Large-Eddy Simulation of Axisymmetric Compression Corner Flow

The Wall-Modeled Large Eddy Simulation (WMLES) approach is used to study the interaction of a shock wave with a high Reynolds number turbulent boundary layer. Since the near wall region is modeled, high Reynolds number turbulent flows can be simulated at a moderate computational cost. The case considered is that of an axisymmetric Mach 2.85 turbulent boundary layer over a 30 compression corner. The Reynolds number of the boundary layer upstream of the interaction based on momentum thickness (Re theta = u sub infinity theta/v sub infinity) is ~12,000. The geometry and flow conditions match the experiments of Dunagan et al. (NASA TM 88227, 1986). The simulations were performed using equilibrium and non-equilibrium wall models. The agreement with experiment is encouraging for the finest grid with respect to the separation bubble length, unsteady shock structure and wall pressure distribution. Sensitivity ofWMLES results to grid, wall model, and blockage effects in the tunnel are reported

Temporal trends in hepatitis B and C infection in family blood donors from interior Sindh, Pakistan

<p>Abstract</p> <p>Background</p> <p>Hepatitis B (HBV) and C (HCV) infections are a serious global and national public health problem. Earlier studies have reported increasing rates of hepatitis infection in Pakistan, particularly in rural areas. Pakistan has no active surveillance program to monitor trends of these infections. The objective of this study was to verify this trend in blood donors from the rural Sindh area of the country.</p> <p>Methods</p> <p>The study analysed the data of blood donors of interior Sindh who donated blood at JPMC blood bank from January 1, 2004 to September 15, 2007. HBsAg status was determined by using HBsAg Serodia kit and antibodies to HCV using the Detect HCV ™ V.3 Kit. Samples repeatedly reactive for HBsAg or anti-HCV were considered positive for HBV or HCV infection respectively.</p> <p>Results</p> <p>The overall seroprevalence of HBV infection among donors was 6.2 % (95% CI 5.5%–6.9%) and did not change significantly over the study period. Overall seroprevalence of HBV infection in literate blood donors was 5.7 %(95% CI 4.7%–6.8%). Prevalence decreased significantly in this group over the study period (p = 0.05). No other significant trends in seroprevalence of HBV infection were seen in the stratified analyses.</p> <p>The overall seroprevalence of HCV among donors was 7.5% (95% CI 6.8%–8.3%) and increased significantly over the study period from 7.2% (95% CI 5.8%–8.7%) in 2004 to 8.9% (95% CI 7.4%–10.6%) in 2007 (p = 0.02). Significant increase in seroprevalence was particularly seen in literate (p = 0.03), non–first time (p = 0.01) and Sindhi speaking (p = 0.01) donors.</p> <p>Conclusion</p> <p>Our study finds a steady increase in the prevalence of HCV infection in blood donors from interior Sindh between 2004 and 2007. On the contrary, decreasing prevalence of HBV was found, particularly in literate blood donors. There may be a need to have rural community-based epidemiological studies to identify the determinants of the spread of HCV infection and also those that are limiting the spread of HBV infection particularly in the literate blood donor population.</p

Sensitivity analysis of hydrodynamic stability operators

The eigenvalue sensitivity for hydrodynamic stability operators is investigated. Classical matrix perturbation techniques as well as the concept of epsilon-pseudoeigenvalues are applied to show that parts of the spectrum are highly sensitive to small perturbations. Applications are drawn from incompressible plane Couette, trailing line vortex flow and compressible Blasius boundary layer flow. Parametric studies indicate a monotonically increasing effect of the Reynolds number on the sensitivity. The phenomenon of eigenvalue sensitivity is due to the non-normality of the operators and their discrete matrix analogs and may be associated with large transient growth of the corresponding initial value problem

Patients\u27 perceptions of blood transfusion risks in Karachi, Pakistan

Objective: To evaluate the understanding of and attitudes toward risks of blood transfusions among transfusion recipients in Karachi.Methods: One hundred forty-one transfusion recipients from 13 major Karachi hospitals were interviewed. Indications for transfusion were obtained by reviewing the patients\u27 medical records.Results: The most common indications for transfusion were surgical complications (n = 77, 55%), anemia (n = 34, 24%), and generalized weakness (n = 15, 11%). Most recipients (n = 103, 80%) had never heard of viral hepatitis, and 44 (31%) had never heard of acquired immunodeficiency syndrome (AIDS). Ninety-four recipients (66%) believed that generalized weakness was a valid indication for blood transfusion. Sixty-nine recipients (49%) were not willing to pay an increased price for blood that was screened for blood-borne pathogens.CONCLUSIONS: Blood recipients in Karachi are unaware of the risks of transfusions, and the reasons given by the ordering physician for many of the transfusions were not consistent with international guidelines. Steps to educate the public about the risks of transfusions and practitioners about the indications for transfusion could prevent blood-borne virus transmission in Karachi

