IPA Recipients for November 2018

Emil Emmanuel C. Estilo and Alonzo A. Gabriel
Department of Food Science and Nutrition
College of Home Economics
UP Diliman

A Model for the Influences of Soluble and Insoluble Solids, and Treated Volume on the Ultraviolet-C Resistance of Heat-Stressed Salmonella enterica in Simulated Fruit Juices. Food Microbiology, 69: 72-81, February 2018.

Perturbation plots showing the individual influences of SS (○), insoluble solids (●) and volume () on the DUV-C of heat-adapted Salmonella enterica in UV-C irradiated simulated fruit juice system (SS: −1 = 0 °Brix, 0 = 35 °Brix, 1 = 70 °Brix; insoluble solid: −1 = 0.00%, 0 = 1.50%, 1 = 3.00%; volume: −1 = 250 mL, 0 = 625 mL, 1 = 1000 mL). Each plot was generated at fixed coded SS, insoluble solid, or volume levels of 0 correspondingly.

The effects of selected intrinsic juice characteristics and extrinsic process parameter on the UV-C inactivation rates of heat-stressed Salmonella enterica in simulate fruit juices (SFJs) was studied. Intrinsic juice characteristics include soluble solids (0-3% w/v) and insoluble solids (0-70 °Brix) while treated volume was selected as extrinsic process parameter. These stated parameters were used in setting the various formulations of fruit juice for better control of physical and chemical properties and limit effects of other variables in a juice system. Strains of Salmonella enterica were incubated at 40°C for 24 hours, pooled and centrifuged to extract bacterial cells. These cells we adapted in the juice system for not more than 15 minutes and followed by UV-C treatment with continuous stirring. A model equation is then generated from results which is then validated using unique set of formulation within the same stated parameters. Results showed that individual and combined intrinsic and extrinsic variables significantly affect the resistance of Salmonella enterica against UV-C, thus suggesting that specific fruit juices with specific composition must be subjected to unique process schedules.

Link to the article: https://www.sciencedirect.com/science/article/pii/S0740002017300722
Impact Factor: (2017/2018) 4.090


Emil Emmanuel C. Estilo and Alonzo A. Gabriel
Department of Food Science and Nutrition
College of Home Economics
UP Diliman

Previous Stress exposures Influence Subsequent UV-C Resistance of Salmonella enterica in Coconut Liquid Endosperm. LWT – Food Science and Technology, 86: 139-147, December 2017.

Emission spectra of the 15-W UV-C lamp source showing predominant emission wavelength at 254 nm.

This research studied the effects of common physical and chemical stresses on the effectiveness of UV-C light against Salmonella enterica in coconut water. Individual and combination of selected stresses (gradual acidification, abrupt desiccation, and heat exposure at 40°C) were applied separately to seven (7) different strains of Salmonella enterica. All these seven strains were then pooled according to stress treatment, added to sterile coconut water, and exposed to UV-C light with constant stirring. Results showed that all strains of Salmonella enterica, when exposed to individual and combined stresses, exhibited 1 st order, log-linear inactivation behavior which means that individual strains have equal levels of vulnerability/resistance to UV- C treatment. Individual heat stress and combined heat, acid and desiccation stress exposure resulted to highest and least UV-C resistance, respectively. Meanwhile, Salmonella enterica developed resistance to UV-C light when exposed to acid, heat, acid + heat, acid + desiccation stress. Results of this study can be used as reference in choosing appropriate target organism in establishment of a UV-C process schedule for coconut water and similar commodities.


Link to the article: https://www.sciencedirect.com/science/article/pii/S0023643817305534
Impact Factor: (2017) 3.129


Bienvenido S. Balotro
Department of Industrial Pharmacy
College of Pharmacy
UP Manila

Characterization of Verapamil Hydrochloride Entrapped in Poly(Lactide-Co-Glycolide) (PLGA) Particles. International Journal of Pharmaceutical Sciences and Research, 9 (10): 4472-4480, 2018.

Verapamil hydrochloride is a commonly prescribed drug in the management of hypertension, angina, and cluster headache prophylaxis. Verapamil hydrochloride suffers from the disadvantage of low bioavailability because of extensive hepatic metabolism (only 10% to 20% becomes bioavailable) and short half-life (2 to 4 hours). As a result, it requires frequent dosing leading to the problem of noncompliance in patients and alternating over and under doses of the drug. A method of circumventing hepatic first pass effect is by making the drug particle microsized (<10µm) and lipophilic. This research aims to address this need by preparing an optimized formulation of Verapamil HCl entrapped in PLGA particles by solvent displacement method and lyophilization and the characterization of its properties.

Link to the article: http://ijpsr.com/bft-article/characterization-of-verapamil-hydrochloride-entrapped-in-poly-lactide-co-glycolide-plga-particles/?view=fulltext
Impact Factor: Not yet available


Alonzo A. Gabriel, Monica R. Manalo, Rodney J. Feliciano, Nadine Kristel A. Garcia, Una Grace M. Dollete and Juliane Czarine B. Paler 
Department of Food Science and Nutrition
College of Home Economics
UP Diliman

A Candida parapsilosis Inactivation-Based UV-C Process for Calamansi (Citrus microcarpa) Juice Drink. LWT – Food Science and Technology, 90: 157-163, April 2018.

