45 research outputs found

    Water Quality at the Inlet to the St. Lawrence River, 1977 to 1983

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    Daily nutrients analyses and weekly major ions and trace metals analyses have been performed since 1977 on water samples collected in the south channel of the St. Lawrence River at Wolfe Island. This report presents the results of the first seven years of this program. Data analyses showed that pH and total phosphorus were underestimated. Calcium carbonate precipitation is suspected to occur almost every year in August or September. Most of the major ions have decreased, especially chloride and sodium. All trace metal data were below the objectives of the International Joint Commission in 90% of the cases or more. The Wolfe Island station was found to be a good tool for following the general trend of the main water quality parameters. More attention, however, should be focused on the problems of shipping delays and containers

    Pembuatan Arang Aktif Dari Tulang Ikan Tuna

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    Untuk menunjang kelebihan hasil perikanan di Kepulauan Indonesia. Pemerintah melalui Badan Usaha Milik Negara (BUMN) berusaha mengolah ikan-ikan tersebut dalam bentuk ikan kalengan untuk memenuhi kebutuhan ikan di dalam negeri atau kebutuhan ekspor. Tulang ikan yang merupakan salah satu limbah industri pengalengan kurang banyak dimanfaatkan. Oleh karena itu peneliti tergerak untuk meneliti limbah industri pengalengan tersebut sebagai bahan baku pembuatan arang aktif, karena dalam tulang ikan mengandung karbon dimana arang aktif merupakan senyawa karbon amorph, yang dapat dihasilkan dari bahan-bahan yang mengandung karbon atau dari arang yang diperlakukan dengan cara khusus untuk mendapatkan permukaan yang lebih luas. Arang aktif dapat mengadsorpsi gas dan senyawa-senyawa kimia tertentuatau sifat adsorpsinya selektif, tergantung pada besar atau volume pori-pori dan luas permukaan. Tulang ikan diarangkan dengan proses pirolisis. Untuk mendapatkan arang aktif, maka arang hasil pirolisis diaktifasi dengan cara penambahan CaCl2 sebagai bahan pengaktif serta dilakukan pemanasan pada suhu dan waktu tertentu, selanjutnya direndam dalam larutan H2SO4 12%. Arang aktif diuji keaktifannya dengan menggunakan larutan Methelyn Blue melalui peniteran. Hasil dari penelitian ini didapat kondisi yang paling baik untuk pembuatan arang aktif yaitu konsentrasi CaCl2 20%, waktu aktifasi 40 menit, suhu aktifasi 75 °C dan daya serap terhadap Methelyn Blue 99,12 ml/g

    Resonant nonlinear magneto-optical effects in atoms

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    In this article, we review the history, current status, physical mechanisms, experimental methods, and applications of nonlinear magneto-optical effects in atomic vapors. We begin by describing the pioneering work of Macaluso and Corbino over a century ago on linear magneto-optical effects (in which the properties of the medium do not depend on the light power) in the vicinity of atomic resonances, and contrast these effects with various nonlinear magneto-optical phenomena that have been studied both theoretically and experimentally since the late 1960s. In recent years, the field of nonlinear magneto-optics has experienced a revival of interest that has led to a number of developments, including the observation of ultra-narrow (1-Hz) magneto-optical resonances, applications in sensitive magnetometry, nonlinear magneto-optical tomography, and the possibility of a search for parity- and time-reversal-invariance violation in atoms.Comment: 51 pages, 23 figures, to appear in Rev. Mod. Phys. in Oct. 2002, Figure added, typos corrected, text edited for clarit

    Postcolonial healing landscapes and mental health in a remote Indigenous community in subarctic Ontario, Canada

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    The concept of therapeutic landscape is concerned with a holistic, socio-ecological model of health, but most studies have attempted to explore land-health links from a Western perspective. On an Indigenous reserve in Northern Ontario, part of the Canadian subarctic, we explore the importance of spaces and places in creating postcolonial therapeutic landscapes to treat the wounds inflicted by colonialism. The aim of this research is to gain insight from views and experiences of First Nations residents living on reservations that are undergoing a process of regaining traditional spiritual beliefs and teachings to construct therapeutic spaces to face mental health problems caused by legal opioid analgesic abuse. This qualitative study used semi-structured interviews with Cree and Ojibwe participants to understand how they are reconnecting with earth, spirituality and traditional animist beliefs on their way to recovery. We find that practices such as taking part in ceremonies and ritual spaces, and seeking knowledge and advice from Elders assist with personal healing and enable Indigenous people to be physically and mentally healthy. Our research findings provide important insights into the relationship between space, healing and culture as determinants of health and well-being and document some key factors that contribute to substance abuse recovery.This work was supported by the Ministry of Education and Science (Spain) [I + D+i SEJ2005-09344/SOCI]; Social Sciences and Humanities Research Council (Canada) [I + D+i CURA/NORTHERN]

    Rapid determination of anti-tuberculosis drug resistance from whole-genome sequences

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    Mycobacterium tuberculosis drug resistance (DR) challenges effective tuberculosis disease control. Current molecular tests examine limited numbers of mutations, and although whole genome sequencing approaches could fully characterise DR, data complexity has restricted their clinical application. A library (1,325 mutations) predictive of DR for 15 anti-tuberculosis drugs was compiled and validated for 11 of them using genomic-phenotypic data from 792 strains. A rapid online ‘TB-Profiler’ tool was developed to report DR and strain-type profiles directly from raw sequences. Using our DR mutation library, in silico diagnostic accuracy was superior to some commercial diagnostics and alternative databases. The library will facilitate sequence-based drug-susceptibility testing

    Finishing the euchromatic sequence of the human genome

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    The sequence of the human genome encodes the genetic instructions for human physiology, as well as rich information about human evolution. In 2001, the International Human Genome Sequencing Consortium reported a draft sequence of the euchromatic portion of the human genome. Since then, the international collaboration has worked to convert this draft into a genome sequence with high accuracy and nearly complete coverage. Here, we report the result of this finishing process. The current genome sequence (Build 35) contains 2.85 billion nucleotides interrupted by only 341 gaps. It covers ∼99% of the euchromatic genome and is accurate to an error rate of ∼1 event per 100,000 bases. Many of the remaining euchromatic gaps are associated with segmental duplications and will require focused work with new methods. The near-complete sequence, the first for a vertebrate, greatly improves the precision of biological analyses of the human genome including studies of gene number, birth and death. Notably, the human enome seems to encode only 20,000-25,000 protein-coding genes. The genome sequence reported here should serve as a firm foundation for biomedical research in the decades ahead
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