Journal articles: 'C:N balance'

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Kim, Hyung-Sub, Florent Noulèkoun, Nam-Jin Noh, and Yo-Whan Son. "Impacts of the National Forest Rehabilitation Plan and Human-Induced Environmental Changes on the Carbon and Nitrogen Balances of the South Korean Forests." Forests 12, no. 9 (August 25, 2021): 1150. http://dx.doi.org/10.3390/f12091150.

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Humans have affected the carbon (C) and nitrogen (N) cycles in forests; however, the quantification of the responses of forest C and N balances to human activities is limited. In this study, we have quantified the impacts of the long-term national forest rehabilitation plan and the contribution of the increase in air temperature, CO2 concentration, and N deposition on the C and N balances of the South Korean forests during 1973–2020 by using a biogeochemical model. During the simulation period, the C balance increased from 0.2 to 4.3 Mg C ha−1 year−1, and the N balance increased from 0.2 to 17.4 kg N ha−1 year−1. This resulted in the storage of 825 Tg C and 3.04 Tg N by the whole South Korean forests after the national forest rehabilitation plan. The increase in air temperature, CO2 concentration, and N deposition contributed −11.5, 17.4, and 177 Tg C to the stored C stock, respectively, and −25.4, 8.90, and 1807 Mg N to the stored N stock, respectively. This study provides references for future forest rehabilitation efforts and broadens our knowledge on the impacts of human-induced environmental changes on the C and N balances of forests.

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Zhang, Ruo-Xi, Siwen Li, Jingjing He, and Yun-Kuan Liang. "BIG regulates sugar response and C/N balance in Arabidopsis." Plant Signaling & Behavior 14, no. 11 (October 3, 2019): 1669418. http://dx.doi.org/10.1080/15592324.2019.1669418.

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Peng, Kui. "Main Chemical Nutrient Balances of a Typical Arable Ecosystem in North China." Advanced Materials Research 550-553 (July 2012): 2728–32. http://dx.doi.org/10.4028/www.scientific.net/amr.550-553.2728.

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Changes of nutrient cycle and balance in agricultural ecosystem will bring heavy impacts not only on land production, but also on ecological and environmental condition. We studied on the balances of main nutrients (carbon, nitrogen and phosphor) and their long-term changes in a typical arable ecosystem in North China, based on the resource data got from household surveys combined with land use data derived from remote sensing imagery. The results show that C and N balances of large-scale irrigated land changed from deficits in 1945 into great surpluses in 2002, respectively, and P surpluses also doubled in 2002. C, N and P balances in overall arable ecosystem showed significant surpluses despite of decreased total arable area after 60 years. Contrarily, C and N fluxes of arable landscape in 1945 showed overall deficits. Nutrient balance changes of arable lands were impacted mainly by anthropogenic factors such as fertilizer input, land productivity crop residue utility and land use.

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Kruse, J., I. Hetzger, R. Hänsch, R. R. Mendel, and H. Rennenberg. "Elevated pCO2Affects C and N Metabolism in Wild Type and Transgenic Tobacco Exhibiting Altered C/N Balance in Metabolite Analysis." Plant Biology 5, no. 5 (September 2003): 540–49. http://dx.doi.org/10.1055/s-2003-44792.

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Luyssaert, S., G. Abril, R. Andres, D. Bastviken, V. Bellassen, P. Bergamaschi, P. Bousquet, et al. "The European CO2, CO, CH4 and N2O balance between 2001 and 2005." Biogeosciences Discussions 9, no. 2 (February 21, 2012): 2005–53. http://dx.doi.org/10.5194/bgd-9-2005-2012.

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Abstract. Globally, terrestrial ecosystems have absorbed about 30% of anthropogenic emissions over the period 20007–2007 and inter-hemispheric gradients indicate that a significant fraction of terrestrial carbon sequestration must be north of the Equator. We present a compilation of the CO2, CO, CH4 and N2O balance of Europe following a dual constraint approach in which (1) a land-based balance derived mainly from ecosystem carbon inventories and (2) a land-based balance derived from flux measurements are confronted with (3) the atmospheric-based balance derived from inversion informed by measurements of atmospheric GHG concentrations. Good agreement between the GHG balances based on fluxes (1249 ± 545 Tg C in CO2-eq y−1), inventories (1299 ± 200 Tg C in CO2-eq y−1) and inversions (1210 ± 405 Tg C in CO2-eq y−1) increases our confidence that current European GHG balances are accurate. However, the uncertainty remains large and largely lacks formal estimates. Given that European net land-atmosphere balances are determined by a few dominant fluxes, the uncertainty of these key components needs to be formally estimated before efforts could be made to reduce the overall uncertainty. The dual-constraint approach confirmed that the European land surface, including inland waters and urban areas, is a net source for CO2, CO, CH4 and N2O. However, for all ecosystems except croplands, C uptake exceeds C release and us such 210 ± 70 Tg C y−1 from fossil fuel burning is removed from the atmosphere and sequestered in both terrestrial and inland aquatic ecosystems. If the C cost for ecosystem management is taken into account, the net uptake of ecosystems was estimated to decrease by 45% but still indicates substantial C-sequestration. Also, when the balance is extended from CO2 towards the main GHGs, C-uptake by terrestrial and aquatic ecosystems is compensated for by emissions of GHGs. As such the European ecosystems are unlikely to contribute to mitigating the effects of climate change.

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Zheng, Yu Ge, and Yan Ming Chang. "On the Edge-Balance Index Sets of the Net Graph C_n²×P_{2_n}(n=0(mod2))." Advanced Materials Research 314-316 (August 2011): 2556–59. http://dx.doi.org/10.4028/www.scientific.net/amr.314-316.2556.

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In this paper, we mainly use the methods and techniques of graph theory and combinatorial mathematics to research the largest edge-balance index of the graph Cn2*P2n(n=0(mod2)), the edge-balance index sets of the graph are discussed, and finally getting the constructive proof about all the edge-balance index sets of Cn2*P2n(n=0(mod2))

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Lu, Guofeng, and Gengsheng Jiao. "Balance the oxidation resistance and mechanical properties of C/Si–C–N composite by a Si–O–C interphase." Composite Interfaces 19, no. 2 (March 2012): 83–91. http://dx.doi.org/10.1080/09276440.2012.688721.

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Ji, Yu Rong, Ai Jun Li, and Jing Jing Yao. "On Edge-Balance Index Sets of the Graph C_nxP₆(n=3,4,5mod6)." Advanced Materials Research 339 (September 2011): 662–65. http://dx.doi.org/10.4028/www.scientific.net/amr.339.662.

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Let G be a simple graph with vertex set V(G) and edge set E(G), and let Z2 = {0,1}. For a given binary edge labeling f :E(G)→Z2 , the edge labeling f induces a partial vertex labeling f*:V(G)→Z2 such that f*(v) =1(0) iff the number of 1-edges (0-edges) is strictly greater than the number of 0-edges (1-edges) incident to v , otherwise f*(v) is idefined. For i∈Z2 , let v(i)=card{v∈V(G): f*(v) =i} and e(i) = card{e∈E(G) : f (e)=i}. The edge-balance index sets of a graph G,EBI(G), is defined as {|v(0) −v(1) |: the edge labeling f satisfies |e(0)−e(1) |≤1}.In this paper, we completely determine the edge-balance CnxP 6(n=3,4,5mod6).

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Schreiner, Edward P., Shewangizaw Teketel, and Raul F. Lobo. "Catalytic n-pentane conversion on H-ZSM-5 at high pressure." New Journal of Chemistry 40, no. 5 (2016): 4245–51. http://dx.doi.org/10.1039/c5nj02733k.

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Sidra, Lala Rukh, Nafeesa Mushtaq, Guofei Chen, and Xingzhong Fang. "Synthesis of high Tg and organosoluble poly(N-arylene benzimidazole ether imide) copolymers by C–N/C–O coupling reaction." High Performance Polymers 30, no. 4 (April 5, 2017): 465–74. http://dx.doi.org/10.1177/0954008317701822.

