IPA Recipients for April 2020

Jose P. Peralta1, Lhumen A. Tejano1 and Honey Lyn R. Gomez1
1Institute of Fish Processing Technology, College of Fisheries and Ocean Sciences (UP Visayas)

True Bulk As-antisite Defect in GaAs(110) Identified by DFT Calculations and Probed by STM/STS Measurements,
Applied Surface Science, 511: 145590, doi: 10.1016/j.apsusc.2020.145590, 2020

Most people nowadays are suffering from different health problems (hypertension, diabetes, cancer, etc.,) even at a very young age. To control/ minimize the occurrence of these diseases, synthetic drugs have been developed and administered to patients. However, these synthetic or “unnatural” drugs have caused some negative effects such as cough, skin rashes, taste disturbances, etc. With this, more and more people are now showing interest in using natural products as a treatment to certain diseases.

Many food proteins including those from marine resources are very popular for its curative effects. These proteins are made of peptides (short chain of amino acids) that are known to provide specific health benefits to the body, like synthetic drugs do. This gave so much urge to the researchers and drug formulators to discover and develop an effective product from natural sources.

In this study, we identified the potential curative effects of Portuguese oysters from Taiwan. Using in silico (computer-based) technique, we were able to find peptides that can control certain diseases such as hypertension and Diabetes Mellitus Type 2 (DMT-2). Thus, to confirm these findings, we performed an in silico (test-tube) experiment using Portuguese oyster meat and tested its efficacy in controlling hypertension and DMT-2. The results of the test-tube experiment agreed with the computer-based findings. Therefore, this study proved the reliability of in silico technique in identifying specific health benefits from a food protein. Moreover, this study revealed that Portuguese oyster can be an alternative source of peptides with nutraceutical and pharmaceutical applications.

Research outputs provided baseline information on the usefulness and potentiality of Portuguese oyster (Crassostrea angulata) proteins as a functional food ingredient with anti-hypertensive and blood sugar regulation benefits. This research work also highlighted the usefulness and efficacy of in silico technique in predicting the potential bioactivities of C. angulata proteins and choosing the best enzyme for hydrolysis.

Link to the article: https://www.ncbi.nlm.nih.gov/pubmed/31635140
Impact factor: (2018/2019) 4.183

Peñafrancia E. Ching1 and Rolando T. Lazaro1
1Department of Occupational Therapy, College of Allied Medical Professions (UP Manila)

Preparation, Roles, and Responsibilities of Filipino Occupational Therapists in Disaster Preparedness, Response, and Recovery, Disability and Rehabilitation, doi: 10.1080/09638288.2019.1663945, 2019

The Philippines is prone to many disasters caused by natural hazards. Seated in the Pacific Ring of Fire and the typhoon belt, the country has continuously suffered from major catastrophic events. Because of these events, many lives perish with countless others left having to face displacement, economic hardships and even long-term disability. Much attention has been given to disaster management and preparedness to reduce unfavorable outcomes; however, not much attention has been given to rehabilitation needs of affected survivors or the specific needs of people with disabilities in these situations.

Occupational therapy is a health profession with roles in disaster management identified in literature. The Philippine Academy of Occupational Therapists has a framework that guides its members to engage in this area. This paper describes the specific roles and responsibilities performed by Filipino occupational therapists. This study describes how occupational therapists can serve as additional health human resource to address general and specific needs.

The results of the study show that occupational therapists were mostly engaged in roles related to the recovery phase followed by roles in the response phase. They were least engaged in roles in the preparedness phase.

Given these findings, Filipino occupational therapists in the study are engaged in all phases of disaster management and may address concerns of people with special needs and contribute towards mental health response.

The research results will guide rehabilitation professionals particularly occupational therapists to engage in disaster related work and serve as additional health and human resource in providing mental health services to people with special needs in disasters.

TThe research also specifies that there is a need to integrate disaster preparedness in the scope of practice of rehabilitation professionals to help with the preparedness of people with special needs whose needs are often not addressed by mainstream humanitarian workers.

