IPA Recipients for June 2017

Junius André F. Balista
Institute of Mathematical Sciences and Physics
College of Arts and Sciences
UP Los Baños

Axial Segregation of Granular Mixtures as the Rotational Stabilization of the Radial Core. Granular Matter, 19 (2): 39, 9 pages, May 2017.

Catchy title of research: Explanation of granular material segregation inspired by asteroids and artificial satellites

A binary mixture of granular materials partially
filling a cylindrical or spherical container rotating along the horizontal axis will first radially segregate (larger and smoother grains aggregate to the periphery while the smaller and rougher grains form the core of the bulk) then axially segregate (the sheath made of the larger grains breaks up exposing the radial core).

The deformation of the prolate radial core to an array of more oblate structures (discs, spheres, or “shish-kebab”) increases the moment of inertia.

At an appropriate rotational speed, a mixture of large and small grains inside a rotating horizontal cylindrical container first radially segregate, such that the larger grains go to the periphery and the smaller grains form the core. Then axial segregation occurs, such that the sheath made of larger grains breaks up. This second segregation forms an alternating bands of large and small grains. These fascinating pattern formation occur if the container is rotating at a speed such that the mixture appears like a single rod rolling at a steady pace. We propose that this phenomenon occurs because an elongated object is unstable if it is made to rotated along its longer axis. Since the granular mixture is deformable, it stabilizes by deforming to a series of discs or sphere, where the individual rotation axis is shorter. This explanation was inspired by the observation that asteroids tend to be spinning spheres or discs, and not spinning cylinders.

Link to the article: https://link.springer.com/article/10.1007/s10035-017-0721-x
Impact Factor: (2015/2016) 1.740


Julius Fergy T. Rabago
Department of Mathematics and Computer Science
College of Science
UP Baguio

Supplement to the paper of Halim, Touafek and Elsayed: Part I. Dynamics of Continuous, Discrete and Impulsive Systems Series A: Mathematical Analysis, 24 (2): 121-131, 2017.

Catchy title of research: Solution of a nonlinear difference equation in terms of Fibonacci numbers

This work supplements the paper [Closed form solutions of some systems of rational difference equations in terms of Fibonacci numbers, Dynam. Cont. Dis. Ser. A, 21(6) (2014), 473–486.]. That is, an alternative proof – short and elegant – is offered in order to explain theoretically the results presented in the paper which were established through a mere application of the induction principle. Further results regarding the periodicity of solution of the system being examined is also presented.

Link to the article: http://online.watsci.org/abstract_pdf/2017v24/v24n2a-pdf/2.pdf
Impact Factor: Not yet available


Erlinda Castro-Palaganas and Ruel Caricativo
Institute of Management
Department of Economics and Political Science
College of Social Sciences
UP Baguio

An Examination of the Causes, Consequences, and Policy Responses to the Migration of Highly Trained Health Personnel from the Philippines: The High Cost of Living/Leaving—A Mixed Method Study. Human Resources for Health, 15 (25): 14 pages, 2017.

An examination of the causes, consequences, and policy responses to the migration of highly trained health personnel from the Philippines: the high cost of living/leaving—a mixed method study.