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A series of poly( N-arylene benzimidazole ether imide) copolymers PEIBIs were prepared from 1H,3′H-5,5′-bis-benzimidazole, bisphenol-A and 4,4′-bis(4-fluorophthalimido)diphenyl ether by nucleophilic displacement polymerization. The resulting copolymers PEIBI(10–90) demonstrated moderate to good solubility in polar aprotic solvents and high glass transition temperatures ( Tgs) of 228–336°C, good thermal stability with 10% weight loss temperatures in the range of 503–548°C. All copolymer films showed good mechanical properties with tensile strengths of 101–130 MPa, tensile moduli of 3.3–4.0 GPa, elongations at break of 5–7%, and also presented low water uptake (0.15–0.34%). The wide-angle X-ray diffraction results revealed the amorphous nature of copolymers. The copolymer PEIBI-80 showed good balance in solubility, thermal and mechanical properties.

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McKIVER, WILLIAM J., and DAVID G. DRITSCHEL. "Balance in non-hydrostatic rotating stratified turbulence." Journal of Fluid Mechanics 596 (January 17, 2008): 201–19. http://dx.doi.org/10.1017/s0022112007009421.

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It is now well established that two distinct types of motion occur in geophysical turbulence: slow motions associated with potential vorticity advection and fast oscillations due to inertia–gravity waves (or acoustic waves). Many studies have theorized the existence of a flow for which the entire motion is controlled by the potential vorticity (or one ‘master variable’) – this is known as balance. In real geophysical flows, deviations from balance in the form of inertia–gravity waves or ‘imbalance’ have often been found to be small. Here we examine the extent to which balance holds in rotating stratified turbulence which is nearly balanced initially.Using the non-hydrostatic fluid dynamical equations under the Boussinesq approximation, we analyse properties of rotating stratified turbulence spanning a range of Rossby numbers (Ro≡|ζ|max/f) and the frequency ratios (c≡N/f) where ζ is the relative vertical vorticity, f is the Coriolis frequency and N is the buoyancy frequency. Using a recently introduced diagnostic procedure, called ‘optimal potential vorticity balance’, we extract the balanced part of the flow in the simulations and assess how the degree of imbalance varies with the above parameters.We also introduce a new and more efficient procedure, building upon a quasi-geostrophic scaling analysis of the complete non-hydrostatic equations. This ‘nonlinear quasi-geostrophic balance’ procedure expands the equations of motion to second order in Rossby number but retains the exact (unexpanded) definition of potential vorticity. This proves crucial for obtaining an accurate estimate of balanced motions. In the analysis of rotating stratified turbulence at Ro≲1 and N/f≫1, this procedure captures a significantly greater fraction of the underlying balance than standard (linear) quasi-geostrophic balance (which is based on the linearized equations about a state of rest). Nonlinear quasi-geostrophic balance also compares well with optimal potential vorticity balance, which captures the greatest fraction of the underlying balance overall.More fundamentally, the results of these analyses indicate that balance dominates in carefully initialized simulations of freely decaying rotating stratified turbulence up to O(1) Rossby numbers when N/f≫1. The fluid motion exhibits important quasi-geostrophic features with, in particular, typical height-to-width scale ratios remaining comparable to f/N.

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Ji, Yu Rong, Ying Fang Zhang, and Yu Ge Zheng. "On Edge-Balance Index Sets of the Graph C_n×P_b(n=0,1,2mod6)." Applied Mechanics and Materials 143-144 (December 2011): 750–54. http://dx.doi.org/10.4028/www.scientific.net/amm.143-144.750.

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Let G be a simple graph with vertex set V(G) and edge set E(G), and let Z2=(0,1) For a given binary edge labeling f:E(G)→Z2,the edge labeling f induces a partial vertex labeling f*:V(G)→Z2 such that f*(v)=1(0) iff the number of 1-edges (0-edges) is strictly greater than the number of 0-edges (1-edges) incident to , otherwise f*(v) is undefined. For i∈Z2, let v(i)=card(e∈V(G):f*(v)=i) and e(i)=card(e∈E(G):f(e)=i). The edge-balance index sets of a graph G,EBI(G), is defined as {|v(0)-v(1): the edge labeling f satisfies } . In this paper, we completely determine the edge-balance index |e(0)-e(1)|≤1 sets of the graph Cn×Pb(n=0,1,2 mod 6)

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Smith, S. V., and H. H. Veeh. "Mass balance of biogeochemically active materials (C, N, P) in a hypersaline gulf." Estuarine, Coastal and Shelf Science 29, no. 3 (September 1989): 195–215. http://dx.doi.org/10.1016/0272-7714(89)90053-x.

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Peters, Morten K., Christian Näther, and Rainer Herges. "Crystal structure of bis(4-methoxypyridine-κN)(meso-5,10,15,20-tetraphenylporphyrinato-κ4 N,N′,N′′,N′′′)iron(III) perchlorate." Acta Crystallographica Section E Crystallographic Communications 75, no. 6 (May 10, 2019): 762–65. http://dx.doi.org/10.1107/s2056989019006194.

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In the crystal structure of the title compound, [Fe(C44H28N4)(C6H7NO)2]ClO4, the FeIII ions are coordinated in an octahedral fashion by four N atoms of the porphyrin moiety and two N atoms of two 4-methoxypyridine ligands into discrete complexes that are located on inversion centers. Charge-balance is achieved by perchlorate anions that are disordered around twofold rotation axes. In the crystal structure, the discrete cationic complexes and the perchlorate anions are arranged into layers with weak C—H...O interactions between the cations and the anions. The porphyrin moieties of neighboring layers show a herringbone-like arrangement.

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Volk, Matthias, Jan Enderle, and Seraina Bassin. "Subalpine grassland carbon balance during 7 years of increased atmospheric N deposition." Biogeosciences 13, no. 12 (July 1, 2016): 3807–17. http://dx.doi.org/10.5194/bg-13-3807-2016.

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Abstract. Air pollution agents interact when affecting biological sinks for atmospheric CO2, e.g., the soil organic carbon (SOC) content of grassland ecosystems. Factors favoring plant productivity, like atmospheric N deposition, are usually considered to favor SOC storage. In a 7-year experiment in subalpine grassland under N- and O3-deposition treatment, we examined C fluxes and pools. Total N deposition was 4, 9, 14, 29 and 54 kg N ha−1 yr−1 (N4, N9, etc.); annual mean phytotoxic O3 dose was 49, 65 and 89 mmol m−2 projected leaf area. We hypothesized that between years SOC of this mature ecosystem would not change in control treatments and that effects of air pollutants are similar for plant yield, net ecosystem productivity (NEP) and SOC content, leading to SOC content increasing with N deposition. Cumulative plant yield showed a significant N and N × N effect (+38 % in N54) but no O3 effect. In the control treatment SOC increased significantly by 9 % in 7 years. Cumulative NEP did show a strong, hump-shaped response pattern to N deposition with a +62 % increase in N14 and only +39 % increase in N54 (N effect statistically not significant, N × N interaction not testable). SOC had a similar but not significant response to N, with highest C gains at intermediate N deposition rates, suggesting a unimodal response with a marginal (P = 0.09) N × N interaction. We assume the strong, pollutant-independent soil C sink developed as a consequence of the management change from grazing to cutting. The non-parallel response of SOC and NEP compared to plant yield under N deposition is likely the result of increased respiratory SOC losses, following mitigated microbial N-limitation or priming effects, and a shift in plant C allocation leading to smaller C input from roots.

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Haezam, Farah Natasha, Normah Awang, Nurul Farahana Kamaludin, Mukesh M. Jotani, and Edward R. T. Tiekink. "(N,N-Diisopropyldithiocarbamato)triphenyltin(IV): crystal structure, Hirshfeld surface analysis and computational study." Acta Crystallographica Section E Crystallographic Communications 75, no. 10 (September 12, 2019): 1479–85. http://dx.doi.org/10.1107/s2056989019012490.

