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Faculty Publication (2017)

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1. Anticamara, J. A., & Go, K. T. B. (2017). Impacts of super-typhoon Yolanda on Philippine reefs and communities. Regional Environmental Change, 17(3), 1–11.more

Abstract:

This report presents super-typhoon Yolanda’s impacts on coral reefs of Eastern Samar, Philippines, and evaluates its implications on resource management in the area. Coral reefs suffer regular impacts of typhoons, and typhoons nowadays are stronger in magnitude, longer in duration, more frequent in occurrence, and larger in scale. Thus, there is a great need to understand the impacts and consequences of super-typhoons on reefs and the coastal communities. Yolanda is the strongest recorded typhoon to make a landfall. Here is the first account of Yolanda’s impacts on corals and benthic organisms, reef fish, and fisheries production. Our study sites covered Lawaan, Balangiga, Giporlos, Quinapondan, Salcedo, and Guiuan in Eastern Samar, Philippines—municipalities that were greatly damaged by Yolanda. To quantify the impacts of Yolanda on coral reefs, we compared coral cover and diversity, and fish abundance, biomass, and diversity between sites before and after Yolanda. We found that some reef areas were completely wiped out by Yolanda (i.e., the shallow branching reefs), but other reef sites were only partially damaged. The extent of damages depends on reef locations relative to Yolanda’s trajectory, depth, coral species composition, and reef condition prior to Yolanda. We also found that most reefs in the area already suffered degradation prior to Yolanda (i.e., due to overfishing, destructive fishing, and siltation from land). Active coral restoration, reduction in fishing effort, diversification of economic activities, and effective management of no-take marine reserves should play key roles in the recovery of resources and human lives in these devastated areas.

2. Buhian, W. P. C., Rubio, R. O., & Martin-Puzon, J. J. (2017). Chromatographic fingerprinting and free-radical scavenging activity of ethanol extracts of Muntingia calabura L. leaves and stems. Asian Pacific Journal of Tropical Biomedicine, 7(2), Pages 139–143. more

Abstract:

Objective

To determine the thin-layer chromatography (TLC) fingerprint profiles and to evaluate the in vitro antioxidant activity of ethanol extracts of Muntingia calabura (M. calabura) leaves and stems.

Methods

The leaves and stems were extracted using ethanol as solvent. The TLC separation of the phytochemical constituents of the leaf and ethanol extracts was carried out in ethyl acetate: n-hexane and chloroform: ethyl acetate mobile phase systems. Distinct spots were visualized under visible light, UV 254 nm, UV 366 nm and after spraying with vanillin-sulfuric acid. The 2,2-diphenyl-1-picrylhydrazyl free-radical scavenging assay was used to evaluate the antioxidant activity of the extracts.

Results

Both the leaf and stem ethanol extracts at 4 mg/mL exhibited 2,2-diphenyl-1-picrylhydrazyl inhibition of more than 90%, relative to gallic acid. The results of TLC showed that the degree of resolution between the constituent spots was comparable between the two mobile phase systems using the different visualization wavelengths. Under the 254 nm visualization, few spots were observed in leaf and stem extracts. Visualization at 366 nm yielded the greatest number of observable spots of various colors in both leaf and stem extracts. More spots were visualized upon post-derivatization with vanillin-sulfuric acid in the TLC chromatograms using chloroform: ethyl acetate mobile phase, compared to those in ethyl acetate: n-hexane mobile phase.

Conclusions

M. calabura exhibited very high antioxidant activity in its leaves and stems ethanol extracts, both of which are used in traditional medicine. The TLC results demonstrated the presence of diverse secondary metabolites in the leaf and stem ethanol extracts, indicating that the antioxidant activity, including other bioactivities may be attributed to these phytochemical constituents. This paper has reported for the first time the TLC fingerprinting of M. calabura using visible light, UV 254 nm, UV 366 and post-derivatization with vanillin-spray to visualize separate spots on TLC plates. 

3. Calayag, A. M. B., Paclibare, P. A. P., Santos, P. D. M., Bautista, C. A. C., & Rivera, W. L. (2017). Molecular characterization and antimicrobial resistance of Salmonella enterica from swine slaughtered in two different types of Philippine abattoir. Food Microbiology, 65, 51–56. more

Abstract:

Salmonella entericais a well-known pathogen commonly acquired from the consumption of contaminated food. It has been estimated to affect millions of humans and cause hundreds of thousands of deaths per year globally. Pork, one of the most commonly consumed meats worldwide, has been identified as one of the main sources of human salmonellosis. In this study, we aimed to detect and characterizeS. entericafrom slaughtered swine and generate antimicrobial resistance profiles of select isolates. Tonsils and jejunum with mesenteric lymph nodes (MLN) were collected from a total of 240 swine from eight abattoirs (five accredited and three locally registered abattoirs) across Metro Manila.S. entericawere isolated using conventional culture methods and confirmed by PCR amplification of theinvAgene. Isolates were further characterized based on somatic antigen by multiplex PCR. We report that there is no significant difference (P = 0.42) between the incidences ofS. entericain swine slaughtered in accredited (44.0%) and in locally registered abattoirs (46.7%). Most samples were contaminated withS. entericaunder serogroup O:3,10. Antimicrobial susceptibility testing of 183 isolates using the VITEK®2 system revealed high resistance to ampicillin (67.8%) and trimethoprim/sulfamethoxazole (80.3%). Multidrug-resistance was found in 124 (67.8%) isolates.

4. Cruaud, P., Rasplus, J.-Y., Rodriguez, L. J., & Cruaud, A. (2017). High throughput sequencing of multiple amplicons for barcoding and integrative taxonomy. Scientific Reports, 7more

Abstract:

Until now, the potential of NGS for the construction of barcode libraries or integrative taxonomy has been seldom realised. Here, we amplified (two-step PCR) and simultaneously sequenced (MiSeq) multiple markers from hundreds of fig wasp specimens. We also developed a workflow for quality control of the data. Illumina and Sanger sequences accumulated in the past years were compared. Interestingly, primers and PCR conditions used for the Sanger approach did not require optimisation to construct the MiSeq library. After quality controls, 87% of the species (76% of the specimens) had a valid MiSeq sequence for each marker. Importantly, major clusters did not always correspond to the targeted loci. Nine specimens exhibited two divergent sequences (up to 10%). In 95% of the species, MiSeq and Sanger sequences obtained from the same sampling were similar. For the remaining 5%, species were paraphyletic or the sequences clustered into divergent groups on the Sanger+MiSeq trees (>7%). These problematic cases may represent coding NUMTS or heteroplasms. Our results illustrate that Illumina approaches are not artefact-free and confirm that Sanger databases can contain non-target genes. This highlights the importance of quality controls, working with taxonomists and using multiple markers for DNA-taxonomy or species diversity assessment.

5. Dumilag, R. V., & Aguinaldo, Z.-Z. A. (2017). Genetic differentiation and distribution of Pyropia acanthophora (Bangiales, Rhodophyta) in the Philippines. European Journal of Phycology, 0(0), Pages 1–12. more

Abstract:

Pyropia acanthophorais a foliose Bangiales with widely known endemic populations in Indo-Pacific region. This alga has expanded its range recently as a consequence of introduction. In an attempt to explore the genetic diversity of Py. acanthophora within the Philippines and the impact of the introduction of the species from elsewhere, an examination of molecular differentiation and distribution was undertaken using the mitochondrial COI-5P and plastid rbcL gene sequences. The results revealed that the populations of Py. acanthophora in the Philippines exhibited high haplotypic and genetic diversities, and were found to be distinct from those previously reported as conspecific populations found in Taiwan, India, Japan, Hawaii, and from those introduced populations from Brazil. The network analyses as inferred fromrbcL and from the combined COI-5P and rbcL genes showed evidence that the Philippine populations of Py. acanthophora exhibited a chaotic patchiness pattern characterized by a population with highly site-exclusive haplotypes, wide genet ic variability and lack of local geographic patterns. The distribution of Py. acanthophora within the Philippines was also found to be greater than what was previously known, ranging from the extreme northwest to extreme northeast mainland Luzon coasts, including Camiguin Is., Cagayan. Understanding the genetic diversity and distribution of Py. acanthophora in the Philippines provides valuable information in relation to the conservation and effective resource management of native populations of Py. acanthophora in the tropical Asian region.

 

6. Hallare, A. V, Luis, J., Chan, A. C., Maria, B., Tan, S. P., Rubio, P. Y. M., … Macabeo, A. P. G. (2017). Toxicological Analysis of Phthalates from Dust Samples Collected in Selected Philippine Light Rail Transit Stations. Nature Environment and Pollution Technology, 16(1), 11–19. 

Abstract:

Phthalates are the most common form of plasticizers. Due to the ease with which phthalates diffuse from their plastics and the sheer volume of plastics that have been introduced to the environment, they represent one of the most ubiquitous and persistent chemicals known. Phthalates are known to have several toxic effects. The study was carried out to identify the phthalates found in the urban dusts that have accumulated from underneath the LRT1 stations at Monumento, R. Papa, and EDSA in Metro Manila, and to determine their embryotoxic potential. The urban dust samples were subjected to solid phase extraction (SPE) and gas chromatography-mass spectrometry (GC-MS). Six phthalates were identified, and the extract was then used in the zebrafish embryo toxicity (ZFET) test. Lethal and sublethal end points were observed in the zebrafish embryos. Low dilutions were found to be highly embryo toxic and a dose-response relationship was seen in dilutions ranging from 1:4 to 1:40. The LC50of the phthalate mixture was also obtained and found to be 9.188 μg/mL. This study elucidated some of the toxic effects of the phthalates, but further studies must be performed to evaluate the toxicity of the individual phthalates, some of whose effects are relatively unknown.

