Judul: Harvesting models in fishery management
Abstrak: Harvesting is one of the common activities in using natural resources, such as harvesting of marine resources. In fishery management, there are several harvesting strategies which can be applied, i.e. constant, proportional, proportional with threshold, and seasonal harvesting. Fishing effort is defined as a control variable in the harvesting strategies. It is important to be able to find an optimal fishing effort that gives maximum sustainable yield, so that extinction of fish population does not happen. In this paper the effect of control variable toward the dynamics of fish population has been discussed by proposing suitable mathematical models. Furthermore, the optimal fishing effort has been determined. Computer simulations are performed to investigate the dynamics of fish population and optimal harvesting with the given value of parameters.
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Judul: Capture fisheries management model in alas strait West Nusa Tenggara
Abstrak: Capture fisheries in Alas Strait of Nusa Teggara Barat contributes an important role not only for fishers, but also for local communities. Previous research showed that fish resources in this area need an appropriate management immediately. However, the scientific information as management option of the commodities in this area is very poor. This research intended to: identify the selected priority of fish resources, asses stock, define exploitation status of the selected priority of fish resources, define appropriate fishing gears, optimize the number of fishing gears to exploit the selected priority, formulate management model for capture fisheries in Alas Strait. Scoring method was applied for selecting the fish resources and the appropriate fishing gears, while surplus production model (Schaefer model) was used to asses the fish stock size. Linear goal programming was applied to allocate the number of fishing gears used in the stock fishing. There were five species of fishes identified as selected priorities: squid, sardine, red snapper, anchovy, and herring. Of the five selected fishes, the highest maximum sustainable yield (MSY) was anchovy (7,915.76 tons/year) followed by red snapper (2, 00.01 tons/year), sardine (1,282.21 tons/year), herring (867.49 tons/year), and squid (638.40 tons/year) respectively. The exploitation status of these selected commodities was classified into three categories. They were over exploited (squid), fully exploited (sardine and herring) and lightly exploited (anchovy and red snapper).This research also identified four appropriate fishing gears to exploit fish resources in Alas Strait. They were purse seine, boat lifting net, gill net, and hook and line. Refers to total allowable catch (TAC) of each fish species, fishing gears yearly productivity, requirement of gasoline, lubricant, spirituous liquid, ice blocks, number of fishers, and benefit gotten by each fishing gears, the optimum number of fishing gears allocated to exploit the selected priority fishes in Alas Strait is purse seine 43 units, lift net 30 units, gill net 395 units, and hand line 1628 units. The whole process constructed model is applicable not only in Alas Strait, but also in other areas similar to Alas Strait condition.
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Judul: Enteric Collibacillosis Pada Anak Babi Baru Lahir: Patogenesa dan Perubahan-Perubahan Patologisnya
Abstrak: Diare disebabkan oleh infeksi bakteri Escherichia coli pada anak-anak babi baru lahir yang peka terhadap en terotoksin produk bakteri tersebut. Dikenal sebagai colibacillosis. Patogenesa dari colibacillosis anak babi baru lahir adalah (1) infeksi oleh E. coli patogen, (2) proliferasi E. coli di lumen usus halus, (3) produksi dan pelepasan enterotoksin, dan (4) aktifitas toksin pada usus halus. Dalam proses proliferasi, adanya antigen pili K88 sangat penting karena memungkinkan bakteri perlekatan dengan epitel mucosa usus halus. mengadakan Setelah ko lonisasi dan proliferasi segera toksin dilepaskan. Akti- fitas toksin menginduksi sekresi yang berlebihan dari u- sus sehingga banyak cairan yang dikeluarkan ke lumen usus. Hal ini mengakibatkan banyak cairan dan elektrolit hilang sehingga timbul diare, dehidrasi dan asidosis yang sering menyebabkan kematian. Perubahan-perubahan patologis yang umum adalah dis tensi usus halus, dilatasi lambung dan infark pada kurva- tura mayor. Perubahan-perubahan histologis yang terjadi adalah enteritis hemorrhagica acuta, oedem dan kongesti pembuluh darah di lamina propria, akumulassi leukosit inti polimorf, sel monosit, dan inti sel mengalami piknosis Thrombus pada vena dan degenerasi serta desquamasi sel epitel usus….
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