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The crystal and molecular structures of the title triorganotin dithiocarbamate, [Sn(C6H5)3(C7H14NS2)], are described. The molecular geometry about the metal atom is highly distorted being based on a C3S tetrahedron as the dithiocarbamate ligand is asymmetrically chelating to the tin centre. The close approach of the second thione-S atom [Sn...S = 2.9264 (4) Å] is largely responsible for the distortion. The molecular packing is almost devoid of directional interactions with only weak phenyl-C—H...C(phenyl) interactions, leading to centrosymmetric dimeric aggregates, being noted. An analysis of the calculated Hirshfeld surface points to the significance of H...H contacts, which contribute 66.6% of all contacts to the surface, with C...H/H...C [26.8%] and S...H/H...H [6.6%] contacts making up the balance.

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Blanco, Susana, Alberto Macario, and Juan Carlos López. "Pyridine–acetaldehyde, a molecular balance to explore the n→π* interaction." Physical Chemistry Chemical Physics 21, no. 37 (2019): 20566–70. http://dx.doi.org/10.1039/c9cp04088a.

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Weak n→π* and C–H⋯O interactions determine the structure of pyridine–acetaldehyde adduct. The n→π* distance oscillates with the methyl group internal rotation which acts as a sort of molecular balance to explore the n→π* interaction energy.

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Overton, J. Michael, Todd D. Williams, James Bradley Chambers, Ross P. Henderson, and Michael E. Rashotte. "Central Leptin Infusion Attenuates the Cardiovascular and Metabolic Responses to Negative Energy Balance." Hypertension 36, suppl_1 (October 2000): 689. http://dx.doi.org/10.1161/hyp.36.suppl_1.689-c.

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65 Caloric restriction is commonly prescribed to obese individuals to reduce their risk for cardiovascular disease. Hypothalamic pathways regulated by leptin are important in activating homeostatic responses to reduced caloric intake. We tested the hypothesis that central infusion of leptin would prevent reductions in blood pressure (BP), heart rate (HR), and oxygen consumption (VO 2 ) produced by acute caloric deprivation. Male Sprague-Dawley rats were instrumented with telemetry devices for measuring blood pressure and icv guide cannulae for chronic infusion of vehicle or murine leptin. After 10 d of recovery, rats were housed in metabolic chambers for continuous assessment of BP and HR by telemetry, and VO 2 and respiratory quotient (RQ) by indirect calorimetry. For group comparisons, data were averaged for the light (inactive) and dark (active) phases. After obtaining baseline data (3 days), rats (n=22) were briefly anesthetized with halothane to attach osmotic pumps containing either vehicle (PBS, 0.5 μl/h) or leptin (42 ng/h) for chronic icv infusion during either ad lib feeding or 48h of fasting. In ad lib feeding animals (n=5) receiving PBS infusions, transient (24 h) reductions in caloric intake and active phase VO 2, with no effect on body weight, HR and MAP were observed. We attribute these effects to anesthesia required for pump attachment. After 48 h, leptin infusion (in ad lib animals; n=5) significantly reduced caloric intake (50-60%), body weight (-15±5 g) and RQ (-0.07±0.02); indicating lipolysis), while increasing HR (+28±4 bpm) and having no effect on MAP. Fasting reduced active phase MAP (-9±3 mmHg), HR (-60±3 bpm), and VO 2 (-25 %) in rats receiving PBS infusions (n=6). ICV leptin infusion (n=6) had no effect on the reduction in active phase MAP, but significantly attenuated fasting-induced active phase decreases in HR (-25±4 bpm) and VO 2 (-17%). In addition, leptin completely prevented fasting-induced decreases in inactive phase HR and VO 2 . The results are consistent with the hypothesis that reductions in central leptin signaling mediate the homeostatic decreases in HR and metabolic rate in response to acute caloric deprivation.

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Benson, Ronald E., Tapashi G. Roy, Saroj K. S. Hazari, Kanak K. Barua, and Edward R. T. Tiekink. "3,10-C-meso-2,5,5,7,9,12,12,14-Octamethyl-1,8-diaza-4,11-diazoniacyclotetradecane bis(thiocyanate)." Acta Crystallographica Section E Structure Reports Online 62, no. 5 (April 21, 2006): o1968—o1970. http://dx.doi.org/10.1107/s1600536806013869.

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The title compound, C18H42N4 2+·2CNS−, contains diprotonated cations located about centres of inversion, with charge balance provided by thiocyanate anions. Intermolecular N—H...N and N—H...S hydrogen bonds are formed in the crystal structure, which comprises columns of macrocyclic cations that define channels in which the thiocyanate anions reside.

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Luyssaert, S., G. Abril, R. Andres, D. Bastviken, V. Bellassen, P. Bergamaschi, P. Bousquet, et al. "The European land and inland water CO2, CO, CH4 and N2O balance between 2001 and 2005." Biogeosciences 9, no. 8 (August 24, 2012): 3357–80. http://dx.doi.org/10.5194/bg-9-3357-2012.

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Abstract. Globally, terrestrial ecosystems have absorbed about 30% of anthropogenic greenhouse gas emissions over the period 2000–2007 and inter-hemispheric gradients indicate that a significant fraction of terrestrial carbon sequestration must be north of the Equator. We present a compilation of the CO2, CO, CH4 and N2O balances of Europe following a dual constraint approach in which (1) a land-based balance derived mainly from ecosystem carbon inventories and (2) a land-based balance derived from flux measurements are compared to (3) the atmospheric data-based balance derived from inversions constrained by measurements of atmospheric GHG (greenhouse gas) concentrations. Good agreement between the GHG balances based on fluxes (1294 ± 545 Tg C in CO2-eq yr−1), inventories (1299 ± 200 Tg C in CO2-eq yr−1) and inversions (1210 ± 405 Tg C in CO2-eq yr−1) increases our confidence that the processes underlying the European GHG budget are well understood and reasonably sampled. However, the uncertainty remains large and largely lacks formal estimates. Given that European net land to atmosphere exchanges are determined by a few dominant fluxes, the uncertainty of these key components needs to be formally estimated before efforts could be made to reduce the overall uncertainty. The net land-to-atmosphere flux is a net source for CO2, CO, CH4 and N2O, because the anthropogenic emissions by far exceed the biogenic sink strength. The dual-constraint approach confirmed that the European biogenic sink removes as much as 205 ± 72 Tg C yr−1 from fossil fuel burning from the atmosphere. However, This C is being sequestered in both terrestrial and inland aquatic ecosystems. If the C-cost for ecosystem management is taken into account, the net uptake of ecosystems is estimated to decrease by 45% but still indicates substantial C-sequestration. However, when the balance is extended from CO2 towards the main GHGs, C-uptake by terrestrial and aquatic ecosystems is offset by emissions of non-CO2 GHGs. As such, the European ecosystems are unlikely to contribute to mitigating the effects of climate change.

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Leroux, Shawn J., Dror Hawlena, and Oswald J. Schmitz. "Predation risk, stoichiometric plasticity and ecosystem elemental cycling." Proceedings of the Royal Society B: Biological Sciences 279, no. 1745 (August 15, 2012): 4183–91. http://dx.doi.org/10.1098/rspb.2012.1315.

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It is widely held that herbivore growth and production is limited by dietary nitrogen (N) that in turn constrains ecosystem elemental cycling. Yet, emerging evidence suggests that this conception of limitation may be incomplete, because chronic predation risk heightens herbivore metabolic rate and shifts demand from N-rich proteins to soluble carbohydrate–carbon (C). Because soluble C can be limiting, predation risk may cause ecosystem elemental cycling rates and stoichiometric balance to depend on herbivore physiological plasticity. We report on a stoichiometrically explicit ecosystem model that investigates this problem. The model tracks N, and soluble and recalcitrant C through ecosystem compartments. We evaluate how soluble plant C influences C and N stocks and flows in the presence and absence of predation risk. Without risk, herbivores are limited by N and respire excess C so that plant-soluble C has small effects only on elemental stocks and flows. With predation risk, herbivores are limited by soluble C and release excess N, so plant-soluble C critically influences ecosystem elemental stocks flows. Our results emphasize that expressing ecosystem stoichiometric balance using customary C : N ratios that do not distinguish between soluble and recalcitrant C may not adequately describe limitations on elemental cycling.

