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Experiments were performed, using eighteen 280 cm deep soil columns with 20 cm inside diameter, to determine the relative amounts of nitrogenous compounds leached and volatilized from soils receiving high application rates of cheese whey during two seasons. Three soils (loamy sand, sandy loam and sandy clay loam) and two cheese whey application rates (560 and 840 kg-N [ha.sup.-1]), that provided twice and three times the nitrogen requirement for corn crop, were investigated. The leaching and volatilization processes were monitored over a period of five months each season. The concentrations of nitrogenous compounds in the leachates obtained from three soils decreased with time and the soil type and whey application rate did not have any significant effect on the soil removal efficiency of these compounds. However, higher concentrations were observed in the second season of application. The decline in the ammonium nitrogen concentrations in the absence of plants and the initial increase in the nitrite nitrogen and nitrate nitrogen concentrations indicated that the nitrification process had taken place. The organic nitrogen losses in the leachates were 3.02-4.14 kg [h.sup.-1] (0.54-0.74 % of the initial total nitrogen). The total inorganic ([NH.sub.4], [NO.sub.2], [NO.sub.3]) nitrogen losses in the leachates were 59-76 mg which is higher than the initial concentration of 55 mg indicating that the mineralization process had taken place. Volatilization of [NH.sub.3] was independent of soil type and whey application rate. About 3.41 [g.sup.-1][ha.sup.-1] (0.59 % of the initial total nitrogen) of nitrogen was lost to the atmosphere through volatilization Nitrite and nitrate are highly soluble and easily leach out of soil solution. Therefore, continuous application of cheese whey at higher rates may result in ground water contamination and eventually becomes a threat to human and animal health. Key words: Cheese whey, soil, organic nitrogen, ammonium nitrogen, nitrite nitrogen, nitrate nitrogen, ammonia nitrogen, soil depth, air, water, pollution, INTRODUCTION Cheese whey is a greenish liquid by-product of the cheese making industry. About 9 kg of whey are produced for each kilogram of cheese. The whey contains approximately 5% [...]

Synergy study is of great importance to optimize the two-stage plasma-facilitated catalysis system and also necessary to gain a mechanistic understanding of the overall reaction process. In this paper, the effects of the long-lived chemical products of plasma pretreatment on the subsequent selective catalytic reduction (SCR) of N[O.sub.x] at fixed and changed energy density of dielectric-barrier-discharge plasma reactor were investigated, respectively, for the aim of the synergy study of plasma-facilitated [C.sub.2][H.sub.4]-SCR (PF-SCR) of N[O.sub.x] over Ag/[gamma]-[Al.sub.2][O.sub.3] catalyst at lower temperature. For comparison, [C.sub.2][H.sub.4]-SCR of N[O.sub.x] over Ag/[gamma]-[Al.sub.2][O.sub.3] catalyst alone was also considered. Results showed that PF-SCR for N[O.sub.x] removal exhibited obvious synergistic effect at 240 [degrees]C, and the N[O.sub.x] removal efficiency for plasma alone, [C.sub.2][H.sub.4]-SCR alone, and PF-SCR were 43.6%, 6.7%, and 90.1%, respectively. In the NO/N[O.sub.2]/[C.sub.2][H.sub.4]/[O.sub.2]/[N.sub.2] system, the long-lived chemical products of plasma pretreatment for the synergistic link between plasma and catalysis included N[O.sub.2], aldehyde (formaldehyde and acetaldehyde), and nitrogen-contained organic compounds (methyl nitrate, nitro methyl, and ethyl nitrate). Among the nitrogen-contained chemical products of plasma pretreatment, the major synergistic link between plasma and catalysis was N[O.sub.2] at lower input energy density, transferred to the mutual action of N[O.sub.2] and nitrogen-contained organic compounds over catalyst at higher input energy density. Index Terms--Long-lived chemical products, nitrogen-contained organic compounds, N[O.sub.x] removal, plasma-facilitated catalysis, synergy.

