IPA Recipients for May 2019

Ann Selma C. Morata
Department of Chemistry
College of Arts and Sciences
UP Visayas

Trace organic chemical pollutants from the lake waters of San Pablo City, Philippines by targeted and non-targeted analysis, Science of the Total Environment, Vol 639, p 588-595.

The study investigated the water of the seven lakes of San Pablo City in Laguna, Philippines to determine the occurrence of pollutants and their sources. Three out of the seven lakes were focused to represent different human activities surrounding the lakes – Lake Sampaloc is found in the middle of the city that has large population and high load of untreated waste, Lake Palakpakin has intensive aquaculture activities and Lake Pandin is mainly used for eco-tourism. The pollutants were identified as pesticides from agricultural areas, artificial sweeteners and antibiotics from domestic activities, fire retardants and plasticizers from household materials and laundry washings, and surfactants from oils and its by-products. The results show that none of the pollutants are toxic to aquatic organisms as set by United States Environmental Protection Agency.

The results also suggest the poor management and lack of proper waste treatment of small lakes in our country. This study can serve as a basis for setting a guideline on waste discharges for lake management and help in creating sustainable livelihood practices to the community, fisherfolk and the local government.

Significance:
This study was conducted to put an emphasis on the environmental and anthropogenic impacts on small lakes in the Philippines specifically the Seven Lakes of San Pablo City, Laguna, Philippines. Different human activities influence the presence of pollutants in the lakes from farming, aquaculture, domestic activities, and eco-tourism. Small lakes are shown to be more exposed to pollution and prone to deterioration due to lack of wastewater treatment facilities and poor management. The results of this study have been shared with the lakeside households, fisherfolk, and local governments to help mitigate threats in the lakes, develop sustainable livelihood and practices, and guide their lake management strategies.

Link to the article: https://www.sciencedirect.com/science/article/pii/S0048969718318680
Impact factor: (2017/2018) 4.610

---

Andrei A. Domogo and Juancho A. Collero
Department of Mathematics and Computer Science
College of Science
UP Baguio

Symmetric solutions to a system of mutually delay-coupled oscillators with conjugate coupling. Journal of Physics: Conference Series, Vol. 1123, No. 1, p. 012028. DOI :10.1088/1742-6596/1123/1/012028

Coupled oscillators are the subject of different studies because they display interesting behavior, such as synchrony. In this paper, we investigate the dynamics of a system of two delay-coupled oscillators and show that they display some kind of synchrony. We use the Stuart-Landau equations to represent this system, which is linked via conjugate coupling. These equations form a system of delay differential equations, which we have found to have symmetry isomorphic to Z2×Z2. We looked into the form of steady-states that inherit part of the symmetry of this system and the birth of periodic solutions with symmetry. In particular, we found bifurcating steady-state and periodic solutions with symmetry isomorphic to Z2 emanating from the branch of trivial solutions. As an illustration, we performed numerical continuation to generate a bifurcating branch of symmetric solutions from the branch of trivial solutions. These symmetric solutions provide us with the type of synchrony that can be displayed by the oscillators. Finally, we determined the stability of the different branches of symmetric solutions numerically.

Significance:
We investigated the dynamics of a system of two delay-coupled oscillators from a symmetry perspective and showed that the kind of synchrony displayed by the model is due to system’s symmetry structure.

Link to the article: https://iopscience.iop.org/article/10.1088/1742-6596/1123/1/012028/meta
Impact factor: Not yet available

---

Charlotte E. Elmido, Teodora D. Balangcod and Kryssa D. Balangcod
Department of Biology
College of Science
UP Baguio

Inhibition of Pseudomonas aeruginosa by the extracts of indigenous plants from the Cordillera Region, Philippines. Indian Journal of Traditional Knowledge. 18(1): 41-46.

Indigenous plants are used for various medicinal purposes in the Cordillera Administrative Region (CAR) in the Philippines. However, there is little to no scientific basis that these plants are medicinal. Thirteen plants are then selected from different parts of CAR to be tested on their antibacterial activity against Pseudomonas aeruginosa, an opportunistic pathogen which is a causative agent of pneumonia and can contribute to serious bloodstream infection.

The 13 plants were extracted using absolute ethanol to which a crude extract was obtained. Standard disk diffusion assay was done wherein the extracts were placed in 6mm sterile discs in a petri dish inoculated with the bacterial strain. The zone of inhibition was then measured using a ruler. Out of the 13 plants, only four plants exhibited positive activity against P. aeruginosa. These plants are Nepenthes alata pitcher, Bauhinia purpurea leaves, Ficus septic stem, and Melastoma malabathricum leaves. Results of the study show that there are indigenous plants that have medicinal capabilities and can be used as substitutes for synthetic drugs.

Significance:
Indigenous plants in the Cordillera Administrative Region in the Philippines are being used for various purposes including treatment of several ailments. This article studies the antibacterial activity of 13 indigenous plants against Pseudomonas aeruginosa, an opportunistic pathogen. This study hopes to provide scientific basis for the antibacterial potential of these indigenous plants that are being used by local communities.