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Sarma, Banashree, Sundar Bhattacharya, Nirmali Gogoi, Sreyashi Paul, and Bhaswatee Baroowa. "Impact of N fertilization on C balance and soil quality in maize-dhaincha cropping sequence." Journal of Agricultural Sciences, Belgrade 60, no. 2 (2015): 135–48. http://dx.doi.org/10.2298/jas1502135s.

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Tsang, Wing Y., Naveed Ahmed, Karl Hemming, and Michael I. Page. "Competitive endo- and exo-cyclic CN fission in the hydrolysis of N-aroyl β-lactams." Canadian Journal of Chemistry 83, no. 9 (September 1, 2005): 1432–39. http://dx.doi.org/10.1139/v05-153.

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The balance between endo- and exo-cyclic CN fission in the hydrolysis of N-aroyl β-lactams shows that the difference in reactivity between strained β-lactams and their acyclic analogues is minimal. Attack of hydroxide ion occurs preferentially at the exocyclic acyl centre rather than that of the β-lactam during the hydrolysis of N-p-nitrobenzoyl β-lactam. In general, both endo- and exo-cyclic CN bond fission occurs in the alkaline hydrolysis of N-aroyl β-lactams, the ratio of which varies with the aryl substituent. Hence, the Brønsted β-values differ for the two processes: 0.55 for the ring-opening reaction and 1.54 for the exocyclic CN bond fission reaction. For the pH-independent and acid-catalysed hydrolysis of N-benzoyl β-lactam, less than 3% of products are derived from exocyclic CN bond fission. Key words: β-lactams, hydrolysis, linear free energy relationships, strain.

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Liu, Li-Lin, Xiao-Ling Zhou, Hong-Jian Yang, and Rong Chen. "Effect of Dietary Forage/Concentrate Ratio on Nutrient Digestion and Energy and Protein Metabolism in Adult Donkeys." Animals 10, no. 6 (June 12, 2020): 1025. http://dx.doi.org/10.3390/ani10061025.

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The domestic donkey is a unique equid species with specific nutritional requirements; however, limited feeding studies have been addressed so far to understand nutrient digestion and metabolism in donkeys. In the present study, six adult female Xinjiang donkeys (180 ± 10 kg live weight) were applied in a 3 × 3 Latin square design to investigate the effect of the forage/concentrate ratio (F/C) in three experimental diets on N and energy balance within 12 weeks. Rice straw and alfalfa hay were chosen as forage ingredients, and the diets included the following: (1) a high-fiber (HF) ration (F/C = 80:20), (2) a medium-fiber (MF) ration (F/C = 55:45), and (3) a low-fiber (LF) ration (35:45). After the fixed amount of diets were daily allowed to the animals, total feces and urine were collected to determine total tract digestibility, N and energy balance. As a result, dry matter intake did not differ among the three diet groups. Decreasing the dietary F/C significantly promoted protein digestibility and decreased fiber digestibility. The N and energy balance analysis showed that increasing the F/C remarkably (p < 0.01) decreased N retention through the increase in N excretion in urine, and the highest N loss relative to N intake was observed in MF. Meanwhile, decreasing the F/C linearly increased the conversion efficiency of digestible energy to metabolizable energy. Taken together, the results obtained in the present study implicated that the dietary forage level should not be less than 55% to maintain greater N and energy utilization in feeding practice, otherwise, a donkey’s N utilization might be highly discounted.

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ZHANG, HUI, ZHONGQIN LI, PING ZHOU, XIAOFAN ZHU, and LIN WANG. "Mass-balance observations and reconstruction for Haxilegen Glacier No.51, eastern Tien Shan, from 1999 to 2015." Journal of Glaciology 64, no. 247 (August 15, 2018): 689–99. http://dx.doi.org/10.1017/jog.2018.58.

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ABSTRACTHaxilegen Glacier No.51 (43.731°N, 84.391°E; CN5Y741C0051) is located in the Kuytun river basin, Erenharbirga range, eastern Tien Shan. This study presents the annual mass balance of Haxilegen Glacier No.51 for 7 hydrological years and uses a temperature-index and an accumulation model to reconstruct the annual mass balance from 1999 to 2015. The model is calibrated against annual altitudinal mass-balance measurements and then applied to the period with no measurements. We find an accumulated mass balance of −6.06 ± 0.88 m w.e.a−1 over the period of 16 hydrological years, with an average annual value of −0.32 ± 0.22 m w.e.a−1. The mean glacier-wide annual, summer and winter balances for 1999 to 2015 are −0.37, −0.54 and 0.16 ± 0.22 m w.e.a−1, respectively, with a high correlation coefficient (r = 0.95, p < 0.001) between annual balance and summer balance. The calculated mass-balance sensitivity of the glacier to temperature is −0.51 m w.e.a−1 °C−1 and to precipitation is 0.08 m w.e.a−1 for a 10% increase. The sensitivity of seasonal mass balance indicates that temperature during the melt season (May–August) and annual precipitation are the major contributors to mass-balance fluctuation.

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Thompson, Mary, Ann Medley, and Steve Teran. "Validity of the Sitting Balance Scale in older adults who are non-ambulatory or have limited functional mobility." Clinical Rehabilitation 27, no. 2 (July 26, 2012): 166–73. http://dx.doi.org/10.1177/0269215512452879.

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Objective: To determine whether the Sitting Balance Scale is an acceptable alternative to the Trunk Impairment Scale for measuring the construct of sitting balance, to examine relationships with other clinical outcomes and to establish discriminative validity. Design: Prospective descriptive methodological study. Setting: Acute care, inpatient rehabilitation, skilled nursing facility and home health. Participants: Patients receiving physical therapy ( N = 98; n = 20 acute care, n = 18 inpatient rehabilitation, n = 30 skilled nursing facility, n = 30 home setting) mean (SD) age, 80.5 (7.9) years. Nineteen were non-ambulatory and 79 had limited functional mobility with Timed Up and Go scores ≥20 seconds. Main measures: Sitting Balance Scale, Trunk Impairment Scale, Timed Up and Go, length of stay and setting specific clinical measures of sitting balance (OASIS-C M1850; MDS G-3b). Results: Moderate association between ambulatory status and sitting balance measures (Sitting Balance Scale r = 0.67, Trunk Impairment Scale r = 0.61; P = 0.0001). Moderate to strong relationships between Sitting Balance Scale, Trunk Impairment Scale and clinical outcomes varying by setting. MANOVA results revealed differences between ambulators and non-ambulators and among diagnostic categories for both instruments ( P < 0.001). Conclusions: The Sitting Balance Scale is comparable to the Trunk Impairment Scale for measuring sitting balance in older adults who are non-ambulatory or have limited mobility.

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Wang, Xiao, Xiaoli Wei, Gaoyin Wu, and Shengqun Chen. "Ammonium application mitigates the effects of elevated carbon dioxide on the carbon/nitrogen balance of Phoebe bournei seedlings." Tree Physiology 41, no. 9 (February 14, 2021): 1658–68. http://dx.doi.org/10.1093/treephys/tpab026.

