Node-Connectivity Terminal Backup, Separately-Capacitated Multiflow, and Discrete Convexity

The terminal backup problems (Anshelevich and Karagiozova (2011)) form a class of network design problems: Given an undirected graph with a requirement on terminals, the goal is to find a minimum cost subgraph satisfying the connectivity requirement. The node-connectivity terminal backup problem requires a terminal to connect other terminals with a number of node-disjoint paths. This problem is not known whether is NP-hard or tractable. Fukunaga (2016) gave a $4/3$-approximation algorithm based on LP-rounding scheme using a general LP-solver. In this paper, we develop a combinatorial algorithm for the relaxed LP to find a half-integral optimal solution in $O(m\log (nUA)\cdot \operatorname{MF}(kn,m+k^2n))$ time, where $n$ is the number of nodes, $m$ is the number of edges, $k$ is the number of terminals, $A$ is the maximum edge-cost, $U$ is the maximum edge-capacity, and $\operatorname{MF}(n',m')$ is the time complexity of a max-flow algorithm in a network with $n'$ nodes and $m'$ edges. The algorithm implies that the $4/3$-approximation algorithm for the node-connectivity terminal backup problem is also efficiently implemented. For the design of algorithm, we explore a connection between the node-connectivity terminal backup problem and a new type of a multiflow, called a separately-capacitated multiflow. We show a min-max theorem which extends Lov\'{a}sz-Cherkassky theorem to the node-capacity setting. Our results build on discrete convexity in the node-connectivity terminal backup problem.Comment: A preliminary version of this paper was appeared in the proceedings of the 47th International Colloquium on Automata, Languages and Programming (ICALP 2020

Left ventricular deformation and torsion assessed by speckle-tracking echocardiography in patients with mutated transthyretin-associated cardiac amyloidosis and the effect of diflunisal on myocardial function

AbstractBackgroundMutated transthyretin-associated (ATTRm) amyloidosis with heart failure is associated with decreased longitudinal left ventricular (LV) myocardial contraction, as measured by strain Doppler echocardiography. We sought to clarify whether speckle-tracking echocardiography (STE) would provide useful information in patients with ATTRm cardiac amyloidosis.MethodsOne hundred twenty-three consecutive patients with ATTRm amyloidosis were divided into 3 groups. Group 1 had no evidence of cardiac involvement (n=47), group 2 had heart involvement but no congestive heart failure (CHF) and/or serum brain natriuretic peptide (BNP) levels <100pg/mL (n=35), and group 3 had heart involvement and CHF and/or serum BNP levels ≥100pg/mL (n=41). All patients underwent standard 2-dimensional (2D), Doppler echo, and STE.ResultsBy standard 2D and Doppler echo, differences in parameters were only apparent between group 3 and groups 1 and 2. Global circumferential strains by STE at each LV level and LV torsion were different between group 1 and groups 2 and 3, but not between group 2 and group 3. In contrast, global longitudinal LV strain showed significant intergroup differences (−17.3±2.3%, −13.3±2.3%, −9.9±3.3% for groups 1 to 3, respectively, P<0.0001). Radial strain also showed significant intergroup differences for each basal LV segment. Among 41 patients who could have been followed up after 1year, 34 patients with diflunisal treatment had shown improvement in apical rotation and torsion without deterioration in multidirectional strains.ConclusionATTRm cardiac amyloidosis is characterized by progressive impairment in longitudinal and basal LV radial function when global circumferential shortening and torsion remain unchanged

Initial Experience of Percutaneous Extraction of Infected Cardiac Implantable Electric Devices Using Excimer Laser

Article信州医学雑誌 63(2):103-108 (2015)journal articl

The Traditional Japanese Medicine (Kampo) Boiogito has a Dual Benefit in Cardiorenal Syndrome: A Pilot Observational Study

Article信州医学雑誌 62(2):89-97(2014)journal articl

Importance of Fatty Acid Compositions in Patients with Peripheral Arterial Disease

Objective: Importance of fatty acid components and imbalances has emerged in coronary heart disease. In this study, we analyzed fatty acids and ankle-brachial index (ABI) in a Japanese cohort. Methods: Peripheral arterial disease (PAD) was diagnosed in 101 patients by ABI <= 0.90 and/or by angiography. Traditional cardiovascular risk factors and components of serum fatty acids were examined in all patients (mean age 73.2 +/- 0.9 years; 81 males), and compared with those in 373 age- and sex-matched control subjects with no evidence of PAD. Results: The presence of PAD (mean ABI: 0.71 +/- 0.02) was independently associated with low levels of gamma-linolenic acid (GLA) (OR: 0.90; 95% CI: 0.85-0.96; P = 0.002), eicosapentaenoic acid: arachidonic acid (EPA: AA) ratio (OR: 0.38; 95% CI: 0.17-0.86; P = 0.021), and estimated glomerular filtration rate (OR: 0.97; 95% CI: 0.96-0.98; P<0.0001), and with a high hemoglobin A1c level (OR: 1.34; 95% CI: 1.06-1.69; P = 0.013). Individuals with lower levels of GLA (<= 7.95 mu g/mL) and a lower EPA: AA ratio (<= 0.55) had the lowest ABI (0.96 +/- 0.02, N = 90), while the highest ABI (1.12 +/- 0.01, N = 78) was observed in individuals with higher values of both GLA and EPA: AA ratio (P<0.0001). Conclusion: A low level of GLA and a low EPA: AA ratio are independently associated with the presence of PAD. Specific fatty acid abnormalities and imbalances could lead to new strategies for risk stratification and prevention in PAD patients.ArticlePLOS ONE. 9(9):e107003 (2014)journal articl

Photoelastic Stress Analysis Error Quantification in Vasculature Models for Robot Feedback Control

