162 research outputs found
Using native warm-season grass, forb and legume mixtures for biomass, livestock forage and wildlife benefits : a case study (2017)
Case StudyThis guide is a companion to MU Extension publications G9422, Integrating Practices That Benefit Wildlife With Crops Grown for Biomass in Missouri, and G9423, Mixtures of Native Warm-Season Grasses, Forbs and Legumes for Biomass, Forage and Wildlife Habitat, which outlines the benefits of using these mixtures of native warm-season forages and provides information to help landowners make informed decisions on enhancing wildlife habitats while producing crops for biomass. Establishment and management practices, as well as yield results, are presented as a case study in this guide so that others can implement similar practices on their property
Soil Berms as an Alternative to Steel Plate Borders for Runoff Plots
ABSTRACT 2000), reducing soil surface sealin
The influence of external factors on bacteriophages—review
The ability of bacteriophages to survive under unfavorable conditions is highly diversified. We summarize the influence of different external physical and chemical factors, such as temperature, acidity, and ions, on phage persistence. The relationships between a phage’s morphology and its survival abilities suggested by some authors are also discussed. A better understanding of the complex problem of phage sensitivity to external factors may be useful not only for those interested in pharmaceutical and agricultural applications of bacteriophages, but also for others working with phages
Waterborne microbial risk assessment : a population-based dose-response function for Giardia spp. (E.MI.R.A study)
BACKGROUND: Dose-response parameters based on clinical challenges are frequently used to assess the health impact of protozoa in drinking water. We compare the risk estimates associated with Giardia in drinking water derived from the dose-response parameter published in the literature and the incidence of acute digestive conditions (ADC) measured in the framework of an epidemiological study in a general population. METHODS: The study combined a daily follow-up of digestive morbidity among a panel of 544 volunteers and a microbiological surveillance of tap water. The relationship between incidence of ADC and concentrations of Giardia cysts was modeled with Generalized Estimating Equations, adjusting on community, age, tap water intake, presence of bacterial indicators, and genetic markers of viruses. The quantitative estimate of Giardia dose was the product of the declared amount of drinking water intake (in L) by the logarithm of cysts concentrations. RESULTS: The Odds Ratio for one unit of dose [OR = 1.76 (95% CI: 1.21, 2.55)] showed a very good consistency with the risk assessment estimate computed after the literature dose-response, provided application of a 20 % abatement factor to the cysts counts that were measured in the epidemiological study. Doing so, a daily water intake of 2 L and a Giardia concentration of 10 cysts/100 L, would yield an estimated relative excess risk of 12 % according to the Rendtorff model, against 11 % when multiplying the baseline rate of ADC by the corresponding OR. This abatement parameter encompasses uncertainties associated with germ viability, infectivity and virulence in natural settings. CONCLUSION: The dose-response function for waterborne Giardia risk derived from clinical experiments is consistent with epidemiological data. However, much remains to be learned about key characteristics that may heavily influence quantitative risk assessment results
Renewable energy from Cyanobacteria: energy production optimization by metabolic pathway engineering
The need to develop and improve sustainable energy resources is of eminent importance due to the finite nature of our fossil fuels. This review paper deals with a third generation renewable energy resource which does not compete with our food resources, cyanobacteria. We discuss the current state of the art in developing different types of bioenergy (ethanol, biodiesel, hydrogen, etc.) from cyanobacteria. The major important biochemical pathways in cyanobacteria are highlighted, and the possibility to influence these pathways to improve the production of specific types of energy forms the major part of this review
A somatic coliphage threshold approach to improve the management of activated sludge wastewater treatment plant effluents in resource-limited regions
Versión aceptada para publicaciónEffective wastewater management is crucial to ensure the safety of water reuse projects and
29 effluent discharge into surface waters. Multiple studies have demonstrated that municipal
30 wastewater treatment with conventional activated sludge processes is inefficient for the removal
31 of the wide spectrum of viruses in sewage. In this study, a well-accepted statistical approach was
32 used to investigate the relationship between viral indicators and human enteric viruses during
33 wastewater treatment in a resource-limited region. Influent and effluent samples from five urban
34 wastewater treatment plants (WWTP) in Costa Rica were analyzed for somatic coliphage and
35 human enterovirus, hepatitis A virus, norovirus genotype I and II, and rotavirus. All WWTP
36 provide primary treatment followed by conventional activated sludge treatment prior to
37 discharge into surface waters that are indirectly used for agricultural irrigation. The results
38 revealed a statistically significant relationship between the detection of at least one of the five
39 human enteric viruses and somatic coliphage. Multiple logistic regression and Receiver
Operating Characteristic curve analysis identified a threshold of 3.0 ×103 40 (3.5-log10) somatic
41 coliphage plaque forming unit per 100 mL, which corresponded to an increased likelihood of
encountering enteric viruses above the limit of detection (>1.83×102 42 virus target/100 mL).
43 Additionally, quantitative microbial risk assessment was executed for famers indirectly reusing
44 WWTP effluent that met the proposed threshold. The resulting estimated median cumulative
45 annual disease burden complied with World Health Organization recommendations. Future
46 studies are needed to validate the proposed threshold for use in Costa Rica and other regions.Universidad de Costa Rica/[]/UCR/Costa RicaNational Science Foundation/[OCE-1566562]/NSF/Estados UnidosUCR::Vicerrectoría de Investigación::Unidades de Investigación::Ciencias de la Salud::Instituto de Investigaciones en Salud (INISA)UCR::Vicerrectoría de Docencia::Salud::Facultad de Microbiologí
Fates of bacteriophages and bacterial indicators in the Moselle river (France)
International audienceIt has been suggested that bacteriophages can provide useful information about the pathogenic microorganisms, particularly enteric viruses, present in water. This information is complementary to that obtained from bacterial indicators of faecal contamination, which would be of great value for evaluating the risks associated with the use of certain types of water. Before bacteriophages can be used as indicators of faecal contamination, we need to confirm that bacteriophages give a different response to that given by the well-known bacteria indicators and to determine what happens to bacteriophages in river water. Indeed, drinking water is often produced from river water, either by natural filtration through the soil or after undergoing various treatments. We collected 96 river water samples from six different sites between February and November 2000. The samples were analysed for three faecal indicator bacteria (thermotolerant coliforms, enterococci and spores of sulphite-reducing anaerobes) and three types of bacteriophages (somatic coliphages, F-specific phages and Bacteroides fragilis phages). The densities of thermotolerant coliforms and enterococci depended mainly on physical factors such as flow rate and water temperature. High temperature and low flow rate led to a decrease in the density of these microorganisms, especially in the absence of a major input of faecal pollution. Conversely, the densities of somatic coliphages, F-specific phages and spores of sulphite-reducing anaerobes remained constant regardless of the flow rate and temperature. The density of Bacteroides fragilis phages was too low for unambiguous determination of their fate in river water
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