40 research outputs found

    Getting Out of Your Way to Help Others: Responsibility to Help and Warm-Glow

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    In the past decades, three major theories emerged as key motivators in altruistic behaviors: pure altruism, external motivation, and warm-glow, which refers to utility that people derive from altruistic actions in a form of warm, positive feeling. Recently, more studies have focused on understanding warm-glow and its components, such as social image concern and empathic stimuli, in order to better comprehend and encourage altruistic behaviors. We propose that responsibility to help is a potential factor that influences warm-glow from altruistic behavior. In our proposed experimental design, we will test the hypothesis that people would anticipate less warm-glow if the responsibility to help is high, but would anticipate more warm-glow if the responsibility to help is low. We also hypothesize that higher responsibility to help would lead to more altruistic behaviors. Support for our hypothesis, as shown in the preliminary data, would render significant implications to charities as their tendency to make people feel responsible to give may have a tradeoff between increased short-term donation and reduced warm-glow feeling that donors experience

    Local Metric Learning for Off-Policy Evaluation in Contextual Bandits with Continuous Actions

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    We consider local kernel metric learning for off-policy evaluation (OPE) of deterministic policies in contextual bandits with continuous action spaces. Our work is motivated by practical scenarios where the target policy needs to be deterministic due to domain requirements, such as prescription of treatment dosage and duration in medicine. Although importance sampling (IS) provides a basic principle for OPE, it is ill-posed for the deterministic target policy with continuous actions. Our main idea is to relax the target policy and pose the problem as kernel-based estimation, where we learn the kernel metric in order to minimize the overall mean squared error (MSE). We present an analytic solution for the optimal metric, based on the analysis of bias and variance. Whereas prior work has been limited to scalar action spaces or kernel bandwidth selection, our work takes a step further being capable of vector action spaces and metric optimization. We show that our estimator is consistent, and significantly reduces the MSE compared to baseline OPE methods through experiments on various domains

    Capicua suppresses hepatocellular carcinoma progression by controlling the ETV4–MMP1 axis

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    Hepatocellular carcinoma (HCC) is developed by multiple steps accompanying progressive alterations of gene expression, which leads to increased cell proliferation and malignancy. Although environmental factors and intracellular signaling pathways that are critical for HCC progression have been identified, gene expression changes and the related genetic factors contributing to HCC pathogenesis are still insufficiently understood. In this study, we identify a transcriptional repressor Capicua/CIC as a suppressor of HCC progression and a potential therapeutic target. Expression of CIC is posttranscriptionally reduced in HCC cells. CIC levels are correlated with survival rates in patients with HCC. CIC overexpression suppresses HCC cell proliferation and invasion, whereas loss of CIC exerts opposite effects in vivo as well as in vitro. The levels of PEA3 group genes, the best-known CIC target genes, are correlated with lethality in patients with HCC. Among the PEA3 group genes, ETV4 is the most significantly upregulated gene in CIC-deficient HCC cells, consequently promoting HCC progression. Furthermore, ETV4 induces expression of MMP1, the MMP gene highly relevant to HCC progression, in HCC cells, and knockdown of MMP1 completely blocks the CIC deficiency-induced HCC cell proliferation and invasion. CONCLUSION: Our study demonstrates that the CIC-ETV4-MMP1 axis is a novel regulatory module controlling HCC progression. This article is protected by copyright. All rights reserved.113sciescopu

    Retinoic Acid Promotes the Generation of Pancreatic Endocrine Progenitor Cells and Their Further Differentiation into β-Cells

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    The identification of secreted factors that can selectively stimulate the generation of insulin producing β-cells from stem and/or progenitor cells represent a significant step in the development of stem cell-based β-cell replacement therapy. By elucidating the molecular mechanisms that regulate the generation of β-cells during normal pancreatic development such putative factors may be identified. In the mouse, β-cells increase markedly in numbers from embryonic day (e) 14.5 and onwards, but the extra-cellular signal(s) that promotes the selective generation of β-cells at these stages remains to be identified. Here we show that the retinoic acid (RA) synthesizing enzyme Raldh1 is expressed in developing mouse and human pancreas at stages when β-cells are generated. We also provide evidence that RA induces the generation of Ngn3+ endocrine progenitor cells and stimulates their further differentiation into β-cells by activating a program of cell differentiation that recapitulates the normal temporal program of β-cell differentiation

