Structure of the DBL3x domain of pregnancy-associated malaria protein VAR2CSA complexed with chondroitin sulfate A

Energy Technology Data Exchange (ETDEWEB)

Singh, K.; Gittis, A.G.; Nguyen, P.; Gowda, D.C.; Miller, L.H.; Garboczi, D.N. (NIH); (Penn)

2008-09-19

Plasmodium falciparum-infected erythrocytes bind to chondroitin sulfate A (CSA) in the placenta via the VAR2CSA protein, a member of the P. falciparum erythrocyte membrane protein-1 family, leading to life-threatening malaria in pregnant women with severe effects on their fetuses and newborns. Here we describe the structure of the CSA binding DBL3x domain, a Duffy binding-like (DBL) domain of VAR2CSA. By forming a complex of DBL3x with CSA oligosaccharides and determining its structure, we have identified the CSA binding site to be a cluster of conserved positively charged residues on subdomain 2 and subdomain 3. Mutation or chemical modification of lysine residues at the site markedly diminished CSA binding to DBL3x. The location of the CSA binding site is an important step forward in the molecular understanding of pregnancy-associated malaria and offers a new target for vaccine development.

Development of CSA N1600-14: general requirements for nuclear emergency management programs

Energy Technology Data Exchange (ETDEWEB)

Sellar, C. [Canadian Standards Association Group, Mississauga, ON (Canada); Coles, J. [Ontario Power Generation, Darlington, ON (Canada)

2014-07-01

CSA Group has published a new standard on General requirements for nuclear emergency management programs (CSA N1600-14). The standard establishes criteria for the emergency management programs of on- and off-site organizations to address nuclear emergencies at Canadian nuclear power plants (NPPs). It provides the requirements to develop, implement, evaluate, maintain, and continuously improve a nuclear emergency management program for prevention and mitigation, preparedness, response, and recovery from a nuclear emergency at a NPP. This paper discusses the development of the standard, and provides the key drivers, structure, scope, and outline of the standard, while highlighting key features, impacts, and benefits. (author)

Utilizing nanobody technology to target non-immunodominant domains of VAR2CSA.

Directory of Open Access Journals (Sweden)

Sisse B Ditlev

Full Text Available Placental malaria is a major health problem for both pregnant women and their fetuses in malaria endemic regions. It is triggered by the accumulation of Plasmodium falciparum-infected erythrocytes (IE in the intervillous spaces of the placenta and is associated with foetal growth restriction and maternal anemia. IE accumulation is supported by the binding of the parasite-expressed protein VAR2CSA to placental chondroitin sulfate A (CSA. Defining specific CSA-binding epitopes of VAR2CSA, against which to target the immune response, is essential for the development of a vaccine aimed at blocking IE adhesion. However, the development of a VAR2CSA adhesion-blocking vaccine remains challenging due to (i the large size of VAR2CSA and (ii the extensive immune selection for polymorphisms and thereby non-neutralizing B-cell epitopes. Camelid heavy-chain-only antibodies (HcAbs are known to target epitopes that are less immunogenic to classical IgG and, due to their small size and protruding antigen-binding loop, able to reach and recognize cryptic, conformational epitopes which are inaccessible to conventional antibodies. The variable heavy chain (VHH domain is the antigen-binding site of camelid HcAbs, the so called Nanobody, which represents the smallest known (15 kDa intact, native antigen-binding fragment. In this study, we have used the Nanobody technology, an approach new to malaria research, to generate small and functional antibody fragments recognizing unique epitopes broadly distributed on VAR2CSA.

Residual nitrogen-15 recovery by corn as influenced by tillage and fertilization method

International Nuclear Information System (INIS)

Timmons, D.R.; Cruse, R.M.

1991-01-01

Tillage systems that create different surface residue conditions may also affect the recovery of residual fertilizer N during subsequent growing seasons. This study evaluated the recovery of residual labeled N fertilizer in the soil by corn (Zea mays L.) for two tillage systems and two fertilization methods. Five atom % 15 N-enriched 28% urea-ammonium nitrate solution (UAN) at 224 kg N ha -1 was either surface-applied in the fall before any primary tillage or banded (knifed in) just before planting in the spring. Continuous corn was grown with either fall moldboard-plow (MP) or ridge-till (RT) systems. After the initial growing season, the recovery of residual labeled N in the soil by corn was determined for three consecutive growing seasons, and the soil profile was sampled periodically to measure residual 15 N in the organic and inorganic pools. One year after labeled UAN application, from 16 to 27% of the initial 15 N applied was found in the organic N pool and only 1% as inorganic N[NH 4 +(NO 2 +NO 3 )-N]. After four seasons, residual 15 N in the organic N pool ranged from 13 to 24%. Less than 0.5% remained as inorganic N. Regression analyses indicated that about 5 kg 15 N ha -1 year -1 became available for both MP and RT systems with banded N, so the amounts were small. Total residual 15 N recovery by corn grain plus stover for three seasons ranged from 1.7 to 3.5%, and was greatest for spring-banded fertilizer. Because the amounts of residual 15 N utilized were too small to affect corn growth, this N source appears to be negligible when considering corn-N needs

Mineralization of nitrogen from nitrogen-15 labeled crop residues and utilization by rice

International Nuclear Information System (INIS)

Norman, R.J.; Gilmour, J.T.; Wells, B.R.

1990-01-01

The availability of N from the residues of the previous crop to the subsequent rice (Oryza sativa L.) crop is largely unknown. The objectives of this study were to (1) measure the mineralization of N from 15 N-labeled rice, soybean (Glycine max L.), and wheat (Triticum aestivum L.) residues and the uptake by a subsequent rice crop; and (2) compare the 15 N tracer method with the standard fertilizer-N response method used in field studies to quantify the N contribution from the crop residue to the next crop. Nitrogen mineralization from decomposing crop residues was measured by soil sampling prior to seeding the rice crop and after seeding by plant sampling the rice at maturity. The minimum estimate of the amount of residue N mineralized from the time of residue incorporation until rice harvest was 9, 52, and 38% of the rice, soybean, and wheat residue N, respectively. The amount of residue N recovered in the rice crop was 3, 11, and 37% of the rice, soybean, and wheat residue N, respectively. The lower the C/N ratio and the higher the amount of N in the residue, the lower was the amount of residue N recovered in the soil organic fraction at harvest and the higher was the amount of residue N mineralized. The 15 N tracer method compared favorably with the fertilizer N response method when the uptake efficiency of the fertilizer N was taken into account

Identification of a Major Dimorphic Region in the Functionally Critical N-Terminal ID1 Domain of VAR2CSA

DEFF Research Database (Denmark)

Doritchamou, Justin; Sabbagh, Audrey; Jespersen, Jakob S

2015-01-01

The VAR2CSA protein of Plasmodium falciparum is transported to and expressed on the infected erythrocyte surface where it plays a key role in placental malaria (PM). It is the current leading candidate for a vaccine to prevent PM. However, the antigenic polymorphism integral to VAR2CSA poses...... a challenge for vaccine development. Based on detailed analysis of polymorphisms in the sequence of its ligand-binding N-terminal region, currently the main focus for vaccine development, we assessed var2csa from parasite isolates infecting pregnant women. The results reveal for the first time the presence...

Molecular dissection of placental malaria protein VAR2CSA interaction with a chemo-enzymatically synthesized chondroitin sulfate library.

Science.gov (United States)

Sugiura, Nobuo; Clausen, Thomas Mandel; Shioiri, Tatsumasa; Gustavsson, Tobias; Watanabe, Hideto; Salanti, Ali

2016-12-01

Placental malaria, a serious infection caused by the parasite Plasmodium falciparum, is characterized by the selective accumulation of infected erythrocytes (IEs) in the placentas of the pregnant women. Placental adherence is mediated by the malarial VAR2CSA protein, which interacts with chondroitin sulfate (CS) proteoglycans present in the placental tissue. CS is a linear acidic polysaccharide composed of repeating disaccharide units of D-glucuronic acid and N-acetyl-D-galactosamine that are modified by sulfate groups at different positions. Previous reports have shown that placental-adhering IEs were associated with an unusually low sulfated form of chondroitin sulfate A (CSA) and that a partially sulfated dodecasaccharide is the minimal motif for the interaction. However, the fine molecular structure of this CS chain remains unclear. In this study, we have characterized the CS chain that interacts with a recombinant minimal CS-binding region of VAR2CSA (rVAR2) using a CS library of various defined lengths and sulfate compositions. The CS library was chemo-enzymatically synthesized with bacterial chondroitin polymerase and recombinant CS sulfotransferases. We found that C-4 sulfation of the N-acetyl-D-galactosamine residue is critical for supporting rVAR2 binding, whereas no other sulfate modifications showed effects. Interaction of rVAR2 with CS is highly correlated with the degree of C-4 sulfation and CS chain length. We confirmed that the minimum structure binding to rVAR2 is a tri-sulfated CSA dodecasaccharide, and found that a highly sulfated CSA eicosasaccharide is a more potent inhibitor of rVAR2 binding than the dodecasaccharides. These results suggest that CSA derivatives may potentially serve as targets in therapeutic strategies against placental malaria.

Estimates of matter yield and N-uptake in sorghum grown on saline and non-saline soils manured with dhaincha (sesbania aculeata) plant residues utilizing 15N tracer techniques

International Nuclear Information System (INIS)

Kurdali, F.

2002-11-01

Pot experiments were conducted to study the effect of manuring with three types of plant residues (roots, shoots or roots plus shoots) of Dhaincha (Sesbania aculeata Pers.) on the yield and N-uptake of Sorghum bicolor grown in saline and non-saline soils. For measuring various sources of N-uptake, two isotopic dilution techniques were utilized by adding to these soils either 15 N-labelled inorganic N-fertilizer (indirect method) or 15 N-labelled sesbania leaves (direct method). For the indirect method, both soils manured with each type of sesbania residue, received four split applications of 15 N-labelled ammonium sulphate. Results indicated that each type of sesbania residue, applied as a green manure, resulted in significant increases in both dry matter yield and N-uptake of sorghum as compared with the un manured control. Moreover, sesbania residues decreased the harmful effect of salinity on plant growth. Percentages of N derived from residues (%Ndfr) in sorghum grown in non saline soil ranged between 3.9 and 33%; whereas, in saline soil, the observed values ranged between 4.9 and 19.8%. N recoveries in sorghum grown in non saline soil were 61, 45 and 37% of the total amount contained in the sesbania root, shoot and root plus shoot; whereas, values in sorghum grown in saline soils were 48, 14,8 and 15.7%, respectively. The beneficial effects of sesbania residues have been attributed not only to the additional N availability to the plants, but also to its effects on the enhancement of soil N uptake. Percentages and amounts of Ndfr calculated using the indirect method were not significantly different from those obtained by the direct method indicating that the indirect method used herein is feasible and simple for measuring N release from organic residues. It is suggested that the use of Sesbania aculeata residues, particularly the shoots, as a green manure, can provide a substantial portion of total N in sorghum. Moreover, the use of sesbania green manure in

Studies of liver-specific metabolic reactions with 15N. 1

International Nuclear Information System (INIS)

Hirschberg, K.; Jung, K.; Faust, H.; Matkowitz, R.

1987-01-01

The 15 N tracer technique was used to investigate liver-specific reactions (urea and hippurate synthesis) for studying the metabolism in the healthy and damaged pig liver. After [ 15 N]ammonium chloride administration the tracer distribution on non-protein compounds of serum and urine was followed. Blood samplings before and after liver passage rendered possible a direct analysis of the [ 15 N]ammonium metabolism. The thioacetamide-induced liver damage was used as model for an acute liver intoxication. The capacity for urea synthesis was not influenced by means of this noxious substance, but the metabolism of amino acids and hippuric acid. The considerably depressed excretion of [ 15 N]hippurate seems to be a suitable indicator of liver disfunction. (author)

Using N-15 Technique for Assessing Organic.N Turnover in Sandy Soil

International Nuclear Information System (INIS)

Soliman, S.; El-Akel, E.A.; Ismail, M.M.; El-Sherbiny, E.; Awad, E.E.

2008-01-01

Turnover of organic-N was traced under greenhouse condition. 15 N-labelled wheat and/or soybean residues were used as organic additives which applied individually or in combinations. These residues were applied at rates of 100, 75 and 25μg N g - 1 soil. Also, labelled ammonium sulfate with 2% 15 N atom excess, was applied either alone or in combination with the plant residues, at rates of 100, 75 and 25μg N g - 1 soil as single dose after 10 days from planting. Relative positive effect of the nitrogen plant residues on N-uptake and yield components can be arranged as follows: Soybean > wheat + > soybean > wheat residues. Tracer technique indicated that the mixture of labeled residues and ammonium sulfate at rates of (*50 + 50) and (*25 + 75), was effective on dry matter and N uptake. Effect of organic and inorganic nitrogen sources on portions N derived from residue (Ndfr) and N derived from fertilizer (Ndff) to wheat could be arranged as following: ammonium sulfate > soybean > mixture > wheat. Higher 15 N recovery percentage was noticed in grains as affected by addition of soybean residues combined with ordinary ammonium sulfate at rates of (*25 + 75) and (*50 + 50), respectively

DNA binding properties of the small cascade subunit Csa5.

Directory of Open Access Journals (Sweden)

Michael Daume

Full Text Available CRISPR-Cas systems provide immunity against viral attacks in archaeal and bacterial cells. Type I systems employ a Cas protein complex termed Cascade, which utilizes small CRISPR RNAs to detect and degrade the exogenic DNA. A small sequence motif, the PAM, marks the foreign substrates. Previously, a recombinant type I-A Cascade complex from the archaeon Thermoproteus tenax was shown to target and degrade DNA in vitro, dependent on a native PAM sequence. Here, we present the biochemical analysis of the small subunit, Csa5, of this Cascade complex. T. tenax Csa5 preferentially bound ssDNA and mutants that showed decreased ssDNA-binding and reduced Cascade-mediated DNA cleavage were identified. Csa5 oligomerization prevented DNA binding. Specific recognition of the PAM sequence was not observed. Phylogenetic analyses identified Csa5 as a universal member of type I-A systems and revealed three distinct groups. A potential role of Csa5 in R-loop stabilization is discussed.

Identificación de proteínas que interaccionan con CypA, CypB y FKBP12 y su implicación en la toxicidad renal producida por los inmunosupresores CsA y FK506

OpenAIRE

Suñé Rodríguez, Guillermo

2008-01-01

La Ciclosporina A (CsA) es un fármaco inmunosupresor que ha supuesto una revolución en el trasplante de órganos. A pesar de sus propiedades anti-inflamatorias, su uso se ha visto limitado por los efectos tóxicos que causa en algunos pacientes. La CsA inhibe la trascripción de genes involucrados en el sistema inmune. Se cree que esta inhibición es la causante de los efectos tóxicos producidos por el fármaco. El modo de acción de CsA está mediado por la unión de sus principales receptores intra...

Disruption of var2csa gene impairs placental malaria associated adhesion phenotype.

Directory of Open Access Journals (Sweden)

Nicola K Viebig

Full Text Available Infection with Plasmodium falciparum during pregnancy is one of the major causes of malaria related morbidity and mortality in newborn and mothers. The complications of pregnancy-associated malaria result mainly from massive adhesion of Plasmodium falciparum-infected erythrocytes (IE to chondroitin sulfate A (CSA present in the placental intervillous blood spaces. Var2CSA, a member of the P. falciparum erythrocyte membrane protein 1 (PfEMP1 family is the predominant parasite ligand mediating CSA binding. However, experimental evidence suggests that other host receptors, such as hyaluronic acid (HA and the neonatal Fc receptor, may also support placental binding. Here we used parasites in which var2csa was genetically disrupted to evaluate the contribution of these receptors to placental sequestration and to identify additional adhesion receptors that may be involved in pregnancy-associated malaria. By comparison to the wild-type parasites, the FCR3delta var2csa mutants could not be selected for HA adhesion, indicating that var2csa is not only essential for IE cytoadhesion to the placental receptor CSA, but also to HA. However, further studies using different pure sources of HA revealed that the previously observed binding results from CSA contamination in the bovine vitreous humor HA preparation. To identify CSA-independent placental interactions, FCR3delta var2csa mutant parasites were selected for adhesion to the human placental trophoblastic BeWo cell line. BeWo selected parasites revealed a multi-phenotypic adhesion population expressing multiple var genes. However, these parasites did not cytoadhere specifically to the syncytiotrophoblast lining of placental cryosections and were not recognized by sera from malaria-exposed women in a parity dependent manner, indicating that the surface molecules present on the surface of the BeWo selected population are not specifically expressed during the course of pregnancy-associated malaria. Taken

Effect of CSA Concentration on the Ammonia Sensing Properties of CSA-Doped PA6/PANI Composite Nanofibers

Directory of Open Access Journals (Sweden)

Zengyuan Pang

2014-11-01

Full Text Available Camphor sulfonic acid (CSA-doped polyamide 6/polyaniline (PA6/PANI composite nanofibers were fabricated using in situ polymerization of aniline under different CSA concentrations (0.02, 0.04, 0.06, 0.08 and 0.10 M with electrospun PA6 nanofibers as templates. The structural, morphological and ammonia sensing properties of the prepared composite nanofibers were studied using scanning electron microscopy (SEM, Fourier transform infrared spectroscopy (FT-IR, four-point probe techniques, X-ray diffraction (XRD and a home-made gas sensing test system. All the results indicated that the CSA concentration had a great influence on the sensing properties of CSA-doped PA6/PANI composite nanofibers. The composite nanofibers doped with 0.02 M CSA showed the best ammonia sensing properties, with a significant sensitivity toward ammonia (NH3 at room temperature, superior to that of the composite nanofibers doped with 0.04–0.10 mol/L CSA. It was found that for high concentrations of CSA, the number of PANI–H+ reacted with NH3 would not make up a high proportion of all PANI–H+ within certain limits. As a result, within a certain range even though higher CSA-doped PA6/PANI nanofibers had better conductivity, their ammonia sensing performance would degrade.

Studies of liver-specific metabolic reactions with /sup 15/N. 1. Metabolism of /sup 15/N-ammonium chloride in pigs

Energy Technology Data Exchange (ETDEWEB)

Hirschberg, K; Jung, K; Faust, H; Matkowitz, R

1987-07-01

The /sup 15/N tracer technique was used to investigate liver-specific reactions (urea and hippurate synthesis) for studying the metabolism in the healthy and damaged pig liver. After (/sup 15/N)ammonium chloride administration the tracer distribution on non-protein compounds of serum and urine was followed. Blood samplings before and after liver passage rendered possible a direct analysis of the (/sup 15/N)ammonium metabolism. The thioacetamide-induced liver damage was used as model for an acute liver intoxication. The capacity for urea synthesis was not influenced by means of this noxious substance, but the metabolism of amino acids and hippuric acid. The considerably depressed excretion of (/sup 15/N)hippurate seems to be a suitable indicator of liver disfunction.

Sequence-specific {sup 1}H, {sup 13}C, and {sup 15}N resonance assignments for intestinal fatty-acid-binding protein complexed with palmitate (15.4 kDA)

Energy Technology Data Exchange (ETDEWEB)

Hodsdon, M.E.; Toner, J.J.; Cistola, D.P. [Washington Univ. School of Medicine, St. Louis, MO (United States)

1994-12-01

Intestinal fatty-acid-binding protein (I-FABP) belongs to a family of soluble, cytoplasmic proteins that are thought to function in the intracellular transport and trafficking of polar lipids. Individual members of this protein family have distinct specificities and affinities for fatty acids, cholesterol, bile salts, and retinoids. We are comparing several retinol- and fatty-acid-binding proteins from intestine in order to define the factors that control molecular recognition in this family of proteins. We have established sequential resonance assignments for uniformly {sup 13}C/{sup 15}N-enriched I-FABP complexed with perdeuterated palmitate at pH7.2 and 37{degrees}C. The assignment strategy was similar to that introduced for calmodulin. We employed seven three-dimensional NMR experiments to establish scalar couplings between backbone and sidechain atoms. Backbone atoms were correlated using triple-resonance HNCO, HNCA, TOCSY-HMQC, HCACO, and HCA(CO)N experiments. Sidechain atoms were correlated using CC-TOCSY, HCCH-TOCSY, and TOCSY-HMQC. The correlations of peaks between three-dimensional spectra were established in a computer-assisted manner using NMR COMPASS (Molecular Simulations, Inc.) Using this approach, {sup 1}H, {sup 13}C, and {sup 15}N resonance assignments have been established for 120 of the 131 residues of I-FABP. For 18 residues, amide {sup 1}H and {sup 15}N resonances were unobservable, apparently because of the rapid exchange of amide protons with bulk water at pH 7.2. The missing amide protons correspond to distinct amino acid patterns in the protein sequence, which will be discussed. During the assignment process, several sources of ambiguity in spin correlations were observed. To overcome this ambiguity, the additional inter-residue correlations often observed in the HNCA experiment were used as cross-checks for the sequential backbone assignments.

Relative availability of crop residue-N in rice cultivation

International Nuclear Information System (INIS)

Sirwando, H; Abdullah, N.

1988-01-01

The use of plant residues for soil amendment will reduce the use of chemical fertilizers. The experiment to study the uptake of N from various plant residues by rice crop. Three kinds of plant residue of soybean labelled with 15-N. Four levels of urea (0, 15, 30, 40 kg N/ha) were applied to aluvial soil from Pusakanegara. The factorial experiment was conducted in fully randomize design, with plant residues as the main treatment, and rate of urea as substreatment. The results obtained from this experiment showed that plant dry weight, N content of grain, straw, and the whole plant of Atomita I rice treated with soybean strow seens to be higher than those treated with the straw of rice or corn. (author). 6 refs.; 7 tabs

Full-length recombinant Plasmodium falciparum VAR2CSA binds specifically to CSPG and induces potent parasite adhesion blocking antibodies

DEFF Research Database (Denmark)

Khunrae, Pongsak; Dahlbäck, Madeleine; Nielsen, Morten A

2010-01-01

in the pathogenesis of severe P. falciparum infection. In pregnant women the parasites express a single and unique member of the PfEMP1 family named VAR2CSA, which is associated with the ability of the infected erythrocytes to adhere specifically to chondroitin sulphate A (CSA) in the placenta. Several DBL domains......Plasmodium falciparum malaria remains one of the world's leading causes of human suffering and poverty. Each year, the disease takes 1-3 million lives, mainly in sub-Saharan Africa. The adhesion of parasite-infected erythrocytes to the vascular endothelium or the placenta is the key event...

Dynamics of anti-VAR2CSA immunoglobulin G response in a cohort of senegalese pregnant women

DEFF Research Database (Denmark)

Tuikue Ndam, N G; Salanti, A; Le-Hesran, J-Y

2006-01-01

demonstrated that a single P. falciparum infection was able to trigger a VAR2CSA-specific antibody response. Among women with infected placentas, women with high anti-VAR2CSA IgG levels at enrollment were more likely to present with a past infection than with an acute/chronic infection. CONCLUSIONS: Anti-VAR2...... (VSAPAM). Several studies have shown that 1 var gene, var2csa, is transcribed at high levels and expressed in CSA-binding Plasmodium falciparum parasites. METHODS: Plasma levels of anti-VAR2CSA immunoglobulin G (IgG) in Senegalese women were measured during pregnancy by enzyme-linked immunosorbent assay......, using 3 recombinant proteins representing 3 domains of the var2csa gene product. RESULTS: The 3 recombinant proteins were specifically recognized by plasma from pregnant women but not by control plasma. A parity-dependent recognition pattern was observed with 2 of the 3 VAR2CSA antigens. A kinetic study...

Two standards - CSA-N288.1 and USNRC regulatory guides 1.109, 1.111 for chronic atmospheric releases from nuclear facilities - compared

International Nuclear Information System (INIS)

Peterson, S-R.

1997-05-01

Although the Canadian Standards Association's 'Guidelines for Calculating Derived Release Limits for Radioactive Material in Airborne and Liquid Effluents for Normal Operation of Nuclear Facilities', CSA-N288.1-M87 (CSA 1987) can be used to license CANDU (CANadian Deuterium Uranium) reactors sold off-shore, in practice purchasers may wish to use the United States Regulatory Guides (RG) 1.109 (United States Nuclear Regulatory Commission 1977a) and 1.111 (USNRC 1977b) to calculate doses from routine atmospheric releases to members of a critical group. When differences in dose predictions are found between the two standards, CSA-N288.1 comes under attack. This paper explains the differences between the two models. The two atmospheric dispersion models were compared for a ground level release and an elevated release such as from CANDU 6. For a ground level release, CSA's dilution factors were slightly more than half of RG's. For the elevated release, following recommendations in each guide, CSA's dilution coefficient is higher than RG's within 1000 m of the stack and only slightly lower farther away. All differences can be accounted for by different mathematical formulations and assumptions about height at which wind speed is measured. Ingestion, inhalation, immersion and external doses predicted by the two models were compared for unit release (Bq s -1 ) and for realistic source terms of a suite of 33 radionuclides commonly released from both CANDUs and Pressurized Water Reactors (PWRs). To demonstrate real differences in the models, ingestion doses for the two models were compared using the CSA diet in both models and CSA predictions were recalculated to account for decay which occurs between harvest and ingestion in RG. Once all assumptions are equalized, there is very little difference in dose predictions of the two models that cannot be explained by different parameter values. Both models have outdated dose conversion factors, and the use of improved numbers will

Use of /sup 15/N in following organic matter turnover, with specific reference to rotation systems

Energy Technology Data Exchange (ETDEWEB)

Ladd, J N [Commonwealth Scientific and Industrial Research Organization, Glen Osmond (Australia). Div. of Soils

1981-01-01

The results of this experiment indicate that the use of the technique described, (based on the degree of /sup 15/N-labelling of an N/sub 2/ fixer and a non-fixer), may be of value in assessing N/sub 2/ fixation in the field by legumes, but it is apparent that there are some problems to be overcome. Analyses of the whole plant are necessary, since the proportions of legume N due to N/sub 2/ fixation vary with the plant part. The extent to which legumes take up available N from the soil obviously will vary with soil profile and plant properties; and they will be affected by sward density and competition from other plants. These latter factors will increase the difficulty of using this method for assessing N/sub 2/ fixation by legumes in grazed pastures, but probably they would not be big problems when applying the method to grain legume crops. It is important that, in comparing the extent of labelling of the N of fixing and non-fixing plants, both types of plants should have access to soil inorganic-N of the same enrichment. This will be difficult to achieve under field conditions. However soils which contain relatively stable /sup 15/N-labelled organic residues may yield NO/sub 3/-N of tolerably constant enrichments. An experiment is in progress at Avon in which soils, amended 15 months previously with /sup 15/N-labelled legume residues and then cropped to wheat, will remain in situ and will be sown with fixing and non-fixing plants during the 1980 and 1981 seasons. These soils may prove to be suitable for measuring N/sub 2/ fixation in the field.

Doses from aquatic pathways in CSA-N288.1: deterministic and stochastic predictions compared

Energy Technology Data Exchange (ETDEWEB)

Chouhan, S.L.; Davis, P

2002-04-01

The conservatism and uncertainty in the Canadian Standards Association (CSA) model for calculating derived release limits (DRLs) for aquatic emissions of radionuclides from nuclear facilities was investigated. The model was run deterministically using the recommended default values for its parameters, and its predictions were compared with the distributed doses obtained by running the model stochastically. Probability density functions (PDFs) for the model parameters for the stochastic runs were constructed using data reported in the literature and results from experimental work done by AECL. The default values recommended for the CSA model for some parameters were found to be lower than the central values of the PDFs in about half of the cases. Doses (ingestion, groundshine and immersion) calculated as the median of 400 stochastic runs were higher than the deterministic doses predicted using the CSA default values of the parameters for more than half (85 out of the 163) of the cases. Thus, the CSA model is not conservative for calculating DRLs for aquatic radionuclide emissions, as it was intended to be. The output of the stochastic runs was used to determine the uncertainty in the CSA model predictions. The uncertainty in the total dose was high, with the 95% confidence interval exceeding an order of magnitude for all radionuclides. A sensitivity study revealed that total ingestion doses to adults predicted by the CSA model are sensitive primarily to water intake rates, bioaccumulation factors for fish and marine biota, dietary intakes of fish and marine biota, the fraction of consumed food arising from contaminated sources, the irrigation rate, occupancy factors and the sediment solid/liquid distribution coefficient. To improve DRL models, further research into aquatic exposure pathways should concentrate on reducing the uncertainty in these parameters. The PDFs given here can he used by other modellers to test and improve their models and to ensure that DRLs

Production of 15N-Labelled Liquid Organic Fertilisers Based on Manure and Crop Residue for Use in Fertigation Studies.

Directory of Open Access Journals (Sweden)

Belén Martínez-Alcántara

Full Text Available Large quantities of crop residue and animal manure from agricultural and livestock activities are annually produced worldwide. With proper management, these residues are potentially valuable sources of plant nutrients, mainly N. Recycling such subproducts in sustainably-based agricultural systems can minimise the use of mineral fertilisers, and hence reduce the potential risk of surface and groundwater pollution. Therefore, the purpose of this study was to obtain (small scale two liquid labelled-organic fertilisers, an animal- and a vegetal-based organic (AO and VO, respectively fertiliser, to be used as organic N sources in subsequent fertigation studies. Forage maize (Zea mays L. grown under 15N-labelled fertiliser supply was used as raw material for VO fertiliser production, and also as 15N-labelled sheep feed to obtain 15N-labelled manure. The labelled faeces fraction was used as raw material for the AO fertiliser. The VO fertiliser was obtained after an acidic and an enzyme-driven hydrolysis. The AO fertiliser was obtained after acidic hydrolysis. The VO liquid fertiliser presented an N concentration of 330 mg·L-1, 85% of total N was organic, while ammonium and nitrate N accounted for 55% and 45% of the mineral nitrogen fraction, respectively. This fertiliser also exhibited high K, Ca and S concentrations and notable values for the remaining macro- and micronutrients. The AO liquid fertiliser had a similar total N concentration (496 mg·L-1, 82% of total N in an organic form to that of VO, but its mineral N fraction significantly differed, which came in a predominantly (95% ammonia form. It also had a high content of N, P, K and other macronutrients, and sufficient Fe, Zn, Mn, Cu and B levels, which suggests its suitability as a potential fertiliser. The percentage of 15N enrichment in both VO and AO liquid fertilisers exceeded 2% 15N atom excess, which enabled their use in subsequent assays run to assess nitrogen uptake efficiency.

Resonances in the nuclear reactions 15N + 12C and 15N + 16O

International Nuclear Information System (INIS)

Monnehan, G.A.

1987-06-01

The reaction 12 C + 15 N have been studied at 15 N beam energies between 30 and 70 MeV. For each reaction, about twelve residual nuclei have been identified through the γ-ray detection method. Excitation functions were obtained for the fusion and peripheral channels. Resonances are seen in the channels containing at least one α particle at energies below 50 MeV. At higher energies, strong structures are observed in the direct reaction channels. The evolution of the fusion cross section is well reproduced by a model based on the statistical desexcitation of the compound nucleus if the discrete states of the residual nuclei are taken into account. The favourable observation of resonant phenomena in 15 N induced reactions can be understood in terms of a small number of channels open to the grazing wave. In the range 50 to 60 MeV, there is a strong coupling between the fusion and the direct reaction channels. The occurrence of resonances above E lab = 50 MeV in the peripheral channels is explained with the band crossing and effective barrier models. In the 15 N induced reactions, the absorption of the surface waves is weak [fr

performance of sorghum grown on a salt affected soil manured with dhaincha plant residues using a 15N isotopic dilution technique

International Nuclear Information System (INIS)

Kurdali, F.; Al-Ain, F.; Razok, A.; Al-Shamma, M.

2008-01-01

A field experiment was conducted on a salt-affected soil to determine the effect of application of three types of Dhaincha (Sesbania aculeata pers.) residues (R, roots; L, shoots; L+R, shoots plus roots) of on the performance of sorghum (Sorghum bicolor L.) using the indirect 15 N isotopic dilution technique. Results indicated that Sesbania residues (L and L+R), used as green manures significantly increased grain yield, dry matter production, N uptake, and water use efficiency of sorghum. Percentages of N derived from residues (%Ndfr) in sorghum ranged from 6.4 to 28%. The N recoveries in sorghum were 52, 19. and 19.7% of the total amount contained in Sesbania roots, shoots and roots plus shoots, respectively. The beneficial effects of Sesbania residues are attributed not only to the additional N availability to the plants, but also to effects on the enhancement of soil N uptake, particularly in the L+R treatment. The findings suggest that the use of Sesbania aculeata residues, as a green manure, can provide a substantial portion of total N in sorghum. In addition, the use of Sesbania green manure in salt-affected soils, as a bio-reclaiming material, can be a promising approach for enhancing plant growth on a sustainable basis. (author)

15N Isotopic Study on Decomposition of Organic Residues Incorporated into Alluvial and Sandy Saline Soils

International Nuclear Information System (INIS)

El-Kholi, A. F.; Galal, Y. G. M.

2004-01-01

Incubation experiment was conducted to study the effect of the nitrogenous fertilizer on the decomposition and mineralization of organic residues (soybean powdered forage) as well as the release of the soil inorganic nitrogen. This technique was carried out using two types of soils, one is alluvial and the other is saline sandy soil collected from Fayoum governorate. Soybean forage has an organic carbon 23.1%, total N 1.6% and C/N ratio 14.4. Regarding the effect of incubation period on the two soil samples, the evolved NH 4 -N was generally reached its highest peak after 30-45 days, in the presence of either the added 15 No3-fertilizer solely or in combination with soybean forage. Reversible trend was occurred with regard to the evolved No3-N. The highest peak of evolved No3-N recorded in unfertilized control, as compared to 15 No3-N treatment, at 30 day incubation period indicated that the addition of labeled mineral fertilizer had appreciably enhanced the immobilization process. Net nitrification revealed that it was the highest in unfertilized control soil where it was significantly decreased in the treated two soil samples. Gross mineralization as affected by the addition of soybean forage in combination with labeled mineral fertilizer had been promoted by 75% in the alluvial soil and by 18% in the sandy saline soil, as compared with the soil samples received 15 No3-fertilizer only. Gross immobilization, in soil samples received 15 No3-fertilizer plus soybean forage had surpassed those received 15 No3-fertilizer only by 16% in the alluvial soil and by 25% in the sandy saline soil. (Authors)

Dynamic CO₂ inhalation: a novel treatment for CSR-CSA associated with CHF.

Science.gov (United States)

Wan, Zhi Hui; Wen, Fang Jing; Hu, Ke

2013-05-01

Cheyne-Stokes respiration with central sleep apnea (CSR-CSA) is very common in patients with chronic congestive heart failure (CHF). A current concept of the key pathophysiological mechanism leading to CSR-CSA is a fluctuation of PaCO2 below and above the apneic threshold. A number of therapeutic approaches for CSR-CSA have been proposed-all with varying success, some of which include various modes of positive airway pressure among other strategies. However, CO2 oscillations seen in CSR-CSA have yet to be looked at as a specific therapeutic target by current treatments. Previous studies have shown that delivery of constant CO2 is efficacious in eliminating CSR-CSA by raising PaCO2, but there are serious concerns about the potential side effects, such as unwanted elevations in ventilation, work of breathing, and sympathetic nerve activity (SNA), and consequently CO2 inhalation therapy has not been recommended as a routine option for therapy. However, recent new studies into CO2 inhalation therapy have been made that may reshape its role as therapeutic. In this review, we will focus on the recent developments of administration of dynamic CO2 in the management of CSR-CSA in CHF patients.

Wheat Yield Production Grown on Sandy Soil as Fertilized by Different N-Sources Using 15N-Technique

International Nuclear Information System (INIS)

Ismail, M. M.; Soliman, S. M.; El-Akel, E. A.; El-Sherbieny, A. E.; Awad, E. A. M.

2007-01-01

A pot experiment was carried out to evaluate the ability of some plant residues to meet total N demand of wheat crop in sandy soil and their performance to reduce chemical N fertilizer requirements. Residue-N sources, i.e. soybean and wheat residues were compared to ammonium sulfate as inorganic N source as well as mixtures of residue-N sources and (NH 4 )SO 4 in ratios of (3:1), (1:1) and (1:3), respectively. The nitrogen application rate in all amended pots was kept at 100 mg N pot -1 . The obtained results could be summarized as follows: 1) ry weight of straw and grains of wheat crop was significantly increased this at the addition of nitrogen sources as a result of N-uptake increased. The highest value was observed at the application treatment ratios of (1:1) and (1:3) on the basis of (residue: ammonium sulfate), which can be arranged in this order: Soybean > wheat + soybean > wheat residues. 2) he value of N derived from residues (Ndfr) and fertilizer (Ndff), as well as 15N -recovery ratios can be arranged in this order: Ammonium sulfate > soybean residue > Soybean + wheat residue > wheat residue. 3) he values indicated that 15N -labelled soybean residue in combination with ordinary, ammonium sulfate at the ratios of (*25: 75) and (*50: 50), respectively was found to be effective on 15N -recovery ratios in the straw and grains of wheat crop. 4) he present study indicates that the entire N requirements of wheat crop cannot be met by the separate application of any residue-N source examined.

Space astronomy and astrophysics program by CSA

Science.gov (United States)

Laurin, Denis; Ouellet, Alain; Dupuis, Jean; Chicoine, Ruth-Ann

2014-07-01

Canada became actively engaged in space astronomy in the 1990s by contributing two fine guidance sensors to the FUSE Far-UV mission (NASA 1999-2008). In the same period, Canada contributed to ODIN's infrared instrument (ESA 2001-2006) and correlators for VSOP (JAXA 1997-2005). In early 2000, Canada developed its own space telescope, Micro-variability and Observations of STars (MOST), a 15-cm telescope on a microsatellite, operating since 2003, and more recently contributed to the realization of the BRITE nanosatellites constellation. Canada also provided hardware to the European Space Agency's Herschel HIFI instrument and simulators to the SPIRE instrument and data analysis tools for Planck. More recently the Canadian Space Agency (CSA) delivered detector units for the UVIT instrument on board the Indian Space Research Organisation's (ISRO) ASTROSAT. The CSA's most important contribution to a space astronomy mission to date is the Fine Guidance Senor (FGS) and Near Infrared Imager and Slitless Spectrograph (NIRISS) instrument to NASA's James Webb Space Telescope. The CSA is currently building the laser metrology system for JAXA's ASTRO-H hard X-ray telescope. Canadian astronomers contributed to several high profile stratospheric balloon projects investigating the CMB and the CSA recently established a balloon launch facility. As expressed in Canada's new Space Policy Framework announced in February 2014, Canada remains committed to future space exploration endeavors. The policy aims at ensure that Canada is a sought-after partner in the international space exploration missions that serve Canada's national interests; and continuing to invest in the development of Canadian contributions in the form of advanced systems and optical instruments. In the longer term, through consultations and in keeping the Canadian astronomical community's proposed Long Range Plan, the CSA is exploring possibilities to contributions to important missions such as WFIRST, SPICA and Athena

Use of Bio-Organic Fertilizers to Develop N Uptake Using 15N Technique

International Nuclear Information System (INIS)

Galal, Y.G.M.

2008-01-01

Experimental work either in field scale or in green house conditions were conducted using 15 N technique to evaluate the role of different bio fertilizers and different plant residues as organic amendments on enhancement of plant N nutrition. Nitrogen fixation by a symbiotic bacteria has been observed in greenhouse and field experiments under dry land cropping systems. Biological N 2 fixation associated with crop residues (legumes or cereals) was investigated in pot experiments with wheat and chickpea cultivars. In these experiments, labelled wheat and rice straw were used as organic N sources in comparison with either 15 N-labelled ammonium sulfate or ammonium nitrate as chemical nitrogen fertilizers. Rhizobium inoculation extended to be used with wheat gave the best results of N uptake and N 2 fixation when combined with Azospirillum brasilense as heterotrophic diazotrophs. The nitrogen uptake by wheat plants was significantly increased by application of soybean residues and inoculation with Azospirillum brasilense. From the field trial we can conclude that soybean residue as enriched N material, and Azospirillum brasilense inoculation enhanced N yields of wheat cultivars grown in poor fertile sandy soil

The Dynamic of the N-Turnover of Plant Residues in The soil using nuclear technique

International Nuclear Information System (INIS)

Ismail, M.M.A.

2004-01-01

Laboratory and greenhouse experiments were carried out to study the dynamic of the N-turnover of leguminous and non-leguminous plant residues in sandy soil using N-15 . tracer technique. Also, the availability of N from labelled or unlabelled ammonium sulfate was included. using 15 N-technique, data obtained generally indicated that 15 N-mineralization percent for soybean (narrow C/N ratio) increased with time, being more effective and superior over wheat residue-N (wide C/N ratio) on the net 15 N-mineralization through out the time of incubation (10 weeks).Data obtained generally indicated that the N-mineralization significantly decreased due to the application of soybean, wheat, wheat + soybean and / or ammonium sulfate along with the time of vegetative growth stage until harvesting period under with or without wheat stands . In general at any period of growth plant stages of wheat, the amount of microbial biomass-N under wheat residue and/or ammonium sulfate treated and untreated soil significantly decreased rapidly from an initial of vegetative stage until harvesting time. the positive effect of plant residues on the amount of biomass-N was arranged as follows : soybean>wheat + soybean> wheat residues

Multidimensional oriented solid-state NMR experiments enable the sequential assignment of uniformly 15N labeled integral membrane proteins in magnetically aligned lipid bilayers

International Nuclear Information System (INIS)

Mote, Kaustubh R.; Gopinath, T.; Traaseth, Nathaniel J.; Kitchen, Jason; Gor’kov, Peter L.; Brey, William W.; Veglia, Gianluigi

2011-01-01

Oriented solid-state NMR is the most direct methodology to obtain the orientation of membrane proteins with respect to the lipid bilayer. The method consists of measuring 1 H- 15 N dipolar couplings (DC) and 15 N anisotropic chemical shifts (CSA) for membrane proteins that are uniformly aligned with respect to the membrane bilayer. A significant advantage of this approach is that tilt and azimuthal (rotational) angles of the protein domains can be directly derived from analytical expression of DC and CSA values, or, alternatively, obtained by refining protein structures using these values as harmonic restraints in simulated annealing calculations. The Achilles’ heel of this approach is the lack of suitable experiments for sequential assignment of the amide resonances. In this Article, we present a new pulse sequence that integrates proton driven spin diffusion (PDSD) with sensitivity-enhanced PISEMA in a 3D experiment ([ 1 H, 15 N]-SE-PISEMA-PDSD). The incorporation of 2D 15 N/ 15 N spin diffusion experiments into this new 3D experiment leads to the complete and unambiguous assignment of the 15 N resonances. The feasibility of this approach is demonstrated for the membrane protein sarcolipin reconstituted in magnetically aligned lipid bicelles. Taken with low electric field probe technology, this approach will propel the determination of sequential assignment as well as structure and topology of larger integral membrane proteins in aligned lipid bilayers.

An assay of the utilization of the residual use of a N fertilizer [(15NH4)2SO4] made by a wheat crop, using an isotope technique

International Nuclear Information System (INIS)

Bujan, A.; Quitegui, M.I.; Quitegui, M.C.; Ghelfi, L.E.P. de; Deybe, D.

1982-01-01

An experimental study was carried out in order to determine the residual use of a N fertilizer made by wheat during a year. Wheat was seeded in plots which had been cropped the year before with inoculated soybean (glycine max), non-inoculated soybean and sorghum (sorghum caffrorum) fertilized with (NH 4 ) 2 SO 4 at two different levels: 20 and 100kg N/ha tagged with 5% excess 15 N and 1% respectively. It was concluded that:1) the % excess 15 N used in the previous crops were sufficient to determine residuality from the N fertilizer. 2)when the previous crop was non-inoculated soybean, the total nitrogen content of the wheat grains was significantly higher than when the previous crop was either inoculated soybean or sorghum. The total N content was significantly higher on the plots fertilized with 100KgN/ha than on those with 20kgN/ha.3) non-inoculated - and inoculated soybeans determined higher wheat grain yields than sorghum as previous crops. Higher wheat grain yields ocurred on the 100kgN/ha fertilized plots. Higher residual N content ocurred on the 100KgN/ha fertilized plots. Non-inoculated soybean determined higher residual N content in grain than inoculated soybean and sorghum; inoculated soybean determined higher content than sorghum. There were no significant differences in residual N content in the plants depending on the previous crop. (Author) [pt

Draft CSA standard on environmental risk assessments at class I nuclear facilities and uranium mines and mills

International Nuclear Information System (INIS)

Hart, D.; Garisto, N.; Parker, R.; Kovacs, R.; Thompson, B.

2012-01-01

The Canadian Standards Association (CSA) is preparing a draft Standard on environmental risk assessments (ERAs) at Class I nuclear facilities and uranium mines and mills (CSA N288.6). It is being prepared by a technical subcommittee of the CSA N288 Technical Committee, including experts from across the nuclear industry, government and regulatory authorities, and environmental service providers, among others. It addresses the design, implementation, and management of environmental risk assessment programs, and is intended to standardize practice across the industry. This paper outlines the scope of the draft Standard and highlights key features. It is under development and subject to change. (author)

Compound-specific δ15N amino acid measurements in littoral mussels in the California upwelling ecosystem: a new approach to generating baseline δ15N Isoscapes for coastal ecosystems.

Directory of Open Access Journals (Sweden)

Natasha L Vokhshoori

Full Text Available We explored δ(15N compound-specific amino acid isotope data (CSI-AA in filter-feeding intertidal mussels (Mytilus californianus as a new approach to construct integrated isoscapes of coastal primary production. We examined spatial δ(15N gradients in the California Upwelling Ecosystem (CUE, determining bulk δ(15N values of mussel tissue from 28 sites between Port Orford, Oregon and La Jolla, California, and applying CSI-AA at selected sites to decouple trophic effects from isotopic values at the base of the food web. Bulk δ(15N values showed a strong linear trend with latitude, increasing from North to South (from ∼ 7‰ to ∼ 12‰, R(2 = 0.759. In contrast, CSI-AA trophic position estimates showed no correlation with latitude. The δ(15N trend is therefore most consistent with a baseline δ(15N gradient, likely due to the mixing of two source waters: low δ(15N nitrate from the southward flowing surface California Current, and the northward transport of the California Undercurrent (CUC, with (15N-enriched nitrate. This interpretation is strongly supported by a similar linear gradient in δ(15N values of phenylalanine (δ(15NPhe, the best AA proxy for baseline δ(15N values. We hypothesize δ(15N(Phe values in intertidal mussels can approximate annual integrated δ(15N values of coastal phytoplankton primary production. We therefore used δ(15N(Phe values to generate the first compound-specific nitrogen isoscape for the coastal Northeast Pacific, which indicates a remarkably linear gradient in coastal primary production δ(15N values. We propose that δ(15N(Phe isoscapes derived from filter feeders can directly characterize baseline δ(15N values across major biochemical provinces, with potential applications for understanding migratory and feeding patterns of top predators, monitoring effects of climate change, and study of paleo- archives.

Measurement of {sup 1}H-{sup 15}N and {sup 1}H-{sup 13}C residual dipolar couplings in nucleic acids from TROSY intensities

Energy Technology Data Exchange (ETDEWEB)

Ying Jinfa [National Institutes of Health, Laboratory of Chemical Physics, National Institute of Diabetes and Digestive and Kidney Diseases (United States); Wang Jinbu [National Cancer Institute, National Institutes of Health, Structural Biophysics Laboratory (United States); Grishaev, Alex [National Institutes of Health, Laboratory of Chemical Physics, National Institute of Diabetes and Digestive and Kidney Diseases (United States); Yu Ping; Wang Yunxing [National Cancer Institute, National Institutes of Health, Structural Biophysics Laboratory (United States); Bax, Ad, E-mail: bax@nih.gov [National Institutes of Health, Laboratory of Chemical Physics, National Institute of Diabetes and Digestive and Kidney Diseases (United States)

2011-09-15

Analogous to the recently introduced ARTSY method for measurement of one-bond {sup 1}H-{sup 15}N residual dipolar couplings (RDCs) in large perdeuterated proteins, we introduce methods for measurement of base {sup 13}C-{sup 1}H and {sup 15}N-{sup 1}H RDCs in protonated nucleic acids. Measurements are based on quantitative analysis of intensities in {sup 1}H-{sup 15}N and {sup 13}C-{sup 1}H TROSY-HSQC spectra, and are illustrated for a 71-nucleotide adenine riboswitch. Results compare favorably with those of conventional frequency-based measurements in terms of completeness and convenience of use. The ARTSY method derives the size of the coupling from the ratio of intensities observed in two TROSY-HSQC spectra recorded with different dephasing delays, thereby minimizing potential resonance overlap problems. Precision of the RDC measurements is limited by the signal-to-noise ratio, S/N, achievable in the 2D TROSY-HSQC reference spectrum, and is approximately given by 30/(S/N) Hz for {sup 15}N-{sup 1}H and 65/(S/N) Hz for {sup 13}C-{sup 1}H. The signal-to-noise ratio of both {sup 1}H-{sup 15}N and {sup 1}H-{sup 13}C spectra greatly benefits when water magnetization during the experiments is not perturbed, such that rapid magnetization transfer from bulk water to the nucleic acid, mediated by rapid amino and hydroxyl hydrogen exchange coupled with {sup 1}H-{sup 1}H NOE transfer, allows for fast repetition of the experiment. RDCs in the mutated helix 1 of the riboswitch are compatible with nucleotide-specifically modeled, idealized A-form geometry and a static orientation relative to the helix 2/3 pair, which differs by ca 6 Degree-Sign relative to the X-ray structure of the native riboswitch.

Computer Science and Convergence : CSA 2011 & WCC 2011 Proceedings

CERN Document Server

Chao, Han-Chieh; Obaidat, Mohammad; Kim, Jongsung

2012-01-01

Computer Science and Convergence is proceedings of the 3rd FTRA International Conference on Computer Science and its Applications (CSA-11) and The 2011 FTRA World Convergence Conference (FTRA WCC 2011). The topics of CSA and WCC cover the current hot topics satisfying the world-wide ever-changing needs. CSA-11 will be the most comprehensive conference focused on the various aspects of advances in computer science and its applications and will provide an opportunity for academic and industry professionals to discuss the latest issues and progress in the area of CSA. In addition, the conference will publish high quality papers which are closely related to the various theories and practical applications in CSA. Furthermore, we expect that the conference and its publications will be a trigger for further related research and technology improvements in this important subject. The main scope of CSA-11 is as follows: -      Mobile and ubiquitous computing -      Dependable, reliable and autonomic computi...

Interception of residual nitrate from a calcareous alluvial soil profile on the North China Plain by deep-rooted crops: A 15N tracer study

International Nuclear Information System (INIS)

Ju, X.T.; Gao, Q.; Christie, P.; Zhang, F.S.

2007-01-01

15 N-labeled nitrate was injected into different depths of an alluvial calcareous soil profile on the North China Plain. Subsequent movement of NO 3 - N and its recovery by deep-rooted maize (Zea mays L.) and shallow-rooted eggplant (Solanum melongena L.) were studied. Under conventional water and nutrient management the mean recoveries of 15 N-labeled nitrate from K 15 NO 3 injected at depths 15, 45, and 75 cm were 22.4, 13.8, and 7.8% by maize and 7.9, 4.9, and 2.7% by eggplant. The recovery rate by maize at each soil depth was significantly higher than by eggplant. The deeper the injection of nitrate the smaller the distance of its downward movement and this corresponded with the movement of soil water during crop growth. Deeper rooting crops with high root length density and high water consumption may therefore be grown to utilize high concentrations of residual nitrate in the subsoil from previous intensive cropping and to protect the environment. - Deep-rooted crops have a greater capacity than shallow-rooted crops to intercept residual nitrate from the subsoil and restrict its movement down to the shallow groundwater

Sedentary behavior and residual-specific mortality

OpenAIRE

Paul D. Loprinzi; Meghan K. Edwards; Eveleen Sng; Ovuokerie Addoh

2016-01-01

Background: The purpose of this study was to examine the association of accelerometer-assessed sedentary behavior and residual-specific mortality. Methods: Data from the 2003-2006 National Health and Nutrition Examination Survey (NHANES) were used (N = 5536), with follow-up through 2011. Sedentary behavior was objectively measured over 7 days via accelerometry. Results: When expressing sedentary behavior as a 60 min/day increase, the hazard ratio across the models ranged from 1.07-1.40 (P < 0...

