Multitask reinforcement learning on the distribution of mdps,”

Abstract In this paper we address a new problem in reinforcement learning. Here we consider an agent that faces multiple learning tasks within its lifetime. The agent's objective is to maximize its total reward in the lifetime as well as a conventional return in each task. To realize this, it has to be endowed an important ability to keep its past learning experiences and utilize them for improving future learning performance. This time we try to phrase this problem formally. The central idea is to introduce an environmental class, BV-MDPs that is defined with the distribution of MDPs. As an approach to exploiting past learning experiences, we focus on statistics (mean and deviation) about the agent's value tables. The mean can be used as initial values of the table when a new task is presented. The deviation can be viewed as measuring reliability of the mean, and we utilize it in calculating priority of simulated backups. We conduct experiments in computer simulation to evaluate the effectiveness

Automated bone marrow analysis using the CD4000 automated haematology analyser

At present, bone marrow analysis is performed microscopically, but is time consuming and labour intensive. No automated methods have been successfully applied to classification of bone marrows cells because automated blood cell analysers have been incapable of identifying erythroblasts. The present study was designed to evaluate automated analysis of bone marrow aspirates with the CELL-DYN 4000 (CD4000) haematology analyser, which enables automated determination of erythroblast counts in both the normal mode (haemolytic time; 11.5s) and the resistant RBC mode (34.0s). The percentages of subpopulations including lymphocytes, neutrophils and erythroblasts were obtained with the CD4000, and as a reference, differential counts by microscopic observation of May–Grünwald–Giesa-stained films of bone marrow aspirates were performed (n=98). Significant correlations (P < 0.01) between the results obtained with the two methods were observed for total nucleated cell count and lymphocytes, neutrophils, erythroblasts and myeloid/erythroid (M/E) ratio. However, there were biases in the average percentages of erythroblasts, lymphocytes and M/E ratio obtained using the normal mode with the CD4000 toward values lower than those obtained with the microscopic method. Using the RBC resistant mode with the CD4000, the average percentages of erythroblasts, lymphocytes and M/E ratio approximated those obtained with the microscopic method. In conclusion, the CD4000 in resistant RBC mode is more useful for analysis of bone marrow aspirates than is the normal mode, because the former better approximates the M/E ratio than the latter

Infection of human CD4+ rabbit cells with HIV-1 the possibility of the rabbit as a model for HIV-1 infection

Although human T cell surface glycoprotein CD4 is the cellular receptor for human immunodeficiency virus 1 (HIV-1), the introduction of the human CD4 gene into murine cells does not render them susceptible to HIV-1 infection. Here we have established rabbit transfectant cell lines expressing human CD4 on the cell surface and demonstrated that the CD4+ rabbit transfectants could be readily infected by HIV-1 by co-cultivating with a HIV-1-infected human MOLT-4 T cell line (MOLT-4/HIV). Avid syncytia formation was observed upon co-cultivation and the syncytia abundantly produced HIV-1 mature particles, as revealed by electron microscopy. A significant increase of HIV-1 p24 antigen was also detected in the culture supernatant. The syncytia formation was blocked by pretreating the transfectant with anti-human CD4 or by pretreating the MOLT-4/HIV with anti-HIV-1 serum obtained from an infected individual, indicating that the syncytia formed as a result of the interaction of human CD4 on the rabbit transfectant with the HIV-1 envelope protein expressed on MOLT-4/HIV. In contrast, only a very small proportion of the rabbit transfectants expressed HIV-1-specific antigens upon infection with an HIV-1 stock. This may indicate that, although rabbit cells have partially acquired susceptibility to HIV-1 by transfection of human CD4 gene, rabbit cells may further require such a molecule as might be provided by MOLT-4 to become fully susceptible to HIV-1 infection. The possibility of the rabbit as a model for HIV-1 infection is also discusse

High-K Precession modes: Axially symmetric limit of wobbling motion

The rotational band built on the high-K multi-quasiparticle state can be interpreted as a multi-phonon band of the precession mode, which represents the precessional rotation about the axis perpendicular to the direction of the intrinsic angular momentum. By using the axially symmetric limit of the random-phase-approximation (RPA) formalism developed for the nuclear wobbling motion, we study the properties of the precession modes in $^{178}$W; the excitation energies, B(E2) and B(M1) values. We show that the excitations of such a specific type of rotation can be well described by the RPA formalism, which gives a new insight to understand the wobbling motion in the triaxial superdeformed nuclei from a microscopic view point.Comment: 14 pages, 8 figures (Spelling of the authors name was wrong at the first upload, so it is corrected

Construction of a genetic AND gate under a new standard for assembly of genetic parts

<p>Abstract</p> <p>Background</p> <p>Appropriate regulation of respective gene expressions is a bottleneck for the realization of artificial biological systems inside living cells. The modification of several promoter sequences is required to achieve appropriate regulation of the systems. However, a time-consuming process is required for the insertion of an operator, a binding site of a protein for gene expression, to the gene regulatory region of a plasmid. Thus, a standardized method for integrating operator sequences to the regulatory region of a plasmid is required.</p> <p>Results</p> <p>We developed a standardized method for integrating operator sequences to the regulatory region of a plasmid and constructed a synthetic promoter that functions as a genetic AND gate. By standardizing the regulatory region of a plasmid and the operator parts, we established a platform for modular assembly of the operator parts. Moreover, by assembling two different operator parts on the regulatory region, we constructed a regulatory device with an AND gate function.</p> <p>Conclusions</p> <p>We implemented a new standard to assemble operator parts for construction of functional genetic logic gates. The logic gates at the molecular scale have important implications for reprogramming cellular behavior.</p

シンキン バイヨウ ケンサ ニオケル カンジダ ノ ケンシュツ ニ エイキョウ スル リンショウテキ ヨウイン ノ ケントウ : コウクウ カンソウ ノ カンレン ニツイテ

In order to analyze the clinical factors affecting the fungal culture test, we examined the oral mucosae of 89 individuals with various complaints: pain, xerostomia etc. The subjects, age ranged from 36 to 87 years (mean age: 64.8 ± 11.8). Based on the fungal culture, 56 patients were found Candida-positive, and the remaining 33 patients were Candida-negative. The mean ages of the Candida-positive and -negative groups, respectively, were 67.4 ± 12.0 and 60.5 ± 10.3 years old, with the Candida-positive group being significantly older than Candida-negative group. The Candida-positive group showed a smaller amount of salivary secretion (10.9 ± 5.3 ml/10 min) than the Candida-negative group (13.8 ± 6.0 ml/10 min); this difference was also statistically significant. Patients with Candida infection suffered from different diseases and conditions, including hypertension, gastrointestinal disease, and xerostomia. The above findings suggest that one of the factors in the fungal culture test is dry mouth. Specifically, old age, dry mouth, chronic disease or medication leading to dry mouth were the clinical factors affecting the fungal culture test. However, neither the Candida species detected in the fungal culture nor the clinical appearance of the oral mucosa influenced these clinical features