Judul: Potensi antibakteri propolis lebah Trigona spp asal Bogor
Abstrak: Propolis contains resinous substances collected by honey bees from various plant sources. Analysis of numerous samples from different geographic regions led to the disclosure that the chemical composition of propolis is highly variable depends on the specificity of the local flora at the site of collection and thus on the geographic and climatic characteristics of this site. This fact results in the striking diversity of propolis chemical composition, especially of propolis originating from tropical regions. The ethanol extract of Trigona spp propolis collected in Bogor, Indonesia was prepared an assayed to get information about it’s potential ability as antimicrobial substance. Antimicrobial activity was determined by disk diffusion assay. The result of this study shows that the propolis more effective against Gram positive bacterias, Bacillus subtilis and Staphylococcus aureus than Gram negative, E. coli and Pseudomonas aeruginosa. Minimum inhibitory concentration of extract were up to 1.563% against the Gram positive bacterias, and 3.125% against the Gram negative bacterias.
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Judul: Antibacterial Activity of Trigona spp. Bee Propolis From Pandeglang Against Enterobacter sakazakii.
Abstrak: Propolis has many advantages and specific potencies, due to its properties as antibacterial, antivirus, and anticancer. The characteristics and properties of E. sakazakii has been studied well due to its physiological properties and resistances in the environment. The research aim is to determine the propolis potency of Trigona spp as antibacterial agent against E. sakazakii. Propolis was extracted from bee hives of Trigona spp using maceration method with ethanol 70% (propolis extract) yielded 17,76% extract. The antibacterial activity test was performed by a modified agar well diffusion against three isolates of bacteria E. sakazakii IB-19b, IB-29a, and ATCC 35217. Through the initiation test, propolis activity was higher than commercial propolis, and lower than ampicillin. The effectivities of propolis extract to commercial propolis for each isolate IB-19b, IB-29a, and ATCC 35217 were 143,99%, 169,65%, and 155,76% respectively. The effectivities of propolis extract to ampicillin for each isolate IB-19b, IB-29a, and ATCC 35217 were 39,37%, 38,94%, and 47,37% respectively. The minimum inhibition concentration differed for each isolate, the minimum inhibition concentration for IB-19b, IB-29a, and ATCC 35217 were 12,50%, 25,00%, and 50,00% respectively. The propolis activity to each isolate showed the concentration dependent activity, the antibacterial activity decrease as the propolis concentration decrease.
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Judul: Thermal Characteristics and Dynamics of Tropical Cyclone over Western North Pacific Ocean: A Case Study of Typhoon Songda (Chedeng) 2011
Abstrak: The frequent occasion of Tropical Cyclone (TC) over Western North Pacific (WNP) Ocean lies from 10˚N to 26˚N and 121˚E to 170˚E. Sources of TC development come from warm ocean temperature where latent heat is released during condensation processes and subsequently concentrated in the boundary layer. Relative humidity at 850-700 hPa is responsible to produce the most intense storm. Meanwhile, weak vertical wind shear between 850-200 hPa is one of the dynamical factors that lead to the development of TC. Pressure level of 850-200 hPa is chosen to minimize the thermodynamic effect in the lower troposphere. Typhoon Songda (Chedeng in the Philippines) or TSC lasted from May 18th to 30th, 2011 and strengthened into powerful Super Typhoon stage between May 24th and 27th. Long curving track and the exhibition of all sequences of TC life cycle, TSC is then considered as an ideal case of TC. The objective of the study with case of TSC is to investigate the role of thermal characteristics and dynamics on TC intensity. The research is carried out by using Advanced Research of Weather Research and Forecasting model (WRF ARW model) version 3.3. Two domains are employed in the model. The first domain situate from 02˚N to 40˚N and 118˚E to 149˚E and cover spatial resolution () of 33.1 km. The second domain situate from 09˚N to 27˚N and 119˚E to 132˚E with of 11 km. Timestep of the model () is 120 seconds. The model is supported by the following physical parameterization, i.e., Yonsei University Scheme (YSU) in the boundary layer, Kain-Fritsch scheme (KF) in the cumulus, and WRF Single-Moment 3-class scheme in the microphysics. Initial meteorological condition prior to the formation of the cyclone is generated using WRF ARW standard-release model. Sensitivity of the model output is obtained from a selected single-parameter change scenarios, namely, 10 % to 20 % decrease and increase of wind shear initial data at 850-200 hPa, and by 10 % to 20 % decrease of relative humidity initial data at 850-700 hPa. The result showed that the negative correlations between wind shear and intensity are found in wind shear scenarios. Wind shears of 10 ms-1 which lead to strengthening of the wind intensity in the early period of Typhoon development are found in wind shear scenarios. The effect of wind shear changes on wind intensity is statistically significant in the 20 % wind shear scenarios. During mature stage, weak wind intensity occurred when wind shear increase as given in the WRF standard-release and the 20 % decreasing scenario. Different situation is found in the 20 % increasing scenario where wind shear tend to weak and lead to strong wind intensity at this stage. Meanwhile, the reduction of moisture supply at 850-700 hPa resulting from 20 % decreasing relative humidity play a major role in the weakening of wind intensity and reduces mechanical energy of the cycle process as much as 300 J kg-1.
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