Prediction of flow induced sound generated by cross flow past finite length circular cylinders.

The paper presents aeroacoustic results for the flow around finite-length circular cylinders at Reynolds number 84 770 for various length-to-diameter (L/D) ratios (= 3, 9, 20, 25, 30, and 35). The incompressible Navier-Stokes equations are solved using the large eddy simulation model of turbulence followed by acoustic predictions in the far field using Ffwocs Williams and Hawkings method. The comparisons of numerical and anechoic wind tunnel measurements show good agreement in terms of the aerodynamic forces and acoustic parameters such as tonal frequency, tonal sound pressure level, and overall sound pressure level. The cylinder L/D ratio was observed to be a significant parameter that controls vortex shedding and consequently the flow induced sound generation.

Smarter-lighter-greener: research innovations for the automotive sector.

This paper reviews the changing nature of research underpinning the revolution in the automotive sector. Legislation controlling vehicle emissions has brought urgency to research, so we are now noticing a more rapid development of new technologies than at any time in the past century. The light-weighting of structures, the refinement of advanced propulsion systems, the advent of new smart materials, and greater in-vehicle intelligence and connectivity with transport infrastructure all require a fundamental rethink of established technologies used for many decades-defining a range of new multi-disciplinary research challenges. While meeting escalating emission penalties, cars must also fulfil the human desire for speed, reliability, beauty, refinement and elegance, qualities that mark out the truly great automobile.

Isolation and identification of a gallotannin 1,2,6-tri-O-galloyl-ß-D-glucopyranose from hydroalcoholic extract of Terminalia chebula fruits effective against multidrug-resistant uropathogens.

AIMS: In this study, an attempt has been made to isolate and identify the bioactive compounds from hydroalcoholic extract of Terminalia chebula fruits effective against multidrug-resistant uropathogens and also to elucidate the influence of metal ions on the growth inhibitory activity of isolated compounds against the studied bacteria, if any. METHODS AND RESULTS: Bioassay-guided fractionation and extensive spectrometric analyses (FT-IR, (1) H NMR, (13) C NMR and ESI-MS) were used to isolate and characterize the bioactive compound. Growth inhibitory activities of isolated compound were studied by agar well diffusion and microbroth dilution assay methods. Checkerboard titration method was used for combination study between antibiotics and isolated compound. Influence of metal ions on growth inhibitory activity of this bioactive compound against the test isolates were also studied by INT [P-iodonitrotetrazolium violet; 2-(4-iodophenyl)-3-(4-nitrophenyl)-5-phenyltetrazolium chloride] colorimetric assay. The isolated bioactive compound 1, 2, 6-tri-O-galloyl-ß-D-glucopyranose was found to be responsible for antibacterial activity against multidrug-resistant uropathogens and showed synergy with trimethoprim and gentamicin. This antibacterial activity of bioactive compound was counteracted by the supplementation of iron in the medium. CONCLUSION: Terminalia chebula fruit extract contains bioactive compound effective against multidrug-resistant uropathogens, and this antibacterial activity may be due to its iron-complexing property. SIGNIFICANCE AND IMPACT OF THE STUDY: To the best of our knowledge, the antibacterial activity exhibited by isolated gallotannin against multidrug-resistant uropathogens is first time reported by us. Besides, these promising findings may lead to the development of antimicrobial agents from T. chebula fruits for the treatment of urinary tract infections caused by these pathogens.

Receiving sensitivity and transmitting voltage response of a fluid loaded spherical piezoelectric transducer with an elastic coating.

A method is presented to determine the response of a spherical acoustic transducer that consists of a fluid-filled piezoelectric sphere with an elastic coating embedded in infinite fluid to electrical and plane-wave acoustic excitations. The exact spherically symmetric, linear, differential, governing equations are used for the interior and exterior fluids, and elastic and piezoelectric materials. Under acoustic excitation and open circuit boundary condition, the equation governing the piezoelectric sphere is homogeneous and the solution is expressed in terms of Bessel functions. Under electrical excitation, the equation governing the piezoelectric sphere is inhomogeneous and the complementary solution is expressed in terms of Bessel functions and the particular integral is expressed in terms of a power series. Numerical results are presented to illustrate the effect of dimensions of the piezoelectric sphere, fluid loading, elastic coating and internal material losses on the open-circuit receiving sensitivity and transmitting voltage response of the transducer.

