Read full-textFluctuations in photosynthetic characteristics related to chloroplast translocation have been known in the foliose green algae Ulva lactuca var. latissima and var. rigida and U. mutabilis according to photoperiod. In Ulva, the single parietal chloroplast is found along the thallus surface wall and exhibits high photosynthetic activity during the light period; the chloroplast then moves towards the side walls and shows low photosynthetic activity during the dark period. In this study, we re‐investigated whether the photosynthetic ability is dependent on chloroplast location in a unialgal culture of U. conglobata grown and maintained under low irradiance regime by analyzing in vivo absorption spectra, oxygen evolution, and pulse amplitude modulation chlorophyll fluorescence. The light absorbance of the thallus was higher when chloroplast was along the thallus surface wall than when along the side walls and, therefore, the thallus absorbance at 680 nm was used as an index of chloroplast position. Some photosynthetic parameters such as maximum net photosynthetic rate per thallus area and effective quantum yield of photosystem II correlated with the thallus absorbance. The highest rate and absorption were reached 3 to 9 h after the beginning of light period (12 h), which gradually decreased at 10 to 15 h after the beginning of light or dark period. The lowest rate and absorption was observed after the beginning of the dark period. The chloroplast movement was inhibited for 12 h by colchicine, and photosynthetic parameters were found to be dependent on various chloroplast positions in the thallus. Interestingly, the chloroplast moved to the surface and the side walls of the cells under continuous dark and light conditions, respectively, at approximately 48 to 72 h. However, decreased maximum quantum yield was observed under both continuous dark and light conditions.

Read full-textThe Philippines is said to be the center of the center of marine shore fish biodiversity because of a key marine biodiversity corridor known as the Verde Island Passage (VIP), which has up to 1,736 species over a 10 x 10 km area (Carpenter and Springer 2005). The VIP harbors a vast and rich marine life and is home to numerous other marine organisms, from microorganisms to seagrass, seaweeds, mangroves, corals and other invertebrates, cetaceans, and other species of fish, many of which have yet to be documented. Given the known threats on the marine environment, studies have noted that the VIP is an area of extremely high priority for biodiversity conservation (PAWB 2009; Asaad et al. 2018).

Read full-textThe precipitation and deposition of asphaltene are among the most pressing issues in the petroleum industry. This flow assurance issue may cause formation damage in porous media, the plugging and coking of wellbore and production pipelines and difficulties in the refining process. Such events lead to additional operating costs for the company. Therefore, knowing the conditions at which asphaltene may precipitate and can be stable may enable its management. Existing models of asphaltene stability are dependent on saturate, aromatic, resin and asphaltene (SARA) analysis which can be very expensive and time-consuming. Therefore, using regression analysis as well as MATLAB curve fitting and optimization procedures, a new set of correlations and asphaltene stability envelops (ASEs) based on the newly developed Density-Based Asphaltene/Resin ratio (DBAR), Density-Based Saturate/Aromatic ratio (DBSAr) and the Density-Based Colloidal Instability Index (DBCII) all as functions of oil density have been developed to consistently predict asphaltene stability. The new criteria were developed for the correlations by considering the boundary between stable and unstable regions in their respective plots. The new envelopes showed 83% reliability by accurately predicting asphaltene stability in 24 (eight stable and 16 unstable samples) out of 29 (13 stable and 16 unstable) crude oil samples. The correlation coefficient (R²), average absolute relative error (AARE) and the root-mean-square error (RMSE) for the new DBAR correlation are 0.9456, 0.8357 and 0.1219 respectively. The DBSAr correlation resulted in R² of 0.9437, AARE of 0.1860 and RMSE of 0.2450. For the DBCII, the statistical indicator results were 0.9639 for the R², 0.1376 for the RMSE and 0.1038 for the AARE.

Read full-textGraphs considered in this paper are  finite simple undirected graphs. Let G = (V(G), E(G)) be a graph with E(G) = {e₁, e₂,…, e_m}, for some positive integer m. The edge space of G, denoted by ℰ(G), is a vector space over the  field ℤ₂. The elements of ℰ(G) are all the  subsets of E(G). Vector addition is defined as X+Y = X ∆ Y, the symmetric difference of sets X and Y, for X,Y ∈ ℰ(G). Scalar multiplication is defined as 1.X =X and 0.X = ∅ for X ∈  ℰ(G). Let H be a subgraph of G. The uniform set of H with respect to G, denoted by E_H(G), is the set of all elements of ℰ(G) that induces a subgraph isomorphic to H. The subspace of ℰ(G) generated by  ℰ_H(G) shall be denoted by ℰ_H(G). If E_H(G) is a generating set, that is ℰ_H(G)= ℰ(G), then H is called a generator subgraph of G. This study determines the dimension of subspace generated by the set of all subsets of E(G) with even cardinality and   the subspace generated by the set of all k-subsets of E(G), for some positive integer k, 1 ≤ k ≤ m. Moreover, this paper  determines all the generator subgraphs of star graphs. Furthermore, it gives a characterization  for a graph G so that star is a generator subgraph of G.

