Phosphorous forms in cultivated indian black earth (anthrosols) of varying texture in the brazilian Amazon

Despite the agricultural importance of Indian Black Earth (IBE) in the Amazon region, there are few studies that report on the relation between soil texture and chemical fertility of IBE. These soils of pre-Colombian origin, with high contents of P, Ca and other nutrients are found across the Amazon valley. IBE profiles were studied to evaluate the total contents of P, its primary chemical forms and the P transformation phases in areas with IBE soils of variable texture and in adjacent reference soils. The soil texture strongly influenced soil fertility, changing in terms of transformation of the primary P forms and, consequently, predominant P forms in IBE. Soils with texture varying between clay and heavy clay had higher total P contents and primary Ca-P forms. Highest P-Al and lowest total P amounts were observed at the site Rio Preto da Eva, where texture varies from sandy loam to sandy clay loam. In the IBE with clay texture the amounts of soluble P, extracted with NH4Cl were highest, although different from Mehlich 1-extractable amounts.

Contribution of humic substances from different composts to the synthesis of humin in a tropical soil

The contribution of humic substances of different composts to the synthesis of humin in a tropical soil was evaluated. Increasing doses (0, 13, 26, 52, and 104 Mg ha-1) of five different composts consisting of agroinpowderrial residues were applied to a Red-Yellow Latosol. These composts were chemically characterized and 13C NMR determined and the quantity of the functional alkyl groups of humic acids applied to the soil as compost was estimated. Thirty days after application of the treatments, organic matter samples were collected for fractionation of humic acids (HA), fulvic acids (FA) and humin (HU), from which the ratios HA/FA and (HA + FA)/HU were calculated. The application of the composts based on castor cake resulted in the highest HU levels in the soil; alkyl groups of the HA fraction of the composts were predominant in the organic components added to the HU soil fraction.

Effects of Exemestane and Tamoxifen Treatment on Bone Texture Analysis Assessed by TBS in Comparison With Bone Mineral Density Assessed by DXA in Women With Breast Cancer.

We performed an analysis of a substudy of the randomized Tamoxifen Exemestane Adjuvant Multinational trial to determine the effects of exemestane (EXE) and tamoxifen (TAM) adjuvant treatment on bone mineral density (BMD) measured by dual-energy X-ray absorptiometry compared with the trabecular bone score, a novel grey-level texture measurement that correlates with 3-dimensional parameters of bone texture in postmenopausal women with hormone receptor-positive breast cancer for the first time. In total, 36 women were randomized to receive TAM (n = 17) or EXE (n = 19). Patients receiving TAM showed a mean increase of BMD in lumbar spine from baseline of 1.0%, 1.5%, and 1.9% and in trabecular bone score of 2.2%, 3.5%, and 3.3% at 6-, 12-, and 24-mo treatment, respectively. Conversely, patients receiving EXE showed a mean decrease from baseline in lumbar spine BMD of -2.3%, -3.6%, and -5.3% and in trabecular bone score of -0.9%, -1.7%, and -2.3% at 6-, 12-, and 24-mo treatment, respectively. Changes in trabecular bone score from baseline at spine were also significantly different between EXE and TAM: p = 0.05, 0.007, and 0.006 at 6, 12, and 24mo, respectively. TAM induced an increase in BMD and bone texture analysis, whereas EXE resulted in decreases. The results were independent from each other.

Clear Zone – A Synthesis of Practice and an Evaluation of the Benefi ts of Meeting the 10-ft Clear Zone Goal on Urban Streets, November 2008