Development of Quality Standards of Aegle marmelos L. Leaves

Aegle marmelos L (Rutaceae) is a moderately size deciduous tree, growing wild throughout the deciduous forest of India. It is commonly used in day to day life. In present investigation an attempt has been made for the pharmacognostical standardization and evaluation of Aegle marmelos leaves. The pharmacognostical evaluation comprises of detailed macroscopy, powdered microscopy, fluorescence analysis, quantitative microscopy and physical constants such as ash and extractive values. The leaves extracts were subjected to preliminary phytochemical screening. The data obtained in present study will serve as valuable tool for identification, authentication and detection of adulterants, standardization and quality control of the drug. The developed technique will also be useful for the standardization of formulations containing A. marmelos.ÂÂ

Molecular analysis of genetic diversity in elite II synthetic hexaploid wheat screened against Barley yellow dwarf virus

The presence of sufficient genetic diversity in the germplam is an important prerequisite for the improve-ment and efficient use of available material. Traditionally, the data on agronomic, morphological and physiological plants traits are used to estimate the genetic diversity. But now molecular markers are available for authenticated and reliable studies for genetic diversity. The present study was conducted to assess the genetic diversity of Elite-II synthetic hexaploid (SH) wheat by genome DNA fingerprinting as revealed by random amplified polymorphic DNA (RAPD) analysis. Ten decamer RAPD primers (OPG-1, OPG-2, OPG-3, OPG-4, OPG-5, OPA-3, OPA-4, OPA-5, OPA-8, and OPA-15) were used to evaluate the diversity profile of the selected SH entries. Primers OPG-2 andOPA-4 gave the highly polymorphic results. The pair wise similarity values shows that genotypes 1, 20 and 30 have most closest relationship with highest similarity values i.e., 100% while genotypes 9and 13 show dictinct relationship with minimum similarity value that is, 54%. Therefore, the allelic variation of the SH resistance germplasm is a potent means to enrich and improve bread wheat cultivars where BYDV is a production threat and these can be used in future wheat breeding programme

An electroplating-based plasmonic platform for giant emission enhancement in monolayer semiconductors

Two dimensional semiconductors have attracted considerable attention owing to their exceptional electronic and optical characteristics. However, their practical application has been hindered by the limited light absorption resulting from their atomically thin thickness and low quantum yield. A highly effective approach to manipulate optical properties and address these limitations is integrating subwavelength plasmonic nanostructures with these monolayers. In this study, we employed electron beam lithography and electroplating technique to fabricate a gold nanodisc (AuND) array capable of enhancing the photoluminescence (PL) of monolayer MoS$_2$ giantly. Monolayer MoS$_2$ placed on the top of the AuND array yields up to 150-fold PL enhancement compared to that on a gold film. We explain our experimental findings based on electromagnetic simulations

Rifampicin-monoresistant Mycobacterium tuberculosis among the patients visiting chest clinic, state specialist hospital, Akure, Nigeria

Background:Tuberculosis (TB), one of the most important contagious diseases, is a leading cause of death due to a single pathogen worldwide. Co-infection of people living with HIV with M. tuberculosis has been shown to increase the mortality rate in sub-Saharan Africa.Methods:This present study was carried out to establish the rifampicin resistant profiles among the patients attending chest clinic, state specialist hospital, Akure. We enrolled clinical samples submitted between January 2013 and December 2013 for this study. The sputum samples were analyzed using GeneXpert.Results:Of the 135 sputum processed by GeneXpert, 48 (35.6%) contained Mycobacteria tuberculosis (MTB) and 9 (18.8%) were rifampicin resistant Mycobacteria tuberculosis. Patients within the age group of 24-32 years showed the highest resistant to RIF 6 (12.5%).Conclusion:This study has helped to establish that there is presence of rifampicin resistant Mycobacterium tuberculosis in Akure, Ondo state, Nigeria and most of them were observed among patients who default treatment. This is considered as a threat to TB control programme in Akure, Nigeria and it is recommended that strategies should be put in place in order to ensure patients’ compliance and monitoring of patients’ response to TB treatment.