144 research outputs found

    An analysis of the Brown-Biefeld effect

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    When a high voltage is applied on an asymmetric capacitor, it experiences a force acting toward its thinner electrode. This effect is called Brown-Biefeld effect (BB), after its discoverers Thomas-Townsend Brown and Paul-Alfred Biefeld. Many theories have been proposed to explain this effect, and many speculations can be found on the net suggesting the effect is an antigravitation or a space warp effect. However, in the recent years, more an more researchers attribute the BB effect to a unicharge ion wind. This work calculates the levitation force due to ion wind and presents experimental results which confirm the theoretical results.Comment: 34 pages, 9 figure

    Obtaining of FeCO3 microparticles

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    Usinghydrothermal decomposition of the Fe(III)-EDTA complex in the presence of urea, we developed a new procedure for synthesizing highly crystalline FeCO3 starting from Ferric Ammonium Sulfate and Na4EDTA as main precursors. Single phase FeCO3 microcrystals with size in the range of 50Β΅m-200Β΅m have been obtained after high pressure-temperature treatment time between 15 hours and 26 hours at 230ΒΊC and 250ΒΊC

    Disinfection of football protective equipment using chlorine dioxide produced by the ICA TriNova system

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    <p>Abstract</p> <p>Backround</p> <p>Community-associated methicillin-resistant <it>Staphylococcus aureus </it>outbreaks have occurred in individuals engaged in athletic activities such as wrestling and football. Potential disease reduction interventions include the reduction or elimination of bacteria on common use items such as equipment. Chlorine dioxide has a long history of use as a disinfectant. The purpose of this investigation was to evaluate the ability of novel portable chlorine dioxide generation devices to eliminate bacteria contamination of helmets and pads used by individuals engaged in football.</p> <p>Methods</p> <p>In field studies, the number of bacteria associated with heavily used football helmets and shoulder pads was determined before and after overnight treatment with chlorine dioxide gas. Bacteria were recovered using cotton swabs and plated onto trypticase soy agar plates. In laboratory studies, <it>Staphylococcus aureus </it>was applied directly to pads. The penetration of bacteria into the pads was determined by inoculating agar plates with portions of the pads taken from the different layers of padding. The ability to eliminate bacteria on the pad surface and underlying foam layers after treatment with chlorine dioxide was also determined.</p> <p>Results</p> <p>Rates of recovery of bacteria after treatment clearly demonstrated that chlorine dioxide significantly (p < 0.001) reduce and eliminated bacteria found on the surface of pads. For example, the soft surface of shoulder pads from a university averaged 2.7 Γ— 10<sup>3 </sup>recoverable bacteria colonies before chlorine dioxide treatment and 1.3 Γ— 10<sup>2 </sup>recoverable colonies after treatment. In addition, the gas was capable of penetrating the mesh surface layer and killing bacteria in the underlying foam pad layers. Here, 7 Γ— 10<sup>3 </sup>to 4.5 Γ— 10<sup>3 </sup>laboratory applied <it>S. aureus </it>colonies were recovered from underlying layers before treatment and 0 colonies were present after treatment. Both naturally occurring bacteria and <it>S. aureus </it>were susceptible to the treatment process.</p> <p>Conclusion</p> <p>Results of this study have shown that chlorine dioxide can easily and safely be used to eliminate bacteria contamination of protective pads used by football players. This could serve to reduce exposure to potential pathogens such as the methicillin-resistant <it>Staphylococcus aureus </it>among this group of individuals.</p

    Ascl2 Knockdown Results in Tumor Growth Arrest by miRNA-302b-Related Inhibition of Colon Cancer Progenitor Cells

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    Background: Achaete scute-like 2 (Ascl2), a basic helix-loop-helix (bHLH) transcription factor, controls the fate of intestinal stem cells. However, the role of Ascl2 in colon cancer progenitor cells remains unknown. The cell line HT-29 (47.5–95 % of CD133 + population) and LS174T (0.45 % of CD133 + population) were chosen for functional evaluation of Ascl2 in colon cancer progenitor cells after gene knockdown by RNA interference. Methodology/Principal Findings: Immunohistochemistry demonstrated that Ascl2 was significantly increased in colorectal adenocarcinomas. Downregulation of Ascl2 using RNA interference in cultured colonic adenocarcinoma HT-29 and LS174T cells reduced cellular proliferation, colony-forming ability, invasion and migration in vitro, and resulted in the growth arrest of tumor xenografts in vivo. The Ascl2 protein level in CD133 + HT-29 cells was significantly higher than in CD133 2 HT-29 cells. Ascl2 blockade via shRNA interference in HT-29 cells (shRNA-Ascl2/HT-29 cells) resulted in 26.2 % of cells staining CD133 + compared with 54.7 % in control shRNA-Ctr/HT-29 cells. The levels of β€˜stemness ’ associated genes, such as CD133, Sox2, Oct4, Lgr5, Bmi1, and C-myc, were significantly decreased in shRNA-Ascl2/HT-29 and shRNA-Ascl2/LS174T cells in vitro as well as in the corresponding tumor xenograft (CD133 was not performed in shRNA-Ascl2/LS174T cells). The shRNA-Ascl2/ HT-29 cells had inhibited abilities to form tumorspheres compared with control. The microRNA (miRNAs) microarrays, identified 26 up-regulated miRNAs and 58 down-regulated miRNAs in shRNA-Ascl2/HT-29 cells. Expression levels of let-7b

    Putting carbon markets into practice: a case study of financial accounting in Europe