In urban communities, there are often limited amounts of right-of-way available for establishing a large setback distance from the curb for fixed objects. Urban communities must constantly weigh the cost of purchasing additional right-of-way for clear zones against the risk of fixed object crashes. From 2004 to 2006, this type of crash on curbed roads represented 15% of all fatal crashes and 3% of all crashes in the state of Iowa. Many states have kept the current minimum AASHTO recommendations as their minimum clear zone standards; however, other states have decided that these recommendations are insufficient and have increased the required minimum clear zone distance to better suit the judgment of local designers. This report presents research on the effects of the clear zone on urban curbed streets. The research was conducted in two phases. The first phase involved a synthesis of practice that included a literature review and a survey of practices in jurisdictions that have developmental and historical patterns similar to those of Iowa. The second phase involved investigating the benefits of a 10 ft clear zone, which included examining urban corridors in Iowa that meet or do not meet the 10 ft clear zone goal. The results of this study indicate that a consistent fixed object offset results in a reduction in the number of fixed object crashes, a 5 ft clear zone is most effective when the goal is to minimize the number of fixed object c ashes, and a 3 ft clear zone is most effective when the goal is to minimize the cost of fixed object crashes.

The small RNA PhrS stimulates synthesis of the Pseudomonas aeruginosa quinolone signal.

Quorum sensing, a cell-to-cell communication system based on small signal molecules, is employed by the human pathogen Pseudomonas aeruginosa to regulate virulence and biofilm development. Moreover, regulation by small trans-encoded RNAs has become a focal issue in studies of virulence gene expression of bacterial pathogens. In this study, we have identified the small RNA PhrS as an activator of PqsR synthesis, one of the key quorum-sensing regulators in P. aeruginosa. Genetic studies revealed a novel mode of regulation by a sRNA, whereby PhrS uses a base-pairing mechanism to activate a short upstream open reading frame to which the pqsR gene is translationally coupled. Expression of phrS requires the oxygen-responsive regulator ANR. Thus, PhrS is the first bacterial sRNA that provides a regulatory link between oxygen availability and quorum sensing, which may impact on oxygen-limited growth in P. aeruginosa biofilms.

Durable, Cost-Effective Pavement Markings Phase I: Synthesis of Current Research, June 2001

Pavement marking technology is a continually evolving subject. There are numerous types of materials used in the field today, including (but not limited to) paint, epoxy, tape, and thermoplastic. Each material has its own set of unique characteristics related to durability, retro reflectivity, installation cost, and life-cycle cost. The Iowa Highway Research Board was interested in investigating the possibility of developing an ongoing program to evaluate the various products used in pavement marking. This potential program would maintain a database of performance and cost information to assist state and local agencies in determining which materials and placement methods are most appropriate for their use. The Center for Transportation Research and Education at Iowa State University has completed Phase I of this research: to identify the current practice and experiences from around the United States to recommend a further course of action for the State of Iowa. There has been a significant amount of research completed in the last several years. Research from Michigan, Pennsylvania, South Dakota, Ohio, and Alaska all had some common findings: white markings are more retro reflective than yellow markings; paint is by-and-large the least expensive material; paint tends to degrade faster than other materials; thermoplastic and tapes had higher retro reflective characteristics. Perhaps the most significant program going on in the area of pavement markings is the National Transportation Product Evaluation Program (NTPEP). This is an ongoing research program jointly conducted by the American Association of State Highway and Transportation Officials and its member states. Field and lab tests on numerous types of pavement marking materials are being conducted at sites representing four climatological areas. These results are published periodically for use by any jurisdiction interested in pavement marking materials performance.At this time, it is recommended that the State of Iowa not embark on a test deck evaluation program. Instead, close attention should be paid to the ongoing evaluations of the NTPEP program. Materials that fare well on the NTPEP test de cks should be considered for further field studies in Iowa.

The Design of Forest Taxation: A Synthesis with New Directions

Summary

Metabolic engineering of plants for the synthesis of polyhydroxyalkanoates

Synthesis of polyhydroxyalkanoates (PHAs) in crop is viewed as an attractive approach for the production of this family of biodegradable plastics in large quantities and at low costs. Synthesisof PHAs containing various monomers has so far been demonstrated in the cytosol, plastids, and peroxisomes of plants. Several biochemical pathways have been modifies to achieve this, including the isoprenois pathway, the fatty acid biosynthetic pathway, and the fatty acid

Synthesis, structure, and magnetic studies on self-assembled BiFeO3-CoFe2O4 nanocomposite thin films