Abstract-Real-time and accurate stress calculation in walls of vasculature is desired to provide catheter insertion robots of feedback control without changing the catheter stiffness and lumen. This feedback source has also applications in endovascular surgery simulation for human skills and medical tools evaluation. For that purpose we consider photoelastic effect, as birefringence produced by light retardation relates with the stress inside the photoelastic materials. In this research a polariscope was designed for urethane elastomer vasculature models, the photoelastic coefficient of urethane elastomer was measured, and the camera system was calibrated to quantify and reduce error of the measurement system. An average error of 3.6% was found for the pressure range of 70-189 mmHg inside the model of urethane elastomer, this enables to calculate accurately stress in vasculature models during Human Blood Pressure Simulation (HBPS). That way we will be able to compare in a closed loop stress produced by HBPS and by the catheter motion when manipulated by a robot. I. INTRODUCTION RAINING with simulators reduces risks of injury and costs during practice for minimally invasive surgery C. Tercero is with Nagoya University, Aiichi-ken Nagoya-shi Chikusa-ku Furo-cho 1, 464-8603 JAPAN (phone: +81-52-788-6013; fax: +81-52-788-6013; e-mail: [email protected]). S. Ikeda is with Nagoya University, Aiichi-ken Nagoya-shi Chikusa-ku Furo-cho 1, 464-8603 JAPAN (phone: +81-52-788-6013; fax: +81-52-788-6013; e-mail: ikeda @robo.mein.nagoya-u.ac.jp). In previous studies photoelastic effect was used with a catheter insertion robot to evaluate catheters In this research we will present a calibration method for the transmittance equation to measure the optical path length, a polariscope designed for our simulation purpose, the deduction of the photoelastic coefficient of urethane elastomer, and the normalization parameters calibration to calculate the principal component of stress in the vasculature model with an inner pressure range of 40-189mmHg. It is desirable to measure stress with an error below 5% for the HBPS range, to use it as reference for control loop illustrated in figure 2. Photoelastic Stress Analysis Error Quantification i

Dietary acrylamide intake and the risk of liver cancer: The japan public health center-based prospective study

Acrylamide has been studied for its carcinogenicity in experimental animals, causing tumors at several organ sites, and has been considered probably carcinogenic to humans as well. Given the small number of epidemiological studies that have been conducted, it is still uncertain whether the consumption of acrylamide is associated with liver cancer. Therefore, we investigated a study to determine the possible relationship between acrylamide intake and the risk of developing liver cancer in the Japanese population. A total of 85,305 participants, from the Japan Public Health Center-based Prospective Study, who provided a validated food-frequency questionnaire were enrolled between 1995 and 1998. During a median of 16.0 years follow-up, 744 new liver cancer cases were identified. Compared to the lowest tertile of acrylamide consumption (<4.8 μg/day), the multivariate hazard ratio (HR) for the highest tertile (≥7.6 μg/day) was 0.79 (95% confidence interval [CI] = 0.65-0.95) for liver cancer using multivariable model 1, adjusted for smoking status, body mass index (BMI), physical activity, medical history, and alcohol consumption; whereas the inverse relationship disappeared after additionally adjusting for coffee consumption in multivariable model 2 with HR of 1.08 (95% CI = 0.87-1.34) for the highest tertile. The effect of dietary acrylamide intake on the risk of liver cancer was not observed in the Japanese population.Zha, L.; Sobue, T.; Kitamura, T.; Kitamura, Y.; Ishihara, J.; Kotemori, A.; Liu, R.; Ikeda, S.; Sawada, N.; Iwasaki, M.; Tsugane, S.; JPHC Study Group, f.t. Dietary Acrylamide Intake and the Risk of Liver Cancer: The Japan Public Health Center-Based Prospective Study. Nutrients 2020, 12, 2503. https://doi.org/10.3390/nu1209250

Serum High-density Lipoprotein Cholesterol Level and Lifestyle Habits among Japanese Junior High School Students

Article信州医学雑誌 61(4):205-215(2013)journal articl

High concentrations of omega-3 fatty acids are associated with the development of atrial fibrillation in the Japanese population

The favorable effect of fish oils rich in n-3 polyunsaturated fatty acids (PUFAs) on the development of atrial fibrillation (AF) is controversial. The relationship between the serum concentrations of n-3 PUFAs and the incidence of AF is unclear; therefore, in the present study, we aimed to elucidate this relationship. We evaluated the serum concentrations of n-3 PUFAs in 110 patients with AF, 46 patients with ischemic heart disease (IHD) and no AF, and 36 healthy volunteers. Thirty-six patients had a history of IHD (IHD-AF group) and 74 did not (L-AF group). The eicosapentaenoic acid (EPA) levels in the L-AF group were higher than those in the IHD-AF and control groups (117 +/- A 64, 76 +/- A 30, and 68 +/- A 23 mu g/ml, respectively); the docosahexaenoic acid (DHA) levels showed the same pattern (170 +/- A 50, 127 +/- A 27, and 126 +/- A 35 mu g/ml, respectively). In both the L-AF and IHD-AF groups, the EPA levels in patients with persistent and permanent AF were higher than those in patients with paroxysmal AF (L-AF 131 +/- A 74 vs. 105 +/- A 51 mu g/ml; IHD-AF 82 +/- A 28 vs 70 +/- A 33 mu g/ml). Multivariate analysis showed that cases of AF were associated with higher levels of EPA but not DHA. In this Japanese population study, the EPA and DHA levels in patients with L-AF were higher than those in normal subjects. In particular, the EPA level was associated with the incidence of AF. These findings suggest that an excess of EPA might be a precipitating factor of AF.ArticleHEART AND VESSELS. 28(4):497-504 (2013)journal articl