IPA Recipients for February 2019

Jonathan V. Caalim and Clarisson Rizzie P. Canlubo
Institute of Mathematics, College of Science
University of the Philippines Diliman

On the Lie algebra associated to S-unitary matrices. Linear Algebra Appl 553 (2018), 167-181. doi.org/10.1016/j.laa.2018.05.010.

This article deals with a natural generalization of unitary groups arising from sesquilinear forms (which are assumed neither Hermitian nor skew-Hermitian). Let S be a square matrix of size n. We say a nonsingular square matrix A of size n is S-unitary if ASA*=S. The set of all S-unitary matrices is a matrix Lie group. It is an interesting problem to classify these Lie groups and determine which of them are Lie isomorphic. An approach to this problem is to look at the associated Lie algebra. We derive a formula for the real dimension of the associated Lie algebra when S is nonsingular and normal. We apply this formula to a class of permutation matrices. Moreover, we prove that the associated Lie algebra is the direct sum of some Lie algebras related to the indefinite unitary groups when S is nonsingular and unitary. This is a joint work with Dr. Yu-ichi Tanaka.

Link to the article: https://www.sciencedirect.com/science/article/pii/S0024379518302416
Impact factor: (2017/2018) 0.972

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Minin J. Sinsona and b. Marie Antonette Juinio-Meñez
Marine Science Institute
University of the Philippines Diliman

Effects of sediment enrichment with macroalgae, Sargassum spp., on the behavior, growth, and survival of juvenile sandfish, Holothuria scabra. Aquaculture Reports. 12: 56-63.

Holothuria scabra or sandfish, is a highly-valued sea cucumber species. As such, it is a source of livelihood for coastal dwellers. However, it has been overexploited for international trade and it is currently listed in the IUCN Red List as endangered. Thus, efforts to restore depleted wild stocks are ongoing. Sandfish has been successfully cultured in the hatchery, and the bottleneck now lies in growing out juveniles (~3g) to marketable size (>320 g). One of the major causes of juvenile mortality is predation, and the smaller a juvenile is, the more vulnerable it will be to predators in the wild. Our hypothesis was that juveniles released in microhabitats abundant in food would hasten growth rates, allowing juveniles to reach larger sizes in a shorter amount of time. We tested this hypothesis by enriching sediment with detritus from macroalgae, Sargassum spp., that naturally washes ashore in Bolinao. We found that adding Sargassum spp. detritus to sediment increased microalgal and bacterial abundance, which serve as nutrition for sandfish juveniles. Enrichment with Sargassum also significantly increased growth rates and survival in the field. Results of our study show that sediment enrichment is a viable option in ocean nursery systems for short-term grow out of juveniles to larger sizes of predator refuge within 30 days.

Significance:
Our paper discusses how enriching sediment with Sargassum spp. detritus significantly hastens the growth of juvenile H. scabra, or sandfish, one of the most commercially important tropical sea cucumbers, by increasing food abundance (i.e., microalgae and bacteria) in the sediment, while relatively increasing burying frequency, and promoting significantly higher survival after release. The results of our study are important in addressing bottlenecks in the grow out of juvenile sandfish to marketable size. Juveniles (~ 3 g) can be protected from predators in sea pens enriched with Sargassum spp. and conditioned to bury and grow to larger sizes (> 20 g) of predator refuge within 30 days.

Link to the article: https://doi.org/10.1016/j.aqrep.2018.09.002
Impact factor: Not yet available

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Aurelio A. de los Reyes V and Jose Maria L. Escaner IV
Institute of Mathematics, College of Science
University of the Philippines Diliman

Dengue in the Philippines: model and analysis of parameters affecting Transmission. Journal of Biological Dynamics. 12:1, 894-912. Doi: 10.1080/17513758.2018.1535096

Dengue is one of the major public health concern in the Philippines which poses a substantial economic burden in the country. In order to understand the qualitative behavior of the disease transmission dynamics, a mathematical model is developed including human and mosquito populations. Incorporated in the model is a healthcare-seeking class depicting the reported dengue cases. This class gives insight on the influence of the number of individuals who get medical attention and/or treatment at the onset of the disease. It further captures the impact of under-reported cases due to passive surveillance. Data on weekly morbidity cases from 2014-2015 obtained from Epidemiology Bureau, Department of Health were used to identify model parameters which are influential in the spread of the disease. These parameters include the mosquito biting rate, transmission probability from mosquito to human, respectively, from human to mosquito, and fraction of individuals who seek healthcare at the onset of the disease. Results of model identification indicate that very few dengue-infected individuals seek treatment and/or there is an inadequate public health facility which eventually lead to unreported cases. Hence, efforts on dengue surveillance should be intensified in order to control dengue virus transmission and better assess the burden estimate of the disease in the country. Further, the model provides information on relative effects of different perturbations in both human and vector population dynamics and could aid in developing more informed decisions on specific control strategies.