Link to the article: https://www.tandfonline.com/doi/full/10.1080/09638288.2019.1663945
Impact factor: (2018/2019) 2.054

John Paul A. Mendoza1, Maria Ines Rosana Balangue-Tarriela2
1Department of Physical Sciences, College of Science (UP Baguio)
2National Institute of Geological Sciences, College of Science (UP Diliman)

Modeling Adiabatic Boiling in the Biliran Geothermal Wells Using CHIM-XPT (2016),
Philippine Journal of Science, 148 (4): 117-124, 2019

In geothermal systems, a process called boiling happens when hot water rises to the surface. In this process, the hot water cools down as steam is created in response to lowering of pressure when it goes closer to the surface.

This study presents the results of changes in the chemical composition of hot water from the deeper portions of the geothermal system as it ascends to the surface together with the description of minerals which are expected to be produced as a by-product of this process. The results of the study will contribute to the assessment of scaling potential (possible blockage in pipelines) in a geothermal field.

Using computer programs SOLVEQ and CHIM-XPT, the process called boiling was simulated for the wells of Biliran geothermal field. Calculted reservoir temperatures from the program are consistent with the reported estimated temperatures based on other conventional methods (chemical geothermometry). The gases produced from the Biliran wells are dominated by water vapor along with CO2. Chlorite, calcite and talc minerals are expected to be produced in the process. This was confirmed from the company reports identifying calcite scales and veins in BN-1 while BN-2 is dominated by aragonite (a very close relative of calcite). Minor differences in the mineralogy of the wells are mainly due to the significant difference in the fluid and gas chemistry amongst wells in the field. The formation of CO2 into a gas phase is the main cause for the increase in pH for both wells.

This work predicts which particular minerals will precipitate and what factors drive their formation during the process of adiabatic boiling in geothermal wells. Such minerals are known as scale minerals which may reduce the maximum output and thus the efficiency of these wells. By knowing these minerals, the geothermal company will be able to strategically plan scale inhibiting methods to maximize their outputs.

Link to the article: http://philjournalsci.dost.gov.ph/next-issue/83-vol-148-no-1-march-2019/929-modeling-adiabatic-boiling-in-the-biliran-geothermal-wells-using-chim-xpt-2016
Impact factor: Not Applicable

Jillian Aira Gabo-Ratio
National Institute of Geological Sciences
College of Science
UP Diliman

Exploring Public Engagement and Social Acceptability of Geothermal Energy in the Philippines: A Case Study on the Makiling-Banahaw Geothermal Complex, Geothermics, 85: 101774, 2020

The study focused on the social acceptability of geothermal projects in the Philippines by looking at the Makiling-Banahaw Geothermal Complex (Mak-ban), one of the earliest geothermal sites in the country operating for >30 years. The research collected data through interviews, surveys, and focus group discussions with various stakeholders: non-government organizations (NGOs), academe, national government agencies, developers, the local government unit (LGU), and residents near the location of the project. The results reveal that stakeholders of the barangays where the geothermal facilities are located were agreeable to geothermal energy compared with those from the other barangays farther from the geothermal facilities. Among the local residents, geothermal energy supporters tend to be male stakeholders, those who reside in barangays with geothermal facilities, and those living on public land. While there were limited interactions between the local residents and geothermal energy developers, they still trusted the geothermal resource developers and local government but their trust may be fragile. Stakeholder dialogues and focus group discussions, rather than mass media, are more effective tools to increase technology literacy and develop trust among the various stakeholders. Transparent communication policy on the side of geothermal resource developers, such as sharing solid data about the environmental impacts of the operations, through quarterly information campaigns can assure the local communities of the stability and safety of their operations. Launching and maintaining a dialogue among all relevant stakeholders that takes into account the views of the local communities is the way forward to ensure social acceptance in the future.

The research identified critical issues and supporting factors for developing geothermal energy projects in the Philippines using the Makiling-Banahaw Geothermal Complex as a case study.

Link to the article: https://www.sciencedirect.com/science/article/pii/S0375650519303359?via%3Dihub
Impact factor: (2018/2019) 3.470

Leonardo A. Guevarra Jr.1 and Leslie Michelle M. Dalmacio1
1Department of Biochemistry and Molecular Biology, College of Medicine (UP Manila)

A Synthetic Peptide Analog of in Silico‐predicted Immunogenic epitope Unique to Dengue Virus Serotype 2 NS1 Antigen Specifically binds Immunoglobulin G Antibodies Raised in Rabbits,
Microbiology and Immunology, 64 (2):153-161, 2020

Dengue virus has four types namely dengue 1-4.
Certain types of dengue, which is called a serotype, has been associated with the severity of the symptoms of infection and co-exist in places where dengue is common.

