University of Selangor

About: University of Selangor is a education organization based out in Shah Alam, Malaysia. It is known for research contribution in the topics: Government & Rhodococcus. The organization has 423 authors who have published 457 publications receiving 4931 citations. The organization is also known as: UNISEL.

Determining Sample Size for Research Activities

Abstract: Sample size determination is often an important step and decision that educational and organizational researchers are facing. The quality and precision of research is being influenced by inadequate, excessive or inappropriate sample sizes. Selecting the sample size for a study requires compromise between balancing the need for statistical power, economy and timeliness. There is a temptation for the researchers to take some short cuts. The paper describes the importance and procedure of determining sample size for continuous and categorical variables using Cochran’s (1977) formula. The paper illustrates the usage of sample sizes formula, including the formula for adjusting for Cochran’s (1977) correction when the sample size exceeds 5% of the population. Tables are included to help researchers in determining the sample size for a research problem based on any three alpha levels and a set of standard error rate for categorical and continuous data. Procedures for determining the appropriate sample size for multiple regression, factor analysis and structural equation modeling are discussed. Common issues in sample size determination are examined. Non-respondent sampling issues are also addressed.

Biogenic phosphorus compounds in sediment and suspended particles in a shallow eutrophic lake: a ³¹P-nuclear magnetic resonance (³¹P NMR) study.

Abstract: Differences in biogenic phosphorus (P) compounds between sediment and suspended particles in aquatic environments are important for understanding the mechanisms of internal P loading, but these differences are still unknown. We used solution-state (31)P-nuclear magnetic resonance spectroscopy ((31)P NMR) with NaOH-ethylenediaminetetraacetic extraction to detect the multiple P compounds in suspended particles and sediment in the eutrophic Lake Kasumigaura, including orthophosphate monoesters, orthophosphate diesters, pyrophosphate, and polyphosphate. We tested the hypothesis that there is a significant difference between these groups in suspended particles and sediment. Biogenic P other than orthophosphate was found in significantly higher proportions in suspended particles (74.3% of total P) than in sediment (25.6%). Orthophosphate monoesters were comparatively more abundant in suspended particles, as indicated by the ratio of orthophosphate diesters to monoesters (average, 0.31 for suspended particles; 1.05 for sediment). The compounds identified as orthophosphate monoesters by (31)P NMR spectroscopy originated mainly from phospholipids (α-glycerophosphate and β-glycerophosphate) and ribonucleic acid (RNA-P), whereas the orthophosphate diesters included mostly DNA (DNA-P). These results suggest that the dynamics of orthophosphate diesters, the production of DNA-P, or the degradation of phospholipids, play an important role in P cycling in Lake Kasumigaura.

Particulate matter (PM 2.5 ) as a potential SARS-CoV-2 carrier.

Abstract: The rapid spread of the SARS-CoV-2 in the COVID-19 pandemic had raised questions on the route of transmission of this disease. Initial understanding was that transmission originated from respiratory droplets from an infected host to a susceptible host. However, indirect contact transmission of viable virus by fomites and through aerosols has also been suggested. Herein, we report the involvement of fine indoor air particulates with a diameter of ≤ 2.5 µm (PM2.5) as the virus's transport agent. PM2.5 was collected over four weeks during 48-h measurement intervals in four separate hospital wards containing different infected clusters in a teaching hospital in Kuala Lumpur, Malaysia. Our results indicated the highest SARS-CoV-2 RNA on PM2.5 in the ward with number of occupants. We suggest a link between the virus-laden PM2.5 and the ward's design. Patients' symptoms and numbers influence the number of airborne SARS-CoV-2 RNA with PM2.5 in an enclosed environment.