Malaysian Journal of Science

MOLECULAR ANALYSIS OF SOME FORENSICALLY SIGNIFICANT DIPTERANS ASSOCIATED WITH DECOMPOSING PIG (SUS SCROFA) CARCASS IN IWO SOUTH-WESTERN NIGERIA USING THE COI GENE

2022-09-13T09:22:55+08:00

Identification of many forensically important insects has been achieved using morphological keys with only a few relying on molecular techniques. Yet, information regarding the molecular identification of Dipteran flies from sub-Saharan Africa is scarce. Therefore, this study used the COI gene to analyze fly specimens collected from decomposing pig (Sus scrofa) carcasses in Iwo South-Western Nigeria. Several batches of eggs from carcasses were reared to adults and preserved in 75% ethanol for subsequent identification using molecular techniques in triplicate. A total of 450 bp sequences was obtained from BLAST analysis of the samples from the population, which has led to the identification of four families consisting of five species with the following breakdown: Sarcophaga africa (95.4%), Chrysomya putoria (99.1%), Chrysomya inclinata (98.3%), Tricogena rubricosa (89.6%), and Chirosia flavipennis (88.8%). The phylogenetic analysis identified Chrysomya chloropyga (AY139694) as the same as C. putoria and S. africa as the same as Sarcophaga cruentata, suggesting them as sister species. This study concluded that T. rubricosa and C. flavipennis are implicated in carrion decomposition, which provides crucial insights for forensic investigations

DNA BARCODING IN THE VALIDATION OF SCAD SPECIES IDENTIFICATION (GENUS: DECAPTERUS) IN AMBON

2023-06-08T12:11:07+08:00

Limitations on the morphology-based identification system and the decreasing number of taxonomists have become a problem that requires a molecular approach toward the recognition and identification of species. DNA barcoding has been considered an efficient solution to solve a few of taxonomy’s problems. This research intended to identify several scads species which have been found in the waters surrounding Ambon morphologically and molecularly through DNA barcoding. Fish samples were collected from January to June 2018 at the Mardika fish market Ambon, and then brought to the Laboratory of the Maritime and Marine Science Centre of Excellence Pattimura University for further analysis. Based on morphological identification, six species of scad were discovered, being Decapterus macarellus, D. macarellus (suspected), D. macrosoma, D. macrosoma (suspected), D. russelli (suspected)and D. kurroides. Using DNA barcoding, only four species of scad were found, being D. macarellus, D. macrosoma, D. russelli and D. kurroides with identification percentage ranging from 99-100%. After validation, the species of scad which can be found in Ambon’s waters are D. macarellus, D. macrosoma, D. russelli and D. kurroides. DNA barcoding is a complementary alternative that can reinforce morphology-based identification quickly and accurately.

MOLECULAR APPROACH AND PRELIMINARY SCREENING OF CULTURABLE FREE-LIVING RHIZOBIUM AS PLANT GROWTH ENHANCER

2023-08-14T10:53:57+08:00

The population increase and changes in consumption are the main challenges in agriculture production related to the increase in basic needs, especially food. The high demand for food leads to fertilizer application to effectively speed up and manage plant growth. The search for alternative biofertilizers from unique microorganisms is needed to tackle this issue. Rhizobium is known as a plant growth enhancer. In this study, they were isolated from Aek Natonang, famous as “the lake above the lake”, located on Samosir Island, North Sumatra, at more than 1400 m. These geographical conditions offer various potential unique microorganisms. The collected free-living Rhizobium from the sample was identified by morphological characteristics and molecular approach through 16S rDNA sequence. They were assessed for their abilities as plant growth promoters. Based on the morphological characterization, they showed a creamy yellow colony, excessive mucus production, Gram-staining negative, and catalase positive. Through the molecular approach, they have 98-100% similarity with Rhizobium sp.. A combination of morphological and molecular approaches strengthens the identification results. Six Rhizobium sp. produced IAA, siderophore, ACC Deaminase, and ammonia. They could also solubilize phosphate tolerated to high pH and salt concentrations. All the collected Rhizobium were qualitatively potential to enhance the plant growth. They performed diverse abilities in vitro, and Rhizobium radiobacter strain DT 14.16 displayed the best features. Hence, they can be a candidate for biofertilizer. However, none of the collected Rhizobium could suppress the growth of Ralstonia solanacearum. Using quality indigenous bacteria such as Rhizobium, is an environmentally friendly technology to increase agricultural productivity and hopefully provide better yield.