While current blood testing methods can detect dengue with high accuracy, they cannot distinguish serotypes Distinguishing serotypes is crucial for surveillance and control and, for the government, decision-making for immunization programs. It may prevent the incidence of severe dengue which may happen if a person previously infected with one serotype has been exposed to another serotype, either by a bite from a mosquito or by immunization. This phenomenon has already been observed in humans and has led to severe health consequences and death.

Because of this problem, our group aimed to look for unique markers of dengue serotype 2, one of the most common type of dengue in the Philippines and Southeast Asia. We identified sequences small portions of the proteins present in dengue called peptides that is unique to one serotype using computer-aided technologies. This were synthesized and acquired from commercial sources. Rabbits were immunized with these synthetic peptides and the production of antibodies, as a reaction to immunization, was tested. The specific binding of the antibodies produced by the rabbits to the peptide was also determined.

Based on the results of our experiment, the peptide was able to elicit the production of antibodies in rabbits which means that it is immunogenic. The antibodies produced by the rabbits specifically binds to the synthetic peptide. This confirms that we were able to identify a peptide that specifically binds antibodies against the peptide sequence exclusive to dengue serotype 2.

Dengue serotype identification is important because: 1) cross-reactivity among dengue serotype and other flaviviruses is very common and is the cause of erroneous results in diagnosis; 2) certain serotypes are associated with clinical manifestations and severe forms of dengue, and 3) the second infection of dengue from other serotypes have been associated with severe forms of dengue. Unfortunately, currently available serological methods of dengue cannot differentiate individual dengue serotype. This, however, can be resolved by identifying unique antigenic sequence for each serotype and use it to develop highly sensitive and highly specific diagnostic devices can discriminate dengue serotypes.

Link to the article: https://onlinelibrary.wiley.com/doi/abs/10.1111/1348-0421.12757
Impact factor: (2018/2019) 1.442

Maria Herminia M. Baglos1, Elizabeth Ann P. Prieto1, Elmer S. Estacio1, Arnel A. Salvador1and Armando S. Somintac1
1National Institute of Physics, College of Science (UP Diliman)

True Bulk As-antisite Defect in GaAs(110) Identified by DFT Calculations and Probed by STM/STS Measurements,
Applied Surface Science, 511: 145590, doi: 10.1016/j.apsusc.2020.145590, 2020

For semiconductor-based devices such as lasers, solar cells, among others, defect incorporation is unavoidable. Thus, a better understanding of the nature of the defects is important. In this work, we studied both the structural and electronic characteristics of a point defect in gallium arsenide (GaAs), a common semiconductor used for modern optoelectronic devices. In particular, we combined modeling and experiments to investigate the arsenic antisite (AsGa) defect, that is, an arsenic atom, located in a gallium lattice site. This defect introduces a new electronic state that can lead to additional absorption below that bandgap in gallium arsenide. Based on the model, the AsGa defect located on the 3rd atomic layer of the GaAs lattice mimics the bulk characteristics, that is, more than 5 layers from the surface. The results of the model were confirmed by scanning tunneling microscopy and spectroscopy. These techniques are capable of atomic-scale imaging and electronic probing, respectively. We found a one-to-one correspondence between the modeled and experimental STM images and electronic spectra.

Defects in semiconductors are responsible for below bandgap conduction. In GaAs, the midgap states induced by the arsenic antisite (AsGa) defect results to below bandgap absorption in GaAs. For terahertz (THz) applications, this means that the less expensive 1.55 μm laser can be used which can considerably reduce the cost of terahertz wave-based spectroscopy setups. A prerequisite in the optimization of GaAs for THz is a fundamental understanding of the midgap states. In our work, we combined density functional theory (DFT) and scanning tunneling microscopy/spectroscopy (STM/STS) to study the As antisite defect. We showed that the AsGa defect in the 3rd (3-AsGa) layer gives rise to the midgap states that is observed in bulk GaAs. The results of the DFT were corroborated by STM and STS. Based on the simulated and experimental STM image, the AsGa defect in the 3rd layer registers as an asymmetric two-lobe feature in the GaAs lattice. We also observed 3 peaks associated to this defect.