Significance:
Dengue is endemic in the Philippines causing it as one of the major public health concern and thus, poses an economic burden in the country. In this work, a mathematical model is developed to describe the dengue transmission dynamics in the country. Included in the model is a healthcare-seeking class to give insight on the influence of the number of individuals who get medical attention and/or treatment at the onset of the disease. Inclusion of this class captures the impact of under-reported cases due to passive surveillance causing a chronic challenge in endemic countries like the Philippines. Model parameters sensitive to the healthcare-seeking infected class were estimated using the morbidity week (2014-2015) obtained from Epidemiology Bureau, Department of Health. Results of model identification indicate that very few dengue-infected individuals seek treatment and/or there is an inadequate public health facility which eventually lead to unreported cases. Hence, efforts on dengue surveillance should be intensified in order to control dengue virus transmission and better assess the burden estimate of the disease in the country. Further, the model provides information on relative effects of different perturbations in both human and vector population dynamics and could aid in developing more informed decisions on specific control strategies.

Link to the article: https://www.tandfonline.com/doi/full/10.1080/17513758.2018.1535096
Impact factor: Not yet available

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

Plants and Culture:Plant utilization among the local communities in Kabayan, Benguet Province, Philippines. Indian Journal of Traditional Knowledge. 17(4): 609-622

The use of plants by the local communities in Kabayan, Benguet has been closely entwined with their cultural practices. From the interviews, the use of plants ranges from food, shelter, clothing, preservation of the dead and mummification, offerings to appease the spirits and many more. Medicinal plants include treatment of skin-related diseases such as wounds, scabies and burns; other illnesses treated using plants are headache, stomach ache, diarrhea, stomach ulcer, anemia, sore throat, and many more.
Plants that are used for ritual activities and paraphernalia include aba (Colocasia esculenta), camote (Ipomoea batatas) and rice wine or tapuy. Rono (Miscanthus sp.) and banana (Musa paradisiaca) are versatile plants as these have varied uses, as ritual paraphernalia and in agriculture. Tapuy, made from rice varieties, is an inevitable component during festivities and served on a coconut shell. The sweet and savory taste of the tapuy, can make anyone brave and utter anything, which add up to the merry making. Tobacco with tapuy are offered to appease the gods and spirits so they will not inflict pain over the village. Acorus calamus, an aromatic plant, is pinned on one’s clothes to drive away evil spirits. The shoot of Cyathea contaminans, a giant tree fern, is used as a substitute for a human head and offered to bargain for a very sick person to get well. In the old times, a human head, may be taken from a neighboring village member. Other uses of plants include for construction, ornamentals, clothing, cigarette and many others.

Significance:
Ethnobotanical knowledge in the Cordillera region is not many yet the region is a repository of rich cultural diversity and diverse flora and fauna. This piece of literature is a great contribution to the dearth of publications about the ethnobotanical knowledge. It also hopes to provide baseline information on the various plant uses especially on medicinal plants which the area is very rich. Conversely, the knowledge on medicinal plants can also initiate efforts on drug discovery.

Link to the article: http://nopr.niscair.res.in/bitstream/123456789/45073/1/IJTK%2017%284%29%20609-622.pdf
Impact factor: (2017/2018) 1.061

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Butch G. Bataller
Department of Chemical Engineering, College of Engineering and Agro-Industrial Technology
UP Los Baños

A rapid and non-destructive method for quantifying biomolecules in Spirulina platensis via Fourier transform infrared – Attenuated total reflectance spectroscopy. Algal Research, Vol. 32, pp. 341-352.

This study aimed to develop a method that rapidly quantifies protein, carbohydrates and lipid content of the algae, Spirulina platensis, through the use of Fourier Transform Infrared (FTIR) spectroscopy and partial least square regression. In FTIR, infrared light is irradiated to the sample to cause vibrations in the covalent bonds of the target molecules in the sample. The target molecules are detected, as a plot of absorbance or transmittance, at characteristic wavelengths. Higher concentrations of the target biomolecule will have higher absorbance. Therefore, a regression model can be made at different concentrations of the target molecule. However, for an FTIR data that usually contains numerous, noisy and collinear variables, Partial least square (PLS) regression is most applicable. In this study, model spectra of Spirulina biomass were made from the individual spectra of glucose (carbohydrate), bovine serum albumin (protein) and glycerol tripalmitate (lipid) standards at various concentrations. Then, PLS-regression models were made from the model spectra of the biomass for each biomolecule at their characteristic wavelengths. These regression models were tested and validated by comparing the predicted results to the conventional analytical methods for determining protein, carbohydrate, and lipid content. It was found that the PLS-regression models were statistically similar to the results of the conventional methods. Thus, FTIR spectroscopy coupled with PLS-regression technique can replace conventional methods that are usually time-consuming and destructive to algal cells.