Localized proliferation of lateral roots in N[O.sub.3]-rich patches is a striking example of the nutrient-induced plasticity of root development. In Arabidopsis, N[O.sub.3] stimulation of lateral root elongation is apparently under the control of a N[O.sub.3]-signaling pathway involving the ANR1 transcription factor. ANR1 is thought to transduce the N[O.sub.3] signal internally, but the upstream N[O.sub.3] sensing system is unknown. Here, we show that mutants of the NRT1.1 nitrate transporter display a strongly decreased root colonization of N[O.sub.3]-rich patches, resulting from reduced lateral root elongation. This phenotype is not due to lower specific N[O.sub.3] uptake activity in the mutants and is not suppressed when the N[O.sub.3]-rich patch is supplemented with an alternative N source but is associated with dramatically decreased ANR1 expression. These results show that NRT1.1 promotes localized root proliferation independently of any nutritional effect and indicate a role in the ANR1dependent N[O.sub.3] signaling pathway, either as a N[O.sub.3] sensor or as a facilitator of N[O.sub.3] influx into N[O.sub.3]-sensing cells. Consistent with this model, the NRT1.1 and ANR1 promoters both directed reporter gene expression in root primordia and root tips. The inability of NRT1.1-deficient mutants to promote increased lateral root proliferation in the N[O.sub.3]-rich zone impairs the efficient acquisition of N[O.sub.3] and leads to slower plant growth. We conclude that NRT1.1, which is localized at the forefront of soil exploration by the roots, is a key component of the N[O.sub.3]-sensing system that enables the plant to detect and exploit N[O.sub.3]-rich soil patches. adaptive root development | ANR1 signaling pathway | plant growth | nitrate sensing | nitrogen nutrition

The net impact of biological production and regeneration (Net Community Production) on surface water dissolved in inorganic carbon, nitrogen, phosphorus and silica are evaluated from data collected in the Antarctic Circumpolar Current (ACC). The inter-nutrient comparisons highlight the functional differences among the nutrient fluxes, in that, low surface remineralization nutrients like silicic acid depend on meridional transport to replenish surface pools, while phosphates are replenished by vertical mixing in water.

Rhizobium (Sinorhizobium) sp. strain NGR234 contains three replicons, the smallest of which (pNGR234a) carries most symbiotic genes, including those required for nodulation and lipo-chito-oligosaccharide (Nod factor) biosynthesis. Activation of nod gene expression depends on plant-derived flavonoids, NodD transcriptional activators, and nod box promoter elements. Nod boxes NB6 and NB7 delimit six different types of genes, one of which (fixF) is essential for the formation of effective nodules on Vigna unguiculata. In vegetative culture, wild-type NGR234 produces a distinct, flavonoid-inducible lipopolysaccharide (LPS) that is not produced by the mutant (NGR[OMEGA]fixF); this LPS is also found in nitrogen-fixing bacteroids isolated from V. unguiculata infected with NGR234. Electron microscopy showed that peribacteroid membrane formation is perturbed in nodule cells infected by the fixF mutant. LPSs were purified from free-living NGR234 cultured in the presence of apigenin. Structural analyses showed that the polysaccharide portions of these LPSs are specialized, rhamnose-containing O antigens attached to a modified core-lipid A carrier. The primary sequence of the O antigen is [[-3)-[alpha]-L-Rhap-(1,3)-[alpha]-L-Rhap-(l,2)-[alpha]-L-Rhap-(1-].sub.n], and the LPS core region lacks the acidic sugars commonly associated with the antigenic outer core of LPS from noninduced cells. This rhamnan O antigen, which is absent from noninduced cells, has the same primary sequence as the A-band O antigen of Pseudomonas aeruginosa, except that it is composed of L-rhamnose rather than the D-rhamnose characteristic of the latter. It is noteworthy that A-band LPS is selectively maintained on the P. aeruginosa cell surface during chronic cystic fibrosis lung infection, where it is associated with an increased duration of infection.

