Hybrid mesh for nasal airflow studies

The accuracy of the numerical result is closely related to mesh density as well as its distribution. Mesh plays a very significant role in the outcome of numerical simulation. Many nasal airflow studies have employed unstructured mesh and more recently hybrid mesh scheme has been utilized considering the complexity of anatomical architecture. The objective of this study is to compare the results of hybrid mesh with unstructured mesh and study its effect on the flow parameters inside the nasal cavity. A three-dimensional nasal cavity model is reconstructed based on computed tomographic images of a healthy Malaysian adult nose. Navier-Stokes equation for steady airflow is solved numerically to examine inspiratory nasal flow. The pressure drop obtained using the unstructured computational grid is about 22.6 Pa for a flow rate of 20 L/min, whereas the hybrid mesh resulted in 17.8 Pa for the same flow rate. The maximum velocity obtained at the nasal valve using unstructured grid is 4.18 m/s and that with hybrid mesh is around 4.76 m/s. Hybrid mesh reported lower grid convergence index (GCI) than the unstructured mesh. Significant differences between unstructured mesh and hybrid mesh are determined highlighting the usefulness of hybrid mesh for nasal airflow studies

Comparison of estimators efficiency for linear regressions with joint presence of autocorrelation and multicollinearity

This paper proposes a new estimator called Two stage K-L estimator by combining these two estimators previously proposed by Prais Winsten (1958) and Kibra with Lukman (2020) for autocorrelation and multicollinearity respectively and to derived the necessary and sufficient condition for its superiority over other competing estimators. Simulation study was used to ascertain the dominance of this new estimator using the finite sample properties of estimators in terms of the estimated mean squared error. The study findings shows that under severe autocorrelation and collinearity condition, the proposed Two stage K-L estimator appears to be having a similar performance with RMLE and MLE. Also, under severe autocorrelation and moderate collinearity condition, regardless of the sample size, the proposed Two stage K-L estimator is seen to outperform all other estimators and lastly, the Two stage K-L estimator appears to have an improved performance as the large sample sizes. The study recommends that when autocorrelation and multicollinearity level is at moderate to severe, the proposed Two stage K-L estimator will perform better regardless of the size of the data, and the degree of autocorrelation and multicollinearity should be considered while estimating parameters and thus applying an efficient estimator to avoid erroneous inferences

The long reign of the United States is over; the 21st century belongs to China

United States has been the global leader since overtaking Britain in 1871. Recently economists are anticipating China could be the global leader by 2019 as US is on the edge of losing its status of largest economy in the world.  This paper focuses on the current situation of these two emperors to identify whether China could overtake US economy—an outstanding controversial issue. Keywords: global economic power, US economy, China econom

Pre-clinical development of human apurinic/apyrimidinic endonuclease (APE1) inhibitors for cancer therapy

Modulation of DNA base excision repair (BER) has the potential to enhance response to chemotherapy and improve outcomes in tumours such as melanoma, glioma and pancreatic cancer. APE1, a critical protein in BER that processes potentially cytotoxic abasic sites (AP sites), is a promising new target in cancer. In the current study, my aim was to develop small molecule inhibitors of APE1 for cancer therapy. An industry-standard high throughput virtual screening strategy was adopted. The SYBYL8.0 (Tripos, St Louis, MO, USA) molecular modelling software suite was used to build inhibitor templates. Similarity searching strategies were then applied using ROCS 2.3 (Open Eye Scientific, Santa Fe, NM, USA) to extract pharmacophorically related subsets of compounds from a chemically diverse database of 2.6 million compounds. The compounds in these subsets were subjected to docking against the active site of the APE1 model, using the genetic algorithm-based programme GOLD2.7 (CCDC, Cambridge, UK). Predicted ligand poses were ranked on the basis of several scoring functions. The top virtual hits with promising pharmaceutical properties underwent detailed in vitro analyses using fluorescence-based APE1 AP-site cleavage assays and counter screened using endonuclease IV AP-site cleavage assays, fluorescence quenching assays and Whole cell extract AP-site cleavage assays. Biochemical APE1 inhibitors were then subjected to detailed cytotoxicity analyses. Several specific APE1 inhibitors were isolated by this approach. The IC50 for APE1 inhibition ranged between 50 nM and 25 µM. I also demonstrated that APE1 inhibitors lead to accumulation of AP sites in genomic DNA and potentiated the cytotoxicity of alkylating agents in melanoma, glioma and pancreatic cancer cell lines. I have also shown that APE1 inhibitors induce delay in cell cycle progression and caused delay in cancer cell growth. I also demonstrated that APE1 knockdown by shRNA results in decrease cancer cell growth and enhanced cell killing by alkylating agent in Glioma cell line. This PhD project provides evidence that APE1 is an emerging drug target and could have therapeutic application in patients with melanoma, glioma and pancreatic cancer