The migration of highly skilled health professionals from developing to developed nations has increased dramatically in the last ten years in response to a range of social, economic and political factors. The consequences of this shift in health human resources can be of critical importance to the overall sustainability of health systems in many of these ‘source’ countries.  These consequences have become much more salient in the ongoing debate about the reliance of some high income countries on health workers who migrate from low and middle income countries. Few studies examine these trends and their consequences from a comparative approach – those that do exist typically focus on macro health indicators which do not allow for a broader investigation of the range of implications the migration of health workers has for patients, providers and health systems. Further, an almost exclusive focus has been on medical and nursing practitioners without considering the roles of other highly skilled health professionals who are also critical to the sustainability of developing health systems. Research to date has also given less attention to the range of responses that various policy decision-makers can and have undertaken to stem the tide of emigrating workers.
The study explored the following questions: 1) What is the present picture of /recent historic trends in the migration of highly skilled health personnel from the Philippines; 2) What, according to various stakeholders ‘on the ground’ in these countries, are the most critical consequences of the migration of highly skilled health workers; 3) How could these consequences be ‘measured’ optimizing the potential for comparative policy analysis? and 4) What is the range of policy responses that have been considered, proposed and implemented to address the critical causes and consequences of health worker migration from these countries, and what have been some of the outcomes of these responses?
This mixed method study employed a decentered, comparative approach that involved three phases: (a) a scoping review on health workers’ migration of relevant policy documents and academic literature on health workers’ migration from the Philippines; and primary data collection with (b) 37 key stakeholders and (c) household surveys with seven doctors, 329 nurses, 66 midwives, and 18 physical therapists.
Filipino health worker migration is best understood within the context of macro-, meso-, and micro-level factors that are situated within the political, economic, and historical/colonial legacy of the country. Underfunding of the health system and un- or underemployment were push factors for migration, as were concerns for security in the Philippines, the ability to practice to full scope or to have opportunities for career advancement. The migration of health workers has both negative and positive consequences for the Philippine health system and its health workers. Stakeholders focused on issues such as on brain drain, gain, and circulation, and on opportunities for knowledge and technology transfer. Concomitantly, migration has resulted in the loss of investment in human capital. The gap in the supply of health workers has affected the quality of care delivered, especially in rural areas. The opening of overseas opportunities has commercialized health education, compromised its quality, and stripped the country of skilled learning facilitators. The social cost of migration has affected émigrés and their families. At the household level, migration has engendered increased consumerism and materialism and fostered dependency on overseas remittances. Addressing these gaps requires time and resources. At the same time, migration is, however, seen by some as an opportunity for professional growth and enhancement, and as a window for drafting more effective national and inter-country policy responses to HRH mobility.
Unless socioeconomic conditions are improved and health professionals are provided with better incentives, staying in the Philippines will not be a viable option. The massive expansion in education and training designed specifically for outmigration creates a domestic supply of health workers who cannot be absorbed by a system that is underfunded. This results in a paradox of underservice, especially in rural and remote areas, at the same time as underemployment and outmigration. Policy responses to this paradox have not yet been appropriately aligned to capture the multilayered and complex nature of these intersecting phenomena.

Link to the article: https://human-resources-health.biomedcentral.com/articles/10.1186/s12960-017-0198-z
Impact Factor: (2015/2016) 2.416


Joyce Raymond B. Punzalan
School of Statistics
UP Diliman

Binocular Sensitivity and Specificity of Screening Tests in Cross-Sectional Diagnostic Studies of Paired Organs. Statistics in Medicine, 36 (11): 1754–1766, 20 May 2017.

Link to the article: http://onlinelibrary.wiley.com/doi/10.1002/sim.7251/abstract
Impact Factor: (2015/2016) 1.533


Emilia A. Lastica-Ternura, Maria Sofiea C. Ty and Dennis V. Umali
Department of Veterinary Clinical Sciences
College of Veterinary Medicine
UP Los Baños

Serological and Molecular Detection of Newcastle Disease Virus from Captive Raptors in a Wildlife Rescue Center in the Philippines. Philippine Journal of Veterinary Medicine, 53 (2): 96-102, July-December 2016.

Catchy title of research: Detection of Newcastle Disease Virus from Captive Raptors in the Philippines

Fig 1. Restraint of a White bellied sea eagle.

Fig 2. Collection of oropharyngeal swabs from captive raptors.

