Manila Journal of Science

ISSN 2243-9129
Peer-reviewed · Electronic and Open-access · Downloadable

ISSN 2243-9129

De La Salle University
2401 Taft Avenue, Manila 0922

Email:
[email protected]

EDITORIAL BOARD

EDITOR-IN-CHIEF

Dr. Esperanza C. Cabrera
College of Science
De La Salle University
Manila, Philippines

ASSOCIATE EDITORS

Dr. Emelina H. Mandia
College of Science
De La Salle University
Manila, Philippines

Dr. Rafael A. Espiritu
College of Science
De La Salle University
Manila, Philippines

Mr. Frumencio F. Co
College of Science
De La Salle University
Manila, Philippines

Dr. Conrado D. Ruiz, Jr.
College of Computer Studies
De La Salle University
Manila, Philippines

Universitat Ramon Llull
Barcelona, Spain

Dr. Allan Abraham B. Padama
Institute of Mathematical Sciences and Physics
University of the Philippines – Los Baños
Laguna, Philippines

Dr. Marilou G. Nicolas
College of Arts and Sciences
University of the Philippines – Manila
Manila, Philippines

Dr. Aleyla Escueta De Cadiz
College of Science and Mathematics
University of the Philippines – Mindanao
Davao, Philippines

Dr. Julieta Z. Dungca
School of Science and Technology
Centro Escolar University
Manila, Philippines

MANAGING EDITOR

Dr. Prane Mariel B. Ong
College of Science
De La Salle University
Manila, Philippines

ADVISORY BOARD

Dr. Rhodora V. Azanza 
University of the Philippines – Diliman
Quezon City, Philippines

Dr. Ramon S. Del Fierro
University of San Carlos
Cebu, Philippines

Dr. Victoria Espaldon
University of the Philippines – Los Banos
Laguna, Philippines

Prof. Hideaki Kasai 
Osaka University
Osaka Prefecture, Japan

Prof. Michio Murata 
Osaka University
Osaka Prefecture, Japan

Dr. Vernon R. Morris
Howard University
Washington, D.C., USA

Dr. John C. Wise 
Michigan State University
Michigan, USA

Dr. Kainam Thomas Wong 
Hong Kong Polytechnic
Hung Hom, Hong Kong

Dr. Mudjekeewis D. Santos 
Bureau of Fisheries and Aquatic Resources
Quezon City, Philippines

Dr. Raymond Girard R. Tan 
De La Salle University
Manila, Philippines

Dr. Windell A. Rivera 
University of the Philippines – Diliman
Quezon City, Philippines

Dr. Mamoru Sakaue
Osaka University
Osaka Prefecture, Japan

Scope and Aims

MJS publishes original researches in the fields of Biology, Chemistry, Mathematics, Statistics, Physics, Computer Science and Science Education. It evaluates submissions based on scientific rigor and soundness; and not on subjective indicators such as novelty or impact. A thorough presentation of the methodology and discussion of results is encouraged.

MJS does not have article processing fees or page charges, and all papers can be downloaded freely. It adopts a publication model wherein accepted papers are uploaded immediately. The journal has annual volumes with at least two issues per volume.

Latest Articles

This study quantitatively determined the concentration of toxic trace metals in hair and fingernails as bioindicators of occupational exposure among auto repairers of vehicles in workshops within Yola, Nigeria. Exposure was evaluated from the concentrations of toxic metals in the hair and fingernail samples using an atomic absorption spectrophotometer. This was carried out with regard to the years of practice and smoking habits of the occupationally exposed individuals examined. The concentration of metals in the hair samples of auto repairers who had practiced for ≤5, ≤10, ≤15, and 15–20 years followed the order cadmium (Cd) > lead (Pb) > chromium (Cr) > nickel (Ni) > arsenic (As), while the fingernail samples followed the order Pb > Cd > Cr > Ni > As. Mean concentrations of toxic metals in the hair samples of smokers were Cd = 0.55 ± 0.25 μg/g, Ni = 0.30 ± 0.06 μg/g, Pb = 0.69 ± 0.18 μg/g, As = 0.34 ± 0.11 μg/g, and Cr = 0.42 ± 0.17 μg/g, while the mean concentrations in nails were Cd = 0.49 ± 0.21 μg/g, Ni = 0.28 ± 0.20 μg/g, Pb = 0.48 ± 0.11 μg/g, As = 0.25 ± 0.13 μg/g, and Cr = 0.36 ± 0.02 μg/g. The mean metal concentrations obtained fall within the acceptable limits of regulatory guideline values. This study proved that hair and nails are viable bioindicators to monitor the heavy metal toxicity in the human body.

