Demethylation inhibitors (DMI) fungicides are commonly used to mitigate fungal diseases in crops by inhibiting ergosterol biosynthesis. Alternaria alternata and Alternaria tenuissima are fungal plant pathogens being controlled with DMIs. However, with unregulated use of fungicides, reports on reduced sensitivity to DMIs have been documented in these fungal species. Previous studies have shown the accumulation of point mutations in CYP 51 and CYP 61 genes that are involved in ergosterol biosynthesis to the development of resistance to DMI fungicides. Understanding the phylogeographic trends of isolates based on the DMI gene targets is critical to identify sustainable management strategies against fungicide resistance. In this study, a phylogenetic approach was used to determine the association of geographic origin of isolates with fungicide resistance across A. alternata and A. tenuissima isolates. Phylogeographic and haplotype analyses revealed genetic patterns in CYP 51 and CYP 61, associated with DMI resistance. Generally, clusters formed within specific geographic areas such as Asia and North America. Moreover, nucleotide variation estimates revealed the presence of polymorphic nucleotide bases in response to DMI exposure as a selection pressure. These results provided insights in further testing in vitro assays regarding the selection patterns associated with specific regions.
The study investigated the levels of heavy metals (Hg, As, Cd, Cr, Pb) in frequently consumed vegetables in urban and rural farms in the Philippines and assessed their associated health risks. Results revealed that the Hg concentration was at method detection limit (MDL), while for other heavy metals, the values ranged from Cr>As>Cd>Hg. Single factor ANOVA demonstrated a significant difference ( alpha = 0.05) between urban and rural sites. Assessment of noncarcinogenic risk by combined impact of all metals (Hazard Index, HI) indicated no concern (<1) for both adults and children for Hg, Cd, Cr and Pb except for As in taro and red chili (HI: 1.2 - 1.9) from specific urban sites. The carcinogenic risk by Target Cancer Risk (TCR) assessment was >10E-5 (USEPA limit) for As (1.8E-4 to 7.9E-4) and Cr (1.2E-4 to 1.2E-3) exposing future risk from long-term consumption of contaminated vegetables. While urban farming produce can serve as food source for the community, review of regulatory measures is recommended to avert potential health risks.
Diseases and pests hamper Philippine coffee production. Identification of defense-associated genes, which are present in certain plants, can be used to identify which resistant coffee cultivars to propagate. This study aimed to identify Coffea canephora candidate resistance (R) and resistance -associated genes within a region (19-23 Mb) of chromosome 5, encompassing the Sat229 SSR marker. After using "BioMart" to retrieve data from Ensembl Plants, genes were screened based on their Gene Ontology (GO) annotations. Their predicted protein products were identified using BLASTp. For R genes, architecture was further evaluated using hmm scan, PCoils, and LRR search while clustering was analyzed manually. The genes were mapped using the R package "chromoMap". The results reveal 23 putative R genes that encode NLR proteins detecting pathogenic effectors, and 52 resistance -associated genes. Notable ones were predicted to encode an isoform of diacylglycerol kinase 5 (DGK5), programmed cell death -associated proteins, transcription factors containing AP2/ERF domain, two potential novel proteins with C-terminal leucine-rich repeat (LRR) domains involved in defense against fungi, and isoprene synthase. Thus, this study was able to screen the Sat229 region of chromosome 5 of the C. canephora genome and identify candidate el el defense-associated gene loci, which can be used as reference for marker -assisted breeding programs.
Dimethylcardamonin (DMC) or (E)-2',4'-dihydroxy-6'-methoxy-3',5'-dimethyl chalcone was isolated from Syzygium samarangense (Blume) Merr. leaves using vacuum liquid chromatography and normal phase silica-gel column chromatography. DMC was purified from the fraction that eluted out of 9:1 (v/v) hexane: ethyl acetate to 7:3 (v/v) hexane: ethyl acetate. Using a modified method from Geissman (1948), DMC was derivatized via alkaline peroxidation from which compounds A and B were obtained. Compound A was identified to be (2S)-7-hydroxy-5-methoxy-6,8-dimethyl flavanone (C18H18O4) while B had a methoxy group on its 4' position instead of a hydroxyl group with respect to DMC. The flavanone derivative may have been formed due to substituent effects on the ring.DMC, A, and B were tested for their inhibitory activity against cyclooxygenase enzymes at 10 and 100 ppm. A and B gave at least 50% inhibitory activity at 100 ppm and were found to be COX-2 selective inhibitors. DMC was inactive at both 10 and 100 ppm.
