Judul: In Silico Study: The Potential of Kaffir lime leaves  (Citrus hystrix) as an Alternative to Antibiotic Growth Promoter (AGP) in Broiler  Chickens
Abstrak: Ayam broiler merupakan ternak yang rentan terinfeksi mikroorganisme pa togen, sehingga banyak peternak menggunakan Antibiotic Growth Promoter (AGP). AGP merupakan imbuhan pakan yang diberikan untuk memacu pertum buhan dan memperbaiki saluran pencernaan, namun kini sudah dilarang penggunaannya. Pelarangan AGP menyebabkan peralihan penggunaan imbuhan pakan seperti imbuhan pakan fitogenik. Daun jeruk purut (Citrus hystrix) mem iliki senyawa aktif metabolit sekunder sehingga berpotensi untuk dijadikan im buhan pakan fitogenik. Penelitian ini bertujuan menganalisis potensi senyawa ak tif daun jeruk purut dengan melihat berbagai aktivitas biologi dan kemampuan dalam menghambat bakteri E. coli dan S. aureus menggunakan metode in silico. In silico merupakan metode komputasi yang digunakan untuk memprediksi kiner ja senyawa aktif suatu bahan. Senyawa aktif yang diperoleh berasal dari jurnal terindeks scopus, kemudian dilakukan pencarian kode SMILES, nilai probable activity (Pa), dan prediksi interaksi antara senyawa aktif dengan protein bakteri E.coli dan S.aureus. Hasil yang didapatkan yaitu 143 senyawa aktif memiliki kode SMILES dan 96 dari 143 senyawa aktif memiliki nilai Pa 0,300 pada ak tivitas antibakteri, antioksidan, penghambat glikosiltransferase peptidoglikan, antiinfeksi, imunomodulator, dan antiinflamasi sehingga berpotensi sebagai alter natif AGP. Daun jeruk purut juga mampu menghambat bakteri E. coli dan S. aureus secara in silico., Broiler chickens are livestock that are susceptible to infection with pathogenic microorganisms, so many farmers use Antibiotic Growth Promoter (AGP). AGP is a feed additive given to stimulate growth and improve the digestive tract, but its use is now prohibited. The prohibition of AGP has led to a shift in the use of feed additives such as phytogenic feed additives. Kaffir lime leaves (Citrus hystrix) have active secondary metabolite compounds that have the potential to be used as phytogenic feed additives. This study aims to analyzing the potential of the active compounds and the activity kaffir lime leaves by looking at various biological activities and abilited E. coli and S. aureus bacteria using the in silico method. In silico is a computational method used to predict the performance of the active compound of a material. The active compounds were obtained from scopus indexed journals, then searched for the SMILES code, probable activity (Pa) values, and predicted interactions between the active compounds and the proteins of E.coli and S.aureus bacteria. The results obtained were 143 active compounds had SMILES code and 96 of 143 active compounds had a Pa 0,300 value for antibacterial, antioxidant, peptidoglycan glycosyltransferase inhibitor, anti-infective, immunomodulatory, and anti-inflammatory so that it has the potential to be used as an alternative to AGP. Kaffir lime leaves are also able to inhibit E. coli and S. aureus bacteria in silico.
Keyword: antibiotik growth promoter, in silico

Judul: Potensi Daun Sambung Nyawa (Gynura procumbens (Lour.) Merr.) sebagai Alternatif Antibiotic Growth Promoter pada Ayam Broiler”
Abstrak: Antibiotic Growth Promoter (AGP) merupakan antibiotik yang sudah dilarang penggunaanya pada ayam broiler. Senyawa fitokimia tumbuhan atau fitogenik dapat ditambahkan pada pakan sebagai alternatif AGP, salah satunya adalah daun sambung nyawa. Penelitian ini bertujuan menganalisis aktivitas dan menguji kemampuan senyawa aktif daun sambung nyawa (Gynura procumbens (Lourr.) Merr.) terhadap penghambatan bakteri E. coli dan C. perfringens melalui simulasi secara komputasi untuk memprediksi potensinya sebagai alternatif pengganti AGP pada ayam broiler. Analisis metode in silico yang digunakan yaitu PASS dan STITCH. Analisis PASS menunjukkan nilai Pa lebih dari 0,3 dinyatakan berpotensi. Daun sambung nyawa berpotensi sebagai alternatif AGP melalui aktivitas antibakteri, penghambatan peptidoglikan glikosiltransferase, antiinfeksi, antiinflamasi, dan antioksidan. Senyawa quercetin dan apigenin daun sambung nyawa mempunyai potensi untuk menghambat pertumbuhan bakteri E. coli dan C. perfringens melalui penghambatan biosintesis asam lemak dan pembentukan dinding sel bakteri., Antibiotic Growth Promoter (AGP) is an antibiotic that has been banned for use in broiler chicken. One of phytochemical compound as an alternative AGP substitute is Gynura procumbens leaves. The aims of this research was to analyze the activity and to evaluate the active compound of Gynura procumbens (Lour.) Merr. leaves against the inhibition of E. Coli and C. Perfringens through computational simulation to predict its potential as an alternative to AGP in broiler chickens.The method used is PASS and STITCH analysis. PASS analysis shows a Pa value of more than 0.3 as a potential source. Gynura procumbens (Lour.) Merr. leaves had potential as an alternative AGP through its antibacterial activity, inhibition of peptidoglycan glycosyltransferase, anti-infection, anti-inflammatory, and antioxidant activity. Quercetin and apigenin compounds in Gynura procumbens (Lour.) Merr. leaves had a potency to inhibit the growth of E. Coli bacteria and C. perfringens through fatty acid biosynthesis and formation of bacterial cell walls inhibition.
Keyword: AGP, C. perfringens, E. coli, Gynura procumbens leaves, in silico

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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