Judul: Efek Suplementasi Selenium dan Vitamin E Terhadap Status Antioksidan Unggas : Kajian Non Eksperimental
Abstrak: Selenium dan vitamin E merupakan antioksidan yang dapat meningkatkan sistem imun. Penelitian ini bertujuan mengetahui pengaruh dari level pemberian selenium dan vitamin E pada status antioksidan unggas dengan metode analisis regresi dari data penelitian sebelumnya. Data yang digunakan sebanyak 95 titik yang berasal dari 23 studi yang melaporkan suplementasi selenium terhadap status antioksidan unggas serta sebanyak 57 titik data dari 16 studi yang melaporkan suplementasi vitamin E terhadap status antioksidan. Peubah yang digunakan meliputi aktivitas glutation peroksidase (GSH-Px) dan kadar malondialdehid (MDA). Data dianalisis menggunakan analisis regresi linier dan kuadratik dengan perangkat lunak IBM SPSS versi 26. Hasil analisis menujukkan bahwa suplementasi selenium tidak berpengaruh signifikan (P>0,1) pada aktivitas GSHPx, namun cenderung signifikan (0,1�����P>0,05) terhadap penurunan kadar MDA. Suplementasi vitamin E juga tidak berpengaruh signifikan (P>0,1) pada aktivitas GSH-Px, namun cenderung signifikan (0,1�����P>0,05) terhadap penurunan kadar MDA. Dapat disimpulkan bahwa suplementasi selenium dan vitamin E berpengaruh dalam penurunan kadar MDA., Selenium and vitamin E are antioxidants which can improve immune system status on poultry. The aim of this study was to examine the effect of selenium and vitamin E levels on the antioxidant status of poultry using a linear and quadratic regression model on secondary data obtained from Scopus indexed and international reputable journals. The data used were 95 data points from 23 journals which reported different levels of selenium on poultry antioxidant status and 57 data points from 16 journals which reported various levels of vitamin E on poultry antioxidant status. The observed parameters were glutathione peroxidase (GSH-Px) activity and malondialdehyde (MDA) level. Data were analyzed by linear and quadratic regression analysis using IBM SPSS software version 26. The results showed that selenium supplementation had no significant effect (P>0.1) on GSHPx activity, but slightly decrease on MDA (0.1 ����� P>0.05). Vitamin E supplementation had no significant effect (P>0.1) on GSH-Px activity, but slightly significant on MDA (0.1�����P>0.05). It can be concluded that selenium and vitamin E supplementation decreasing MDA level on poultry.
Keyword: antioxidant status, poultry, regression analysis, selenium, vitamin E

Judul: Suplementasi Selenium Dan Vitamin E Terhadap Kandungan Mda, Gsh-Px Plasma Darah Dan Bobot Organ Limfoid Ayam Broiler Yang Diberi Cekaman Panas
Abstrak: High environmental temperatures may cause heat stress in poultry. High temperatures contributes to oxidative stress, a condition where oxidant activity (free radical) exceeds antioxidant activity. In this research, selenium and vitamin E were utilized as anti heat-stress agents for heat stress broilers. The research used 465 unsex broilers and they were divided into 2 conditions, comfort zone (25.22±0.05 oC) and high temperatures (29.80±0.76 oC). Variables measured were malondialdehyde (MDA), glutathione peroxidase (GSH-Px) in blood plasma and weight of lymphoid organ (bursa fabricius and tymus). The data collected were analyzed with a factorial completely randomized design of 3x3 (3 levels of vitamin E, 3 levels of selenium and 3 replication) and continued with Duncan test. The result showed that selenium and vitamin E supplementation was significantly decreased on MDA (p<0.05) and GSHPx (p<0.01) in blood plasma of heat stressed broilers, but it did not effect the weight of bursa fabricius and thymus of broilers. It could be concluded that the combination vitamin E (200 or 100 ppm) and selenium (0.3 ppm) is the most effective as anti heat-stress agent in broilers.
Keyword: 

Judul: Hamiltonian formulation for linear waves motion in two layers fluid
Abstrak: The surface wave could be considered as a wave that separates two fluids, namely water and air. Based on this assumption, it is introduced the interfacial wave, a wave between two layers of fluid with different density. The formulation of interfacial waves motion begins with deriving the base equation of irrotational ideal fluid. Furthermore, according to irrotational fluid assumption, the base equation can be stated in velocity potential. In this derivation, the fluids domain is assumed to be restricted by rigid lid boundary conditions, both at the upper and lower limit. Therefore, the interfacial waves motion can be explained in a hamiltonian formulation. In the hamiltonian formulation, total energy is defined as the sum of kinetic and potential energy. The hamiltonian system is obtained from reduction of kinetic energy by using the Dirichlet Neumann Operator. The resulted kinetic energy equation is nonlinear. Therefore, this form is linearized by first part of the Taylor expansion. This linearization gives a dispersion relation of linear wave. Based on this dispersion relation, the phase speed of the linear wave depends on the density ratio of the two layers fluid.
Keyword: