513 research outputs found

    Fluid evolution in an Oceanic Core Complex: a fluid inclusion study from IODP hole U1309 D - Atlantis Massif, 30°N, Mid-Atlantic Ridge

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    In the detachment mode of slow seafloor spreading, convex-upward detachment faults take up a high proportion of the plate separation velocity exposing gabbro and serpentinized peridotite on the seafloor. Large, long-lived hydrothermal systems such as TAG are situated off axis and may be controlled by fluid flow up a detachment fault, with the source of magmatic heat being as deep as 7 kmbsf. The consequences of such deep circulation for the evolution of fluid temperature and salinity have not previously been investigated. Microthermometry on fluid inclusions trapped in diabase, gabbro, and trondjhemite, recovered at the Atlantis Massif Oceanic Core Complex (30°N, Mid-Atlantic Ridge), reveals evidence for magmatic exsolution, phase separation, and mixing between hydrothermal fluids and previously phase-separated fluids. Four types of fluid inclusions were identified, ranging in salinity from 1.4 to 35 wt % NaCl, although the most common inclusions have salinities close to seawater (3.4 wt % NaCl). Homogenization temperatures range from 160 to >400°C, with the highest temperatures in hypersaline inclusions trapped in trondjhemite and the lowest temperatures in low-salinity inclusions trapped in quartz veins. The fluid history of the Atlantis Massif is interpreted in the context of published thermochronometric data from the Massif, and a comparison with the inferred circulation pattern beneath the TAG hydrothermal field, to better constrain the pressure temperature conditions of trapping and when in the history of exhumation of the rocks sampled by IODP Hole U1309D fluids have been trapped

    Profiling commenters on mental health-related online forums : a methodological example focusing on eating disorder-related commenters

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    Background Understanding the characteristics of commenters on mental health-related online forums is vital for the development of effective psychological interventions in these communities. The way in which commenters interact can enhance our understanding of their characteristics. Objective Using eating disorder-related (EDR) forums as an example, this study details a methodology that aimed to determine subtypes of mental health-related forums, and profile their commenters based on the other forums to which they contributed. Methods The researchers identified all public EDR-forums (with ≥500 contributing commenters between March 2017 and February 2018) on a large online discussion platform (Reddit). A mixed-methods approach comprising network analysis with community-detection, text-mining and manual review identified subtypes of EDR-forums. For each subtype, another network analysis with community-detection was conducted using the EDR-forum commenter-overlap between 50 forums on which the commenters also commented. The topics of forums in each detected community were then manually reviewed to identify the shared interests of each subtype of EDR-forum commenters. Results Six subtypes of EDR-forums were identified, to which 14024 commenters had contributed. The results focus on two subtypes – pro-eating disorder, and thinspiration – and communities of commenters within both subtypes. Within the pro-eating disorder subtype, three communities of commenters were detected that related to the body and eating, mental health, and women, appearance and mixed topics. Regarding the thinspiration group, 78% of commenters had also commented on pornographic forums, and 17% had contributed to pro-eating disorder forums. Conclusions The article exemplifies a methodology that provides insight into subtypes of mental health-related forums, and the characteristics of their commenters. The findings have implications for future research, and online psychological interventions. With the publicly available data and code provided, researchers can easily reproduce the analyses, or utilise the methodology to investigate other mental health-related forums

    Inhibition of NF-κB-mediated signaling by the cyclin-dependent kinase inhibitor CR8 overcomes pro-survival stimuli to induce apoptosis in chronic lymphocytic leukemia cells

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    Purpose: Chronic lymphocytic leukemia (CLL) is currently incurable with standard chemotherapeutic agents, highlighting the need for novel therapies. Overcoming proliferative and cytoprotective signals generated within the microenvironment of lymphoid organs is essential for limiting CLL progression and ultimately developing a cure. Experimental Design: We assessed the potency of cyclin-dependent kinase (CDK) inhibitor CR8, a roscovitine analog, to induce apoptosis in primary CLL from distinct prognostic subsets using flow cytometry–based assays. CLL cells were cultured in in vitro prosurvival and proproliferative conditions to mimic microenvironmental signals in the lymphoid organs, to elucidate the mechanism of action of CR8 in quiescent and proliferating CLL cells using flow cytometry, Western blotting, and quantitative real-time PCR. Results: CR8 was 100-fold more potent at inducing apoptosis in primary CLL cells than roscovitine, both in isolated culture and stromal-coculture conditions. Importantly, CR8 induced apoptosis in CD40-ligated CLL cells and preferentially targeted actively proliferating cells within these cultures. CR8 treatment induced downregulation of the antiapoptotic proteins Mcl-1 and XIAP, through inhibition of RNA polymerase II, and inhibition of NF-κB signaling at the transcriptional level and through inhibition of the inhibitor of IκB kinase (IKK) complex, resulting in stabilization of IκBα expression. Conclusions: CR8 is a potent CDK inhibitor that subverts pivotal prosurvival and proproliferative signals present in the tumor microenvironment of CLL patient lymphoid organs. Our data support the clinical development of selective CDK inhibitors as novel therapies for CLL