Multidimensional oriented solid-state NMR experiments enable the sequential assignment of uniformly 15N labeled integral membrane proteins in magnetically aligned lipid bilayers.

Science.gov (United States)

Mote, Kaustubh R; Gopinath, T; Traaseth, Nathaniel J; Kitchen, Jason; Gor'kov, Peter L; Brey, William W; Veglia, Gianluigi

2011-11-01

Oriented solid-state NMR is the most direct methodology to obtain the orientation of membrane proteins with respect to the lipid bilayer. The method consists of measuring (1)H-(15)N dipolar couplings (DC) and (15)N anisotropic chemical shifts (CSA) for membrane proteins that are uniformly aligned with respect to the membrane bilayer. A significant advantage of this approach is that tilt and azimuthal (rotational) angles of the protein domains can be directly derived from analytical expression of DC and CSA values, or, alternatively, obtained by refining protein structures using these values as harmonic restraints in simulated annealing calculations. The Achilles' heel of this approach is the lack of suitable experiments for sequential assignment of the amide resonances. In this Article, we present a new pulse sequence that integrates proton driven spin diffusion (PDSD) with sensitivity-enhanced PISEMA in a 3D experiment ([(1)H,(15)N]-SE-PISEMA-PDSD). The incorporation of 2D (15)N/(15)N spin diffusion experiments into this new 3D experiment leads to the complete and unambiguous assignment of the (15)N resonances. The feasibility of this approach is demonstrated for the membrane protein sarcolipin reconstituted in magnetically aligned lipid bicelles. Taken with low electric field probe technology, this approach will propel the determination of sequential assignment as well as structure and topology of larger integral membrane proteins in aligned lipid bilayers. © Springer Science+Business Media B.V. 2011

In vivo evaluation of [11C]SA4503 as a PET ligand for mapping CNS sigma1 receptors

International Nuclear Information System (INIS)

Kawamura, Kazunori; Ishiwata, Kiichi; Tajima, Hisashi; Ishii, Shin-Ichi; Matsuno, Kiyoshi; Homma, Yoshio; Senda, Michio

2000-01-01

The potential of the 11 C-labeled selective sigma 1 receptor ligand 1-(3,4-dimethoxyphenethyl)-4-(3-phenylpropyl)piperazine ([ 11 C]SA4503) was evaluated in vivo as a positron emission tomography (PET) ligand for mapping sigma 1 receptors in rats. SA4503 is known to have a high affinity (IC 50 17.4 nM) and a higher selectivity (sigma 1 /sigma 2 =103) for the sigma 1 receptor. A high and increasing brain uptake of [ 11 C]SA4503 was found. Pre-, co- and postinjection of cold SA4503 significantly decreased uptake of [ 11 C]SA4503 in the brain, spleen, heart, lung, and kidney in which sigma receptors are present as well as in the skeletal muscle. In the blocking study with one of four sigma receptor ligands including haloperidol, (+)-pentazocine, SA4503, and (-)-pentazocine (in the order of their affinity for sigma 1 receptor subtype), SA4503 and haloperidol significantly reduced the brain uptake of [ 11 C]SA4503 to approximately 30% of the control, but the other two benzomorphans did not. A high specific uptake of [ 11 C]SA4503 by the brain was also confirmed by ex vivo autoradiography (ARG) and PET. Ex vivo ARG showed a higher uptake in the vestibular nucleus, temporal cortex, cingulate cortex, inferior colliculus, thalamus, and frontal cortex, and a moderate uptake in the parietal cortex and caudate putamen. Peripherally, the blocking effects of the four ligands depended on their affinity for sigma 1 receptors. No 11 C-labeled metabolite was detected in the brain 30 min postinjection, whereas approximately 20% of the radioactivity was found as 11 C-labeled metabolites in plasma. These results have demonstrated that the 11 C-labeled sigma 1 receptor ligand [ 11 C]SA4503 has a potential for mapping sigma 1 receptors in the central nervous system and peripheral organs

Cockayne syndrome group B (Csb) and group a (Csa) deficiencies predispose to hearing loss and cochlear hair cell degeneration in mice.

Science.gov (United States)

Nagtegaal, A Paul; Rainey, Robert N; van der Pluijm, Ingrid; Brandt, Renata M C; van der Horst, Gijsbertus T J; Borst, J Gerard G; Segil, Neil

2015-03-11

Sensory hair cells in the cochlea, like most neuronal populations that are postmitotic, terminally differentiated, and non-regenerating, depend on robust mechanisms of self-renewal for lifelong survival. We report that hair cell homeostasis requires a specific sub-branch of the DNA damage nucleotide excision repair pathway, termed transcription-coupled repair (TCR). Cockayne syndrome (CS), caused by defects in TCR, is a rare DNA repair disorder with a broad clinical spectrum that includes sensorineural hearing loss. We tested hearing and analyzed the cellular integrity of the organ of Corti in two mouse models of this disease with mutations in the Csb gene (CSB(m/m) mice) and Csa gene (Csa(-/-) mice), respectively. Csb(m/m) and Csa(-/-) mice manifested progressive hearing loss, as measured by an increase in auditory brainstem response thresholds. In contrast to wild-type mice, mutant mice showed reduced or absent otoacoustic emissions, suggesting cochlear outer hair cell impairment. Hearing loss in Csb(m/m) and Csa(-/-) mice correlated with progressive hair cell loss in the base of the organ of Corti, starting between 6 and 13 weeks of age, which increased by 16 weeks of age in a basal-to-apical gradient, with outer hair cells more severely affected than inner hair cells. Our data indicate that the hearing loss observed in CS patients is reproduced in mouse models of this disease. We hypothesize that accumulating DNA damage, secondary to the loss of TCR, contributes to susceptibility to hearing loss. Copyright © 2015 the authors 0270-6474/15/354280-07$15.00/0.

Evidence for denitrification as main source of N2O emission from residue-amended soil

DEFF Research Database (Denmark)

Li, Xiaoxi; Sørensen, Peter; Olesen, Jørgen Eivind

2016-01-01

-leguminous species (ryegrass). Plant material was placed in a discrete layer surrounded by soil in which the nitrate View the MathML source pool was enriched with 15N to distinguish N2O derived from denitrification and nitrification. Net N mineralisation from leguminous catch crops was significant (30–48 mg N kg−1....... Emission of N2O occurred at all moisture levels, but was higher at 50 and 60% WFPS than at 40% in soil with leguminous residues. The 15N enrichment of N2O indicated that denitrification was the dominant source independent of moisture level and residue type. We conclude that catch crop residues...... will stimulate N2O emissions via denitrification over a wide range of soil moisture conditions, but that emission levels may depend significantly on residue quality and soil moisture....

Dynamic of N fertilizers: urea (15 N) and aqua ammonia (15 N) incorporated to the sugar cane soil. Final report

International Nuclear Information System (INIS)

Trivelin, P.C.O.

1988-05-01

The dynamic of N fertilizers, urea and aqua ammonia, in the soil of sugar cane crops are studied with an emphasis on the horizontal and vertical moving. The nitrogen routing from urea and aqua ammonia sources, by isotopic technique with 15 N in relation to the leaching, volatilization and extraction by the cultivation and residue of N immobilized manure in the soil with sugar cane plantation is also analysed. (C.G.C.)

Comparison of 15N- and 13C-determined parameters of mobility in melittin

International Nuclear Information System (INIS)

Zhu Lingyang; Prendergast, Franklyn G.; Kemple, Marvin D.

1998-01-01

Backbone and tryptophan side-chain mobilities in the 26-residue, cytolytic peptide melittin (MLT) were investigated by 15 N and 13 C NMR. Specifically, inverse-detected 15 N T 1 and steady-state NOE measurements were made at 30 and 51 MHz on MLT at 22 deg. C enriched with 15 N at six amide positions and in the Trp 19 side chain. Both the disordered MLT monomer (1.2 mM peptide at pH 3.6 in neat water) and α-helical MLT tetramer (4.0 mM peptide at pH 5.2 in 150 mM phosphate buffer) were examined. The relaxation data were analyzed in terms of the Lipari and Szabo model-free formalism with three parameters: τ m , the correlation time for the overall rotation; S 2 , a site-specific order parameter which is a measure of the amplitude of the internal motion; and τ e , a local, effective correlation time of the internal motion. A comparison was made of motional parameters from the 15 N measurements and from 13 C measurements on MLT, the latter having been made here and previously [Kemple et al. (1997) Biochemistry, 36, 1678-1688]. τ m and τ e values were consistent from data on the two nuclei. In the MLT monomer, S 2 values for the backbone N-H and Cα-H vectors in the same residue were similar in value but in the tetramer the N-H order parameters were about 0.2 units larger than the Cα-H order parameters. The Trp side-chain N-H and C-H order parameters, and τ e values were generally similar in both the monomer and tetramer. Implications of these results regarding the dynamics of MLT are examined

The Antibody Response of Pregnant Cameroonian Women to VAR2CSA ID1-ID2a, a Small Recombinant Protein Containing the CSA-Binding Site

Science.gov (United States)

Babakhanyan, Anna; Leke, Rose G. F.; Salanti, Ali; Bobbili, Naveen; Gwanmesia, Philomina; Leke, Robert J. I.; Quakyi, Isabella A.; Chen, John J.; Taylor, Diane Wallace

2014-01-01

In pregnant women, Plasmodium falciparum-infected erythrocytes expressing the VAR2CSA antigen bind to chondroitin sulfate A in the placenta causing placental malaria. The binding site of VAR2CSA is present in the ID1-ID2a region. This study sought to determine if pregnant Cameroonian women naturally acquire antibodies to ID1-ID2a and if antibodies to ID1-ID2a correlate with absence of placental malaria at delivery. Antibody levels to full-length VAR2CSA and ID1-ID2a were measured in plasma samples from 745 pregnant Cameroonian women, 144 Cameroonian men, and 66 US subjects. IgM levels and IgG avidity to ID1-ID2a were also determined. As expected, antibodies to ID1-ID2a were absent in US controls. Although pregnant Cameroonian women developed increasing levels of antibodies to full-length VAR2CSA during pregnancy, no increase in either IgM or IgG to ID1-ID2a was observed. Surprisingly, no differences in antibody levels to ID1-ID2a were detected between Cameroonian men and pregnant women. For example, in rural settings only 8–9% of males had antibodies to full-length VAR2CSA, but 90–96% had antibodies to ID1-ID2a. In addition, no significant difference in the avidity of IgG to ID1-ID2a was found between pregnant women and Cameroonian men, and no correlation between antibody levels at delivery and absence of placental malaria was found. Thus, the response to ID1-ID2a was not pregnancy specific, but predominantly against cross-reactivity epitopes, which may have been induced by other PfEMP1 antigens, malarial antigens, or microbes. Currently, ID1-ID2a is a leading vaccine candidate, since it binds to the CSA with the same affinity as the full-length molecule and elicits binding-inhibitory antibodies in animals. Further studies are needed to determine if the presence of naturally acquired cross-reactive antibodies in women living in malaria endemic countries will alter the response to ID1-ID2a following vaccination with ID1-ID2a. PMID:24505415

The antibody response of pregnant Cameroonian women to VAR2CSA ID1-ID2a, a small recombinant protein containing the CSA-binding site.

Directory of Open Access Journals (Sweden)

Anna Babakhanyan

Full Text Available In pregnant women, Plasmodium falciparum-infected erythrocytes expressing the VAR2CSA antigen bind to chondroitin sulfate A in the placenta causing placental malaria. The binding site of VAR2CSA is present in the ID1-ID2a region. This study sought to determine if pregnant Cameroonian women naturally acquire antibodies to ID1-ID2a and if antibodies to ID1-ID2a correlate with absence of placental malaria at delivery. Antibody levels to full-length VAR2CSA and ID1-ID2a were measured in plasma samples from 745 pregnant Cameroonian women, 144 Cameroonian men, and 66 US subjects. IgM levels and IgG avidity to ID1-ID2a were also determined. As expected, antibodies to ID1-ID2a were absent in US controls. Although pregnant Cameroonian women developed increasing levels of antibodies to full-length VAR2CSA during pregnancy, no increase in either IgM or IgG to ID1-ID2a was observed. Surprisingly, no differences in antibody levels to ID1-ID2a were detected between Cameroonian men and pregnant women. For example, in rural settings only 8-9% of males had antibodies to full-length VAR2CSA, but 90-96% had antibodies to ID1-ID2a. In addition, no significant difference in the avidity of IgG to ID1-ID2a was found between pregnant women and Cameroonian men, and no correlation between antibody levels at delivery and absence of placental malaria was found. Thus, the response to ID1-ID2a was not pregnancy specific, but predominantly against cross-reactivity epitopes, which may have been induced by other PfEMP1 antigens, malarial antigens, or microbes. Currently, ID1-ID2a is a leading vaccine candidate, since it binds to the CSA with the same affinity as the full-length molecule and elicits binding-inhibitory antibodies in animals. Further studies are needed to determine if the presence of naturally acquired cross-reactive antibodies in women living in malaria endemic countries will alter the response to ID1-ID2a following vaccination with ID1-ID2a.

Dynamic of N fertilizers: urea ({sup 15} N) and aqua ammonia ({sup 15} N) incorporated to the sugar cane soil. Final report; Dinamica do N dos fertilizantes: ureia ({sup 15} N) e aquamonia ({sup 15} N) incorporados ao solo na cultura da cana-de-acucar. Relatorio final

Energy Technology Data Exchange (ETDEWEB)

Trivelin, P C.O. [Centro de Energia Nuclear na Agricultura (CENA), Piracicaba, SP (Brazil)

1988-05-01

The dynamic of N fertilizers, urea and aqua ammonia, in the soil of sugar cane crops are studied with an emphasis on the horizontal and vertical moving. The nitrogen routing from urea and aqua ammonia sources, by isotopic technique with {sup 15} N in relation to the leaching, volatilization and extraction by the cultivation and residue of N immobilized manure in the soil with sugar cane plantation is also analysed. (C.G.C.).

Fate of 15N and 14C from labelled plant material

DEFF Research Database (Denmark)

Rasmussen, Jim; Gjettermann, Birgitte; Eriksen, Jørgen

2008-01-01

strength of labelled plant residues in dissolved inorganic N (DIN) and dissolved organic N (DON) in pore water from the plough layer, and (ii) the plant uptake of organically bound N. Litterbags containing 14C- and 15N-labelled ryegrass or clover roots or leaves were inserted into the sward of a ryegrass......–clover mixture in early spring. The fate of the released 14C and 15N was monitored in harvested biomass, roots, soil, and pore water percolating from the plough layer. No evidence of plant uptake of dual-labelled organic compounds from the dual-labelled residues could be observed. N in pore water from the plough...

Chondroitin sulphate A (CSA)-binding of single recombinant Duffy-binding-like domains is not restricted to Plasmodium falciparum Erythrocyte Membrane Protein 1 expressed by CSA-binding parasites

DEFF Research Database (Denmark)

Resende, Mafalda; Ditlev, Sisse B; Nielsen, Morten A

2009-01-01

Individuals living in areas with high Plasmodium falciparum transmission acquire immunity to malaria over time and adults have a markedly reduced risk of contracting severe disease. However, pregnant women constitute an important exception. Pregnancy-associated malaria is a major cause of mother....... In this study, we confirm the CSA-binding of these DBL domains, however, the analysis of a number of DBL domains of a non-VAR2CSA origin shows that CSA-binding is not exclusively restricted to VAR2CSA DBL domains. Furthermore, we show that the VAR2CSA DBL domains as well as other DBL domains also bind heparan...

Turnover of grain legume N rhizodeposits and effect of rhizodeposition on the turnover of crop residues

DEFF Research Database (Denmark)

Mayer, J.; Buegger, F.; Jensen, E.S.

2004-01-01

The turnover of N derived from rhizodeposition of faba bean (Vicia faba L.), pea (Pisum sativum L.) and white lupin (Lupinus albus L.) and the effects of the rhizodeposition on the subsequent C and N turnover of its crop residues were investigated in an incubation experiment (168 days, 15 degrees....... In the experiment the turnover of C and N was compared in soils with and without previous growth of three legumes and with and without incorporation of crop residues. After 168 days, 21% (lupin), 26% (faba bean) and 27% (pea) of rhizodeposition N was mineralised in the treatments without crop residues. A smaller...... amount of 15-17% was present as microbial biomass and between 30 and 55% of mineralised rhizodeposition N was present as microbial residue pool, which consists of microbial exoenzymes, mucous substances and dead microbial biomass. The effect of rhizodeposition on the C and N turnover of crop residues...

Interception of residual nitrate from a calcareous alluvial soil profile on the North China Plain by deep-rooted crops: A {sup 15}N tracer study

Energy Technology Data Exchange (ETDEWEB)

Ju, X.T. [Key Laboratory of Plant-Soil Interactions, Ministry of Education, College of Agricultural Resources and Environmental Sciences, China Agricultural University, 2 Yuan Ming Yuan West Road, Hai Dian District, Beijing 100094 (China)]. E-mail: juxt@cau.edu.cn; Gao, Q. [Key Laboratory of Plant-Soil Interactions, Ministry of Education, College of Agricultural Resources and Environmental Sciences, China Agricultural University, 2 Yuan Ming Yuan West Road, Hai Dian District, Beijing 100094 (China); College of Agricultural Resources and Environmental Sciences, Jilin Agricultural University, Changchun 130118 (China); Christie, P. [Key Laboratory of Plant-Soil Interactions, Ministry of Education, College of Agricultural Resources and Environmental Sciences, China Agricultural University, 2 Yuan Ming Yuan West Road, Hai Dian District, Beijing 100094 (China); Agricultural and Environmental Science Department, Queen' s University Belfast, Belfast BT9 5PX (United Kingdom); Zhang, F.S. [Key Laboratory of Plant-Soil Interactions, Ministry of Education, College of Agricultural Resources and Environmental Sciences, China Agricultural University, 2 Yuan Ming Yuan West Road, Hai Dian District, Beijing 100094 (China)

2007-03-15

{sup 15}N-labeled nitrate was injected into different depths of an alluvial calcareous soil profile on the North China Plain. Subsequent movement of NO{sub 3} {sup -}N and its recovery by deep-rooted maize (Zea mays L.) and shallow-rooted eggplant (Solanum melongena L.) were studied. Under conventional water and nutrient management the mean recoveries of {sup 15}N-labeled nitrate from K{sup 15}NO{sub 3} injected at depths 15, 45, and 75 cm were 22.4, 13.8, and 7.8% by maize and 7.9, 4.9, and 2.7% by eggplant. The recovery rate by maize at each soil depth was significantly higher than by eggplant. The deeper the injection of nitrate the smaller the distance of its downward movement and this corresponded with the movement of soil water during crop growth. Deeper rooting crops with high root length density and high water consumption may therefore be grown to utilize high concentrations of residual nitrate in the subsoil from previous intensive cropping and to protect the environment. - Deep-rooted crops have a greater capacity than shallow-rooted crops to intercept residual nitrate from the subsoil and restrict its movement down to the shallow groundw0010at.

Ammonia detection of 1-D ZnO/polypyrrole nanocomposite: Effect of CSA doping and their structural, chemical, thermal and gas sensing behavior

Energy Technology Data Exchange (ETDEWEB)

Jain, Shilpa [Department of Chemistry, University of Mumbai, Santacruz (East), Mumbai-400098,India (India); Karmakar, Narayan [Department of Physics, University of Mumbai, Santacruz (East), Mumbai-400098,India (India); Shah, Akshara [Department of Chemistry, University of Mumbai, Santacruz (East), Mumbai-400098,India (India); Kothari, D.C. [Department of Physics, University of Mumbai, Santacruz (East), Mumbai-400098,India (India); National Centre for Nanosciences& Nanotechnology, University of Mumbai, Santacruz (East), Mumbai-400098,India (India); Mishra, Satyendra [University Institute of Chemical Technology, North Maharashtra University, Jalgaon (India); Shimpi, Navinchandra G, E-mail: navin_shimpi@rediffmail.com [Department of Chemistry, University of Mumbai, Santacruz (East), Mumbai-400098,India (India)

2017-02-28

Highlights: • Synthesis of 1-Dimensional ZnO-Polypyrrole nanocomposite using In-situ oxidative polymerization technique. • High response ammonia sensing. • Optimization of ZnO content in nanocomposites for maximum sensor response. • Effect of CSA doping on structural, thermal, optical and sensing behavior. • Optimization of CSA concentration for high sensitivity, fast response and recovery time. - Abstract: Nanocomposites of polypyrrole (PPy) with varying concentration of ZnO nanorods (ZnO NRs) were synthesized using in-situ oxidative polymerization technique. The prepared nanocomposites (PPy, PPy-ZnO and CSA doped PPy-ZnO) were studied for various oxidizing and reducing gases at room temperature and found to be more selective towards ammonia gas. Various concentrations of ZnO NRs in Ppy matrix were studied and 15% was found to be optimum in terms of sensor response (66% towards 120 ppm NH{sub 3}). Further, with 15% doping of camphor sulphonic acid (CSA) in PPy-ZnO nanocomposite for 15% ZnO NRs in Ppy matrix, sensor response increased from 66 to 79% towards 120 ppm of NH{sub 3}. Structural, Optical and thermal behavior of nanocomposites were studied using powder X-ray diffraction (XRD), Fourier Transform Infra-Red (FTIR) spectroscopy, X-ray Photoelectron Spectroscopy (XPS), UV–vis (UV–vis) absorption spectroscopy, room temperature Photoluminescence (PL) Spectroscopy, Thermo-gravimetric analysis (TGA) and Field Emission Scanning Electron Microscopy (FESEM). ZnO has been completely embedded inside the polymeric chains as observed from in SEM. Meanwhile, FT-IR spectra indicate better conjugation and interaction in nanocomposites. With CSA doping interaction grows stronger due to extended delocalization over π electrons leading to higher sensor response and with response time and recovery time of 24 s and 34 s respectively. CSA doped PPy-ZnO (15%) nanocomposites observed to be a potential candidate for ammonia detection at lower ppm level.

1H and 15N resonance assignments of oxidized flavodoxin from Anacystis nidulans with 3D NMR

International Nuclear Information System (INIS)

Clubb, R.T.; Thanabal, V.; Wagner, G.; Osborne, C.

1991-01-01

Proton and nitrogen-15 sequence-specific nuclear magnetic resonance assignments have been determined for recombinant oxidized flavodoxin from Anacystis nidulans. Assignments were obtained by using 15 N- 1 H heteronuclear three-dimensional (3D) NMR spectroscopy on a uniformly nitrogen-15 enriched sample of the protein, pH 6.6, at 30C. For 165 residues, the backbone and a large fraction of the side-chain proton resonances have been assigned. Medium- and long-range NOE's have been used to characterize the secondary structure. In solution, flavodoxin consists of a five-stranded parallel β sheet involving residues 3-9, 31-37, 49-56, 81-89, 114-117, and 141-144. Medium-range NOE's indicate that presence of several helices. Several 15 N and 1 H resonances of the flavin mononucleotide (FMN) prosthetic group have been assigned. The FMN-binding site has been investigated by using polypeptide-FMN NOE's

Fertilizer 15N balance and recovery of N from organic sources by rice in Typic Ustochrept

International Nuclear Information System (INIS)

Bhattacharyya, Ranjan; Sachdev, M.S.; Sachdev, P.; Kundu, S.; Sutradhar, G.

2002-01-01

To investigate the fertilizer-N balance and recovery of N from organics (as determined by A-value technique) by rice as affected by urea application alone or in combination with FYM or green manure, a field experiment was conducted in the khariff season if 1997 at IARI, New Delhi on a sandy loam soil (Typic Ustochrept). 15 N-labelled urea was applied at 0.90 and 120 kg N ha -1 levels alone and in combination with either FYM or green manure in 2:1 or 1:1 ratios. Organic sources were incorporated seven days before transplanting whereas, urea was applied in three equal splits at 15 DAT, 28 DAT and 42 DAT. The residual 15 N in soil was determined only in the surface soil layer (0-15 cm) of rice crop. The combined source helped in conserving more of urea-N in soil as residual (42-45%) than urea alone (23-27%) treatment due to the fact that the unaccounted fertilizer 15 N was more in urea alone treatment (43-45%) than combined sources (12-15%) at both the levels. The efficiency of uptake of organic N by rice as determined through A-value technique was similar or better than urea-N at both the levels. (author)

HN-NCA heteronuclear TOCSY-NH experiment for {sup 1}H{sup N} and {sup 15}N sequential correlations in ({sup 13}C, {sup 15}N) labelled intrinsically disordered proteins

Energy Technology Data Exchange (ETDEWEB)

Wiedemann, Christoph; Goradia, Nishit; Häfner, Sabine [Leibniz Institute for Age Research, Fritz Lipmann Institute, Research Group Biomolecular NMR Spectroscopy (Germany); Herbst, Christian [Ubon Ratchathani University, Department of Physics, Faculty of Science (Thailand); Görlach, Matthias; Ohlenschläger, Oliver; Ramachandran, Ramadurai, E-mail: raman@fli-leibniz.de [Leibniz Institute for Age Research, Fritz Lipmann Institute, Research Group Biomolecular NMR Spectroscopy (Germany)

2015-10-15

A simple triple resonance NMR experiment that leads to the correlation of the backbone amide resonances of each amino acid residue ‘i’ with that of residues ‘i−1’ and ‘i+1’ in ({sup 13}C, {sup 15}N) labelled intrinsically disordered proteins (IDPs) is presented. The experimental scheme, {HN-NCA heteronuclear TOCSY-NH}, exploits the favourable relaxation properties of IDPs and the presence of {sup 1}J{sub CαN} and {sup 2}J{sub CαN} couplings to transfer the {sup 15}N{sub x} magnetisation from amino acid residue ‘i’ to adjacent residues via the application of a band-selective {sup 15}N–{sup 13}C{sup α} heteronuclear cross-polarisation sequence of ∼100 ms duration. Employing non-uniform sampling in the indirect dimensions, the efficacy of the approach has been demonstrated by the acquisition of 3D HNN chemical shift correlation spectra of α-synuclein. The experimental performance of the RF pulse sequence has been compared with that of the conventional INEPT-based HN(CA)NH pulse scheme. As the availability of data from both the HCCNH and HNN experiments will make it possible to use the information extracted from one experiment to simplify the analysis of the data of the other and lead to a robust approach for unambiguous backbone and side-chain resonance assignments, a time-saving strategy for the simultaneous collection of HCCNH and HNN data is also described.

New CSA guideline for the exemption or clearance from regulatory control of materials that contain, or potentially contain, nuclear substances

International Nuclear Information System (INIS)

Rhodes, M.; Kwong, A.

2011-01-01

The Canadian Standards Association (CSA) guideline N292.5, Guideline for the exemption or clearance from regulatory control of materials that contain, or potentially contain, nuclear substances, was recently developed to address a need for guidance on approaches for clearance of materials from facilities licensed by the Canadian Nuclear Safety Commission (CNSC) consistent with Canadian and international recommendations. This guideline is also applicable to determining if an activity associated with materials that contain nuclear substances is exempt from requiring a CNSC licence. The guideline summarizes the regulatory requirements associated with the exemption and clearance of materials and provides a graded approach to designing a survey based on the risk of residual contamination being present. (author)

[Effect of reduced N application on soil N residue and N loss in maize-soybean relay strip intercropping system].

Science.gov (United States)

Liu, Xiao-Ming; Yong, Tai-Wen; Liu, Wen-Yu; Su, Ben-Ying; Song, Chun; Yang, Feng; Wang, Xiao-Chun; Yang, Wen-Yu

2014-08-01

A field experiment was conducted in 2012, including three planting pattern (maize-soybean relay strip intercropping, mono-cultured maize and soybean) and three nitrogen application level [0 kg N x hm(-2), 180 kg N x hm(-2) (reduced N) and 240 kg N x hm(-2) (normal N)]. Fields were assigned to different treatments in a randomized block design with three replicates. The objective of this work was to analyze the effects of planting patterns and nitrogen application rates on plant N uptake, soil N residue and N loss. After fertilization applications, NH4(+)-N and NO3(-)-N levels increased in the soil of intercropped maize but decreased in the soil of intercropped soybean. Compared with mono-crops, the soil N residue and loss of intercropped soybean were reduced, while those of intercropped maize were increased and decreased, respectively. With the reduced rate of N application, N residue rate, N loss rate and ammonia volatilization loss rate of the maize-soybean intercropping relay strip system were decreased by 17.7%, 21.5% and 0.4% compared to mono-cultured maize, but increased by 2.0%, 19.8% and 0.1% compared to mono-cultured soybean, respectively. Likewise, the reduced N application resulted in reductions in N residue, N loss, and the N loss via ammonia volatilization in the maize-soybean relay strip intercropping system compared with the conventional rate of N application adopted by local farmers, and the N residue rate, N loss rate and ammonia volatilization loss rate reduced by 12.0%, 15.4% and 1.2%, respectively.

The new CSA standard for leak detection

Energy Technology Data Exchange (ETDEWEB)

Pietsch, Ulli [TAU, Edmonton, Alberta, (Canada); Scott, Don [TransCanada Pipelines, Edmonton, Alberta, (Canada)

2010-07-01

Standards need to be updated regularly to reflect current technology and industry practices. This paper describes the new Canadian Standards Association (CSA) for leak detection called Recommended Practice for Liquid Hydrocarbon Pipeline System Leak Detection, Annex E, which can be found in the CSA Z662 Oil and Gas Pipeline Systems standard. The CSA formed a task force of industry experts and regulators for a period of 18 months to draft the new standards. Several comparisons were made with the American Petroleum Institute (API) recommended practice API 1130. This new version introduces and defines the terms, critical instrument, critical process and dependent instrument. The most significant improvement made by the new Annex E is the new requirement that an operating company must develop a leak detection strategy. The writing of a leak detection manual is given high priority. The use of both Annex E and API 1130 is recommended.

Fate of 15N-urea applied to wheat-soybean succession crop

International Nuclear Information System (INIS)

Boaretto, Antonio Enedi; Trivelin, Paulo Cesar Ocheuze; Muraoka, Takashi; Spolidorio, Eduardo Scarpari; Freitas, Jose Guilherme de; Cantarella, Heitor

2004-01-01

The wheat crop in Sao Paulo State, Brazil, is fertilized with N, P and K. The rate of applied N (0 to 120 kg.ha -1 ) depends on the previous grown crop and the irrigation possibility. The response of wheat to rates and time of N application and the fate of N applied to irrigated wheat were studied during two years. Residual N recovery by soybean grown after the wheat was also studied. The maximum grain productivity was obtained with 92 kg.ha -1 of N. The efficiency of 15 N-urea utilization ranged from 52% to 85%. The main loss of applied 15 N, 5% to 12% occurred as ammonia volatilized from urea applied on soil surface. The N loss by leaching even at the N rate of 135 kg.ha -1 , was less than 1% of applied 15 N, due to the low amount of rainfall during the wheat grown season and a controlled amount of irrigated water, that were sufficient to moisten only the wheat root zone. The residual 15 N after wheat harvest represents around 40% of N applied as urea: 20% in soil, 3% in wheat root system and 16% in the wheat straw. Soybean recovered less than 2% of the 15 N applied to wheat at sowing or at tillering stage. (author)

Stereospecific assignments of glycine in proteins by stereospecific deuteration and {sup 15}N labeling

Energy Technology Data Exchange (ETDEWEB)

Hansen, A.P.; Curley, R.W. Jr.; Panigot, M.J.; Fesik, S.W. [Ohio State Univ., Columbus, OH (United States)

1994-12-01

Stereospecific assignments are important for accurately determining the three-dimensional structures of proteins through the use of multidimensional NMR techniques. It is especially important to stereospecifically assign the glycine {alpha}-protons in proteins because of the potential for different backbone conformations of this residue. These stereospecific assignments are critical for interpreting the {sup 3}J{sub NH,{alpha}H} coupling constants and NOEs involving the glycine {alpha}-protons that determine the conformation of this part of the protein. However, it is often difficult to unambiguously obtain the stereospecific assignments for glycine residues by using only NOE data. In this poster, we present a method for unambiguous, stereospecific assignment of the {alpha}-protons of glycine residues. This method involves synthesis of stereo-specifically deuterated and {sup 15}N-labeled Gly using a slightly modified procedure originally described by Woodard and coworkers for the stereoselective deuteration of glycine. The stereospecifically deuterated and {sup 15}N-labeled Gy has been incorporated into recombinant proteins expressed in both bacterial systems (FKBP) and mammalian cells (u-PA). Two- and three-dimensional isotope-filtered and isotope-edited NMR experiments were used to obtain the stereospecific assignments of the glycine {alpha}-protons for these proteins.

Application of amino acid type-specific 1H- and 14N-labeling in a 2H-, 15N-labeled background to a 47 kDa homodimer: Potential for NMR structure determination of large proteins

International Nuclear Information System (INIS)

Kelly, Mark J.S.; Krieger, Cornelia; Ball, Linda J.; Yu Yihua; Richter, Gerald; Schmieder, Peter; Bacher, Adelbert; Oschkinat, Hartmut

1999-01-01

NMR investigations of larger macromolecules (>20 kDa) are severely hindered by rapid 1H and 13C transverse relaxation. Replacement of non-exchangeable protons with deuterium removes many efficient 1H-1H and 1H-13C relaxation pathways. The main disadvantage of deuteration is that many of the protons which would normally be the source of NOE-based distance restraints are removed. We report the development of a novel labeling strategy which is based on specific protonation and 14N-labeling of the residues phenylalanine, tyrosine, threonine, isoleucine and valine in a fully deuterated, 15N-labeled background. This allows the application of heteronuclear half-filters, 15N-editing and 1H-TOCSY experiments to select for particular magnetization transfer pathways. Results from investigations of a 47 kDa dimeric protein labeled in this way demonstrated that the method provides useful information for the structure determination of large proteins

Baculovirus-expressed constructs induce immunoglobulin G that recognizes VAR2CSA on Plasmodium falciparum-infected erythrocytes

DEFF Research Database (Denmark)

Barfod, Lea; Nielsen, Morten A; Turner, Louise

2006-01-01

We raised specific antisera against recombinant VAR2CSA domains produced in Escherichia coli and in insect cells. All were reactive in enzyme-linked immunosorbent assay, but only insect cell-derived constructs induced immunoglobulin G (IgG) that was reactive with native VAR2CSA on the surface...

Long-term heat storage in calcium sulfoaluminate cement (CSA) based concrete

Energy Technology Data Exchange (ETDEWEB)

Kaufmann, Josef P.; Winnefeld, Frank [Empa Swiss Federal Laboratories for Materials Science and Technology, Duebendorf (Switzerland). Lab. for Concrete and Construction Chemistry

2011-07-01

In general, the selection of materials proposed for solar heat storage is based on one of two principal processes: sensible heat storage or latent heat storage. Sensible heat storage utilizes the specific heat capacity of a material, while latent heat storage is based on the change in enthalpy (heat content) associated with a phase change of the material. Long time sensible heat storage requires excellent thermal insulation whereas latent heat storage allows permanent (seasonal) storage without significant energy losses and any special insulation. Ettringite, one of the cement hydration products, exhibits a high dehydration enthalpy. Calcium sulfoaluminate cement based concrete containing a high amount of ettringite is henceproposed as an efficient latent heat storage material. Compared to conventional heat storage materials this innovative concrete mixture has a high loss-free storage energy density (> 100-150 kWh/m{sup 3}) which is much higher than the one of paraffin or the (loss-sensitive) sensible heat of water. Like common concrete the CSA-concrete is stable and even may carry loads. The dehydration of the CSA-concrete is achieved at temperatures below 100 C. The rehydration process occurs as soon as water (liquid or vapor) is added. In contrast to paraffin, the phase change temperature is not fixed and the latent heat may be recovered at any desired temperature. Furthermore the heat conductivity of this material is high, so that the energy transfer from/to an exchange medium is easy. Additionally CSA-concrete is not flammable and absolutely safe regarding any health aspects. The cost of such CSA-concrete isin the order of normal concrete. The main application is seen in house heating systems. Solar heat, mostly generated during the summer period by means of roof collectors, can be stored in CSA-concrete until the winter. A part or even the whole annual heatingenergy may be produced and saved locally by the householder himself. Additional applications may be

15N-labelled glycine synthesis

International Nuclear Information System (INIS)

Tavares, Claudineia R.O.; Bendassolli, Jose A.; Sant'Ana Filho, Carlos R.; Prestes, Clelber V.; Coelho, Fernando

2006-01-01

This work describes a method for 15 N-isotope-labeled glycine synthesis, as well as details about a recovery line for nitrogen residues. To that effect, amination of α-haloacids was performed, using carboxylic chloroacetic acid and labeled aqueous ammonia ( 15 NH 3 ). Special care was taken to avoid possible 15 NH 3 losses, since its production cost is high. In that respect, although the purchase cost of the 13 N-labeled compound (radioactive) is lower, the stable tracer produced constitutes an important tool for N cycling studies in living organisms, also minimizing labor and environmental hazards, as well as time limitation problems in field studies. The tests were carried out with three replications, and variable 15 NH 3(aq) volumes in the reaction were used (50, 100, and 150 mL), in order to calibrate the best operational condition; glycine masses obtained were 1.7, 2, and 3.2 g, respectively. With the development of a system for 15 NH 3 recovery, it was possible to recover 71, 83, and 87% of the ammonia initially used in the synthesis. With the required adaptations, the same system was used to recover methanol, and 75% of the methanol initially used in the amino acid purification process were recovered. (author)

Balance study of the fate of 15N fertilizer

International Nuclear Information System (INIS)

Korte, F.; Sotiriou, N.

1980-01-01

An interim report is presented on a series of experiments with wooden box-type lysimeters (60 cm x 60 cm x 70 cm) loaded with a sandy soil, a loess soil and straw-amended soil. The lysimeters support crops rotated over a five-year period to be studied - potato, barley, sugar-beet, barley (with winter rape) and finally (1979) potato. Each lysimeter received split applications of urea at total rates of 0, 50 or 100 kg.ha -1 . The effects of soil residues of the herbicide monolinuron were also studied. The report deals with data collected during the first three years of the planned experiments (1975 - 1977 inclusive). 15 N-labelled urea (47 atom 15 N% excess) was initially used but in some experiments this was followed by applications of unlabelled urea in order to study the fate of the residual 15 N in the subsequent years. The results to date indicated that in the first year highest recoveries in the plant of the applied 15 N obtained on the sandy soil. The low recoveries of 15 N in the subsequent years when unlabelled urea was supplied also indicated significant storage by soil or root organic matter of the applied 15 N. Compared with the control (zero application of urea nitrogen), potato took up more total nitrogen in the presence of fertilizer including more of the unlabelled soil pool nitrogen. Analyses of the soil profiles in terms of total soil nitrogen and fertilizer-derived nitrogen (on the basis of 15 N assays) indicated leaching of the labelled nitrogen down the soil profile in all cases during the three-year period. Analysis of NO 3 -N in leachates confirmed the presence of labelled urea-derived nitrogen. (author)

Measurement of conformational constraints in an elastin-mimetic protein by residue-pair selected solid-state NMR

International Nuclear Information System (INIS)

Hong, Mei; McMillan, R. Andrew; Conticello, Vincent P.

2002-01-01

We introduce a solid-state NMR technique for selective detection of a residue pair in multiply labeled proteins to obtain site-specific structural constraints. The method exploits the frequency-offset dependence of cross polarization to achieve 13 CO i → 15 N i → 13 Cα i transfer between two residues. A 13 C, 15 N-labeled elastin mimetic protein (VPGVG) n is used to demonstrate the method. The technique selected the Gly3 Cα signal while suppressing the Gly5 Cα signal, and allowed the measurement of the Gly3 Cα chemical shift anisotropy to derive information on the protein conformation. This residue-pair selection technique should simplify the study of protein structure at specific residues

Influence of organic N Sources on N transformation and uptake by lupine plants using 15N technique

International Nuclear Information System (INIS)

Abdel-Salam, A.A.; Gadalla, A.M.; Abdel- Aziz, H.A.; Galal, Y.G.M.; EL-degwy, S.M.

2008-01-01

A pot experiment was carried out under greenhouse conditions to evaluate the comparative efficiency and transformation of nitrogen applied either as mineral or organic forms. The obtained data showed that shoot dry weight was enhanced by compost and its mixture with leucaena. When organic sources were combined with 15 N, the leucaena.compost mixture (LC p ) gave the highest yield, and the other two were not significantly different from each other. Reinforcing the organic N with mineral N caused an average greater N.uptake over the non reinforced treatment. Similar trend was noticed with root system. Nitrogen uptake by roots was increased according to the order of LC > L > C. N derived from fertilizer (% Ndff) by lupine shoots was significantly affected by fertilizer addition either alone or reinforced with organic plant residues. Both, the portions (%) or absolute values (mg pot -1 ) of Ndff were increased by adding the organic residues. The highest value of Ndfs was recorded with application of leucaena followed by compost, then Leucaena + compost. Portion Ndfa reflected an effective response of lupines plants to Rhizobium inoculation. Addition of LC mixture combined with 15 N-fertilizer had enhanced the N 2 fixation and increased Ndfa value by about 66.7 % over those recorded with 15 N0 treatment. Organic amendment of leucaena could be an efficient source for N to infertile sandy soils

Estimation of the endogenous N proportions in ileal digesta and faeces in 15N-labelled pigs

International Nuclear Information System (INIS)

Simon, O.; Bergner, H.

1987-01-01

4 castrated male pigs 40 kg fitted with simple 'T' cannulas in the terminal ileum were given 15 N-labelled ammonium salts, added to a low protein diet, for 6 days. Excretion of 15 N in urine and feces was monitored daily throughout the labelling and subsequent experimental periods. During the experimental period the pigs were given a diet based on wheat and fish meal, supplemented with varying levels of partially hydrolyzed straw meal to give crude fiber contents ranging from 40 to 132 g/kg. After adaptation to the particular levels of straw meal, feces and ileal digesta were collected during successive 24 h periods. N digestibility values were determined by the chromium oxide ratio method. The retention of 15 N-labelled non-specific N was 0.46 of the dose given. The validity of using urine values as a measure of 15 N abundance in endogenous N was demonstrated by the similarity of 15 N abundance in urine immediately before slaughter at the end of the experiment and in the digestive secretory organs thereafter. The average amount of endogenous N passing the terminal ileum was 3.4 g/day or 0.30-0.50 of total ileal N flow. This was not affected by dietary fiber level. The proportion of fecal N which was of endogenous origin was similar to that in ileal digesta, suggesting similar utilization of endogenous and residual dietary N by hindgut bacteria. Half the endogenous N entering the large intestine was reabsorbed there. Increasing dietary crude fiber from 40 to 132 g/kg increased fecal endogenous N excretion from 1.3 to 2.0 g/animal and day. (author)

DNA Packaging Specificity of Bacteriophage N15 with an Excursion into the Genetics of a Cohesive End Mismatch.

Directory of Open Access Journals (Sweden)

Michael Feiss

Full Text Available During DNA replication by the λ-like bacteriophages, immature concatemeric DNA is produced by rolling circle replication. The concatemers are processed into mature chromosomes with cohesive ends, and packaged into prohead shells, during virion assembly. Cohesive ends are generated by the viral enzyme terminase, which introduces staggered nicks at cos, an approx. 200 bp-long sequence containing subsites cosQ, cosN and cosB. Interactions of cos subsites of immature concatemeric DNA with terminase orchestrate DNA processing and packaging. To initiate DNA packaging, terminase interacts with cosB and nicks cosN. The cohesive ends of N15 DNA differ from those of λ at 2/12 positions. Genetic experiments show that phages with chromosomes containing mismatched cohesive ends are functional. In at least some infections, the cohesive end mismatch persists through cyclization and replication, so that progeny phages of both allelic types are produced in the infected cell. N15 possesses an asymmetric packaging specificity: N15 DNA is not packaged by phages λ or 21, but surprisingly, N15-specific terminase packages λ DNA. Implications for genetic interactions among λ-like bacteriophages are discussed.

Species specific and environment induced variation of δ13C and δ15N in alpine plants

Directory of Open Access Journals (Sweden)

Yang eYang

2015-06-01

Full Text Available Stable carbon and nitrogen isotope signals in plant tissues integrate plant-environment interactions over long periods. In this study, we hypothesized that humid alpine life conditions are narrowing the scope for significant deviations from common carbon, water and nitrogen relations as captured by stable isotope signals. We explored the variation in δ13C and δ15N in 32 plant species from tissue type to ecosystem scale across a suite of locations at c. 2500 m elevation in the Swiss Alps. Foliar δ13C and δ15N varied among species by about 3-4 ‰ and 7-8 ‰ respectively. However, there was no overall difference in means of δ13C and δ15N for species sampled in different plant communities or when bulk plant dry matter harvests of different plant communities were compared. δ13C was found to be highly species specific, so that the ranking among species was mostly maintained across 11 habitats. However, δ15N varied significantly from place to place in all species (a range of 2.7 ‰ except in Fabaceae (Trifolium alpinum and Juncaceae (Luzula lutea. There was also a substantial variation among individuals of the same species collected next to each other. No difference was found in foliar δ15N of non-legumes, which were either collected next to or away from the most common legume, T. alpinum. δ15N data place Cyperaceae and Juncaceae, just like Fabaceae, in a low discrimination category, well separated from other families. Soil δ15N was higher than in plants and increased with soil depth. The results indicate a high functional diversity in alpine plants that is similar to that reported for low elevation plants. We conclude that the surprisingly high variation in δ13C and δ15N signals in the studied high elevation plants is largely species specific (genetic and insensitive to obvious environmental cues.

Differential recognition of terminal extracellular Plasmodium falciparum VAR2CSA domains by sera from multigravid, malaria-exposed Malian women.

Science.gov (United States)

Travassos, Mark A; Coulibaly, Drissa; Bailey, Jason A; Niangaly, Amadou; Adams, Matthew; Nyunt, Myaing M; Ouattara, Amed; Lyke, Kirsten E; Laurens, Matthew B; Pablo, Jozelyn; Jasinskas, Algis; Nakajima, Rie; Berry, Andrea A; Takala-Harrison, Shannon; Kone, Abdoulaye K; Kouriba, Bourema; Rowe, J Alexandra; Doumbo, Ogobara K; Thera, Mahamadou A; Laufer, Miriam K; Felgner, Philip L; Plowe, Christopher V

2015-06-01

The Plasmodium falciparum erythrocyte membrane protein 1 (PfEMP1) family mediates parasite sequestration in small capillaries through tissue-specific cytoadherence. The best characterized of these proteins is VAR2CSA, which is expressed on the surface of infected erythrocytes that bind to chondroitin sulfate in the placental matrix. Antibodies to VAR2CSA prevent placental cytoadherence and protect against placental malaria. The size and complexity of the VAR2CSA protein pose challenges for vaccine development, but smaller constitutive domains may be suitable for subunit vaccine development. A protein microarray was printed to include five overlapping fragments of the 3D7 VAR2CSA extracellular region. Malian women with a history of at least one pregnancy had antibody recognition of four of these fragments and had stronger reactivity against the two distal fragments than did nulliparous women, children, and men from Mali, suggesting that the C-terminal extracellular VAR2CSA domains are a potential focus of protective immunity. With carefully chosen sera from longitudinal studies of pregnant women, this approach has the potential to identify seroreactive VAR2CSA domains associated with protective immunity against pregnancy-associated malaria. © The American Society of Tropical Medicine and Hygiene.

Determination of 13C CSA Tensors: Extension of the Model-independent Approach to an RNA Kissing Complex Undergoing Anisotropic Rotational Diffusion in Solution

International Nuclear Information System (INIS)

Ravindranathan, Sapna; Kim, Chul-Hyun; Bodenhausen, Geoffrey

2005-01-01

Chemical shift anisotropy (CSA) tensor parameters have been determined for the protonated carbons of the purine bases in an RNA kissing complex in solution by extending the model-independent approach [Fushman, D., Cowburn, D. (1998) J. Am. Chem. Soc. 120, 7109-7110]. A strategy for determining CSA tensor parameters of heteronuclei in isolated X-H two-spin systems (X = 13 C or 15 N) in molecules undergoing anisotropic rotational diffusion is presented. The original method relies on the fact that the ratio κ 2 =R 2 auto /R 2 cross of the transverse auto- and cross-correlated relaxation rates involving the X CSA and the X-H dipolar interaction is independent of parameters related to molecular motion, provided rotational diffusion is isotropic. However, if the overall motion is anisotropic κ 2 depends on the anisotropy D parallel /D -perpendicular of rotational diffusion. In this paper, the field dependence of both κ 2 and its longitudinal counterpart κ 1 =R 1 auto /R 1 cross are determined. For anisotropic rotational diffusion, our calculations show that the average κ av = 1/2 (κ 1 +κ 2 ), of the ratios is largely independent of the anisotropy parameter D parallel /D -perpendicular . The field dependence of the average ratio κ av may thus be utilized to determine CSA tensor parameters by a generalized model-independent approach in the case of molecules with an overall motion described by an axially symmetric rotational diffusion tensor

Structural Insight into Epitopes in the Pregnancy-Associated Malaria Protein VAR2CSA

DEFF Research Database (Denmark)

Andersen, P; Nielsen, MA; Resende, M

2008-01-01

Pregnancy-associated malaria is caused by Plasmodium falciparum malaria parasites binding specifically to chondroitin sulfate A in the placenta. This sequestration of parasites is a major cause of low birth weight in infants and anemia in the mothers. VAR2CSA, a polymorphic multi-domain protein o...

The effect of adaptive servo ventilation (ASV) on objective and subjective outcomes in Cheyne-Stokes respiration (CSR) with central sleep apnea (CSA) in heart failure (HF): A systematic review.

Science.gov (United States)

Yang, Hyunju; Sawyer, Amy M

2016-01-01

To summarize the current evidence for adaptive servo ventilation (ASV) in Cheyne-Stokes respiration (CSR) with central sleep apnea (CSA) in heart failure (HF) and advance a research agenda and clinical considerations for ASV-treated CSR-CSA in HF. CSR-CSA in HF is associated with higher overall mortality, worse outcomes and lower quality of life (QOL) than HF without CSR-CSA. Five databases were searched using key words (n = 234). Randomized controlled trials assessed objective sleep quality, cardiac, and self-reported outcomes in adults (≥18 years) with HF (n = 10). ASV has a beneficial effect on the reduction of central sleep apnea in adult patients with CSR-CSA in HF, but it is not be superior to CPAP, bilevel PPV, or supplemental oxygen in terms of sleep quality defined by polysomnography, cardiovascular outcomes, subjective daytime sleepiness, and quality of life. ASV is not recommended for CSR-CSA in HF. It is important to continue to refer HF patients for sleep evaluation to clearly discern OSA from CSR-CSA. Symptom management research, inclusive of objective and subjective outcomes, in CSR-CSA in HF adults is needed. Copyright © 2016 Elsevier Inc. All rights reserved.