Link to the article: http://nopr.niscair.res.in/bitstream/123456789/45684/1/IJTK%2018%281%29%2041-46.pdf
Impact factor: (2017/2018) 1.061

---

Richie Eve G. Ragas
Department of Biology and Environmental Science
College of Science
UP Cebu

Analysis of the morpho-anatomical traits of four major garlic (Allium sativum L.) cultivars in the Philippines. Applied Ecology and Environmental Research 17(1):1143-1157. DOI: http://dx.doi.org/10.15666/aeer/1701_11431157

Garlic planted after rice in areas where rice production is constrained by water scarcity has been increasingly attractive for rice farmers in Occidental Mindoro. The province shares 17% of the country’s garlic production where common cultivars planted include ‘Lubang’ (LB), ‘Mindoro White’(MW), ‘Batanes White’ (BW), and ‘Ilocos White’ (IW). Since garlic is highly adaptive to its growth environment, evaluation and characterization of the morphological traits that are stable regardless of growth location can be a reliable diagnostic classification key for local garlic. This study provides an in-depth analysis of major local garlic cultivars for classification and for selection of those with improved adaptation and marketability. For classification, we focused on phenotypic stable traits. Among these traits analyzed, clove weight and number of bulb leaf sheaths were significantly different implying that these two traits are useful in distinguishing one garlic cultivar and the other. BW has the largest bulb circumference and weight while MW has the smallest and is lightest. In addition, when we examined the relationship among cultivars whether there exists an association of different traits among them, we found out that the highest bulb circumference and weight values of MW population correspond to the lowest values of BW population suggesting that these cultivars are two distinct populations. At the anatomical level, across cultivars, measurements of the epidermal and parenchymal cells were also different. Qualitative analysis of the bulb characteristics showed that BW exhibits traits (i.e three layers of large cloves) that imply market attractiveness while the potential for long storage owing to the clove’s tight skin are characteristics of IW’s population.

Significance:
This study provides an in-depth analysis of the morpho-anatomical characteristics of four major Philippine garlic cultivars in Mindoro by analyzing stable phenotypic traits. The four cultivars analyzed include ‘Mindoro White’ (MW), ‘Lubang’ (LB), ‘Batanes White’ (BW), and ‘Ilocos White’ (IW). Among traits analyzed, clove weight and number of bulb leaf sheath revealed significant relationships which can be used to detect morphologically similar garlic cultivars for classification and for selection of those with improved adaptation and marketability. The results point at BW population that displayed significant bulb traits and suggest that this cultivar could be further improved to match desirable traits of an imported garlic available in the Philippine market.

Link to the article: http://aloki.hu/indvolOF.htm
Impact factor: Not yet available

---

Christine Aubrey C. Justo, Mary Ann Cielo V. Relucio-San Diego and Windell L. Rivera
Natural Science Research Institute
College of Science
UP Diliman

Metronidazole susceptibility and TVV-infection of Trichomonas vaginalis from Metro Manila and Angeles City. Acta Medica Philippina. 52(6): 553-556

Trichomonas vaginalis is a parasite that causes trichomoniasis, the world’s most prevalent sexually transmitted infection (STI). It can infect men, women, and infants born from infected mothers. To date, the only FDA-approved drugs for the treatment of trichomoniasis are tinidazole and metronidazole. Metronidazole is more commonly used in the treatment of trichomoniasis but cases of metronidazole resistance have been reported. This study reported the metronidazole susceptibility of T. vaginalis isolated from women attending social hygiene clinics in Pampanga and Metro Manila. Of the forty-two laboratory-isolated parasites, all but one was susceptible to metronidazole. This suggests that trichomoniasis can still be treated with the standard treatment drug, metronidazole. The parasite that was resistant to metronidazole contains virus. However, the resistance to metronidazole was not due the virus since twelve of the metronidazole-susceptible parasites also contain the virus. Thirteen of the forty-two (31%) lab-isolated parasites have virus. To date, the role of the virus in the parasite remains unclear but it is known to worsen the inflammation in Trichomonas-infected women. The information in the presence of virus and metronidazole susceptibility of Trichomonas may aid in determining the transmission dynamics of the parasite and in choosing the drug for treatment of trichomoniasis.

Significance:
This study determined the presence of Trichomonas virus and the metronidazole susceptibility of Trichomonas vaginalis isolated from women attending social hygiene clinics in Pampanga and Metro Manila. The presence of virus and metronidazole susceptibility can be used in typing T. vaginalis, which in turn, may help in determining the transmission dynamics of T. vaginalis. Moreover, knowing the metronidazole susceptibility of the parasite may aid in the choice of drug for treatment of the infection, i.e., cases of metronidazole resistance have been reported and metronidazole is one of the only two FDA-approved drugs for trichomoniasis.

Link to the article: https://www.actamedicaphilippina.org/article/6840-metronidazole-susceptibility-and-tvv-infection-of-trichomonas-vaginalis-from-metro-manila-and-angeles-city-philippines
Impact factor: Not yet available

---

Karl Ezra S. Pilario
Department of Chemical Engineering
College of Engineering
UP Dilliman

Canonical Variate Dissimilarity Analysis for Process Incipient Fault Detection. IEEE Transactions on Industrial Informatics. doi: 10.1109/TII.2018.2810822

Large industrial plants (chemical, pharmaceutical, etc.) must be monitored continuously for any errors or faults that could lead to process performance degradation, equipment failure, or worse, human casualties. These faults usually start from small magnitudes before developing into disastrous magnitudes. Hence, they are called incipient faults. Fortunately, there is a big opportunity nowadays to use statistical machine learning tools for early detection of incipient faults by extracting useful information from large data sets obtained from the plant’s monitoring systems. Canonical Variate Analysis (CVA) is one such tool effective for dynamic process monitoring. In our paper, we derived a more sensitive statistical detection index for monitoring incipient faults under varying plant operating conditions. This has led to an extension of CVA called Canonical Variate Dissimilarity Analysis. Results have shown earlier detection of specific faults in a reactor (e.g. fouling in the cooling jacket, catalyst decay, etc.) against other methods in literature and CVA itself. Hence, greater lead time before process or equipment failure is realized. Our work has important implications in predictive maintenance activities for the process industries.

