Judul: Leaf morphology and Anatomy Characters of Some Sansevieria Species
Abstrak: Penelitian ini bertujuan untuk mengkaji karakter morfologi dan anatomi daun pada lima spesies tumbuhan Sansevieria. Berdasarkan pengamatan karakter morfologi, dijumpai variasi morfologi daun meliputi ukuran panjang, lebar dan tebal daun serta pola warna pada daun ke lima spesies Sansevieria. S. sufruticosa memiliki daun berbentuk silindris berwarna hijau, dengan ujung daun berduri merah kecoklatan. S. masoniana congo memiliki daun berbentuk jorong, warna hijau tua, dengan tepi daun berwarna merah. S. samurai dwarf memiliki daun berwarna hijau dengan permukaan cekung membentuk saluran. S. trifasciata gold flame memiliki daun berbentuk lanset, tebal berwarna hijau tua bergaris hijau muda dengan tepi daun berwarna kuning, sedangkan S. kirkii brown memiliki daun berbentuk lanset, berwarna coklat dengan bercak putih, permukaannya bergelombang. Pada ke lima spesies Sansevieria daun dilapisi selapis epidermis berbentuk poligonal dengan 4 hingga 6 sisi yang berdinding tipis, kecuali spesies S. samurai dwarf sel epidermis berdinding tebal merata. Stomata dijumpai pada kedua permukaan daun, terdapat lebih banyak pada permukaan bawah daun (abaksial). S. masoniana congo memiliki stomata berukuran (panjang x lebar) terbesar, sedangkan S. kirkii brown memiliki stomata terkecil. S. masoniana congo memiliki kerapatan stomata terkecil dengan indeks stomata terbesar, sebaliknya S. sufruticosa memiliki kerapatan stomata terbesar dengan indeks stomata terkecil. Diantara kelima spesies yang diteliti, daun S. masoniana congo memiliki kutikula yang paling tebal sebaliknya S. trifasciata gold flame memiliki kutikula paling tipis., This research aims to describe leaf morphology and anatomy characters of five Sansevieria species. Based on the morphology characters, there are some variation in the length, width, thickness and leaf color pattern. S. sufruticosa has green cylindrical leaf, with auburn thorny leaf tip. S. masoniana congo has elliptical leaf, dark green with red stripe on the leaf margins. S. samurai dwarf has green leaf blade with concave surface forms thick wide channel. S. trifasciata gold flame has thick lanceolate leaf, light green striped dark green with yellow stripe in the leaf margin, while S. kirkii brown has white spotted brown lanceolate leaf with wavy surface. Sansevieria was leaf covered with a layer of epidermis. Epidermal cells are polygonal in shape with four to six thin wall sides, except S. samurai dwarf with thick cell wall. Stomata were found on both leaf sides, more stomata present on the lower epidermis than the upper epidermis. S. masoniana congo has the biggest (length x width) stomata, while S. kirkii brown has the smallest stomata. S. masoniana congo has the lowest stomatal density with the highest stomatal index, whereas S. sufruticosa has the highest stomatal density with the lowest stomatal index. Among all species, S. masoniana congo leaf has the thickest cuticula while S. trifasciata gold flame has the thinnest. Key words: Leaf anatomy, leaf morphology, Sansevieria, stomata
Keyword: Anatomi daun, morfologi daun, Sansevieria, stomata

Judul: Karakteristik Morfologi, Anatomi, Dan Kandungan Klorofil Lima Kultivar Tanaman Penyerap Polusi Udara Sansevieria trifasciata
Abstrak: Sansevieria trifasciata is a uniquely houseplant that can provide clean air to occupied room because it can absorb harmful substances from the air. This research aim to compare chlorophyll content, morphological-, and anatomicalcharacters of five cultivars of this plant. Morphological characters of all S. trifasciata observed varied in pattern, colour, and size of the leaf. Stomata of all cultivars can be found on both leaf surfaces, abaksial (lower surface) have higher stomatal density. Distribution of single stomata was presented in all cultivars, while clustered stomata were also found in cv. Moonsine. Among all cultivars, stomatal density and stomatal index were found the highest in cv. Moonsine. The highest chlorophyll content, the largest size of leaf and the thinnest leaf were found in the cv. African Dawn. Potentially, S. trifasciata cv. African Dawn and S. trifasciata cv. Moonsine could absorb air pollution better than other cultivars.
Keyword: Bogor Agricultural University (IPB), air pollution, chlorophyll content, anatomy, morphology, Sansevieria trifasciata

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.
Keyword: