29 research outputs found

    Return from Exile

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    Return from Exile

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    Doing the right thing for the right reason: Evaluating artificial moral cognition by probing cost insensitivity

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    Is it possible to evaluate the moral cognition of complex artificial agents? In this work, we take a look at one aspect of morality: `doing the right thing for the right reasons.' We propose a behavior-based analysis of artificial moral cognition which could also be applied to humans to facilitate like-for-like comparison. Morally-motivated behavior should persist despite mounting cost; by measuring an agent's sensitivity to this cost, we gain deeper insight into underlying motivations. We apply this evaluation to a particular set of deep reinforcement learning agents, trained by memory-based meta-reinforcement learning. Our results indicate that agents trained with a reward function that includes other-regarding preferences perform helping behavior in a way that is less sensitive to increasing cost than agents trained with more self-interested preferences.Comment: 11 pages, 3 figure

    Spectroscopy and carrier dynamics in CdSe self-assembled quantum dots embedded in ZnxCdyMg1−x−ySe

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    Time-resolved and steady-state photoluminescence,reflectivity, and absorption experiments were performed on CdSequantum dots in ZnxCdyMg1−x−ySe barriers. Studies of the capture times of the photoexcited carriers into the quantum dots and of electron-hole recombination times inside the dots were performed. Photoluminescence rise time yielded capture times from 20 ps to 30 ps. All samples exhibit fast and slow photoluminescence decays, consistent with observing two independent but energetically overlapping decays. The faster relaxation times for the sample emitting in the blue range is 90 ps, whereas for the two samples emitting in the green it is 345 ps and 480 ps. The slower relaxation times for the sample emitting in blue is 310 ps, whereas for the samples emitting in green is 7.5 ns. These results are explained on the basis of the structural differences among the quantum-dot samples

    Patient Preferences in the Medical Product Life Cycle: What do Stakeholders Think? Semi-Structured Qualitative Interviews in Europe and the USA.

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    Background Patient preferences (PP), which are investigated in PP studies using qualitative or quantitative methods, are a growing area of interest to the following stakeholders involved in the medical product lifecycle: academics, health technology assessment bodies,

    Crystal structure of catena-poly[[potassium-tri-μ-dimethylacetamide-κ6O:O] iodide]

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    The structure of catena-poly[[potassium-tri-μ-dimethylacetamide-κ6O:O] iodide], {[K(C4H9NO)3]I}n, at 120 K has trigonal (P-3) symmetry. The structure adopts a linear chain motif parallel to the crystallographic c axis. Two crystallographically independent K+ cations are present in the asymmetric unit located on threefold rotoinversion axes at [0, 0, 0] and [0, 0, 1/2] and are bridged by the O atoms of the acetamide moiety. This is an example of a rare μ2-bridging mode for dimethylacetamide O atoms. The iodide counter-ion resides on a threefold rotation axis in the channel formed by the [K(C4H9NO)]+ chains

    The redox biology network in cancer pathophysiology and therapeutics

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    PubMed ID: 26122399The review pinpoints operational concepts related to the redox biology network applied to the pathophysiology and therapeutics of solid tumors. A sophisticated network of intrinsic and extrinsic cues, integrated in the tumor niche, drives tumorigenesis and tumor progression. Critical mutations and distorted redox signaling pathways orchestrate pathologic events inside cancer cells, resulting in resistance to stress and death signals, aberrant proliferation and efficient repair mechanisms. Additionally, the complex inter-cellular crosstalk within the tumor niche, mediated by cytokines, redox-sensitive danger signals (HMGB1) and exosomes, under the pressure of multiple stresses (oxidative, inflammatory, metabolic), greatly contributes to the malignant phenotype. The tumor-associated inflammatory stress and its suppressive action on the anti-tumor immune response are highlighted. We further emphasize that ROS may act either as supporter or enemy of cancer cells, depending on the context. Oxidative stress-based therapies, such as radiotherapy and photodynamic therapy, take advantage of the cytotoxic face of ROS for killing tumor cells by a non-physiologically sudden, localized and intense oxidative burst. The type of tumor cell death elicited by these therapies is discussed. Therapy outcome depends on the differential sensitivity to oxidative stress of particular tumor cells, such as cancer stem cells, and therefore co-therapies that transiently down-regulate their intrinsic antioxidant system hold great promise. We draw attention on the consequences of the damage signals delivered by oxidative stress-injured cells to neighboring and distant cells, and emphasize the benefits of therapeutically triggered immunologic cell death in metastatic cancer. An integrative approach should be applied when designing therapeutic strategies in cancer, taking into consideration the mutational, metabolic, inflammatory and oxidative status of tumor cells, cellular heterogeneity and the hypoxia map in the tumor niche, along with the adjoining and systemic effects of oxidative stress-based therapies. © 2015 The Authors.BM1203/EU-ROS E05/2014 European Social Fund, ESF European Cooperation in Science and Technology POSDRU141531Gina Manda, Adrian Manea, Bilge Debelec Butuner and Kemal Sami Korkmaz were supported by the European Cooperation in Science and Technology (COST Action BM1203/EU-ROS ); Gheorghita Isvoranu was supported by the Sectorial Operational Program Human Resources Development (SOPHRD), financed by the European Social Fund and the Romanian Government under the Contract no. POSDRU141531 ; the work of Maria Victoria Comanescu was supported by the Romanian National Agency for Research and Innovation , under the Program Capacities, Romania-CERN (Grant E05/2014 ). -
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