Significance:
By deriving a new statistical index for monitoring large industrial plants, our work has improved the detection of incipient faults that may otherwise lead to performance degradation or equipment failure. This has important implications in predictive maintenance activities for the process industries.

Link to the article: https://ieeexplore.ieee.org/document/8304817/
Impact factor: (2017/2018) 5.430

---

Ansyl Marie B. Naraga, Oliver John V. Belleza and Aaron Joseph L. Villaraza
Institute of Chemistry
College of Science
UP Diliman

Total synthesis of μ-conotoxin lt5d. RSC Advances, 8, 36579-36583

Lt5d is a neuroactive peptide isolated from the venom of the cone snail Conus litteratus. It consists of 12 amino acids with 2 disulfide bonds. It is a μ-conotoxin found to exhibit inhibitory activity on tetrodotoxin-sensitive Na channels, which makes it a potential anti-pain drug. Prior to this study, its total chemical synthesis had not yet been described. Our study is the first account of the total synthesis of lt5d using two folding methods: glutathione-assisted (Method 1), and orthogonal Cys protection (Method 2). The linear peptide was first synthesized using conventional solid-phase peptide synthesis and Fmoc strategy. In Method 1, the linear peptide was folded in solution using glutathione to achieve the most thermodynamically favored product. In Method 2, the disulfide bonds were formed sequentially through the use of orthogonal protection of cysteines. The first pair of Cys that was trityl-protected was deprotected by TFA and oxidized by DMSO. The second pair of Cys with acetamidomethyl protecting group was deprotected and oxidized by iodine. Co-injection of products yielded from Methods 1 and 2 in HPLC and MS showed that the same folded peptide was achieved using both methods. Additional NMR characterization data presented also further confirm that the target peptide was successfully synthesized. The established capability to synthesize larger quantities of lt5d in this report allows further studies on its structure and activity towards its development as an anti-pain drug candidate.

Significance:
The total synthesis of the μ-conotoxin lt5d is reported for the first time. The natural product was previously found to exhibit inhibitory activity on tetrodotoxin-sensitive Na channels, making it an anti-pain drug candidate that is worth pursuing. The established capability to chemically synthesize lt5d in larger quantities allows further studies on its structure and activity towards drug development.

Link to the article: https://pubs.rsc.org/en/content/articlelanding/2018/ra/c8ra03706j
Impact factor: (2017/2018) 2.936

---

Aldwin Christian T. Lacuesta¹, Marvin U. Herrera¹ and Mary Donnabelle L. Balela^2
1Department of Mining, Metallurgical and Materials Engineering
College of Engineering
UP Diliman
¹Institute of Mathematical Sciences and Physics
College of Arts and Sciences
UP Los Baños

Fabrication of Zinc Oxide-Polyaniline Composite on Kapok Paper for Methylene Blue Dye Removal in Aqueous Solution, Key Engineering Materials, Volume 779, Pages 137-141

We synthesized a material that could potentially remove charged contaminants from waste water. We took advantage of the cellulosic properties of kapok fibers, which are abundantly found in the Philippines, to make a flexible substrate: paper. The kapok fibers were cleaned and chemically treated to remove unnecessary substances. This is important so we can render the fibers into paper. Once paper have been fabricated, we deposited zinc oxide and polyaniline in the pre-cut kapok paper by dip-coating and successive ionic layer adsorption and reaction, respectively. To specify in detail, the paper was first dipped in zinc acetate and sodium hydroxide, then oven-dried to attach zinc oxide particles. This was succeeded with dipping in aniline, then in ammonium persulfate 50 times to deposit polyaniline. After the deposition, the material was dipped in sodium hydroxide solution to modify the polyaniline by altering its charged backbone. This way, polyaniline is able to remove cationic dye, in contrast to anionic dyes. We tested our material using different techniques to examine its potency. First, the morphology was determined by SEM, then the elemental composition was validated using EDX. The presence of polyaniline in our material was confirmed by FT-IR. After these tests, we used our material to remove methylene blue, a type of cationic dye. After a series of tests, we compared the removal percentage of the modified material and the as-synthesized material. We determined that the modified material is able to remove 75% more dye compared to the unmodified polyaniline.

Significance:
A composite made up of zinc oxide and polyaniline was synthesized on kapok paper. Kapok is a highly cellulosic material that is abundant here in the country which normally has no use other than stuffing for pillows. We took advantage of that property to create a paper made up of chemically-treated kapok which served as a substrate for the composite. Polyaniline is extensively used as an adsorbent of anionic metals and dyes due to its cationic backbone. However, in our study, we modified the polyaniline to allow it to remove cationic dyes from wastewater by a simple de-doping method using a NaOH solution. This method proved that our material can be used to remove both cationic and anionic contaminants in water by simple modification.