7. Lee, J., Rodriguez, J.P., Quilantang, N.G., Lee, M.-H., Cho, E.J., Jacinto, S.D., Lee, S. (2017). Determination of flavonoids from Perilla frutescens var. japonica seeds and their inhibitory effect on aldose reductaseApplied Biological Chemistry, 60(2), pages 155-162. more

Abstract:

Perilla frutescens var. japonica (PF) is an annual aromatic herb has been consumed as a food ingredient and medicinal crop in Asian countries. To evaluate the therapeutic efficacy of aldose reductase (AR) inhibition, we tested the PF seeds. The stepwise polarities of PF were tested for AR inhibition, and we determined the CH2Cl2and EtOAc fractions to be good inhibitors (5.81 and 3.99 μg/mL, respectively). Compounds 1–3 were isolated from the CH2Cl2and EtOAc fractions and identified as luteolin (1), apigenin (2), and diosmetin (3) by physicochemical and spectroscopic data. Among them, luteolin (1) and apigenin (2) had high AR inhibitory activity (1.89 and 4.18 μM). Deulsaem, a variety of PF, was determined to have the highest flavonoid content among ten PF seeds tested (2.10 mg/g). This study suggests that PF could be utilized as a natural source to treat diabetic complications. 

 

8. Marquez, C. M. D., Ibana, J. A., & Velarde, M. C. (2017). The female reproduction and senescence nexus. American Journal of Reproductive Immunology.more

Abstract:

Successful pregnancy is regulated by several soluble factors that are differentially expressed throughout gestation. These factors are important to initiate and establish embryo implantation and parturition. Senescent cells, which undergo permanent cell proliferation arrest in response to stress, also produce several secreted factors, referred to as the senescence-associated secretory phenotype (SASP). Here, we review some of the secreted factors found during early and late pregnancy and compare their expression profile with those of the SASP. Because senescent cells are found in the uterus and embryo during pregnancy, we hypothesize that SASP factors contribute to successful pregnancy. We discuss how senescent cells may support embryo development and signal parturition. We provide evidences for potential contribution of SASP to the physiology and pathophysiology of pregnancy.

9. Moritz, G.L., Ong, P.S., Perry, G.H., Dominy, N.J. (2017). Functional preservation and variation in the cone opsin genes of nocturnal tarsiers. Philosophical Transaction of the Royal Society B: Biological Science, 372 (1717).more

Abstract:

The short-wavelength sensitive (S-) opsin gene OPN1SW is pseudogenized in some nocturnal primates and retained in others, enabling dichromatic colour vision. Debate on the functional significance of this variation has focused on dark conditions, yet many nocturnal species initiate activity under dim (mesopic) light levels that can support colour vision. Tarsiers are nocturnal, twilight-active primates and exemplary visual predators; they also express different colour vision phenotypes, raising the possibility of discrete adaptations to mesopic conditions. To explore this premise, we conducted a field study in two stages. First, to estimate the level of functional constraint on colour vision, we sequenced OPN1SW in 12 wild-caught Philippine tarsiers (Tarsius syrichta). Second, to explore whether the dichromatic visual systems of Philippine and Bornean (Tarsius bancanus) tarsiers—which express alternate versions of the medium/long-wavelength sensitive (M/L-) opsin gene OPN1MW/OPN1LW—confer differential advantages specific to their respective habitats, we used twilight and moonlight conditions to model the visual contrasts of invertebrate prey. We detected a signature of purifying selection for OPN1SW, indicating that colour vision confers an adaptive advantage to tarsiers. However, this advantage extends to a relatively small proportion of prey–background contrasts, and mostly brown arthropod prey amid leaf litter. We also found that the colour vision of T. bancanus is advantageous for discriminating prey under twilight that is enriched in shorter (bluer) wavelengths, a plausible idiosyncrasy of understorey habitats in Borneo.

10. Pagalilauan, H.A.M, Paraoan, C.E.M., Vital, P.G. (2017). Detection of pathogenic bioaerosols and occupational risk in a Philippine landfill site. Journal Archives of Environmental & Occupational Health. Pages 1-8. more

Abstract:

Payatas landfill site is one of the major dumpsites in the Philippines. In this study, the landfill was evaluated regarding the presence and concentration of pathogenic bacterial aerosols through culture and molecular techniques. Bioaerosols are biological airborne particles that may or may not cause diseases. Active sampling was done using MAS-100 Air Sampler from both indoor and outdoor locations. To test the accuracy of the culture method, those that were presumptively identified as Staphylococcus aureus and Klebsiella pneumoniae were subjected to molecular analysis using 16s rRNA sequencing, and as a result, they were identified as different species. The exposure assessment done by interview showed matches among prevalent diseases. The results of this study can be used as a basis for creating standards and regulations for workers' and residents' safety and health in the landfill site.

 

11. Paraoan, C.E.M., Rivera, W.L., Vital, P.G. (2017). Detection of Class I and II integrons for the assessment of antibiotic and multidrug resistance amongEscherichia coliisolates from agricultural irrigation waters in Bulacan, Philippines. Journal of Environmental Science and Health - Part B Pesticides, Food Contaminants, and Agricultural Wastes. 52 (5), Pages 306-313. more

Abstract:

Contaminated irrigation water may greatly affect not only the quality of produce but also the people exposed to it. In this study, agricultural irrigation waters in Bulacan, Philippines were assessed and found to be contaminated with Escherichia coli (E. coli) ranging from 0.58 to 4.51 log10 CFU/mL. A total of 79 isolates of E. coli were confirmed through polymerase chain reaction (PCR) amplifying the uidA gene and were tested for phenotypic resistance using 10 antimicrobials through the Kirby–Bauer disc diffusion method. Forty-six isolates (58.22%) were noted to be multidrug resistant (MDR) with high resistance rate to cephalothin, tetracycline, streptomycin, ampicillin, trimethoprim, nalidixic acid, and chloramphenicol. Moreover, this study also examined the prevalence of Class I and II integrons accounting to 67.39% and 17.39%, respectively, of the MDR E. coli strains using multiplex PCR. The results imply that the agricultural water used in Bulacan is contaminated with the fecal material of man or other animals present in the area, and the presence of MDR bacteria, which pose a potential threat to individuals in these areas, is alarming. In addition, detection of integrons could be a good marker for the identification of MDR isolates. Lastly, this study could develop strategies for the proper management of farming sites leading to the detection of food-borne pathogens and prevention of infectious diseases.

12. Rodriguez, L. J., Young, F., Rasplus, J.-, Kjellberg, F., & Compton, S. G. (2017). Constraints on convergence: hydrophobic hind legs allow some male pollinator fig wasps early access to submerged females. Journal of Natural History, 51(13–14), 761–782.more

Abstract:

Pollinator fig wasps (Hymenoptera: Agaonidae) display numerous adaptations linked to their obligate association with fig trees (Ficus). Ceratosolen fig wasps pollinate figs that often fill temporarily with liquid, and one clade has males with unusually long hind legs. We investigated their morphology and behaviour. Scanning electron microscopy (SEM) revealed that the cuticle of their hind legs is highly modified and covered with numerous hydrophobic setae and microtrichia that can prevent blockage of the wasps’ large propodeal spiracles by liquids. In deep liquid, the males floated on the surface, but when only a thin layer of liquid was present, the legs allowed males to access females without the risk of drowning. Access to females was facilitated by an air bubble that forms between the hind legs and maintains a column of air between the spiracles and the centre of the figs. Sexual selection should favour males that can gain earlier access to mates, and the modified legs represent an adaptation to achieve this. Convergent adaptations are known in some unrelated non-pollinating fig wasps that develop in similar liquid-filled figs, but these species have enlarged hydrophobic peritremata at the ends of their metasoma to protect the spiracles located there. Unlike non-pollinating fig wasps, pollinator males need to insert their metasoma deep into females’ galls during mating. This difference in mating behaviour has constrained the extent of convergence.

13. Tayaban, K.M.M., Pintor, K.L., Vital, P.G. (2017). Detection of potential harmful algal bloom-causing microalgae from freshwater prawn farms in Central Luzon,Philippines, for bloom monitoring and prediction. Springer Science+Business Media Dordrecht. doi:10.1007/s10668-017-9942-8more

Abstract:

Prawn aquaculture industry is one of the developing economic activities in thePhilippines. Generally, a wide range of microalgae typically grow and proliferate in many aquaculture ponds. However, certain species of microalgae have the ability to form harmful algal blooms (HABs) which often bring damaging consequences to the aquaculture industry, food safety, and the environment. The study aims to identify and characterize the composition of microalgae (particularly Cyanophyta) that are capable of forming HABs in selected freshwater prawn culture ponds in Central Luzon,Philippines, using morphological, ultrastructural, and molecular characterizations. From water samples collected in ten selected ponds across Central Luzon (Bulacan, Nueva Ecija, Pampanga, Tarlac, and Zambales), potential HAB formers such as Oscillatoria agardhii, O. princeps, Microcystis aeruginosa, and M. wesenbergii were observed to have occurred mostly, while Anabaena circinalis was only observed in one site. Both morphological and ultrastructural methods brought upon some challenges and limitations while molecular methods using 16S rRNA gene and phylogenetic analysis which were optimized in this study offered better and more efficient ways of identification and were helpful in resolving genus-level and species-level relationships. The influence of physicochemical properties of pond water, especially nutrient levels (nitrate, nitrite, and orthophosphate) on the occurrence of these cyanobacteria was also analyzed. As a pioneering study on freshwater HABs in aquaculture ponds in the country, results of the study can provide information to improve the knowledge in bloom occurrence and prediction, and to develop freshwater HAB prevention and control methods. 