Effect of different transplanting leaf age on rice yield, nitrogen utilization efficiency and fate of 15N-fertilizer

International Nuclear Information System (INIS)

Fan Hongzhu; Lu Shihua; Zeng Xiangzhong

2010-01-01

Field experiments were conducted to study rice yield, N uptake and fate by using 15 N-urea at transplanting leaf age of 2-, 4-and 6-leaf, respectively. The results showed that rice yield significantly decreased with delay of transplanting leaf age, and 15 N-fertilizer uptake by grain and straw of rice, nitrogen utilization and residue also decreased, but loss of 15 N-fertilizer increased. Under different transplanting leaf age, N absorption by rice mainly came from the soil. Almost 1/3 of total N was supplied by fertilizer, and 2/3 came from soil. The efficiency of fertilizer was 20.8% ∼ 25.7%, 15 N-fertilizer residue ratio was 17.9% ∼ 32.2%, and 15 N-fertilizer loss was 42.1% ∼ 61.3%. 15 N-fertilizer residue mainly distributed in 0 ∼ 20 cm top soil under different treatments. The results indicated that transplanting young leaf age could increase rice yield and nitrogen utilization efficiency, and decrease loss of nitrogen fertilizer and pollution level on environment. (authors)

Positive Selection of Plasmodium falciparum Parasites With Multiple var2csa-Type PfEMP1 Genes During the Course of Infection in Pregnant Women

Science.gov (United States)

Salanti, Ali; Lavstsen, Thomas; Nielsen, Morten A.; Theander, Thor G.; Leke, Rose G. F.; Lo, Yeung Y.; Bobbili, Naveen; Arnot, David E.; Taylor, Diane W.

2011-01-01

Placental malaria infections are caused by Plasmodium falciparum–infected red blood cells sequestering in the placenta by binding to chondroitin sulfate A, mediated by VAR2CSA, a variant of the PfEMP1 family of adhesion antigens. Recent studies have shown that many P. falciparum genomes have multiple genes coding for different VAR2CSA proteins, and parasites with >1 var2csa gene appear to be more common in pregnant women with placental malaria than in nonpregnant individuals. We present evidence that, in pregnant women, parasites containing multiple var2csa-type genes possess a selective advantage over parasites with a single var2csa gene. Accumulation of parasites with multiple copies of the var2csa gene during the course of pregnancy was also correlated with the development of antibodies involved in blocking VAR2CSA adhesion. The data suggest that multiplicity of var2csa-type genes enables P. falciparum parasites to persist for a longer period of time during placental infections, probably because of their greater capacity for antigenic variation and evasion of variant-specific immune responses. PMID:21592998

Antibody levels to recombinant VAR2CSA domains vary with Plasmodium falciparum parasitaemia, gestational age, and gravidity, but do not predict pregnancy outcomes.

Science.gov (United States)

Fried, Michal; Kurtis, Jonathan D; Swihart, Bruce; Morrison, Robert; Pond-Tor, Sunthorn; Barry, Amadou; Sidibe, Youssoufa; Keita, Sekouba; Mahamar, Almahamoudou; Andemel, Naissem; Attaher, Oumar; Dembele, Adama B; Cisse, Kadidia B; Diarra, Bacary S; Kanoute, Moussa B; Narum, David L; Dicko, Alassane; Duffy, Patrick E

2018-03-09

Maternal malaria is a tropical scourge associated with poor pregnancy outcomes. Women become resistant to Plasmodium falciparum pregnancy malaria as they acquire antibodies to the variant surface antigen VAR2CSA, a leading vaccine candidate. Because malaria infection may increase VAR2CSA antibody levels and thereby confound analyses of immune protection, gravidity-dependent changes in antibody levels during and after infection, and the effect of VAR2CSA antibodies on pregnancy outcomes were evaluated. Pregnant women enrolled in a longitudinal cohort study of mother-infant pairs in Ouelessebougou, Mali provided plasma samples at enrollment, gestational week 30-32, and delivery. Antibody levels to VAR2CSA domains were measured using a multiplex bead-based assay. Antibody levels to VAR2CSA were higher in multigravidae than primigravidae. Malaria infection was associated with increased antibody levels to VAR2CSA domains. In primigravidae but not in secundigravidae or multigravidae, antibodies levels sharply declined after an infection. A relationship between any VAR2CSA antibody specificity and protection from adverse pregnancy outcomes was not detected. During malaria infection, primigravidae acquire short-lived antibodies. The lack of an association between VAR2CSA domain antibody reactivity and improved pregnancy outcomes suggests that the recombinant proteins may not present native epitopes targeted by protective antibodies.

The antibody response of pregnant Cameroonian women to VAR2CSA ID1-ID2a, a small recombinant protein containing the CSA-binding site

DEFF Research Database (Denmark)

Babakhanyan, Anna; Leke, Rose G F; Salanti, Ali

2014-01-01

In pregnant women, Plasmodium falciparum-infected erythrocytes expressing the VAR2CSA antigen bind to chondroitin sulfate A in the placenta causing placental malaria. The binding site of VAR2CSA is present in the ID1-ID2a region. This study sought to determine if pregnant Cameroonian women natura...

A novel pig feed formulation containing Aspergillus niger CSA35 ...

African Journals Online (AJOL)

This study investigated the effects of Aspergillus niger CSA35 pretreated-cassava (Manihot esculenta Crantz) peel feed (CPFG) on the body weight gain and some selected biochemical parameters of pigs. Cassava peels treated with biomass of A. niger CSA35 for a period of three weeks to initiate enzymatic digestion of ...

CSA guide to Canadian wind turbine codes and standards

International Nuclear Information System (INIS)

2008-01-01

The Canadian wind energy sector has become one of the fastest-growing wind energy markets in the world. Growth of the industry has been supported by various government agencies. However, many projects have experienced cost over-runs or cancellations as a result of unclear regulatory requirements, and wind energy developers are currently subject to a variety of approval processes involving several different authorities. This Canadian Standards Association (CSA) guide provided general information on codes and standards related to the design, approval, installation, operation, and maintenance of wind turbines in Canada. CSA codes and standards were developed by considering 5 new standards adopted by the International Electrotechnical Commission (IEC) Technical Committee on Wind Turbines. The standards described in this document related to acoustic noise measurement techniques; power performance measurements of electricity-producing wind turbines; lightning protection for wind turbine generator systems; design requirements for turbines; and design requirements for small wind turbines. The guide addressed specific subject areas related to the development of wind energy projects that involve formal or regulatory approval processes. Subject areas included issues related to safety, environmental design considerations, site selection, and mechanical systems. Information on associated standards and codes was also included

Measurement of conformational constraints in an elastin-mimetic protein by residue-pair selected solid-state NMR

Energy Technology Data Exchange (ETDEWEB)

Hong, Mei [Iowa State University, Department of Chemistry (United States)], E-mail: mhong@iastate.edu; McMillan, R. Andrew; Conticello, Vincent P. [Emory University, Department of Chemistry (United States)

2002-02-15

We introduce a solid-state NMR technique for selective detection of a residue pair in multiply labeled proteins to obtain site-specific structural constraints. The method exploits the frequency-offset dependence of cross polarization to achieve {sup 13}CO{sub i} {sup {yields}} {sup 15}N{sub i} {sup {yields}} {sup 13}C{alpha}{sub i} transfer between two residues. A {sup 13}C, {sup 15}N-labeled elastin mimetic protein (VPGVG){sub n} is used to demonstrate the method. The technique selected the Gly3 C{alpha} signal while suppressing the Gly5 C{alpha} signal, and allowed the measurement of the Gly3 C{alpha} chemical shift anisotropy to derive information on the protein conformation. This residue-pair selection technique should simplify the study of protein structure at specific residues.

CSA/AZA, in the absence of prednisone, improves linear growth in renal transplanted children.

Science.gov (United States)

David-Neto, E; Nahas, W; Sampaio, E C; Ianhez, L E; Sabbaga, E; Arap, S

1992-01-01

We compared the results of 44 renal transplants in children, of whom 24 were treated with CSA/AZA and 20 with prednisone in combination with AZA and/or CSA. There were no differences in age distribution or mean ages at transplant between the two treatment groups. The CSA/AZA group had a longer follow-up (29 +/- 33 vs 17 +/- 18 months). At the last follow-up, five children in the CSA/AZA and none in the prednisone group had lost their grafts. Serum creatinine increased in both groups from 0.7 +/- 0.1 mg/dl and 0.9 +/- 0.1 mg/dl at the end of the first month to 1.1 +/- 0.2 mg/dl in the 36th month (CSA/AZA group) (P renal transplant in children, but only 75% tolerated AZA/CSA without same damage to their grafts.

Purification, characterization of Chondroitinase ABC from Sphingomonas paucimobilis and in vitro cardiocytoprotection of the enzymatically degraded CS-A.

Science.gov (United States)

Fu, Jingyun; Jiang, Zhiwen; Chang, Jing; Han, Baoqin; Liu, Wanshun; Peng, Yanfei

2018-04-24

An extracellular chondroitinase ABC (ChSase ABC) produced by Sphingomonas paucimobilis was purified to homogeneity through ammonium sulfate precipitation, DEAE-Sepharose Fast Flow and Sephadex G-100 chromatography. The molecular weight was 82.3 kDa. It showed specific lyase activity toward chondroitin sulfate A (CS-A), CS-B, CS-C and hyaluronan (HA). Using CS-A as substrate, the specific activity was 98.04 U/mg, the maximal reaction rate (V max ) and Michaelis-Menten constant (K m ) were 0.49 μmol/min/ml and 0.79 mg/ml, respectively. Highest activity was obtained at pH 6.5 and 40 °C, and Hg 2+ could strongly inhibit the enzyme activity. Mass spectrometry analysis indicated CS-A was degraded to unsaturated disaccharides by ChSase ABC. In vitro cytotoxic tests showed that CS-A oligosaccharide at the concentration of 50 and 100 μg/ml could promote the proliferation of normal H9c2 myocardial cells, decrease the damage induced by isoproterenol (ISO) and accelerate the recovery of cells injured by ISO. These findings suggested that ChSase ABC from Sphingomonas paucimobilis could be a promising tool for the structural analysis and bioactive oligosaccharide preparation of glucosaminoglycans. Copyright © 2018 Elsevier B.V. All rights reserved.

Autocatalytic activity and substrate specificity of the pestivirus N-terminal protease N{sup pro}

Energy Technology Data Exchange (ETDEWEB)

Gottipati, Keerthi; Acholi, Sudheer [Department of Biochemistry and Molecular Biology, Sealy Center for Structural Biology and Molecular Biophysics, The University of Texas Medical Branch, Galveston, TX 77555-0647 (United States); Ruggli, Nicolas [Institute of Virology and Immunology, CH-3147 Mittelhäusern (Switzerland); Choi, Kyung H., E-mail: kychoi@utmb.edu [Department of Biochemistry and Molecular Biology, Sealy Center for Structural Biology and Molecular Biophysics, The University of Texas Medical Branch, Galveston, TX 77555-0647 (United States)

2014-03-15

Pestivirus N{sup pro} is the first protein translated in the viral polypeptide, and cleaves itself off co-translationally generating the N-terminus of the core protein. Once released, N{sup pro} blocks the host's interferon response by inducing degradation of interferon regulatory factor-3. N{sup pro'}s intracellular autocatalytic activity and lack of trans-activity have hampered in vitro cleavage studies to establish its substrate specificity and the roles of individual residues. We constructed N{sup pro}-GFP fusion proteins that carry the authentic cleavage site and determined the autoproteolytic activities of N{sup pro} proteins containing substitutions at the predicted catalytic sites Glu22 and Cys69, at Arg100 that forms a salt bridge with Glu22, and at the cleavage site Cys168. Contrary to previous reports, we show that N{sup pro'}s catalytic activity does not involve Glu22, which may instead be involved in protein stability. Furthermore, N{sup pro} does not have specificity for Cys168 at the cleavage site even though this residue is conserved throughout the pestivirus genus. - Highlights: • N{sup pro'}s autoproteolysis is studied using N{sup pro}-GFP fusion proteins. • N-terminal 17 amino acids are dispensable without loss of protease activity. • The putative catalytic residue Glu22 is not involved in protease catalysis. • No specificity for Cys168 at the cleavage site despite evolutionary conservation. • N{sup pro} prefers small amino acids with non-branched beta carbons at the P1 position.

A novel virus-like particle based vaccine platform displaying the placental malaria antigen VAR2CSA

DEFF Research Database (Denmark)

Thrane, Susan; Janitzek, Christoph M; Agerbæk, Mette Ø

2015-01-01

, this difference was not statistically significant after 3rd immunization. Importantly, the VLP-VAR2CSA induced antibodies were functional in inhibiting the binding of parasites to CSA. This study demonstrates that the described Avi-L1 VLP-platform may serve as a versatile system for facilitating optimal VLP......SA-VAR2CSA vaccines induced higher antibody titers than the soluble naked VAR2CSA vaccine after three immunizations. The VAR2CSA Avi-L1 VLP vaccine induced statistically significantly higher endpoint titres compared to the soluble mSA-VAR2CSA vaccine, after 1st and 2nd immunization; however...

CSA-90 Promotes Bone Formation and Mitigates Methicillin-resistant Staphylococcus aureus Infection in a Rat Open Fracture Model.

Science.gov (United States)

Mills, Rebecca; Cheng, Tegan L; Mikulec, Kathy; Peacock, Lauren; Isaacs, David; Genberg, Carl; Savage, Paul B; Little, David G; Schindeler, Aaron

2018-06-01

Infection of open fractures remains a significant cause of morbidity and mortality to patients worldwide. Early administration of prophylactic antibiotics is known to improve outcomes; however, increasing concern regarding antimicrobial resistance makes finding new compounds for use in such cases a pressing area for further research. CSA-90, a synthetic peptidomimetic compound, has previously demonstrated promising antimicrobial action against Staphylococcus aureus in rat open fractures. However, its efficacy against antibiotic-resistant microorganisms, its potential as a therapeutic agent in addition to its prophylactic effects, and its proosteogenic properties all require further investigation. (1) Does prophylactic treatment with CSA-90 reduce infection rates in a rat open fracture model inoculated with S aureus, methicillin-resistant S aureus (MRSA), and methicillin-resistant Staphylococcus epidermidis (MRSE) as measured by survival, radiographic union, and deep tissue swab cultures? (2) Does CSA-90 reduce infection rates when administered later in the management of an open fracture as measured by survival, radiographic union, and deep tissue swab cultures? (3) Does CSA-90 demonstrate a synergistic proosteogenic effect with bone morphogenetic protein 2 (BMP-2) in a noninfected rat ectopic bone formation assay as assessed by micro-CT bone volume measurement? (4) Can CSA-90 elute and retain its antimicrobial efficacy in vitro when delivered using clinically relevant agents measured using a Kirby-Bauer disc diffusion assay? All in vivo studies were approved by the local animal ethics committee. In the open fracture studies, 12-week-old male Wistar rats underwent open midshaft femoral fractures stabilized with a 1.1-mm Kirschner wire and 10 µg BMP-2 ± 500 µg CSA-90 was applied to the fracture site using a collagen sponge along with 1 x 10 colony-forming units of bacteria (S aureus/MRSA/MRSE; n = 10 per group). In the delayed treatment study, débridement and

Production, crystallization and X-ray diffraction analysis of two nanobodies against the Duffy binding-like (DBL) domain DBL6∊-FCR3 of the Plasmodium falciparum VAR2CSA protein

International Nuclear Information System (INIS)

Vuchelen, Anneleen; Pardon, Els; Steyaert, Jan; Gamain, Benoît; Loris, Remy; Nuland, Nico A. J. van; Ramboarina, Stéphanie

2013-01-01

Two nanobodies generated against the VAR2CSA DBL6∊-FCR3 domain involved in pregnancy-associated malaria were selected, expressed, purified and crystallized. The VAR2CSA protein has been closely associated with pregnancy-associated malaria and is recognized as the main adhesin exposed on the surface of Plasmodium falciparum-infected erythrocytes. Chondroitin sulfate A was identified as the main host receptor in the placenta. Single-domain heavy-chain camelid antibodies, more commonly called nanobodies, were selected and produced against the DBL6∊-FCR3 domain of VAR2CSA. Crystals of two specific nanobodies, Nb2907 and Nb2919, identified as strong binders to DBL6∊-FCR3 and the full-length VAR2CSA exposed on the surface of FCR3 P. falciparum-infected erythrocytes, were obtained. Crystals of Nb2907 diffract to 2.45 Å resolution and belong to space group C2 with unit-cell parameters a = 136.1, b = 78.5, c = 103.4 Å, β = 118.8°, whereas Nb2919 crystals diffract to 2.15 Å resolution and belong to space group P4 3 2 1 2 with unit-cell parameters a = b = 62.7, c = 167.2 Å

Backbone dynamics of free barnase and its complex with barstar determined by 15N NMR relaxation study

International Nuclear Information System (INIS)

Sahu, Sarata C.; Bhuyan, Abani K.; Udgaonkar, Jayant B.; Hosur, R.V.

2000-01-01

Backbone dynamics of uniformly 15 N-labeled free barnase and its complex with unlabelled barstar have been studied at 40 deg. C, pH 6.6, using 15 N relaxation data obtained from proton-detected 2D { 1 H}- 15 N NMR spectroscopy. 15 N spin-lattice relaxation rate constants (R 1 ), spin-spin relaxation rate constants (R 2 ), and steady-state heteronuclear { 1 H}- 15 N NOEs have been measured at a magnetic field strength of 14.1 Tesla for 91 residues of free barnase and for 90 residues out of a total of 106 in the complex (excluding three prolines and the N-terminal residue) backbone amide 15 N sites of barnase. The primary relaxation data for both the cases have been analyzed in the framework of the model-free formalism using both isotropic and axially symmetric models of the rotational diffusion tensor. As per the latter, the overall rotational correlation times (τ m ) are 5.0 and 9.5 ns for the free and complexed barnase, respectively. The average order parameter is found to be 0.80 for free barnase and 0.86 for the complex. However, the changes are not uniform along the backbone and for about 5 residues near the binding interface there is actually a significant decrease in the order parameters on complex formation. These residues are not involved in the actual binding. For the residues where the order parameter increases, the magnitudes vary significantly. It is observed that the complex has much less internal mobility, compared to free barnase. From the changes in the order parameters, the entropic contribution of NH bond vector motion to the free energy of complex formation has been calculated. It is apparent that these motions cause significant unfavorable contributions and therefore must be compensated by many other favorable contributions to effect tight complex formation. The observed variations in the motion and their different locations with regard to the binding interface may have important implications for remote effects and regulation of the enzyme

Experiments and strategies for the assignment of fully13 C/15N-labelled polypeptides by solid state NMR

International Nuclear Information System (INIS)

Straus, Suzana K.; Bremi, Tobias; Ernst, Richard R.

1998-01-01

High-resolution heteronuclear NMR correlation experiments and strategies are proposed for the assignment of fully 13 C/ 15 N-labelled polypeptides in the solid state. By the combination of intra-residue and inter-residue 13 C- 15 N correlation experiments with 13 C- 13 C spin-diffusion studies, it becomes feasible to partially assign backbone and side-chain resonances in solid proteins. The performance of sequences using 15 N instead of 13 C detection is evaluated regarding sensitivity and resolution for a labelled dipeptide (L-Val-L-Phe). The techniques are used for a partial assignment of the 15 N and 13 C resonances in human ubiquitin

The chondroitin sulfate A-binding site of the VAR2CSA protein involves multiple N-terminal domains

DEFF Research Database (Denmark)

Dahlbäck, Madeleine; Jørgensen, Lars M; Nielsen, Morten A

2011-01-01

Malaria during pregnancy is a major health problem for African women. The disease is caused by Plasmodium falciparum malaria parasites, which accumulate in the placenta by adhering to chondroitin sulfate A (CSA). The interaction between infected erythrocytes and the placental receptor is mediated...

Engineering application of in-core fuel management optimization code with CSA algorithm

Energy Technology Data Exchange (ETDEWEB)

Liu, Zhihong; Hu, Yongming [INET, Tsinghua university, Beijing 100084 (China)

2009-06-15

PWR in-core loading (reloading) pattern optimization is a complex combined problem. An excellent fuel management optimization code can greatly improve the efficiency of core reloading design, and bring economic and safety benefits. Today many optimization codes with experiences or searching algorithms (such as SA, GA, ANN, ACO) have been developed, while how to improve their searching efficiency and engineering usability still needs further research. CSA (Characteristic Statistic Algorithm) is a global optimization algorithm with high efficiency developed by our team. The performance of CSA has been proved on many problems (such as Traveling Salesman Problems). The idea of CSA is to induce searching direction by the statistic distribution of characteristic values. This algorithm is quite suitable for fuel management optimization. Optimization code with CSA has been developed and was used on many core models. The research in this paper is to improve the engineering usability of CSA code according to all the actual engineering requirements. Many new improvements have been completed in this code, such as: 1. Considering the asymmetry of burn-up in one assembly, the rotation of each assembly is considered as new optimization variables in this code. 2. Worth of control rods must satisfy the given constraint, so some relative modifications are added into optimization code. 3. To deal with the combination of alternate cycles, multi-cycle optimization is considered in this code. 4. To confirm the accuracy of optimization results, many identifications of the physics calculation module in this code have been done, and the parameters of optimization schemes are checked by SCIENCE code. The improved optimization code with CSA has been used on Qinshan nuclear plant of China. The reloading of cycle 7, 8, 9 (12 months, no burnable poisons) and the 18 months equilibrium cycle (with burnable poisons) reloading are optimized. At last, many optimized schemes are found by CSA code

Evidence for the involvement of VAR2CSA in pregnancy-associated malaria

DEFF Research Database (Denmark)

Salanti, Ali; Dahlbäck, Madeleine; Turner, Louise

2004-01-01

In Plasmodium falciparum-endemic areas, pregnancy-associated malaria (PAM) is an important health problem. The condition is precipitated by accumulation of parasite-infected erythrocytes (IEs) in the placenta, and this process is mediated by parasite-encoded variant surface antigens (VSA) binding...... to chondroitin sulfate A (CSA). Parasites causing PAM express unique VSA types, VSAPAM, which can be serologically classified as sex specific and parity dependent. It is sex specific because men from malaria-endemic areas do not develop VSAPAM antibodies; it is parity dependent because women acquire anti...

A Novel Virus-Like Particle Based Vaccine Platform Displaying the Placental Malaria Antigen VAR2CSA.

Directory of Open Access Journals (Sweden)

Susan Thrane

Full Text Available Placental malaria caused by Plasmodium falciparum is a major cause of mortality and severe morbidity. Clinical testing of a soluble protein-based vaccine containing the parasite ligand, VAR2CSA, has been initiated. VAR2CSA binds to the human receptor chondroitin sulphate A (CSA and is responsible for sequestration of Plasmodium falciparum infected erythrocytes in the placenta. It is imperative that a vaccine against malaria in pregnancy, if administered to women before they become pregnant, can induce a strong and long lasting immune response. While most soluble protein-based vaccines have failed during clinical testing, virus-like particle (VLP based vaccines (e.g., the licensed human papillomavirus vaccines have demonstrated high efficacy, suggesting that the spatial assembly of the vaccine antigen is a critical parameter for inducing an optimal long-lasting protective immune response. We have developed a VLP vaccine display platform by identifying regions of the HPV16 L1 coat protein where a biotin acceptor site (AviTagTM can be inserted without compromising VLP-assembly. Subsequent biotinylation of Avi-L1 VLPs allow us to anchor monovalent streptavidin (mSA-fused proteins to the biotin, thereby obtaining a dense and repetitive VLP-display of the vaccine antigen. The mSA-VAR2CSA antigen was delivered on the Avi-L1 VLP platform and tested in C57BL/6 mice in comparison to two soluble protein-based vaccines consisting of naked VAR2CSA and mSA-VAR2CSA. The mSA-VAR2CSA Avi-L1 VLP and soluble mSA-VAR2CSA vaccines induced higher antibody titers than the soluble naked VAR2CSA vaccine after three immunizations. The VAR2CSA Avi-L1 VLP vaccine induced statistically significantly higher endpoint titres compared to the soluble mSA-VAR2CSA vaccine, after 1st and 2nd immunization; however, this difference was not statistically significant after 3rd immunization. Importantly, the VLP-VAR2CSA induced antibodies were functional in inhibiting the binding of

Application of 15N labeling to topics in molecular hematology

International Nuclear Information System (INIS)

Lapidot, A.; Irving, C.S.

1975-01-01

The amount of information which can be obtained from many types of spectrometric analysis of compounds of hematological interest can be greatly enhanced when measurements are made on a series of isotopically labeled compounds. A murine Friend virus-induced erythroleukemic cell (FLC) culture was found to be a superior biosynthetic system for the preparation of highly and selectively 15 N and 13 C enriched hemoglobins. A mutant of Rhodopseudomonas spheroides was found suitable for the preparation of larger quantities of >90 percent enriched protoporphyrin-IX- 15 N and coproporphyrin-III-- 15 N. A comparison of the 15 N and 13 C NMR spectra of FLC carbomonoxy-[Gly- 15 N]-hemoglobin, carbomonoxy-[Gly- 13 C/sub alpha/]-hemoglobin, α and β globin-[Gly- 15 N] and globin-[Gly- 13 C/sub alpha/] demonstrated 1) 15 N peptide chemical shifts are sensitive to polypeptide sequence, whereas 13 C α-carbon chemical shifts are not, (2) variations in the solvation of the peptide N-H group can be detected in the 15 N spectra but not the 13 C spectra, (3) 15 N heme resonances could not be detected, whereas 13 C resonances could. These studies indicated that in hemoglobin the glycyl N-H resonances are either solvated by H 2 O or hydrogen bonded to peptide C=0 groups. In denatured globin, the majority of the glycyl residues are rapidly exchanging between these two states

Synthesis and in vivo evaluation of [11C]SA6298 as a PET sigma1 receptor ligand

International Nuclear Information System (INIS)

Kawamura, Kazunori; Ishiwata, Kiichi; Tajima, Hisashi; Ishii, Shin-Ichi; Shimada, Yuhei; Matsuno, Kiyoshi; Homma, Yoshio; Senda, Michio

1999-01-01

The potential of a 11 C-labeled selective sigma 1 receptor ligand, 1-(3,4-dimethoxyphenethyl)-4-[3-(3,4-dichlorophenyl)propyl]piperazine ([ 11 C]SA6298), was evaluated as a positron emission tomography (PET) ligand for mapping sigma 1 receptors in the central nervous system and peripheral organs. [ 11 C]SA6298 was synthesized by methylation of the desmethyl SA6298 with [ 11 C]CH 3 I, with the decay-corrected radiochemical yield of 39±5% based on [ 11 C]CH 3 I and with the specific activity of 53±17 TBq/mmol within 20 min from end of bombardment (EOB). In mice, the uptake of [ 11 C]SA6298 was significantly decreased by carrier loading in the brain, liver, spleen, heart, lung, small intestine, and kidney in which sigma receptors are present as well as in the skeletal muscle. Pretreatment with SA6298 also blocked the uptake of [ 11 C]SA6298 by these organs except for the small intestine, but significant displacement of [ 11 C]SA6298 by posttreatment with SA6298 was observed only in the heart, lung, and muscle. In the blocking study with one of the eight sigma receptor ligands, including haloperidol, SA6298, NE-100, (+)-pentazocine, SA4503, (-)-pentazocine, (+)-3-PPP, and (+)-SKF 10,047 (in the order of the affinity for sigma 1 receptor subtype), only SA6298 and an analog SA4503 significantly reduced the brain uptake of [ 11 C]SA6298 to approximately 80% of the control, but the other six ligands did not. Peripherally, the uptake of [ 11 C]SA6298 by the organs described above was decreased predominantly by SA6298 or SA4503, but the blocking effects of the other five ligands except for NE-100 depended on their affinity for sigma 1 receptors. The saturable brain uptake of [ 11 C]SA6298, approximately 20%, was also observed by tissue dissection method in rats and by PET in a cat. Ex vivo autoradiography of the rat brain showed a high uptake in the cortex and thalamus. In the cat brain a relatively high uptake was found in the cortex, thalamus, striatum, and cerebellum

Detailed description of the Ócsa Bird Ringing Station, Hungary

OpenAIRE

Csörgő Tibor; Harnos Andrea; Rózsa Lajos; Karcza Zsolt; Fehérvári Péter

2016-01-01

The present paper acts as an introduction to a series that will describe the exploratory analyses of migration phenology and morphometrics of the most common passerine species at the Ócsa Bird Ringing Station. This station is situated in the Ócsa Landscape Protection Area that belongs to the Duna–Ipoly National Park, Hungary. The area is somewhat cooler and more humid than the surrounding agricultural fields and tree plantations, covered by a mosaic of diverse hygrophilous vegetation patches....

Clinical development of a VAR2CSA-based placental malaria vaccine PAMVAC

DEFF Research Database (Denmark)

Gbédandé, Komi; Fievet, Nadine; Viwami, Firmine

2017-01-01

Background  The antigen VAR2CSA plays a pivotal role in the pathophysiology of pregnancy-associated malaria (PAM) caused by Plasmodium falciparum. A VAR2CSA-based vaccine candidate, PAMVAC, is under development by an EU-funded multi-country consortium (PlacMalVac project). As part of PAMVAC...

Antibody responses to the full-length VAR2CSA and its DBL domains in Cameroonian children and teenagers

DEFF Research Database (Denmark)

Fodjo, Barriere A Y; Atemnkeng, Njika; Esemu, Livo

2016-01-01

villages and 160 children with severe malaria from the city.  Results: Low Ab levels to VAR2CSA were detected in children; however, Ab levels to FV2 in teenagers were rare. Children preferentially recognized DBL2 (56-70%) and DBL4 (50-60%), while multigravidae produced high levels of IgG to DBL3, DBL5...... and FV2. Sixty-seven percent of teenage girls (n = 16/24) recognized ID1-ID2a region of VAR2CSA. Children with severe forms of malaria had significantly higher IgG to merozoite antigens (all p 0.05) when compared to the healthy children.  Conclusion: The study...... suggests that children, including teenage girls acquire Ab to VAR2CSA domains and FV2, but Ab levels are much lower than those needed to protect women from placental infections and repertoire of Ab responses to DBL domains is different from those in pregnant women. Interestingly, children with severe...

Residual pathological stage at radical cystectomy significantly impacts outcomes for initial T2N0 bladder cancer.

Science.gov (United States)

Isbarn, Hendrik; Karakiewicz, Pierre I; Shariat, Shahrokh F; Capitanio, Umberto; Palapattu, Ganesh S; Sagalowsky, Arthur I; Lotan, Yair; Schoenberg, Mark P; Amiel, Gilad E; Lerner, Seth P; Sonpavde, Guru

2009-08-01

We hypothesized that in patients with T2N0 stage disease at transurethral bladder tumor resection a lower residual cancer stage (P1N0 or less) at radical cystectomy may correlate with improved outcomes relative to those with residual P2N0 disease. We analyzed 208 patients with T2N0 stage disease at transurethral bladder tumor resection whose tumors were organ confined at radical cystectomy (P2 or lower, pN0). None received perioperative chemotherapy. Kaplan-Meier as well as univariable and multivariable Cox regression models addressed the effect of residual pT stage at radical cystectomy on recurrence and cancer specific mortality rates. Covariates consisted of age, gender, grade, lymphovascular invasion, carcinoma in situ, number of lymph nodes removed and year of surgery. Residual pT stage at radical cystectomy was P0 in 24 (11.5%) patients, Pa in 9 (4.3%), PCIS in 22 (10.6%), P1 in 35 (16.8%) and P2 in 118 (56.7%). Median followup of censored patients was 55.7 months for recurrence and 52.1 months for cancer specific mortality analyses. The 5-year recurrence-free survival rates of patients with P0/Pa/PCIS, P1 and P2 stage disease were 100%, 85% and 75%, respectively. The 5-year cancer specific survival rates for the same cohorts were 100%, 93% and 81%, respectively. On multivariable analysis the effect of residual stage P1 or lower at radical cystectomy achieved independent predictor status for recurrence (adjusted HR 0.20, p = 0.002) and cancer specific mortality (adjusted HR 0.24, p = 0.02). Down staging from initial T2N0 bladder cancer at transurethral bladder tumor resection to lower stage at radical cystectomy significantly reduces recurrence and cancer specific mortality. Further validation of this finding is warranted.

Carbon material formation on SBA-15 and Ni-SBA-15 and residue constituents during acetylene decomposition

Energy Technology Data Exchange (ETDEWEB)

Chiang, Hung-Lung, E-mail: hlchiang@mail.cmu.edu.tw [Department of Risk Management, China Medical University, Taichung 40402, Taiwan (China); Wu, Trong-Neng [Department of Public Health, China Medical University, Taichung 40402, Taiwan (China); Ho, Yung-Shou [Department of Applied Chemistry and Materials Science, Fooyin University, Kaohsiung 831, Taiwan (China); Zeng, Li-Xuan [Department of Risk Management, China Medical University, Taichung 40402, Taiwan (China)

2014-07-15

Highlights: • Acetylene was decomposed on SBA-15 and Ni-SBA-15 at 650–850 °C. • Carbon spheres and filaments were formed after acetylene decomposition. • PAHs were determined in tar and residues. • Exhaust constituents include CO{sub 2}, H{sub 2}, NO{sub x} and hydrocarbon species. - Abstract: Carbon materials including carbon spheres and nanotubes were formed from acetylene decomposition on hydrogen-reduced SBA-15 and Ni-SBA-15 at 650–850 °C. The physicochemical characteristics of SBA-15, Ni-SBA-15 and carbon materials were analyzed by field emission scanning electronic microscopy (FE-SEM), Raman spectrometry, and energy dispersive spectrometry (EDS). In addition, the contents of polyaromatic hydrocarbons (PAHs) in the tar and residue and volatile organic compounds (VOCs) in the exhaust were determined during acetylene decomposition on SBA-15 and Ni-SBA-15. Spherical carbon materials were observed on SBA-15 during acetylene decomposition at 750 and 850 °C. Carbon filaments and ball spheres were formed on Ni-SBA-15 at 650–850 °C. Raman spectroscopy revealed peaks at 1290 (D-band, disorder mode, amorphous carbon) and 1590 (G-band, graphite sp{sup 2} structure) cm{sup −1}. Naphthalene (2 rings), pyrene (4 rings), phenanthrene (3 rings), and fluoranthene (4 rings) were major PAHs in tar and residues. Exhaust constituents of hydrocarbon (as propane), H{sub 2}, and C{sub 2}H{sub 2} were 3.9–2.6/2.7–1.5, 1.4–2.8/2.6–4.3, 4.2–2.4/3.2–1.7% when acetylene was decomposed on SBA-15/Ni-SBA-15, respectively, corresponding to temperatures ranging from 650 to 850 °C. The concentrations of 52 VOCs ranged from 9359 to 5658 and 2488 to 1104 ppm for SBA-15 and Ni-SBA-15 respectively, at acetylene decomposition temperatures from 650 to 850 °C, and the aromatics contributed more than 87% fraction of VOC concentrations.

Synthesis of {sup 15}N isotope labeled alanine; Sintese da alanina enriquecida com {sup 15}N

Energy Technology Data Exchange (ETDEWEB)

Oliveira, Claudineia R. de; Bendassolli, Jose Albertino; Sant' Ana, Carlos Roberto; Tagliassachi, Romulo Barbieri; Maximo, Everaldo; Prestes, Clelber Vieira [Centro de Energia Nuclear na Agricultura (CENA), Piracicaba, SP (Brazil). Dept. de Isotopos Estaveis]. E-mail: crolivei@cena.usp.br

2005-07-01

The application of light chemical elements and their stable isotopes in biological studies have been increased over the last years. The use of {sup 15}N labeled amino acids is an important tool for elucidation of peptides structures. This paper describe a method for the synthesis of {sup 15}N isotope labeled alanine at lower costs than international ones, as well as the details of the recovery system of the nitrogen residues. In the present work an amination of {alpha}-haloacids, with the bromopropionic carboxylic acid and labeled aqua ammonia ({sup 15}NH{sub 3} aq) was carried out. In order to avoid eventually losses of {sup 15}NH{sub 3}, special cares were adopted, since the production cost is high. Although the acquisition cost of the {sup 13}N (radioactive) labeled compounds is lower, the obtained stable tracer will allow the accomplishment of important studies of the nitrogen cycling in living things, less occupational and environment hazards, and the time limitation problems in field studies. The tests took place in triplicates with NH{sub 3} (aq) being employed. With the establishment of the system for {sup 15}NH{sub 3} recovery, an average of 94 % of the ammonia employed in the synthesis process was recovered. The purity of the amino acid was state determined by TLC (Thin Layer Chromatography) and HPLC (High-Performance Liquid Chromatography) with a fluorescence detector. The Rf and the retention time of the synthesized sample were similar the sigma standard. Finally, regarding the established conditions, it was possible to obtain the alanine with a production cost about 40 % lower than the international price. (author)

Subtype Specific Differences in NS5A Domain II Reveals Involvement of Proline at Position 310 in Cyclosporine Susceptibility of Hepatitis C Virus

Directory of Open Access Journals (Sweden)

Israr-ul H. Ansari

2012-11-01

Full Text Available Hepatitis C virus (HCV is susceptible to cyclosporine (CsA and other cyclophilin (CypA inhibitors, but the genetic basis of susceptibility is controversial. Whether genetic variation in NS5A alters cell culture susceptibility of HCV to CypA inhibition is unclear. We constructed replicons containing NS5A chimeras from genotypes 1a, 2a and 4a to test how variation in carboxy terminal regions of NS5A altered the genotype 1b CsA susceptibility. All chimeric replicons including genotype 1b Con1LN-wt replicon exhibited some cell culture sensitivity to CsA with genotype 4a being most sensitive and 1a the least. The CypA binding pattern of truncated NS5A genotypes correlated with the susceptibility of these replicons to CsA. The Con1LN-wt replicon showed increased susceptibility towards CsA when proline at position 310P was mutated to either threonine or alanine. Furthermore, a 15 amino acid long peptide fused N terminally to GFP coding sequences confirmed involvement of proline at 310 in CypA binding. Our findings are consistent with CypA acting on multiple prolines outside of the previously identified CypA binding sites. These results suggest multiple specific genetic variants between genotype 1a and 1b in the C-terminus of NS5A alter the CsA susceptibility of replicons, and some variants may oppose the effects of others.

Induction of adhesion-inhibitory antibodies against placental Plasmodium falciparum parasites by using single domains of VAR2CSA

DEFF Research Database (Denmark)

Nielsen, Morten A; Pinto, Vera V; Resende, Mafalda

2009-01-01

between a parasite protein expressed on erythrocytes named variant surface antigen 2-chondroitin sulfate A (VAR2CSA) and CSA on syncytiotrophoblasts. VAR2CSA is a large polymorphic protein consisting of six Duffy binding-like (DBL), domains and with current constraints on recombinant protein production...... which induce antibodies that inhibit CSA binding of different parasite strains. In this study, we produced a large panel of VAR2CSA proteins and raised antibodies against these antigens. We show that antibodies against the DBL4 domain effectively inhibit parasite binding. As the inhibition...... was not limited to homologous parasite strains, it seems feasible to base a protective malaria vaccine on a single VAR2CSA DBL domain....

Natural abundance 15N NMR assignments delineate structural differences between intact and reactive-site hydrolyzed Cucurbita maxima trypsin inhibitor III.

Science.gov (United States)

Krishnamoorthi, R; Nemmers, S; Tobias, B

1992-06-15

15N NMR assignments were made to the backbone amide nitrogen atoms at natural isotopic abundance of intact and reactive-site (Arg5-Ile6) hydrolyzed Cucurbita maxima trypsin inhibitor III (CMTI-III and CMTI-III*, respectively) by means of 2D proton-detected heteronuclear single bond chemical shift correlation (HSBC) spectroscopy, utilizing the previously made sequence-specific 1H NMR assignments (Krishnamoorthi et al. (1992) Biochemistry 31, 898-904). Comparison of the 15N chemical shifts of the two forms of the inhibitor molecule revealed significant changes not only for residues located near the reactive-site region, but also for those distantly located. Residues Cys3, Arg5, Leu7, Met8, Cys10, Cys16, Glu19, His25, Tyr27, Cys28 and Gly29 showed significant chemical shift changes ranging from 0.3 to 6.1 ppm, thus indicating structural perturbations that were transmitted throughout the molecule. These findings confirm the earlier conclusions based on 1H NMR investigations.

The role of 15N in elucidating processes governing integrated soil fertility management strategies

International Nuclear Information System (INIS)

Vanlauwe, B.; Sanginga, N.; Merckx, R.

2005-01-01

Full text: Nitrogen is the most limiting nutrient for crop production in most of sub-Saharan Africa and has negative impacts on the environment if inputs, both mineral and organic, are not properly managed. Integrated Soil Fertility Management (ISFM) aims at integrating organic and mineral inputs and at site-specific management of mineral inputs to maximize the N use efficiency of both inputs. A series of experiments with 15 N labelled urea and organic matter of varying biochemical quality was carried out to test the hypothesis that mixing urea with organic matter will lead to temporary immobilization of urea-derived N and subsequently to a better utilization of urea-N by the crop and reduced losses of urea-N. Another set of experiments addressed the issue whether organic matter status affects the recovery of applied N fertilizer. First of all, in a lysimeter experiment, mixing 15 N-labeled urea with various organic materials with varying quality was observed not to significantly affect the drainage of urea-derived mineral N. Outflow of water at the bottom of the lysimeters was affected by the type of residue and the way of application. Secondly, in a nanoplot experiment with square metal cubes, 0.43 by 0.43 m, the recovery of applied 15 N-labeled urea was not affected by applying the urea together with incorporated organic materials of varying quality and averaged 23%. Recovery of applied urea in the soil (0-90 cm), however, was significantly higher after mixing the urea with maize stover than in the treatment which received only 90 kg urea-N ha -1 . This is likely to be related to the rather large N-immobilization potential of maize stover in view of its low quality. Leucaena residues have also been shown to initially immobilize N and this was related to the rather high content of soluble polyphenols. Cowpea stover is likely to decompose very fast and may have little impact on the urea-N dynamics. Thirdly, the recovery of 15 N-labeled urea, as affected by the

Autocatalytic activity and substrate specificity of the pestivirus N-terminal protease Npro

International Nuclear Information System (INIS)

Gottipati, Keerthi; Acholi, Sudheer; Ruggli, Nicolas; Choi, Kyung H.

2014-01-01

Pestivirus N pro is the first protein translated in the viral polypeptide, and cleaves itself off co-translationally generating the N-terminus of the core protein. Once released, N pro blocks the host's interferon response by inducing degradation of interferon regulatory factor-3. N pro' s intracellular autocatalytic activity and lack of trans-activity have hampered in vitro cleavage studies to establish its substrate specificity and the roles of individual residues. We constructed N pro -GFP fusion proteins that carry the authentic cleavage site and determined the autoproteolytic activities of N pro proteins containing substitutions at the predicted catalytic sites Glu22 and Cys69, at Arg100 that forms a salt bridge with Glu22, and at the cleavage site Cys168. Contrary to previous reports, we show that N pro' s catalytic activity does not involve Glu22, which may instead be involved in protein stability. Furthermore, N pro does not have specificity for Cys168 at the cleavage site even though this residue is conserved throughout the pestivirus genus. - Highlights: • N pro' s autoproteolysis is studied using N pro -GFP fusion proteins. • N-terminal 17 amino acids are dispensable without loss of protease activity. • The putative catalytic residue Glu22 is not involved in protease catalysis. • No specificity for Cys168 at the cleavage site despite evolutionary conservation. • N pro prefers small amino acids with non-branched beta carbons at the P1 position

Integrating multi-omics analyses of Nonomuraea dietziae to reveal the role of soybean oil in [(4'-OH)MeLeu]4-CsA overproduction.

Science.gov (United States)

Liu, Huanhuan; Huang, Di; Jin, Lina; Wang, Cheng; Liang, Shaoxiong; Wen, Jianping

2017-07-14

Nonomuraea dietziae is a promising microorganism to mediate the region-specific monooxygenation reaction of cyclosporine A (CsA). The main product [(4'-OH)MeLeu] 4 -CsA possesses high anti-HIV/HCV and hair growth-stimulating activities while avoiding the immunosuppressive effect of CsA. However, the low conversion efficiency restricts the clinical application. In this study, the production of [(4'-OH)MeLeu] 4 -CsA was greatly improved by 55.6% from 182.8 to 284.4 mg/L when supplementing soybean oil into the production medium, which represented the highest production of [(4'-OH)MeLeu] 4 -CsA so far. To investigate the effect of soybean oil on CsA conversion, some other plant oils (corn oil and peanut oil) and the major hydrolysates of soybean oil were fed into the production medium, respectively. The results demonstrated that the plant oils, rather than the hydrolysates, could significantly improve the [(4'-OH)MeLeu] 4 -CsA production, suggesting that soybean oil might not play its role in the lipid metabolic pathway. To further unveil the mechanism of [(4'-OH)MeLeu] 4 -CsA overproduction under the soybean oil condition, a proteomic analysis based on the two-dimensional gel electrophoresis coupled with MALDI TOF/TOF mass spectrometry was implemented. The results showed that central carbon metabolism, genetic information processing and energy metabolism were significantly up-regulated under the soybean oil condition. Moreover, the gas chromatography-mass spectrometry-based metabolomic analysis indicated that soybean oil had a great effect on amino acid metabolism and tricarboxylic acid cycle. In addition, the transcription levels of cytochrome P450 hydroxylase (CYP) genes for CsA conversion were determined by RT-qPCR and the results showed that most of the CYP genes were up-regulated under the soybean oil condition. These findings indicate that soybean oil could strengthen the primary metabolism and the CYP system to enhance the mycelium growth and the

Prácticas de activismo audiovisual con objetivo de integración social: el caso del colectivo Cine sin Autor (CsA

Directory of Open Access Journals (Sweden)

Ana María Sedeño Valdellós

2016-03-01

Full Text Available En los últimos años viene produciéndose una cierta tendencia hacia el empleo de la tecnología audiovisual por parte de colectivos activistas: con un objetivo transformador de realidades, las prácticas de activismo audiovisual se han enfocado a propiciar el empoderamiento de colectivos sociales como generadores de universos simbólicos propios. El texto reflexiona sobre el audiovisual como integración social desde un enfoque generalista y atendiendo a sus precedentes. En primer lugar, se comienza una exploración teórica sobre el concepto de activismo audiovisual y sus posibilidades educativas, activistas y para la integración social; en segundo lugar, se aborda un análisis en torno al trabajo del colectivo Cine sin Autor (CsA que, con una metodología participativa, construye “procesos audiovisuales abiertos” con comunidades y colectivos desfavorecidos.

Estimates of methyl 13C and 1H CSA values (Δσ) in proteins from cross-correlated spin relaxation

International Nuclear Information System (INIS)

Tugarinov, Vitali; Scheurer, Christoph; Brueschweiler, Rafael; Kay, Lewis E.

2004-01-01

Simple pulse schemes are presented for the measurement of methyl 13 C and 1 H CSA values from 1 H- 13 C dipole/ 13 C CSA and 1 H- 13 C dipole/ 1 H CSA cross-correlated relaxation. The methodology is applied to protein L and malate synthase G. Average 13 C CSA values are considerably smaller for Ile than Leu/Val (17 vs 25 ppm) and are in good agreement with previous solid state NMR studies of powders of amino acids and dipeptides and in reasonable agreement with quantum-chemical DFT calculations of methyl carbon CSA values in peptide fragments. Small averaged 1 H CSA values on the order of 1 ppm are measured, consistent with a solid state NMR determination of the methyl group 1 H CSA in dimethylmalonic acid

Investigation of the binding free energies of FDA approved drugs against subtype B and C-SA HIV PR: ONIOM approach.

Science.gov (United States)

Sanusi, Z K; Govender, T; Maguire, G E M; Maseko, S B; Lin, J; Kruger, H G; Honarparvar, B

2017-09-01

Human immune virus subtype C is the most widely spread HIV subtype in Sub-Sahara Africa and South Africa. A profound structural insight on finding potential lead compounds is therefore necessary for drug discovery. The focus of this study is to rationalize the nine Food and Drugs Administration (FDA) HIV antiviral drugs complexed to subtype B and C-SA PR using ONIOM approach. To achieve this, an integrated two-layered ONIOM model was used to optimize the geometrics of the FDA approved HIV-1 PR inhibitors for subtype B. In our hybrid ONIOM model, the HIV-1 PR inhibitors as well as the ASP 25/25' catalytic active residues were treated at high level quantum mechanics (QM) theory using B3LYP/6-31G(d), and the remaining HIV PR residues were considered using the AMBER force field. The experimental binding energies of the PR inhibitors were compared to the ONIOM calculated results. The theoretical binding free energies (?G bind ) for subtype B follow a similar trend to the experimental results, with one exemption. The computational model was less suitable for C-SA PR. Analysis of the results provided valuable information about the shortcomings of this approach. Future studies will focus on the improvement of the computational model by considering explicit water molecules in the active pocket. We believe that this approach has the potential to provide much improved binding energies for complex enzyme drug interactions. Copyright © 2017 Elsevier Inc. All rights reserved.

Cycling of grain legume residue nitrogen

DEFF Research Database (Denmark)

Jensen, E.S.

1995-01-01

Symbiotic nitrogen fixation by legumes is the main input of nitrogen in ecological agriculture. The cycling of N-15-labelled mature pea (Pisum sativum L.) residues was studied during three years in small field plots and lysimeters. The residual organic labelled N declined rapidly during the initial...... management methods in order to conserve grain legume residue N sources within the soil-plant system....

Bactericidal Activity of Ceragenin CSA-13 in Cell Culture and in an Animal Model of Peritoneal Infection.

Science.gov (United States)

Bucki, Robert; Niemirowicz, Katarzyna; Wnorowska, Urszula; Byfield, Fitzroy J; Piktel, Ewelina; Wątek, Marzena; Janmey, Paul A; Savage, Paul B

2015-10-01

Ceragenins constitute a novel family of cationic antibiotics characterized by a broad spectrum of antimicrobial activities, which have mostly been assessed in vitro. Using a polarized human lung epithelial cell culture system, we evaluated the antibacterial activities of the ceragenin CSA-13 against two strains of Pseudomonas aeruginosa (PAO1 and Xen5). Additionally, the biodistribution and bactericidal activity of a CSA-13-IRDye 800CW derivate were assessed using an animal model of peritoneal infection after PAO1 challenge. In cell culture, CSA-13 bactericidal activities against PAO1 and Xen5 were higher than the activities of the human cathelicidin peptide LL-37. Increased CSA-13 activity was observed in polarized human lung epithelial cell cultures subjected to butyric acid treatment, which is known to increase endogenous LL-37 production. Eight hours after intravenous or intraperitoneal injection, the greatest CSA-13-IRDye 800CW accumulation was observed in mouse liver and kidneys. CSA-13-IRDye 800CW administration resulted in decreased bacterial outgrowth from abdominal fluid collected from animals subjected to intraperitoneal PAO1 infection. These observations indicate that CSA-13 may synergistically interact with antibacterial factors that are naturally present at mucosal surfaces and it maintains its antibacterial activity in the infected abdominal cavity. Cationic lipids such as CSA-13 represent excellent candidates for the development of new antibacterial compounds. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

Mutation update for the CSB/ERCC6 and CSA/ERCC8 genes involved in Cockayne syndrome.