Because of the crucial role of wild birds in the transmission of Newcastle disease virus (NDV), it is vital to identify its distribution in wild birds in the Philippines. Detection of NDV in wild birds can provide important insights on how the disease is transmitted to domestic poultry. Disease screening in wild birds is also important especially in rehabilitation programs. Introducing disease into wild bird facilities and into the wild during release can cause concern in the spread of diseases, especially economically important ones such as ND. Since raptors are predatory birds that feed on live animals or scavenge on dead or dying animals such as other mammals and birds, it is highly likely that they may get infected with the virus. Raptors that co-mingle with migratory birds during migration may also help disseminate the virus from one location to another.
In the present study, 42 captive raptors originating from various parts of the Philippines were monitored serologically and molecularly for NDV infection. Serological analyses showed that 38.11% (16/42) of the captive raptors were positive for NDV antibodies. Molecular detection using nested RT-PCR showed that all captive raptors (100%) sampled from the facility were negative for NDV. The negative results in the nested RT-PCR assay and the presence of unusually high antibody titers may suggest that birds were exposed to the virus but may have already recovered from clinical disease.
Over-all It was shown that apparently healthy and clinically ill captive raptors from the Philippines maybe infected with NDVs and that they may play an important role in the epidemiology of the disease in the wild. Continued surveillance over multiple years will allow us to increase our understanding of the potential role of raptors in the spread of NDVs in domestic poultry and other bird species in the field.

Link to the article: https://journals.uplb.edu.ph/index.php/PJVM/article/view/1564
Impact Factor: Not yet available


Barry Leonard M. Tumbokon and Augusto E. Serrano Jr.
National Institute of Molecular Biology and Biotechnology
UP Visayas

Androgenic and Anabolic Effects of Pinus tabulaeformis Carr. Pollen in Clarias gariepinus. Israeli Journal of Aquaculture – Bamidgeh, 69: 1388, 8 pages, 2017.

After feeding the African catfish larvae with diets containing various concentrations of pine pollen, the female was converted to male while male stayed as male.  When compared to the current practice of using synthetic hormone methyltestosterone as well as testosterone, the effect on sex reversion was similar.  When the three treatments were compared in terms of their effects on growth, catfish fed diets containing pine pollen grew faster than did the two hormones.  The use of pine pollen is recommended over the two hormones since it is way cheaper than the two and also it could be accepted by the consumers.

Link to the article: https://evols.library.manoa.hawaii.edu/bitstream/10524/56854/1/IJA_69.2017.1388.Serrano.pdf
Impact Factor: (2016/2017) 0.348


Jeric R. Distor* and Nelson R. Villarante**
*College of Medicine
**Department of Physical Sciences and Mathematics
College Arts and Sciences
UP Manila

Biosorption Kinetic Models on the Removal of Congo Red onto Unripe Calamansi (Citrus microcarpa) Peels. Oriental Journal of Chemistry, 32 (6): 2889-2900, 2016.

Catchy title of research: Biosorption kinetics of unripe Calamansi (Citrus microcarpa)

Unripe calamansi was dried, pulverized, and made in int into a material that can be used to adsorb toxic dye such as as congo red.It is a promising biosorbent for the removal of toxic component in wastewater such as heavy metals, organic pollutants such as dyes and surfactants.

Link to the article: http://www.orientjchem.org/vol32no6/biosorption-kinetic-models-on-the-removal-of-congo-red-onto-unripe-calamansi-citrus-microcarpa-peels/
Impact Factor: Not yet available


Marilen P. Balolong*, Leslie Michelle M. Dalmacio** and Arnold V. Hallare*
Department of Biology*
College of Arts and Sciences
Department of Biochemistry and Molecular Biology**
College of Medicine
UP Manila

Next-Generation Sequencing Revealed Dominant Fungal Populations in Collected Dust from Selected Public School Classrooms in Metro Manila. Aerobiologia, 33 (1): 127–135, March 2017.

Catchy title of research: Fungi in Metro Manila public school classrooms

Relative abundances of clones in the collected dust samples classified into genera of fungi based on the ITScan database (Ferro et al. 2014).

Public school classrooms in Metro Manila normally hold an average range of 40-70 students per room, forcing them to share a small amount of space for approximately eight hours daily. Being a tropical country, the high level of humidity can provide ideal growth conditions for indoor microbes such as fungi. To our knowledge, this is the first assessment of the fungal community profile of collected dust from public school classrooms in Metro Manila using next-generation sequencing (NGS) of a segment of the DNA, the 18S rRNA gene, of fungi. Culture-dependent technique was also done by gravimetric sampling to note the importance of existing viable spores present in the rooms that can possibly contribute to respiratory health conditions of the children. Composite samples of settled dust from each classroom were collected and pooled to represent one sample per school. The number of fungal operational taxonomic units (OTUs) that correspond to fungal species varied from 16 to 29 per sample. Our results confirmed the detection of Alternaria, Aspergillus, Cladosporium and Penicillium from settled dust. In addition, NGS data have expanded our knowledge of the fungal genera that were present but have been missed by the culturing method including Fusariumand Phoma along with the yeasts Candida, Crytococcus, Rhdosporidium and Rhodotorula. Our findings necessitate a follow-up investigation to confirm the influence of these fungal genera to respiratory health of the children concerned.