Link to the article: https://www.scientific.net/KEM.779.137
Impact factor: Not yet available

---

Betchaida D. Payot
National Institute of Geological Sciences
College of Science
UP Diliman

Mantle Evolution from Ocean to Arc: The Record in Spinel Peridotite Xenoliths in Mt. Pinatubo, Philippines. Minerals, 8 (11): 515; https://doi.org/10.3390/min8110515

The term “xenolith” came from the word “xenos” meaning foreign, and “lithos” which means stone. Xenoliths are therefore foreign rock fragments enveloped in another rock of a different composition. In this study, xenoliths from the uppermost mantle beneath Mt. Pinatubo were exhumed to the surface during the 1991 Mt. Pinatubo eruption. The samples were collected from the lahar deposits along the O’Donnell River, one of the major rivers in the vicinity of Mt. Pinatubo. The presence of these xenoliths in the eruptive products of Mt. Pinatubo suggests quick storage and exhumation of these rocks to surface. This also implies that the magmas hosting these xenoliths spent little time at the magma chamber enroute to the surface. Thus, the mantle xenoliths were preserved and did not dissolve within the hot and molten material hosting them. Moreover, the different rock types in the sampling suite further imply the heterogeneous nature of the mantle wedge beneath Mt. Pinatubo.

Significance:
This research investigates the characteristics of the mantle wedge and the processes occurring beneath the Philippine island arc system using mantle xenoliths from Mt. Pinatubo. Through this study, we aim to understand how magmatic processes operate within volcanoes. The presence of xenoliths in the eruptive products of Mt. Pinatubo suggest quick storage and exhumation of these rocks to the surface by magmas.

Link to the article: http://www.mdpi.com/2075-163X/8/11/515
Impact factor: (2017/2018) 1.835

---

Eric A. Galapon and John Jaykel P. Magadan
National Institute of Physics
College of Science
UP Diliman

Quantizations of the classical time of arrival and their dynamics. Annals of Physics, Vo. 397, pp. 278-302 (2018)

Time is part of our everyday lives and it is something that we “measure” with our clocks and watches. If we are shrunk to the sizes of atoms and molecules, is our conception of time preserved? This question underlies the problem known as the quantum time problem. For a long time, the consensus is that “time” in the quantum world of atoms and molecules does not correspond to a property of a molecule or to an atom that can be subject to measurement. The problem revolves around the question of whether a mathematical entity called time-operator exists or not. It has been thought that such an entity does not exist. However, the paper shows that many such operators can be constructed, and that they possess properties that we expect from a quantity that can be subject to measurement.

Significance:
The work addresses the question whether it is meaningful or not to quantize the classical time of arrival (CTOA) in the presence of an interaction potential for a one-dimensional structureless particle. It has been the consensus that the classical time of arrival cannot be meaningfully quantized because the CTOA can be multiple and complex valued. However, the paper shows that the CTOA can be quantized even in the presence of an interaction potential. The paper formulates the general framework where the CTOA can be quantized for any chosen ordering rule. The paper then goes to demonstrate that the eigenfunctions of the quantized time of arrival operators evolve to unitarily collapse at the arrival point at their corresponding eigenvalues.

Link to the article: https://www.sciencedirect.com/science/article/pii/S0003491618302173
Impact factor: (2017/2018) 2.367

---

Alwin C. Aguirre
Department of Filipino and Philippine Literature
College of Arts and Letters
UP Diliman

Crossing the Gain Line: Migration, Sport and National Belongings on Facebook. Discourse and Society, 30 (1): 3-23, 2019

Hosting the Rugby World Cup in 2011 offered a chance for New Zealand to showcase itself on the world stage, but also provided immigrants to the country an opening to assert their legitimate place in the nation. We present the particular case of Leslie, a Filipina migrant, and her Facebook activities during the tournament. As a social media platform, Facebook afforded her a chance to perform support for the national rugby team, which gradually transitioned into an expression of her affinity, not only with the sport but more importantly, with the country as her family’s new home and a sense of shifting identification with its culture, the sentiments of a people, and a seemingly unified aspiration of a nation. Leslie’s case demonstrates how social media and the sport mega-event acted as the means through which immigrants potentially perform belonging and negotiate their unsteady place in the new home.

Significance:
The study privileges the cultural and semiotic aspect of migration, in particular, the identity work of a particular case of a Filipino migrant in New Zealand. Despite the singularity of the case, it is hoped that it sheds light on the complexities of navigating the self, place, and belonging in the migration experience. At the heart of the project is an analysis of individual discourses of identity produced and consumed on platforms made available by new media developments, affording migrants not only novel ways of communicating and maintaining transnational relationships but also opportunities for meaning-making and self-presentation. What the study enables, at the very least, is a venue for the voices of ordinary people to figure in the complex interactions of large and inescapable forces of change in society. Identity, after all, is a major area of struggle for dominance and resistance in the networked arena of globalized life. Manuel Castells (2010) maintains that in highly networked global flows of wealth, power, and images, the search for identity cannot be set aside since it becomes the fundamental source of social meaning amidst the overarching primacy of structural networks of finance, policies, and politics.

Link to the article: https://journals.sagepub.com/doi/full/10.1177/0957926518801073
Impact factor: Not yet available

---

Eric A. Galapon and Christian D. Tica
National Institute of Physics
College of Science
UP Diliman

Finite-part integration of the generalized Stieltjes Transform and its dominant asymptotic behavior for small values of the parameter. II. Non-integer orders. Journal of Mathematical Physics, Vol. 60, Issue no. 1, 10.1063/1.5038900 (2019)

Infinities inevitably arise in many different forms and under different context in mathematics. They play an important role and sometimes even undermine the mathematical foundation of the most esoteric theories of physics which provide our best understanding of nature at some fundamental level. For this reason, plenty of schemes were invented to give meaning to these mathematical pathologies. In the current work, we used one of these schemes and elevated it to a more rigorous status. As a result, we were able to systematically assign a unique and consistent definition for some class of divergent integrals which could then be used to obtain the exact values of absolutely convergent integrals.

