Judul: Evaluation of Dietary Coffee Coffea canephora Husk Utilization on the Growth and Antioxidative Activity of Red Tilapia Oreochromis sp.
Abstrak: Penelitian ini bertujuan untuk mengevaluasi pemanfaatan tepung kulit dengan dosis berbeda terhadap kinerja pertumbuhan, kimia darah dan antioksidan ikan nila merah (Oreochromis sp.). Ikan nila merah (bobot awal 10,59 ± 0,29 g) disebar di dalam 15 akuarium dengan padat tebar ikan sebanyak 15 ekor per akuarium dan diberi pakan perlakuan yaitu, P0 (kontrol), P1 (1% kulit kopi), P2 (2% kulit kopi), P3 (3% kulit kopi) dan P4 (4% kulit kopi) yang dipelihara selama delapan minggu. Hasil penelitian menunjukkan bahwa, suplementasi tepung kulit kopi meningkatkan bobot akhir, laju pertumbuhan harian, efisiensi pakan, retensi protein dan retensi lemak dibandingkan kontrol. Suplementasi tepung kulit kopi secara signifikan menurunkan total kolesterol dan trigliserida darah (P<0,05) diikuti juga terjadinya penurunan nilai LDL dan secara signifikan mampu meningkatkan HDL dibandingkan kontrol. Suplementasi tepung kulit kopi secara signifikan meningkatkan aktivitas superoxide dismutase (SOD) dibandingkan dengan kontrol (P<0,05). Selanjutnya, suplementasi tepung kulit kopi juga secara signifikan mampu menurunkan nilai malondialdehyde (MDA) dibandingkan kontrol (P<0,05). Semua perlakuan suplementasi tepung kulit kopi menghasilkan nilai hepatosomatic indeks yang lebih rendah dibandingkan kontrol. Selanjutnya, suplementasi tepung kulit kopi secara signifikan meningkatkan glikogen hati dibandingkan kontrol (P<0,05). Semua perlakuan suplementasi tepung kulit kopi menunjukkan hasil yang lebih baik dibandingkan kontrol. Penerapan dosis 4% kulit kopi dalam pakan memberikan hasil yang lebih baik dibandingkan perlakuan lainnya. Sehingga penelitian ini menyimpulkan bahwa, penggunaan tepung kulit kopi sebesar 4% dapat diaplikasikan pada pakan ikan nila untuk meningkatkan pertumbuhan dan aktivitas antioksidan. Kata kunci: antioksidan, kulit kopi, pakan, pertumbuhan, ikan nila, This study aimed to evaluate the utilization of different dietary coffee husk supplementation dosages on the growth, blood chemicals, and antioxidative activity of red Nile tilapia (Oreochromis sp.). Red Nile tilapia (initial weight 10.59 ± 0.29 g) were raised in 15 aquaria at a density of 15 fish per aquarium and treated in five different diets: P0 (control), P1 (1% coffee husk), P2 (2% coffee husk), P3 (3% coffee husk), and P4 (4% coffee husk) for eight weeks. The results determined that coffee husk powder inclusion improved final weight, daily growth rate, feed efficiency, protein retention, and lipid retention compared to the control. Dietary supplementation of coffee husk significantly decreased total cholesterol and triglycerides in serum (P<0.05) followed by a decrease in LDL and significantly increased HDL compared to the control. Dietary supplementation of coffee husk significantly increased superoxide dismutase (SOD) activity compared to the control (P<0.05). Furthermore, coffee husk supplementation was also significantly able to reduce the malondialdehyde (MDA) compared to the control (P<0.05). All coffee husk supplementation treatments produced a lower hepatosomatic index than the control. Furthermore, coffee husk supplementation significantly increased liver glycogen compared to the control (P<0.05). All dietary coffee husk supplementation treatments showed better results than the control. The application of a dose of 4% coffee husk in the diet provides better results than other treatments. Then, this study concluded that the dietary of 4% coffee husk supplementation could be applied in the red Nile tilapia diet to improve growth and antioxidative activity. Keywords: antioxidant, coffee husk, diet, growth, tilapia
Keyword: antioxidant, tilapia, coffee husk, growth

Judul: The influence of coconut testa oil as a source of lipids on the feed of Red Nile Tilapia (Oreochromis sp.)