Link to the article: https://link.springer.com/article/10.1007/s10453-016-9455-1
Impact Factor: (2015/2016) 1.452


Ma. Josie V. Sumague, Wilson T. Tan, Dennis Marvin O. Santiago, Floirendo P. Flores, Ara Fatima C. Algar. Lotis Mopera and Lilia S. Collado
Institute of Food Science and Technology
College of Agriculture and Food Science
UP Los Baños

Physico-Chemical Composition and Functional Properties of Native Chicken Meats. Philippine Journal of Science, 145 (4): 357-363, Decemebr 2016.

Catchy title of research: Physico-chemical Composition and Functional Properties of Native Chicken Meats

Commercial broilers are the main sources of chicken meat in the country, however, there is insufficient supply as indicated by the increased chicken meat importation from 146 metric tons in 2011 to 210,000 metric tons in 2015 (USDA, 2016). Chicken meat importation can be reduced by evaluating the potential of other sources of poultry meats such as native chickens. In this study, native chicken genetic groups namely Paraokan (Figure 1), Banaba, Joloanaon (Figure 2) from BAI/DA station in Tiaong, Quezon and commercial broiler were analyzed for meat yield, pH and proximate composition, water holding capacity, emulsion activity and emulsion stability. Results were analyzed statistically using Analysis of Variance and Duncan’s New Multiple Range Test. There was no significant difference among the meat yields of the native chicken genetic groups and commercial broiler. Variations in the proximate compositions were affected by genetic groups. Broiler samples gave the highest pH. Emulsion activity and emulsion stability of Broiler’s breast and leg were significantly higher than those of the native chicken genetic groups. Meat from genetic groups of native chicken has the potential as a healthy substitute to commercial broiler because it had higher crude protein and lower fat than commercial broiler. However, commercial broiler has better processing potential than native chicken meat because of its significantly higher pH, emulsion activity and emulsion stability.

Link to the article: http://philjournalsci.dost.gov.ph/pdf/pjs%20pdf/vol145no4/physico_chemical_composition_and_functional_properties_of_native_chicken_meats_FinalCopy_22_Mar_2017.pdf
Impact Factor: Not yet available


Val Randolf M. Madrid and Lei Kristoffer Lactuan
Institute of Computer Science
College of Arts and Sciences
UP Los Baños

Exploring Utility of Formal Concept Analysis Approach to Coral Reef Assessment. Journal of Environmental Science and Management, Special Issue 2: 47-57, 2016.

Marine scientists have been doing coral reef assessment for a long time and data mining has emerged recently because of its ability to analyze and discover new knowledge on huge volumes of data. This research explored the potential of Formal Concept Analysis, a data mining technique, as a different way to look at coral reef assessment data and see if the results from the data mining approach would have similar conclusions as it was in the original report. The data used in this research came from the coral reef assessment study conducted in Lobo, Batangas. Formal concept analysis (FCA) approach in this paper looks at a photo-transect data as the “object” and the coral lifeforms found in that image as “attributes”. In this way, FCA can then navigate photo-transect data and mine different concepts that were derived to either monitor the health of the reef, verify the existing coral assessment reports, or to try to discover coral lifeform association/relationships. This research showed that FCA generated a similar conclusion to that of the traditional coral assessment report given the same data. It is interesting to see data mining techniques, such as FCA, weave its way to other existing accumulated coral reef assessment report as it can be easily adapted, modified, and automated for both data and marine scientist.

