931 research outputs found

    Pseudomonas sp. strain WJ04 enhances current generation of Synechocystis sp. PCC6803 in photomicrobial fuel cells

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    Photomicrobial fuel cells (pMFCs) are a new technology for transforming the light energy or bioenergy of algae into bioelectricity. However, the current methods of generating algal pMFCs have poor efficiency due to the complex electron transfer network in algal cells. In this study, pMFCs containing the model electricity-producing cyanobacterium Synechocystis sp. PCC6803 contaminated by additional bacteria exhibited a 12.6-fold greater voltage output compared to the control pMFCs with axenic Synechocystis sp. PCC6803. To explain this phenomenon, the compositions of symbiotic bacterial communities in bacterial-contaminated pMFCs were analyzed, and a pure strain WJ04 belonging to the genus Pseudomonas, which was the second most abundant (30.2%) among the total symbiotic bacteria, was obtained. The strain WJ04 was able to raise the voltage output by 8.3 fold compared with the control treatments, meaning that strain WJ04 contributed to the increased voltage output of pMFCs. Through the coculture experiment, strain WJ04 was found to influence the growth of Synechocystis, improve photosynthesis rates by regulating algal genes and further affect algal metabolite production compared with control treatments. In addition, nicotinamide, c-homocysteic acid and 4-aminobutyric acid (fold change analysis, F.C. &gt;= 10) could regulate algal gene expression and enhance the coculture current density by 6.1-12.3 fold compared with the control treatments. Thus, these results provide a clear explanation for the high current production in bacterial-contaminated pMFCs, clarify the interaction mechanisms between algae and bacteria in the anode and provide accurate evidence for the role of bacteria in improving algal bioelectricity utilization.</p

    Embracing integrated watershed revitalization in Suzhou, China: learning from global case studies

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    AbstractSuzhou is China’s historic water town, and a sustainable approach to watershed revitalization is firmly on the agenda. The practice of integrated watershed management requires collaborative planning involving a significant number of stakeholders; no single organization can solve the problems of ecosystem management unilaterally. The changing social–political environment in China has led to the development of a new form of governance. China is in transition from the traditional government image of a regulator and a controller towards an enabler that facilitates provision and action by, and through, others. Global case studies show that sustainability issues are essential to tackling watershed ecosystem management by creating a win–win strategy for wider stakeholders. Viewed from an institutional perspective, the emergence of a new collaborative partnership model requires a different implementation process to tackle practical problems in the face of complex watershed agendas. Drawing upon global and China’s experiences, the paper concludes that some planning processes require government leadership continuity, while others need bottom–up approaches.</jats:p

    Geochemistry of reduced inorganic sulfur, reactive iron, and organic carbon in fluvial and marine surface sediment in the Laizhou Bay region, China

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    Understanding the geochemical cycling of sulfur in sediments is important because it can have implications for both modern environments (e.g., deterioration of water quality) and interpretation of the ancient past (e.g., sediment C/S ratios can be used as indicators of palaeodepositional environment). This study investigates the geochemical characteristics of sulfur, iron, and organic carbon in fluvial and coastal surface sediments of the Laizhou Bay region, China. A total of 63 sediment samples were taken across the whole Laizhou Bay marine region and the 14 major tidal rivers draining into it. Acid volatile sulfur, chromium (II)-reducible sulfur and elemental sulfur, total organic carbon, and total nitrogen were present in higher concentrations in the fluvial sediment than in the marine sediment of Laizhou Bay. The composition of reduced inorganic sulfur in surface sediments was dominated by acid volatile sulfur and chromium (II)-reducible sulfur. In fluvial sediments, sulfate reduction and formation of reduced inorganic sulfur were controlled by TOC and reactive iron synchronously. High C/S ratios in the marine sediments indicate that the diagenetic processes in Laizhou Bay have been affected by rapid deposition of sediment from the Yellow River in recent decades

    GIVE: portable genome browsers for personal websites.

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    Growing popularity and diversity of genomic data demand portable and versatile genome browsers. Here, we present an open source programming library called GIVE that facilitates the creation of personalized genome browsers without requiring a system administrator. By inserting HTML tags, one can add to a personal webpage interactive visualization of multiple types of genomics data, including genome annotation, "linear" quantitative data, and genome interaction data. GIVE includes a graphical interface called HUG (HTML Universal Generator) that automatically generates HTML code for displaying user chosen data, which can be copy-pasted into user's personal website or saved and shared with collaborators. GIVE is available at: https://www.givengine.org/

    Use of the ODD-Luciferase Transgene for the Non-Invasive Imaging of Spontaneous Tumors in Mice

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    In humans, imaging of tumors provides rapid, accurate assessment of tumor growth and location. In laboratory animals, however, the imaging of spontaneously occurring tumors continues to pose many technical and logistical problems. Recently a mouse model was generated in which a chimeric protein consisting of HIF-1α oxygen-dependent degradation domain (ODD) fused to luciferase was ubiquitously expressed in all tissues. Hypoxic stress leads to the accumulation of ODD-luciferase in the tissues of this mouse model which can be identified by non-invasive bioluminescence measurement. Since solid tumors often contain hypoxic regions, we performed proof-of-principle experiments testing whether this transgenic mouse model may be used as a universal platform for non-invasive imaging analysis of spontaneous solid tumors.ODD-luciferase transgenic mice were bred with MMTV-neu/beclin1+/- mice. Upon injection of luciferin, bioluminescent background of normal tissues in the transgenic mice and bioluminescent signals from spontaneously mammary carcinomas were measured non-invasively with an IVIS Spectrum imaging station. Tumor volumes were measured manually and the histology of tumor tissues was analyzed.Our results show that spontaneous mammary tumors in ODD-luciferase transgenic mice generate substantial bioluminescent signals, which are clearly discernable from background tissue luminescence. Moreover, we demonstrate a strong quantitative correlation between the bioluminescent tumor contour and the volume of palpable tumors. We further demonstrate that shrinkage of the volume of spontaneous tumors in response to chemotherapeutic treatment can be determined quantitatively using this system. Finally, we show that the growth and development of spontaneous tumors can be monitored longitudinally over several weeks. Thus, our results suggest that this model could potentially provide a practical, reliable, and cost-effective non-invasive quantitative method for imaging spontaneous solid tumors in mice