Significance:
The current work further advances the range of applicability of finite part integration in the calculation of the non-integer order Stieltjes Transform. Finite part integration is a novel approach at utilizing the finite information extracted from divergent integrals in calculating exact values of convergent integrals. This new prescription of assigning meaningful and well-defined representations to divergent integrals and consequently using them in rigorous calculations sheds an interesting perspective on the proper treatment of infinities arising in various fields of applied mathematics and mathematical physics. Infinite mathematical objects, although overwhelmingly ubiquitous, are far less understood and undeniably more subtle than their finite counterparts

Link to the article: https://aip.scitation.org/doi/10.1063/1.5038900
Impact factor: (2017/2018) 1.165

---

Mary Donnabelle L. Balela, Thomas Jay Angostura, Amiel Marc Domingo and Charmaine Grace Facal
Department of Mining, Metallurgical and Materials Engineering
College of Engineering
UP Diliman

Two-Step Synthesis of Cobalt Oxide Nanowires via Electroless Deposition and Thermal Oxidation for Supercapacitor Applications. Key Engineering Materials, Vol. 775, pp. 336-341, 2018

With the purpose of producing more efficient and powerful electrical energy storage, efforts are being made to develop supercapacitors. Unlike batteries, supercapacitors have a very high power density and long operating lifetime. It has high charge-discharge stability making it suitable for high-performance applications such as in electric vehicles, uninterruptable power sources, digital communication systems, and high power apparatuses. Cobalt oxide is one of the best candidates for supercapacitor materials because of its high theoretical specific capacitance of 3569 F/g, well-defined electrochemical redox activity and low cost. As the active material of these devices, it is important that cobalt oxide is prepared with high surface area. Thus, this work presents a very easy way of synthesizing high surface area nanowire electrodes by utilizing the magnetic properties of cobalt, the parent material of cobalt oxide. Cobalt nanowires were first prepared by simple chemical reduction under an external magnetic field. Commercial neodymium magnets were used as the magnetic field, causing the self-alignment of the cobalt particles to nanowires. Then, the cobalt nanowires were converted to cobalt oxide by oxidation in hot air.

Significance:
Cobalt oxide is one the most promising electrode materials for supercapacitors. As the active material of these devices, it is important that cobalt oxide should be prepared with high surface area. Thus, this work presents a very easy way of synthesizing high surface area nanowire electrodes by utilizing the magnetic properties of cobalt, which is the parent material of cobalt oxide. Cobalt nanowires were first prepared by simple chemical reduction under an external magnetic field. Commercial neodymium magnets were used as the magnetic field, causing the self-alignment of the cobalt particles to nanowires. Then, the cobalt nanowires were converted to cobalt oxide by oxidation in hot air.

Link to the article: https://doi.org/10.4028/www.scientific.net/KEM.775.336
Impact factor: Not yet available

---

Remil L. Galay
Department of Veterinary Paraclinical Sciences
College of Veterinary Medicine
UP Los Baños

Hemolymph defensin from the hard tick Haemaphysalis longicornis attacks Gram-positive bacteria. J Invertebr Patho. 156:14-18. 2018

Ticks can transmit various diseases to humans and animals. It is remarkable how they become infected with pathogens, yet are not adversely affected by them. Antimicrobial peptides such as defensins are among the components of tick innate immunity. In this study, the antibacterial properties of a previously identified defensin, HEdefensin, from the hemolymph of the hard tick Haemaphysalis longicornis was evaluated. Synthetic HEdefensin was prepared and subjected to bactericidal assay against Gram-positive and Gram-negative bacteria. The minimal inhibitory concentration (MIC) was determined. HEdefensin showed significant antimicrobial activities against Gram-positive bacteria, especially Micrococcus luteus with MIC of 12.5 µM. The bactericidal effect of HEdefensin against M. luteus was further investigated through fluorescence propidium iodide exclusion assay and binding assay. The fluorescence propidium iodide exclusion assay demonstrated that HEdefensin can disrupt the bacterial membrane, thus increasing the membrane permeability. It was also found through confocal microscopy that HEdefensin can bind to the membrane of M. luteus. Collectively, these results suggest that HEdefensin can protect the tick from Gram-positive bacteria.

Significance:
This work adds knowledge on immune mechanism of ticks, which helps in understanding tick-pathogen interaction and vector competence of ticks. The study also demonstrated a potential antimicrobial that might be useful in treating infections with Gram-positive bacteria.

Link to the article: https://www.sciencedirect.com/science/article/pii/S0022201118300533?via%3Dihub
Impact factor: (2017/2018) 2.511

---

Salcedo L. Eduardo
Department of Veterinary Paraclinical Sciences
College of Veterinary Medicine
UP Los Baños

A new species of Saemundssonia and new records of Quadraceps species (Phthiraptera: Ischnocera: Philopteridae) found on some Philippine charadriiform birds. Philippine Journal of Veterinary Medicine, 55(2): 115-126

A species of louse new to science (Saemundssonia philippina) was discovered from the wild bird, greater painted-snipe (Rostratula benghalensis benghalensis) in the Philippines contributing to our knowledge of lice affecting birds in the world. Two others belonging to another genus. although previously known lice species of birds, Quadraceps quadrisetaceius and Q. birostris were reported for the first time in the Philippines. These are all described and figured based on the Philippine materials: the former from three bird hosts, the greater painted snipe, Jack snipe and common sandpiper; and the latter from the common re-shank. These bird hosts belong the order Charadriiformes that inhabit shoreline and inland waterways and form an important component of the ecosystem. These lice can have injurious effects on the bird hosts especially in heavy infestation. Many of these birds are becoming rare because of the loss of habitat due to population encroachment. Key to successful conservation efforts like captive breeding of these bird hosts is basic information on the birds’ health aspects including ectoparasitism (lice infestation).