Link to the article: https://journals.uplb.edu.ph/index.php/JESAM/article/view/1596
Impact Factor: (2015/2016) 0.146


Tina S. Clemente
Asian Center
UP Diliman

Loyalty on Trial: Chinese-Filipino and the West Philippine Sea Dispute” in Precarious Belongings: Affect and Nationalism in Asia. Chih-Ming Wang and Daniel P.S. Goh (editors). London: Rowman & Littlefield International, 2017.


Rachel Jellan R. Saracanlao, Eureka Teresa M. Ocampo, Alma O. Canama, Sarah Jane B. Manaday, Rodel G. Maghirang and Evelyn F. Delfin
Crop Science Cluser
College of Agriculture
UP Los Baños

Catchy title of research: SSR Molecular Markers for Assessing Genetic Diversity in Eggplant

SSR-Based Genetic Relationship in Eggplant (Solanum melongena) Genotypes with Varying Morphological Response to Drought. Philippine Journal of Crop Science, 41 (3): 57-64, December 2016.

Genomic DNA Extraction and Quantification.

Simple Sequence Repeats (SSRs) markers were used to determine the genetic relationship among 20 eggplant accessions known to have varying responses to drought. The accessions came from Turkey, China, India, Laos, Taiwan, Africa and the Philippines. The drought reactions of these accessions ranged from susceptible to drought tolerant. The selections include 15 Solanum melongena and 5 genotypes from 4 Solanum species (S. ferox, S. linociera, S. parkinsonii and S. nodiflorum). For the genetic relationship analysis, 18 polymorphic SSR markers were used to differentiate the accessions in terms of banding pattern. Results showed that at 0.70 similarity coefficient, S. melongena accessions mainly clustered together. The rest of the Solanum species (S. ferox, S. linociera, S. parkinsonii and S. nodiflorum) formed distinct single groups except for S. linociera, SLT6. The highest similarity of 0.95 was obtained between S. melongena accessions while the least similarity was observed between S. nodiflorum and the rest of the eggplant accessions used. The grouping of commercial varieties with other landraces indicates that the commercial varieties used were similar to the landraces and that the commercial varieties were bred from local materials. Cluster analysis did not distinctly separate the 20 accessions based on drought response. However, the results of the present study can be used in the selection of candidate eggplant accessions for the development of eggplant varieties for drought tolerance.

Link to the article: http://agris.fao.org/agris-search/search.do?recordID=PH2014000985
Impact Factor: (2015/2016) 0.333


Bernard Alan B. Racoma*, Carlos Primo C. David* and Gerry Bagtasa**
*National Institute of Geological Sciences
**Institute of Environmental Science and Meteorology
College of Science
UP Diliman

The Change in Rainfall from Tropical Cyclones Due to Orographic Effect of the Sierra Madre Mountain Range in Luzon, Philippines. Philippine Journal of Science, 145 (4): 313-326, December 2016.

Catchy title of research: The Sierra Madre Mountain Range enhances rainfall in unexpected areas

Due to a Tropical Cyclone’s cyclonic nature, rainfall is along different parts of the mountain range depending on the storm direction. During Tropical Storm Ondoy, the Sierra Madre Mountain Range increased the rainfall over Metro Manila. On the other hand, during Typhoon Glenda, there was less rainfall over Metro Manila because of the Sierra Madre Mountain Range.

As the Philippines is in constant exposure to Tropical Cyclones, it is important to determine the behavior of Tropical Cyclones when they interact with large topographic features such as mountain ranges. While it is believed that mountain ranges will “shield” certain areas from Tropical Cyclones, it was discovered that it also enhances rainfall in the leeward side of the mountain (or behind the mountain) depending on the storm direction.
Interestingly, during Tropical Storm Ondoy rainfall was increased in the Metro Manila due to the interaction of the Tropical Cyclone and the Sierra Madre Mountain Range. Similarly, the presence of mountain ranges slow down the movement of Tropical Cyclones, allowing more rain to pour over the country.
As such, the unique climatological and geological environment of the Philippines poses dynamic risks for the country. It would be important to take into consideration in predicting the distribution of rainfall where the Tropical Cyclone will pass, and if a mountain range is present over the area.