PHYTOCHEMICAL AND ANTIOXIDANT ASSESSMENT OF ALLIUM HYPSISTUM, ALLIUM PRZEWALSKIANUM AND ALLIUM WALLICHII

2023-03-27T13:13:24+08:00

High altitude plants are tremendously used mostly as food and traditional medicine for their role on prevention and treatment of several diseases. Thus, this study focused on comprehensive analysis of the phyto-constituents and the antioxidant activities of three plants; .Allium hypsistum, Allium przewalskanium, and Allium wallichii. Upon analysis, the phytoconstituents such as alkaloids, terpenoids, steroidal compounds, glycosides, carbohydrates and aminoacids were identified in ethanolic, n-hexane and aqueous extracts of the plant whereas saponins and quinones were not detected at all. Other photochemicals like flavonoids, phenolic compound, and tannins were found in ethanolic and water extracts but not in the n-hexane extract. The antioxidant activities were evaluated using total phenolic content (TPC) and 2, 2-diphenyl -1-picrylhydrazyl (DPPH) radical scavenging assay. TPC was assayed by Folin-Ciocalteu reagent method. The phenolic compounds were present in all three types of extracts; however, the highest TPC was estimated only in ethanolic extract of A. hypsistum i.e. 172mgGAE/100g. Among the extracts, ethanol extract of A. hypsistum showed the highest DPPH free radical scavenging property 59.44 %RSA (radical scavenging activity) when compared to the reference molecule ascorbic acid that had 75.11 %RSA. Among selected three plants, both TPC and %RSA revealing the antioxidant activities were found to be higher in A. hypsistum followed by A. prsewalskanium and A. wallichii. Furthermore, relationship between TPC and DPPH activity (%RSA) were established and found weak to strong correlation but they were statistical non-significant. From this study, such findings may help to know chemical constituents and medicinal values of Allium species which may lead to develop new phytomedicines and use of these plants in herbal therapy.

COMPLEX OF Co(II) WITH LIGAND 2,2’-BIPYRIDINE AND ANIONIC TRIFLUOROACETATE: SYNTHESIS, PHYSICAL PROPERTY, STRUCTURAL ANALYSIS AND ITS ANTIBACTERIAL ACTIVITY

2023-05-26T08:49:13+08:00

The complex containing Co(II), bipyridine (bipy), and trifluoroacetate (TFA) was prepared and characterized. The metal content, conductance, and TGA-DTG analysis estimate the formula of [Co(bipy)₃](CF₃COO)₂.5,5H₂O. The magnetic property shows the moment of 4.2-5.3 BM which should correspond to the three unpaired electrons with the typically strong orbital contribution in cobalt(II). The UV-VIS spectral profiles indicate the three possible spin-allowed transitions of the corresponding quartet states. The characteristic vibration modes of bipy and TFA confirm the complex formula. The SEM photographs support the crystalline particle size, and the corresponding EDX signifies the existence of all elemental contents. The powder XRD profile has been refined according to the Le Bail method of the Rietica program, and the result suggests being a structurally monoclinic system of space group C2/c. This complex exhibits a weak inhibition against S. aureus and E. coli bacterial activity.

FORMULATION OF RTS FROM PINEAPPLE (ANANAS COMOSUS) AND ALOE VERA (ALOE BARBADENSIS) PULP: EVALUATION OF NUTRACEUTICAL PROFILE AND SHELF-LIFE STUDIES

2023-02-17T20:42:02+08:00

Pineapple and aloe vera are rich sources of nutraceutical compounds such as flavonoids, ascorbic acid, and phenolic compounds with antioxidant properties, making them highly appealing to both consumers and processors. Aloe vera’s beneficial qualities are attributed to its polysaccharide content. Ready-to-serve (RTS) beverages are popular non-fermented drinks that are appreciated for their flavor and therapeutic potential. This study focused on developing RTS drinks from blends of aloe vera and pineapple pulp with varying sugar content (10 °Brix, 12 °Brix, 14 °Brix, and 16 °Brix) and evaluating their physicochemical, microbiological, and sensory properties over 45 days. Storage at 9 °C resulted in a slight increase in TSS, titratable acidity, reducing sugar, and microbial load, while significant decreases were observed in total sugar, pH, phenolic content, and DPPH content. Among the formulations, the RTS beverage with 12 ^O Brix exhibited superior physicochemical and sensory qualities. Combining aloe vera and pineapple in RTS beverages offers not only an appealing flavor profile but also potential health benefits, making them an ideal choice for product innovation.