The prevalence of nocturia and its effect on health-related quality of life and sleep in a community sample in the USA.

OBJECTIVE: To evaluate the prevalence of nocturia and its effects, with and without concomitant overactive bladder (OAB, i.e. urgency, frequency, urge incontinence and nocturia), on health-related quality of life (HRQoL) and sleep. SUBJECTS AND METHODS: A national survey was conducted in the USA to assess the prevalence of OAB and nocturia. A nested case-control study was conducted among respondents with OAB symptoms and age- and gender-matched controls, with participants completing a series of questionnaires on HRQoL (OAB-q, Short Form-36, and Medical Outcomes Study (MOS) sleep scale). Descriptive analyses, t-tests, analysis of variance with post hoc comparisons and multivariate regressions were used to analyse the data. RESULTS: In all, 5204 people participated in the survey, with 919 in the nested case-control study. The sample population had a mean age of 45.8 years, was 52.6% female and 80% Caucasian. In the community sample, 31% reported > 1 void/night and 14.2% reported > 2 voids/night. The prevalence of nocturia increased with age, with no gender differences. For OAB cases, 66.8% reported > 1 void/night and 42.2% reported > 2. In the case-control cohort there were significant HRQoL differences (P < 0.01), with increasing episodes of nocturia in all OAB-q subscales except social interaction. The amount of sleep per night was significantly correlated with the sleep, concern and social interaction OABq subscale scores. The number of nocturia episodes/night was also significantly (P = 0.02) associated with the number of hours of sleep/night. CONCLUSION: Nocturia is widely prevalent and increases with age, affecting men and women equally. Incremental increases in the number of voids/night have further negative effects on sleep, symptom bother, and HRQoL.

Transient fluid-structure interaction of elongated bodies by finite-element method using elliptical and spheroidal absorbing boundaries.

In a domain method of solution of exterior scalar wave equation, the radiation condition needs to be imposed on a truncation boundary of the modeling domain. The Bayliss, Gunzberger, and Turkel (BGT) boundary dampers, which require a circular cylindrical and spherical truncation boundaries in two-(2D) and three-(3D)-dimensional problems, respectively, have been particularly successful in the analysis of scattering and radiation problems. However, for an elongated body, elliptical (2D) or spheroidal (3D) truncation boundaries have potential to reduce the size of modeling domain and hence computational effort. For harmonic problems, such extensions of the first- and second-order BGT dampers are available in the literature. In this paper, BGT dampers in both elliptical and spheroidal coordinate systems have been developed for transient problems involving acoustic radiation as well as fluid-structure interaction and implemented in the context of finite-element method based upon unsymmetric pressure-displacement formulation. Applications to elongated radiators and shells are reported using several numerical examples with excellent comparisons. It is demonstrated that significant computational economy can be achieved for elongated bodies with the use of these dampers.

An epidemiological survey of carcinoma cervix in north Bengal zone.

Correlation between various epidemiological factors and carcinoma cervix patients in North Bengal zone has been studied for the first time. Significant correlation between elderly women (41-50 years age group), low socio-economic status (SES), first coitus before 17 years of age, low literacy rate and this illness has been established. Suggestion has been made for improvement of the picture. Oncology and radiotherapy department of North Bengal Medical College and Hospital should be utilised as the centre for National Cancer Registration Project in North Bengal zone.

