2,539 research outputs found

    Cadmium affects the mitochondrial viability and the acid soluble thiols concentration in liver, kidney, heart and gills of Ancistrus brevifilis (Eigenmann, 1920)

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    The freshwater fish Ancistrus brevifilis, which is found in Venezuelan rivers, is considered a potential sentinel fish in ecotoxicological studies. The cadmium (Cd) effect on the mitochondrial viability (MV) and acid soluble thiols levels (AST) in A. brevifilis tissues (liver, kidney, heart, and gill) was evaluated. Forty-two fish with similar sizes and weights were randomly selected, of which 7 fish (with their respective replicate) were exposed for 7 and 30 days to a Cd sublethal concentration (0.1 mg.l-1). We determined the MV through a Janus Green B colorimetric assay and we obtained the concentration of AST by Ellman’s method. Mitochondrial viability decreased in fish exposed to Cd for 30 days with the liver being the most affected tissue. We also detected a significant decrease in AST levels was in fishes exposed to Cd for 7 days in liver and kidney tissues; these results suggests that AST levels are elevated in some tissues may act as cytoprotective and adaptive alternative mechanism related to the ROS detoxification, maintenance redox status and mitochondrial viability. Organ-specifics variations were observed in both assays. We conclude that the Cd exposure effect on AST levels and MV, vary across fish tissues and is related to the exposure duration, the molecule dynamics in different tissues, the organism and environmental conditions.Keywords: Ancistrus brevifilis, Cadmium, Soluble thiols, Janus Green B, Mitochondrial viability

    Killer-cell immunoglobulin-like receptor diversity in an admixed South American population

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    Natural Killer (NK) cells are innate immune cells that mediate antiviral and antitumor responses. NK cell activation and induction of effector functions are tightly regulated by the integration of activating and inhibitory receptors such as killer immunoglobulin-like receptors (KIR)

    Selecting the most suitable classification algorithm for supporting assistive technology adoption for people with dementia: A multicriteria framework

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    The number of people with dementia (PwD) is increasing dramatically. PwD exhibit impairments of reasoning, memory, and thought that require some form of self‐management intervention to support the completion of everyday activities while maintaining a level of independence. To address this need, efforts have been directed to the development of assistive technology solutions, which may provide an opportunity to alleviate the burden faced by the PwD and their carers. Nevertheless, uptake of such solutions has been limited. It is therefore necessary to use classifiers to discriminate between adopters and nonadopters of these technologies in order to avoid cost overruns and potential negative effects on quality of life. As multiple classification algorithms have been developed, choosing the most suitable classifier has become a critical step in technology adoption. To select the most appropriate classifier, a set of criteria from various domains need to be taken into account by decision makers. In addition, it is crucial to define the most appropriate multicriteria decision‐making approach for the modelling of technology adoption. Considering the above‐mentioned aspects, this paper presents the integration of a five‐phase methodology based on the Fuzzy Analytic Hierarchy Process and the Technique for Order of Preference by Similarity to Ideal Solution to determine the most suitable classifier for supporting assistive technology adoption studies. Fuzzy Analytic Hierarchy Process is used to determine the relative weights of criteria and subcriteria under uncertainty and Technique for Order of Preference by Similarity to Ideal Solution is applied to rank the classifier alternatives. A case study considering a mobile‐based self‐management and reminding solution for PwD is described to validate the proposed approach. The results revealed that the best classifier was k‐nearest‐neighbour with a closeness coefficient of 0.804, and the most important criterion when selecting classifiers is scalability. The paper also discusses the strengths and weaknesses of each algorithm that should be addressed in future research

    High-density Au nanorod optical field-emitter arrays

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    We demonstrate the design, fabrication, characterization, and operation of high-density arrays of Au nanorod electron emitters, fabricated by high-resolution electron beam lithography, and excited by ultrafast femtosecond near-infrared radiation. Electron emission characteristic of multiphoton absorption has been observed at low laser fluence, as indicated by the power-law scaling of emission current with applied optical power. The onset of space-charge-limited current and strong optical field emission has been investigated so as to determine the mechanism of electron emission at high incident laser fluence. Laser-induced structural damage has been observed at applied optical fields above 5 GV m[superscript −1], and energy spectra of emitted electrons have been measured using an electron time-of-flight spectrometer.United States. Defense Advanced Research Projects Agency (Contract N66001-11-1-4192)Gordon and Betty Moore Foundatio

    New Online Ecology of Adversarial Aggregates: ISIS and beyond

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    Support for extremist entities - whether from the far right, or far left - often manages to survive globally online despite significant external pressure, and may ultimately inspire violent acts by individuals having no obvious prior history of extremism. Examining longitudinal records of extremist online activity, we uncovered an ecology evolving on a daily timescale that drives online support, and we provide a mathematical theory that describes it. The ecology features self-organized aggregates (online groups such as on Facebook or another social media analog) that proliferate preceding the onset of recent real-world campaigns, and adopt novel adaptive mechanisms to enhance their survival. One of the predictions is that development of large, potentially potent online groups can be thwarted by targeting smaller ones.Comment: Similar to version that appeared in Science (2016

    Racial disparity and survival outcomes between African-American and Caucasian American men with penile cancer

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    Objective: To determine whether there is a survival difference for African-American men (AAM) versus Caucasian American men (CM) with penile squamous cell carcinoma (pSCC), particularly in locally advanced and metastatic cases where disease mortality is highest. Patients and Methods: Using the Florida Cancer Data System, we identified men with pSCC from 2005 to 2013. We compared age, follow-up, stage, race, and treatment type between AAM and CM. We performed Kaplan\u2013Meier analysis for overall survival (OS) between AAM and CM for all stages, and for those with locally advanced and metastatic disease. A multivariable model was developed to determine significant predictors of OS. Results: In all, 653 men (94 AAM and 559 CM) had pSCC and 198 (30%) had locally advanced and/or metastatic disease. A higher proportion of AAM had locally advanced and/or metastatic disease compared to CM (38 [40%] vs 160 [29%], P = 0.03). The median (interquartile range) follow-up for the entire cohort was 12.6 (5.4\u201332.0) months. For all stages, AAM had a significantly lower median OS compared to CM (26 vs 36\ua0months, P = 0.03). For locally advanced and metastatic disease, there was a consistent trend toward disparity in median OS between AAM and CM (17 vs 22\ua0months, P = 0.06). After adjusting for age, stage, grade, and treatment type, AAM with pSCC had a greater likelihood of death compared to CM (hazard ratio 1.64, P = 0.014). Conclusions: AAM have worse OS compared to CM with pSCC and this may partly be due to advanced stage at presentation. Treatment disparity may also contribute to lessened survival in AAM, but we were unable to demonstrate a significant difference in treatment utilisation between the groups
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