No abstract

spp. in powdered infant formula has been etiologically linked to meningitis and necrotizing enterocolitis in certain groups of infants. This study aimed to determine whether Yrt2a strain experiencing desiccation stress could enter viable but nonculturable (VBNC) state as well as to examine the expression of genes associated with stress and virulence during the above states. Stress and VBNC conditions were determined based on viability and culturability assays. Expression of genes related to stress (S) and virulence ( and A) was evaluated by real-time PCR. The results showed that Yrt2a entered VBNC 24 days post exposure to 2 h of desiccation treatment. The expression of S, and A genes was up-regulated during stress conditions, suggesting that successfully managed stress to maintain its culturability while maintaining its virulence. The expression of the target genes decreased at VBNC state but remained higher than that of a normal state. These findings reinforce the assumption that undergoing VBNC state maintains its pathogenicity.

Pencemaran lingkungan dapat menurunkan kesejahteraan subyektif (subjective well-being). Studi ini bertujuan membuktikan berlakunya hipotesis Environmental Kuznets Curve (EKC) di negara-negara berpendapatan tinggi dan menengah Asia, juga untuk menganalisis perbedaan pengaruh GDP per kapita, konsumsi energi, dan populasi penduduk pada emisi CO2 di wilayah yang sama pada periode sebelum dan setelah MDGs. Data diperoleh dari World Bank dengan periode waktu 1987-2014, di mana analisisnya menggunakan metode kuantitatif dan expose facto, dan melalui persamaan regresi data panel guna mencapai tujuan penelitian. Hasil penelitian membuktikan bahwa sampai 2014 hipotesis EKC yang berbentuk U-terbalik belum terjadi di negara-negara high income yang diteliti, namun akan terjadi ketika GDP per kapita sudah mencapai USD 51.44 ribu. Sedangkan di negara-negara lower middle income, pola hubungan antara GDP per kapita dan emisi CO2 masih membentuk kurva U, atau dengan kata lain hipotesis EKC belum akan terjadi di negara-negara ini, karena di beberapa negara tersebut masih dalam tahap awal pembangunan. Hasil penelitian juga menunjukkan bahwa sebelum MDGs (tahun 2000), GDP per kapita, konsumsi energi dan jumlah penduduk di negara-negara high income berkontribusi atas naiknya emisi CO2, namun pasca MDGs ditetapkan, meningkatnya GDP per kapita mampu menurunkan emisi CO2. Sedangkan di negara-negara low middle income, di awal penelitian sebelum MDGs, data menunjukkan bahwa CO2 sudah tinggi pada saat GDP per kapita masih rendah, dan pasca MDGs, kenaikan GDP per kapita masih berkontribusi atas meningkatnya emisi CO2.

The mechanical properties of edible films upon variation of gelatin (G) and chitosan (C) concentration (G%/C%) were compared using constrained mixture and response surface methodology (RSM) and their antibacterial activities against P. aeruginosa, B. cereus, and L. monocytogenes by the addition of sodium nitrite and garlic essential oil (GEO) were analyzed. Both methods show that increasing chitosan concentration will gradually enhance edible film tensile strength but decrease their elongation at break. Optimization to find the gelatin–chitosan edible film with the maximum elasticity was performed by minimizing the Young’s modulus which yields a value of 0.41 MPa corresponding to a G60/C40 gelatin–chitosan concentration using constrained mixture and 0.31 MPa corresponding to a G76/C24 gelatin–chitosan concentration using the RSM method. Antibacterial analysis of the edible film showed that the addition of sodium nitrite and GEO in gelatin–chitosan edible film enhances their antibacterial activity significantly and increasing the GEO concentration also improve the antibacterial activity of the film. Practical applications The outcome of our work has practical applications in the field of biodegradable edible film, for example, for environmentally friendly meat coatings due to its optimum elasticity property. In addition, our gelatin–chitosan film with garlic essential oil also exhibits significant antibacterial properties which can compete with commercial film that uses nitrite addition and therefore prolong the shelf life of the food without the risk of carcinogenic effects. From the potential point of view, our work should stimulate more research toward the development and optimization of biodegradable edible films with noncarcinogenic antibacterial properties.

Penelitian ini bertjuan untuk menelaah bagaimana hubungan antara kemampuan berpikir kreatifmatematis dengan motivasi belajar siswa dalam pembelajaran yang menggunakan pendekatanCreative Problem Solving (CPS). Metode penelitian yang digunakan adalah metode kuasieksperimen, dengan cara mengambil dua kelas yang berbeda, kemudian kelas pertamamendapatkan pembelajaran dengan CPS dan kelas kedua menggunakan pembelajaran biasa.Populasinya adalah seluruh siswa SMP di Kota Cimahi, dengan sampel diambil dua kelas. Keduakelas diberi pretes agar mengetahui kemampuan awal mereka, selanjutnya kelas eksperimendiberi pembelajaran dengan CPS dan kelas kontrol diberi pembeljaran biasa, dan terakhir keduakelas diberikan postes dan angket motivasi belajar yang mana data tersebut akan diolah dandianalisis korelasinya menggunakan Product Moment Person. Hasil penelitian menunjukan adanyahubungan yang signifikan antara kemampuan berpikir kretif matematis dan motivasi belajar siswadalam pembelajaran matematika