Significance:
This research work developed a novel analytical method in quantifying biomolecules such as protein, carbohydrates, and lipids in Spirulina biomass through the use of chemometric (partial least square regression) technique and FTIR spectroscopy. This method is fast as results can be obtained in a few minutes. Tedious sample preparation and extraction of the target analyte are eliminated. The method is also non-destructive to the cells since high temperature and use of toxic solvents for extraction are not needed. Losses from sample preparation and extraction steps are also prevented since the method can determine the biomolecule content directly from the whole-cell biomass. This method can be used for instantaneous monitoring of biomolecule production of the algal cells. This method is highly species specific and has not yet been done on Spirulina platensis.

Link to the article: https://doi.org/10.1016/j.algal.2018.04.023
Impact Factor: Not yet available

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Merdelyn T. Caasi-Lit, Artemio A. Salazar, Jefferson F. Paril, Ayn Kristina M. Beltran, Maria Alma B. Sanchez and Bryan V. Novio
Institute of Plant Breeding, College of Agriculture and Food Science
UP Los Baños

Sources of resistance to Asian corn borer, [Ostrinia furnacalis (Guenee)] in Philippine’s maize varieties. Society for the Advancement of Breeding Research in Asia and Oceania (SABRAO) Journal of Breeding and Genetics, Volume 50 (3), 254-269

Maize in the Philippines is an important cash crop second to rice. Several insect pests are main constraints in production. One of the major insect pests of corn is the Asian corn borer (ACB), Ostrinia furnacalis (Guenee). This pest is able to consume all parts of corn thus at very high level of infestation, farmer’s harvest is greatly decreased. With this, different control methods have been developed to manage these pests. One is the use of insecticides, however most active chemical principles pose hazard to farmer’s health and even the consumers. Biological and cultural methods such as use of Trichogramma wasps and detasselling are also useful but need to be integrated in an Integrated Pest Management (IPM) program to ensure effective control. One of the components of IPM is the use of resistant varieties to insect pests. Deployment of varieties resistant to ACB can serve as environment-friendly and cheaper control method. These varieties can serve as primary line of farmer’s defense against ACB attack. Traditional corn in the country has not yet been utilized to target sources of resistance against ACB. These varieties have been cultivated in various corn growing areas and thrived despite emergence of biotic stresses. A keyfinding of this study is that selected traditional varieties showed moderate to high levels of resistance against ACB through screening tests conducted in the laboratory and field. The resistant materials can be used as donor parents for breeding Philippine’s traditional corn for improved ACB resistance.

Significance:
There has been no breeding program for resistance to Asian corn borer (ACB) a major insect pest of corn in the country, where many areas still mainly utilize native or traditional corn. Genetic variability among these traditional varieties can be the main reason why these landraces still survive in the Philippines soil despite the various existing and emerging abiotic and biotic stresses. With rich genetic diversity of native corn populations or accessions in the tropics, sources of resistance to ACB may be available.

Link to the article: http://sabraojournal.org/wp-content/uploads/2018/09/SABRAO-J-Breed-Genet-50-3-254-269-CAASI-LIT.pdf
Impact Factor: Not yet available

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Marjorie Anne A. Layosa, Liezl M. Atienza and Angelina DR. Felix
Institute of Human Nutrition and Food, College of Human Ecology
UP Los Baños

Cadmium and Lead Contents and Potential Health Risk of Brown Rice (NSIC Rc222 Tubigan 18) Cultivated in Selected Provinces in the Philippines. Malaysian Journal of Nutrition, 24 (2): 287-292, 2018

White rice is a big part of the Filipino diet; however, brown rice is being promoted because it is a healthier option as compared to white rice. Brown rice is less milled hence it has more tendency to retain its nutrients, as well as the contamination absorbed from air, water and soil such as heavy metals cadmium (Cd) and lead (Pb). With the deteriorating environmental quality, human exposures to heavy metals have increased dramatically through their diet.
We investigated the potential health risk of brown rice from Nueva Ecija, Ilo-ilo and Bukidnon with the assumption that Filipinos will consume it as part of their regular diet as a result of its promotion. Analyses showed that Cd content is within the safe limit but Pb content in all provinces exceeds the allowable limit. Nonetheless, calculating the potential hazard of consuming the brown rice in the long run shows that it is still safe and has low probability for carcinogenic effects. However, there are other heavy metals possibly present and may contaminate brown rice such as mercury (Hg) that it is worth investigating. Also, this study shows the importance of the entire pathways of the food systems from production to food utilization in the totality of health and nutrition.