 

14. Vallejo, B., J., Conejar-Espedido, J., Manubag, L. d., Artiaga, K. C. C., Damatac, A.M., Ii., Imperial, I. C. V. J., … Cao, E. P. (2017). First record of the charru Mussel mytella charruana d’orbignyi, 1846 (Bivalvia: Mytilidae) from Manila Bay, Luzon, Philippines. BioInvasions Records, 6(1), 49–55. more

 

Abstract:

This study reports the presence of the Charru mussel Mytella charruana d'Orbignyi, 1846 (Bivalvia: Mytilidae) in Manila South Harbor, Manila Bay, Luzon Island, Philippines. In 2014, mussels previously identified as Mytilus spp. were reported in Manila Bay. The species was detected as part of an ecological dynamics study of previously-recorded marine non-indigenous mollusc species. DNA barcoding results suggest that the previously identified Mytilus are in fact Mytella charruana with an average identity match of 94%. The trends in abundance of Mytella during the 2014–2015 sampling season are described and the potential of this new species to become invasive and competitive with native Perna viridis (Linnaeus, 1758).

15. Villacorta, R. B., Faith Javier Roque, K., Tapang, G. A., & Jacinto, S. D. (2017). Plant extracts as natural photosensitizers in photodynamic therapy: in vitro activity against human mammary adenocarcinoma MCF-7 cells. Asian Pacific Journal of Tropical Biomedicine, 7(4), 358–366. more

 

Abstract:

Objective

To examine three plant extracts [Lumnitzera racemosa(Combretaceae) (L. racemosa),Albizia procera(Fabaceae) (A. procera) andCananga odorata(Annonaceae)] for their potential as source of photosensitizers in photodynamic therapy.

Methods

Human mammary adenocarcinoma (MCF-7) cells were treated with the plant extracts, which were irradiated with 5.53 mW and 0.553 mW broadband light. Cell viability was assessed using MTT assay and induction of apoptosis was determined using terminal deoxynucleotidyl transferase-dUTP nick end labeling assay.

Results

The crude ethanolic extracts, independently, were nontoxic against cancer and non-cancer cells but when irradiated with 5.53 mW broadband light,L. racemosaandA. proceraextracts were cytotoxic against MCF-7 with IC50of 11.63 μg/mL and 10.73 μg/mL, respectively. With 0.553 mW broadband light, the IC50values were higher at 17.14 μg/mL and 19.59 μg/mL, respectively. PhotoactivatedL. racemosaandA. proceraextracts were found to be more cytotoxic against MCF-7 than the non-cancer cell line, human dermal fibroblast-neonatal. Moreover, the cytotoxicity of the extracts was mediated by apoptosis.

Conclusions

Two of the plant extracts used,L. racemosaandA. procerawere toxic and induced apoptosis to mammary cell adenocarcinoma, MCF-7 when photoactivated. These extracts were also more toxic to human cancer than non-cancer cell lines.

16. Vital, P. G., Van Ha, N. T., Tuyet, L. T., & Widmer, K. W. (2017). Application of quantitative real-time PCR compared to filtration methods for the enumeration of Escherichia coli in surface waters within Vietnam. Journal of Water and Health, 15(1), 155–162. more

 

Abstract:

Surface water samples in Vietnam were collected from the Saigon River, rural and suburban canals, and urban runoff canals in Ho Chi Minh City, Vietnam, and were processed to enumerate Escherichia coli. Quantification was done through membrane filtration and quantitative real-time polymerase chain reaction (PCR). Mean log colony-forming unit (CFU)/100 ml E. coli counts in the dry season for river/suburban canals and urban canals were log 2.8 and 3.7, respectively, using a membrane filtration method, while using Taqman quantitative real-time PCR they were log 2.4 and 2.8 for river/suburban canals and urban canals, respectively. For the wet season, data determined by the membrane filtration method in river/suburban canals and urban canals samples had mean counts of log 3.7 and 4.1, respectively. While mean log CFU/100 ml counts in the wet season using quantitative PCR were log 3 and 2, respectively. Additionally, the urban canal samples were significantly lower than those determined by conventional culture methods for the wet season. These results show that while quantitative real-time PCR can be used to determine levels of fecal indicator bacteria in surface waters, there are some limitations to its application and it may be impacted by sources of runoff based on surveyed samples.

Chemistry logo

1. Atayde, E. C., Jr., Berenguel, M. M., & Arco, S. D. (2017). RAFT Polymerization of Dual Responsive Hyperbranched-Star Copolymers of Methacrylic Acid and Poly(Ethylene Glycol). Materials Science Forum, 890. Pages 78-81. doi:10.4028/www.scientific.net/MSF.890.78. more

Abstract:

Smart polymers are materials that respond to external stimuli via reversible morphological changes, making them potential systems for drug delivery applications. In this study, dualresponsive star copolymers with a hyperbranched core composed of ethylene glycol dimethacrylate (EGDMA) - methacrylic acid (MAA) and poly(ethylene glycol) methyl ether methacrylate (PEGMA) arms were synthesized via two-step Reversible Addition-fragmentation Chain Transfer (RAFT) block copolymerization. The synthesis involved the formation of the hyperbranched MAA core followed by arm extension with PEGMA. The formation of the hyperbranched core and subsequent copolymerization with PEGMA were verified by FT-IR and 1H-NMR spectroscopic techniques. The distinct EGDMA peak was found at 4.3 ppm while the peak attributed to PEGMA was found at around 3.5 ppm. Furthermore, the synthesized block copolymers were both temperature and pH-responsive with LCST value at 57ºC and morphological transition at pH 5.6. The synthesized smart polymer was also biocompatible based on Trypan blue cytotoxicity assay. The inherent dual responsive behavior and biocompatibility of the copolymer render it a good candidate for drug delivery systems.  

2. Edanõl, Y. D. G., Ferrer, M. R. R., Raguindin, R. K. M., & Arco, S. D. (2016). Potentiometric determination of a regulated veterinary drug via MIP-modified electrodeProceedings of the 3rd International Conference on Biomedical and Bioinformatics Engineering, Pages 71-74. doi>10.1145/3022702.3022723.more

Abstract:

Potentiometric sensor based on a molecularly imprinted polymer was fabricated for the detection of chloramphenicol (CAP), a broad spectrum antibiotic which is regulated by the government due to its toxicity at high doses, adverse effects and suspected carcinogenicity. The molecularly imprinted polymer for chloramphenicol (MIP-CAP) was prepared via precipitation polymerization with MAA as the functional monomer, EGDMA as cross-linker, and CAP as template. UV-Vis and FT-IR spectroscopy were used to confirm the synthesis of the MIP. The MIP has a binding capacity of 27.827±1.267 mg CAP per gram MIP. Potentiometric measurements revealed a response of 57.85 mV/decade at the linear range of 10-5 to 10-3 M at the working pH 7.4. The limit of detection for the electrode was 7.639x10-6 M or 2.42 ppm. Response of the MIP and the MIP-modified electrode against structural analogues of CAP were also investigated.

3. Hubilla, F. A. D., Mabilangan, A. I., Advincula, R. C., & Del Mundo, F. R. (2017). A surface plasmon resonance histamine sensor based on an electropolymerized molecularly imprinted polymer (E-MIP). MATEC Web of Conferences, 95. doi:10.1051/matecconf/20179502006.more

Abstract:

In this paper, histamine sensing by surface plasmon resonance (SPR) spectroscopy using an electropolymerized molecularly imprinted polymer (E-MIP) of functionalized polyterthiophene and histamine is reported. The MIP histamine sensor showed good linear relationship (R2 = 0.995) between the SPR angle shift and the logarithm of histamine concentration, ranging from 15-500 μg/mL, with a limit of detection (LOD) of 2.0 μg/mL and a calibration sensitivity of 44.6 m° per log μg/mL histamine. Results also showed higher binding affinity of histamine for the MIP sensor than for the non-imprinted (NIP) sensor indicating excellent specificity. Moreover, the selectivity of the MIP histamine sensor against some of its structural analogues was demonstrated.

IESM logo 

1. Aragones, L. V., Laggui, H. L., & Amor, A. K. (2017). The Philippine Marine Mammal Strandings from 2005 to 2016. A PMMSN Publication. Technical Report No. 1.

2. Bagtasa, G. (2017). Contribution of tropical cyclones to rainfall in the Philippines. Journal of Climate, 30(10), 3621–3633. 

3. Ringor, C.L., Pascua, C.S., Villanueva, J.C.B., Garcia, A.K.H., Agulo, I.J.A., Matsushita, Y., Miyazawa, K. (2017). Multiwalled carbon nanofibers and nanocapsules synthesized from plant oil via atmospheric CVD process. Journal of Nanoscience and Nanotechnology, 17 (5), Pages 3543-3550. more

Abstract:

Calophyllum inophyllum (CI) oil was used as precursor source material in carbon nanomaterial synthesis. CI is a non-edible and native plant species in the Philippines, which makes production of seeds and kernel sustainable. An atmospheric pressure chemical vapor deposition system was designed and built for the synthesis. Different carbon-based nanostructures were synthesized by varying the Argon gas flow rates (3.5–5 liter/min) and temperatures (1000–1200 °C). Crystalline multiwalled nanofibers and iron carbide-encapsulated nanocapsules were formed at 1000 °C and a gas flow rate of 5 liter/min. On the other hand, oils synthesized at 1100–1200 °C produced amorphous film-like carbon materials. The different morphologies reflect the influence of the gas flow rate on the dilution and atomization of the oil and its decomposition at various temperatures used. Raman spectroscopy and surface potential measurements indicate the potential applications of these nanofibers for hydrogen storage and semiconducting devices.

