Tightly-Secure Key-Encapsulation Mechanism in the Quantum Random Oracle Model

Key-encapsulation mechanisms secure against chosen ciphertext attacks (IND-CCA-secure KEMs) in the quantum random oracle model have been proposed by Boneh, Dagdelen, Fischlin, Lehmann, Schafner, and Zhandry (CRYPTO 2012), Targhi and Unruh (TCC 2016-B), and Hofheinz, Hövelmanns, and Kiltz (TCC 2017). However, all are non-tight and, in particular, security levels of the schemes obtained by these constructions are less than half of original security levels of their building blocks. In this paper, we give a conversion that tightly converts a weakly secure public-key encryption scheme into an IND-CCA-secure KEM in the quantum random oracle model. More precisely, we define a new security notion for deterministic public key encryption (DPKE) called the disjoint simulatability, and we propose a way to convert a disjoint simulatable DPKE scheme into an IND-CCA-secure key-encapsulation mechanism scheme without incurring a significant security degradation. In addition, we give DPKE schemes whose disjoint simulatability is tightly reduced to post-quantum assumptions. As a result, we obtain IND-CCA-secure KEMs tightly reduced to various post-quantum assumptions in the quantum random oracle model

Clinical and laboratory predictors for plaque erosion in patients with acute coronary syndromes

Background-—Plaque erosion is responsible for 25% to 40% of patients with acute coronary syndromes (ACS). Recent studies suggest that anti-thrombotic therapy without stenting may be an option for this subset of patients. Currently, however, an invasive procedure is required to make a diagnosis of plaque erosion. The aim of this study was to identify clinical or laboratory predictors of plaque erosion in patients with ACS to enable a diagnosis of erosion without additional invasive procedures. Methods and Results-—Patients with ACS who underwent optical coherence tomography imaging were selected from 11 institutions in 6 countries. The patients were classified into plaque rupture, plaque erosion, or calcified plaque, and predictors were identified using multivariable logistic modeling. Among 1241 patients with ACS, 477 (38.4%) patients were found to have plaque erosion. Plaque erosion was more frequent in non–ST-segment elevation-ACS than in ST-segment–elevation myocardial infarction (47.9% versus 29.8%, P=0.0002). Multivariable logistic regression models showed 5 independent parameters associated with plaque erosion: age 15.0 g/dL, and normal renal function. When all 5 parameters are present in a patient with non–ST-segment elevation-ACS, the probability of plaque erosion increased to 73.1%. Conclusions-—Clinical and laboratory parameters associatedwith plaque erosion are explored in this retrospective registry study. These parametersmay be useful to identify the subset ofACS patients with plaque erosion and guide themto conservativemanagement without invasive procedures. The results of this exploratory analysis need to be confirmed in large scale prospective clinical studiesDr. Jang has received an educational grant from Abbott Vascular and Medicure. Dr. Adriaenssens has received grants and consulting fees from Abbott Vascula

Safety and efficacy of the supreme biodegradable polymer sirolimus-eluting stent in patients with diabetes mellitus

Patients with diabetes mellitus (DM) have worse outcomes following percutaneous coronary intervention than nondiabetic patients. The novel Supreme DES is a biodegradable polymer sirolimus-eluting stent designed to synchronize early drug delivery, limiting the potential for long-term inflammatory response. The purpose of this study was to evaluate the safety and efficacy of the Supreme DES in patients with DM. Methods This is a prespecified analysis of the diabetic subgroup from the PIONEER III randomized (2:1), controlled trial, comparing the Supreme DES with a durable polymer everolimus-eluting stent (DP-EES). The primary safety and efficacy composite endpoint was target lesion failure at 1 year, a composite of cardiac death, target vessel myocardial infarction, or clinically driven target lesion revascularization. Results The PIONEER III trial randomized 1629 patients, of which 494 (30.3%) had DM with 331 (398 lesions) randomly assigned to Supreme DES and 163 (208 lesions) to DP-EES. Among patients with DM, target lesion failure at 1 year was 6.1% (20/331) with Supreme DES vs 3.7% (6/163) with DP-EES (hazard ratio = 1.65; 95% confidence interval = 0.66-4.10, P = .28). The composite of cardiac death or target vessel myocardial infarction was 3.3% (11/331) with Supreme DES and 3.7% (6/163) with DP-EES (hazard ratio = 0.90; 95% confidence interval = 0.33-2.44, P = .83). There were no significant differences in other secondary endpoints. Conclusions This prespecified substudy of the PIONEER III trial demonstrated the relative safety and efficacy of the novel Supreme DES when compared with commercially available DP-EES in diabetics at 1 year. Longer term follow-up will be required to ensure continued safety and efficacy of the Supreme DES

A Study on International Tourist Receipts and National Economic Growth in the World

