Detrimental land cover conversion has emerged as a pressing issue in the Quinali A Watershed, Albay, the Philippines. However, there has been a lack of monitoring regarding the change and its repercussions. Establishing baseline information is imperative to enable informed decisions and policies toward sustainable development. Landsat images were used to analyze the land cover changes in Quinali A Watershed from 1990–2020. Two-dimensional flood models and landscape metrics derived from FRAGSTATS were employed to assess the impacts of land cover change on flood exposure and landscape fragmentation. Results revealed that cropland, artificial surfaces, submerged vegetation, and inland water increased since 1990, but at the expense of forest, brushland, and barrenland. Generally, flooding occurs in areas of topographic lows of the watershed. The expansion of artificial surfaces took place in flood-prone areas, nearly doubling the flood exposure rates recorded in 1990. Despite cropland expansion, it decreased in the low-lying areas of the watershed, resulting in reduced exposure to flooding. The annual rate of change indicates substantial increases of 2.77 and 0.79% in NP for artificial surfaces and barren land, respectively, with ED increasing by 2.73 and 0.74%. AWM increased by 1.62% in non-forest areas, whereas forest areas showed an increase of 0.65%. Although the PAFRAC decreased by 0.02%, it maintained a high value of 1.53 in 1990 and 1.52 in 2020, indicating low stability of the land cover structure within the watershed landscape. Continuous monitoring of these changes is imperative to recommend science- based policies that can regulate resource utilization in Quinali A Watershed.
Mangroves are regarded as one of the most productive, biologically complex, and considered the most significant element of the coastal ecosystem. Assessment of mangroves is essential to have sufficient data on the diversity of species to ensure ongoing conservation efforts to support effective management of the environment and resources. This research examined the mangrove species in Sta. Cruz, Davao del Sur, the Philippines, by establishing eight plots in four barangays and identifying environmental management practices through personal communications with the barangay officials of the respective covered barangays and the leaders of non-government organizations for mangrove conservation. The results of the assessment yielded 20 species from nine families, with the family Rhizophoraceae as the most represented with seven species. Two species, namely Avicennia rumphiana Hallier f. and Aegiceras floridum Roem. & Schult., were categorized as vulnerable and near threatened, respectively. The diversity indices of the four barangays in Sta. Cruz, Davao del Sur, revealed that Brgy. Tuban has the highest evenness index (E = 0.810) and Shannon-Weiner diversity index (H’ = 1.913), with the lowest dominance value (D = 0.180) indicating a good distribution and very few species dominating the area. Conversely, Brgy. Astorga showed the lowest evenness index (E = 0.372) and lowest Shannon-Weiner diversity index (H’ = 1.201). It recorded the highest dominance value of (D = 0.486), which implies a poor and uneven distribution of species and some species dominating the area. Identified management practices and conservation efforts include ordinances passed for the protection of fish sanctuary and mangrove forests, designating personnel for monitoring, giving incentives to those who catch people who are illegally cutting mangroves, partnerships for tree planting, adopt-a-tree initiatives, and assigning areas to divide the ocean to conserve mangrove areas.
The significance of a marine biological station (MBS) was recognized worldwide in the mid-19th century. In the Philippines, the first MBS was established by the University of the Philippines (UP) in 1923 at Puerto Galera and led to significant scientific contributions. This foundational station began when UP conducted marine biological surveys at Puerto Galera together with the Bureau of Science in 1912. In stark contrast with this long-standing history, only two non-SCIE-indexed review papers are published with coverage until 1949. This study aims to provide updates on UP’s scientific contribution over a century, integrate our findings with the existing information, as well as present a newly constructed Center for Research and Awareness of Diverse Living Environments (UP CRADLE), the university research and extension facility at Puerto Galera. Early scientific studies involved the collection and identification (taxonomy and systematics) of marine fauna and flora, most of which were new to science and few were endemic species. Over time, research works progressed into biological and ecological studies, including hydrodynamics, chemical oceanography, fisheries, coastal resource management, and human impacts on the marine environment brought about by booming tourism. Given these scientific achievements, it becomes evident that the symbiotic partnership between UP and Puerto Galera played a vital role in fostering the progression and growth of marine science in the country. The creation of UP CRADLE will help to ensure the continuation and expansion of the scientific groundwork established by UPMBS. This is the torch to be carried on by the Center, from a mere marine station to a biodiversity field station, and enlarges its scope covering the terrestrial environment and human dimensions. In effect, we are ensuring a holistic ridge-to-reef-to-sociocultural perspective and integrating the science-based management of a UNESCO Man-and-Biosphere reserve, which serves as a “living laboratory.”