4. Rollon, R.N., Villamayor, B.M.R., Oropesa, L.J.B., and Samson, M.S. (2017). Prop root production response of planted Rhizophora to abrupt subsidence-induced sea level rise. Ocean and Coastal Management, 142, Pages 198-208. more

Abstract:

The 7.2 Mw Bohol earthquake in 2013 caused significant ground subsidence in some coastal zones northwest of the province, shifting the tidal inundation regime of intertidal habitats. These habitats included more than 500 ha of mangrove plantations particularly in island barangays which substrates are now 85% inundated annually from the 40% pre-quake conditions. Consequently, in less than three years after the quake, the effort of the subsided individual trees to produce new prop roots above the pre-quake height limits was found to be immediate, substantial, and tidally-linked. This prop root response resulted in an increase in the total length and volume by 74% and 39%, respectively, at 2.5-year post-quake relative to the 20-year pre-quake cumulative. With a mean elongation rate of ca. 1.1 m y−1, some 1.5–2.2 year period was necessary for these new prop roots to reach the substrate, and effectively establish a new equilibrium. The results highlight the role of prop roots on the aeration and stability requirements of Rhizophora, and provide quantitative evidence against the common practice of harvesting prop roots for firewood, charcoal, and other various purposes. The study presents a short-term glimpse of the prop root response of Rhizophora to the otherwise long-term gradual process of sea level rise.

5. Vallejo, B., Jr., Conejar-Espedido, J., Manubag, L., Artiaga, K.C.C., Damatac, A.M., II, Imperial, I.C.V.J., Itong, T.A.B., Fontanilla, I.K., Cao, E.P. (2017). First record of the Charru mussel Mytella charruana d’Orbignyi, 1846 (Bivalvia: Mytilidae) from Manila Bay, Luzon, Philippines. BioInvasions Records, 6 (1), Pages 49-55. more

Abstract:

This study reports the presence of the Charru mussel Mytella charruana d’Orbignyi, 1846 (Bivalvia: Mytilidae) in Manila South Harbor, Manila Bay, Luzon Island, Philippines. In 2014, mussels previously identified as Mytilus spp. were reported in Manila Bay. The species was detected as part of an ecological dynamics study of previously-recorded marine non-indigenous mollusc species. DNA barcoding results suggest that the previously identified Mytilus are in fact Mytella charruana with an average identity match of 94%. The trends in abundance of Mytella during the 2014–2015 sampling season are described and the potential of this new species to become invasive and competitive with native Perna viridis (Linnaeus, 1758)

6. Vergara, R.L., Macalalad, E.P., Bagtasa, G., Vallar, E.A., Galvez, M.C.D., Francisco, R.V. (2017). Correlation of aerosol optical properties with surface meteorological parameters over ManilaAdvance Science Letters, 23 (2), Pages 1448-1451.  more

Abstract:

Aerosol optical properties such as aerosol optical depth (AOD) at 500 nm together with wavelength exponent (α) and Ångstrom turbidity coefficient (β) obtained from a sunphotometer over Manila were used to analyze their response to the changes in temperature, relative humidity (RH) and zonal wind. Data retrieved for a one year period of measurements (August 2009–July 2010) were used to describe the variations of the aerosol optical properties. Temperature showed weak correlations with the aerosol optical properties. Surface RH confirmed evidence for its influence on aerosols size distribution and dominant aerosol type. Zonal wind demonstrated influences on the prevailing aerosol present at a certain area and caused alteration the amount of its loading.

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1. Akiyama, S., & Caalim, J. (2017). Invariant Measure of Rotational Beta Expansion and Tarski’s Plank Problem. Discrete & Computational Geometry, 57(2), Pages 357–370.more

Abstract:

We study the invariant measures of a piecewise expanding map in RmRm defined by an expanding similitude modulo a lattice. Using the result of Bang (Proc Am Math Soc 2:990–993, 1951) on the plank problem of Tarski, we show that when the similarity ratio is at least m+1m+1, the map has an absolutely continuous invariant measure equivalent to the m-dimensional Lebesgue measure, under some mild assumption on the fundamental domain. Applying the method to the case m=2m=2, we obtain an alternative proof of the result in Akiyama and Caalim (J Math Soc Japan 69:1–19, 2016) together with some improvement.

2. Akiyama, S.  & Caalim, J. (2017). Rotational beta expansion: Ergodicity and soficness. Journal of the Mathematical Society of Japan, 69(1), 397–415. more

Abstract:

We study a family of piecewise expanding maps on the plane, generated by composition of a rotation and an expansive similitude of expansion constant β. We give two constants B1and B2 depending only on the fundamental domain that if β > B1 then the expanding map has a unique absolutely continuous invariant probability measure, and if β > B2 then it is equivalent to 2-dimensional Lebesgue measure. Restricting to a rotation generated by q-th root of unity ζ with all parameters in ℚ(ζ,β), the map gives rise to a sofic system when cos(2π/q) ℚ(β) and β is a Pisot number. It is also shown that the condition cos(2π/q) ℚ(β) is necessary by giving a family of non-sofic systems for q = 5.

3. Arceo, C. P. P., Jose, E. C., Lao, A. R., & Mendoza, E. R. (2017). Reaction networks and kinetics of biochemical systems. Mathematical Biosciences, 283, Pages 13–29.more

Abstract:

This paper further develops the connection between Chemical Reaction Network Theory (CRNT) and Biochemical Systems Theory (BST) that we recently introduced [1]. We first use algebraic properties of kinetic sets to study the set of complex factorizable kinetics CFK(N) on a CRN, which shares many characteristics with its subset of mass action kinetics. In particular, we extend the Theorem of Feinberg-Horn [9] on the coincidence of the kinetic and stoichiometric subsets of a mass action system to CF kinetics, using the concept of span surjectivity. We also introduce the branching type of a network, which determines the availability of kinetics on it and allows us to characterize the networks for which all kinetics are complex factorizable: A “Kinetics Landscape” provides an overview of kinetics sets, their algebraic properties and containment relationships. We then apply our results and those (of other CRNT researchers) reviewed in [1] to fifteen BST models of complex biological systems and discover novel network and kinetic properties that so far have not been widely studied in CRNT. In our view, these findings show an important benefit of connecting CRNT and BST modeling efforts.

 

4. Calderon, P. G. B., Habib, M., Kappel, F., & Reyes V, A. A. de los. (2017). Control aspects of the human cardiovascular-respiratory system under a nonconstant workload. Mathematical Biosciences, 289, 142–152.more

Abstract:

The human cardiovascular system (CVS) and respiratory system (RS) work together in order to supply oxygen (O2) and other substrates needed for metabolism and to remove carbon dioxide (CO2). Global and local control mechanisms act on the CVS in order to adjust blood flow to the different parts of the body. This, in turn, affects the RS since the amount of O2 and CO2 transported, respectively to and away from the tissues depends on the cardiac output and blood flow in both the systemic and pulmonary circuits of the CVS. Local metabolic control is influenced by local concentrations of blood gases affecting systemic resistance, resulting to vasoconstriction/vasodilation. Thus, the exchange of blood gases demands a tight coordination between blood flow and ventilation of the lungs. In this work, a model of the cardiovascular-respiratory system (CVRS) is considered to obtain an optimal control for time-dependent ergometric workloads by using the Euler-Lagrange formulation of the optimal control problem. The essential controls in the CVRS model are variations in the heart rate and alveolar ventilation through which the central nervous system restricts the arterial partial pressure of CO2 (Pa,CO2) close to 40  mmHg. Further, penalization terms in the cost functional are included to match the metabolic need for O2 and the metabolic production of CO2with O2- and CO2-transport by blood.

5. Celeste, R. O., Corcino, R. B., & Gonzales, K. J. M. (2017). Two approaches to normal order coefficients. Journal of Integer Sequences, 20(3). more

Abstract:

We consider the normal ordering coefficients of strings consisting of the symbols V, U which satisfy the commutation rule UV - qVU = hVs. These coefficients are studied using two approaches. First, we continue the study by Varvak, where the coefficients were interpreted as q-rook numbers under the row creation rook model introduced by Goldman and Haglund. Second, we express the coefficients in terms of a kind of generalization of some symmetric functions. We derive identities involving the coefficients including some explicit formulas.

6. David, G., Pedrigi, R. M., & Humphrey, J. D. (2017). Accommodation of the human lens capsule using a finite element model based on nonlinear regionally anisotropic biomembranes. Computer Methods in Biomechanics and Biomedical Engineering, 20(3), 302–307. more

Abstract:

Accommodation of the eyes, the mechanism that allows humans to focus their vision on near objects, naturally diminishes with age via presbyopia. People who have undergone cataract surgery, using current surgical methods and artificial lens implants, are also left without the ability to accommodate. The process of accommodation is generally well known; however the specific mechanical details have not been adequately explained due to difficulties and consequences of performing in vivo studies. Most studies have modeled the mechanics of accommodation under assumptions of a linearly elastic, isotropic, homogenous lens and lens capsule. Recent experimental and numerical studies showed that the lens capsule exhibits nonlinear elasticity and regional anisotropy. In this paper we present a numerical model of human accommodation using a membrane theory based finite element approach, incorporating recent findings on capsular properties. This study seeks to provide a novel perspective of the mechanics of accommodation. Such findings may prove significant in seeking biomedical solutions to restoring loss of visual power.

7. de la Cruz, R. J., & dela Rosa, K. (2017). Each 2n-by-2n complex symplectic matrix is a product of n+1 commutators of J-symmetries. Linear Algebra and Its Applications, 517, 53–62. more

Abstract:

A 2n×2n complex matrix A   is symplectic if  . If A   is symplectic and rank(A−I)=1, then it is called a J-symmetry. For each n  , we prove that every 2n×2n symplectic matrix M   is a product of n+1 commutators of J-symmetries and this number cannot be smaller for some M.

8. John, R., Cruz, D., Merino, D. I., & Paras, A. T. (2017). Every 2 n -by-2 n complex matrix is a sum of three symplectic matrices. Linear Algebra and Its Applications, 517, Pages 199–206.more

Abstract:

Let. AnAM2n(C)is calledsymplectic  ifATJ2nA=J2n. Ifn=1, then we show that every matrix inM2n(C)is a sum of two symplectic matrices. Ifn>1, then we show that every matrix inM2n(C)is a sum of three symplectic matrices; moreover, we show that some matrices cannot be written with less than three symplectic matrices. We also show that for everyAM2n(C), there exist symplecticP  ,QM2n(C)andB,C  ,DMn(C)such that. IfA  is skew Hamiltonian (), then we show thatAis a sum of two symplectic matrices.