本論文は、今日世界的な重要性が指摘されるようになった観光(tourism)について、国際観光収入(tourist receipts)と観光客受け入れ国の経済成長との関係を考察することを目的とする。本論文において対象とした1987年から1996年の期間において、世界各国における観光収入の伸び率とGDPの伸び率には密接な関係があると言え、また、これらは国際収支統計上のサービス・所得収入を介して形成される。本論文ではこれら3者の関係について分析する。 さらに、本論文では新たな視点から観光収入を対象とした推定を試みる。観光推計モデルに関する既往研究は、需要側の側面からのアプローチが主流であり、時系列タイプのモデルに基づくものが多い。本論文では、供給側、すなわち観光客の受け入れ国における経済的特性を示す諸指標を用いて、供給型およびグラビティ・モデルのアナロジーに基づいて観光収入の推定を行う。推定結果は、為替レートが観光収入の減少要因として大きな規定力をもち、次いで航空輸送が増加要因として抽出された。The aim of this paper is to consider relationships between international tourist receipts and economic growth of countries as tourism destination. In the period of 1987 to 1996, we can point out close relationships between the growth of tourist receipts and the growth of GDP in many countries. Tourist receipts and GDP are formed through credit of services & income in balance of payments. Therefore, in this paper we focus on these three elements. Moreover, we attempt to estimate tourist receipts in another point of view. In preceding literatures of estimating models for tourism, mainly the aspects of demand were emphasized, and many of them belong to the type of time series. In this paper, we estimate tourist receipts from the aspects of supply side by using data of economical characteristics in tourist destinations. We attempt to construct a model by analogy with a gravity type of model as the base. The estimation work clarifies that the exchange rate strongly prescribes a factor to diminish tourist receipts, and aviation service is extracted as an increasing element

Sustainable Tourism Development and its Comparative analyses among Developing Countries

本稿は、持続可能な観光開発(Sustainable Tourism Development)への提言の前段として、観光の概念と実態を考察することを目的とするものである。持続可能な観光とは、開発と保全という軸でとらえた場合、保全がなされることを前提とした観光を意味し、選択的観光(Selective Tourism)と持続可能なマス観光(Mass Tourism)に大きく分類できる。持続可能な観光の開発へ向けてどのような施策が必要であるのかを検討するために、発展途上国36カ国における国別のデータを用いて、観光の実態を分析する。分析にあたっては、マクロ指標として面積および1人当たりGDPをとりあげ、各国の状況を比較・考察する。さらに、観光に関して需要、供給、収入、収支、開発、保全6つの側面からの指標を用い、上段のマクロ指標との関係からみた観光の実態を考察する。とりわけ、規模の小さい国では外貨獲得の手段としての観光が果たす役割は大きいと考えられ、それらの国々を中心にその実態について検討する。The aim of this paper is to examine the concept and its state of the art towards sustainable tourism development, which is a tourism under the condition of natural & cultural preservation and can be classified roughly into selective tourism and sustainable mass tourism. This paper clarifies what kind of policies will be required to promote sustainable tourism through the analyses of quantitative data of tourism and development in thirty-six developing countries. Moreover, six indices representing each aspect of demand, supply, income, income & expenditure, development level and preservation level are adopted and the real state of tourism development is examined by the correlation analyses between these six indices and macro indices related with country scale. Particularly, the tourism has an important role to acquire foreign currency in small countries and actual state of tourism development in these countries is examined carefully

Clinical Usefulness of FRAX Score for Predicting Sarcopenia in Patients with Chronic Liver Disease

We investigated the usefulness of the Fracture Risk Assessment tool (FRAX) for predicting sarcopenia in chronic liver disease (CLD). In this cross-sectional study, we evaluated 321 patients with CLD. The FRAX with and without bone mineral density (BMD) was employed to calculate the 10-year risks of major osteoporotic and hip fractures. The FRAX score for high fracture risk was defined as a 10-year major osteoporotic fracture probability of ≥20% or a 10-year hip fracture probability of ≥3%. The diagnosis of sarcopenia was based on the Japan Society of Hepatology criteria. According to the FRAX, with and without BMD, 134 (41.7%) and 193 (60.1%) patients had a high fracture risk, respectively. The high fracture risk group had a significantly higher frequency of sarcopenia than the non-high fracture risk group. FRAX scores of major osteoporotic and hip fractures were negatively correlated with handgrip strength and muscle mass. Using the FRAX with BMD, the cutoff scores of major osteoporotic and hip fractures for predicting sarcopenia were 8.55% (sensitivity/specificity, 0.847/0.568) and 3.35% (0.729/0.746), respectively. Using the FRAX without BMD, they were 18.5% (0.635/0.725) and 7.65% (0.729/0.758), respectively. The FRAX is a simple and convenient screening tool for predicting sarcopenia in patients with CLD