Neutron Irradiation Effects of Iron Alloys and Ceramics

Positron annihilation angular correlation measurements have been performed for the neutron irradiated various metals and ceramics in order to obtain the information of the microvoids and positronium formation in them. Positronium (Ps) formation was observed in Nb containing a small amount of oxygen and Fe-15%Cr-16%Ni-0.006%B^. In practical steels such as JPCA and JFMS no Ps formation was observed. High temperature deformation might induce microvoids into metals, but the positron annihilation angular correlation measurements could not confirm this. In non-metallic materials neutron irradiated no Ps formation has so far been observed

Análisis de sensibilidad en modelos de equilibrio general aplicado: una evaluación alternativa para el análisis de políticas

O artigo tem como objetivo realizar a análise de sensibilidade das variaveis exógenas e dos parâmetros de um modelo aplicado de equilibrio geral com extensão regional adaptado para a economia chilena. A análise realizou-se com base nos resultados obtidos de uma simulação que diminui o imposto sobre valor agregado em 1%. O resultado da análise de sensibilidade mostra como os resultados podem ser afetados pela variação dos valores dos parâmetros e das variaveis exógenas do modelo. A análise de sensibilidade também ajuda a indentificar possiveis problemas na qualidade dos dados utilizados como parâmetros no modelo

A Lightweight Transmission Parameter Selection Scheme Using Reinforcement Learning for LoRaWAN

The number of IoT devices is predicted to reach 125 billion by 2023. The growth of IoT devices will intensify the collisions between devices, degrading communication performance. Selecting appropriate transmission parameters, such as channel and spreading factor (SF), can effectively reduce the collisions between long-range (LoRa) devices. However, most of the schemes proposed in the current literature are not easy to implement on an IoT device with limited computational complexity and memory. To solve this issue, we propose a lightweight transmission-parameter selection scheme, i.e., a joint channel and SF selection scheme using reinforcement learning for low-power wide area networking (LoRaWAN). In the proposed scheme, appropriate transmission parameters can be selected by simple four arithmetic operations using only Acknowledge (ACK) information. Additionally, we theoretically analyze the computational complexity and memory requirement of our proposed scheme, which verified that our proposed scheme could select transmission parameters with extremely low computational complexity and memory requirement. Moreover, a large number of experiments were implemented on the LoRa devices in the real world to evaluate the effectiveness of our proposed scheme. The experimental results demonstrate the following main phenomena. (1) Compared to other lightweight transmission-parameter selection schemes, collisions between LoRa devices can be efficiently avoided by our proposed scheme in LoRaWAN irrespective of changes in the available channels. (2) The frame success rate (FSR) can be improved by selecting access channels and using SFs as opposed to only selecting access channels. (3) Since interference exists between adjacent channels, FSR and fairness can be improved by increasing the interval of adjacent available channels.Comment: 14 pages, 12 figures, 8 tables. This work has been submitted to the IEEE for possible publication. Copyright may be transferred without notice, after which this version may no longer be accessibl

Identification of Myocardial Damage in Systemic Sclerosis: A Nuclear Cardiology Approach

Myocardial involvement is an important prognostic factor in patients with systemic sclerosis, and early diagnosis and staging of the disease have been sought after. Since myocardial damage is characterized by connective tissue disease, including fibrosis and diffuse vascular lesions or microcirculation, nuclear myocardial perfusion imaging has been a promising option for evaluating myocardial damages in early stages. In addition to the conventional stress-rest perfusion imaging, the current use of quantitative electrocardiographic gated imaging has contributed to more precise evaluation of cardiac perfusion, ventricular wall motion, and diastolic function, all of which have enhanced diagnostic ability of evaluating myocardial dysfunction. Abnormal sympathetic imaging with Iodine-123 metaiodobenzylguanidine might be another option for identifying myocardial damage. This paper deals with approaches from nuclear cardiology to detect perfusion and functional abnormality as an early sign of myocardial involvement as well as possible prognostic values in patients with abnormal imaging results. The role of nuclear cardiology in the era of multiple imaging modalities is discussed

On the Existence of Minimal Sufficient Subfield

1 online resource (PDF, 16 pages

Eisenhart Lift of 22--Dimensional Mechanics

The Eisenhart lift is a variant of geometrization of classical mechanics with $d$ degrees of freedom in which the equations of motion are embedded into the geodesic equations of a Brinkmann-type metric defined on $(d+2)$-dimensional spacetime of Lorentzian signature. In this work, the Eisenhart lift of $2$-dimensional mechanics on curved background is studied. The corresponding $4$-dimensional metric is governed by two scalar functions which are just the conformal factor and the potential of the original dynamical system. We derive a conformal symmetry and a corresponding quadratic integral, associated with the Eisenhart lift. The energy--momentum tensor is constructed which, along with the metric, provides a solution to the Einstein equations. Uplifts of $2$-dimensional superintegrable models are discussed with a particular emphasis on the issue of hidden symmetries. It is shown that for the $2$-dimensional Darboux--Koenigs metrics, only type I can result in Eisenhart lifts which satisfy the weak energy condition. However, some physically viable metrics with hidden symmetries are presented.Comment: 20 page

Okun's law: evidence for the Brazilian economy

In this article we seek to estimate the Brazilian “Okun’s law” with quarterly data ranging from 1980Q1 until 2013Q3. Considering the typical Okun's relationship, Δu=α-βg_y, where β is the Okun coefficient, we have obtained estimates of β between -0.1878 and -0.2055, such values are in general lower than the values obtained to other countries in similar studies

CD21/35欠損マウスの作成と解析

金沢大学附属病院マウスCD21/35遺伝子のシグナルシークエンスを置換するためのターゲッティングベクターを作成し、エレクトロポレーションによりES細胞に遺伝子導入を行い、組み換え体の解析、キメラの作成を経てCD21/35欠損マウスを作成した。CD21/35に対する特異抗体を用いて、CD21/35の発現が全くみられないことを確認した。CD21/35欠損マウスには外観上大きな異常はみられず、B細胞の分化も正常であった。骨髄、末梢血、脾臓、パイエルパッチ、リンパ節、腹水などのB細胞の分化や活性化には異常がみられなかった。血清中のIgM、IgG1、IgG2b、IgG3は野性型に比べて有意に低下していた。注目すべきことに、T細胞依存性またはT細胞非依存性の低容量の抗原に対する抗体反応が有意に低下しており、特にIgG3で顕著であった。このため、細菌などに対する特異抗体反応も障害されている可能性を考え、肺炎連鎖球菌を感染させて抗体産生や生存率を検討した。CD21/35欠損マウスは、肺炎連鎖球菌の感染に対して非常に弱く、生存率の低いことが明らかになった。この理由としては、肺炎連鎖球菌に対するIgG3型の抗体産生の著しい低下が要因と考えられた。このように、CD21/35欠損マウスではT細胞依存性または非依存性の抗原や細菌抗原に対する抗体反応が低下していることが明らかになった。細菌感染などにおける早期の免疫応答にCD21/35が大変重要であることが明らかになった。研究課題/領域番号:15790572, 研究期間(年度):2003 – 2004出典：「CD21/35欠損マウスの作成と解析」研究成果報告書　課題番号15790572（KAKEN：科学研究費助成事業データベース（国立情報学研究所））（https://kaken.nii.ac.jp/ja/grant/KAKENHI-PROJECT-15790572/)を加工して作