Significance:
This work has shown that there are still species of lice that need to be discovered and that other species known in other areas of the world also exist in other parts like the Philippines. This contributes to our knowledge of lice infesting wild birds which form an important component of the ecosystem as well as to the extent of parasitic invertebrate biodiversity worldwide.

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

---

Remil L. Galay
Department of Veterinary Paraclinical Sciences
College of Veterinary Medicine
UP Los Baños

Vector competence of Haemaphysalis longicornis ticks for a Japanese isolate of the Thogoto virus. Sci. Rep. 8(1):9300. 2018

Ticks can transmit a wide array of pathogens such as viruses to humans and animals. Recently, Thogoto virus, which was previously not reported in East Asia and is known to utilize hard ticks belonging to genera Rhipicephalus, Amblyomma and Hyalomma as vectors, was isolated in the Haemaphysalis longicornis tick from Kyoto, Japan. To investigate the competence of H. longicornis as a vector of Thogoto virus, the virus was introduced into the tick through microinjection into the tick’s anal opening or by infesting them into mice infected with the virus. Viral RNA was detected by real-time RT-PCR. Viral isolation from different tick organs was also performed, as well as detection of the viral antigen through immunofluorescent confocal microscopy. Results showed that Thogoto virus can replicate in H. longicornis and can transmit the virus into non-infected mice. The virus can be isolated from the midgut and salivary glands, which was supported by the results of immunofluorescent visualization in the midgut and salivary glands. Althogether, the results of this study imply that H. longicornis is a competent vector of Thogoto virus.

Significance:
This work adds knowledge on elucidation of tick-pathogen interaction and vector competence of ticks, which is essential in controlling tick-borne pathogens.

Link to the article: https://www.nature.com/articles/s41598-018-27483-1
Impact factor: (2017/2018) 4.122

---

Maritess L. Magalona¹, Milagros M. Peralta¹,Marivic S. Lacsamana¹, Veronica C. Sabularse¹ and Constancio C. de Guzman^2
1Institute of Chemistry
¹Institute of Crop Science
College of Arts and Sciences
UP Los Baños

Optimization and validation of a Differential Pulse Anodic Stripping Voltammetric (DPASV) method for trace analysis of inorganic arsenic in contaminated water. JOURNAL OF ISSAAS. June 2018. 24(1) pp. 137-151. ISSN 0859-3132

Arsenic is an element that is found in nature. It ranks 20th in abundance in the earth’s crust, 14th in seawater, and 12th in the human body (Khan and Ho 2011). Additionally, in the past, during the Green Revolution, the use of farmers with fertilizers, herbicides, and pesticides that contain phosphorus increase the exposure of humans to arsenic because arsenic is a natural contaminant of phosphate minerals (Jayasumana et al. 2015). Thus, humans are always exposed to arsenic in food, water, and soil.

Arsenic is in the WHO’s list of 10 chemicals of greatest public health concern. In fact, numerous cases of arsenic poisoning have been reported worldwide including in the Philippines. With this incidence, the maximum contamination set by the Environmental Protection Agency (EPA) in drinking water is lowered from 50 ppb to 10 ppb. Few methods were developed to analyze arsenic at this level. Expensive and high – maintenance equipment are required for these methods of analysis.

This study focuses on the development of a differential pulse anodic stripping voltammetric method (DPASV) for trace arsenic analysis as As(III) that can analyze arsenic levels below 10 ppb. This method utilizes gold electrode as working electrode, Pt/Ti rod as auxiliary electrode, and Ag/AgCl electrode as reference electrode. The advantages of the said method over other analytical method are high selectivity for arsenic, low maintenance cost, and low detection limit that allows for analysis of arsenic as As (III) at levels as low as 2.24 ppb.

References:
Khan, M.A. and Y. Ho. 2011. Arsenic in drinking water: a review on toxicological effects, mechanism of accumulation and remediation. Asian Journal of Chemistry. 23(5): 1889-1901.

Jayasumana, C., S. Fonseka, A. Fernando, K. Jayalath, M. Amarasinghe, S. Siribaddana, S. Gunatilake and P. Paranagama. 2015. Phosphate fertilizer is a main source of arsenic in areas affected with chronic kidney disease of unknown etiology in Sri Lanka. Springer Plus 4:90-98.

Significance:
Arsenic is in the World Health Organization’s (WHO) list of ten chemicals of greatest public health concern (WHO 2010). High incidence of chronic poisoning due to arsenic contamination in water has been reported all over the world including in the Philippines (Khan and Ho 2011; Sun Star Manila 2016). As of June 2016, 123 cases of arsenicosis were recorded by the Department of Health in Central Luzon, Philippines (Sun Star Manila 2016). With the reduction of the maximum contamination limit for arsenic from 50 ppb to 10 ppb in drinking water, the development of simple and cost – effective methods for trace detection of this metalloid has become urgent. This study focuses on the development of a differential pulse anodic stripping voltammetric method (DPASV) for trace arsenic analysis as As(III) that can analyze arsenic levels below 10 ppb.

