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: Use of Coffee Coffea canephora husk waste in feed on the growth performance of goldfish Cyprinus carpio
Abstrak: Permasalahan pada budidaya ikan mas (Cyprinus carpio) adalah rendahnya efisiensi pakan, maka dari itu diperlukan suatu bahan untuk meningkatkan efisiensi pakan pada ikan mas. Penelitian ini bertujuan mengevaluasi pengaruh penggunaan limbah kulit kopi robusta (Coffea canephora) dengan dosis berbeda pada pakan terhadap kinerja pertumbuhan ikan mas. Ikan mas yang diuji pada penelitian ini memiliki bobot 7,14±0,2 g. Ikan dipelihara selama 60 hari pada akuarium berukuran 40×40×50 cm. Penelitian ini menerapkan rancangan acak lengkap dengan lima perlakuan pakan yang diberi limbah kulit kopi sebanyak 0%, 1%, 2%, 3%, dan 4% serta masing-masing perlakuan terdiri dari tiga kali ulangan. Hasil penelitian menunjukkan kinerja pertumbuhan terbaik pada perlakuan pemberian 1% kulit kopi dengan efisiensi pakan 49,53±0,03 %, dan laju pertumbuhan harian sebesar 1,36±0,00 g (p<0,05). Penambahan 1% dosis kulit kopi dapat meningkatkan laju pertumbuhan pada ikan mas., The problem in carp farming (Cyprinus carpio) is the low feed efficiency. Therefore, an ingredient is needed to increase feed efficiency in goldfish. This study aims to evaluate the effect of using robusta coffee skin waste (Coffea canephora) with different doses in feed on the growth performance of goldfish. The goldfish tested in this study weighed 7.14±0.2 g. The fish were reared for 60 days in an aquarium. The fish were reared for 60 days in an aquarium measuring 40×40×50 cm. This study applied a completely randomised design with five feed treatments containing 0%, 1%, 2%, 3%, and 4% coffee skin waste and each treatment consisted of three replicates. The results showed the best growth performance in the treatment of 1% coffee peel with, feed efficiency of 49.53±0.03%, and daily growth rate of 1.36±0.00 g (P < 0.05). The addition of 1% dose of coffee skin can increase the growth rate of goldfish.
Keyword: ikan mas, kinerja pertumbuhan, kulit kopi

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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