We have cloned and functionally characterized a N[a.sup.+]-coupled dicarboxylate transporter, SdcS, from Staphylococcus aureus. This carrier protein is a member of the divalent anion/N[a.sup.+] symporter (DASS) family and shares significant sequence homology with the mammalian N[a.sup.+]/dicarboxylate cotransporters NaDC-1 and NaDC-3. Analysis of SdcS function indicates transport properties consistent with those of its eukaryotic counterparts. Thus, SdcS facilitates the transport of the dicarboxylates fumarate, malate, and succinate across the cytoplasmic membrane in a N[a.sup.+]-dependent manner. Furthermore, kinetic work predicts an ordered reaction sequence with N[a.sup.+] ([K.sub.0.5] of 2.7 mM) binding before dicarboxylate ([K.sub.m] of 4.5 [micro]M). Because this transporter and its mammalian homologs are functionally similar, we suggest that SdcS may serve as a useful model for DASS family structural analysis.

Cyanobacteria are equipped with numerous mechanisms that allow them to survive under conditions of nutrient starvation, some of which are unique to these organisms. This review surveys the molecular mechanisms underlying acclimation responses to nitrogen and phosphorus deprivation, with an emphasis on non-diazotrophic freshwater cyanobacteria. As documented for other micro-organisms, nutrient limitation of cyanobacteria elicits both general and specific responses. The general responses occur under any starvation condition and are the result of the stresses imposed by arrested anabolism. In contrast, the specific responses are acclimation processes that occur as a result of limitation for a particular nutrient; they lead to modification of metabolic and physiological routes to compensate for the restriction. First, the general acclimation processes are discussed, with an emphasis on modifications of the photosynthetic apparatus. The molecular mechanisms underlying specific responses to phosphorus and nitrogen-limitation are then outlined, and finally the cross-talk between pathways modulating specific and general responses is described.

The interaction of 2'-azido-2'-deoxyuridine-5'-diphosphate (N(sub 3)UDP) with ribonucleotide reductase (RNR) results in the loss of the diiron tyrosyl radical (Y.) in ribonucleotide reductase 2 and formation of a nitrogen-centered radical (N.) covalently attached to C225(R-S-N.-X) in the active site of ribonucleotide reductase 1. This interaction with respect to N. showed that N. is covalently attached to the nucleotide through either the oxygen of the 3'-OH (R-S-N.-O-R') or the 3'-C (R-S-N.-C-OH).

We conducted two experiments using a modified version of the N-Back task. For younger adults, there was an abrupt increase in reaction time of about 250 ms in passing from N = 1 to N > 1, indicating a cost associated with switching of the focus of attention within working memory. Response time costs remained constant over the range N = 2 to N = 5. Accuracy declined steadily over the full range of N (Experiment 1). Focus switch costs did not interact with either working memory updating (Experiment 1), or global task switching (Experiment 2). There were no age differences in RT costs once general slowing was taken into account, but there was a larger focus-switch-related accuracy cost in older adults than in younger adults. No age sensitivity was found for either updating or global task switching. The results suggest (a) that focus switching is a cognitive primitive, distinct from task switching and updating, and (b) that focus switching shows a specific age-related deficit in the accuracy domain.

Generation of singlet and triplet 2-silylcyclopentane-1,3,-diyls and their reactivity is investigated in the thermal and photochemical denitrogenation of 2,3-diaza--7-silylbicyclo[2.2.1]-hept-2-ene. 5-Silylcyclopentene (silyl migration product) is quantitatively obtained, while 5-silylbicyclo[2.1.0]pentane (intramolecular ring-closure product) is not detected in the denitrogenation reactions.

