Judul: Kelimpahan Anggang-anggang (Ptilomera dromas Breddin) di Sungai Ciliwung yang Berpotensi sebagai Bioindikator Kualitas Air.
Abstrak: People and home industries activities along Ciliwung river impact to water quality. Pollutant in body of river will impact to water quality and organisms, included water strider. Water striders (Gerridae: Hemiptera) are semiaquatic insect. Gerrids, Ptilomera Amyot and Serville is easy to know, because have rather big body and have sexual dimorfism. A bigger body male than female is unusual in gerrids. Some species of water striders were used as water bioindicator. Gerris spinolae is effective bioindicators for monitoring pollution in some tropical ponds under anthropogenic stress, whereas G. argentatus, G. odontogaster, G. lateralis, dan G. thoracicus used as bioindicator of heavy metals. The purpose of this research was to study the abundance of P. dromas in Ciliwung river related to water quality. Five stations in upper Ciliwung river were used i.e, Cilember, Cijulang, Gadog, Katulampa, and Sempur stations. Abundance of water striders were observed by census method. Water striders were count directly along the edge of the river on each station. Observations were conducted four times each day, at 07.00-11.00 am. Abundance of water striders each stations was observed five times in November, December 2013, April, and May 2014. Measurement of environmental parameters was conducted at each station with five replicates, i.e. water temperature, air temperature, pH, and water flow. Water sampling was conducted by using a sampel bottle 1 L, then put in an ice box 4oC. Water samples were analyzed in the Laboratory PROLING Faculty of Fisheries and Marine Science Bogor Agricultural University, consist of biological oxygen demand (BOD), dissolved oxygen (DO), CO2 free, total Nitrogen (N), hardness, and total suspended solid (TSS). A normal data of environmental parameters were analyzed by One-Way ANOVA followed by Tukey test. Abundance of adult, nymph and total P. dromas were analyzed by Kruskal Wallis. Abundances of water strider related with environmental parameters were analyzed by GLM using a Poisson distribution, then followed by GLM using negative binomial distribution. Analyses were performed using program R 3.0.0. Results showed that three species of water striders were found in Ciliwung river, i.e. Ptilomera dromas Breddin, Limnogonus nitidus and Tenagogonus robustus. Gerrids, P. dromas was found in Ciliwung river in the fast current, while L. nitidus and T. robustus was found in slow current and tends to stagnant. In the Sempur station, both water strider species were found, i.e. L. nitidus and T. robustus in a puddle located on the edge of the river. The highest abundance of adult P. dromas was found in Katulampa (78.8 individuls), followed by Gadog (63.4 individuals), Cilember (41.0 individuals), and Cijulang (16.8 individuals) respectively. Cilember station has highest abundance of nymph of P. dromas (178.2 individuals), followed by Gadog (158.4 individuals), Katulampa (133.4 individuals), and Cijulang (80.2 individuals). The average of abundance of total P. dromas (adult and nymph) in Gadog station was highest (221.8 individuals), followed by Cilember (219.2 individuals), Katulampa (212.2 individuals), and Cijulang (97.0 individuals). P. dromas didn’t found in Sempur station. The ANOVA analysis showed that significant differences in water temperature (p=0.000), air temperature (p=0.000) dan pH (p=0.029) in each stations. The Tukey tests revealed significant
Keyword: Ptilomera dromas, abundance, Ciliwung river, water bioindicator

Judul: Aquatic Insect Communities in Several Waterfalls of Mount Halimun Salak and Babakan Madang