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Abstract The study of plant responses to increases in atmospheric carbon dioxide (CO2) concentration is crucial to understand and to predict the effect of future global climate change on plant adaptation and evolution. Increasing amount of nitrogen (N) can promote the positive effect of CO2, while how N forms would modify the degree of CO2 effect is rarely studied. The aim of this study was to determine whether the amount and form of nitrogen (N) could mitigate the effects of elevated CO2 (eCO2) on enzyme activities related to carbon (C) and N metabolism, the C/N ratio, and growth of Phoebe bournei (Hemsl.) Y.C. Yang. One-year-old P. bournei seedlings were grown in an open-top air chamber under either an ambient CO2 (aCO2) (350 ± 70 μmol•mol−1) or an eCO2 (700 ± 10 μmol•mol−1) concentration and cultivated in soil treated with either moderate (0.8 g per seedling) or high applications (1.2 g per seedling) of nitrate or ammonium. In seedlings treated with a moderate level of nitrate, the activities of key enzymes involved in C and N metabolism (i.e., Rubisco, Rubisco activase and glutamine synthetase) were lower under eCO2 than under aCO2. By contrast, key enzyme activities (except GS) in seedlings treated with high nitrate or ammonium were not significantly different between aCO2 and eCO2 or higher under eCO2 than under aCO2. The C/N ratio of seedlings treated with moderate or high nitrate under eCO2was significantly changed compared with the seedlings grown under aCO2, whereas the C/N ratio of seedlings treated with ammonium was not significantly different between aCO2 and eCO2. Therefore, under eCO2, application of ammonium can be beneficial C and N metabolism and mitigate effects on the C/N ratio.

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Barham, Joshua P., Souma Tamaoki, Hiromichi Egami, Noriyuki Ohneda, Tadashi Okamoto, Hiromichi Odajima, and Yoshitaka Hamashima. "C-Alkylation of N-alkylamides with styrenes in air and scale-up using a microwave flow reactor." Organic & Biomolecular Chemistry 16, no. 41 (2018): 7568–73. http://dx.doi.org/10.1039/c8ob02282h.

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Gollan, Peter J., Dorota Muth-Pawlak, and Eva-Mari Aro. "Rapid Transcriptional Reprogramming Triggered by Alteration of the Carbon/Nitrogen Balance Has an Impact on Energy Metabolism in Nostoc sp. PCC 7120." Life 10, no. 11 (November 20, 2020): 297. http://dx.doi.org/10.3390/life10110297.

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Nostoc (Anabaena) sp. PCC 7120 is a filamentous cyanobacterial species that fixes N2 to nitrogenous compounds using specialised heterocyst cells. Changes in the intracellular ratio of carbon to nitrogen (C/N balance) is known to trigger major transcriptional reprogramming of the cell, including initiating the differentiation of vegetative cells to heterocysts. Substantial transcriptional analysis has been performed on Nostoc sp. PCC 7120 during N stepdown (low to high C/N), but not during C stepdown (high to low C/N). In the current study, we shifted the metabolic balance of Nostoc sp. PCC 7120 cultures grown at 3% CO2 by introducing them to atmospheric conditions containing 0.04% CO2 for 1 h, after which the changes in gene expression were measured using RNAseq transcriptomics. This analysis revealed strong upregulation of carbon uptake, while nitrogen uptake and metabolism and early stages of heterocyst development were downregulated in response to the shift to low CO2. Furthermore, gene expression changes revealed a decrease in photosynthetic electron transport and increased photoprotection and reactive oxygen metabolism, as well a decrease in iron uptake and metabolism. Differential gene expression was largely attributed to change in the abundances of the metabolites 2-phosphoglycolate and 2-oxoglutarate, which signal a rapid shift from fluent photoassimilation to glycolytic metabolism of carbon after transition to low CO2. This work shows that the C/N balance in Nostoc sp. PCC 7120 rapidly adjusts the metabolic strategy through transcriptional reprogramming, enabling survival in the fluctuating environment.

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Nemeth, Michael, Stacie Anderson, Martha Kirby, and David Bodine. "Hmgb3 Regulates the Balance between HSC Differentiation and Self Renewal." Blood 106, no. 11 (November 16, 2005): 1718. http://dx.doi.org/10.1182/blood.v106.11.1718.1718.

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Abstract Hmgb3 is an X-linked member of a family of sequence-independent chromatin-binding proteins that is preferentially expressed in hematopoietic stem cells (HSC; lin−, c-kitHI, Sca-1HI, IL-7Rα−). Hmgb3 deficient mice (Hmgb3−/Y: KO) contain normal numbers of HSCs, capable of repopulation and self-renewal, but fewer common lymphoid (CLP: lin−, c-kitLO, Sca-1LO, IL-7Rα+) and myeloid (CMP: lin−, c-kit+, Sca-1−, IL-7Rα−) progenitors (Nemeth et al. Blood, 2005). We hypothesized this reduction may be due to impaired production of CLP and CMP by KO HSCs or by rapid differentiation of KO CLP and CMP. CMP were isolated from littermate control (WT) and KO mice. The initial CFU number was compared to CFU numbers from CMP cultured for 5 days in serum-free media containing SCF, Flt3L, IL-3, IL-6 and TPO. WT CMP (n = 12) increased 2.7 ± 1.8-fold in CFU-GM/1000 CMP between d0 and d5. KO CMP (n = 12) increased 4.9 ± 1.9-fold between d0 and d5 (p = .16, ns). We conclude that WT and KO CMP are functionally similar. To test whether reduced CMP levels in KO mice are due to decreased CMP production, we compared the effect of 5-fluorouracil (5-FU) on WT and KO HSC, CLP, and CMP populations. FACS analysis showed that lin− cells from untreated WT mice were 0.14% HSC, 0.10 % CLP and 1.2% CMP compared to 0.13% HSC, 0.06% CLP, and 0.84% CMP in KO mice. 2 days post-injection (p.i.) of 150 mg/kg 5-FU, lin− cells from WT mice were 0% HSC, 0.12% CLP, and 1.4% CMP compared to 0.01%, 0.09%, and 1.1% respectively in KO mice. 4 days p.i., WT mice had 0% HSC, 0.25% CLP, and 0.03% CMP, but KO mice showed a recovery of HSC (1.04 ± 0.34%; p < .001), CLP (0.68%) and CMP (2.8%). 8 days later, WT mice recovered comparable levels of HSC (1.06%) CLP (0.19%) and CMP (0.44%). We analyzed repopulating activity by transplanting 1 x 104 lin−, Sca-1+, IL-7Rα−, c-kitHI or c-kitNEG cells (Ly 5.2) from untreated and 4-day p.i. WT or KO mice with 1 x 106 congenic (Ly 5.1) bone marrow cells into Ly5.1/5.2 recipients. 12 weeks after transplant, untreated WT and KO c-kitHI cells repopulated recipients (> 90% Ly 5.2) but not untreated c-kitNEG cells. In agreement with previous results (Randall et al., Blood, 1997), recipients of c-kitNEG cells from 4-day p.i. WT bone marrow contained 78.4 ± 18.0% Ly5.2 cells (n = 6), representing all of the repopulating ability as c-kitHI cells from 4-day p.i. WT mice were absent. In contrast, recipients of either KO c-kitNEG cells (86.3 ± 7.2% Ly 5.2; n = 7) or ckitHI cells (82.8 ± 6.9% Ly5.2; n = 6) from 4-day p.i. KO mice showed long-term repopulation. Because c-kit cannot be used as an HSC marker in post 5-FU bone marrow, we isolated lin−, Sca-1+, IL-7Rα−, side-population (SP)+ cells to analyze the cell cycle status of WT and KO HSCs 2 and 4 days p.i. 14.0% of untreated WT and 13.3% of KO HSCs are in the S/G2/M phases (Nemeth et al., Blood, 2005). 2 days p.i. 32.3% of WT SP+ HSCs and 31.9% of KO SP+ HSCs were in the S/G2/M phases. 4 days p.i., 21.2 ± 0.2% of WT SP+ HSCs were cycling while only 12.4 ± 2.2% of KO SP+ HSCs were cycling (p < .01), leading us to hypothesize that KO HSCs have recovered and resumed steady-state cycling levels. To determine whether Wnt signaling regulated KO HSC self-renewal, KO mice were mated with mice containing a lacZ reporter gene for the Wnt pathway (TOPGAL). We observed a 2.8-fold increase in lacZ expression in steady-state HSCs isolated from TOPGAL x KO mice compared to TOPGAL controls. We conclude that Hmgb3 deficiency allows for rapid HSC self-renewal, corresponding with increased Wnt signaling, and that Hmgb3 regulates the balance between the production of CLP and CMP and self-renewal.