SIMPLEX OPTIMIZATION FOR THE SPECTROPHOTOMETRIC DETERMINATION OF AZITHROMYCIN DRUG VIA ION-PAIR FORMATION

2023-06-22T15:56:24+08:00

A spectrophotometric determination of azithromycin was optimized using the simplex model. The approach has been proven to be accurate and sensitive. The analyte has been reacted with bromothymol blue (BTB) to form a colored ion pair which has been extracted in chloroform in a buffer medium of pH=4 of potassium phthalate. The extracted colored product was assayed at 415 nm and exhibited a linear quantification range over (1 - 20) g/ml. The excipients did not exhibit any interferences with the proposed approach for assaying azithromycin in pharmaceutical formulations.

ANALYSIS OF PLANT GROWTH DYNAMICS UNDER THE EFFECT OF TOXICITY: A DELAY DIFFERENTIAL EQUATION MODEL

2023-04-12T12:08:01+08:00

A mathematical model is designed to examine plant growth under stress in the presence of toxicity with a delay. It is observed that toxic substances change the soil's structure and activity, which has a negative impact on the concentration of nutrients there. The availability of soil nutrients is one of the most significant elements affecting biomass. Total biomass is seen to be adversely affected by both nutrition deficiency and toxicity. It has been noted that the presence of toxicity changes the physiology and growth of the plant, which ultimately reduces crop growth and production. This adverse effect of toxicity is not seen immediately, but after an incubation period. This effect is demonstrated by taking into account the delay in the state variable. Additionally, Hopf bifurcation is observed for the crucial value of the delay parameter. Utilizing explicit techniques, the direction and stability of bifurcating periodic solutions are found. Sensitivity analysis is used to determine the sensitivity of solutions of the model when values of parameters are varied. MATLAB is used for simulation.

A COMPARATIVE STUDY OF A CLASS OF LINEAR AND NONLINEAR PANTOGRAPH DIFFERENTIAL EQUATIONS VIA DIFFERENT ORTHOGONAL POLYNOMIAL WAVELETS

2023-04-20T11:25:25+08:00

We propose a wavelet approach on different orthogonal polynomials for solving linear and nonlinear pantograph equations with stretch kind. The pantograph differential equation is a unique proportional delay functional differential equation class. It has been used to deal with numerous physics, mathematics, and engineering applications, such as quantum mechanics, control systems, electrodynamics, and number theory. This scheme is based on constructing the operational matrix for integration via different wavelets with their collocation nodes. This study aims to examine the numerical dynamics of the pantograph equation under stretch kind through different orthogonal polynomial wavelets. Illustrative examples are presented to highlight the flexibility of this scheme, and comparisons are made between the mentioned scheme and other existing schemes using tables and graphs. These numerical results correctly predict the applicability and effectiveness of the mentioned scheme.

COMPLEX OF Co(II) WITH LIGAND 2,2’-BIPYRIDINE AND ANIONIC TRIFLUOROACETATE: SYNTHESIS, PHYSICAL PROPERTY, STRUCTURAL ANALYSIS AND ITS ANTIBACTERIAL ACTIVITY

2023-05-08T08:05:21+08:00

The increasing demand for optical sensors is driven by their wide applications, making surface plasmon resonance (SPR) play a crucial role in this field. In this study, a multilayered thin film consisting of tantalum pentoxide (Ta₂O₅) and silver (Ag) deposited on a glass prism was used to study SPR. The Ag layer thickness was fixed at 50 nm, while the Ta₂O₅ layer thickness varied from 0 to 70 nm. The Kretschmann configuration was employed to assess the sensitivity of air and gases with different refractive indices. Therefore, different layer thicknesses along with different wavelengths and angles were investigated. MATLAB software was employed to simulate and analyze SPR with a half-sphere prism to extend the incident angle. The simulation conditions with Fresnel equations were used to calculate the reflectivity and transmittance coefficients for the studied sample. The results revealed that the best output was at a Ta₂O₅ thickness of 50 nm to get optimal full width at half maximum of 2.4 and sensitivity factor of 162.5. This device works in the visible and infrared regions.