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Detection of Paralytic Shellfish Poisoning (PSP) Toxins in Philippine Mussel Samples by Electrospray Mass Spectrometry

Abstract

The occurrence of toxic red tide outbreaks is an environmental and public health hazard in the Philippines. Thus, it is necessary to develop ‘monitoring programs to protect the shellfish industry and the general public. Previous methods for the detection of paralytic shellfish poisoning (PSP) toxins make use of mouse bioassays and/or fluorescence detection through High Performance Liquid Chromatography (HPLC). The mouse bioassay, while cheap and rapid, requires a large amount of sample, and is capable of detection of toxin concentrations that are already near the regulatory limit. Read More

The Bandwidth of the Cartesian Product of a Double Star and a Path

The Bandwidth of the Cartesian Product of a Double Star and a Path

Abstract

The cartesian product of two graphs G and H, written G x H, IS the graph with vertex set V(G) x V(H) and with (u1, v1 ) adjacent to (U2, V2) if U1 is adjacent to U2 in G and V1 = V2 or U1 = U2 and V1 is adjacent to v2 in H. This paper establishes the bandwidth of the Cartesian product of a double star and a path. Read More

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Antimicrobial Compounds from Spondias purpurea

Abstract

The dichloromethane, ethyl acetate, ethanol and water extracts of the freeze-dried bark of Spondias purpurea were tested for antimicrobial activities against seven microorganisms. Results of the study indicated that all the extracts at 30 µg have low antimicrobial activities against E. Coli, P. aeruginosa and T. mentagrophytes. The water and ethanol extracts showed low activity against C. Albicans, while the ethyl acetate extract gave low activity against A. niger. All the extracts were inactive against S. Aureus and B. subtilis. Read More

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Lead Uptake and Growth Responses in Pistia Stratiotes Linn. (Quiapo)

Abstract

Pistia stratiotes was cultured in hydroponics solutions amended with three different lead (Ph) levels-2ppm, 4ppm, and 8ppm AAS analysis revealed that Ph accumulation in the plant tissue (BCF) increased with increasing Ph levels in the culture solutions, Ph accumulation had caused the development of chlorotic leaves and decreases in the fresh biomass of the plants. However, there was no interference of the Ph accumulation on the growth responses of Pistia in terms of moisture, chlorophyll, and protein contents. These findings imply that P. stratiotes might be useful in heavy metal decontamination process in industrial and domestic wastewaters. Read More

On Maximal Biconnected Graphs

On Maximal Biconnected Graphs

Abstract

A biconnected graph is a connected graph that contains no complete bipartite spanning subgraph. This paper deals mainly with maximal biconnected graphs. We provide a characterization and some properties of this class of graphs. We determine their dominance and independence numbers. We also prove some properties in G and format. Read More

Hydrothermal Synthesis and Characterization of an Akaganeite-type Iron Oxide Octahedral Molecular Sieves

Hydrothermal Synthesis and Characterization of an Akaganeite-type Iron Oxide Octahedral Molecular Sieves

Abstract

Iron oxide octahedral molecular sieve with 2×2 tunnel, designated as FeOx-OMS (2×2) was successfully synthesized by hydrothermal method. FeOx-OMS (2×2) has high degree ofpurity and higher thermal stability than those of previously reported akaganeite-type materials. The X-ray powder diffraction (XRD) pattern shows peaks that are characteristic of pure akaganeite-system. Based on its TGA profile, its thermal stability is reported up to 255 ° C. and beyond 402 °C new phases are formed which is a mixture of hematite and magnetite-based on its XRD pattern. Read More