Judul: Antibacterial Activity of White Pepper Extract (Piper nigrum) against Escherichia coli Isolate from Cattle In Vitro
Abstrak: Indonesia merupakan negara produsen dan eksportir lada (Piper nigrum) terbesar ketiga di dunia. Olahan lada yang sering ditemukan dalam kehidupan seharihari masyarakat Indonesia yaitu lada putih bubuk. Beberapa senyawa pada lada putih bubuk ditemukan memiliki aktivitas antibakteri. Penelitian bertujuan untuk mengetahui aktivitas antibakteri oleh ekstrak lada putih terhadap bakteri Escherichia coli asal sapi. Penelitian dimulai dengan melakukan ekstraksi simplisia lada putih dengan metode maserasi menggunakan pelarut alkohol 96%. Ekstrak lada putih yang diperoleh kemudian diuji aktivitas antibakterinya terhadap isolat Escherichia coli yang dikoleksi dari anal swab sapi dengan metode difusi menurut Kirby-Bauer. Uji aktivitas antibakteri akan dilakukan pada ekstrak lada putih dan beberapa konsentrasi ekstrak lada putih 80%, 60%, 40%, 20%, serta 10% dengan pelarut aquades. Kontrol positif yang digunakan adalah cakram tetrasiklin, dan kontrol negatif yang digunakan adalah aquades. Penelitian menunjukkan tidak terbentuknya zona hambat pada isolat bakteri Escherichia coli asal sapi oleh ekstrak lada putih. Faktor-faktor yang dapat menyebabkan hasil tersebut seperti komposisi unsur fitokimia tanaman lada di Bogor, proses pengolahan simplisia, hingga kualitas simplisia lada putih yang digunakan seperti parameter kadar air, kelembaban, hingga kontaminasi oleh bakteri pada simplisia.
Keyword: lada putih, lada, aktivitas antibakteri

Judul: IN VITRO ANTIBACTERIAL ACTIVITY TEST OF  GARLIC EXTRACT (Allium sativum L.) AGAINST Klebsiella sp.
Abstrak: Klebsiella sp. merupakan bakteri infeksius dari famili Enterobacteriaceae yang dapat menginfeksi hewan maupun manusia. Ekstrak bawang putih digunakan sebagai antibakteri alternatif untuk meminimalisir penggunaan antibiotik komersil. Metode penelitian adalah uji re-identifikasi isolat Klebsiella sp. dan ekstraksi simplisia bawang putih. Uji aktivitas antibakteri dilakukan secara in vitro terhadap bakteri Klebsiella sp. menggunakan ekstrak bawang putih dengan konsentrasi 20%, 40%, 60%, 80%, dan 100%. Analisis data penelitian dilakukan dengan uji Shapiro-Wilk (normalitas) menunjukkan data berdistribusi tidak normal. Uji dilanjut dengan Kruskal-Wallis untuk menjelaskan adanya perbedaan yang signifikan (P < 0,05), hasil uji Kruskal-Wallis menghasilkan data diameter zona hambat Klebsiella sp. memiliki p = 0,003 sehingga p < 0,05 yang berarti ekstrak bawang putih mampu bekerja sebagai antibakteri terhadap Klebsiella sp. Kemudian dilanjut uji Mann-Whitney untuk mengetahui besar perbedaan aktivitas antibakteri dari setiap kelompok uji. Ekstrak bawang putih konsentrasi 20% dan 40% memiliki daya hambat sedang, sedangkan ekstrak bawang putih konsentrasi 40%, 60%, dan 100% memiliki daya hambat kuat. Namun, daya hambat yang dihasilkan dari ekstrak bawang putih masih belum mampu menghambat Klebsiella sp. sebaik antibiotik komersil., Klebsiella sp. is an infectious bacterium from the Enterobacteriaceae family that can infect both animals and humans. Garlic extract is used as an antibacterial alternative to minimize the use of commercial antibiotics. The research method is the re-identification test of Klebsiella sp. and garlic simplicia extraction. Antibacterial activity test is conducted in vitro to Klebsiella sp. using garlic extract with concentrations of 20%, 40%, 60%, 80%, and 100%. Analysis of research data is carried out using the Shapiro-Wilk test (normality) which showed that the data were not normally distributed. The test continued with Kruskal-Wallis to explain the significant difference (p < 0.05), the results of the Kruskal-Wallis test resulted in the diameter of the inhibition zone of Klebsiella sp. has p = 0.003 so p < 0.05, which means that garlic extract is able to work as an antibacterial against Klebsiella sp. Then continued the Mann-Whitney test to determine the difference in antibacterial activity of each test group. Garlic extracts with concentrations of 20% and 40% had moderate inhibition, while garlic extracts with concentrations of 60%, 80%, and 100% had strong inhibition. However, the inhibition power of garlic extract was not able to inhibit Klebsiella sp. better than commercial antibiotics.
Keyword: Antibakteri, Bawang putih, Ekstrak, Klebsiella sp., Uji in vitro, Antibacterial, Extract, Garlic, In vitro test

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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