An 18,493 base pair mitogenome of the Philippine Cockatoo (Cacatua haematuropygia) is presented, containing 13 complete protein-coding genes, two rRNAs, 24 tRNAs, two control regions, and two partial duplicate copies of cytb and nd6. The mitogenome contains two complete copies of tRNA-Leu, tRNA-Ser, tRNA-Thr, and tRNA-Pro. Phylogenetic analysis places the Philippine Cockatoo within the subgenus Licmetis, with its closest relatives being the Tanimbar Corella (Cacatua goffiniana) and the Western Corella (Cacatua pastinator) and all three species being sisters to other white cockatoos in the subgenus Cacatua. The gene order and content of the mitogenome are most similar to C. pastinator, containing a partial duplication of cytb, and whole duplications of the control region and several tRNA genes. However, the total duplication of nd6 could not be verified. Analysis of the control regions indicates that these are paralogs of each other; both copies contain preserved features such as the Extended Termination Associated Sequences 1 and 2 (ETAS1, ETAS2) and Conserved Sequence Block 1 (CSB1) associated with d-loop or control region replication in mitogenomes. Gene order for the species cannot be verified since the region corresponding to duplicate copies of tRNA-Glu and nd6 in other cockatoos could not be properly sequenced.
Antibiotic resistance against common microbes is an ongoing concern worldwide. This warrants continuous studies that aim to discover new compounds with antimicrobial properties. In this study, sixteen low molecular weight bis-urea derivatives were screened for their in vitro antimicrobial properties using agar well diffusion method. The structure of the bis-urea compounds is comprised of cyclic and aromatic linkers and a variety of symmetric end groups such as aliphatic chains and heteroaromatic groups. Significant antimicrobial activity against strains of Escherichia coli, Staphylococcus aureus, and Klebsiella pneumoniae was observed for compounds with long aliphatic chains compared to those with benzyl and heteroaromatic end groups. Further studies on the minimum inhibitory concentration and cytotoxicity can aid in the development of these compounds as antimicrobial agents as well as for other possible biomedical and environmental applications.
An inventory of the non-avian terrestrial vertebrate species found within the 493-hectare land area of the UP Diliman campus is presented. Visual encounter surveys for amphibians and reptiles, as well as mist-netting and trapping for mammals, were conducted last August 2019 to early February 2020 on selected study grids on campus. To determine habitat associations, the species richness of each vertebrate class (i.e., amphibia, reptilia, and mammalia) was analyzed with habitat characteristics of the grid using regression analysis. Based on the surveys and recent records (2015 onwards) in literature, a total of 33 species were recorded: seven amphibians, 15 reptiles, and 11 mammals. Comparison with historical records from 1998 revealed that an additional two amphibian species, seven reptile species, and six mammalian species have been sighted within the area since 2015. However, a fork-tongued frog, falling under the genus Fejervarya, and four reptilian species that had previously been recorded within the study sites were not observed. Habitat association analysis revealed that building area is correlated with species richness, with reptilian species richness being positively correlated with it. Overall, this study shows that the UP Diliman campus supports considerable urban biodiversity despite recent developments.
The study of the spectroscopy of solid materials is not as extensive compared to that of homogeneous liquid solutions. Optical properties, such as reflectance, transmittance, and absorbance, may be used for the characterization of new materials. Qualitative characterization of colored materials and quantitative determination of surface modification and band gap analysis through the Tauc plot method were obtained using visible-reflectance spectroscopy. Differentiation of reflectance peaks was observed in the spectra of colored papers and acrylic spray paints. Expected trends of higher reflectance according to the ability of a color to reflect light were also observed. Surface analysis through the reflectance method indicated that spectra of pristine and surface-modified samples showed a significant difference in signals, which is attributed to the roughening and contamination of the surface of the materials. Using the Tauc plot method on the absorbance spectrum data of an electrodeposited zinc oxide film, the calculated BGE was 3.80 eV, with a 15.15% deviation from its literature value of 3.30 eV. In addition, zinc sulfide, which was chemically deposited on glass slides, had an average band gap of 3.0 eV, with an 8.82% error against its literature value of 3.4 eV. These experiments on specular reflectance of solid materials, particularly optical and new materials, may be incorporated in undergraduate laboratory courses.