9. Lope, J., & Ona, M. (2017). Solvability of a system of totally characteristic equations related to Kähler metrics. Electronic Journal of Differential Equations

Abstract:

We consider a system of equations composed of a higher order singular partial differential equation of totally characteristic type and several higher order non-Kowalevskian linear equations. This system is a higher order version of a system that arose in Bielawski's investigations on Kähler metrics. We first prove that this system has a unique holomorphic solution. We then show that if the coefficients of the system are in some formal Gevrey class, then the unique solution is also in the same formal Gevrey class.

10. Loquias, M. J. C., Valdez, L. D., & Walo, M. L. B. (2017). Color groups of colorings of N-planar modules. In Journal of Physics: Conference Series (Vol. 809). more

Abstract:

A submodule of a  -module determines a coloring of the module where each coset of the submodule is associated to a unique color. Given a submodule coloring of a  -module, the group formed by the symmetries of the module that induces a permutation of colors is referred to as the color group of the coloring. In this contribution, a method to solve for the color groups of colorings of N-planar modules where N = 4 and N = 6 are given. Examples of colorings of rectangular lattices and of the vertices of the Ammann-Beenker tiling are given to exhibit how these methods may be extended to the general case.

11. Loquias, M. J. C., Mkaouar, M., Scheicher, K., & Thuswaldner, J. M. (2017). Rational digit systems over finite fields and Christol’s Theorem. Journal of Number Theory, 171, Pages 358–390. more

Abstract:

LetP,QFq[X]{0}be two coprime polynomials over the finite fieldFqwithdeg⁡P>deg⁡Q. We represent each polynomialw  overFqby  im loquias

using a rationalbase  P/Qanddigits  siFq[X]satisfyingdeg⁡si<deg⁡P.Digit expansions  of this type are also defined for formal Laurent series overFq. We prove uniqueness and automatic properties of these expansions. Although theω  -language of the possible digit strings is not regular, we are able to characterize the digit expansions of algebraic elements. In particular, we give a version of Christol's Theorem by showing that the digit string of the digit expansion of a formal Laurent series is automatic if and only if the series is algebraic overFq[X]. Finally, we study relations between digit expansions of formal Laurent series and a finite fields version of Mahler's 3/2-problem.

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1. Felix, M. J., Muldera, J., Somintac, A., Salvador, A., & Estacio, E. (2017). Enhanced Terahertz emission and raman signal from silicon nanopyramids. Science of Advanced Materials, 9(2), Pages 214–219.

 

2. Rosete, M.M., Zosa, M.H., & Sarmago, R.V. (2017). Effect of Potassium Chloride as a Supporting Electrolyte on the Dispersion Towards the Fabrication of Films by Electrophoretic Deposition of Bi2Sr2CaCu2O8 in EthanolJournal of Superconductivity and Novel Magnetism, Pages 1-6more

Abstract:

Bi2Sr2CaCu2O8 (Bi-2212) powder was fabricated using solid state reaction method. The suspensions were prepared containing finely ground Bi-2212 powder with and without potassium chloride (KCl) addition. Settling experiments and measurements of zeta potential, particle size distribution, and electrophoretic mobility were performed to determine the optimal concentration of the supporting electrolyte. Bi-2212 suspensions were used in electrophoretic deposition (EPD), and the films were heat treated. The results showed that the optimal concentration of KCl is 5.21 wt %. The zeta potential at this concentration is highest at about 31.10 mV, the settling velocity is lowest ∼3.84 mm/min, and the particle size is smallest (∼450 nm), which indicate that the dispersion is better due to the reduction of intermolecular attraction. The effects of KCl as a flux were observed in the microstructure and superconducting properties of Bi-2212 film. The smoothest surface morphology, high c-axis orientation, and highest critical temperature (Tc)-onset of 84.73 K were obtained from the film prepared with optimized Bi-2212 suspension.

3. Tingzon, P., Lopez, L., Oliver, N., Cabello, N., Cafe, A., De Los Reyes, A., … Somintac, A. (2017). Terahertz emission and photoluminescence of Silicon Nanowires electrolessly etched on the surface of Silicon (100), (110), and (111) substrates for photovoltaic cell applications. Photonics and Nanostructures - Fundamentals and Applications, 24, 1–6. 

 

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1. Abesamis, R. A., Berumen, P. S. M. L., Bode, M., Renato, C., Leilani, L. J., Cesar, A. S., … Garry, C. A. (2017). Reef-fish larval dispersal patterns validate no-take marine reserve network connectivity that links human communities. Coral Reefs, Pages 1–11. 

2. Atrigenio, M., Aliño, P., & Conaco, C. (2017). Influence of the Blue Coral Heliopora coerulea on Scleractinian Coral Larval Recruitment. Journal of Marine Biology

3. Billones, J. B. a., Carrillo, M. C. O. ., Organo, V. G., Sy, J. B. A., Clavio, N. A. B., Macalino, S. J. Y., … Concepcion, G. P. (2017). In silico discovery and in vitro activity of inhibitors against Mycobacterium tuberculosis 7,8-diaminopelargonic acid synthase (Mtb BioA). Drug Design, Development and Therapy, 11, Pages 563–574. 

4. Cabaitan, P. C., & Conaco, C. (2017). Bringing back the giants: juvenile Tridacna gigas from natural spawning of restocked giant clams. Coral Reefs

5. Da-Anoy, J. P., Villanueva, R. D., Cabaitan, P. C., & Conaco, C. (2017). Effects of coral extracts on survivorship, swimming behavior, and settlement of Pocillopora damicornis larvaeJournal of Experimental Marine Biology and Ecology486, Pages 93–97.

6. Dumilag, R. V., & Aguinaldo, Z.-Z. A. (2017). Genetic differentiation and distribution of Pyropia acanthophora (Bangiales, Rhodophyta) in the PhilippinesEuropean Journal of Phycology0(0), Pages 1–12.

7. Gajigan, A. P., & Conaco, C. (2017). A microRNA regulates the response of corals to thermal stress. Molecular Ecology

8. Jamodiong, E. A., Maboloc, E. A., Leriorato, J. C., Talledo, M. C. S., Diaz, L. A., Tabalanza, T. D., … Villanueva, R. D. (2017). Coral spawning and spawn-slick observation in the Philippines. Marine Biodiversity, Pages 1–6. 

9. Mizuno, K. ., Asada, A. ., Matsumoto, Y. ., Sugimoto, K. ., Fujii, T. ., Yamamuro, M. ., … Jimenez, L. A. (2017). A simple and efficient method for making a high-resolution seagrass map and quanti fi cation of dugong feeding trail distribution : A field test at the Mayo Bay, Philippines. Ecological Informatics, 38, Pages 89–94.

10. Morimoto, N., Umezawa, Y., San Diego-McGlone, M. L., Watanabe, A., Siringan, F. P., Tanaka, Y., … Miyajima, T. (2017). Spatial dietary shift in bivalves from embayment with river discharge and mariculture activities to outer seagrass beds in northwestern Philippines. Marine Biology, 164(4), Pages 1–16.

11. Naval, P.C., J., & David, L. (2017). FishDrop: Estimation of reef fish population density and biomass using stereo cameras. In Techno-Ocean 2016: Return to the Oceans. Pages 527–531. 

12. Noblezada, M. M., Miyamoto, H., Campos, W. L., Yusoff, F. M., & Nishida, S. (2017). Phylogeography of the planktonic shrimp Lucifer hanseni Nobili 1905 in the Indo-Malayan ArchipelagoJournal of the Marine Biological Association of the United Kingdom97(1), Pages 129–140.

13. Palomar-Abesamis, N., Abesamis, R. A., & Juinio-Menez, M. A. (2017). Distribution and microhabitat associations of the juveniles of a high-value sea cucumber, Stichopus cf. horrens, in northern Philippines. Aquatic Ecology, Pages 1–15. 

14. Quiros, T. E. A. L., Croll, D., Tershy, B., Fortes, M. D., & Raimondi, P. (2017). Land use is a better predictor of tropical seagrass condition than marine protection. Biological Conservation, 209, Pages 454–463. 

15. Ramos, R. D., Goodkin, N. F., Siringan, F. P., & Hughen, K. (2017). Diploastrea heliopora Sr/Ca and δ 18 O records from northeast Luzon, Philippines: an assessment of inter-species coral proxy calibrations and climate controls of sea surface temperature and salinity. Paleoceanography, Pages 424–438. 

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1. Knittel, U., Walia, M., Suzuki, S., Dimalanta, C. B., Tamayo, R., Yang, T. F., & Yumul, G. P. (2017). Diverse protolith ages for the Mindoro and Romblon Metamorphics (Philippines): Evidence from single zircon U-Pb dating. Island Arc, 26(1), e12160.more

Abstract:

Within the north-eastern part of the Palawan Continental Terrane, which forms the south-western part of the Philippine archipelago, several metamorphic complexes are exposed that are considered to be rifted parts of the Asian margin in South-East China. The protolith age(s) and correlations of these complexes are contentious. The largest metamorphic complex of the Palawan Continental Terrane comprises the Mindoro Metamorphics. The north-eastern part of this metamorphic complex has recently been found to be composed of protoliths of Late Carboniferous to Late Permian protolith age. However, meta-sediments exposed at the westernmost tip and close to the southern boundary of the exposure of the Mindoro Metamorphics contain detrital zircons and with U–Pb ages, determined by LA–ICP–MS, in the range 22–56 Ma. In addition, zircons as young as 112 Ma were found in a sample of the Romblon Metamorphics in Tablas. As the youngest detrital zircons provide an upper age limit for the time of deposition in meta-sediments, these results suggest that the Mindoro and Romblon Metamorphics comprise protoliths of variable age: Late Carboniferous to Late Permian in NE Mindoro; Eocene or later in NW Mindoro; Miocene at the southern margin of the Mindoro metamorphics; and Cretaceous or later on Tablas. The presence of non-metamorphic sediments of Late Eocene to Early Oligocene age in Mindoro (Lasala Formation), which are older than the youngest metasediments, suggests that metamorphism of the young meta-sediments of Mindoro is the result of the collision of the Palawan Continental terrane with the Philippine Mobile Belt in Late Miocene. Similarities of the age spectra of zircons from the Eocene to Miocene metamorphics with the Eocene to Early Miocene Lasala Formation suggest that the protoliths of the young metamorphics may be equivalents of the Lasala Formation or were recycled from the Lasala Formation.

