Manila Journal of Science

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

Manila Journal of Science

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


ISSN 2243-9129

De La Salle University

2401 Taft Avenue, Manila 0922










Dr. Esperanza C. Cabrera


College of Science
De La Salle University, Philippines











Dr. Emelina H. Mandia


College of Science
De La Salle University, Philippines




Dr. Rafael A. Espiritu


College of Science
De La Salle University, Philippines




Mr. Frumencio F. Co


College of Science
De La Salle University, Philippines




  Dr. Conrado D. Ruiz, Jr.


College of Computer Studies
De La Salle University, Philippines;

Universitat Ramon Llull
Barcelona, Spain




Dr. Allan Abraham B. Padama


Institute of Mathematical Sciences and Physics
University of the Philippines – Los Baños, Philippines




Dr. Marilou G. Nicolas


College of Arts and Sciences
University of the Philippines – Manila, Philippines




Dr. Aleyla Escueta De Cadiz


College of Science and Mathematics
University of the Philippines – Mindanao, Philippines





Dr. Julieta Z. Dungca


School of Science and Technology
Centro Escolar University, Philippines





Dr. Joaquin Lorenzo V. Moreno


College of Science
De La Salle University, Philippines















Dr. Rhodora V. Azanza


University of the Philippines – Diliman, Philippines




Dr. Ramon S. Del Fierro


University of San Carlos, Philippines




Dr. Victoria Espaldon


University of the Philippines – Los Banos, Philippines




Prof. Hideaki Kasai


Osaka University, Japan




Prof. Michio Murata


Osaka University, Japan




Dr. Vernon R. Morris


Howard University, USA




Dr. Consolacion Y. Ragasa


De La Salle University, Philippines




Dr. John C. Wise


Michigan State University, USA




Dr. Kainam Thomas Wong


Hong Kong Polytechnic University




Dr. Mudjekeewis D. Santos


Bureau of Fisheries and Aquatic Resources, Philippines




Dr. Raymond Girard R. Tan


De La Salle University, Philippines




Dr. Windell A. Rivera


University of the Philippines Diliman




Dr. Mamoru Sakaue


Osaka University, 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

Craciun’s E-MAK Method: A Dynamics-focused Approach to Poly-PL Kinetics

pp 1-21 (Vol 13 2020)

D.M. Magpantay 1,2*,
E.R. Mendoza
1,3,4,5, and
E.G. Nocon

1 Mathematics and Statistics Department, De La Salle University, Manila, Philippines
2 College of Arts and Sciences, Batangas State University, Batangas City, Philippines
3 Institute of Mathematical Sciences and Physics, University of the Philippines Los Baños, Laguna, Philippines
4 Max Planck Institute of Biochemistry, Martinsried, Munich, Germany
5 LMU Faculty of Physics, Geschwister-Scholl-Platz 1, Munich 80539, Germany
*Corresponding author:


This paper studies chemical reaction networks with poly-PL kinetics, i.e. positive linear combinations of power law kinetics. The analysis of such systems is motivated by the study of veloz et al., that proposed to analyze the dynamics of Evolutionary Game Theory models using Chemical Reaction Network Theory (CRNT) in the form of polynomial kinetics (POK). Our approach is based on the fact that poly-PL kinetics generate power law dynamical systems, which via a method recently introduced by G. Craciun can be mapped to EMAK systems. These are the analogue of mass action kinetics on Euclidean embedded graphs (E-graph). Our main structural results show the coincidence of the stoichiometric subspaces of the original network and its associated E-graph as well as the conservation of the positive dependency, which is a necessary condition for the existence of positive equilibria. However, our overall analysis shows Craciun’s method is only of limited use for studying PYK systems since only very special kinetics reflect the structural properties of the original chemical kinetic system.

Frequency of Twinning in Nigeria: A Review

pp 78-88 (Vol 12 2019)

K.M. Akinseye 1,a,
A.T. Anifowoshe
O.A. Owolodun
O.M. Aina
2, and
O.A. Iyiola

1 Department of Biology, Adeyemi College of Education, Ondo, Ondo State, Nigeria
2 Cell Biology and Genetics Unit, Department of Zoology, Faculty of Life Sciences, University of Ilorin, Ilorin, Nigeria
3 Department of Molecular Reproduction, Development and Genetics, Indian Institute of Science, Bangalore, India
*Corresponding author:
aShared first author and contributed equally to the work


Increased twinning rate in developing countries, especially Nigeria, which has the highest twinning rate, exposes mothers and infants to extremely high risks. Multiple births can contribute significantly to maternal and perinatal morbidity and mortality, women with multiple gestations are at increased risk of preeclampsia, preterm labor, delivery of low–birth weight infants, antepartum or postpartum hemorrhage, cesarean section, ongenital anomalies, intrauterine growth retardation, and maternal and perinatal death as compared to women with singleton gestations. This review was undertaken with the objective of providing data on the frequency of twinning across Nigeria, which is implementing measures for safe delivery and monitoring susceptibility to disease. Literature search for incidence of twinning in Nigeria between 2008 and 2014 was carried out and twin birth per 1,000 deliveries was calculated from the frequency recorded across various states in Nigeria. We reported the frequency of twinning across Nigeria to be 6,070 out of 189,178 total births and twin birth per 1,000 deliveries to be 32.1. The maternal age range of 25–34 years showed the highest rate of twinning in this study. Our result also revealed that Nigeria had the highest rate of twinning when compared to studies from other countries except Benin Republic. This might be as a result of massive migration of Nigerians most especially the Yorubas to Benin. This study provides information on incidence/frequency of twinning across Nigeria. It also reveals how the Nigerian populations in the north, south, west, and east vary with respect to twin birth. This vital information will be germane for population genetics and anthropological studies and may be helpful in planning future health strategy, particularly in management of diseases associated with women with multiple gestations.