Abstrak: Air terjun Gunung Halimun Salak dan Babakan Madang merupakan sumber air yang sangat penting bagi masyarakat Bogor. Kualitas air di tempat tersebut perlu dijaga dengan baik melalui monitoring lingkungan menggunakan bioindikator serangga akuatik. Ordo EPT (Ephemeroptera, Plecoptera, dan Trichoptera) paling umum digunakan sebagai bioindikator karena kelompok serangga tersebut sering dijumpai di perairan bersih dan sangat sensitif terhadap perubahan faktor fisikokimia perairan. Oleh karena itu, penelitian ini bertujuan mengidentifikasi dan membandingkan komunitas serangga akuatik di beberapa air terjun Gunung Halimun Salak dan Babakan Madang serta menentukan kualitas perairan berdasarkan komunitas serangga akuatiknya. Metode yang digunakan adalah purposive sampling pada jalur transek sepanjang 10 m dari titik nol sekitar + 15 m dari air terjun. Pengambilan sampel dilakukan di 3 stasiun pengamatan Gunung Halimun Salak dan Babakan Madang sebanyak 3 kali ulangan. Sampel serangga akuatik diambil menggunakan hand net berukuran 30 x 30 cm dan disimpan dalam botol sampel yang berisi alkohol 70%. Parameter lingkungan yang diambil berupa kelembaban relatif, suhu air, TDS (total dissolve solid), kecepatan arus, dan pH air. Sampel diidentifikasi menggunakan mikroskop stereo, buku identifikasi, dan Aplikasi Waterbug. Analisis data dilakukan menggunakan Indeks Keanekaragaman Shannon-Wienner, kelimpahan EPT, NMDS, dan Indeks BMWP-ASPT. Jumlah individu serangga akuatik lebih banyak ditemukan di air terjun Babakan Madang, namun keanekaragaman serangga akuatik lebih tinggi di air terjun Gunung Halimun Salak. Kelimpahan EPT didominasi oleh Famili Baetidae. NMDS Ordination menunjukkan persebaran famili di 6 stasiun pengamatan. Berdasarkan pengukuran Indeks BMWP-ASPT, Air terjun Gunung Halimun Salak dan Babakan Madang memiliki kualitas air tercemar sedang., The waterfalls of Mount Halimun Salak and Babakan Madang are very important water sources for the people of Bogor. Water quality in these places needs to be properly maintained through environmental monitoring using aquatic insect bioindicators. The orders EPT (Ephemeroptera, Plecoptera, and Trichoptera) are most commonly used as bioindicators because these insect groups are often found in clean waters and are very sensitive to changes in water physicochemical factors. Therefore, this study aims to identify and compare aquatic insect communities in several waterfalls of Mount Halimun Salak and Babakan Madang and determine water quality based on the aquatic insect community. The method used is purposive sampling on a 10 m long transect from the zero point around + 15 m from the waterfall. Sampling was carried out at 3 observation stations of Mount Halimun Salak and Babakan Madang with 3 replications. Aquatic insect samples were taken using a hand net measuring 30 x 30 cm and stored in a sample bottle containing 70% alcohol. Environmental parameters taken in the form of relative humidity, water temperature, TDS (total dissolve solid), current velocity, and water pH. Samples were identified using a stereo microscope, identification book, and the Waterbug Application. Data analysis was performed using the Shannon-Wienner Diversity Index, EPT abundance, NMDS, and BMWP-ASPT Index. The number of individual aquatic insects was more found in Babakan Madang waterfall, but the diversity of aquatic insects was higher in Mount Halimun Salak waterfall. The abundance of EPT is dominated by the Baetidae Family. NMDS Ordination shows the distribution of families in 6 observation stations. Based on the measurement of
Keyword: Aquatic insect, bioindicator, purposive sampling, waterfall, water quality

Judul: Sifat operasi dan eksistensi invers suatu matriks dalam aljabar max-plus
Abstrak: Karya ilmiah ini membahas sifat-sifat operasi dalam aljabar max-plus dan sifat-sifat yang diaplikasikan pada matriks serta eksistensi invers matriks dalam aljabar max-plus. Operasi-operasi matriks yang dapat diaplikasikan dalam aljabar max-plus meliputi operasi penjumlahan dan perkalian antar matriks, matriks transpose, matriks identitas, matriks segi pangkat ke-k, serta perkalian matriks dengan skalar. Sifat- sifat yang berlaku untuk matriks dalam aljabar max-plus yaitu sifat asosiatif (untuk operasi penjumlahan dan perkalian), komutatif (hanya untuk operasi penjumlahan), dan distributif. Eksistensi invers suatu matriks a ∈ dalam aljabar max-plus dapat dipastikan ada jika dan hanya jika a merupakan perkalian matriks permutasi dan matriks diagonal . Max nxn p ( ) i d 
Keyword: matriks, aljabar max-plus