Read full-textThis quantitative investigation involved 1,054 pre-service teacher respondents with mean age = 20.21 (SD=3.124). This cross-sectional study gathered data through the creation of four research tools validated and pilot tested. Moreover, three of the research tools (AChavQ, AFilQ, AEngQ) were determined to be of ‘excellent’ reliability, while one is of ‘acceptable’ reliability (CogMT). The study purposed to derive a model explaining the possible relationships, mediation or moderation, of language attitude towards Chavacano with ethnicity, cognition towards mother tongue and language attitude toward Filipino and English. The model with “best fit” showed that that language attitude toward Filipino and English has a direct influence on cognition in the mother tongue. In contrast, ethnicity’s influence is mediated by language attitude toward Chavacano. The results and findings of this study provide vital information and insights in the implementation of the Mother Tongue Based Education in a multilingual context.

Read full-textIn this study, the authors design and implement a real time system as an autonomous robot–camera to capture many targets in the scene. The robot has only one camera, but it is capable of capturing more than one moving object through proper movement. The system uses Gaussian Filtering for motion detection and then performs partitioning to grab location of all targets in the scene. Due to partitioning, the scene has three major regions while each of which has different sub-regions. Based on the partitioning and position of all targets, the system might be in three states of unsafe state, safe state, and over-safe state. In each state regarding specific regions or sub-regions, the system picks appropriate movement not only to be capable of capturing all moving objects, but also to give equal chance of capturing to new targets entering to the scene from different direction. The system is tested in both of indoor and outdoor with different values for different parameters such as resolutions, fps (frame-per-second), minimum number of motion frames, and minimum areas of motion.

Read full-textRust is a severe disease affecting many productive coffee regions. It is caused by a pathogenic fungi that attacks the underside of coffee leaves and it is characterized by the presence of yellow-orange and powdery points. If not treated, rust can cause a drop in coffee production of up to 45%. In this sense, this paper presents a contribution to the problem of rust identification that doesn’t use “handcrafted” features, i.e., features extracted according to rules established by human programmers. Instead, we propose to train a Convolutional Neural Network (CNN) to learn to identify rust infection. We evaluated our CNN in a set of images provided by an expert and comparison results show that our approach is able to to detect the infection with a high precision, as corroborated by the high Dice coefficient obtained.

Read full-textAlkali precipitation and electrodeposition for copper removal in artisanal gold smelting wastewater were evaluated. Alkali precipitation was done by dosing the wastewater with sodium hydroxide solution. Electrodeposition was conducted at operating current of 4 A for 3 and 6 h. Alkali treatment exhibited 99.83% removal efficiency, albeit residual copper concentration was still above effluent standards. Lead was no longer detected at pH ≥ 6 while 87.82% of cadmium was removed at maximum precipitation. Generation of metal hydroxide sludge implied the need for a post-treatment. Electrodeposition demonstrated superior copper removal efficiency (99.98%). With appropriate selection of electrolysis time, it could achieve complete copper removal. It had low energy consumption and indicative treatment cost, and no sludge generation. Electrodeposition current efficiency was relatively low due to other wastewater components which could have consumed a fraction of applied current. Kinetics evaluation showed a three-step electrodeposition process, each stage having a different reaction rate order. Lead was not detected after 3 h while 50.00% of cadmium was removed after 6-h electrolysis. Considering removal efficiency without sludge generation, indicative treatment cost, and value recovery of deposited copper, results revealed that electrodeposition has some advantage over alkali precipitation for the remediation of artisanal gold smelting wastewater.

Read full-textAs the power of Learning Management System (LMS) in supporting classroom instruction has been observed in Higher Education Institutions (HEIs), only a few have been documented in military environment using this kind of learning technology. This paper is the first attempt to investigate the satisfaction of air force officers on the use of Squadron Officer Course Virtual Classroom (SOCVC) in the Philippines. The popular Modular Object-Oriented Dynamic Learning Environment (MOODLE) was used to implement the SOCVC. A total of 47 Philippine Air Force (PAF) officers enrolled in the SOC participated in this study. Satisfaction in terms of learner interface, learning community, content and usefulness on the use of SOCVC was obtained using a questionnaire. The respondents are seen comfortable and satisfied with the use of the virtual classroom. Profile variables used in the study when taken separately do not show significant difference as to the respondents’ satisfaction on the use of the virtual classroom. The findings oppose what are already established pertaining to the variables that affect the use of Virtual Learning Environment (VLE) in civilian setting.