Cigarette smoking is associated with numerous respiratory diseases. To help mitigate the adverse effects of cigarette smoke on human health, different strategies have been introduced, with the most recent strategy being the introduction of electronic cigarettes (e-cigarettes). However, there is a lack of information regarding the effect of e-cigarettes on humans, including its effect on oral health. While some studies have explored the effects of e-cigarettes on the oral cavity, little is known about their effects on the oral microbiota, especially those that cause dental caries. To determine the effects of e-cigarettes on the leading cause of dental caries, we evaluated its effect on the growth, biofilm formation, lactic acid production, induced autolysis, acid stress, and oxidative stress tolerance of Streptococcus mutans, the main causative agent of dental caries. Our results showed a decrease in S. mutans growth with increasing e-liquid concentration. E-liquid concentrations higher than or equal to 10% inhibited S. mutans growth. Furthermore, e-liquid nicotine content had no significant effect on S. mutans growth at sub-inhibitory e-liquid concentrations of 5% (p > 0.05). The results also revealed that S. mutans biofilm formation and lactic acid production did not significantly differ between treatments with and without 5% e-liquid (p > 0.05). Additionally, the rate of autolysis in S. mutans was not significantly affected by exposure to a sub-inhibitory concentration of e-liquid regardless of the nicotine content (p > 0.05). Finally, the acid stress tolerance with or without adaptive response and oxidative stress tolerance by hydrogen peroxide was not significantly different between S. mutans grown with or without the sub-inhibitory concentration of the e-liquid (p > 0.05). These findings suggest that e-cigarettes may not significantly impact the physiology of S. mutans. However, it is important to emphasize that e-cigarettes are not without health risks and that the long-term health effects of e-cigarettes are still under investigation.
Satellite-derived observations of chlorophyll-a (Chl-a) concentration reveal patterns of enhancement, particularly at the west side of Camiguin Island in Bohol Sea, the Philippines. Previous studies have linked basin-scale chlorophyll variability with interannual rainfall anomalies due to the El Niño–Southern Oscillation. However, the role of other mesoscale processes such as upwelling, eddies, and island effects remains unexplored. Here, we analyzed ocean data to determine the related processes to the observed enhancement. We determined the spatiotemporal variability and distribution of Chl-a in the Bohol Sea. We found that Chl-a varies most on the seasonal scale following monsoon forcing. The west Camiguin enhancement is prominent during the northeast monsoon (NEM). We found that strong NEM winds drive mixing, upwelling, and particle entrainment (i.e. Chl-a as a proxy for phytoplankton). The monsoonal physical processes create favorable conditions for finer-scale enhancement through island wakes generated from the interaction of winds and currents with Camiguin Island.
As traditional knowledge and its transmission gradually decimate, this study responds to the pressing need to document the local traditional knowledge regarding the use of seaweeds in eastern Camarines Sur. A semi-structured survey revealed that the locals were familiar with the food use of five seaweed species – namely, Acanthopora spicifera, Caulerpa lentillifera, C. racemosa, Gelidiella acerosa, and Kappaphycus alvarezii. Caulerpa lentillifera (use value or UV: 0.87; fidelity level or FL: 43.64) and C. racemosa (UV: 0.66; FL: 38.86) claimed medicinal properties to cure digestive and glandular diseases. Caulerpa species appeared to be the most ethnobotanically important seaweeds, whereas the carrageenan-producing species – Kappaphycus alvarezii – is farmed for livelihood purposes. Locals from Caramoan and Garchitorena have significantly better knowledge of seaweed use than the other municipalities. The transmission of traditional knowledge largely involved women as they were the primary source. Our results validated previous reports with traditional uses corresponding to their phytochemical properties (i.e. antimicrobial, antioxidant, and anti-inflammatory). Our study provides fundamental information for the sustainable resource management of these targeted species. The present results extend future work in extensive spatial and temporal coverages, the implication of modernization, and existing gaps in the sustainable management of seaweed ethnotaxa resources in eastern Camarines Sur and elsewhere in the Philippines.