Study of the influence of normal and high blood pressure on normal and stenosed carotid bifurcation using fluid-structure interaction

Atherosclerosis (stenosis) is a common cardiovascular disease in which the blood vessel restructures by narrowing, thickening and gets hardened due to the deposition of plaque. A detailed study of narrowing of arteries applying computational aspects which leads to better findings in order to know the underlying mechanics of development and progression of such diseases. Such kind of analysis can be a useful tool for the medical professionals to study the realistic physiological conditions. They can simulate and observe the blood flow in arteries. In the present study, a case of normal and stenosed carotid bifurcation is simulated. The models are generated in CATIA based on the clinical data obtained from a patient using Ultrasound Doppler. A transient FSI analysis considering Newtonian behavior is performed to compare the significance of High Blood Pressure (HBP) and Normal Blood Pressure (NBP) on carotid bifurcation. The FSI simulation is carried out for both HBP and NBP conditions for several pulse cycles on normal and stenosed models using ANSYS13.0 to demonstrate the changes in flow behavior at various sections of the model. The computed results agree well with clinical observations and available literature as seen in case of NBP

Review: A critical overview of limitations CFD Modeling in nasal airflow.

Computational fluid dynamics (CFD) modeling of nasal airflow has been carried out by several researchers. Virtual surgical treatment and aerosol deposition studies have also been conducted. However, the appropriateness of such modeling practices with regards to modeling and medical constraints needs careful consideration. The current numerical models for the study of nasal airflow, developed from the scanned images obtained from computed tomography or magnetic resonance imaging, are influenced by postural changes. These models neglect the mucous layer, other vital anatomical features, and nasal cycle effects, CFD studies make numerous assumptions that seriously limit their usefulness. Unless these constraints can be addressed, the interpretation of results from a CFD output cannot be considered as an appropriate definition of the flow behavior. This review provides a critical overview of the limit actions of the CFD mode ling of nasal air-low. Some of the limitations and constraints associated with CFD modeling are reviewed and possible studies that could be carried out in the future to ascertain the effect of neglecting these parameters are discussed. This study also proposes a standard station of the computational modeling procedure, which is necessary for studying airflow inside the nasal cavity

Microfinance in Nigeria and the prospects of introducing its Islamic version there in the light of selected Muslim countries' experience

Today widespread poverty is one of the major problems of mankind and its alleviation one of her major agendas. In recent years microfinance has emerged as an important instrument to relieve poverty in the developing countries. Today there are more than 7000 micro lending institutions providing loans to more than 25 million poor individuals across the world, their vast majority being the women. However these institutions face some serious challenges, especially in less developed countries where the proportion of people in poverty is high. The existing microfinance in Nigeria serves less than 1 million people out of 40 million being the potential number that need the service. Also, the aggregate micro credit facilities in Nigeria, account for about 0.2 percent of the GDP and is less than one percent of total credit in the economy. Addressing this situation inadequately would further accentuate the problem and slow down growth and development of the country. We find that the microfinance institutions charge interest rate as high as up to 100% for lending and pay as low as 5% on savings. This aggravates the existing inequalities in the distribution of wealth and income in Nigeria. Finally, Nigeria being a country with a Muslims majority, represents a potential for Islamic microfinance especially that most Muslims reject the conventional interest based micro financing, which is not tailored in line with their faith. This might cause failure of government project to combat poverty in the country through micro financing. Under the circumstance Islamic micro financing has potential to serve the country better. The paper has relied on the sources of Shari`ah law, secondary data from journals, periodicals, conference proceedings, text book , internet search and other sources of published data to support the argument

Teacher Education, Teacher Preparation and Professional Development of Secondary Schoolteachers in Light of Recent Global Trends

The purpose of this study is to present a brief overview of the nature of teacher education and preparation programs, and the professional development of secondary schoolteachers in the Arab world, and to offer insights into recent global trends in the matter.By examining some of the relevant literature and scholarly work, this study’s main objective is to provide a comprehensive picture of the teacher-program-related policies offered by education colleges/institutions in the region in the light of global trends. To achieve this, the researchers surveyed most of the existing related studies conducted in the region. This was pursued through analysis of evidence, methodologies, underlying ideologies, and indicators of examined literature. Similarly, an analysis of publications relating to recent global trends was undertaken.Results suggest that a comprehensive “five-year” teacher programs is ideal to be integrated into higher education in the Arab world due to its feasibility, affordability as well as lower financial costs. It was found that that the components of existing teacher programs must be subject to evaluation and review for further development. However, the results indicate not only that the strategy of candidate admission and enrollment in colleges are not based on appropriate criteria, but also that a clear policy for teaching licensure is ignored.The study emphasizes the need to establish fully equipped teacher training centers. To attain this, we strongly suggest selecting or creating well-equipped and administratively affiliated schools to the colleges to provide an experimental environment for candidates to practice what they have learned. Achieving a balance between different course packages should be considered