Aceh International Journal of Science and Technology
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Removal of Eggs Adhesiveness of African catfish (Clarias gariepinus) at Different Concentrations of Urea Solution
Get PDFAbstract The objective of the present study was to determine the best concentration of urea solution and rinsing time to remove adhesiveness of African catfish eggs. Four different concentrations of rinse solution were used in this experiment comprising of 2 g, 4 g, 6 g and 8 g of urea diluted in 4 g NaCl/L of water producing a concentration of 0.486 mM, 0.973 mM, 1.458 mM, and 1.946 mM of urea concentration respectively, while 4 g NaCl/L of water without urea were used as control. The fish eggs were rinsed with the solutions at different durations namely; 1, 5 and 10 minutes. Each rinsing solution concentration and rinsing time were conducted in three replicates. The fertilization and hatching rates increased and peaked from the control (0 mM of urea) to 0.466 mN urea and decreased when concentration of urea was increased to 0.973 mM urea and 1.458 mM urea, then increased again at 1.946 mM urea, but these values were lower than at 0.486 mM urea. Thus, the best concentration for fertilization and hatching rates were 0.486 urea of urea. However 0.973 mM of urea was optimum in reducing clumping of eggs.Keywords: Clumping; Fertilization; Hatching; Brood fis
Relationship of Soilborne Mycoflora of Cassava Growing Fields to Incidence of Postharvest Rots of Cassava Tubers in Sokoto, Nigeria
Get PDFIn this study the fungi associated with cassava growing fields in Sokoto were isolated and identified using soil dilution technique. A total of 215 fungal colonies from 9 fungal species were isolated from soil samples of different cassava fields between the month of June and August, 2012. It was observed that soil samples from Lambara recorded the highest number (64) of fungal species followed by Damba and the least number (44) of fungal species was observed in Wamakko.The fungi isolated were Alternaria species, Aspergillus niger, Aspergillus fumigatus, Cylindrocarpon lichenicola, Fusarium oxysporum, Geotrichum candidum, Mucor hiemalis, Rhizopus orgyzae and Scopulariopsis candida.The highest percentage frequency of occurrence was observed in Aspergillus niger (39.5%) seconded by Fusarium oxysporum (18.2%) and the least was seen in Rhizopus oryzae ( 2.3%). The pathogenicity test indicated that all the fungal isolates were pathogenic on cassava tubers.The fungus M. hiemalis is the most pathogenic followed by F. oxysporum and the least was recorded by R. oryzae. Therefore, it would be concluded that there is relationship between soilborne fungi and incidence of postharvest rots of cassava tubers
Tyrosinase Inhibition Type of Isolated Compounds Obtained from Pachyrhizus erosus
Get PDFAbstract - In Indonesia, Bengkoang (Phacyrhizus erosus) have been used as one of cosmetics especially as sun screening and skin whitening materials. Six active compounds in Bengkoang with antioxidant and skin whitening activities have been isolated, namely daidzein, daidzin, genistin, (8,9)-furanyl-pterocarpan-3-ol, 4-(2-(furane-2-yl)ethyl)-2-methyl-2,5-dihydro-furane-3-carbaldehyde and 2-butoxy-2,5-bis(hydroxymethyl)-tetrahydrofurane-3,4-diol. According to literatures, the type of their tyrosinase inhibitory activity has not yet reported. The determination of whitening activity of each compound was evaluated by the evaluation of Lineweaver-Burk plot. The result showed that five compounds had competitive inhibitory activity and 8,9-furanyl-pterocarpan-3-ol showed a non-competitive inhibition.Keywords: Pachyrhizus erosus, tyrosinase, competitive inhibition and non-competitive inhibitio
Runoff Prediction Using an Aggregation Hydrology Model on Seulimum River Sub Watershed, Aceh Province, Indonesia
Get PDFThe objective of the present study was to predict the runoff in Seulimeum River sub watershed by utilizing an aggregation hydrology model. The method in this research consisted of field observation, collecting data and map, testing model, and analyzing data. Some parameters were used as the inputs on the model, such as: maximum storage, actual groundwater storage, soil moisture, and the constant of soil moisture k(t). The aggregation hydrology model was tested using 3 (three) statistical parameters, such as; determination coefficient (R2), biased percentage (PBIAS), and Nash-Sutcliffe coefficient (ENS). The result showed that the minimum runoff occured in 1998 was 70.22 mm and the maximum runoff occurred in 1987 was 759.12 mm. The model testing showed that the aggregation hydrology model had a good performance in predicting the discharge of Krueng Seulimemum Sub Watershed; the R2, P biased, and ENS resulted 0.92, -5.21%, and 0.90, respectivel
Serological Survey of Dengue Virus Immunoglobulin M Among Febrile Patients in Kaduna Metropolis, Nigeria
Get PDFThe purposes of this research were to determine the prevalence of dengue virus in the study population, to determine the relationship between the occurrence of dengue virus IgM and potential risk factors and to determine the association between the occurrence of dengue virus and some symptoms. In this study, blood specimen were collected from 340 subjects with febrile complaints attending hospitals in Kaduna metropolis, Nigeria and who gave their consent to participate. Serological determination of dengue virus IgM was carried out using enzyme linked immunosorbent assay technique. Structured questionnaires were also administered to obtain data on demographic, risk factors, and symptoms of illness. A total of 6 subjects were positive for dengue virus IgM giving a prevalence of 1.8%. There was no statistically significant association between the occurrence of dengue virus IgM and potential risk factors, demographic factors and symptoms of the illness. The occurrence of dengue virus in the study population was confirmed
Preliminary Study on the Effect of Ethylene Diamine- n, n-diacetic Acid on Methane Gas Production Rate from Cow Manure
