequent testing of the SDSS observing system, and they provide unique wide-area imaging data in regions of high obscuration and star formation, including numerous young stellar objects, Herbig-Haro objects and young star clusters. Because these data are outside the Survey regions in the Galactic caps, they are not part of the standard SDSS data releases. This paper presents imaging data for 832 square degrees of sky (including repeats), in the star-forming regions of Orion, Taurus, and Cygnus. About 470 square degrees are now released to the public, with the remainder to follow at the time of SDSS Data Release 4. The public data in Orion include the star-forming region NGC 2068/NGC 2071/HH24 and a large part of Barnard's loop.Comment: 31 pages, 9 figures (3 missing to save space), accepted by AJ, in press, see http://photo.astro.princeton.edu/oriondatarelease for data and paper with all figure

    TOG–tubulin binding specificity promotes microtubule dynamics and mitotic spindle formation

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    XMAP215, CLASP, and Crescerin use arrayed tubulin-binding tumor overexpressed gene (TOG) domains to modulate microtubule dynamics. We hypothesized that TOGs have distinct architectures and tubulin-binding properties that underlie each family’s ability to promote microtubule polymerization or pause. As a model, we investigated the pentameric TOG array of a Drosophila melanogaster XMAP215 member, Msps. We found that Msps TOGs have distinct architectures that bind either free or polymerized tubulin, and that a polarized array drives microtubule polymerization. An engineered TOG1-2-5 array fully supported Msps-dependent microtubule polymerase activity. Requisite for this activity was a TOG5-specific N-terminal HEAT repeat that engaged microtubule lattice-incorporated tubulin. TOG5–microtubule binding maintained mitotic spindle formation as deleting or mutating TOG5 compromised spindle architecture and increased the mitotic index. Mad2 knockdown released the spindle assembly checkpoint triggered when TOG5–microtubule binding was compromised, indicating that TOG5 is essential for spindle function. Our results reveal a TOG5-specific role in mitotic fidelity and support our hypothesis that architecturally distinct TOGs arranged in a sequence-specific order underlie TOG array microtubule regulator activity
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