Aquaculture farms surrounding Manila Bay are crucial to the Philippines’ seafood industry, contributing significantly to regional production. However, these areas face mounting environmental and public health challenges due to foodborne pathogens. This paper is a comprehensive study that evaluated fecal coliform levels in aquaculture farms from Regions III and IVA from March 2021–December 2023. It also investigated the presence of Escherichia coli O157:H7 in aquaculture commodities using conventional and real-time PCR or quantitative PCR (qPCR) methods. High fecal coliform concentrations were noted in 50 environmental water samples collected. Sixty (60) percent of samples exceeded the DAO No. 2021-19 Class SC 200MPN/ 100 mL. Contamination levels were generally higher during the wet season than in the dry season (p < 0.05). Concurrently, aquaculture commodities, including bivalves, finfishes, and crustaceans, were analyzed for E. coli O157:H7. The overall prevalence was 13.24%, with shrimp and oysters showing the highest contamination rates. While conventional methods identified E. coli O157:H7, qPCR allowed for more precise detection of key virulence genes such as stx1, stx2, and wzy. These findings underscore the critical need for consistent water quality monitoring, strict implementation of good aquaculture practices (GAqPs), and rigorous food safety measures. This research provides a baseline for future guidelines and policies to address food safety risks in the Philippines’ aquaculture sector. Further research and targeted interventions are essential to mitigate contamination risks and protect public health.
Phytohormones act as signal transmitter molecules to manage abiotic stresses and regulate plant morphogenesis. Abscisic acid (ABA) responds under toxic salt stress as a signal passed at danger in the regulation of plant metabolism. The seed germination rate has been considered as the key to final crop yields. In this study alleviation effect of ABA (50 and 100 μM) on germination than subsequent growth of Basmati-370 cultivar of rice (Oryza sativa L.) seedlings stressed under 150-mM salts (NaCl: Na2SO4, 9:1, pH 6.45 ± 1) for 2 wk were assessed. In the 1st week, both ABA and salts were sprayed to moisturize the filter paper on which seeds were sown, whereas in the 2nd week, only ABA was foliarly sprayed. ABA decreases in gibberellic acid (GA3) concentrations and α-amylases activities of control (without salts) and salt-stressed seeds, which results in a significant decrease in seed germination (%) rate. Salinity significantly decreases seedling growth, relative water contents, pigments, K+, proteins, and total sugars, whereas reducing sugars, malondialdehyde (MDA), proline contents, hydrogen peroxide (H2O2), Na+ and Cl– increased (p ≤ 0.05). These above observations were measured as reversed due to the ameliorated effects of ABA supplementation. In conclusion, an increase in ABA levels leads to a decrease in GA3 contents at the seed germination stage, which contributes toward a lower seed germination rate, whereas after germination exogenous ABA applications enhance salt tolerance by promoting nutrient uptake and balancing endogenous hormones to accelerate seedlings growth effectively.
Flaviviruses are transmitted by Aedes aegypti and can cause dengue, yellow fever, and Zika infections, which are a significant public health concern in the tropics and subtropics. This study aimed to detect and identify flaviviruses in the viromes of Ae. aegypti population in Liloan, Cebu, the Philippines. RNA was extracted from pooled adult male and female mosquitoes reared from field-collected eggs. The RNA was reverse-transcribed to produce complementary single-stranded DNA and was amplified by PCR using primers targeting a portion of the NS5 gene, and amplicons were sequenced using next-generation sequencing (Illumina). Flavivirus- like sequences were identified from the sequence data of pooled male and female mosquitoes by similarity search using BLAST and phylogenetic analysis. Results revealed the absence of human-pathogenic flaviviruses and the presence of three genera of insect-specific flaviviruses: [1] cell fusing agent virus (CFAV), [2] Aedes flavivirus (AeFLAV), and [3] the existence of novel or uncharacterized lineages within Flavivirus (i.e. Flaviviridae sp.). These CFAV sequences showed closer genetic relatedness to the clade of CFAVs from Cairns, Cambodia, USA, and Surabaya, whereas AeFLAV sequences were closer to those from Bangkok, China, and Narita. The Liloan Flavivirus sequences were apparently conspecific with species from Argentina. Results highlighted the importance of local or regional studies to understand viral genetic diversity useful in mitigating the transmission of vector-borne diseases.