Link to the article: http://philjournalsci.dost.gov.ph/index.php/50-volume-145-no-4-2016/616-the-change-in-rainfall-from-tropical-cyclones-due-to-orographic-effect-of-the-sierra-madre-mountain-range-in-luzon-philippines
Impact Factor: Not yet available


Carlos Primo C. David
National Institute of Geological Sciences
College of Science
Up Diliman

Stream Sediment Geochemical Mapping of the Mount Pinatubo-Dizon Mine Area, the Philippines: Implications for Mineral Exploration and Environmental Risk. Journal of Geochemical Exploration, 175: 18–35, April 2017.

Catchy title of research: Stream sediment geochemical mapping of the Mount Pinatubo-Dizon Mine area, the Philippines: Implications for mineral exploration and environmental risk

Factor score maps for (A) F1 association, (B) F2 association and (C) F3 association. In each map the elements are ordered with decreasing loading.

Stream sediments transport elements that are mobilized from adjacent slopes, representing the composition of the upstream watersheds. Thus, the analysis of the stream sediments allows depicting the spatial distribution of geochemical anomalies at the watershed level. In this study, 39 samples of stream sediments were collected in the Zambales Province, in the Philippines, characterized by the presence of the Mount Pinatubo volcano, the abandoned Cu Dizon Mine, small-mining of black sand, agriculture of rice, animal breeding, and fishing. Each sample was digested in aqua regia and was analyzed by ICP-MS to detect the content of 53 elements. This study is focused on elements with an environmental impact or associated to mineralization/ore occurring in the area. Background values for these elements have been evaluated by cumulative frequency curve to identify the occurrence of geochemical anomalies of geogenic or anthropogenic origin, mainly associated to the mining activity. Factor analysis, performed on normalized data with Additive Log Ratio transformation (ALR), allowed identifying three geochemical data associations, and a Geographic Information System (GIS) has been used to define the spatial distribution of the anomalies at the watersheds level. The GIS procedure assigns the value of the element concentration in the sampling location to the upstream watershed by hydrologic analysis of a Digital Elevation Model (DEM) of the study area. The main result of this study is a new type of geochemical mapping of the of the Mount Pinatubo-Dizon Mine area, representing a first approach to the definition of the environmental risk and the assessment of potential mineral resources.

Link to the article: http://www.sciencedirect.com/science/article/pii/S0375674216304605
Impact Factor: (2015/2016) 2.147


Mario A. Aurelio and John Dale B. Dianala
National Institute of Geological Sciences
College of Science
Up Diliman

Seismotectonics of the 6 February 2012 Mw 6.7 Negros Earthquake, Central Philippines. Journal of Asian Earth Sciences, 142: 93-108, July 2017.

Link to the article: http://www.sciencedirect.com/science/article/pii/S1367912016304187
Impact Factor: (2015/2016) 2.647


Kristoffer Berse
National College of Public Administration and Governance
UP Diliman

Climate Change from the Lens of Malolos Children: Perception, Impact and Adaptation. Disaster Prevention and Management, 26 (2): 217-229, 2017.

Catchy title of research: Children and Climate Change: Perception, Impacts and Adaptation

Impacts of Climate Change on Children According to Children.

This qualitative study was conducted in three peri-urban communities in Malolos, Philippines, looking at the perception and adaptation mechanisms of children in the face of climate change, using as lens Lazarus and Folkman’s typology for children’s coping strategies in stressful situations. The support that children receive at the household, community, and city levels was also examined. Primary data were gathered through a combination of focus group discussions and interviews with children, parents, community leaders and city officials. Secondary sources, including official plans and documents of the City of Malolos were likewise reviewed.
Findings showed that climate change has impacted the daily lives of children, aggravating in particular the “everyday” and “invisible” risks of those who belong to poor households. In general, emotion-focused coping that hinges on denial or distancing did not seem to be prominent among children; many of them were rather pre-disposed to problem-focused coping as they try to cope with the impacts of climate change in their immediate environment. Unfortunately, however, interventions to mitigate the impacts of climate change on children at the household, community, and city levels were found to be lacking.

