467 research outputs found

    Interactive Restless Multi-armed Bandit Game and Swarm Intelligence Effect

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    We obtain the conditions for the emergence of the swarm intelligence effect in an interactive game of restless multi-armed bandit (rMAB). A player competes with multiple agents. Each bandit has a payoff that changes with a probability pcp_{c} per round. The agents and player choose one of three options: (1) Exploit (a good bandit), (2) Innovate (asocial learning for a good bandit among nIn_{I} randomly chosen bandits), and (3) Observe (social learning for a good bandit). Each agent has two parameters (c,pobs)(c,p_{obs}) to specify the decision: (i) cc, the threshold value for Exploit, and (ii) pobsp_{obs}, the probability for Observe in learning. The parameters (c,pobs)(c,p_{obs}) are uniformly distributed. We determine the optimal strategies for the player using complete knowledge about the rMAB. We show whether or not social or asocial learning is more optimal in the (pc,nI)(p_{c},n_{I}) space and define the swarm intelligence effect. We conduct a laboratory experiment (67 subjects) and observe the swarm intelligence effect only if (pc,nI)(p_{c},n_{I}) are chosen so that social learning is far more optimal than asocial learning.Comment: 18 pages, 4 figure

    Past hepatitis B virus infection in rheumatoid arthritis patients receiving biological and/or nonbiological disease-modifying antirheumatic drugs

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    To evaluate the prevalence of past infection with hepatitis B virus (HBV) in patients with rheumatoid arthritis (RA) and the incidence of its reactivation under treatment with biological and/or nonbiological disease-modifying antirheumatic drugs (DMARDs), 239 patients receiving DMARD therapy were consecutively enrolled and tested for HBV-DNA, using a real-time polymerase chain reaction assay, HBV serology including hepatitis B surface antigen (HBsAg) and hepatitis B core antibody (anti-HBc), and serum levels of aminotransferase. Data prior to DMARD therapy and during follow-up were examined by reviewing medical records. Two patients (0.8%) were positive for HBsAg at the start of therapy. Sixty patients (25.1%) showed HBsAg-negative and anti-HBc-positive serology indicative of past HBV infection. Among these 60 patients, 2 patients (3.3%) experienced reactivation of viral replication (<2.1 log copies/ml) during DMARD therapy. One had been receiving tacrolimus, prednisolone, and methotrexate (MTX); the other had been treated with adalimumab, prednisolone, and MTX. Their serum aminotransferase levels remained normal, and HBsAg was negative. Ten weeks after reactivation of viral replication had been noted, the HBV-DNA titer in the former patient had increased to 2.9 log copies/ml, and HBsAg and hepatitis B e antigen had become weakly positive. In contrast, the latter patient had become negative for viral DNA without any antiviral prophylaxis. In conclusion, the use of biological and nonbiological DMARDs is relatively safe in most RA patients with past HBV infection, even when no anti-HBV prophylaxis is administered. Considering the high prevalence of past infection in RA patients and the high cost of prophylaxis against HBV reactivation, universal prophylaxis is impractical. Regular monitoring of serum viral DNA seems to be the most rational approach to preventing the development of clinically apparent hepatitis

    The probability of double-strand breaks in giant DNA decreases markedly as the DNA concentration increases

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    DNA double-strand breaks (DSBs) represent a serious source of damage for all living things and thus there have been many quantitative studies of DSBs both in vivo and in vitro. Despite this fact, the processes that lead to their production have not yet been clearly understood, and there is no established theory that can account for the statistics of their production, in particular, the number of DSBs per base pair per unit Gy, here denoted by P1, which is the most important parameter for evaluating the degree of risk posed by DSBs. Here, using the single-molecule observation method with giant DNA molecules (166 kbp), we evaluate the number of DSBs caused by gamma-ray irradiation. We find that P1 is nearly inversely proportional to the DNA concentration above a certain threshold DNA concentration. A simple model that accounts for the marked decrease of P1 shows that it is necessary to consider the characteristics of giant DNA molecules as semiflexible polymers to interpret the intrinsic mechanism of DSBs

    Primary lack of efficacy of infliximab therapy for rheumatoid arthritis: pharmacokinetic characterization and assessment of switching to tocilizumab

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    To characterize primary failure to infliximab and determine the efficacy of switching to tocilizumab in patients with rheumatoid arthritis (RA), we examined 24 RA patients who had started on infliximab therapy (3 mg/kg) as their first biological agent. Nine of the 24 patients were found to be primary nonresponders, defined as patients who had never achieved a 20% clinical improvement according to the American College of Rheumatology criteria (ACR20) during induction therapy. The remaining 15 patients had achieved an ACR20 response to infliximab, without any relapses, for at least the first 14 weeks. A higher baseline health assessment questionnaire score was markedly associated with primary unresponsiveness to infliximab (p = 0.0005). Six of the 9 primary nonresponders showed rapid clearance of infliximab: their trough concentrations of infliximab were under 1 μg/ml. The other 3 were classified as exhibiting the residual type of unresponsiveness, which was defined as unresponsiveness in patients who maintained serum infliximab levels above 1 μg/ml. Human antichimeric antibody was not detected in the rapid-clearance nonresponders. Dose escalation (5 mg/kg) was insufficiently effective. Primary nonresponders to infliximab were started on tocilizumab therapy (8 mg/kg, every 4 weeks), and their responses were assessed after 24 weeks of this second attempt at therapy. All the nonresponders, except for a single rapid-clearance patient, had achieved an ACR20 clinical improvement at the time of assessment. In conclusion, primary nonresponders to infliximab can be classified into rapid-clearance and residual types, based on their trough concentrations of infliximab, but both types of nonresponders seem to benefit from an early decision to discontinue infliximab therapy and switch to tocilizumab