The details of copper-catalyzed N-arylation of pi-excessive nitrogen heterocycles are specified. The coupling of either aryl iodides or aryl bromides with common nitrogen heterocycles (pyrroles, pyrazoles, indazoles, imidazoles, and triazoles) is successfully performed in good yield with catalysts derived from diamine ligands and CuI.

The O-O bond breaking reactions of methyl peroxynitrite and peroxynitrous acid was investigated using various methods. Analyses have confirmed that RO/NO2radical pairs are readily formed from cis-ROONO conformations than from trans-ROONO conformations.

The photochemistry of 2,4,6-triazido-1,3,5 triazine in a nitrogen matrix in a nitrogen matrix at 20K was studied. With the help of matrix EPR spectroscopy one could observe the generation of triplet NCN and CNN.

The findings demonstrate that the pH-dependency for NO release is linked to loop dynamics and that solvent reorganization is apparently rate-limiting for formation of the initial iron-nitrsyl bond. The fact that NO diffusion out of the distal pocket is facilitated in proteins with destabilized loop conformations suggest that binding site loop opening does indeed regulate the release of NO.

The kinase/phosphatase nitrogen regulator II(NRII, NtrB) is a member of the transmitter protein family of conserved two-component signal transduction systems. Genetic and biochemical studies of the PII-activated phosphatase activity of NRII indicate that two distinct surfaces of the C-terminal domain are involved, as identified by clusters of mutations that reduce the activity.

New applications of dibenzyl carbonate are explored by studying its reactivity with other N-nucleophiles, especially with aliphatic amines in the presence of tetraalkylphosphonium salts. The phosphonium salt promotes high selectivity toward the benzylated amine and an increase in the reaction rate too.

A novel solid-phases intramolecular N-acyliminium Pictet-Spengler reaction is presented. A range of pharmacologically interesting tri- and tetracyclic scaffolds can be accessed when the intramolecular reaction is extended to other substituted indoles and reactive heterocycles.

The use of cascade cycloaddition to synthesize new polysulfur-nitrogen heterocycles with readily available polycyclic 1,2-dithiole-3-thiones is reported. Treatment of the [1,2]dithiolo[1,4]thiazine dithione with dibenzoylacetylene give the 1:2, 1:3 or 1:4 adducts and selectivity in fair to high yields.

The examination on cage isomers of N24, N30, and N36 by theoretical calculations to determine their relative thermodynamic stability is presented. It is concluded that the specific arrangement of pentagons relative to triangles plays a central role, leading to cylindrical structures in which nitrogen atoms keep their preferred pyramidal environments.

To validate the coexistence of the canonical form and the N3 and N7 tautomers in bulk water, a study of fourteen amino and imino tautomers of adenine was conducted in the gas phase, in a microhydrated environment and bulk water environment using the thermodynamic integration method, conductor-like polarizable continuum model and a hybrid model. It is reported that the results are consistent with the available experimental data from NMR measurement of the adenine tautometers in dimethyl sulfoxide (DMSO).

The individual H-bond energies were calculated at the B3LYP/D95 level for linear chains of H-bonding formamides containing from 2 to 15 monomeric units. The results are discussed with respect to their utility for improving the modeling of peptide structure and protein folding.

Ionic liquids based on various chelated orthoborate anions of different N-containing onium cations were synthesized using an economic synthesis strategy. The hydrophobic properties and their high fragilities of these liquids may provide model systems for fundamental liquid investigations.

The original and extended model-free (MF) formulas are perturbational expansions of slowly relaxing local structure (SRLS) models. A detailed analysis of eigenmodes and spectral densities is given.

The adsorption of nitromethane and 1,1-diamino-2,2-dinitroethylene molecules on the A1(111) surface is studied by using first-principles calculations that are based on spin-unrestricted density functional theory and the generalized gradient approximation. Determining the possible reaction mechanisms at the molecule--metallic-surface interface, is the main objective of the study.

