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

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

Cloning of mouse integrin alphaV cDNA and role of the alphaV-related matrix receptors in metanephric development.

Metanephrogenesis has been a long-standing model to study cell-matrix interactions. A number of adhesion molecules, including matrix receptors (i.e., integrins), are believed to be involved in such interactions. The integrins contain alpha and beta s ubunits and are present in various tissues in different heterodimeric forms. In this study, one of the members of the integrin superfamily, alphaV, was characterized, and its relevance in murine nephrogenesis was investigated. Mouse embryonic renal cDNA libraries were prepared and screened for alphaV, and multiple clones were isolated and sequenced. The deduced amino acid sequence of the alpha-v cDNA clones and hydropathic analysis revealed that it has a typical signal sequence and extracellular, transmembrane, and cytoplasmic domains, with multiple Ca2+ binding sites. No A(U)nA mRNA instability motifs were present. Conformational analysis revealed no rigid long-range-ordered structure in murine alphaV. The alphaV was expressed in the embryonic kidney at day 13 of the gestation, with a transcript size of approximately 7 kb. Its expression increased progressively during the later gestational stages and in the neonatal period. It was distributed in the epithelial elements of developing nephrons and was absent in the uninduced mesenchyme. In mature metanephroi, the expression was relatively high in the glomeruli and blood vessels, as compared to the tubules. Various heterodimeric associations of alphaV, i.e., with beta1, beta3, beta5, and beta6, were observed in metanephric tissues. Inclusion of alphaV-antisense-oligodeoxynucleotide or -antibody in metanephric culture induced dysmorphogenesis of the kidney with reduced population of the nephrons, disorganization of the ureteric bud branches, and reduction of mRNA and protein expressions of alphaV. The expressions of integrin beta3, beta5, and beta6 were unaltered. These findings suggest that the integrin alphaV is developmentally regulated, has a distinct spatio-temporal expression, and is relevant in the mammalian organogenesis

Micropropagation of 'Wild Pear' Pyrus pyrifolia (Burm F.) Nakai. I. Explant Establishment and Shoot Multiplication

The study was undertaken to standardize in vitro explant establishment and shoot multiplication technique for wild pear. The highest explant establishment (77.88%) was observed during spring, which was on a par with explant establishment frequency during winter season (76.21%). The lowest explant establishment was observed during rainy season (61.94%). The establishment frequency for shoot tips (69.07%) was significantly less than the establishment frequency for nodal segments (71.95%). The antibrowning agents decreased explant browning, yet they could not eliminate it. The magnitude of the effect of the antibrowning agents depended on the season of explant collection and type of explant. Antibrowning agents were more useful during spring and winter seasons when the incidence of browning was low, in comparison to rainy, summer and autumn seasons when the browning was comparatively high. Though, the highest number of shoots (11.24/ culture) were obtained with 2.0 mg per litre BA, but this BA level did not produce shoots of desirable length (>2.0 cm). BA (1.5 mg per litre) + IBA (0.5 mg per litre) was the best growth regulator combination for shoot multiplication in wild pear as it produced sufficient number of shoots (10.21 shoots per culture) having desirable shoot length. The highest number of shoots per culture (11.20) was obtained with Woody Plant Medium (WPM), followed by MS medium (10.21). The highest shoot length (3.21 cm) was observed with MS Medium and it was on a par with WPM

Poulty Manure Impacts on Water Quality

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

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

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)

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

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

Decision support for nitrogen management in tile-drained agriculture

Farmers will adopt alternative management systems to improve water quality more readily if they understand how those management alternatives affect the release of contaminants, crop yields, and ultimately, their net income. We propose a method to address these issues by integrating observed data from field experiments, a comprehensive simulation model, review by local experts, and application through a decision support system by technically trained conservationists. An example for reducing nitrogen loading from tile-drained corn and soybean production in Iowa demonstrates the approach. Fourteen years of observed data from 30 research plots on the Northeast Research and Demonstration Farm near Nashua, Iowa were used to calibrate the Root Zone Water Quality Model (RZWQM) to simulate the effects of 35 management systems on crop yields and nitrogen (N) loadings into tile drains. The EconDocs tool was used for an economic analysis of the management effects. An Expert Panel reviews the simulations and the long term average annual management effects. Those management effects, as well as the daily values of variables that describe the crop growth and nitrogen loading in tile flow processes, are put into a database. As part of the conservation planning process, Conservationists and farmers would use the database inside a decision support system to select management systems that meet the farmers\u27 goals and reduce water quality problems

Comparison of Saturated Hydraulic Conductivity Measurement Methods for a Glacial-Till Soil

Hydraulic conductivity is the single most important hydraulic parameter for flow and transport-related phenomena in soil, but the results from different measuring methods vary under different field conditions. To evaluate the performance of four in situ saturated hydraulic conductivity (Ks) measuring methods, Ks measurements were made at four depths (15, 30, 60, and 90 cm) and five locations on a glacial-till soil of Nicollet (fine-loamy, mixed, mesic Aquic Hapludoll)-Clarion (fine-loamy, mixed, mesic Typic Hapludoll) association. The four in situ methods were: (i) Guelph permeameter, (ii) velocity permeameter, (iii) disk permeameter, and (iv) double-tube method. The Ks was also determined in the laboratory on undisturbed soil cores collected from all the five sites and four depths. The Guelph permeameter method gave the lowest Ks values, possibly because of small sample size, whereas the disk permeameter and double-tube methods gave maximum values for Ks with minimum variability, possibly because of large sample size. Maximum variability in Ks values for soil cores at shallow depths may have occurred because of the presence or absence of open-ended macropores. Estimates of Ks, however, are most comparable for the velocity permeameter and the laboratory method using a constant-head permeameter