Judul: Diversity of Mites in Litter of Chicken and Horse Farms
Abstrak: Tungau (Acari : Arachnida) mempunyai ukuran tubuh relatif kecil (kurang dari 1000 μm), bentuk tubuh bulat atau oval, berwarna putih kekuningan atau kecoklatan, dan memiliki 4 pasang tungkai. Tubuh tungau terbagi menjadi dua bagian yaitu gnathosoma dan idiosoma. Tungau dapat hidup bebas atau sebagai parasit. Penelitian ini bertujuan menganalisis keanekaragaman tungau yang ditemukan pada serasah kandang ayam broiler dan kandang kuda. Metode tulgren digunakan untuk koleksi tungau dengan mengekstrak serasah. Dari 97 individu tungau yang teridentifikasi 5 spesies tungau, yaitu Cheletophyes, Sancassania boharti, Sancassania rodionovi, Macrocheles, Saproglyphus dan satu spesies belum teridentifikasi (Subordo Oribatida). Tungau S. boharti dan S. rodionovi memiliki tingkat keanekaragaman tertinggi dan ditemukan semua lokasi pengambilan sampel.
Keyword: keanekaragaman tungau, serasah kandang, tulgren

Judul: Diversity and Prevalence of Chewing Lice (Phthiraptera: Mallophaga) in a Poultry Farm in Laladon, Bogor.
Abstrak: Poultry lice are notorious ectoparasites that pose significant challenges to the health and productivity of poultry, thereby affecting their economic value. This study aimed to investigate the diversity, prevalence, and degree of infestation of chewing lice in five different bird species: domestic chicken (Gallus gallus domesticus), turkey (Meleagris gallapavo), fantail pigeon (Columba livia domestica), swan geese (Anser cygnoides), and Muscovy duck (Cairina moschata). Specimens were collected from various body regions and identified using established identification keys. The results revealed the presence of Menacanthus and Menopon genera in chickens and turkeys, exclusive presence of Lipeurus in chickens, Anaticola in Muscovy ducks and swan geese, Colpocephalum in fantail pigeons and swan geese, Columbicola and Campanulotes exclusively in fantail pigeons, and Holomenopon exclusively in swan geese. The prevalence of lice infestation was determined, with all bird species exhibiting a 100% prevalence, except for Muscovy ducks, which showed a prevalence of 40%. The study highlighted the challenges in identifying poultry lice at the species level due to the unavailability of identification keys, leading to incomplete identification results. Moreover, farmers need to be aware of the detrimental effects of chronic lice infestations on poultry health and productivity, Kutu unggas merupakan ektoparasit yang menyebabkan gangguan terhadap kesehatan dan produktivitas unggas, sehingga mempengaruhi nilai ekonomi komoditi unggas. Penelitian ini bertujuan untuk mengetahui keragaman spesies, prevalensi, dan tingkat infestasi kutu pada lima spesies burung yang berbeda, yaitu ayam ras (Gallus gallus domesticus), kalkun (Meleagris gallapavo), merpati kipas (Columba livia domestica), angsa (Anser cygnoides), dan entog (Cairina moschata). Sampel kutu diambil dari berbagai bagian tubuh unggas dan diidentifikasi menggunakan kunci identifikasi morfologi. Hasil identifikasi menunjukkan keberadaan genus Menacanthus dan Menopon pada ayam dan kalkun, dan keberadaan eksklusif Lipeurus pada ayam. Kutu Anaticola pada entog dan angsa, Colpocephalum pada merpati kipas dan angsa, Columbicola dan Campanulotes secara eksklusif pada merpati kipas, serta Holomenopon secara eksklusif pada angsa. Infestasi kutu pada semua jenis unggas menunjukkan prevalensi 100%, kecuali pada entog dengan prevalensi 40%. Ketidaktersediaan kunci identifikasi kutu unggas sampai tingkat spesies, menjadikan hasil identifikasi tidak lengkap. Hasil penelitian menunkjukkan bahwa peternak harus berwaspada tentang dampak infestasi kutu yang kronis dan merugikan
Keyword: chewing lice, poultry, prevalence, species diversity

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.
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