Judul: The Studied Of Food Habit And Growth Of Barb (Barbonymus Balleroides Val. 1842) In Serayu River, Banjarnegara, Central Java
Abstrak: A study of food habit and growth was conducted in the Serayu River, where there is Mrica Reservoir. The damming activity has led to habitat fragmentation which affects the pattern of food habits and growth. The aims of this study were, to examine the composition of fish food, to learn about relationship between chemical composition and energy content of the food related to gonad maturity level, and to find out the effects of habitat fragmentation on the composition of food and the growth of fish. The research was conducted from October 2012 to January 2013. Fish sampling was carried out in three zones (downstream, middlestream, and upstream), which consisted of 6 stations. The sampling locations were determined based on the existence of the reservoir, river characteristics and fish habitat. Fish samplings were done using a 3-meter long nets and gill nets with 3 mesh size (¾, 1 ½ and 2 inches) measuring 20 meters in length and 2 meters in width, and electrofishing. There were 1 602 fishes captured and total length are ranged from 64 to 250 mm. Barb was categorized as omnivore fish (with a tendency of being herbivore) with a diet composition of phytoplankton, aquatic plants, detritus, insects, pieces of fish, gastropods and crustaceans. Small-sized fish (64-114 mm) ate phytoplankton and insects, while large fish (115-250 mm) had such food composition as fitoplanton, insects, gastropods, fish, and crustaceans. The food composition was different in each zone. To support the reproduction, the fish consumpt gastropod. The stomach contents of the male and the female are similar. To support their reproduction barb was usually increase the kind of their food from aquatic animal. The chemical composition of 3rd gonad maturity in the middle zone had the highest number of food calories (4.83 kcal /g). The number of calories based on gonad maturity ranged from 3.90 to 5.16 kcal/g. The food of Barb in 1st and 2nd gonad maturity (5.13 and 5.16) have higher energy than 3rd and 4th gonad maturity (3.90 and 4.55). The growth pattern of Barb was positive allometric (p <0.05). The average condition factor of female fish was larger than male. The middle zone had a higher condition factor than the other zones. The asymptotic length of fish (L∞) was 253 mm, the coefficient growth (k) was 1 per year, and the theoretical age when the fish length was equal to zero (t0) -0,087 so that the growth equation of von Bertalanffy of Barb was Lt=253(1-e -1(t+0.087)). The highest natural mortality rate of Barb was found in the downstream zone (0.73), and then by the middle zone (0.58) and the upstream zone (0.57). The highest exploitation rate of Barb was found in the downstream zone (0.93), and then the upper zone (0.70), and middle zone (0.57). The exploitation rate Val.ue of Barb in upstream area of Serayu river was exceeded the optimum exploitation rate value of 0.5.
Keyword: Barbonymus balleroides, food, growth, Serayu River

Judul: Morphological and molecular genetic characters of Barb (Barbonymus balleroides Val. 1842; Cyprinidae) in Serayu River Central Java.
Abstrak: The goverment builded the Mrica Reservoir in Banjarnegara at 1988. The reservoir affected of fish population and community in the ecosystem. The research aimed to evaluated the morphological and genetic characters of the Barb (Barbonymusballeroides) at several habitats in Serayu River. The research was conducted during February to September 2013. Sampling was carried out used applying purposive sampling method, continued by road sampling at six stations representing three zones, i.e., upper, middle, and lower zones. Fishing gear used were net, gill net and electrofishing. Morphological characters were completed based on morphometric, meristic, and asymmetric characters with the R (PCA and Discriminant). Definitive species identification and genetic difference between locationswere accomplished using mithochondrial DNA marker, cytochrome oxidase 1 (CO1) using Mega 4 programe. Physical and chemical characteristics of aquatic environment were observed based on position of the stations. Physical and chemical characteristics of aquatic environment indicated that the condition of sampling stations to support fish survival. Morphologically, Barb of the Serayu River was separated into two groups, group A inhabiting lower zone of the reservoir (station I and II) and group B inhabiting the middle zone (station III and IV), and the upper zone (station V and VI). Morphological clustering distance between Barb in station I and II were 2.5; while between group A and B were 8.53. Whereas, meristic analysis did not show any separation of fish population. Genetic analysis based on mtDNA CO1 of Barb in the sampling stations was successfully accomplished, resulting in 710 bp in fragment length. Phylogenetic analysis showed that six samples of the Barb formed one cluster and separated from outgroup (B. gonoinotus dan Puntius orphoides) with genetic distance of 6.34%. It implied that species identification of the Barb (B. balleroides) was true. Be found intraspecific variation on Barb of Serayu River genetic distance analysis using p-distance performed two clusters with the value of 2%. The first was Barb of station I and II, and the second was stations III, IV, V, and VI. Genetic distance between stations of III and IV was 0.15%; while between station V and VI was 0.3%. Genetic difference based on CO1 gene between station I and II was 2%.
Keyword: Fragmentation, mtDNA, habitat

Judul: Protokol Pertukaran Kunci Berbasis Kriptosistem Kunci Publik Diffie-Hellman
Abstrak: Karya ilmiah ini menjelaskan teori-teori yang digunakan dalam protokol pertukaran kunci berbasis kriptosistem kunci publik Diffie-Hellman, mekanisme protokol tersebut dan menganalisis keamanan dari kriptosistem kunci publik Diffie-Hellman. Algoritme Diffie-Hellman merupakan salah satu protokol komunikasi dengan sistem kriptografi kunci asimetri atau kunci publik. Algoritma ini digunakan untuk mempertukarkan kunci rahasia bersama (kunci rahasia yang digunakan untuk komunikasi dengan menggunakan sistem kriptografi simetri) antara dua orang atau lebih. Tingkat keamanan dari algoritme Diffie-Hellman didasarkan pada masalah logaritma diskret bagi grup pergandaan bilangan bulat modulo prima. Karena tidak adanya proses autentifikasi dalam algoritme Diffie- Hellman, mengakibatkan algoritme ini rentan terhadap ancaman dari penyerang aktif dalam proses pertukaran kunci.
Keyword: Diffie-Hellman, kunci publik, kunci rahasia bersama, masalah logaritma diskret, pertukaran kunci