Significance:
The research demonstrates that promotion of healthier food options, such as brown rice as part of the Filipino diet, should also ensure the quality and safety from environmental effluents such as heavy metals cadmium (Cd) and lead (Pb). The study is significant as it showed that lead content among sampled brown rice exceeds the allowable limit set by FAO/WHO Food Standards Program. Fortunately, the detected amount is still safe for long-term consumption. Nonetheless, the study shows the importance of environmental quality in safe and healthy food production and consequently, promotion. 

Link to the article: http://nutriweb.org.my/mjn/publication/24-2/n.pdf
Impact Factor: Not yet available

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Allan Abraham B. Padama
Institute of Mathematical Sciences and Physics, College of Arts and Sciences
UP Los Baños

Adsorption of H on Cs/W(110): Impact of H on the Stability of Cs on the Surface. e-Journal of Surface Science and Nanotechnology, 16 (2018) 391-395

This study investigated the impact and influence of Hydrogen (H) on the stability of Cesium (Cs) atoms on Tungsten (W) surface. Cs finds importance in lowering the work function of metal surfaces. Low work function materials are used to produce negative hydrogen ions which are used as sources in fusion research and in high energy accelerators. Despite the effectiveness of Cs in such application, experimentalists observed that Cs atoms become unstable during actual operations. The atoms are sputtered out from the surface which makes the process inefficient and usually damages the system. This phenomenon is attributed to the presence of impurities. In this regard, we investigated the influence of H to the Cs atoms and analyzed the interactions in the atomic scale. We found that adsorption of H weakens the adsorption of Cs on W surface. It is therefore necessary to reconsider current designs of Cs/metal systems to further enhance their stability without affecting the desired performance. The electronic properties presented in our work could serve as benchmark for future designs of the systems.

Significance:
This work is a computational/theoretical based research that aimed to understand the co-adsorption of hydrogen and cesium on metal surface in the atomic-scale level. Cesiated metal systems are used as electrodes to produce negative hydrogen ions which are essential in fusion research and in high energy accelerators. This study provides explanation on the experimentally observed unstable behavior of Cs on surfaces in the presence of other adsorbates. While previous studies attributed the phenomenon to the presence of ionized particles and to the plasma environment, this present work revealed that even the hydrogen itself contributes to the weakening of Cs adsorption on the metal surface. The analysis on the electronic and geometric properties of the systems will serve as guide in future designs to stabilize Cesium atoms in metal surfaces.

Link to the article: https://doi.org/10.1380/ejssnt.2018.391
Impact Factor: Not yet available

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Menandro N. Acda
Department of Forest Products and Paper Science, College of Forestry and Natural Resources
UP Los Baños

Tobacco (Nicotiana tabacum) stalk particles as additive in urea formaldehyde bonded plywood. Journal of Adhesion Science and Technology DOI: 10.1080/01694243.2018.1509501

The study investigated the use of tobacco (Nicotiana tabacum L) stalk particles as an additive in the adhesive formulation used for plywood manufacture. The effects of varying amounts of tobacco stalk particles on adhesive working properties, shear strength and wood failure of 3-ply plywood were investigated. Adhesive mix containing urea formaldehyde resin with tobacco stalk particles up to 8% by mass blended very well and remained stable for at least one hour. An increase or no significant effect on shear strength and wood failure up to 8% tobacco stalk loading was observed compared to plywood that used a commercial glue formulation. Based on shear strength and wood failure, panels containing 4%–8% tobacco stalk particles would pass the requirements of ISO 12466-2. Examination of adhesive penetration and plywood strength suggests that tobacco particles could function as both filler and extender. Tobacco stalk particles offer an environment-friendly, low cost, strong and non-abrasive alternative to conventional fibers used in plywood production.

Significance:
Tobacco (Nicotiana spp.) is one of the most valuable agricultural products in the world. It is grown in over 125 countries on over 4 million hectares of land. In the Philippines, over 37,000 hectares of land are planted with tobacco with a production value of over 4.6 billion pesos. After the leaves are harvested, the tobacco stalks are incorporated into the soil or burned in the field. However, the presence of nicotine in waste tobacco stalks poses increasing solid waste disposal and pollution problems in many countries. Considering the insecticidal properties of nicotine in tobacco stalks, an attractive utilization of these waste materials is as fillers in the glue formulation used in plywood manufacture. Plywood is a major building material in the Philippines used as paneling, table tops, cabinets, door skin, furniture components, etc. Fillers are inert materials used to improve glue properties. The incorporation of ground tobacco stalks in the adhesive formulation used to manufacture plywood can render the panel toxic or repellent to wood-boring insects such as termites and powder post beetles (“bukbok”). The repellent effects of tobacco stalks against termites had already been demonstrated when used as components of particleboard. The potential use of waste tobacco stalks as raw materials in plywood manufacture could benefit the Philippine wood industry by providing plywood panels with increased termite resistant properties. In addition, the proposed use of tobacco stalks could alleviate waste disposal problems and pollution through efficient utilization of this biomass material.