Science.gov (United States)

Laugel, V; Dalloz, C; Durand, M; Sauvanaud, F; Kristensen, U; Vincent, M C; Pasquier, L; Odent, S; Cormier-Daire, V; Gener, B; Tobias, E S; Tolmie, J L; Martin-Coignard, D; Drouin-Garraud, V; Heron, D; Journel, H; Raffo, E; Vigneron, J; Lyonnet, S; Murday, V; Gubser-Mercati, D; Funalot, B; Brueton, L; Sanchez Del Pozo, J; Muñoz, E; Gennery, A R; Salih, M; Noruzinia, M; Prescott, K; Ramos, L; Stark, Z; Fieggen, K; Chabrol, B; Sarda, P; Edery, P; Bloch-Zupan, A; Fawcett, H; Pham, D; Egly, J M; Lehmann, A R; Sarasin, A; Dollfus, H

2010-02-01

Cockayne syndrome is an autosomal recessive multisystem disorder characterized principally by neurological and sensory impairment, cachectic dwarfism, and photosensitivity. This rare disease is linked to mutations in the CSB/ERCC6 and CSA/ERCC8 genes encoding proteins involved in the transcription-coupled DNA repair pathway. The clinical spectrum of Cockayne syndrome encompasses a wide range of severity from severe prenatal forms to mild and late-onset presentations. We have reviewed the 45 published mutations in CSA and CSB to date and we report 43 new mutations in these genes together with the corresponding clinical data. Among the 84 reported kindreds, 52 (62%) have mutations in the CSB gene. Many types of mutations are scattered along the whole coding sequence of both genes, but clusters of missense mutations can be recognized and highlight the role of particular motifs in the proteins. Genotype-phenotype correlation hypotheses are considered with regard to these new molecular and clinical data. Additional cases of molecular prenatal diagnosis are reported and the strategy for prenatal testing is discussed. Two web-based locus-specific databases have been created to list all identified variants and to allow the inclusion of future reports (www.umd.be/CSA/ and www.umd.be/CSB/). (c) 2009 Wiley-Liss, Inc.

Combining specificity determining and conserved residues improves functional site prediction

Directory of Open Access Journals (Sweden)

Gelfand Mikhail S

2009-06-01

Full Text Available Abstract Background Predicting the location of functionally important sites from protein sequence and/or structure is a long-standing problem in computational biology. Most current approaches make use of sequence conservation, assuming that amino acid residues conserved within a protein family are most likely to be functionally important. Most often these approaches do not consider many residues that act to define specific sub-functions within a family, or they make no distinction between residues important for function and those more relevant for maintaining structure (e.g. in the hydrophobic core. Many protein families bind and/or act on a variety of ligands, meaning that conserved residues often only bind a common ligand sub-structure or perform general catalytic activities. Results Here we present a novel method for functional site prediction based on identification of conserved positions, as well as those responsible for determining ligand specificity. We define Specificity-Determining Positions (SDPs, as those occupied by conserved residues within sub-groups of proteins in a family having a common specificity, but differ between groups, and are thus likely to account for specific recognition events. We benchmark the approach on enzyme families of known 3D structure with bound substrates, and find that in nearly all families residues predicted by SDPsite are in contact with the bound substrate, and that the addition of SDPs significantly improves functional site prediction accuracy. We apply SDPsite to various families of proteins containing known three-dimensional structures, but lacking clear functional annotations, and discusse several illustrative examples. Conclusion The results suggest a better means to predict functional details for the thousands of protein structures determined prior to a clear understanding of molecular function.

Steroid hormones affect binding of the sigma ligand 11C-SA4503 in tumour cells and tumour-bearing rats

International Nuclear Information System (INIS)

Rybczynska, Anna A.; Elsinga, Philip H.; Sijbesma, Jurgen W.; Jong, Johan R. de; Vries, Erik F. de; Dierckx, Rudi A.; Waarde, Aren van; Ishiwata, Kiichi

2009-01-01

Sigma receptors are implicated in memory and cognitive functions, drug addiction, depression and schizophrenia. In addition, sigma receptors are strongly overexpressed in many tumours. Although the natural ligands are still unknown, steroid hormones are potential candidates. Here, we examined changes in binding of the sigma-1 agonist 11 C-SA4503 in C6 glioma cells and in living rats after modification of endogenous steroid levels. 11 C-SA4503 binding was assessed in C6 monolayers by gamma counting and in anaesthetized rats by microPET scanning. C6 cells were either repeatedly washed and incubated in steroid-free medium or exposed to five kinds of exogenous steroids (1 h or 5 min before tracer addition, respectively). Tumour-bearing male rats were repeatedly treated with pentobarbital (a condition known to result in reduction of endogenous steroid levels) or injected with progesterone. Binding of 11 C-SA4503 to C6 cells was increased (∝50%) upon removal and decreased (∝60%) upon addition of steroid hormones (rank order of potency: progesterone > allopregnanolone = testosterone = androstanolone > dehydroepiandrosterone-3-sulphate, IC 50 progesterone 33 nM). Intraperitoneally administered progesterone reduced tumour uptake and tumour-to-muscle contrast (36%). Repeated treatment of animals with pentobarbital increased the PET standardized uptake value of 11 C-SA4503 in tumour (16%) and brain (27%), whereas the kinetics of blood pool radioactivity was unaffected. The binding of 11 C-SA4503 is sensitive to steroid competition. Since not only increases but also decreases of steroid levels affect ligand binding, a considerable fraction of the sigma-1 receptor population in cultured tumour cells or tumour-bearing animals is normally occupied by endogenous steroids. (orig.)

Synthesis of 15N isotope labeled alanine

International Nuclear Information System (INIS)

Oliveira, Claudineia R. de; Bendassolli, Jose Albertino; Sant'Ana, Carlos Roberto; Tagliassachi, Romulo Barbieri; Maximo, Everaldo; Prestes, Clelber Vieira

2005-01-01

The application of light chemical elements and their stable isotopes in biological studies have been increased over the last years. The use of 15 N labeled amino acids is an important tool for elucidation of peptides structures. This paper describe a method for the synthesis of 15 N isotope labeled alanine at lower costs than international ones, as well as the details of the recovery system of the nitrogen residues. In the present work an amination of α-haloacids, with the bromopropionic carboxylic acid and labeled aqua ammonia ( 15 NH 3 aq) was carried out. In order to avoid eventually losses of 15 NH 3 , special cares were adopted, since the production cost is high. Although the acquisition cost of the 13 N (radioactive) labeled compounds is lower, the obtained stable tracer will allow the accomplishment of important studies of the nitrogen cycling in living things, less occupational and environment hazards, and the time limitation problems in field studies. The tests took place in triplicates with NH 3 (aq) being employed. With the establishment of the system for 15 NH 3 recovery, an average of 94 % of the ammonia employed in the synthesis process was recovered. The purity of the amino acid was state determined by TLC (Thin Layer Chromatography) and HPLC (High-Performance Liquid Chromatography) with a fluorescence detector. The Rf and the retention time of the synthesized sample were similar the sigma standard. Finally, regarding the established conditions, it was possible to obtain the alanine with a production cost about 40 % lower than the international price. (author)

Disruption of Var2csa Gene Impairs Placental Malaria Associated Adhesion Phenotype

OpenAIRE

Viebig, Nicola K.; Levin, Emily; Dechavanne, Sébastien; Rogerson, Stephen J.; Gysin, Jürg; Smith, Joseph D.; Scherf, Artur; Gamain, Benoit

2007-01-01

Infection with Plasmodium falciparum during pregnancy is one of the major causes of malaria related morbidity and mortality in newborn and mothers. The complications of pregnancy-associated malaria result mainly from massive adhesion of Plasmodium falciparum-infected erythrocytes (IE) to chondroitin sulfate A (CSA) present in the placental intervillous blood spaces. Var2CSA, a member of the P. falciparum erythrocyte membrane protein 1 (PfEMP1) family is the predominant parasite ligand mediati...

Effect of crop sequence and crop residues on soil C, soil N and yield of maize

International Nuclear Information System (INIS)

Shafi, M.; Bakht, J.; Attaullah; Khan, M.A.

2010-01-01

Improved management of nitrogen (N) in low N soils is critical for increased soil productivity and crop sustainability. The objective of the present study was to evaluate the effects of residues incorporation, residues retention on soil surface as mulch, fertilizer N and legumes in crop rotation on soil fertility and yield of maize (Zea may L.). Fertilizer N was applied to maize at the rate of 160 kg ha/sup -1/, and to wheat at the rate of 120 kg ha/sup -1/ or no fertilizer N application. Crop rotation with the sequence of maize after wheat (Triticum aestivum L.), maize after lentil (Lens culinaris Medic) or wheat after mash bean (Vigna mungo L.) arranged in a split plot design was followed. Post-harvest incorporation of crop residues and residues retention on soil surface as mulch had significantly (p=0.05) affected grain and stover yield during 2004 and 2005. Two years average data revealed that grain yield was increased by 3.31 and 6.72% due to mulch and residues incorporation. Similarly, stover yield was also enhanced by 5.39 and 10.27% due to the same treatment respectively. Mulch and residues incorporation also improved stover N uptake by 2.23 and 6.58%, respectively. Total soil N and organic matter was non significantly (p=0.05) increased by 5.63 and 2.38% due to mulch and 4.13, 7.75% because of crop residues incorporation in the soil. Maize grain and stover yield responded significantly (p=0.05) to the previous legume (lentil) crop when compared with the previous cereal crop (wheat). The treatment of lentil - maize(+N), on the average, increased grain yield of maize by 15.35%, stover yield by 16.84%, total soil N by 10.31% and organic matter by 10.17%. Similarly, fertilizer N applied to the previous wheat showed carry over effect on grain yield (6.82%) and stover yield (11.37%) of the following maize crop. The present study suggested that retention of residues on soil surface as mulch, incorporation of residues in soil and legume (lentil - maize) rotation

Practical aspects of the 2D 15N-{1H}-NOE experiment

International Nuclear Information System (INIS)

Renner, Christian; Schleicher, Michael; Moroder, Luis; Holak, Tad A.

2002-01-01

The heteronuclear 15 N-NOE experiment was extensively tested with respect to statistical and systematic experimental error. The dependence of signal intensity in the NOE experiment and in the reference experiment on the saturation and relaxation time was experimentally investigated. The statistics of the experimental values were accessed by numerous repetitions of identical set-ups. As a model system a protein of typical size for NMR studies was chosen, i.e., a 120 amino acid residues containing fragment of the F-actin binding gelation factor (ABP-120). The fragment exhibits fast dynamics that are accessible with the 15 N-NOE experiment with various amplitudes. The results of this study show that commonly used parameters are only adequate for accurate measurement of motions with moderate amplitude. Highly flexible parts require longer delay times and thus more experimental time than commonly used. On the other hand, a qualitative or semi-quantitative assessment of a protein's mobility on fast times scales can be obtained from rapidly recorded experiments with unusual short delay times. The findings of this study are of equal importance for highly accurate measurement of the 15 N-NOE as well as for quick identification of mobile or even unstructured residues/parts of a protein

Easy and unambiguous sequential assignments of intrinsically disordered proteins by correlating the backbone 15N or 13C′ chemical shifts of multiple contiguous residues in highly resolved 3D spectra

International Nuclear Information System (INIS)

Yoshimura, Yuichi; Kulminskaya, Natalia V.; Mulder, Frans A. A.

2015-01-01

Sequential resonance assignment strategies are typically based on matching one or two chemical shifts of adjacent residues. However, resonance overlap often leads to ambiguity in resonance assignments in particular for intrinsically disordered proteins. We investigated the potential of establishing connectivity through the three-bond couplings between sequentially adjoining backbone carbonyl carbon nuclei, combined with semi-constant time chemical shift evolution, for resonance assignments of small folded and larger unfolded proteins. Extended sequential connectivity strongly lifts chemical shift degeneracy of the backbone nuclei in disordered proteins. We show here that 3D (H)N(COCO)NH and (HN)CO(CO)NH experiments with relaxation-optimized multiple pulse mixing correlate up to seven adjacent backbone amide nitrogen or carbonyl carbon nuclei, respectively, and connections across proline residues are also obtained straightforwardly. Multiple, recurrent long-range correlations with ultra-high resolution allow backbone 1 H N , 15 N H , and 13 C′ resonance assignments to be completed from a single pair of 3D experiments

Analysis of the backbone dynamics of interleukin-1β using two-dimensional inverse detected heteronuclear 15N-1H NMR spectroscopy

International Nuclear Information System (INIS)

Clore, G.M.; Driscoll, P.C.; Wingfield, P.T.; Gronenborn, A.M.

1990-01-01

The backbone dynamics of uniformly 15 N-labeled interleukin-1β are investigated by using two-dimensional inverse detected heteronuclear 15 N- 1 H NMR spectroscopy. 15 N T 1 , T 2 , and NOE data at a spectrometer frequency of 600 MHz are obtained for 90% of the backbone amide groups. The data provide evidence for motions on three time scales. All the residues exhibit very fast motions on a time scale of approx-lt 20-50 ps that can be characterized by a single-order parameter with an average value of 0.82 ± 0.05. Thirty-two residues also display motions on a time scale of 0.5-4 ns, slightly less than the overall rotational correlation time of the protein (8.3 ns). While the simple formulation can account for the 15 N T 1 and T 2 data, it fails to account for the 15 N- 1 H NOE data and yields calculated values for the NOEs that are either too small or negative, whereas the observed NOEs are positive. Another 42 residues are characterized by some sort of motion on the 30-ns-10-ms time scale, which results in 15 N line broadening due to chemical exchange between different conformational substates with distinct 15 N chemical shifts. In general, the motions on both the 0.5-4-ns and 30-ns-10-ms time scales are localized in surface-accessible loops and turns connecting the β-strands, as well as at the beginning and end of strands. Finally, the kinetic and equilibrium properties of a slow conformational equilibrium between a major and a minor species, involving at least 19 residues and located on one contiguous face of the molecule, are characterized by using 1 H- 15 N correlation spectroscopy, 1 H- 15 N heteronuclear multiple quantum coherence-nuclear Overhauser enhancement spectroscopy, and 1 H- 1 H nuclear Overhauser enhancement spectroscopy

Target-specific NMR detection of protein–ligand interactions with antibody-relayed {sup 15}N-group selective STD

Energy Technology Data Exchange (ETDEWEB)

Hetényi, Anasztázia [University of Szeged, Department of Medical Chemistry (Hungary); Hegedűs, Zsófia [University of Szeged, SZTE-MTA Lendület Foldamer Research Group, Institute of Pharmaceutical Analysis Department (Hungary); Fajka-Boja, Roberta; Monostori, Éva [Biological Research Center of the Hungarian Academy of Sciences, Lymphocyte Signal Transduction Laboratory, Institute of Genetics (Hungary); Kövér, Katalin E. [University of Debrecen, Department of Inorganic and Analytical Chemistry (Hungary); Martinek, Tamás A., E-mail: martinek@pharm.u-szeged.hu [University of Szeged, SZTE-MTA Lendület Foldamer Research Group, Institute of Pharmaceutical Analysis Department (Hungary)

2016-12-15

Fragment-based drug design has been successfully applied to challenging targets where the detection of the weak protein–ligand interactions is a key element. {sup 1}H saturation transfer difference (STD) NMR spectroscopy is a powerful technique for this work but it requires pure homogeneous proteins as targets. Monoclonal antibody (mAb)-relayed {sup 15}N-GS STD spectroscopy has been developed to resolve the problem of protein mixtures and impure proteins. A {sup 15}N-labelled target-specific mAb is selectively irradiated and the saturation is relayed through the target to the ligand. Tests on the anti-Gal-1 mAb/Gal-1/lactose system showed that the approach is experimentally feasible in a reasonable time frame. This method allows detection and identification of binding molecules directly from a protein mixture in a multicomponent system.

Nuclear safety in France after Fukushima - Critical analysis of complementary safety assessments (CSA) carried out on French nuclear installations after Fukushima

International Nuclear Information System (INIS)

Makhijani, Arjun; Marignac, Yves

2012-02-01

This report proposes a critical analysis of the approach carried out on the basis of the CSA (complementary safety assessment), from their specifications to the IRSN conclusions. It is notably based on the analysis performed by EDF on three nuclear sites (Gravelines, Civaux and Flamanville) which encompass the different levels of the nuclear power plants in France and the EPR project under construction, and on the analysis performed by Areva for La Hague reprocessing plants. Due to the short delay, only some sites and some problems have been considered. The CSA methodology is described. The EDF approach is discussed as well as the IRSN analysis of reports made by EDF, and then the different case studies. Beyond the conclusions of these reports, the authors highlight several major possible accidents which must be taken into account. They also outline that this CSA approach is a good starting point for the strengthening of nuclear safety

13C, 15N Resonance Assignment of Parts of the HET-s Prion Protein in its Amyloid Form

International Nuclear Information System (INIS)

Siemer, Ansgar B.; Ritter, Christiane; Steinmetz, Michel O.; Ernst, Matthias; Riek, Roland; Meier, Beat H.

2006-01-01

The partial 15 N and 13 C solid-state NMR resonance assignment of the HET-s prion protein fragment 218-289 in its amyloid form is presented. It is based on experiments measured at MAS frequencies in the range of 20-40 kHz using exclusively adiabatic polarization-transfer schemes. The resonance assignment within each residue is based on two-dimensional 13 C-- 13 C correlation spectra utilizing the DREAM mixing scheme. The sequential linking of the assigned residues used a set of two- and three-dimensional 15 N-- 13 C correlation experiments. Almost all cross peaks visible in the spectra are assigned, but only resonances from 43 of the 78 amino-acid residues could be detected. The missing residues are thought to be highly disordered and/or highly dynamic giving rise to broad resonance lines that escaped detection in the experiments applied. The line widths of the observed resonances are narrow and comparable to line widths observed in micro-crystalline samples. The 43 assigned residues are located in two fragments of about 20 residues

An upstream open reading frame controls translation of var2csa, a gene implicated in placental malaria.

Directory of Open Access Journals (Sweden)

Borko Amulic

2009-01-01

Full Text Available Malaria, caused by the parasite Plasmodium falciparum, is responsible for substantial morbidity, mortality and economic losses in tropical regions of the world. Pregnant women are exceptionally vulnerable to severe consequences of the infection, due to the specific adhesion of parasite-infected erythrocytes in the placenta. This adhesion is mediated by a unique variant of PfEMP1, a parasite encoded, hyper-variable antigen placed on the surface of infected cells. This variant, called VAR2CSA, binds to chondroitin sulfate A on syncytiotrophoblasts in the intervillous space of placentas. VAR2CSA appears to only be expressed in the presence of a placenta, suggesting that its expression is actively repressed in men, children or non-pregnant women; however, the mechanism of repression is not understood. Using cultured parasite lines and reporter gene constructs, we show that the gene encoding VAR2CSA contains a small upstream open reading frame that acts to repress translation of the resulting mRNA, revealing a novel form of gene regulation in malaria parasites. The mechanism underlying this translational repression is reversible, allowing high levels of protein translation upon selection, thus potentially enabling parasites to upregulate expression of this variant antigen in the presence of the appropriate host tissue.

Placental Sequestration of Plasmodium falciparum Malaria Parasites Is Mediated by the Interaction Between VAR2CSA and Chondroitin Sulfate A on Syndecan-1

Science.gov (United States)

Mao, Yang; Resende, Mafalda; Daugaard, Mads; Riis Kristensen, Anders; Damm, Peter; G. Theander, Thor; R. Hansson, Stefan; Salanti, Ali

2016-01-01

During placental malaria, Plasmodium falciparum infected erythrocytes sequester in the placenta, causing health problems for both the mother and fetus. The specific adherence is mediated by the VAR2CSA protein, which binds to placental chondroitin sulfate (CS) on chondroitin sulfate proteoglycans (CSPGs) in the placental syncytium. However, the identity of the CSPG core protein and the cellular impact of the interaction have remain elusive. In this study we identified the specific CSPG core protein to which the CS is attached, and characterized its exact placental location. VAR2CSA pull-down experiments using placental extracts from whole placenta or syncytiotrophoblast microvillous cell membranes showed three distinct CSPGs available for VAR2CSA adherence. Further examination of these three CSPGs by immunofluorescence and proximity ligation assays showed that syndecan-1 is the main receptor for VAR2CSA mediated placental adherence. We further show that the commonly used placental choriocarcinoma cell line, BeWo, express a different set of proteoglycans than those present on placental syncytiotrophoblast and may not be the most biologically relevant model to study placental malaria. Syncytial fusion of the BeWo cells, triggered by forskolin treatment, caused an increased expression of placental CS-modified syndecan-1. In line with this, we show that rVAR2 binding to placental CS impairs syndecan-1-related Src signaling in forskolin treated BeWo cells, but not in untreated cells. PMID:27556547

Novel adenovirus encoded virus-like particles displaying the placental malaria associated VAR2CSA antigen

DEFF Research Database (Denmark)

Andersson, Anne-Marie C; dos Santos Marques Resende, Mafalda; Salanti, Ali

2017-01-01

The malaria parasite Plasmodium falciparum presents antigens on the infected erythrocyte surface that bind human receptors expressed on the vascular endothelium. The VAR2CSA mediated binding to a distinct chondroitin sulphate A (CSA) is a crucial step in the pathophysiology of placental malaria a...

15N-tomatine

International Nuclear Information System (INIS)

Elliger, C.A.

1988-01-01

A method for preparative isolation of 15 N-tomatine from foliage of tomato plants grown hydroponically with 15 N-containing nutrient salts is described. Extractive workup of plant material gave a crude product which was chromatographed on Sephadex LH-20 to yield pure tomatine. Assay of 15 N content by mass spectrometry showed that isotopic purity was ca. 95%. (author)

Preparation, quality control and biological evaluation of 99mTc-labelled cationic steroid antibiotic (CSA-13)

International Nuclear Information System (INIS)

Roohi, S.; Amir, N.; Mushtaq, A.; Salahuddin, S.M.; Jehangir, M.; Savage, P.B.

2009-01-01

Ceragenins (CSAs) are a new class of antimicrobial agents that display broad spectrum antibacterial activity and may find use in the treatment of various infections. A member of this class CSA-13 was labelled with 99m Tc using SnCl 2 .H 2 O as a reducing agent. The labelling efficiency depended on the ligand/reductant ratio, pH and volume of the reaction mixture. The radiochemical purity and stability of 99m Tc-CSA was determined by thin layer chromatography. Biodistribution studies of 99m Tc-CSA were performed in Sprague Dawley rats. Liver and spleen uptake was quite high. A significantly higher accumulation of 99m Tc-CSA was seen at sites of S. aureus infected rats. The results were compared with 99m Tc-Ciprofloxacin. (orig.)

Gas chromatography and isotope ratio mass spectrometry of Pinot Noir wine volatile compounds (δ13C) and solid residues (δ13C, δ15N) for the reassessment of vineyard water-status.

Science.gov (United States)

Spangenberg, Jorge E; Vogiatzaki, Maria; Zufferey, Vivian

2017-09-29

This paper describes a novel approach to reassess the water status in vineyards based on compound-specific isotope analysis (CSIA) of wine volatile organic compounds (δ 13 C VOC/VPDB ) and bulk carbon and nitrogen isotopes, and the C/N molar ratios of the wine solid residues (δ 13 C SR/VPDB , δ 15 N SR/Air-N2 ). These analyses link gas chromatography/combustion and elemental analysis to isotope ratio mass spectrometry (GC/C/IRMS, EA/IRMS). Field-grown cultivars of Pinot Noir grapevines were exposed during six growing seasons (2009-2014) to controlled soil water availability, while maintaining identical the other environmental variables and agricultural techniques. Wines were produced from the grapes by the same oenological protocol. This permitted for the assessment of the effects in the biochemistry of wines solely induced by the changes in the plant-soil water status. This mimicked the more recurrent and prolonged periods of soil water deficiency due to climate changes. Water stress in grapevine was assessed by the measurement of the predawn leaf water potential (Ψ pd ) and the stable carbon isotope composition of the berry sugars during harvest (must sugars). For quantitation purposes and the normalization of the measured stable carbon isotope ratios of the VOCs, the wine samples were spiked with three standard compounds with known concentration and δ 13 C VPDB values. VOCs were extracted by liquid-liquid extraction and analyzed by gas chromatography/flame ionization detection (GC/FID), gas chromatography/mass spectrometry (GC/MS), and GC/C/IRMS. δ 13 C values were obtained for eighteen VOCs. The solid residues were obtained by freeze-drying wine aliquots and were analyzed for their C and N content and isotope composition by EA/IRMS. All the isotopic ratios (δ 13 C SR , δ 15 N SR , δ 13 C VOC ) are highly correlated with the Ψ pd values, indicating that the proposed gas chromatography and isotope ratio mass spectrometry approach is a useful tool to

Biotransformación del pelo residual de curtiembres

Directory of Open Access Journals (Sweden)

Ruth Viviana Numpaque

2016-12-01

Full Text Available La industria de curtiembres genera una alta carga contaminante representada por residuos líquidos, sólidos y gaseosos. Entre los residuos sólidos, el pelo residual es vertido directamente al río Bogotá y/o en rellenos sanitarios, desencadenando serios conflictos de orden ambiental, social y económico. El objetivo de esta investigación fue evaluar la capacidad de los microorganismos del EM y Agroplux en la transformación del pelo residual en compost. Se evaluaron tres tratamientos con pelo residual y materiales orgánicos de plaza en diferentes porcentajes y dos controles, utilizando el diseño completamente al azar, con tres repeticiones. Durante el compostaje se determinaron las variables temperatura, formación de agregados, pH y conductividad eléctrica. El desarrollo de la temperatura ocurrió en ciclos que concordaron con los volteos y re-inoculaciones. En el tercer ciclo el mayor incremento de temperatura fue obtenido en los tres tratamientos, cuando ya se había agotado la mayor parte de los residuos orgánicos. La formación de agregados indicó que el proceso se llevó a efecto principalmente en el tratamiento con 20% de pelo residual más 80% de residuos orgánicos. Además de su color oscuro y la ausencia de olor y fragmentos, el compost producido mediante dicho tratamiento mostró la conductividad eléctrica más baja y un pH casi neutro. Se concluye que los microorganismos del EM y Agroplux tienen capacidad para transformar el pelo residual en compost y por lo tanto representan una alternativa viable para la continuación del funcionamiento de la industria de curtiembres en Villapinzón (Cundinamarca y en otras regiones de Colombia.

Effects of topical 0.2% Cyclosporine A on corneal neovascularization induced by xenologous amniotic membrane implantation into a corneal stroma micropocket of rats Efeitos do uso tópico da Ciclosporina A (CsA 0,2% na neovascularização corneal induzida pelo implante de membrana amniótica xenógena em microbolsa no estroma da córnea de ratos

Directory of Open Access Journals (Sweden)

Juliana F. Milani

2008-08-01

efeitos tópicos da Ciclosporina a 0,2% (CsA sobre a neovascularização corneana de ratos após implante cirúrgico de membrana amniótica eqüina em microbolsa do estroma corneana. O implante da membrana foi feito bilateralmente em 90 ratos. O tratamento com CsA iniciou-se no mesmo dia da cirurgia, nos olhos direitos dos animais, duas vezes ao dia. Os olhos esquerdos não receberam nenhum tratamento e serviram de controle. A avaliação da neovascularização corneana foi feita por análise de imagem computadorizada e por exame histopatológico aos dias 1, 3, 7, 15, 30 e 60 de pós-cirúrgico. Para a análise de imagem foram utilizados 10 animais por período, e para o exame histopatológico, 5 por período. A análise de imagem demonstrou que a neovascularização iniciou-se no 3° dia pós-cirúrgico, alcançou seu pico no 7° dia e então regrediu rápida e progressivamente até o 60° dia. A análise estatística indicou que a neovascularização no 7º dia nos olhos tratados com CsA foi significantemente mais acentuada do que aquela observada nos olhos não tratados. Entretanto, no 30º dia este fato se reverteu, e a neovascularização observada nos olhos tratados com CsA diminuíra a níveis baixos comparáveis àquela do 3º dia. Já nos olhos não tratados, o grau de neovascularização somente pôde ser comparado àquele nível básico encontrado no 3º dia aos 60 dias de pós-operatório. A análise histopatológica demonstrou que a deposição de colágeno no tecido implantado se completou no 15º dia. Desta maneira, foi possível concluir que (1 a membrana amniótica em estroma corneano de ratos produz intensa neovascularização até o 15º dia de pós-operatório com posterior regressão, (2 a deposição de colágeno do tecido implantado foi completa ao 15º dia de pós-operatório, e que (3 o uso de CsA esteve associado com aumento inicial da neovascularização corneana, seguido de rápida e intensa regressão.

Autocatalytic activity and substrate specificity of the pestivirus N-terminal protease Npro.

Science.gov (United States)

Gottipati, Keerthi; Acholi, Sudheer; Ruggli, Nicolas; Choi, Kyung H

2014-03-01

Pestivirus N(pro) is the first protein translated in the viral polypeptide, and cleaves itself off co-translationally generating the N-terminus of the core protein. Once released, N(pro) blocks the host׳s interferon response by inducing degradation of interferon regulatory factor-3. N(pro׳)s intracellular autocatalytic activity and lack of trans-activity have hampered in vitro cleavage studies to establish its substrate specificity and the roles of individual residues. We constructed N(pro)-GFP fusion proteins that carry the authentic cleavage site and determined the autoproteolytic activities of N(pro) proteins containing substitutions at the predicted catalytic sites Glu22 and Cys69, at Arg100 that forms a salt bridge with Glu22, and at the cleavage site Cys168. Contrary to previous reports, we show that N(pro׳)s catalytic activity does not involve Glu22, which may instead be involved in protein stability. Furthermore, N(pro) does not have specificity for Cys168 at the cleavage site even though this residue is conserved throughout the pestivirus genus. Copyright © 2014 Elsevier Inc. All rights reserved.

Distribution of 15N fertilizer in field-lysimeters sown with garlic (Allium sativum) and foxtail millet (Setaria italica)

International Nuclear Information System (INIS)

Lazzari, M.A.

1982-01-01

We examined the distribution of residual 15 N and its uptake by a foxtail millet crop grown in field lysimeters following a previous garlic crop fertilized with either 15 N-urea or 15 N-ammonium sulphate. Garlic apparently removed more N from the lysimeters treated with urea-N than from those treated with (NH 4 ) 2 SO 4 . Fertilizer-N in the lysimeters was similar (ca. 32% of original) following millet harvest. About 16 per cent of both fertilizers in the lysimeters was removed by the millet. (orig.)

Importance of the content and localization of tyrosine residues for thyroxine formation within the N-terminal part of human thyroglobulin

NARCIS (Netherlands)

den Hartog, M. T.; Sijmons, C. C.; Bakker, O.; Ris-Stalpers, C.; de Vijlder, J. J.

1995-01-01

Thyroxine (T4) is formed by coupling of iodinated tyrosine residues within thyroglobulin (TG). In mature TG, some iodinated tyrosine residues are involved preferentially in T4 formation. In order to investigate the specific role of various tyrosine residues in T4 formation, N-terminal TG fragments

{sup 99m}Tc-N.T.P. 15-5 imaging for the early and specific diagnosis of chondrosarcoma: proof of concept in rats

Energy Technology Data Exchange (ETDEWEB)

Miot-Noirault, E.; Vidal, A.; Rapp, M.; Madelmont, J.C.; Maublant, J.; Moins, N. [Institut National de la Sante et de la Recherche Medicale (INSERM), UMR 484, 63 - Clermont Ferrand (France); Redini, F.; Gouin, F.; Heymann, D. [Institut National de la Sante et de la Recherche Medicale (INSERM), ERI 7, EA 3822, 44 - Nantes (France)

2008-02-15

Aim. - The U.M.R. 484 I.N.S.E.R.M. develops a 'cartilage imaging strategy' with the {sup 99m}Tc-N.T.P. 15-5 tracer that selectively binds to cartilage proteoglycans, allowing a highly specific cartilage imaging. Since chondro-genic tumours are characterized by the presence of cartilaginous matrix, we hypothesized that the {sup 99m}Tc-N.T.P. 15-5 tracer would allow chondrosarcoma imaging, which is currently lacking in clinics. In the rat model of grade II para-tibial chondrosarcoma, we evaluated the relevance of {sup 99m}Tc-N.T.P. 15-5 imaging for an early and specific diagnosis of chondrosarcoma. Methods. - {sup 99m}Tc-N.T.P. 15-5 longitudinal imaging of animals was performed during two months after para-tibial ortho-topic tumour implantation in the right paw, the left being used as control. At regular intervals, animals were submitted to {sup 99m}Tc-M.D.P. bone imaging, the only examination used for SPECT diagnosis of chondrosarcoma in patients. Tumour volume was monitored for two months when the tumours became palpable, with the two perpendicular diameters measured. For both cartilage and bone imaging, the scans were considered positive when areas of tracer uptake were present at sites consistent with the sites of inoculation. For each animal, positive scans were analyzed at each stage using the semiquantitative method of the target to background ratio (T.B.R.), with the target R.O.I. being delineated over the tumour and background R.O.I. over vertebra and muscle. T.B.R. time-course was followed as a function of tumour growth.At study ending, each animal was sacrificed for histopathological control. Results. - {sup 99m}Tc-N.T.P. 15-5 scans were positive in 100% of the animals at very early stage (three days) after implantation, while no palpable nor measurable tumour could be assessed. Quantitative analysis of {sup 99m}Tc-N.T.P. 15-5 scans evidenced a significant uptake of the tracer at the implantation site at early stage. The time-course of T

Cyclosporin A treatment of Leishmania donovani reveals stage-specific functions of cyclophilins in parasite proliferation and viability.

Directory of Open Access Journals (Sweden)

Wai-Lok Yau

Full Text Available BACKGROUND: Cyclosporin A (CsA has important anti-microbial activity against parasites of the genus Leishmania, suggesting CsA-binding cyclophilins (CyPs as potential drug targets. However, no information is available on the genetic diversity of this important protein family, and the mechanisms underlying the cytotoxic effects of CsA on intracellular amastigotes are only poorly understood. Here, we performed a first genome-wide analysis of Leishmania CyPs and investigated the effects of CsA on host-free L. donovani amastigotes in order to elucidate the relevance of these parasite proteins for drug development. METHODOLOGY/PRINCIPAL FINDINGS: Multiple sequence alignment and cluster analysis identified 17 Leishmania CyPs with significant sequence differences to human CyPs, but with highly conserved functional residues implicated in PPIase function and CsA binding. CsA treatment of promastigotes resulted in a dose-dependent inhibition of cell growth with an IC50 between 15 and 20 microM as demonstrated by proliferation assay and cell cycle analysis. Scanning electron microscopy revealed striking morphological changes in CsA treated promastigotes reminiscent to developing amastigotes, suggesting a role for parasite CyPs in Leishmania differentiation. In contrast to promastigotes, CsA was highly toxic to amastigotes with an IC50 between 5 and 10 microM, revealing for the first time a direct lethal effect of CsA on the pathogenic mammalian stage linked to parasite thermotolerance, independent from host CyPs. Structural modeling, enrichment of CsA-binding proteins from parasite extracts by FPLC, and PPIase activity assays revealed direct interaction of the inhibitor with LmaCyP40, a bifunctional cyclophilin with potential co-chaperone function. CONCLUSIONS/SIGNIFICANCE: The evolutionary expansion of the Leishmania CyP protein family and the toxicity of CsA on host-free amastigotes suggest important roles of PPIases in parasite biology and implicate

Compound-specific amino acid δ15N patterns in marine algae: Tracer potential for cyanobacterial vs. eukaryotic organic nitrogen sources in the ocean

Science.gov (United States)

McCarthy, Matthew D.; Lehman, Jennifer; Kudela, Raphael

2013-02-01

Stable nitrogen isotopic analysis of individual amino acids (δ15N-AA) has unique potential to elucidate the complexities of food webs, track heterotrophic transformations, and understand diagenesis of organic nitrogen (ON). While δ15N-AA patterns of autotrophs have been shown to be generally similar, prior work has also suggested that differences may exist between cyanobacteria and eukaryotic algae. However, δ15N-AA patterns in differing oceanic algal groups have never been closely examined. The overarching goals of this study were first to establish a more quantitative understanding of algal δ15N-AA patterns, and second to examine whether δ15N-AA patterns have potential as a new tracer for distinguishing prokaryotic vs. eukaryotic N sources. We measured δ15N-AA from prokaryotic and eukaryotic phytoplankton cultures and used a complementary set of statistical approaches (simple normalization, regression-derived fractionation factors, and multivariate analyses) to test for variations. A generally similar δ15N-AA pattern was confirmed for all algae, however significant AA-specific variation was also consistently identified between the two groups. The relative δ15N fractionation of Glx (glutamine + glutamic acid combined) vs. total proteinaceous N appeared substantially different, which we hypothesize could be related to differing enzymatic forms. In addition, the several other AA (most notably glycine and leucine) appeared to have strong biomarker potential. Finally, we observed that overall patterns of δ15N values in algae correspond well with the Trophic vs. Source-AA division now commonly used to describe variable AA δ15N changes with trophic transfer, suggesting a common mechanistic basis. Overall, these results show that autotrophic δ15N-AA patterns can differ between major algal evolutionary groupings for many AA. The statistically significant multivariate results represent a first approach for testing ideas about relative eukaryotic vs. prokaryotic

Comparison of three 15N methods to correct for microbial contamination when assessing in situ protein degradability of fresh forages.

Science.gov (United States)

Kamoun, M; Ammar, H; Théwis, A; Beckers, Y; France, J; López, S

2014-11-01

The use of stable (15)N as a marker to determine microbial contamination in nylon bag incubation residues to estimate protein degradability was investigated. Three methods using (15)N were compared: (15)N-labeled forage (dilution method, LF), (15)N enrichment of rumen solids-associated bacteria (SAB), and (15)N enrichment of rumen liquid-associated bacteria (LAB). Herbage from forages differing in protein and fiber contents (early-cut Italian ryegrass, late-cut Italian ryegrass, and red clover) were freeze-dried and ground and then incubated in situ in the rumen of 3 steers for 3, 6, 12, 24, and 48 h using the nylon bag technique. The (15)N-labeled forages were obtained by fertilizing the plots where herbage was grown with (15)NH4 (15)NO3. Unlabeled forages (obtained from plots fertilized with NH4NO3) were incubated at the same time that ((15)NH4)2SO4 was continuously infused into the rumen of the steers, and then pellets of labeled SAB and LAB were isolated by differential centrifugation of samples of ruminal contents. The proportion of bacterial N in the incubation residues increased from 0.09 and 0.45 g bacterial N/g total N at 3 h of incubation to 0.37 and 0.85 g bacterial N/g total N at 48 h of incubation for early-cut and late-cut ryegrass, respectively. There were differences (P forage (late-cut ryegrass) was 0.51, whereas the corrected values were 0.85, 0.84, and 0.77 for the LF, SAB, and LAB methods, respectively. With early-cut ryegrass and red clover, the differences between uncorrected and corrected values ranged between 6% and 13%, with small differences among the labeling methods. Generally, methods using labeled forage or labeled SAB and LAB provided similar corrected degradability values. The accuracy in estimating the extent of degradation of protein in the rumen from in situ disappearance curves is improved when values are corrected for microbial contamination of the bag residue.

Placental sequestration of Plasmodium falciparum malaria parasites is mediated by the interaction between VAR2CSA and chondroitin sulfate A on syndecan-1

DEFF Research Database (Denmark)

Ayres Pereira, Marina; Mandel Clausen, Thomas; Pehrson, Caroline

2016-01-01

During placental malaria, Plasmodium falciparum infected erythrocytes sequester in the placenta, causing health problems for both the mother and fetus. The specific adherence is mediated by the VAR2CSA protein, which binds to placental chondroitin sulfate (CS) on chondroitin sulfate proteoglycans......-down experiments using placental extracts from whole placenta or syncytiotrophoblast microvillous cell membranes showed three distinct CSPGs available for VAR2CSA adherence. Further examination of these three CSPGs by immunofluorescence and proximity ligation assays showed that syndecan-1 is the main receptor...... for VAR2CSA mediated placental adherence. We further show that the commonly used placental choriocarcinoma cell line, BeWo, express a different set of proteoglycans than those present on placental syncytiotrophoblast and may not be the most biologically relevant model to study placental malaria. Syncytial...

Steroid hormones affect binding of the sigma ligand {sup 11}C-SA4503 in tumour cells and tumour-bearing rats

Energy Technology Data Exchange (ETDEWEB)

Rybczynska, Anna A.; Elsinga, Philip H.; Sijbesma, Jurgen W.; Jong, Johan R. de; Vries, Erik F. de; Dierckx, Rudi A.; Waarde, Aren van [University of Groningen, Nuclear Medicine and Molecular Imaging, University of Groningen Medical Center, Groningen (Netherlands); Ishiwata, Kiichi [Tokyo Metropolitan Institute of Gerontology, Positron Medical Center, Tokyo (Japan)

2009-07-15

Sigma receptors are implicated in memory and cognitive functions, drug addiction, depression and schizophrenia. In addition, sigma receptors are strongly overexpressed in many tumours. Although the natural ligands are still unknown, steroid hormones are potential candidates. Here, we examined changes in binding of the sigma-1 agonist {sup 11}C-SA4503 in C6 glioma cells and in living rats after modification of endogenous steroid levels. {sup 11}C-SA4503 binding was assessed in C6 monolayers by gamma counting and in anaesthetized rats by microPET scanning. C6 cells were either repeatedly washed and incubated in steroid-free medium or exposed to five kinds of exogenous steroids (1 h or 5 min before tracer addition, respectively). Tumour-bearing male rats were repeatedly treated with pentobarbital (a condition known to result in reduction of endogenous steroid levels) or injected with progesterone. Binding of {sup 11}C-SA4503 to C6 cells was increased ({proportional_to}50%) upon removal and decreased ({proportional_to}60%) upon addition of steroid hormones (rank order of potency: progesterone > allopregnanolone = testosterone = androstanolone > dehydroepiandrosterone-3-sulphate, IC{sub 50} progesterone 33 nM). Intraperitoneally administered progesterone reduced tumour uptake and tumour-to-muscle contrast (36%). Repeated treatment of animals with pentobarbital increased the PET standardized uptake value of {sup 11}C-SA4503 in tumour (16%) and brain (27%), whereas the kinetics of blood pool radioactivity was unaffected. The binding of {sup 11}C-SA4503 is sensitive to steroid competition. Since not only increases but also decreases of steroid levels affect ligand binding, a considerable fraction of the sigma-1 receptor population in cultured tumour cells or tumour-bearing animals is normally occupied by endogenous steroids. (orig.)

Ultra-violet absorption cross sections of isotopically substituted nitrous oxide species: 14N14NO, 15N14NO, 14N15NO and 15N15NO

Directory of Open Access Journals (Sweden)

P. von Hessberg

2004-01-01

Full Text Available The isotopically substituted nitrous oxide species 14N14NO, 15N14NO, 14N15NO and 15N15NO were investigated by ultra-violet (UV absorption spectroscopy. High precision cross sections were obtained for the wavelength range 181 to 218nm at temperatures of 233 and 283K. These data are used to calculate photolytic isotopic fractionation constants as a function of wavelength. The fractionation constants were used in a three-dimensional chemical transport model in order to simulate the actual fractionation of N2O in the stratosphere, and the results were found to be in good agreement with field studies.

Fate of N and relative efficiency of 15N-labeled organic materials applied to transplanted rice in northern Kyushu region of Japan

International Nuclear Information System (INIS)

Nishida, Mizuhiko; Tsuchiya, Kazunari; Yamamuro, Shigekazu

2004-01-01

Seven kinds of 15 N-labeled organic materials were applied to transplanted rice to investigate their N fate and relative efficiency in the northern Kyushu region of Japan. The 15 N-labeled organic materials examined in a micro-plot experiment were cattle manure compost, poultry manure compost, swine feces, rice straw compost, rice bran, rice straw, and wheat straw. Regarding swine feces, rice bran, and wheat straw, the direct evaluation of their N fate in paddy fields using 15 N organic materials has not been reported. A significant difference in the N fate in response to the type of organic materials was observed in the uptake rate by rice plants. The uptake rate at the maturity stage was significantly higher in poultry manure (29%), swine feces (25%), and rice bran (26%) than for the other organic materials (6-13%). Cattle manure compost showed the lowest value, namely 6-7%. Using the uptake rate of ( 15 NH 4 ) 2 SO 4 observed earlier, the relative efficiency of organ nic materials (relative uptake rate of organic material N to chemical fertilizer N) was calculated as the index of the organic material N efficiency. These relative efficiencies of organic materials derived from animal wastes were 16-19, 81, 72, and 71% for cattle manure compost, poultry manure compost, poultry manure compost without inherent NH 4 -H, and swine feces, respectively, and were similar to those estimated by indirect way. The relative efficiencies of organic materials derived from plant residues were 25-31, 73, 33 and 34% for rice straw compost, rice bran, rice straw, and wheat straw, respectively. The N uptake from the organic materials (OM-N uptake) in swine feces and cattle manure compost continued throughout the rice growth period, whereas the OM-N uptake of the other organic materials declined remarkably after 54 DAT. No significant difference was observed in the residual rate and the loss rate among the organic materials. However, some tendencies that might be related to the

[Studies with 15N-labeled lysine in colostomized hens. 2. 15N excretion in feces].

Science.gov (United States)

Gruhn, K; Wiefel, P

1983-05-01

Over a period of four days colostomised hens were given 15N-lysine, and the development of 15N-excretion both in the TCA-soluble and the TCA-precipitable fraction of the faeces was measured over eight days. In both fractions the total, lysine, histidine and arginine N and 15N-excess (15N') was determined. The average apparent digestibility of 14N was 81.2% +/- 1.1% and of 15N' 93.2% +/- 0.7%. Labelled N is already excreted in faeces 3 hours after its application. The TCA-precipitable N is less strongly labelled than the TCA-soluble N. During the application of 15N' the labelling in faecal lysine is nearly one power of ten higher than in total N. The atom-% 15N' of the lysine could also be distinctly detected in arginine and histidine. The quotas of the total 15N' in faeces were 3.5% for arginine-15N' and 0.8% for histidine 15N'; 15N' can mainly be detected in the soluble fraction.

NMR experiments for resonance assignments of 13C, 15N doubly-labeled flexible polypeptides: Application to the human prion protein hPrP(23-230)

International Nuclear Information System (INIS)

Liu Aizhuo; Riek, Roland; Wider, Gerhard; Schroetter, Christine von; Zahn, Ralph; Wuethrich, Kurt

2000-01-01

A combination of three heteronuclear three-dimensional NMR experiments tailored for sequential resonance assignments in uniformly 15 N, 13 C-labeled flexible polypeptide chains is described. The 3D (H)N(CO-TOCSY)NH, 3D (H)CA(CO-TOCSY)NH and 3D (H)CBCA(CO-TOCSY)NH schemes make use of the favorable 15 N chemical shift dispersion in unfolded polypeptides, exploit the slow transverse 15 N relaxation rates of unfolded polypeptides in high resolution constant-time [ 1 H, 15 N]-correlation experiments, and use carbonyl carbon homonuclear isotropic mixing to transfer magnetization sequentially along the amino acid sequence. Practical applications are demonstrated with the 100-residue flexible tail of the recombinant human prion protein, making use of spectral resolution up to 0.6 Hz in the 15 N dimension, simultaneous correlation with the two adjacent amino acid residues to overcome problems associated with spectral overlap, and the potential of the presently described experiments to establish nearest-neighbor correlations across proline residues in the amino acid sequence

Residual symptoms and specific functional impairments in euthymic patients with bipolar disorder.

Science.gov (United States)

Samalin, Ludovic; de Chazeron, Ingrid; Vieta, Eduard; Bellivier, Frank; Llorca, Pierre-Michel

2016-03-01

The aims of the present study were to confirm the impact of residual symptoms on overall functioning in a large sample of euthymic patients with bipolar disorder in real-life conditions and to explore the relationship between residual symptoms and specific areas of functional impairment. This was a multicenter, cross-sectional, non-interventional study of euthymic outpatients with bipolar disorder. The Functioning Assessment Short Test was used to assess overall and specific domains of functioning (autonomy, occupational functioning, cognitive functioning, financial issues, interpersonal relationships, and leisure time). Various residual symptoms were assessed (residual mood symptoms, emotional dysregulation, sleep and sexual disorders, stigma, and perceived cognitive impairment). Logistic regression was used to determine the best model of association between functional domains and residual symptoms. Almost half of the 468 patients included (42%) had poor overall functioning. Residual depressive symptoms appeared to have an impact on overall functioning and in nearly all areas of functioning. In addition, specific residual symptoms had significantly more negative effects on some domains of functioning in euthymic patients with bipolar disorder (residual manic symptoms and occupational stigma on autonomy, emotional inhibition on occupational functioning, residual manic symptoms on financial issues, family stigma on interpersonal relationships, and sexual function and occupational stigma on leisure time). Our findings highlight the importance of evaluating overall functioning in clinical practice as well as functional domains. They also indicate that some residuals symptoms in patients with bipolar disorder should be targeted in personalized treatment plans, in order to improve functioning in the domains in which the patient is most impaired. © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Category Specificity in Normal Episodic Learning: Applications to Object Recognition and Category-Specific Agnosia

Science.gov (United States)

Bukach, Cindy M.; Bub, Daniel N.; Masson, Michael E. J.; Lindsay, D. Stephen

2004-01-01

Studies of patients with category-specific agnosia (CSA) have given rise to multiple theories of object recognition, most of which assume the existence of a stable, abstract semantic memory system. We applied an episodic view of memory to questions raised by CSA in a series of studies examining normal observers' recall of newly learned attributes…

Llama immunization with full-length VAR2CSA generates cross-reactive and inhibitory single-domain antibodies against the DBL1X domain.

Science.gov (United States)

Nunes-Silva, Sofia; Gangnard, Stéphane; Vidal, Marta; Vuchelen, Anneleen; Dechavanne, Sebastien; Chan, Sherwin; Pardon, Els; Steyaert, Jan; Ramboarina, Stephanie; Chêne, Arnaud; Gamain, Benoît

2014-12-09

VAR2CSA stands today as the leading vaccine candidate aiming to protect future pregnant women living in malaria endemic areas against the severe clinical outcomes of pregnancy associated malaria (PAM). The rational design of an efficient VAR2CSA-based vaccine relies on a profound understanding of the molecular interactions associated with P. falciparum infected erythrocyte sequestration in the placenta. Following immunization of a llama with the full-length VAR2CSA recombinant protein, we have expressed and characterized a panel of 19 nanobodies able to recognize the recombinant VAR2CSA as well as the surface of erythrocytes infected with parasites originating from different parts of the world. Domain mapping revealed that a large majority of nanobodies targeted DBL1X whereas a few of them were directed towards DBL4ε, DBL5ε and DBL6ε. One nanobody targeting the DBL1X was able to recognize the native VAR2CSA protein of the three parasite lines tested. Furthermore, four nanobodies targeting DBL1X reproducibly inhibited CSA adhesion of erythrocytes infected with the homologous NF54-CSA parasite strain, providing evidences that DBL1X domain is part or close to the CSA binding site. These nanobodies could serve as useful tools to identify conserved epitopes shared between different variants and to characterize the interactions between VAR2CSA and CSA.

Molecular dissection of placental malaria protein VAR2CSA interaction with a chemo-enzymatically synthesized chondroitin sulfate library

DEFF Research Database (Denmark)

Sugiura, Nobuo; Clausen, Thomas Mandel; Shioiri, Tatsuasa

2016-01-01

with chondroitin sulfate (CS) proteoglycans present in the placental tissue. CS is a linear acidic polysaccharide composed of repeating disaccharide units of d-glucuronic acid and N-acetyl-d-galactosamine that are modified by sulfate groups at different positions. Previous reports have shown that placental......-adhering IEs were associated with an unusually low sulfated form of chondroitin sulfate A (CSA) and that a partially sulfated dodecasaccharide is the minimal motif for the interaction. However, the fine molecular structure of this CS chain remains unclear. In this study, we have characterized the CS chain...... that interacts with a recombinant minimal CS-binding region of VAR2CSA (rVAR2) using a CS library of various defined lengths and sulfate compositions. The CS library was chemo-enzymatically synthesized with bacterial chondroitin polymerase and recombinant CS sulfotransferases. We found that C-4 sulfation...

