Publications

This randomized, single-masked, controlled trial examined the effects of nutrient-fortified milk-based formula supplementation on nutritional status, nutrient intake, and psychomotor skills of selected preschool children with mean age of 4.10 ± 0.14 years. The study participants were divided equally into three major groups, normal, underweight, and severely underweight based on WHO-Child Growth Standards, and were further divided into two groups: fortified milk group who was given two glasses of fortified milk (50 g of powdered milk/serving) a day for twelve weeks in addition to their usual diet and the nonintervention group who was not given fortified milk and thus maintained their usual intake. Anthropometric measurements, dietary intake, and psychomotor developmental score were analyzed. Results showed that consumption of two servings of fortified milk a day for twelve weeks significantly increased the height of preschool children by 1.40 cm, weight by 1.35 kg, body mass index by 0.96 kg/m², mid-upper arm circumference by 0.66 cm, and psychomotor scores by 13.74% more than those children who did not consume fortified milk (). Hence, fortified milk-based supplement in the diet of preschool children improved overall nutritional status, nutrient intake, and performance in psychomotor scale. This study is registered in Philippine Health Research Registry: PHRR140923-000234.

The effects of radio-frequency (RF) argon (Ar) plasma treatment on the structural, morphological, electrical and compositional properties of the spray-pyrolyzed p-type copper oxide films on n-type (100) silicon (Si) substrates were investigated. The films were successfully synthesized using 0.3 M copper acetate monohydrate sprayed on precut Si substrates maintained at 350 °C. X-ray diffraction revealed cupric oxide (CuO) with a monoclinic structure. An apparent improvement in crystallinity was realized after Ar plasma treatment, attributed to the removal of residues contaminating the surface. Scanning electron microscope images showed agglomerated monoclinic grains and revealed a reduction in size upon plasma exposure induced by the sputtering effect. The current–voltage characteristics of CuO/Si showed a rectifying behavior after Ar plasma exposure with an increase in turn-on voltage. Four-point probe measurements revealed a decrease in sheet resistance after plasma irradiation. Fourier transform infrared spectral analyses also showed O–H and C–O bands on the films. This work was able to produce CuO thin films via spray pyrolysis on Si substrates and enhancement in their properties by applying postdeposition Ar plasma treatment.

This study aimed to determine the effect of the mixing speed and pre-polymer dropping rate during synthesis of microencapsulated phase change materials (MEPCMs), and to assess the performance of MEPCM-incorporated paint as a latent heat storage (LHS) system. N-octadecane as phase change material was encapsulated with resorcinol-modified urea- melamine-formaldehyde at two different mixing speeds and four different pre-polymer dropping rates, and Fourier transform infrared (FTIR) spectroscopy was done to confirm success of microencapsulation. Scanning electron microscopy (SEM) revealed that increasing the homogenization speed and decreasing the pre-polymer dropping rate decreases the microcapsule size. Differential scanning calorimetry results showed that latent heat and encapsulation ratio increases with increasing mixing speed and decreasing pre-polymer dropping rate. The synthesized MEPCMs were incorporated into white paint at three different concentrations, and temperature profiling revealed that the paint’s temperature buffering capacity generally increases with increasing mixing speed, decreasing pre-polymer dropping rate and increasing MEPCM concentration.

Natural fiber reinforced polymer (NFRP) composites have been a focus of various research projects because of their advantages compared to traditional fiber reinforced plastics. In this study, Anahaw (Saribus rotundifolius) was used as fiber source because it is abundant in the Philippines. The fibers were treated by immersing in a sodium alginate solution and then in a calcium chloride solution. The treated fibers were used to reinforce the orthophthalic unsaturated polyester. Mechanical properties were tested using a universal testing machine (UTM) and the fracture surfaces were characterized using a scanning electron microscope (SEM). Sodium alginate treatment resulted in higher tensile and flexural strengths of the composites as compared to those reinforced with untreated fibers. On the other hand, the sodium alginate treatment was not able to show any improvement on the wet mechanical properties of the material. The increase in fiber load was also found to increase the stiffness of the composites. The measured stiffness and modulus of the treated Anahaw fiber-reinforced composite was found to be comparable to those of commercially available particle boards and fiber boards.

This paper examines two sets of ethical issues relating to the health of human migrants and the delivery of healthcare across the globe. The first set pertains to the access of migrants to health care services in their adopted (or adopting) countries. The second set of issues arises in connection with the migration of healthcare professionals from low- and middle-income countries to high-income countries. In the final section the paper looks at these two sets of issues as interconnected concerns within a broader global justice framework of healthcare delivery. We show how the justice issues in the first set relate to the justice issues in the second set. In the end, we propose the adoption of that broader framework, making reference not only to issues of justice but also to the question of the integrity of medicine and the noble objectives of healthcare delivery.

