19 research outputs found

    Optimizing pessimism in dynamic treatment regimes: a Bayesian learning approach

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    In this article, we propose a novel pessimismbased Bayesian learning method for optimal dynamic treatment regimes in the offline setting. When the coverage condition does not hold, which is common for offline data, the existing solutions would produce sub-optimal policies. The pessimism principle addresses this issue by discouraging recommendation of actions that are less explored conditioning on the state. However, nearly all pessimism-based methods rely on a key hyper-parameter that quantifies the degree of pessimism, and the performance of the methods can be highly sensitive to the choice of this parameter. We propose to integrate the pessimism principle with Thompson sampling and Bayesian machine learning for optimizing the degree of pessimism. We derive a credible set whose boundary uniformly lower bounds the optimal Q-function, and thus we do not require additional tuning of the degree of pessimism. We develop a general Bayesian learning method that works with a range of models, from Bayesian linear basis model to Bayesian neural network model. We develop the computational algorithm based on variational inference, which is highly efficient and scalable. We establish the theoretical guarantees of the proposed method, and show empirically that it outperforms the existing state-of-theart solutions through both simulations and a real data example

    Elephant Culture Matter for China’s Asian Elephants Conservation

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    Traditional anthropogenic impacts such as hunting, using as war-elephant, trading of ivory, paying tribute to the imperial court and so on, were once thought to be directly responsible for the rapid decline of Asian elephants in China. But in Yunnan Province, China, a unique human factor such as the traditional elephant culture of local ethnic minorities, is an important factor in the conservation of Asian elephants. In these areas, we investigated by means of village interviews, field surveys and data collection, the results show that the elephant culture of ethnic minorities has a great impact on people's thoughts and behaviors, these traditional culture and belief (that mean taking elephant as the God, holding elephant as a belief, worshipping elephant and praise it) urges people to actively protect elephants and avoid more human-elephant conflicts. To enhance the public awareness of Asian elephant conservation, the Chinese Government or international environmental organizations should give higher attention and support to these elephant cultures.

    Aedes albopictus salivary proteins adenosine deaminase and 34k2 interact with human mast cell specific proteases tryptase and chymase

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    When mosquitoes probe to feed blood, they inoculate a mixture of salivary molecules into vertebrate hosts' skin causing acute inflammatory reactions where mast cell-derived mediators are involved. Mosquito saliva contains many proteins with largely unknown biological functions. Here, two Aedes albopictus salivary proteins - adenosine deaminase (alADA) and al34k2 - were investigated for their immunological impact on mast cells and two mast cell-specific proteases, the tryptase and the chymase. Mouse bone marrow-derived mast cells were challenged with increased concentrations of recombinant alADA or al34k2 for 1, 3, and 6 h, and to measure mast cell activation, the activity levels of beta-hexosaminidase and tryptase and secretion of IL-6 were evaluated. In addition, a direct interaction between alADA or al34k2 with tryptase or chymase was investigated. Results show that bone marrow-derived mast cells challenged with 10 mu g/ml of alADA secreted significant levels of beta-hexosaminidase, tryptase, and IL-6. Furthermore, both al34k2 and alADA are cut by human tryptase and chymase. Interestingly, al34k2 dose-dependently enhance enzymatic activity of both tryptase and chymase. In contrast, while alADA enhances the enzymatic activity of tryptase, chymase activity was inhibited. Our finding suggests that alADA and al34k2 via interaction with mast cell-specific proteases tryptase and chymase modulate mast cell-driven immune response in the local skin microenvironment. alADA- and al34k2-mediated modulation of tryptase and chymase may also recruit more inflammatory cells and induce vascular leakage, which may contribute to the inflammatory responses at the mosquito bite site

    A New Approach for Mining Order-Preserving Submatrices Based on All Common Subsequences

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    Order-preserving submatrices (OPSMs) have been applied in many fields, such as DNA microarray data analysis, automatic recommendation systems, and target marketing systems, as an important unsupervised learning model. Unfortunately, most existing methods are heuristic algorithms which are unable to reveal OPSMs entirely in NP-complete problem. In particular, deep OPSMs, corresponding to long patterns with few supporting sequences, incur explosive computational costs and are completely pruned by most popular methods. In this paper, we propose an exact method to discover all OPSMs based on frequent sequential pattern mining. First, an existing algorithm was adjusted to disclose all common subsequence (ACS) between every two row sequences, and therefore all deep OPSMs will not be missed. Then, an improved data structure for prefix tree was used to store and traverse ACS, and Apriori principle was employed to efficiently mine the frequent sequential pattern. Finally, experiments were implemented on gene and synthetic datasets. Results demonstrated the effectiveness and efficiency of this method

    Role of Calcitonin Gene-Related Peptide in Bone Repair after Cyclic Fatigue Loading

