Volume 7 No. 2March 2012
pp 26-44 (Vol 7 No. 2 2012)
Marie Paz E. Morales
Department of Physical Sciences, College of Science, Philippine Normal University
This study is focused on the development and validation of a concept test in Introductory Physics for Biology students as a diagnostic tool, a misconception test, a formative assessment tool, and a summative test. Its final form is a 50-item multiple-choice concept test in Introductory Physics for Biology 1st term (Mechanics, Fluids & Heat) students wherein each item has four choices. One among the choices serves as the correct answer while the rest are considered distracters. It was originally developed as a 67-item multiple-choice concept test in Introductory Physics for Biology students covering all the topics specified in the syllabus of the course offered at the Philippine Normal University. Classical test item analysis and validation were conducted to establish test validity while item reliability was tested using Cronbach’s Alpha, which was 0.67, and K-R 21, which was 0.70. Analysis of the distracters was done to determine the Physics misconceptions that can be diagnosed by the instrument. The misconception diagnostic capability of the test is a feature, which can be of help to Physics teachers for better concept understanding of students.
MALDI-TOF MASS SPECTROMETRY AND ANALYTICAL PROFILING INDEX CHARACTERIZATION OF AIRBORNE STAPHYLOCOCCI
pp 19-25 (Vol 7 No. 2 2012)
Oscar Torres 1 *, Esperanza Cabrera 2, Edgar Vallar 3, Clarisse Yeung 1, Bryan Montalban 4, Jaran Jainhuknan 5, and Amornmart Jaratrungtawee 5
1 Chemistry Department,
2 Biology Department, and
3 Physics Department De La Salle University, Manila,Philippines, 1004;
4 Dynalab Corporation, San Juan, Philippines, 1502;
5 Bruker BioSpin AG, Bangkok, Thailand, 10400
Indoor air quality is often measured in terms of nonviable contaminants. In the Philippines, the viable components of air have not received as much attention as the nonviable counterparts. Among the viable components of indoor air are airborne bacteria, which are potential health hazards. In this initial study, airborne bacteria present in an indoor cafeteria were characterized. Bacterial isolates from indoor air were analyzed using Matrix-Assisted Laser Desorption Ionization Time-of-Flight Mass Spectrometer (MALDI-TOF MS). Mass spectral analyses of the 64 environmental isolates revealed high proportions of Staphylococcus spp., Bacillus spp., Micrococcus spp., and Lactobacillus spp. Among the Staphylococcus species identified by MALDI-TOF MS were that of S. epidermidis, S. haemolyticus, S. hominis, S. saprophyticus and S. lentus. We further investigated the metabolism profiles of Staphylococcus genus using Analytical Profiling Index (API). Notably, MALDI-TOF MS and API provided similar identification of the Staphylococcus spp. isolates. To the best of our knowledge, this is the first report of MALDI-TOF MS airborne bacterial identification in the Philippines.