Composites made of zeolites with silver (Ag) and high molecular weight chitosan matrices were synthesized using a solvent-casting technique. XRD, ED-XRF, and FTIR results revealed the successful inclusion of Ag into the natural zeolite. Results also showed the possible redistribution of the exchangeable cations within the zeolite framework after the ion-exchange process. Plasma treatment modified the surface properties of the composites as revealed by AFM and surface free energy (SFE) calculations. Roughness increased with increasing Ag-zeolite content and increased further by at least 2.3 times after plasma exposure. Water contact angle decreased by half after treatment. SFE increased by at least 25% due to the increased contribution of the polar component after plasma treatment. This work showed that the ion-exchange method is effective in incorporating Ag into the zeolite framework and plasma treatment can tune the surface properties such as roughness and wettability. With the promising properties of the composites attributed to the biocompatibility of chitosan and zeolite, the antibacterial activity of Ag and the improved surface characteristics due to plasma treatment, the material is a suitable candidate for biomedical applications.

Vibration-based damage detection from frequency changes requires the calculation of natural frequencies from assumed damage scenarios and conduct a comparison to the actual frequency of the structure. Analytical solutions in obtaining the natural frequency of homogeneous beams are currently limited to beams with uniform cross-sectional area. Changes in cross-sectional area might occur due to damage within the length of the beam. Finite element modeling and analysis is required in these instances, but may not be efficient in terms of computational effort. For the assumed damaged scenarios, there are unlimited number of possible damage combinations for which the natural frequency will be obtained. There is a need for an analytical alternative as a substitute to the finite element method to calculate these frequencies. This study presents an analytical method to estimate the natural frequencies of locally damaged homogeneous beams based on statistical data obtained from finite element modeling and analysis. The method proposes a multiplier function in terms of the extent of area reduction, length, and location of damage in order to estimate the damaged frequency. The function was derived using curve-fitting techniques of data obtained from finite element modeling and analysis of typical beams with assumed damage cases. Examples show that the method is a good alternative to finite element analysis in estimating the natural frequencies of locally damaged homogeneous beams. The method can be used for vibration-based structural health monitoring to predict the damage state of beams given the change in frequency without the computational burden of finite element modeling and analysis.

Keywords: natural frequency, finite element method, least squares fitting, beam, area reduction, corrosion, vibration based damage detection

Peer-review under responsibility of the organizing committee of EURODYN 2017.

Logistic regression is often confronted with separation of likelihood problem, especially with unbalanced success–failure distribution. We propose to address this issue by drawing a ranked set sample (RSS). Simulation studies illustrated the advantages of logistic regression models fitted with RSS samples with small sample size regardless of the distribution of the binary response. As sample size increases, RSS eventually becomes comparable to SRS, but still has the advantage over SRS in mitigating the problem of separation of likelihood. Even in the presence of ranking errors, models from RSS samples yield higher predictive ability than its SRS counterpart.

Logistic regression is often confronted with separation of likelihood problem, especially with unbalanced success–failure distribution. We propose to address this issue by drawing a ranked set sample (RSS). Simulation studies illustrated the advantages of logistic regression models fitted with RSS samples with small sample size regardless of the distribution of the binary response. As sample size increases, RSS eventually becomes comparable to SRS, but still has the advantage over SRS in mitigating the problem of separation of likelihood. Even in the presence of ranking errors, models from RSS samples yield higher predictive ability than its SRS counterpart.

In the course of collecting data from over fifty Philippine languages around the country for our research project entitled The Automated Constructions of Phylogenetic Trees and Networks of Languages in the Greater Central Philippines by a Feature-Sensitive Metric, or the Phylogeny Project in short, we interview correspondents from these different Philippine ethnolinguistic groups to find out the language situation in their community, their attitudes towards implemented language policies, and their opinions about projects that promote or would promote the maintenance or revitalization of minority languages in the country, including research projects like ours, which seek to document languages for academic study in a specialized field of linguistics, but which may contribute to future language revitalization projects. From these interviews and observations during our fieldwork, we find that different groups express varying levels of enthusiasm and optimism for their languages, which relate to their willingness to maintain their languages, or be involved in the revitalization of their languages. We have also gathered reports of varying degrees of increase or decrease in their sense of cultural identity and belongingness to the overall national discourse. This study provides insights on factors that cause and/or shape such varying perspectives, including existing language policies, socio-economic forces, and the influence of mainstream media. We also provide a preliminary report on the applicability, effectiveness, and the intended and/or unintended consequences of the implementation of national language policies, such as the relatively recent educational reforms like the Mother Tongue-Based Multilingual Education (MTB-MLE) Program and the National Indigenous Peoples Education (IP Ed) Framework, from the perspectives of the communities that we have visited. Based on the reports from our fieldwork, we will offer recommendations on how to approach future language documentation and language revitalization projects in the Philippines.