Vitex negundo (lagundi, VNE), Peperomia pellucida (ulasimang bato, PPE), Alium sativum (bawang, ASA), Psidium guajava (bayabas, PGU), Mentha cordifolia Opiz (yerba buena, MCO), Blumea balsamifera (sambong, BBA), Momordica charantia (ampalaya, MCH), Quisqualis indica L. (QIN, niyog-niyogan), Carmona retusa (tsaang gubat, CRE), and Cassia alata (akapulko, CAL) have been approved by the Department of Health through Republic Act No. 8423, known as the Traditional and Alternative Medicine Act of 1997, which is aimed toward developing traditional and alternative medicines in the Philippines. In this study, we assessed the antimicrobial activity of the methanol extracts alone and in combination against Staphylococcus aureus, Bacillus subtilis, Escherichia coli, and Pseudomonas aeruginosa. At least 50% growth inhibition was observed for MCH and MCO against B. subtilis at 1.25 mg/mL, for MCO against S. aureus and P. aeruginosa at 0.63 mg/mL, and CAL against E. coli at 0.16 mg/mL. In the resazurin assay, MCO showed bactericidal activity against S. aureus. CAL, MCH, and MCO, when combined, are generally non-interactive against B. subtilis, S. aureus, and P. aeruginosa. However, amplification of the antimicrobial activity of MCH was observed after combining with CAL or with MCO. For the CAL and MCO combination, CAL activity was increased in the presence of MCO against all organisms tested. In conclusion, MCO, MCH, and CAL have the highest antimicrobial activity among the rest of the medicinal plants. Combining these plants exhibited no synergism. This study provides insights into the potential use of these plant extracts as antimicrobials.
Bimetallic iron-copper catalysts supported in porous material have attracted attention for the improvement of the Fenton reaction to remove organic pollutants in water and in wastewater systems. Moreover, several studies shed light on the effectiveness of hierarchical zeolites as a solid support for the bimetallic catalyst, which addresses the metal sludge formation and acidic limitation of a classical homogeneous Fenton system. This study presented a simple and faster preparation of a hierarchical zeolite HZSM-5 by the microwave-assisted route through the one-pot soft templating method. The prepared HZSM-5 reported a smaller particle size and larger surface area, which is ideal for inorganic catalysis compared to a conventional ZSM- 5. Iron and copper metals were effectively incorporated in the HZSM-5 by incipient wetness impregnation, as confirmed by X-ray diffraction analysis. The catalytic activity of the prepared iron-copper zeolite (FeCu-HZSM-5) samples for Fenton-like reactions was evaluated at different pH conditions against the azo dye, Acid Orange 7. In this study, immediate dye removal of AO7 was achieved by all the bimetallic catalysts, FeCu-HZSM-5, at basic conditions. Furthermore, almost complete dye removal was achieved by all the FeCu-HZSM-5 with different Fe:Cu ratios after 3 d of reaction time. This demonstrated the satisfactory removal efficiency of AO7 by the synthesized zeolite incorporated with iron and copper.