2. Li, H., Sun, H.-S., Wu, J.-H., Evans, N. J., Xi, X.-S., Peng, N.-L., … Gabo-Ratio, J. A. S. (2017). Re–Os and U–Pb geochronology of the Shazigou Mo polymetallic ore field, Inner Mongolia: Implications for Permian–Triassic mineralization at the northern margin of the North China Craton. Ore Geology Reviews, 83, Pages 287–299.more

Abstract:

The recently discovered polymetallic Shazigou Mo–W–Pb–Zn ore field is located at the northern margin of the North China Craton. This integrated metallogenic system is comprised of quartz vein mineralization in three deposits: Shazigou Mo–W, Jindouzishan Pb–Zn and Mantougou Pb–Zn. The total reserves are estimated to be 50 kt Mo, 626 t WO3, 244 kt Pb and 150 kt Zn. Molybdenite Re–Os dating of five quartz vein-type ores yielded a mean model age of 243.8 ± 1.6 Ma (MSWD = 0.81) and hydrothermal zircons yielded a concordant U–Pb age of 245 ± 2.6 Ma (MSWD = 0.65). These results suggest that the mineralization was formed in the early Triassic and could be related to Paleo-Asian Ocean subduction. Microthermometry and quartz fluid inclusion compositions indicate that fluids related to the Mo–W mineralization were mainly derived from magmatic sources and precipitated under relatively high temperature (280–340 °C) and salinity conditions (6–9 wt% NaCl equiv.), whereas subsequent Pb–Zn mineralization-related fluids may have been modified by metamorphic and meteoric waters. The discovery of the Shazigou ore field suggests conditions may be favourable for more extensive mineralization in the western Xilamulun Mo metallogenic belt at the northern margin of the North China Craton.

3. Ramos, N. T., Maxwell, K. V., Tsutsumi, H., Chou, Y.-C., Duan, F., Shen, C.-C., & Satake, K. (2017). Occurrence of 1 ka-old corals on an uplifted reef terrace in west Luzon, Philippines: Implications for a prehistoric extreme wave event in the South China Sea region. Geoscience Letters, 4(1). more

 

Abstract:

Recent 230Th dating of fossil corals in west Luzon has provided new insights on the emergence of late Quaternary marine terraces that fringe west Luzon Island facing the Manila Trench. Apart from regional sea level changes, accumulated uplift from aseismic and seismic processes may have influenced the emergence of sea level indicators such as coral terraces and notches. Varied elevations of middle-to-late Holocene coral terraces along the west Luzon coasts reveal the differential uplift that is probably associated with the movement of local onland faults or upper-plate structures across the Manila Trench forearc basin. In Badoc Island, offshore west of Luzon mainland, we found notably young fossil corals, dated at 945.1 ± 4.6 years BP and 903.1 ± 3.9 years BP, on top of a ~5-m-high reef platform. To constrain the mechanism of emergence or emplacement of these fossil corals, we use field geomorphic data and wave inundation models to constrain an extreme wave event that affected west Luzon about 1000 years ago. Our preliminary tectonic and tsunami models show that a megathrust rupture will likely lead to subsidence of a large part of the west Luzon coast, while permanent coastal uplift is attributed to an offshore upper-plate rupture in the northern Manila Trench forearc region. The modeled source fault ruptures and tsunami lead to a maximum wave height of more than 3 m and inundation distance as far as 2 km along the coasts of western and northern Luzon. While emplacement of coral boulders by an unusually strong typhoon is also likely, modeled storm surge heights along west Luzon do not exceed 2 m even with Typhoon Haiyan characteristics. Whether tsunami or unusually strong typhoon, the occurrence of a prehistoric extreme wave event in west Luzon remains an important issue in future studies of coastal hazards in the South China Sea region.

 

4. Yasuhara, M., Iwatani, H., Hunt, G., Okahashi, H., Kase, T., Hayashi, H., … Renema, W. (2017). Cenozoic dynamics of shallow-marine biodiversity in the Western Pacific. Journal of Biogeography, 44(3), Pages 567–578. more

 

Abstract:

Aim: Cenozoic dynamics of large-scale species diversity patterns remain poorly understood, especially for the Western Pacific, in part, because of the paucity of well-dated fossil records from the tropics. This article aims to reveal the spatiotemporal dynamics of species diversity in the Western Pacific through the Cenozoic, focusing on the tropical Indo-Australian Archipelago (IAA) biodiversity hotspot. Location: Tropical and north-western Pacific Ocean. Methods: We analysed well-preserved fossil ostracodes from the tropical Western Pacific and combined their diversity data with other published data from the region to reconstruct Cenozoic dynamics of species diversity in the tropical and north-western Pacific Ocean. We fitted generalized additive models to test for differences in richness over time and across geographical regions while accounting for sample-size variation among samples. Results: Low-, mid- and high-latitude regions all show a similar diversity trajectory: diversity is low in the Eocene and Oligocene, increases from the Early Miocene to the Plio-Pleistocene but then declines to the present day. Present-day high biodiversity in these regions was established during the Pliocene with a remarkable diversity increase at that time. Latitudinal diversity patterns are relatively flat and never show a simple decline from the tropics to higher latitudes. Main conclusions: Western Pacific Cenozoic ostracodes exhibit a spatiotemporal pattern of species diversity that is inconsistent with the commonly reported and persistent pattern of declining diversity from the tropics to the extratropics. While this inconsistency could be interpreted as evidence that ostracodes are a contrarian clade, Atlantic ostracodes display a standard latitudinal species diversity gradient. Contrasting patterns between oceans suggest an important role for regional factors (e.g. plate tectonics and temporal geomorphological dynamics) in shaping the biodiversity of the Western Pacific.

 

5. Zuluaga, M. C., Norini, G., Lima, A., Albanese, S., David, C. P., & De Vivo, B. (2017). 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, Pages 18–35. more

Abstract:

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.

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1. de la Peña, L. D., Cabillon, N. A. R., Amar, E. C., Catedral, D. D., Usero, R. C., Faisan, J. P., … Saloma, C. P. (2017). Mortality of Pond-cultured Litopenaeus vannamei Associated with Acute Hepatopancreatic Necrosis Disease (AHPND) and White Spot Syndrome Virus (WSSV) Infection in the Philippines. Fish Pathology, 52(1), Pages 38–41.more

Abstract:

Mortalities of up to 60% were observed in pond-culturedLitopenaeusvannamei in Bohol, Philippines. Histopathological examination revealed typical acute hepatopancreatic necrosis disease (AHPND) pathology. PCR test generated 1,269 bp and 230 bp amplicons confirmative for the toxin-producing AHPND strain ofVibrioparahaemolyticus among shrimp sampled from eight ponds. The same samples were subjected to PCR analyses for the presence of other viruses, namely WSSV, IHHNV, IMNV, and TSV. The samples were negative for the viruses except WSSV, which was detected after one-step PCR in six out of eight ponds. These results suggested that shrimp were infected dually with AHPNDV.parahaemolyticus and WSSV.

2. Zumaraga, M. P., Medina, P. J., Recto, J. M., Abrahan, L., Azurin, E., Tanchoco, C. C., … Palmes-Saloma, C. (2017). Targeted next generation sequencing of the entire vitamin D receptor gene reveals polymorphisms correlated with vitamin D deficiency among older Filipino women with and without fragility fracture. The Journal of Nutritional Biochemistry, 41, Pages 98–108.more

Abstract:

This study aimed to discover genetic variants in the entire 101 kB vitamin D receptor (VDR) gene for vitamin D deficiency in a group of postmenopausal Filipino women using targeted next generation sequencing (TNGS) approach in a case–control study design. A total of 50 women with and without osteoporotic fracture seen at the Philippine Orthopedic Center were included. Blood samples were collected for determination of serum vitamin D, calcium, phosphorus, glucose, blood urea nitrogen, creatinine, aspartate aminotransferase, alanine aminotransferase and as primary source for targeted VDR gene sequencing using the Ion Torrent Personal Genome Machine. The variant calling was based on the GATK best practice workflow and annotated using Annovar tool. A total of 1496 unique variants in the whole 101-kb VDR gene were identified. Novel sequence variations not registered in the dbSNP database were found among cases and controls at a rate of 23.1% and 16.6% of total discovered variants, respectively. One disease-associated enhancer showed statistically significant association to low serum 25-hydroxy vitamin D levels (Pearson chi-square P-value=0.009). The transcription factor binding site prediction program PROMO predicted the disruption of three transcription factor binding sites in this enhancer region. These findings show the power of TNGS in identifying sequence variations in a very large gene and the surprising results obtained in this study greatly expand the catalog of known VDR sequence variants that may represent an important clue in the emergence of vitamin D deficiency. Such information will also provide the additional guidance necessary toward a personalized nutritional advice to reach sufficient vitamin D status.