Papaya plants (Carica papaya L.) were assessed for tree and fruit morphological traits. During eight months of drought conditions, papaya plants showed signs of drought from March to May 2016. Drought affected fruit development and fruit qualities. Significant decrease in fruit weight, length, width, flesh thickness, and seed weight were observed in drought-affected papayas; however, total soluble solids (TSS) of fruit flesh were significantly higher compared to the TSS of fruits harvested during normal conditions. Drought-tolerant papaya trees were selected based on morphological responses. Drought-tolerant papaya trees were significantly taller and had thicker stems, wider crowns, and more functional green leaves compared to drought-affected trees. Selected plants that thrived well under drought condition were identified for use in breeding. Recovery of plants was evident in increase in fruit weight, length, and width. Correlation of fruit characters of selected drought-tolerant papaya trees revealed that fruit weight was strongly positively correlated with fruit length, fruit width, peel weight, flesh thickness, and TSS.
The Marilao-Meycauayan-Obando River System is known to be heavily polluted with organics and heavy metals, thus affecting the ecosystem. This study used probiotics as an ecological approach to improve environmental quality, with a focus on determining the impacts of probiotics on fish health and survival as well as water quality. Probiotics are microbial feed supplements that can improve the survival and health of organisms. Probiotics were applied at the start and after two months of culture period. Physico-chemical water quality parameters were recorded. Growth parameters such as fish body weight, feed conversion ratio (FCR), and survival rate were determined. Polymerase chain reaction-denaturing gradient gel electrophoresis (PCR-DGGE) method was used to determine the microbial community present in the guts of milkfish (Chanos chanos) grown in polluted water treated with probiotics. The results showed that ponds treated with probiotics had higher dissolved oxygen and lower biochemical oxygen demand (BOD) and nitrate and phosphate levels, which are beneficial for the growth of milkfish. However, higher ammonia and chemical oxygen demand (COD) were observed in the probiotic ponds. Higher survival rate (95.3%) was obtained in treated ponds compared to non-treated ponds (74.1%). The FCR was less in probiotic-treated ponds (0.74) than non-treated ponds (1.35), which is beneficial for fish production. The study showed that the probiotic strains (Bacillus) were not able to establish in the milkfish gut. Instead, strains related to Cetobacterium, Clostridium, Conexibacter, Cyanobium, Cyanothece, Cylindrospermum, Helicobacter, Romboutsia, Synechococcus, and Vibrio were detected in the guts of milkfish. Overall, the probiotics had an impact on water quality and fish health through improvement of growth and survival rate.
Prior to this study, there had been no malacofaunal study in the University of the Philippines Laguna Land Grant (UPLLG). To address this, a diversity survey of its freshwater and land mollusks was conducted. A total of 25 quadrats (15 m2) on upstream and downstream stations along Dakil River and its tributaries for freshwater mollusks and 12 quadrats (100 m2) for land snails were set randomly to correlate their diversity patterns with environmental variables. From 115 individuals of freshwater mollusks, seven species (six gastropods, one bivalve) belonging to six families (Ampullariidae, Corbiculidae, Lymnaeidae, Neritinidae, Thiaridae, and Viviparidae) were identified. On the other hand, seven species belonging to three families (Ariophantidae, Camaenidae, and Chronidae) were identified among 28 land snail individuals. Malacofaunal survey revealed that the area along Dakil River has low diversity in both freshwater mollusk (H'=1.40) and land snail (H'=1.19). Generalized linear mixed models (GLMM) revealed river velocity was the most significant predictor for species richness of freshwater mollusks, and abundance was highly affected by temperature and inversely affected by canopy cover. Furthermore, altitude was the most significant predictor for species richness of land snails and canopy cover for abundance. Understanding the molluscan diversity could help determine the environment and ecological conditions of the watershed for its effective management and conservation.