Litopenaeus vannamei requires a specific range of water quality parameters for optimal growth and health. Monitoring these parameters, as water enters (inlet) and exits (outlet) the shrimp ponds and throughout the canal system, is crucial in optimizing shrimp production, nutrient management, disease prevention, environmental protection, and compliance with regulatory standards. This study aimed to analyze water quality parameters at three different sites in Barangay Dahican, City of Mati, Davao Oriental, the Philippines, where all shrimp ponds in the area are located. Sampling stations were established at the inlet, canal, and outlet of each site, with sampling conducted in February and March to assess residual impacts of pond operations, assuming that most residues would be flushed out by March, leading to improved water quality. Assessed water quality parameters assessed included temperature, pH, salinity, dissolved oxygen (DO), chemical oxygen demand (COD), total suspended solids (TSS), ammonia, nitrite, nitrate, phosphorus, and alkalinity. Statistical analyses were performed. Results revealed that the temperature (26–28 ºC), pH (7.5–8.0), salinity (26–37 ppt), DO (3.5–6.4 mg/L), TSS (8–29 mg/L), ammonia (< 0.007 mg/L), nitrite (< 0.055 mg/L), nitrate (1.73–2.36 mg/L), phosphorus (< 0.12 mg/L), and alkalinity (129–187 mg/L) had values that fall within the safe, recommended and optimal range (with insignificant deviations) for L. vannamei ponds except for COD, which was substantially high (1,383–1,805 mg/L), comparable to domestic wastewater, and beyond the safe limit set by the Philippine regulatory standards for shrimp pond effluents (300 mg/L). It is recommended to reduce COD levels through efficient water quality management and treat effluents before discharge. Regular monitoring and management of water quality in shrimp ponds must be done to maintain the optimal conditions of the water quality parameters, thus improving the growth and production of L. vannamei and ensuring that the effluents are safe and non-hazardous to the environment.
The vermiculated sailfin catfish (Pterygoplichthys disjunctivus Weber 1991) is considered one of the most invasive fish species worldwide. Although it has been introduced in various aquatic ecosystems in the Philippines, studies on its invasion impacts and distribution in the country are still limited. In this paper, we present additional information on the occurrence of P. disjunctivus based on our recent fish survey in March 2023. The study was conducted in Naujan Lake National Park (NLNP), Oriental Mindoro, the Philippines, a Ramsar Wetland Site recognized for its international importance. During our survey, a single individual of P. disjunctivus was caught as a bycatch in the gill nets used by local fishermen. The species’ presence poses a significant threat to the lake’s native biodiversity and ecosystem. This finding highlights the urgent need for comprehensive monitoring and management strategies to prevent the proliferation of this invasive species and further unregulated introductions of non-native species to safeguard the ecological balance of NLNP and its native biodiversity.
Supercapacitors have high power and long cycle lives and can use renewable materials like biochar. This study explores the use of biochar derived from rice straw, an abundant agricultural waste, to enhance fabric-based supercapacitors. Rice straw was processed into biochar via nitric acid treatment (RSB), followed by pyrolysis under N2 atmosphere, and then wet milled with 10% carbon black using a planetary ball mill (MRSB). The carbon material was coated onto pineapple-cotton woven fabrics (PACF) via the dip-and-dry method, followed by in situ polymerization of pyrrole monomer to coat with polypyrrole (PPy). These electrodes were characterized and then assembled into symmetrical coin cell devices for electrochemical testing. Globular PPy was seen in the micrographs of the composites, preferring to form on and around RSB and MRSB. Gas adsorption data analysis shows a large surface area and pore volume increase after milling the biochar. The PPy/RSB/PACF and PPy/MRSB/PACF show higher conductivity values (1.22 x 10–2 S cm–1 and 17.85 x 10–2 S cm–1, respectively) and areal capacitance values (309.77 mF cm–2 and 266.12 mF cm–2, respectively, at 5 mV s–1) compared to the PPy/PACF composites’ values (0.107 x 10–2 S cm–1 and 87.02 mF cm–2 at 5 mV s–1), indicating the positive interaction between PPy, RSB, and MRSB. A symmetrical coin cell supercapacitor was assembled using the fabric composites as electrodes. The PPy/MRSB/ PACF devices demonstrated higher areal capacitance values (741.85 mF cm–2 at 1 mA cm–2), columbic efficiency (92.84%), specific energy (15.45 Wh kg–1), and specific power (199.69 W kg–1) over the other devices. These results show the positive and extensive effect of MRSB on the electrochemical performance of the composite electrodes, showing its great potential as active materials for energy storage applications, and adding value to waste rice straw.