Link to the article: https://www.sciencedirect.com/science/article/pii/S0023643817309143
Impact Factor: (2017/2018) 3.129


Rogelio Alicor P. Panao
Department of Political Science
College of Social Sciences and Philosophy
UP Diliman

Balancing the Interests of Labor and Capital: An Empirical Analysis of Philippine Supreme Court Labor Cases from 1987 to 2016. Philippine Political Science Journal, 39 (1): 24-46, 2 January 2018.

In the Philippines, what are the odds of aggrieved employees winning if they sue their employers? The conventional wisdom is that success before courts in the Philippines is determined by the amount of wealth at the disposal of the parties or the extent of their political connection. This view seems to make sense in light of wide social inequalities and the pace by which the wheels of justice grinds in the country. However, our analysis of all labor cases decided by the Supreme Court since 1987 suggests that aggrieved workers who bring their suits to court are actually more likely to win compared to corporations. This is because social justice as a constitutional policy has been enshrined in many labor laws and is the standard of adjudication before courts. But since for many workers it costs an arm and a leg to bring suits before courts, the expectation of success among parties with limited resources also constrain them to bring only suits that are based on real defensible and justiciable grievances. Consequently, individual laborers and unions are likely to emerge victorious, whether as petitioners or respondents, when their actions involve compensation related claims, illegal dismissal, or unfair labor practices. Does this mean though that courts are biased in favor of workers? Interestingly, we do not find evidence of courts swinging justice in favor of labor when actions involve the exercise of management prerogatives and discipline of employees. This suggests that courts are generally circumspect and balance social justice with rational fairness.

Link to the article: https://www.tandfonline.com/doi/abs/10.1080/01154451.2018.1498606
Impact Factor: (2017/2018) 0.391


Maria Paz Marquez, Maria Midea Kabamalan and Elma Laguna
Population Institute
College of Social Sciences and Philosophy
UP Diliman

Traditional and Modern Contraceptive Method Use in the Philippines: Trends and Determinants 2003–2013. Studies in Family Planning, 49 (2): 95-113, June 2018.

This study examines recent levels, patterns, and determinants of traditional contraceptive method use, based on pooled data from the 2003, 2008, and 2013 Philippines Demographic and Health Surveys. Most contraceptive users in the Philippines rely on modern methods, but over the past ten years traditional method use has continued to account for about a third of all contraceptive use. There is also very little change in characteristics of women who use traditional methods over the past decade. Knowing the characteristics of traditional contraceptive method users can help establish policies and programs that promote more effective contraceptive use, including encouraging users of traditional contraceptive methods to switch to the more effective modern methods.

Link to the article: https://onlinelibrary.wiley.com/doi/abs/10.1111/sifp.12051
Impact Factor: 92017/2018) 1.478


Renerio P. Gentallan Jr., Nestor C. Altoveros, Teresita H. Borromeo, Leah E. Endonela and Allison C. Morales
Institute of Crop Science
College of Agriculture and Food Sciences
UP Los Baños

Seed Morphology, Storage Behaviour and Germination Pattern of Atuna racemosaSeed Science and Technology, 46 (3): 483-487, 2018.

Atuna racemosa, also known as tabon-tabon, is used as a condiment crop in Mindanao. Despite its potential, its seed tolerance to drying is still unknown. The researchers identified the behavior of seeds in storage and characterized the seed and seedling morphology in order to identify the approach and measures needed to effectively conserve, handle and propagate the species. The seeds were slow-dried to approximately 12% moisture content and tested for viability. The seeds of A. racemosa did not survive drying; hence, seeds cannot undergo long-term storage and conservation as living plants is suggested. This is the first report of the seed storage behaviour of a species from the genus Atuna. It was also characterized that A. racemosa trees bear fibrous drupes that have cotyledons with color ranging from pale yellowish-pink to light orange. It is a large-seeded crop and there is a characteristic emergence of the radicle at the peduncle end of the seed. This indicates that positioning studies during planting should be undertaken.

Link to the article: https://www.ingentaconnect.com/content/ista/sst/pre-prints/content-05_sst46-3_483-487
Impact Factor: (20172018) 0.593


Roberto F. Rañola Jr.* and Leni D. Camacho**
*Department of Agricultural and Applied Economics
College of Economics and Management
**Department of Social Forestry & Forest Governance
College of Forestry and Natural Resources
UP Los Baños

Determinants of Farmers’ Adaptation to Climate Change in Agricultural Production in the Central Region of Vietnam. Land Use Policy, 70: 224-231, January 2018.