Self-assembled (0.65)BiFeO3-(0.35)CoFe2O4 (BFO-CFO) nanostructures were deposited on SrTiO3 (001) and (111) substrates by pulsed laser deposition at various temperatures from 500 to 800°C. The crystal phases and the lattice strain for the two different substrate orientations have been determined and compared. The films grow epitaxial on both substrates but separation of the spinel and perovskite crystallites, without parasitic phases, is only obtained for growth temperatures of around 600-650°C. The BFO crystallites are out-of-plane expanded on STO(001), whereas they are almost relaxed on (111). In contrast, CFO crystallites grow out-of-plane compressed on both substrates. The asymmetric behavior of the cell parameters of CFO and BFO is discussed on the basis of the role of the epitaxial stress caused by the substrate and the spinel-perovskite interfacial stress. It is concluded that interfacial stress dominates the elastic properties of CFO crystallites and thus it may play a fundamental on the interface magnetoelectric coupling in these nanocomposites.

Synthesis, structural order and magnetic behavior of self-assembled epsilon-Co nanocrystal arrays

The synthesis of magnetic nanoparticles with monodispere size distributions, their self assembly into ordered arrays and their magnetic behavior as a function of structural order (ferrofluids and 2D assemblies) are presented. Magnetic colloids of monodispersed, passivated, cobalt nanocrystals were produced by the rapid pyrolysis of cobalt carbonyl in solution. The size, size distribution (std. dev.< 5%) and the shape of the nanocrystals were controlled by varying the surfactant, its concentration, the reaction rate and the reaction temperature. The Co particles are defect-free single crystals with a complex cubic structure related to the beta phase of manganese (epsilon-Co). In the 2D assembly, a collective behavior was observed in the low-field susceptibility measurements where the magnetization of the zero field cooled process increases steadily and the magnetization of the field cooling process is independent the temperature. This was different from the observed behavior in a sample comprised of disordered interacting particles. A strong paramagnetic contribution appears at very low temperatures where the magnetization increases drastically after field cooling the sample. This has been attributed to the Co surfactant-particle interface since no magnetic atomic impurities are present in these samples.

Synthesis of sodium-zinc spinel ferrites

The synthesis of spinel ferrites with composition Zn1-2xNaxFe2+xO4has been performed and the composition range in which single phase samples are obtained has been defined. The characterization of the samples has been carried out from atomic absorption and X-ray fluorescence analyses, X-ray diffraction patterns, Mössbauer spectroscopy and thermomagnetic measurements. It is show that significant loss of Na does exist when the synthesis is performed at high temperatures. When the Na volatilization is avoided spinel oxides with Na content up to 0.25 atoms per unit formula can be obtained. In this case the increase of the interatomic distances leads to differing fundamental magnetic properties as compared to the equivalent lithium-zinc ferrites.

The squeeze cell hypothesis for the activation of jasmonate synthesis in response to wounding

Jasmonates are lipid mediators that control defence gene expression in response to wounding and other environmental stresses. These small molecules can accumulate at distances up to several cm from sites of damage and this is likely to involve cell-to-cell jasmonate transport. Also, and independently of jasmonate synthesis, transport and perception, different long-distance wound signals that stimulate distal jasmonate synthesis are propagated at apparent speeds of several cmmin(-1) to tissues distal to wounds in a mechanism that involves clade 3 GLUTAMATE RECEPTOR-LIKE (GLR) genes. A search for jasmonate synthesis enzymes that might decode these signals revealed LOX6, a lipoxygenase that is necessary for much of the rapid accumulation of jasmonic acid at sites distal to wounds. Intriguingly, the LOX6 promoter is expressed in a distinct niche of cells that are adjacent to mature xylem vessels, a location that would make these contact cells sensitive to the release of xylem water column tension upon wounding. We propose a model in which rapid axial changes in xylem hydrostatic pressure caused by wounding travel through the vasculature and lead to slower, radially dispersed pressure changes that act in a clade 3 GLR-dependent mechanism to promote distal jasmonate synthesis.

Synthesis of chemically functionalized superparamagnetic nanoparticles as delivery vectors for chemotherapeutic drugs.

