510 research outputs found
The effects of algae pre-treatment on the biomethane potential of swine wastewater
Anaerobic digestion is a common method of waste treatment in the agro-industrial and municipal sectors, which utilizes microbial metabolisms that take place in an environment closed to the atmosphere to convert the organic content of wastewater into gas composed of approximately 65% methane and 35% carbon dioxide. This gas can be used as a combustible fuel for the production of heat and/or electricity. Anaerobic digestion is not typically used to treat swine waste because of its low carbon to nitrogen ratio being below the ideal range of 20-30:1. This high nitrogen content of swine waste results in ammonia inhibition of the methanogen microbial consortia, which are responsible for the production of methane. A periphytic algae cultivator (PAC) is a system in which high nutrient wastewaters; such as swine waste, can be circulated over a bed of algae. In this process, all ammonia nitrogen is taken out of solution through volatilization into the atmosphere and uptake by the algae. Also, the algae facilitate the conversion of carbon dioxide into organic compounds, increasing the carbon to nitrogen ratio of wastewater. The goal of the project was to test the hypothesis that treating swine wastewaters with a PAC results in a significant increase in biomethane potential of the waste by increasing its carbon to nitrogen ratio and overall organic content, making it a more suitable feedstock for anaerobic digestion. This is significant because, if successful, the research could contribute to the development of a more economically feasible method of utilizing and recycling nutrients in agro-industrial and municipal wastewaters for the cultivation of algae to be used as a renewable energy source. It was found in the project that algae pre-treatment of swine wastewater results in a lower ammonia concentration and higher VS and COD contents, which leads to a better conversion of the substrate into methane and a larger reductions of VS and COD contents of the wastewater resulting from anaerobic digestion
A Laboratory-Scale Study on the Production of High-Value Products from Broiler Litter Involving Solid-State Anaerobic Digestion and Mushroom Cultivation
There is a need to investigate alternate uses and treatments of broiler litter that lessen environmental impacts and decrease costs associated with its disposal. Anaerobic digestion is a biological process in which organic material is converted to a renewable fuel source. However, the substrate for anaerobic digestion often requires some form or pretreatment. Certain types of fungus have been investigated as a pretreatment for anaerobic digestion, one of which is Pleurotis ostreatus or the oyster mushroom, which also produces an edible fruiting body. Thus, this study was performed to investigate the use of broiler litter for oyster mushroom cultivation and anaerobic digestion in terms of effects their effects on broiler litter characteristics, effects of mushroom cultivation on anaerobic digestion, and the yields associated with the two treatments.
It was found that the addition of 75% wheat straw was required to culture edible oyster mushrooms using broiler litter and that mushroom yields were larger than those for 100% wheat straw. Mushroom cultivation had either negative to no impacts on subsequent methane yields from anaerobic digestion. However, it was also found that lignin and soluble phosphorus contents could be reduced by mushroom cultivation while soluble nitrogen and extractives contents were increased. It was also found that nitrate concentrations were increased by mushroom cultivation, which could explain the decrease in yields from subsequent anaerobic digestion.
Although methane yields were not increased by fungal pretreatment, it was concluded that the cultivation of oyster mushrooms on broiler litter could have significant impacts by adding more value to the waste material through the production of edible mushrooms and the improvement of fertilizer value. It was also concluded that there is a need for further research to explain the decrease in methane production following the fungal pretreatment, and to possibly find an additional pretreatment to account for this. Several questions were answered as to the general concept of utilizing broiler litter for both oyster mushroom cultivation and anaerobic digestion, but many other question must be answered before the findings discussed can be used to make recommendations to those involved in the poultry and mushroom industries
Urban Agriculture and Community Food Security in the United States: Farming from the City Center To the Urban Fringe
Urban Agriculture and Community Food Security in the United States: Farming from the City Center To the Urban Fringe is prepared by the Urban Agriculture Committee of the Community Food Security Coalition to raise awareness of the ways that urban agriculture can respond to food insecurity. The document advocates for policies that promote small-scale urban and peri-urban farming, and thereby prepare the next generation of urban farming leaders
Using the INTACT method to study PICKLE in individual cell types
Cell differentiation is an essential part of development in multicellular organisms. Cells with identical genomic DNA are able to differentiate into a variety of tissues due to selective expression and repression of genes. This tissue-specific gene expression is enabled in part by proteins called chromatin remodelers, which can move, remove, or restructure histone proteins to restrict or allow physical access to genomic DNA. PICKLE (PKL) is a member of the CHD family of ATP-dependent chromatin remodelers that promotes cellular identity in the plant model organism Arabidopsis thaliana. PKL promotes cell identity by silencing embryonic genes during seed germination by promoting the repressive epigenetic modification trimethylation of lysine 27 on histone H3 (H3K27me3). However, the contributions of PKL to H3K27me3 and gene expression have only been studied on an organism-wide scale. Due to the wide variety of tissues that comprise a plant, the specific role of PKL in a given cell type cannot be determined by examining levels of gene expression and epigenetic modifications as averaged across the organism. Through use of the INTACT (isolating nuclei tagged in specific cell types) method, nuclei of two different cell types will be tagged and purified from both wild-type Arabidopsis and Arabidopsis lacking functional PKL. Isolating nuclei from one cell type at a time will allow us to study the function of PKL at a much higher resolution. This will provide both a better understanding of PKL function and a precedent for studies of how CHD chromatin remodelers regulate gene expression in other organisms
Fetal alcohol spectrum disorder and Risk-Need-Responsivity Model: A guide for criminal justice and forensic mental health professionals
Fetal alcohol spectrum disorder (FASD) is an umbrella term used to describe a range of significant neurodevelopmental, brain-based disorders and impairments that result from prenatal alcohol exposure. FASD is a high prevalence but underdiagnosed group of disorders affecting between 17 and 36% of individuals in criminal justice settings. Despite being a high-impact disorder associated with lifelong impairments with a significant need for services and interventions, little research has been completed on how to best support individuals with these conditions in criminal justice settings. This article proposes a renewed focus on applying and adapting the Risk-Need-Responsivity (RNR) approach to individuals with FASD in criminal justice settings. This will assist in better determining the needs and interventions likely to effect change and reduce recidivism for this prominent criminal justice-based population. The RNR approach has been used with multiple corrections populations to determine the need and most appropriate interventions, as well as how to best allocate scarce resources. As the prevalence of FASD becomes better understood and recognized, evidence-based approaches to addressing this specific sub-population are necessary to effect change and reduce recidivism and ongoing involvement in the criminal justice system
Research Notes : United States : Seed yield on field-grown ms2 ms2 male-sterile plants
Seed set on male-sterile plants is of general interest to geneticists. For the quantitative geneticist, high seed set allows greater flexibility in the design of basic genetic experiments, including selection and variance com-ponent estimation studies. For the plant breeder, high seed set raises a hope of hybrid soybean production. Hybrid production, to be economical, requires adequate seed yield on male-sterile plants grown in the field
Research Notes : Seed set on G. falcata and a proposal to use ms2 male-sterility in its hybridization with G. max
Seed set: Limited seed supply has severely curtailed research on G. falcata. Seed supply is limited primarily because G. falcata sets few seed in the greenhouse, even though flower production is rather profuse. We noticed this past summer that seed set is quite high when we grow this species out-of-doors near a honeybee hive
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