Read full-textEducators have the responsibility of assessing their students’ metacognitive knowledge and identifying students who may need support in developing effective metacognitive skills and providing them with necessary learning intervention. This study assessed the customs administration students’ metacognitive knowledge and its usage in their internships. The dimensions, declarative knowledge, procedural knowledge and conditional knowledge were correlated to academic performance. Differences in metacognitive knowledge and its dimensions and their usage were also ascertained. The study used the descriptive-survey method, using a questionnaire for data gathering. The respondents were 99 randomly selected final year BS in Customs Administration students. The results showed that the majority of students were female, had a capital city based internship and had an average academic performance. The majority of high performers had an internship in a capital city while the majority of low performers had an internship in their home city. Male and female students had similar performance while capital city internship students had better performance than home city internship students. The declarative, procedural and total metacognitive knowledge and their usage were high while conditional knowledge and its usage were very high. The dimensions of metacognitive knowledge and usage, except procedural knowledge had significant relationships with academic performance. Statistical differences in the responses of students when they were grouped according to sex were found only with procedural knowledge and its usage but when they were grouped by internship location – on declarative, procedural and total metacognitive knowledge usage; and when grouped by academic performance – on declarative knowledge, total metacognitive knowledge, conditional knowledge usage and total metacognitive knowledge usage.

Read full-textThis study documents the threats of the critically endangered Tectona philippinensis in the backdrop of the past conservation policies and projects. Twelve 20m x 50m plots were distributed in three altitudinal strata (S1= 50 – 100 m asl, S2= 150 to 200 m asl, and S3= 250 – 300 m asl) using stratified random sampling. Every tree was examined to detect presence of pest and diseases on foliage, stem, buttress and exposed root system. Threats of anomalous weather patterns like intense drought and human disturbances were also recorded. Leaf skeletonizers, shotholes, buttrot, heartrot, rootrot, illegal harvesting, charcoal making, wind damages, and intense dry season are among the most alarming threats of T. philippinensis. Germinants and wildlings are most susceptible to wilting during intense drought during dry season. A number of interesting species of arthropods and macrofungi within the stand were also encountered. There are variations on the incidence and infection across altitudinal habitat and across diameter classes. Poles and standards at lower altitudinal habitat (<100 m asl) are the most disturbed and susceptible to the disturbances. Existing conservation and protection policies should be strictly implemented especially in hotspot habitats.

Read full-textThe photosynthesis and growth of the commercially important and edible green seaweed, Monostroma latissimum (Ulvophyceae), from a naturally occurringpopulation in the intertidal area were examined in the laboratory. The natural population inhabits the middle to upper intertidal area and is usually attached to rocks. Cultivation occurs mostly in the shallow and calm waters under full light. The species was subjected to 10, 15, 20, or 25° C temperatures, and irradiances ranging from 0 to 1200 μmol photon m-2 s -1 in order to evaluate the effect of photosynthesis on growth. Photosynthesis was determined and characterized usingphotosynthesis-irradiance curves from oxygen production and PAM fluorometry. The maximum net photosynthetic rate (per thallus area and total chlorophyll content) did not differ significantly at the different temperatures, which were chosen to reflect the autumn to mid-springtemperatures that the seaweed would be expected to experience. The growth rates over 5 and 10 days were the same for all temperatures, but it decreased at 25° C after 15 days of culturing, which suggested that prolonged exposure to higher temperatures might have an adverse effect on growth. Similarly, the maximum quantum yield decreased as the temperature increased, which indicated that photosystem II (PSII) was under physiological stress at higher temperatures. In contrast, the light compensation point, saturating irradiance, initial slope, and PSII light absorption efficiency increased as the temperature rose. This suggested that the species optimized photosynthesis to accommodate the low and high light conditions that it may experience through its growing season. These conditions are characterized by irradiance limitation and low temperatures in winter, and higher irradiance and temperatures in spring. There were no photoinhibitory responses, which suggested that this alga was tolerant to higher irradiance. The growth rate significantly increased as irradiance rose, which may indicate higher growth rate responses at higher irradiances. Overall, the photosynthetic responses were in parallel with the growth rate response by M.latissimum. Therefore, the results from this study on M.latissimum, photosynthetic characteristics can be used to improve its cultivation.

Read full-textThis research paper aimed to determine the crop bearing capability of bitter melon or bitter gourd more commonly called “Ampalaya” in the Filipino language. Images of bitter melon leaves were gathered from Ampalaya farms and these were used as main data of the research. The leaves were classified as good and bad through their description. The research used Machine Learning Algorithm through Convolutional Neural Network. Training of data was through the capabilities of Keras, Tensor Flow and Python worked together. In conclusion, increasing number of images could enable a machine to learn the difference between a good and a bad Ampalaya plant when presented an image for prediction.

Read full-textMorphological and phylogenetic analysis showed that the Gambierdiscus isolate from Bolinao, Philippines belongs to the species of G. carpenteri. It was morphologically more similar to the Merimbula strain than the subtropical Florida Keys strain. Growth and toxin production were also investigated at varying levels of temperature, salinity, and irradiance. Gambierdiscus are known to grow favorably in a low light environment. However, this study showed high growth rates of G. carpenteri even at high irradiance levels. Generally, cells produced more toxins at lower treatment levels. Highest cellular toxin content recorded was 7.48 ± 0.49 pg Pbtx eq/cell at culture conditions of 25 °C, 100 μmol photons m^-2 s^-1, and salinity of 26. Growth rate and toxin production data suggest that cells produced more toxins during the slowest growth at certain range of treatments. This information gives insight into how changes in environmental conditions may affect toxin production and growth of G. carpenteri.