    AAC W1876 hard red spring wheat

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    AAC W1876 hard red spring wheat (Triticum aestivum L.) has grain yield and time to maturity within the range of the check cultivars: Katepwa, Laura, Lillian, Carberry, and CDC Kernen. AAC W1876 has an awned spike, a low lodging score indicative of strong straw, and a short plant stature typical of a semidwarf wheat. AAC W1876 expressed resistance to prevalent races of leaf rust, moderate resistance to stem rust, intermediate resistance to fusarium head blight, yellow rust, common bunt, and loose smut. Compared to the Canada Western Red Spring check cultivars, AAC W1876 had improved flour yield and lower flour ash. AAC W1876 is eligible for grades of Canada Western Red Spring

    AAC Penhold Canada Prairie Spring Red Wheat

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    AAC Penhold, an awned hard red spring wheat (Triticum aestivum L.) cultivar, yielded significantly more grain than 5700PR while maturing 2 days earlier, and 7.5 cm shorter stature. The seed size was significantly larger than 5700PR and 5701PR, with a test weight significantly heavier than both checks. AAC Penhold expressed resistance to prevalent races of leaf rust and common bunt, and moderate resistance to fusarium head blight and stem rust. AAC Penhold had higher grain and flour protein than the checks and improved Hagberg Falling Number, amylograph viscosity, and water absorption. AAC Penhold is eligible for grades of the market class, Canada Prairie Spring Red wheat

    AAC Congress Durum Wheat

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    Congress durum wheat (Triticum turgidum L. subsp. durum (Desf.) Husn.) is adapted to the durum production area of the Canadian prairies. Averaged over three years, AAC Congress yielded significantly more grain than Strongfield and AC Navigator. AAC Congress had protein concentration significantly lower than Strongfield but significantly higher than Brigade. AAC Congress is eligible for grades of Canada Western Amber Durum. It has lower grain cadmium concentration and higher yellow pigment concentration than the check cultivars, except AAC Cabri

    Dasatinib inhibits CXCR4 signaling in chronic lymphocytic leukaemia cells and impairs migration towards CXCL12

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    Chemokines and their ligands play a critical role in enabling chronic lymphocytic leukaemia (CLL) cells access to protective microenvironmental niches within tissues, ultimately resulting in chemoresistance and relapse: disruption of these signaling pathways has become a novel therapeutic approach in CLL. The tyrosine kinase inhibitor dasatinib inhibits migration of several cell lines from solid-organ tumours, but effects on CLL cells have not been reported. We studied the effect of clinically achievable concentrations of dasatinib on signaling induced by the chemokine CXCL12 through its' receptor CXCR4, which is highly expressed on CLL cells. Dasatinib pre-treatment inhibited Akt and ERK phosphorylation in CLL cells upon stimulation with CXCL12. Dasatinib also significantly diminished the rapid increase in actin polymerisation observed in CLL cells following CXCL12 stimulation. Moreover, the drug significantly inhibited chemotaxis in a transwell assay, and reduced the percentage of cells able to migrate beneath a CXCL12-expressing murine stromal cell line. Dasatinib also abrogated the anti-apoptotic effect of prolonged CXCL12 stimulation on cultured CLL cells. These data suggest that dasatinib, akin to other small molecule kinase inhibitors targeting the B-cell receptor signaling pathway, may redistribute CLL cells from protective tissue niches to the peripheral blood, and support the investigation of dasatinib in combination strategies

    Engagement with MyFitnessPal in eating disorders : qualitative insights from online forums

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    Objective Using calorie‐counting and fitness‐tracking technologies is concerning in relation to eating disorders. While studies in this area typically assess one aspect of use (e.g., frequency), engagement with a device or application is more complex. Consequently, important relationships between the use of these technologies and the eating disorder symptomatology might remain undetected. The current study therefore used comments from online eating disorder‐related forums to generate comprehensive qualitative insights into engagement with a popular calorie‐counting and fitness‐tracking application, MyFitnessPal. Method First, we extracted every comment mentioning MyFitnessPal made on three eating disorder‐related forums between May 2015 and January 2018 (1,695 comments from 920 commenters). Then, we conducted an inductive thematic analysis using these comments to identify important aspects of engagement with MyFitnessPal. Results The analyses resulted in three themes: Preventing misuse, describing ways in which MyFitnessPal attempts to prevent pathological use and actions taken by users to circumvent its interventions; Accuracy, outlining distrust of MyFitnessPal's accuracy and ways in which perceived inaccuracy is reduced or compensated for; and Psychosocial factors, comprising cognitive, behavioral, and social factors that influence, or are influenced by, engagement with MyFitnessPal. Discussion The qualitative insights provide a detailed overview of how people with high levels of eating disorder symptomatology likely engage with MyFitnessPal. The insights can be used as a basis to develop valid, quantitative assessment of pathological patterns of engagement with calorie‐counting and fitness‐tracking technologies. The findings can also provide clinicians with insight into how their patients likely engage with, and are affected by, these devices and applications

    Modelling the Dynamics of an Aedes albopictus Population

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    We present a methodology for modelling population dynamics with formal means of computer science. This allows unambiguous description of systems and application of analysis tools such as simulators and model checkers. In particular, the dynamics of a population of Aedes albopictus (a species of mosquito) and its modelling with the Stochastic Calculus of Looping Sequences (Stochastic CLS) are considered. The use of Stochastic CLS to model population dynamics requires an extension which allows environmental events (such as changes in the temperature and rainfalls) to be taken into account. A simulator for the constructed model is developed via translation into the specification language Maude, and used to compare the dynamics obtained from the model with real data.Comment: In Proceedings AMCA-POP 2010, arXiv:1008.314
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