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Erhart, Eva, Harald Schmid, Wilfried Hartl, and Kurt-Jürgen Hülsbergen. "Humus, nitrogen and energy balances, and greenhouse gas emissions in a long-term field experiment with compost compared with mineral fertilisation." Soil Research 54, no. 2 (2016): 254. http://dx.doi.org/10.1071/sr15127.

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Compost fertilisation is one way to close material cycles for organic matter and plant nutrients and to increase soil organic matter content. In this study, humus, nitrogen (N) and energy balances, and greenhouse gas (GHG) emissions were calculated for a 14-year field experiment using the model software REPRO. Humus balances showed that compost fertilisation at a rate of 8 t/ha.year resulted in a positive balance of 115 kg carbon (C)/ha.year. With 14 and 20 t/ha.year of compost, respectively, humus accumulated at rates of 558 and 1021 kg C/ha.year. With mineral fertilisation at rates of 29–62 kg N/ha.year, balances were moderately negative (–169 to –227 kg C/ha.year), and a clear humus deficit of –457 kg C/ha.year showed in the unfertilised control. Compared with measured soil organic C (SOC) data, REPRO predicted SOC contents fairly well with the exception of the treatments with high compost rates, where SOC contents were overestimated by REPRO. GHG balances calculated with soil C sequestration on the basis of humus balances, and on the basis of soil analyses, indicated negative GHG emissions with medium and high compost rates. Mineral fertilisation yielded net GHG emissions of ~2000 kg CO2-eq/ha.year. The findings underline that compost fertilisation holds potential for C sequestration and for the reduction of GHG emissions, even though this potential is bound to level off with increasing soil C saturation.

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Moreno-Vivián, Conrado, Francisco J. Caballero, Jacobo Cárdenas, and Francisco Castillo. "Effect of the C/N balance on the regulation of nitrogen fixation in Rhodobacter capsulatus E1F1." Biochimica et Biophysica Acta (BBA) - Bioenergetics 977, no. 3 (December 1989): 297–300. http://dx.doi.org/10.1016/s0005-2728(89)80083-0.

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Huarancca Reyes, Thais, Andrea Scartazza, Antonio Pompeiano, Andrea Ciurli, Yu Lu, Lorenzo Guglielminetti, and Junji Yamaguchi. "Nitrate Reductase Modulation in Response to Changes in C/N Balance and Nitrogen Source in Arabidopsis." Plant and Cell Physiology 59, no. 6 (March 21, 2018): 1248–54. http://dx.doi.org/10.1093/pcp/pcy065.

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34

Ghiso, Jorge, Erwin Cabrera, Thomas A. Neubert, and Agueda Rostagno. "N‐ and C‐Terminal Alzheimer’s Aβ Heterogeneity Modulates the Balance Between Brain Clearance and Amyloid Formation." FASEB Journal 34, S1 (April 2020): 1. http://dx.doi.org/10.1096/fasebj.2020.34.s1.02002.

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35

Hagen, Jon Ove, and Olav Liestøl. "Long-Term Glacier Mass-Balance Investigations in Svalbard, 1950–88." Annals of Glaciology 14 (1990): 102–6. http://dx.doi.org/10.1017/s0260305500008351.

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Mass-balance investigations on glaciers in Svalbard at high latitudes (78°N) show that the ice masses have been steadily decreasing during the period 1950–88. Detailed annual observations have been carried out on Brøggerbreen since 1966 and Lovénbreen since 1967. The mean specific net balances are −0.46 and −0.37 m year−1 water equivalent respectively. Only one year had positive net balance in this period. The cumulative mass lost in the period is then more than 10% of the volume in 1967. Zero net balance would be obtained if the summer temperature was lowered about 1°C or if the winter precipitation increased about 50%. There is a strong correlation between the net mass balance and the height of the equilibrium-line altitude (ELA). Because of the high amount of superimposed ice (10–30% of winter balance) stake readings are necessary to find the ELA. There is no sign of climatic warming through increased melting. The trend analysis of the data from the last 20 years shows stable conditions with a slight increase of the winter balance. The net balance is then slightly increasing and thus less negative than 20 years ago.

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Hagen, Jon Ove, and Olav Liestøl. "Long-Term Glacier Mass-Balance Investigations in Svalbard, 1950–88." Annals of Glaciology 14 (1990): 102–6. http://dx.doi.org/10.3189/s0260305500008351.

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Mass-balance investigations on glaciers in Svalbard at high latitudes (78°N) show that the ice masses have been steadily decreasing during the period 1950–88. Detailed annual observations have been carried out on Brøggerbreen since 1966 and Lovénbreen since 1967. The mean specific net balances are −0.46 and −0.37 m year−1 water equivalent respectively. Only one year had positive net balance in this period. The cumulative mass lost in the period is then more than 10% of the volume in 1967. Zero net balance would be obtained if the summer temperature was lowered about 1°C or if the winter precipitation increased about 50%. There is a strong correlation between the net mass balance and the height of the equilibrium-line altitude (ELA). Because of the high amount of superimposed ice (10–30% of winter balance) stake readings are necessary to find the ELA. There is no sign of climatic warming through increased melting. The trend analysis of the data from the last 20 years shows stable conditions with a slight increase of the winter balance. The net balance is then slightly increasing and thus less negative than 20 years ago.

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Liu, Weishu, Hee Seok Kim, Shuo Chen, Qing Jie, Bing Lv, Mengliang Yao, Zhensong Ren, et al. "n-type thermoelectric material Mg2Sn0.75Ge0.25 for high power generation." Proceedings of the National Academy of Sciences 112, no. 11 (March 2, 2015): 3269–74. http://dx.doi.org/10.1073/pnas.1424388112.

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Thermoelectric power generation is one of the most promising techniques to use the huge amount of waste heat and solar energy. Traditionally, high thermoelectric figure-of-merit, ZT, has been the only parameter pursued for high conversion efficiency. Here, we emphasize that a high power factor (PF) is equivalently important for high power generation, in addition to high efficiency. A new n-type Mg2Sn-based material, Mg2Sn0.75Ge0.25, is a good example to meet the dual requirements in efficiency and output power. It was found that Mg2Sn0.75Ge0.25 has an average ZT of 0.9 and PF of 52 μW⋅cm−1⋅K−2 over the temperature range of 25–450 °C, a peak ZT of 1.4 at 450 °C, and peak PF of 55 μW⋅cm−1⋅K−2 at 350 °C. By using the energy balance of one-dimensional heat flow equation, leg efficiency and output power were calculated with Th = 400 °C and Tc = 50 °C to be of 10.5% and 6.6 W⋅cm−2 under a temperature gradient of 150 °C⋅mm−1, respectively.

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Everts, H., and R. A. Dekker. "Effect of nitrogen supply on nitrogen and energy metabolism in lactating sows." Animal Science 59, no. 3 (December 1994): 445–54. http://dx.doi.org/10.1017/s0003356100007972.

