58,020 research outputs found

    Potential mechanism of action of J5 vaccine in protection against severe bovine coliform mastitis.

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    Coliform mastitis is one of the most difficult diseases to treat in the modern dairy industry. Curative therapy with antibiotics remains only moderately effective and depends on the stage at which the disease is treated, The most successful strategies for combating coliform. mastitis appear to be prevention by hygienic management or prophylactic immunization. The severity of clinical symptoms of coliform mastitis has been shown to be reduced by immunization with the Escherichia coli J5 vaccine. However, although the J5 vaccine has been licensed in the United States for about 10 years, the immunological basis of its mechanism of action is still unknown. Until now, protection by J5 vaccination has often been explained by a straight forward mechanism of enhanced antibody production resulting in increased opsonization of coliform bacteria and lipopolysaccharides (LPS). The possibility that J5 vaccination could decrease risk factors for coliform mastitis such as impaired blood polymorphonuclcar neutrophil leukocyte (PMN) diapedesis has never been investigated. This review provides arguments to support the hypothesis that J5 vaccination may reduce the severity of coliform mastitis by inducing a condition of mammary gland hyper-responsiveness, characterized by a T helper 1 (Th1) response and mediated by memory cells inside the mammary gland, finally resulting in enhanced PMN diapedesis upon an intramammary infection

    Disinfection of sea water by ultraviolet radiation

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    Hydraulic Modelling and Optimization of a Wastewater Treatment System for Developing Nations Using Computational Fluid Dynamics

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    Waste stabilization pond (WSP) is globally one of the most popular wastewater treatment options because of its high efficiency and low cost. However, no rigorous assessment of WSPs that account for cost in addition to hydrodynamics and treatment efficiency has been performed. A study was conducted that utilized Computational Fluid Dynamics (CFD) coupled with an optimization program to optimize the selection of the best WSP configuration based on cost and treatment efficiency. Several designs generated by the CFD/optimization model showed that both shorter and longer baffles, alternative depths, and reactor length to width ratios could improve the hydraulic efficiency of the ponds at a reduced overall construction cost. In addition, a study was conducted on the optimized WSP which consisted of an anaerobic, facultative, and a maturation stage whose baffle orientation, length to width ratio, was specified by a CFD model prediction and was compared with a three stage WSP designed according to literature suggested reactor geometric configurations. Experimental tests were performed on a pilot scale version of the threestage WSP where the removal performance was based on a number of parameters (Faecal coliform, pH, TDS, and Conductivity). Results showed that the significantly lower cost design based on the optimized CFD simulations displayed slightly better removal performance compared to the standard WSP design developed from literature data. The results of this study clearly showed that unit treatment process designs based on rigorous numerical optimization can aid in producing cost effective designs that make it more possible for developing nations to incorporate adequate and effective sanitation

    Pengaruh Penyiangan Dan Suhu Penyimpanan Terhadap Mutu Kimiawi, Mikrobiologis Dan Organoleptik Ikan Tongkol (Auxis Tharzard, Lac)

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    Ikan tongkol merupakan salah satu bahan pangan yang dikonsumsi masyarakat dan jika dibiarkanpada suhu kamar, maka terjadi proses penurunan mutu menjadi busuk. Ikan yang sudah mengalami prosespembusukan, bila dikonsumsi dapat menimbulkan keracunan (Histamine fish poisoning). Keracunan inidisebabkan oleh kontaminasi bakteri pathogen dengan dekarboksilasi asam amino histidin oleh enzimhistidin dekarboksilase menghasilkan histamin. Bakteri ini banyak terdapat pada anggota tubuh manusiayang tidak higienis, kotoran/tinja, isi Perut ikan, insang serta peralatan yang tidak bersih.Penelitian eksperimental dengan pola faktorial, yaitu faktor P adalah faktor penyiangan dengan 2 taraf,tanpa penyiangan dan penyiangan, sedangkan faktor T adalah suhu penyimpanan dengan 3 taraf yaitu suhupenyimpanan 30oC, 15oC dan 0oC.Analisis statistik terhadap mutu kimiawi seperti kadar histamin, kadar total volatil bases (TVB) dantrimetilamin (TMA) menunjukkan perbedaan nyata (P<0,05) pada pengaruh penyiangan dan suhupenyimpanan. Terjadi peningkatan kadar histamin, kadar TVB dan TMA selama penelitian. Selamapenelitian terjadi peningkatan jumlah koloni bakteri, jumlah Coliform, kecuali bakteri Vibrioparahaemolyticus negatif. Perlakuan penyiangan dan suhu penyimpanan 0oC memiliki mutu kimiawi,mikrobiologis terbaik sampai hari ke 10 serta masih diterima panelis.Hubungan antara kadar histamin dengan jumlah bakteri mempunyai hubungan sangat kuat, ditunjukkandengan nilai r ? 0,7 kecuali kadar histamin dengan waktu memiliki hubungan agak lemah r ? 0,5.Keamanan ikan tongkol dengan penerapan teknologi tepat guna berupa tanpa penyiangan danpenyiangan pada suhu 30oC hanya aman untuk dikonsumsi sampai hari ke 0. Perlakuan tanpa penyiangandan suhu penyimpanan 15oC aman sampai hari ke 4, sedangkan dengan penyiangan aman sampai hari ke 6.Untuk perlakuan tanpa penyiangan dan penyiangan dengan suhu penyimpanan 0oC aman sampai hari ke 10

    Converting rain into drinking water: Quality issues and technological advances

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    With growing pressures on water supplies worldwide, rainwater harvesting is increasingly seen as a viable option to provide drinking water to an ever expanding population, particularly in developing countries. However, rooftop runoff is not without quality issues. Microbiological and chemical contamination have been detected in several studies, well above local and international guidelines, posing a health risk for consumers. Our research explores the use of silver ions, combined with conventional filtration and settling mechanisms, as a safe and affordable model for purification that can be applied on a small scale. The complete systems were installed and tested in rural communities in a Mexican semi-arid region. Efficiencies up to 99.9% were achieved in the removal of indicator microorganisms, with a marked exception where cross-contamination from external seepage occurs. Sites without overhanging branches or with relatively clean surfaces show an absence of total coliforms in the untreated runoff, compared with others where values as high as 1,650 CFU/100 ml were recorded. Thus, given adequate maintenance, the system can successfully deliver high quality drinking water, even when storage is required for long periods of time. © IWA Publishing 2011

    Effect of weed management strategies on the risk of enteric pathogen transfer into the food chain and lettuce quality

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    The hygienic quality of raw edible vegetables such as lettuce may be influenced by pathogen transfer from soil to plant, which might occur during weed control by hoeing or as splash-effects during rainfall. The hygienic quality is often discussed when farmyard manures are applied during production, as e.g. in organic farming systems. In a field experiment, the effects of weed control on pathogen transfer from soil fertilised with farmyard manure to lettuce (Lactuca sativa, var. capitata) were evaluated. First results do not confirm pathogen transfer by mechanical weeding or splash effects during rainfall

    Great Bay Coast Watch: A Citizen Water Monitoring Program Volunteer Water Quality Monitoring Manual, 2004

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    The Great Bay Coast Watch is citizen volunteers, working within the UNH Cooperative Extension/NH Sea Grant Program, protecting the long-term health and natural resources of New Hampshire’s coastal waters and estuarine systems through monitoring and education projects. The purpose of this document is to present step-by-step instructions for conducting water quality testing in support of the Great Bay Coast Watch (GBCW)
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