Judul: Penerapan Pohon Klasifikasi Dan Bootstrap Aggregating Dalam Klasifikasi Usia Menarche (Studi Kasus: Smpn Ragunan Dan Smpn 1 Dramaga).
Abstrak: Menarche adalah menstruasi pertama bagi remaja putri. Menarche cepat merupakan salah satu penyebab wanita terkena kanker payudara sedangkan menarche terlambat merupakan salah satu penyebab osteoporosis. Penelitian ini bertujuan menentukan faktor-faktor yang memengaruhi usia menarche remaja putri di SMPN Ragunan dan SMPN 1 Dramaga. Peubah respons yang digunakan yaitu kategori usia menarche (cepat, ideal, dan lambat). Metode analisis yang digunakan adalah Classification and Regression Trees (CART) dan bootsrap aggregating (bagging). CART menghasilkan pohon klasifikasi tunggal sedangkan bagging menghasilkan pohon agregat untuk meningkatkan akurasi pendugaan pohon klasifikasi tunggal. Peubah-peubah penting yang memengaruhi usia menarche pada pohon klasifikasi tunggal secara berurutan adalah jenis sekolah, asupan protein, asupan kalsium, dan asupan lemak. Sementara itu, pada pohon agregat urutannya adalah jenis sekolah, asupan kalsium, asupan protein, dan asupan lemak. Pohon agregat dengan berbagai versi replikasi memberikan ketepatan klasifikasi yang lebih baik dibandingkan pohon klasifikasi tunggal. Selain itu, hasil validasi silang lipat 5 menunjukkan bahwa ketepatan klasifikasi pohon agregat dengan 100 replikasi lebih baik dibandingkan dengan pohon klasifikasi tunggal. Pada penelitian ini, bagging mampu meningkatkan ketepatan klasifikasi pohon tunggal dari 60.00% menjadi 62.50%.
Keyword: bootstrap aggregating (bagging), Classification and Regression Trees (CART), menarche, validasi silang

Judul: Penerapan Metode CART dan Agregat Bootstrap dalam Klasifikasi Status Gizi Balita Di Kecamatan Taman Sari, Kabupaten Bogor.
Abstrak: Nutrition problem is a multidimensional problem that affect health and productivity of Indonesian society. The number of short nutritional status (stunting) and high malnutrition is a serious health problem because it picturizes life for the next 100 years. About 90% of the short children problems in the world occur in 36 countries, and the rank of Indonesia is number five. The purpose of this study is to determine the factors that affect the nutritional status of children and evaluate the stability of classification trees with bootstrap aggregating method.The research is conducted at Taman Sari subdistrict, Bogor with the number of samples 120 mothers who have toddlers. Statistical analysis used to analyze the factors that influence the nutritional status of children is the method of CART (Classification and Regression Tree). CART is a method of data exploration which uses decision tree technique. This study also applies bagging method (bootstrap aggrergating) to evaluate the stability of classification trees generated by CART. The results of the classification tree formed produces optimum tree with eight terminal nodes. Explanatory variables into the main node is the nutritional behavior. Level of accuracy for the CART method was 69.17%.The percentage of the classification on the delimitation of the best z using z-score -2.5 SD with level of accuracy 76.67% and 88.33%, and z-score -3 SDwith level of accuracy 73.33% and 79.17%. Bagging method has been able to evaluate the stability of classification trees by 79.28%.
Keyword: bootstrap aggregating, CART, the nutritional status of children

Judul: Extracellular Expression of thermostable Geobacillus stearothermophilus T1.2RQ Lipase for Biodiesel Production
Abstrak: The extracellular expression of enzymes in an excellent secretion host such as Bacillus subtilis is a useful strategy for making enzymes of industrial significance more affordable by lowering the cost of its downstream processing. Lipases are a category of hydrolases that catalyze the hydrolysis of triglycerides to glycerol and free fatty acids. Also, lipases catalyze the hydrolysis and transesterification of other esters as well as the synthesis of esters. They can perform very specific biotransformation reactions and are widely used in food, organic synthesis, detergents, cosmetic, and pharmaceutical industries. Geobacillus stearothermophilus T1.2RQ lipase is an industrially-desired thermostable lipolytic enzyme with an excellent hydrolytic and transesterification activity. This study aimed to express T1.2RQ lipase, in B. subtilis WB800 and ensure its secretion into the extracellular medium. Three signal peptides (AmyQ, Epr, LipA) and two promoters (Pgrac01 and Pgrac100) were used in the secretory-expression of T1.2RQ lipase, based on five constructed expression vectors constructed by restriction cloning and PCR mutagenesis. Sangers sequencing was used to verify constructs to ensure they are in the correct reading frame. Recombinants vectors, pHT43 (plasmid control), pHT43-T1.2RQ, pHT43- T1.2RQ_AmyQ, pHT43-T1.2RQ_Epr, and pHT43-T1.2RQ_LipA, were transformed by electroporation into Bacillus subtilis WB800. The electroporation was successful with the optimum condition of 2500V, 200 ohms, 25µF, and 5milliseconds. Recombinant B. subtilis pHT43 (negative control) and pHT43-T1.2RQlip + signal peptides were streaked on the lipidic agar, LA+TBN. All four recombinants, including the negative control (B. subtilis WB800-pHT43), produced clear zones on the TBN agar plate after overnight incubation (fig 2), indicating the presence of a lipolytic enzyme in all of the recombinant B. subtilis cells. pHT43-T1.2RQlip + signal peptides (AmyQ, Epr, and LipA) have clear zones with significantly higher diameters than B. subtilis WB800-pHT43 (negative control). This phenomenon suggests that the recombinant thermostable lipase T1.2RQ introduced into these cells was successfully expressed, thereby increasing the lipolytic capability of its host cells T1.2RQ lipase was expressed in 50ml terrific broth medium (TB) and the expression induced with 1mM IPTG. Lipase activity assay using p-nitrophenyl esters showed that all three signal peptides directed the secretion of T1.2RQ lipase into the extracellular medium. Signal peptide, LipA, resulted in the highest extracellular activity of 5.6 U/mL, which corresponds to a 6-fold increase over the parent B. subtilis WB800 strain. Meanwhile, signal peptides, AmyQ and Epr produced 4.2 U/mL and 3.4 U/mL activity respectively. SDS-Zymogram analysis confirmed that T1.2RQ lipase was correctly processed and secreted in its original size of 44 kDa. An attempt to further increase lipase expression level by promoter optimization showed that, contrary to expectation, promoter Pgrac100 exhibited similar expression levels as the original Pgrac01. Nevertheless, the demonstration of the successful secretion of T1.2RQ lipase in this work confirms the latter as a promising approach for the industrial production of the enzyme
Keyword: Bacillus subtilis, Expression, Extracellular, Heterologous, Lipase, Thermostable