944 research outputs found

    Growth-promoting activity of desmopressin in murine leukemia cells treated in vitro

    Get PDF
    The synthetic vasopressin analogue, desmopressin (dDAVP), has been shown to influence membrane transport of melphalan in murine L5178Y lymphoblasts. Accordingly, the effect of dDAVP on the cytocidal activity of melphalan in L5178Y cells was evaluated. dDAVP did not affect the cytocidal activity of melphalan in these cells, but significantly affected the cloning efficiency of stationary phase or slowly dividing L5178Y cells over a range of concentrations. In particular, stationary phase cells showed an increase in cloning efficiency from 4.3 ± 0.5% in control cells to 7.0 ± 0.3% in cells treated with 25 nM dDAVP (P < 0.001), whereas cells doubling every 26 h showed an increase from 10.8 ± 1.2% in control cells to 21.0 ± 2.0% in cells treated with 150 nM dDAVP (P < 0.001). This phenomenon was associated with significant elevations of 1,2[3H] diacylglycerol after incubation with dDAVP for 9 min (P < 0.01) and total [3H]diacylglycerols after incubation for both 3 min (P < 0.05) and 9 min (P < 0.02). Within 10 s of treatment with 100 nM dDAVP, there was a marked decrease in the levels of inositol 1,4,5-trisphosphate and inositol 1-phosphate, but subsequently no change was observed for up to 9 min after treatment. We postulate that the increase of diacylglycerol content produced by dDAVP might be primarily from a phosphatidylcholine source and that the growth-promoting activity of desmopressin may be a consequence of activation of protein kinase C

    What’s in a (pseudo)name?: Ethical conundrums for the principles of anonymisation in social media research

    Get PDF
    Scholars from wide-ranging disciplines are turning to social media platforms as research sites, and as platforms expand their communicative possibilities, they create more spaces for users to enact a multitude of identities. Most platforms allow users to have ‘pseudonymous’ identities; that is, they can engage in practices intended to facilitate nonidentifiable content. But pseudonymity presents a series of unique challenges to the principles of anonymisation in qualitative research. This article explores the slippery nature of dealing with pseudonymous social media users’ personally identifiable data during research, framed around my responses to four questions I was asked when I applied for ethical approval to conduct research with pseudonymous fan communities on social media. The four questions concern: (Q1) changing notions of ‘public’ and ‘private’ forms of data; (Q2) identifying underage and therefore vulnerable participants online; (Q3) changes to the processes of obtaining informed consent from social media users; and (Q4) the risks social media research might bring to those conducting it. This article concludes by calling for qualitative researchers and Ethics Review Boards (ERBs) to engage with institutional ethics review across the duration of a project, or at the very least to advocate for ongoing consent as research progresses, especially for (but certainly not limited to) research involving pseudonymous social media users. The article aims to be useful to other researchers facing similar dilemmas. Indeed, given the popularity of pseudonymity on social media and the growing penetration of platforms across global demographics, a need for ethical discussions of this kind is surely set to increase

    Large Scale Proactive Power-Quality Monitoring: An Example from Australia

    Get PDF
    In Australia and many other countries, distribution network service providers (DNSPs) have an obligation to their customers to provide electrical power that is reliable and of high quality. Failure to do so may have significant implications ranging from financial penalties theoretically through to the loss of a license to distribute electricity. In order to ensure the reliability and quality of supply are met, DNSPs engage in monitoring and reporting practice. This paper provides an overview of a large long-running power-quality monitoring project that has involved most of Australia\u27s DNSPs at one time or another. This paper describes the challenges associated with conducting the project as well as some of the important outcomes and lessons learned. A number of novel reporting techniques that have been developed as part of the monitoring project are also presented. A discussion about large-volume data management, and issues related to reporting requirements in future distribution networks is included

    Human helminth therapy to treat inflammatory disorders - where do we stand?

