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UPV Theses and Dissertations

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    A comparative study of the microorganisms found in the vaginal flora of pill and non pill user by Pap smear
    Bayate, Aimee Sarena L. (Division of Biological Sciences, College of Arts and Sciences, University of the Philippines Visayas, 1994-03)
    This study was conducted to identify and classify the organisms that are present in pill users and non-pill users. It will determine if taking of pills cause changes in the microflora of pill (combined) users and will describe the profile of both pill and non-pill users. The study use 200 prepared smears of the vagina, divided equally to both pill and non-pill users. The slides were collected at Dr. Ricardo Y. Ladrido Memorial Hospital, Lambunao, Iloilo by the family planning physician with the help of the medical technologist. The profile of the patients were also gathered to provide more information about the subjects. The organisms were identified according to their basic morphological characteristic. The results indicate that bacilli which is the normal inhabitant of the vagina is present in 200 samples. Cocci is present in both groups but occure more in women who are pill users. In the parasite group, Trichomonas vaginalis is present in women who are pill user and Candida is present in both groups but occur more in women who are pill users. The test for the estimation of the difference between two proportions reveal that the z values obtained from the experiment falls between the critical region which has a value of 2.58. Such a value indicate that the prevalence of parasites and bacteria are equal among pill and non-pill users.
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    Influence of tidal levels on meiofaunal communities in a rocky shore area in Taklong Island National Marine Reserve, Guimaras
    Barbasa, Maria Carla A. (Division of Biological Sciences, College of Arts and Sciences, University of the Philippines Visayas, 2013-04)
    Rocky shores present an exuberant richness of life, which can be attributed to the hard substrate provided by rocks, necessary for the attachment of sessile organisms. There are many factors affecting community structure in rocky shores, including tidal levels. Tidal levels affect communities by periodically exposing them to air, causing drying up and dessication. Among those affected are meiofauna. Meiofauna in rocky shores are the least studied of all habitats, thus this study serves as baseline information regarding meiofauna in rocky shores, particularly in TINMAR, and how tidal levels affect them. Sorting and identification of meiofauna from 18 samples (5 TST, 5 TLT, 4 TMT, 4 THT) yielded 17 identified taxa, with Harpacticoids being numerically dominant followed by Tanaids (Copepods) and Polychaetes. Mean meiofaunal abundance was found to higher in lower tides (low and sub-tide), but differences were not statistically significant. A similar lack of significant differences between transects was shown for abundances of all and common taxa in edge or mid-section quadrats, although abundances appeared to be higher in low and sub-tidal transects. Cluster analyses based on similarities in abundance of taxa in the transect quadrats showed which asemblages are characteristic of mid- and high tide levels (Insect larvae and Sipunculids). Nematodes, which are typically dominant in soft-bottom substrates, were also most abundant in the upper intertidal in the present study. Other taxa like Tanaids, on the other hand, were more abundant in the low intertidal and subtidal transects. Harpacticoids were observed to be dominant in higher tides.
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    Removal of Harmful Algal Bloom (HAB)-forming organisms using ball clay: Factors and effects of clay addition
    Rivera, Peter Paolo L. (Marine Science Institute, College of Science, University of the Philippines Visayas, 2015-05)
    Global concern for Harmful Algal Blooms (HABs) has increased due to their frequency of occurrence and associated negative health and economic effects. Control measures for HABs/red tides have been developed to alleviate their effects in the marine and coastal environments. The use of clays and modified sands/sediments to remove/control HABs is one of the promising and attractive direct control options for areas with persistent HAB problems. However, factors such as pH and ionic strength and mechanisms and kinetics of algal removal through clay addition/spreading are not fully understood. This study examined the effect of different pH levels and varying ionic strength on the removal efficiency (RE) of ball clay on toxic dinoflagellates: Pyrodinium bahamense var. compression, Gymnodinium catenation, and Alexandrium tamarense complex. High REs by ball clay were observed on Pyrodinium and Gymnodinium. On the other hand, only minimal removal was observed with Alexandrium. This implies that ball clay has a varying affinity towards different HAB species. Removal was also found to be highly dependent on bloom stages and varies for a given target species. RE of ball clay for the three test organisms increases as the pH of the solution decreases (83.1% for Pyrodinium, 81.2% for Gymnodinium, 89.4% for Alexandrium at pH 6. Results from this study show that with increasing salinity and/or ionic strength, RE also increases (82.7% for Pyrodinium, 88% for Gymnodinium, and 79.5% for Alexandrium at ionic strength of 1.0). Results show that changing the pH and ionic strength influenced the zeta potential (electrokinetic potential) of both the toxic algal cells and ball clay, hence affecting algal flocculation and leading to the effective removal of the algal cells. Microalgal cells are