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    In this paper we explore how carbon markets have entered the world of financial accounting. The advent of the European Union Emissions Trading System (EU ETS) in 2005 provided the opportunity for global climate change concerns to be translated from policy into something that could, and should, be recognised within financial accounting. That is, the EU ETS provided a mechanism whereby greenhouse gas emission allowances acquired a financial value, simultaneously creating an obligation (or liability) on certain European organisations when they emit greenhouse gases. Prima facie, this process created the need for financial accounts of companies covered by the EU ETS to reflect the new commodity of carbon. Disagreement amongst accountants about how to treat emission allowances has arisen, with the initial international accounting guidance issued in late 2004 subsequently being withdrawn, and not yet replaced. Taking this absence of guidance as a starting point, we undertake an empirical project (through a survey, consultation analysis, and interviews) to establish what financial reporting practices are being adopted by participants in the EU ETS, and the level of momentum for standardisation. We draw on sociological theories about accounting, measurement, and markets

    The Stem Cell Marker CD133 Associates with Enhanced Colony Formation and Cell Motility in Colorectal Cancer

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    CD133 is a membrane molecule that has been, controversially, reported as a CSC marker in colorectal cancer (CRC). In this study, we sought to clarify the expression and role of CD133 in CRC. Initially the size of the CD133βˆ’expressing (CD133+) population in eight well-described CRC cell lines was measured by flow cytometry and was found to range from 0% to >95%. The cell line HT29 has a CD133+ population of >95% and was chosen for functional evaluation of CD133 after gene knockdown by RNA interference. A time course assay showed that CD133 inhibition had no significant effect on cell proliferation or apoptosis. However, CD133 knockdown did result in greater susceptibility to staurosporine-induced apoptosis (pβ€Š=β€Š0.01) and reduction in cell motility (p<0.04). Since gene knockdown may cause β€œoff-target” effects, the cell line SW480 (which has a CD133+ population of 40%) was sorted into pure CD133+ and CD133βˆ’ populations to allow functional comparison of isogenic populations separated only by CD133 expression. In concordance with the knockdown experiments, a time course assay showed no significant proliferative differences between the CD133+/CD133βˆ’ populations. Also greater resistance to staurosporine-induced apoptosis (pβ€Š=β€Š0.008), greater cell motility (pβ€Š=β€Š0.03) and greater colony forming efficiency was seen in the CD133+ population than the CD133βˆ’ population in both 2D and 3D culture (p<0.0001 and p<0.003 respectively). Finally, the plasticity of CD133 expression in tumour cells was tested. Quantitative PCR analysis showed there was transcriptional repression in the CD133βˆ’ population of SW480. Prolonged culture of a pure CD133βˆ’ population resulted in re-emergence of CD133+ cells. We conclude that CD133 expression in CRCs is associated with some features attributable to stemness and that there is plasticity of CD133 expression. Further studies are necessary to delineate the mechanistic basis of these features

    Beyond the public and private divide: Remapping transnational climate governance in de 21th century

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    This article provides a first step towards a better theoretical and empirical knowledge of the emerging arena of transnational climate governance. The need for such a re-conceptualization emerges from the increasing relevance of non-state and transnational approaches towards climate change mitigation at a time when the intergovernmental negotiation process has to overcome substantial stalemate and the international arena becomes increasingly fragmented. Based on a brief discussion of the increasing trend towards transnationalization and functional segmentation of the global climate governance arena, we argue that a remapping of climate governance is necessary and needs to take into account different spheres of authority beyond the public and international. Hence, we provide a brief analysis of how the public/private divide has been conceptualized in Political Science and International Relations. Subsequently, we analyse the emerging transnational climate governance arena. Analytically, we distinguish between different manifestations of transnational climate governance on a continuum ranging from delegated and shared public-private authority to fully non-state and private responses to the climate problem. We suggest that our remapping exercise presented in this article can be a useful starting point for future research on the role and relevance of transnational approaches to the global climate crisis

    Prospectively Isolated Cancer-Associated CD10+ Fibroblasts Have Stronger Interactions with CD133+ Colon Cancer Cells than with CD133βˆ’ Cancer Cells

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    Although CD133 has been reported to be a promising colon cancer stem cell marker, the biological functions of CD133+ colon cancer cells remain controversial. In the present study, we investigated the biological differences between CD133+ and CD133βˆ’ colon cancer cells, with a particular focus on their interactions with cancer-associated fibroblasts, especially CD10+ fibroblasts. We used 19 primary colon cancer tissues, 30 primary cultures of fibroblasts derived from colon cancer tissues and 6 colon cancer cell lines. We isolated CD133+ and CD133βˆ’ subpopulations from the colon cancer tissues and cultured cells. In vitro analyses revealed that the two populations showed similar biological behaviors in their proliferation and chemosensitivity. In vivo analyses revealed that CD133+ cells showed significantly greater tumor growth than CD133βˆ’ cells (Pβ€Š=β€Š0.007). Moreover, in cocultures with primary fibroblasts derived from colon cancer tissues, CD133+ cells exhibited significantly more invasive behaviors than CD133βˆ’ cells (P<0.001), especially in cocultures with CD10+ fibroblasts (P<0.0001). Further in vivo analyses revealed that CD10+ fibroblasts enhanced the tumor growth of CD133+ cells significantly more than CD10βˆ’ fibroblasts (P<0.05). These data demonstrate that the in vitro invasive properties and in vivo tumor growth of CD133+ colon cancer cells are enhanced in the presence of specific cancer-associated fibroblasts, CD10+ fibroblasts, suggesting that the interactions between these specific cell populations have important roles in cancer progression. Therefore, these specific interactions may be promising targets for new colon cancer therapies
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