Piston-driven numerical wave tank based on WENO solver of well-balanced shallow water equations

A numerical wave tank equipped with a piston type wave-maker is presented for long-duration simulations of long waves in shallow water. Both wave maker and tank are modelled using the nonlinear shallow water equations, with motions of the numerical piston paddle accomplished via a linear mapping technique. Three approaches are used to increase computational efficiency and accuracy. First, the model satisfies the exact conservation property (C-property), a stepping stone towards properly balancing each term in the governing equation. Second, a high-order weighted essentially non-oscillatory (WENO) method is used to reduce accumulation of truncation error. Third, a cut-off algorithm is implemented to handle contaminated digits arising from round-off error. If not treated, such errors could prevent a numerical scheme from satisfying the exact C-property in long-duration simulations. Extensive numerical tests are performed to examine the well-balanced property, high order accuracy, and shock-capturing ability of the present scheme. Correct implementation of the wave paddle generator is verified by comparing numerical predictions against analytical solutions of sinusoidal, solitary, and cnoidal waves. In all cases, the model gives satisfactory results for small-amplitude, low frequency waves. Error analysis is used to investigate model limitations and derive a user criterion for long wave generation by the model

Karma, reincarnation, and medicine: Hindu perspectives on biomedical research

Prior to the completion of the Human Genome Project, bioethicists and other academics debated the impact of this new genetic information on medicine, health care, group identification, and peoples’ lives. A major issue is the potential for unintended and intended adverse consequences to groups and individuals. When conducting research in, for instance, American Indian and Alaskan native (AI/AN) populations, political, cultural, religious and historical issues must be considered. Among African Americans, the Tuskegee Syphilis Experiment is a reminder of racism and discrimination in this country. The goal of the current study is to understand reasons for participating, or not, in genetic research such as the HapMap project and other genetic/medical research from the perspective of the Indian American community in Houston, Texas. In this article, we report on a topic central to this discussion among Indian Americans: karma and reincarnation. Both concepts are important beliefs when considering the body and what should happen to it. Karma and reincarnation are also important considerations in participation in medical and genetic research because, according to karma, what is done to the body can affect future existences and the health of future descendants. Such views of genetic and medical research are culturally mediated. Spiritual beliefs about the body, tissue, and fluids and what happens to them when separated from the body can influence ideas about the utility and acceptability of genetic research and thereby affect the recruitment process. Within this community it is understood that genetic and environmental factors contribute to complex diseases such as diabetes, hypertension, and cancer; and acknowledgment of the significance of environmental stressors in the production of disease. A commitment to service, i.e. “betterment of humanity,” karmic beliefs, and targeting environmental stressors could be prominent avenues for public health campaigns in this population. This study suggests that minority status does not automatically indicate unwillingness to participate in genetic or medical research. Indian Americans were not skeptical about the potential benefits of biomedical research in comparison to other ethnic minority communities in the United States

Do Race and Gender Influence the Use of Invasive Procedures?

OBJECTIVE: To assess the influence of race and gender influence on the use of invasive procedures in patients with acute myocardial infarction (AMI) in community hospitals. DESIGN: Prospective, observational. SETTING: Five mid-Michigan community hospitals. PATIENTS: All patients (838) identified with AMI between January 1994 and April 1995 in 1 of these hospitals. MEASUREMENTS AND MAIN RESULTS: After adjusting for age, hospital of admission, insurance type, severity of AMI, and comorbidity, using white men as the reference group, the rate of being offered cardiac catheterization (CC) was 0.88 (95% confidence interval [95% CI], 0.60 to 1.29) for white women; 0.79 (95% CI, 0.41 to 1.50) for black men; and 1.14 (95% CI, 0.53 to 2.45)for black women. Among patients who underwent CC, after also adjusting for coronary artery anatomy, the rate of being offered angioplasty, using white men as the reference group, was 1.22 (95% CI, 0.75 to 1.98) for white women; 0.61 (5% CI, 0.29 to 1.28, P = .192) for black men; and 0.40 (95% CI, 0.14 to 1.13) for black women The adjusted rate of being offered bypass surgery was 0.47 (95% CI, 0.24 to 0.89) for white women; 0.36 (95% CI, 0.12 to 1.06) for black men; and 0.37 (95% CI, 0.11 to 1.28)for black women. CONCLUSIONS: Our study shows that white women are less likely than white men to be offered bypass surgery after AMI. Although black men and women with AMI are less likely than white men to be offered percutaneous transluminal coronary angioplasty or coronary artery bypass grafting in both unadjusted and adjusted analyses, these findings did not reach statistical significance. Our study is limited in power due to the small number of blacks in the sample

Racial/ethnic disparities among Asian Americans in inpatient acute myocardial infarction mortality in the United States

Abstract Background Acute myocardial infarction (AMI) is a common high-risk disease with inpatient mortality of 5% nationally. But little is known about this outcome among Asian Americans (Asians), a fast growing racial/ethnic minority in the country. The objectives of the study are to obtain near-national estimates of differences in AMI inpatient mortality between minorities (including Asians) and non-Hispanic Whites and identify comorbidities and sociodemographic characteristics associated with these differences. Method This is a retrospective analysis of 2010–2011 state inpatient discharge data from 10 states with the largest share of Asian population. We identified hospitalization with a primary diagnosis of AMI using the ICD-9 code and used self-reported race/ethnicity to identify White, Black, Hispanic, and Asian. We performed descriptive analysis of sociodemographic characteristics, medical comorbidities, type of AMI, and receipt of cardiac procedures. Next, we examined overall inpatient AMI mortality rate based on patients’ race/ethnicity. We also examined the types of AMI and a receipt of invasive cardiac procedures by race/ethnicity. Lastly, we used sequential multivariate logistic regression models to study inpatient mortality for each minority group compared to Whites, adjusting for covariates. Results Over 70% of the national Asian population resides in the 10 states. There were 496,472 hospitalizations with a primary diagnosis of AMI; 75% of all cases were Whites, 10% were Blacks, 12% were Hispanics, and 3% were Asians. Asians had a higher prevalence of cardiac comorbidities, including hypertension, diabetes, and kidney failure compared to Whites (p-value< 0.01). There were 158,623 STEMI (ST-elevation AMI), and the proportion of hospitalizations for STEMI was the highest for Asians (35.2% for Asians, 32.7% for Whites, 25.3% for Blacks, and 32.1% for Hispanics). Asians had the highest rates of inpatient AMI mortality: 7.2% for Asians, 6.3% for Whites, 5.4% for Blacks, and 5.9% for Hispanics (ANOVA p-value < 0.01). In adjusted analyses, Asians (OR = 1.11 [95% CI: 1.04–1.19]) and Hispanics (OR = 1.14 [1.09–1.19]) had a higher likelihood of inpatient mortality compared to Whites. Conclusions Asians had a higher risk-adjusted likelihood of inpatient AMI mortality compared to Whites. Further research is needed to identify the underlying reasons for this finding to improve AMI disparities for Asians