Judul: Kondisi Histopatologi Ikan Mas Budidaya pada Lingkungan yang Tercemar Merkuri dan Selenium di Kawasan Pongkor Bogor dan Strategi Pengelolaannya
Abstrak: Mercury emissions from upstream gold mining and processing areas were found in high levels in waters, sediments, agricultural products, and fishes in Pongkor area led to conduct a study on reared carp fishes in same area from histopathological view. Selenium effect as antagonist of mercury, has never been studied before in this area. The study presents the total Hg and Se amount in water, sediments, and fish organs (gill, liver, kidney, intestine, spleen, and muscle), histopathology finding, and enviromental parameters that could influence the fish condition. Mercury and selenium were analyzed using acid digestion followed by determination of total mercury by atomic absorption spectrophotometry. Routine histopathological procedure was use after paraffin embedding and hematoxylin-eosin (HE) staining. The mercury concentrations in waters and organs was undetected, but there hundreds fold above the maximum limited permitted by Canadian Environment Quality Guidelines were detected in sediments. Tens fold selenium concentrations above the threshold level proposed by Lemly (2002) were also observed in sediments. In tissue, Se concentrations also reached tens fold above the threshold proposed by DeForrest et al. (1999). However, these higher concentration of fishes tissues could be worthwhile to metabolisms of fishes and people as antagonistic role of Se to Hg and either heavy metals found in this area. The histopathological changes that found within were degenerations and, necrosis, blood circulation alterations, and some parasites infections. This conditions could influenced by some environmental factors such as sediment type, hardness and alkalinity, water resources, leaching and flushing, and interaction with the other metals. Beside the good aquaculture practices, the strategy of management that could implemented to diminishing pollution of Hg and Se are : modification of construction of ponds; tandonitation; and biological, physical and chemical remediations.
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Judul: Analisis merkuri (Hg) dan sianida (CN) pada beberapa ikan hasil tangkapan nelayan di Teluk Kao, Halmahera Utara
Abstrak: The disposal of mercury (Hg) and cyanide (CN) in the gold mining activities in North Halmahera Regency Kao Bay can cause habitat damage and contamination or poisoning and death of various types of biota that live around the area, including fish and humans. Therefore the aim of this study is to determine the content of mercury (Hg) and cyanide (CN) in water consumption and some types of fish catches around the Gulf of Kao and the level of appropriateness for consumption. Location of fish sampling conducted near the mouth of the river in the Cape Taolas Kao Bay (station 1) and Tanjung Akesone (station 2). While the analysis of heavy metal content in water and the fish is done at the in laboratory research centers and industrial development Manado and Limnology Laboratory in Bogor Agricultural University Bogor using AAS method. Samples of fish that contain mercury in measuring and sianidanya is white shrimp or fish Panaeus merguensis jackfruit seeds or Upeneus sp, fish red Snapper or Lutjanus sp, and Belanak/Mugil sp. Based on laboratory reults showed that mercury (Hg) and cyanide (CN) in seawater around the Gulf of Kao is still below the threshold limit (0.0002 ppm Hg, and CN 0.001 ppm). Compared with water quality standards according to category C Kep-20/MENKLH/I/1990. The content of mercury (Hg) in the liver into 4 types of fish was higher (0.13 to 0.51 ppm) compared to the flesh (0.02 to 0.19 ppm). The most high fish liver content of mercury is fish jackfruit seeds (from 0.45 to 0.51). The content of cyanide (CN) in the liver was also higher (6.0 to 18 ppm) than in meat (4,2 to 9,7 ppm). Referring to the standard intake of mercury on the human body that have been established by WHO in Darmono (2008) of 0.5 ppm, the red Snapper fish, Belanak fish, fish and shrimp jackfruit seeds safe for consumption. While the content of cyanide into the body already exceed safe levels. ranging from 1.52 ppm - 4.5 ppm, WHO (2004). Thus, red snapper, mullet, and shrimp are caught in the Cape and Cape Akesone Taolas Kao Bay is at a critical level (harmful) when consumed.
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Judul: Invers Drazin dari Matriks Toeplitz Singular
Abstrak: Matriks Toeplitz adalah matriks yang setiap unsur pada diagonal utama bernilai sama dan setiap unsur pada subdiagonal yang bersesuaian dengan diagonal utama juga bernilai sama. Matriks singular adalah matriks yang tidak bisa ditentukan inversnya. Akan tetapi, dapat diupayakan untuk ditentukan inversnya menggunakan invers matriks yang diperumum. Invers Drazin merupakan salah satu jenis invers matriks yang diperumum. Pada karya ilmiah ini ditentukan invers Drazin dari matriks Toeplitz singular dengan menggunakan metode Leverrier Faddeev. Kemudian, ditentukan invers Drazin dari matriks Toeplitz singular yang direpresentasikan sebagai penjumlahan segitiga bawah dan segitiga atas matriks Toeplitz berdasar pada teorema Gohberg dan Semencul., Toeplitz matrix is a matrix in with element on the main diagonal has the same value and on the subdiagonal corresponding to the main diagonal also has the same value. Singular matrix is a matrix that has no inverse. However, it can be attempted to determine the inverse using a generalized inverse matrix. Inverse Drazin is a type of generalized matrix inverse. This paper discussed the inverse Drazin for a singular Toeplitz matrix using the Leverrier Faddeev method. Then, the Drazin inverse of the singular Toeplitz matrix which is represented as a sum of products of lower and upper triangular Toeplitz matrix based on Gohberg and Semencul theorem.
Keyword: inverse Drazine, singular Toeplitz matrix