Link to the article: http://www.emeraldinsight.com/doi/full/10.1108/DPM-10-2016-0214
Impact Factor: Not yet available


Oscar B. Zamora
Crop Science Cluster
College of Agriculture
UP Los Baños

Carbon Storage of Corn-Based Cropping Systems in Isabela, Philippines. Philippine Journal of Crop Science, 41 (3): 20-29, December 2016.

Catchy title of research: Corn-based cropping systems for increased C-storage for mitigation of climate change

Corn inter-cropped with peanut.

Greenhouse gas emissions from the agricultural  sector  account  for  10–12%  or  5.1–6.1  Gt  of  the  total anthropogenic  annual  emissions  of  CO2 equivalents including  only  direct  agricultural  emission. Agricultural management systems are main contributors to GHG emission.
The total system carbon storage (soil, above and below-ground) of corn-based cropping systems was evaluated for one cropping season in selected farmers fields in Isabela. Philippines. The total system C stocks in monocropping (3.67 Mg ha-1), intercropping system  (2.36 Mg  ha-1)  and  the  legume  in  crop  rotation  system  (0.72  Mg  ha-1) increased from fallow period to crop maturity. The decrease in total SOC was highest in the monocropping system. This was 1.25 and 1.94 times higher than the decrease in intercropping and legume in crop rotation.
Both monocropping and intercropping systems had higher C than legume in crop rotation. The lower level of chemical fertilizer applied and the reduction in the SOC resulted to higher C sequestration and reduced C emission in the intercropping system than the monocropping system. It is concluded that intercropping system increased C stored in surface litter due to high crop diversity at crop maturity. 
Also, planting leguminous crop such as peanuts during corn fallow period (September – November/ December) could increase C sequestration of corn-based agricultural lands.

Link to the article: https://www.researchgate.net/publication/312549431_Carbon_Storage_of_Corn-based_Cropping_Systems_in_Isabela_Philippines
Impact Factor: (2015/2016) 0.333


Erna C. Arollado, Leslie P. Bucog, Richelle Ann M. Manalo, Irizh-Lyn R. Sampang and Janvin Jessel A. Cariscal
Institute of Pharmaceutical Sciences
National Institutes of Health
College of Manila

Selected Philippine Plant Extracts as Alternative Preservatives for a Pharmaceutical Liquid Preparation. Philippine Journal of Science, 146 (1): 7-13, March 2017.

Preservatives play an essential role in enhancing quality and prolonging shelf-life ofpharmaceutical products by improving antimicrobial stability or reducing the amounts ofoxidative degradation products. Persistent use of synthetic compounds as preservatives resultedin several reports of undesirable effects. Hence, development of alternatives is necessary tomaintain their vital function while minimizing adverse effects. In this study, ethanolic extractsof plants with known antimicrobial activities, Psidiumguajava, Premnaodorata, Mimosa pudica, Allium sativum and Zingiberofficinale, were formulated into suspensions and evaluatedfor preservative activity using the United States Pharmacopeia (USP) 2015 guidelines.Phytochemical test, antioxidant activity and compatibility test were also conducted on theextracts. The antioxidant activity of Premnaodorata and Mimosa pudica at 5.00 mg/mL concentrationexhibited comparable activity with standard antioxidant preservative,butylated hydroxytoluene, using the ferric reducing power assay. Possible incompatibilities of the extracts with other ingredients in the formulation were not observed in the compatibility test using thin layer chromatography. Based on thecriteria for product category 4 of the USP, suspensions of Premnaodorata and Psidiumguajavademonstrated acceptable preservative activity against Escherichia coliand Staphylococcus aureus. These bioactivities can be attributed to the phytochemicals presentin the extracts such as glycosides, reducing substances, flavonoids and alkaloids. In conclusion,for the USP category 4 products,Psidiumguajava can be utilizedas an alternative source of antimicrobial preservative, Mimosa pudica as an alternative sourceof antioxidant preservative, and Premnaodorata as an alternative source of preservative with both antimicrobial and antioxidant efficacy.

