Judul: Uji Toksisitas Akut (LC50-96 jam) Logam Berat Kadmium (Cd) pada Benur Udang Windu (Penaeus monodon)
Abstrak: Logam berat terlarut dapat merusak ekosistem dan fungsi fisiologis organisme hingga berakibat pada kematian. Kadmium tidak esensial dan berpotensi beracun bagi organisme. Kadmium sangat toksik meskipun dalam kadar yang rendah. Informasi akurat mengenai kadar konsentrasi maksimum kadmium di lingkungan perairan sangat diperlukan karena tidak banyak informasi mengenai toksisitas kadmium terhadap udang windu. Penelitian ini bertujuan untuk menentukan nilai uji toksisitas akut (LC50-96 jam) logam berat kadmium pada benur udang windu (Penaeus monodon). Eksperimen ini didasari pada metode statis short-term bioassay. Konsentrasi kadmium yang digunakan sebagai perlakuan adalah kontrol (0); 0,56; 1; 1,8; 3,2; dan 5,6 mg L-1. Percobaan dilakukan dengan lima perlakuan konsentrasi beserta kontrol. Sebanyak 30 ekor hewan uji dimasukkan ke dalam satu wadah uji. Hasil penelitian menunjukkan bahwa tingginya konsentrasi kadmium berbanding lurus dengan mortalitas benur udang windu. Nilai LC50-96 jam logam berat kadmium pada benur udang windu (Penaeus monodon) adalah 2,6896 mg L-1. Berdasarkan nilai LC50-96 jam yang diperoleh, logam berat kadmium termasuk logam berat yang sangat toksik., Dissolved heavy metals can damage ecosystems and physiological functions of organisms, resulting in death. Cadmium is not essential and is potentially toxic to organisms. There needs to be accurate information about the maximum concentration of cadmium in the aquatic environment because there is not much information about the toxicity of cadmium to tiger shrimp. This study aimed to find the LC50-96 hours value of cadmium at different concentrations of tiger prawn (Penaeus monodon). This experiment is based on a static short-term bioassay method. The concentration of cadmium in shrimp rearing media used as treatment was control (0); 0.56; 1; 1.8; 3.2; and 5.6 mg L-1. The test was carried out with five concentration treatments and controls. Around 30 test animals were used in each replication. The results showed that the high concentration of cadmium was directly proportional to the mortality of tiger shrimp. The LC50-96 hours value of heavy metal cadmium in tiger prawn was 2.6896 mg L-1. According to LC50-96 hours value, cadmium is a very toxic heavy metal.
Keyword: Kadmium, toksisitas akut, udang windu

Judul: Acute Toxicity Test (LC 50-96 Hours) Heavy Metal Copper (Cu) Lead to Tiger Shrimp (Penaeus monodon) Post larvae
Abstrak: Cemaran logam berat menyebabkan toksisitas pada hewan dan mempengaruhi kesehatan bagi manusia yang mengkonsumsinya. Logam tembaga (Cu) sangat dibutuhkan oleh organisme tetapi hanya dalam jumlah sedikit. Tujuan penelitian ini mendapatkan nilai uji toksisitas akut (LC 50-96 jam) logam berat tembaga terhadap benur udang windu (Penaeus monodon) dengan pendekatan metode eksperimen. Metode yang digunakan dalam penelitian ini yaitu eksperimen yang mengacu pada short-term bioassay. Konsentrasi tembaga yang digunakan sebagai perlakuan adalah kontrol (0); 0,32; 0,56; 1; 1,8; dan 3,2 mg L-1. Percobaan dilakukan dengan lima perlakuan konsentrasi beserta kontrol. Sebanyak 30 ekor hewan uji dimasukkan ke dalam satu wadah uji. Hasil penelitian menunjukkan bahwa tingginya konsentrasi tembaga berbanding lurus dengan mortalitas benur udang windu. Nilai LC50-96 jam logam berat tembaga pada benur udang windu (Penaeus monodon) adalah 3,2940 mg L-1. Berdasarkan nilai LC50-96 jam yang diperoleh, tembaga merupakan logam berat esensial namun dapat bersifat toksik bagi benur udang windu., Heavy metal contamination causes toxicity in animals and affects the health of humans who consume it. Copper metal (Cu) is needed by organisms but only in small quantities. This study aimed to obtain acute toxicity test scores (LC50-96 hours) of heavy metals copper lead to tiger shrimp larvae (Penaeus monodon) with an experimental method approach. The method used in this study is an experiment that refers to short-term bioassay. The concentration of copper used as a treatment is control (0); 0,32; 0,56; 1; 1,8; and 3.2 mg L-1. The experiment was conducted with five concentration treatments along with controls. A total of 30 test animals were put into one test vessel. The results showed that the high concentration of copper was directly proportional to the mortality of tiger shrimp larvae. LC50-96 hours value of copper heavy metals in tiger shrimp (Penaeus monodon) is 3,9240 mg L-1. Based on the LC50-96 hours value obtained, copper is an essential heavy metal but can be toxic for tiger shrimp larvae.
Keyword: Acute toxicity, copper, tiger shrimp

Judul: Penggunaan Teorema Homeomorphy 2-Manifold dan Teorema Euler Poincare pada Torus 𝑇�� dan Simplicial Complex 𝐾��
Abstrak: Two dimensional topological spaces are said to be homeomorphic if they have the same topological invariant, where one of topological invariant used is an Euler characteristic. Homeomorphy 2-Manifold’s Theorem and Euler Poincare’s Theorem are used to distinguish two topological spaces. Homeomorphy 2-Manifold’s Theorem uses Euler characteristic to identify two dimensional topological spaces. Euler Poincare’s Theorem is an alternative way to find Euler characteristic with Betti number, which is topological invariant as well. The objective of this paper is to investigate the homeomorphism of torus 𝑇����� and simplicial complex 𝐾�����. Topological space torus and simplicial complex 𝐾����� have the same Euler characteristic, which is two. Based on Homeomorphy 2-Manifold’s Theorem topological space torus 𝑇����� and simplicial complex 𝐾����� is homeomorphic.
Keyword: simplicial, torus, Euler, homeomorphism, topology