1,387 research outputs found

    IMR90 ER:RAS: A cell model of oncogene-induced senescence

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    Oncogene-induced senescence (OIS) is a cellular response that limits the replication of cells expressing oncogenes. As a result, OIS is a potent tumor suppressor mechanism limiting cancer progression. Here we describe IMR90 ER:RAS, a widely used model to study OIS in cell culture. This model takes advantage of IMR90 human primary fibroblast infected with a 4-hydroxy-tamoxifen (4-OHT) inducible ER:RAS construct. RAS activation upon 4-OHT treatment results in a coordinated induction of senescence, recapitulating different aspects of the phenotype such as the growth arrest and the establishment of a senescence-associated secretory phenotype (SASP)

    Seasonal changes in phytoplankton biomass on the Western Agulhas bank, South Africa

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    Data on temporal and spatial changes in phytoplankton biomass and distribution on the western Agulhas Bank during the main spawning season of pelagic fish were obtained from monthly cruises conducted betweenAugust and March in 1993/94 and September and March in 1994/95. The period was divided into three oceanographic seasons based on different levels of upwelling activity: late winter (August and September), spring(October–December) and summer (January–March). Cross-shelf and vertical distribution patterns of chlorophyll changed markedly during these seasonal periods, reflecting changes in hydrographic structure and in nutrient availability. During late winter, chlorophyll was evenly distributed in the deep, upper-mixed layer (>40 m) across the shelf. A clump-forming Thalassiosira sp. contributed to the moderately high mean chlorophyllconcentration (1.9 mg·m–3) in the upper 30 m. In October and/or September, warming of surface waters inshore gave rise to a modest (2–5 mg chl·m–3) spring bloom, typical of the temperate zone. This was terminated in November by an influx across the shelf of warm, nutrient-impoverished water. Upwelling was sporadic and weak in spring. Summer was characterized by intense, episodic upwelling inshore, with pronounced cross-shelf thermal gradients, intensified by the presence of water of Agulhas origin along the shelf-edge. During an upwelling cycle, rapid hydrographic and biological changes occur over four phases: onset of upwelling, sustained upwelling, quiescence and downwelling. The upwelling productive zone, bounded by the 20°C isotherm, varied fro

    Identification and classification of vertical chlorophyll patterns in the Benguela upwelling system and Angola-Benguela front using an artificial neural network

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    Information on the vertical chlorophyll structure in the ocean is important for estimating integrated chlorophyll a and primary production from satellite. For this study, vertical chlorophyll profiles from the Benguela upwelling system and the Angola-Benguela front were collected in winter to identify characteristic profiles. A shifted Gaussian model was fitted to each profile to estimate four parameters that defined the shape of the curve: the background chlorophyll concentration (B0), the height parameter of the peak (h), the width of the peak (&#963) and the depth of the chlorophyll peak (zm). A type of artificial neural network called a self-organizing map (SOM) was then used on these four parameters to identify characteristic profiles. The analysis identified a continuum of chlorophyll patterns, from those with large surface peaks (>10 mg m-3) to those with smaller near-surface peaks

    ‘Our voice started off as a whisper and now it is a great big roar’ : The Salford Dementia Associate Panel as a model of involvement in research activities

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    This paper presents the work of the ‘Salford Dementia Associate Panel’, based at the Salford Institute for Dementia, Salford University (UK). We discuss the roles of the Dementia Associates, in particular around the areas of engagement and research. The panel is made up of people living with dementia, and current and former care partners. It highlights the development of this group over a four-year period and demonstrates over time how the role of a Dementia Associate member has evolved. The panel is involved in research, education and public engagement activities conducted by staff and students within the Institute. The motivations for becoming involved are clearly articulated and demonstrate how the personal backgrounds of individuals have driven the collective involvement and desire to bring about change. The benefits and challenges associated with working as part of a panel are discussed. We conclude by bringing together our experiences as a set of suggestions for others who may wish to create a similar forum to promote the involvement of people living with dementia and former and current care partners

    The effect of sea temperature and food availability on the spawning success of Cape Anchovy engraulis capensis in the Southern Benguela