Several domains from VAR2CSA can induce Plasmodium falciparum adhesion-blocking antibodies

DEFF Research Database (Denmark)

Salanti, Ali; Resende, Mafalda; Ditlev, Sisse B

2010-01-01

. In this study, it is demonstrated that other domains of VAR2CSA also can induce antibodies with inhibitory activity. METHODS: All VAR2CSA domains from the 3D7 and HB3 parasites were produced in Baculovirus-transfected insect cells. Groups of three rats per protein were immunized and anti-sera were tested...

Shortened protocol in practical [11C]SA4503-PET studies for sigma1 receptor quantification

International Nuclear Information System (INIS)

Sakata, Muneyuki; Kimura, Yuichi; Ishikawa, Masatomo; Oda, Keiichi; Ishii, Kenji; Ishiwata, Kiichi; Naganawa, Mika; Hashimoto, Kenji; Chihara, Kunihiro

2008-01-01

In practical positron emission tomography (PET) diagnosis, a shortened protocol is preferred for patients with brain disorders. In this study, the applicability of a shortened protocol as an alternative to the 90-min PET scan with [ 11 C]SA4503 for quantitative sigma 1 receptor measurement was investigated. Tissue time-activity curves of 288 regions of interest in the brain from 32 [ 11 C]SA4503-PET scans of 16 healthy subjects prior to and following administration of a selective serotonin reuptake inhibitor (fluvoxamine or paroxetine) were applied to two algorithms of quantitative analysis; binding potential (BP) was derived from compartmental analysis based on nonlinear estimation, and total distribution volume (tDV) was derived from Logan plot analysis. As a result, although both BP and tDV tended to be underestimated by the shortened method, the estimates from the shortened protocol had good linear relationships with those of the full-length protocol. In conclusion, if approximately 10% differences in the estimated results are acceptable for a specific purpose, then a 60-min measurement protocol is capable of providing reliable results. (author)

Positive selection of Plasmodium falciparum parasites with multiple var2csa-type PfEMP1 genes during the course of infection in pregnant women

DEFF Research Database (Denmark)

Sander, Adam F; Salanti, Ali; Lavstsen, Thomas

2011-01-01

multiple genes coding for different VAR2CSA proteins, and parasites with >1 var2csa gene appear to be more common in pregnant women with placental malaria than in nonpregnant individuals. We present evidence that, in pregnant women, parasites containing multiple var2csa-type genes possess a selective...... advantage over parasites with a single var2csa gene. Accumulation of parasites with multiple copies of the var2csa gene during the course of pregnancy was also correlated with the development of antibodies involved in blocking VAR2CSA adhesion. The data suggest that multiplicity of var2csa-type genes...

Practical analysis of specificity-determining residues in protein families.

Science.gov (United States)

Chagoyen, Mónica; García-Martín, Juan A; Pazos, Florencio

2016-03-01

Determining the residues that are important for the molecular activity of a protein is a topic of broad interest in biomedicine and biotechnology. This knowledge can help understanding the protein's molecular mechanism as well as to fine-tune its natural function eventually with biotechnological or therapeutic implications. Some of the protein residues are essential for the function common to all members of a family of proteins, while others explain the particular specificities of certain subfamilies (like binding on different substrates or cofactors and distinct binding affinities). Owing to the difficulty in experimentally determining them, a number of computational methods were developed to detect these functional residues, generally known as 'specificity-determining positions' (or SDPs), from a collection of homologous protein sequences. These methods are mature enough for being routinely used by molecular biologists in directing experiments aimed at getting insight into the functional specificity of a family of proteins and eventually modifying it. In this review, we summarize some of the recent discoveries achieved through SDP computational identification in a number of relevant protein families, as well as the main approaches and software tools available to perform this type of analysis. © The Author 2015. Published by Oxford University Press. For Permissions, please email: journals.permissions@oup.com.

Nitrogen fertilization (15NH4NO3 of palisadegrass and residual effect on subsequent no-tillage corn

Directory of Open Access Journals (Sweden)

Emerson Borghi

2014-10-01

Full Text Available Nitrogen is required in large amounts by plants and their dinamics in corn and perennial forages intercropped is little known. This study analyzed the efficiency of nitrogen fertilization (15NH4NO3 applied after corn grain harvest to palisadegrass (Brachiaria brizantha cv. Marandu in intercrops sown at two times, as well as the N residual effect on the subsequent corn crop. The field experiment was performed in Botucatu, São Paulo State, in southeastern Brazil, on a structured Alfisol under no-tillage. The experiment was arranged in a randomized block design in a split plot scheme with four replications. The main plots consisted of two intercropping systems (corn and palisadegrass sown together and palisadegrass sown later, at corn top-dressing fertilization. The subplots consisted of four N rates (0, 30, 60, and 120 kg ha-1 N. The subplots contained microplots, in which enriched ammonium nitrate (15NH4NO3 was applied at the same rates. The time of intercrop sowing affected forage dry matter production, the amount of fertilizer-derived N in and the N use efficiency by the forage plants. Nitrogen applied in autumn to palisadegrass intercropped with corn, planted either at corn sowing or at N top-dressing fertilization, increased the forage yield up to a rate of 60 kg ha-1. The amount of fertilizer-derived N by the forage plants and the fertilizer use efficiency by palisadegrass were highest 160 days after fertilization for both intercrop sowing times, regardless of N rates. Residual N did not affect the N nutrition of corn plants grown in succession to palisadegrass, but increased grain yield at rates of 60 and 120 kg ha-1 N, when corn was grown on palisadegrass straw from the intercrop installed at corn fertilization (top-dressing. Our results indicated that the earlier intercropping allowed higher forage dry matter production. On the other hand, the later intercrop allowed a higher corn grain yield in succession to N-fertilized palisadegrass.

Chlorocholine chloride residue distribution in eggs, breast and ...

African Journals Online (AJOL)

The distribution of chlorocholine chloride (CCC) residue or its metabolites in the meat and eggs of laying hens was studied using the 15N delta value (d15N) and 15N atom % derived from 15N-CCC containing diets. In a completely randomised design, 20 laying hens were divided into four groups allocated four different ...

Common bean growth, N uptake and seed production in sandy loam soil as affected by application of plant residues, nitrogen and irrigation level

International Nuclear Information System (INIS)

Abdallah, A.A.G.

2002-01-01

Field experiment was conducted at the experimental farm, Inshas, atomic energy authority, egypt. Common bean seeds e.v. Nebrasks were cultivated in sandy loan soil using drip irrigation system prepared for this purpose. Two water regimes, i.e., 100% (793.0 m 3 /fed.) and 65% (513.0 m 3 /fed.) of maximum available water were used in main plots. Where in sub plots two fertilizers types were applied i.e., soybean plant residues which contains N 15 labelled as an organic matter without any addition of any fertilizer and nitrogen as chemical fertilizer without using organic matter. The obtained results indicated that, application of plant residues was superior for total seed yield comparing to nitrogen fertilization treatments. This N source with irrigation level of 793.33 m 3 /fed. had a slight increase in total seed yield comparing with (513.0 m 3 /fed.). Irrigation level of 513.0 m 3 /fed. (65% MAW) as well as application of soybean plant residues showed the highest value of water use efficiency. The highest value of N seed percentage was obtained irrigation level with (513.0 m 3 /fed.). Soybean plant residues improved and increased seeds N content, and total seeds protein content. Both N chemical and irrigation level (65% Maw) recorded highest values with N 15 % atom excess. This result has been obtained at two growth stages and seed yield. The same trend of N 15 % atom excess reflected N utilized with both growth stages and seed yield

Distribution of /sup 15/N fertilizer in field-lysimeters sown with garlic (Allium sativum) and foxtail millet (Setaria italica)

Energy Technology Data Exchange (ETDEWEB)

Lazzari, M.A. (Universidad Nacional del Sur, Bahia Blanca (Argentina). Dept. de Ciencas Agrarias)

1982-01-01

We examined the distribution of residual /sup 15/N and its uptake by a foxtail millet crop grown in field lysimeters following a previous garlic crop fertilized with either /sup 15/N-urea or /sup 15/N-ammonium sulphate. Garlic apparently removed more N from the lysimeters treated with urea-N than from those treated with (NH/sub 4/)/sub 2/SO/sub 4/. Fertilizer-N in the lysimeters was similar (ca. 32% of original) following millet harvest. About 16 per cent of both fertilizers in the lysimeters was removed by the millet.

Facile measurement of {sup 1}H-{sup 15}N residual dipolar couplings in larger perdeuterated proteins

Energy Technology Data Exchange (ETDEWEB)

Fitzkee, Nicholas C.; Bax, Ad, E-mail: bax@nih.go [National Institutes of Health, Laboratory of Chemical Physics, National Institute of Diabetes and Digestive and Kidney Diseases (United States)

2010-10-15

We present a simple method, ARTSY, for extracting {sup 1}J{sub NH} couplings and {sup 1}H-{sup 15}N RDCs from an interleaved set of two-dimensional {sup 1}H-{sup 15}N TROSY-HSQC spectra, based on the principle of quantitative J correlation. The primary advantage of the ARTSY method over other methods is the ability to measure couplings without scaling peak positions or altering the narrow line widths characteristic of TROSY spectra. Accuracy of the method is demonstrated for the model system GB3. Application to the catalytic core domain of HIV integrase, a 36 kDa homodimer with unfavorable spectral characteristics, demonstrates its practical utility. Precision of the RDC measurement is limited by the signal-to-noise ratio, S/N, achievable in the 2D TROSY-HSQC spectrum, and is approximately given by 30/(S/N) Hz.

Neuromuscular adaptations associated with knee joint angle-specific force change.

Science.gov (United States)

Noorkõiv, Marika; Nosaka, Kazunori; Blazevich, Anthony J

2014-08-01

Neuromuscular adaptations to joint angle-specific force increases after isometric training have not yet been fully elucidated. This study examined angle-specific neuromuscular adaptations in response to isometric knee extension training at short (SL, joint angle 38.1° ± 3.7°) versus long (LL, 87.5° ± 6.0°) muscle lengths. Sixteen men trained three times a week for 6 wk either at SL (n = 8) or LL (n = 8). Voluntary maximal isometric knee extensor (MVC) force, doublet twitch force, EMG amplitudes (EMG/Mmax), and voluntary activation during MVC force (VA%) were measured at eight knee joint angles (30°-100°) at weeks 0, 3, and 6. Muscle volume and cross-sectional area (CSA) were measured from magnetic resonance imaging scans, and fascicle length (Lf) was assessed using ultrasonography before and after training. Clear joint angle specificity of force increase was seen in SL but not in LL. The 13.4% ± 9.7% (P = 0.01) force increase around the training angle in SL was related to changes in vastus lateralis and vastus medialis EMG/Mmax around the training angle (r = 0.84-0.88, P < 0.05), without changes in the doublet twitch force-angle relation or muscle size. In LL, muscle volume and CSA increased and the changes in CSA at specific muscle regions were correlated with changes in MVC force. A 5.4% ± 4.9% (P = 0.001) increase in Lf found in both groups was not associated with angle-specific force changes. There were no angle-specific changes in VA%. The EMG/Mmax, although not VA%, results suggest that neural adaptations underpinned training-related changes at short quadriceps lengths, but hypertrophic changes predominated after training at long lengths. The findings of this study should contribute to the development of more effective and evidence-based rehabilitation and strength training protocols.

Utilizing nanobody technology to target non-immunodominant domains of VAR2CSA

DEFF Research Database (Denmark)

Ditlev, Sisse B; Florea, Raluca; Nielsen, Morten A

2014-01-01

adhesion. However, the development of a VAR2CSA adhesion-blocking vaccine remains challenging due to (i) the large size of VAR2CSA and (ii) the extensive immune selection for polymorphisms and thereby non-neutralizing B-cell epitopes. Camelid heavy-chain-only antibodies (HcAbs) are known to target epitopes...... that are less immunogenic to classical IgG and, due to their small size and protruding antigen-binding loop, able to reach and recognize cryptic, conformational epitopes which are inaccessible to conventional antibodies. The variable heavy chain (VHH) domain is the antigen-binding site of camelid HcAbs, the so...

Comercializacion Directa de Alimentos Locales: Diferencias entre los Consumidores de los CSA y los Consumidores de los Mercados de Granjeros y Agricultores

OpenAIRE

Curtis, Kynda

2011-01-01

Los programas de extensión enfocados en asistir a los agricultores en movilizar o expandir sus esfuerzos de mercadeo directo a menudo consideran todos los mercados de comercialización directa (mercado de agricultores, programas de agricultura sustentada por la comunidad (CSA por sus siglas en inglés), puestos de granja, etc.) y consumidores asociados como una canal o grupo de comercialización general.

Murine Model for Preclinical Studies of Var2CSA-Mediated Pathology Associated with Malaria in Pregnancy

Science.gov (United States)

Dechavanne, Sebastien; Sousa, Patrícia M.; Barateiro, André; Cunha, Sónia F.; Nunes-Silva, Sofia; Lima, Flávia A.; Murillo, Oscar; Marinho, Claudio R. F.; Gangnard, Stephane; Srivastava, Anand; Braks, Joanna A.; Janse, Chris J.; Gamain, Benoit; Penha-Gonçalves, Carlos

2016-01-01

Plasmodium falciparum infection during pregnancy leads to abortions, stillbirth, low birth weight, and maternal mortality. Infected erythrocytes (IEs) accumulate in the placenta by adhering to chondroitin sulfate A (CSA) via var2CSA protein exposed on the P. falciparum IE membrane. Plasmodium berghei IE infection in pregnant BALB/c mice is a model for severe placental malaria (PM). Here, we describe a transgenic P. berghei parasite expressing the full-length var2CSA extracellular region (domains DBL1X to DBL6ε) fused to a P. berghei exported protein (EMAP1) and characterize a var2CSA-based mouse model of PM. BALB/c mice were infected at midgestation with different doses of P. berghei-var2CSA (P. berghei-VAR) or P. berghei wild-type IEs. Infection with 104 P. berghei-VAR IEs induced a higher incidence of stillbirth and lower fetal weight than P. berghei. At doses of 105 and 106 IEs, P. berghei-VAR-infected mice showed increased maternal mortality during pregnancy and fetal loss, respectively. Parasite loads in infected placentas were similar between parasite lines despite differences in maternal outcomes. Fetal weight loss normalized for parasitemia was higher in P. berghei-VAR-infected mice than in P. berghei-infected mice. In vitro assays showed that higher numbers of P. berghei-VAR IEs than P. berghei IEs adhered to placental tissue. Immunization of mice with P. berghei-VAR elicited IgG antibodies reactive to DBL1-6 recombinant protein, indicating that the topology of immunogenic epitopes is maintained between DBL1-6–EMAP1 on P. berghei-VAR and recombinant DBL1-6 (recDBL1-6). Our data suggested that impairments in pregnancy caused by P. berghei-VAR infection were attributable to var2CSA expression. This model provides a tool for preclinical evaluation of protection against PM induced by approaches that target var2CSA. PMID:27045035

{sup 13}C, {sup 15}N Resonance Assignment of Parts of the HET-s Prion Protein in its Amyloid Form

Energy Technology Data Exchange (ETDEWEB)

Siemer, Ansgar B. [Physical Chemistry (Switzerland); Ritter, Christiane [Salk Institute, Structural Biology Laboratory (United States); Steinmetz, Michel O. [Paul Scherrer Institut, Biomolecular Research, Structural Biology (Switzerland); Ernst, Matthias [Physical Chemistry (Switzerland); Riek, Roland [Salk Institute, Structural Biology Laboratory (United States); Meier, Beat H. [Physical Chemistry (Switzerland)

2006-02-15

The partial {sup 15}N and {sup 13}C solid-state NMR resonance assignment of the HET-s prion protein fragment 218-289 in its amyloid form is presented. It is based on experiments measured at MAS frequencies in the range of 20-40 kHz using exclusively adiabatic polarization-transfer schemes. The resonance assignment within each residue is based on two-dimensional {sup 13}C--{sup 13}C correlation spectra utilizing the DREAM mixing scheme. The sequential linking of the assigned residues used a set of two- and three-dimensional {sup 15}N--{sup 13}C correlation experiments. Almost all cross peaks visible in the spectra are assigned, but only resonances from 43 of the 78 amino-acid residues could be detected. The missing residues are thought to be highly disordered and/or highly dynamic giving rise to broad resonance lines that escaped detection in the experiments applied. The line widths of the observed resonances are narrow and comparable to line widths observed in micro-crystalline samples. The 43 assigned residues are located in two fragments of about 20 residues.

Cyber security. Compliance to the new CSA 290.7 standard

Energy Technology Data Exchange (ETDEWEB)

Daley, M.; Doucet, R.; Echlin, M.; MacDonald, M.; Mihaylov, V.; Sijs, J.; Trask, D. [Canadian Nuclear Laboratories, Chalk River, Ontario (Canada)

2015-12-15

Since 2008, the Canadian Nuclear Safety Commission (CNSC), similar to regulators of other critical industries, has requested their licensees to implement cyber security programs and conduct self- assessments without the benefit of an industry specific cyber security standard that provides common metrics for coverage and effectiveness of their programs. However, for the nuclear industry, a new CSA standard 290.7 entitled 'Cyber security for nuclear power plants and small reactor facilities', released in December 2014, will have the CNSC looking to facility operators to be compliant to the new standard. This paper will discuss initiatives at Canadian Nuclear Laboratories to develop of a suite of tools, techniques, and best practices that can be used by the regulator and industry for assessing compliance and effectiveness of cyber security technology and implementations. (author)

Cyber security - compliance to the new CSA 290.7 standard

Energy Technology Data Exchange (ETDEWEB)

Daley, M.; Doucet, R.; Echlin, M.; MacDonald, M.; Mihaylov, V.; Sijs, J.; Trask, D., E-mail: Matthew.Daley@cnl.ca [Canadian Nuclear Laboratories, Chalk River, ON, (Canada)

2015-07-01

Since 2008, the Canadian Nuclear Safety Commission (CNSC), similar to regulators of other critical industries, has requested their licensees to implement cyber security programs and conduct self-assessments without the benefit of an industry specific cyber security standard that provides common metrics for coverage and effectiveness of their programs. However, for the nuclear industry, a new CSA standard 290.7 entitled 'Cyber security for nuclear power plants and small reactor facilities' [1], released in December 2014, will have the CNSC looking to facility operators to be compliant to the new standard. This paper will discuss initiatives at Canadian Nuclear Laboratories to develop of a suite of tools, techniques, and best practices that can be used by the regulator and industry for assessing compliance and effectiveness of cyber security technology and implementations. (author)

Cyber security. Compliance to the new CSA 290.7 standard

International Nuclear Information System (INIS)

Daley, M.; Doucet, R.; Echlin, M.; MacDonald, M.; Mihaylov, V.; Sijs, J.; Trask, D.

2015-01-01

Since 2008, the Canadian Nuclear Safety Commission (CNSC), similar to regulators of other critical industries, has requested their licensees to implement cyber security programs and conduct self- assessments without the benefit of an industry specific cyber security standard that provides common metrics for coverage and effectiveness of their programs. However, for the nuclear industry, a new CSA standard 290.7 entitled 'Cyber security for nuclear power plants and small reactor facilities', released in December 2014, will have the CNSC looking to facility operators to be compliant to the new standard. This paper will discuss initiatives at Canadian Nuclear Laboratories to develop of a suite of tools, techniques, and best practices that can be used by the regulator and industry for assessing compliance and effectiveness of cyber security technology and implementations. (author)

Cyber security - compliance to the new CSA 290.7 standard

International Nuclear Information System (INIS)

Daley, M.; Doucet, R.; Echlin, M.; MacDonald, M.; Mihaylov, V.; Sijs, J.; Trask, D.

2015-01-01

Since 2008, the Canadian Nuclear Safety Commission (CNSC), similar to regulators of other critical industries, has requested their licensees to implement cyber security programs and conduct self-assessments without the benefit of an industry specific cyber security standard that provides common metrics for coverage and effectiveness of their programs. However, for the nuclear industry, a new CSA standard 290.7 entitled 'Cyber security for nuclear power plants and small reactor facilities' [1], released in December 2014, will have the CNSC looking to facility operators to be compliant to the new standard. This paper will discuss initiatives at Canadian Nuclear Laboratories to develop of a suite of tools, techniques, and best practices that can be used by the regulator and industry for assessing compliance and effectiveness of cyber security technology and implementations. (author)

Effect of 15n-labeled hairy vetch and nitrogen fertilization on maize nutrition and yield under no-tillage

International Nuclear Information System (INIS)

Almeida Acosta, Jose Alan de; Amado, Telmo Jorge Carneiro; Silva, Leandro Souza da; Silveira Nicoloso, Rodrigo da

2011-01-01

This study evaluated the effect of hairy vetch (Vicia villosa Roth) as cover crop on maize nutrition and yield under no tillage using isotope techniques. For this purpose, three experiments were carried out: quantification of biological nitrogen fixation (BNF) in hairy vetch; estimation of the N release rate from hairy vetch residues on the soil surface; quantification of 15 N recovery by maize from labeled hairy vetch under three rates of mineral N fertilization. This two year field experiment was conducted on a sandy Acrisol (FAO soil classification) or Argissolo Vermelho distrofico arenico (Brazilian Soil Classification), at a mean annual temperature of 18 deg C and mean annual rainfall of 1686 mm. The experiment was arranged in a double split-plot factorial design with three replications. Two levels of hairy vetch residue (50 and 100 % of the aboveground biomass production) were distributed on the surface of the main plots (5 x 12 m). Maize in the sub-plots (5 x 4 m) was fertilized with three N rates (0, 60, and 120 kg ha -1 N), with urea as N source. The hairy vetch-derived N recovered by maize was evaluated in microplots (1.8 x 2.2 m). The BFN of hairy vetch was on average 72.4 %, which represents an annual input of 130 kg ha -1 of atmospheric N. The N release from hairy vetch residues was fast, with a release of about 90 % of total N within the first four weeks after cover crop management and soil residue application. The recovery of hairy vetch 15 N by maize was low, with an average of 12.3 % at harvest. Although hairy vetch was not directly the main source of maize N nutrition, the crop yield reached 8.2 Mg ha -1 , without mineral fertilization. There was an apparent synergism between hairy vetch residue application and the mineral N fertilization rate of 60 kg ha -1 , confirming the benefits of the combination of organic and inorganic N sources for maize under no tillage. (author)

The relative isotopic abundance (δ13C, δ15N) during composting of agricultural wastes in relation to compost quality and feedstock.

Science.gov (United States)

Inácio, Caio T; Magalhães, Alberto M T; Souza, Paulo O; Chalk, Phillip M; Urquiaga, Segundo

2018-05-01

Variations in the relative isotopic abundance of C and N (δ 13 C and δ 15 N) were measured during the composting of different agricultural wastes using bench-scale bioreactors. Different mixtures of agricultural wastes (horse bedding manure + legume residues; dairy manure + jatropha mill cake; dairy manure + sugarcane residues; dairy manure alone) were used for aerobic-thermophilic composting. No significant differences were found between the δ 13 C values of the feedstock and the final compost, except for dairy manure + sugarcane residues (from initial ratio of -13.6 ± 0.2 ‰ to final ratio of -14.4 ± 0.2 ‰). δ 15 N values increased significantly in composts of horse bedding manure + legumes residues (from initial ratio of +5.9 ± 0.1 ‰ to final ratio of +8.2 ± 0.5 ‰) and dairy manure + jatropha mill cake (from initial ratio of +9.5 ± 0.2 ‰ to final ratio of +12.8 ± 0.7 ‰) and was related to the total N loss (mass balance). δ 13 C can be used to differentiate composts from different feedstock (e.g. C 3 or C 4 sources). The quantitative relationship between N loss and δ 15 N variation should be determined.

Willingness to disclose child maltreatment: CSA vs other forms of child abuse in relation to gender.

Science.gov (United States)

Lev-Wiesel, Rachel; First, Maya

2018-05-01

The aim of the study was to examine the role of gender in willingness to disclose childhood sexual abuse (CSA) compared to other forms of abuse (physical, emotional and neglect) in young adolescents. Willingness was examined through two terms: reluctance- the level of unwillingness or disinclination to disclose, and urge-the need to share in order to get rid of unbearable feelings. The sample consisted of 3,156 boys (n = 1,544) and girls (n = 1,612) between the ages of 11-16 who reported having been abused at least once during their life. Participants were divided into three groups: experiencing other than CSA, sexual abuse with no physical contact, and sexual abuse with physical contact. Regarding measures, a self-report questionnaire incorporating the following instruments was administered: Demographics, the Juvenile Victimization Questionnaire (JVQ), and the Disclosure of Trauma Questionnaire (DTQ). Study results indicated that CSA victims were more reluctant to disclose than victims of other than CSA forms of abuse. The more severe the CSA (physical contact) the lower was the willingness to disclose. Boys were more reluctant than girls to disclose sexual abuse whether or not it involved physical contact. Reluctance to disclose was positively associated with emotional reactions to disclosure while urge to talk was negatively correlated with emotional reactions to disclosure. Copyright © 2018. Published by Elsevier Ltd.

High efficacy of anti DBL4e-VAR2CSA antibodies in inhibition of CSA-binding Plasmodium falciparum-infected erythrocytes from pregnant women

DEFF Research Database (Denmark)

Magistrado, Pamela A; Minja, Daniel; Doritchamou, Justin

2011-01-01

Malaria during pregnancy is a major cause of intra-uterine growth-retardation and infant death in sub-Saharan Africa. Ideally, this could be prevented by a vaccine delivered before the first pregnancy. Antibodies against domain DBL4¿ from VAR2CSA has been shown to inhibit adhesion of laboratory i...

Nitrogen management in tomato (Lycopersicon esculentum) using 15N-enriched fertilizer

International Nuclear Information System (INIS)

Shivananda, T.N.; Iyengar, B.R.V.; Kotur, S.C.

1996-01-01

An experiment was conducted during 1991 to study nitrogen management using 15 N-enriched fertilizer, to achieve economy in fertilizer N input by reduction and postponement of the basal dose in Arka Vikas tomato (Lycopersicon esculentum Miller nom. cons). Application of 90 kg N/ha in 3 equal splits at 10, 30 and 50 days after transplanting did not show any reduction in total N uptake, dry-matter and fruit yields compared with 120 kg N/ha applied in 3 splits (60 kg N/ha basal and 30 kg top-dressed 20 and 40 days after transplanting). Band application of the basal dose and top-dressing at 20 days after transplanting resulted in higher N derived from fertilizer (Ndff), its uptake and utilization. Top-dressing of 30 or 40 kg N/ha at 10 days after transplanting resulted in better utilization than broadcasting the basal dose of 60 kg N/ha. Application at 40-50 days after transplanting showed poor uptake and utilization of applied N. The succeeding Arka Kalyan onion (Allium cepa L.) utilized 2.95-6.37% residual N, the highest being from the split application at 40 days after transplanting. Thus there was economy in fertilizer N input and higher carry-over of residual N for determinate cultivar of tomato be delaying as well as reducing the basal dose and confining the top-dressing to 30 days after transplanting. (author)

The relationship between passive stiffness and evoked twitch properties: the influence of muscle CSA normalization

International Nuclear Information System (INIS)

Ryan, E D; Thompson, B J; Sobolewski, E J; Herda, T J; Costa, P B; Walter, A A; Cramer, J T

2011-01-01

Passive stiffness measurements are often used as a clinical tool to examine a muscle's passive lengthening characteristics. The purpose of this study was to examine the relationship between passive stiffness and evoked twitch properties prior to and following normalization of passive stiffness to muscle cross-sectional area (CSA). Ten healthy volunteers (mean ± SD age = 23 ± 3 year) performed passive range of motion, evoked twitch, and muscle CSA assessments of the plantar flexor muscles. Passive stiffness was determined from the slope of the final 5° of the angle–torque curve. Peak twitch torque (PTT) and rate of torque development (RTD) were determined via transcutaneous electrical stimulation, and muscle CSA was assessed using a peripheral quantitative computed tomography scanner. Pearson product moment correlation coefficients (r) were used to assess the relationships between passive stiffness and PTT and RTD and normalized passive stiffness (passive stiffness . muscle CSA −1 ) and PTT and RTD. Significant positive relationships were observed between passive stiffness and PTT (P = 0.003, r = 0.828) and RTD (P = 0.003, r = 0.825). There were no significant relationships between normalized passive stiffness and PTT (P = 0.290, r = 0.372) or RTD (P = 0.353, r = 0.329) demonstrating that stiffness did not account for a significant portion of the variance in twitch properties. Passive stiffness was largely influenced by the amount of muscle tissue in this study. Future studies that examine muscle stiffness and its relationship with performance measures, among different populations, and following various interventions may consider normalizing stiffness measurements to muscle CSA

Electrical conductivity retention and electrochemical activity of CSA doped graphene/gold nanoparticle@ polyaniline composites

Directory of Open Access Journals (Sweden)

Md. Akherul Islam

2016-08-01

Full Text Available This paper reports the synthesis of CTAB mediated CSA doped PANI and GN/GNP@ PANI composite nanofibers. The as synthesized composite nanofibers were examined by TEM, SEM, XRD, Raman spectroscopy; UV–visible diffused reflectance spectroscopy and TGA. The CTAB mediated CSA doped composite nanofibers showed 59% higher DC electrical conductivity at ambient temperature than that of PANI, which might be due to the enhancement in the mobility of the charge carriers and reduction in hopping distance in the composite system. The CTAB mediated CSA doped composite nanofibers compared to PANI was observed to be showing enhanced DC electrical conductivity retention after various cycles of heating, suggesting an enhancement in thermal stability of the composite structure, which could be attributed to the synergistic effect of GN, GNP and PANI. Additionally, the composite nanofibers showed greater electrochemical activity and better capacitive performance and reduced optical bandgap than that of PANI.

Accurate Determination of Leucine and Valine Side-chain Conformations using U-[15N/13C/2H]/[1H-(methine/methyl)-Leu/Val] Isotope Labeling, NOE Pattern Recognition, and Methine Cγ-Hγ/Cβ-Hβ Residual Dipolar Couplings

International Nuclear Information System (INIS)

Tang, Chun; Iwahara, Junji; Clore, G. Marius

2005-01-01

An isotope labeling scheme is described in which specific protonation of methine and methyl protons of leucine and valine is obtained on a 15 N/ 13 C labeled background with uniform deuteration of all other non-exchangeable protons. The presence of a protonated methine group has little effect on the favorable relaxation properties of the methyl protons of Leu and Val. This labeling scheme permits the rotameric state of leucine side-chains to be readily determined by simple inspection of the pattern of Hγ(i)-H N (i) and Hγ(i)-H N (i+1) NOEs in a 3D 15 N-separated NOE spectrum free of complications arising from spectral overlap and spin-diffusion. In addition, one-bond residual dipolar couplings for the methine 13 C- 1 H bond vectors of Leu and Val can be accurately determined from an intensity J-modulated constant-time HCCH-COSY experiment and used to accurately orient the side-chains of Leu and Val. Incorporation of these data into structure refinement improves the accuracy with which the conformations of Leu and Val side-chains can be established. This is important to ensure optimal packing both within the protein core and at intermolecular interfaces. The impact of the method on protein structure determination is illustrated by application to enzyme IIA Chitobiose , a 34 kDa homotrimeric phosphotransferase protein

Distribution of nitrogen ammonium sulfate (15N) soil-plant system in a no-tillage crop succession

International Nuclear Information System (INIS)

Fernandes, Flavia Carvalho da Silva; Libardi, Paulo Leonel

2012-01-01

the n use by maize (Zea mays, l.) is affected by n-fertilizer levels. this study was conducted using a sandy-clay texture soil (Hapludox) to evaluate the efficiency of n use by maize in a crop succession, based on 15 N labeled ammonium sulfate (5.5 atom %) at different rates, and to assess the residual fertilizer effect in two no-tillage succession crops (signal grass and corn). Two maize crops were evaluated, the first in the growing season 2006, the second in 2007, and brachiaria in the second growing season. The treatments consisted of n rates of 60, 120 and 180 kg ha -1 in the form of labeled 15 N ammonium sulfate. This fertilizer was applied in previously defined subplots, only to the first maize crop (growing season 2006). The variables total accumulated n; fertilizer-derived n in corn plants and pasture; fertilizer-derived n in the soil; and recovery of fertilizer-n by plants and soil were evaluated.The highest uptake of fertilizer n by corn was observed after application of 120 kg ha -1 N and the residual effect of n fertilizer on subsequent corn and brachiaria was highest after application of 180 kg ha -1 N. After the crop succession, soil n recovery was 32, 23 and 27 % for the respective applications of 60, 120 and 180 kg ha -1 N. (author)

The MARS15-based FermiCORD code system for calculation of the accelerator-induced residual dose

Energy Technology Data Exchange (ETDEWEB)

Grebe, A.; Leveling, A.; Lu, T.; Mokhov, N.; Pronskikh, V.

2018-01-01

The FermiCORD code system, a set of codes based on MARS15 that calculates the accelerator-induced residual doses at experimental facilities of arbitrary configurations, has been developed. FermiCORD is written in C++ as an add-on to Fortran-based MARS15. The FermiCORD algorithm consists of two stages: 1) simulation of residual doses on contact with the surfaces surrounding the studied location and of radionuclide inventories in the structures surrounding those locations using MARS15, and 2) simulation of the emission of the nuclear decay gamma-quanta by the residuals in the activated structures and scoring the prompt doses of these gamma-quanta at arbitrary distances from those structures. The FermiCORD code system has been benchmarked against similar algorithms based on other code systems and showed a good agreement. The code system has been applied for calculation of the residual dose of the target station for the Mu2e experiment and the results have been compared to approximate dosimetric approaches.

Multiple var2csa-type PfEMP1 genes located at different chromosomal loci occur in many Plasmodium falciparum isolates

DEFF Research Database (Denmark)

Sander, Adam F; Salanti, Ali; Lavstsen, Thomas

2009-01-01

in the VAR2CSA protein, sequence variation in the DBL2X region of var2csa genes in 54 P.falciparum samples was analyzed. Chromosome mapping of var2csa loci was carried out and a quantitative PCR assay was developed to estimate the number of var2csa genes in P.falciparum isolates from the placenta of pregnant....... falciparum isolates. One gene is on chromosome 12 but additional var2csa-type genes are on different chromosomes in different isolates. Multiplicity of var2csa genes appears more common in infected placentae than in samples from non-pregnant donors indicating a possible advantage of this genotype...

Reverse Conservation Analysis Reveals the Specificity Determining Residues of Cytochrome P450 Family 2 (CYP 2

Directory of Open Access Journals (Sweden)

Tai-Sung Lee

2008-01-01

Full Text Available The concept of conservation of amino acids is widely used to identify important alignment positions of orthologs. The assumption is that important amino acid residues will be conserved in the protein family during the evolutionary process. For paralog alignment, on the other hand, the opposite concept can be used to identify residues that are responsible for specificity. Assuming that the function-specific or ligand-specific residue positions will have higher diversity since they are under evolutionary pressure to fit the target specificity, these function-specific or ligand-specific residues positions will have a lower degree of conservation than other positions in a highly conserved paralog alignment. This study assessed the ability of reverse conservation analysis to identify function-specific and ligand-specific residue positions in closely related paralog. Reverse conservation analysis of paralog alignments successfully identified all six previously reported substrate recognition sites (SRSs in cytochrome P450 family 2 (CYP 2. Further analysis of each subfamily identified the specificity-determining residues (SDRs that have been experimentally found. New potential SDRs were also predicted and await confirmation by further experiments or modeling calculations. This concept may be also applied to identify SDRs in other protein families.

Effect of {sup 15}n-labeled hairy vetch and nitrogen fertilization on maize nutrition and yield under no-tillage

Energy Technology Data Exchange (ETDEWEB)

Almeida Acosta, Jose Alan de [Drakkar Solos, Santa Maria, RS (Brazil); Amado, Telmo Jorge Carneiro; Silva, Leandro Souza da, E-mail: tamado@smail.ufsm.b, E-mail: leandro@smail.ufsm.b [Universidade Federal de Santa Maria (UFSM), RS (Brazil). Soil Dept.; Neergaard, Andreas de; Vinther, Mads, E-mail: adn@life.ku.d [University of Copenhagen (Denmark); Silveira Nicoloso, Rodrigo da, E-mail: rodrigo.nicoloso@cnpsa.embrapa.b [Embrapa Swine and Poultry, Concordia, SC (Brazil)

2011-07-15

This study evaluated the effect of hairy vetch (Vicia villosa Roth) as cover crop on maize nutrition and yield under no tillage using isotope techniques. For this purpose, three experiments were carried out: quantification of biological nitrogen fixation (BNF) in hairy vetch; estimation of the N release rate from hairy vetch residues on the soil surface; quantification of {sup 15}N recovery by maize from labeled hairy vetch under three rates of mineral N fertilization. This two year field experiment was conducted on a sandy Acrisol (FAO soil classification) or Argissolo Vermelho distrofico arenico (Brazilian Soil Classification), at a mean annual temperature of 18 deg C and mean annual rainfall of 1686 mm. The experiment was arranged in a double split-plot factorial design with three replications. Two levels of hairy vetch residue (50 and 100 % of the aboveground biomass production) were distributed on the surface of the main plots (5 x 12 m). Maize in the sub-plots (5 x 4 m) was fertilized with three N rates (0, 60, and 120 kg ha{sup -1} N), with urea as N source. The hairy vetch-derived N recovered by maize was evaluated in microplots (1.8 x 2.2 m). The BFN of hairy vetch was on average 72.4 %, which represents an annual input of 130 kg ha{sup -1} of atmospheric N. The N release from hairy vetch residues was fast, with a release of about 90 % of total N within the first four weeks after cover crop management and soil residue application. The recovery of hairy vetch {sup 15}N by maize was low, with an average of 12.3 % at harvest. Although hairy vetch was not directly the main source of maize N nutrition, the crop yield reached 8.2 Mg ha{sup -1}, without mineral fertilization. There was an apparent synergism between hairy vetch residue application and the mineral N fertilization rate of 60 kg ha{sup -1}, confirming the benefits of the combination of organic and inorganic N sources for maize under no tillage. (author)

An introduction and overview of DRAFT CSA Standard N288.7 Groundwater Protection at Class I Nuclear Facilities and Uranium Mines and Mills

Energy Technology Data Exchange (ETDEWEB)

DeWilde, J., E-mail: john_dewilde@golder.com [Golder Associates Ltd., Whitby, ON (Canada); Klukas, M.; Audet, M., E-mail: marc.audet@cnl.ca [Canadian Nuclear Laboratories, Chalk River, ON (Canada)

2015-07-01

The DRAFT CSA Standard N288.7 entitled Groundwater Protection at Class I Nuclear Facilities and Uranium Mines and Mills is currently under development and is anticipated to publish in June of 2015. This draft standard identifies a process for the protection and monitoring of groundwater at nuclear facilities but may also be used at any facility (i.e. nuclear facilities that are not Class I or non-nuclear facilities). The paper discusses the background to the draft standard, the formalized methodology described in the draft standard and provides some input on implementation. The paper is intended for people that have responsibilities related to groundwater protection at facilities that may need to comply with the draft standard or any site/facility that has some form of groundwater monitoring program. (author)

Non-"g" Residuals of the SAT and ACT Predict Specific Abilities

Science.gov (United States)

Coyle, Thomas R.; Purcell, Jason M.; Snyder, Anissa C.; Kochunov, Peter

2013-01-01

This research examined whether non-"g" residuals of the SAT and ACT subtests, obtained after removing g, predicted specific abilities. Non-"g" residuals of the verbal and math subtests of the SAT and ACT were correlated with academic (verbal and math) and non-academic abilities (speed and shop), both based on the Armed Services…

High avidity antibodies to full-length VAR2CSA correlate with absence of placental malaria

DEFF Research Database (Denmark)

Tutterrow, Yeung Lo; Salanti, Ali; Avril, Marion

2012-01-01

VAR2CSA mediates sequestration of Plasmodium falciparum-infected erythrocytes in the placenta, increasing the risk of poor pregnancy outcomes. Naturally acquired antibodies (Ab) to placental parasites at delivery have been associated with improved pregnancy outcomes, but Ab levels and how early...... in pregnancy Ab must be present in order to eliminate placental parasites before delivery remains unknown. Antibodies to individual Duffy-binding like domains of VAR2CSA have been studied, but the domains lack many of the conformational epitopes present in full-length VAR2CSA (FV2). Thus, the purpose...... of this study was to describe the acquisition of Ab to FV2 in women residing in high and low transmission areas and determine how Ab levels during pregnancy correlate with clearance of placental parasites. Plasma samples collected monthly throughout pregnancy from pregnant women living in high and low...

Continuous In Situ Measurements of Near Bottom Chemistry and Sediment-Water Fluxes with the Chimney Sampler Array (CSA)

Science.gov (United States)

Martens, C. S.; Mendlovitz, H. P.; White, B. L.; Hoer, D.; Sleeper, K.; Chanton, J.; Wilson, R.; Lapham, L.

2011-12-01

The Chimney Sampler Array (CSA) was designed to measure in situ chemical and physical parameters within the benthic boundary layer plus methane and oxygen sediment-water chemical fluxes at upper slope sites in the northern Gulf of Mexico. The CSA can monitor temporal changes plus help to evaluate oceanographic and sub-seafloor processes that can influence the formation and stability of gas hydrates in underlying sediments. The CSA consists of vertical cylinders (chimneys) equipped with internal chemical sensors and with laboratory flume-calibrated washout rates. Chimney washout rates multiplied by chimney mean versus ambient concentrations allow calculation of net O2 and methane sediment-water fluxes. The CSA is emplaced on the seafloor by a ROVARD lander using a ROV for chimney deployments. The CSA presently includes two 30 cm diameter by 90 cm length cylinders that seal against the sediment with lead pellet beanbags; within each chimney cylinder are optode, conductivity and methane sensors. The CSA's data logger platform also includes pressure and turbidity sensors external to the chimneys along with an acoustic Doppler current meter to measure temporal variation in ambient current velocity and direction. The CSA was deployed aboard a ROVARD lander on 9/13/2010 in the northern Gulf of Mexico (Lat. 28 51.28440, Long. 088 29.39421) on biogeochemically active sediments within Block MC-118. A ROV was utilized for chimney deployment away from the ROVARD lander. The CSA monitored temporal changes in water column physical parameters, obtained near-bottom chemical data to compare with pore fluid and sediment core measurements and measured temporal variability in oxygen and methane sediment-water fluxes at two closely spaced stations at MC-118. A continuous, three-week data set was obtained that revealed daily cycles in chemical parameters and episodic flux events. Lower than ambient chimney dissolved O2 concentrations controlled by temporal variability in washout rates

Two dose-estimation models CSA-N288.1 and Nureg 1.109, 1.113 - compared for chronic aquatic releases from nuclear facilities

CERN Document Server

Sheppard, S C; Peterson, S R

2000-01-01

Both the Canadian Standards Association (CSA) and the United States Nuclear Regulatory Commission (US-NRC) have published guidelines for the calculation of doses to the public due to emissions from nuclear facilities. In the sale of CANDU reactors overseas, either of these guidelines may be used as part of the approval process in the recipient country. This study compares the aquatic exposure pathways described in the guidelines. These include direct consumption of contaminated water and food, and exposure to contaminated sediments. The CSA and US-NRC guidelines for estimating dilution of aquatic emissions are of a general nature and the choice of model used to quantify dilution is left to the user. The models prescribed for the different exposure pathways by these two regulatory guides are similar in many attributes. Many of the recommended parameter values are identical and many of the formulations are either identical, or become identical under general conditions. However, despite these similarities, there...

Residual N effects from livestock manure inputs to soils

DEFF Research Database (Denmark)

Schröder, Jaap; Bechini, Luca; Bittman, Shabtai

Organic inputs including livestock manures provide nitrogen (N) to crops beyond the year of their application. This so-called residual N effect should be taken into account when making decisions on N rates for individual fields, but also when interpreting N response trials in preparation...

Mitigating N2O emissions from clover residues by 3,4-dimethylpyrazole phosphate (DMPP) without adverse effects on the earthworm Lumbricus terrestris

DEFF Research Database (Denmark)

Kong, Xianwang; Duan, YunFeng; Schramm, Andreas

2017-01-01

in a 28-d mesocosm experiment, where DMPP spraying prior to tillage was simulated. Above-ground parts of 15N-labelled clover residues were treated with DMPP and either placed at 10 cm depth to simulate ploughing (PL), or mixed with soil at 0–10 cm depth to simulate rotovation (RO). Earthworms (Lumbricus...... terrestris) were introduced to study their role in residue decomposition and N2O emissions. Fluxes and isotopic composition of N2O were determined with dynamic chambers using laser spectroscopy. A gradual increase in 15N-enrichment of N2O indicated that denitrification was the main source. DMPP reduced...... cumulative N2O emissions in PL from 241 to 146 mg N m−2; the reduction in RO was smaller, from 103 to 94 mg N m−2, and not significant, possibly due to higher oxygen and soil NO3− availability. After 28 d incubation, on average > 90% of the earthworms were recovered, and in vivo N2O production from L...

Prospects and Pitfalls of Pregnancy-Associated Malaria Vaccination Based on the Natural Immune Response to Plasmodium falciparum VAR2CSA-Expressing Parasites

Directory of Open Access Journals (Sweden)

Elizabeth G. Kane

2011-01-01

Full Text Available Pregnancy-associated malaria, a manifestation of severe malaria, is the cause of up to 200,000 infant deaths a year, through the effects of placental insufficiency leading to growth restriction and preterm delivery. Development of a vaccine is one strategy for control. Plasmodium falciparum-infected red blood cells accumulate in the placenta through specific binding of pregnancy-associated parasite variants that express the VAR2CSA antigen to chondroitin sulphate A on the surface of syncytiotrophoblast cells. Parasite accumulation, accompanied by an inflammatory infiltrate, disrupts the cytokine balance of pregnancy with the potential to cause placental damage and compromise foetal growth. Multigravid women develop immunity towards VAR2CSA-expressing parasites in a gravidity-dependent manner which prevents unfavourable pregnancy outcomes. Although current vaccine design, targeting VAR2CSA antigens, has succeeded in inducing antibodies artificially, this candidate may not provide protection during the first trimester and may only protect those women living in areas endemic for malaria. It is concluded that while insufficient information about placental-parasite interactions is presently available to produce an effective vaccine, incremental progress is being made towards achieving this goal.

Recovery of nitrogen by spring barley following incorporation of 15N-labelled straw and catch crop material

DEFF Research Database (Denmark)

Thomsen, I.K.; Jensen, E.S.

1994-01-01

The recovery by spring barley (Hordeum vulgare L.) of nitrogen mineralized from N-15-labelled straw and ryegrass material was followed for 3 years in the field. The effects of separate and combined applications of straw and ryegrass were studied using cross-labelling with N-15. Reference plots re...... mineral fertilizer was in the second and third barley crop similar to the recovery of N from incorporated plant residues.......The recovery by spring barley (Hordeum vulgare L.) of nitrogen mineralized from N-15-labelled straw and ryegrass material was followed for 3 years in the field. The effects of separate and combined applications of straw and ryegrass were studied using cross-labelling with N-15. Reference plots...... receiving (NH4NO3)-N-15-N-15 were included. Plant samples were taken every second week until maturity during the first growing season and at maturity in the two following years. Incorporation of plant material had no significant influence on the above-ground dry matter yield of the barley. The barley...

Synthesis and NMR characterization of ( sup 15 N)taurine (2-( sup 15 N)aminoethanesulfonic acid)

Energy Technology Data Exchange (ETDEWEB)

Philippossian, G.; Welti, D.H.; Fumeaux, R.; Richli, U.; Anantharaman, K. (Nestle Research Centre, Nestec Ltd., Lausanne (Switzerland))

1989-11-01

The title compound was prepared in three steps with 55% overall yield starting from potassium ({sup 15}N)phthalimide. The synthetic route involved reaction with 1,2-dibromoethane, hydrolysis of the resulting N-(2-bromoethyl) ({sup 15}N)phthalimide with HBr and treatment of the 2-bromoethyl({sup 15}N)amine thus formed with sodium sulphite. The product was characterized by {sup 13}C, {sup 1}H and {sup 15}N NMR spectroscopy. The absolute coupling constants of {sup 15}N with the {sup 13}C nuclei and the non-exchanging protons were determined and an unambiguous assignment of the proton signals obtained. (author).

Ferrochelatase from Rhodopseudomonas sphaeroides: substrate specificity and role of sulfhydryl and arginyl residues

International Nuclear Information System (INIS)

Dailey, H.A.; Fleming, J.E.; Harbin, B.M.

1986-01-01

Purified ferrochelatase from the bacterium Rhodopseudomonas sphaeroides was examined to determine the roles of cationic and sulfhydryl residues in substrate binding. Reaction of the enzyme sulfhydryl residues with N-ethylmaleimide or monobromobimane resulted in a rapid loss of enzyme activity. Ferrous iron, but not porphyrin substrate, had a protective effect against inactivation by these two reagents. Quantitation with 3 H-labeled N-ethylmaleimide revealed that inactivation required one to two sulfhydryl groups to be modified. Modification of arginyl residues with either 2,3-butanedione or camphorquinone 10-sulfonate resulted in a loss of ferrochelatase activity. A kinetic analysis of the modified enzyme showed that the K/sub m/ for ferrous iron was not altered but that the K/sub m/ for the prophyrin substrate was increased. These data suggested that arginyl residues may be involved in porphyrin binding, possibly via charge pair interactions between the arginyl residue and the anionic porphyrin propionate side chain. Modification of lysyl residues had no effect on enzyme activity. The authors also examined the ability of bacterial ferrochelatase to use various 2,4-disubstituted porphyrins as substrates. The authors found that 2,4-bis-acetal- and 2,4-disulfonate deuteroporphyrins were effective substrates for the purified bacterial enzyme and that N-methylprotoporphyrin was an effective inhibitor of the enzyme. Data for the ferrochelatase of R. sphaeroides are compared with previously published data for the eucaryotic enzyme

Evidence for globally shared, cross-reacting polymorphic epitopes in the pregnancy-associated malaria vaccine candidate VAR2CSA

DEFF Research Database (Denmark)

Avril, Marion; Kulasekara, Bridget R; Gose, Severin O

2008-01-01

Pregnancy-associated malaria (PAM) is characterized by the placental sequestration of Plasmodium falciparum-infected erythrocytes (IEs) with the ability to bind to chondroitin sulfate A (CSA). VAR2CSA is a leading candidate for a pregnancy malaria vaccine, but its large size ( approximately 350 k...

Residual N effects from livestock manure inputs to soils

NARCIS (Netherlands)

Schroder, J.J.; Bechini, L.; Bittman, S.; Brito, M.P.; Delin, S.; Lalor, S.T.J.; Morvan, T.; Chambers, B.J.; Sakrabani, R.; Sørensen, P.B.