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AbstractIn 56 balance trials sows received diets in pregnancy containing (g/kg diet) either 24·7 nitrogen (N) (C) or 16·7 N (L) followed by diets in lactation containing (g/kg dietary dry matter) either 28·5 N and 8·4 lysine (C) or 32·8 N and 10·3 lysine (H). N and energy balance during lactation (day 4 to 25) were made during three successive parities (23, 17 and 16 sows in parities 1,2 and 3, respectively). Retention in piglets was calculated from their body composition at weaning.Mean daily litter gain was 2·72 kg/day and was not affected by the dietary treatments. Mean body-weight loss of sows was 0·67 kg/day and was lower only in parity 2 on lactation treatment H compared with lactation treatment C. N retention was less negative on lactation treatment H than on lactation treatment C (significant in parity 1) and N retention was less negative on pregnancy treatment L than on pregnancy treatment C (significant in parity 3). Fat mobilization on lactation treatment H was higher than on lactation treatment C (significant in parities 2 and 3). The proportion of energy mobilized as protein to the total energy mobilization was significantly lower on lactation treatment H compared with lactation treatment C. Estimated daily N, lysine and Heal digestible lysine requirements for first parity lactating sows were 162 g, 48 g and 37 g respectively. For second parity sows 179 g, 54 g and 42 g and for third parity sows 185 g, 56 g and 43 g. N excretion during lactation was proportionately about 0·6 of ingested N. This resulted in an N excretion of about 2·3 kg N during a 25-day lactation period. After correction for differences in litter size, body weight of sows, daily litter gain and N mobilization increased with parity number.

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Nimthong, Ruthairat, Nattakunya Thepsena, Walailak Puetpaiboon, and Yupa Wattanakanjana. "Diaqua{μ2-N,N′-bis[(cyclohexanylidene)amino]oxamide}bis(triphenylphosphane)silver(I) dinitrate." Acta Crystallographica Section E Structure Reports Online 70, no. 2 (January 4, 2014): m30—m31. http://dx.doi.org/10.1107/s1600536813034454.

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The dinuclear title compound, [Ag2(C14H22N4O2)(C18H15P)2(H2O)2](NO3)2, lies across an inversion center and consists of two [Ag(H2O)(PPh3)] units bridged by a bis(cyclohexanone)oxalydihydrazone ligand. The charge-balance is supplied by two nitrate anions. The symmetry-unique AgIion is in a distorted tetrahedral geometry coordinated by a P atom from a triphenylphosphane ligand, an O atom from a water molecule and a bis(cyclohexanone)oxalydihydrazone ligand bidentate chelating through the O atom and one of N atoms. In the crystal, O—H...O and N—H...O hydrogen bonds link the components, forming chains along theb-axis direction. These chains are connected through weak C—H...O hydrogen bonds, leading to the formation of a two-dimensional supramolecular network parallel to (001).

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Valles de la Mora, Braulio, and Epigmenio Castillo-Gallegos. "Nitrogen balance of bullocks fed Cratylia argentea and Brachiaria arrecta Hay." Ecosistemas y Recursos Agropecuarios 5, no. 15 (September 3, 2018): 523. http://dx.doi.org/10.19136/era.a5n15.1491.

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Four experimental diets or treatments formed with incremental proportions of the foliage of tropical shrub legume Cratylia argentea and decremental proportions of Tanner grass (Brachiaria arrecta) hay: T1, 0:100; T2, 15:85; T3, 30:70; and T4, 45:55 were evaluated using four Holstein-Zebu bullocks (214.5 9.3 kg) conned in individual pens, under a balanced 4 x 4 latin square design. The crude protein (CP, %) content of C. argentea was 19.3 ± 6%, and in the grass was 6.2 ± 3%. The intake of DM increased as the C. argentea level in the diet increased. Blood urea-N (BUN) showed a linear increase from T1 to T4, observing its highest concentration at feeding time and six-hours after in T4: 12.00 and 14.75 mg dL-1, respectively. Purine derivatives (uric acid and allantoin) were not affected by treatments (p > 0.05). The increase of the legume in the diet improved the DM intake and digestibility, and led to N-balance from negative in T1 and T2, to positive in T3 and T4. The legume proportion in a basal diet of the grass B. arrecta must be 30% at least.

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Noriega, Carlos E. D., and Moacyr Araujo. "Nutrient budgets (C, N and P) and trophic dynamicsof a Brazilian tropical estuary: Barra das Jangadas." Anais da Academia Brasileira de Ciências 83, no. 2 (June 2011): 441–56. http://dx.doi.org/10.1590/s0001-37652011000200007.

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This paper focuses on the nutrient dynamics of a tropical estuary on the northeastern Brazilian coast, studied using the LOICZ biogeochemical budgeting protocol. We describe the methodology and assumptions underlying this model. Input data (monthly for rainfall, evaporation, river discharge, and concentrations of salt, phosphorus and nitrogen) were obtained during field campaigns in the Barra das Jangadas Estuary (BJE) over a 5 years period (1999 to 2003). Mass balance results indicate large inputs of nutrients to the system. The model shows that the seasonal variation of the Net Ecosystem Metabolism (NEM) indicates that the system passes from a stage of organic matter liquid production and mineralization during the dry season (-0.5 mmoles C m-2 d-1) to liquid mineralization during the rainy season (-19 mmoles C m-2 d-1). We suggest that the system varies slightly between autotrophy and heterotrophy during the year due to the rainfall regime, human activities in the basin (density population and sugarcane plantations), and associated DIP riverine loads. High per capita loads of N and P indicate a high population density and high runoff. The application of flux balance modeling was useful to understand the nutrient dynamics of this typical small tropical estuary

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Wang, Lihua, Jinniu Wang, Wei Liu, Youmin Gan, and Yan Wu. "Biomass Allocation, Compensatory Growth and Internal C/N Balance ofLolium perennein Response to Defoliation and Light Treatments." Polish Journal of Ecology 64, no. 4 (December 2016): 485–99. http://dx.doi.org/10.3161/15052249pje2016.64.4.004.

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Taylor-Piliae, Ruth E., Kathryn A. Newell, Rise Cherin, Martin J. Lee, Abby C. King, and William L. Haskell. "Effects of Tai Chi and Western Exercise on Physical and Cognitive Functioning in Healthy Community-Dwelling Older Adults." Journal of Aging and Physical Activity 18, no. 3 (July 2010): 261–79. http://dx.doi.org/10.1123/japa.18.3.261.

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Objective:To compare the effects of Tai Chi (TC,n= 37) and Western exercise (WE,n= 39) with an attention-control group (C,n= 56) on physical and cognitive functioning in healthy adults age 69 ± 5.8 yr, in a 2-phase randomized trial.Methods:TC and WE involved combined class and home-based protocols. Physical functioning included balance, strength, flexibility, and cardiorespiratory endurance. Cognitive functioning included semantic fluency and digit-span tests. Data were analyzed using intention-to-treat analysis.Results:At 6 mo, WE had greater improvements in upper body flexibility (F= 4.67,p= .01) than TC and C. TC had greater improvements in balance (F= 3.36,p= .04) and a cognitive-function measure (F= 7.75,p< .001) than WE and C. The differential cognitive-function improvements observed in TC were maintained through 12 mo.Conclusion:The TC and WE interventions resulted in differential improvements in physical functioning among generally healthy older adults. TC led to improvement in an indicator of cognitive functioning that was maintained through 12 mo.

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Rasmussen, L. A. "Meteorological controls on glacier mass balance in High Asia." Annals of Glaciology 54, no. 63 (2013): 352–59. http://dx.doi.org/10.3189/2013aog63a353.

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AbstractThe aim of this study is to investigate spatial and temporal variations of meteorological variables known to control glacier mass-balance processes, and to demonstrate their relevance in High Asia. The study uses the NCEP/NCAR reanalysis database (US National Centers for Environmental Prediction and US National Center for Atmospheric Research), which is global and continuous since 1 January 1948. A positive degree-day (PDD) model of annual glacier-wide summer surface balance, Bs, uses upper-air temperatures at NCEP/NCAR gridpoints near each of six glaciers between 40 and 45° N and between 71 and 87°E and two others near 50° N, 87° E. Model error ranged between 0.19 and 0.41 mw.e., comparable with the observational accuracy of Bs. Sensitivity to temperature change, dBs=dT, ranges between –0.5 and –0.2 m w.e. a–1 °C–1 for these glaciers.