References:
Khan, M.A. and Y. Ho. 2011. Arsenic in drinking water: a review on toxicological effects, mechanism of accumulation and remediation. Asian Journal of Chemistry. 23(5): 1889-1901.

Sun Star Manila. 2016. June 30. DOH on alert vs arsenic contamination in Central Luzon. Sun.Star Manila newspaper. Retrieved from: http://www.philippines-addicts.com/forum/topic/57791-arsenic-poisoning-worries-pampanga-town-folk/#
[WHO] World Health Organization. 2010. Preventing disease through healthy environments: Action is needed on chemicals of major public health concern. WHO Document Production Services, Switzerland.

Link to the article: http://www.issaas.org/journal/issues.html
Impact factor: Not yet available

---

Raymundo R. Pavo
Department of Social Science
College of Humanities and Social Science
UP Mindanao

Night market as lived space: The case of Davao City, Philippines. Asia-Pacific Social Science Review, 19(1), 66–89

This paper explores the Roxas Night Market in Davao City as a gathering of stories of struggles and hope for enabling vending spaces. Coming from different historical backgrounds, these vendors bring with them their histories and experiences as they subsist in small vending spaces in the night market. This makes the Roxas Night Market as one of the nodes in their departures or quests for enabling spaces. Is the Roxas Night Market providing them an opportunity to find fulfilling spaces of work? This paper suggests that the night market temporarily gives them respite from the uncertainties of street vending but is not a stable option in ensuring that their vending enterprise will thrive. Since the night market is a gathering of stories, the contributions of the street vendors in the unfolding history of the city should also be listened to, assessed, and acknowledged. Through their stories, the street vendors speak about their hope a space will be given – perhaps similar to the night market, which will eventually be their last stop in their seemingly unending departures.

Significance:
This work tackles the experiences of street night market vendors in Davao City, and shows how their stories contribute to the unfolding of Roxas Night Market as a narrative. Emphasizing the experiences of the street night market vendors, the night market can be seen as part of the street vendors’ quest for well-being and economic security. Hoping that they will have their rightful place in the fast-changing urban landscapes, the study stands as a challenge to the local government unit to come up with policies, designs, and interventions that acknowledge the vendors’ history and capacity to contribute to the overall significance of the Roxas Night Market to the city.

Link to the article: https://apssr.com/volume-19-no-1/night-market-as-lived-space-the-case-of-davao-city-philippines/
Impact factor: Not yet available

---

Cybele Lara R. Abad
Department of Medicine
College of Medicine
UP Manila

Mycobacterium tuberculosis after solid organ transplantation: A review of more than 2000 cases. Clin Transplant. 2018 Apr 15:e13259

Mycobacterium tuberculosis (TB) is endemic in the Philippines and a common pathogen worldwide, and it may cause significant infection after solid organ transplantation (SOT). We reviewed all reported TB cases to provide an update on its epidemiology, clinical presentation, management, and outcome after SOT. We found 187 publications reporting 2082 cases of TB among kidney (n = 1719), liver (n = 253), heart (n = 77), lung (n = 25), and kidney-pancreas (n = 8) recipients. Among cohort studies, the median incidence was 2.37% (range, 0.05%-13.27%) overall. Most TB disease was considered reactivation of latent infection, occurring beyond the first year after SOT. Fever was the most common symptom. Radiologic findings were highly variable. Extrapulmonary and disseminated TB occurred frequently, at 29.84% and 15.96%, respectively. Treatment using 4 or 5 drugs was commonly associated with hepatotoxicity and graft dysfunction. All-cause mortality was 18.84%. This large review highlights the complexity of TB after SOT. Reactivation TB, donor-transmitted infection, extrapulmonary involvement, and disseminated disease are common occurrences. Treatment of TB was commonly associated with hepatotoxicity and graft dysfunction.

Significance:
This research is the only contempary and comprehensive review of tuberculosis among solid organ transplant recipients. With this review, provide a thorough evaluation of the epidemiology, risk factors, treatment, and outcome of tuberculosis in the transplant population.

Link to the article: https://www.ncbi.nlm.nih.gov/pubmed/29656530
Impact factor: (2017/2018) 1.518

---

Janus Ong
Department of Medicine
College of Medicine
UP Manila

Nonalcoholic Steatohepatitis Is the Fastest Growing Cause of Hepatocellular Carcinoma in Liver Transplant Candidates. Clinical Gastroenterology and Hepatology. https://doi.org/10.1016/j.cgh.2018.05.057

While hepatitis B and C have been the main drivers of hepatocellular carcinoma (HCC), non-alcoholic steatohepatitis (NASH) has recently become an important cause of HCC. The aim of this study was to assess the causes of HCC among liver transplant (LT) candidates in the U.S. Methods: The Scientific Registry of Transplant Recipients (2002-2016) was used to estimate the trends in prevalence of HCC in LT candidates with the most common types of chronic liver disease: alcoholic liver disease (ALD), chronic hepatitis B (CHB), chronic hepatitis C, and NASH. RESULTS: 158,347 adult LT candidates were included. Of these, 26,121 (16.5%) had HCC; this proportion increased from 6.4% (2002) to 23.0% (2016) (trend p<0.0001). Over the study period, CHC remained the most common etiology for HCC (65%). The proportions of HCC accounted for by CHC and ALD remained stable (both trend p>0.10), the proportion of CHB decreased 3.1-fold (p<0.0001), while the proportion of NASH in HCC increased 7.7-fold (from 2.1% to 16.2%, p<0.0001). Furthermore, since 2002, the prevalence of HCC in LT candidates with NASH increased 11.8-fold, while this rate increased 6.0-fold in CHB, 3.4-fold in ALD and 2.3-fold in CHC (all p<0.0001); the increasing trend in NASH was steeper than that for any other etiology (p<0.0001 in a trend regression model). The proportion of LT candidates with HCC who were ultimately transplanted or died while waiting did not differ between etiologies (p>0.05). CONCLUSIONS: Non-alcoholic steatohepatitis is the most rapidly growing cause of HCC among U.S. patients listed for liver transplantation.