Link to the article: https://www.sciencedirect.com/science/article/abs/pii/S0169433220303469?via%3Dihub
Impact factor: (2018/2019) 5.155

Rontgen B. Gapusan1, Mary Donnabelle L. Balela1
1Department of Mining, Metallurgical, and Materials Engineering, College of Engineering (UP Diliman)

Adsorption of Anionic Methyl Orange Dye and Lead(II) Heavy Metal Ion by Polyaniline-kapok Fiber Nanocomposite,
Materials Chemistry and Physics, 243: 122682, https://doi.org/10.1016/j.matchemphys.2020.122682, 2020

Kapok fibers were used as support for the synthesis of reusable and relatively high efficiency polyaniline-based adsorbent for the removal of heavy metal ions and ionic dyes from aqueous environment. Initially, raw fibers were isolated from the seed pods of kapok tree and washed thoroughly with distilled water to remove some surface impurities. Then, the fibers were bleached in order to improve the adhesion of polyaniline on its surface. The deposition of polyaniline on the surface of the kapok fiber was performed via oxidative polymerization of aniline monomer in acidic solution. The addition of ammonium persulfate initiated the polymerization of aniline. The deposition of polyaniline was optimized by adjusting the amount of ammonium persulfate at constant aniline concentration. The collected polyaniline-kapok fiber nanocomposites were thoroughly washed and dried in an oven. The properties of the nanocomposite were studied using different characterizations, such as scanning electron microscopy, contact angle measurement, and compositional analysis. Lead (Pb) and methyl orange (MO) were used as model heavy metal and ionic dye pollutants. It was revealed that the nanocomposite adsorbent can effectively remove the said pollutants, and the spent adsorbent could be regenerated and reused for another adsorption process. The effects of solution pH, initial concentration of pollutants and temperature on the removal of Pb and MO were also investigated.

In this study, microtubular kapok fiber was used as support for the preparation of a potential adsorbent of water pollutants, such as heavy metals and ionic dyes. Kapok fibers are abundant in our country and it is conventionally used as filling in pillows, mattresses and life vests. Its high surface area owing to its high porosity it can be used as support or carrier of various nanomaterials including adsorbing polymers. Polyaniline, a conducting polymer, exhibits a high affinity to polar analytes like heavy metal ions and ionic dyes because of its charged surface. Due to its high efficiency and ease in synthesis, polyaniline-kapok composite is a promising adsorbent for industrial applications. In addition, it was demonstrated in this study that the composite adsorbent can be easily regenerated and reused. This modification could potentially add value to the kapok fiber, and consequently could provide additional income for our local farmers.

Link to the article: https://www.sciencedirect.com/science/article/abs/pii/S025405842030064X?via%3Dihub
Impact factor: (2018/2019) 2.781

Ruby P. Napata1, Liberty N. Espectato1 and Genna D. Serofia1
1Institute of Fisheries Policy and Development Studies, College of Fisheries and Ocean Sciences (UP Visayas)

Closed Season Policy in Visayan Sea, Philippines: A Second Look,
Ocean & Coastal Management, 187: 105115, https://doi.org/10.1016/j.ocecoaman.2020.105115, 2020

Closed season policy is being implemented in the Visayan Sea during the period 15 November to 15 February of each year for the management and conservation of sardines. A study was conducted to examine the policy whether or not it has resulted in an increase or decrease in fish stock which will eventually result to increase on fish catch of the fishers. Results reveal that stakeholders of the sardine industry have different perceptions of its results. Catch per unit of effort (CPUE) of the fisher-respondents substantially decreased. On the other hand, processors and traders perceived that the sardine production increased. Data from the Philippine Statistics Agency show that there is no significant increase in the country’s total sardine production. While the majority of the respondents believed that they comply with the regulation, night light detection system of the Earth Observation Group – NOAA shows that there are still fishers that continue to operate during closed season. This non-compliance may be attributed to the negative economic impact of the policy on the livelihood of the fishers. For the closed season to be effective it has to be applied along with other management strategies such as mesh size regulation, establishment of Marine Protected Areas, and provision of alternative sources of livelihood.

The result of our research could serve as a reference for policy amendment or policy reform, policy brief and policy paper on the closed season policy in the Visayan Sea. It can also help the local government units (LGUs) within the Visayan Sea to fine tune their municipal fisheries ordinance.

Link to the article: https://www.sciencedirect.com/science/article/abs/pii/S0964569120300259?via%3Dihub
Impact factor: (2018/2019) 2.595