Judul: Phosphorus Dynamic Model of Situ Patenggang, Bandung Regency, Jawa Barat
Abstrak: Fosfor merupakan elemen yang biasa digunakan untuk menggambarkan kesuburan perairan. Namun, upaya mengkaji dinamika fosfor perairan tawar Indonesia menggunakan model relatif masih belum banyak dilakukan. Penelitian ini bertujuan membangun model dinamika fosfor di badan air Situ Patenggang. Contoh air dan sedimen diambil pada bulan Juni, Juli, dan Agustus 2022 di empat stasiun pengambilan. Berdasarkan potensi pengadukan, Situ Patenggang merupakan danau polymictic yang sering mengalami pengadukan massa air hingga ke dasar perairan. Rasio parameter besi dengan fosfat total, serta besi dengan sulfat menunjukkan bahwa desorpsi dan absorpsi fosfor kurang dipengaruhi oleh elemen besi dalam air. Hasil regresi linear menunjukkan bahwa oksigen terlarut dan alkalinitas di hipolimnion merupakan parameter kunci primer, serta oksigen terlarut epilimnion, curah hujan, dan kecepatan angin merupakan parameter kunci sekunder. Parameter kunci primer dan sekunder tersebut menjadi acuan dalam pembangunan model. Model dijalankan untuk mengekstrapolasi dinamika oksigen terlarut, alkalinitas, dan fosfat total untuk satu tahun berikutnya berdasarkan curah hujan dan kecepatan angin rata-rata yang telah dijadikan normal iklim. Hasil pemodelan menunjukkan bahwa dinamika fosfor secara tidak langsung ditentukan oleh fluktuasi curah hujan dan kecepatan angin., Phosphorus has been widely used to describe a water body’s trophic level. However, there are still few efforts to study the phosphorus dynamic of freshwater ecosystems in Indonesia by modeling. This study aims to build Situ Patenggang’s phosphorus dynamic model. Water and sediment samples were taken in June, July, and August 2022 with four sampling sites. Based on mixing potential, Situ Patenggang is a polymictic lake that frequently experiences entire water mixing from bottom to surface. Iron-total phosphate ratio and iron-sulfate ratio show that the phosphorus dynamic is not dependent on iron availability. Linear regression shows that primary key parameters consist of dissolved oxygen and alkalinity in the hypolimnion, on the other hand, secondary key parameters consist of dissolved oxygen in the epilimnion, rainfall, and wind speed. Model creation is based on primary and secondary key parameters. The model was run to approximate dissolved oxygen, alkalinity, and phosphorus data for the coming year based on rainfall and average wind speed that has been converted into climate normal. The simulation results show that the phosphorus dynamic is indirectly related to rainfall and wind speed fluctuations.
Keyword: meteorology, modeling, phosphorus dynamic, Situ Patenggang

Judul: Keterkaitan Keberadaan Fosfor dalam Sedimen dan Air di Waduk Jatigede, Sumedang, Jawa Barat
Abstrak: Keberadaan fosfor berupa materi yang mengendap pada sedimen dan materi terlarut pada kolom air. Namun faktor yang mempengaruhi keberadaan fosfor sedimen dan air pada dasar perairan belum dapat dipahami dengan baik penyebabnya. Penelitian ini bertujuan menganalisis faktor yang mempengaruhi sebaran fosfor dalam sedimen dan air di Waduk Jatigede. Pengambilan contoh dilakukan pada bulan Febuari, Maret, dan April 2021 di enam stasiun pengamatan. Analisis data terdiri dari uji signifikansi kesamaan antarwaktu, penentuan musim, pengelompokan stasiun, sebaran fosfor sedimen dan air, keterkaitan fosfor sedimen dan air dengan parameter fisika-kimia sedimen dan kualitas air, serta pendugaan pertukaran fosfor antar sedimen dan air. Berdasarkan curah hujan BMKG kondisi musim Waduk Jatigede yaitu musim hujan. Waduk Jatigede terdiri dari Zona Riverin, Zona Transisi, dan Zona Lakustrin. Konsentrasi fosfor sedimen dan air lapisan hipolimnion tertinggi pada Zona Lakustrin. Sebaran fosfor sedimen dan air menunjukan adanya keterkaitan. Faktor yang mempengaruhi keterkaitan tersebut adalah parameter fisika-kimia sedimen (debu, liat, P-tersedia, pH sedimen, dan DO) dan kualitas air (suhu, kekeruhan, TSS, ortofosfat, DO, pH, dan alkalinitas)., The presence of phosphorus in the form of material that settles in the sediment and dissolved material in the water column. However, the factors that affect the presence of phosphorus in sediments and water at the bottom of the water are not well understood. This study aims to analyze the factors that influence the distribution of phosphorus in sediment and water in the Jatigede Reservoir. Sampling was carried out in February, March, and April 2021 on six observation stations. Data analysis consists of testing the the similarity between times, determining the season, grouping stations, distribution of phosphorus in sediment and water, the relationships between phosphorus in sediment and water with the physico-chemical parameters of sediment and water quality, as well as estimation of the exchange of phosphorus between sediment and water. Based on rainfall intensity, the study period in the Jatigede Reservoir occured in the rainy season. Jatigede Reservoir consists of Riverine Zone, Transition Zone, and Lacustrine Zone. Results showed the highest concentration of phosphorus in sediment and water in the hypolimnion layer was in the Lacustrine Zone. There were strong relationships between phosphorus in sediment and water. The most influencing factors of these relationships were physico-chemical parameters of sediment (i.e. dust, clay, available P, sediment pH, and DO) and water quality (i.e. temperature, turbidity, TSS, orthophosphate, DO, pH, and alkalinity).
Keyword: Fosfor, Sedimen, Hipolimnion

Judul: Onset, Durasi, dan Gejala Klinis Anestesi pada Kelinci New Zealand White (Oryctolagus cuniculus) dengan Kombinasi Ketamin-Xylazin Intramuskular
Abstrak: The aim of this research was to expound the onset, duration, and clinical signs observed on anaesthesia phase using ketamine-xylazine combination in New Zealand White rabbits. Fifteen New Zealand White rabbits (Oryctolagus cuniculus) were randomly subjected into three groups of five animals each. Those in group A were anaesthetized using a combination of 35 mg/kg ketamine and 5 mg/kg xylazine given i/m. Group B animals were anaesthetized using a combination of 40 mg/kg ketamine and 5 mg/kg xylazine while group C were anaesthetized using a combination of 45 mg/kg ketamine and 5 mg/kg xylazine, both given i/m. The result of this study indicated that the onset of anaesthesia marked by loss of pain response differ not significantly among the three groups (P < 0.05). Duration of anaesthesia and recovery significantly differ (P < 0.05) as the dose of ketamine increased. The onset of anaesthesia clinical signs within induction phase showed significant differences on sternal recumbency, lateral recumbency, and constricted pupil. Meanwhile the onset of anaesthesia clinical signs showed no significant differences (P<0.05) within recovery phase. It was concluded that onset of anaesthesia and clinical signs in induction phase were directly proportional as the ketamine’s dose increased. Meanwhile duration of anaesthesia and duration of recovery were inversely proportional with the dose increasing.
Keyword: anesthesia, ketamine-xylazine, New Zealand White, rabbit