negatively charged in growth media at pH values (7-9 for most algal species) typical for growth and the charges cause adjacent cells to repel each other and remain suspended in the medium. The negative charges apparently derived from the water and dissociation of functional groups on algal cell walls, and vary among different algal species. The changes in pH influence the degree of surface dissociation, thus affecting the cell surface charge. The zeta potential of ball clay as a function of varying ionic strength and salt concentrations showed that zeta potential decreases (more negative) with increasing ionic strength from 0 to 1 and/or salinity from 0 to 36 ppt (in contrast to algal cells). When the ionic strength of the solution is increased, the charge potential difference between clay particles and algal cells also increases, thereby increasing the affinity between the two particles. Cell death and lysis were evident within the suspended and settled clay matrix from direct microscopic observation. The cells appeared moribund, and stained cytoplasmic material could be seen leaking into the medium. Cell death may have been due to the direct physical contact between the cells and clay particles. Cell lysis occurred over a 1–2-hour period in single-species cultures of HAB organisms. Measurement of fluorescence properties through confocal laser scanning microscopy (CLSM) of microalgae has proven that a rapid and sensitive ecotoxicity method could be developed where the motility and viability of cells flocculated with clay could be examined. The substantial release of the nucleotides and intracellular materials from the algal cells indicates the expulsion of the thecal plates and cell membrane leading to the disintegration of the algal cells upon clay addition. Cellular damage was further confirmed by metabolic imaging through an esterase activity assay. Esterase activity in control and treated cells was studied by fluorescence imaging after staining with fluorescence diacetate (FDA), a technique to probe cell membrane integrity and cell viability. FDA-positive cells decreased through time until 24-hour upon exposure to ball clay. Future studies are needed to investigate the actual mechanism of how clay induces cell lysis or mortality. Cell mortality may be due to natural senescence or programmed cell death (PCD) under stress-promoting conditions and not related to any chemical or physical interaction between the clay and the algal cells. It is also interesting to look at the possible formation of ecdysal and temporary pellicle cysts upon clay treatment. The possible formation of temporary cysts by HAB cells may play a role in bloom regrowth. The encystment and excystment may enable HAB cells to escape entrapment, allowing a bloom to reform.
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    Evaluation of feeding performance of early siganid, Siganus guttatus, larvae fed with mixed zooplankton
    Andrade, Maria Shiela S. (Division of Biological Sciences, College of Arts and Sciences, University of the Philippines Visayas, 1999-04)
    Siganus guttatus is an economically important rabbitfish for commercial farming. It is very important to evaluate their feeding performance particularly the effects of different diets for this larvae and to determine their growth and survival after being fed on different diets. Newly-hatched siganid, Siganus guttatus, larvae were reared in 500-L fiberglass tanks and fed either on copepod nauplii and rotifers alone or combination of both. Copepod nauplii proliferated in tanks consisted mainly of Pseudodiaptomus sp., and Acartia sp. Siganid larvae successfully commenced feeding (feeding incidence) on early stage copepod nauplii even if their abundance was low. Selective feeding ability of larvae seemed to start from day 6 and the larvae thereafter preferred to feed nauplii than rotifers. Survival of the siganid larvae was significantly higher when fed with with combination of rotifers and copepod nauplii compared to those fed with either rotifers or copepod alone. The growth of the larvae however are the same for all treatments. Results of this study suggest that coastal calanoid copepods of the genus Pseudodiaptomus sp. and Acartia sp. could be reproduced in tanks and their nauplii can be used as food for siganid larval rearing.
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    Biosorption of Copper (CU) and Lead (PB) by heavy metal-resistant bacterial isolates from Iloilo River
    Ampuan, Naira Mitz W. (Division of Biological Sciences, College of Arts and Sciences,University of the Philippines Visayas, 2012-04)
    Many indigenous organisms isolated from sites contaminated with heavy metals have tolerance to heavy metal toxicity and these microbial activities have always been the natural starting point for all biotechnological applications. It is therefore necessary to isolate bacterial strains with novel metabolic capabilities. In this study, a total number of 18 heavy metal-resistant bacteria (10 Pb-resistant and 8 Cu-resistant) were isolated from Iloilo River sediment samples (10° 41.974’N, 122°34.187’ E). Biosorption of Cu and Pb by the bacterial isolates was characterized to evaluate their applicability for heavy metal removal from industrial waters. Selecting the highest resistance to metal toxicity’ and biosorption, 4 isolates were identified by phenotypic characterization. Identification of the top four metal-resistant isolates designates: Vibrio charchariae (83%) for Cu4; Vibrio harveyi (79%) for Cu6; Moraxella equi (100%) for Pb8; and Phoecoenobacter uteri (92%) for Pb9. Evaluation of specific metal biosorption by the isolates after incubation for 48 h suggested that none of the isolates have good potential for bioremoval of metals from contaminated environments.