Judul: Behavior and Food of Reintroduced Bornean Orangutan (Pongo pygmaeus wurmbii) at Feeding Site and Forest Area in Lamandau Wildlife Sanctuary
Abstrak: Orangutan Kalimantan (Pongo pygameus wurmbii) adalah primata besar Asia berstatus ‘Dalam Bahaya Kritis’. Reintroduksi dilakukan untuk menekan penurunan populasi mereka di alam. Penelitian yang dilaksanakan pada bulan Februari-April 2021 di Suaka Margasatwa Lamandau bertujuan mengidentifikasi perbedaan perilaku di feeding site dan hutan alam, komposisi dan preferensi pakan tambahan dan alami orangutan kalimantan reintroduksi. Sebanyak empat kategori dari enam individu berbeda telah teramati selama 219 jam. Kedatangan orangutan ke feeding site secara nyata (P = 1 > α = 0,05) tidak dipengaruhi oleh pemberian pakan tambahan, sehingga aktivitas harian di hutan alamlebih besar. Aktvitas harian tertinggi yang dilakukan berturut-turut adalah makan, istirahat, dan berpindah. Komposisi pakan tambahan yang diberikan dalam bentuk buah berupa pisang (Musa spp.) dan pepaya (Carica papaya). Komposisi pakan alami tertinggi orangutan dari jenis-jenis tumbuhan adalah buah (51%), daun muda 25%, dan bagian tumbuhan lainnya (15%). Jenis pakan yang termasuk kategori sangat disukai adalah papung (Sandoricum emarginatum) sebesar 0,73, dan kumpang darah (Knema conferta) sebesar 0,66. Kategori lainnya yaitu sembilan jenis tumbuhan ‘Disukai’, tujuh jenis tumbuhan ‘Kurang Disukai’, 16 jenis tumbuhan ‘Tidak Disukai’, dan delapan jenis tumbuhan ‘Tidak Dikategorikan’., The Bornean orangutan (Pongo pygameus wurmbii) is a 'Critically Endangered' large Asian primate. Reintroduction had been implementing to suppress their population decline in the wild. The research was conducted in February-April 2021 at Lamandau Nature Sanctuary, aimed to identify differences in behaviour at the feeding site and natural forest, composition and preferences for additional and nature feed for Bornean orangutan reintroduced. A total of six different individuals with four categories had observed for 219 hours. The arrival of orangutans to the feeding site significantly (P = 1 > = 0,05) was not affected by additional feeding, so daily activities in natural forestswere longer. The highest daily activities performed consecutively were eating, resting, and moving. The composition of the supplementary feed had given in the form of fruit in the form of banana (Musa spp.) and papaya (Carica papaya). The highest composition of natural food for orangutans from plant species is fruit (51%), young leaves 25%, and other plant parts (15%). Types of feed which included in the category of 'Highly Favoured' were papung (Sandoricum ermarginatum) of 0,73 and kumpang darah (Knema conferta) of 0,66. Other categories are nine plant species 'Preferred', seven plant species 'Less Like', 16 plant species 'Disliked', and eight plant species 'Not Categorized'.
Keyword: Bornean orangutan, daily activities, feed preferences, feeding site, Lamandau nature sanctuary, reintroduction

Judul: Daily Activities and Food Selection Bornean Orangutan (Pongo pygmaeus) at Taru Jurug Animal Park, Surakarta City
Abstrak: Orangutan Kalimantan atau Bornean Orangutan (Pongo pygmaeus) merupakan satwa endemik yang hanya dapat dijumpai di Pulau Kalimantan dan tergolong ke dalam ordo Primata serta famili Hominidae. Pada umumnya, aktivitas harian yang biasa dilakukan orangutan diantaranya ialah makan, bergerak, istirahat, dan sosial. Orangutan sebagai satwa yang termasuk frugivor cenderung memiliki preferensi pakan pada buah. Penelitian ini bertujuan menganalisis aktivitas harian, preferensi pakan, serta palatabilitas pakan yang dikonsumsi orangutan kalimantan di Taman Satwa Taru Jurug, Kota Surakarta. Subjek yang diamati ialah dua individu orangutan berjenis kelamin betina dan jantan. Metode yang digunakan ialah focal animal sampling, penyajian pakan berupa cafetaria, penimbangan bobot konsumsi pakan. Hasil pengamatan menunjukkan bahwa lokomosi dan istirahat menjadi aktivitas yang dominan dilakukan oleh individu tori (♀) dan didi (♂). Apel, pear, pisang dan tempe rebus menjadi preferensi pakan dari kedua individu tersebut dengan bobot konsumsi pakan yang tidak berbeda signifikan berdasarkan perhitungan uji t terhadap jenis kelamin dengan jumlah bobot konsumsi pakan., Bornean Orangutan (Pongo pygmaeus) is an endemic animal that can only be found on the island of Borneo and belongs to the order Primate and family Hominidae. Orangutans' daily activities generally include eating, moving, resting, and social activity. Orangutans, as frugivores, tend to have a preference for food on fruit. This study aims to analyze the daily activities, feed preferences, and palatability of the feed consumed by the Bornean orangutan at Taru Jurug Animal Park, Surakarta City. The subjects observed were two male and female orangutans. The method used was focal animal sampling, serving food in the form of a cafeteria, and weighing feed consumption. The results showed that locomotion and resting were the dominant activities carried out by tori (♀) and didi (♂). Apples, pears, bananas, and boiled tempeh became the feed preferences of the two individuals with feed consumption weights that were not significantly different based on the calculation of the t-test for sex with the total weight of feed consumption.
Keyword: endemic, focal animal sampling, palatability, preference, Taru Jurug Animal Park

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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