Links to the article:
https://www.tandfonline.com/eprint/de9HGgn7iVFnJ7qArADh/full
https://www.tandfonline.com/doi/full/10.1080/01694243.2018.1509501
Impact factor: Impact Factor: (2017/2018) 1.039

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Arnold R. Salvacion
Department of Community and Environmental Resource Planning
College of Human Ecology
UP Los Baños

Spatial pattern and determinants of village level poverty in Marinduque Island, Philippines. GeoJournal. https://doi.org/10.1007/s10708-018-9944-6

This study explores the spatial patterns and determinants of poverty at the village level in the province of Marinduque, Philippines. Based on the results, poverty in the province varies spatially. Village characteristics such as slope, annual rainfall, population growth rate, distance to town centers, and distance to ports were found to have significant effects on village-level poverty incidence.

Significance:
The study explores the spatial patterns and potential determinants of poverty in the province of Marinduque, Philippines. Results from this study can be used by the province to address its poverty problem. The methodology can also be used in studying other poverty-stricken provinces in the country.

Link to the article: https://link.springer.com/article/10.1007/s10708-018-9944-6
Impact Factor: Not yet available
 
 

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

Characterization and expression analysis of a newly identified glutathione S-transferase of the hard tick Haemaphysalis longicornis during blood feeding. Parasites and Vectors, 11:91

Ticks suck large amounts of blood from their host, which exposes them to harmful substances that can result to oxidative stress and induce cellular damage. To prevent that, ticks have antioxidant molecules. In this study, a new glutathione s-transferase (GST), HlGST2, was identified and characterized together with the previously identified GST, HlGST. Recombinant GSTs prepared from Escherichia coli were analyzed for enzymatic activity. The gene and protein expressions of GSTs in different organs and developmental stages of the tick during blood feeding were analyzed. The localization of GSTs in different organs were also examined through immunofluorescent antibody technique. Results showed that recombinant GSTs exhibit GST activity. High GST gene and protein expression were observed in the tick midgut, upregulated as blood feeding progressed, suggesting its protective role against promoters of oxidative stress that are acquired from the tick’s blood meal. The high expression of GSTs in the hemocytes of the ticks also suggest their function in tick immunity. Taken together, the results of the study indicate the importance of GSTs in tick physiology.

Significance:
A new glutathione s-transferase, an antioxidant, was identified in the tick Haemaphysalis longicornis. This molecule has been found to be crucial to tick biology. Understanding of the different aspects of tick biology is important in design of tick control strategies.

Link to the article: https://parasitesandvectors.biomedcentral.com/articles/10.1186/s13071-018-2667-1
Impact factor: 3.163

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Rhoda Mae C. Simora and Ernestina M. Peralta
Institute of Fish processing Technology
College of Fisheries and Ocean Sciences
UP Visayas

Occurrence of Histamine and Histamine-forming bacteria in Philippine Traditional Dried-salted Fish Products. Asian Fisheries Science  31; 73-88.    

Traditional dried-salted fish locally known as “tuyo” is one of the Philppines’ ethnic products that Filipinos relish and will keep as part of their daily meal.  However, these products can be implicated with histamine poisoning, an illness with a variety of symptoms such as rash, vomiting, diarrhea and itching of the skin. The formation of histamine in these dried-salted fish products can be attributed to poor hygiene practices and sanitation during handling and storage.  The research assessed the histamine levels in dried fish products sold in major retail markets in Iloilo.  Results revealed that the histamine content in the tested products was above the safe limit for consumption and can cause health risks to consumers.  Equally, the detection of histamine- producing bacteria, which could have been introduced in the tested products during handling, supported the high histamine levels obtained.  With the creation of the Food Safety Act of 2013, government food regulating agencies should strictly implement and monitor these products to ensure consumer safety.

Significance:
The research provided a safety quality assessment of traditional dried-salted fish products sold in major retail markets in Iloilo, Philippines.  Results revealed that 16 out of 21 (76.2%) tested samples contained histamine levels above the USFDA guideline (5mg.100g^-1) for scombroid fish and/or product such that consumption of these dried fish products could pose health risks to consumers.  Likewise, the presence of histamine-forming bacteria in the tested products is indicative of poor standards of process hygiene and sanitation coupled with mishandling during storage.

