1,547 research outputs found

    Poulty Manure Impacts on Water Quality

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    Iowa\u27s egg industry continues to grow each year. In 2001, Iowa became the number one egg producing state in the US, producing 8.69 billion eggs (USDA, 2003; USDA 2002). Iowa broke its record the following year producing 10.1 billion eggs which it topped again in 2003 producing 10.1 billion eggs, thus maintaining its position as number one egg producing state in the US (USDA, 2003; USDA, 2004). With this success comes the added weight of maintaining this status, as well as, managing for all the manure that is generated by being the number one producer. Poultry manure can be a valuable soil amendment for adding organic matter and nutrients to farm fields, but if not managed properly, it can also impact the environment by deteriorating water quality. Lakes, rivers, and streams can receive excessive nutrient loads and be contaminated by surface runoff and subsurface drain water. It is the purpose of this study to gain a better understanding on how poultry manure applied to Iowa soils impacts crop growth, soil nutrients, and water quality

    Toll like receptors play a role in general immunity, eye infection and inflammation : TLRs for nanodelivery

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    Dendritic cells [DCs] are potent antigen presenting cells [APC], which plays a vital role in immune system by detecting and capturing pathogens in the body. DCs perform a pivotal role in induction of T cell response. Regulation of immune response can be achieved by specific antigen [Ag] delivery to DCs. A delivery system that can efficiently target and present Ags to DCs for the purpose of anti-tumour activity is currently a topic of significant research interest. DCs are receiving attention due to their key role in anti cancer host response and due to their adjuvanic property in tumour vaccines. Role of toll like receptors [TLR] in innate immune system and their part in eventual stimulation of adaptive immunity is exploited to develop vaccines. TLR agonists in conjugation with vaccines are shown to increase therapeutic efficacy in some cases. TLRs also play a vital role in protecting the cornea from invading pathogens. Due to adverse effects in the treatment of ocular inflammations, cancer and in viral infections, an alternate approach such as the use of TLRs will solve the inquisitive question regarding side effects. The intended delivery is attained by the use of nanoparticles which in turn leads to prolonged half-life in the body. Co-delivery of Ags, TLRs and immunomodulators using nanoparticles has been demonstrated to elicit potent cellular immune responses and are currently under development of clinically applicable immunisations and vaccines

    Polycation-siRNA nanoparticles can disassemble at the kidney glomerular basement membrane

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    Despite being engineered to avoid renal clearance, many cationic polymer (polycation)-based siRNA nanoparticles that are used for systemic delivery are rapidly eliminated from the circulation. Here, we show that a component of the renal filtration barrier—the glomerular basement membrane (GBM)—can disassemble cationic cyclodextrin-containing polymer (CDP)-based siRNA nanoparticles and, thereby, facilitate their rapid elimination from circulation. Using confocal and electron microscopies, positron emission tomography, and compartment modeling, we demonstrate that siRNA nanoparticles, but not free siRNA, accumulate and disassemble in the GBM. We also confirm that the siRNA nanoparticles do not disassemble in blood plasma in vitro and in vivo. This clearance mechanism may affect any nanoparticles that assemble primarily by electrostatic interactions between cationic delivery components and anionic nucleic acids (or other therapeutic entities)

    Comparison of Simulated (DRAINMOD) and Measured Tile Outflow and Water Table Elevations From Two Field Sites in Iowa

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    Four years of field data on subsurface drain flows and water table elevations from two experimental sites in Iowa were used to compare the predicted values by DRAINMOD, a water management model. DRAINMOD simulations conducted for Nicollet silt loam and Kenyon loam soils of Iowa predicted water table elevations within an average deviation of 15 cm and 19 cm, respectively. The subsurface drain outflows predicted by DRAINMOD were within an average deviation of 0.065 cm/day

    E. coli Fate and Transport in Macroporous Soils: Short-Circuiting to the Subsurface

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    Pathogen concentrations in streamflow are commonly reported as a significant cause of water quality degradation throughout the world. Research has begun to attempt to model pathogen fate and transport, primarily through surface runoff mechanisms. A significant component of pathogen movement to streams commonly identified but not explicitly simulated in many models is pathogen movement to the subsurface, which can be important in several scenarios such as tile drainage systems. As colloidal contaminants, pathogens such as E. coli tend to become physically trapped in the soil matrix but can move quickly through soil macropores. In fact, concerns exist about the rapid transport of contaminants, such as pesticides, pathogens, and nutrients, from the soil surface to ground water through macropores. Recent research suggests short-circuiting or direct hydrologic connectivity between macropores and subsurface drains. The objective of this paper is to provide an overview of the current research regarding the fate and transport of E. coli through soil macropores and into subsurface drain systems. This paper reports early results from the first year of a multi-year study funded by the USDA Cooperative State Research, Education, and Extension Service as part of the their National Research Initiative program. Field experiments to document short-circuiting by macropores are described and also laboratory data is presented from soil column experiments, capable of simulating surface-connected macropores, with artificial subsurface drainage boundary conditions. These column studies generated information regarding the importance of directly connected macropores on pathogen transport to subsurface drains
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