Bioassays for coastal water quality: an assessment using the larval development of Haliotis midae L

The United States Environmental Protection Agency (USEPA) has established a suite of methods that use coastal invertebrate species as bioassay organisms to test industrial and domestic effluent as well as coastal waters for potential toxicity. Although these methods are used globally, the potential of such toxicity tests has not been adequately explored for South African coastal waters. This study serves to describe a simple, cost-effective and relatively quick testing procedure using the development of Haliotis midae larvae as a bioassay of coastal water quality. This test is based on the sensitivity of these larvae to low concentrations of zinc (Zn). Its performance in a field trial demonstrates not only that this test has the potential to identify coastal waters of poor quality, but also that such identification could be of value in attempts to restock natural abalone populations, which are under extreme pressure from legal and illegal exploitation. Further work in this line should focus on the refinement of the methodology for this and other local species and should aim to contribute to the development of suitable criteria for the management of coastal water quality in South Africa. WaterSA Vol.28(4) 2002: 457-46

VALUASI EKONOMI MANFAAT REKREASI TEBING KERATON DENGAN METODE TRAVEL COST METHOD

Jasa rekreasi hutan sebagai produk tambahan yang sifatnya intangible, tidak dapat dihitung secara kuantitatif karena tidak memiliki harga pada sistem pasar normal. Hal ini mendasari penelitian untuk mengetahui nilai ekonomi rekreasi, dengan studi kasus Tebing Keraton menggunakan metode Individual Travel Cost Method. Analisis data dari kuesioner, menggunakan alat pengolah data SPSS versi 21 dengan metode regresi linier berganda untuk mendapatkan fungsi permintaan rekreasi Tebing Keraton. Variabel yang diduga berpengaruh terhadap jumlah kunjungan yaitu : biaya perjalanan (X1), total pendapatan (X2), umur (X3), jarak tempuh (X4), dan jenis kelamin (X5). Nilai koefisien variabel menentukan kecenderungan dalam meningkatkan atau menurunkan jumlah kunjungan wisata. Fungsi permintaan rekreasi Tebing Keraton dibedakan menjadi dua yaitu fungsi rekreasi untuk pelajar/mahasiswa dan untuk yang sudah bekerja dikarenakan perbedaan tolak ukur pada pendapatan perbulan. Untuk memperoleh fungsi permintaan Tebing Keraton harus diketahui data-data variabel pada model fungsi permintaan berdistribusi normal dengan uji normalitas. Berdasarkan hasil regresi diperoleh fungsi permintaan rekreasi untuk pelajar/mahasiswa yaitu Y = -2,179 – 0,0000347 X1 + 0,286 X2 + 0.159 X3 - 0.0000794 X4 - 0.267 X5, dan yang sudah bekerja Y = 1,994 – 0,00000164 X1 + 0,53 X2 - 0.32 X3 - 0.003 X4 - 0.334 X5. Dari hasil regresi didapatkan nilai koefisien determinasi (R ) yaitu persentase keragaman permintaan jumlah kunjungan ke Tebing Keraton yang dapat dijelaskan oleh variabel-variabel bebas dalam model. Pada model fungsi permintaan rekreasi untuk pelajar/mahasiswa R 2 2 sebesar 67,1% dan menurut ketetapan, terdapat pada rentang > 0,5 yaitu ketepatannya tinggi. Sedangkan untuk yang sudah bekerja R sebesar 48,9% terdapat pada rentang 0,31 - 0,5 yaitu ketepatannya cukup. Surplus konsumen didapat sebesar Rp 22.863,00 per individu per kunjungan untuk pelajar/mahasiswa. sebesar Rp 468.307,00 per individu per kunjungan untuk pekerja. Lalu dikalikan dengan jumlah pengunjung dalam setahun didapat nilai ekonomi rekreasi Tebing Keraton untuk pelajar/mahasiswa sebesar Rp. 1.603.585.014 dan nilai ekonomi Tebing Keraton untuk pekerja sebesar Rp 21.898.035.320. 2 Kata kunci : fungsi permintaan rekreasi, regresi linier berganda, Tebing Keraton, variabe

It’s about time: A synthesis of changing phenology in the Gulf of Maine ecosystem