Link to the article: https://linkinghub.elsevier.com/retrieve/pii/S1542356518306116
Impact factor: (2017/2018) 7.683

---

Michelle D. Lingao
Department of Ophthalmology and Visual Sciences
College of Medicine
UP Manila

Review of Craniofacial Syndromes. Acta Medica Philippina. 2017; 51(3): 162-166

We see a number of craniofacial syndromes in our community and yet there is only very little understanding of its etiology. These are exciting times in terms of genetics where we now have the ability to know the genetic basis of certain conditions. This review may help the reader understand craniosynostosis better from a genetics viewpoint. I hope that this would encourage our researchers to do studies on Filipinos with this condition and perhaps lead to future identification of new mutations or new genes in our population. This would help clinicians in counseling patients and their families and also lead to a better multidisciplinary management of these patients.

Link to the article: http://actamedicaphilippina.com.ph/content/volume-51-no-3-genetics-issue
Impact factor: Not yet available

---

Derick Erl P. Sumalapao¹ and Roland Dominic G. Jamora^2
1Department of Medical Microbiolog
²Department of Neurosciences
College of Medicine
UP Manila

Quality of life and Parkinson’s disease: Philippine translation and validation of the Parkinson’s disease questionnaire. J Clin Neurosci (2018), https://doi.org/10.1016/j.jocn.2018.06.013

The 39-item Parkinson’s Disease Quality of Life Questionnaire (PDQ-39) is the most widely used self-administered questionnaire assessing the quality of life of Parkinson’s disease (PD) patients. We translated the PDQ-39 into the Filipino language as the Philippine-PDQ-39 (P-PDQ-39) and used it to assess the quality of life of Filipino patients with PD. The original PDQ-39 was translated into Filipino using forward and backward translation by independent bilingual translators and used among 100 consecutively sampled PD patients. The P-PDQ-39 is a valid assessment tool for assessing the quality of life of Filipino-speaking PD patients.

Significance:
A Filipino version of the Parkinson’s Disease (PD) quality of life questionnaire is necessary to assess the health-related quality of life of Filipino PD patients.

Link to the article: https://doi.org/10.1016/j.jocn.2018.06.013
Impact factor: (2017/2018) 1.640

---

Ma. Dominga B. Padilla
Department of Ophthalmology and Visual Sciences
College of Medicine
UP Manila

The Asia Cornea Society Infectious Keratitis Study: A Prospective Multicenter Study of Infectious Keratitis in Asia. American Journal of Ophthalmology. November, 2018. Vol. 195, pages 161-170

Infectious keratitis, or infection of the cornea, is the fourth leading cause of blindness in the world. This study is the first multinational, standardized survey of infectious keratitis in Asia where the incidence of infectious keratitis is particularly high. It has established a comparative baseline description of the risk factors, microbiology and outcomes of these infections in both developed and developing Asian countries.

This study showed that the most common risk factor for corneal infections in developing Asian countries like the Philippines, China and India is trauma while in developed countries like Singapore, Korea and Japan, it is contact lens wear. Pseudomonas aerogenosa, a very virulent bacteria, was the most common bacterial pathogen isolated overall, and had the percentage in the Philippines. Fungi were the most common cause of corneal infections in India. The outcomes of corneal infections are bleak, with a large percentage needing corneal transplants, and with more than half of the 6563 eyes resulting in visual impairment even with treatment and surgery. Sadly, the necessity for corneal transplant surgery was greatest in India, China and the Philippines where there is a severe lack of corneal tissue for transplant. Given the magnitude of the problem, and given that trauma is the main cause of corneal infections in developing countries where outcome is poorer, primary prevention with protective eyewear is important. But failing this, secondary prevention by training public health workers on recognizing corneal abrasions and on the use of prophylactic topical antibiotics for eye trauma, is suggested.

Significance:
Infectious Keratitis, or infections of the cornea, is the fourth leading cause of blindness in the world. These are called silent epidemics particularly in developing countries such as China, India, Thailand and the Philippines, where corneal infections still remain among the main reasons for corneal transplants because of the corneal scarring and perforation they can cause. Yet, up to the time this study was undertaken, epidemiological studies and research efforts on the subject varied widely among Asian Countries, with a scarcity of data in many countries with a heavy burden of corneal infections. The Philippines was one such country. Furthermore, the researches differed in methodology, definitions and patient population, making it difficult to compile and compare data. This study is the first multinational, standardized survey of infectious keratitis in Asia. It has established a comparative baseline description of the risk factors, microbiology and outcomes of these infections in both developed and developing Asian countries. These findings may help primary physicians and ophthalmologists make the correct management decisions; as well as help doctors, advocates and policy makers take steps to reduce or mitigate the identified risks, and in so doing, help reduce the burden of blindness due to infectious keratitis.

Link to the article: https://www.sciencedirect.com/science/article/pii/S0002939418304331
Impact factor: (2017/2018) 4.795