Fructophilic lactic acid bacteria (FLAB) is a recently discovered group of lactic acid bacteria that prefers fructose as carbohydrate source. The isolation of FLAB from fructose-rich niches like flowers, in particular, and the gut of insect pollinators suggests that it may be used as probiotics. The objective of this study was to determine if FLAB can be isolated from flowers at the Institute of Biology, University of the Philippines Diliman, and to screen them for antimicrobial activity against bacteria that are commonly associated with intestinal diseases. A total of 20 different isolates were obtained from 14 species of flowers. All isolates were identified as LAB, but only 17 out of 18 isolates were osmotolerant in 30% fructose, and only 8 out of 15 isolates had higher absorbance in Fructose Yeast Peptone Broth, which are characteristics of presumptive FLAB. Seven isolates exhibited inhibitory activity in at least three test bacteria in the primary screening and only four isolates had inhibitory activity in at least two test bacteria, particularly against Enterococcus faecalis and Campylobacter jejuni, in the secondary screening. DNA sequencing and phylogenetic analysis identified isolates MFPS 4.1 and MFRU 7.2 as Weissella spp. The in vitro antimicrobial activities of these isolates can be studied further for possible applications in food and medicine, and their low sequence similarities suggest that the isolates might be novel Weissella species.
We consider binary interactions in an N-particle system. In particular, we use probability distributions known as recombination models to describe these interactions. Chaos propagates when the stochastic independence of two random particles in a particle system persists in time, as the number of particles tends to infinity. The concept of propagation of chaos was first introduced by Kac in connection with the Boltzmann equation, while modeling binary collisions in a gas. We obtain a development of Kac's program in the framework of recombination models. Specifically, our aim is to prove the relevant propagation of chaos phenomenon for our particle system. We first show that the solution for the master equation of our time-continuous process converges. Then, we use this solution together with the concepts of marginal measure and chaos to prove our desired result. Our main theorem for this study says that if a sequence of measures on our defined particle system is chaotic, then the resulting sequence of measures that had undergone the recombination process is also chaotic. This implies that the study of one particle after recombination gives information on the behavior of a group of particles in our particle system.
Underwater noise poses serious threats to marine mammals, which rely on underwater sound primarily for communication, orientation and foraging. In this study, underwater noise from dynamite fishing was analyzed to infer possible effects on local marine mammals, particularly cetaceans. Simulated explosions were performed on 9 July 2018 using confiscated explosives from illegal fishers in San Fernando, La Union. The acoustic properties of blasts from single pulse explosions were characterized using sound recordings captured by a hydrophone. Dominant frequencies from the sound recordings showed that the noise generated by the explosions can be perceived by marine mammals sensitive to the auditory bandwidth of 7 Hz to 180 kHz. Blast charge weights were estimated to determine sound pressure levels generated by the explosions at varying distances from the source. These results imply that marine mammals within 150 m of the explosion will experience debilitating injuries (e.g., acoustic trauma, disorientation) even from a single pulse. By characterizing the acoustic properties of these local explosives, its potential impacts to local marine mammals and other marine organisms can be elucidated. These acoustic calculations can be further enhanced by considering backscattered waves and determining the actual chemical composition of these explosives.
Tectonic deformation displaces the physical positions of regional or national coordinate reference system and/or survey network reference markers quite significantly when situated within fast-deforming, seismically active Plate Boundary Zone (PBZ) regions. Due to unusually high station velocities that reflect high strains near and within active PBZs, the coordinate positions of such survey reference markers need to be re-evaluated within short time spans to remain useful. Such rapid changes must be measured to assess the nature of deformation, and then construct models to accurately quantify changes and then apply proper component corrections (i.e., in-between surveys) in order to maintain the spatial integrity of geodetic networks as a function of time. To determine the effects of regional tectonic deformation on existing survey networks, we evaluate the GPS velocity field gathered from GPS stations situated in Luzon, a region sandwiched between two active, opposing subduction zones: the Manila Trench and the Philippine Trench. This region is traversed by numerous active faults such as the Philippine Fault System, and the (Marikina) Valley Fault System. Using GPS observations, we model the Luzon region as made up of independently rotating but interacting tectonic microplates or blocks, separated by active faults. We then quantify the individual contributions of tectonic block rotation and transient elastic locking strain to estimate the overall deformation field that affects the Philippine Survey Network from its establishment in 1992-1993 to the present. Our preferred block model results show that most stations have been affected by g1 m displacement, with a handful having ~2 m of accumulated displacement in the Sundaland reference frame from their observed initial positions in 1993. Differential inter-block motions of stations dictate that stations need to be reobserved at shorter time spans. Continuum models of residual strain rates further reveal regions of complex internal deformation that may further exacerbate the geometric instability of existing geodetic networks.