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1. Aguilar, R., & Hermosa, N. (2017). Quadrant detector sensitivity and linearity index measurement with Laguerre-Gaussian beams. In Proceedings of SPIE - The International Society for Optical Engineering

 

2.Agulto, V.C., Agulo, I.J., Sarmago, R.V. (2017). FTIR and UV-visible absorbance studies of hydrothermally grown ZnO coated with polyvinylpyrrolidone. Materials Science Forum, 895, Pages 73-78.more

Abstract:

Hydrothermally grown hexagonal wurtzite ZnO microrods coated with polyvinylpyrrolidone (PVP) via an ex-situ method, was successfully synthesized without using complex procedure or experimental setup. FTIR results confirm the presence of different functional groups of PVP at the ZnO surface and the chemical interaction of ZnO with the C=O ligand of the PVP molecule. The presence of PVP molecules prevents the absorption of atmospheric CO2 by the Zn2+ ions since PVP chemically interacts with ZnO by attaching to the exposed cations. The coating concentration doesn’t induce a frequency shift in the vibrations of the PVP functional groups. The ZnO microrods possess good optical quality as indicated by the high UV absorption and pronounced excitonic peak at room temperature, even after coating with higher PVP concentrations. 

3. Batac, R.C., Paguirigan, A.A., Tarun, A.B.,  Longjas, A.G. (2017). Sandpile-based model for capturing magnitude distributions and spatiotemporal clustering and separation in regional earthquakes. Nonlinear Processes in Geophysics, 24(2), Pages 179-187.more

Abstract: 

We propose a cellular automata model for earthquake occurrences patterned after the sandpile model of self-organized criticality (SOC). By incorporating a single parameter describing the probability to target the most susceptible site, the model successfully reproduces the statistical signatures of seismicity. The energy distributions closely follow power-law probability density functions (PDFs) with a scaling exponent of around-1. 6, consistent with the expectations of the Gutenberg-Richter (GR) law, for a wide range of the targeted triggering probability values. Additionally, for targeted triggering probabilities within the range 0.004-0.007, we observe spatiotemporal distributions that show bimodal behavior, which is not observed previously for the original sand pile. For this critical range of values for the probability, model statistics show remarkable comparison with long-period empirical data from earthquakes from different seismogenic regions. The proposed model has key advantages, the foremost of which is the fact that it simultaneously captures the energy, space, and time statistics of earthquakes by just introducing a single parameter, while introducing minimal parameters in the simple rules of the sand pile. We believe that the critical targeting probability parameterizes the memory that is inherently present in earthquake-generating regions. 

4. Bernardo, R.C.S., Esguerra, J.P.H. (2017). Euclidean path integral formalism in deformed space with minimum measurable length. Journal of Mathematical Physics, 58(4).more

Abstract: 

We study time-evolution at the quantum level by developing the Euclidean path integral approach for the general case where there exists a minimum measurable length. We derive an expression for the momentum-space propagator which turns out to be consistent with recently developed canonical transformation. We also construct the propagator for maximal localization which corresponds to the amplitude that a state which is maximally localized at location ↑0 propagates to a state which is maximally localized at location ↑00 in a given time. Our expression for the momentum space propagator and the propagator for maximal localization is valid for any form of time-independent Hamiltonian. The nonrelativistic free particle, particle in a linear potential, and the harmonic oscillator are discussed as examples.

5. Caballar, R., Butanas, B., Villegas, B., & Estrella, M. (2017). Dissipation induced quantum transport on a finite one-dimensional lattice.

 

6. Cabello, N. I., Tingzon, P., Cervantes, K., Cafe, A., Lopez, J., Mabilangan, A., … Estacio, E. (2017). Luminescence and carrier dynamics in nanostructured silicon. Journal of Luminescence, 186, Pages 312–317. 

 

7. Cafe, A.I., Lopez, J., Lopez, L., Jr., Faustino, M.A.,  Mabilangan, A.,  Salvador, A., Somintac, A. (2017). Porous silicon optical template for determination of chromatic dispersion of transparent liquid mixture. AIP Conference Proceedings, 1808(1). doi: http://dx.doi.org/10.1063/1.4975245.more

Abstract:

Porous silicon was fabricated through electrochemical etching and is used as an optical template for liquid sensing application. Using reflectance spectroscopy, change in optical properties such as refractive index and reflectivity upon liquid introduction were obtained. Chromatic dispersion of porous silicon upon detection of transparent liquids such as absolute ethanol, methanol, 2-propanol and distilled water were determined for spectral range 450nm to 1100nm. Mixture of the organic transparent liquid and water was also tested. In this study, porosity and liquid's concentration were varied to establish the sensitivity of detection. Expected ideal values were also simulated for comparison and correction factor computation. Results provide calibration basis for water quality assessment, environmental monitoring, and diagnostic application. 

8. Calaque, P.M., Vergara, C.J., Ballesteros, L.I., Somintac, A. (2017). Development and characterization of a novel ZnO nanorods-SnO2:F nanoflakes thin film for room-temperature ammonia and humidity sensing (Conference Paper). AIP Conference Proceedings, 1808.more

Abstract: 

A unique and novel thin film of fluorine-doped tin oxide (SnO2:F) nanoflakes on ZnO nanorods were fabricated using nebulized spray pyrolysis technique (NSPT) and hydrothermal growth method, respectively, for ammonia and humidity sensing applications. XRD studies confirm the growth of a hexagonal wurtzite ZnO and a tetragonal SnO2:F. SEM images of the film fabricated for preliminary studies evidently revealed ZnO nanorods and SnO2:F nanoflakes. The response of the fabricated ZnO-SnO2:F nanostructure thin film sensor on varying concentrations of water vapor and ammonia at room temperature were investigated. Results have shown that it had higher sensor response to ammonia than to water vapor. Moreover, it was observed to have a higher sensor response on ammonia and humidity compared to the fabricated sensor of SnO2:F thin film alone. The films could detect humidity and ammonia even at a low level of 9 ppm and 5 ppm, respectively, showing its potential use for various fields such as environmental monitoring and chemical industries. 

9. Cruz, P. C. S., Bernardo, R. C. S., & Esguerra, J. P. H. (2017). Energy levels of a quantum particle on a cylindrical surface with non-circular cross-section in electric and magnetic fields. Annals of Physics, 379, Pages 159–174.

 

10. de los Reyes, A., Prieto, E. A. P., Omambac, K., Porquez, J., Lopez, L., Gonzales, K. C., … Salvador, A. A. (2017). Terahertz emission characteristics of GaMnAs dilute magnetic semiconductor under 650 mT external magnetic field. Current Applied Physics, 17(4), Pages 522–526.more

Abstract:

We investigate the effects of an externally applied magnetic field on the terahertz (THz) emission of Gallium Manganese Arsenide (GaMnAs) films grown via molecular beam epitaxy (MBE). Results show that low Mn-doping in GaMnAs resulted to increased THz emission as compared with a SI-GaAs substrate. Further increase in Mn-doping content resulted to a comparably less THz emission, which is attributed to reduced crystallinity and higher free-carrier absorption. Under an external magnetic field, the contributions of the Bup and Bdown-related THz emission were observed to be asymmetric: possibly due to intrinsic magnetic properties of GaMnAs. 

11. Empizo, M.J.F., Santos-Putungan, A.B., Yamanoi, K., Salazar, H.T., Jr., Anguluan, E.P., Mori, K., Arita, R., Minami, Y., Luong, M.V., Shimizu, T., Estacio, E.S., Somintac, A.S., Salvador, A.A., Sarmago, R.V., Fukuda, T., Sarukura, N. (2017). Structural and optical characterization and scintillator application of hydrothermal-grown ZnO microrods. Optical Materials, 65, Pages 82-87.more

Abstract:

ZnO microrods are fabricated by a simple hydrothermal growth route using zinc acetate dihydrate [Zn(CH3COO)2·2H2O] and hexamethylenetetramine [(CH2)6N4] aqueous solutions. The as-prepared microrods exhibit uniform dimensions, well-faceted surfaces, and hexagonal crystal structure. The microrods also have an intense ultraviolet (UV) emission at 392 nm with an average lifetime of 80 ps. No peaks are observed at the visible wavelengths that can be attributed to defect-related emissions. With excellent structural and optical properties and with loose adhesion to their substrates, the ZnO microrods can be isolated, harvested, and manipulated and can be integrated as building blocks of a microstructured scintillator screen. The proposed scintillator screen possibly offers efficient and precise detection with high resolution. Hydrothermal-grown ZnO microrods then hold a promise towards radiation detector innovation and integrated optoelectronic microsystems. 

12. Felix, M. J., Muldera, J., Somintac, A., Salvador, A., & Estacio, E. (2017). Enhanced Terahertz emission and raman signal from silicon nanopyramids. Science of Advanced Materials, 9(2), Pages 214–219. 

 

13. Galapon, E. A. (2017). The problem of missing terms in term by term integration involving divergent integrals. Proceedings of the Royal Society A: Mathematical, Physical and Engineering Sciences, 473(2197).more

Abstract:

Term by term integration may lead to divergent integrals, and naive evaluation of them by means of, say, analytic continuation or by regularization or by the finite part integral may lead to missing terms. Here, under certain analyticity conditions, the problem of missing terms for the incomplete Stieltjes transform, ∫ a0 f (x)(ω + x)-1 dx, and the Stieltjes transform itself, ∫ 0 f (x)(ω + x)-1 dx, is resolved by lifting the integration in the complex plane. It is shown that the missing terms arise from the singularities of the complex-valued function f (z)(ω + z)-1, with the divergent integrals arising from term by term integration interpreted as finite part integrals. 

14. Galapon, E. A. (2017). Erratum: “The Cauchy principal value and the Hadamard finite part integral as values of absolutely convergent integrals.Journal of Mathematical Physics, 58(19901–1), 2016–2017. 

