Philippine Journal of Science

Includes bibliographical references.

Twin Calf Production in Water Buffaloes Following Non-Surgical Transfer of in vitro-produced-vitrified Embryos -- Predisposing Factors Contributing to Spoilage of Soy Sauce by Bacillus circulans -- Genetic Characterization of Pili (Canarium ovatum Engl.) from Albay, Camarines Norte, and Camarines Sur Through Isozyme Analysis -- Effects of Sodium Channel-Targeted Conotoxins on Catecholamine Release in Adrenal Chromaffin Cell -- Direct Dependence of Covalent, Van Der Waals, and Valence Shell Radii of Atoms on their Bohr Radii for the Main Group Elements -- Effects of Polychlorinated Biphenyls (PCBs) on Root Meristem Cells of Common Onion (Allium cepa L.) and on Early Life Stages of Zebrafish (Danio rerio) -- Accumulation of Copper by Golden Apple Snail Pomacea canaliculata Lamarck -- Use of Relative Density-based Schedules in Kiln-Drying Big-Leafed Mahogany (Swietenia macrophylla King) Lumber -- Zooplankton Composition and Diversity in Paoay Lake, Luzon Is., Philippines -- Photolytical Degradation Products of Pentachlorophenol in Aqueous Solution and Organic Solvent.

[Article Title : Twin Calf Production in Water Buffaloes Following Non-Surgical Transfer of in vitro-produced-vitrified Embryos / Danilda Hufana-Duran, Prudencio B. Pedro, Apolinario L. Salazar Jr., Hernando V. Venturina, Peregrino G. Duran, Yoshiyuki Takahashi, Yukio Kanai, and Libertado C. Cruz, p. 99-104] Abstract : Twinning in buffalo cows is only about 0.01%. Effecting twin pregnancies by transferring more than one embryo of different developmental stages was tested. Cumulus-oocyte complexes collected from slaughterhouse-derived ovaries were matured and fertilized in vitro. Presumptive zygotes were cultured, on Day 6-7, developed blastocysts stage embryos were removed, frozen by vitrification, and stored in liquid nitrogen. After 2 to 5 months, 130 embryos were warmed; 72 were cultured in vitro to test for viability while 58 were non-surgically transferred in two's (n= 20 recipients) or three's (n = 6 recipients) to 26 buffalo cows. No significant difference was observed on post-warming survival rate of the embryos at different developmental stages with 85-88% hatched within 72 h of in vitro culture. Embryo transfer resulted to birth of one twin (3.8%) and five single births (19.2%) presenting 23.1% (6/26) calving rate. This demonstrates the possibility of enhancing twinning in buffaloes by embryo transfer techniques.;[Article Title : Predisposing Factors Contributing to Spoilage of Soy Sauce by Bacillus circulans / Ma. Josie V. Sumague, Reynaldo C. Mabesa, Erlinda I. Dizon, Ernesto V. Carpio, and Ninfa P. Roxas, p. 105-114] Abstract : This study investigated the factors that predispose soy sauce to spoilage by Bacillus circulans. Factors studied that would likely spoil soy sauce were dilution, inoculum, incubation temperature, and incubation period. Determinants of spoilage monitored were viable cell count of B. circulans, pH, titratable acidity, and sodium chloride content of soy sauce. Dilution, inoculum, and incubation temperature significantly affected the viable cell count and pH of soy sauce inoculated with B. circulans at 95% level of confidence. Dilution, inoculum, temperature, and incubation period significantly affected the titratable acidity, and sodium chloride content of soy sauce inoculated with B. circulans at 95% confidence level. Dilution and inoculum were the most important factors that affected all the determinants of soy sauce spoilage. Optimum conditions for spoilage of soy sauce by B. circulans were found in the range of 70-80% dilution and 14-18% inoculum. Under these conditions, soy sauce has viable cell count of 8 (log CFU/mL), pH of 5.7-6.5, 0.2-0.4% titratable acidity, and 4.0-6.0% sodium chloride content. The multiplication of B. circulans in diluted soy sauce indicated that this microorganism is slight to moderate halophile. Soy sauce in the original unaltered state was very stable.;[Article Title : Genetic Characterization of Pili (Canarium ovatum Engl.) from Albay, Camarines Norte, and Camarines Sur Through Isozyme Analysis / Merlyn S. Mendioro, Ma. Geneleen Q. Diaz, Vera Marjorie E. Velasco, Maylynn C. Alcaraz, Roselle C. Lalamunan, Karen G. Amoloza and Luisa N. Villamael, p. 115-125] Abstract : Based on esterase (EST), acid phosphatase (ACP), and alkaline phosphatase (ALP), genetic variability was noted in 19 accessions of pili (Canarium ovatum Engl.) from Albay, Camarines Norte, and Camarines Sur and in the 11 accessions of unknown origin. Seven presumptive loci were determined. Two presumptive loci were observed in EST (EST1 and EST2), ACP (ACP1, and ACP2) while three for ALP (ALP1, ALP2, and