    Prevalence, associated factors and outcomes of pressure injuries in adult intensive care unit patients: the DecubICUs study

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    Funder: European Society of Intensive Care Medicine; doi: http://dx.doi.org/10.13039/501100013347Funder: Flemish Society for Critical Care NursesAbstract: Purpose: Intensive care unit (ICU) patients are particularly susceptible to developing pressure injuries. Epidemiologic data is however unavailable. We aimed to provide an international picture of the extent of pressure injuries and factors associated with ICU-acquired pressure injuries in adult ICU patients. Methods: International 1-day point-prevalence study; follow-up for outcome assessment until hospital discharge (maximum 12 weeks). Factors associated with ICU-acquired pressure injury and hospital mortality were assessed by generalised linear mixed-effects regression analysis. Results: Data from 13,254 patients in 1117 ICUs (90 countries) revealed 6747 pressure injuries; 3997 (59.2%) were ICU-acquired. Overall prevalence was 26.6% (95% confidence interval [CI] 25.9–27.3). ICU-acquired prevalence was 16.2% (95% CI 15.6–16.8). Sacrum (37%) and heels (19.5%) were most affected. Factors independently associated with ICU-acquired pressure injuries were older age, male sex, being underweight, emergency surgery, higher Simplified Acute Physiology Score II, Braden score 3 days, comorbidities (chronic obstructive pulmonary disease, immunodeficiency), organ support (renal replacement, mechanical ventilation on ICU admission), and being in a low or lower-middle income-economy. Gradually increasing associations with mortality were identified for increasing severity of pressure injury: stage I (odds ratio [OR] 1.5; 95% CI 1.2–1.8), stage II (OR 1.6; 95% CI 1.4–1.9), and stage III or worse (OR 2.8; 95% CI 2.3–3.3). Conclusion: Pressure injuries are common in adult ICU patients. ICU-acquired pressure injuries are associated with mainly intrinsic factors and mortality. Optimal care standards, increased awareness, appropriate resource allocation, and further research into optimal prevention are pivotal to tackle this important patient safety threat

    Memristors with Nociceptor Characteristics Using Threshold Switching of Pt/HfO2/TaOx/TaN Devices

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    As artificial intelligence technology advances, it is necessary to imitate various biological functions to complete more complex tasks. Among them, studies have been reported on the nociceptor, a critical receptor of sensory neurons that can detect harmful stimuli. Although a complex CMOS circuit is required to electrically realize a nociceptor, a memristor with threshold switching characteristics can implement the nociceptor as a single device. Here, we suggest a memristor with a Pt/HfO2/TaOx/TaN bilayer structure. This device can mimic the characteristics of a nociceptor including the threshold, relaxation, allodynia, and hyperalgesia. Additionally, we contrast different electrical properties according to the thickness of the HfO2 layer. Moreover, Pt/HfO2/TaOx/TaN with a 3 nm thick HfO2 layer has a stable endurance of 1000 cycles and controllable threshold switching characteristics. Finally, this study emphasizes the importance of the material selection and fabrication method in the memristor by comparing Pt/HfO2/TaOx/TaN with Pt/TaOx/TaN, which has insufficient performance to be used as a nociceptor

    The effect of seawater on the phase assemblage of hydrated cement paste: A study on PC, CAC and CSA

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    The present study investigates the effect of seawater on hydration of Portland cement (PC), calcium aluminate cement (CAC) and calcium sulfoaluminate cement (CSA). The cement samples were exposed to seawater at various curing ages and were characterized using thermogravimetric analysis and X-ray diffraction. The phase assemblages of the exposed samples are then compared with the unexposed samples to observe the changes that occur during the exposure to seawater. The exposure to seawater mainly affected the AFm phases in hydrated cements. The chloride uptake results in the formation of Friedel's salt. Monocarbonate, hemicarbonate and C2AH8 are the primary chloride binding phases in PC, CSA and CAC, respectively. Another observed effect of seawater exposure is the stabilization and formation of more ettringite in PC and CSA due to sulfate ions. The findings from these experiments are essential to better understand the phase assemblage changes that occur in structures exposed to marine environments
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