Link to the article: https://www.sciencedirect.com/science/article/pii/S0264837717307834
Impact Factor: (2017/2018) 3.194


Dennis C. Ong*, Mark Daniel G. de Luna** and Sheila Mae B. Pingul-Ong*
*School of Technology
UP Visayas
**Department of Chemical Engineering
College of Engineering
UP Diliman

Manganese and Iron Recovery from Groundwater Treatment Sludge by Reductive Acid Leaching and Hydroxide Precipitation. Journal of Environmental Management, 223: 723-730, 1 October 2018.

SEM images of (a) sludge, (b) leaching residue, (c) Fe precipitates and (d) MnSO4 solids, and (e) FTIR spectra of the sludge and leaching products.

Manganese (Mn) and iron (Fe) are commonly found in the earth’s crust and are removed from extracted groundwater to produce water for domestic use, more importantly for drinking purposes. During the treatment process, these heavy metals accumulate in the groundwater treatment sludge, and are disposed in landfills, dumps, or directly into the oceans. This study explored the recovery of Mn and Fe from groundwater treatment sludge through reductive acid leaching and hydroxide precipitation. The recovered metals may be utilized in other applications, while the resulting residue with lesser components will require simpler disposal options. Results showed that maximum leached Mn (100%) was obtained using sulfuric acid and hydrogen peroxide at 25 °C. Leached Mn and Fe decreased with the increase in the solid-liquid ratio. Leaching time had minimal effect on Mn and Fe leaching beyond 5 min, while agitation rate had minimal effect beyond 150 rpm. At 25 °C, the rate-limiting step of Mn leaching was diffusion through inert solid components of the sludge, composed mainly of insoluble sand particles. Fe leaching was governed by diffusion through the insoluble components of the sludge, including the unreacted manganese dioxide (MnO 2 ). Maximum precipitation of Fe and separation from Mn in the leachate through addition of potassium hydroxide occurred at pH 4.0. The results demonstrated that reductive acid leaching and hydroxide precipitation is an effective means of recovering Mn and Fe from groundwater treatment sludge. The applicability of the recovered Mn for nickel ion removal from aqueous solution was also explored in the study. Highest nickel ion uptake by the MnO2 synthesized from the recovered Mn was at 111.67 mg g −1 . Utilization of the recovered Mn, as MnO 2 , in nickel removal from aqueous solution is promising because of its high nickel adsorption capacity even exceeding previously explored nickel adsorbents.

Link to the article: https://www.sciencedirect.com/science/article/pii/S0301479718307047
Impact Factor: (2017/2018) 4.005


Ivy Razado-Colambo
Institute of Mathematical Sciences and Physics
College of Arts and Sciences
UP Los Baños

Structural Determination of Bilayer Graphene on SiC(0001) using Synchrotron Radiation Photoelectron Diffraction. Scientific Reports, 8 (1): 10190, 10 pages, 1 December 2018.

(Left) Atomic plane arrangement of bilayer graphene with AB stacking showing the different nearneighbour interlayer forward scattering directions. The angles shown correspond to the layer spacing of bulk graphite. (Right) C 1s core-level photoemission spectrum of graphene on SiC obtained at photon energy of 600 eV. The best-fit curve and its chemically resolved components are superimposed.

(Left) Experimental photoelectron diffraction angular distributions from the graphene C 1s component at a photoelectron kinetic energy of 326.1 eV. White spots are superimposed at polar emission angles of 12.2°, 20.2°, 26.7°, 32.7° and 37.5°, from the inner to the external part of the pattern, respectively. (Right) Comparison of experimental (data points) and simulated (continuous lines) intensity modulationsof the graphene C 1s photoelectron peak as a function of azimuth at different polar emission angles with a photoelectron energy of 326.1 eV.

Graphene is like a honeycomb or 'chicken wire' structure, made of single sheet of carbon atoms and their bonds. Graphite is many graphene sheets stacked together. Graphene is said to be the lightest, strongest, thinnest, best heat – and electricity – conducting material ever discovered. In recent years there has been growing interest in the electronic properties of ‘few layer’ graphene films. Twisted layers, different stacking and register with the substrate result in remarkable unconventional couplings. These distinctive electronic behaviours have been attributed to structural differences such has interlayer spacing, even if only a few structural determinations are available. The objective of the investigation was to determine the stacking sequence of bilayer graphene and the associated interlayer spacings in an effort to reconcile the different values found in existing theoretical and experimental literature. We have exploited the combination of photoelectron diffraction and multiple scattering simulations to show that bilayer graphene grown on the Si- terminated SiC(0001) face has an AB stacking and has an interlayer distance between the buffer layer and the first graphene layer of 3.24±0.20 Å while the interlayer spacing of the bilayer graphene is found to be 3.48±0.10 Å. The smaller spacing between the buffer layer and the first graphene layer than in bulk graphite (3.35 Å), and the fact that the interlayer graphene bilayer spacing is larger than that in bulk graphite, are consistent with several previous theoretical studies.

Link to the article: https://www.nature.com/articles/s41598-018-28402-0
Impact Factor: (2017/2018) 4.122