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    Data on the thermal structure, copepod biomass and production, and total number of eggs of the Cape anchovy Engraulis capensis were obtained from monthly surveys during the periods August 1993 – March1994 and September 1994 – March 1995 on the western Agulhas Bank and off the South-Western Cape, South Africa. Previous work suggested that anchovy spawn on the western Agulhas Bank in temperaturesbetween 16 and 19°C, where they feed predominantly on copepods. This study shows that the western Bank is a more suitable spawning area for anchovy, having greater thermal stability, a larger area of 16–19°Cwater and a more consistent food environment than off the South-Western Cape. Also, copepod production on the western Bank was highest in 16–19°C water. To identify factors controlling the area of this watermass, a cluster analysis was used on a suite of hydrographic variables. Three periods were identified: winter (August-September), spring (October-December) and summer (January-March), reflecting changes in theextent of the 16–19°C water and anchovy spawning, both of which peaked during spring. Spring was further characterized by infrequent surface upwelling. During summer, upwelling frequently reached the surface andthe upwelling front migrated offshore, constricting the area of 16–19°C water. It is hypothesized that spawning success in anchovy is dependent upon the extent of suitable spawning habitat, both spatially (16–19°Cwater) and temporally (spring). To put this concept into a predictive framework, the number of anchovy eggs was regressed against the area of 16–19°C water; a significant, positive relationship (p < 0.001, r2 = 0.56, n = 17) was found. An implication of the hypothesis is that the duration of spawning may be important to recruitment

    A Quantitative Metric to Identify Critical Elements within Seafood Supply Networks

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    A theoretical basis is required for comparing key features and critical elements in wild fisheries and aquaculture supply chains under a changing climate. Here we develop a new quantitative metric that is analogous to indices used to analyse food-webs and identify key species. The Supply Chain Index (SCI) identifies critical elements as those elements with large throughput rates, as well as greater connectivity. The sum of the scores for a supply chain provides a single metric that roughly captures both the resilience and connectedness of a supply chain. Standardised scores can facilitate crosscomparisons both under current conditions as well as under a changing climate. Identification of key elements along the supply chain may assist in informing adaptation strategies to reduce anticipated future risks posed by climate change. The SCI also provides information on the relative stability of different supply chains based on whether there is a fairly even spread in the individual scores of the top few key elements, compared with a more critical dependence on a few key individual supply chain elements. We use as a case study the Australian southern rock lobster Jasus edwardsii fishery, which is challenged by a number of climate change drivers such as impacts on recruitment and growth due to changes in largescale and local oceanographic features. The SCI identifies airports, processors and Chinese consumers as the key elements in the lobster supply chain that merit attention to enhance stability and potentially enable growth. We also apply the index to an additional four real-world Australian commercial fishery and two aquaculture industry supply chains to highlight the utility of a systematic method for describing supply chains. Overall, our simple methodological approach to empiricallybased supply chain research provides an objective method for comparing the resilience of supply chains and highlighting components that may be critical

    Disease prevention not decolonization – a model for fecal microbiota transplantation in patients colonized with multidrug-resistant organisms

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    Fecal microbiota transplantation (FMT) yields variable intestinal decolonization results for multidrug-resistant organisms (MDROs). This study showed significant reductions in antibiotic duration, bacteremia and length of stay in 20 patients colonized/ infected with MDRO receiving FMT (compared to pre-FMT history, and a matched group not receiving FMT), despite modest decolonization rates

    Fecal microbiota transplant mitigates adverse outcomes in patients colonized with multidrug-resistant organisms undergoing allogeneic hematopoietic cell transplantation

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    The gut microbiome can be adversely affected by chemotherapy and antibiotics prior to hematopoietic cell transplantation (HCT). This affects graft success and increases susceptibility to multidrug-resistant organism (MDRO) colonization and infection. We performed an initial retrospective analysis of our use of fecal microbiota transplantation (FMT) from healthy donors as therapy for MDRO-colonized patients with hematological malignancy. FMT was performed on eight MDRO-colonized patients pre-HCT (FMT-MDRO group), and outcomes compared with 11 MDRO colonized HCT patients from the same period. At 12 months, survival was significantly higher in the FMT-MDRO group (70% versus 36% p = 0.044). Post-HCT, fewer FMT-MDRO patients required intensive care (0% versus 46%, P = 0.045) or experienced fever (0.29 versus 0.11 days, P = 0.027). Intestinal MDRO decolonization occurred in 25% of FMT-MDRO patients versus 11% non-FMT MDRO patients. Despite the significant difference and statistically comparable patient/transplant characteristics, as the sample size was small, a matched-pair analysis to non-MDRO colonized control cohorts (2:1 matching) was performed. At 12 months, the MDRO group who did not have an FMT had significantly lower survival (36.4% versus 61.9% respectively, p=0.012), and higher non relapse mortality (NRM; 60.2% versus 16.7% respectively, p=0.009) than their paired non-colonized cohort. There was no difference in survival (70% versus 43.4%, p=0.14) or NRM (12.5% versus 31.2% respectively, p=0.24) between the FMT-MDRO group and their paired cohort. Negative outcomes, including mortality associated with MDRO colonization, may be ameliorated by pre-HCT FMT, despite lack of intestinal decolonization. Further work is needed to explore the observed benefit
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