Judul: The effect of parenting style, self-control, and reference group on impulse buying of virtual item of game online
Abstrak: Pembelian impulsif merupakan perilaku pembelian yang tidak terencana dan menimbulkan permasalahan keuangan termasuk pembelian impulsif virtual item game online. Umumnya pembelian impulsif virtual item game online dilakukan oleh remaja. Penelitian ini menggunakan teknik non probability sampling yang melibatkan 148 remaja tingkat SMP dan SMA. Lokasi penelitian di Jawa Barat dan DKI Jakarta. Pengambilan data dilakukan secara voluntary sampling. Data kuesioner diisi secara online, selanjutnya diolah menggunakan analisis deskriptif, uji korelasi, dan uji regresi linear berganda. Sebagian besar remaja memiliki gaya pengasuhan otoriter dan otoritatif. Hasil penelitian menunjukkan bahwa lebih dari separuh responden memiliki kontrol diri yang sangat baik. Hasil uji korelasi menunjukkan bahwa usia ayah berhubungan negatif dengan gaya pengasuhan otoriter dan otoritatif. Usia Ibu berhubungan negatif dengan gaya pengasuhan otoriter. Pendapatan keluarga berhubungan negatif dengan kelompok referensi. Hasil uji regresi menunjukkan bahwa kontrol diri memiliki pengaruh negatif secara signifikan terhadap pembelian impulsif virtual item game online. Kelompok referensi berpengaruh positif terhadap pembelian impulsif virtual item game online
Keyword: impulsive buying, parenting style, reference group, self-control, teenager

Judul: The Influence of Social Media Exposure, Reference Group, Social Comparison, and Materialism on Impulsive Buying Behavior
Abstrak: Pembelian impulsif merupakan pembelian yang dilakukan secara spontan tanpa perencanaan sebelumnya dan tanpa mempertimbangkan konsekuensi yang didapat. Penelitian ini bertujuan menganalisis pengaruh paparan media sosial, kelompok acuan, perbandingan sosial, dan materialisme terhadap perilaku pembelian impulsif. Contoh dalam penelitian ini merupakan pengguna Instagram dan seorang pengambil keputusan pembelian barang dan jasa yang berusia 17-55 tahun. Desain penelitian yang digunakan adalah cross-sectional study dengan survei online pada 292 contoh. Hasil penelitian menemukan bahwa kelompok acuan berpengaruh signifikan positif terhadap perbandingan sosial. Perbandingan sosial berpengaruh signifikan positif terhadap materialisme. Hasil penelitian ini menunjukkan terdapat pengaruh yang signifikan positif dari paparan media sosial dan materialisme terhadap perilaku pembelian impulsif. Hal tersebut patut menjadi pertimbangan bagi pemerintah/nonpemerintah untuk menyelenggarakan edukasi melalui lembaga, seperti YLKI, BPSK, OJK atau BPKN sehingga konsumen terhindar dari perilaku belanja impulsif yang merugikan.
Keyword: kelompok acuan, materialisme, media sosial, pembelian impulsif, perbandingan sosial

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