 

15. Husay, H.A., Balgos, M.H., Tumanguil, M.A., Estacio, E., Salvador, A., Somintac, A. (2017). Terahertz emission from CuO nanowires synthesized through thermal oxidation of Cu foils. Science of Advanced Materials, 9(2), Pages 193-198.

Abstract:

We demonstrate terahertz (THz) emission from cupric oxide nanowires (CuO NWs) synthesized through thermal oxidation of Cu foils in ambient air by heating the foils in a hotplate for two hours at 300, 350, 400, and 450 °C. Scanning electron microscopy revealed the changes in the morphology of the foils; from the formation of a film composed of grains at 300 and 350 °C to the formation of NWs at 400 and 450 °C. The NWs were seen to have densities and dimensions that vary depending on the oxidation temperature. X-ray diffractometry showed that the grains that form at 300 and 350 °C were composed of a mixed phase of Cu2O and CuO, while the CuO NWs were observed to crystallize at temperatures greater than 400 °C. THz time domain spectroscopy (THz-TDS) showed that the foils containing CuO NWs were observed to emit THz radiation. It was further shown that increasing the density and dimensions of the NWs enhances the transient photocurrent generated throughout the length of the NWs, resulting in a stronger THz emission. 

16. Pang, J. C. S., & Monterola, C. P. (2017). Dendritic growth model of multilevel marketing. Communications in Nonlinear Science and Numerical Simulation, 43, Pages 100–110.more

Abstract:

Biologically inspired dendritic network growth is utilized to model the evolving connections of a multilevel marketing (MLM) enterprise. Starting from agents at random spatial locations, a network is formed by minimizing a distance cost function controlled by a parameter, termed the balancing factor bf, that weighs the wiring and the path length costs of connection. The paradigm is compared to an actual MLM membership data and is shown to be successful in statistically capturing the membership distribution, better than the previously reported agent based preferential attachment or analytic branching process models. Moreover, it recovers the known empirical statistics of previously studied MLM, specifically: (i) a membership distribution characterized by the existence of peak levels indicating limited growth, and (ii) an income distribution obeying the 80−20 Pareto principle. Extensive types of income distributions from uniform to Pareto to a “winner-take-all” kind are also modeled by varying bf. Finally, the robustness of our dendritic growth paradigm to random agent removals is explored and its implications to MLM income distributions are discussed. 

17. Rosario, L.M.D.ab, Lee, H.V., Jr.a, Penafiel, E.a, Ramos, H.J.c, Bo-Ot, L.M.T.d,  Fischer, R.V.e, Tumlos, R.B. (2017). Characterization of a Microwave-Induced Atmospheric-Pressure Ar-N2 Plasma Pencil. IEEE Transactions on Plasma Science, 45(2), Pages 301-309.more

Abstract:

A microwave-induced atmospheric-pressure plasma pencil was developed with an Ar-N2 gas mixture supplied to a coaxial transmission line. High-frequency simulation showed sufficient high electric field at the tip of the inner conductor, which resulted to automatic plasma ignition and a stable operation. The dependence of the characteristics of the plasma pencil from Ar and N2 gas flow rates was extensively studied. At moderate Ar gas flow rates, the plasma pencil can be operated at several tens of watts to achieve a near room-temperature and centimeter-long Ar-N2 plasma plume with OH and NO radicals as active species. Optical emission spectroscopy was also used to determine the vibrational and rotational temperatures of the plasma pencil. The vibrational temperature of N2 from the second positive system (2PS) can be obtained at moderate gas flow rates, since there was a good linear fitting with the Boltzmann distribution. At these gas flow rates, the vibrational and rotational temperatures of N2 from 2PS were found to be 0.42 and 0.29 eV, respectively. 

18. Rosete, M. M., Zosa, M. H., & Sarmago, R. V. (2017). Effect of Potassium Chloride as a Supporting Electrolyte on the Dispersion Towards the Fabrication of Films by Electrophoretic Deposition of Bi2Sr2CaCu2 O 8 in Ethanol. Journal of Superconductivity and Novel Magnetism, Pages 3–8.more

Abstract:

Bi2Sr2CaCu2O8 (Bi-2212) powder was fabricated using solid state reaction method. The suspensions were prepared containing finely ground Bi-2212 powder with and without potassium chloride (KCl) addition. Settling experiments and measurements of zeta potential, particle size distribution, and electrophoretic mobility were performed to determine the optimal concentration of the supporting electrolyte. Bi-2212 suspensions were used in electrophoretic deposition (EPD), and the films were heat treated. The results showed that the optimal concentration of KCl is 5.21 wt %. The zeta potential at this concentration is highest at about 31.10 mV, the settling velocity is lowest 3.84 mm/min, and the particle size is smallest (450 nm), which indicate that the dispersion is better due to the reduction of intermolecular attraction. The effects of KCl as a flux were observed in the microstructure and superconducting properties of Bi-2212 film. The smoothest surface morphology, high c-axis orientation, and highest critical temperature (Tc)-onset of 84.73 K were obtained from the film prepared with optimized Bi-2212 suspension. 

19. Tinacba, E. J. C., Nuñez, J. A., Tumlos, R. B., & Ramos, H. J. (2017). ZnO/Zn and ZnO film deposited via microwave atmospheric plasma jet as photo-catalyst for Rhodamine 6G dye degradation. Thin Solid Films, 624, Pages 197–200. 

 

20. Tingzon, P., Lopez, L., Oliver, N., Cabello, N., Cafe, A., De Los Reyes, A., … Somintac, A. (2017). Terahertz emission and photoluminescence of Silicon Nanowires electrolessly etched on the surface of Silicon (100), (110), and (111) substrates for photovoltaic cell applications. Photonics and Nanostructures - Fundamentals and Applications, 24, Pages 1–6.more

Abstract:

Silicon nanowires (SiNWs) were etched on Si (100), (110), and (111) substrates. Slanted nanowires with respect to the surface normal were produced on the Si (110) and (111) substrates, and vertical nanowires were produced on the Si (100) substrate. Photoluminescence spectroscopy exhibited luminescence lines attributed to oxide defects from the nanowires. A comparison of the transient photocurrent as measured using terahertz time-domain spectroscopy revealed an increase in the THz emission from the SiNWs on Si (110) substrate compared to those grown on (100) substrate. Reorienting the dipole moment by applying an external 650 mT magnetic field suggested that the carrier transport was confined along the axis of the nanowires. Understanding the photocarrier and transport recombination properties in SiNWs may prove useful in the design considerations for future SiNW photovoltaic cell applications. 

21. Villacorta, R. B., Faith Javier Roque, K., Tapang, G. A., & Jacinto, S. D. (2017). Plant extracts as natural photosensitizers in photodynamic therapy: in vitro activity against human mammary adenocarcinoma MCF-7 cells. Asian Pacific Journal of Tropical Biomedicine, 7(4), Pages 358–366. 

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1. Apaga, D. L. T., Dennis, S. E., Salvador, J. M., Gayvelline, C., & Ungria, M. C. A. De. (2017). Comparison of Two Massively Parallel Sequencing Platforms using 83 Single Nucleotide Polymorphisms for Human Identification. Scientific Reports, Pages 1–6. 

 

2. Atayde, E.C., J., Berenguel, M. M., & Arco, S. . (2017). RAFT polymerization of dual responsive hyperbranched-star copolymers of methacrylic acid and poly(Ethylene glycol). Materials Science Forum, 890, Pages 78–81. 

 

3.Buhian, W. P. C., Rubio, R. O., & Martin-Puzon, J. J. (2017). Chromatographic fingerprinting and free-radical scavenging activity of ethanol extracts of Muntingia calabura L. leaves and stems. Asian Pacific Journal of Tropical Biomedicine, 7(2), Pages 139–143. 

 

4. Calayag, A. M. B., Paclibare, P. A. P., Santos, P. D. M., Bautista, C. A. C., & Rivera, W. L. (2017). Molecular characterization and antimicrobial resistance of Salmonella enterica from swine slaughtered in two different types of Philippine abattoir. Food Microbiology, 65, Pages 51–56. 

 

5. Celeste, R. O., Corcino, R. B., & Gonzales, K. J. M. (2017). Two approaches to normal order coefficients. Journal of Integer Sequences, 20(3). 

 

6. de la Cruz, R. J., Merino, D. I., & Paras, A. T. (2017). Every 2 n -by-2 n complex matrix is a sum of three symplectic matrices. Linear Algebra and Its Applications, 517, Pages 199–206.

 

7. Loquias, M. J. C., Valdez, L. D., & Walo, M. L. B. (2017). Color groups of colorings of N-planar modules. In Journal of Physics: Conference Series (Vol. 809). 

 

8. Nuñez, J. A. P., Salapare, H. S., Villamayor, M. M. S., Siringan, M. A. T., & Ramos, H. J. (2017). Antibacterial efficiency of magnetron sputtered TiO 2 on poly(methyl methacrylate). Surfaces and Interfaces, 8, Pages 28–35. 

 

9. Pagalilauan, H. A. M., Paraoan, C. E. M., & Vital, P. G. (2017). Detection of pathogenic bioaerosols and occupational risk in a Philippine landfill site. Archives of Environmental & Occupational Health, Pages 1–8. 

 

10. Paraoan, C. E. M., Rivera, W. L., & Vital, P. G. (2017). Detection of Class I and II integrons for the assessment of antibiotic and multidrug resistance among Escherichia coli isolates from agricultural irrigation waters in Bulacan, Philippines. Journal of Environmental Science and Health, Part B, 1234(March), Pages 1–8. 

 

11. Tayaban, K. M. M., Pintor, K. L., & Vital, P. G. (2017). Detection of potential harmful algal bloom-causing microalgae from freshwater prawn farms in Central Luzon, Philippines, for bloom monitoring and prediction. Environment, Development and Sustainability, Pages 1–18.