Link to the article: http://philjournalsci.dost.gov.ph/pdf/pjs%20pdf/vol146no1/selected_phil_plant_extracts_as_alternative_preservaties_FinalCopy.pdf
Impact Factor: Not yet available


Allan Abraham B. Padama
Institute of Mathematical Sciences and Physics
College of Arts and Sciences
UP Los Baños

On the Structural and Optoelectronic Properties of Chemically Modified Oligothiophenes with Electron-Withdrawing Substituents for Organic Solar Cell Applications: A DFT/TDDFT Study. Journal of the Physical Society of Japan, 86 (6): 064802, 8 pages, 2017.

Catchy Title of Research: Tuning the properties of organic polymers for solar cell application

It is still a challenge for researchers and scientists to exploit the use of solar energy as alternative to the depleting conventional fossil fuels. It is projected that the supply of fossil fuels will only last few decades from now due to the world’s increasing demand for energy. While solar energy seems to be a practical energy source, utilizing it is still expensive due to the ineffectiveness or high cost of available materials that are used to convert it to other forms of energy. In order to realize this goal, cheap, efficient and flexible solar cells are necessary. While silicon based devices are known to have high efficiency, issues in fabrication and cost hamper its massive application. Organic polymers (which are known to be cheaper, easily fabricated and are flexible) are promising materials as solar cells; however, their low efficiency is always a concern. If the efficiency of organic photovoltaics can be improved, then the goal to utilize solar energy will materialize.
In this present work, the solar cell properties of poly(3-hexylthiophene-2,5-diyl) (P3HT)   is studied using computational method. Various electron- withdrawing substituents are introduced to this polymer and the properties of substituent-P3HT systems are compared with a clean P3HT. The modification of the properties of the system in the presence of substituent is evaluated computationally. The results suggest that cyano substituted P3HT is a good polymer blend candidate for organic solar cells. In general, this study shows how the optoelectronic properties of P3HT could be significantly improved via electron- withdrawing substitutions for solar cell applications.

Link to the article: http://journals.jps.jp/doi/abs/10.7566/JPSJ.86.064802
Impact Factor: (2016/2017) 1.45


Allan Abraham B. Padama
Institute of Mathematical Sciences and Physics
College of Arts and Sciences
UP Los Baños

Ab Initio Study on Hydrogen Interaction with Calcium Decorated Silicon Carbide Nanotube. International Journal of Hydrogen Energy, 42 (16): 11452–11460, 20 April 2017.

Catchy Title of Research: Agreement between experimental and computational data: The case of H atom absorption in Pd(110)

Photo 1. Electronic properties (density of states and partial charge density distribution) of Calcium decorated Silicon Carbide Nanotube (Int. J. Hydrogen Energy 42 (2017) 11452-11460).

Photo 2. Adsorption structures of multiple H2 adsobed on Calcium decorated Silicon Carbide Nanotube. (Int. J. Hydrogen Energy 42 (2017) 11452-11460).

Photo 3. Charge density distribution illustrating the interaction between the Calcium atom on the Silicon Carbide Nanotube and the H2 molecule. (Int. J. Hydrogen Energy 42 (2017) 11452-11460).

Modifying the properties of materials is currently being done, computationally and experimentally, in order to meet the desired requirements for a specific application. This modification is conducted by alloying or by introducing other atoms that can improve the properties of a particular material. In this study, properties of Silicon Carbide nanotubes  (SiCNT) are modified by putting Ca atom. SiCNT are known to have better reactivity than other carbon based nanostructures. Thus it can accommodate the Ca atom. Ca, on the other hand, tends to avoid clustering on surfaces and therefore, it can exist as small particle system on the walls of SiCNT.
The results show that the Ca decorated SiCNT can possibly hold seven H2 molecules. The Ca atom acts as the active site for H2 adsorption. The calculated adsorption energies indicate that the H2 molecules are moderately adhered on the system. This is an advantage because it means that it will require less amount of energy to remove the molecules. The interaction between H2 and Ca is governed by polarization which is depicted from the charge density analysis. It is suggested that this theoretically designed material be experimentally verified in future studies.

Link to the article: http://www.sciencedirect.com/science/article/pii/S036031991730976X
Impact Factor: (2016/2017) 3.582