ALP3). Percent polymorphism was 100%. Using a similarity coefficient of 0.60, the 30 accessions were divided into 5 clusters. Accessions of different origin grouped together which would indicate that variability exists in the accessions considered. To further prove that genetic diversity exists in pili, 25 accessions collected from Oas, Albay were also subjected to isozyme analysis.;[Article Title : Effects of Sodium Channel-Targeted Conotoxins on Catecholamine Release in Adrenal Chromaffin Cell / Elsie C. Jimenez, Nobuyuki Sasakawa, and Konosuke Kumakura, p. 127-132] Abstract : Veratridine, a sodium channel inactivation inhibitor causes Ca2+ influx and catecholamine (CA) release. Adrenal chromaffin cells were treated with sodium channel-targeted conotoxins, ╬╝O-MrVIA and ╬╝-PIIIA, prior to the application of 20 ╬╝M veratridine that was completely inhibited by tetrodotoxin (TTX). At 2.5 ╬╝M, ╬╝O-MrVIA completely abolished the veratridine-induced TTX-sensitive CA release. On the other hand, ╬╝-PIIIA (0.5 - 2.5 ╬╝M) is a less potent inhibitor; the inhibition leveled off at ~ 60%. The results indicate that in adrenal chromaffin cells, the TTX-sensitive sodium channels can be classified into two categories: (1) sensitive to both ╬╝O-MrVIA and ╬╝-PIIIA (60%), and (2) sensitive to ╬╝O-MrVIA but resistant to ╬╝-PIIIA (40%). Conotoxins ╬╝O-MrVIA and ╬╝-PIIIA may be used in discriminating structurally different sodium channels. Specifically, PIIIA may be useful in determining the functional significance and regulation of co-expression of sodium channel subtypes during differentiation in various types of cells.;[Article Title : Direct Dependence of Covalent, Van Der Waals, and Valence Shell Radii of Atoms on their Bohr Radii for the Main Group Elements / Raji Heyrovska, p. 133-139] Abstract : Recent work by the author has shown that ionic, atomic, and the ground state Bohr radii (aB) of elements are inter-related. An earlier work by others has shown that the ratio, van der Waals radii/de Broglie wavelengths is nearly constant for each group of some non-metallic elements. Since aB and the de Broglie wavelength are directly related, the author shows here that, in fact, for all the main group elements from 1A - 8A, the van der Waals radii are directly proportional to aB. It was found that the valence shell and covalent radii also vary linearly with aB. Thus, all the above radii (R) can be unified by a single linear equation, R = maB + c. Therefore, aB can be considered as a unit of length for the above radii as much as for the smaller Compton wavelength and classical radii (sum) of electron and proton.;[Article Title : Effects of Polychlorinated Biphenyls (PCBs) on Root Meristem Cells of Common Onion (Allium cepa L.) and on Early Life Stages of Zebrafish (Danio rerio) / Jonas P. Quilang, Margaret C. de Guzman, Maria Helen de Hitta-Catalan, Raquel O. Rubio, Sonia D. Jacinto, Evangeline C. Santiago, and Ernelea P. Cao, p. 141-151] Abstract : Polychlorinated biphenyls (PCBs) are chemical mixtures that are common environmental pollutants and considered potential carcinogens. In this study, the common onion, Allium cepa, was used to determine the cytotoxicity and genotoxicity of a mixture of PCBs at three concentrations, namely, 10 nM, 100 nM, and 1000 nM. Distilled deionized water and 0.2% dimethylsulfoxide (DMSO) were used as negative controls. Cytotoxicity was observed at the three concentrations tested as shown by a significant reduction in average mitotic indices. Chromosomal aberrations were also observed, which is suggestive of the genotoxicity of these pollutants. The effects of PCBs on the early life stages of zebrafish, Danio rerio, were also investigated.;[Article Title : Accumulation of Copper by Golden Apple Snail Pomacea canaliculata Lamarck / Silvia C. Pe├▒a and Glorina N. Pocsidio, p. 153-158] Abstract : The golden apple snail (Pomacea canaliculata) accumulated copper (Cu) from 20, 30, 45, 67.5, and 101.25 ┬╡g Cu/L but showed behavioral regulation at 67.5 and 101.25 ┬╡g Cu/L. Bioaccumulation factor (1.04), biotransference factor (1.01), assimilation efficiency (89%), and accumulation rate (8.97 ┬╡g Cu/g/day) were high in 7 days of exposure. Copper accumulation from the dissolved copper, food, and sediment by the organs such as kidney, digestive gland, foot, and gills were not significantly different from one another. But the Cu accumulation in dissolved Cu and sediment by the whole soft tissue were significantly higher than those from the food and the control. Gill was the main route of exposure for dissolved Cu. Results obtained favored golden apple snail as Cu biomonitor at sublethal concentrations (0-45 ┬╡g Cu/L) using its whole tissue for analysis.