Medicinal plants have been of interest in discovering new xanthine oxidase inhibitors (XOIs) and α-glucosidase inhibitors (AGIs) in recent years. The aim of this study was to evaluate the XOI and AGI capacities of Jatropha curcas L. and Mimosa pudica L. from Itogon and Mankayan, Benguet. The methanol crude extracts (M), ethyl acetate fractions (E), and n-hexane fractions (H) of J. curcas (JM, JE, JH) and M. pudica (MM, ME, MH) were used. Thin-layer chromatography (TLC) direct bioautography detected the presence of XOIs in the fractions, and spectrophotometry evaluated the XOIs in the crude extracts and fractions. Samples were also subjected to an AGI assay. The fractions exhibited positive results, with yellow and white spots. MM (79.09 µg/ml and 74.35 µg/ml), ME (72.66 µg/ml and 69.90 µg/ml), and JE (82.03 µg/ml and 60.42 µg/ml) had the lowest XOI half-maximal inhibitory concentration (IC50). The positive control, allopurinol, had an IC50 of 8.68 µg/ml. M. pudica demonstrated better AGI than J. curcas. MH showed higher inhibition at 97.36 ± 1.23% and 98.33 ± 0.78%, for Itogon and Mankayan, respectively, than acarbose, at 92.58 ± 0.63%. Both plants may be used as sources of lead compounds beneficial for patients with gout, while M. pudica is a potential source of new antidiabetic compounds upon clinical trials. Further studies should be conducted to purify and identify the bioactive compounds.

In this study, Burkholderia cepacia was identified as the causal agent of sour skin disease of onion in the Philippines. The bacterium’s identity was validated by analyzing the DNA sequence of the 16S ribosomal RNA gene region. The Philippine isolate had 99.51% identity to B. cepacia (GenBank accession number: KF681774). B. cepacia caused sour skin symptoms in inoculated red and yellow onions. Repeated assays also revealed that scallions are susceptible to B. cepacia infection. Since B. cepacia was previously reported to infect bulb onions in the field and this study showed severe rotting once the disease developed during storage, efficient detection methods and integrated pest management strategies would be needed to reduce the source of inoculum in the field and mitigate disease development when onion bulbs are in storage.

Railways have been one of the most efficient modes of transportation. They enable economic progress by mobilizing people and goods. With this, the researchers designed a regional railway network using graph theory with weighted nodes. The weight of each node will be obtained using the grey correlation coefficient of the following variables: total population, distance, perceived passengers, annual income, and the number of tourists. These factors will give an improved gravity model that will be used as the road weight between two cities. The layout for the regional railway network will be obtained using Kruskal’s algorithm. The model will be applied to Region III (Central Luzon) of the Philippines to verify its validity.

Cassia is a genus of leguminous trees that bear attractive colorful flowers with tropical distribution. The pink-to-white-flowered trees are commonly cultivated and are considered as exotic to the Philippines. Balayong is a local botanical name that broadly refers to Cassia trees in Palawan and became the flagship species of Puerto Princesa City, the capital of Palawan, because of its floral blooms and the trees symbolize feisty femininity and beauty. It is annually celebrated as a festival, namely, the Balayong Festival. However, several scientific names for balayong have been claimed as the correct name as well as their unending presumptions of origin. This study aimed to resolve the identity and botanical indigeneity of the balayong (Cassia) of Palawan. A review of the literature, examination of actual and digital images of herbarium specimens, fieldwork, and analysis of nomenclature were conducted. Three taxa of the pink-to-white-flowered Cassia, namely, Cassia grandis, C. javanica subsp. javanica, and C. javanica subsp. nodosa, and the yellow-flowered C. fistula are recognized to occur in Palawan. Among these, C. javanica subsp. javanica is indigenous to the Philippines, with historical records of collections from Palawan. A key to the identification of the species, literature citations, brief description, and taxonomic notes are presented to delineate the different kinds of Cassia in Palawan.

The basidiomycete Ustilago maydis causes smut in corn (Zea mays). The pathogen was first reported in the Philippines in 1919. However, characterization data and knowledge of its current isolate for use as reference are scarce. This study provides knowledge of the morphocultural characteristics of a Laguna isolate of Ustilago maydis and, for the first time, confirms the species and identity through DNA sequencing of the partial sequence of internal transcribed spacer (ITS) in the ribosomal DNA gene region. The teliospore size (n = 30) ranged from 8.09 to 11.36 μM (averaged at 9.21 μM). Washed teliospores were successfully isolated in a potato dextrose agar (PDA) medium supplemented with CuSO4. The teliospore and the haplotype DNA (from PDA) were extracted and used in a polymerase chain reaction assay. A ~800 base pair product was amplified, and sequences of the ITS rDNA revealed teliospore and haplotype of the Philippine isolate were 100% similar to known U. maydis. Phylogenetic analysis also revealed a close resemblance of the Philippine isolate to U. maydis isolated from corn in Mexico. Description and DNA sequence information of the U. maydis Philippine isolate MBZM001 provided in this study can be used as references for future studies.