Link to the article: https://www.asianfisheriessociety.org/publication/current.php
Impact factor: Not yet available

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Raycen v. Visto¹, Barry Leonard M. Tumbokon², Jant Crers C. Caigoy² and Augusto E. Serrano, Jr.^1
1Institute of Aquaculture
²National Institute of Molecular Biology and Biotechnology
College of Fisheries and Ocean Sciences
UP Visayas

Optimum replacement value of fish silage for protein source in Pacific white shrimp diets. The Israeli Journal of Aquaculture-Bamidgeh, IJA_70.2018.1510, 11 pages.

Tuna flesh was processed into a silage by adding a proper amount of formic acid and aged for 30 days. The resulting slurry (i.e. fish silage) was evaluated in terms of its chemical and biological analyses. For the chemical analyses, we determined its proximate composition, i.e. its moisture, crude protein, crude fat, fiber, ash and digestible carbohydrates and amino acid profile. Biological evaluation included a measurement of the attractability of feeds with or without fish silage as well as a feeding trial in which groups of shrimps were fed diets containing varying amounts of fish silage, i.e. 12.5%, 25%, 37.5% and 50% replacement of fish meal. Biological evaluation also included evaluation of the diets whether or not they enhance the immune response of the white shrimp against a bacterial pathogen Vibrio parahaemolyticus. Results showed fish silage contained 58.8% crude protein and only 4.24% fat on a dry weight basis while on a wet weight basis, it contained 71.5% moisture, 16.8% crude protein and only 1.2% fat. Its amino acid profile contained a well-balanced essential amino acids. For the attractability trial, only the diet with 50% fish meal replacement by fish silage was remarkably the most attractive diet to white shrimps. Growth trial results showed that post larval shrimps grew faster when fish meal is replaced by fish silage. Conversion of feed to flesh and dietary protein to flesh were not affected by fish silage replacement. Also, after the growth trial, shrimps were challenged with the bacterial pathogen Vibrio parahaemolyticus and shrimps fed diets containing the fish silage exhibited protection against the bacterial and the optimum dietary amount for the best protection was estimated to be 24.5% fish meal replacement. In conclusion, fish silage could serve as a feeding stimulant, growth and immune enhancer in white shrimps.

Significance:
Byproducts from fish processing industry could be utilized in the manufacture of fish feeds replacing the imported fish meal. In General Santos where Ms. Visto came from, tuna by-products abound most of the time. The present research evaluated the biological value of the silaged tuna product as a protein source replacement of fish meal. This study is significant in the exploration of protein source choices that could replace the imported ones. Fish silage can be prepared and stored by simple means and represents

an additional option for fish farmers and feed manufacturers.

Link to the article: https://evols.library.manoa.hawaii.edu/bitstream/10524/58328/1/70.2018.1510.Serrano.pdf
Impact factor: (2017/2018) 0.439

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Yrla Mey P. Santander and Harold M. Monteclaro
Institute of Marine Fisheries and Oceanology
College of Fisheries and Ocean Sciences
UP Visayas

Catch composition and catch per unit effort of filter net fishery in Jordan, Guimaras, Central Philippines: Its implication for management. Journal of Applied Ichthyology. 2018;34:937-944

In Jordan, Guimaras, the use of filter net is common. This fishing gear uses fine‐mesh netting to capture small organisms such as anchovies and small shrimps of the genus Acetes. However, the use of fine‐mesh nets triggered issues on conservation and overfishing. Therefore, this study was conducted to determine the catch per unit effort and catch composition of filter nets in Jordan, Guimaras during the summer season of 2016. The total length of the gear was 23–40 m. The cod end had the smallest mesh size (3 mm) with a non‐return valve. It was set during periods of strong current. Results showed that the amount of catch increased with the increase in current speed. CPUE for the sampling period ranged from 21 to 25 kg per operation. The amount of catch was more than 90% juvenile and fish larvae. According to filter net owners, months of February to May were considered lean season due to insufficient amount of catch while the peak season occurs during the months of September to January when the catch of anchovy and Acetes were abundant. Clearly, the use of this gear showed some environment concerns due to the catch of juvenile and fish larvae. However, fishers benefit from adult fish as well as both juvenile organisms and fish larvae. Both national and local polices currently do not define the allowable percentage of these organisms from the total catch in order to be considered ecologically sensible. Aside from providing baseline data, these results are essential in amending existing policies or formulating new ordinances that could help in regulating the use of filter net in Jordan, Guimaras.

Significance:
The filter net fishery uses fine mesh netting to capture anchovies and shrimps of the genus Acetes. These organisms provide high profit to fishers compared to other species. The study was conducted in order to determine the catch per unit effort and catch composition of filter net in Jordan, Guimaras. This study provided scientific data that could help in the evaluation of the biodiversity in the ecosystem. Furthermore, data shown in this study are essential in amending or formulating policies for a sound fisheries management.