Abstrak: Penelitian ini bertujuan untuk mengevaluasi pengaruh pemanfaatan minyak kulit ari kelapa sebagai sumber lemak dalam pakan terhadap kinerja pertumbuhan ikan nila merah. Metode yang digunakan adalah rancangan acak lengkap (RAL) dengan lima perlakuan dan empat ulangan. Ikan nila merah yang digunakan rata-rata berbobot 9,15 ± 0,01 g/ekor dipelihara di akuarium berukuran 90 x 40 x 45 cm³ sebanyak 20 unit dengan kepadatan 15 ekor/akuarium yang diberi pakan minyak kulit ari kelapa (MK) dengan dosis berbeda: MK0 (kontrol), MK1 (1% minyak kulit ari kelapa), MK2 (2% minyak kulit ari kelapa), MK3 (3% minyak kulit ari kelapa), MK4 (4% minyak kulit ari kelapa) selama 60 hari. Hasil penelitian menunjukkan kinerja pertumbuhan berbeda nyata (P<0,05) terhadap biomassa akhir, pertambahan bobot, laju pertumbuhan harian, jumlah konsumsi pakan, rasio konversi pakan, dan efisiensi pakan. Nilai hepatosomatic index (HSI) dan intraperitoneal fat (IPF) menunjukkan tidak ada perbedaan yang nyata antar perlakuan (P>0,05). Retensi protein dan retensi lemak pada perlakuan minyak kulit ari kelapa lebih tinggi dibandingkan kontrol (P<0,05). Kondisi kimia darah ikan menunjukkan kadar kolesterol dan LDL tidak berbeda nyata (P>0,05) antar perlakuan, sedangkan kondisi HDL dan trigliserida (TG) berbeda nyata (P<0,05) dengan perlakuan kontrol. Pemberian minyak kulit ari kelapa 1% merupakan dosis terbaik yang memberikan hasil kinerja pertumbuhan paling tinggi., This study aims to evaluate the effect of using coconut testa oil as a source of lipid in feed on the growth performance of red tilapia. The method used was a completely randomized design (CRD) with five treatments and four replications. The red tilapia fish used an average weight of 9.15 ± 0.01 g/fish and were reared in aquariums measuring 90 x 40 x 45 cm³, totaling 20 units with a density of 15 fish/aquarium. They were fed with coconut testa oil (MK) at different doses: MK0 (control), MK1 (1% coconut testa oil), MK2 (2% coconut testa oil), MK3 (3% coconut testa oil), MK4 (4% coconut testa oil) for 60 days period. The results showed that growth performance was significantly different (P<0.05) to final biomass, weight gain, daily growth rate, amount of feed consumption, feed conversion ratio, and feed efficiency. The hepatosomatic index (HSI) and intraperitoneal fat (IPF) values showed no significant differences between treatments (P>0.05). Protein retention and lipid retention in coconut testa oil treatment were higher than control (P<0.05). The chemical condition of the fish's blood showed that cholesterol and low-density lipoprotein (LDL) levels were not significantly different (P>0.05) between treatments, while high density lipoprotein (HDL) and triglyceride (TG) conditions were significantly different (P<0.05) from the control treatment. This means that dosage of 1% coconut testa oil is the best dose which provides the highest growth performance results.
Keyword: alternative ingredients, coconut testa oil, growth, lipid, red tilapia

Judul: Penentuan Nilai Eigen dan Vektor Eigen dari Matriks Tridiagonal 2-Toeplitz dengan Pendekatan Polinomial Chebyshev
Abstrak: The eigenvalues and eigenvectors of a matrix can be determined by finding its characteristic polynomials. The characteristic polynomials of a tridiagonal 2-Toeplitz matrix is shown to be closely connected to polynomials which satisfy the Chebyshev recurrence relationship. If the order of the matrix is odd, then the eigenvalues are found explicitly in terms of the Chebyshev zeros and the eigenvectors are found in terms of the polynomials satisfying the recurrence relationship. For even ordered matrices, the situation is more complicated. The problem in these cases is that although the Chebyshev recurrence formula is still applied, its initial values are not generating Chebyshev polynomials
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