Despite its wide array of applications and unique properties, collagen – typically sourced from land animals – faces ethical, resource, and disease-related challenges. Fish viscera, often discarded as byproducts in the fishing industry, represent an untapped collagen reservoir. This study aimed to isolate and characterize acid-soluble collagen (ASC) from the viscera of yellowfin tuna and milkfish. The process involved deproteinization, defatting, filtration, precipitation, purification, and extraction using 0.5M acetic acid. The extracted ASC underwent physical and chemical analyses. Collagen yields from milkfish and yellowfin tuna were 8.35 ± 0.14% and 4.99 ± 0.05%, respectively. Differential scanning calorimetry revealed melting temperatures of 101.80 °C and 105.89 °C for milkfish and yellowfin tuna, respectively. Glycine predominated in the amino acid composition of yellowfin tuna, while proline prevailed in milkfish. Fourier transform infrared analysis showed a triple helical structure with a band intensity ratio of approximately 1.0 between the Amide III and 2450 cm–1. Visual examination of ASC resembled a soft sponge conformation. Scanning electron microscopy revealed ASC's porous, interconnected, and fibrillar structure. This study demonstrates that collagen can be effectively extracted from the viscera of yellowfin tuna and milkfish, showcasing promising physicochemical characteristics for various potential applications.
Nile Red (NR) fluorescence is an emerging method for microplastics (MPs) detection due to its efficiency in distinguishing MPs from non-plastic materials. However, drawbacks to the use of NR include plastics that cannot be stained, whereas others show changes in physical and chemical characteristics at higher NR concentrations. As a practical approach, this study optimizes MP staining concentration combining NR fluorescence (approx. 170 million a.u.) in an inexpensive stereomicroscope adaptation with UV-LED at an excitation wavelength of 365 nm. The effects of NR staining concentration were then measured in terms of polymer recovery, polymer surface area, fluorescence intensity, and infrared spectra. Our findings revealed that the tested stain concentrations did not significantly alter MP recovery counts and surface area. At 10 μg/mL NR concentration, only polyethylene terephthalate (PET) and polystyrene (PS) fluoresced, indicating polypropylene’s (PP) resistance to NR staining. The potential functional groups involved in the excitation are mainly alkenes (for PET, PS, and PP) and aldehydes (for PET), as confirmed by the FTIR analysis that could be attributed to polymer structural rearrangement, aggregation, or depolymerization. This study also demonstrates that NR staining, when paired with an adapted stereomicroscope, can be effectively used to detect and quantify MPs in sardines (Sardinella lemuru)
The life histories of Altica cyanea and other Altica species have been reported in several Ludwigia species. However, no reports yet on the life history of Altica aenea (Olivier, 1808), particularly on L. hyssopifolia (G. Don) Exell under Philippine conditions. This research study was carried out to investigate and describe the life cycle, reproduction, growth, and survival rate of A. aenea on L. hyssopifolia (G. Don) Exell. Altica aenea completed seven growth stages on the weed: egg, first larval instar, second larval instar, third larval instar, pre-pupa, pupa, and adult. Female beetles lay eggs in clusters on the lower surface of leaves. The mean incubation period for the eggs is 5 d, whereas the first, second, and third larval instars developed in 3.0, 3.3, and 7.2 d, respectively. The pupa had a developmental period of 5–6 d. On average, the females were longer (6.2 mm) than the males (5.2 mm). The male-to-female sex ratio was 2.42:1, with a mortality rate of 31.18%. The courtship and copulation of males and females took 4–8 h. The females laid eggs 5–8 d after emergence from the pupa and 1–4 d after mating. During their lifetime, the females deposited a mean of 708.4 eggs (263–1004 eggs) at 26.3 eggs/d (17.7–35.9 eggs). When fed via L. hyssopifolia (G. Don) Exell, the developmental period of A. aenea from egg to adult was 22.7 d for the female and 21.1 d for the male. The mean adult females’ longevity was 60.9 d (34–81 d) and 45.5 d (24–76 d) for adult males. The lifespan of A. aenea on L. hyssopifolia (G. Don) Exell was 88 d for females and 72 d for males. The results of this study could provide insights into assessing its suitability as a biological control against the weed.