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    Calcitonin gene related peptide (CGRP) is a neuropeptide that is abundant in the sensory neurons which innervate bone. The effects of CGRP on isolated bone cells have been widely studied, and CGRP is currently considered to be an osteoanabolic peptide that has effects on both osteoclasts and osteoblasts. However, relatively little is known about the physiological role of CGRP in-vivo in the skeletal responses to bone loading, particularly fatigue loading.We used the rat ulna end-loading model to induce fatigue damage in the ulna unilaterally during cyclic loading. We postulated that CGRP would influence skeletal responses to cyclic fatigue loading. Rats were fatigue loaded and groups of rats were infused systemically with 0.9% saline, CGRP, or the receptor antagonist, CGRP(8-37), for a 10 day study period. Ten days after fatigue loading, bone and serum CGRP concentrations, serum tartrate-resistant acid phosphatase 5b (TRAP5b) concentrations, and fatigue-induced skeletal responses were quantified. We found that cyclic fatigue loading led to increased CGRP concentrations in both loaded and contralateral ulnae. Administration of CGRP(8-37) was associated with increased targeted remodeling in the fatigue-loaded ulna. Administration of CGRP or CGRP(8-37) both increased reparative bone formation over the study period. Plasma concentration of TRAP5b was not significantly influenced by either CGRP or CGRP(8-37) administration.CGRP signaling modulates targeted remodeling of microdamage and reparative new bone formation after bone fatigue, and may be part of a neuronal signaling pathway which has regulatory effects on load-induced repair responses within the skeleton

    Political connection heterogeneity and corporate innovation

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    This paper examines whether political connection heterogeneity plays a role in corporate innovation in a sample of all listed firms in China from 2008 to 2016. Our results show that connections with central government officials promote innovation, while connections with local government officials inhibit innovation. The nonconformity between the influence of federalism and that of the local authorities is associated with the personnel promotion and tenure requirements that induce differential innovation-promotion strategies. We use the Heckman two-stage estimation to address selection bias, and we adopt a setting as a quasi-natural experiment, leveraging the decrease in local GDP growth rates to abate endogeneity. Our results endure these econometric treatments and a series of robustness checks. In mechanism tests, we document evidence that the central government promotes corporate innovation by improving innovation efficiency, while the local government inhibits innovation by reducing both innovation inputs and efficiency. We also find that the effect is even larger on high-tech firms and that it can be mitigated by marketization

    Moving Beyond Protection : a strategic communication campaign to fight stigmatisation of people affected by HIV/AIDS.

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    One Life Experience (OLE) is a strategic communication campaign that aims to reduce the stigma of people affected by HIV/AIDS among Singaporean youth. The campaign, carried out from August 2007 to March 2008, was planned and executed by Team OLE, a group of four undergraduates from Nanyang Technological University’s Wee Kim Wee School of Communication and Information, in collaboration with World Vision Singapore (WVS). Supported by theoretical frameworks and research, the report documents the public relations tools and strategies used in the programming and execution of the campaign so as to effectively reach out to the target audience. The campaign evaluation and limitations are also included.Bachelor of Communication Studie

    Identifying a competency improvement strategy for infection prevention and control professionals: A rapid systematic review and cluster analysis

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    Abstract Remarkable progress has been made in infection prevention and control (IPC) in many countries, but some gaps emerged in the context of the coronavirus disease 2019 (COVID‐19) pandemic. Core capabilities such as standard clinical precautions and tracing the source of infection were the focus of IPC in medical institutions during the pandemic. Therefore, the core competences of IPC professionals during the pandemic, and how these contributed to successful prevention and control of the epidemic, should be studied. To investigate, using a systematic review and cluster analysis, fundamental improvements in the competences of infection control and prevention professionals that may be emphasized in light of the COVID‐19 pandemic. We searched the PubMed, Embase, Cochrane Library, Web of Science, CNKI, WanFang Data, and CBM databases for original articles exploring core competencies of IPC professionals during the COVID‐19 pandemic (from January 1, 2020 to February 7, 2023). Weiciyun software was used for data extraction and the Donohue formula was followed to distinguish high‐frequency technical terms. Cluster analysis was performed using the within‐group linkage method and squared Euclidean distance as the metric to determine the priority competencies for development. We identified 46 studies with 29 high‐frequency technical terms. The most common term was “infection prevention and control training” (184 times, 17.3%), followed by “hand hygiene” (172 times, 16.2%). “Infection prevention and control in clinical practice” was the most‐reported core competency (367 times, 34.5%), followed by “microbiology and surveillance” (292 times, 27.5%). Cluster analysis showed two key areas of competence: Category 1 (program management and leadership, patient safety and occupational health, education and microbiology and surveillance) and Category 2 (IPC in clinical practice). During the COVID‐19 pandemic, IPC program management and leadership, microbiology and surveillance, education, patient safety, and occupational health were the most important focus of development and should be given due consideration by IPC professionals
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