Synthesis and Antimicrobial Activities of 2H-Chromene-3- Carboxamide Derivatives: Experimental and Computational Studies

pp 64-77 (Vol 12 2019)

T.O. Olomola 1,*,
L.O. Olasunkanmi
J.O. Fadakinni
A.J. Akinboye
T.O. Kelani
1,2, and
O.O. Olasunkanmi

1 Department of Chemistry, Faculty of Science, Obafemi Awolowo University, Ile-Ife, Nigeria
2 Department of Chemistry, Faculty of Science, Edo University Iyamho, Nigeria
3 Department of Microbiology, Faculty of Science, Obafemi Awolowo University, Ile-Ife, Nigeria

Corresponding author:


Coupling reaction between Baylis–Hillman-derived 2H-chromene-3-carboxylic acid derivatives and some amines afforded the corresponding 2H-chromene-3-carboxamides. The synthesized carboxamides and their acid precursors were screened for their in vitro antifungal and antibacterial activities using nystatin and streptomycin, respectively, as standard drugs. Among the tested compounds, it has been found that compounds 3a, 3c, and 4c (minimum inhibitory concentration = 0.062 mg/mL) exhibited better activities than the reference drug, streptomycin (minimum inhibitory concentration = 0.125 mg/mL) against Bacillus cereus. Compound 4a showed the best inhibitory profile against gram-negative bacterial strains, while compound 4b appeared to be the most active against fungal strains Candida albicans and Aspergillus niger. Molecular quantum chemical calculations suggested that the activities of the compounds against gram-negative bacterial strains could have some correlations with the electron-donating abilities of the molecules, while their activities against gram-positive bacterial strains showed some correlations with the electron-accepting abilities of the molecules.

Generating Spanning Maximal Planar Subgraphs of Complete 4-Partite Graphs

pp 56-63 (Vol 12 2019)

T.J.B. Estrada1,* and
I.B. Jos

1 Don Mariano Marcos Memorial State University–SLUC, Agoo, La Union, Philippines
2 Mathematics and Statistics Department, De La Salle University, Manila, Philippines

Corresponding Author:


A spanning maximal planar subgraph (SMPS) T of a simple, finite, undirected graph G is a spanning subgraph of G that is also a maximal planar graph. In this paper, we introduce some methods of constructing complete 4-partite graphs Kw,x,y,z with SMPS. We utilize these methods to the SMPS problem for complete tripartite graphs to generate complete 4-partite graphs with SMPS and provide some relationships between the cardinalities of the two graphs.

Attritions on Success Probability Models

Attritions on Success Probability Models

pp 44-55 (Vol 12 2019)

A. Wee and
A. Nocon

Mathematics and Statistics Department, De La Salle University, Manila, Philippines

Corresponding Author:


The mathematical model called the process-based strategy (or PBS) model describes a situation wherein a particular end goal is obtained by undergoing an n-step process. As this describes some practical applications in real-life situations, it is of great interest to focus on other relevant and valid scenarios that treat the process as an iterative model. In this research study, we give an insightful extension of the results found in the paper “Success Probability of an n-Step Process with n Independent Step Probabilities.” More specifically, we extend the results of the paper by showing new applications of the PBS model pertaining to the concept of saturations as introduced in the paper. We consider various exposure scenarios and introduce the concept of prime agents acting as producers of new agents out of the success cases, which in turn also become catalysts for the succeeding cycles. In this sense, the PBS model becomes iterative. The interest is shifted to determining the number of prime agents that each cycle produces. Also discussed in this paper is the consideration of exposure scenarios where attrition is present. Lastly, the concept of critical points is also discussed, which examines conditions that determine whether the number of prime agents in the iterative PBS model will exponentially increase, remain constant, or be reduced to zero. It is perceived that the iterative PBS model can describe real-life situations such as multilevel marketing tactics and personnel training and development with the aim of using it for practical purpose of optimizing the results of such schemes.

Zero Ring Index of Cactus Graphs

Zero Ring Index of Cactus Graphs

pp 37-43 (Vol 12 2019)

M. Dela Rosa-Reynera 1*, and
L. Aquino-Ruivivar

1 Mathematics Department, Mariano Marcos State University, Quiling Sur, Batac City, Philippines
2 Mathematics and Statistics Department, De La Salle University, Manila, Philippines

Corresponding Author:;


A new notion of graph labeling called zero ring labeling is realized by assigning distinct elements of a zero ring to the vertices of the graph such that the sum of the labels of adjacent vertices is not equal to the additive identity of the zero ring. The zero ring index of a graph G is the smallest positive integer ξ(G) such that there exists a zero ring of order ξ(G) for which G admits a zero ring labeling. Any zero ring labeling of G is optimal if it uses a zero ring consisting of ξ(G) elements. It is known that any tree of order n has a zero ring index equal to n. Considering that cactus graphs are interesting generalizations of trees, in this paper, we extend the optimal zero ring labeling scheme for trees to cactus graphs that leads us to establish that cactus graphs have also zero ring indices equal to their orders.