Quantum chemical calculations were used to examine which of the three proposed atoms, C, N, or O, was present in the center of the active site of nitrogenase. The calculations yield structural, spectroscopic, and energetic support for the hypothesis that the central atom sitting in the six-iron prismane of the FeMoco is an N(super 3-) anion.

Equilibrium and kinetic isotope effects were measured for several phosphorothioate esters of p-nitrophenol (pNPPT) and the results were compared with data from phosphate esters to study the comparative inherent chemistry of the two types of esters. Results of the study suggested that leading a group bond fission in the transition state of reactions of the monoester pNPPT was more advanced than for its phosphate counterpart pNNP, while alkaline hydrolysis of the phosphorothioate diester and triester somewhat less advanced bond fission than that of their phosphate ester counterparts.

Electron paramagnetic resonance (EPR) and photoluminescence (PL) spectroscopies have been used to study Brazilian and Central African carbonados. We report the first observation of the [N.sub.2][V.sup.+] and [N.sup.+.sub.2] nitrogen defect centers in carbonados. The fact that Brazilian carbonados contain the [N.sub.3]V (previously reported), [N.sub.2][V.sup.+], and [N.sup.+.sub.2] defects, the formation of which requires complicated aggregation of nitrogen, indicates histories at elevated temperature and pressure. The observation of both the radiation-induced A1 defect, which has an annealing temperature of 700 K, and radiation defects containing two and/or five vacancies, suggest a continuous process of the formation and transformation of radiation defects in the carbonado under variable pressure and temperature conditions while in the upper mantle. The temperature at which these defects are formed varies from 300 to 1500 K. In addition we report a hydrogen-containing defect labeled H1, previously only observed in synthetic diamonds prepared by chemical vapor deposition. Together with the previously reported light carbon isotope ratio, the results of this study confirm the hypothesis that carbonados are derived from hydrocarbon source material.

The study of the lowest 18 electronic surfaces of the NCl + NCl system is presented. It plays a significant role in search of low-energy self-annihilation pathways for two dNCl molecules in their first excited state.

Quenching and self-annihilation rate constants for NCI(a) are determined using pulsed 248 nm photolysis of CIN3 to generate the metastable. Previous quenching measurements that employed different sources for NCl(a) yielded dramatically different rate constants.

The first direct kinetic measurements on the NS radical are reported. The NS radical was produced from the photolysis of N4S4 at 248nm and detected via laser-induced fluorescence.

The kinetics of N2(X, epsilon) is studied with silane and N2(X, epsilon) diagnostics employing metastable energy transfer reactions are used for this purpose. Comparison of the relative excitation rate of SiH4(epsilon3) with that for N2O(epsilon3) excitation when N2O is added to the reactor, however, indicates that at most 15% of the N2(X, epsilon) quenching events result in epsilon3 excitation.

The rovibronic Renner-Teller (RT) effect in the N[(super 2)D] + H2 reaction is studied. A new approach to describe RT coupling within the framework of trajectory surface hopping is developed for this purpose and it is predicted that the RT effect is not important to the thermal rate constant but has measurable consequences for certain state-resolved experiments.

A study demonstrates that horseradish peroxidase (HRP) catalyzes the formation of nitric oxide (NO) from the clinically used drug hydroxyurea. The results indicate that peroxidase-cataylsed nitric oxide (NO) release form hydroxy urea could play an important role in the overall pharmacological properties of the drug.

Ammonolysis of reactive oxide precursors affords the vanadium(V) phase Ba2VO3N that is shown by x-ray and neutron powder diffraction and Raman spectroscopy to contain pseudotetrahedral VO3N4- anions. Ba3V2O8 is reported to be stable under NH3, it is formed here and then reacts with BaO or Ba-rich vanadium oxide phases to afford Ba2VO3N, indicating the higher Ba:V ratio is important in stabilizing the tetrahedral oxynitride anion.

The photophysics of a series of Poly-( L-lysines) and monomer cyanine dye are studied and the photophysics of the series and monomer cyanine dye is studied in the solution. The study permits a semiquantitative analysis of superquenching of fluorescent polyelectrolytes in solution and the factors that control it.