    Get PDF
    Parasitic helminths have evolved together with the mammalian immune system over many millennia and as such they have become remarkably efficient modulators in order to promote their own survival. Their ability to alter and/or suppress immune responses could be beneficial to the host by helping control excessive inflammatory responses and animal models and pre-clinical trials have all suggested a beneficial effect of helminth infections on inflammatory bowel conditions, MS, asthma and atopy. Thus, helminth therapy has been suggested as a possible treatment method for autoimmune and other inflammatory disorders in humans

    Multiwavelength Study of M8.9/3B Solar Flare from AR NOAA 10960

    Full text link
    We present a multi-wavelength analysis of a long duration white-light solar flare (M8.9/3B) event that occurred on 4 June 2007 from NOAA AR 10960. The flare was observed by several spaceborne instruments, namely SOHO/MDI, Hinode/SOT, TRACE and STEREO/SECCHI. The flare was initiated near a small, positive-polarity, satellite sunspot at the centre of the AR, surrounded by opposite-polarity field regions. MDI images of the AR show considerable amount of changes in a small positive-polarity sunspot of delta configuration during the flare event. SOT/G-band (4305 A) images of the sunspot also suggest the rapid evolution of the positive-polarity sunspot with highly twisted penumbral filaments before the flare event, which were oriented in the counterclockwise direction. It shows the change in orientation and also remarkable disappearance of twisted penumbral filaments (~35-40%) and enhancement in umbral area (~45-50%) during the decay phase of the flare. TRACE and SECCHI observations reveal the successive activations of two helical twisted structures associated with this sunspot, and the corresponding brightening in the chromosphere as observed by the time-sequence images of SOT/Ca II H line (3968 A). The secondary-helical twisted structure is found to be associated with the M8.9 flare event. The brightening starts 6-7 min prior to the flare maximum with the appearance of secondary helical-twisted structure. The flare intensity maximizes as this structure moves away from the AR. This twisted flux-tube associated with the flare triggering, is found to be failed in eruption. The location of the flare is found to coincide with the activation site of the helical twisted structures. We conclude that the activations of successive helical twists in the magnetic flux tubes/ropes plays a crucial role in the energy build-up process and triggering of M-class solar flare without a CME.Comment: 22 pages, 12 figures, Accepted for Publication in Solar Physic

    Heterogeneously catalyzed hydrothermal processing of C5-C6 sugars

    Get PDF
    Biomass has been long exploited as an anthropogenic energy source; however, the 21st century challenges of energy security and climate change are driving resurgence in its utilization both as a renewable alternative to fossil fuels and as a sustainable carbon feedstock for chemicals production. Deconstruction of cellulose and hemicellulose carbohydrate polymers into their constituent C5 and C6 sugars, and subsequent heterogeneously catalyzed transformations, offer the promise of unlocking diverse oxygenates such as furfural, 5-hydroxymethylfurfural, xylitol, sorbitol, mannitol, and gluconic acid as biorefinery platform chemicals. Here, we review recent advances in the design and development of catalysts and processes for C5-C6 sugar reforming into chemical intermediates and products, and highlight the challenges of aqueous phase operation and catalyst evaluation, in addition to process considerations such as solvent and reactor selection

    Supporting Innovation in Organic Agriculture: A European Perspective Using Experience from the SOLID Project

    Get PDF
    Organic farming is recognized as one source for innovation helping agriculture to develop sustainably. However, the understanding of innovation in agriculture is characterized by technical optimism, relying mainly on new inputs and technologies originating from research. The paper uses the alternative framework of innovation systems describing innovation as the outcome of stakeholder interaction and examples from the SOLID (Sustainable Organic Low-Input Dairying) project to discuss the role of farmers, researchers and knowledge exchange for innovation. We used a farmer-led participatory approach to identify problems of organic and low-input dairy farming in Europe and develop and evaluate innovative practices. Experience so far shows that improvements of sustainability can be made through better exploitation of knowledge. For example, it is recognized that optimal utilization of good quality forage is vitally important, but farmers showed a lack of confidence in the reliability of forage production both in quantity and quality. We conclude that the systems framework improves the understanding of innovation processes in organic agriculture. Farmer-led research is an effective way to bring together the scientific approach with the farmers’ practical and context knowledge in finding solutions to problems experienced by farmers and to develop sustainability
    corecore