The Chinese pond mussel Sinanodonta woodiana (Lea, 1834) is a large freshwater bivalve species of the family Unionidae and a known invasive alien species. Proper verification of its identity as well as its source population is crucial for the control of its spread. However, its high plastic shell morphology that resembles other non-invasive species of unionids can be an obstacle. The distribution and ecological impact of this invasive unionid is not fully understood and should be further investigated to prevent further spread in the Philippines. In this study, we used the cytochrome oxidase I (cox1) gene to verify the identity of putative S. woodiana samples collected from Bato Creek in Oriental Mindoro and Lake Danao in Leyte, Philippines and elucidate their source populations. Eighteen cytochrome oxidase subunit 1 (cox1) barcodes were generated from samples collected from Lake Danao, Leyte (n=13) and Bato Creek, Oriental Mindoro (n=5). These barcodes were subjected to Basic Local Alignment Search Tool (BLAST) analysis, which showed that the cox1 sequences from the Philippine samples matched with those of S. woodiana (>94%) found in GenBank. The sequences were then aligned with cox1 sequences of S. woodiana and other unionid representatives from GenBank. * Corresponding Author Molecular Identification of the Chinese Pond Mussel Sinanodonta woodiana (Lea, 1834) 78 Phylogenetic and haplotype network analyses also showed three haplotypes (Hap 1, 2, and 4) of S. woodiana samples from Lake Danao and Bato Creek. Hap 1 and 2 are distinct haplotypes observed in Lake Danao samples while Hap 4 is shared between Lake Danao and Bato Creek samples and have clustered with conspecific specimens from Malaysia and Indonesia, suggesting their potential Island Southeast Asian origin.
This study presents an electrochemical biosensor developed for uric acid (UA) determination using carbon paste electrode (CPE) modified with copper (II) oxide (CuO) particles and urate oxidase (UOx) enzyme. Base CPE is prepared using a multi-walled carbon nanotube (MWCNT) and a polydimethylsiloxane (PDMS) binder. The main sensing process is based on the oxidation of UA into 5-hydroxyisourate (HIU) as catalyzed by UOx, forming H2O2 as byproduct, and then the H2O2 reduction-oxidation (redox) reaction converts CuO to form Cu2O; the amount of H2O2 and hence UA in the sample is measured by the oxidative current measured for the conversion of Cu2O back to CuO. Cyclic Voltammetry (CV) measurements revealed that the activity of UOx was retained with an apparent Michaelis constant (K-m(app)) to be equal to 41.46 mu M. Differential Pulse Voltammetry (DPV) measurements of UA using UOx-CuO-CPE showed a linear response ranging from 10 mu M to 79.4 mu M UA with a limit of detection (LOD) determined to be equal to 8.82 mu M. UOx-CuO-CPE was shown to be selective towards UA even in the presence of creatinine, xanthine, and glucose. Furthermore, UOx-CuO-CPE was shown to be reusable (3.28% RSD), and its fabrication is repeatable using single factor Analysis of Variance (ANOVA) [F(1.396) < F-critical(5.143)]. UOx-CuO-CPE was also shown to be stable even after five weeks of storage using the two-sample t-test [t(0.156) < t(critical) (4.303)]. Based on a recovery test using synthetic urine sample, this study showed the applicability of UOx-CuO-CPE in the detection of UA in human urine with 90.27%-102.03% recovery (n = 3).