Research describes the stereospecific synthesis of beta-amino diacid 3-(N-carboxymethyl)-aminodecanoic acid enantiomers and the two diastereomers of minalemine A. Results reveal that nuclear magnetic resonance spectra of the natural and the diastereomers are similar but circular dichroism spectra of the former indicate a 3R,2S configuration.

A number of bimetallic complexes of Ni(II) and Cu-(II) of the type is isolated and characterized. The four ligands are used were bis-amines of\r bis-imines and with both di- or trimethylene links between the nonaromatic nitrogen atoms.

The preparation of an anionic 2-amidopyridine tungsten-(0) tetracarbonyl complex through the deprotonation of the corresponding 2-aminopyridine derivatives is described. Crystals of the product obtained from the deprotonation of the pyridine bound W(CO)(sub 5)(2APH) by NzH, with subsequent complexation of the sodium ion by 18-crown-6 is characterized by X-ray crystallography and display strong -NH(super -)...Na(super +) interactions.

The redox properties of the intermediate radicals derived from OH radical reactions of 5-substituted uracils 1c-h (R = F, Cl, Br, NO2, NH2, OH) was determined by using a redox titration method in the pulse radiolysis of N2O-saturated phosphate buffer solution. The product study showed that the yield of isobarbituric acid and isodialuric acid increased due to the one-electron reduction of 5-oxyl radical 5 by N,N,N',N'-tetramethyl-p-phenylenediamine and the one electron oxidation of 5-oxo radical by tetranitromethane respectively.

Depending upon the reagents used, the products of double silylation of aliphatic nitro compounds may behave either as beta-C-electrophiles or beta-C-nucleophiles, thereby allowing diverse functionalization of beta-carbon atom of starting nitro compounds. The realization of a general principle in electrophile or nucleophile combination in which incipient positive charge is stabilized by conjugation with silicon bearing functionality is presented.

The phenylsulfonyl group is known as a group leaving group and is also beneficial in the synthesis of optically active benzenesulfonyl lactams that, being solid compounds are easily purified by crystallization. The reactivity and stereoselectivity displayed by acyclic N-acyliminium ion intermediates prepared using optically active phenylsulfonylimidazolidin-2-ones is studied.

A research report examines the techniques involved in detecting nitrous acid in its gaseous state through the use of cavity ring-down spectroscopy.

Gas-phase reactions of HONO with N2, O3, and HCI were investigated by means of ab initio transition-state theory (TST). The results indicate that the three gas-phase reactions were too slow to be significant under the stratospheric and tropospheric conditions.

A comprehensive analyzes of the (CH)(sub 2)(BR)(sub 2) potential energy surface is carried out at the [MP4/6-311+G(d,p)]/MP2/6-31G(d) level. The rearrangement of 1,3-diamino-1,3-diboretene (1-NH2) to 1,-diamino-1,2-diamino-1,2-diboretene (2-NH2) was computed and compared to the rearrangement in the parent and the effect of the amino group was to substantially increase the barrier height and stabilize the product, 2-NH2.

The cyclization of acetylenic sulfones through the conjugate additions of acyclic or cyclic secondary beta- or gamma-chloroamines is described. The products obtained include variously substituted piperidines, pyrrolizidines, indolizidines and quinolizidines all containing the enamine sulfone moiety.

Sub Antarctic soft coral Alcyonium paessleri provided extracts for fifteen illudalane sesquiterpenoids, alcyopterosins A-O and their structures were determined using spectroscopic techniques. Eight of these compounds are the first natural nitrate esters.

Structure of the compound tetraphenylphosphonium tetrachlorooxo-S,S-diphenylphosphonium is prepared and reported. The coordination around the uranium is isostructural with the uranyl ion with the oxygen and nitrogen groups arranged in a trans configuration with a short U - N bond length.