In this study, we explored the use of rice-husk-derived nanosilica (nSiO2) as fillers in epoxy resins. The nSiO2 was irradiated with a capacitively coupled 13.56 MHz radio frequency (RF) plasma using an admixture of argon (Ar) and hexamethyldisiloxane (HMDSO) or 1,7-octadiene (OD) monomers. The plasma-polymerized nSiO2 was loaded at various concentrations (1–5%) into the epoxy matrix. Surface hydrophobicity of the plasma-treated nSiO2-filled composites increased, which is attributed to the attachment of functional groups from the monomer gases on the silica surface. Microhardness increased by at least 10% upon the inclusion of plasma-modified nSiO2 compared with pristine nSiO2–epoxy composites. Likewise, hardness increased with increasing loading volume, with the HMDSO-treated silica composite recording the highest increase. Elastic moduli of the composites also showed an increase of at least 14% compared with untreated nSiO2-filled composites. This work demonstrated the use of rice husk, an agricultural waste, as a nSiO2 source for epoxy resin fillers.

This paper utilised a sequential explanatory mixed-methods design comparing the experiences of 17 parents who use; and 23 parents who do not use psychotropic medicine for their children diagnosed with autism. The main objective is to identify the factors influencing their decision-making process. Quantitative analyses revealed that attitude towards treatment significantly differentiates parents who use (with more positive attitude levels) and parents who do not use (with more negative attitude levels) prescribed medicines. Furthermore, treatment attitude has been found to have significant association with three treatment decision variables. There was a low negative correlation with treatment cost and a high positive correlation with treatment belief and perceived behaviour severity. In the qualitative analysis, six factors were identified that influenced parents’ decision to use or not to use medicine: (1) perceived  mental health condition; (2) perception towards autism diagnosis; (3) doctor’s prescription and recommendation; (4) beliefs and attitudes towards treatment; (5) perceived necessity and expectation of treatment decision which include perceived improvement of the child (from parents who decided to have both therapy and medication and from parents who decided to have only therapy); and, (6) the problems encountered. Integrating both the quantitative and qualitative data led to the formulation of a treatment decision model that explains the interaction of five major variables (child, parent, doctor, decision, and treatment) in the decision-making process from which the parent variable, specifically perception and beliefs towards treatment directs the decision to use on not to use such treatment.

Training actors in English-language theatre since 1967, Repertory Philippines is one of the major producers of musical theatre in Manila. Since the launch of Atlantis Productions in 1999, these two companies have dominated Filipino musical theatre. Part of the companies’ vibrancy comes from their occasional battles to license productions of the same British and American musicals.

High-dimensional data often exhibit multi-collinearity, leading to unstable regression coefficients. To address sample selection bias and problems associated with high dimensionality, principal components were extracted and used as predictors in a switching regression model. Since principal component regression often results to decline in predictive ability due to the selection of few principal components, we formulate the model with nonparametric function of principal components in lieu of individual predictors. Simulation studies indicated better predictive ability for nonparametric principal component switching regression over the parametric counterpart while mitigating the adverse effects of multi-collinearity and high dimensionality.

A nonparametric test for the presence of clustering in survival data is proposed. Assuming a model that incorporates the clustering effect into the Cox ProportionalHazards model, simulation studies indicate that the procedure is correctly sized and powerful in a reasonably wide range of scenarios. The test for the presence of clustering over time is also robust to modelmisspecification.With large number of clusters, the test is powerful even if the data is highly heterogeneous.

We incorporate a random clustering effect into the nonparametric version of Cox Proportional Hazards model to characterize clustered survival data. The simulation studies provide evidence that clustered survival data can be better characterized through a nonparametric model. Predictive accuracy of the nonparametric model is affected by number of clusters and distribution of the random component accounting for clustering effect. As the functional form of the covariate departs from linearity, the nonparametric model is becoming more advantageous over the parametric counterpart. Finally, nonparametric is better than parametric model when data are highly heterogenous and/or there is misspecification error.