Link to the article: https://doi.org/10.1111/jai.13708
Impact factor: (2017/2018) 0.774

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Leizel B. Secretaria, Emma Ruth V. Bayogan and Angelyn T. Lacap
Dept. of Biological Sciences and Environmental Studies
College of Science and Mathematics
UP Mindanao

Evaluation of various methods to break dormancy of potato (Solanum tuberosum L. ‘Granola’) minitubers. Acta Horticulturae. 1205, 401-410.

G-0 minitubers have average weights of 0.1 to 10 g while seed tubers weigh 30 to 40 g. Minitubers are produced from stem cuttings derived from tissue culture and usually have longer dormancy than conventional seed potato tubers. There is a need to break the dormancy of minitubers in order to attain shorter period to sprouting with good and uniform quality of sprouts. In this study, different postharvest treatments were used to break the dormancy of ‘Granola’ potato minitubers including ethephon, modified atmosphere (MAP) using polyethylene bag, calcium carbide (CaC₂, locally known as ‘carburo’) plus MAP (i.e., CaC₂ wrapped tightly in paper and added to minitubers in polyethylene bag), gibberellic acid (GA₃), and 1-methylcyclopropene (1-MCP). As early as 3 weeks after treatment, minitubers treated with 3 g CaC₂ per kg of minitubers packed in MAP had the highest sprouting percentage of 50%. CaC₂ plus MAP also resulted in G-0 potato minitubers with high sprouting percentage (76.09%), the most number of sprouts (2 to 3) per minituber, and the longest apical sprouts (3.5 mm) relative to untreated minitubers with only 65% sprouting, 0.90 sprouts per minituber, and 1.4 mm sprout length after 12 weeks. However, the treatment of CaC₂ also resulted in high weight loss and decay. Sprouting that resulted from the other treatments ranged from 60% to 77% in 12 weeks indicating long dormancy in ‘Granola’ minitubers. The ethephon and 5 μL/L GA₃ treatments exhibited more than 50% sprouting after 9 weeks, but not the control, 1 μL/L GA₃ and 1-MCP. The use of 3 g/kg CaC₂ can break dormancy in G-0 potato minitubers.

Significance:
Potato (Solanum tuberosum L.) is one of the high value crops of the world and ranks as the fourth most important staple crop next to wheat, maize, and rice. In the Philippines, potato production has increased over the years due to its growing demand. Thus, there is a need to sustain year-round production of potato. However, certain problems like disease build-up in tubers and inherent tuber dormancy immediately after harvest limit production. Minitubers are an alternative source of clean planting material with high health quality. These minitubers (0.1 to 10 g) are also known as G-0 (for generation 0) progeny tubers which are produced from in vitro or tissue culture-derived plantlets. Potato tuber dormancy starts at tuber detachment from the mother plant and continues until it breaks dormancy with visible sprout growth. Stem cuttings from in vitro plantlets grown in greenhouses produce G-0 minitubers that have longer dormancy than conventional seed potato tubers. Uniform sprout growth is highly desirable as it maximizes crop yield and value. Therefore, breaking the dormancy of seed potatoes is essential in order to attain shorter period to sprouting, coupled with good and uniform quality of sprouts which in turn benefits the farmers. The application of plant hormone, chemical stimulants, and manipulation of micro-environmental conditions were studied to break the dormancy of potato minitubers. In this study, the sprouting of ‘Granola’ G-0 minitubers was evaluated after treatment of ethephon, modified atmosphere packaging (MAP), calcium carbide and MAP, gibberellic acid, and 1-methylcyclopropene to break its dormancy.

Link to the article: 10.17660/ActaHortic.2018.1205.47
Impact factor: Not yet available

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Leizel B. Secretaria, Emma Ruth V. Bayogan and Angelyn T. Lacap
Dept. of Biological Sciences and Environmental Studies
College of Science and Mathematics
UP Mindanao

Efficacy of Guava and Mangosteen Extracts in Reducing Soft Rot (Pectobacterium carotovorum) in Harvested Chinese Cabbage. Acta Horticulturae. 1205, 393-400.

The effect of mature guava leaf and mangosteen rind extracts was evaluated in controlling soft rot of harvested Chinese cabbage heads. Use of substance from chemical extraction with methanol or ethanol resulted in higher antibacterial properties in the bioassay compared to extraction with water. Different concentrations of guava leaf and mangosteen rind extracts in inhibiting the growth of soft rot-causing bacteria, Pectobacterium carotovorum, were similar to each other but significantly better than without any treatment. Upon application of the extracts to Chinese cabbage heads that were inoculated with P. carotovorum 24, 48 or 72 hours after trimming, results showed that the extracts inhibited the growth of soft rot lesion compared to the control; however, less effective as spraying with 10% alum. Soft rot progression was minimized when treated with 10% alum thus, it also had better visual quality than the rest of the treatments. Chinese cabbage heads treated with 10% alum had the longest shelf life (7 days) followed by those treated with guava leaves or mangosteen rind extracts (4 days) and lastly by the control (3 days). This study confirms efficacy of 10% alum and the two plant extracts in reducing soft rot in Chinese cabbage butt-ends. Further assessment is needed to evaluate other concentrations of the two plant extracts.

