Representing settlement for soft ground tunneling

Thesis (M.S.)--Massachusetts Institute of Technology, Dept. of Civil and Environmental Engineering, 1995.Includes bibliographical references (leaves 120-122).by Takahiro Aoyagi.M.S

Interaction between compressible fluid and sound in a flue instrument

In order to study the generation of (aerodynamic) sound in flue instruments, we numerically apply Howe’s energy corollary for a 2D model of flue instrument. Howe’s energy corollary enables us to estimate the energy transfer between fluid flow and acoustic field. To implement it, separating the acoustic field from the fluid flow is needed. However the complete method to numerically achieve it has not been established yet. In this work, we develop an approximate method, which has been recently proposed in their experimental studies by Yoshikawa et al (2012 J. Sound Vib. 331 2558-2577) and others, and we apply it to the simulation of the model instrument. We first calculate fluid flow and acoustic oscillation simultaneously by a compressible fluid solver. Next referring to the information on the acoustic oscillation obtained we set up a pressure source on an acoustic solver and reproduce almost the same acoustic oscillation with it. Combining those results, we are able to calculate Howe’s energy corollary. The numerical result shows that the aerodynamic sound is generated from the oscillating jet rather than the vortices shed by the collision of it with the edge of the mouth opening, namely vortex shedding

Assessment of Growth Disturbance in Japanese Children with IBD

In Japan, there is as yet no report on growth retardation in children with IBD. We therefore investigated the cause of growth retardation in Japanese children with IBD. We investigated the height, body weight, serum levels of albumin, IGF-I, CRP, and cytokines, and the amount of corticosteroid administered in children with Crohn's disease (CD, n = 15) and ulcerative colitis (UC, n = 18). Our results suggest that growth retardation is already present before the initial visit in children with CD, and chronic inflammation may be responsible this growth disturbance. Moreover, the amount of PSL used may contribute to growth retardation by decreasing the serum levels of IGF-I in children with IBD

Numerical Study on Acoustic Oscillations of 2D and 3D Flue Organ Pipe Like Instruments with Compressible LES

Acoustic oscillations of flue instruments are investigated numerically using compressible Large Eddy Simulation (LES). Investigating 2D and 3D models of flue instruments, we reproduce acoustic oscillations excited in the resonators as well as an important characteristic feature of flue instruments – the relation between the acoustic frequency and the jet velocity described by the semi-empirical theory developed by Cremer & Ising, Coltman and Fletcher et al. based on experimental results. Both 2D and 3D models exhibit almost the same oscillation frequency for a given jet velocity, but the acoustic oscillation as well as the jet motion is more stable in the 3D model than in the 2D model, due to less stability in 3D fluid of the rolled up eddies created by the collision of the jet with the edge, which largely disturb the jet motion and acoustic field in the 2D model. We also investigate the ratio of the amplitude of the acoustic flow through the mouth opening to the jet velocity, comparing with the experimental results and semi-empirical theory given by Hirschberg et al.

Association of serum gamma-glutamyltransferase (GGT) and diabetes with triglycerides-to-HDL cholesterol ratio in Japanese subjects: The Nagasaki Study

Background: Although we reported in a previous study that diabetes with a high serum triglycerides to high-density lipoproteincholesterol (TG-HDL) ratio constitutes a risk for atherosclerosis, associations in terms of TG-HDL ratio between diabetes and gamma-glutamyltransferase (GGT), which is also known as an independent risk factor for atherosclerosis, have not yet been clarified. The purpose of this study was to test the hypothesis that a positive association between GGT and diabetes may be confined to high TG-HDL. Methods: This was a cross-sectional study of 2,302 Japanese subjects who were undergoing a general health check in 2014. All subjects were divided into TG-HDL level tertiles and serum GGT and diabetes status were investigated. Results: Of 207 diabetes patients identified in this study, 94 had high TG-HDL, 63 intermediate TG-HDL, and 50 low TG-HDL. Independent of classical cardiovascular risk factors, serum GGT showed a positive association with diabetes in patients with high TG-HDL, but not in patients with intermediate and low TG-HDL diabetes. The multivariable adjusted odds ratios (OR) and 95% coincidence intervals (95%CI) of diabetes for 1 standard deviation (SD) increment of GGT were 1.64 (95%CI: 1.16-2.31) for high TG-HDL, 1.46 (95%CI: 0.95-2.26) for intermediate TG-HDL, and 1.04 (95%CI: 0.60-1.79) for low TG-HDL diabetes. Conclusion: Serum GGT is positively associated with diabetes in patients with high TG-HDL but not with intermediate or low TG-HDL diabetes. This finding may prove to be an efficient tool for estimating atherosclerotic risk in diabetes patients