    Detection and Quantification of Calcium Ions in the Endoplasmic Reticulum and Cytoplasm of Cultured Cells Using Fluorescent Reporter Proteins and ImageJ Software

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    This protocol describes a method for detecting and quantifying calcium ions in the endoplasmic reticulum (ER) and cytoplasm of cultured cells using fluorescent reporter proteins and ImageJ software. Genetically engineered fluorescent reporter proteins, such as G-CEPIA1er and GCaMP6f, localize to intracellular regions of interest (i.e., ER and cytoplasm) and emit green fluorescence upon binding to calcium ions. In this way, the fluorescence brightness of cells transfected with expression vectors for these reporters reflects the calcium ion concentration in each intracellular region. Here, we describe procedures for observing cultured cells expressing these fluorescent reporters under a fluorescence microscope, analyzing the obtained image using the free image analysis software ImageJ (https://imagej.net/ij/index.html), and determining the average fluorescence brightness of multiple cells present in the image. The current method allows us to quickly and easily quantify calcium ions on an image containing multiple cells and to determine whether there are relative differences in intracellular calcium ion concentration among experiments with different conditions

    System Dynamics Model and Policy Scenario Analyses on International Movements of Indonesian Scientists and Engineers

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    Abstract. The necessity to face technology challenges in industrialization in Indonesia causes the current condition to be not preferable. Conditions in higher education which relates closely to the research and development in Indonesia trigger questions of what future holds in Indonesia’s technology development in the future. This paper looks back at the previous literatures on international movements of scientists and engineers abroad and proposes to apply a causal loop diagram model. This paper also analyzes the relationships based on Indonesia’s context and set a parameter for each variable. The relationships were checked through interview with representation from Indonesian research institutions and Ministry of Foreign Affairs. The result of this paper confirms that the diagram is able to symbolize the circumstances in Indonesia’s context. Second important finding is that based on simulation and policy scenarios implemented, the policy to increase the number of scholarships by the government is predicted as the most effective to all important parameters for future development in Indonesia in relation to education and technology development, which will eventually lead to economic development.Keywords:  Engineers, international students, policy scenarios, scientists, system dynamic

    Small airway obstruction in patients with rheumatoid arthritis

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    This work was intended to evaluate the prevalence of obstructive small-airway disease in patients with rheumatoid arthritis (RA) and its association with clinical characteristics. Pulmonary function testing (PFT) and high-resolution computed tomography (HRCT) were performed on 189 consecutive RA patients. Each case was diagnosed based on abnormal HRCT findings. We defined obstructive dysfunction of small airways as a forced expiratory flow from 25% to 75% of vital capacity (FEF25–75) value >1.96 residual standard deviation (RSD) below predicted values. We found 19 patients (10.1%) with an interstitial pneumonia (IP) pattern and 15 (7.9%) with a bronchiolitis pattern; the other 155 (82.0%) had no abnormal HRCT patterns. In patients with neither abnormal pattern, median values of percentage predicted for carbon monoxide diffusing capacity (DLCO) and ratio of DLCO to alveolar ventilation (DLco/VA) were within the normal range, but median FEF25–75, forced expiratory flow at 25% of vital capacity (V25), and V25/height were <70% of predicted values. Forty-seven patients (30.3%) in this group had obstructive small-airway dysfunction. Multivariate logistic regression analysis indicated that this type of abnormality is strongly associated with respiratory symptoms [odds ratio (OR) 5.18; 95% confidence interval (CI) 1.70–15.75; p = 0.012), smoking history (OR 2.78; 95% CI 1.10–6.99; p = 0.03), and disease duration >10 years (OR 2.86; 95% CI 1.27–6.48; p = 0.012). Parenchymal micronodules, bronchial-wall thickening, and bronchial dilatation on HRCT scans were also predictive factors for abnormal FEF25–75, although these morphological changes were too limited for us to diagnose these patients with the bronchiolitis pattern. Obstructive dysfunction of small airways is apparently common among RA patients, even among those with neither the IP nor the bronchiolitis pattern on HRCT scans. Factors significantly associated with abnormal FEF25–75 are respiratory symptoms, smoking history, and RA duration

    Analysis of Influences of ICT on Structural Changes in Japanese Commerce, Business Services and Office Supplies, and Personal Services Sectors Using Multivariate Analysis: 1985–2005

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    This study analyzes influences of Information and Communication Technology (ICT) in the structural changes of Japanese industrial sectors from 1985 through 2005. ICT is represented by two explanatory variables, computers (including main parts and accessories) and telecommunications equipment. We investigate influences by the Constrained Multivariate Regression (CMR) model and test the statistical significance of this model by the Likelihood Ratio Test (LRT) method. We then perform microscopic analysis, focusing on the commerce, business services and office supplies, and personal services sectors. The results show that these variables, separately and jointly, had significant influence on structural changes in Japanese industrial sectors, including the analyzed ones. The patterns of influence in analyzed sectors are, however, different. Based on this difference, we can say that during 1985–2005 the business circumstances of the analyzed sectors were dissimilar.Keywords: ICT, Industrial Structural Changes, CMR, LRT, Japandoi:10.12695/ajtm.2013.6.2.5 How to cite this article:Zuhdi, U., Mori, S., and Kamegai, K. (2013). Analysis of Influences of ICT on Structural Changes in Japanese Commerce, Business Services and Office Supplies, and Personal Services Sectors Using Multivariate Analysis: 1985–2005. The Asian Journal of Technology Management 6 (2): 102-111. Print ISSN: 1978-6956; Online ISSN: 2089-791X. doi:10.12695/ajtm.2013.6.2.
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