Significance:
Chinese cabbage (Brassica rapa subsp. pekinensis) is one of the most valuable crops in the Philippines and has contributed around PHP 1.08 B revenue to the local economy. However, various problems may arise during postharvest operations in Chinese cabbage including soft rot infection. Soft rot is an important disease commonly caused by Pectobacterium carotovorum which effectively induce cellular maceration by releasing enzymes that can degrade cell walls. Using natural agents with antibacterial properties to inhibit infection can be a practical way to mitigate this postharvest disease. Two of the potential agents are guava (Psidium guajava) leaf and mangosteen (Garcinia mangostana) rind extracts which are known to exhibit antibacterial property. One component that provides this property of guava leaf is tannin which is known to have antiseptic properties that can inhibit the growth of disease-causing microorganisms. On the other hand, mangosteen has broad-spectrum antibacterial components such as α-mangostin and xanthones, which are known to exert potent antimicrobial activity in human pathogens. The antibacterial properties of the two extracts could be used as potential bioagents in controlling plant pathogens. Hence, in this study, guava leaf and mangosteen rind extracts were assessed for their control of soft rot in Chinese cabbage compared with postharvest alum treatment.

Link to the article: 10.17660/ActaHortic.2018.1205.46
Impact Factor: Not yet available

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Isidoro Malaque III
Department of Architecture
College of Humanities and Social Science
UP Mindanao

Thriving in The Slums: Progressive Development and Empowerment of the Urban Poor to Achieve Secure Tenure in the Philippines. Architectural Science Review, 61 (5): 313-318, 2018

Thriving cities are characterized by vigorous growth and associated with concepts and the existence of flourishing, healthy communities. However, such concepts are not immediately connected with the living conditions in squatter settlements in developing countries. With a rapidly increasing urban population, slum dwellers in developing countries continue to occupy vulnerable positions, functions and appearances in urban areas, leaving their residents exposed to the fear of eviction and displacement from their livelihoods, lifestyles and homes. While acknowledging a range of different approaches to the housing of slum dwellers, including the experience of problematic efforts to relocate inhabitants from a squatter settlement into a regular housing market in a single step, this paper examines a different case study. It describes the circumstances which have enabled squatter settlers in Davao City, in the Philippines, to achieve legal tenure and to build homes, incrementally, that are eventually compliant with the local building codes. Based on a detailed physical analysis of individual homes in combination with interviews with householders, this paper presents the findings of a comprehensive study of slum settlements in which the progressive development of urban settlements was analyzed in the context of Filipino pro-people policies. These have prioritized the rights of the urban poor and empowered them to build low-income housing, enabling them to develop sustainable, secure, thriving urban settlements within cities which provide a credible and hopeful role model for the foundation of better communities and cities for the future.

Significance:
In 2015, the United Nations declared that 54% of the world’s population lives in urban areas, with rapid increase concentrated in cities in developing countries mostly in Asia and Africa. In this context of unprecedented urbanization, coupled with widespread urban poverty, squatting is often the only means to access affordable shelter for the urban poor. Consequently, slum dwellers in developing countries continue to occupy a vulnerable position in urban areas living with fear of eviction and threats of displacement from their livelihoods, lifestyles and dwellings.

Acknowledging that housing is a basic human right, governments are committed to provide shelter for the low-income sector of their respective countries. However, housing policies and programs in developing countries, like the Philippines, are often based on models (applied with varying degrees of success) which originate in high-income countries. Thus, towards more feasible housing and urban interventions considering developing country conditions, there is a need to explore new progressive forms of urban development in relation to recent developments in housing and urban policies, in this case, in the Philippines.

This paper maintains that the progressive form of development of urban settlements coincides with the legalization of land tenure, and the incremental construction of housing units and improvements to sites and services. To further understand the dynamic urban phenomenon in the case of a city in a developing country, the aim of this paper is to illustrate the progressive development of urban settlements. The physical phenomenon of this economic upgrading of buildings is discussed in the context of pro-people housing and urban policies in the Philippines, and their impact on empowering the poor and enabling them to develop sustainable, secure, thriving low-income urban settlements.

Link to the article: https://doi.org/10.1080/00038628.2018.1502154
Impact factor: Not yet available