Judul: Perbandingan transformasi laplace, heun, dan runge-kutta-fehlberg dalam menyelesaikan model matematik
Abstrak: Model Romeo-Juliet dan model Lotka-Volterra merupakan contoh model dari sistem persamaan diferensial linear dan taklinear. Menggunakan metode Heun dan metode Runge-Kutta-Fehlberg dapat dicari grafik penyelesaian dari model tersebut. Pada kedua model ini diterapkan juga metode transformasi Laplace sebagai metode pembanding. Berdasarkan hasil yang diperoleh, metode Runge-Kutta-Fehlberg lebih baik dibandingkan metode Heun, berdasarkan nilai error yang diperoleh. Hal ini sesuai dengan fakta bahwa orde yang dimiliki oleh metode Runge-Kutta-Fehlberg lebih tinggi dibandingkan dengan orde dari metode Heun. Hal itu mengakibatkan solusi yang dihasilkan metode Runge-Kutta-Fehlberg lebih teliti dibandingkan dengan metode Heun.
Keyword: Heun, Runge-Kutta-Fehlberg, Laplace transform

Judul: Metode Transformasi Diferensial untuk Sistem Persamaan Diferensial Linear
Abstrak: Salah satu metode pendekatan analitik yang cukup sederhana dan efektif untuk menyelesaikan sistem persamaan diferensial linear adalah metode transformasi diferensial. Metode transformasi diferensial merupakan metode iteratif untuk memperoleh penyelesaian analitik berupa polinom dengan ide dasar deret Taylor. Hasil penelitian menunjukkan pendekatan penyelesaian analitik menggunakan metode transformasi diferensial cukup akurat untuk sistem persamaan diferensial yang mengandung bentuk trigonometri dan eksponensial dengan jangka waktu pengamatan yang relatif pendek. Selanjutnya, tingkat keakuratannya semakin baik jika derajat polinom pada penyelesaian analitik tersebut semakin besar. Hasil tersebut diperoleh dari perbandingan penyelesaian analitik metode transformasi diferensial dengan penyelesaian analitik metode transformasi Laplace
Keyword: differential transform method, Laplace transform method, system of linear differential equations

Judul: Identifikasi dan Studi Patomorfologi Avian Coronavirus pada Ayam dan Beberapa Spesies Psittacine.\
Abstrak: Birds has an important role in daily lives of Indonesia. Poultry in Indonesia is important as the main source of protein and companion birds are bred to fulfill market demand for pets. Infectious bronchitis virus (IBV) is one of avian coronaviruses that can cause economic loss in poultry and found in various birds. The finding of IBV in birds other than poultry suggests a link between poultry and other birds, but there is limited information on IBV in other birds in Indonesia to assess the risk. Indonesia has several endemic Psittacine species often bred to be kept as pet to help in conservation effort. Research of viral diseases which affect productivity such as IBV in these species is very limited, despite its importance for conservation and disease prevention. Meanwhile in poultry, IBV prevention in Indonesia still faces trouble such as difficulty for IBV detection, ineffective vaccination, and lack of information of pathological lesion in field cases. Sufficient information from both sectors is required to assess the link between poultry and companion birds. Thus, this research aimed to find better detection method of IBV cases and its pathomorphological lesion in chicken as well as identifying avian coronavirus in several Psittacine species commonly bred for companion birds. For poultry research, a total of 11 flock samples of suspected IBV infections were collected from cases submitted to Pathology Division, Faculty of Veterinary Medicine, IPB University, and from farms around Bogor, Sukabumi, and Padang. Organ samples were analyzed by RT PCR using two primer sets: IBVN+/IBVN- targeting partial gene N and XCE+/XCE- targeting partial gene S of IBV. RT PCR result showed one sample is positive for gene S, 5 samples are positives for gene N. All positive samples of N gene were proven positive by immunohistochemistry, showing that RT PCR targeting N gene had better sensitivity than S1 gene. Due to mutations often occurring within S1 gene, detection by RT PCR targeting S1 gene can be challenging despite pathological lesion showing IBV infection. The mutation may caused primers unable to capture new field strains, causing false negatives and requires researchers to design new primers. However, S1 gene is still important because it plays a role in immunoprotectivity, which is important for vaccination, and thus still need to be identified after N gene positive result is found. Immunohistochemistry by Ostrich IgY anti-IB Antibody showed the virus could be found on the trachea, kidney, and oviduct of positive samples which may differ in the degree of severity and or microscopic lesion depending on the phase of infection and the strain of infecting virus. For psittacine research, cloacal swabs were taken from 41 healthy Psitaccine birds from two breeding facilities consisted of 15 sulfur-crested cockatoos (Cacatua sulphurea), 10 palm cockatoos (Probosciger aterrimus), 10 Eclectus parrot (Eclectus roratus), two blue and yellow macaws (Ara ararauna), two green winged macaws (Ara chloropterus), and two scarlet macaws (Ara macao). One batch of swab samples were inoculated to Specific Pathogen Free (SPF) embryonated egg for allantoic fluid and embryo. Swab samples and allantoic fluid samples were tested by RT PCR for avian
Keyword: Avian Coronavirus, Immunohistochemistry, Psittacine, Infectious Bronchitis, RT PCR