Judul: Kandungan Prolin Dan Asam Askorbat Beberapa Spesies Hoya Dengan Tingkat Sukulensi Berbeda Pada Cekaman Kekeringan
Abstrak: Hoya merupakan tanaman epifit merambat yang memiliki tipe daun sukulen dan non sukulen. Hoya sukulen lebih memiliki sifat tahan terhadap kekeringan dibandingkan dengan Hoya non sukulen. Salah satu mekanisme pertahanan tanaman terhadap kekeringan adalah dengan mengakumulasi senyawa prolin dan asam askorbat. Penelitian ini bertujuan mengetahui pengaruh cekaman kekeringan terhadap kandungan prolin dan asam askorbat pada tanaman Hoya dengan tingkat sukulensi yang berbeda sebagai indikasi ketahanan terhadap kekeringan. Perlakuan cekaman dilakukan selama 28 hari terhadap empat spesies Hoya yaitu H. densifolia (non sukulen), H. bandaensis (semi sukulen), H. verticillata, dan H. latifolia (sukulen). Hasil menunjukkan bahwa cekaman kekeringan meningkatkan kadar prolin dan asam askorbat (ASA) pada spesies Hoya yang diuji. Hoya sukulen memiliki kadar prolin dan ASA yang lebih tinggi dibandingkan dengan Hoya non sukulen. Hoya verticillata (sukulen) memiliki peningkatan kandungan prolin dan ASA tertinggi saat tercekam kekeringan. Oleh karena itu H. verticillata merupakan spesies Hoya yang tahan kekeringan yang dicirikan dengan daun sukulen dan kadar prolin dan ASA yang tinggi.
Keyword: Hoya, asam askorbat, prolin, kekeringan, sukulen, non sukulen

Judul: Karakteristik Anatomi Daun beberapa Spesies Hoya spp. Bertipe Daun Sukulen serta Analisis Hubungan Kekerabatannya
Abstrak: Hoya (Hoya spp.) is an epiphyte or lithophyte vine or shrub. Hoya’s flower has beautiful unique shape and it is considered as original plant from Southeast Asia and surroundings. This plant has two type of leaf, succulent and non succulent. Succulent plant can adapt well in extreme condition, especially in dry period. Anatomy characters can be used to identify, classify, and determine plant relationship. The aims of this research were to identify anatomical character of succulent Hoya’s leaf and to determine their relationship. Ten exmined species Hoya spp. (H. diversifolia, H. latifolia, H. dolichosparte, H. bilobata, H. lacunosa, H. verticillata, H. purpureofusca, H. kuhlii, H. oblanceolata, and H. micrantha) showed anatomical similarity which was epidermal layer, hipodermal, mesophil, and the absence of sponge tissue at mesophil. However there were many diversities between specieses. Based on paradermal section of the leaf, stomata was only found on the abaxial side and have two type, individual stomata and both individual and stomatal cluster. Hoya diversifolia had the smallest stomatal size, while Hoya latifolia had the biggest. Hoya lacunosa had the lowest stomatal density, while Hoya bilobata had the highest. Hoya diversifolia, Hoya lacunosa, and Hoya oblanceolata had the lowest stomatal index, while Hoya bilobata had the highest. Observation on transversal section showed that Hoya purpureofusca had the lowest leaf thickness, while Hoya kuhlii had the highest. The hierarchical cluster analysis based on anatomical leaf character showed different patterns of relationship which diversed as three groups at relationship scale 15.
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Judul: Zero-inflated negative binomial models in small area estimation.
Abstrak: The problem of over-dispersion in Poisson data is usually solved by introducing prior distributions which lead to negative binomial models. Poisson data sometime is also suffered by excess zero problems, a condition when data contains too many zero or exceeds the distribution's expectation. Zero Inflated Negative Binomial (ZINB) method can be utilized to solve such problems. This paper demonstrates the adaption of ZINB methods in Small Area Estimation with excess zero data. It is shown that the excess zero problem has substantially influenced the Empirical Bayes (EB) estimates, and the adaption of ZINB methods has improved the precision and reliability of the estimates. Key Words: Small Area Estimation, Zero-Inflation, Poisson-Gamma, Negative Binomial Regression, Empirical Bayes
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