Judul: Habitat suitability and waterbirds distribution in Percut Sei Tuan, North Sumatra
Abstrak: Percut Sei Tuan is an important bird habitat in Sumatera. Not only important habitat for resident waterbirds, this area is a stop-over area for migratory waterbirds every year. This study aimed at analyzing the importance of Percut Sei Tuan as waterbird habitats, including its macrozoobenthic food source, and examining its habitat suitability for waterbirds. The study was conducted from September 2010 to March 2011. Concentration count and block method were used to assess the number and species of waterbirds in four sites, namely Bagan Percut, Tanjung Rejo, Pematang Lalang and Pantai Labu. Samples of macrozoobenthos (n = 10 plots) were taken using sweep nets and core samplers. A spatial analysis using ArcGis 9.3 was used to identify habitat suitability. Waterbirds and macrozoobenthic communities were calculated with Shannon, evenness and similarity indences. Similarity among communities were showed with a dendrogram. Stepwise regression was used to analyze physical and chemical factor. A total of 190,375 individuals of 50 waterbird species were recorded. Percut Sei Tuan have waterbirds diversity index of 2.20. Species diversity at four sites varied among 1.69 and 2.84. Wading birds were dominant in Tanjung Rejo while shorebirds were dominant at three sites. The highest diversity was found in Pematang Lalang while the lowest was found in Tanjung Rejo. Waterbirds were classified into four groups based on guild, i.e. wading birds, shorebirds, waterfowls and seabirds. Based on migratory habit, waterbirds were classified into three groups i.e. resident, migrant and unkown. The research revealed that there were 26 macrozoobenthos species in Percut Sei Tuan. Diversity index of macrozoobenthos was 2.68, diversity was varied among sites, the highest was at Bagan Percut 3 (2.26) and the lowest was at Bagan Percut 2 (0.71). Similarity index was 0.82. Sediment depth and texture were affected macrozoobenthic abundance and diversity. Bivalves were the highest abundance group of species in the community. This research found only five of 10 land cover used to feeding ground by waterbirds i.e. mud flat, rice field, fish pond, forest marsh and shrub. Waterbirds used mudflat at Bagan Pecut, Pematang Lalang and Pantai Labu for feeding ground. The analysis to physical and chemical factor (i.e. macrozoobenthic, height sediment, water depth, pH, BOD, and salinity) showed significant effect up to 60% for waterbirds presence. Feeding ground selected by waterbirds depend on food availability, habitat availability and degree of disturbance. Human distrubance had a high impact on the population and distribution of endangered Mycteria cinerea and Leptoptilos javanicus. Habitat suitability of wading birds and shorebirds was generally found in the same place, namely mudflat, rice fields and fishponds. However, the feeding ground of both bird guilds was different.
Keyword: Habitat Suitability, Percut Sei Tuan, Sumatera Utara, Macrozoobenthos

Judul: Diversity of Shorebirds in Wetland Habitat Types in Cimanuk Estuary Area, West Java.
Abstrak: Provinsi Jawa Barat merupakan salah satu kawasan yang terdaftar sebagai Daerah Penting bagi Burung (Important Bird Area/IBA) dengan nomor ID 086 (Rombang & Rudyanto 1999, Birdlife International 2011). Perubahan habitat dan perburuan oleh masyarakat sekitar kawasan telah menjadi ancaman akan kelestarian burung pantai. Tujuan penelitian ini yaitu (1) Mengidentifikasi spesies burung pantai pada di KMC, (2) membandingkan keanekaragaman burung pantai pada tipe di KMC (3) mengidetifikasi spesies makrozoobentos di KMC, (4) Menjelaskan hubungan antara burung pantai dengan makrozoobentos, (5) menjelaskan perburuan burung pantai di sekitar KMC. Penelitian dilaksanakan pada lima lokasi di sekitar kawasan Muara Cimanuk Kabupaten Indramayu, Jawa Barat, yaitu Pertambakan Rambatan Baru, Pertambakan Pangkalan, Pertambakan Cimanuk Lama, Persawahan Singakerta dan Pesisir Pantai Pabean. Pengambilan data dilakukan selama lima bulan pada 26 Oktober 2010-26 Maret 2011. Peralatan utama yang digunakan dalam penelitian ini adalah binokuler Nikon Action 10 x 50 6,5o dan monokuler 20-60 x 60, buku panduan lapang burung Sumatera, Jawa, Bali dan Kalimantan (MacKinnon et al. 1998), GPS Garmin 60i, Nikon Coolpix L100. Objek yang diamati dibatasi hanya pada spesies burung dari ordo Charadriiformes tidak termasuk Stercorariidae dan Laridae. Pengambilan data mengenai burung pantai menggunakan metode jalur (line transect) dengan panjang tiap jalurnya 1.000 m dan lebar 30 m. Pada setiap lokasi dilakukan pengamatan sejauh 8.000 m, kecuali Pabean 2.000 m. Uji-t digunakan untuk mengetahui perbedaan keanekaragaman jenis burung antara habitat r pada tingkat kepercayaan 95%
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Judul: Konstruksi aritmetika kurva eliptik F(2m) supersingular dan non-supersingular untuk skema kunci publik ElGamal
Abstrak: Algoritme ElGamal adalah salah satu algoritme kunci publik dengan aritmetik modular p yang mempunyai struktur grip siklik Z(p). Tingkat keanaman algoritme ini terletak pada pemecahan masalah logaritme diskret dari Z(p). Akan tetapi, tingkat keamanan tadi tahun ke tahun semakin menurun yang disebabkan kemampuan pemecahan algoritme diskret semakin meningkat. Untuk memenuhi tingkat keamanan yang memadai dibutuhkan p yang cukup besar yang menyebabkan proses enkripsi dan dekripsi menjadi lambat.
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