PIP: This paper presents the findings of an epidemiological survey aimed at detecting and recognizing women at high risk for cervical carcinoma with special reference to social habits, economic background, and educational standard in sub-Himalayan region, West Bengal, India. Analyses revealed that cervical carcinoma forms the largest group (73%) of all malignancies affecting the female reproductive organs. Significant correlations between cervical carcinoma and being 41-50 years old, being of low socioeconomic status, having had the first coitus before age 17, and having low literacy have been established. The authors suggest that the oncology and radiotherapy departments of North Bengal Medical College and Hospital be utilized as the center for the National Cancer Registration Project in North Bengal.

Medical costs of managed care in patients with type 2 diabetes mellitus.

The main objective of this study was to analyze the principal treatment cost drivers in patients with type 2 diabetes mellitus in a managed care setting. The study used retrospective integrated (linked) medical and pharmacy claims data for the calendar year 1995. The data were obtained from, and in cooperation with, the Hawaii Medical Service Association, Honolulu, Hawaii. The medical claims data included paid claims for services and procedures for diabetes and commonly associated comorbidities. Claims and associated costs for pharmacotherapy administered to the patient population were recorded in the pharmacy data. Patients aged > or =65 years were excluded because Medicare claims were unavailable for the type 2 diabetic population. The sample used in this study included 5171 patients. An ordinary least squares regression model was employed to identify principal cost drivers among the identified cohort to the managed care system. Independent variables in the analysis consisted of the presence or absence of a number of commonly observed comorbidities associated with diabetes mellitus (hypertension, hyperlipidemia, cardiovascular diseases, congestive heart failure, renal disorders, retinopathy, neurologic disorders, and any cardiac or noncardiac comorbidity combinations), pharmacologic therapy variables (insulin, oral medication, or both), a number of significant events (hospitalization, dialysis, hemoglobin A1c testing, and eye examination), patient enrollment category (fee-for-service vs a capitated system), and patient age and sex. The dependent variable was the natural logarithm of total medical costs of treatment for diabetes and commonly observed comorbidities. Results showed that among comorbidity variables, the 3 largest treatment cost drivers for patients with type 2 diabetes were the presence of neurologic disorders, renal disorders, and any comorbidity combination (cardiac or noncardiac or both), in decreasing order of significance. Similarly, higher costs of treatment were associated with episodes of hospitalization, use of antidiabetic medication, dialysis services, and hemoglobin A1c testing. Whether the patient was being treated under a capitated provider payment system or a fee-for-service system did not have any significant impact on the medical costs of diabetes-related treatment. Age was positively associated with these costs, indicating that older patients were more likely to incur higher costs to the system. The overall explanatory power of the model was 40%. In summary, unless diabetes is properly managed and glucose levels monitored, some component of an integrated health system (hospital vs pharmacy) necessarily bears financial risk. An understanding of the underlying cost distribution for a chronic disease could help in targeting interventions, integrating disease-management services, and managing the formal structure of the health plan being considered.

Predicting hospitalisation of patients with diabetes mellitus. An application of the Bayesian discriminant analysis.

The objective of this study was to develop, and subsequently test, a Bayesian discrimination model for the purpose of identifying both the personal and the healthcare system characteristics predictive of hospitalisation for the treatment of patients with diabetes mellitus or commonly observed cormorbidities associated with the disease. First, a Bayesian classification framework was proposed. The model was then tested by using a logit regression technique in order to estimate the probability of one or more hospitalisation events among patients with diabetes. The study used claims data extracted from the Hawaii Medical Service Association (HMSA) Private Business Claims (PBS) files for the 1995 calendar year. Patients under 65 years were identified by paid claims with ICD-9-CM diagnosis codes of 250.xx which gave a sample size of 6841 patients. Age, gender, various pharmacotherapy variables, presence of hypertension, hyperlipidaemia, congestive heart failure, multiple cardiovascular diseases, any combination of commonly observed comorbidities, dialysis services and annual eye examination are highly predictive of 1 or more hospitalisation events. The model shows a predictive power of almost 90%. This study found that multivariate discriminant analysis using a logit regression model successfully identifies: (i) important explanatory variables predictive of hospitalisation; (ii) assigns patients into 1 of 2 mutually exclusive classes; and (iii) offers a benchmark for a comprehensive disease management strategy for patients with more complicated diabetes.