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Zhang, Bofan, Liang Zhang, and Xiuxia Zhang. "Bioremediation of petroleum hydrocarbon-contaminated soil by petroleum-degrading bacteria immobilized on biochar." RSC Advances 9, no. 60 (2019): 35304–11. http://dx.doi.org/10.1039/c9ra06726d.

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Tao, Siyi, Suqin Wang, Lirong Song, and Nanqin Gan. "Understanding the Differences in the Growth and Toxin Production of Anatoxin-Producing Cuspidothrix issatschenkoi Cultured with Inorganic and Organic N Sources from a New Perspective: Carbon/Nitrogen Metabolic Balance." Toxins 12, no. 11 (November 19, 2020): 724. http://dx.doi.org/10.3390/toxins12110724.

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Cyanotoxins are the underlying cause of the threat that globally pervasive Cyanobacteria Harmful algal blooms (CyanoHABs) pose to humans. Major attention has been focused on the cyanobacterial hepatotoxin microcystins (MCs); however, there is a dearth of studies on cyanobacterial neurotoxin anatoxins. In this study, we explored how an anatoxin-producing Cuspidothrix issatschenkoi strain responded to culture with inorganic and organic nitrogen sources in terms of growth and anatoxins production. The results of our study revealed that ʟ- alanine could greatly boost cell growth, and was associated with the highest cell productivity, while urea significantly stimulated anatoxin production with the maximum anatoxin yield reaching 25.86 μg/mg dry weight, which was 1.56-fold higher than that in the control group (BG11). To further understand whether the carbon/nitrogen balance in C. issatschenkoi would affect anatoxin production, we explored growth and toxin production in response to different carbon/nitrogen ratios (C/N). Anatoxin production was mildly promoted when the C/N ratio was within low range, and significantly inhibited when the C/N ratio was within high range, showing approximately a three-fold difference. Furthermore, the transcriptional profile revealed that anaC gene expression was significantly up-regulated over 2–24 h when the C/N ratio was increased, and was significantly down-regulated after 96 h. Overall, our results further enriched the evidence that urea can stimulate cyanotoxin production, and ʟ-alanine could boost C. issatschenkoi proliferation, thus providing information for better management of aquatic systems. Moreover, by focusing on the intracellular C/N metabolic balance, this study explained the anatoxin production dynamics in C. issatschenkoi in response to different N sources.

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Liu, Xufei, Xiaofang Zhang, Yu Dou, Peng Mei, Xiaolan Ma, and Yingkui Yang. "Ultrasmall Mo2C nanocrystals embedded in N-doped porous carbons as a surface-dominated capacitive anode for lithium-ion capacitors." Chemical Communications 57, no. 40 (2021): 4966–69. http://dx.doi.org/10.1039/d1cc00630d.

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WANG, He, Rui GUO, Yongjun HU, and Defu HAN. "Carbon-Nitrogen Metabolic Responses and Adaptive Strategies to Low-Nitrogen Stress in Glycine soja." Notulae Botanicae Horti Agrobotanici Cluj-Napoca 47, no. 4 (November 28, 2019): 1215–23. http://dx.doi.org/10.15835/nbha47411567.

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Nitrogen (N) is an essential mineral nutrient for plant growth and development. Wild soybean (Glycine soja), which has many superior traits, is an important germplasm resource and is also an excellent experimental material for researching the mechanisms of low-N tolerance. In this study, the physiological differences between common wild soybean (W1) and low-N tolerant wild soybean (W2) among growth characteristics, photosynthetic carbon (C) metabolism, N metabolism and C-N metabolic-coupling relationship were investigated, and the mechanism of low-N tolerance of wild soybean was explained at three different levels of low-N stress. Both W1 and W2 showed some resistance to low-level N stress. However, W2 could withstand the damage by increasing the root length and root–shoot ratio under high-level stress conditions. Moreover, when resisting low-N stress, W2 maintained a stable photosynthetic rate and coordinated ion balance to maintain required nutrient levels. W2 also tolerated low N by coordinating the C-N metabolic balance through the accumulation of soluble sugars to provide energy and C skeletons for N metabolism and through enhanced N metabolic enzyme activities and soluble protein accumulation levels to supply the enzyme proteins and photosynthetic pigments for C metabolism. The current results provide a physiological methodology and theoretical basis for protecting wild soybean germplasm resources and improving cultivated soybean. ********* In press - Online First. Article has been peer reviewed, accepted for publication and published online without pagination. It will receive pagination when the issue will be ready for publishing as a complete number (Volume 47, Issue 4, 2019). The article is searchable and citable by Digital Object Identifier (DOI). DOI link will become active after the article will be included in the complete issue. *********

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Smith, C. J., B. C. T. Macdonald, H. Xing, O. T. Denmead, E. Wang, G. McLachlan, S. Tuomi, D. Turner, and D. Chen. "Measurements and APSIM modelling of soil C and N dynamics." Soil Research 58, no. 1 (2020): 41. http://dx.doi.org/10.1071/sr19021.

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Process-based models capture our understanding of key processes that interact to determine productivity and environmental outcomes. Combining measurements and modelling together help assess the consequences of these interactions, identify knowledge gaps and improve understanding of these processes. Here, we present a dataset (collected in a two-month fallow period) and list potential issues related to use of the APSIM model in predicting fluxes of soil water, heat, nitrogen (N) and carbon (C). Within the APSIM framework, two soil water modules (SoilWat and SWIM3) were used to predict soil evaporation and soil moisture content. SWIM3 tended to overestimate soil evaporation immediately after rainfall events, and SoilWat provided better predictions of evaporation. Our results highlight the need for testing the modules using data that includes wetting and drying cycles. Two soil temperature modules were also evaluated. Predictions of soil temperature were better for SoilTemp than the default module. APSIM configured with different combinations of soil water and temperature modules predicted nitrate dynamics well, but poorly predicted ammonium-N dynamics. The predicted ammonium-N pool empties several weeks after fertilisation, which was not observed, indicating that the processes of mineralisation and nitrification in APSIM require improvements. The fluxes of soil respiration and nitrous oxide, measured by chamber and micrometeorological methods, were roughly captured by APSIM. Discrepancies between the fluxes measured with chamber and micrometeorological techniques highlight difficulties in obtaining accurate measurements for evaluating performance of APSIM to predict gaseous fluxes. There was uncertainty associated with soil depth, which contributed to surface emissions. Our results showed that APSIM performance in simulating N2O fluxes should be considered in relation to data precision and uncertainty, especially the soil depths included in simulations. Finally, there was a major disconnection between the predicted N loss from denitrification (N2 + N2O) and that measured using the 15N balance technique.

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Zistl-Schlingmann, Marcus, Steve Kwatcho Kengdo, Ralf Kiese, and Michael Dannenmann. "Management Intensity Controls Nitrogen-Use-Efficiency and Flows in Grasslands—A 15N Tracing Experiment." Agronomy 10, no. 4 (April 23, 2020): 606. http://dx.doi.org/10.3390/agronomy10040606.

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The consequences of land use intensification and climate warming on productivity, fates of fertilizer nitrogen (N) and the overall soil N balance of montane grasslands remain poorly understood. Here, we report findings of a 15N slurry-tracing experiment on large grassland plant–soil lysimeters exposed to different management intensities (extensive vs. intensive) and climates (control; translocation: +2 °C, reduced precipitation). Surface-applied cattle slurry was enriched with both 15NH4+ and 15N-urea in order to trace its fate in the plant–soil system. Recovery of 15N tracer in plants was low (7–17%), while it was considerably higher in the soil N pool (32–42%), indicating N stabilization in soil organic nitrogen (SON). Total 15N recovery was only 49% ± 7% indicating substantial fertilizer N losses to the environment. With harvest N exports exceeding N fertilization rates, the N balance was negative for all climate and management treatments. Intensive management had an increased deficit relative to extensive management. In contrast, simulated climate change had no significant effects on the grassland N balance. These results suggest a risk of soil N mining in montane grasslands under land use intensification based on broadcast liquid slurry application.

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Journal articles on the topic 'C:N balance'

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