2013-01-01

Organic inputs including livestock manures provide nitrogen (N) to crops beyond the year of their application. This so-called residual N effect should be taken into account when making decisions on N rates for individual fields, but also when interpreting N response trials in preparation of

Two dose-estimation models CSA-N288.1 and Nureg 1.109, 1.113 - compared for chronic aquatic releases from nuclear facilities

Energy Technology Data Exchange (ETDEWEB)

Sheppard, S.C. [ECOMatters Inc., Pinawa, Manitoba (Canada); Klukas, M.H. [Atomic Energy of Canada Limited, Chalk River, Ontario (Canada); Peterson, S.-R. [Lawrence Livermore National Lab., Livermore, California (United States)

2000-04-01

Both the Canadian Standards Association (CSA) and the United States Nuclear Regulatory Commission (US-NRC) have published guidelines for the calculation of doses to the public due to emissions from nuclear facilities. In the sale of CANDU reactors overseas, either of these guidelines may be used as part of the approval process in the recipient country. This study compares the aquatic exposure pathways described in the guidelines. These include direct consumption of contaminated water and food, and exposure to contaminated sediments. The CSA and US-NRC guidelines for estimating dilution of aquatic emissions are of a general nature and the choice of model used to quantify dilution is left to the user. The models prescribed for the different exposure pathways by these two regulatory guides are similar in many attributes. Many of the recommended parameter values are identical and many of the formulations are either identical, or become identical under general conditions. However, despite these similarities, there is substantial variation between dose estimates for a common case. These differences are limited to certain nuclides and exposure pathways and are primarily due to differences in parameter values prescribed by the guidelines. The total dose from all pathways and from all nuclides for the case considered is within a factor of 1.3 for the two models. The convergence in results for the total dose for all radionuclides largely reflects the similarity in the way the models deal with the dominant dose contributor, tritium. Considering the results for each radionuclide, however, the models differ more and on average the CSA model estimates a 20-fold higher dose. (author)

The MARS15-based FermiCORD code system for calculation of the accelerator-induced residual dose

Science.gov (United States)

Grebe, A.; Leveling, A.; Lu, T.; Mokhov, N.; Pronskikh, V.

2018-01-01

The FermiCORD code system, a set of codes based on MARS15 that calculates the accelerator-induced residual doses at experimental facilities of arbitrary configurations, has been developed. FermiCORD is written in C++ as an add-on to Fortran-based MARS15. The FermiCORD algorithm consists of two stages: 1) simulation of residual doses on contact with the surfaces surrounding the studied location and of radionuclide inventories in the structures surrounding those locations using MARS15, and 2) simulation of the emission of the nuclear decay γ-quanta by the residuals in the activated structures and scoring the prompt doses of these γ-quanta at arbitrary distances from those structures. The FermiCORD code system has been benchmarked against similar algorithms based on other code systems and against experimental data from the CERF facility at CERN, and FermiCORD showed reasonable agreement with these. The code system has been applied for calculation of the residual dose of the target station for the Mu2e experiment and the results have been compared to approximate dosimetric approaches.

Investigation into endogenous N metabolism in /sup 15/N-labelled pigs. 1. /sup 15/N labelling and /sup 15/N excretion in urine and feces after feeding 4 different diets

Energy Technology Data Exchange (ETDEWEB)

Bergner, H; Bergner, U; Adam, K [Humboldt-Universitaet, Berlin (German Democratic Republic). Sektion Tierproduktion und Veterinaermedizin

1984-07-01

4 male castrated pigs (55-65 kg) either received a wheat-fish meal diet (1 and 2) or a wheat-horse bean diet (3 and 4) without straw meal supplement (1 and 3) or with a supplement of 20% dry matter (2 and 4). In order to investigate whether a /sup 15/N labelling of the pigs is also possible with a protein excess in the ration, the animals received 24.8 g (1 and 2) and 11.6 g crude protein/kg/sup 0.75/ live weight (3 and 4). During a 10-day /sup 15/N-labelling 385 mg /sup 15/N excess (/sup 15/N') per kg/sup 0.75/ were applied with /sup 15/N labelling the following quotas of the applied /sup 15/N amount were incorporated: 1 = 10.2%, 2 = 7.2%, 3 = 18.7%, 4 = 14.4%. /sup 15/N excretion in both TCA fractions of feces showed a highly significant positive correlation to the increasing content of crude fibre in the 4 diets. The immediate /sup 15/N incorporation into the TCA-precipitable fraction of feces proves that /sup 15/N enters the large intestine endogenously and serves bacterial protein synthesis. 3 days after the last /sup 15/N application the pigs were killed. The values of atom-% /sup 15/N' were determined in the TCA-precipitable blood plasma and in the TCA-precipitable fraction of the liver. The other examined organs and tissues showed smaller differences between the test animals. The results show that the /sup 15/N labelling of tissues and organs of pigs is also possible at a high level of protein supply by means of an oral application of (/sup 15/N) ammonia salts.

Wheat nitrogen fertilizer residues on an ultisol from the IX Region

International Nuclear Information System (INIS)

Rouanet M, Juan Luis; Pino N, Ines; Nario M, Adriana; Jobet, Claudio; Parada V, Ana Maria; Videla L, Ximena

2005-01-01

The soil nitrogen fertilizer residue is a relevant issue on a wheat production system at the IX Region of Chile, due to the high level of yield and use of resources, having an environmental impact from the use of fertilizer economy. The N-soil residue, not absorb by the plant, can be leach and contaminate the groundwater with nitrates or be redistributed by erosion. The application of isotopic techniques, using fertilizer labeled with 15 N, providing the quantitative information of the fate of this nutrient in the plant-soil system, important in the rate formulation based on the nitrogen use efficiency and in the benefit/cost relation. An assay was carried out in an Ultisol Metrenco Soil (Family fine, mixed, mesic, Typic Paleudults) at Pumalal locality. A Kumpa wheat variety was used, with a control treatment and five N rates applied as Urea labeled with 10% 15 N a.e., split in four times during the crop growth cycle. Total N (Kjeldhal) and 15 N optical emission spectrometer were determined in grain and straw samples harvested in February. Before to the next sow on may, soil sample were taken with an 3 cm diameter hugger (0-20; 20-40 and 40-60 cm depth). The samples were air dried, sieved and analyzed for total N and 15 N. The parameters determined for each depth were: N total (%), 15 N a.e. to obtain the plant-soil system N fertilizer recovery and its N residues in the soil profile. The wheat yield obtained was related with a cubic model using the N fertilizer rate applied (R 2 =0.75). The highest yield for the grain, 9.8 Mg ha -1 , was obtained applying 197 k ha -1 of N, with 45% of 15 N recovered by the grain. Nevertheless, the soil-crop system obtained a high 15 N recovery (>88%), in the soil remained 32-60% as N residue, being not used by the plant during the growth period. Between 27-54% of the 15 N total residue was found at the 0-20 cm soil depth, portion that is susceptible of distribution by erosion, implied in the use of fertilizer economy. Around 4

The use of δ15N in assessing sewage stress on coral reefs

International Nuclear Information System (INIS)

Risk, Michael J.; Lapointe, Brian E.; Sherwood, Owen A.; Bedford, Bradley J.

2009-01-01

While coral reefs decline, scientists argue, and effective strategies to manage land-based pollution lag behind the extent of the problem. There is need for objective, cost-effective, assessment methods. The measurement of stable nitrogen isotope ratios, δ 15 N, in tissues of reef organisms shows promise as an indicator of sewage stress. The choice of target organism will depend upon study purpose, availability, and other considerations such as conservation. Algae are usually plentiful and have been shown faithfully to track sewage input. The organic matrix of bivalve shells can provide time series spanning, perhaps, decades. Gorgonians have been shown to track sewage, and can provide records potentially centuries-long. In areas where baseline data are lacking, which is almost everywhere, δ 15 N in gorgonians can provide information on status and trends. In coral tissue, δ 15 N combined with insoluble residue determination can provide information on both sewage and sediment stress in areas lacking baseline data. In the developed world, δ 15 N provides objective assessment in a field complicated by conflicting opinions. Sample handling and processing are simple and analysis costs are low. This is a method deserving widespread application.

Improving protein fold recognition by extracting fold-specific features from predicted residue-residue contacts.

Science.gov (United States)

Zhu, Jianwei; Zhang, Haicang; Li, Shuai Cheng; Wang, Chao; Kong, Lupeng; Sun, Shiwei; Zheng, Wei-Mou; Bu, Dongbo

2017-12-01

Accurate recognition of protein fold types is a key step for template-based prediction of protein structures. The existing approaches to fold recognition mainly exploit the features derived from alignments of query protein against templates. These approaches have been shown to be successful for fold recognition at family level, but usually failed at superfamily/fold levels. To overcome this limitation, one of the key points is to explore more structurally informative features of proteins. Although residue-residue contacts carry abundant structural information, how to thoroughly exploit these information for fold recognition still remains a challenge. In this study, we present an approach (called DeepFR) to improve fold recognition at superfamily/fold levels. The basic idea of our approach is to extract fold-specific features from predicted residue-residue contacts of proteins using deep convolutional neural network (DCNN) technique. Based on these fold-specific features, we calculated similarity between query protein and templates, and then assigned query protein with fold type of the most similar template. DCNN has showed excellent performance in image feature extraction and image recognition; the rational underlying the application of DCNN for fold recognition is that contact likelihood maps are essentially analogy to images, as they both display compositional hierarchy. Experimental results on the LINDAHL dataset suggest that even using the extracted fold-specific features alone, our approach achieved success rate comparable to the state-of-the-art approaches. When further combining these features with traditional alignment-related features, the success rate of our approach increased to 92.3%, 82.5% and 78.8% at family, superfamily and fold levels, respectively, which is about 18% higher than the state-of-the-art approach at fold level, 6% higher at superfamily level and 1% higher at family level. An independent assessment on SCOP_TEST dataset showed consistent

Prediction of Detailed Enzyme Functions and Identification of Specificity Determining Residues by Random Forests

Science.gov (United States)

Nagao, Chioko; Nagano, Nozomi; Mizuguchi, Kenji

2014-01-01

Determining enzyme functions is essential for a thorough understanding of cellular processes. Although many prediction methods have been developed, it remains a significant challenge to predict enzyme functions at the fourth-digit level of the Enzyme Commission numbers. Functional specificity of enzymes often changes drastically by mutations of a small number of residues and therefore, information about these critical residues can potentially help discriminate detailed functions. However, because these residues must be identified by mutagenesis experiments, the available information is limited, and the lack of experimentally verified specificity determining residues (SDRs) has hindered the development of detailed function prediction methods and computational identification of SDRs. Here we present a novel method for predicting enzyme functions by random forests, EFPrf, along with a set of putative SDRs, the random forests derived SDRs (rf-SDRs). EFPrf consists of a set of binary predictors for enzymes in each CATH superfamily and the rf-SDRs are the residue positions corresponding to the most highly contributing attributes obtained from each predictor. EFPrf showed a precision of 0.98 and a recall of 0.89 in a cross-validated benchmark assessment. The rf-SDRs included many residues, whose importance for specificity had been validated experimentally. The analysis of the rf-SDRs revealed both a general tendency that functionally diverged superfamilies tend to include more active site residues in their rf-SDRs than in less diverged superfamilies, and superfamily-specific conservation patterns of each functional residue. EFPrf and the rf-SDRs will be an effective tool for annotating enzyme functions and for understanding how enzyme functions have diverged within each superfamily. PMID:24416252

Cycling of fertilizer and cotton crop residue nitrogen

International Nuclear Information System (INIS)

Rochester, I.J.; Constable, G.A.; MacLeod, D.A.

1993-01-01

Mineral nitrogen (N), nitrate and ammonium contents were monitored in N-fertilized soils supporting cotton crops to provide information on the nitrification, mineralization and immobilization processes operating in the soil. The relative contributions of fertilizer N, previous cotton crop residue N and indigenous soil N to the mineral N pools and to the current crop's N uptake were calculated. After N fertilizer (urea) application, the soil's mineral N content rose rapidly and subsequently declined at a slower rate. The recovery of 15 N-labelled urea as mineral N declined exponentially with time. Biological immobilization (and possibly denitrification to some extent) were believed to be the major processes reducing post-application soil mineral N content. Progressively less N was mineralized upon incubation of soil sampled through the growing season. Little soil N (either from urea or crop residue) was mineralized at crop maturity. Cycling of N was evident between the soil mineral and organic N pools throughout the cotton growing season. Considerable quantities of fertilizer N were immobilized by the soil micro biomass; immobilized N was remineralized and subsequently taken up by the cotton crop. A large proportion of the crop N was taken up in the latter part of the season when the soil mineral N content was low. It is suggested that much of the N taken up by cotton was derived from microbial sources, rather than crop residues. The application of cotton crop residue (stubble) slightly reduced the mineral N content in the soil by encouraging biological immobilization. 15 N was mineralized very slowly from the labelled crop residue and did not contribute significantly to the supply of N to the current crop. Recovery of labelled fertilizer N and labelled crop residue N by the cotton crop was 28% and 1%, respectively. In comparison, the apparent recovery of fertilizer N was 48%. Indigenous soil N contributed 68% of the N taken up by the cotton crop. 33 refs., 1 tab

Computational learning on specificity-determining residue-nucleotide interactions

KAUST Repository

Wong, Ka-Chun; Li, Yue; Peng, Chengbin; Moses, Alan M.; Zhang, Zhaolei

2015-01-01

The protein–DNA interactions between transcription factors and transcription factor binding sites are essential activities in gene regulation. To decipher the binding codes, it is a long-standing challenge to understand the binding mechanism across different transcription factor DNA binding families. Past computational learning studies usually focus on learning and predicting the DNA binding residues on protein side. Taking into account both sides (protein and DNA), we propose and describe a computational study for learning the specificity-determining residue-nucleotide interactions of different known DNA-binding domain families. The proposed learning models are compared to state-of-the-art models comprehensively, demonstrating its competitive learning performance. In addition, we describe and propose two applications which demonstrate how the learnt models can provide meaningful insights into protein–DNA interactions across different DNA binding families.

Computational learning on specificity-determining residue-nucleotide interactions

KAUST Repository

Wong, Ka-Chun

2015-11-02

The protein–DNA interactions between transcription factors and transcription factor binding sites are essential activities in gene regulation. To decipher the binding codes, it is a long-standing challenge to understand the binding mechanism across different transcription factor DNA binding families. Past computational learning studies usually focus on learning and predicting the DNA binding residues on protein side. Taking into account both sides (protein and DNA), we propose and describe a computational study for learning the specificity-determining residue-nucleotide interactions of different known DNA-binding domain families. The proposed learning models are compared to state-of-the-art models comprehensively, demonstrating its competitive learning performance. In addition, we describe and propose two applications which demonstrate how the learnt models can provide meaningful insights into protein–DNA interactions across different DNA binding families.

Using 15N to study the effect of additament on N balance of urea

International Nuclear Information System (INIS)

Pan Jiarong; Wen Xianfang; Liu Baojun; Zheng Xingyun

1994-08-01

It was showed that the dry weight and grain yield of rice were 2.3%∼12.7% and 1.6%∼11.8% higher respectively than those of urea applied alone when urea applied with cow slurry, rare-earth, Maifanshi, calcium chloride and dicyandiamine (DCD). Among the treatments, DCD and Maifanshi increased the nitrogen use efficiency of urea from 4.3 kg grain/kg N applied when urea applied alone to 10.7 kg grain and 12.5 kg grain per kg N applied. It was shown from 15 N tracing experiment that the nitrogen uptake efficiency of urea for rice when applied alone was 20.6% while 25.9, 26.3, 24.0, 28.3 and 27.9% respectively when applied with cow slurry, rare-earth, maifanshi, calcium chloride and DCD. Application of urea with above various materials contributed to a apparent effect on increase of nitrogen residue in soil and nitrogen loss (particularly in loss by air) from urea, among which , the best effect was obtained on nitrogen residue in soil from urea when applied with cow slurry and rare-earth, the residues were 30.3% and 27.3% of applied nitrogen respectively, and DCD could decrease the nitrogen loss greatly, from 57.5% of applied nitrogen when applied alone to 36.3% of applied nitrogen. It was also showed that the difference of effect on kinetics of soil available nitrogen between one treatment and another was not significant, but significant difference existed in effect of different treatments on loss of soil nitrogen and soil nitrogen mineralization. Compared with labelled urea applied alone, application with cow slurry and DCD resulted in great decrease in loss of soil nitrogen and soil nitrogen mineralization while not apparent effect for application with rare-earth, calcium chloride and Maifanshi. (7 tabs.)

Physical activity and gastric residuals as biomarkers for region-specific NEC lesions in preterm neonates

DEFF Research Database (Denmark)

Cao, Muqing; Andersen, Anders Daniel; Li, Yanqi

2016-01-01

onset of NEC can be predicted by decreased physical activity during the first few days after birth. Methods: Cesarean-delivered preterm pigs were fed parenteral nutrition and increasing amounts of formula for 5 days after birth (n = 120). Their physical activity was quantified by a continuous camera....... Results: Half of the pigs (48%) showed clear NEC-like lesions on day 5, and these individuals had more adverse clinical symptoms from day 3 but decreased physical activity already from day 2 relative to the unaffected pigs (both p ... physical activity on days 2 and 3, and the increased volume of gastric residuals was specifically related to colon lesions (both p physical activity precedes the clinical symptoms of NEC in the small intestine of preterm pigs, and increased gastric residuals predict NEC...

HECTR [Hydrogen Event Containment Transient Response] Version 1.5N: A modification of HECTR Version 1.5 for application to N Reactor

International Nuclear Information System (INIS)

Camp, A.L.; Dingman, S.E.

1987-05-01

This report describes HECTR Version 1.5N, which is a special version of HECTR developed specifically for application to the N Reactor. HECTR is a fast-running, lumped-parameter containment analysis computer program that is most useful for performing parametric studies. The main purpose of HECTR is to analyze nuclear reactor accidents involving the transport and combustion of hydrogen, but HECTR can also function as an experiment analysis tool and can solve a limited set of other types of containment problems. Version 1.5N is a modification of Version 1.5 and includes changes to the spray actuation logic, and models for steam vents, vacuum breakers, and building cross-vents. Thus, all of the key features of the N Reactor confinement can be modeled. HECTR is designed for flexibility and provides for user control of many important parameters, if built-in correlations and default values are not desired

Short-term residual N unaffected by forbs in grass-clover mixtures

DEFF Research Database (Denmark)

Dhamala, Nawa Raj; Rasmussen, Jim; Cong, Wenfeng

2017-01-01

We determined the effect on residual nitrogen (N) of including forbs (chicory, ribwort plantain and caraway) in perennial ryegrass-red clover mixtures. Although soil N inputs during the grassland phase differed markedly between mixtures, in a pot experiment we found no differences...... in the potentially mineralizable N of the soil or in the dry matter production and N content of the spring barley test crop. The fertilizer value of the grassland mixtures corresponded to 10 g N/m2, irrespective of forb inclusion. Thus, the inclusion of nonlegume forbs did not negatively affect short-term residual N...

Residual analysis applied to S-N data of a surface rolled cast iron

Directory of Open Access Journals (Sweden)

Omar Maluf

2005-09-01

Full Text Available Surface rolling is a process extensively employed in the manufacture of ductile cast iron crankshafts, specifically in regions containing stress concentrators with the main aim to enhance fatigue strength. Such process hardens and introduces compressive residual stresses to the surface as a result of controlled strains, reducing cyclic tensile stresses near the surface of the part. The main purpose of this work was to apply the residual analysis to check the suitability of the S-N approach to describe the fatigue properties of a surface rolled cast iron. The analysis procedure proved to be very efficient and easy to implement and it can be applied in the verification of any other statistical model used to describe fatigue behavior. Results show that the conventional S-N methodology is able to model the high cycle fatigue behavior of surface rolled notch testpieces of a pearlitic ductile cast iron submitted to rotating bending fatigue tests.

Primary amine/CSA ion pair: A powerful catalytic system for the asymmetric enamine catalysis

KAUST Repository

Liu, Chen; Zhu, Qiang; Huang, Kuo-Wei; Lu, Yixin

2011-01-01

A novel ion pair catalyst containing a chiral counteranion can be readily derived by simply mixing cinchona alkaloid-derived diamine with chiral camphorsulfonic acid (CSA). A mixture of 9-amino(9-deoxy)epi-quinine 8 and (-)-CSA was found to be the best catalyst with matching chirality, enabling the direct amination of α-branched aldehydes to proceed in quantitative yields and with nearly perfect enantioselectivities. A 0.5 mol % catalyst loading was sufficient to catalyze the reaction, and a gram scale enantioselective synthesis of biologically important α-methyl phenylglycine has been successfully demonstrated. © 2011 American Chemical Society.

Primary amine/CSA ion pair: A powerful catalytic system for the asymmetric enamine catalysis

KAUST Repository

Liu, Chen

2011-05-20

A novel ion pair catalyst containing a chiral counteranion can be readily derived by simply mixing cinchona alkaloid-derived diamine with chiral camphorsulfonic acid (CSA). A mixture of 9-amino(9-deoxy)epi-quinine 8 and (-)-CSA was found to be the best catalyst with matching chirality, enabling the direct amination of α-branched aldehydes to proceed in quantitative yields and with nearly perfect enantioselectivities. A 0.5 mol % catalyst loading was sufficient to catalyze the reaction, and a gram scale enantioselective synthesis of biologically important α-methyl phenylglycine has been successfully demonstrated. © 2011 American Chemical Society.

MODEL FOR THE CORRECTION OF THE SPECIFIC GRAVITY OF BIODIESEL FROM RESIDUAL OIL

Directory of Open Access Journals (Sweden)

Tatiana Aparecida Rosa da Silva

2013-06-01

Full Text Available Biodiesel is a important fuel with economic benefits, social and environmental. The production cost of the biodiesel can be significantly lowered if the raw material is replaced by a alternative material as residual oil. In this study, the variation of specific gravity with temperature increase for diesel and biodiesel from residual oil obtained by homogeneous basic catalysis. All properties analyzed for biodiesel are within specification Brazil. The determination of the correction algorithm for the specific gravity function of temperature is also presented, and the slope of the line to diesel fuel, methylic biodiesel (BMR and ethylic biodiesel (BER from residual oil were respectively the values -0.7089, -0.7290 and -0.7277. This demonstrates the existence of difference of the model when compared chemically different fuels, like diesel and biodiesel from different sources, indicating the importance of determining the specific algorithm for the operations of conversion of volume to the reference temperature.

Caracterización de biodiesel obtenido de aceite residual de cocina

Directory of Open Access Journals (Sweden)

Betselene Murcia Ordoñez

2013-01-01

Full Text Available Título corto: Biodiesel de aceite residual de cocina Título en ingles: "Characterization of Biodiesel obtained from waste cooking oil" Resumen Se realizó un análisis físico y químico a cada uno de los siguientes tipos de aceite: desechado proveniente de asaderos de pollo, usado de hogares y fresco adquirido en el mercado local de la ciudad de Florencia, Caquetá (Colombia. Se evaluaron los siguientes parámetros: Peso específico, índice de yodo, índice de saponificación, índice de refracción, humedad y materia volátil, punto de fusión, impurezas insolubles, índice de acidez, coeficiente específico de extinción valores K232 y K270, color y prueba de Kreiss. Igualmente se evaluaron los espectros UV-VIS de los tres tipos de aceite estudiados. Se ensayaron siete diferentes tipos de catalizadores para la reacción de transesterificación manteniendo en todos los casos la proporción de catalizador: aceite 38:190 (v/v, tiempo de reacción (2h y temperatura de reacción (60°C. Se lograron rendimientos de biodiesel de 75.8% de aceite desechado usando KOH 1,269%p/v/MeOH 99%; 87.50% de aceite usado con KOH 0,537%p/v/MeOH 99% y 86.60% de aceite fresco usando KOH 0,457%p/v/MeOH 99%. Al biodiesel obtenido en cada caso se le determinó peso específico, índice de refracción, humedad y materia volátil, cenizas sulfatadas, carbón residual, corrosión a la lámina de cobre y perfil de ácidos grasos. En todos los casos hubo predominio de ácido  palmítico, ácido  oléico y ácido  esteárico en los aceites usados y desechados. Del análisis por cromatografía de gases acoplada a espectrometría de masas se pudo establecer que el contenido total de ésteres metílicos de ácidos  grasos es del 98,38% para el biodiesel de aceite desechado; 99,53% para el biodiesel de aceite usado y 97, 69% para el biodiesel de aceite fresco. Palabras clave: aceite residual de cocina; biodiesel; ácidos grasos; transesterificación Abstract Aphysical and

Empirical correlation between protein backbone {sup 15}N and {sup 13}C secondary chemical shifts and its application to nitrogen chemical shift re-referencing

Energy Technology Data Exchange (ETDEWEB)

Wang Liya [Cold Spring Harbor Laboratory (United States); Markley, John L. [University of Wisconsin, Biochemistry Department (United States)], E-mail: markley@nmrfam.wisc.edu

2009-06-15

The linear analysis of chemical shifts (LACS) has provided a robust method for identifying and correcting {sup 13}C chemical shift referencing problems in data from protein NMR spectroscopy. Unlike other approaches, LACS does not require prior knowledge of the three-dimensional structure or inference of the secondary structure of the protein. It also does not require extensive assignment of the NMR data. We report here a way of extending the LACS approach to {sup 15}N NMR data from proteins, so as to enable the detection and correction of inconsistencies in chemical shift referencing for this nucleus. The approach is based on our finding that the secondary {sup 15}N chemical shift of the backbone nitrogen atom of residue i is strongly correlated with the secondary chemical shift difference (experimental minus random coil) between the alpha and beta carbons of residue i - 1. Thus once alpha and beta {sup 13}C chemical shifts are available (their difference is referencing error-free), the {sup 15}N referencing can be validated, and an appropriate offset correction can be derived. This approach can be implemented prior to a structure determination and can be used to analyze potential referencing problems in database data not associated with three-dimensional structure. Application of the LACS algorithm to the current BMRB protein chemical shift database, revealed that nearly 35% of the BMRB entries have {delta}{sup 15}N values mis-referenced by over 0.7 ppm and over 25% of them have {delta}{sup 1}H{sup N} values mis-referenced by over 0.12 ppm. One implication of the findings reported here is that a backbone {sup 15}N chemical shift provides a better indicator of the conformation of the preceding residue than of the residue itself.

Networks of High Mutual Information Define the Structural Proximity of Catalytic Sites: Implications for Catalytic Residue Identification

DEFF Research Database (Denmark)

Buslje, Cristina Marino; Teppa, Elin; Di Doménico, Tomas

2010-01-01

other non-functional conserved residues. Using a data set of 434 Pfam families included in the catalytic site atlas (CSA) database, we tested this hypothesis and demonstrated that MI can complement amino acid conservation scores to detect CR. The Kullback-Leibler (KL) conservation measurement was shown.......90, the Cls method was found to have a sensitivity of 0.816. In summary, we demonstrate that networks of residues with high MI provide a distinct signature on CR and propose that such a signature should be present in other classes of functional residues where the requirement to maintain a particular function...

Mutations at the S1 sites of methionine aminopeptidases from Escherichia coli and Homo sapiens reveal the residues critical for substrate specificity.

Science.gov (United States)

Li, Jing-Ya; Cui, Yong-Mei; Chen, Ling-Ling; Gu, Min; Li, Jia; Nan, Fa-Jun; Ye, Qi-Zhuang

2004-05-14

Methionine aminopeptidase (MetAP) catalyzes the removal of methionine from newly synthesized polypeptides. MetAP carries out this cleavage with high precision, and Met is the only natural amino acid residue at the N terminus that is accepted, although type I and type II MetAPs use two different sets of residues to form the hydrophobic S1 site. Characteristics of the S1 binding pocket in type I MetAP were investigated by systematic mutation of each of the seven S1 residues in Escherichia coli MetAP type I (EcMetAP1) and human MetAP type I (HsMetAP1). We found that Tyr-65 and Trp-221 in EcMetAP1, as well as the corresponding residues Phe-197 and Trp-352 in HsMetAP1, were essential for the hydrolysis of a thiopeptolide substrate, Met-S-Gly-Phe. Mutation of Phe-191 to Ala in HsMetAP1 caused inactivity in contrast to the full activity of EcMetAP1(Y62A), which may suggest a subtle difference between the two type I enzymes. The more striking finding is that mutation of Cys-70 in EcMetAP1 or Cys-202 in HsMetAP1 opens up the S1 pocket. The thiopeptolides Leu-S-Gly-Phe and Phe-S-Gly-Phe, with previously unacceptable Leu or Phe as the N-terminal residue, became efficient substrates of EcMetAP1(C70A) and HsMetAP1(C202A). The relaxed specificity shown in these S1 site mutants for the N-terminal residues was confirmed by hydrolysis of peptide substrates and inhibition by reaction products. The structural features at the enzyme active site will be useful information for designing specific MetAP inhibitors for therapeutic applications.

Regeneration of Used Frying Palm Oil with Coffee Silverskin (CS), CS Ash (CSA) and Nanoparticles of CS (NCS).

Science.gov (United States)

Ismail, Samir Abd-Elmonem A; El-Anany, Ayman Mohammed; Ali, Rehab Farouk M

2017-01-01

The present investigation aimed to evaluate the efficiency of coffee silverskin (CS), CS ash (CSA) and nanoparticles of CS (NCS) in regeneration the quality of used frying palm oil. The adsorbents were mixed individually with used frying palm oil at level 4% (w/v) for 60 min. The properties of CS, CSA and NCS adsorbents were studied using (SEM) scanning electron microscopy technique. Some of physico-chemical characteristics of used frying palm oil (UFPO) and UFPO treated with adsorbents were determined. The results showed that the CS ash particles composed of irregular spherical and semispherical grains with deep cavities. The size of particles of CS ash ranged in diameter from 1.1 to 1.7 µm. The morphology of NCS consisted of cluster-type spherical nanoparticles and flakes. The particle size of NCS varies from 0.9 to 1.7 µm. Purification treatments caused marked (poil compared to untreated oil. The treatment of UFPO with 4% of adsorbents caused significant reductions in the content of free fatty acids ranged from 51.2 to 65.0%. The lowest level of peroxide (2.1 meq/kg) was recorded for UFPO treated with 4% of NCS. The highest reductions (72.8; 70.0%) in p-anisidine value were observed in UFPO treated with 4% of CSA and NCS, respectively. Treatment of UFPO with 4% of CS, CSA and NCS significantly lowered the polar content from 13.9% to 6.3, 4.8 and 3.9%, respectively. The results also indicate that CSA and NCS have nearly the same adsorption efficiency in lowering polymer content of UFPO. Filtration treatment of UFPO with 4% of CS, CSA and NCS markedly lowered the viscosity and colour values of treated UFPO.

40 CFR 180.303 - Oxamyl; tolerances for residues.

Science.gov (United States)

2010-07-01

... PROGRAMS TOLERANCES AND EXEMPTIONS FOR PESTICIDE CHEMICAL RESIDUES IN FOOD Specific Tolerances § 180.303... methyl N,N-dimethyl-N-hydroxy-1-thiooxamimidate calculated as oxamyl in or on the following food..., nonbell 5.0 Pineapple 1 Pineapple, process residue 2.0 Pumpkin 2.0 Soybean, seed 0.1 Spearmint, tops 10.0...

Synthesis of 15N-enriched fertilizers. Pt. II. Synthesis of 15N-enriched urea

International Nuclear Information System (INIS)

Bondassolli, J.A.; Trivelin, P.C.O.; Mortatti, J.; Victoria, R.L.

1988-01-01

The results of studies on the production of 15 N-urea through the reaction between 15 N-enriched anhidrous ammonia, carbon monoxide and sulfur, using hydrogen sulfite as a auto catalizers and methyl alcohol as a liquid reaction medium is presented. The influence of the quantities of reagents on final yield of synthesised urea were studied. Analysis of the cost of 5 Atoms % 15 N-enriched urea were made. (M.A.C.) [pt

Fate of 15N applied as ammonium sulphate to a bean crop

International Nuclear Information System (INIS)

Cervellini, A.; Ruschel, A.P.; Matsui, E.

1980-01-01

An instrumented 10 X 10-m site was used to study the fate of 15 N-labelled ammonium sulphate (3.289 atom 15 N % excess) applied at the rate of 100 kg N.ha -1 with P and K supplements. Data were collected for the year January through December, 1977. The first bean crop (Phaseolus vulgaris, L) was planted in March, followed by the fertilizer, and harvested three months later. The plot was left fallow for three months when a second bean crop was planted without further fertilizer. The data indicated that the total drainage (22 cm) represented approximately 16% of the total water input (precipitation plus irrigation). It was estimated that nitrate leaching below the 120-cm depth was equivalent to approximately 16 kg N.ha -1 of which less than 10% was derived from the labelled fertilizer. The low recovery of labelled fertilizer (30%) by the first total harvest of straw and grain, and the less than 2.5% further recovery of initial labelled fertilizer by the second crop, suggest high immobilization by the soil-plant residue system. (author)

Effect of paddy urease inhibitors on fate of 15N-urea

International Nuclear Information System (INIS)

Chen Wei; Lu Wanfang

1997-01-01

Urea applied to the paddy field rapidly released ammonium (NH 4 + ) through hydrolysis. The released NH 4 + -N usually reached to a maximum value 2 days after the application. The maximum value was found to be lower and delay 1 day when a mixture of urea and urease inhibitors was applied. Based on 15 N tracing in the urea, it was found that the two urease inhibitors, phenylphosphordiamidate (PPD) and N-(N-butyl) thiophosphoric triamine (NBPT), could enhance the efficiency of urea utilization by rice plants due to more absorption and also stimulated rice growth. The grain yields were higher in the treatments applied with the mixture containing PPD or NBPT, especially at high N level, than that in the treatment applied with urea only. However, the urea inhibitor, hydroquinone (HQ), had far less effect than PPD and NBPT in the experiment. The application of rice straw was found to reduce the urea-N absorption by rice plants but increase its residue in the soil

Lignin biochemistry and soil N determine crop residue decomposition and soil priming

Science.gov (United States)

Cropping history can affect soil properties, including available N, but little is known about the interactive effects of residue biochemistry, temperature and cropping history on residue decomposition. A laboratory incubation examined the role of residue biochemistry and temperature on the decomposi...

Complete fusion of the 12C+12O, 14N+12C and 15N+12C systems

International Nuclear Information System (INIS)

Conjeaud, M.; Gary, S.; Harar, S.; Wieleczko, J.P.

1978-01-01

Cross sections for evaporation residues following the complete fusion of the 12 C+ 12 C, 14 N+ 12 C and 15 N+ 12 C systems have been measured with a E-ΔE counter telescope in a wide range of incident energies. They are fairly well reproduced by evaporation calculations based on the statistical theory. The total fusion excitation function of the 12 C+ 12 C system shows strong structure, which is compared to the predictions of the reaction cross sections derived from coupled channel calculations and to the integrated inelastic cross sections. Critical angular momenta have been obtained from the fusion cross-section data and these values are discussed in the framework of compound nucleus and entrance channel effects. A striking difference is observed between the fusion cross sections of the 14 N+ 12 C and 15 N+ 12 C systems and shows the importance of the valence nucleons of colliding ions in the fusion process. A possible interpretation might be the influence of the yrast line of the compound nuclei. (Auth.)

Study of the reaction π-p→ωn in the 15-40 GeV/c momentum range

International Nuclear Information System (INIS)

Saleem, M.; Shaukat, M.A.

1981-08-01

Recent measurements of differential cross sections and density matrix elements for the reaction π - p→ωn in the 15-40 GeV/c momentum range and for 0 2 have been fitted by using a simple Regge pole model with phenomenological residue functions. (author)

Changes in mineral 15 N from soils treated with 15 N-urea and 15 N-vinasse incorporated or not to sugar cane straw

International Nuclear Information System (INIS)

Silva, Vilma M.; Colaco, Waldeciro; Encarnacao, Fernando A.F.

1999-01-01

Changes in N derived from 15 N sources (urea and vinasse), applied to two soils differing in texture (PV sandy, LR clayey), incorporated or not to sugar cane straw (dry leaves and sheathes) and incubated in an open system for 35 days, were evaluated through an isotope technique. Soil samples were collected 7, 14, 21, 28 and 35 days after applications to determine nitrogen fractions (total-N, N H 4 + - N and NO 3 - - N) derived from the labelled sources. Mineral N was taken as the sum of N H 4 + - N and N H 3 - -N. 15 N-abundances were determined in the concentrated extracts of these fractions. The mineral N net transformation rates were found from the mineral N obtained by taking the difference between the values of two subsequent incubation times. The results showed that mineral N transformation rates were initially positives in the treatments of 15 N-urea, and significantly higher (10,30 mg kg -1 d -1 , PV and 8,08 mg kg -1 d -1 , LR) than those obtained in the treatments with 15 N vinasse (1,11 mg kg -1 dia -1 , PV and 0,55 mg kg -1 dia -1 , LR). In general terms, mineral-N net transformation rates were negative (0,06 and 0,26 mg.kg -1 d -1 , PV; -1,44 and 0,07 mg.kg -1 .d -1 , LR, respective;y for urea and vinasse) indicating prevalence of immobilization. The results also showed small fluctuations among treatments at some of the incubation periods, which reflects the influence of characteristics and properties of both soils. (author)

Charge Sensitive Amplifier (CSA) in cold gas of Liquid Argon (LAr) Time Projection Chamber (TPC)

International Nuclear Information System (INIS)

Bechetoille, E; Mathez, H; Zoccarato, Y

2011-01-01

This paper presents our work on a 8-channel low noise Front-End electronic coupled to a Liquid Argon (LAr) TPC (Time Projection Chamber). Each channel consists of a Charge Sensitive Amplifier (CSA), a band pass filter and a 50 Ohms buffer as line driver. A serial link based on a 'i2c-like' protocol, provides multiple configuration features to the circuit by accessing slow control registers. In this paper, we describe the CSA, the shaper and the slow control part. The feedback network of the CSA is made of a capacitance and a resistor. Their values are respectively 250 fF and 4 MΩ. An input referred noise of, at most, 1500 e- rms must be achieved at -100 deg. C with an input detector capacitance of 250 pF to ensure a correct measurement of the minimal signal of 18000e- (2.88 fC). The power consumption in this cryogenic setup must be less than 40 mW from a 3.3 V power supply.

Using {sup 15}N to study the effect of additament on N balance of urea

Energy Technology Data Exchange (ETDEWEB)

Jiarong, Pan; Xianfang, Wen; Baojun, Liu; Xingyun, Zheng [Institute for Application of Atomic Energy, Chinese Academy of Agricultural Sciences, Beijing (China)

1994-08-01

It was showed that the dry weight and grain yield of rice were 2.3%{approx}12.7% and 1.6%{approx}11.8% higher respectively than those of urea applied alone when urea applied with cow slurry, rare-earth, Maifanshi, calcium chloride and dicyandiamine (DCD). Among the treatments, DCD and Maifanshi increased the nitrogen use efficiency of urea from 4.3 kg grain/kg N applied when urea applied alone to 10.7 kg grain and 12.5 kg grain per kg N applied. It was shown from {sup 15}N tracing experiment that the nitrogen uptake efficiency of urea for rice when applied alone was 20.6% while 25.9, 26.3, 24.0, 28.3 and 27.9% respectively when applied with cow slurry, rare-earth, maifanshi, calcium chloride and DCD. Application of urea with above various materials contributed to a apparent effect on increase of nitrogen residue in soil and nitrogen loss (particularly in loss by air) from urea, among which , the best effect was obtained on nitrogen residue in soil from urea when applied with cow slurry and rare-earth, the residues were 30.3% and 27.3% of applied nitrogen respectively, and DCD could decrease the nitrogen loss greatly, from 57.5% of applied nitrogen when applied alone to 36.3% of applied nitrogen. It was also showed that the difference of effect on kinetics of soil available nitrogen between one treatment and another was not significant, but significant difference existed in effect of different treatments on loss of soil nitrogen and soil nitrogen mineralization. Compared with labelled urea applied alone, application with cow slurry and DCD resulted in great decrease in loss of soil nitrogen and soil nitrogen mineralization while not apparent effect for application with rare-earth, calcium chloride and Maifanshi. (7 tabs.).

Redox-controlled backbone dynamics of human cytochrome c revealed by 15N NMR relaxation measurements

International Nuclear Information System (INIS)

Sakamoto, Koichi; Kamiya, Masakatsu; Uchida, Takeshi; Kawano, Keiichi; Ishimori, Koichiro

2010-01-01

Research highlights: → The dynamic parameters for the backbone dynamics in Cyt c were determined. → The backbone mobility of Cyt c is highly restricted due to the covalently bound heme. → The backbone mobility of Cyt c is more restricted upon the oxidation of the heme. → The redox-dependent dynamics are shown in the backbone of Cyt c. → The backbone dynamics of Cyt c would regulate the electron transfer from Cyt c. -- Abstract: Redox-controlled backbone dynamics in cytochrome c (Cyt c) were revealed by 2D 15 N NMR relaxation experiments. 15 N T 1 and T 2 values and 1 H- 15 N NOEs of uniformly 15 N-labeled reduced and oxidized Cyt c were measured, and the generalized order parameters (S 2 ), the effective correlation time for internal motion (τ e ), the 15 N exchange broadening contributions (R ex ) for each residue, and the overall correlation time (τ m ) were estimated by model-free dynamics formalism. These dynamic parameters clearly showed that the backbone dynamics of Cyt c are highly restricted due to the covalently bound heme that functions as the stable hydrophobic core. Upon oxidation of the heme iron in Cyt c, the average S 2 value was increased from 0.88 ± 0.01 to 0.92 ± 0.01, demonstrating that the mobility of the backbone is further restricted in the oxidized form. Such increases in the S 2 values were more prominent in the loop regions, including amino acid residues near the thioether bonds to the heme moiety and positively charged region around Lys87. Both of the regions are supposed to form the interaction site for cytochrome c oxidase (CcO) and the electron pathway from Cyt c to CcO. The redox-dependent mobility of the backbone in the interaction site for the electron transfer to CcO suggests an electron transfer mechanism regulated by the backbone dynamics in the Cyt c-CcO system.

Compound-specific nitrogen isotope analysis of D-alanine, L-alanine, and valine: application of diastereomer separation to delta15N and microbial peptidoglycan studies.

Science.gov (United States)

Takano, Yoshinori; Chikaraishi, Yoshito; Ogawa, Nanako O; Kitazato, Hiroshi; Ohkouchi, Naohiko

2009-01-01

We have developed an analytical method to determine the compound-specific nitrogen isotope compositions of individual amino acid enantiomers using gas chromatography/combustion/isotope ratio mass spectrometry. A novel derivatization of amino acid diastereomers by optically active (R)-(-)-2-butanol or (S)-(+)-2-butanol offers two advantages for nitrogen isotope analysis. First, chromatographic chiral separation can be achieved without the use of chiral stationary-phase columns. Second, the elution order of these compounds on the chromatogram can be switched by a designated esterification reaction. We applied the method to the compound-specific nitrogen isotope analysis of D- and L-alanine in a peptidoglycan derived from the cell walls of cultured bacteria (Firmicutes and Actinobacteria; Enterococcus faecalis, Staphylococcus aureus, Staphylococcus staphylolyticus, Lactobacillus acidophilus, Bacillus subtilis, Micrococcus luteus, and Streptomyces sp.), natural whole bacterial cells (Bacillus subtilis var. natto), (pseudo)-peptidoglycan from archaea (Methanobacterium sp.), and cell wall from eukaryota (Saccharomyces cerevisiae). We observed statistically significant differences in nitrogen isotopic compositions; e.g., delta15N ( per thousand vs air) in Staphylococcus staphylolyticus for d-alanine (19.2 +/- 0.5 per thousand, n = 4) and L-alanine (21.3 +/- 0.8 per thousand, n = 4) and in Bacillus subtilis for D-alanine (6.2 +/- 0.2 per thousand, n = 3) and L-alanine (8.2 +/- 0.4 per thousand, n = 3). These results suggest that enzymatic reaction pathways, including the alanine racemase reaction, produce a nitrogen isotopic difference in amino acid enantiomers, resulting in 15N-depleted D-alanine. This method is expected to facilitate compound-specific nitrogen isotope studies of amino acid stereoisomers.

Distribution of nitrogen ammonium sulfate ({sup 15}N) soil-plant system in a no-tillage crop succession; Distribuicao do nitrogenio do sulfato de amonio ({sup 15}N) no sistema solo-planta, em uma sucessao de culturas, sob sistema plantio direto

Energy Technology Data Exchange (ETDEWEB)

Fernandes, Flavia Carvalho da Silva, E-mail: flcsfernandes@gmail.com [Universidade Estadual de Maringa - Campus de Umuarama, PR (Brazil); Libardi, Paulo Leonel, E-mail: pllibard@esalq.usp.br [Departamento de Engenharia de Biossistemas, Escola Superior de Agricultura Luiz de Queiroz, Piracicaba, SP (Brazil)

2012-05-15

the n use by maize (Zea mays, l.) is affected by n-fertilizer levels. this study was conducted using a sandy-clay texture soil (Hapludox) to evaluate the efficiency of n use by maize in a crop succession, based on {sup 15}N labeled ammonium sulfate (5.5 atom %) at different rates, and to assess the residual fertilizer effect in two no-tillage succession crops (signal grass and corn). Two maize crops were evaluated, the first in the growing season 2006, the second in 2007, and brachiaria in the second growing season. The treatments consisted of n rates of 60, 120 and 180 kg ha{sup -1}in the form of labeled {sup 15}N ammonium sulfate. This fertilizer was applied in previously defined subplots, only to the first maize crop (growing season 2006). The variables total accumulated n; fertilizer-derived n in corn plants and pasture; fertilizer-derived n in the soil; and recovery of fertilizer-n by plants and soil were evaluated.The highest uptake of fertilizer n by corn was observed after application of 120 kg ha{sup -1}N and the residual effect of n fertilizer on subsequent corn and brachiaria was highest after application of 180 kg ha{sup -1}N. After the crop succession, soil n recovery was 32, 23 and 27 % for the respective applications of 60, 120 and 180 kg ha{sup -1}N. (author)

Nitrogen mineralization and denitrification as influenced by crop residue particle size

DEFF Research Database (Denmark)

Ambus, P.; Jensen, E.S.

1997-01-01

1: N-15-labelled ground (less than or equal to 3 mm) and cut (25 mm) barley residue, and microcrystalline cellulose+glucose were mixed into a sandy loam soil with additional inorganic N. Experiment 2: inorganic N-15 and C2H2 were added to soils with barley and pea material after 3, 26, and 109 days......Managing the crop residue particle size has the potential to affect N conservation in agricultural systems. We investigated the influence of barley (Hordeum vulgare) and pea (Pisum sativum) crop residue particle size on N mineralization and denitrification in two laboratory experiments. Experiment...... for measuring gross N mineralization and denitrification. Net N immobilization over 60 days in Experiment 1 cumulated to 63 mg N kg(-1) soil (ground barley), 42 (cut barley), and 122 (cellulose+glucose). More N was seemingly net mineralized from ground barley (3.3 mg N kg(-1) soil) than from cut barley (2.7 mg...

High avidity antibodies to full-length VAR2CSA correlate with absence of placental malaria.

Directory of Open Access Journals (Sweden)

Yeung Lo Tutterrow

Full Text Available VAR2CSA mediates sequestration of Plasmodium falciparum-infected erythrocytes in the placenta, increasing the risk of poor pregnancy outcomes. Naturally acquired antibodies (Ab to placental parasites at delivery have been associated with improved pregnancy outcomes, but Ab levels and how early in pregnancy Ab must be present in order to eliminate placental parasites before delivery remains unknown. Antibodies to individual Duffy-binding like domains of VAR2CSA have been studied, but the domains lack many of the conformational epitopes present in full-length VAR2CSA (FV2. Thus, the purpose of this study was to describe the acquisition of Ab to FV2 in women residing in high and low transmission areas and determine how Ab levels during pregnancy correlate with clearance of placental parasites. Plasma samples collected monthly throughout pregnancy from pregnant women living in high and low transmission areas in Cameroon were evaluated for Ab to FV2 and the proportion of high avidity Ab (i.e., Ab that remain bound in the presence of 3M NH(4SCN was assessed. Ab levels and proportion of high avidity Ab were compared between women with placental malaria (PM(+ and those without (PM(- at delivery. Results showed that PM(- women had significantly higher Ab levels (p = 0.0047 and proportion of high avidity Ab (p = 0.0009 than PM(+ women throughout pregnancy. Specifically, women with moderate to high Ab levels (>5,000 MFI and those with ≥ 35% high avidity Ab at 5-6 months were found to have 2.3 (95% CI, 1.0-4.9 and 7.6-fold (p = 0.0013, 95% CI: 1.2-50.0 reduced risk of placental malaria, respectively. These data show that high levels of Ab to FV2, particularly those with high avidity for FV2, produced by mid-pregnancy are important in clearing parasites from the placenta. Both high Ab levels and proportion of high avidity Ab to FV2 may serve as correlates of protection for assessing immunity against placental malaria.

Analysis of IgG with specificity for variant surface antigens expressed by placental Plasmodium falciparum isolates

Directory of Open Access Journals (Sweden)

Kremsner Peter G

2004-07-01

Full Text Available Abstract Background Pregnancy-associated malaria (PAM is caused by Plasmodium falciparum-infected erythrocytes that can sequester in placental intervillous space by expressing particular variant surface antigens (VSA that can mediate adhesion to chondroitin sulfate A (CSA in vitro. IgG antibodies with specificity for the VSA expressed by these parasites (VSAPAM are associated with protection from maternal anaemia, prematurity and low birth weight, which is the greatest risk factor for death in the first month of life. Methods In this study, the development of anti-VSAPAM antibodies in a group of 151 women who presented to the maternity ward of Albert Schweitzer Hospital in Lambaréné, Gabon for delivery was analysed using flow cytometry assays. Plasma samples from placenta infected primiparous women were also investigated for their capacity to inhibit parasite binding to CSA in vitro. Results In the study cohort, primiparous as well as secundiparous women had the greatest risk of infection at delivery as well as during pregnancy. Primiparous women with infected placentas at delivery showed higher levels of VSAPAM-specific IgG compared to women who had no malaria infections at delivery. Placental isolates of Gabonese and Senegalese origin tested on plasma samples from Gabon showed parity dependency and gender specificity patterns. There was a significant correlation of plasma reactivity as measured by flow cytometry between different placental isolates. In the plasma of infected primiparous women, VSAPAM-specific IgG measured by flow cytometry could be correlated with anti-adhesion antibodies measured by the inhibition of CSA binding. Conclusion Recognition of placental parasites shows a parity- and sex- dependent pattern, like that previously observed in laboratory strains selected to bind to CSA. Placental infections at delivery in primiparous women appear to be sufficient to induce functional antibodies which can both recognize the surface of

15N Hyperpolarization of Imidazole-15N2 for Magnetic Resonance pH Sensing via SABRE-SHEATH.

Science.gov (United States)

Shchepin, Roman V; Barskiy, Danila A; Coffey, Aaron M; Theis, Thomas; Shi, Fan; Warren, Warren S; Goodson, Boyd M; Chekmenev, Eduard Y

2016-06-24

15 N nuclear spins of imidazole- 15 N 2 were hyperpolarized using NMR signal amplification by reversible exchange in shield enables alignment transfer to heteronuclei (SABRE-SHEATH). A 15 N NMR signal enhancement of ∼2000-fold at 9.4 T is reported using parahydrogen gas (∼50% para-) and ∼0.1 M imidazole- 15 N 2 in methanol:aqueous buffer (∼1:1). Proton binding to a 15 N site of imidazole occurs at physiological pH (p K a ∼ 7.0), and the binding event changes the 15 N isotropic chemical shift by ∼30 ppm. These properties are ideal for in vivo pH sensing. Additionally, imidazoles have low toxicity and are readily incorporated into a wide range of biomolecules. 15 N-Imidazole SABRE-SHEATH hyperpolarization potentially enables pH sensing on scales ranging from peptide and protein molecules to living organisms.