Monitoring patients with diabetes mellitus: an application of the probit model using managed care claims data.

The primary objective of this study was to estimate the likelihood of the use of either a glycosylated hemoglobin (HbA1c) test or an eye examination, or both, among a cohort of patients diagnosed with diabetes mellitus. A secondary objective was to provide a step-by-step discussion of the applicability of an econometric model to managed care organizations. The study used medical and pharmacy claims data from a managed care organization for the calendar year 1995. A probit regression model was specified to estimate the probability of occurrence for either an HbA1c test or an eye examination among patients with insulin-dependent, non-insulin dependent, or atypical/unclassified diabetes. Data were available only for patients under 65 years of age due to data truncation for patients covered by Medicare, resulting in a study sample size of 6,841. Results indicate that age, presence of hypertension, hyperlipidemia, multiple cardiovascular comorbidities, ophthalmic disease, and combinations of multiple commonly observed comorbidities were positively correlated with the probability of either HbA1c testing or eye examination. Gender and the type of benefit plan were not statistically significant as predictors of disease monitoring. A total of 1,860 patients with diabetes mellitus were predicted by the model to have undergone one of the two monitoring procedures; but in actuality, these patients were not monitored in 1995. They could be considered as high-risk patients who were not getting recommended monitoring. The probit model shows a predictive power of 64.48%.

Treatment costs, equilibrium, and the allocation of patients to therapy alternatives.

This paper addresses the problem of increasing costs (or decreasing returns) in the treatment of patients within health care systems. We examine the implications of such a situation for (1) the allocation of patients to alternative drug therapies within a disease area; and (2) the proportions of patients being treated within the disease area to the total patient population as a function of the equilibrium conditions for maximized health care outcomes, given alternative assumptions about the existence of budget constraints on the resources allocated to the disease area. The reason for considering these issues (in this case, from a purely theoretical perspective) is that such a model and the assumptions that drive it stand in marked contrast to those underlying (implicitly if not explicitly) the traditional approach to cost-effectiveness modeling. In traditional cost-effectiveness analysis, the assumption is that costs and outcomes exhibit constant returns to scale and that the process of patient selection and the characteristics of the treating population need not be taken into account. However, our analysis demonstrates that once the assumption of constant returns in abandoned, any assessment of the net impact of therapeutic interventions can be made only within an equilibrium, or comparative static, framework that is subject to budget constraints and in which the cost functions that drive patterns of switching between therapies are specified. Under such conditions, the traditional, clinical-trial-based notion of cost-effectiveness loses all meaning.

A genetic study among the Lepchas of the Darjeeling area of eastern India.

A total of 215 Lepchas (75 Buddhists and 140 Christians) living in the Kalimpong subdivision, Darjeeling district, West Bengal, India, were investigated for the distribution of haemoglobin, serum proteins and red cell enzymes. The gene frequencies were as follows: HbE = 0.02; Hp1 = 0.18; TfB = 0.007; TfDChi = 0.005; Gc2 = 0.22; pa = 0.18; pc = 0.03; PGM2(1) = 0.18; PGM6(1) = 0.002; PGDc = 0.17; AK2 = 0.02; GLO1 = 0.21. The most striking features were the complete lack of G6PD deficiency and very high frequency of PGDC. The remaining loci (serum albumin, lactate dehydrogenase, malate dehydrogenase and glucose-6-phosphate dehydrogenase, phosphohexose isomerase and superoxide dismutase) were monomorphic. The gene frequencies were similar in the Buddhist and Christian Lepchas. The observed average heterozygosity (9 loci) was 0.20 in the entire sample.

Kaolin powder as a fungal carrier.

Kaolin powder may be used to carry and preserve an Aspergillus sp. for at least 90 days without contamination and with retention of its activity in softening and upgrading barky jute.