University of the Philippines

About: University of the Philippines is a education organization based out in Quezon City, Philippines. It is known for research contribution in the topics: Population & Health care. The organization has 4589 authors who have published 4437 publications receiving 114846 citations. The organization is also known as: UP.

Development and use of a two-gene marker-aided selection system for fertility restorer genes in rice

Abstract: We have established marker-aided selection strategies for the two major Rf genes (Rf3 and Rf4) governing fertility restoration of␣cytoplasmic-genetic male sterility (CMS) in rice. Polymorphisms between restorer and non-restorer␣lines were observed using RG140/PvuII for Rf3 located on chromosome 1 and S10019/BstUI for Rf4 located on chromosome 10. DNA polymorphisms associated with these two loci in restorer lines of wild abortive (WA), Dissi, and Gambiaca cytoplasm are conserved, suggesting that similar biological processes control pollen fertility in this diverse cytoplasm. Because of their close linkage to Rf genes and distinct banding patterns, STS markers RG140/PvuII and S10019/BstUI are well suited for marker-aided selection, enhanced backcross procedures, and pyramiding of Rf genes in agronomically superior non-restorer lines. The combined use of markers associated with these two loci improved the efficiency of screening for putative restorer lines from a set of elite lines. Positional analyses of Rf4 and the inheritance pattern of the polymorphism in S10019/BstUI suggest that Rf4, governing fertility restoration in WA-CMS in rice, is likely to be the same gene governing fertility restoration in BT- and HL-CMS that has a gametophytic effect, which explains why 100% pollen fertility in hybrids is impossible to attain.

Lactic acid bacterial fermentation of burong dalag.

Abstract: The fermented food, burong dalag, prepared in many Filipino homes, was studied to determine the nature of the microbiological and chemical changes that occur during fermentation. This is a lactic acid bacterial fermentation in which the species Leuconostoc mesenteroides, Pediococcus cerevisiae, and Lactobacillus plantarum played the major acid-producing role. The pH was lowered to below 4.0, and about 0.9% acid as lactic acid was attained in 1 week. It was essential to keep the product covered well to exclude air and subsequent growth of yeasts and mold.

Quaternary sector collapses of Nevado de Toluca volcano (Mexico) governed by regional tectonics and volcanic evolution

Abstract: Nevado de Toluca volcano is an andesiticdacitic composite volcano of Late Pliocene– Holocene age located in the central-eastern sector of the Trans-Mexican Volcanic Belt, an active continental arc. The latest stage of Nevado de Toluca evolution, in the past 50 k.y., has shown an interplay between volcanic activity and kinematics of the basement structures. Geological mapping, stratigraphic analysis, morphological and structural interpretation, and analogue modeling were used to investigate these complex volcano-tectonics relationships. In the past 50 k.y., Nevado de Toluca volcano underwent at least three sector collapses on the east, east-southeast, and west fl anks because of faulting and destabilization of young dacitic domes at its summit. Field and remotely sensed data supported by analogue models of transtensive basement tectonics revealed that these catastrophic events were strongly correlated to the presence of the east-west–striking active Tenango fault system. The geometry, kinematics, and dynamics of the basement structure controlled the growth of a dome complex in the volcano summit and its destabilization. As a consequence of the active basement tectonics, the most probable sector collapse directions in the case of future gravitational failures of the volcano summit will be east-southeas t, west-northwest, east, and west. Nevado de Toluca poses potential hazards to more than 25 million inhabitants; the analysis presented in this paper can improve hazard mitigation on the basis of better knowledge of growth and collapse mechanism of the volcano. The numerous examples of composite volcanoes in continental and island volcanic arcs with similar structural-volcanological characteristics of Nevado de Toluca volcano imply that the model results can also act as a guide to study the growth and collapse of other composite volcanoes affected by basement structures.

Possible immunomodulatory actions of Carica papaya seed extract.

Abstract: Carica papaya seed extract is currently being marketed as a nutritional supplement with purported ability "to rejuvenate the body condition and to increase energy". The product claims to improve immunity against common infection and body functioning. The present study was initiated to analyze the chemical constituents of the Carica Seed Extract and determine the potential immunomodulatory properties of the different bioactive fractions. These immunomodulatory activities of crude Carica Seed Extract and its bioactive fractions were examined in vitro using lymphocyte proliferation assays and complement-mediated hemolytic assay. Three major observations were made in this study: (1) the crude Carica Seed Extract and two other bioactive fractions significantly enhanced the phytohemagglutinin responsiveness of lymphocytes; (2) none of the Carica Seed Extract (at the concentrations used in this study) was able to protect the lymphocytes from the toxic effects of chromium; and (3) some of the bioactive fractions of Carica Seed Extract were able to significantly inhibit the classical complement-mediated hemolytic pathway. These findings provide evidence for immunostimulatory and anti-inflammatory actions of Carica Seed Extract. No single compound is likely responsible for these activities. Further purification, isolation and characterization of the active components are needed.

The central Philippine Fault Zone : Location of great earthquakes, slow events, and creep activity

Abstract: The central Philippine Fault Zone is found to be the locus of great earthquakes, a transition zone with slow slip and creep activity. This is based on the analysis and correlation of seismic historic data and detailed documentation of recent seismic events in the region. Based on this study the Guinyangan fault is defined to be the northern locked portion with recurrence interval of as short as 65 years. The Masbate fault is the central part with large and medium earthquakes accompanied by unusually large ground rupture. The north Central Leyte fault and the south Central Leyte fault, on the other hand, are characterized by aseismic creep and medium-sized events, usually with clusters of foreshocks, respectively. Unusual seismic activity both on the Masbate fault and Central Leyte fault somehow correlates well with the behavior of known slow events and creep activity. Further investigation of this region could lead to deeper understanding of impending major earthquakes, especially along the Guinyangan fault, which usually produces larger damaging events, and for further understanding of the impact of slow events and creep on the adjoining active structures.