The timing of recurring biological and seasonal environmental events is changing on a global scale relative to temperature and other climate drivers. This study considers the Gulf of Maine ecosystem, a region of high social and ecological importance in the Northwest Atlantic Ocean and synthesizes current knowledge of (a) key seasonal processes, patterns, and events; (b) direct evidence for shifts in timing; (c) implications of phenological responses for linked ecological-human systems; and (d) potential phenology-focused adaptation strategies and actions. Twenty studies demonstrated shifts in timing of regional marine organisms and seasonal environmental events. The most common response was earlier timing, observed in spring onset, spring and winter hydrology, zooplankton abundance, occurrence of several larval fishes, and diadromous fish migrations. Later timing was documented for fall onset, reproduction and fledging in Atlantic puffins, spring and fall phytoplankton blooms, and occurrence of additional larval fishes. Changes in event duration generally increased and were detected in zooplankton peak abundance, early life history periods of macro-invertebrates, and lobster fishery landings. Reduced duration was observed in winter-spring ice-affected stream flows. Two studies projected phenological changes, both finding diapause duration would decrease in zooplankton under future climate scenarios. Phenological responses were species-specific and varied depending on the environmental driver, spatial, and temporal scales evaluated. Overall, a wide range of baseline phenology and relevant modeling studies exist, yet surprisingly few document long-term shifts. Results reveal a need for increased emphasis on phenological shifts in the Gulf of Maine and identify opportunities for future research and consideration of phenological changes in adaptation efforts

SISTEM PAKAR UNTUK INISIASI PENYELENGGARAAN RESEPSI PERNIKAHAN (Studi Kasus : Event Organizer Dot Of Corner, Bandung)

Sebuah pernikahan tidak pernah jauh dengan urusan sebuah resepsi, keduanya merupakan serangkaian acara yang berkesinambungan. Dalam melaksanakan sebuah resepsi pernikahan di zaman sekarang ini bukanlah hal yang mudah dimana setiap orang memiliki kesibukan yang sangat padat setiap harinya. Hal yang perlu dipersiapkanpun tidaklah sedikit seperti sewa gedung, undangan, dokumentasi, catering, pelaminan, dekorasi, perias, grup musik. Pada umumnya customer mencari informasi mengenai perlengkapan pernikahan dan mendatangi langsung konsultan untuk berkonsultasi perihal resepsi pernikahan. Sistem pakar untuk inisiasi penyelenggaraan resepsi pernikahan merupakan hal yang penting mengingat proses inisiasi penyelenggaraan pernikahan di event organizer dot of corner masih menggunakan cara konvensional. Permasalahan yang dijadikan titik tolak dalam pembuatan tugas akhir ini adalah bagaimana cara meningkatkan kualitas layanan inisiasi penyelenggaraan pernikahan. Tujuan dari tugas akhir ini adalah meningkatkan kualitas layanan inisiasi penyelenggaraan pernikahan dan memberikan kenyamanan kepada customer dalam berkonsultasi. Metodologi penelitian dilakukan dengan metode pengembangan sistem pakar ES DLC. Metode akuisisi pengetahuan yang digunakan adalah metode manual dengan melakukan wawancara dan studi literatur. Mesin inferensi pada sistem pakar ini dibangun dengan menggunakan metode forward chaining. Untuk membangun sistem pakar ini menggunakan aplikasi sistem pakar yang sudah ada yaitu Dexsys. Hasil dari penelitian ini adalah aplikasi sistem pakar untuk berkonsultasi pada tahap inisiasi penyelengaraan resepsi pernikahan yang memuat opsi budgeting, solusi, basis aturan dan rekomendasi spesifikasi resepsi pernikahan. Berdasarkan hasil verifikasi dan validasi dapat disimpulkan bahwa aplikasi sistem pakar ini dapat menjadi alat bantu untuk berkonsultasi perihal inisiasi penyelenggaraan pernikahan. Kata Kunci : Sistem Pakar, Inisiasi Penyelenggaraan Resepsi Pernikahan, Forward Chaining