Get PDFIn an effort to improve methane gas production rate from cattle slurry; ethylene diamine- N, N-diacetic acid chelating ligand was introduced into the digester system. Experimental analysis involving the determination of trace metals, pH and methane gas yield, were carried out with the use of the Flame Atomic Absorption Spectrophotometer and Biogas5000 analyser. The results showed that there was an increase in the pH of the system; the amount of methane gas yield equally increased by 12% and the Hydraulic Retention Time decreased from 50 days to 25 days on addition of ethylene diamine- N, N-diacetic acid chelating ligand. Also, increasing the concentration of the chelating ligand further decreased the HRT of the digester system from 25 days to 19days. Concentration of trace metals like Iron, Cobalt and Nickel within the digester system ranged from 0.001-0.050 mg/L; these metals reacted with ethylene diamine- N, N-diacetic acid chelating ligand to form metal chelates. The metal chelate formed resulted in the catalysis of the hydrolysis stage (which is the rate determining step) of the anaerobic digestion process. Thus, the decrease in HRT was due to the metal chelate catalysis of the hydrolysis stage of the anaerobic digestion process were the metal chelate formation served as the driving force in the solvolysis process
A General Overview on Some Aspects of Fish Reproduction
Get PDFAbstract - Reproduction is one of the important physiological systems that are crucial in the life cycle of living organisms including fish. The main objective of the reproduction is to maintain the existence of the species and therefore fish have a strategies and tactics to achieve this objective. The reproduction behaviours are important to be studied in relation to know the population dynamic of fishes and their spawning seasons. This information is very crucial in relation to the development of breeding technology for aquaculture and conservation (restocking) purposes. This paper reviews the reproductive strategy, fecundity and spawning frequency of fishes.Keywords: Fecundity; Spawning frequency; Gonadal development; Synchronous; gonadosomoatic inde
Surface Energy Balance in Jakarta and Neighboring Regions As Simulated Using Fifth Mesoscale Model (MM5)
Get PDFAbstract The objective of the present research was to assess the surface energy balance particularly in terms of the computed surface energy and radiation balance and the development of boundary layer over Jakarta and Neighboring Regions (JNR) by means of numerical model of fifth generation of Mesoscale Model (MM5). The MM5 with four domains of 9 kilometers in spatial resolution presenting the outermost and the innermost of JNR is utilized. The research focuses on the third and fourth domains covering the entire JNR. The description between radiation and energy balance at the surface is obtained from the model. The result showed that energy balance is higher in the city area during daytime. Meanwhile, energy components, e.g., surface sensible and latent heat flux showed that at the sea and in the city areas were higher than other areas. Moreover, ground flux showed eastern region was higher than others. In general, radiation and energy balance was higher in the daytime and lower in the nighttime for all regions. The calculation of Bowen Ratio, the ratio of surface sensible and latent heat fluxes, was also higher in the city area, reflecting the dominations of urban and built-up land in the region. Meanwhile, Bowen Ratio in the rural area dominated by irrigated cropland was lower. It is consistent with changes of land cover properties, e.g. albedo, soil moisture, and thermal characteristics. In addition, the boundary layer is also higher in the city. Meanwhile western region dominated by suburban showed higher boundary layer instead of eastern region.Keywords: MM5; Energy components; Land cover propertie
Adaptive Thermal Comfort in The Tropic: A Case Study of The Aceh Tsunami Museum
Get PDFAbstract - Thermal comfort calculated using ISO 7730 has been questioned and responded by more adaptive thermal comfort methods. This study was therefore conducted to assess the acceptable thermal comfort for the local people in the tropical Aceh using the measurement based on ISO 7730 and with adaptive thermal comfort method by questionnaires. In this research, Aceh Tsunami Museum building, located in Banda Aceh, Indonesia, was in an open designed layout to be assessed as a case study. This study was conducted onsite using mechanical equipment and involving 138 respondents. The result shows that the comfort temperature calculated by mechanical equipment based on ISO 7730 is 23.140C. This is in contrast with the result of the questionnaires that showed people in an open building design rate the air temperature up to 320C as slightly cool. This condition is influenced by the mean air speed of 2.34 m/s and the mean relative humidity of 66.25%. This finding agrees that obtaining the comfort air temperature especially in tropics merely from the prediction of comfort index in ISO 7730 is inaccurate since the respondents actually could adapt with the higher air temperature.Keywords: Adaptive thermal comfort; Tropics; Aceh Tsunami Museu
Production of Alpha Amylase by Bacillus cereus in Submerged Fermentation
Get PDFMicroorganisms have the ability to secrete enzymes when they are grown in the presence of certain substrates. Amylases are among the most important industrial enzymes and are of great significance in biotechnological studies. Bacteria belonging to the genus Bacillus were isolated using mannitol egg yolk polymyxin B (MYP) agar a highly selective media for Bacillus cereus isolation. The isolates were tested for -amylase production on nutrient agar supplemented with starch and in submerged fermentation. The bacteria isolated and identified (using the Microgen Bacillus identification kit) were all Bacillus cereus and SB2 had the largest zone of hydrolysis of 12mm on nutrient agar supplemented with starch as well as the highest enzyme activity of 1.62U/ml. Amylase activity of 2.56U/ml was obtained after 24 hours incubation in submerged fermentation. When amylase enzyme production parameters where optimized, maximum amylase activity was obtained at a pH of 6.5, temperature of 350C, incubation time of 24 hours and 4% inoculums concentration. Bacillus cereus SB2 is a potential isolate for alpha-amylase production with soluble starch as the sole carbon source in submerged fermentation