Superparamagnetic iron oxide nanoparticles (SPIONs) are in clinical use for disease detection by MRI. A major advancement would be to link therapeutic drugs to SPIONs in order to achieve targeted drug delivery combined with detection. In the present work, we studied the possibility of developing a versatile synthesis protocol to hierarchically construct drug-functionalized-SPIONs as potential anti-cancer agents. Our model biocompatible SPIONs consisted of an iron oxide core (9-10 nm diameter) coated with polyvinylalcohols (PVA/aminoPVA), which can be internalized by cancer cells, depending on the positive charges at their surface. To develop drug-functionalized-aminoPVA-SPIONs as vectors for drug delivery, we first designed and synthesized bifunctional linkers of varied length and chemical composition to which the anti-cancer drugs 5-fluorouridine or doxorubicin were attached as biologically labile esters or peptides, respectively. These functionalized linkers were in turn coupled to aminoPVA by amide linkages before preparing the drug-functionalized-SPIONs that were characterized and evaluated as anti-cancer agents using human melanoma cells in culture. The 5-fluorouridine-SPIONs with an optimized ester linker were taken up by cells and proved to be efficient anti-tumor agents. While the doxorubicin-SPIONs linked with a Gly-Phe-Leu-Gly tetrapeptide were cleaved by lysosomal enzymes, they exhibited poor uptake by human melanoma cells in culture.

Glutamine synthesis rate in the hyperammonaemic rat brain using simultaneous localized in vivo H-1 and N-15 MRS

Objectives: Glutamine synthetase is a critical step in the glutamate-glutamine cycle, the major mechanism of glutamate neurotransmission and is implicated in the mechanism of ammonia toxicity. 15N MRS is an alternative approach to 13C MRS in studying glutamate- glutamine metabolism. 15N MRS studies allow to measure an apparent glutamine synthesis rate (Vsyn) which reflects a combination of the glutamate- glutamine cycle activity (Vnt) and net glutamine accumulation. The net glutamine synthesis (Vsyn-Vnt) can be directly measured from 1H NMR. Therefore, the aim of this study was to perform in vivo localized 1H MRS interleaved with 15N MRS to directly measure the net glutamine synthesis rate and the apparent glutamine synthesis rate under 15N labeled ammonia infusion in the rat brain, respectively. Methods: 1H and 15N MRS data were acquired interleaved on a 9.4T system (Varian/Magnex Scientific) using 5 rats. 15NH4Cl solution was infused continuously into the femoral vein for up to 10 h (4.5 mmol/h/kg).1 The plasma ammonia concentration was increased to 0.95±0.08 mmol/L (Analox GM7 analyzer). 1H spectra were acquired and quantified as described previously.2 15N unlocalized and localized spectra were acquired using the sequence;3 and quantified using AMARES and an external reference method.4 The metabolic model used to analyze the total Gln and 5-15N labeled Gln time courses is shown on Figure 1A. Results: Glutamine concentration increased from 2.5±0.3 to 15±3.3 mmol/kg whereas the total glutamate concentrations remained unchanged (Figure 1B). The linear fit of the time-evolution of the total Gln from the 1H spectra gave the net synthesis flux (Vsyn-Vnt), which was 0.021± 0.006 mmol/min per g (Figure 1D). The 5-15N Gln peak (_271 ppm) was visible in the first and all subsequent scans, whereas the 2-15N Gln/Glu peak (_342 ppm) appeared after B1.5 h (Figure 1C). From the in vivo 5-15N Gln time course, Vsyn = 0.29±0.1 mmol/min per g and a plasma NH3 fractional enrichment of 71%±6% were calculated. Vnt was 0.26±0.1 mmol/min/g, obtained assuming a negligible Gln efflux.5 Vsyn and Vnt were within the range of 13C NMR measurements.6 Conclusion: The combination of 1H and 15N NMR allowed for the first time a direct and localized measurement of Vnt and apparent glutamine synthesis rate. Vnt is approximately one order of magnitude faster than the net glutamine accumulation.