Diversity has stronger top-down than bottom-up effects on decomposition

The flow of energy and nutrients between trophic levels is affected by both the trophic structure of food webs and the diversity of species within trophic levels. However, the combined effects of trophic structure and diversity on trophic transfer remain largely unknown. Here we ask whether changes in consumer diversity have the same effect as changes in resource diversity on rates of resource consumption. We address this question by focusing on consumer-resource dynamics for the ecologically important process of decomposition. This study compares the top-down effect of consumer (detritivore) diversity on the consumption of dead organic matter (decomposition) with the bottom-up effect of resource (detrital) diversity, based on a compilation of 90 observations reported in 28 studies. We did not detect effects of either detrital or consumer diversity on measures of detrital standing stock, and effects on consumer standing stock were equivocal. However, our meta-analysis indicates that reductions in detritivore diversity result in significant reductions in the rate of decomposition. Detrital diversity has both positive and negative effects on decomposition, with no overall trend. This difference between top-down and bottom-up effects of diversity is robust to different effect size metrics and could not be explained by differences in experimental systems or designs between detritivore and detrital manipulations. Our finding that resource diversity has no net effect on consumption in brown\u27\u27 (detritus-consumer) food webs contrasts with previous. ndings from green\u27\u27 (plant-herbivore) food webs and suggests that effects of plant diversity on consumption may fundamentally change after plant death

IDENTIFIKASI PENGARUH KUALITAS AIR SUNGAI TERHADAP KUALITAS AIR SUMUR DI RW 08 KELURAHAN BABAKAN CIAMIS KECAMATAN SUMUR BANDUNG KOTA BANDUNG BERDASARKAN PARAMETER BIOLOGIS E-COLI

Air merupakan kebutuhan paling vital bagi kehidupan manusia dan makhluk hidup lainnya. Penyediaan air minum yang aman harus diupayakan karena kemungkinan adanya pencemaran mikroorganisme pada air minum, seperti pencemaran bakteri Escherichia coli (E.coli) yang menjadi indikator patogen penyebab terjadinya diare. Menurut persyaratan Peraturan Menteri Kesehatan Republik Indonesia Nomor 492/Menkes/Per/IV/2010 tentang persyaratan kualitas air minum bahwa kadar maksimum bakteri E.coli untuk air minum yang diperbolehkan dalam per 100 ml sampel adalah 0/100 ml. Tujuan dari penelitian ini adalah untuk mengetahui ada atau tidaknya bakteri E.coli pada air sumur warga RW 08 Kelurahan Babakan Ciamis dan berapa kadar MPN/100 ml serta untuk mengetahui apakah terdapat hubungan bahwa jarak air sungai ke setiap sumur, jarak toilet ke sumur dan kedalaman sumur mempengaruhi pencemaran air sumur dengan mengguna kan metode regresi linier. Semua sampel positif mengandung bakteri E.coli, dimana untuk nilai E.coli tertinggi adalah 210 MPN/100 ml dan terendah adalah 5,6 MPN/100 ml. Hubungan yang didapat berdasarkan menggunakan Software Statistical Product and Service Solutions (SPSS) didapat hubungan antara jarak sungai dengan sumur memiliki hubungan keterkaitan yang sangat baik dibandingkan dengan variabel bebas lainnya dan nilai yang didapat bernilai negatif, dimana dapat diartikan jika jarak dari sungai ke setiap sumur dekat, maka bakteri E.coli akan tinggi begitu juga sebaliknya. Dan variabel jarak dari sungai ke sumur ini berpengaruh signifikan karena nilai Signifikansi hasil SPSS tidak melebihi 25% yaitu 0,052 atau 5,2% error nya. Kata Kunci: Escherichia coli (E.coli), MPN, Regresi Linie

Bottom-Up versus Top-Down Induction of Sleep by Zolpidem Acting on Histaminergic and Neocortex Neurons