    Influence of salinity on COD measurements in coastal water management

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    COD is an important parameter in water quality assessment. COD values by different determination methods were investigated in coastal rivers. The results show that there is no clear relationship between CODCr and CODMn in coastal areas. CODCr does not reflect the degree of pollution of coastal waters. As salinity increased, CODCr and acidic CODMn increased significantly, but there was little/no change observed for alkaline CODMn. Coastal zone water quality standards should be proposed to solve the connection problems between the marine quality standard and surface water quality standard

    Onset Rivalry: Brief Presentation Isolates an Early Independent Phase of Perceptual Competition

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    When the left and right eyes are simultaneously presented with different images, observers typically report exclusive awareness of only one image. This phenomenon is termed binocular rivalry, reflecting the fact that the dominant image alternates every few seconds in a cycle of perceptual competition that continues indefinitely. Despite the apparent continuity in perceptual switching, we now demonstrate that the initial “onset” period is fundamentally different to all subsequent rivalry epochs. Using brief intermittent presentations, rivalry dominance shows strong biases such that the same target is perceived with each successive stimulus onset. These biases remain consistent within any given location, but vary across the visual field in a distribution that is stable over multiple weeks but highly idiosyncratic across observers. If the presentation exceeds ∼1sec at any location, however, the very different and much more balanced alternations of sustained binocular rivalry become apparent. These powerful onset biases are observed with brief intermittent presentations at a single location or with continual smooth motion of the targets. Periods of adaptation to one of the rivaling targets induced local switches in dominance to the non-adapted target. However, these effects were generally limited to the spatial site of adaptation and had less influence over each subsequent cycle of the target. We conclude that onset rivalry is independent of sustained rivalry and cannot be explained by local regions of monocular dominance or memory of past perceptual history, but rather reflects low-level, spatially localized factors that are stable over periods of weeks. These findings suggest that brief presentation paradigms are inappropriate for their current use in studies of the mechanisms underlying sustained rivalry. However, brief presentations are ideal for investigating early stages of perceptual competition

    Titin mutations in iPS cells define sarcomere insufficiency as a cause of dilated cardiomyopathy

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    Human mutations that truncate the massive sarcomere protein titin [TTN-truncating variants (TTNtvs)] are the most common genetic cause for dilated cardiomyopathy (DCM), a major cause of heart failure and premature death. Here we show that cardiac microtissues engineered from human induced pluripotent stem (iPS) cells are a powerful system for evaluating the pathogenicity of titin gene variants. We found that certain missense mutations, like TTNtvs, diminish contractile performance and are pathogenic. By combining functional analyses with RNA sequencing, we explain why truncations in the A-band domain of TTN cause DCM, whereas truncations in the I band are better tolerated. Finally, we demonstrate that mutant titin protein in iPS cell-derived cardiomyocytes results in sarcomere insufficiency, impaired responses to mechanical and {beta}-adrenergic stress, and attenuated growth factor and cell signaling activation. Our findings indicate that titin mutations cause DCM by disrupting critical linkages between sarcomerogenesis and adaptive remodeling

    Regulation of DNA synthesis and the cell cycle in human prostate cancer cells and lymphocytes by ovine uterine serpin

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    <p>Abstract</p> <p>Background</p> <p>Uterine serpins are members of the serine proteinase inhibitor superfamily. Like some other serpins, these proteins do not appear to be functional proteinase inhibitors. The most studied member of the group, ovine uterine serpin (OvUS), inhibits proliferation of several cell types including activated lymphocytes, bovine preimplantation embryos, and cell lines for lymphoma, canine primary osteosarcoma and human prostate cancer (PC-3) cells. The goal for the present study was to evaluate the mechanism by which OvUS inhibits cell proliferation. In particular, it was tested whether inhibition of DNA synthesis in PC-3 cells involves cytotoxic actions of OvUS or the induction of apoptosis. The effect of OvUS in the production of the autocrine and angiogenic cytokine interleukin (IL)-8 by PC-3 cells was also determined. Finally, it was tested whether OvUS blocks specific steps in the cell cycle using both PC-3 cells and lymphocytes.</p> <p>Results</p> <p>Recombinant OvUS blocked proliferation of PC-3 cells at concentrations as low as 8 μg/ml as determined by measurements of [<sup>3</sup>H]thymidine incorporation or ATP content per well. Treatment of PC-3 cells with OvUS did not cause cytotoxicity or apoptosis or alter interleukin-8 secretion into medium. Results from flow cytometry experiments showed that OvUS blocked the entry of PC-3 cells into S phase and the exit from G<sub>2</sub>/M phase. In addition, OvUS blocked entry of lymphocytes into S phase following activation of proliferation with phytohemagglutinin.</p> <p>Conclusion</p> <p>Results indicate that OvUS acts to block cell proliferation through disruption of the cell cycle dynamics rather than induction of cytotoxicity or apoptosis. The finding that OvUS can regulate cell proliferation makes this one of only a few serpins that function to inhibit cell growth.</p
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