It could be used as biomarker at high concentrations.;[Article Title : Use of Relative Density-based Schedules in Kiln-Drying Big-Leafed Mahogany (Swietenia macrophylla King) Lumber / Aileen A. Jara, Emmanuel D. Bello, Stella Villa A. Castillo, Virgilio A. Fernandez, and Ponciano S. Madamba, p. 159-167] Abstract : Kiln-drying experiments were conducted to determine the seasoning characteristics of and drying schedules for small-diameter plantation-grown big-leafed mahogany (Swietenia macrophylla King) based on its relative density. Three schedules of increasing degree of severity - recommended (T7-D3), severe (T8-D4), and accelerated (modified T9-D5) were used. The study showed evidence that small-diameter plantation-grown mahogany is easy to dry as illustrated by its fast drying rate and resulting minimum defects. The mahogany boards could be subjected to temperatures as high as 82.2┬░ C without severe drying defects. The species is further characterized by low radial and tangential shrinkage. The severe (T8-D4) and accelerated (modified T9-D5) drying schedules appeared promising for 23-year old mahogany, resulting in shorter drying times and boards comparable in quality to those kiln-dried using the recommended schedule. However, casehardening and moisture content variation were observed in all the drying runs.;[Article Title : Zooplankton Composition and Diversity in Paoay Lake, Luzon Is., Philippines / Ma. Riyel Y. Aquino, Carmela D. Cho, May Ann S. Cruz Ma. Angelica G. Saguiguit, and Rey Donne S. Papa, p. 169-177] Abstract : A study on zooplankton species composition and diversity of Paoay Lake in Luzon Is., Philippines was conducted to update the previous zooplankton species lists in the area and provide new insights into its ecology. Samples were collected monthly from April to September 2006. Twenty-seven species were found in Paoay Lake. Of these, 45% belong to Rotifera, 29% to Cladocera, and 26% to Copepoda. Five (2 Copepoda and 3 Rotifera) species that have been reported to be rare in previous studies were frequently encountered in all sampling sites such as Paracyclops fimbriatus, Tropocyclops prasinus, Conochiloides dossuarius, Keratella cochlearis, and Trichocerca capucina. Nineteen species are new records for Paoay Lake. The rotifer Keratella tropica was noted to be the most abundant among all zooplankton species observed. Species diversity and richness was lowest during April and May, the same time when high densities of K. tropica was observed, and was higher during the succeeding months due to the absence of any dominant species.;[Article Title : Photolytical Degradation Products of Pentachlorophenol in Aqueous Solution and Organic Solvent / Maria Pythias B. Espino, p. 179-188, p. 179-188] Abstract : The photolytical degradation of pentachlorophenol in water, ethyl alcohol, and ethyl acetate was investigated to provide an understanding of its persistence and the nature of its degradation products. The photodegradation of pentachlorophenol in water was found to be most efficient resulting in complete dechlorination and production of acetic acid, oxalic acid, and chloride ion as final products. The chlorinated degradation products of pentachlorophenol in water (2,3,4,6-tetrachlorophenol; 2,3,5,6-tetrachlorophenol; 2,4,5-trichlorophenol; 2,3,6-trichlorophenol; 2,6-dichlorophenol; dichlorobenzenediol), ethyl alcohol (2,4,6-trichlorophenol; 2,3,6-trichlorophenol; 2,5-dichlorophenol; 2,3-dichlorophenol), and ethyl acetate (2,3,6-trichlorophenol; 2,4-dichlorophenol) were identified. A theoretical determination of the degradation products using density functional theory computations of atomic charge distribution that correlated with the experimental findings of this study is proposed.