Testing CAN/CSA-N288.1-M87 (Air-to-forage-to-milk or -beef pathways for 131I and 137Cs and the water-to-fish and sediment pathways for 137Cs) against post-Chernobyl observations

International Nuclear Information System (INIS)

Peterson, S-R.

1993-05-01

The Canadian Standards Association's 'Guidelines for Calculating Derived Release Limits for Radioactive Material in Airborne and Liquid Effluents for Normal Operation of Nuclear Facilities' (CAN/CSA-N288.1-M87) is a steady-state chronic release model. Although it has been assumed that (because dose calculations involve several steps and because each step has some degree of conservatism) predictions usually should be conservative, the model had not been tested. An opportunity to test the model arose due to the activities of BIOMOVS (Biospheric Model Validation Study), which developed several scenarios with which to assess model performance. Each of these scenarios asked for predictions for several steps in the pathways studied (e.g., deposition, concentrations in forage and concentrations in milk or meat). The first of these, Scenario B1, was a chronic release over 30 years of 131 I and 137 Cs; predictions of CSA-N288.1-M87 have been compared with those of the sixteen models participating in the scenario. Scenario A4 was developed using world-wide 131 I and 137 Cs data from the Chernobyl accident, and from the following six months. Predictions made using CSA-N288.1-M87 were compared with observations. In addition, the results were compared with those of the 25 participating models. Finally, the model was used to calculate 137 Cs concentrations in water, sediment and fish in a Swedish lake for 18 months post-Chernobyl, for comparison with observations and other predictions. As assumed, most of the transfer parameters are conservative, so that the predictions are usually conservative for a source term of atmospheric 131 I. However, estimates of deposition for both 131 I and 137 Cs are not conservative, which has profound implications for estimating external dose. Furthermore, at some of the sites in the A4 Scenario, concentrations in milk and beef are underestimated for 137C s, which suggests that the transfer parameters are not as conservative as might be desired

Nitrogen Transfer from Cover Crop Residues to Onion Grown under Minimum Tillage in Southern Brazil

Directory of Open Access Journals (Sweden)

Leoncio de Paula Koucher

2017-08-01

Full Text Available ABSTRACT Nitrogen derived from cover crop residues may contribute to the nutrition of onion grown under minimum tillage (MT and cultivated in rotation. The aim of this study was to evaluate the N transferred from different cover crop residues to the onion crop cultivated under MT in southern Brazil. In June 2014, oilseed radish, black oat, and oilseed radish + black oat residues labeled with 15N were deposited on the soil surface before transplanting onions. During the growth season and at harvest, young expanded onion leaves, complete plants, and samples from different soil layers were collected and analyzed for recovery of 15N-labeled residue. Oilseed radish decomposed faster than other residues and 4 % of residue N was recovered in leaves and bulbs at harvest, but in general, N in plant organs was derived from sources other than the cover crop residues. In addition, leaf N was in the proper range for all treatments and was adequately mobilized to the bases for bulbing. The N derived from decomposing residues contributed little to onion development and the use of these plants should be chosen based on their advantages for physical and biological soil quality.

Identification and characterization of B-cell epitopes in the DBL4e domain of VAR2CSA

DEFF Research Database (Denmark)

Ditlev, Sisse B; Nielsen, Morten A; Resende, Mafalda

2012-01-01

and is the leading candidate for a placental malaria vaccine. Antibodies induced in rats against the recombinant DBL4e domain of VAR2CSA inhibit the binding of a number of laboratory and field parasite isolates to CSA. In this study, we used a DBL4e peptide-array to identify epitopes targeted by DBL4e...... might be involved in the induction of inhibitory antibodies induced by the recombinant DBL4e domain....

Influence of intermittent preventive treatment on antibodies to VAR2CSA in pregnant Cameroonian women

DEFF Research Database (Denmark)

Babakhanyan, Anna; Tutterrow, Yeung L; Bobbili, Naveen

2016-01-01

Intermittent preventive treatment (IPT) and insecticide-treated bed nets are the standard of care for preventing malaria in pregnant women. Since these preventive measures reduce exposure to malaria, their influence on the antibody (Ab) response to the parasite antigen VAR2CSA was evaluated...... in pregnant Cameroonian women exposed to holoendemic malaria. Ab levels to full-length VAR2CSA (FV2), variants of the six Duffy binding like (DBL) domains, and proportion of high avidity Ab to FV2 were measured longitudinally in 92 women before and 147 women after IPT. As predicted, reduced exposure...

Influence of residual oxygen-15-labeled carbon monoxide radioactivity on cerebral blood flow and oxygen extraction fraction in a dual-tracer autoradiographic method.

Science.gov (United States)

Iwanishi, Katsuhiro; Watabe, Hiroshi; Hayashi, Takuya; Miyake, Yoshinori; Minato, Kotaro; Iida, Hidehiro

2009-06-01

Cerebral blood flow (CBF), cerebral metabolic rate of oxygen (CMRO(2)), oxygen extraction fraction (OEF), and cerebral blood volume (CBV) are quantitatively measured with PET with (15)O gases. Kudomi et al. developed a dual tracer autoradiographic (DARG) protocol that enables the duration of a PET study to be shortened by sequentially administrating (15)O(2) and C(15)O(2) gases. In this protocol, before the sequential PET scan with (15)O(2) and C(15)O(2) gases ((15)O(2)-C(15)O(2) PET scan), a PET scan with C(15)O should be preceded to obtain CBV image. C(15)O has a high affinity for red blood cells and a very slow washout rate, and residual radioactivity from C(15)O might exist during a (15)O(2)-C(15)O(2) PET scan. As the current DARG method assumes no residual C(15)O radioactivity before scanning, we performed computer simulations to evaluate the influence of the residual C(15)O radioactivity on the accuracy of measured CBF and OEF values with DARG method and also proposed a subtraction technique to minimize the error due to the residual C(15)O radioactivity. In the simulation, normal and ischemic conditions were considered. The (15)O(2) and C(15)O(2) PET count curves with the residual C(15)O PET counts were generated by the arterial input function with the residual C(15)O radioactivity. The amounts of residual C(15)O radioactivity were varied by changing the interval between the C(15)O PET scan and (15)O(2)-C(15)O(2) PET scan, and the absolute inhaled radioactivity of the C(15)O gas. Using the simulated input functions and the PET counts, the CBF and OEF were computed by the DARG method. Furthermore, we evaluated a subtraction method that subtracts the influence of the C(15)O gas in the input function and PET counts. Our simulations revealed that the CBF and OEF values were underestimated by the residual C(15)O radioactivity. The magnitude of this underestimation depended on the amount of C(15)O radioactivity and the physiological conditions. This underestimation

Computational design, construction, and characterization of a set of specificity determining residues in protein-protein interactions.

Science.gov (United States)

Nagao, Chioko; Izako, Nozomi; Soga, Shinji; Khan, Samia Haseeb; Kawabata, Shigeki; Shirai, Hiroki; Mizuguchi, Kenji

2012-10-01

Proteins interact with different partners to perform different functions and it is important to elucidate the determinants of partner specificity in protein complex formation. Although methods for detecting specificity determining positions have been developed previously, direct experimental evidence for these amino acid residues is scarce, and the lack of information has prevented further computational studies. In this article, we constructed a dataset that is likely to exhibit specificity in protein complex formation, based on available crystal structures and several intuitive ideas about interaction profiles and functional subclasses. We then defined a "structure-based specificity determining position (sbSDP)" as a set of equivalent residues in a protein family showing a large variation in their interaction energy with different partners. We investigated sequence and structural features of sbSDPs and demonstrated that their amino acid propensities significantly differed from those of other interacting residues and that the importance of many of these residues for determining specificity had been verified experimentally. Copyright © 2012 Wiley Periodicals, Inc.

Boys and CSA Prevention: Issues Surrounding Gender and Approaches for Prevention

Science.gov (United States)

Scholes, Laura; Jones, Christian; Nagel, Michael

2014-01-01

Freda Briggs (2007), a leader in the field of child protection in Australia continues to raise concerns about the vulnerability and victimisation of boys that she believes is substantially under-recognised. She argues that boys have not been well supported by child sexual abuse (CSA) prevention programs with child protection curriculum not yet…

Analysis of the backbone dynamics of capsicein using 15N NMR relaxation rate measurements

International Nuclear Information System (INIS)

Van Heijenoort, C.; Bouaziz, S.; Guittet, E.

1994-01-01

15 N relaxation times T 1 and T 1ρ , and heteronuclear steady state nOes, were measured on capsicein, a 98 residue protein. The classical analysis of these data using directly the Lipari and Szabo formalism was shown to give incoherent results, probably due to the presence of a slow exchange along the whole protein. This global exchange broadening made the usual preliminary evaluation of the overall correlation time of capsicein using the Lipari and Szabo expression for the spectral densities impossible. (authors). 2 figs., 23 refs

The influence of tannin, pectin and polyethylene glycol on attachment of 15N-labelled rumen microorganisms to cellulose

International Nuclear Information System (INIS)

Bento, M.H.L.; Acamovic, T.; Makkar, H.P.S.

2005-01-01

The microbial attachment to and gas production from α-cellulose (Sigma; C-8002) without and with mimosa tannin (MT), pectin (P), polyethylene glycol (PEG), MT + P or MT + PEG, were investigated using the in vitro gas production system. Microbial attachment based on 15 N-labelled rumen microorganisms in the residual pellet after 24 h incubation was estimated, which varied from 113.7 to 161.3 μg 15 N per g residual pellet. C + MT had the lowest microbial attachment (P 2 = 0.84, P 15 N) in the residual pellet measured for C + MT (0.054) and C + MT + P (0.159), compared with the other treatments (0.32 for C; 0.34 for C + P; 0.33 for C + PEG; and 0.33 for C + MT + PEG). A MT concentration of 194 g/kg diet reduced microbial attachment and activity of rumen microorganisms in vitro. Polyethylene glycol counteracted the effect of MT on microbial attachment and activity. Pectin exerted a beneficial effect on attachment and fermentation in the initial hours of incubation. A ratio of pectin to MT of 1:1 improved microbial activity of C + MT but inhibition of microbial activity by MT remained at 24 h as indicated by the lower gas production of C + MT + P compared with the control. The results support the hypothesis that there is considerable interaction between tannins, microbes and non-starch-polysaccharides (NSP) in animal feeds and that these interactions may influence the functional ability of microbes in the gastrointestinal tract of animals. (author)

Compared cycling in a soil-plant system of pea and barley residue nitrogen

DEFF Research Database (Denmark)

Jensen, E.S.

1996-01-01

Field experiments were carried out on a temperate soil to determine the decline rate, the stabilization in soil organic matter and the plant uptake of N from N-15-labelled crop residues. The fate of N from field pea (Pisum sativum L.) and spring barley (Hordeum vulgare L.) residues was followed...... mineralization of N was highly correlated to the concentrations of soluble C and N and the lignin:N ratio of residues. The contribution of residue-derived N to the inorganic N pool was at its maximum 30 DAI (10-55%) and declined to on average 5% after 3 years of decomposition. Residual organic labelled N...... in the top 10 cm soil declined rapidly during the initial 86 DAI for all residue types. Leaching of soluble organic materials may have contributed to this decline. At 216 DAI 72, 59 and 45% of the barley, mature pea and green pea residue N, respectively, were present in organic N-forms in the topsoil. During...

Production of 15N-enriched nitric acid (H15NO3

Directory of Open Access Journals (Sweden)

C. R. Sant Ana Filho

2008-12-01

Full Text Available Techniques that employ 15N have proved to be an important tool in many areas of the agronomic and biomedical sciences. Nevertheless, their use is limited by methodological difficulties and by the price of compounds in the international market. Nitric compounds (15NO3- have attracted the interest of researchers. However, these compounds are not currently produced in Brazil. Thus, in the present work H15NO3 was obtained from the oxidation of anhydrous 15NH3. The method we used differs from the industrial process in that the absorption tower is replaced with a polytetrafluoroethylene-lined, stainless-steel hydration reactor. The process output was evaluated based on the following parameters: reaction temperature; ratio of reagents; pressure and flow of 15NH3(g through the catalyst (Pt/Rh. The results showed that, at the best conditions (500 ºC; 50 % excess O2; 0.4 MPa; and 3.39 g.min-1 of 15NH3, a conversion percentage (N-15NH3 to N-15NO3- of 62.2 %, an overall nitrogen balance (N-15NH3 + N-15NO3- of 86.8 %, and purity higher than 99 % could be obtained.

Study of residual gas adsorption on GaN nanowire arrays photocathode

Energy Technology Data Exchange (ETDEWEB)

Xia, Sihao; Liu, Lei, E-mail: liu1133_cn@sina.com.cn; Diao, Yu; Kong, Yike

2017-05-01

Highlights: • H{sub 2}O is more easily to absorb on the nanowire surface. • The work function increase after residual gas adsorption. • Bandgaps of the nanowire increase slightly. • Absorption coefficient is reduced and moves to higher energy side. - Abstract: In order to find out the influences of residual gas on GaN nanowire arrays photocathode, the optoelectronic properties of adsorption system are calculated on the basis of first principles. Results suggest that the residual gas adsorption will increase the work function and introduce a dipole moment with a direction from the nanowire to the adsorbates. The surface structures are changed and electrons transfer from nanowire to gas molecule. The bandgaps are enhanced after adsorption. Besides, the peak of absorption coefficients is reduced and moves to higher energy side. It is discovered that residual gas will drastically degrade the characteristics and lifetime of GaN nanowire arrays photocathode.

Studies on the protein and amino acid metabolism of laying hens using 15N-labelled casein. 8

International Nuclear Information System (INIS)

Richter, G.

1977-01-01

Four colostomized Leghorn hens were fed, during 6 days, 15 N-labelled casein as sole protein source. Two animals were slaughtered 48 hours, the other two 144 hours after the last 15 N-application. The share of TCE-soluble N in total N averaged 16% for the body parts analysed, i.e. meat, bone, liver, kidneys, oviducts, residual viscera and other. The variation of the lysine, histidine and arginine levels in the body parts ranged from 3.6 to 7.9 g, 1.1 to 3.7 g and 6.4 to 7.4 g in 16.7 g hydrolysate N, respectively. Except for feathers, the analysed body parts contained an excess amount of heavy nitrogen. The degree of labelling was found to depend on the time of slaughtering after the tracer application. In the liver and in the oviduct being metabolically active organs, the 15 N-excess in the total N fraction decreased by 45% between the 2nd and the 6th days after 15 N-feeding, whilst in the meat it went down by 20%. The decline of the 15 N-concentration in the TCE-soluble N compounds was faster than in the total N-fraction. Out of the body samples analysed, the lysine of the liver having 0.26 atom% 15 N-excess was found to be more strongly labelled in hens 1 and 2. The amino acid arginine reached about the same level of labelling, the 15 N-frequency of histidine being the lowest. (author)

Quantifying biological nitrogen fixation of different catch crops, and residual effects of roots and tops on nitrogen uptake in barley using in-situ 15N labelling

DEFF Research Database (Denmark)

Li, Xiaoxi; Sørensen, Peter; Li, F C

2015-01-01

–46 % in macro-roots (0–18 cm soil). Macro-roots represented 31–50 % of total plant N. LBCCs showed similar capacity for soil N extraction as non-LBCCs. After incorporation of LBCC residues, the dry matter and N yields of spring barley were comparable to the effect of 50 kg N fertilisation ha−1, whereas no extra...

Multi-Seasonal Nitrogen Recoveries from Crop Residue in Soil and Crop in a Temperate Agro-Ecosystem.

Science.gov (United States)

Hu, Guoqing; Liu, Xiao; He, Hongbo; Zhang, Wei; Xie, Hongtu; Wu, Yeye; Cui, Jiehua; Sun, Ci; Zhang, Xudong

2015-01-01

In conservation tillage systems, at least 30% of the soil surface was covered by crop residues which generally contain significant amounts of nitrogen (N). However, little is known about the multi-seasonal recoveries of the N derived from these crop residues in soil-crop systems, notably in northeastern China. In a temperate agro-ecosystem, 15N-labeled maize residue was applied to field surfaces in the 1st year (2009). From the 2nd to 4th year (2010-2012), one treatment halted the application of maize residue, whereas the soil in the second treatment was re-applied with unlabeled maize residue. Crop and soil samples were collected after each harvest, and their 15N enrichments were determined on an isotope ratio mass spectrometer to trace the allocation of N derived from the initially applied maize residue in the soil-crop systems. On average, 8.4% of the maize residue N was recovered in the soil-crop in the 1st year, and the vast majority (61.9%-91.9%) was recovered during subsequent years. Throughout the experiment, the cumulative recovery of the residue N in the crop increased gradually (18.2%-20.9%), but most of the residue N was retained in the soil, notably in the 0-10 cm soil layer. Compared to the single application, the sequential residue application significantly increased the recovery of the residue N in the soil profile (73.8% vs. 40.9%) and remarkably decreased the total and the initially applied residue derived mineral N along the soil profile. Our results suggested that the residue N was actively involved in N cycling, and its release and recovery in crop and soil profile were controlled by the decomposition process. Sequential residue application significantly enhanced the retention and stabilization of the initially applied residue N in the soil and retarded its translocation along the soil profile.

Abuse-Specific Self-Schemas and Self-Functioning: A Prospective Study of Sexually Abused Youth

Science.gov (United States)

Feiring, Candice; Cleland, Charles M.; Simon, Valerie A.

2010-01-01

Potential pathways from childhood sexual abuse (CSA) to negative self-schemas to subsequent dissociative symptoms and low global self-esteem were examined in a prospective longitudinal study of 160 ethnically diverse youth with confirmed CSA histories. Participants were interviewed at the time of abuse discovery, when they were 8 to 15 years of…

Nitrogen-15-labeled deoxynucleosides. 3. Synthesis of [3-15N]-2'-deoxyadenosine

International Nuclear Information System (INIS)

Rhee, Young-Sook; Jones, R.A.

1990-01-01

The synthesis of [3- 15 N]-labeled adenine has been reported by several groups. Each of these syntheses followed essentially the same route, in which the 15 N is introduced by nitration of 4-bromoimidazole under forcing conditions using [ 15 N]-HNO 3 . The authors have devised an alternate route which uses an azo coupling reaction for introduction of the 15 N and proceeds through the intermediacy of [5- 15 N]-labeled 5-aminoimidazole-4-carboxamide (AICA). An unrelated route to the [5- 15 N]-labeled 5-amino-imidazole ribonucleoside (AIRs) was recently reported. AICA is a versatile precursor, which is most commonly used for entry into the guanine or isoguanine families, although it is usually used as the AICA-riboside rather than the heterocycle itself. The authors have found that AICA also can be used for the adenine family by cyclization to hypoxanthine using diethoxymethyl acetate in DMF at reflux. Although these conditions are more vigorous than those required for cyclization of 4,5-diaminopyrimidines using this reagent, the reaction works well. In addition, they report high-yield enzymatic conversion of [3- 15 N]-adenine to [3- 15 N]-2'-deoxyadenosine

Modulation of procaspase-7 self-activation by PEST amino acid residues of the N-terminal prodomain and intersubunit linker.

Science.gov (United States)

Alves, Juliano; Garay-Malpartida, Miguel; Occhiucci, João M; Belizário, José E

2017-12-01

Procaspase-7 zymogen polypeptide is composed of a short prodomain, a large subunit (p20), and a small subunit (p10) connected to an intersubunit linker. Caspase-7 is activated by an initiator caspase-8 and -9, or by autocatalysis after specific cleavage at IQAD 198 ↓S located at the intersubunit linker. Previously, we identified that PEST regions made of amino acid residues Pro (P), Glu (E), Asp (D), Ser (S), Thr (T), Asn (N), and Gln (Q) are conserved flanking amino acid residues in the cleavage sites within a prodomain and intersubunit linker of all caspase family members. Here we tested the impact of alanine substitution of PEST amino acid residues on procaspase-7 proteolytic self-activation directly in Escherichia coli. The p20 and p10 subunit cleavage were significantly delayed in double caspase-7 mutants in the prodomain (N18A/P26A) and intersubunit linker (S199A/P201A), compared with the wild-type caspase-7. The S199A/P201A mutants effectively inhibited the p10 small subunit cleavage. However, the mutations did not change the kinetic parameters (k cat /K M ) and optimal tetrapeptide specificity (DEVD) of the purified mutant enzymes. The results suggest a role of PEST-amino acid residues in the molecular mechanism for prodomain and intersubunit cleavage and caspase-7 self-activation.

The contamination of commercial 15N2 gas stocks with 15N-labeled nitrate and ammonium and consequences for nitrogen fixation measurements.

Science.gov (United States)

Dabundo, Richard; Lehmann, Moritz F; Treibergs, Lija; Tobias, Craig R; Altabet, Mark A; Moisander, Pia H; Granger, Julie

2014-01-01

We report on the contamination of commercial 15-nitrogen (15N) N2 gas stocks with 15N-enriched ammonium, nitrate and/or nitrite, and nitrous oxide. 15N2 gas is used to estimate N2 fixation rates from incubations of environmental samples by monitoring the incorporation of isotopically labeled 15N2 into organic matter. However, the microbial assimilation of bioavailable 15N-labeled N2 gas contaminants, nitrate, nitrite, and ammonium, is liable to lead to the inflation or false detection of N2 fixation rates. 15N2 gas procured from three major suppliers was analyzed for the presence of these 15N-contaminants. Substantial concentrations of 15N-contaminants were detected in four Sigma-Aldrich 15N2 lecture bottles from two discrete batch syntheses. Per mole of 15N2 gas, 34 to 1900 µmoles of 15N-ammonium, 1.8 to 420 µmoles of 15N-nitrate/nitrite, and ≥21 µmoles of 15N-nitrous oxide were detected. One 15N2 lecture bottle from Campro Scientific contained ≥11 µmoles of 15N-nitrous oxide per mole of 15N2 gas, and no detected 15N-nitrate/nitrite at the given experimental 15N2 tracer dilutions. Two Cambridge Isotopes lecture bottles from discrete batch syntheses contained ≥0.81 µmoles 15N-nitrous oxide per mole 15N2, and trace concentrations of 15N-ammonium and 15N-nitrate/nitrite. 15N2 gas equilibrated cultures of the green algae Dunaliella tertiolecta confirmed that the 15N-contaminants are assimilable. A finite-differencing model parameterized using oceanic field conditions typical of N2 fixation assays suggests that the degree of detected 15N-ammonium contamination could yield inferred N2 fixation rates ranging from undetectable, detected in field assays. These results indicate that past reports of N2 fixation should be interpreted with caution, and demonstrate that the purity of commercial 15N2 gas must be ensured prior to use in future N2 fixation rate determinations.

Investigation into endogenous N metabolism in 15N-labelled pigs. 1

International Nuclear Information System (INIS)

Bergner, H.; Bergner, U.; Adam, K.

1984-01-01

4 male castrated pigs (55-65 kg) either received a wheat-fish meal diet (1 and 2) or a wheat-horse bean diet (3 and 4) without straw meal supplement (1 and 3) or with a supplement of 20% dry matter (2 and 4). In order to investigate whether a 15 N labelling of the pigs is also possible with a protein excess in the ration, the animals received 24.8 g (1 and 2) and 11.6 g crude protein/kg/sup 0.75/ live weight (3 and 4). During a 10-day 15 N-labelling 385 mg 15 N excess ( 15 N') per kg/sup 0.75/ were applied with 15 N labelling the following quotas of the applied 15 N amount were incorporated: 1 = 10.2%, 2 = 7.2%, 3 = 18.7%, 4 = 14.4%. 15 N excretion in both TCA fractions of feces showed a highly significant positive correlation to the increasing content of crude fibre in the 4 diets. The immediate 15 N incorporation into the TCA-precipitable fraction of feces proves that 15 N enters the large intestine endogenously and serves bacterial protein synthesis. 3 days after the last 15 application the pigs were killed. The values of atom-% 15 N' were determined in the TCA-precipitable blood plasma and in the TCA-precipitable fraction of the liver. The other examined organs and tissues showed smaller differences between the test animals. The results show that the 15 N labelling of tissues and organs of pigs is also possible at a high level of protein supply by means of an oral application of [ 15 N] ammonia salts. (author)

Different effects of CSA and CSB deficiency on sensitivity to oxidative DNA damage.

NARCIS (Netherlands)

H. de Waard (Harm); J. de Wit (Jan); J.-O. Andressoo (Jaan-Olle); C.T.M. van Oostrom (Conny); B. Riis (Bente); A. Weimann (Allan); H.E. Poulsen (Henrik); H. van Steeg (Harry); J.H.J. Hoeijmakers (Jan); G.T.J. van der Horst (Gijsbertus)

2004-01-01

textabstractMutations in the CSA and CSB genes cause Cockayne syndrome, a rare inherited disorder characterized by UV sensitivity, severe neurological abnormalities, and progeriod symptoms. Both gene products function in the transcription-coupled repair (TCR) subpathway of nucleotide excision repair

Sources and transformation of dissolved and particulate organic nitrogen in the North Pacific Subtropical Gyre indicated by compound-specific δ15N analysis of amino acids

Science.gov (United States)

Yamaguchi, Yasuhiko T.; McCarthy, Matthew D.

2018-01-01

This study explores the use of compound-specific nitrogen isotopes of amino acids (δ15NAA) of coupled dissolved and particulate organic nitrogen (DON, PON) samples as a new approach to examine relative sources, transformation processes, and the potential coupling of these two major forms of N cycle in the ocean water column. We measured δ15NAA distributions in high-molecular-weight dissolved organic nitrogen (HMW DON) and suspended PON in the North Pacific Subtropical Gyre (NPSG) from surface to mesopelagic depths. A new analytical approach achieved far greater δ15NAA measurement precision for DON than earlier work, allowing us to resolve previously obscured differences in δ15NAA signatures, both with depth and between ON pools. We propose that δ15N values of total hydrolysable amino acids (THAA) represents a proxy for proteinaceous ON δ15N values in DON and PON. Together with bulk δ15N values, this allows δ15N values and changes in bulk, proteinaceous, and ;other-N; to be directly evaluated. These novel measurements suggest three main conclusions. First, the δ15NAA signatures of both surface and mesopelagic HMW DON suggest mainly heterotrophic bacterial sources, with mesopelagic HMW DON bearing signatures of far more degraded material compared to surface material. These results contrast with a previous proposal that HMW DON δ15NAA patterns are essentially ;pre-formed; by cyanobacteria in the surface ocean, undergo little change with depth. Second, different δ15NAA values and patterns of HMW DON vs. suspended PON in the surface NPSG suggest that sources and cycling of these two N reservoirs are surpisingly decoupled. Based on molecular δ15N signatures, we propose a new hypothesis that production of surface HMW DON is ultimately derived from subsurface nitrate, while PON in the mixed layer is strongly linked to N2 fixation and N recycling. In contrast, the comparative δ15NAA signatures of HMW DON vs. suspended PON in the mesopelagic also suggest a

δ(15) N from soil to wine in bulk samples and proline.

Science.gov (United States)

Paolini, Mauro; Ziller, Luca; Bertoldi, Daniela; Bontempo, Luana; Larcher, Roberto; Nicolini, Giorgio; Camin, Federica

2016-09-01

The feasibility of using δ(15) N as an additional isotopic marker able to link wine to its area of origin was investigated. The whole production chain (soil-leaves-grape-wine) was considered. Moreover, the research included evaluation of the effect of the fermentation process, the use of different types of yeast and white and red vinification, the addition of nitrogen adjuvants and ultrasound lysis simulating wine ageing. The δ(15) N of grapes and wine was measured in bulk samples and compounds, specifically in proline, for the first time. Despite isotopic fractionation from soil to wine, the δ(15) N values of leaves, grapes, wine and particularly must and wine proline conserved the variability of δ(15) N in the growing soil. Fermentation and ultrasound treatment did not affect the δ(15) N values of grape must, which was therefore conserved in wine. The addition of inorganic or organic adjuvants was able to influence the δ(15) N of bulk wine, depending on the amount and the difference between the δ(15) N of must and that of the adjuvant. The δ(15) N of wine proline was not influenced by adjuvant addition and is therefore the best marker for tracing the geographical origin of wine. Copyright © 2016 John Wiley & Sons, Ltd. Copyright © 2016 John Wiley & Sons, Ltd.

Nitrous oxide and N-leaching losses from agricultural soil: Influence of crop residue particle size, quality and placement

DEFF Research Database (Denmark)

Ambus, P.; Jensen, E.S.; Robertson, G.P.

2001-01-01

protection of the crop residue material against microbial attack. Leaching of N tended to be reduced about 40 % with barley and 20 % with pea, but the numbers were not significantly different from residue-free soil, which leached 4.7-4.9 g N m(-2). When wheat and alfalfa residues were mixed into the soil N2O...... emissions increased 6.5 and 1.6 times, respectively, compared with residue placed in a layer. Wheat residue in a layer evolved 3.4-times less N2O than alfalfa in a layer, whereas when mixed the two residue types evolved similar amounts of N2O. This difference was probably due to N-limitations in localised...

sup 15 N-ammonium test in clinical research. Der ( sup 15 N)-Ammoniumtest in der klinischen Forschung

Energy Technology Data Exchange (ETDEWEB)

Jung, K; Metzner, C; Teichmann, B [Akademie der Wissenschaften der DDR, Leipzig (German Democratic Republic). Zentralinstitut fuer Isotopen- und Strahlenforschung Leipzig Univ. (German Democratic Republic). Bereich Medizin

1989-01-01

By use of the {sup 15}N-ammonium test the liver function is investigated under influence of hormonal contraceptives in women and in liver diseases in children. With the described noninvasive nonradioactive isotope test the ammonia detoxification capability and the urea synthesis capacity of the liver is determined by measuring of the {sup 15}N excretion in ammonia and urea in urine after oral administering of {sup 15}N-ammonium chloride. The {sup 15}N-ammonium test shows a significant influence of the hormonal contraceptives on the liver function and gives diagnostic evidence for liver diseases in children. (author).

Theoretical study of the effective chemical shielding anisotropy (CSA) in peptide backbone, rating the impact of CSAs on the cross-correlated relaxations in L-alanyl-L-alanine

Czech Academy of Sciences Publication Activity Database

Benda, Ladislav; Bouř, Petr; Müller, N.; Sychrovský, Vladimír

2009-01-01

Roč. 113, č. 15 (2009), s. 5273-5281 ISSN 1520-6106 R&D Projects: GA AV ČR IAA400550701; GA AV ČR IAA400550702; GA MŠk MEB060705 Institutional research plan: CEZ:AV0Z40550506 Keywords : chemical shielding anisotropy * CSA * L-alanyl-L-alanine Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 3.471, year: 2009

Incorporating residual temperature and specific humidity in predicting weather-dependent warm-season electricity consumption

Science.gov (United States)

Guan, Huade; Beecham, Simon; Xu, Hanqiu; Ingleton, Greg

2017-02-01

Climate warming and increasing variability challenges the electricity supply in warm seasons. A good quantitative representation of the relationship between warm-season electricity consumption and weather condition provides necessary information for long-term electricity planning and short-term electricity management. In this study, an extended version of cooling degree days (ECDD) is proposed for better characterisation of this relationship. The ECDD includes temperature, residual temperature and specific humidity effects. The residual temperature is introduced for the first time to reflect the building thermal inertia effect on electricity consumption. The study is based on the electricity consumption data of four multiple-street city blocks and three office buildings. It is found that the residual temperature effect is about 20% of the current-day temperature effect at the block scale, and increases with a large variation at the building scale. Investigation of this residual temperature effect provides insight to the influence of building designs and structures on electricity consumption. The specific humidity effect appears to be more important at the building scale than at the block scale. A building with high energy performance does not necessarily have low specific humidity dependence. The new ECDD better reflects the weather dependence of electricity consumption than the conventional CDD method.

Hotspots of soil N2O emission enhanced through water absorption by plant residue

Energy Technology Data Exchange (ETDEWEB)

Kravchenko, A.N.; Toosi, E.R.; Guber, A.K.; Ostrom, N.E.; Yu, J.; Azeem, K.; Rivers, M.L.; Robertson , G.P. (UAF Pakistan); (UC); (Hubei); (MSU)

2017-06-05

N2O is a highly potent greenhouse gas and arable soils represent its major anthropogenic source. Field-scale assessments and predictions of soil N2O emission remain uncertain and imprecise due to the episodic and microscale nature of microbial N2O production, most of which occurs within very small discrete soil volumes. Such hotspots of N2O production are often associated with decomposing plant residue. Here we quantify physical and hydrological soil characteristics that lead to strikingly accelerated N2O emissions in plant residue-induced hotspots. Results reveal a mechanism for microscale N2O emissions: water absorption by plant residue that creates unique micro-environmental conditions, markedly different from those of the bulk soil. Moisture levels within plant residue exceeded those of bulk soil by 4–10-fold and led to accelerated N2O production via microbial denitrification. The presence of large (Ø >35 μm) pores was a prerequisite for maximized hotspot N2O production and for subsequent diffusion to the atmosphere. Understanding and modelling hotspot microscale physical and hydrologic characteristics is a promising route to predict N2O emissions and thus to develop effective mitigation strategies and estimate global fluxes in a changing environment.

Fate of 15N-labelled urea as affected by organic amendments and oils applied to rice

International Nuclear Information System (INIS)

Singh, G.R.; Singh, T.A.

1987-01-01

The present study was undertaken to explore the possibility of using 2 organic compounds (p-benzoquinone and catechol), 2 oils (neem oil (Azadirachta indica A. Juss) and linseed oil (Linum usitatissimum Linn.) oil) and 3 polyphenolic plant residues, viz. catechu (Acacia catechu (L.f.) Willd.), babul acacia (Acacia nilotica (Linn.) Willd. ex Del. sub.indica (Benth.) Brenan, syn. A. arabica (Lamk.) Willd.) and yellow myrobalan (Terminalia chebula Retz.) when applied with 15 N-tagged urea to observe their effectiveness in decreasing N losses. (author). 8 refs

Multi-Seasonal Nitrogen Recoveries from Crop Residue in Soil and Crop in a Temperate Agro-Ecosystem.

Directory of Open Access Journals (Sweden)

Guoqing Hu

Full Text Available In conservation tillage systems, at least 30% of the soil surface was covered by crop residues which generally contain significant amounts of nitrogen (N. However, little is known about the multi-seasonal recoveries of the N derived from these crop residues in soil-crop systems, notably in northeastern China. In a temperate agro-ecosystem, 15N-labeled maize residue was applied to field surfaces in the 1st year (2009. From the 2nd to 4th year (2010-2012, one treatment halted the application of maize residue, whereas the soil in the second treatment was re-applied with unlabeled maize residue. Crop and soil samples were collected after each harvest, and their 15N enrichments were determined on an isotope ratio mass spectrometer to trace the allocation of N derived from the initially applied maize residue in the soil-crop systems. On average, 8.4% of the maize residue N was recovered in the soil-crop in the 1st year, and the vast majority (61.9%-91.9% was recovered during subsequent years. Throughout the experiment, the cumulative recovery of the residue N in the crop increased gradually (18.2%-20.9%, but most of the residue N was retained in the soil, notably in the 0-10 cm soil layer. Compared to the single application, the sequential residue application significantly increased the recovery of the residue N in the soil profile (73.8% vs. 40.9% and remarkably decreased the total and the initially applied residue derived mineral N along the soil profile. Our results suggested that the residue N was actively involved in N cycling, and its release and recovery in crop and soil profile were controlled by the decomposition process. Sequential residue application significantly enhanced the retention and stabilization of the initially applied residue N in the soil and retarded its translocation along the soil profile.

Estimación de la seguridad residual en estructuras de hormigón con problemas patológicos

Directory of Open Access Journals (Sweden)

Morán Cabré, F.

1994-12-01

Full Text Available The problems encountered in the survey, the diagnosis and the residual safety assessment of damaged reinforced concrete structures are schematically presented, together with the techniques and methods most commonly used for their solution.

Se presentan, de forma esquemática, los problemas que se plantean en la inspección, en el diagnóstico y en la estimación de la seguridad residual de estructuras de hormigón que presentan problemas patológicos, así como las técnicas y los métodos más comunes para su resolución.

Development and validation of a Spanish diabetes-specific numeracy measure: DNT-15 Latino.

Science.gov (United States)

White, Richard O; Osborn, Chandra Y; Gebretsadik, Tebeb; Kripalani, Sunil; Rothman, Russell L

2011-09-01

Although deficits in health literacy and numeracy have been described among Latinos, the impact of low numeracy on diabetes outcomes has not been studied. Study objectives were (1) to establish the reliability and validity of a 15-item Spanish, diabetes-specific numeracy measure (Diabetes Numeracy Test [DNT]-15 Latino) and (2) to examine the relationship between diabetes-specific numeracy and diabetes-related outcomes among a sample of Latino adults with diabetes. Data collection included patient demographics, health literacy, general numeracy, diabetes-specific numeracy, acculturation, self-efficacy, self-care behaviors, and most recent glycosylated hemoglobin (HbA1c). Participants (n=144) were on average 47.8 years old (SD=12.1). The majority were female (62%), uninsured (81%), and of Mexican nationality (78%) and reported low levels of acculturation (96%). The DNT-15 Latino had high internal reliability (Kruder-Richardson 20=0.78). The DNT-15 Latino demonstrated construct validity, correlating with measures of health literacy (ρ=0.291), general numeracy (ρ=0.500), education (ρ=0.361), and income (ρ=0.270) (Pvalid measure of diabetes-specific numeracy for Latino patients with diabetes; however, additional studies are needed to further explore the association between diabetes-specific numeracy and acculturation and their impact on diabetes-related outcomes for Latinos.

Synthesis of fertilizers nitrogen and 15N-enriched. Pt. I. Production of enriched 15N-anhydrous ammonia

International Nuclear Information System (INIS)

Bendassolli, J.A.; Mortatti, J.; Trivelin, P.C.O.; Victoria, R.L.

1988-01-01

The results of 15 N-anhydrous ammonia production through reaction between 15 N-enriched ammonium sulphate and sodium hidroxide are reported. Influence of the reaction temperature, carrier gas flow, reaction time and mass of ammonium sulphate on the production of anhydrous ammonia were studied. Analyses for the cost of production of 5% atoms in 15 N-enriched anhydrous ammonia were made. (M.A.C.) [pt

Separating the contributions to 15N transverse relaxation in a fibronectin type III domain

International Nuclear Information System (INIS)

Meekhof, Alison E.; Freund, Stefan M.V.

1999-01-01

In proteins, dynamic mobility is an important feature of structure, stability, and biomolecular recognition. Uniquely sensitive to motion throughout the milli- to picosecond range, rates of transverse relaxation, R2, are commonly obtained for the characterization of chemical exchange, and the construction of motional models that attempt to separate overall and internal mobility. We have performed an in-depth study of transverse relaxation rates of backbone 15N nuclei in TNfn31-90, the third fibronectin type III domain from human tenascin. By combining the results of spin-echo (CPMG) and off-resonance T1ρ experiments, we present R2 rates at effective field strengths of 2 to 40 krad/s, obtaining a full spectrum of 16 independent R2 data points for most residues. Collecting such a large number of replicate measurements provides insight into intrinsic uncertainties. The median standard deviation in R2 for non-exchanging residues is 0.31, indicating that isolated measurements may not be sufficiently accurate for a precise interpretation of motional models. Chemical exchange events on a timescale of 570 μs were observed in a cluster of residues at the C terminus. Rates of exchange for five other residues were faster than the sampled range of frequencies and could not be determined. Averaged 'exchange free' transverse relaxation rates, R20, were used to calculate the diffusion tensor for rotational motion. Despite a highly asymmetric moment of inertia, the narrow angular dispersion of N-H vectors within the β sandwich proves insufficient to define deviations from isotropic rotation. Loop residues provide exclusive evidence for axially symmetric diffusion (Dpar/Dper=1.55)

Resolution of the 15N balance enigma?

International Nuclear Information System (INIS)

Clough, T.J.; Sherlock, R.R.; Cameron, K.C.; Stevens, R.J.; Laughlin, R.J.; Mueller, C.

2001-01-01

The enigma of soil nitrogen balance sheets has been discussed for over 40 years. Many reasons have been considered for the incomplete recovery of 15 N applied to soils, including sampling uncertainty, gaseous N losses from plants, and entrapment of soil gases. The entrapment of soil gases has been well documented for rice paddy and marshy soils but little or no work appears to have been done to determine entrapment in drained pasture soils. In this study 15 N-labelled nitrate was applied to a soil core in a gas-tight glovebox. Water was applied, inducing drainage, which was immediately collected. Dinitrogen and N -2 were determined in the flux through the soil surface, and in the gases released into the glovebox as a result of irrigation or physical destruction of the core. Other components of the N balance were also measured, including soil inorganic-N and organic-N. Quantitative recovery of the applied 15 N was achieved when the experiment was terminated 484 h after the 15 N-labelled material was applied. Nearly 23% of the 15 N was recovered in the glovebox atmosphere as N 2 and N 2 O due to diffusion from the base of the soil core, convective flow after irrigation, and destructive soil sampling. This 15 N would normally be unaccounted for using the sampling methodology typically employed in 15 N recovery experiments. Copyright (2001) CSIRO Publishing

Involvement of the N-terminal part of cyclophilin B in the interaction with specific Jurkat T-cell binding sites.

Science.gov (United States)

Mariller, C; Haendler, B; Allain, F; Denys, A; Spik, G

1996-07-15

Cyclophilin B (CyPB) is secreted in biological fluids such as blood or milk and binds to a specific receptor present on the human lymphoblastic cell line Jurkat and on human peripheral blood lymphocytes. This study was intended to specify the areas of CyPB that are involved in the interaction with the receptor. A synthetic peptide corresponding to the first 24 N-terminal amino acid residues of CyPB was shown to specifically recognize the receptor. Moreover, modification of Arg18 of CyPB by p-hydroxyphenlglyoxal led to a dramatic loss of affinity for the receptor. However, when this residue was replaced by an alanine residue using site-directed mutagenesis, no modification of the binding properties was found, suggesting that Arg18 is not directly involved but is sufficiently close to the interaction site to interfere with the binding when modified. Competitive binding experiments using a chimaeric protein made up of the 24 N-terminal amino acid residues of CyPB fused to the cyclophilin A core sequence confirmed the involvement of this region of CyPB in receptor binding.

N-15 analysis by emission spectroscopy

Energy Technology Data Exchange (ETDEWEB)

NONE

1983-12-31

The stable isotope of nitrogen, N-15, has become widely used as tracer in agriculture, medicine and biology research. The film gives an overview of the sample preparation and analytical procedures followed in the analysis of the nitrogen isotopic composition (14N/15N ratio) by optical emission spectrometry at the Seibersdorf Laboratory. The subsampling of plant material and the several steps of chemical pretreatment such as Kjeldahl digestion, distillation, titration and adjustment of the proper N concentration in the extract are demonstrated. The preparation of the discharge tubes is shown in detail. Final measurement of the 14N/15N ratio is carried out with the NOI-5 and JASCO emission spectrometers

Emission spectroscopic 15N analysis 1985

International Nuclear Information System (INIS)

Meier, G.

1986-01-01

The state of the art of emission spectroscopic 15 N analysis is demonstrated taking the NOI-6e 15 N analyzer as an example. The analyzer is equipped with a microcomputer to ensure a high operational comfort, computer control, and both data acquisition and data processing. In small amounts of nitrogen-containing substances (10 to 50 μg N 2 ) the 15 N abundance can be very quickly determined in standard discharge tubes or in aqueous ammonium salt solutions with a standard deviation less than 0.6 percent

Complete Measurement of Stable Isotopes in N2O (δ15N, δ15Nα, δ15Nβ, δ18O, δ17O) Using Off-Axis Integrated Cavity Output Spectroscopy (OA-ICOS)

Science.gov (United States)

Leen, J. B.; Gupta, M.

2014-12-01

Nitrate contamination in water is a worldwide environmental problem and source apportionment is critical to managing nitrate pollution. Fractionation caused by physical, chemical and biological processes alters the isotope ratios of nitrates (15N/14N, 18O/16O and 17O/16O) and biochemical nitrification and denitrification impart different intramolecular site preference (15N14NO vs. 14N15NO). Additionally, atmospheric nitrate is anomalously enriched in 17O compared to other nitrate sources. The anomaly (Δ17O) is conserved during fractionation processes, providing a tracer of atmospheric nitrate. All of these effects can be used to apportion nitrate in soil. Current technology for measuring nitrate isotopes is complicated and costly - it involves conversion of nitrate to nitrous oxide (N2O), purification, preconcentration and measurement by isotope ratio mass spectrometer (IRMS). Site specific measurements require a custom IRMS. There is a pressing need to make this measurement simpler and more accessible. Los Gatos Research has developed a next generation mid-infrared Off-Axis Integrated Cavity Output Spectroscopy (OA-ICOS) analyzer to quantify all stable isotope ratios of N2O (δ15N, δ15Nα, δ15Nβ, δ18O, δ17O). We present the latest performance data demonstrating the precision and accuracy of the OA-ICOS based measurement. At an N2O concentration of 322 ppb, the analyzer quantifies [N2O], δ15N, δ15Na, δ15Nb, and δ18O with a precision of ±0.05 ppb, ±0.4 ‰, ±0.45 ‰, and ±0.6 ‰, and ±0.8 ‰ respectively (1σ, 100s; 1σ, 1000s for δ18O). Measurements of gas standards demonstrate accuracy better than ±1 ‰ for isotope ratios over a wide dynamic range (200 - 100,000 ppb). The measurement of δ17O requires a higher concentration (1 - 50 ppm), easily obtainable through conversion of nitrates in water. For 10 ppm of N2O, the instrument achieves a δ17O precision of ±0.05 ‰ (1σ, 1000s). This performance is sufficient to quantify atmospheric

Characteristic statistic algorithm (CSA) for in-core loading pattern optimization

International Nuclear Information System (INIS)

Liu Zhihong; Hu Yongming; Shi Gong

2007-01-01

To solve the problem of PWR in-core loading pattern optimization, a more suitable global optimization algorithm, i.e., Characteristic statistic algorithm (CSA), is used. The searching process of this algorithm and how to apply it to this problem are presented. Loading pattern optimization code SCYCLE is developed. Two different problems on real PWR models are calculated and the results are compared with other algorithms. It is shown that SCYCLE has high efficiency and good global performance on this problem. (authors)

Crop residue decomposition, residual soil organic matter and nitrogen mineralization in arable soils with contrasting textures

NARCIS (Netherlands)

Matus, F.J.

1994-01-01

To evaluate the significance of cropping, soil texture and soil structure for the decomposition of ¹⁴C- and ¹⁵N-labelled crop residues, a study was conducted in a sand and a

Glyphosate Mineralization: Effect of Temperature and Soybean and Corn Crop Residues Mineralización de Glifosato: Efecto de la Temperatura y los Residuos Vegetales de Soya y Maíz

Directory of Open Access Journals (Sweden)

Ariel Rampoldi

2008-03-01

Full Text Available Mineralization is the main mechanism of dissipation of glyphosate herbicide (N-[phosphonomethyl] glycine in soil. However, there is scarce information about the mineralization process in strata formed by stubbles in no-tillage systems. The kinetics and rate of mineralization of herbicide in stubbles of soybean (Glycine max L. Merr. and corn (Zea mays L. were investigated. To evaluate the effect of age of crop residues, samples of soybean stubbles were collected immediately after harvest (Soja 1 and four months after harvest (Soja 2. Corn crop residues were collected three months after harvest. Glyphosate evolution and total microbial activity (TMA were monitored by release of 14C-CO2 and C-CO2 under laboratory conditions with two temperatures, 15 and 28 ºC. Crop residues size was evaluated using grinding (1 mm and cut (1 to 2 cm stubbles. Results showed that glyphosate mineralization was affected by the incubation temperature and the origin and age of crop residues. Size of crop residues did not modify glyphosate mineralization. Average glyphosate mineralization after 56 days of incubation at 15 and 28 ºC was of 3.9 and 9.9%, respectively, of the 14C-glyphosate initially applied. In maize crop residues the percentages were 2.0 and 3.0%, respectively, at 15 and 28 ºC. A similar evolution was detected for TMA. The co-metabolic nature of glyphosate mineralization was corroborated. An inverse relation between C/N ratio and glyphosate mineralization was detected. Higher glyphosate mineralization was detected in fresh soybean stubbles, suggesting that applications on aged crop residues could increase the persistence of glyphosate in no-tillage systemsLa mineralización es el principal mecanismo de disipación del herbicida glifosato (N-[fosfonometil] glicina en el suelo. Existe escasa información sobre el proceso de mineralización de glifosato en el estrato formado por rastrojos en suelos cultivados en sistema de siembra directa. Las muestras de

Saline irrigation water and its effect on N.use efficiency, growth and yield of Sorghum plant using 15N

International Nuclear Information System (INIS)

Abd El-Latteef, E.M.

2010-01-01

Series of pot experiments were conducted and randomly arranged under greenhouse conditions for evaluating the effect of irrigation with saline water (alternative source) in combination with different organic sources (amendments) i.e. leucaena plant residue (LU), Quail feces (QF) and chicken manure (ChM) added in different percentages against the mineral form (ammonium sulfate) either in ordinary or 15 N labeled (2 and 5% 15 N atom excess) forms, on sorghum growth and nutrients acquisition. Artificial saline water with different EC and SAR values was prepared at laboratory using computer program designed by the author with guiding of the designed Package named Artificial Saline Irrigation Water (ASIW) (Manual of Salinity Research Methods). In addition, proline acid was also sprayed (foliar) on leaves of sorghum plants at different concentrations. The experimental results indicated the positive effect of organic amendments, as compared to mineral fertilizer, and foliar application of proline acid on enhancement of plant growth and nutrient uptake. This phenomenon was pronounced under water salinity conditions. In this regard, increasing of water salinity levels induced reduction in plant growth as well as nutrients acquisition. Data of 14 N/ 15 N ratio analysis pointed out enhancement of N derived from mineral source as affected by organic amendments. At the same time, considerable amounts of N was derived from organic sources and utilized by plants. The superiority of organic sources on each others was fluctuated depending on interaction with water salinity levels and proline concentrations. In conclusion, organic additives and proline acid has an improvement effects especially under adverse condition of irrigation water salinity.

The Canadian approach to nuclear codes and standards. A CSA forum for development of standards for CANDU: radioactive waste management and decommissioning

International Nuclear Information System (INIS)

Shin, T.; Azeez, S.; Dua, S.