Zolpidem, a GABAA receptor-positive modulator, is the gold-standard drug for treating insomnia. Zolpidem prolongs IPSCs to decrease sleep latency and increase sleep time, effects that depend on α2 and/or α3 subunit-containing receptors. Compared with natural NREM sleep, zolpidem also decreases the EEG power, an effect that depends on α1 subunit-containing receptors, and which may make zolpidem-induced sleep less optimal. In this paper, we investigate whether zolpidem needs to potentiate only particular GABAergic pathways to induce sleep without reducing EEG power. Mice with a knock-in F77I mutation in the GABAA receptor γ2 subunit gene are zolpidem-insensitive. Using these mice, GABAA receptors in the frontal motor neocortex and hypothalamic (tuberomammillary nucleus) histaminergic-neurons of γ2I77 mice were made selectively sensitive to zolpidem by genetically swapping the γ2I77 subunits with γ2F77 subunits. When histamine neurons were made selectively zolpidem-sensitive, systemic administration of zolpidem shortened sleep latency and increased sleep time. But in contrast to the effect of zolpidem on wild-type mice, the power in the EEG spectra of NREM sleep was not decreased, suggesting that these EEG power-reducing effects of zolpidem do not depend on reduced histamine release. Selective potentiation of GABAA receptors in the frontal cortex by systemic zolpidem administration also reduced sleep latency, but less so than for histamine neurons. These results could help with the design of new sedatives that induce a more natural sleep

Antibacterial activity of watermelon (Citrullus lanatus) seed against selected microorganisms

This study was aimed at evaluating the effect of extraction methods on the antibacterial activity of Citrullus lanatus seed extract. C. lanatus  (watermelon) is a popular fruit consumed all over the world. Three solvents were used for the extraction process: chloroform, methanol and distilled water while two extraction conditions- cold extraction and Soxhlet extraction (coded as hot in this study) were employed. Antibacterial activity of the seed extracts was determined by agar well diffusion method. The seed extracts were tested against clinical isolates including Staphylococcus sp., Escherichia coli, Proteus sp., Klebsiella sp. and a type Pseudomonas aeruginosa (ATCC 27853). It was observed that the cold methanol extracts had the highest antibacterial effect on Staphylococcus sp. followed by hotmethanol extract while cold chloroform extract showed no antibacterial activity. In the presence of P.aeruginosa only the hot methanol and chloroform extracts showed significant antibacterial potentials (p.0.05). Also, saponins which have been implicated in antimicrobial activity were found to be present in moderate and high concentrations in the hot and cold methanol extracts respectively. Results of this study reveal that the kind of solvent employed as well as the conditions for extraction (cold maceration and Soxhlet extraction) influenced the efficacy of the extract against specific test organisms. Furthermore, the presence of saponins may have influence the relatively high zone of inhibition recorded with coldand hot methanol extracts against some of the test organisms.Key words: Watermelon seed, antibacterial, Soxhlet extraction, cold maceration, solvents

Effect of social media in improving knowledge among patients having fixed appliance orthodontic treatment: A single-center randomized controlled trial

Research has shown that orthodontic patients are more likely to retain information presented in an audiovisual format. However, there has been little research on the effectiveness of audiovisual information provided through different routes such as the Internet. This parallel-group randomized controlled trial assessed whether provision of audiovisual information on the YouTube (Google, San Bruno, Calif) Web site to orthodontic patients undergoing fixed appliance treatment results in improved patient knowledge when compared with conventional methods of information provision. The effects of sex and ethnicity were also investigated

Individual differences in visual salience vary along semantic dimensions

What determines where we look? Theories of attentional guidance hold that image features and task demands govern fixation behavior, while differences between observers are interpreted as a “noise-ceiling” that strictly limits predictability of fixations. However, recent twin studies suggest a genetic basis of gaze-trace similarity for a given stimulus. This leads to the question of how individuals differ in their gaze behavior and what may explain these differences. Here, we investigated the fixations of >100 human adults freely viewing a large set of complex scenes containing thousands of semantically annotated objects. We found systematic individual differences in fixation frequencies along six semantic stimulus dimensions. These differences were large (>twofold) and highly stable across images and time. Surprisingly, they also held for first fixations directed toward each image, commonly interpreted as “bottom-up” visual salience. Their perceptual relevance was documented by a correlation between individual face salience and face recognition skills. The set of reliable individual salience dimensions and their covariance pattern replicated across samples from three different countries, suggesting they reflect fundamental biological mechanisms of attention. Our findings show stable individual differences in salience along a set of fundamental semantic dimensions and that these differences have meaningful perceptual implications. Visual salience reflects features of the observer as well as the image