Natural disasters have been more frequent and severe, making mitigation policies such as evacuation protocols extremely important in reducing the negative impact of such disasters. Volcanic eruptions, in particular, may cause damage to properties and thousands of deaths. The unique tectonic setting of the Philippines makes it particularly prone to volcanic events. One of the most disastrous volcanic eruptions in the 20th century was caused by Mount Pinatubo in 1991, with the province of Pampanga as one of the most affected. The recent volcanic activities and the changing population and economic dynamics near and around the volcano suggest that communities and local government units in the region should re-evaluate, establish, and reinforce their contingency, emergency, and other disaster preparation plans such as their evacuation protocols since this is the most common approach in avoiding the loss of life and property in the face of a volcanic eruption. An aspect of evacuation planning is the evacuation site assignment of stakeholders. To move individuals from hazardous conditions to safe ones, mathematical models are used, focusing on determining the best utilization of routes and vehicles in complex urban transportation systems. While there are several studies on Mount Pinatubo, the literature is very limited in terms of the mathematical models used in the evacuation site assignment of affected communities. A transportation model is used to assign residents of Pampanga affected, as observed in the Lahar Zonation map, to evacuation sites outside the 40-km danger zone. The goal is to minimize the total distance traveled by the evacuees from their respective municipalities to the evacuation sites. Three cases were considered in the study. The first case allocates evacuees to provincial evacuation centers only. As provincial evacuation centers are not sufficient, covered courts in Pampanga were included as evacuation sites in the second case. Lastly, a prioritization scheme is implemented in the third case. The number of affected populations for each municipality, the list of evacuation centers and covered courts with their capacity, and the distances between each municipality and an evacuation site were gathered. Results of each case are presented, and network flow models are used to present the allocation of evacuees to the sites.
Chromosome numbers, karyotype, and genome size provide fundamental information for genome sequencing and breeding studies. Here, we analyzed the karyotype and genome size of four Philippine medicinal plants – namely Carica papaya (papaya), Citrus microcarpa (calamansi), Cymbopogon citratus (tanglad), and Moringa oleifera (malunggay). We performed a triple-color fluorescence in situ hybridization to detect the chromosomal distribution of the 5S and 35S rDNA and the Arabidopsis-type telomeric repeat. Citrus microcarpa (2n = 18, 2C = 0.95 pg) had one pair of 5S and 35S rDNA and a hemizygous 35S rDNA in the centromeric region of Chromosome 3. Carica papaya (2n = 18, 1.08 pg) had five pairs of 5S rDNA and one pair of 35S rDNA. Cymbopogon citratus (2n = 60, 3.79 pg) had four pairs of 5S rDNA and one pair of 35S rDNA. Moringa oleifera (2n = 28, 1.36 pg) had two pairs of 5S rDNA and five pairs of 35S rDNA. The telomeric repeat was detected in the chromosome termini of all chromosomes. Here, we present basic cytogenomics information on these four species, which can be useful for genomics, breeding, and evolutionary research. This approach can be replicated to gather cytogenomic information on endemic Philippine plants for genomics and conservation.
A toxic epibenthic dinoflagellate Coolia malayensis is reported for the first time in Cancabato Bay, Tacloban City, the Philippines. Typically found in tropical and subtropical waters, this genus is observed to often coexist with other ciguatoxigenic dinoflagellates. Two strains of C. malayensis were established into clonal cultures, both producing mucus as a common characteristic of benthic dinoflagellates. Based on LM and SEM, cells were globular with slightly asymmetrical theca, and its apical pore plate and 2ʹ plate ratio shared close morphometrics (0.74 ± 0.02 μm) withC. malayensis. Phylogenetic analysis based on the LSU rDNA and ITS regions placed the Cancabato isolate in the clade of C. malayensis from other areas. The pilot screening of C. malayensis showed hemolytic activity, which might be light-triggered. Its hemolytic activity peaked at its exponential phase. C. malayensis tolerated salinities ranging from 20–35 ppt, and salinity significantly affected its cell sizes across the various treatments. In this study, the complementary identification of C. malayensis isolated from Cancabato Bay expanded its geographical range to include Philippine waters.