2006-01-01

Together with the Canadian Standards Association (CSA), industry stakeholders, governments, and the public have developed a suite of standards for CANDU nuclear power plants that generate electricity in Canada and abroad. In this paper, we will describe: CSA's role in national and international nuclear standards development; the key issues and priority projects that the nuclear standards program has addressed; the new CSA nuclear committees and projects being established, particularly those related to waste management and decommissioning; the hierarchy of nuclear regulations, nuclear, and other standards in Canada, and how they are applied by AECL; the standards management activities; and the future trends and challenges for CSA and the nuclear community. CSA is an accredited Standards Development Organization (SDO) and part of the international standards system. CSA's Nuclear Strategic Steering Committee (NSSC) provides leadership, direction, and support for a standards committee hierarchy comprised of members from a balanced matrix of interests. The NSSC strategically focuses on industry challenges; a new nuclear regulatory system, deregulated energy markets, and industry restructuring. As the first phase of priority projects is nearing completion, the next phase of priorities is being identified. These priorities address radioactive waste management, environmental radiation management, decommissioning, structural, and seismic issues. As the CSA committees get established in the coming year, members and input will be solicited for the technical committees, subcommittees, and task forces for the following related subjects: Radioactive Waste Management; a) Dry Storage of Irradiated Fuel; b) Short-Term Radioactive Waste Management; c) Long-Term Storage and Disposal of Radioactive Waste. 2. Decommissioning Nuclear Power is highly regulated, and public scrutiny has focused Codes and Standards on public and worker safety. Licensing and regulation serves to control

Constraints on oceanic N balance/imbalance from sedimentary 15N records

Directory of Open Access Journals (Sweden)

M. A. Altabet

2007-01-01

Full Text Available According to current best estimates, the modern ocean's N cycle is in severe deficit. N isotope budgeting provides an independent geochemical constraint in this regard as well as the only means for past reconstruction. Overall, it is the relative proportion of N2 fixation consumed by water column denitrification that sets average oceanic δ15N under steady-state conditions. Several factors (conversion of organic N to N2, Rayleigh closed and open system effects likely reduce the effective fractionation factor (ε for water column denitrification to about half the inherent microbial value for εden. If so, the average oceanic δ15N of ~5‰ is consistent with a canonical contribution from water column denitrification of 50% of the source flux from N2 fixation. If an imbalance in oceanic N sources and sinks changes this proportion then a transient in average oceanic δ15N would occur. Using a simple model, changing water column denitrification by ±30% or N2 fixation by ±15% produces detectable (>1‰ changes in average oceanic δ15N over one residence time period or more with corresponding changes in oceanic N inventory. Changing sedimentary denitrification produces no change in δ15N but does change N inventory. Sediment δ15N records from sites thought to be sensitive to oceanic average δ15N all show no detectible change over the last 3 kyr or so implying a balanced marine N budget over the latest Holocene. A mismatch in time scales is the most likely meaningful interpretation of the apparent conflict with modern flux estimates. Decadal to centennial scale oscillations between net N deficit and net surplus may occur but on the N residence timescale of several thousand years, net balance is achieved in sum. However, sediment δ15N records from the literature covering the period since the last glacial maximum show excursions of up to several ‰ that are consistent with sustained N deficit during the deglaciation followed by readjustment

Distribution of spin dipole transition strength in the 15N(n,p)15C reaction

International Nuclear Information System (INIS)

Cellar, A.; Alford, W.P.; Helmer, R.; Abegg, R.; Frekers, D.; Haeusser, O.; Henderson, R.S.; Jackson, K.P.; Vetterli, M.; Yen, S.; Jeppesen, R.; Larson, B.; Mildenberger, J.; Pointon, B.W.; Trudel, A.

1990-08-01

The reaction 15 N(n,p) 15 C was studied at a neutron energy of 288 MeV using the TRIUMF (n,p) charge exchange facility and a high pressure gas target. The angular distributions for spin dipole (ΔL=1) transitions to the states in 15 C at energies 0 MeV and 0.740 MeV, as well as for higher excitation energies, were measured and the results were compared with DWIA calculations. The measured distribution of the spin dipole strength agrees well with shell model predictions, indicating that a rather simple model provides a satisfactory description of the 15 N ground state, and of positive parity states in 15 C up to about 18 MeV excitation. The magnitude of the peak cross sections (at ≅ 7 degrees) is described well by the calculations when the theoretical cross section is renormalized by a factor 0.7. The calculated cross sections near zero degrees are generally smaller than experimental data. It this is a general feature of ΔL=1 transitions, it suggests that estimates of GT strength based on a multipole decomposition of measured cross sections may be too high. (Author) (41 refs., 3 tabs., 14 figs.)

Ecosystem Nitrogen Retention Following Severe Bark Beetle and Salvage Logging Disturbance in Lodgepole Pine Forests: a 15N Enrichment Study

Science.gov (United States)

Avera, B.; Rhoades, C.; Paul, E. A.; Cotrufo, M. F.

2017-12-01

In recent decades, bark beetle outbreaks have caused high levels of tree mortality in lodgepole pine (Pinus contorta) dominated forests across western North America. Previous work has found increased soil mineral nitrogen (N) with tree mortality in beetle infested stands, but surprisingly little change in stream N export. These findings suggest an important role of residual live vegetation and altered soil microbial response for retaining surplus N and mitigating N losses from disturbed lodgepole forests. Post outbreak salvage of merchantable timber reduces fuel levels and promotes tree regeneration; however, the implications of the combined bark beetle and harvesting disturbances on ecosystem N retention and productivity are uncertain. To advance understanding of post-disturbance N retention we compare unlogged beetle-infested forests and salvage logged stands with post-harvest woody residue retention or removal. We applied 15N-labeled (2 atom%) and natural abundance ammonium sulfate to eight year old lodgepole pine seedlings in three replicate plots of the three forest management treatments. This approach allows us to quantify the relative contributions of N retention in soil, microbial biomass, and plant tissue. Our study targets gaps in understanding of the processes that regulate N utilization and transfer between soil and vegetation that result in effective N retention in lodgepole pine ecosystems. These findings will also help guide forest harvest and woody residue management practices in order to maintain soil productivity.

Synthesis of hydroxylamine-15 N.HCl

International Nuclear Information System (INIS)

Baldea, Aurel

2001-01-01

15 N labelled hydroxylamine is one of the starting substance for synthesis of labelled oximes. Industrial procedure was chosen to prepare hydroxylamine- 15 N. Sodium nitrite reduced by sodium bisulfite and sulfur dioxide, at temperature of 0-2 deg. C, produces sodium hydroxylamine disulfonate. The reaction mixture is treated with acetone and the resulting acetoxime is distilled. In order to obtain crystalline hydroxylamine hydrochloride, hydrochloric acid is added to the distillate and the solution is evaporated to dryness. The crude product was purified by recristallization, yielding 62-65% of theoretical amount. Labelled ammonium chloride formed as byproduct can be recovered improving 15 N balance. IR spectra is used for chemical analysis and mass spectrometry for isotopic analysis. For this purpose hydroxylamine- 15 N is converted into molecular nitrogen. (author)

Mechanism of the reactions 14N(d,p)15N and 14N(d,n)15O by Doppler shift line shape method

International Nuclear Information System (INIS)

Abdel-Moneim, A.M.

1976-06-01

In this investigation the total and the differential absolute cross sections of the 14 N(d,p) 15 N reaction leading to excited states at 7.3, 8.3 and 9.05 MeV levels in 15 N and the 14 N(d,n) 15 O reaction leading to the 6.79 MeV level in 15 O, have been studied over the energy range from 0.5 MeV to 3 MeV. Doppler shift line shape method as well as γ-ray yield measurements have been used. The absolute cross sections are determined relative to the known 14 N(p,p) elastic differential cross sections. A comparison with previously determined values for the same reactions at selected energies shows good agreement in angular distribution as well as in absolute values. The total cross section for the d,p reaction shows a general energy dependence which is typical for direct reactions, but with minor contribution from compound nucleus formation at certain energy ranges. For the 14 N(d,n) 15 N reaction, the method applied is unique, since it allows the differential cross section to be studied all the way down to the threshold energy of deuterons at 2 MeV, with a detectorsystem efficiency which is constant over the entire range of neutron energies. The larger part of the energy range that has been investigated is dominated by a resonance at 2.55 π+ 0.05 MeV deuteron energy and a halfwidth depending on the amount of contribution from the direct reaction of the order of 200-400 keV. (JIW)

Study on the utilization of N fertilizers by labelling with 15N in a microplot experiment

International Nuclear Information System (INIS)

Latkovics, I.

1982-01-01

The effect and residual effect of urea and NH 4 NO 3 on the dry matter yield and N uptake of rye-grass and Sudan grass, as well as on the N status of the soil and the distribution of N within the soil profile were studied with 15 N indication on a chernozem-like calcareous sandy soil in an isolated microplot experiment. It has been found that 57-79% of the N contents of the first cuttings came from the fertilizer, and the percentage N amounts decreased with each cutting. Under the given experimental conditions there was no significant difference between the N amounts taken up from urea or from NH 4 NO 3 . Rye-grass utilized N both from urea and NH 4 NO 3 in the same degree (55%), while Sudan grass utilized 29.8% from urea and 36.1% from NH 4 NO 3 . Depending on the treatment, 22.8-31.7% of fertilizer-N was found in the 0-120 cm layer of the soil, while the larger part (74.8-84.6%) of this amount accumulated in the upper 40 cm layer. The amount of fertilizer-N not recovered (and thus 'lost' for the plants) was 13.3-21.6% in the case of rye-grass and 34.4-43.1% of Sudan grass. (author)

Labelled compounds for agrochemical residue studies in developing countries

International Nuclear Information System (INIS)

1977-01-01

Potential applications of stable and radioactive isotopic tracers for assessing undesirable contaminants in agriculture, fisheries and food are discussed as related to developing countries. Sources and types of residues are considered, and their local implications; also, the availability of suitably labelled compounds, including possible international cooperation to facilitate more centralized and economic preparation, and the distribution of labelled intermediates and compounds for use by local scientists. The provision of training courses and their syllabus are reviewed. Experience in the Joint FAO/IAEA chemical residue and pollution programme has indicated a need for longer-lived radioisotopically labelled pesticides (insecticides, acaricides, fungicides, herbicides, fumigants, etc.) for studying their behaviour. 15 N-, 13 C- or 2 H-labelled fertilizers and fertilizer additives such as nitrification inhibitors will shortly be needed, for studying the behaviour of fertilizer nitrogen residues, and their regulation and conservation, under conditions prevailing in the developing countries. Compounds labelled with stable isotopes are considered particularly valuable under field conditions. The report reviews the present situation and presents specific recommendations to the Directors General of FAO and IAEA

Accurate Determination of Leucine and Valine Side-chain Conformations using U-[{sup 15}N/{sup 13}C/{sup 2}H]/[{sup 1}H-(methine/methyl)-Leu/Val] Isotope Labeling, NOE Pattern Recognition, and Methine C{gamma}-H{gamma}/C{beta}-H{beta} Residual Dipolar Couplings

Energy Technology Data Exchange (ETDEWEB)

Tang, Chun; Iwahara, Junji; Clore, G. Marius [National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Laboratory of Chemical Physics (United States)], E-mail: mariusc@intra.niddk.nih.gov

2005-10-15

An isotope labeling scheme is described in which specific protonation of methine and methyl protons of leucine and valine is obtained on a {sup 15}N/{sup 13}C labeled background with uniform deuteration of all other non-exchangeable protons. The presence of a protonated methine group has little effect on the favorable relaxation properties of the methyl protons of Leu and Val. This labeling scheme permits the rotameric state of leucine side-chains to be readily determined by simple inspection of the pattern of H{gamma}(i)-H{sub N}(i) and H{gamma}(i)-H{sub N}(i+1) NOEs in a 3D {sup 15}N-separated NOE spectrum free of complications arising from spectral overlap and spin-diffusion. In addition, one-bond residual dipolar couplings for the methine {sup 13}C-{sup 1}H bond vectors of Leu and Val can be accurately determined from an intensity J-modulated constant-time HCCH-COSY experiment and used to accurately orient the side-chains of Leu and Val. Incorporation of these data into structure refinement improves the accuracy with which the conformations of Leu and Val side-chains can be established. This is important to ensure optimal packing both within the protein core and at intermolecular interfaces. The impact of the method on protein structure determination is illustrated by application to enzyme IIA{sup Chitobiose}, a 34 kDa homotrimeric phosphotransferase protein.

15C-15F Charge Symmetry and the 14C(n,γ)15C Reaction Puzzle

International Nuclear Information System (INIS)

Timofeyuk, N.K.; Thompson, I.J.; Baye, D.; Descouvemont, P.; Kamouni, R.

2006-01-01

The low-energy reaction 14 C(n,γ) 15 C provides a rare opportunity to test indirect methods for the determination of neutron capture cross sections by radioactive isotopes versus direct measurements. It is also important for various astrophysical scenarios. Currently, puzzling disagreements exist between the 14 C(n,γ) 15 C cross sections measured directly, determined indirectly, and calculated theoretically. To solve this puzzle, we offer a strong test based on a novel idea that the amplitudes for the virtual 15 C→ 14 C+n and the real 15 F→ 14 O+p decays are related. Our study of this relation, performed in a microscopic model, shows that existing direct and some indirect measurements strongly contradict charge symmetry in the 15 C and 15 F mirror pair. This brings into question the experimental determinations of the astrophysically important (n,γ) cross sections for short-lived radioactive targets

The production of IL-1, IL-3, CSA by bone marrow nuclears during bone marrow haemopoiesis after lethal irradiation and syngenic bone marrow transplantation

International Nuclear Information System (INIS)

Dygaj, A.M.; Buznik, D.V.; Bogdashin, I.V.; Agafonov, V.I.

1994-01-01

The production of haemopoietic factors (IL-1, IL-3, CSA) by adherent and unadherent cells of lethally irradiate CBA mice bone marrow and after syngenic myelokaryocyte transplantation was studied. Radioresistant myelokaryocytes capable to produce haemopoetic factors IL-1, CSA as early as 24 hr after irradiation were found in adherent cell fraction. The synthesis of humoral factors (IL-3, CSA) by unadherent bone marrow elements was realised in a late of experiment (3-6 days) that was connected with forming of functionally valuable cell forms from transplanted or viable stem cells

A residual life prediction model based on the generalized σ -N curved surface

Directory of Open Access Journals (Sweden)

Zongwen AN

2016-06-01

Full Text Available In order to investigate change rule of the residual life of structure under random repeated load, firstly, starting from the statistic meaning of random repeated load, the joint probability density function of maximum stress and minimum stress is derived based on the characteristics of order statistic (maximum order statistic and minimum order statistic; then, based on the equation of generalized σ -N curved surface, considering the influence of load cycles number on fatigue life, a relationship among minimum stress, maximum stress and residual life, that is the σmin(n- σmax(n-Nr(n curved surface model, is established; finally, the validity of the proposed model is demonstrated by a practical case. The result shows that the proposed model can reflect the influence of maximum stress and minimum stress on residual life of structure under random repeated load, which can provide a theoretical basis for life prediction and reliability assessment of structure.

Roles of s3 site residues of nattokinase on its activity and substrate specificity.

Science.gov (United States)

Wu, Shuming; Feng, Chi; Zhong, Jin; Huan, Liandong

2007-09-01

Nattokinase (Subtilisin NAT, NK) is a bacterial serine protease with high fibrinolytic activity. To probe their roles on protease activity and substrate specificity, three residues of S3 site (Gly(100), Ser(101) and Leu(126)) were mutated by site-directed mutagenesis. Kinetics parameters of 20 mutants were measured using tetrapeptides as substrates, and their fibrinolytic activities were determined by fibrin plate method. Results of mutation analysis showed that Gly(100) and Ser(101) had reverse steric and electrostatic effects. Residues with bulky or positively charged side chains at position 100 decreased the substrate binding and catalytic activity drastically, while residues with the same characters at position 101 could obviously enhance protease and fibrinolytic activity of NK. Mutation of Leu(126) might impair the structure of the active cleft and drastically decreased the activity of NK. Kinetics studies of the mutants showed that S3 residues were crucial to keep protease activity while they moderately affected substrate specificity of NK. The present study provided some original insight into the P3-S3 interaction in NK and other subtilisins, as well as showed successful protein engineering cases to improve NK as a potential therapeutic agent.

CRISPR-Cas type I-A Cascade complex couples viral infection surveillance to host transcriptional regulation in the dependence of Csa3b

Science.gov (United States)

He, Fei; Vestergaard, Gisle; Peng, Wenfang; She, Qunxin

2017-01-01

Abstract CRISPR-Cas (clustered regularly interspaced short palindromic repeats and the associated genes) constitute adaptive immune systems in bacteria and archaea and they provide sequence specific immunity against foreign nucleic acids. CRISPR-Cas systems are activated by viral infection. However, little is known about how CRISPR-Cas systems are activated in response to viral infection or how their expression is controlled in the absence of viral infection. Here, we demonstrate that both the transcriptional regulator Csa3b, and the type I-A interference complex Cascade, are required to transcriptionally repress the interference gene cassette in the archaeon Sulfolobus. Csa3b binds to two palindromic repeat sites in the promoter region of the cassette and facilitates binding of the Cascade to the promoter region. Upon viral infection, loading of Cascade complexes onto crRNA-matching protospacers leads to relief of the transcriptional repression. Our data demonstrate a mechanism coupling CRISPR-Cas surveillance of protospacers to transcriptional regulation of the interference gene cassette thereby allowing a fast response to viral infection. PMID:27980065

15N-ammonium test in clinical research

International Nuclear Information System (INIS)

Jung, K.; Metzner, C.; Teichmann, B.; Leipzig Univ.

1989-01-01

By use of the 15 N-ammonium test the liver function is investigated under influence of hormonal contraceptives in women and in liver diseases in children. With the described noninvasive nonradioactive isotope test the ammonia detoxification capability and the urea synthesis capacity of the liver is determined by measuring of the 15 N excretion in ammonia and urea in urine after oral administering of 15 N-ammonium chloride. The 15 N-ammonium test shows a significant influence of the hormonal contraceptives on the liver function and gives diagnostic evidence for liver diseases in children. (author)

Origin and tracing techniques of high 15N nitrogen compounds in industrial environments

International Nuclear Information System (INIS)

Talma, A.S.; Meyer, R.

2002-01-01

Effluents and process waters from various industrial plants were investigated for the 15 N/ 14 N isotope ratio in nitrate and ammonia. It was found that large isotope fractionation occurs in cases where ammonia is involved in gas-liquid phase changes. This feature was found to occur in two coke oven plants where ammonia gas is removed from a gas stream by solution in water, in an ammonia sulphate plant where ammonia gas is absorbed in sulphuric acid and in a water treatment plant where ammonia is removed from (high pH) water by blowing air through the process water. In all these cases 15 N isotope enrichments (in the range of 10 to 30 per mille) occurred. These enrichments are in excess of those found naturally. Ammonia in such wastewaters essentially retains this high 15 N content when it is converted to nitrate underground: which occurs rapidly under well-oxidised conditions. Nitrate is a fairly conservative tracer and its contamination in water can be followed readily. In the low recharge environment in the central parts of South Africa evidence of waste management practices of 10-20 years earlier were still quite evident using this isotopic label. The high 15 N nitrate signal could be used to distinguish industrial nitrogen pollution from pollution by local sewage disposal systems. Vegetation that derives its nitrogen from such high 15 N sources retains the isotope signature of its source. Grass and other annual plants then exhibit the isotope signature of the water of a specific year. Trees exhibit the isotope signature of deeper water, which shows the effects of longer term pollution events. The use of high 15 N as tracer enables the source apportionment of nitrogen derived pollution in these specific circumstances. (author)

Protein backbone motions viewed by intraresidue and sequential H{sup N}-H{sup {alpha}} residual dipolar couplings

Energy Technology Data Exchange (ETDEWEB)

Voegeli, Beat; Yao Lishan; Bax, Ad [National Institutes of Health, Laboratory of Chemical Physics, National Institute of Diabetes and Digestive and Kidney Diseases (United States)], E-mail: bax@nih.gov

2008-05-15

Triple resonance E.COSY-based techniques were used to measure intra-residue and sequential H{sup N}-H{sup {alpha}} residual dipolar couplings (RDCs) for the third IgG-binding domain of protein G (GB3), aligned in Pf1 medium. Measurements closely correlate with values predicted on the basis of an NMR structure, previously determined on the basis of a large number of one-bond backbone RDCs measured in five alignment media. However, in particular the sequential H{sup N}-H{sup {alpha}} RDCs are smaller than predicted for a static structure, suggesting a degree of motion for these internuclear vectors that exceeds that of the backbone amide N-H vectors. Of all experimentally determined GB3 structures available, the best correlation between experimental {sup 1}H-{sup 1}H couplings is observed for a GB3 ensemble, previously derived to generate a realistic picture of the conformational space sampled by GB3 (Clore and Schwieters, J Mol Biol 355:879-886, 2006). However, for both NMR and X-ray-derived structures the {sup 1}H-{sup 1}H couplings are found to be systematically smaller than expected on the basis of alignment tensors derived from {sup 15}N-{sup 1}H amide RDCs, assuming librationally corrected N-H bond lengths of 1.041 A.

COMMUNITY SUPPORTED AGRICULTURE (CSA

Directory of Open Access Journals (Sweden)

Atănăsoaie George Sebastian

2013-06-01

Full Text Available Farms of CSA types are a viable alternative to trade of agricultural products coming from conventional agriculture. These farms are faced with a number of policy issues related to product, price, distribution and promotion. In order to elucidate the issues listed above, we have investigated the literature of specialty. Farmers must make more flexible the content of basket both quantitatively and in terms of the nature of food products offered. Consumers need information on ways of preparation or preservation of products. The growth of the processing degree in farm, and inclusion in the offer of services in ecotourism represent effective options to satisfy consumers. To offset the negative impact of high prices measures should be taken in reducing costs, more flexibility in rescheduling of payments due from customers and compensate for the lack of financial resources with the provision of farm work or subsidize a portion of the basket value from private or government sources. Delivery of baskets should be both at fixed points and at customers domicile. Farmers must provide customers the possibility so that they could harvest themselves the products they will buy. Negative influence of prices will be reduced by establishing an effective communication policy with the market, by organizing events on the farm or nearby towns, through blogs and social networks, and through participation in fairs and exhibitions. A greater customer involvement in farming activities will lead to the implementation of an effective marketing mix.

Tracking C and N dynamics and stabilization in soil amended with wheat residue and its correponding bioethanol by-product: a 13C/15C study

NARCIS (Netherlands)

Cayuela, M.L.; Kuikman, P.J.; Bakker, R.R.C.; Groenigen, van J.W.

2014-01-01

Removing agricultural cellulosic residues from fields for the production of ‘second generation biofuels'has the potential to profoundly alter C and N cycling in soil, increasing the risk of soil organic matter depletion and favoring soil–atmosphere gaseous exchanges. However, these negative impacts

Bactericidal activities of the cationic steroid CSA-13 and the cathelicidin peptide LL-37 against Helicobacter pylori in simulated gastric juice

Directory of Open Access Journals (Sweden)

Janmey Paul A

2009-09-01

Full Text Available Abstract Background The worldwide appearance of drug-resistant strains of H. pylori motivates a search for new agents with therapeutic potential against this family of bacteria that colonizes the stomach, and is associated with adenocarcinoma development. This study was designed to assess in vitro the anti-H. pylori potential of cathelicidin LL-37 peptide, which is naturally present in gastric juice, its optimized synthetic analog WLBU2, and the non-peptide antibacterial agent ceragenin CSA-13. Results In agreement with previous studies, increased expression of hCAP-18/LL-37 was observed in gastric mucosa obtained from H. pylori infected subjects. MBC (minimum bactericidal concentration values determined in nutrient-containing media range from 100-800 μg/ml for LL-37, 17.8-142 μg/ml for WLBU2 and 0.275-8.9 μg/ml for ceragenin CSA-13. These data indicate substantial, but widely differing antibacterial activities against clinical isolates of H. pylori. After incubation in simulated gastric juice (low pH with presence of pepsin CSA-13, but not LL-37 or WLBU2, retained antibacterial activity. Compared to LL-37 and WLBU2 peptides, CSA-13 activity was also more resistant to inhibition by isolated host gastric mucins. Conclusion These data indicate that cholic acid-based antimicrobial agents such as CSA-13 resist proteolytic degradation and inhibition by mucin and have potential for treatment of H. pylori infections, including those caused by the clarithromycin and/or metronidazole-resistant strains.

Synthesis of high specific active tritiated Leu-enkephalin in the leucine residue

Energy Technology Data Exchange (ETDEWEB)

Baba, S.; Hasegawa, H.; Shinohara, Y. (Tokyo Coll. of Pharmacy (Japan))

1989-12-01

Leu-enkephalin labelled with tritium in the Leu residue has been prepared. Synthesis of the precursor peptide, (4,5-dehydroLeu{sup 5}-)Leu-enkephalin, was carried out by solid phase synthesis using Fmoc amino acid derivatives. The peptide was tritiated catalytically yielding {sup 3}H-Leu-enkephalin with a specific radioactivity of 4.39 TBq/mmol. The distribution of tritium label was investigated by reversed-phase high performance liquid chromatography with a synchronized accumulating radioisotope detector following acidic and enzymatic hydrolysis, which confirmed that the tritium label was entirely located at the Leu residue. (author).

Analysis of glyphosate residues in cereals using liquid chromatography-mass spectrometry (LC-MS/MS)

DEFF Research Database (Denmark)

Granby, Kit; Johannesen, S.; Gabrielsen, Martin Vahl

2003-01-01

A fast and specific method for the determination of glyphosate in cereals is described. The method is based on extraction with water by ultrasonication. The samples are cleaned up and separated by high-performance liquid chromatography on a polystyrene-based reverse-phase column (clean-up) in ser......A fast and specific method for the determination of glyphosate in cereals is described. The method is based on extraction with water by ultrasonication. The samples are cleaned up and separated by high-performance liquid chromatography on a polystyrene-based reverse-phase column (clean...... monitored m/z 168--> 150 (glyphosate) and 170-->152 (internal standard 2- 13 (CN)-N-15-glyphosate) for quantification. The mean recovery was 85% ( n =32) at spiking levels from 0.03 to 0.33 mg kg(-1) . From 1998 to 2001, from the analysis of about 50 samples per annum, a reduction in the glyphosate residues...... was observed owing to a Danish trade decision not to use grain with glyphosate residues for milling or bread production....

Physical properties of {anisole + n-alkanes} at temperatures between (293.15 and 303.15) K

International Nuclear Information System (INIS)

Al-Jimaz, Adel S.; Al-Kandary, Jasem A.; Abdul-latif, Abdul-Haq M.; Al-Zanki, Adnan M.

2005-01-01

Density ρ, viscosity η, and refractive index n D , values of {anisole + hexane, or heptane, or octane, or nonane, or decane, or dodecane} binary mixtures over the entire range of mole fraction at temperatures (293.15, 298.15, and 303.15) K, have been investigated at atmospheric pressure. The excess molar volume V E , has been calculated from the experimental measurements. These results were fitted to Redlich and Kister polynomial equation to estimate the binary interaction parameters. The viscosity data were correlated with equations of Grunberg and Nissan, and McAllister. The refractive indices data were used to calculate the specific refractivity R 12 , and also correlated with Lorentz-Lorenz equation. While the excess molar volumes of {anisole + hexane} are negative, and {anisole + heptane} are sigmoidal S-shaped, the remaining binary mixtures are positive. The effects of n-alkanes chain length as well as the temperature on the excess molar volume have been studied. The calculated values have been qualitatively used to explain the intermolecular interaction between the mixing components

15N tracer techniques in pediatric research

International Nuclear Information System (INIS)

Heine, W.; Richter, I.; Plath, C.; Wutzke, K.; Stolpe, H.J.; Tiess, M.; Toewe, J.

1983-01-01

The main topics of the review comprise mathematical fundamentals of the determination of N metabolism parameters using the 3-pool method, the value of different 15 N tracer substances for the determination of whole-body protein parameters, the utilization of parenterally applied D-amino acids, studies on the influence of different diets on the N metabolism of premature infants with the 15 N tracer technique, the application of the 15 N-glycine-STH-test for the evaluation of the therapeutic effect of STH in children suffering from hypothalamico-hypophyseal dwarfism, in vivo studies on urea utilization by the infant intestinal flora under various dietary regimens as well as in vitro investigations on the utilization of 15 N-labelled urea and NH 4 Cl, resp., by the intestinal flora

Insight into Antigenic Diversity of VAR2CSA-DBL5 epsilon Domain from Multiple Plasmodium falciparum Placental Isolates

DEFF Research Database (Denmark)

Gnidehou, Sedami; Jessen, Leon Ivar; Gangnard, Stephane

2010-01-01

on the surface of placental parasites. Despite high DBL5e sequence homology among parasite isolates, sequence analyses identified motifs in DBL5e that discriminate parasites according to donor's parity. Moreover, recombinant proteins of two VAR2CSA DBL5e variants displayed diverse recognition patterns by plasma...... from malaria-exposed women, and diverse proteoglycan binding abilities. Conclusions/Significance: This study provides insights into conserved and exposed B cell epitopes in DBL5e that might be a focus for cross reactivity. The importance of sequence variation in VAR2CSA as a critical challenge...

Residual stress, mechanical and microstructure properties of multilayer Mo{sub 2}N/CrN coating produced by R.F Magnetron discharge

Energy Technology Data Exchange (ETDEWEB)

Bouaouina, B., E-mail: b.bouaouina@gmail.com [Department of physic, research unite UR-MPE, Boumerdes University 35000 (Algeria); Besnard, A. [Arts et Metiers ParisTech—LaBoMaP, 71250 Cluny (France); Abaidia, S.E. [Department of physic, research unite UR-MPE, Boumerdes University 35000 (Algeria); Haid, F. [CDTA, Plasma discharges Group, Baba hassen, Algers (Algeria)

2017-02-15

Highlights: • Depositing of crystallized molybdenum nitride and chromium nitride multilayer at room temperature. • Correlation between stress measurement and the shift of the XRD diffraction peak (1 1 1) of Mo{sub 2}N. • Studied the effect of the bi-layer thickness on the mechanical properties. - Abstract: We have investigated the effect of the period thickness of the multilayer Mo{sub 2}N/CrN deposited on Si substrate produced by reactive magnetron sputtering. Mo{sub 2}N presents a face centered cubic structure and CrN an orthorhombic one. The residual stress of the coatings was determined by the measurement of the substrate curvature. The microstructure of the multilayer was investigated from the X-ray diffraction and scanning electron microscopy (cross section images). The residual stresses resulting from the deposition of the different bi-layer thickness were measured and correlated to the structural properties of the coating as well as the nanoindentation analysis of the coating. The stresses are compressive and tensile for the individual Mo{sub 2}N and CrN layer respectively. The result shows that an increase of the multilayer coatings Mo{sub 2}N/CrN thicknesses induce an increase of the hardness and the elastic modulus, in the other hand the tensile stress increases. The shift of the XRD diffraction peak (1 1 1) of Mo{sub 2}N at high angle which means the reduction of the residual stress is in good agreement with the residual stresses measurements.

Human monoclonal IgG selection of Plasmodium falciparum for the expression of placental malaria-specific variant surface antigens

DEFF Research Database (Denmark)

Soerli, J; Barfod, L; Lavstsen, T

2009-01-01

Pregnancy-associated Plasmodium falciparum malaria (PAM) is a major cause of morbidity and mortality in African women and their offspring. PAM is characterized by accumulation of infected erythrocytes (IEs) that adhere to chondroitin sulphate A (CSA) in the placental intervillous space. We show h...... transcription of var2csa. The results corroborate current efforts to develop PAM-specific vaccines based on VAR2CSA....

Study on the utilization of N fertilizers by labelling with /sup 15/N in a microplot experiment

Energy Technology Data Exchange (ETDEWEB)

Latkovics, I. (Magyar Tudomanyos Akademia, Budapest. Talajtani es Agrokemiai Kutato Intezet)

1982-12-01

The effect and residual effect of urea and NH/sub 4/NO/sub 3/ on the dry matter yield and N uptake of rye-grass and Sudan grass, as well as on the N status of the soil and the distribution of N within the soil profile were studied with /sup 15/N indication on a chernozem-like calcareous sandy soil in an isolated microplot experiment. It has been found that 57-79% of the N contents of the first cuttings came from the fertilizer, and the percentage N amounts decreased with each cutting. Under the given experimental conditions there was no significant difference between the N amounts taken up from urea or from NH/sub 4/NO/sub 3/. Rye-grass utilized N both from urea and NH/sub 4/NO/sub 3/ in the same degree (55%), while Sudan grass utilized 29.8% from urea and 36.1% from NH/sub 4/NO/sub 3/. Depending on the treatment, 22.8-31.7% of fertilizer-N was found in the 0-120 cm layer of the soil, while the larger part (74.8-84.6%) of this amount accumulated in the upper 40 cm layer. The amount of fertilizer-N not recovered (and thus 'lost' for the plants) was 13.3-21.6% in the case of rye-grass and 34.4-43.1% of Sudan grass.

Depth-resolved X-ray residual stress analysis in PVD (Ti, Cr) N hard coatings

CERN Document Server

Genzel, C

2003-01-01

Physical vapour deposition (PVD) of thin hard coatings on TiN basis is usually performed at rather low temperatures (T sub D < 500 C) far from thermal equilibrium, which leads to high intrinsic residual stresses in the growing film. In contrast to the extrinsic thermal residual stresses which can easily be estimated from the difference of the coefficients of thermal expansion between the substrate and the coating, a theoretical prediction of the intrinsic residual stresses is difficult, because their amount as well as their distribution within the film depend in a very complex way on the deposition kinetics. By the example of strongly fibre-textured PVD (Ti, Cr)N coatings which have been prepared under defined variation of the deposition parameters in order to adjust the residual stress distribution within the coatings, the paper compares different X-ray diffraction techniques with respect to their applicability for detecting residual stresses which are non-uniform over the coating thickness. (orig.)

pH-dependence of the specific binding of Cu(II) and Zn(II) ions to the amyloid-β peptide

International Nuclear Information System (INIS)

Ghalebani, Leila; Wahlström, Anna; Danielsson, Jens; Wärmländer, Sebastian K.T.S.; Gräslund, Astrid

2012-01-01

Highlights: ► Cu(II) and Zn(II) display pH-dependent binding to the Aβ(1–40) peptide. ► At pH 7.4 both metal ions display residue-specific binding to the Aβ peptide. ► At pH 5.5 the binding specificity is lost for Zn(II). ► Differential Cu(II) and Zn(II) binding may help explain metal-induced AD toxicity. -- Abstract: Metal ions like Cu(II) and Zn(II) are accumulated in Alzheimer’s disease amyloid plaques. The amyloid-β (Aβ) peptide involved in the disease interacts with these metal ions at neutral pH via ligands provided by the N-terminal histidines and the N-terminus. The present study uses high-resolution NMR spectroscopy to monitor the residue-specific interactions of Cu(II) and Zn(II) with 15 N- and 13 C, 15 N-labeled Aβ(1–40) peptides at varying pH levels. At pH 7.4 both ions bind to the specific ligands, competing with one another. At pH 5.5 Cu(II) retains its specific histidine ligands, while Zn(II) seems to lack residue-specific interactions. The low pH mimics acidosis which is linked to inflammatory processes in vivo. The results suggest that the cell toxic effects of redox active Cu(II) binding to Aβ may be reversed by the protective activity of non-redox active Zn(II) binding to the same major binding site under non-acidic conditions. Under acidic conditions, the protective effect of Zn(II) may be decreased or changed, since Zn(II) is less able to compete with Cu(II) for the specific binding site on the Aβ peptide under these conditions.

Fate of [15N]glycine in peat as determined by 13C and 15N CP-MAS NMR spectroscopy

International Nuclear Information System (INIS)

Benzing-Purdie, L.M.; Cheshire, M.V.; Williams, B.L.; Sparling, G.P.; Ratcliffe, C.I.; Ripmeester, J.A.

1986-01-01

Peat samples, nonsterile, sterilized by γ irradiation or autoclaving, were incubated with [ 15 N]glycine for a period of 6 months. The 13 C NMR data showed the established trend of increased humification with decreasing particle size and that autoclaving had significantly disturbed the humification-particle size distribution. The 15 N CP-MAS NMR spectra showed the presence of [ 15 N]glycine in all fractions after incubation. 15 NH 4 + , a result of either biological or chemical deamination, was one of the main products in the nonsterile peat series. The 15 N spectra also showed resonances corresponding to amine, secondary amide, and pyrrole-type nitrogen and the presence of glycine derivatives and melanoidins. The results presented give the first spectroscopic evidence of the possible involvement of the Maillard reaction in the humification process

Residual N effect of long-term applications of cattle slurry using winter wheat as test crop

DEFF Research Database (Denmark)

Suarez, Alfonso; Thomsen, Ingrid Kaag; Rasmussen, Jim

2018-01-01

) as reference treatments. In the test years, the customary nutrient treatments were withheld and each plot divided into six subplots randomly allocated increasing rates of mineral fertilizer N (0–250 kg N ha−1). The winter wheat yielded more in the first test year due to crop rotational effects and more benign...... climatic conditions, substantiating that more test years are needed when estimating residual N effects. The residual value of N added previously with NPK was negligible. In the first year, grain yields at N optimum were similar for NPK and SLU, but the amount of fertilizer N needed to reach optimum yield...... in cattle slurry (50, 100 and 150 kg total-N ha−1 termed ½, 1 and 1½ SLU), we estimated the residual N value over two consecutive growth periods (2014/2015 and 2015/2016). We used winter wheat as test crop and soils with a history of mineral fertilizers only (1 PK (no N)) and 1 NPK (100 kg N ha−1...

Synthesis of [1,3 - 15 N2] uracil

International Nuclear Information System (INIS)

Chiriac, M.; Axente, D.

2001-01-01

The synthesis of 15 N labelled uracil, using CO( 15 NH 2 ) 2 as starting material, is presented. The experimental procedure is an adaptation of the synthesis methods for the corresponding unlabelled compounds. Urea- 15 N 2 used as starting material was obtained from H 15 NO 3 (99 at.% 15 N) produced at National Institute for Research and Development of Isotopic and Molecular Technologies, Cluj-Napoca.The uracil structure was determined using the mass spectrometry method and the isotopic labelling was determined by the same method on the molecular compound. The synthesis scheme of (1,3- 15 N 2 ) uracil is presented. (authors)

Variable δ15N Diet-Tissue Discrimination Factors among Sharks: Implications for Trophic Position, Diet and Food Web Models

Science.gov (United States)

Olin, Jill A.; Hussey, Nigel E.; Grgicak-Mannion, Alice; Fritts, Mark W.; Wintner, Sabine P.; Fisk, Aaron T.

2013-01-01

The application of stable isotopes to characterize the complexities of a species foraging behavior and trophic relationships is dependent on assumptions of δ15N diet-tissue discrimination factors (∆15N). As ∆15N values have been experimentally shown to vary amongst consumers, tissues and diet composition, resolving appropriate species-specific ∆15N values can be complex. Given the logistical and ethical challenges of controlled feeding experiments for determining ∆15N values for large and/or endangered species, our objective was to conduct an assessment of a range of reported ∆15N values that can hypothetically serve as surrogates for describing the predator-prey relationships of four shark species that feed on prey from different trophic levels (i.e., different mean δ15N dietary values). Overall, the most suitable species-specific ∆15N values decreased with increasing dietary-δ15N values based on stable isotope Bayesian ellipse overlap estimates of shark and the principal prey functional groups contributing to the diet determined from stomach content analyses. Thus, a single ∆15N value was not supported for this speciose group of marine predatory fishes. For example, the ∆15N value of 3.7‰ provided the highest percent overlap between prey and predator isotope ellipses for the bonnethead shark (mean diet δ15N = 9‰) whereas a ∆15N value white shark (mean diet δ15N = 15‰). These data corroborate the previously reported inverse ∆15N-dietary δ15N relationship when both isotope ellipses of principal prey functional groups and the broader identified diet of each species were considered supporting the adoption of different ∆15N values that reflect the predators’ δ15N-dietary value. These findings are critical for refining the application of stable isotope modeling approaches as inferences regarding a species’ ecological role in their community will be influenced with consequences for conservation and management actions. PMID:24147026

15N liver function tests - concept, validity, clinical use

International Nuclear Information System (INIS)

Faust, H.; Jung, K.; Krumbiegel, P.; Hirschberg, K.; Reinhardt, R.; Junghans, P.

1987-01-01

Several liver function tests using the oral application of a nitrogen compound labelled with 15 N and the subsequent determination of 15 N in a certain fraction of urine by emission spectrometry are described. Because of the key position of the liver in the metabolism of nitrogen compounds the results of these tests allow conclusions concerning disturbances of special liver functions. Instructions for the clinical use of the '[ 15 N]Ammonium Test', '[ 15 N]Hippurate Test' the '[ 15 N]Methacetin Test', and the '[ 15 N]Glycine Test' are given. (author)

Networks of high mutual information define the structural proximity of catalytic sites: implications for catalytic residue identification.

Directory of Open Access Journals (Sweden)

Cristina Marino Buslje

Full Text Available Identification of catalytic residues (CR is essential for the characterization of enzyme function. CR are, in general, conserved and located in the functional site of a protein in order to attain their function. However, many non-catalytic residues are highly conserved and not all CR are conserved throughout a given protein family making identification of CR a challenging task. Here, we put forward the hypothesis that CR carry a particular signature defined by networks of close proximity residues with high mutual information (MI, and that this signature can be applied to distinguish functional from other non-functional conserved residues. Using a data set of 434 Pfam families included in the catalytic site atlas (CSA database, we tested this hypothesis and demonstrated that MI can complement amino acid conservation scores to detect CR. The Kullback-Leibler (KL conservation measurement was shown to significantly outperform both the Shannon entropy and maximal frequency measurements. Residues in the proximity of catalytic sites were shown to be rich in shared MI. A structural proximity MI average score (termed pMI was demonstrated to be a strong predictor for CR, thus confirming the proposed hypothesis. A structural proximity conservation average score (termed pC was also calculated and demonstrated to carry distinct information from pMI. A catalytic likeliness score (Cls, combining the KL, pC and pMI measures, was shown to lead to significantly improved prediction accuracy. At a specificity of 0.90, the Cls method was found to have a sensitivity of 0.816. In summary, we demonstrate that networks of residues with high MI provide a distinct signature on CR and propose that such a signature should be present in other classes of functional residues where the requirement to maintain a particular function places limitations on the diversification of the structural environment along the course of evolution.

Networks of high mutual information define the structural proximity of catalytic sites: implications for catalytic residue identification.

Science.gov (United States)

Marino Buslje, Cristina; Teppa, Elin; Di Doménico, Tomas; Delfino, José María; Nielsen, Morten

2010-11-04

Identification of catalytic residues (CR) is essential for the characterization of enzyme function. CR are, in general, conserved and located in the functional site of a protein in order to attain their function. However, many non-catalytic residues are highly conserved and not all CR are conserved throughout a given protein family making identification of CR a challenging task. Here, we put forward the hypothesis that CR carry a particular signature defined by networks of close proximity residues with high mutual information (MI), and that this signature can be applied to distinguish functional from other non-functional conserved residues. Using a data set of 434 Pfam families included in the catalytic site atlas (CSA) database, we tested this hypothesis and demonstrated that MI can complement amino acid conservation scores to detect CR. The Kullback-Leibler (KL) conservation measurement was shown to significantly outperform both the Shannon entropy and maximal frequency measurements. Residues in the proximity of catalytic sites were shown to be rich in shared MI. A structural proximity MI average score (termed pMI) was demonstrated to be a strong predictor for CR, thus confirming the proposed hypothesis. A structural proximity conservation average score (termed pC) was also calculated and demonstrated to carry distinct information from pMI. A catalytic likeliness score (Cls), combining the KL, pC and pMI measures, was shown to lead to significantly improved prediction accuracy. At a specificity of 0.90, the Cls method was found to have a sensitivity of 0.816. In summary, we demonstrate that networks of residues with high MI provide a distinct signature on CR and propose that such a signature should be present in other classes of functional residues where the requirement to maintain a particular function places limitations on the diversification of the structural environment along the course of evolution.

15N-urea tracing emission spectroscopy for detecting the infection of Helicobacter pylori

International Nuclear Information System (INIS)

Zhu Yayi

2002-01-01

Objective: To study a noninvasive and nonradioactive method, 15 N-urea tracing emission spectroscopy, for detecting the Helicobacter pylori (Hp) infection. Methods: A group of 26 patients was tested with a method of 15 N-urea tracing emission spectroscopy for detecting the Hp infection. Results: Taking the bacterial culture or (and) Gram stain as a standard, the specificity, sensitivity and positive predicting rate of the test were 81%, 89% and 84%, respectively. Conclusion: The method could be considered useful for clinical practice

Fertilizer-n uptake and distribution in rice plants using 15N tracer technique

International Nuclear Information System (INIS)

Yan Juan; Shen Qirong; Yin Bin; Wan Xinjun

2009-01-01

Fertilizer-nitrogen (N) uptake and distribution in rice were studied using 15 N tracer technique. The results obtained were as follows. At the tillering, jointing and booting, and anthesis stages, 23.1%, 8.3% and 19.9% of N were taken from fertilizer applied in base (N1), tillering (N2) and jointing and booting (N3), respectively. The 15 N translocation from anthesis to maturity was in the order of N3>N1>N2, but the 15 N translocation efficiency was higher in N1 (base fertilizer treatment) than in the other two treatments. At maturity, the 15 N distribution in straw in the treatments of N1, N2 and N3 was only 24.3%, 26.7% and 30.4%, respectively. No matter what time the N fertilizer was applied, the 15 N uptake was mostly distributed in leaves, then in the sheath, the least in stem, and 15 N distribution in spike increased with the increased 15 N translocation from nutritional organs to spike after anthesis. The study also showed that the 15 N uptake at maturity in N1, N2 and N3 treatments was 10.3%, 5.9% and 12.4%, respectively. The results indicated that (1) when soil N content was not high, the base fertilizer application was important to rice growth, and optimal increment might help increase tillering, and improve rice quality; (2) the initiation fertilizer significantly promoted quantities during grain filling, and thus application of N fertilizer in initiation was of considerable advance in increasing N harvest index (NHI); (3) the rice plants absorbed less N applied in tillering stage due to a big N loss in that period. Therefore a little bit increase of base N fertilizer with no or very small amount of tillering fertilizer, together with some topdressing of N fertilizer during initiation could improve N uptake by rice. (authors)

CRISPR-Cas type I-A Cascade complex couples viral infection surveillance to host transcriptional regulation in the dependence of Csa3b.

Science.gov (United States)

He, Fei; Vestergaard, Gisle; Peng, Wenfang; She, Qunxin; Peng, Xu

2017-02-28

CRISPR-Cas (clustered regularly interspaced short palindromic repeats and the associated genes) constitute adaptive immune systems in bacteria and archaea and they provide sequence specific immunity against foreign nucleic acids. CRISPR-Cas systems are activated by viral infection. However, little is known about how CRISPR-Cas systems are activated in response to viral infection or how their expression is controlled in the absence of viral infection. Here, we demonstrate that both the transcriptional regulator Csa3b, and the type I-A interference complex Cascade, are required to transcriptionally repress the interference gene cassette in the archaeon Sulfolobus. Csa3b binds to two palindromic repeat sites in the promoter region of the cassette and facilitates binding of the Cascade to the promoter region. Upon viral infection, loading of Cascade complexes onto crRNA-matching protospacers leads to relief of the transcriptional repression. Our data demonstrate a mechanism coupling CRISPR-Cas surveillance of protospacers to transcriptional regulation of the interference gene cassette thereby allowing a fast response to viral infection. © The Author(s) 2016. Published by Oxford University Press on behalf of Nucleic Acids Research.

Membrane topology and identification of key residues of EaDAcT, a plant MBOAT with unusual substrate specificity.

Science.gov (United States)

Tran, Tam N T; Shelton, Jennifer; Brown, Susan; Durrett, Timothy P

2017-10-01

Euonymus alatus diacylglycerol acetyltransferase (EaDAcT) catalyzes the transfer of an acetyl group from acetyl-CoA to the sn-3 position of diacylglycerol to form 3-acetyl-1,2-diacyl-sn-glycerol (acetyl-TAG). EaDAcT belongs to a small, plant-specific subfamily of the membrane bound O-acyltransferases (MBOAT) that acylate different lipid substrates. Sucrose gradient density centrifugation revealed that EaDAcT colocalizes to the same fractions as an endoplasmic reticulum (ER)-specific marker. By mapping the membrane topology of EaDAcT, we obtained an experimentally determined topology model for a plant MBOAT. The EaDAcT model contains four transmembrane domains (TMDs), with both the N- and C-termini orientated toward the lumen of the ER. In addition, there is a large cytoplasmic loop between the first and second TMDs, with the MBOAT signature region of the protein embedded in the third TMD close to the interface between the membrane and the cytoplasm. During topology mapping, we discovered two cysteine residues (C187 and C293) located on opposite sides of the membrane that are important for enzyme activity. In order to identify additional amino acid residues important for acetyltransferase activity, we isolated and characterized acetyltransferases from other acetyl-TAG-producing plants. Among them, the acetyltransferase from Euonymus fortunei possessed the highest activity in vivo and in vitro. Mutagenesis of conserved amino acids revealed that S253, H257, D258 and V263 are essential for EaDAcT activity. Alteration of residues unique to the acetyltransferases did not alter the unique acyl donor specificity of EaDAcT, suggesting that multiple amino acids are important for substrate recognition. © 2017 The Authors The Plant Journal © 2017 John Wiley & Sons Ltd.

15N fractionation in infrared-dark cloud cores

Science.gov (United States)

Zeng, S.; Jiménez-Serra, I.; Cosentino, G.; Viti, S.; Barnes, A. T.; Henshaw, J. D.; Caselli, P.; Fontani, F.; Hily-Blant, P.

2017-07-01

Context. Nitrogen is one of the most abundant elements in the Universe and its 14N/15N isotopic ratio has the potential to provide information about the initial environment in which our Sun formed. Recent findings suggest that the solar system may have formed in a massive cluster since the presence of short-lived radioisotopes in meteorites can only be explained by the influence of a supernova. Aims: We seek to determine the 14N/15N ratio towards a sample of cold and dense cores at the initial stages in their evolution. Methods: We observed the J = 1 → 0 transitions of HCN, H13CN, HC15N, HN13C, and H15NC towards a sample of 22 cores in four infrared-dark clouds (IRDCs) which are believed to be the precursors of high-mass stars and star clusters. Assuming LTE and a temperature of 15 K, the column densities of HCN, H13CN, HC15N, HN13C, and H15NC are calculated and their 14N/15N ratio is determined for each core. Results: The 14N/15N ratios measured in our sample of IRDC cores range between 70 and ≥763 in HCN and between 161 and 541 in HNC. These ratios are consistent with the terrestrial atmosphere (TA) and protosolar nebula (PSN) values, and with the ratios measured in low-mass prestellar cores. However, the 14N/15N ratios measured in cores C1, C3, F1, F2, and G2 do not agree with the results from similar studies towards the same cores using nitrogen bearing molecules with nitrile functional group (-CN) and nitrogen hydrides (-NH) although the ratio spread covers a similar range. Conclusions: Relatively low 14N/15N ratios amongst the four-IRDCs were measured in IRDC G which are comparable to those measured in small cosmomaterials and protoplanetary disks. The low average gas density of this cloud suggests that the gas density, rather than the gas temperature, may be the dominant parameter influencing the initial nitrogen isotopic composition in young PSN. The reduced spectra (FITS files) are only available at the CDS via anonymous ftp to http

Adiabatic-passage cross polarization in N-15 NMR spectroscopy of peptides weakly associated to phospholipids: Determination of large RDC

International Nuclear Information System (INIS)

Zandomeneghi, Giorgia; Meier, Beat H.

2004-01-01

Structural information can be extracted from one-bond residual dipolar couplings (RDC) measured in NMR spectra of systems in field-ordered media. RDC can be on the order of J-couplings if the anisotropy of alignment is ∼ 10 -2 , 10-fold stronger than that typically used for structural studies of water-soluble proteins. In such systems the performance of 1 H → 15 N polarization transfer methods of the INEPT type is not satisfactory. In this study we show the effectiveness of adiabatic-passage cross-polarization (APCP) in transferring the 1 H → 15 N polarization in the bicelle-associated peptide Leucine Enkephalin (Lenk). APCP is efficient both in static samples and in samples spun at the magic angle (MAS) or any other angle of the spinning axis to the magnetic field (variable-angle spinning, VAS). The anisotropic spectrum of an aligned static sample and the isotropic spectrum of the sample under MAS provide a set of possible values for the 1 H- 15 N RDC of phospholipid-associated Lenk. The unambiguous determination of the 1 H- 15 N RDC was accomplished by means of VAS experiments