Air quality monitoring in urban areas is indispensable in understanding the environment and how anthropogenic factors contribute to the increasing volume of pollutants in the atmosphere. Differential optical absorption spectroscopy (DOAS) is a useful technique in identifying and quantifying trace amounts of air pollutants over a wide region. In this paper, a low-cost DOAS set-up was developed and was used to measure nitrogen dioxide (NO2) concentration and aerosol optical thickness (AOT) in the University of the Philippines Diliman campus. The temporal variation of NO2 concentration from the DOAS measurement was found to agree with the relative NO2 integrated absorbance from 430-450 nm. A calibration curve was then constructed with calculated sensitivity of 4.467 per mg.mm(-3) (8.540 per ppm). The concentration range of the low-cost set-up is also able to detect unhealthy NO2 levels in the Philippines. Aerosol optical thickness was then retrieved and showed similar temporal variation with NO2 throughout the duration of the experiment. The correlation was attributed to the photochemical reaction of NO2 to NO3-, which then forms into aerosol. Average daily AOT at different wavelengths was then determined and was compared to AERONET's data. The results were in agreement with each other and both displayed decreasing AOT at increasing wavelength, which is an expected behavior for a Mie-scattered light due to aerosol. More importantly, proof-of-concept demonstration of low-cost DOAS set-up, capable of measuring trace amounts of NO2 and AOT, was successfully performed. Results show that the low-cost design can provide an alternative, cheaper and portable atmospheric NO2 and aerosol measurement technique with reliable sensitivity for environmental monitoring applications.
Channa striata, locally known as dalag, constitute a major aquaculture resource in Laguna de Bay. Owing to its popularity as a food source, threats such as overfishing may potentially place this species at risk. However, studies regarding its status within the lake is lacking. One way to address this gap is through population studies using geometric morphometrics. In this study, a total of 82 specimens were collected across three areas of the lake, namely, Binangonan, Calamba, and Tanay. These areas were assessed using secondary data for physicochemical parameters, which revealed significantly higher ammonium-nitrogen levels in Binangonan compared to the other areas. Geometric morphometrics was then used to determine whether shape variation existed among C striata populations. Results showed that shape variation was greatest in the cranial region, with fish from Binangonan and Tanay having the greatest variation in shape. On the other hand, specimens from Calamba had the highest morphometric values. Lastly, these findings were then correlated with water quality data using Canonical Correlation Analysis. Results indicated that shape variation in the cranial region was correlated with differences in dissolved oxygen and pH content of the lake. The weight and length of fish were inversely correlated to the levels of ammonium-nitrogen and total dissolved solids, with specimens from Binangonan displaying a high sensitivity to ammonium-nitrogen.
Earthworms and their interactions with microorganisms offer beneficial effects that can improve organic matter decomposition, enhance nutrient availability, and suppress pathogens in the soil. In this study, microorganisms from the gut of Eudrilus eugeniae (Kinberg, 1867), commonly known as African nightcrawler or ANC, were isolated through pour plate method and screened for their activities using assays to confirm nitrogen fixation, phosphate solubilization, polyethyleneutilization, and antagonistic potential. The identifications of eight bacterial and six fungal isolates were confirmed based on nearest phylogenetic affiliations. Fungal isolates Aspergillus aculeatus , Aspergillus japonicus , Fomitopsis sp., and Penicillium citrinum exhibited antagonistic activity against Bacillus subtilis , Escherichia coli , Pseudomonas aeruginosa , and Staphylococcus aureus . Bacterial isolates Aeromonas caviae and Bacillus xiamenensis utilized low- and high-density polyethylene as carbon sources. These isolates were also found to have high phosphate solubilization index (2.55-2.67) with high amount of phosphate solubilized ( A. caviae : 0.799; B. xiamenensis : 0.778) at decreasing pH (i.e. pH 7.0 to 4.0). A. caviae and B. xiamenensis also showed nitrogen-fixing activity which is supported by the detection of nifH gene (>300 bp) and high nitrogen content (50 kg/ha NO3-N) of vermicasts. The activities of these gut-associated bacteria and fungi must be further explored to optimize the use of ANC’s casts and compost for agricultural, medical, and other applications.