Association between white blood cell count and diabetes in relation to triglycerides-to-HDL cholesterol ratio in a Japanese population: The Nagasaki Islands study

Although our previous study found that diabetes combined with a high serum triglycerides to high-density lipoprotein cholesterol (TG-HDL) ratio constitutes a risk for atherosclerosis and chronic kidney disease (CKD), the association, in terms of TG-HDL ratio, between diabetes and white blood cell (WBC) count, which is an independent risk factor for atherosclerosis, has not been clarified. To investigate this association, we conducted a cross-sectional study of 3,998 Japanese subjects aged 30-89 years undergoing a general health check. We investigated the associations between WBC count and diabetes for all subjects, who were divided into tertiles according to TG-HDL level. Independent of classical cardiovascular risk factors, WBC count of both men and women was positively associated with diabetes combined with high but not with low TG-HDL. The multivariable odds ratios (ORs) and 95% confidence intervals (95%CIs) of 1SD (standard deviation) increment in WBC count (1,538/μL for men, 1,382/μL for women) for high TG-HDL diabetes and low TG-HDL diabetes were 1.39 (95%CI: 1.04-1.85) and 0.88 (95%CI: 0.66-1.19) for men, and 1.83 (95%CI: 1.45-2.33) and 0.91 (95%CI: 0.64-1.29) for women, respectively. In conclusion, for both men and women, WBC count is associated with high TG-HDL diabetes but not with low TG-HDL diabetes. These findings suggest that measuring WBC count is clinically relevant for estimating the risk of atherosclerosis and CKD in patients with diabetes categorized according to TG-HDL ratio

Association between Alkaline Phosphatase and Anemia in Rural Japanese Men: The Nagasaki Islands study

Although bone metabolism is reportedly associated with production and maturation of blood corpuscles, and serum alkaline phosphatase (ALP) levels have been associated with bone metabolism, no published study has investigated the association between ALP and anemia. Furthermore, although ALP is known as an enzyme affected by alcohol consumption, there are no reports in the literature on associations between ALP and the risk of anemia in relation to drinking status. We conducted a cross-sectional study of 907 men aged 30-89 years undergoing a general health check-up to investigate the associations between ALP and anemia in relation to drinking status. Of the 907 participants, 120 men were diagnosed with anemia. The association between ALP and anemia was J-shaped. With the second quartile of ALP (194-228 IU/L) (Q2) as the reference group, the multivariable adjusted OR and 95%CI for anemia were 1.91 (95%CI: 0.96-3.82) for 277 IU/L (Q4). When the analysis was limited to non-drinkers, the associations became stronger with corresponding values of 3.34 (95%CI: 1.28-8.74), 3.18 (95%CI: 1.28-7.88) and 3.22 (95%CI:1.37-7.59). Not only lower but also higher levels of serum ALP are associated with anemia for men, especially non-drinkers. For analyses of associations between ALP and anemia, alcohol consumption should thus be considered a potential confounder

Body mass index and triglyceride-to-HDL-cholesterol ratio in relation to risk of diabetes: The Nagasaki Islands study

Body mass index (BMI) is well known as an independent risk factor for insulin resistance. In addition, lower BMI and lower insulin levels are recognized as specific characteristics of Asian diabetes patients. Since the triglyceride-to-HDL-cholesterol ratio (TG-HDL) is positively associated with insulin level, but inversely associated with insulin sensitivity, we supposed that diabetes combined with high but not with low TG-HDL might be positively associated with BMI. We therefore conducted a cross-sectional study of 2,431 Japanese subjects (905 men and 1,526 women) aged 30-79 years, who underwent a general health check, to investigate associations between BMI, diabetes and its subtypes that we defined on the basis of TG-HDL levels, which in turn were categorized according to sex-specific tertiles. Among the 172 diabetic patients identified in the study group, 45 showed low TG-HDL and 82 high TG-HDL. We found a significant inverse association between low-TG-HDL diabetes and BMI, and a significant positive association between high-TG-HDL diabetes and BMI. The multivariable-adjusted odds ratio and 95%CI for a 1SD increment in BMI (3.03 kg/m2 for men and 3.44 kg/m2 for women) for low-TG-HDL diabetes was 0.53 (95%CI: 0.36-0.77) and 1.57 (95%CI: 1.24-2.01) for high-TG-HDL diabetes. These findings demonstrated that for Japanese subjects associations between diabetes and BMI are strongly influenced by the TG-HDL status. Since a previous study of ours found that diabetes combined with high TG-HDL ratios constitutes a risk for atherosclerosis, these findings may serve as an effective tool for estimating risk of atherosclerosis for diabetes patients