Judul: Morfologi oesophagus dan lambung burung layang-layang asia (Hirundo rustica)
Abstrak: Tujuan penelitian ini adalah untuk memberikan informasi mengenai morfologi oesophagus dan lambung burung layang-layang asia (Hirundo rustica) sebagai data dasar dalam kaitannya dengan pola adaptasi terhadap jenis dan perilaku makan burung tersebut. Penelitian ini menggunakan sampel organ oesophagus dan lambung dari lima ekor burung layang-layang asia (Hirundo rustica) untuk diamati secara makroskopik dan mikroskopik. Pengamatan makroskopik meliputi bentuk, ukuran dan letak organ tersebut dalam saluran pencernaan. Sedangkan untuk pengamatan mikroskopik, dilakukan pembuatan preparat histologi dengan pewarnaan standar Hematoxylin Eosin dan Masson's trichome. Hasil penelitian menunjukkan bahwa burung layang-layang asia tidak memiliki tembolok pada oesophagusnya. Lambung terdiri dari proventrikulus (lambung kelenjar) dan ventrikulus (lambung otot gizzard). Letak proventrikulus tidak memiliki batas yang jelas, hanya berupa pelebaran di bagian kaudal oesophagus sebelum memasuki ventrikulus. Tidak adanya zona intermediet yang memisahkan proventrikulus dari oesophagus dan ventrikulus, serta jarak antara gastrooesophageal dan gastroduodenale yang berdekatan, memungkinkan proses transportasi, pencernaan dan absorbsi makanan yang cepat. Secara mikroskopik, oesophagus memiliki lapisan epitel permukaan yang tebal dan kelenjar tubularmukous yang berkembang subur di sepanjang mukosa. Di daerah peralihan dengan proventrikulus, epitel permukaan mukosa oesophagus dan proventrikulus mengalami keratinisasi. Di ventrikulus, keratinisasi epitel permukaan dan sekresi kelenjar mukosa yang berupa zat seperti keratin (keratinoid) tersebut menebal dan membentuk lapisan tersendiri yang melindungi mukosa lambung dari trauma mekanik dan kimiawi…
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Judul: Morfologi Esofagus dan Lambung Burung Serak Jawa (Tyto alba)
Abstrak: This study was aimed to describe the morphology of esophagus and stomach of barn owl (Tyto alba). Two barn owl (T. alba) were used to observed macroscopic and microscopically. The macroscopic observation was done by observing the shape and size of the esophagus and stomach. The microscopic observation was done using standard histological method with hematoksilin eosin (HE) staining. The results showed that the esophagus consist of pars cervicalis and pars thoracalis, was 9.8 centimeters in length, and possessed no crop. Mucosa of the esophagus pars cervicalis was lined with nonkeratinized stratified squamous epithelial cell, and the pars thoracalis lined by simple columnar epithelial cell. The esophageal gland was mucous type distributed in a lot number along the mucosa. The external muscle consists of two layers, which were the inner longitudinal muscle and outer circular muscle. The stomach could be distinguished into proventriculus and ventriculus (gizzard). Proventriculus was a cone shape and gizzard was cuboid with an average length of the greater curvature was 6.5 cm and was 1.88 cm in diameter. The mucosa of proventriculus was lined by simple columnar epithelium. The proventricular gland was consist of superficial and profundal glands. The superficial gland produced mucous, while the profundal produced pepsinogen and hydrochloric acid (HCl). The external muscle layer consist of three layers, two longitudinal muscles in the superficial and profundal layers and circular muscle in the middle between the two of longitudinal muscles. The mucosa of gizzard was lined with simple columnar epithelial cell, with the thin cuticle. The gizzard glands consist of simple tubular gland that produced mucous. The gizzard has two very thick muscle layers composed by inner longitudinal muscle and the outer circular muscle. The characteristic morphology of the esophagus and stomach of barn owl (T. alba), was presumed to supports their behavior, which swallow a whole body of their prey.
Keyword: Bogor Agricultural University (IPB), Tyto alba, proventriculus, esophagus, gizzard

Judul: Approximation of the Median of Poisson Distribution Using the Relation of Poisson-Gamma Distribution
Abstrak: A major drawback of median is that median cannot usually be defined in closed form, even in the cases where their distribution functions are known. This study gives an approximation of the closed form for the median of the Poisson distribution by using the relation of Poisson-Gamma distribution. The approximation uses elementary techniques based on the monotonicity of certain sequences involving tail probabilities of the Poisson distribution and the Central Limit Theorem. Furthermore, a closed form expression for the mean absolute deviation 􀜧|􀜰􀰒 􀵆 􀜯􀝁􀝀􁈺􀜰􀰒􁈻| is also studied. The median is relevant because of the fact that it minimizes the mean absolute deviation of a Poisson random variable (􀜰􀰒􁈻 by considering median as central tendency.
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